Merge pull request #3 from gilardh/master

paper librustzcash sync

.github/workflows/ci.yml

@@ -0,0 +1,120 @@
+name: CI checks
+
+on: [push, pull_request]
+
+jobs:
+  lint:
+    name: Lint
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.37.0
+          override: true
+
+      # cargo fmt does not build the code, and running it in a fresh clone of
+      # the codebase will fail because the protobuf code has not been generated.
+      - name: cargo build
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+          args: --all
+
+      # Ensure all code has been formatted with rustfmt
+      - run: rustup component add rustfmt
+      - name: Check formatting
+        uses: actions-rs/cargo@v1
+        with:
+          command: fmt
+          args: --all -- --check --color always
+
+  test:
+    name: Test on ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macOS-latest]
+
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: 1.37.0
+          override: true
+      - name: cargo fetch
+        uses: actions-rs/cargo@v1
+        with:
+          command: fetch
+      - name: Build tests
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+          args: --verbose --release --all --tests
+      - name: Run tests
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --verbose --release --all
+      - name: Run slow tests
+        uses: actions-rs/cargo@v1
+        with:
+          command: test
+          args: --verbose --release --all -- --ignored
+
+  codecov:
+    name: Code coverage
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      # Use stable for this to ensure that cargo-tarpaulin can be built.
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: stable
+          override: true
+      - name: Install cargo-tarpaulin
+        uses: actions-rs/cargo@v1
+        with:
+          command: install
+          args: cargo-tarpaulin
+      - name: Generate coverage report
+        uses: actions-rs/cargo@v1
+        with:
+          command: tarpaulin
+          args: --release --timeout 600 --out Xml --packages "librustzcash,zcash_client_backend,zcash_primitives,zcash_proofs"
+      - name: Upload coverage to Codecov
+        uses: codecov/codecov-action@v1.0.3
+        with:
+          token: ${{secrets.CODECOV_TOKEN}}
+
+  doc-links:
+    name: Nightly lint
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - uses: actions-rs/toolchain@v1
+        with:
+          toolchain: nightly
+          override: true
+      - name: cargo fetch
+        uses: actions-rs/cargo@v1
+        with:
+          command: fetch
+
+      # Ensure intra-documentation links all resolve correctly
+      # Requires #![deny(intra_doc_link_resolution_failure)] in crates.
+      - name: Check intra-doc links
+        uses: actions-rs/cargo@v1
+        with:
+          command: doc
+          args: --all --document-private-items
+
+      # Build benchmarks to prevent bitrot
+      - name: Build benchmarks
+        uses: actions-rs/cargo@v1
+        with:
+          command: build
+          args: --verbose --all --benches

.travis.yml

@@ -1,8 +1,19 @@
 language: rust
 rust:
-  - 1.32.0
+  - 1.37.0
 
 cache: cargo
 
+before_script:
+  - rustup component add rustfmt
+
 script:
+  - cargo build --verbose --release --all
+  - cargo fmt --all -- --check
   - cargo test --verbose --release --all
+  - cargo test --verbose --release --all -- --ignored
+
+before_cache:
+  - rm -rf "$TRAVIS_HOME/.cargo/registry/src"
+  - cargo install cargo-update || echo "cargo-update already installed"
+  - cargo install-update -a # update outdated cached binaries

Cargo.toml

@@ -5,11 +5,10 @@ members = [
     "group",
     "librustzcash",
     "pairing",
-    "sapling-crypto",
+    "zcash_client_backend",
+    "zcash_history",
     "zcash_primitives",
     "zcash_proofs",
-    "zcash_wallet",
-    "zip32",
 ]
 
 [profile.release]

bellman/Cargo.toml

@@ -1,25 +1,33 @@
 [package]
 authors = ["Sean Bowe <ewillbefull@gmail.com>"]
 description = "zk-SNARK library"
-documentation = "https://github.com/ebfull/bellman"
+readme = "README.md"
 homepage = "https://github.com/ebfull/bellman"
 license = "MIT/Apache-2.0"
 name = "bellman"
 repository = "https://github.com/ebfull/bellman"
-version = "0.1.0"
+version = "0.2.0"
+edition = "2018"
 
 [dependencies]
-rand = "0.4"
 bit-vec = "0.4.4"
-ff = { path = "../ff" }
+blake2s_simd = "0.5"
+ff = { version = "0.5.0", path = "../ff" }
 futures = "0.1"
 futures-cpupool = { version = "0.1", optional = true }
-group = { path = "../group" }
+group = { version = "0.2.0", path = "../group" }
 num_cpus = { version = "1", optional = true }
-crossbeam = { version = "0.3", optional = true }
+crossbeam = { version = "0.7", optional = true }
-pairing = { path = "../pairing", optional = true }
+pairing = { version = "0.15.0", path = "../pairing", optional = true }
+rand_core = "0.5"
 byteorder = "1"
 
+[dev-dependencies]
+hex-literal = "0.2"
+rand = "0.7"
+rand_xorshift = "0.2"
+sha2 = "0.8"
+
 [features]
 groth16 = ["pairing"]
 multicore = ["futures-cpupool", "crossbeam", "num_cpus"]
@@ -29,3 +37,6 @@ default = ["groth16", "multicore"]
 name = "mimc"
 path = "tests/mimc.rs"
 required-features = ["groth16"]
+
+[badges]
+maintenance = { status = "actively-developed" }

bellman/README.md

@@ -1,12 +1,23 @@
 # bellman [![Crates.io](https://img.shields.io/crates/v/bellman.svg)](https://crates.io/crates/bellman) #
 
-This is a research project being built for [Zcash](https://z.cash/).
+`bellman` is a crate for building zk-SNARK circuits. It provides circuit traits
+and primitive structures, as well as basic gadget implementations such as
+booleans and number abstractions.
+
+## Roadmap
+
+`bellman` is being refactored into a generic proving library. Currently it is
+pairing-specific, and different types of proving systems need to be implemented
+as sub-modules. After the refactor, `bellman` will be generic using the `ff` and
+`group` crates, while specific proving systems will be separate crates that pull
+in the dependencies they require.
 
 ## License
 
 Licensed under either of
 
- * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
+   http://www.apache.org/licenses/LICENSE-2.0)
  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 
 at your option.

bellman/src/domain.rs

@@ -1,21 +1,20 @@
-//! This module contains an `EvaluationDomain` abstraction for
+//! This module contains an [`EvaluationDomain`] abstraction for performing
-//! performing various kinds of polynomial arithmetic on top of
+//! various kinds of polynomial arithmetic on top of the scalar field.
-//! the scalar field.
 //!
-//! In pairing-based SNARKs like Groth16, we need to calculate
+//! In pairing-based SNARKs like [Groth16], we need to calculate a quotient
-//! a quotient polynomial over a target polynomial with roots
+//! polynomial over a target polynomial with roots at distinct points associated
-//! at distinct points associated with each constraint of the
+//! with each constraint of the constraint system. In order to be efficient, we
-//! constraint system. In order to be efficient, we choose these
+//! choose these roots to be the powers of a 2<sup>n</sup> root of unity in the
-//! roots to be the powers of a 2^n root of unity in the field.
+//! field. This allows us to perform polynomial operations in O(n) by performing
-//! This allows us to perform polynomial operations in O(n)
+//! an O(n log n) FFT over such a domain.
-//! by performing an O(n log n) FFT over such a domain.
+//!
+//! [`EvaluationDomain`]: crate::domain::EvaluationDomain
+//! [Groth16]: https://eprint.iacr.org/2016/260
 
 use ff::{Field, PrimeField, ScalarEngine};
 use group::CurveProjective;
 
-use super::{
+use super::SynthesisError;
-    SynthesisError
-};
 
 use super::multicore::Worker;
 
@@ -25,24 +24,27 @@ pub struct EvaluationDomain<E: ScalarEngine, G: Group<E>> {
     omega: E::Fr,
     omegainv: E::Fr,
     geninv: E::Fr,
-    minv: E::Fr
+    minv: E::Fr,
+}
+
+impl<E: ScalarEngine, G: Group<E>> AsRef<[G]> for EvaluationDomain<E, G> {
+    fn as_ref(&self) -> &[G] {
+        &self.coeffs
+    }
+}
+
+impl<E: ScalarEngine, G: Group<E>> AsMut<[G]> for EvaluationDomain<E, G> {
+    fn as_mut(&mut self) -> &mut [G] {
+        &mut self.coeffs
+    }
 }
 
 impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
-    pub fn as_ref(&self) -> &[G] {
-        &self.coeffs
-    }
-
-    pub fn as_mut(&mut self) -> &mut [G] {
-        &mut self.coeffs
-    }
-
     pub fn into_coeffs(self) -> Vec<G> {
         self.coeffs
     }
 
-    pub fn from_coeffs(mut coeffs: Vec<G>) -> Result<EvaluationDomain<E, G>, SynthesisError>
+    pub fn from_coeffs(mut coeffs: Vec<G>) -> Result<EvaluationDomain<E, G>, SynthesisError> {
-    {
         // Compute the size of our evaluation domain
         let mut m = 1;
         let mut exp = 0;
@@ -53,7 +55,7 @@ impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
             // The pairing-friendly curve may not be able to support
             // large enough (radix2) evaluation domains.
             if exp >= E::Fr::S {
-                return Err(SynthesisError::PolynomialDegreeTooLarge)
+                return Err(SynthesisError::PolynomialDegreeTooLarge);
             }
         }
 
@@ -67,29 +69,30 @@ impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
         coeffs.resize(m, G::group_zero());
 
         Ok(EvaluationDomain {
-            coeffs: coeffs,
+            coeffs,
-            exp: exp,
+            exp,
-            omega: omega,
+            omega,
             omegainv: omega.inverse().unwrap(),
             geninv: E::Fr::multiplicative_generator().inverse().unwrap(),
-            minv: E::Fr::from_str(&format!("{}", m)).unwrap().inverse().unwrap()
+            minv: E::Fr::from_str(&format!("{}", m))
+                .unwrap()
+                .inverse()
+                .unwrap(),
         })
     }
 
-    pub fn fft(&mut self, worker: &Worker)
+    pub fn fft(&mut self, worker: &Worker) {
-    {
         best_fft(&mut self.coeffs, worker, &self.omega, self.exp);
     }
 
-    pub fn ifft(&mut self, worker: &Worker)
+    pub fn ifft(&mut self, worker: &Worker) {
-    {
         best_fft(&mut self.coeffs, worker, &self.omegainv, self.exp);
 
         worker.scope(self.coeffs.len(), |scope, chunk| {
             let minv = self.minv;
 
             for v in self.coeffs.chunks_mut(chunk) {
-                scope.spawn(move || {
+                scope.spawn(move |_scope| {
                     for v in v {
                         v.group_mul_assign(&minv);
                     }
@@ -98,11 +101,10 @@ impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
         });
     }
 
-    pub fn distribute_powers(&mut self, worker: &Worker, g: E::Fr)
+    pub fn distribute_powers(&mut self, worker: &Worker, g: E::Fr) {
-    {
         worker.scope(self.coeffs.len(), |scope, chunk| {
             for (i, v) in self.coeffs.chunks_mut(chunk).enumerate() {
-                scope.spawn(move || {
+                scope.spawn(move |_scope| {
                     let mut u = g.pow(&[(i * chunk) as u64]);
                     for v in v.iter_mut() {
                         v.group_mul_assign(&u);
@@ -113,14 +115,12 @@ impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
         });
     }
 
-    pub fn coset_fft(&mut self, worker: &Worker)
+    pub fn coset_fft(&mut self, worker: &Worker) {
-    {
         self.distribute_powers(worker, E::Fr::multiplicative_generator());
         self.fft(worker);
     }
 
-    pub fn icoset_fft(&mut self, worker: &Worker)
+    pub fn icoset_fft(&mut self, worker: &Worker) {
-    {
         let geninv = self.geninv;
 
         self.ifft(worker);
@@ -139,13 +139,15 @@ impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
     /// The target polynomial is the zero polynomial in our
     /// evaluation domain, so we must perform division over
     /// a coset.
-    pub fn divide_by_z_on_coset(&mut self, worker: &Worker)
+    pub fn divide_by_z_on_coset(&mut self, worker: &Worker) {
-    {
+        let i = self
-        let i = self.z(&E::Fr::multiplicative_generator()).inverse().unwrap();
+            .z(&E::Fr::multiplicative_generator())
+            .inverse()
+            .unwrap();
 
         worker.scope(self.coeffs.len(), |scope, chunk| {
             for v in self.coeffs.chunks_mut(chunk) {
-                scope.spawn(move || {
+                scope.spawn(move |_scope| {
                     for v in v {
                         v.group_mul_assign(&i);
                     }
@@ -159,8 +161,12 @@ impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
         assert_eq!(self.coeffs.len(), other.coeffs.len());
 
         worker.scope(self.coeffs.len(), |scope, chunk| {
-            for (a, b) in self.coeffs.chunks_mut(chunk).zip(other.coeffs.chunks(chunk)) {
+            for (a, b) in self
-                scope.spawn(move || {
+                .coeffs
+                .chunks_mut(chunk)
+                .zip(other.coeffs.chunks(chunk))
+            {
+                scope.spawn(move |_scope| {
                     for (a, b) in a.iter_mut().zip(b.iter()) {
                         a.group_mul_assign(&b.0);
                     }
@@ -174,8 +180,12 @@ impl<E: ScalarEngine, G: Group<E>> EvaluationDomain<E, G> {
         assert_eq!(self.coeffs.len(), other.coeffs.len());
 
         worker.scope(self.coeffs.len(), |scope, chunk| {
-            for (a, b) in self.coeffs.chunks_mut(chunk).zip(other.coeffs.chunks(chunk)) {
+            for (a, b) in self
-                scope.spawn(move || {
+                .coeffs
+                .chunks_mut(chunk)
+                .zip(other.coeffs.chunks(chunk))
+            {
+                scope.spawn(move |_scope| {
                     for (a, b) in a.iter_mut().zip(b.iter()) {
                         a.group_sub_assign(&b);
                     }
@@ -200,7 +210,7 @@ impl<G: CurveProjective> PartialEq for Point<G> {
     }
 }
 
-impl<G: CurveProjective> Copy for Point<G> { }
+impl<G: CurveProjective> Copy for Point<G> {}
 
 impl<G: CurveProjective> Clone for Point<G> {
     fn clone(&self) -> Point<G> {
@@ -231,7 +241,7 @@ impl<E: ScalarEngine> PartialEq for Scalar<E> {
     }
 }
 
-impl<E: ScalarEngine> Copy for Scalar<E> { }
+impl<E: ScalarEngine> Copy for Scalar<E> {}
 
 impl<E: ScalarEngine> Clone for Scalar<E> {
     fn clone(&self) -> Scalar<E> {
@@ -254,8 +264,7 @@ impl<E: ScalarEngine> Group<E> for Scalar<E> {
     }
 }
 
-fn best_fft<E: ScalarEngine, T: Group<E>>(a: &mut [T], worker: &Worker, omega: &E::Fr, log_n: u32)
+fn best_fft<E: ScalarEngine, T: Group<E>>(a: &mut [T], worker: &Worker, omega: &E::Fr, log_n: u32) {
-{
     let log_cpus = worker.log_num_cpus();
 
     if log_n <= log_cpus {
@@ -265,8 +274,7 @@ fn best_fft<E: ScalarEngine, T: Group<E>>(a: &mut [T], worker: &Worker, omega: &
     }
 }
 
-fn serial_fft<E: ScalarEngine, T: Group<E>>(a: &mut [T], omega: &E::Fr, log_n: u32)
+fn serial_fft<E: ScalarEngine, T: Group<E>>(a: &mut [T], omega: &E::Fr, log_n: u32) {
-{
     fn bitreverse(mut n: u32, l: u32) -> u32 {
         let mut r = 0;
         for _ in 0..l {
@@ -288,22 +296,22 @@ fn serial_fft<E: ScalarEngine, T: Group<E>>(a: &mut [T], omega: &E::Fr, log_n: u
 
     let mut m = 1;
     for _ in 0..log_n {
-        let w_m = omega.pow(&[(n / (2*m)) as u64]);
+        let w_m = omega.pow(&[u64::from(n / (2 * m))]);
 
         let mut k = 0;
         while k < n {
             let mut w = E::Fr::one();
             for j in 0..m {
-                let mut t = a[(k+j+m) as usize];
+                let mut t = a[(k + j + m) as usize];
                 t.group_mul_assign(&w);
-                let mut tmp = a[(k+j) as usize];
+                let mut tmp = a[(k + j) as usize];
                 tmp.group_sub_assign(&t);
-                a[(k+j+m) as usize] = tmp;
+                a[(k + j + m) as usize] = tmp;
-                a[(k+j) as usize].group_add_assign(&t);
+                a[(k + j) as usize].group_add_assign(&t);
                 w.mul_assign(&w_m);
             }
 
-            k += 2*m;
+            k += 2 * m;
         }
 
         m *= 2;
@@ -315,9 +323,8 @@ fn parallel_fft<E: ScalarEngine, T: Group<E>>(
     worker: &Worker,
     omega: &E::Fr,
     log_n: u32,
-    log_cpus: u32
+    log_cpus: u32,
-)
+) {
-{
     assert!(log_n >= log_cpus);
 
     let num_cpus = 1 << log_cpus;
@@ -329,18 +336,18 @@ fn parallel_fft<E: ScalarEngine, T: Group<E>>(
         let a = &*a;
 
         for (j, tmp) in tmp.iter_mut().enumerate() {
-            scope.spawn(move || {
+            scope.spawn(move |_scope| {
                 // Shuffle into a sub-FFT
                 let omega_j = omega.pow(&[j as u64]);
                 let omega_step = omega.pow(&[(j as u64) << log_new_n]);
 
                 let mut elt = E::Fr::one();
-                for i in 0..(1 << log_new_n) {
+                for (i, tmp) in tmp.iter_mut().enumerate() {
                     for s in 0..num_cpus {
                         let idx = (i + (s << log_new_n)) % (1 << log_n);
                         let mut t = a[idx];
                         t.group_mul_assign(&elt);
-                        tmp[i].group_add_assign(&t);
+                        tmp.group_add_assign(&t);
                         elt.mul_assign(&omega_step);
                     }
                     elt.mul_assign(&omega_j);
@@ -357,7 +364,7 @@ fn parallel_fft<E: ScalarEngine, T: Group<E>>(
         let tmp = &tmp;
 
         for (idx, a) in a.chunks_mut(chunk).enumerate() {
-            scope.spawn(move || {
+            scope.spawn(move |_scope| {
                 let mut idx = idx * chunk;
                 let mask = (1 << log_cpus) - 1;
                 for a in a {
@@ -375,16 +382,19 @@ fn parallel_fft<E: ScalarEngine, T: Group<E>>(
 #[test]
 fn polynomial_arith() {
     use pairing::bls12_381::Bls12;
-    use rand::{self, Rand};
+    use rand_core::RngCore;
 
-    fn test_mul<E: ScalarEngine, R: rand::Rng>(rng: &mut R)
+    fn test_mul<E: ScalarEngine, R: RngCore>(rng: &mut R) {
-    {
         let worker = Worker::new();
 
         for coeffs_a in 0..70 {
             for coeffs_b in 0..70 {
-                let mut a: Vec<_> = (0..coeffs_a).map(|_| Scalar::<E>(E::Fr::rand(rng))).collect();
+                let mut a: Vec<_> = (0..coeffs_a)
-                let mut b: Vec<_> = (0..coeffs_b).map(|_| Scalar::<E>(E::Fr::rand(rng))).collect();
+                    .map(|_| Scalar::<E>(E::Fr::random(rng)))
+                    .collect();
+                let mut b: Vec<_> = (0..coeffs_b)
+                    .map(|_| Scalar::<E>(E::Fr::random(rng)))
+                    .collect();
 
                 // naive evaluation
                 let mut naive = vec![Scalar(E::Fr::zero()); coeffs_a + coeffs_b];
@@ -423,10 +433,9 @@ fn polynomial_arith() {
 #[test]
 fn fft_composition() {
     use pairing::bls12_381::Bls12;
-    use rand;
+    use rand_core::RngCore;
 
-    fn test_comp<E: ScalarEngine, R: rand::Rng>(rng: &mut R)
+    fn test_comp<E: ScalarEngine, R: RngCore>(rng: &mut R) {
-    {
         let worker = Worker::new();
 
         for coeffs in 0..10 {
@@ -434,7 +443,7 @@ fn fft_composition() {
 
             let mut v = vec![];
             for _ in 0..coeffs {
-                v.push(Scalar::<E>(rng.gen()));
+                v.push(Scalar::<E>(E::Fr::random(rng)));
             }
 
             let mut domain = EvaluationDomain::from_coeffs(v.clone()).unwrap();
@@ -462,22 +471,23 @@ fn fft_composition() {
 #[test]
 fn parallel_fft_consistency() {
     use pairing::bls12_381::Bls12;
-    use rand::{self, Rand};
+    use rand_core::RngCore;
     use std::cmp::min;
 
-    fn test_consistency<E: ScalarEngine, R: rand::Rng>(rng: &mut R)
+    fn test_consistency<E: ScalarEngine, R: RngCore>(rng: &mut R) {
-    {
         let worker = Worker::new();
 
         for _ in 0..5 {
             for log_d in 0..10 {
                 let d = 1 << log_d;
 
-                let v1 = (0..d).map(|_| Scalar::<E>(E::Fr::rand(rng))).collect::<Vec<_>>();
+                let v1 = (0..d)
+                    .map(|_| Scalar::<E>(E::Fr::random(rng)))
+                    .collect::<Vec<_>>();
                 let mut v1 = EvaluationDomain::from_coeffs(v1).unwrap();
                 let mut v2 = EvaluationDomain::from_coeffs(v1.coeffs.clone()).unwrap();
 
-                for log_cpus in log_d..min(log_d+1, 3) {
+                for log_cpus in log_d..min(log_d + 1, 3) {
                     parallel_fft(&mut v1.coeffs, &worker, &v1.omega, log_d, log_cpus);
                     serial_fft(&mut v2.coeffs, &v2.omega, log_d);
 

bellman/src/gadgets.rs

@@ -1,23 +1,17 @@
-#[cfg(test)]
+//! Self-contained sub-circuit implementations for various primitives.
+
 pub mod test;
 
-pub mod boolean;
-pub mod multieq;
-pub mod uint32;
 pub mod blake2s;
-pub mod num;
+pub mod boolean;
 pub mod lookup;
-pub mod ecc;
+pub mod multieq;
-pub mod pedersen_hash;
 pub mod multipack;
+pub mod num;
 pub mod sha256;
+pub mod uint32;
 
-pub mod sapling;
+use crate::SynthesisError;
-pub mod sprout;
-
-use bellman::{
-    SynthesisError
-};
 
 // TODO: This should probably be removed and we
 // should use existing helper methods on `Option`
@@ -25,7 +19,7 @@ use bellman::{
 /// This basically is just an extension to `Option`
 /// which allows for a convenient mapping to an
 /// error on `None`.
-trait Assignment<T> {
+pub trait Assignment<T> {
     fn get(&self) -> Result<&T, SynthesisError>;
 }
 
@@ -33,7 +27,7 @@ impl<T> Assignment<T> for Option<T> {
     fn get(&self) -> Result<&T, SynthesisError> {
         match *self {
             Some(ref v) => Ok(v),
-            None => Err(SynthesisError::AssignmentMissing)
+            None => Err(SynthesisError::AssignmentMissing),
         }
     }
 }

bellman/src/gadgets/blake2s.rs

@@ -0,0 +1,697 @@
+//! The [BLAKE2s] hash function with personalization support.
+//!
+//! [BLAKE2s]: https://tools.ietf.org/html/rfc7693
+
+use super::{boolean::Boolean, multieq::MultiEq, uint32::UInt32};
+use crate::{ConstraintSystem, SynthesisError};
+use ff::ScalarEngine;
+
+/*
+2.1.  Parameters
+   The following table summarizes various parameters and their ranges:
+                            | BLAKE2b          | BLAKE2s          |
+              --------------+------------------+------------------+
+               Bits in word | w = 64           | w = 32           |
+               Rounds in F  | r = 12           | r = 10           |
+               Block bytes  | bb = 128         | bb = 64          |
+               Hash bytes   | 1 <= nn <= 64    | 1 <= nn <= 32    |
+               Key bytes    | 0 <= kk <= 64    | 0 <= kk <= 32    |
+               Input bytes  | 0 <= ll < 2**128 | 0 <= ll < 2**64  |
+              --------------+------------------+------------------+
+               G Rotation   | (R1, R2, R3, R4) | (R1, R2, R3, R4) |
+                constants = | (32, 24, 16, 63) | (16, 12,  8,  7) |
+              --------------+------------------+------------------+
+*/
+
+const R1: usize = 16;
+const R2: usize = 12;
+const R3: usize = 8;
+const R4: usize = 7;
+
+/*
+          Round   |  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 |
+        ----------+-------------------------------------------------+
+         SIGMA[0] |  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 |
+         SIGMA[1] | 14 10  4  8  9 15 13  6  1 12  0  2 11  7  5  3 |
+         SIGMA[2] | 11  8 12  0  5  2 15 13 10 14  3  6  7  1  9  4 |
+         SIGMA[3] |  7  9  3  1 13 12 11 14  2  6  5 10  4  0 15  8 |
+         SIGMA[4] |  9  0  5  7  2  4 10 15 14  1 11 12  6  8  3 13 |
+         SIGMA[5] |  2 12  6 10  0 11  8  3  4 13  7  5 15 14  1  9 |
+         SIGMA[6] | 12  5  1 15 14 13  4 10  0  7  6  3  9  2  8 11 |
+         SIGMA[7] | 13 11  7 14 12  1  3  9  5  0 15  4  8  6  2 10 |
+         SIGMA[8] |  6 15 14  9 11  3  0  8 12  2 13  7  1  4 10  5 |
+         SIGMA[9] | 10  2  8  4  7  6  1  5 15 11  9 14  3 12 13  0 |
+        ----------+-------------------------------------------------+
+*/
+
+const SIGMA: [[usize; 16]; 10] = [
+    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15],
+    [14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3],
+    [11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4],
+    [7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8],
+    [9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13],
+    [2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9],
+    [12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11],
+    [13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10],
+    [6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5],
+    [10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0],
+];
+
+/*
+3.1.  Mixing Function G
+   The G primitive function mixes two input words, "x" and "y", into
+   four words indexed by "a", "b", "c", and "d" in the working vector
+   v[0..15].  The full modified vector is returned.  The rotation
+   constants (R1, R2, R3, R4) are given in Section 2.1.
+       FUNCTION G( v[0..15], a, b, c, d, x, y )
+       |
+       |   v[a] := (v[a] + v[b] + x) mod 2**w
+       |   v[d] := (v[d] ^ v[a]) >>> R1
+       |   v[c] := (v[c] + v[d])     mod 2**w
+       |   v[b] := (v[b] ^ v[c]) >>> R2
+       |   v[a] := (v[a] + v[b] + y) mod 2**w
+       |   v[d] := (v[d] ^ v[a]) >>> R3
+       |   v[c] := (v[c] + v[d])     mod 2**w
+       |   v[b] := (v[b] ^ v[c]) >>> R4
+       |
+       |   RETURN v[0..15]
+       |
+       END FUNCTION.
+*/
+
+fn mixing_g<E: ScalarEngine, CS: ConstraintSystem<E>, M>(
+    mut cs: M,
+    v: &mut [UInt32],
+    a: usize,
+    b: usize,
+    c: usize,
+    d: usize,
+    x: &UInt32,
+    y: &UInt32,
+) -> Result<(), SynthesisError>
+where
+    M: ConstraintSystem<E, Root = MultiEq<E, CS>>,
+{
+    v[a] = UInt32::addmany(
+        cs.namespace(|| "mixing step 1"),
+        &[v[a].clone(), v[b].clone(), x.clone()],
+    )?;
+    v[d] = v[d].xor(cs.namespace(|| "mixing step 2"), &v[a])?.rotr(R1);
+    v[c] = UInt32::addmany(
+        cs.namespace(|| "mixing step 3"),
+        &[v[c].clone(), v[d].clone()],
+    )?;
+    v[b] = v[b].xor(cs.namespace(|| "mixing step 4"), &v[c])?.rotr(R2);
+    v[a] = UInt32::addmany(
+        cs.namespace(|| "mixing step 5"),
+        &[v[a].clone(), v[b].clone(), y.clone()],
+    )?;
+    v[d] = v[d].xor(cs.namespace(|| "mixing step 6"), &v[a])?.rotr(R3);
+    v[c] = UInt32::addmany(
+        cs.namespace(|| "mixing step 7"),
+        &[v[c].clone(), v[d].clone()],
+    )?;
+    v[b] = v[b].xor(cs.namespace(|| "mixing step 8"), &v[c])?.rotr(R4);
+
+    Ok(())
+}
+
+/*
+3.2.  Compression Function F
+   Compression function F takes as an argument the state vector "h",
+   message block vector "m" (last block is padded with zeros to full
+   block size, if required), 2w-bit offset counter "t", and final block
+   indicator flag "f".  Local vector v[0..15] is used in processing.  F
+   returns a new state vector.  The number of rounds, "r", is 12 for
+   BLAKE2b and 10 for BLAKE2s.  Rounds are numbered from 0 to r - 1.
+       FUNCTION F( h[0..7], m[0..15], t, f )
+       |
+       |      // Initialize local work vector v[0..15]
+       |      v[0..7] := h[0..7]              // First half from state.
+       |      v[8..15] := IV[0..7]            // Second half from IV.
+       |
+       |      v[12] := v[12] ^ (t mod 2**w)   // Low word of the offset.
+       |      v[13] := v[13] ^ (t >> w)       // High word.
+       |
+       |      IF f = TRUE THEN                // last block flag?
+       |      |   v[14] := v[14] ^ 0xFF..FF   // Invert all bits.
+       |      END IF.
+       |
+       |      // Cryptographic mixing
+       |      FOR i = 0 TO r - 1 DO           // Ten or twelve rounds.
+       |      |
+       |      |   // Message word selection permutation for this round.
+       |      |   s[0..15] := SIGMA[i mod 10][0..15]
+       |      |
+       |      |   v := G( v, 0, 4,  8, 12, m[s[ 0]], m[s[ 1]] )
+       |      |   v := G( v, 1, 5,  9, 13, m[s[ 2]], m[s[ 3]] )
+       |      |   v := G( v, 2, 6, 10, 14, m[s[ 4]], m[s[ 5]] )
+       |      |   v := G( v, 3, 7, 11, 15, m[s[ 6]], m[s[ 7]] )
+       |      |
+       |      |   v := G( v, 0, 5, 10, 15, m[s[ 8]], m[s[ 9]] )
+       |      |   v := G( v, 1, 6, 11, 12, m[s[10]], m[s[11]] )
+       |      |   v := G( v, 2, 7,  8, 13, m[s[12]], m[s[13]] )
+       |      |   v := G( v, 3, 4,  9, 14, m[s[14]], m[s[15]] )
+       |      |
+       |      END FOR
+       |
+       |      FOR i = 0 TO 7 DO               // XOR the two halves.
+       |      |   h[i] := h[i] ^ v[i] ^ v[i + 8]
+       |      END FOR.
+       |
+       |      RETURN h[0..7]                  // New state.
+       |
+       END FUNCTION.
+*/
+
+fn blake2s_compression<E: ScalarEngine, CS: ConstraintSystem<E>>(
+    mut cs: CS,
+    h: &mut [UInt32],
+    m: &[UInt32],
+    t: u64,
+    f: bool,
+) -> Result<(), SynthesisError> {
+    assert_eq!(h.len(), 8);
+    assert_eq!(m.len(), 16);
+
+    /*
+    static const uint32_t blake2s_iv[8] =
+    {
+        0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A,
+        0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19
+    };
+    */
+
+    let mut v = Vec::with_capacity(16);
+    v.extend_from_slice(h);
+    v.push(UInt32::constant(0x6A09E667));
+    v.push(UInt32::constant(0xBB67AE85));
+    v.push(UInt32::constant(0x3C6EF372));
+    v.push(UInt32::constant(0xA54FF53A));
+    v.push(UInt32::constant(0x510E527F));
+    v.push(UInt32::constant(0x9B05688C));
+    v.push(UInt32::constant(0x1F83D9AB));
+    v.push(UInt32::constant(0x5BE0CD19));
+
+    assert_eq!(v.len(), 16);
+
+    v[12] = v[12].xor(cs.namespace(|| "first xor"), &UInt32::constant(t as u32))?;
+    v[13] = v[13].xor(
+        cs.namespace(|| "second xor"),
+        &UInt32::constant((t >> 32) as u32),
+    )?;
+
+    if f {
+        v[14] = v[14].xor(
+            cs.namespace(|| "third xor"),
+            &UInt32::constant(u32::max_value()),
+        )?;
+    }
+
+    {
+        let mut cs = MultiEq::new(&mut cs);
+
+        for i in 0..10 {
+            let mut cs = cs.namespace(|| format!("round {}", i));
+
+            let s = SIGMA[i % 10];
+
+            mixing_g(
+                cs.namespace(|| "mixing invocation 1"),
+                &mut v,
+                0,
+                4,
+                8,
+                12,
+                &m[s[0]],
+                &m[s[1]],
+            )?;
+            mixing_g(
+                cs.namespace(|| "mixing invocation 2"),
+                &mut v,
+                1,
+                5,
+                9,
+                13,
+                &m[s[2]],
+                &m[s[3]],
+            )?;
+            mixing_g(
+                cs.namespace(|| "mixing invocation 3"),
+                &mut v,
+                2,
+                6,
+                10,
+                14,
+                &m[s[4]],
+                &m[s[5]],
+            )?;
+            mixing_g(
+                cs.namespace(|| "mixing invocation 4"),
+                &mut v,
+                3,
+                7,
+                11,
+                15,
+                &m[s[6]],
+                &m[s[7]],
+            )?;
+
+            mixing_g(
+                cs.namespace(|| "mixing invocation 5"),
+                &mut v,
+                0,
+                5,
+                10,
+                15,
+                &m[s[8]],
+                &m[s[9]],
+            )?;
+            mixing_g(
+                cs.namespace(|| "mixing invocation 6"),
+                &mut v,
+                1,
+                6,
+                11,
+                12,
+                &m[s[10]],
+                &m[s[11]],
+            )?;
+            mixing_g(
+                cs.namespace(|| "mixing invocation 7"),
+                &mut v,
+                2,
+                7,
+                8,
+                13,
+                &m[s[12]],
+                &m[s[13]],
+            )?;
+            mixing_g(
+                cs.namespace(|| "mixing invocation 8"),
+                &mut v,
+                3,
+                4,
+                9,
+                14,
+                &m[s[14]],
+                &m[s[15]],
+            )?;
+        }
+    }
+
+    for i in 0..8 {
+        let mut cs = cs.namespace(|| format!("h[{i}] ^ v[{i}] ^ v[{i} + 8]", i = i));
+
+        h[i] = h[i].xor(cs.namespace(|| "first xor"), &v[i])?;
+        h[i] = h[i].xor(cs.namespace(|| "second xor"), &v[i + 8])?;
+    }
+
+    Ok(())
+}
+
+/*
+        FUNCTION BLAKE2( d[0..dd-1], ll, kk, nn )
+        |
+        |     h[0..7] := IV[0..7]          // Initialization Vector.
+        |
+        |     // Parameter block p[0]
+        |     h[0] := h[0] ^ 0x01010000 ^ (kk << 8) ^ nn
+        |
+        |     // Process padded key and data blocks
+        |     IF dd > 1 THEN
+        |     |       FOR i = 0 TO dd - 2 DO
+        |     |       |       h := F( h, d[i], (i + 1) * bb, FALSE )
+        |     |       END FOR.
+        |     END IF.
+        |
+        |     // Final block.
+        |     IF kk = 0 THEN
+        |     |       h := F( h, d[dd - 1], ll, TRUE )
+        |     ELSE
+        |     |       h := F( h, d[dd - 1], ll + bb, TRUE )
+        |     END IF.
+        |
+        |     RETURN first "nn" bytes from little-endian word array h[].
+        |
+        END FUNCTION.
+*/
+
+pub fn blake2s<E: ScalarEngine, CS: ConstraintSystem<E>>(
+    mut cs: CS,
+    input: &[Boolean],
+    personalization: &[u8],
+) -> Result<Vec<Boolean>, SynthesisError> {
+    use byteorder::{ByteOrder, LittleEndian};
+
+    assert_eq!(personalization.len(), 8);
+    assert!(input.len() % 8 == 0);
+
+    let mut h = Vec::with_capacity(8);
+    h.push(UInt32::constant(0x6A09E667 ^ 0x01010000 ^ 32));
+    h.push(UInt32::constant(0xBB67AE85));
+    h.push(UInt32::constant(0x3C6EF372));
+    h.push(UInt32::constant(0xA54FF53A));
+    h.push(UInt32::constant(0x510E527F));
+    h.push(UInt32::constant(0x9B05688C));
+
+    // Personalization is stored here
+    h.push(UInt32::constant(
+        0x1F83D9AB ^ LittleEndian::read_u32(&personalization[0..4]),
+    ));
+    h.push(UInt32::constant(
+        0x5BE0CD19 ^ LittleEndian::read_u32(&personalization[4..8]),
+    ));
+
+    let mut blocks: Vec<Vec<UInt32>> = vec![];
+
+    for block in input.chunks(512) {
+        let mut this_block = Vec::with_capacity(16);
+        for word in block.chunks(32) {
+            let mut tmp = word.to_vec();
+            while tmp.len() < 32 {
+                tmp.push(Boolean::constant(false));
+            }
+            this_block.push(UInt32::from_bits(&tmp));
+        }
+        while this_block.len() < 16 {
+            this_block.push(UInt32::constant(0));
+        }
+        blocks.push(this_block);
+    }
+
+    if blocks.is_empty() {
+        blocks.push((0..16).map(|_| UInt32::constant(0)).collect());
+    }
+
+    for (i, block) in blocks[0..blocks.len() - 1].iter().enumerate() {
+        let cs = cs.namespace(|| format!("block {}", i));
+
+        blake2s_compression(cs, &mut h, block, ((i as u64) + 1) * 64, false)?;
+    }
+
+    {
+        let cs = cs.namespace(|| "final block");
+
+        blake2s_compression(
+            cs,
+            &mut h,
+            &blocks[blocks.len() - 1],
+            (input.len() / 8) as u64,
+            true,
+        )?;
+    }
+
+    Ok(h.into_iter().flat_map(|b| b.into_bits()).collect())
+}
+
+#[cfg(test)]
+mod test {
+    use blake2s_simd::Params as Blake2sParams;
+    use hex_literal::hex;
+    use pairing::bls12_381::Bls12;
+    use rand_core::{RngCore, SeedableRng};
+    use rand_xorshift::XorShiftRng;
+
+    use super::blake2s;
+    use crate::gadgets::boolean::{AllocatedBit, Boolean};
+    use crate::gadgets::test::TestConstraintSystem;
+    use crate::ConstraintSystem;
+
+    #[test]
+    fn test_blank_hash() {
+        let mut cs = TestConstraintSystem::<Bls12>::new();
+        let input_bits = vec![];
+        let out = blake2s(&mut cs, &input_bits, b"12345678").unwrap();
+        assert!(cs.is_satisfied());
+        assert_eq!(cs.num_constraints(), 0);
+
+        // >>> import blake2s from hashlib
+        // >>> h = blake2s(digest_size=32, person=b'12345678')
+        // >>> h.hexdigest()
+        let expected = hex!("c59f682376d137f3f255e671e207d1f2374ebe504e9314208a52d9f88d69e8c8");
+
+        let mut out = out.into_iter();
+        for b in expected.iter() {
+            for i in 0..8 {
+                let c = out.next().unwrap().get_value().unwrap();
+
+                assert_eq!(c, (b >> i) & 1u8 == 1u8);
+            }
+        }
+    }
+
+    #[test]
+    fn test_blake2s_constraints() {
+        let mut cs = TestConstraintSystem::<Bls12>::new();
+        let input_bits: Vec<_> = (0..512)
+            .map(|i| {
+                AllocatedBit::alloc(cs.namespace(|| format!("input bit {}", i)), Some(true))
+                    .unwrap()
+                    .into()
+            })
+            .collect();
+        blake2s(&mut cs, &input_bits, b"12345678").unwrap();
+        assert!(cs.is_satisfied());
+        assert_eq!(cs.num_constraints(), 21518);
+    }
+
+    #[test]
+    fn test_blake2s_precomp_constraints() {
+        // Test that 512 fixed leading bits (constants)
+        // doesn't result in more constraints.
+
+        let mut cs = TestConstraintSystem::<Bls12>::new();
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
+        let input_bits: Vec<_> = (0..512)
+            .map(|_| Boolean::constant(rng.next_u32() % 2 != 0))
+            .chain((0..512).map(|i| {
+                AllocatedBit::alloc(cs.namespace(|| format!("input bit {}", i)), Some(true))
+                    .unwrap()
+                    .into()
+            }))
+            .collect();
+        blake2s(&mut cs, &input_bits, b"12345678").unwrap();
+        assert!(cs.is_satisfied());
+        assert_eq!(cs.num_constraints(), 21518);
+    }
+
+    #[test]
+    fn test_blake2s_constant_constraints() {
+        let mut cs = TestConstraintSystem::<Bls12>::new();
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
+        let input_bits: Vec<_> = (0..512)
+            .map(|_| Boolean::constant(rng.next_u32() % 2 != 0))
+            .collect();
+        blake2s(&mut cs, &input_bits, b"12345678").unwrap();
+        assert_eq!(cs.num_constraints(), 0);
+    }
+
+    #[test]
+    fn test_blake2s() {
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
+
+        for input_len in (0..32).chain((32..256).filter(|a| a % 8 == 0)) {
+            let mut h = Blake2sParams::new()
+                .hash_length(32)
+                .personal(b"12345678")
+                .to_state();
+
+            let data: Vec<u8> = (0..input_len).map(|_| rng.next_u32() as u8).collect();
+
+            h.update(&data);
+
+            let hash_result = h.finalize();
+
+            let mut cs = TestConstraintSystem::<Bls12>::new();
+
+            let mut input_bits = vec![];
+
+            for (byte_i, input_byte) in data.into_iter().enumerate() {
+                for bit_i in 0..8 {
+                    let cs = cs.namespace(|| format!("input bit {} {}", byte_i, bit_i));
+
+                    input_bits.push(
+                        AllocatedBit::alloc(cs, Some((input_byte >> bit_i) & 1u8 == 1u8))
+                            .unwrap()
+                            .into(),
+                    );
+                }
+            }
+
+            let r = blake2s(&mut cs, &input_bits, b"12345678").unwrap();
+
+            assert!(cs.is_satisfied());
+
+            let mut s = hash_result
+                .as_ref()
+                .iter()
+                .flat_map(|&byte| (0..8).map(move |i| (byte >> i) & 1u8 == 1u8));
+
+            for b in r {
+                match b {
+                    Boolean::Is(b) => {
+                        assert!(s.next().unwrap() == b.get_value().unwrap());
+                    }
+                    Boolean::Not(b) => {
+                        assert!(s.next().unwrap() != b.get_value().unwrap());
+                    }
+                    Boolean::Constant(b) => {
+                        assert!(input_len == 0);
+                        assert!(s.next().unwrap() == b);
+                    }
+                }
+            }
+        }
+    }
+
+    #[test]
+    fn test_blake2s_256_vars() {
+        let data: Vec<u8> = hex!("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").to_vec();
+        assert_eq!(data.len(), 256);
+
+        let mut cs = TestConstraintSystem::<Bls12>::new();
+
+        let mut input_bits = vec![];
+
+        for (byte_i, input_byte) in data.into_iter().enumerate() {
+            for bit_i in 0..8 {
+                let cs = cs.namespace(|| format!("input bit {} {}", byte_i, bit_i));
+
+                input_bits.push(
+                    AllocatedBit::alloc(cs, Some((input_byte >> bit_i) & 1u8 == 1u8))
+                        .unwrap()
+                        .into(),
+                );
+            }
+        }
+
+        let r = blake2s(&mut cs, &input_bits, b"12345678").unwrap();
+
+        assert!(cs.is_satisfied());
+
+        let expected = hex!("0af5695115ced92c8a0341e43869209636e9aa6472e4576f0f2b996cf812b30e");
+
+        let mut out = r.into_iter();
+        for b in expected.iter() {
+            for i in 0..8 {
+                let c = out.next().unwrap().get_value().unwrap();
+
+                assert_eq!(c, (b >> i) & 1u8 == 1u8);
+            }
+        }
+    }
+
+    #[test]
+    fn test_blake2s_700_vars() {
+        let data: Vec<u8> = hex!("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").to_vec();
+        assert_eq!(data.len(), 700);
+
+        let mut cs = TestConstraintSystem::<Bls12>::new();
+
+        let mut input_bits = vec![];
+
+        for (byte_i, input_byte) in data.into_iter().enumerate() {
+            for bit_i in 0..8 {
+                let cs = cs.namespace(|| format!("input bit {} {}", byte_i, bit_i));
+
+                input_bits.push(
+                    AllocatedBit::alloc(cs, Some((input_byte >> bit_i) & 1u8 == 1u8))
+                        .unwrap()
+                        .into(),
+                );
+            }
+        }
+
+        let r = blake2s(&mut cs, &input_bits, b"12345678").unwrap();
+
+        assert!(cs.is_satisfied());
+
+        let expected = hex!("2ab8f0683167ba220eef19dccf4f9b1a8193cc09b35e0235842323950530f18a");
+
+        let mut out = r.into_iter();
+        for b in expected.iter() {
+            for i in 0..8 {
+                let c = out.next().unwrap().get_value().unwrap();
+
+                assert_eq!(c, (b >> i) & 1u8 == 1u8);
+            }
+        }
+    }
+
+    #[test]
+    fn test_blake2s_test_vectors() {
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
+
+        let expecteds = [
+            hex!("a1309e334376c8f36a736a4ab0e691ef931ee3ebdb9ea96187127136fea622a1"),
+            hex!("82fefff60f265cea255252f7c194a7f93965dffee0609ef74eb67f0d76cd41c6"),
+        ];
+        for i in 0..2 {
+            let mut h = Blake2sParams::new()
+                .hash_length(32)
+                .personal(b"12345678")
+                .to_state();
+            let input_len = 1024;
+            let data: Vec<u8> = (0..input_len).map(|_| rng.next_u32() as u8).collect();
+
+            h.update(&data);
+
+            let hash_result = h.finalize();
+
+            let mut cs = TestConstraintSystem::<Bls12>::new();
+
+            let mut input_bits = vec![];
+
+            for (byte_i, input_byte) in data.into_iter().enumerate() {
+                for bit_i in 0..8 {
+                    let cs = cs.namespace(|| format!("input bit {} {}", byte_i, bit_i));
+
+                    input_bits.push(
+                        AllocatedBit::alloc(cs, Some((input_byte >> bit_i) & 1u8 == 1u8))
+                            .unwrap()
+                            .into(),
+                    );
+                }
+            }
+
+            let r = blake2s(&mut cs, &input_bits, b"12345678").unwrap();
+
+            assert!(cs.is_satisfied());
+
+            let mut s = hash_result
+                .as_ref()
+                .iter()
+                .flat_map(|&byte| (0..8).map(move |i| (byte >> i) & 1u8 == 1u8));
+
+            for b in r {
+                match b {
+                    Boolean::Is(b) => {
+                        assert!(s.next().unwrap() == b.get_value().unwrap());
+                    }
+                    Boolean::Not(b) => {
+                        assert!(s.next().unwrap() != b.get_value().unwrap());
+                    }
+                    Boolean::Constant(b) => {
+                        assert!(input_len == 0);
+                        assert!(s.next().unwrap() == b);
+                    }
+                }
+            }
+
+            assert_eq!(expecteds[i], hash_result.as_bytes());
+        }
+    }
+}

bellman/src/gadgets/lookup.rs

@@ -1,23 +1,16 @@
-use ff::Field;
+//! Window table lookup gadgets.
-use pairing::Engine;
+
+use ff::{Field, ScalarEngine};
 
-use super::*;
-use super::num::{
-    AllocatedNum,
-    Num
-};
 use super::boolean::Boolean;
-use bellman::{
+use super::num::{AllocatedNum, Num};
-    ConstraintSystem
+use super::*;
-};
+use crate::ConstraintSystem;
 
 // Synthesize the constants for each base pattern.
-fn synth<'a, E: Engine, I>(
+fn synth<'a, E: ScalarEngine, I>(window_size: usize, constants: I, assignment: &mut [E::Fr])
-    window_size: usize,
+where
-    constants: I,
+    I: IntoIterator<Item = &'a E::Fr>,
-    assignment: &mut [E::Fr]
-)
-    where I: IntoIterator<Item=&'a E::Fr>
 {
     assert_eq!(assignment.len(), 1 << window_size);
 
@@ -36,19 +29,23 @@ fn synth<'a, E: Engine, I>(
 
 /// Performs a 3-bit window table lookup. `bits` is in
 /// little-endian order.
-pub fn lookup3_xy<E: Engine, CS>(
+pub fn lookup3_xy<E: ScalarEngine, CS>(
     mut cs: CS,
     bits: &[Boolean],
-    coords: &[(E::Fr, E::Fr)]
+    coords: &[(E::Fr, E::Fr)],
 ) -> Result<(AllocatedNum<E>, AllocatedNum<E>), SynthesisError>
-    where CS: ConstraintSystem<E>
+where
+    CS: ConstraintSystem<E>,
 {
     assert_eq!(bits.len(), 3);
     assert_eq!(coords.len(), 8);
 
     // Calculate the index into `coords`
-    let i =
+    let i = match (
-    match (bits[0].get_value(), bits[1].get_value(), bits[2].get_value()) {
+        bits[0].get_value(),
+        bits[1].get_value(),
+        bits[2].get_value(),
+    ) {
         (Some(a_value), Some(b_value), Some(c_value)) => {
             let mut tmp = 0;
             if a_value {
@@ -61,25 +58,15 @@ pub fn lookup3_xy<E: Engine, CS>(
                 tmp += 4;
             }
             Some(tmp)
-        },
+        }
-        _ => None
+        _ => None,
     };
 
     // Allocate the x-coordinate resulting from the lookup
-    let res_x = AllocatedNum::alloc(
+    let res_x = AllocatedNum::alloc(cs.namespace(|| "x"), || Ok(coords[*i.get()?].0))?;
-        cs.namespace(|| "x"),
-        || {
-            Ok(coords[*i.get()?].0)
-        }
-    )?;
 
     // Allocate the y-coordinate resulting from the lookup
-    let res_y = AllocatedNum::alloc(
+    let res_y = AllocatedNum::alloc(cs.namespace(|| "y"), || Ok(coords[*i.get()?].1))?;
-        cs.namespace(|| "y"),
-        || {
-            Ok(coords[*i.get()?].1)
-        }
-    )?;
 
     // Compute the coefficients for the lookup constraints
     let mut x_coeffs = [E::Fr::zero(); 8];
@@ -93,30 +80,38 @@ pub fn lookup3_xy<E: Engine, CS>(
 
     cs.enforce(
         || "x-coordinate lookup",
-        |lc| lc + (x_coeffs[0b001], one)
+        |lc| {
+            lc + (x_coeffs[0b001], one)
                 + &bits[1].lc::<E>(one, x_coeffs[0b011])
                 + &bits[2].lc::<E>(one, x_coeffs[0b101])
-                + &precomp.lc::<E>(one, x_coeffs[0b111]),
+                + &precomp.lc::<E>(one, x_coeffs[0b111])
+        },
         |lc| lc + &bits[0].lc::<E>(one, E::Fr::one()),
-        |lc| lc + res_x.get_variable()
+        |lc| {
+            lc + res_x.get_variable()
                 - (x_coeffs[0b000], one)
                 - &bits[1].lc::<E>(one, x_coeffs[0b010])
                 - &bits[2].lc::<E>(one, x_coeffs[0b100])
-                - &precomp.lc::<E>(one, x_coeffs[0b110]),
+                - &precomp.lc::<E>(one, x_coeffs[0b110])
+        },
     );
 
     cs.enforce(
         || "y-coordinate lookup",
-        |lc| lc + (y_coeffs[0b001], one)
+        |lc| {
+            lc + (y_coeffs[0b001], one)
                 + &bits[1].lc::<E>(one, y_coeffs[0b011])
                 + &bits[2].lc::<E>(one, y_coeffs[0b101])
-                + &precomp.lc::<E>(one, y_coeffs[0b111]),
+                + &precomp.lc::<E>(one, y_coeffs[0b111])
+        },
         |lc| lc + &bits[0].lc::<E>(one, E::Fr::one()),
-        |lc| lc + res_y.get_variable()
+        |lc| {
+            lc + res_y.get_variable()
                 - (y_coeffs[0b000], one)
                 - &bits[1].lc::<E>(one, y_coeffs[0b010])
                 - &bits[2].lc::<E>(one, y_coeffs[0b100])
-                - &precomp.lc::<E>(one, y_coeffs[0b110]),
+                - &precomp.lc::<E>(one, y_coeffs[0b110])
+        },
     );
 
     Ok((res_x, res_y))
@@ -124,19 +119,19 @@ pub fn lookup3_xy<E: Engine, CS>(
 
 /// Performs a 3-bit window table lookup, where
 /// one of the bits is a sign bit.
-pub fn lookup3_xy_with_conditional_negation<E: Engine, CS>(
+pub fn lookup3_xy_with_conditional_negation<E: ScalarEngine, CS>(
     mut cs: CS,
     bits: &[Boolean],
-    coords: &[(E::Fr, E::Fr)]
+    coords: &[(E::Fr, E::Fr)],
 ) -> Result<(Num<E>, Num<E>), SynthesisError>
-    where CS: ConstraintSystem<E>
+where
+    CS: ConstraintSystem<E>,
 {
     assert_eq!(bits.len(), 3);
     assert_eq!(coords.len(), 4);
 
     // Calculate the index into `coords`
-    let i =
+    let i = match (bits[0].get_value(), bits[1].get_value()) {
-    match (bits[0].get_value(), bits[1].get_value()) {
         (Some(a_value), Some(b_value)) => {
             let mut tmp = 0;
             if a_value {
@@ -146,22 +141,19 @@ pub fn lookup3_xy_with_conditional_negation<E: Engine, CS>(
                 tmp += 2;
             }
             Some(tmp)
-        },
+        }
-        _ => None
+        _ => None,
     };
 
     // Allocate the y-coordinate resulting from the lookup
     // and conditional negation
-    let y = AllocatedNum::alloc(
+    let y = AllocatedNum::alloc(cs.namespace(|| "y"), || {
-        cs.namespace(|| "y"),
+        let mut tmp = coords[*i.get()?].1;
-        || {
+        if *bits[2].get_value().get()? {
-            let mut tmp = coords[*i.get()?].1;
+            tmp.negate();
-            if *bits[2].get_value().get()? {
-                tmp.negate();
-            }
-            Ok(tmp)
         }
-    )?;
+        Ok(tmp)
+    })?;
 
     let one = CS::one();
 
@@ -174,21 +166,21 @@ pub fn lookup3_xy_with_conditional_negation<E: Engine, CS>(
     let precomp = Boolean::and(cs.namespace(|| "precomp"), &bits[0], &bits[1])?;
 
     let x = Num::zero()
-            .add_bool_with_coeff(one, &Boolean::constant(true), x_coeffs[0b00])
+        .add_bool_with_coeff(one, &Boolean::constant(true), x_coeffs[0b00])
-            .add_bool_with_coeff(one, &bits[0], x_coeffs[0b01])
+        .add_bool_with_coeff(one, &bits[0], x_coeffs[0b01])
-            .add_bool_with_coeff(one, &bits[1], x_coeffs[0b10])
+        .add_bool_with_coeff(one, &bits[1], x_coeffs[0b10])
-            .add_bool_with_coeff(one, &precomp, x_coeffs[0b11]);
+        .add_bool_with_coeff(one, &precomp, x_coeffs[0b11]);
 
-    let y_lc = precomp.lc::<E>(one, y_coeffs[0b11]) +
+    let y_lc = precomp.lc::<E>(one, y_coeffs[0b11])
-               &bits[1].lc::<E>(one, y_coeffs[0b10]) +
+        + &bits[1].lc::<E>(one, y_coeffs[0b10])
-               &bits[0].lc::<E>(one, y_coeffs[0b01]) +
+        + &bits[0].lc::<E>(one, y_coeffs[0b01])
-               (y_coeffs[0b00], one);
+        + (y_coeffs[0b00], one);
 
     cs.enforce(
         || "y-coordinate lookup",
         |lc| lc + &y_lc + &y_lc,
         |lc| lc + &bits[2].lc::<E>(one, E::Fr::one()),
-        |lc| lc + &y_lc - y.get_variable()
+        |lc| lc + &y_lc - y.get_variable(),
     );
 
     Ok((x, y.into()))
@@ -196,46 +188,52 @@ pub fn lookup3_xy_with_conditional_negation<E: Engine, CS>(
 
 #[cfg(test)]
 mod test {
-    use rand::{SeedableRng, Rand, Rng, XorShiftRng};
     use super::*;
-    use ::circuit::test::*;
+    use crate::gadgets::boolean::{AllocatedBit, Boolean};
-    use ::circuit::boolean::{Boolean, AllocatedBit};
+    use crate::gadgets::test::*;
     use pairing::bls12_381::{Bls12, Fr};
+    use rand_core::{RngCore, SeedableRng};
+    use rand_xorshift::XorShiftRng;
 
     #[test]
     fn test_lookup3_xy() {
-        let mut rng = XorShiftRng::from_seed([0x3dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0656]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..100 {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a_val = rng.gen();
+            let a_val = rng.next_u32() % 2 != 0;
-            let a = Boolean::from(
+            let a = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "a"), Some(a_val)).unwrap());
-                AllocatedBit::alloc(cs.namespace(|| "a"), Some(a_val)).unwrap()
-            );
 
-            let b_val = rng.gen();
+            let b_val = rng.next_u32() % 2 != 0;
-            let b = Boolean::from(
+            let b = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "b"), Some(b_val)).unwrap());
-                AllocatedBit::alloc(cs.namespace(|| "b"), Some(b_val)).unwrap()
-            );
 
-            let c_val = rng.gen();
+            let c_val = rng.next_u32() % 2 != 0;
-            let c = Boolean::from(
+            let c = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "c"), Some(c_val)).unwrap());
-                AllocatedBit::alloc(cs.namespace(|| "c"), Some(c_val)).unwrap()
-            );
 
             let bits = vec![a, b, c];
 
-            let points: Vec<(Fr, Fr)> = (0..8).map(|_| (rng.gen(), rng.gen())).collect();
+            let points: Vec<(Fr, Fr)> = (0..8)
+                .map(|_| (Fr::random(&mut rng), Fr::random(&mut rng)))
+                .collect();
 
             let res = lookup3_xy(&mut cs, &bits, &points).unwrap();
 
             assert!(cs.is_satisfied());
 
             let mut index = 0;
-            if a_val { index += 1 }
+            if a_val {
-            if b_val { index += 2 }
+                index += 1
-            if c_val { index += 4 }
+            }
+            if b_val {
+                index += 2
+            }
+            if c_val {
+                index += 4
+            }
 
             assert_eq!(res.0.get_value().unwrap(), points[index].0);
             assert_eq!(res.1.get_value().unwrap(), points[index].1);
@@ -244,53 +242,63 @@ mod test {
 
     #[test]
     fn test_lookup3_xy_with_conditional_negation() {
-        let mut rng = XorShiftRng::from_seed([0x3dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..100 {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a_val = rng.gen();
+            let a_val = rng.next_u32() % 2 != 0;
-            let a = Boolean::from(
+            let a = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "a"), Some(a_val)).unwrap());
-                AllocatedBit::alloc(cs.namespace(|| "a"), Some(a_val)).unwrap()
-            );
 
-            let b_val = rng.gen();
+            let b_val = rng.next_u32() % 2 != 0;
-            let b = Boolean::from(
+            let b = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "b"), Some(b_val)).unwrap());
-                AllocatedBit::alloc(cs.namespace(|| "b"), Some(b_val)).unwrap()
-            );
 
-            let c_val = rng.gen();
+            let c_val = rng.next_u32() % 2 != 0;
-            let c = Boolean::from(
+            let c = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "c"), Some(c_val)).unwrap());
-                AllocatedBit::alloc(cs.namespace(|| "c"), Some(c_val)).unwrap()
-            );
 
             let bits = vec![a, b, c];
 
-            let points: Vec<(Fr, Fr)> = (0..4).map(|_| (rng.gen(), rng.gen())).collect();
+            let points: Vec<(Fr, Fr)> = (0..4)
+                .map(|_| (Fr::random(&mut rng), Fr::random(&mut rng)))
+                .collect();
 
             let res = lookup3_xy_with_conditional_negation(&mut cs, &bits, &points).unwrap();
 
             assert!(cs.is_satisfied());
 
             let mut index = 0;
-            if a_val { index += 1 }
+            if a_val {
-            if b_val { index += 2 }
+                index += 1
+            }
+            if b_val {
+                index += 2
+            }
 
             assert_eq!(res.0.get_value().unwrap(), points[index].0);
             let mut tmp = points[index].1;
-            if c_val { tmp.negate() }
+            if c_val {
+                tmp.negate()
+            }
             assert_eq!(res.1.get_value().unwrap(), tmp);
         }
     }
 
     #[test]
     fn test_synth() {
-        let mut rng = XorShiftRng::from_seed([0x3dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         let window_size = 4;
 
         let mut assignment = vec![Fr::zero(); 1 << window_size];
-        let constants: Vec<_> = (0..(1 << window_size)).map(|_| Fr::rand(&mut rng)).collect();
+        let constants: Vec<_> = (0..(1 << window_size))
+            .map(|_| Fr::random(&mut rng))
+            .collect();
 
         synth::<Bls12, _>(window_size, &constants, &mut assignment);
 

bellman/src/gadgets/multieq.rs

@@ -1,14 +1,8 @@
-use ff::{Field, PrimeField};
+use ff::{Field, PrimeField, ScalarEngine};
-use pairing::Engine;
 
-use bellman::{
+use crate::{ConstraintSystem, LinearCombination, SynthesisError, Variable};
-    SynthesisError,
-    ConstraintSystem,
-    LinearCombination,
-    Variable
-};
 
-pub struct MultiEq<E: Engine, CS: ConstraintSystem<E>>{
+pub struct MultiEq<E: ScalarEngine, CS: ConstraintSystem<E>> {
     cs: CS,
     ops: usize,
     bits_used: usize,
@@ -16,19 +10,18 @@ pub struct MultiEq<E: Engine, CS: ConstraintSystem<E>>{
     rhs: LinearCombination<E>,
 }
 
-impl<E: Engine, CS: ConstraintSystem<E>> MultiEq<E, CS> {
+impl<E: ScalarEngine, CS: ConstraintSystem<E>> MultiEq<E, CS> {
     pub fn new(cs: CS) -> Self {
         MultiEq {
-            cs: cs,
+            cs,
             ops: 0,
             bits_used: 0,
             lhs: LinearCombination::zero(),
-            rhs: LinearCombination::zero()
+            rhs: LinearCombination::zero(),
         }
     }
 
-    fn accumulate(&mut self)
+    fn accumulate(&mut self) {
-    {
         let ops = self.ops;
         let lhs = self.lhs.clone();
         let rhs = self.rhs.clone();
@@ -36,7 +29,7 @@ impl<E: Engine, CS: ConstraintSystem<E>> MultiEq<E, CS> {
             || format!("multieq {}", ops),
             |_| lhs,
             |lc| lc + CS::one(),
-            |_| rhs
+            |_| rhs,
         );
         self.lhs = LinearCombination::zero();
         self.rhs = LinearCombination::zero();
@@ -48,9 +41,8 @@ impl<E: Engine, CS: ConstraintSystem<E>> MultiEq<E, CS> {
         &mut self,
         num_bits: usize,
         lhs: &LinearCombination<E>,
-        rhs: &LinearCombination<E>
+        rhs: &LinearCombination<E>,
-    )
+    ) {
-    {
         // Check if we will exceed the capacity
         if (E::Fr::CAPACITY as usize) <= (self.bits_used + num_bits) {
             self.accumulate();
@@ -65,70 +57,63 @@ impl<E: Engine, CS: ConstraintSystem<E>> MultiEq<E, CS> {
     }
 }
 
-impl<E: Engine, CS: ConstraintSystem<E>> Drop for MultiEq<E, CS> {
+impl<E: ScalarEngine, CS: ConstraintSystem<E>> Drop for MultiEq<E, CS> {
     fn drop(&mut self) {
         if self.bits_used > 0 {
-           self.accumulate();
+            self.accumulate();
         }
     }
 }
 
-impl<E: Engine, CS: ConstraintSystem<E>> ConstraintSystem<E> for MultiEq<E, CS>
+impl<E: ScalarEngine, CS: ConstraintSystem<E>> ConstraintSystem<E> for MultiEq<E, CS> {
-{
     type Root = Self;
 
     fn one() -> Variable {
         CS::one()
     }
 
-    fn alloc<F, A, AR>(
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         self.cs.alloc(annotation, f)
     }
 
-    fn alloc_input<F, A, AR>(
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         self.cs.alloc_input(annotation, f)
     }
 
-    fn enforce<A, AR, LA, LB, LC>(
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
-        &mut self,
+    where
-        annotation: A,
+        A: FnOnce() -> AR,
-        a: LA,
+        AR: Into<String>,
-        b: LB,
+        LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        c: LC
+        LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-    )
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        where A: FnOnce() -> AR, AR: Into<String>,
-              LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>
     {
         self.cs.enforce(annotation, a, b, c)
     }
 
     fn push_namespace<NR, N>(&mut self, name_fn: N)
-        where NR: Into<String>, N: FnOnce() -> NR
+    where
+        NR: Into<String>,
+        N: FnOnce() -> NR,
     {
         self.cs.get_root().push_namespace(name_fn)
     }
 
-    fn pop_namespace(&mut self)
+    fn pop_namespace(&mut self) {
-    {
         self.cs.get_root().pop_namespace()
     }
 
-    fn get_root(&mut self) -> &mut Self::Root
+    fn get_root(&mut self) -> &mut Self::Root {
-    {
         self
     }
 }

bellman/src/gadgets/multipack.rs

@@ -0,0 +1,111 @@
+//! Helpers for packing vectors of bits into scalar field elements.
+
+use super::boolean::Boolean;
+use super::num::Num;
+use super::Assignment;
+use crate::{ConstraintSystem, SynthesisError};
+use ff::{Field, PrimeField, ScalarEngine};
+
+/// Takes a sequence of booleans and exposes them as compact
+/// public inputs
+pub fn pack_into_inputs<E, CS>(mut cs: CS, bits: &[Boolean]) -> Result<(), SynthesisError>
+where
+    E: ScalarEngine,
+    CS: ConstraintSystem<E>,
+{
+    for (i, bits) in bits.chunks(E::Fr::CAPACITY as usize).enumerate() {
+        let mut num = Num::<E>::zero();
+        let mut coeff = E::Fr::one();
+        for bit in bits {
+            num = num.add_bool_with_coeff(CS::one(), bit, coeff);
+
+            coeff.double();
+        }
+
+        let input = cs.alloc_input(|| format!("input {}", i), || Ok(*num.get_value().get()?))?;
+
+        // num * 1 = input
+        cs.enforce(
+            || format!("packing constraint {}", i),
+            |_| num.lc(E::Fr::one()),
+            |lc| lc + CS::one(),
+            |lc| lc + input,
+        );
+    }
+
+    Ok(())
+}
+
+pub fn bytes_to_bits(bytes: &[u8]) -> Vec<bool> {
+    bytes
+        .iter()
+        .flat_map(|&v| (0..8).rev().map(move |i| (v >> i) & 1 == 1))
+        .collect()
+}
+
+pub fn bytes_to_bits_le(bytes: &[u8]) -> Vec<bool> {
+    bytes
+        .iter()
+        .flat_map(|&v| (0..8).map(move |i| (v >> i) & 1 == 1))
+        .collect()
+}
+
+pub fn compute_multipacking<E: ScalarEngine>(bits: &[bool]) -> Vec<E::Fr> {
+    let mut result = vec![];
+
+    for bits in bits.chunks(E::Fr::CAPACITY as usize) {
+        let mut cur = E::Fr::zero();
+        let mut coeff = E::Fr::one();
+
+        for bit in bits {
+            if *bit {
+                cur.add_assign(&coeff);
+            }
+
+            coeff.double();
+        }
+
+        result.push(cur);
+    }
+
+    result
+}
+
+#[test]
+fn test_multipacking() {
+    use crate::ConstraintSystem;
+    use pairing::bls12_381::Bls12;
+    use rand_core::{RngCore, SeedableRng};
+    use rand_xorshift::XorShiftRng;
+
+    use super::boolean::{AllocatedBit, Boolean};
+    use crate::gadgets::test::*;
+
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
+
+    for num_bits in 0..1500 {
+        let mut cs = TestConstraintSystem::<Bls12>::new();
+
+        let bits: Vec<bool> = (0..num_bits).map(|_| rng.next_u32() % 2 != 0).collect();
+
+        let circuit_bits = bits
+            .iter()
+            .enumerate()
+            .map(|(i, &b)| {
+                Boolean::from(
+                    AllocatedBit::alloc(cs.namespace(|| format!("bit {}", i)), Some(b)).unwrap(),
+                )
+            })
+            .collect::<Vec<_>>();
+
+        let expected_inputs = compute_multipacking::<Bls12>(&bits);
+
+        pack_into_inputs(cs.namespace(|| "pack"), &circuit_bits).unwrap();
+
+        assert!(cs.is_satisfied());
+        assert!(cs.verify(&expected_inputs));
+    }
+}

bellman/src/gadgets/num.rs

@@ -1,78 +1,62 @@
-use ff::{BitIterator, Field, PrimeField, PrimeFieldRepr};
+//! Gadgets representing numbers in the scalar field of the underlying curve.
-use pairing::Engine;
 
-use bellman::{
+use ff::{BitIterator, Field, PrimeField, PrimeFieldRepr, ScalarEngine};
-    SynthesisError,
-    ConstraintSystem,
-    LinearCombination,
-    Variable
-};
 
-use super::{
+use crate::{ConstraintSystem, LinearCombination, SynthesisError, Variable};
-    Assignment
-};
 
-use super::boolean::{
+use super::Assignment;
-    self,
-    Boolean,
-    AllocatedBit
-};
 
-pub struct AllocatedNum<E: Engine> {
+use super::boolean::{self, AllocatedBit, Boolean};
+
+pub struct AllocatedNum<E: ScalarEngine> {
     value: Option<E::Fr>,
-    variable: Variable
+    variable: Variable,
 }
 
-impl<E: Engine> Clone for AllocatedNum<E> {
+impl<E: ScalarEngine> Clone for AllocatedNum<E> {
     fn clone(&self) -> Self {
         AllocatedNum {
             value: self.value,
-            variable: self.variable
+            variable: self.variable,
         }
     }
 }
 
-impl<E: Engine> AllocatedNum<E> {
+impl<E: ScalarEngine> AllocatedNum<E> {
-    pub fn alloc<CS, F>(
+    pub fn alloc<CS, F>(mut cs: CS, value: F) -> Result<Self, SynthesisError>
-        mut cs: CS,
+    where
-        value: F,
+        CS: ConstraintSystem<E>,
-    ) -> Result<Self, SynthesisError>
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        where CS: ConstraintSystem<E>,
-              F: FnOnce() -> Result<E::Fr, SynthesisError>
     {
         let mut new_value = None;
-        let var = cs.alloc(|| "num", || {
+        let var = cs.alloc(
-            let tmp = value()?;
+            || "num",
+            || {
+                let tmp = value()?;
 
-            new_value = Some(tmp);
+                new_value = Some(tmp);
 
-            Ok(tmp)
+                Ok(tmp)
-        })?;
+            },
+        )?;
 
         Ok(AllocatedNum {
             value: new_value,
-            variable: var
+            variable: var,
         })
     }
 
-    pub fn inputize<CS>(
+    pub fn inputize<CS>(&self, mut cs: CS) -> Result<(), SynthesisError>
-        &self,
+    where
-        mut cs: CS
+        CS: ConstraintSystem<E>,
-    ) -> Result<(), SynthesisError>
-        where CS: ConstraintSystem<E>
     {
-        let input = cs.alloc_input(
+        let input = cs.alloc_input(|| "input variable", || Ok(*self.value.get()?))?;
-            || "input variable",
-            || {
-                Ok(*self.value.get()?)
-            }
-        )?;
 
         cs.enforce(
             || "enforce input is correct",
             |lc| lc + input,
             |lc| lc + CS::one(),
-            |lc| lc + self.variable
+            |lc| lc + self.variable,
         );
 
         Ok(())
@@ -83,20 +67,19 @@ impl<E: Engine> AllocatedNum<E> {
     /// order, requiring that the representation
     /// strictly exists "in the field" (i.e., a
     /// congruency is not allowed.)
-    pub fn into_bits_le_strict<CS>(
+    pub fn to_bits_le_strict<CS>(&self, mut cs: CS) -> Result<Vec<Boolean>, SynthesisError>
-        &self,
+    where
-        mut cs: CS
+        CS: ConstraintSystem<E>,
-    ) -> Result<Vec<Boolean>, SynthesisError>
-        where CS: ConstraintSystem<E>
     {
         pub fn kary_and<E, CS>(
             mut cs: CS,
-            v: &[AllocatedBit]
+            v: &[AllocatedBit],
         ) -> Result<AllocatedBit, SynthesisError>
-            where E: Engine,
+        where
-                  CS: ConstraintSystem<E>
+            E: ScalarEngine,
+            CS: ConstraintSystem<E>,
         {
-            assert!(v.len() > 0);
+            assert!(!v.is_empty());
 
             // Let's keep this simple for now and just AND them all
             // manually
@@ -109,7 +92,7 @@ impl<E: Engine> AllocatedNum<E> {
                     cur = Some(AllocatedBit::and(
                         cs.namespace(|| format!("and {}", i)),
                         cur.as_ref().unwrap(),
-                        v
+                        v,
                     )?);
                 }
             }
@@ -145,15 +128,12 @@ impl<E: Engine> AllocatedNum<E> {
             if b {
                 // This is part of a run of ones. Let's just
                 // allocate the boolean with the expected value.
-                let a_bit = AllocatedBit::alloc(
+                let a_bit = AllocatedBit::alloc(cs.namespace(|| format!("bit {}", i)), a_bit)?;
-                    cs.namespace(|| format!("bit {}", i)),
-                    a_bit
-                )?;
                 // ... and add it to the current run of ones.
                 current_run.push(a_bit.clone());
                 result.push(a_bit);
             } else {
-                if current_run.len() > 0 {
+                if !current_run.is_empty() {
                     // This is the start of a run of zeros, but we need
                     // to k-ary AND against `last_run` first.
 
@@ -162,7 +142,7 @@ impl<E: Engine> AllocatedNum<E> {
                     }
                     last_run = Some(kary_and(
                         cs.namespace(|| format!("run ending at {}", i)),
-                        &current_run
+                        &current_run,
                     )?);
                     current_run.truncate(0);
                 }
@@ -175,7 +155,7 @@ impl<E: Engine> AllocatedNum<E> {
                 let a_bit = AllocatedBit::alloc_conditionally(
                     cs.namespace(|| format!("bit {}", i)),
                     a_bit,
-                    &last_run.as_ref().expect("char always starts with a one")
+                    &last_run.as_ref().expect("char always starts with a one"),
                 )?;
                 result.push(a_bit);
             }
@@ -201,30 +181,20 @@ impl<E: Engine> AllocatedNum<E> {
 
         lc = lc - self.variable;
 
-        cs.enforce(
+        cs.enforce(|| "unpacking constraint", |lc| lc, |lc| lc, |_| lc);
-            || "unpacking constraint",
-            |lc| lc,
-            |lc| lc,
-            |_| lc
-        );
 
         // Convert into booleans, and reverse for little-endian bit order
-        Ok(result.into_iter().map(|b| Boolean::from(b)).rev().collect())
+        Ok(result.into_iter().map(Boolean::from).rev().collect())
     }
 
     /// Convert the allocated number into its little-endian representation.
     /// Note that this does not strongly enforce that the commitment is
     /// "in the field."
-    pub fn into_bits_le<CS>(
+    pub fn to_bits_le<CS>(&self, mut cs: CS) -> Result<Vec<Boolean>, SynthesisError>
-        &self,
+    where
-        mut cs: CS
+        CS: ConstraintSystem<E>,
-    ) -> Result<Vec<Boolean>, SynthesisError>
-        where CS: ConstraintSystem<E>
     {
-        let bits = boolean::field_into_allocated_bits_le(
+        let bits = boolean::field_into_allocated_bits_le(&mut cs, self.value)?;
-            &mut cs,
-            self.value
-        )?;
 
         let mut lc = LinearCombination::zero();
         let mut coeff = E::Fr::one();
@@ -237,94 +207,91 @@ impl<E: Engine> AllocatedNum<E> {
 
         lc = lc - self.variable;
 
-        cs.enforce(
+        cs.enforce(|| "unpacking constraint", |lc| lc, |lc| lc, |_| lc);
-            || "unpacking constraint",
-            |lc| lc,
-            |lc| lc,
-            |_| lc
-        );
 
-        Ok(bits.into_iter().map(|b| Boolean::from(b)).collect())
+        Ok(bits.into_iter().map(Boolean::from).collect())
     }
 
-    pub fn mul<CS>(
+    pub fn mul<CS>(&self, mut cs: CS, other: &Self) -> Result<Self, SynthesisError>
-        &self,
+    where
-        mut cs: CS,
+        CS: ConstraintSystem<E>,
-        other: &Self
-    ) -> Result<Self, SynthesisError>
-        where CS: ConstraintSystem<E>
     {
         let mut value = None;
 
-        let var = cs.alloc(|| "product num", || {
+        let var = cs.alloc(
-            let mut tmp = *self.value.get()?;
+            || "product num",
-            tmp.mul_assign(other.value.get()?);
+            || {
+                let mut tmp = *self.value.get()?;
+                tmp.mul_assign(other.value.get()?);
 
-            value = Some(tmp);
+                value = Some(tmp);
 
-            Ok(tmp)
+                Ok(tmp)
-        })?;
+            },
+        )?;
 
         // Constrain: a * b = ab
         cs.enforce(
             || "multiplication constraint",
             |lc| lc + self.variable,
             |lc| lc + other.variable,
-            |lc| lc + var
+            |lc| lc + var,
         );
 
         Ok(AllocatedNum {
-            value: value,
+            value,
-            variable: var
+            variable: var,
         })
     }
 
-    pub fn square<CS>(
+    pub fn square<CS>(&self, mut cs: CS) -> Result<Self, SynthesisError>
-        &self,
+    where
-        mut cs: CS
+        CS: ConstraintSystem<E>,
-    ) -> Result<Self, SynthesisError>
-        where CS: ConstraintSystem<E>
     {
         let mut value = None;
 
-        let var = cs.alloc(|| "squared num", || {
+        let var = cs.alloc(
-            let mut tmp = *self.value.get()?;
+            || "squared num",
-            tmp.square();
+            || {
+                let mut tmp = *self.value.get()?;
+                tmp.square();
 
-            value = Some(tmp);
+                value = Some(tmp);
 
-            Ok(tmp)
+                Ok(tmp)
-        })?;
+            },
+        )?;
 
         // Constrain: a * a = aa
         cs.enforce(
             || "squaring constraint",
             |lc| lc + self.variable,
             |lc| lc + self.variable,
-            |lc| lc + var
+            |lc| lc + var,
         );
 
         Ok(AllocatedNum {
-            value: value,
+            value,
-            variable: var
+            variable: var,
         })
     }
 
-    pub fn assert_nonzero<CS>(
+    pub fn assert_nonzero<CS>(&self, mut cs: CS) -> Result<(), SynthesisError>
-        &self,
+    where
-        mut cs: CS
+        CS: ConstraintSystem<E>,
-    ) -> Result<(), SynthesisError>
-        where CS: ConstraintSystem<E>
     {
-        let inv = cs.alloc(|| "ephemeral inverse", || {
+        let inv = cs.alloc(
-            let tmp = *self.value.get()?;
+            || "ephemeral inverse",
-            
+            || {
-            if tmp.is_zero() {
+                let tmp = *self.value.get()?;
-                Err(SynthesisError::DivisionByZero)
+
-            } else {
+                if tmp.is_zero() {
-                Ok(tmp.inverse().unwrap())
+                    Err(SynthesisError::DivisionByZero)
-            }
+                } else {
-        })?;
+                    Ok(tmp.inverse().unwrap())
+                }
+            },
+        )?;
 
         // Constrain a * inv = 1, which is only valid
         // iff a has a multiplicative inverse, untrue
@@ -333,7 +300,7 @@ impl<E: Engine> AllocatedNum<E> {
             || "nonzero assertion constraint",
             |lc| lc + self.variable,
             |lc| lc + inv,
-            |lc| lc + CS::one()
+            |lc| lc + CS::one(),
         );
 
         Ok(())
@@ -346,44 +313,39 @@ impl<E: Engine> AllocatedNum<E> {
         mut cs: CS,
         a: &Self,
         b: &Self,
-        condition: &Boolean
+        condition: &Boolean,
     ) -> Result<(Self, Self), SynthesisError>
-        where CS: ConstraintSystem<E>
+    where
+        CS: ConstraintSystem<E>,
     {
-        let c = Self::alloc(
+        let c = Self::alloc(cs.namespace(|| "conditional reversal result 1"), || {
-            cs.namespace(|| "conditional reversal result 1"),
+            if *condition.get_value().get()? {
-            || {
+                Ok(*b.value.get()?)
-                if *condition.get_value().get()? {
+            } else {
-                    Ok(*b.value.get()?)
+                Ok(*a.value.get()?)
-                } else {
-                    Ok(*a.value.get()?)
-                }
             }
-        )?;
+        })?;
 
         cs.enforce(
             || "first conditional reversal",
             |lc| lc + a.variable - b.variable,
             |_| condition.lc(CS::one(), E::Fr::one()),
-            |lc| lc + a.variable - c.variable
+            |lc| lc + a.variable - c.variable,
         );
 
-        let d = Self::alloc(
+        let d = Self::alloc(cs.namespace(|| "conditional reversal result 2"), || {
-            cs.namespace(|| "conditional reversal result 2"),
+            if *condition.get_value().get()? {
-            || {
+                Ok(*a.value.get()?)
-                if *condition.get_value().get()? {
+            } else {
-                    Ok(*a.value.get()?)
+                Ok(*b.value.get()?)
-                } else {
-                    Ok(*b.value.get()?)
-                }
             }
-        )?;
+        })?;
 
         cs.enforce(
             || "second conditional reversal",
             |lc| lc + b.variable - a.variable,
             |_| condition.lc(CS::one(), E::Fr::one()),
-            |lc| lc + b.variable - d.variable
+            |lc| lc + b.variable - d.variable,
         );
 
         Ok((c, d))
@@ -398,25 +360,25 @@ impl<E: Engine> AllocatedNum<E> {
     }
 }
 
-pub struct Num<E: Engine> {
+pub struct Num<E: ScalarEngine> {
     value: Option<E::Fr>,
-    lc: LinearCombination<E>
+    lc: LinearCombination<E>,
 }
 
-impl<E: Engine> From<AllocatedNum<E>> for Num<E> {
+impl<E: ScalarEngine> From<AllocatedNum<E>> for Num<E> {
     fn from(num: AllocatedNum<E>) -> Num<E> {
         Num {
             value: num.value,
-            lc: LinearCombination::<E>::zero() + num.variable
+            lc: LinearCombination::<E>::zero() + num.variable,
         }
     }
 }
 
-impl<E: Engine> Num<E> {
+impl<E: ScalarEngine> Num<E> {
     pub fn zero() -> Self {
         Num {
             value: Some(E::Fr::zero()),
-            lc: LinearCombination::zero()
+            lc: LinearCombination::zero(),
         }
     }
 
@@ -428,13 +390,7 @@ impl<E: Engine> Num<E> {
         LinearCombination::zero() + (coeff, &self.lc)
     }
 
-    pub fn add_bool_with_coeff(
+    pub fn add_bool_with_coeff(self, one: Variable, bit: &Boolean, coeff: E::Fr) -> Self {
-        self,
-        one: Variable,
-        bit: &Boolean,
-        coeff: E::Fr
-    ) -> Self
-    {
         let newval = match (self.value, bit.get_value()) {
             (Some(mut curval), Some(bval)) => {
                 if bval {
@@ -442,25 +398,27 @@ impl<E: Engine> Num<E> {
                 }
 
                 Some(curval)
-            },
+            }
-            _ => None
+            _ => None,
         };
 
         Num {
             value: newval,
-            lc: self.lc + &bit.lc(one, coeff)
+            lc: self.lc + &bit.lc(one, coeff),
         }
     }
 }
 
 #[cfg(test)]
 mod test {
-    use rand::{SeedableRng, Rand, Rng, XorShiftRng};
+    use crate::ConstraintSystem;
-    use bellman::{ConstraintSystem};
     use ff::{BitIterator, Field, PrimeField};
     use pairing::bls12_381::{Bls12, Fr};
-    use ::circuit::test::*;
+    use rand_core::SeedableRng;
+    use rand_xorshift::XorShiftRng;
+
     use super::{AllocatedNum, Boolean};
+    use crate::gadgets::test::*;
 
     #[test]
     fn test_allocated_num() {
@@ -489,8 +447,10 @@ mod test {
     fn test_num_multiplication() {
         let mut cs = TestConstraintSystem::<Bls12>::new();
 
-        let n = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::from_str("12").unwrap())).unwrap();
+        let n =
-        let n2 = AllocatedNum::alloc(cs.namespace(|| "b"), || Ok(Fr::from_str("10").unwrap())).unwrap();
+            AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::from_str("12").unwrap())).unwrap();
+        let n2 =
+            AllocatedNum::alloc(cs.namespace(|| "b"), || Ok(Fr::from_str("10").unwrap())).unwrap();
         let n3 = n.mul(&mut cs, &n2).unwrap();
 
         assert!(cs.is_satisfied());
@@ -502,12 +462,15 @@ mod test {
 
     #[test]
     fn test_num_conditional_reversal() {
-        let mut rng = XorShiftRng::from_seed([0x3dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
         {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(rng.gen())).unwrap();
+            let a = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::random(&mut rng))).unwrap();
-            let b = AllocatedNum::alloc(cs.namespace(|| "b"), || Ok(rng.gen())).unwrap();
+            let b = AllocatedNum::alloc(cs.namespace(|| "b"), || Ok(Fr::random(&mut rng))).unwrap();
             let condition = Boolean::constant(false);
             let (c, d) = AllocatedNum::conditionally_reverse(&mut cs, &a, &b, &condition).unwrap();
 
@@ -520,8 +483,8 @@ mod test {
         {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(rng.gen())).unwrap();
+            let a = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(Fr::random(&mut rng))).unwrap();
-            let b = AllocatedNum::alloc(cs.namespace(|| "b"), || Ok(rng.gen())).unwrap();
+            let b = AllocatedNum::alloc(cs.namespace(|| "b"), || Ok(Fr::random(&mut rng))).unwrap();
             let condition = Boolean::constant(true);
             let (c, d) = AllocatedNum::conditionally_reverse(&mut cs, &a, &b, &condition).unwrap();
 
@@ -560,7 +523,7 @@ mod test {
         let mut cs = TestConstraintSystem::<Bls12>::new();
 
         let n = AllocatedNum::alloc(&mut cs, || Ok(negone)).unwrap();
-        n.into_bits_le_strict(&mut cs).unwrap();
+        n.to_bits_le_strict(&mut cs).unwrap();
 
         assert!(cs.is_satisfied());
 
@@ -568,28 +531,37 @@ mod test {
         cs.set("bit 254/boolean", Fr::one());
 
         // this makes the conditional boolean constraint fail
-        assert_eq!(cs.which_is_unsatisfied().unwrap(), "bit 254/boolean constraint");
+        assert_eq!(
+            cs.which_is_unsatisfied().unwrap(),
+            "bit 254/boolean constraint"
+        );
     }
 
     #[test]
     fn test_into_bits() {
-        let mut rng = XorShiftRng::from_seed([0x3dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for i in 0..200 {
-            let r = Fr::rand(&mut rng);
+            let r = Fr::random(&mut rng);
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
             let n = AllocatedNum::alloc(&mut cs, || Ok(r)).unwrap();
 
             let bits = if i % 2 == 0 {
-                n.into_bits_le(&mut cs).unwrap()
+                n.to_bits_le(&mut cs).unwrap()
             } else {
-                n.into_bits_le_strict(&mut cs).unwrap()
+                n.to_bits_le_strict(&mut cs).unwrap()
             };
 
             assert!(cs.is_satisfied());
 
-            for (b, a) in BitIterator::new(r.into_repr()).skip(1).zip(bits.iter().rev()) {
+            for (b, a) in BitIterator::new(r.into_repr())
+                .skip(1)
+                .zip(bits.iter().rev())
+            {
                 if let &Boolean::Is(ref a) = a {
                     assert_eq!(b, a.get_value().unwrap());
                 } else {
@@ -597,7 +569,7 @@ mod test {
                 }
             }
 
-            cs.set("num", Fr::rand(&mut rng));
+            cs.set("num", Fr::random(&mut rng));
             assert!(!cs.is_satisfied());
             cs.set("num", r);
             assert!(cs.is_satisfied());

bellman/src/gadgets/sha256.rs

@@ -1,9 +1,15 @@
-use super::uint32::UInt32;
+//! Circuits for the [SHA-256] hash function and its internal compression
-use super::multieq::MultiEq;
+//! function.
-use super::boolean::Boolean;
+//!
-use bellman::{ConstraintSystem, SynthesisError};
+//! [SHA-256]: https://tools.ietf.org/html/rfc6234
-use pairing::Engine;
 
+use super::boolean::Boolean;
+use super::multieq::MultiEq;
+use super::uint32::UInt32;
+use crate::{ConstraintSystem, SynthesisError};
+use ff::ScalarEngine;
+
+#[allow(clippy::unreadable_literal)]
 const ROUND_CONSTANTS: [u32; 64] = [
     0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
     0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
@@ -12,37 +18,36 @@ const ROUND_CONSTANTS: [u32; 64] = [
     0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
     0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
     0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
-    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2
+    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2,
 ];
 
+#[allow(clippy::unreadable_literal)]
 const IV: [u32; 8] = [
-    0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
+    0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19,
-    0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
 ];
 
 pub fn sha256_block_no_padding<E, CS>(
     mut cs: CS,
-    input: &[Boolean]
+    input: &[Boolean],
 ) -> Result<Vec<Boolean>, SynthesisError>
-    where E: Engine, CS: ConstraintSystem<E>
+where
+    E: ScalarEngine,
+    CS: ConstraintSystem<E>,
 {
     assert_eq!(input.len(), 512);
 
-    Ok(sha256_compression_function(
+    Ok(
-        &mut cs,
+        sha256_compression_function(&mut cs, &input, &get_sha256_iv())?
-        &input,
+            .into_iter()
-        &get_sha256_iv()
+            .flat_map(|e| e.into_bits_be())
-    )?
+            .collect(),
-    .into_iter()
+    )
-    .flat_map(|e| e.into_bits_be())
-    .collect())
 }
 
-pub fn sha256<E, CS>(
+pub fn sha256<E, CS>(mut cs: CS, input: &[Boolean]) -> Result<Vec<Boolean>, SynthesisError>
-    mut cs: CS,
+where
-    input: &[Boolean]
+    E: ScalarEngine,
-) -> Result<Vec<Boolean>, SynthesisError>
+    CS: ConstraintSystem<E>,
-    where E: Engine, CS: ConstraintSystem<E>
 {
     assert!(input.len() % 8 == 0);
 
@@ -62,16 +67,10 @@ pub fn sha256<E, CS>(
 
     let mut cur = get_sha256_iv();
     for (i, block) in padded.chunks(512).enumerate() {
-        cur = sha256_compression_function(
+        cur = sha256_compression_function(cs.namespace(|| format!("block {}", i)), block, &cur)?;
-            cs.namespace(|| format!("block {}", i)),
-            block,
-            &cur
-        )?;
     }
 
-    Ok(cur.into_iter()
+    Ok(cur.into_iter().flat_map(|e| e.into_bits_be()).collect())
-    .flat_map(|e| e.into_bits_be())
-    .collect())
 }
 
 fn get_sha256_iv() -> Vec<UInt32> {
@@ -81,16 +80,19 @@ fn get_sha256_iv() -> Vec<UInt32> {
 fn sha256_compression_function<E, CS>(
     cs: CS,
     input: &[Boolean],
-    current_hash_value: &[UInt32]
+    current_hash_value: &[UInt32],
 ) -> Result<Vec<UInt32>, SynthesisError>
-    where E: Engine, CS: ConstraintSystem<E>
+where
+    E: ScalarEngine,
+    CS: ConstraintSystem<E>,
 {
     assert_eq!(input.len(), 512);
     assert_eq!(current_hash_value.len(), 8);
 
-    let mut w = input.chunks(32)
+    let mut w = input
-                     .map(|e| UInt32::from_bits_be(e))
+        .chunks(32)
-                     .collect::<Vec<_>>();
+        .map(|e| UInt32::from_bits_be(e))
+        .collect::<Vec<_>>();
 
     // We can save some constraints by combining some of
     // the constraints in different u32 additions
@@ -100,30 +102,18 @@ fn sha256_compression_function<E, CS>(
         let cs = &mut cs.namespace(|| format!("w extension {}", i));
 
         // s0 := (w[i-15] rightrotate 7) xor (w[i-15] rightrotate 18) xor (w[i-15] rightshift 3)
-        let mut s0 = w[i-15].rotr(7);
+        let mut s0 = w[i - 15].rotr(7);
-        s0 = s0.xor(
+        s0 = s0.xor(cs.namespace(|| "first xor for s0"), &w[i - 15].rotr(18))?;
-            cs.namespace(|| "first xor for s0"),
+        s0 = s0.xor(cs.namespace(|| "second xor for s0"), &w[i - 15].shr(3))?;
-            &w[i-15].rotr(18)
-        )?;
-        s0 = s0.xor(
-            cs.namespace(|| "second xor for s0"),
-            &w[i-15].shr(3)
-        )?;
 
         // s1 := (w[i-2] rightrotate 17) xor (w[i-2] rightrotate 19) xor (w[i-2] rightshift 10)
-        let mut s1 = w[i-2].rotr(17);
+        let mut s1 = w[i - 2].rotr(17);
-        s1 = s1.xor(
+        s1 = s1.xor(cs.namespace(|| "first xor for s1"), &w[i - 2].rotr(19))?;
-            cs.namespace(|| "first xor for s1"),
+        s1 = s1.xor(cs.namespace(|| "second xor for s1"), &w[i - 2].shr(10))?;
-            &w[i-2].rotr(19)
-        )?;
-        s1 = s1.xor(
-            cs.namespace(|| "second xor for s1"),
-            &w[i-2].shr(10)
-        )?;
 
         let tmp = UInt32::addmany(
             cs.namespace(|| "computation of w[i]"),
-            &[w[i-16].clone(), s0, w[i-7].clone(), s1]
+            &[w[i - 16].clone(), s0, w[i - 7].clone(), s1],
         )?;
 
         // w[i] := w[i-16] + s0 + w[i-7] + s1
@@ -134,29 +124,21 @@ fn sha256_compression_function<E, CS>(
 
     enum Maybe {
         Deferred(Vec<UInt32>),
-        Concrete(UInt32)
+        Concrete(UInt32),
     }
 
     impl Maybe {
-        fn compute<E, CS, M>(
+        fn compute<E, CS, M>(self, cs: M, others: &[UInt32]) -> Result<UInt32, SynthesisError>
-            self,
+        where
-            cs: M,
+            E: ScalarEngine,
-            others: &[UInt32]
+            CS: ConstraintSystem<E>,
-        ) -> Result<UInt32, SynthesisError>
+            M: ConstraintSystem<E, Root = MultiEq<E, CS>>,
-            where E: Engine,
-                  CS: ConstraintSystem<E>,
-                  M: ConstraintSystem<E, Root=MultiEq<E, CS>>
         {
             Ok(match self {
-                Maybe::Concrete(ref v) => {
+                Maybe::Concrete(ref v) => return Ok(v.clone()),
-                    return Ok(v.clone())
-                },
                 Maybe::Deferred(mut v) => {
-                    v.extend(others.into_iter().cloned());
+                    v.extend(others.iter().cloned());
-                    UInt32::addmany(
+                    UInt32::addmany(cs, &v)?
-                        cs,
-                        &v
-                    )?
                 }
             })
         }
@@ -177,22 +159,11 @@ fn sha256_compression_function<E, CS>(
         // S1 := (e rightrotate 6) xor (e rightrotate 11) xor (e rightrotate 25)
         let new_e = e.compute(cs.namespace(|| "deferred e computation"), &[])?;
         let mut s1 = new_e.rotr(6);
-        s1 = s1.xor(
+        s1 = s1.xor(cs.namespace(|| "first xor for s1"), &new_e.rotr(11))?;
-            cs.namespace(|| "first xor for s1"),
+        s1 = s1.xor(cs.namespace(|| "second xor for s1"), &new_e.rotr(25))?;
-            &new_e.rotr(11)
-        )?;
-        s1 = s1.xor(
-            cs.namespace(|| "second xor for s1"),
-            &new_e.rotr(25)
-        )?;
 
         // ch := (e and f) xor ((not e) and g)
-        let ch = UInt32::sha256_ch(
+        let ch = UInt32::sha256_ch(cs.namespace(|| "ch"), &new_e, &f, &g)?;
-            cs.namespace(|| "ch"),
-            &new_e,
-            &f,
-            &g
-        )?;
 
         // temp1 := h + S1 + ch + k[i] + w[i]
         let temp1 = vec![
@@ -200,28 +171,17 @@ fn sha256_compression_function<E, CS>(
             s1,
             ch,
             UInt32::constant(ROUND_CONSTANTS[i]),
-            w[i].clone()
+            w[i].clone(),
         ];
 
         // S0 := (a rightrotate 2) xor (a rightrotate 13) xor (a rightrotate 22)
         let new_a = a.compute(cs.namespace(|| "deferred a computation"), &[])?;
         let mut s0 = new_a.rotr(2);
-        s0 = s0.xor(
+        s0 = s0.xor(cs.namespace(|| "first xor for s0"), &new_a.rotr(13))?;
-            cs.namespace(|| "first xor for s0"),
+        s0 = s0.xor(cs.namespace(|| "second xor for s0"), &new_a.rotr(22))?;
-            &new_a.rotr(13)
-        )?;
-        s0 = s0.xor(
-            cs.namespace(|| "second xor for s0"),
-            &new_a.rotr(22)
-        )?;
 
         // maj := (a and b) xor (a and c) xor (b and c)
-        let maj = UInt32::sha256_maj(
+        let maj = UInt32::sha256_maj(cs.namespace(|| "maj"), &new_a, &b, &c)?;
-            cs.namespace(|| "maj"),
-            &new_a,
-            &b,
-            &c
-        )?;
 
         // temp2 := S0 + maj
         let temp2 = vec![s0, maj];
@@ -244,7 +204,13 @@ fn sha256_compression_function<E, CS>(
         d = c;
         c = b;
         b = new_a;
-        a = Maybe::Deferred(temp1.iter().cloned().chain(temp2.iter().cloned()).collect::<Vec<_>>());
+        a = Maybe::Deferred(
+            temp1
+                .iter()
+                .cloned()
+                .chain(temp2.iter().cloned())
+                .collect::<Vec<_>>(),
+        );
     }
 
     /*
@@ -261,42 +227,42 @@ fn sha256_compression_function<E, CS>(
 
     let h0 = a.compute(
         cs.namespace(|| "deferred h0 computation"),
-        &[current_hash_value[0].clone()]
+        &[current_hash_value[0].clone()],
     )?;
 
     let h1 = UInt32::addmany(
         cs.namespace(|| "new h1"),
-        &[current_hash_value[1].clone(), b]
+        &[current_hash_value[1].clone(), b],
     )?;
 
     let h2 = UInt32::addmany(
         cs.namespace(|| "new h2"),
-        &[current_hash_value[2].clone(), c]
+        &[current_hash_value[2].clone(), c],
     )?;
 
     let h3 = UInt32::addmany(
         cs.namespace(|| "new h3"),
-        &[current_hash_value[3].clone(), d]
+        &[current_hash_value[3].clone(), d],
     )?;
 
     let h4 = e.compute(
         cs.namespace(|| "deferred h4 computation"),
-        &[current_hash_value[4].clone()]
+        &[current_hash_value[4].clone()],
     )?;
 
     let h5 = UInt32::addmany(
         cs.namespace(|| "new h5"),
-        &[current_hash_value[5].clone(), f]
+        &[current_hash_value[5].clone(), f],
     )?;
 
     let h6 = UInt32::addmany(
         cs.namespace(|| "new h6"),
-        &[current_hash_value[6].clone(), g]
+        &[current_hash_value[6].clone(), g],
     )?;
 
     let h7 = UInt32::addmany(
         cs.namespace(|| "new h7"),
-        &[current_hash_value[7].clone(), h]
+        &[current_hash_value[7].clone(), h],
     )?;
 
     Ok(vec![h0, h1, h2, h3, h4, h5, h6, h7])
@@ -305,10 +271,12 @@ fn sha256_compression_function<E, CS>(
 #[cfg(test)]
 mod test {
     use super::*;
-    use circuit::boolean::AllocatedBit;
+    use crate::gadgets::boolean::AllocatedBit;
+    use crate::gadgets::test::TestConstraintSystem;
+    use hex_literal::hex;
     use pairing::bls12_381::Bls12;
-    use circuit::test::TestConstraintSystem;
+    use rand_core::{RngCore, SeedableRng};
-    use rand::{XorShiftRng, SeedableRng, Rng};
+    use rand_xorshift::XorShiftRng;
 
     #[test]
     fn test_blank_hash() {
@@ -317,11 +285,7 @@ mod test {
         let mut cs = TestConstraintSystem::<Bls12>::new();
         let mut input_bits: Vec<_> = (0..512).map(|_| Boolean::Constant(false)).collect();
         input_bits[0] = Boolean::Constant(true);
-        let out = sha256_compression_function(
+        let out = sha256_compression_function(&mut cs, &input_bits, &iv).unwrap();
-            &mut cs,
-            &input_bits,
-            &iv
-        ).unwrap();
         let out_bits: Vec<_> = out.into_iter().flat_map(|e| e.into_bits_be()).collect();
 
         assert!(cs.is_satisfied());
@@ -330,7 +294,7 @@ mod test {
         let expected = hex!("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855");
 
         let mut out = out_bits.into_iter();
-        for b in expected.into_iter() {
+        for b in expected.iter() {
             for i in (0..8).rev() {
                 let c = out.next().unwrap().get_value().unwrap();
 
@@ -341,25 +305,27 @@ mod test {
 
     #[test]
     fn test_full_block() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         let iv = get_sha256_iv();
 
         let mut cs = TestConstraintSystem::<Bls12>::new();
-        let input_bits: Vec<_> = (0..512).map(|i| {
+        let input_bits: Vec<_> = (0..512)
-            Boolean::from(
+            .map(|i| {
-                AllocatedBit::alloc(
+                Boolean::from(
-                    cs.namespace(|| format!("input bit {}", i)),
+                    AllocatedBit::alloc(
-                    Some(rng.gen())
+                        cs.namespace(|| format!("input bit {}", i)),
-                ).unwrap()
+                        Some(rng.next_u32() % 2 != 0),
-            )
+                    )
-        }).collect();
+                    .unwrap(),
+                )
+            })
+            .collect();
 
-        sha256_compression_function(
+        sha256_compression_function(cs.namespace(|| "sha256"), &input_bits, &iv).unwrap();
-            cs.namespace(|| "sha256"),
-            &input_bits,
-            &iv
-        ).unwrap();
 
         assert!(cs.is_satisfied());
         assert_eq!(cs.num_constraints() - 512, 25840);
@@ -367,18 +333,18 @@ mod test {
 
     #[test]
     fn test_against_vectors() {
-        use crypto::sha2::Sha256;
+        use sha2::{Digest, Sha256};
-        use crypto::digest::Digest;
 
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
-        for input_len in (0..32).chain((32..256).filter(|a| a % 8 == 0))
+        for input_len in (0..32).chain((32..256).filter(|a| a % 8 == 0)) {
-        {
             let mut h = Sha256::new();
-            let data: Vec<u8> = (0..input_len).map(|_| rng.gen()).collect();
+            let data: Vec<u8> = (0..input_len).map(|_| rng.next_u32() as u8).collect();
             h.input(&data);
-            let mut hash_result = [0u8; 32];
+            let hash_result = h.result();
-            h.result(&mut hash_result[..]);
 
             let mut cs = TestConstraintSystem::<Bls12>::new();
             let mut input_bits = vec![];
@@ -387,7 +353,11 @@ mod test {
                 for bit_i in (0..8).rev() {
                     let cs = cs.namespace(|| format!("input bit {} {}", byte_i, bit_i));
 
-                    input_bits.push(AllocatedBit::alloc(cs, Some((input_byte >> bit_i) & 1u8 == 1u8)).unwrap().into());
+                    input_bits.push(
+                        AllocatedBit::alloc(cs, Some((input_byte >> bit_i) & 1u8 == 1u8))
+                            .unwrap()
+                            .into(),
+                    );
                 }
             }
 
@@ -395,17 +365,19 @@ mod test {
 
             assert!(cs.is_satisfied());
 
-            let mut s = hash_result.as_ref().iter()
+            let mut s = hash_result
-                                            .flat_map(|&byte| (0..8).rev().map(move |i| (byte >> i) & 1u8 == 1u8));
+                .as_ref()
+                .iter()
+                .flat_map(|&byte| (0..8).rev().map(move |i| (byte >> i) & 1u8 == 1u8));
 
             for b in r {
                 match b {
                     Boolean::Is(b) => {
                         assert!(s.next().unwrap() == b.get_value().unwrap());
-                    },
+                    }
                     Boolean::Not(b) => {
                         assert!(s.next().unwrap() != b.get_value().unwrap());
-                    },
+                    }
                     Boolean::Constant(b) => {
                         assert!(input_len == 0);
                         assert!(s.next().unwrap() == b);

bellman/src/gadgets/test/mod.rs

@@ -1,13 +1,8 @@
-use ff::{Field, PrimeField, PrimeFieldRepr};
+//! Helpers for testing circuit implementations.
-use pairing::Engine;
 
-use bellman::{
+use ff::{Field, PrimeField, PrimeFieldRepr, ScalarEngine};
-    LinearCombination,
+
-    SynthesisError,
+use crate::{ConstraintSystem, Index, LinearCombination, SynthesisError, Variable};
-    ConstraintSystem,
-    Variable,
-    Index
-};
 
 use std::collections::HashMap;
 use std::fmt::Write;
@@ -16,27 +11,27 @@ use byteorder::{BigEndian, ByteOrder};
 use std::cmp::Ordering;
 use std::collections::BTreeMap;
 
-use blake2_rfc::blake2s::Blake2s;
+use blake2s_simd::{Params as Blake2sParams, State as Blake2sState};
 
 #[derive(Debug)]
 enum NamedObject {
     Constraint(usize),
     Var(Variable),
-    Namespace
+    Namespace,
 }
 
 /// Constraint system for testing purposes.
-pub struct TestConstraintSystem<E: Engine> {
+pub struct TestConstraintSystem<E: ScalarEngine> {
     named_objects: HashMap<String, NamedObject>,
     current_namespace: Vec<String>,
     constraints: Vec<(
         LinearCombination<E>,
         LinearCombination<E>,
         LinearCombination<E>,
-        String
+        String,
     )>,
     inputs: Vec<(E::Fr, String)>,
-    aux: Vec<(E::Fr, String)>
+    aux: Vec<(E::Fr, String)>,
 }
 
 #[derive(Clone, Copy)]
@@ -48,7 +43,7 @@ impl PartialEq for OrderedVariable {
         match (self.0.get_unchecked(), other.0.get_unchecked()) {
             (Index::Input(ref a), Index::Input(ref b)) => a == b,
             (Index::Aux(ref a), Index::Aux(ref b)) => a == b,
-            _ => false
+            _ => false,
         }
     }
 }
@@ -63,20 +58,17 @@ impl Ord for OrderedVariable {
             (Index::Input(ref a), Index::Input(ref b)) => a.cmp(b),
             (Index::Aux(ref a), Index::Aux(ref b)) => a.cmp(b),
             (Index::Input(_), Index::Aux(_)) => Ordering::Less,
-            (Index::Aux(_), Index::Input(_)) => Ordering::Greater
+            (Index::Aux(_), Index::Input(_)) => Ordering::Greater,
         }
     }
 }
 
-fn proc_lc<E: Engine>(
+fn proc_lc<E: ScalarEngine>(terms: &[(Variable, E::Fr)]) -> BTreeMap<OrderedVariable, E::Fr> {
-    terms: &[(Variable, E::Fr)],
-) -> BTreeMap<OrderedVariable, E::Fr>
-{
     let mut map = BTreeMap::new();
     for &(var, coeff) in terms {
         map.entry(OrderedVariable(var))
-           .or_insert(E::Fr::zero())
+            .or_insert_with(E::Fr::zero)
-           .add_assign(&coeff);
+            .add_assign(&coeff);
     }
 
     // Remove terms that have a zero coefficient to normalize
@@ -94,11 +86,7 @@ fn proc_lc<E: Engine>(
     map
 }
 
-fn hash_lc<E: Engine>(
+fn hash_lc<E: ScalarEngine>(terms: &[(Variable, E::Fr)], h: &mut Blake2sState) {
-    terms: &[(Variable, E::Fr)],
-    h: &mut Blake2s
-)
-{
     let map = proc_lc::<E>(terms);
 
     let mut buf = [0u8; 9 + 32];
@@ -110,31 +98,30 @@ fn hash_lc<E: Engine>(
             Index::Input(i) => {
                 buf[0] = b'I';
                 BigEndian::write_u64(&mut buf[1..9], i as u64);
-            },
+            }
             Index::Aux(i) => {
                 buf[0] = b'A';
                 BigEndian::write_u64(&mut buf[1..9], i as u64);
             }
         }
-        
+
         coeff.into_repr().write_be(&mut buf[9..]).unwrap();
 
         h.update(&buf);
     }
 }
 
-fn eval_lc<E: Engine>(
+fn eval_lc<E: ScalarEngine>(
     terms: &[(Variable, E::Fr)],
     inputs: &[(E::Fr, String)],
-    aux: &[(E::Fr, String)]
+    aux: &[(E::Fr, String)],
-) -> E::Fr
+) -> E::Fr {
-{
     let mut acc = E::Fr::zero();
 
     for &(var, ref coeff) in terms {
         let mut tmp = match var.get_unchecked() {
             Index::Input(index) => inputs[index].0,
-            Index::Aux(index) => aux[index].0
+            Index::Aux(index) => aux[index].0,
         };
 
         tmp.mul_assign(&coeff);
@@ -144,17 +131,20 @@ fn eval_lc<E: Engine>(
     acc
 }
 
-impl<E: Engine> TestConstraintSystem<E> {
+impl<E: ScalarEngine> TestConstraintSystem<E> {
     pub fn new() -> TestConstraintSystem<E> {
         let mut map = HashMap::new();
-        map.insert("ONE".into(), NamedObject::Var(TestConstraintSystem::<E>::one()));
+        map.insert(
+            "ONE".into(),
+            NamedObject::Var(TestConstraintSystem::<E>::one()),
+        );
 
         TestConstraintSystem {
             named_objects: map,
             current_namespace: vec![],
             constraints: vec![],
             inputs: vec![(E::Fr::one(), "ONE".into())],
-            aux: vec![]
+            aux: vec![],
         }
     }
 
@@ -167,9 +157,9 @@ impl<E: Engine> TestConstraintSystem<E> {
             tmp
         };
 
-        let powers_of_two = (0..E::Fr::NUM_BITS).map(|i| {
+        let powers_of_two = (0..E::Fr::NUM_BITS)
-            E::Fr::from_str("2").unwrap().pow(&[i as u64])
+            .map(|i| E::Fr::from_str("2").unwrap().pow(&[u64::from(i)]))
-        }).collect::<Vec<_>>();
+            .collect::<Vec<_>>();
 
         let pp = |s: &mut String, lc: &LinearCombination<E>| {
             write!(s, "(").unwrap();
@@ -196,7 +186,7 @@ impl<E: Engine> TestConstraintSystem<E> {
                 match var.0.get_unchecked() {
                     Index::Input(i) => {
                         write!(s, "`{}`", &self.inputs[i].1).unwrap();
-                    },
+                    }
                     Index::Aux(i) => {
                         write!(s, "`{}`", &self.aux[i].1).unwrap();
                     }
@@ -226,7 +216,7 @@ impl<E: Engine> TestConstraintSystem<E> {
     }
 
     pub fn hash(&self) -> String {
-        let mut h = Blake2s::new(32);
+        let mut h = Blake2sParams::new().hash_length(32).to_state();
         {
             let mut buf = [0u8; 24];
 
@@ -259,57 +249,52 @@ impl<E: Engine> TestConstraintSystem<E> {
             a.mul_assign(&b);
 
             if a != c {
-                return Some(&*path)
+                return Some(&*path);
             }
         }
 
         None
     }
 
-    pub fn is_satisfied(&self) -> bool
+    pub fn is_satisfied(&self) -> bool {
-    {
         self.which_is_unsatisfied().is_none()
     }
 
-    pub fn num_constraints(&self) -> usize
+    pub fn num_constraints(&self) -> usize {
-    {
         self.constraints.len()
     }
 
-    pub fn set(&mut self, path: &str, to: E::Fr)
+    pub fn set(&mut self, path: &str, to: E::Fr) {
-    {
         match self.named_objects.get(path) {
-            Some(&NamedObject::Var(ref v)) => {
+            Some(&NamedObject::Var(ref v)) => match v.get_unchecked() {
-                match v.get_unchecked() {
+                Index::Input(index) => self.inputs[index].0 = to,
-                    Index::Input(index) => self.inputs[index].0 = to,
+                Index::Aux(index) => self.aux[index].0 = to,
-                    Index::Aux(index) => self.aux[index].0 = to
+            },
-                }
+            Some(e) => panic!(
-            }
+                "tried to set path `{}` to value, but `{:?}` already exists there.",
-            Some(e) => panic!("tried to set path `{}` to value, but `{:?}` already exists there.", path, e),
+                path, e
-            _ => panic!("no variable exists at path: {}", path)
+            ),
+            _ => panic!("no variable exists at path: {}", path),
         }
     }
 
-    pub fn verify(&self, expected: &[E::Fr]) -> bool
+    pub fn verify(&self, expected: &[E::Fr]) -> bool {
-    {
         assert_eq!(expected.len() + 1, self.inputs.len());
 
-        for (a, b) in self.inputs.iter().skip(1).zip(expected.iter())
+        for (a, b) in self.inputs.iter().skip(1).zip(expected.iter()) {
-        {
             if &a.0 != b {
-                return false
+                return false;
             }
         }
 
-        return true;
+        true
     }
 
     pub fn num_inputs(&self) -> usize {
         self.inputs.len()
     }
 
-    pub fn get_input(&mut self, index: usize, path: &str) -> E::Fr
+    pub fn get_input(&mut self, index: usize, path: &str) -> E::Fr {
-    {
         let (assignment, name) = self.inputs[index].clone();
 
         assert_eq!(path, name);
@@ -317,17 +302,17 @@ impl<E: Engine> TestConstraintSystem<E> {
         assignment
     }
 
-    pub fn get(&mut self, path: &str) -> E::Fr
+    pub fn get(&mut self, path: &str) -> E::Fr {
-    {
         match self.named_objects.get(path) {
-            Some(&NamedObject::Var(ref v)) => {
+            Some(&NamedObject::Var(ref v)) => match v.get_unchecked() {
-                match v.get_unchecked() {
+                Index::Input(index) => self.inputs[index].0,
-                    Index::Input(index) => self.inputs[index].0,
+                Index::Aux(index) => self.aux[index].0,
-                    Index::Aux(index) => self.aux[index].0
+            },
-                }
+            Some(e) => panic!(
-            }
+                "tried to get value of path `{}`, but `{:?}` exists there (not a variable)",
-            Some(e) => panic!("tried to get value of path `{}`, but `{:?}` exists there (not a variable)", path, e),
+                path, e
-            _ => panic!("no variable exists at path: {}", path)
+            ),
+            _ => panic!("no variable exists at path: {}", path),
         }
     }
 
@@ -348,8 +333,7 @@ fn compute_path(ns: &[String], this: String) -> String {
     let mut name = String::new();
 
     let mut needs_separation = false;
-    for ns in ns.iter().chain(Some(&this).into_iter())
+    for ns in ns.iter().chain(Some(&this).into_iter()) {
-    {
         if needs_separation {
             name += "/";
         }
@@ -361,15 +345,14 @@ fn compute_path(ns: &[String], this: String) -> String {
     name
 }
 
-impl<E: Engine> ConstraintSystem<E> for TestConstraintSystem<E> {
+impl<E: ScalarEngine> ConstraintSystem<E> for TestConstraintSystem<E> {
     type Root = Self;
 
-    fn alloc<F, A, AR>(
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         let index = self.aux.len();
         let path = compute_path(&self.current_namespace, annotation().into());
@@ -380,12 +363,11 @@ impl<E: Engine> ConstraintSystem<E> for TestConstraintSystem<E> {
         Ok(var)
     }
 
-    fn alloc_input<F, A, AR>(
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         let index = self.inputs.len();
         let path = compute_path(&self.current_namespace, annotation().into());
@@ -396,17 +378,13 @@ impl<E: Engine> ConstraintSystem<E> for TestConstraintSystem<E> {
         Ok(var)
     }
 
-    fn enforce<A, AR, LA, LB, LC>(
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
-        &mut self,
+    where
-        annotation: A,
+        A: FnOnce() -> AR,
-        a: LA,
+        AR: Into<String>,
-        b: LB,
+        LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        c: LC
+        LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-    )
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        where A: FnOnce() -> AR, AR: Into<String>,
-              LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>
     {
         let path = compute_path(&self.current_namespace, annotation().into());
         let index = self.constraints.len();
@@ -420,7 +398,9 @@ impl<E: Engine> ConstraintSystem<E> for TestConstraintSystem<E> {
     }
 
     fn push_namespace<NR, N>(&mut self, name_fn: N)
-    where NR: Into<String>, N: FnOnce() -> NR
+    where
+        NR: Into<String>,
+        N: FnOnce() -> NR,
     {
         let name = name_fn().into();
         let path = compute_path(&self.current_namespace, name.clone());
@@ -428,13 +408,11 @@ impl<E: Engine> ConstraintSystem<E> for TestConstraintSystem<E> {
         self.current_namespace.push(name);
     }
 
-    fn pop_namespace(&mut self)
+    fn pop_namespace(&mut self) {
-    {
         assert!(self.current_namespace.pop().is_some());
     }
 
-    fn get_root(&mut self) -> &mut Self::Root
+    fn get_root(&mut self) -> &mut Self::Root {
-    {
         self
     }
 }
@@ -447,28 +425,26 @@ fn test_cs() {
     let mut cs = TestConstraintSystem::<Bls12>::new();
     assert!(cs.is_satisfied());
     assert_eq!(cs.num_constraints(), 0);
-    let a = cs.namespace(|| "a").alloc(|| "var", || Ok(Fr::from_str("10").unwrap())).unwrap();
+    let a = cs
-    let b = cs.namespace(|| "b").alloc(|| "var", || Ok(Fr::from_str("4").unwrap())).unwrap();
+        .namespace(|| "a")
-    let c = cs.alloc(|| "product", || Ok(Fr::from_str("40").unwrap())).unwrap();
+        .alloc(|| "var", || Ok(Fr::from_str("10").unwrap()))
+        .unwrap();
+    let b = cs
+        .namespace(|| "b")
+        .alloc(|| "var", || Ok(Fr::from_str("4").unwrap()))
+        .unwrap();
+    let c = cs
+        .alloc(|| "product", || Ok(Fr::from_str("40").unwrap()))
+        .unwrap();
 
-    cs.enforce(
+    cs.enforce(|| "mult", |lc| lc + a, |lc| lc + b, |lc| lc + c);
-        || "mult",
-        |lc| lc + a,
-        |lc| lc + b,
-        |lc| lc + c
-    );
     assert!(cs.is_satisfied());
     assert_eq!(cs.num_constraints(), 1);
 
     cs.set("a/var", Fr::from_str("4").unwrap());
 
     let one = TestConstraintSystem::<Bls12>::one();
-    cs.enforce(
+    cs.enforce(|| "eq", |lc| lc + a, |lc| lc + one, |lc| lc + b);
-        || "eq",
-        |lc| lc + a,
-        |lc| lc + one,
-        |lc| lc + b
-    );
 
     assert!(!cs.is_satisfied());
     assert!(cs.which_is_unsatisfied() == Some("mult"));

bellman/src/gadgets/uint32.rs

@@ -1,16 +1,13 @@
-use ff::{Field, PrimeField};
+//! Circuit representation of a [`u32`], with helpers for the [`sha256`]
-use pairing::Engine;
+//! gadgets.
+//!
+//! [`sha256`]: crate::gadgets::sha256
 
-use bellman::{
+use ff::{Field, PrimeField, ScalarEngine};
-    SynthesisError,
-    ConstraintSystem,
-    LinearCombination
-};
 
-use super::boolean::{
+use crate::{ConstraintSystem, LinearCombination, SynthesisError};
-    Boolean,
+
-    AllocatedBit
+use super::boolean::{AllocatedBit, Boolean};
-};
 
 use super::multieq::MultiEq;
 
@@ -20,13 +17,12 @@ use super::multieq::MultiEq;
 pub struct UInt32 {
     // Least significant bit first
     bits: Vec<Boolean>,
-    value: Option<u32>
+    value: Option<u32>,
 }
 
 impl UInt32 {
     /// Construct a constant `UInt32` from a `u32`
-    pub fn constant(value: u32) -> Self
+    pub fn constant(value: u32) -> Self {
-    {
         let mut bits = Vec::with_capacity(32);
 
         let mut tmp = value;
@@ -41,18 +37,16 @@ impl UInt32 {
         }
 
         UInt32 {
-            bits: bits,
+            bits,
-            value: Some(value)
+            value: Some(value),
         }
     }
 
     /// Allocate a `UInt32` in the constraint system
-    pub fn alloc<E, CS>(
+    pub fn alloc<E, CS>(mut cs: CS, value: Option<u32>) -> Result<Self, SynthesisError>
-        mut cs: CS,
+    where
-        value: Option<u32>
+        E: ScalarEngine,
-    ) -> Result<Self, SynthesisError>
+        CS: ConstraintSystem<E>,
-        where E: Engine,
-              CS: ConstraintSystem<E>
     {
         let values = match value {
             Some(mut val) => {
@@ -64,28 +58,28 @@ impl UInt32 {
                 }
 
                 v
-            },
+            }
-            None => vec![None; 32]
+            None => vec![None; 32],
         };
 
-        let bits = values.into_iter()
+        let bits = values
-                         .enumerate()
+            .into_iter()
-                         .map(|(i, v)| {
+            .enumerate()
-                            Ok(Boolean::from(AllocatedBit::alloc(
+            .map(|(i, v)| {
-                                cs.namespace(|| format!("allocated bit {}", i)),
+                Ok(Boolean::from(AllocatedBit::alloc(
-                                v
+                    cs.namespace(|| format!("allocated bit {}", i)),
-                            )?))
+                    v,
-                         })
+                )?))
-                         .collect::<Result<Vec<_>, SynthesisError>>()?;
+            })
+            .collect::<Result<Vec<_>, SynthesisError>>()?;
 
-        Ok(UInt32 {
+        Ok(UInt32 { bits, value })
-            bits: bits,
-            value: value
-        })
     }
 
-    pub fn into_bits_be(&self) -> Vec<Boolean> {
+    pub fn into_bits_be(self) -> Vec<Boolean> {
-        self.bits.iter().rev().cloned().collect()
+        let mut ret = self.bits;
+        ret.reverse();
+        ret
     }
 
     pub fn from_bits_be(bits: &[Boolean]) -> Self {
@@ -96,28 +90,30 @@ impl UInt32 {
             value.as_mut().map(|v| *v <<= 1);
 
             match b.get_value() {
-                Some(true) => { value.as_mut().map(|v| *v |= 1); },
+                Some(true) => {
-                Some(false) => {},
+                    value.as_mut().map(|v| *v |= 1);
-                None => { value = None; }
+                }
+                Some(false) => {}
+                None => {
+                    value = None;
+                }
             }
         }
 
         UInt32 {
-            value: value,
+            value,
-            bits: bits.iter().rev().cloned().collect()
+            bits: bits.iter().rev().cloned().collect(),
         }
     }
 
-
     /// Turns this `UInt32` into its little-endian byte order representation.
-    pub fn into_bits(&self) -> Vec<Boolean> {
+    pub fn into_bits(self) -> Vec<Boolean> {
-        self.bits.clone()
+        self.bits
     }
 
     /// Converts a little-endian byte order representation of bits into a
     /// `UInt32`.
-    pub fn from_bits(bits: &[Boolean]) -> Self
+    pub fn from_bits(bits: &[Boolean]) -> Self {
-    {
         assert_eq!(bits.len(), 32);
 
         let new_bits = bits.to_vec();
@@ -126,48 +122,50 @@ impl UInt32 {
         for b in new_bits.iter().rev() {
             value.as_mut().map(|v| *v <<= 1);
 
-            match b {
+            match *b {
-                &Boolean::Constant(b) => {
+                Boolean::Constant(b) => {
                     if b {
                         value.as_mut().map(|v| *v |= 1);
                     }
-                },
-                &Boolean::Is(ref b) => {
-                    match b.get_value() {
-                        Some(true) => { value.as_mut().map(|v| *v |= 1); },
-                        Some(false) => {},
-                        None => { value = None }
-                    }
-                },
-                &Boolean::Not(ref b) => {
-                    match b.get_value() {
-                        Some(false) => { value.as_mut().map(|v| *v |= 1); },
-                        Some(true) => {},
-                        None => { value = None }
-                    }
                 }
+                Boolean::Is(ref b) => match b.get_value() {
+                    Some(true) => {
+                        value.as_mut().map(|v| *v |= 1);
+                    }
+                    Some(false) => {}
+                    None => value = None,
+                },
+                Boolean::Not(ref b) => match b.get_value() {
+                    Some(false) => {
+                        value.as_mut().map(|v| *v |= 1);
+                    }
+                    Some(true) => {}
+                    None => value = None,
+                },
             }
         }
 
         UInt32 {
-            value: value,
+            value,
-            bits: new_bits
+            bits: new_bits,
         }
     }
 
     pub fn rotr(&self, by: usize) -> Self {
         let by = by % 32;
 
-        let new_bits = self.bits.iter()
+        let new_bits = self
-                                .skip(by)
+            .bits
-                                .chain(self.bits.iter())
+            .iter()
-                                .take(32)
+            .skip(by)
-                                .cloned()
+            .chain(self.bits.iter())
-                                .collect();
+            .take(32)
+            .cloned()
+            .collect();
 
         UInt32 {
             bits: new_bits,
-            value: self.value.map(|v| v.rotate_right(by as u32))
+            value: self.value.map(|v| v.rotate_right(by as u32)),
         }
     }
 
@@ -176,17 +174,18 @@ impl UInt32 {
 
         let fill = Boolean::constant(false);
 
-        let new_bits = self.bits
+        let new_bits = self
-                           .iter() // The bits are least significant first
+            .bits
-                           .skip(by) // Skip the bits that will be lost during the shift
+            .iter() // The bits are least significant first
-                           .chain(Some(&fill).into_iter().cycle()) // Rest will be zeros
+            .skip(by) // Skip the bits that will be lost during the shift
-                           .take(32) // Only 32 bits needed!
+            .chain(Some(&fill).into_iter().cycle()) // Rest will be zeros
-                           .cloned()
+            .take(32) // Only 32 bits needed!
-                           .collect();
+            .cloned()
+            .collect();
 
         UInt32 {
             bits: new_bits,
-            value: self.value.map(|v| v >> by as u32)
+            value: self.value.map(|v| v >> by as u32),
         }
     }
 
@@ -196,121 +195,99 @@ impl UInt32 {
         b: &Self,
         c: &Self,
         tri_fn: F,
-        circuit_fn: U
+        circuit_fn: U,
     ) -> Result<Self, SynthesisError>
-        where E: Engine,
+    where
-              CS: ConstraintSystem<E>,
+        E: ScalarEngine,
-              F: Fn(u32, u32, u32) -> u32,
+        CS: ConstraintSystem<E>,
-              U: Fn(&mut CS, usize, &Boolean, &Boolean, &Boolean) -> Result<Boolean, SynthesisError>
+        F: Fn(u32, u32, u32) -> u32,
+        U: Fn(&mut CS, usize, &Boolean, &Boolean, &Boolean) -> Result<Boolean, SynthesisError>,
     {
         let new_value = match (a.value, b.value, c.value) {
-            (Some(a), Some(b), Some(c)) => {
+            (Some(a), Some(b), Some(c)) => Some(tri_fn(a, b, c)),
-                Some(tri_fn(a, b, c))
+            _ => None,
-            },
-            _ => None
         };
 
-        let bits = a.bits.iter()
+        let bits = a
-                            .zip(b.bits.iter())
+            .bits
-                            .zip(c.bits.iter())
+            .iter()
-                            .enumerate()
+            .zip(b.bits.iter())
-                            .map(|(i, ((a, b), c))| circuit_fn(&mut cs, i, a, b, c))
+            .zip(c.bits.iter())
-                            .collect::<Result<_, _>>()?;
+            .enumerate()
+            .map(|(i, ((a, b), c))| circuit_fn(&mut cs, i, a, b, c))
+            .collect::<Result<_, _>>()?;
 
         Ok(UInt32 {
-            bits: bits,
+            bits,
-            value: new_value
+            value: new_value,
         })
     }
 
     /// Compute the `maj` value (a and b) xor (a and c) xor (b and c)
     /// during SHA256.
-    pub fn sha256_maj<E, CS>(
+    pub fn sha256_maj<E, CS>(cs: CS, a: &Self, b: &Self, c: &Self) -> Result<Self, SynthesisError>
-        cs: CS,
+    where
-        a: &Self,
+        E: ScalarEngine,
-        b: &Self,
+        CS: ConstraintSystem<E>,
-        c: &Self
-    ) -> Result<Self, SynthesisError>
-        where E: Engine,
-              CS: ConstraintSystem<E>
     {
-        Self::triop(cs, a, b, c, |a, b, c| (a & b) ^ (a & c) ^ (b & c),
+        Self::triop(
-            |cs, i, a, b, c| {
+            cs,
-                Boolean::sha256_maj(
+            a,
-                    cs.namespace(|| format!("maj {}", i)),
+            b,
-                    a,
+            c,
-                    b,
+            |a, b, c| (a & b) ^ (a & c) ^ (b & c),
-                    c
+            |cs, i, a, b, c| Boolean::sha256_maj(cs.namespace(|| format!("maj {}", i)), a, b, c),
-                )
-            }
         )
     }
 
     /// Compute the `ch` value `(a and b) xor ((not a) and c)`
     /// during SHA256.
-    pub fn sha256_ch<E, CS>(
+    pub fn sha256_ch<E, CS>(cs: CS, a: &Self, b: &Self, c: &Self) -> Result<Self, SynthesisError>
-        cs: CS,
+    where
-        a: &Self,
+        E: ScalarEngine,
-        b: &Self,
+        CS: ConstraintSystem<E>,
-        c: &Self
-    ) -> Result<Self, SynthesisError>
-        where E: Engine,
-              CS: ConstraintSystem<E>
     {
-        Self::triop(cs, a, b, c, |a, b, c| (a & b) ^ ((!a) & c),
+        Self::triop(
-            |cs, i, a, b, c| {
+            cs,
-                Boolean::sha256_ch(
+            a,
-                    cs.namespace(|| format!("ch {}", i)),
+            b,
-                    a,
+            c,
-                    b,
+            |a, b, c| (a & b) ^ ((!a) & c),
-                    c
+            |cs, i, a, b, c| Boolean::sha256_ch(cs.namespace(|| format!("ch {}", i)), a, b, c),
-                )
-            }
         )
     }
 
     /// XOR this `UInt32` with another `UInt32`
-    pub fn xor<E, CS>(
+    pub fn xor<E, CS>(&self, mut cs: CS, other: &Self) -> Result<Self, SynthesisError>
-        &self,
+    where
-        mut cs: CS,
+        E: ScalarEngine,
-        other: &Self
+        CS: ConstraintSystem<E>,
-    ) -> Result<Self, SynthesisError>
-        where E: Engine,
-              CS: ConstraintSystem<E>
     {
         let new_value = match (self.value, other.value) {
-            (Some(a), Some(b)) => {
+            (Some(a), Some(b)) => Some(a ^ b),
-                Some(a ^ b)
+            _ => None,
-            },
-            _ => None
         };
 
-        let bits = self.bits.iter()
+        let bits = self
-                            .zip(other.bits.iter())
+            .bits
-                            .enumerate()
+            .iter()
-                            .map(|(i, (a, b))| {
+            .zip(other.bits.iter())
-                                Boolean::xor(
+            .enumerate()
-                                    cs.namespace(|| format!("xor of bit {}", i)),
+            .map(|(i, (a, b))| Boolean::xor(cs.namespace(|| format!("xor of bit {}", i)), a, b))
-                                    a,
+            .collect::<Result<_, _>>()?;
-                                    b
-                                )
-                            })
-                            .collect::<Result<_, _>>()?;
 
         Ok(UInt32 {
-            bits: bits,
+            bits,
-            value: new_value
+            value: new_value,
         })
     }
 
     /// Perform modular addition of several `UInt32` objects.
-    pub fn addmany<E, CS, M>(
+    pub fn addmany<E, CS, M>(mut cs: M, operands: &[Self]) -> Result<Self, SynthesisError>
-        mut cs: M,
+    where
-        operands: &[Self]
+        E: ScalarEngine,
-    ) -> Result<Self, SynthesisError>
+        CS: ConstraintSystem<E>,
-        where E: Engine,
+        M: ConstraintSystem<E, Root = MultiEq<E, CS>>,
-              CS: ConstraintSystem<E>,
-              M: ConstraintSystem<E, Root=MultiEq<E, CS>>
     {
         // Make some arbitrary bounds for ourselves to avoid overflows
         // in the scalar field
@@ -320,7 +297,7 @@ impl UInt32 {
 
         // Compute the maximum value of the sum so we allocate enough bits for
         // the result
-        let mut max_value = (operands.len() as u64) * (u32::max_value() as u64);
+        let mut max_value = (operands.len() as u64) * (u64::from(u32::max_value()));
 
         // Keep track of the resulting value
         let mut result_value = Some(0u64);
@@ -336,8 +313,8 @@ impl UInt32 {
             // Accumulate the value
             match op.value {
                 Some(val) => {
-                    result_value.as_mut().map(|v| *v += val as u64);
+                    result_value.as_mut().map(|v| *v += u64::from(val));
-                },
+                }
                 None => {
                     // If any of our operands have unknown value, we won't
                     // know the value of the result
@@ -381,7 +358,7 @@ impl UInt32 {
             // Allocate the bit
             let b = AllocatedBit::alloc(
                 cs.namespace(|| format!("result bit {}", i)),
-                result_value.map(|v| (v >> i) & 1 == 1)
+                result_value.map(|v| (v >> i) & 1 == 1),
             )?;
 
             // Add this bit to the result combination
@@ -402,48 +379,53 @@ impl UInt32 {
 
         Ok(UInt32 {
             bits: result_bits,
-            value: modular_value
+            value: modular_value,
         })
     }
 }
 
 #[cfg(test)]
 mod test {
-    use rand::{XorShiftRng, SeedableRng, Rng};
+    use super::UInt32;
-    use ::circuit::boolean::{Boolean};
+    use crate::gadgets::boolean::Boolean;
-    use super::{UInt32};
+    use crate::gadgets::multieq::MultiEq;
+    use crate::gadgets::test::*;
+    use crate::ConstraintSystem;
     use ff::Field;
-    use pairing::bls12_381::{Bls12};
+    use pairing::bls12_381::Bls12;
-    use ::circuit::test::*;
+    use rand_core::{RngCore, SeedableRng};
-    use bellman::{ConstraintSystem};
+    use rand_xorshift::XorShiftRng;
-    use circuit::multieq::MultiEq;
 
     #[test]
     fn test_uint32_from_bits_be() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0653]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..1000 {
-            let mut v = (0..32).map(|_| Boolean::constant(rng.gen())).collect::<Vec<_>>();
+            let v = (0..32)
+                .map(|_| Boolean::constant(rng.next_u32() % 2 != 0))
+                .collect::<Vec<_>>();
 
             let b = UInt32::from_bits_be(&v);
 
             for (i, bit) in b.bits.iter().enumerate() {
-                match bit {
+                match *bit {
-                    &Boolean::Constant(bit) => {
+                    Boolean::Constant(bit) => {
                         assert!(bit == ((b.value.unwrap() >> i) & 1 == 1));
-                    },
+                    }
-                    _ => unreachable!()
+                    _ => unreachable!(),
                 }
             }
 
             let expected_to_be_same = b.into_bits_be();
 
-            for x in v.iter().zip(expected_to_be_same.iter())
+            for x in v.iter().zip(expected_to_be_same.iter()) {
-            {
                 match x {
-                    (&Boolean::Constant(true), &Boolean::Constant(true)) => {},
+                    (&Boolean::Constant(true), &Boolean::Constant(true)) => {}
-                    (&Boolean::Constant(false), &Boolean::Constant(false)) => {},
+                    (&Boolean::Constant(false), &Boolean::Constant(false)) => {}
-                    _ => unreachable!()
+                    _ => unreachable!(),
                 }
             }
         }
@@ -451,30 +433,34 @@ mod test {
 
     #[test]
     fn test_uint32_from_bits() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0653]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..1000 {
-            let mut v = (0..32).map(|_| Boolean::constant(rng.gen())).collect::<Vec<_>>();
+            let v = (0..32)
+                .map(|_| Boolean::constant(rng.next_u32() % 2 != 0))
+                .collect::<Vec<_>>();
 
             let b = UInt32::from_bits(&v);
 
             for (i, bit) in b.bits.iter().enumerate() {
-                match bit {
+                match *bit {
-                    &Boolean::Constant(bit) => {
+                    Boolean::Constant(bit) => {
                         assert!(bit == ((b.value.unwrap() >> i) & 1 == 1));
-                    },
+                    }
-                    _ => unreachable!()
+                    _ => unreachable!(),
                 }
             }
 
             let expected_to_be_same = b.into_bits();
 
-            for x in v.iter().zip(expected_to_be_same.iter())
+            for x in v.iter().zip(expected_to_be_same.iter()) {
-            {
                 match x {
-                    (&Boolean::Constant(true), &Boolean::Constant(true)) => {},
+                    (&Boolean::Constant(true), &Boolean::Constant(true)) => {}
-                    (&Boolean::Constant(false), &Boolean::Constant(false)) => {},
+                    (&Boolean::Constant(false), &Boolean::Constant(false)) => {}
-                    _ => unreachable!()
+                    _ => unreachable!(),
                 }
             }
         }
@@ -482,14 +468,17 @@ mod test {
 
     #[test]
     fn test_uint32_xor() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0653]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..1000 {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a: u32 = rng.gen();
+            let a = rng.next_u32();
-            let b: u32 = rng.gen();
+            let b = rng.next_u32();
-            let c: u32 = rng.gen();
+            let c = rng.next_u32();
 
             let mut expected = a ^ b ^ c;
 
@@ -505,14 +494,14 @@ mod test {
             assert!(r.value == Some(expected));
 
             for b in r.bits.iter() {
-                match b {
+                match *b {
-                    &Boolean::Is(ref b) => {
+                    Boolean::Is(ref b) => {
                         assert!(b.get_value().unwrap() == (expected & 1 == 1));
-                    },
+                    }
-                    &Boolean::Not(ref b) => {
+                    Boolean::Not(ref b) => {
                         assert!(!b.get_value().unwrap() == (expected & 1 == 1));
-                    },
+                    }
-                    &Boolean::Constant(b) => {
+                    Boolean::Constant(b) => {
                         assert!(b == (expected & 1 == 1));
                     }
                 }
@@ -524,14 +513,17 @@ mod test {
 
     #[test]
     fn test_uint32_addmany_constants() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..1000 {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a: u32 = rng.gen();
+            let a = rng.next_u32();
-            let b: u32 = rng.gen();
+            let b = rng.next_u32();
-            let c: u32 = rng.gen();
+            let c = rng.next_u32();
 
             let a_bit = UInt32::constant(a);
             let b_bit = UInt32::constant(b);
@@ -541,17 +533,18 @@ mod test {
 
             let r = {
                 let mut cs = MultiEq::new(&mut cs);
-                let r = UInt32::addmany(cs.namespace(|| "addition"), &[a_bit, b_bit, c_bit]).unwrap();
+                let r =
+                    UInt32::addmany(cs.namespace(|| "addition"), &[a_bit, b_bit, c_bit]).unwrap();
                 r
             };
 
             assert!(r.value == Some(expected));
 
             for b in r.bits.iter() {
-                match b {
+                match *b {
-                    &Boolean::Is(_) => panic!(),
+                    Boolean::Is(_) => panic!(),
-                    &Boolean::Not(_) => panic!(),
+                    Boolean::Not(_) => panic!(),
-                    &Boolean::Constant(b) => {
+                    Boolean::Constant(b) => {
                         assert!(b == (expected & 1 == 1));
                     }
                 }
@@ -563,15 +556,18 @@ mod test {
 
     #[test]
     fn test_uint32_addmany() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..1000 {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a: u32 = rng.gen();
+            let a = rng.next_u32();
-            let b: u32 = rng.gen();
+            let b = rng.next_u32();
-            let c: u32 = rng.gen();
+            let c = rng.next_u32();
-            let d: u32 = rng.gen();
+            let d = rng.next_u32();
 
             let mut expected = (a ^ b).wrapping_add(c).wrapping_add(d);
 
@@ -583,8 +579,7 @@ mod test {
             let r = a_bit.xor(cs.namespace(|| "xor"), &b_bit).unwrap();
             let r = {
                 let mut cs = MultiEq::new(&mut cs);
-                let r = UInt32::addmany(cs.namespace(|| "addition"), &[r, c_bit, d_bit]).unwrap();
+                UInt32::addmany(cs.namespace(|| "addition"), &[r, c_bit, d_bit]).unwrap()
-                r
             };
 
             assert!(cs.is_satisfied());
@@ -592,16 +587,14 @@ mod test {
             assert!(r.value == Some(expected));
 
             for b in r.bits.iter() {
-                match b {
+                match *b {
-                    &Boolean::Is(ref b) => {
+                    Boolean::Is(ref b) => {
                         assert!(b.get_value().unwrap() == (expected & 1 == 1));
-                    },
-                    &Boolean::Not(ref b) => {
-                        assert!(!b.get_value().unwrap() == (expected & 1 == 1));
-                    },
-                    &Boolean::Constant(_) => {
-                        unreachable!()
                     }
+                    Boolean::Not(ref b) => {
+                        assert!(!b.get_value().unwrap() == (expected & 1 == 1));
+                    }
+                    Boolean::Constant(_) => unreachable!(),
                 }
 
                 expected >>= 1;
@@ -620,9 +613,12 @@ mod test {
 
     #[test]
     fn test_uint32_rotr() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
-        let mut num = rng.gen();
+        let mut num = rng.next_u32();
 
         let a = UInt32::constant(num);
 
@@ -634,11 +630,11 @@ mod test {
 
             let mut tmp = num;
             for b in &b.bits {
-                match b {
+                match *b {
-                    &Boolean::Constant(b) => {
+                    Boolean::Constant(b) => {
                         assert_eq!(b, tmp & 1 == 1);
-                    },
+                    }
-                    _ => unreachable!()
+                    _ => unreachable!(),
                 }
 
                 tmp >>= 1;
@@ -650,11 +646,14 @@ mod test {
 
     #[test]
     fn test_uint32_shr() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..50 {
             for i in 0..60 {
-                let num = rng.gen();
+                let num = rng.next_u32();
                 let a = UInt32::constant(num).shr(i);
                 let b = UInt32::constant(num.wrapping_shr(i as u32));
 
@@ -670,14 +669,17 @@ mod test {
 
     #[test]
     fn test_uint32_sha256_maj() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0653]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..1000 {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a: u32 = rng.gen();
+            let a = rng.next_u32();
-            let b: u32 = rng.gen();
+            let b = rng.next_u32();
-            let c: u32 = rng.gen();
+            let c = rng.next_u32();
 
             let mut expected = (a & b) ^ (a & c) ^ (b & c);
 
@@ -695,10 +697,10 @@ mod test {
                 match b {
                     &Boolean::Is(ref b) => {
                         assert!(b.get_value().unwrap() == (expected & 1 == 1));
-                    },
+                    }
                     &Boolean::Not(ref b) => {
                         assert!(!b.get_value().unwrap() == (expected & 1 == 1));
-                    },
+                    }
                     &Boolean::Constant(b) => {
                         assert!(b == (expected & 1 == 1));
                     }
@@ -711,14 +713,17 @@ mod test {
 
     #[test]
     fn test_uint32_sha256_ch() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0653]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..1000 {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a: u32 = rng.gen();
+            let a = rng.next_u32();
-            let b: u32 = rng.gen();
+            let b = rng.next_u32();
-            let c: u32 = rng.gen();
+            let c = rng.next_u32();
 
             let mut expected = (a & b) ^ ((!a) & c);
 
@@ -736,10 +741,10 @@ mod test {
                 match b {
                     &Boolean::Is(ref b) => {
                         assert!(b.get_value().unwrap() == (expected & 1 == 1));
-                    },
+                    }
                     &Boolean::Not(ref b) => {
                         assert!(!b.get_value().unwrap() == (expected & 1 == 1));
-                    },
+                    }
                     &Boolean::Constant(b) => {
                         assert!(b == (expected & 1 == 1));
                     }

bellman/src/groth16/generator.rs

@@ -1,4 +1,4 @@
-use rand::Rng;
+use rand_core::RngCore;
 
 use std::sync::Arc;
 
@@ -6,55 +6,34 @@ use ff::{Field, PrimeField};
 use group::{CurveAffine, CurveProjective, Wnaf};
 use pairing::Engine;
 
-use super::{
+use super::{Parameters, VerifyingKey};
-    Parameters,
-    VerifyingKey
-};
 
-use ::{
+use crate::{Circuit, ConstraintSystem, Index, LinearCombination, SynthesisError, Variable};
-    SynthesisError,
-    Circuit,
-    ConstraintSystem,
-    LinearCombination,
-    Variable,
-    Index
-};
 
-use ::domain::{
+use crate::domain::{EvaluationDomain, Scalar};
-    EvaluationDomain,
-    Scalar
-};
 
-use ::multicore::{
+use crate::multicore::Worker;
-    Worker
-};
 
 /// Generates a random common reference string for
 /// a circuit.
 pub fn generate_random_parameters<E, C, R>(
     circuit: C,
-    rng: &mut R
+    rng: &mut R,
 ) -> Result<Parameters<E>, SynthesisError>
-    where E: Engine, C: Circuit<E>, R: Rng
+where
+    E: Engine,
+    C: Circuit<E>,
+    R: RngCore,
 {
-    let g1 = rng.gen();
+    let g1 = E::G1::random(rng);
-    let g2 = rng.gen();
+    let g2 = E::G2::random(rng);
-    let alpha = rng.gen();
+    let alpha = E::Fr::random(rng);
-    let beta = rng.gen();
+    let beta = E::Fr::random(rng);
-    let gamma = rng.gen();
+    let gamma = E::Fr::random(rng);
-    let delta = rng.gen();
+    let delta = E::Fr::random(rng);
-    let tau = rng.gen();
+    let tau = E::Fr::random(rng);
 
-    generate_parameters::<E, C>(
+    generate_parameters::<E, C>(circuit, g1, g2, alpha, beta, gamma, delta, tau)
-        circuit,
-        g1,
-        g2,
-        alpha,
-        beta,
-        gamma,
-        delta,
-        tau
-    )
 }
 
 /// This is our assembly structure that we'll use to synthesize the
@@ -68,18 +47,17 @@ struct KeypairAssembly<E: Engine> {
     ct_inputs: Vec<Vec<(E::Fr, usize)>>,
     at_aux: Vec<Vec<(E::Fr, usize)>>,
     bt_aux: Vec<Vec<(E::Fr, usize)>>,
-    ct_aux: Vec<Vec<(E::Fr, usize)>>
+    ct_aux: Vec<Vec<(E::Fr, usize)>>,
 }
 
 impl<E: Engine> ConstraintSystem<E> for KeypairAssembly<E> {
     type Root = Self;
 
-    fn alloc<F, A, AR>(
+    fn alloc<F, A, AR>(&mut self, _: A, _: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        _: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        _: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         // There is no assignment, so we don't even invoke the
         // function for obtaining one.
@@ -94,12 +72,11 @@ impl<E: Engine> ConstraintSystem<E> for KeypairAssembly<E> {
         Ok(Variable(Index::Aux(index)))
     }
 
-    fn alloc_input<F, A, AR>(
+    fn alloc_input<F, A, AR>(&mut self, _: A, _: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        _: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        _: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         // There is no assignment, so we don't even invoke the
         // function for obtaining one.
@@ -114,48 +91,59 @@ impl<E: Engine> ConstraintSystem<E> for KeypairAssembly<E> {
         Ok(Variable(Index::Input(index)))
     }
 
-    fn enforce<A, AR, LA, LB, LC>(
+    fn enforce<A, AR, LA, LB, LC>(&mut self, _: A, a: LA, b: LB, c: LC)
-        &mut self,
+    where
-        _: A,
+        A: FnOnce() -> AR,
-        a: LA,
+        AR: Into<String>,
-        b: LB,
+        LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        c: LC
+        LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-    )
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        where A: FnOnce() -> AR, AR: Into<String>,
-              LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>
     {
         fn eval<E: Engine>(
             l: LinearCombination<E>,
             inputs: &mut [Vec<(E::Fr, usize)>],
             aux: &mut [Vec<(E::Fr, usize)>],
-            this_constraint: usize
+            this_constraint: usize,
-        )
+        ) {
-        {
             for (index, coeff) in l.0 {
                 match index {
                     Variable(Index::Input(id)) => inputs[id].push((coeff, this_constraint)),
-                    Variable(Index::Aux(id)) => aux[id].push((coeff, this_constraint))
+                    Variable(Index::Aux(id)) => aux[id].push((coeff, this_constraint)),
                 }
             }
         }
 
-        eval(a(LinearCombination::zero()), &mut self.at_inputs, &mut self.at_aux, self.num_constraints);
+        eval(
-        eval(b(LinearCombination::zero()), &mut self.bt_inputs, &mut self.bt_aux, self.num_constraints);
+            a(LinearCombination::zero()),
-        eval(c(LinearCombination::zero()), &mut self.ct_inputs, &mut self.ct_aux, self.num_constraints);
+            &mut self.at_inputs,
+            &mut self.at_aux,
+            self.num_constraints,
+        );
+        eval(
+            b(LinearCombination::zero()),
+            &mut self.bt_inputs,
+            &mut self.bt_aux,
+            self.num_constraints,
+        );
+        eval(
+            c(LinearCombination::zero()),
+            &mut self.ct_inputs,
+            &mut self.ct_aux,
+            self.num_constraints,
+        );
 
         self.num_constraints += 1;
     }
 
     fn push_namespace<NR, N>(&mut self, _: N)
-        where NR: Into<String>, N: FnOnce() -> NR
+    where
+        NR: Into<String>,
+        N: FnOnce() -> NR,
     {
         // Do nothing; we don't care about namespaces in this context.
     }
 
-    fn pop_namespace(&mut self)
+    fn pop_namespace(&mut self) {
-    {
         // Do nothing; we don't care about namespaces in this context.
     }
 
@@ -173,9 +161,11 @@ pub fn generate_parameters<E, C>(
     beta: E::Fr,
     gamma: E::Fr,
     delta: E::Fr,
-    tau: E::Fr
+    tau: E::Fr,
 ) -> Result<Parameters<E>, SynthesisError>
-    where E: Engine, C: Circuit<E>
+where
+    E: Engine,
+    C: Circuit<E>,
 {
     let mut assembly = KeypairAssembly {
         num_inputs: 0,
@@ -186,7 +176,7 @@ pub fn generate_parameters<E, C>(
         ct_inputs: vec![],
         at_aux: vec![],
         bt_aux: vec![],
-        ct_aux: vec![]
+        ct_aux: vec![],
     };
 
     // Allocate the "one" input variable
@@ -198,11 +188,7 @@ pub fn generate_parameters<E, C>(
     // Input constraints to ensure full density of IC query
     // x * 0 = 0
     for i in 0..assembly.num_inputs {
-        assembly.enforce(|| "",
+        assembly.enforce(|| "", |lc| lc + Variable(Index::Input(i)), |lc| lc, |lc| lc);
-            |lc| lc + Variable(Index::Input(i)),
-            |lc| lc,
-            |lc| lc,
-        );
     }
 
     // Create bases for blind evaluation of polynomials at tau
@@ -240,10 +226,9 @@ pub fn generate_parameters<E, C>(
         {
             let powers_of_tau = powers_of_tau.as_mut();
             worker.scope(powers_of_tau.len(), |scope, chunk| {
-                for (i, powers_of_tau) in powers_of_tau.chunks_mut(chunk).enumerate()
+                for (i, powers_of_tau) in powers_of_tau.chunks_mut(chunk).enumerate() {
-                {
+                    scope.spawn(move |_scope| {
-                    scope.spawn(move || {
+                        let mut current_tau_power = tau.pow(&[(i * chunk) as u64]);
-                        let mut current_tau_power = tau.pow(&[(i*chunk) as u64]);
 
                         for p in powers_of_tau {
                             p.0 = current_tau_power;
@@ -260,14 +245,15 @@ pub fn generate_parameters<E, C>(
 
         // Compute the H query with multiple threads
         worker.scope(h.len(), |scope, chunk| {
-            for (h, p) in h.chunks_mut(chunk).zip(powers_of_tau.as_ref().chunks(chunk))
+            for (h, p) in h
+                .chunks_mut(chunk)
+                .zip(powers_of_tau.as_ref().chunks(chunk))
             {
                 let mut g1_wnaf = g1_wnaf.shared();
 
-                scope.spawn(move || {
+                scope.spawn(move |_scope| {
                     // Set values of the H query to g1^{(tau^i * t(tau)) / delta}
-                    for (h, p) in h.iter_mut().zip(p.iter())
+                    for (h, p) in h.iter_mut().zip(p.iter()) {
-                    {
                         // Compute final exponent
                         let mut exp = p.0;
                         exp.mul_assign(&coeff);
@@ -320,9 +306,8 @@ pub fn generate_parameters<E, C>(
         beta: &E::Fr,
 
         // Worker
-        worker: &Worker
+        worker: &Worker,
-    )
+    ) {
-    {
         // Sanity check
         assert_eq!(a.len(), at.len());
         assert_eq!(a.len(), bt.len());
@@ -333,31 +318,32 @@ pub fn generate_parameters<E, C>(
 
         // Evaluate polynomials in multiple threads
         worker.scope(a.len(), |scope, chunk| {
-            for ((((((a, b_g1), b_g2), ext), at), bt), ct) in a.chunks_mut(chunk)
+            for ((((((a, b_g1), b_g2), ext), at), bt), ct) in a
-                                                               .zip(b_g1.chunks_mut(chunk))
+                .chunks_mut(chunk)
-                                                               .zip(b_g2.chunks_mut(chunk))
+                .zip(b_g1.chunks_mut(chunk))
-                                                               .zip(ext.chunks_mut(chunk))
+                .zip(b_g2.chunks_mut(chunk))
-                                                               .zip(at.chunks(chunk))
+                .zip(ext.chunks_mut(chunk))
-                                                               .zip(bt.chunks(chunk))
+                .zip(at.chunks(chunk))
-                                                               .zip(ct.chunks(chunk))
+                .zip(bt.chunks(chunk))
+                .zip(ct.chunks(chunk))
             {
                 let mut g1_wnaf = g1_wnaf.shared();
                 let mut g2_wnaf = g2_wnaf.shared();
 
-                scope.spawn(move || {
+                scope.spawn(move |_scope| {
-                    for ((((((a, b_g1), b_g2), ext), at), bt), ct) in a.iter_mut()
+                    for ((((((a, b_g1), b_g2), ext), at), bt), ct) in a
-                                                                       .zip(b_g1.iter_mut())
+                        .iter_mut()
-                                                                       .zip(b_g2.iter_mut())
+                        .zip(b_g1.iter_mut())
-                                                                       .zip(ext.iter_mut())
+                        .zip(b_g2.iter_mut())
-                                                                       .zip(at.iter())
+                        .zip(ext.iter_mut())
-                                                                       .zip(bt.iter())
+                        .zip(at.iter())
-                                                                       .zip(ct.iter())
+                        .zip(bt.iter())
+                        .zip(ct.iter())
                     {
                         fn eval_at_tau<E: Engine>(
                             powers_of_tau: &[Scalar<E>],
-                            p: &[(E::Fr, usize)]
+                            p: &[(E::Fr, usize)],
-                        ) -> E::Fr
+                        ) -> E::Fr {
-                        {
                             let mut acc = E::Fr::zero();
 
                             for &(ref coeff, index) in p {
@@ -422,7 +408,7 @@ pub fn generate_parameters<E, C>(
         &gamma_inverse,
         &alpha,
         &beta,
-        &worker
+        &worker,
     );
 
     // Evaluate for auxiliary variables.
@@ -440,7 +426,7 @@ pub fn generate_parameters<E, C>(
         &delta_inverse,
         &alpha,
         &beta,
-        &worker
+        &worker,
     );
 
     // Don't allow any elements be unconstrained, so that
@@ -461,17 +447,32 @@ pub fn generate_parameters<E, C>(
         gamma_g2: g2.mul(gamma).into_affine(),
         delta_g1: g1.mul(delta).into_affine(),
         delta_g2: g2.mul(delta).into_affine(),
-        ic: ic.into_iter().map(|e| e.into_affine()).collect()
+        ic: ic.into_iter().map(|e| e.into_affine()).collect(),
     };
 
     Ok(Parameters {
-        vk: vk,
+        vk,
         h: Arc::new(h.into_iter().map(|e| e.into_affine()).collect()),
         l: Arc::new(l.into_iter().map(|e| e.into_affine()).collect()),
 
         // Filter points at infinity away from A/B queries
-        a: Arc::new(a.into_iter().filter(|e| !e.is_zero()).map(|e| e.into_affine()).collect()),
+        a: Arc::new(
-        b_g1: Arc::new(b_g1.into_iter().filter(|e| !e.is_zero()).map(|e| e.into_affine()).collect()),
+            a.into_iter()
-        b_g2: Arc::new(b_g2.into_iter().filter(|e| !e.is_zero()).map(|e| e.into_affine()).collect())
+                .filter(|e| !e.is_zero())
+                .map(|e| e.into_affine())
+                .collect(),
+        ),
+        b_g1: Arc::new(
+            b_g1.into_iter()
+                .filter(|e| !e.is_zero())
+                .map(|e| e.into_affine())
+                .collect(),
+        ),
+        b_g2: Arc::new(
+            b_g2.into_iter()
+                .filter(|e| !e.is_zero())
+                .map(|e| e.into_affine())
+                .collect(),
+        ),
     })
 }

bellman/src/groth16/mod.rs

@@ -1,17 +1,16 @@
+//! The [Groth16] proving system.
+//!
+//! [Groth16]: https://eprint.iacr.org/2016/260
+
 use group::{CurveAffine, EncodedPoint};
-use pairing::{
+use pairing::{Engine, PairingCurveAffine};
-    Engine,
-    PairingCurveAffine,
-};
 
-use ::{
+use crate::SynthesisError;
-    SynthesisError
-};
 
-use multiexp::SourceBuilder;
+use crate::multiexp::SourceBuilder;
+use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
 use std::io::{self, Read, Write};
 use std::sync::Arc;
-use byteorder::{BigEndian, WriteBytesExt, ReadBytesExt};
 
 #[cfg(test)]
 mod tests;
@@ -28,23 +27,17 @@ pub use self::verifier::*;
 pub struct Proof<E: Engine> {
     pub a: E::G1Affine,
     pub b: E::G2Affine,
-    pub c: E::G1Affine
+    pub c: E::G1Affine,
 }
 
 impl<E: Engine> PartialEq for Proof<E> {
     fn eq(&self, other: &Self) -> bool {
-        self.a == other.a &&
+        self.a == other.a && self.b == other.b && self.c == other.c
-        self.b == other.b &&
-        self.c == other.c
     }
 }
 
 impl<E: Engine> Proof<E> {
-    pub fn write<W: Write>(
+    pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
-        &self,
-        mut writer: W
-    ) -> io::Result<()>
-    {
         writer.write_all(self.a.into_compressed().as_ref())?;
         writer.write_all(self.b.into_compressed().as_ref())?;
         writer.write_all(self.c.into_compressed().as_ref())?;
@@ -52,48 +45,56 @@ impl<E: Engine> Proof<E> {
         Ok(())
     }
 
-    pub fn read<R: Read>(
+    pub fn read<R: Read>(mut reader: R) -> io::Result<Self> {
-        mut reader: R
-    ) -> io::Result<Self>
-    {
         let mut g1_repr = <E::G1Affine as CurveAffine>::Compressed::empty();
         let mut g2_repr = <E::G2Affine as CurveAffine>::Compressed::empty();
 
         reader.read_exact(g1_repr.as_mut())?;
         let a = g1_repr
-                .into_affine()
+            .into_affine()
-                .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-                .and_then(|e| if e.is_zero() {
+            .and_then(|e| {
-                    Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+                if e.is_zero() {
+                    Err(io::Error::new(
+                        io::ErrorKind::InvalidData,
+                        "point at infinity",
+                    ))
                 } else {
                     Ok(e)
-                })?;
+                }
+            })?;
 
         reader.read_exact(g2_repr.as_mut())?;
         let b = g2_repr
-                .into_affine()
+            .into_affine()
-                .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-                .and_then(|e| if e.is_zero() {
+            .and_then(|e| {
-                    Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+                if e.is_zero() {
+                    Err(io::Error::new(
+                        io::ErrorKind::InvalidData,
+                        "point at infinity",
+                    ))
                 } else {
                     Ok(e)
-                })?;
+                }
+            })?;
 
         reader.read_exact(g1_repr.as_mut())?;
         let c = g1_repr
-                .into_affine()
+            .into_affine()
-                .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-                .and_then(|e| if e.is_zero() {
+            .and_then(|e| {
-                    Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+                if e.is_zero() {
+                    Err(io::Error::new(
+                        io::ErrorKind::InvalidData,
+                        "point at infinity",
+                    ))
                 } else {
                     Ok(e)
-                })?;
+                }
+            })?;
 
-        Ok(Proof {
+        Ok(Proof { a, b, c })
-            a: a,
-            b: b,
-            c: c
-        })
     }
 }
 
@@ -122,27 +123,23 @@ pub struct VerifyingKey<E: Engine> {
     // for all public inputs. Because all public inputs have a dummy constraint,
     // this is the same size as the number of inputs, and never contains points
     // at infinity.
-    pub ic: Vec<E::G1Affine>
+    pub ic: Vec<E::G1Affine>,
 }
 
 impl<E: Engine> PartialEq for VerifyingKey<E> {
     fn eq(&self, other: &Self) -> bool {
-        self.alpha_g1 == other.alpha_g1 &&
+        self.alpha_g1 == other.alpha_g1
-        self.beta_g1 == other.beta_g1 &&
+            && self.beta_g1 == other.beta_g1
-        self.beta_g2 == other.beta_g2 &&
+            && self.beta_g2 == other.beta_g2
-        self.gamma_g2 == other.gamma_g2 &&
+            && self.gamma_g2 == other.gamma_g2
-        self.delta_g1 == other.delta_g1 &&
+            && self.delta_g1 == other.delta_g1
-        self.delta_g2 == other.delta_g2 &&
+            && self.delta_g2 == other.delta_g2
-        self.ic == other.ic
+            && self.ic == other.ic
     }
 }
 
 impl<E: Engine> VerifyingKey<E> {
-    pub fn write<W: Write>(
+    pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
-        &self,
-        mut writer: W
-    ) -> io::Result<()>
-    {
         writer.write_all(self.alpha_g1.into_uncompressed().as_ref())?;
         writer.write_all(self.beta_g1.into_uncompressed().as_ref())?;
         writer.write_all(self.beta_g2.into_uncompressed().as_ref())?;
@@ -157,30 +154,39 @@ impl<E: Engine> VerifyingKey<E> {
         Ok(())
     }
 
-    pub fn read<R: Read>(
+    pub fn read<R: Read>(mut reader: R) -> io::Result<Self> {
-        mut reader: R
-    ) -> io::Result<Self>
-    {
         let mut g1_repr = <E::G1Affine as CurveAffine>::Uncompressed::empty();
         let mut g2_repr = <E::G2Affine as CurveAffine>::Uncompressed::empty();
 
         reader.read_exact(g1_repr.as_mut())?;
-        let alpha_g1 = g1_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
+        let alpha_g1 = g1_repr
+            .into_affine()
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
 
         reader.read_exact(g1_repr.as_mut())?;
-        let beta_g1 = g1_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
+        let beta_g1 = g1_repr
+            .into_affine()
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
 
         reader.read_exact(g2_repr.as_mut())?;
-        let beta_g2 = g2_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
+        let beta_g2 = g2_repr
+            .into_affine()
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
 
         reader.read_exact(g2_repr.as_mut())?;
-        let gamma_g2 = g2_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
+        let gamma_g2 = g2_repr
+            .into_affine()
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
 
         reader.read_exact(g1_repr.as_mut())?;
-        let delta_g1 = g1_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
+        let delta_g1 = g1_repr
+            .into_affine()
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
 
         reader.read_exact(g2_repr.as_mut())?;
-        let delta_g2 = g2_repr.into_affine().map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
+        let delta_g2 = g2_repr
+            .into_affine()
+            .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))?;
 
         let ic_len = reader.read_u32::<BigEndian>()? as usize;
 
@@ -189,25 +195,30 @@ impl<E: Engine> VerifyingKey<E> {
         for _ in 0..ic_len {
             reader.read_exact(g1_repr.as_mut())?;
             let g1 = g1_repr
-                     .into_affine()
+                .into_affine()
-                     .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
+                .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-                     .and_then(|e| if e.is_zero() {
+                .and_then(|e| {
-                         Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+                    if e.is_zero() {
-                     } else {
+                        Err(io::Error::new(
-                         Ok(e)
+                            io::ErrorKind::InvalidData,
-                     })?;
+                            "point at infinity",
+                        ))
+                    } else {
+                        Ok(e)
+                    }
+                })?;
 
             ic.push(g1);
         }
 
         Ok(VerifyingKey {
-            alpha_g1: alpha_g1,
+            alpha_g1,
-            beta_g1: beta_g1,
+            beta_g1,
-            beta_g2: beta_g2,
+            beta_g2,
-            gamma_g2: gamma_g2,
+            gamma_g2,
-            delta_g1: delta_g1,
+            delta_g1,
-            delta_g2: delta_g2,
+            delta_g2,
-            ic: ic
+            ic,
         })
     }
 }
@@ -216,7 +227,7 @@ impl<E: Engine> VerifyingKey<E> {
 pub struct Parameters<E: Engine> {
     pub vk: VerifyingKey<E>,
 
-    // Elements of the form ((tau^i * t(tau)) / delta) for i between 0 and 
+    // Elements of the form ((tau^i * t(tau)) / delta) for i between 0 and
     // m-2 inclusive. Never contains points at infinity.
     pub h: Arc<Vec<E::G1Affine>>,
 
@@ -234,26 +245,22 @@ pub struct Parameters<E: Engine> {
     // G1 and G2 for C/B queries, respectively. Never contains points at
     // infinity for the same reason as the "A" polynomials.
     pub b_g1: Arc<Vec<E::G1Affine>>,
-    pub b_g2: Arc<Vec<E::G2Affine>>
+    pub b_g2: Arc<Vec<E::G2Affine>>,
 }
 
 impl<E: Engine> PartialEq for Parameters<E> {
     fn eq(&self, other: &Self) -> bool {
-        self.vk == other.vk &&
+        self.vk == other.vk
-        self.h == other.h &&
+            && self.h == other.h
-        self.l == other.l &&
+            && self.l == other.l
-        self.a == other.a &&
+            && self.a == other.a
-        self.b_g1 == other.b_g1 &&
+            && self.b_g1 == other.b_g1
-        self.b_g2 == other.b_g2
+            && self.b_g2 == other.b_g2
     }
 }
 
 impl<E: Engine> Parameters<E> {
-    pub fn write<W: Write>(
+    pub fn write<W: Write>(&self, mut writer: W) -> io::Result<()> {
-        &self,
-        mut writer: W
-    ) -> io::Result<()>
-    {
         self.vk.write(&mut writer)?;
 
         writer.write_u32::<BigEndian>(self.h.len() as u32)?;
@@ -284,27 +291,26 @@ impl<E: Engine> Parameters<E> {
         Ok(())
     }
 
-    pub fn read<R: Read>(
+    pub fn read<R: Read>(mut reader: R, checked: bool) -> io::Result<Self> {
-        mut reader: R,
-        checked: bool
-    ) -> io::Result<Self>
-    {
         let read_g1 = |reader: &mut R| -> io::Result<E::G1Affine> {
             let mut repr = <E::G1Affine as CurveAffine>::Uncompressed::empty();
             reader.read_exact(repr.as_mut())?;
 
             if checked {
-                repr
+                repr.into_affine()
-                .into_affine()
             } else {
-                repr
+                repr.into_affine_unchecked()
-                .into_affine_unchecked()
             }
             .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-            .and_then(|e| if e.is_zero() {
+            .and_then(|e| {
-                Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+                if e.is_zero() {
-            } else {
+                    Err(io::Error::new(
-                Ok(e)
+                        io::ErrorKind::InvalidData,
+                        "point at infinity",
+                    ))
+                } else {
+                    Ok(e)
+                }
             })
         };
 
@@ -313,17 +319,20 @@ impl<E: Engine> Parameters<E> {
             reader.read_exact(repr.as_mut())?;
 
             if checked {
-                repr
+                repr.into_affine()
-                .into_affine()
             } else {
-                repr
+                repr.into_affine_unchecked()
-                .into_affine_unchecked()
             }
             .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-            .and_then(|e| if e.is_zero() {
+            .and_then(|e| {
-                Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+                if e.is_zero() {
-            } else {
+                    Err(io::Error::new(
-                Ok(e)
+                        io::ErrorKind::InvalidData,
+                        "point at infinity",
+                    ))
+                } else {
+                    Ok(e)
+                }
             })
         };
 
@@ -371,12 +380,12 @@ impl<E: Engine> Parameters<E> {
         }
 
         Ok(Parameters {
-            vk: vk,
+            vk,
             h: Arc::new(h),
             l: Arc::new(l),
             a: Arc::new(a),
             b_g1: Arc::new(b_g1),
-            b_g2: Arc::new(b_g2)
+            b_g2: Arc::new(b_g2),
         })
     }
 }
@@ -389,39 +398,30 @@ pub struct PreparedVerifyingKey<E: Engine> {
     /// -delta in G2
     neg_delta_g2: <E::G2Affine as PairingCurveAffine>::Prepared,
     /// Copy of IC from `VerifiyingKey`.
-    ic: Vec<E::G1Affine>
+    ic: Vec<E::G1Affine>,
 }
 
 pub trait ParameterSource<E: Engine> {
     type G1Builder: SourceBuilder<E::G1Affine>;
     type G2Builder: SourceBuilder<E::G2Affine>;
 
-    fn get_vk(
+    fn get_vk(&mut self, num_ic: usize) -> Result<VerifyingKey<E>, SynthesisError>;
-        &mut self,
+    fn get_h(&mut self, num_h: usize) -> Result<Self::G1Builder, SynthesisError>;
-        num_ic: usize
+    fn get_l(&mut self, num_l: usize) -> Result<Self::G1Builder, SynthesisError>;
-    ) -> Result<VerifyingKey<E>, SynthesisError>;
-    fn get_h(
-        &mut self,
-        num_h: usize
-    ) -> Result<Self::G1Builder, SynthesisError>;
-    fn get_l(
-        &mut self,
-        num_l: usize
-    ) -> Result<Self::G1Builder, SynthesisError>;
     fn get_a(
         &mut self,
         num_inputs: usize,
-        num_aux: usize
+        num_aux: usize,
     ) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>;
     fn get_b_g1(
         &mut self,
         num_inputs: usize,
-        num_aux: usize
+        num_aux: usize,
     ) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>;
     fn get_b_g2(
         &mut self,
         num_inputs: usize,
-        num_aux: usize
+        num_aux: usize,
     ) -> Result<(Self::G2Builder, Self::G2Builder), SynthesisError>;
 }
 
@@ -429,54 +429,39 @@ impl<'a, E: Engine> ParameterSource<E> for &'a Parameters<E> {
     type G1Builder = (Arc<Vec<E::G1Affine>>, usize);
     type G2Builder = (Arc<Vec<E::G2Affine>>, usize);
 
-    fn get_vk(
+    fn get_vk(&mut self, _: usize) -> Result<VerifyingKey<E>, SynthesisError> {
-        &mut self,
-        _: usize
-    ) -> Result<VerifyingKey<E>, SynthesisError>
-    {
         Ok(self.vk.clone())
     }
 
-    fn get_h(
+    fn get_h(&mut self, _: usize) -> Result<Self::G1Builder, SynthesisError> {
-        &mut self,
-        _: usize
-    ) -> Result<Self::G1Builder, SynthesisError>
-    {
         Ok((self.h.clone(), 0))
     }
 
-    fn get_l(
+    fn get_l(&mut self, _: usize) -> Result<Self::G1Builder, SynthesisError> {
-        &mut self,
-        _: usize
-    ) -> Result<Self::G1Builder, SynthesisError>
-    {
         Ok((self.l.clone(), 0))
     }
 
     fn get_a(
         &mut self,
         num_inputs: usize,
-        _: usize
+        _: usize,
-    ) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>
+    ) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError> {
-    {
         Ok(((self.a.clone(), 0), (self.a.clone(), num_inputs)))
     }
 
     fn get_b_g1(
         &mut self,
         num_inputs: usize,
-        _: usize
+        _: usize,
-    ) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>
+    ) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError> {
-    {
         Ok(((self.b_g1.clone(), 0), (self.b_g1.clone(), num_inputs)))
     }
 
     fn get_b_g2(
         &mut self,
         num_inputs: usize,
-        _: usize
+        _: usize,
-    ) -> Result<(Self::G2Builder, Self::G2Builder), SynthesisError>
+    ) -> Result<(Self::G2Builder, Self::G2Builder), SynthesisError> {
-    {
         Ok(((self.b_g2.clone(), 0), (self.b_g2.clone(), num_inputs)))
     }
 }
@@ -484,41 +469,38 @@ impl<'a, E: Engine> ParameterSource<E> for &'a Parameters<E> {
 #[cfg(test)]
 mod test_with_bls12_381 {
     use super::*;
-    use {Circuit, SynthesisError, ConstraintSystem};
+    use crate::{Circuit, ConstraintSystem, SynthesisError};
 
     use ff::Field;
-    use rand::{Rand, thread_rng};
     use pairing::bls12_381::{Bls12, Fr};
+    use rand::thread_rng;
 
     #[test]
     fn serialization() {
         struct MySillyCircuit<E: Engine> {
             a: Option<E::Fr>,
-            b: Option<E::Fr>
+            b: Option<E::Fr>,
         }
 
         impl<E: Engine> Circuit<E> for MySillyCircuit<E> {
             fn synthesize<CS: ConstraintSystem<E>>(
                 self,
-                cs: &mut CS
+                cs: &mut CS,
-            ) -> Result<(), SynthesisError>
+            ) -> Result<(), SynthesisError> {
-            {
                 let a = cs.alloc(|| "a", || self.a.ok_or(SynthesisError::AssignmentMissing))?;
                 let b = cs.alloc(|| "b", || self.b.ok_or(SynthesisError::AssignmentMissing))?;
-                let c = cs.alloc_input(|| "c", || {
+                let c = cs.alloc_input(
-                    let mut a = self.a.ok_or(SynthesisError::AssignmentMissing)?;
+                    || "c",
-                    let b = self.b.ok_or(SynthesisError::AssignmentMissing)?;
+                    || {
+                        let mut a = self.a.ok_or(SynthesisError::AssignmentMissing)?;
+                        let b = self.b.ok_or(SynthesisError::AssignmentMissing)?;
 
-                    a.mul_assign(&b);
+                        a.mul_assign(&b);
-                    Ok(a)
+                        Ok(a)
-                })?;
+                    },
+                )?;
 
-                cs.enforce(
+                cs.enforce(|| "a*b=c", |lc| lc + a, |lc| lc + b, |lc| lc + c);
-                    || "a*b=c",
-                    |lc| lc + a,
-                    |lc| lc + b,
-                    |lc| lc + c
-                );
 
                 Ok(())
             }
@@ -526,10 +508,9 @@ mod test_with_bls12_381 {
 
         let rng = &mut thread_rng();
 
-        let params = generate_random_parameters::<Bls12, _, _>(
+        let params =
-            MySillyCircuit { a: None, b: None },
+            generate_random_parameters::<Bls12, _, _>(MySillyCircuit { a: None, b: None }, rng)
-            rng
+                .unwrap();
-        ).unwrap();
 
         {
             let mut v = vec![];
@@ -547,19 +528,20 @@ mod test_with_bls12_381 {
         let pvk = prepare_verifying_key::<Bls12>(&params.vk);
 
         for _ in 0..100 {
-            let a = Fr::rand(rng);
+            let a = Fr::random(rng);
-            let b = Fr::rand(rng);
+            let b = Fr::random(rng);
             let mut c = a;
             c.mul_assign(&b);
 
             let proof = create_random_proof(
                 MySillyCircuit {
                     a: Some(a),
-                    b: Some(b)
+                    b: Some(b),
                 },
                 &params,
-                rng
+                rng,
-            ).unwrap();
+            )
+            .unwrap();
 
             let mut v = vec![];
             proof.write(&mut v).unwrap();

bellman/src/groth16/prover.rs

@@ -1,4 +1,4 @@
-use rand::Rng;
+use rand_core::RngCore;
 
 use std::sync::Arc;
 
@@ -8,43 +8,23 @@ use ff::{Field, PrimeField};
 use group::{CurveAffine, CurveProjective};
 use pairing::Engine;
 
-use super::{
+use super::{ParameterSource, Proof};
-    ParameterSource,
-    Proof
-};
 
-use ::{
+use crate::{Circuit, ConstraintSystem, Index, LinearCombination, SynthesisError, Variable};
-    SynthesisError,
-    Circuit,
-    ConstraintSystem,
-    LinearCombination,
-    Variable,
-    Index
-};
 
-use ::domain::{
+use crate::domain::{EvaluationDomain, Scalar};
-    EvaluationDomain,
-    Scalar
-};
 
-use ::multiexp::{
+use crate::multiexp::{multiexp, DensityTracker, FullDensity};
-    DensityTracker,
-    FullDensity,
-    multiexp
-};
 
-use ::multicore::{
+use crate::multicore::Worker;
-    Worker
-};
 
 fn eval<E: Engine>(
     lc: &LinearCombination<E>,
     mut input_density: Option<&mut DensityTracker>,
     mut aux_density: Option<&mut DensityTracker>,
     input_assignment: &[E::Fr],
-    aux_assignment: &[E::Fr]
+    aux_assignment: &[E::Fr],
-) -> E::Fr
+) -> E::Fr {
-{
     let mut acc = E::Fr::zero();
 
     for &(index, coeff) in lc.0.iter() {
@@ -56,7 +36,7 @@ fn eval<E: Engine>(
                 if let Some(ref mut v) = input_density {
                     v.inc(i);
                 }
-            },
+            }
             Variable(Index::Aux(i)) => {
                 tmp = aux_assignment[i];
                 if let Some(ref mut v) = aux_density {
@@ -66,10 +46,10 @@ fn eval<E: Engine>(
         }
 
         if coeff == E::Fr::one() {
-           acc.add_assign(&tmp);
+            acc.add_assign(&tmp);
         } else {
-           tmp.mul_assign(&coeff);
+            tmp.mul_assign(&coeff);
-           acc.add_assign(&tmp);
+            acc.add_assign(&tmp);
         }
     }
 
@@ -89,18 +69,17 @@ struct ProvingAssignment<E: Engine> {
 
     // Assignments of variables
     input_assignment: Vec<E::Fr>,
-    aux_assignment: Vec<E::Fr>
+    aux_assignment: Vec<E::Fr>,
 }
 
 impl<E: Engine> ConstraintSystem<E> for ProvingAssignment<E> {
     type Root = Self;
 
-    fn alloc<F, A, AR>(
+    fn alloc<F, A, AR>(&mut self, _: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        _: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         self.aux_assignment.push(f()?);
         self.a_aux_density.add_element();
@@ -109,12 +88,11 @@ impl<E: Engine> ConstraintSystem<E> for ProvingAssignment<E> {
         Ok(Variable(Index::Aux(self.aux_assignment.len() - 1)))
     }
 
-    fn alloc_input<F, A, AR>(
+    fn alloc_input<F, A, AR>(&mut self, _: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        _: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         self.input_assignment.push(f()?);
         self.b_input_density.add_element();
@@ -122,17 +100,13 @@ impl<E: Engine> ConstraintSystem<E> for ProvingAssignment<E> {
         Ok(Variable(Index::Input(self.input_assignment.len() - 1)))
     }
 
-    fn enforce<A, AR, LA, LB, LC>(
+    fn enforce<A, AR, LA, LB, LC>(&mut self, _: A, a: LA, b: LB, c: LC)
-        &mut self,
+    where
-        _: A,
+        A: FnOnce() -> AR,
-        a: LA,
+        AR: Into<String>,
-        b: LB,
+        LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        c: LC
+        LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-    )
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        where A: FnOnce() -> AR, AR: Into<String>,
-              LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>
     {
         let a = a(LinearCombination::zero());
         let b = b(LinearCombination::zero());
@@ -146,14 +120,14 @@ impl<E: Engine> ConstraintSystem<E> for ProvingAssignment<E> {
             None,
             Some(&mut self.a_aux_density),
             &self.input_assignment,
-            &self.aux_assignment
+            &self.aux_assignment,
         )));
         self.b.push(Scalar(eval(
             &b,
             Some(&mut self.b_input_density),
             Some(&mut self.b_aux_density),
             &self.input_assignment,
-            &self.aux_assignment
+            &self.aux_assignment,
         )));
         self.c.push(Scalar(eval(
             &c,
@@ -164,18 +138,19 @@ impl<E: Engine> ConstraintSystem<E> for ProvingAssignment<E> {
             None,
             None,
             &self.input_assignment,
-            &self.aux_assignment
+            &self.aux_assignment,
         )));
     }
 
     fn push_namespace<NR, N>(&mut self, _: N)
-        where NR: Into<String>, N: FnOnce() -> NR
+    where
+        NR: Into<String>,
+        N: FnOnce() -> NR,
     {
         // Do nothing; we don't care about namespaces in this context.
     }
 
-    fn pop_namespace(&mut self)
+    fn pop_namespace(&mut self) {
-    {
         // Do nothing; we don't care about namespaces in this context.
     }
 
@@ -187,12 +162,15 @@ impl<E: Engine> ConstraintSystem<E> for ProvingAssignment<E> {
 pub fn create_random_proof<E, C, R, P: ParameterSource<E>>(
     circuit: C,
     params: P,
-    rng: &mut R
+    rng: &mut R,
 ) -> Result<Proof<E>, SynthesisError>
-    where E: Engine, C: Circuit<E>, R: Rng
+where
+    E: Engine,
+    C: Circuit<E>,
+    R: RngCore,
 {
-    let r = rng.gen();
+    let r = E::Fr::random(rng);
-    let s = rng.gen();
+    let s = E::Fr::random(rng);
 
     create_proof::<E, C, P>(circuit, params, r, s)
 }
@@ -201,9 +179,11 @@ pub fn create_proof<E, C, P: ParameterSource<E>>(
     circuit: C,
     mut params: P,
     r: E::Fr,
-    s: E::Fr
+    s: E::Fr,
 ) -> Result<Proof<E>, SynthesisError>
-    where E: Engine, C: Circuit<E>
+where
+    E: Engine,
+    C: Circuit<E>,
 {
     let mut prover = ProvingAssignment {
         a_aux_density: DensityTracker::new(),
@@ -213,7 +193,7 @@ pub fn create_proof<E, C, P: ParameterSource<E>>(
         b: vec![],
         c: vec![],
         input_assignment: vec![],
-        aux_assignment: vec![]
+        aux_assignment: vec![],
     };
 
     prover.alloc_input(|| "", || Ok(E::Fr::one()))?;
@@ -221,11 +201,7 @@ pub fn create_proof<E, C, P: ParameterSource<E>>(
     circuit.synthesize(&mut prover)?;
 
     for i in 0..prover.input_assignment.len() {
-        prover.enforce(|| "",
+        prover.enforce(|| "", |lc| lc + Variable(Index::Input(i)), |lc| lc, |lc| lc);
-            |lc| lc + Variable(Index::Input(i)),
-            |lc| lc,
-            |lc| lc,
-        );
     }
 
     let worker = Worker::new();
@@ -259,31 +235,76 @@ pub fn create_proof<E, C, P: ParameterSource<E>>(
     };
 
     // TODO: parallelize if it's even helpful
-    let input_assignment = Arc::new(prover.input_assignment.into_iter().map(|s| s.into_repr()).collect::<Vec<_>>());
+    let input_assignment = Arc::new(
-    let aux_assignment = Arc::new(prover.aux_assignment.into_iter().map(|s| s.into_repr()).collect::<Vec<_>>());
+        prover
+            .input_assignment
+            .into_iter()
+            .map(|s| s.into_repr())
+            .collect::<Vec<_>>(),
+    );
+    let aux_assignment = Arc::new(
+        prover
+            .aux_assignment
+            .into_iter()
+            .map(|s| s.into_repr())
+            .collect::<Vec<_>>(),
+    );
 
-    let l = multiexp(&worker, params.get_l(aux_assignment.len())?, FullDensity, aux_assignment.clone());
+    let l = multiexp(
+        &worker,
+        params.get_l(aux_assignment.len())?,
+        FullDensity,
+        aux_assignment.clone(),
+    );
 
     let a_aux_density_total = prover.a_aux_density.get_total_density();
 
-    let (a_inputs_source, a_aux_source) = params.get_a(input_assignment.len(), a_aux_density_total)?;
+    let (a_inputs_source, a_aux_source) =
+        params.get_a(input_assignment.len(), a_aux_density_total)?;
 
-    let a_inputs = multiexp(&worker, a_inputs_source, FullDensity, input_assignment.clone());
+    let a_inputs = multiexp(
-    let a_aux = multiexp(&worker, a_aux_source, Arc::new(prover.a_aux_density), aux_assignment.clone());
+        &worker,
+        a_inputs_source,
+        FullDensity,
+        input_assignment.clone(),
+    );
+    let a_aux = multiexp(
+        &worker,
+        a_aux_source,
+        Arc::new(prover.a_aux_density),
+        aux_assignment.clone(),
+    );
 
     let b_input_density = Arc::new(prover.b_input_density);
     let b_input_density_total = b_input_density.get_total_density();
     let b_aux_density = Arc::new(prover.b_aux_density);
     let b_aux_density_total = b_aux_density.get_total_density();
 
-    let (b_g1_inputs_source, b_g1_aux_source) = params.get_b_g1(b_input_density_total, b_aux_density_total)?;
+    let (b_g1_inputs_source, b_g1_aux_source) =
+        params.get_b_g1(b_input_density_total, b_aux_density_total)?;
 
-    let b_g1_inputs = multiexp(&worker, b_g1_inputs_source, b_input_density.clone(), input_assignment.clone());
+    let b_g1_inputs = multiexp(
-    let b_g1_aux = multiexp(&worker, b_g1_aux_source, b_aux_density.clone(), aux_assignment.clone());
+        &worker,
+        b_g1_inputs_source,
+        b_input_density.clone(),
+        input_assignment.clone(),
+    );
+    let b_g1_aux = multiexp(
+        &worker,
+        b_g1_aux_source,
+        b_aux_density.clone(),
+        aux_assignment.clone(),
+    );
 
-    let (b_g2_inputs_source, b_g2_aux_source) = params.get_b_g2(b_input_density_total, b_aux_density_total)?;
+    let (b_g2_inputs_source, b_g2_aux_source) =
-    
+        params.get_b_g2(b_input_density_total, b_aux_density_total)?;
-    let b_g2_inputs = multiexp(&worker, b_g2_inputs_source, b_input_density, input_assignment);
+
+    let b_g2_inputs = multiexp(
+        &worker,
+        b_g2_inputs_source,
+        b_input_density,
+        input_assignment,
+    );
     let b_g2_aux = multiexp(&worker, b_g2_aux_source, b_aux_density, aux_assignment);
 
     if vk.delta_g1.is_zero() || vk.delta_g2.is_zero() {
@@ -325,6 +346,6 @@ pub fn create_proof<E, C, P: ParameterSource<E>>(
     Ok(Proof {
         a: g_a.into_affine(),
         b: g_b.into_affine(),
-        c: g_c.into_affine()
+        c: g_c.into_affine(),
     })
 }

bellman/src/groth16/tests/dummy_engine.rs

@@ -1,12 +1,13 @@
 use ff::{
-    Field, LegendreSymbol, PrimeField, PrimeFieldDecodingError,
+    Field, LegendreSymbol, PrimeField, PrimeFieldDecodingError, PrimeFieldRepr, ScalarEngine,
-    PrimeFieldRepr, ScalarEngine, SqrtField};
+    SqrtField,
+};
 use group::{CurveAffine, CurveProjective, EncodedPoint, GroupDecodingError};
 use pairing::{Engine, PairingCurveAffine};
 
+use rand_core::RngCore;
 use std::cmp::Ordering;
 use std::fmt;
-use rand::{Rand, Rng};
 use std::num::Wrapping;
 
 const MODULUS_R: Wrapping<u32> = Wrapping(64513);
@@ -15,18 +16,16 @@ const MODULUS_R: Wrapping<u32> = Wrapping(64513);
 pub struct Fr(Wrapping<u32>);
 
 impl fmt::Display for Fr {
-    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
         write!(f, "{}", (self.0).0)
     }
 }
 
-impl Rand for Fr {
-    fn rand<R: Rng>(rng: &mut R) -> Self {
-        Fr(Wrapping(rng.gen()) % MODULUS_R)
-    }
-}
-
 impl Field for Fr {
+    fn random<R: RngCore + ?std::marker::Sized>(rng: &mut R) -> Self {
+        Fr(Wrapping(rng.next_u32()) % MODULUS_R)
+    }
+
     fn zero() -> Self {
         Fr(Wrapping(0))
     }
@@ -82,9 +81,13 @@ impl SqrtField for Fr {
     fn legendre(&self) -> LegendreSymbol {
         // s = self^((r - 1) // 2)
         let s = self.pow([32256]);
-        if s == <Fr as Field>::zero() { LegendreSymbol::Zero }
+        if s == <Fr as Field>::zero() {
-        else if s == <Fr as Field>::one() { LegendreSymbol::QuadraticResidue }
+            LegendreSymbol::Zero
-        else { LegendreSymbol::QuadraticNonResidue }
+        } else if s == <Fr as Field>::one() {
+            LegendreSymbol::QuadraticResidue
+        } else {
+            LegendreSymbol::QuadraticNonResidue
+        }
     }
 
     fn sqrt(&self) -> Option<Self> {
@@ -102,7 +105,7 @@ impl SqrtField for Fr {
                 let mut m = Fr::S;
 
                 while t != <Fr as Field>::one() {
-                let mut i = 1;
+                    let mut i = 1;
                     {
                         let mut t2i = t;
                         t2i.square();
@@ -145,14 +148,8 @@ impl PartialOrd for FrRepr {
     }
 }
 
-impl Rand for FrRepr {
-    fn rand<R: Rng>(rng: &mut R) -> Self {
-        FrRepr([rng.gen()])
-    }
-}
-
 impl fmt::Display for FrRepr {
-    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
         write!(f, "{}", (self.0)[0])
     }
 }
@@ -266,15 +263,18 @@ impl Engine for DummyEngine {
     type G2Affine = Fr;
     type Fq = Fr;
     type Fqe = Fr;
-    
+
     // TODO: This should be F_645131 or something. Doesn't matter for now.
     type Fqk = Fr;
 
     fn miller_loop<'a, I>(i: I) -> Self::Fqk
-        where I: IntoIterator<Item=&'a (
+    where
-                                    &'a <Self::G1Affine as PairingCurveAffine>::Prepared,
+        I: IntoIterator<
-                                    &'a <Self::G2Affine as PairingCurveAffine>::Prepared
+            Item = &'a (
-                               )>
+                &'a <Self::G1Affine as PairingCurveAffine>::Prepared,
+                &'a <Self::G2Affine as PairingCurveAffine>::Prepared,
+            ),
+        >,
     {
         let mut acc = <Fr as Field>::zero();
 
@@ -288,8 +288,7 @@ impl Engine for DummyEngine {
     }
 
     /// Perform final exponentiation of the result of a miller loop.
-    fn final_exponentiation(this: &Self::Fqk) -> Option<Self::Fqk>
+    fn final_exponentiation(this: &Self::Fqk) -> Option<Self::Fqk> {
-    {
         Some(*this)
     }
 }
@@ -300,6 +299,10 @@ impl CurveProjective for Fr {
     type Scalar = Fr;
     type Engine = DummyEngine;
 
+    fn random<R: RngCore>(rng: &mut R) -> Self {
+        <Fr as Field>::random(rng)
+    }
+
     fn zero() -> Self {
         <Fr as Field>::zero()
     }
@@ -312,9 +315,7 @@ impl CurveProjective for Fr {
         <Fr as Field>::is_zero(self)
     }
 
-    fn batch_normalization(_: &mut [Self]) {
+    fn batch_normalization(_: &mut [Self]) {}
-        
-    }
 
     fn is_normalized(&self) -> bool {
         true
@@ -336,8 +337,7 @@ impl CurveProjective for Fr {
         <Fr as Field>::negate(self);
     }
 
-    fn mul_assign<S: Into<<Self::Scalar as PrimeField>::Repr>>(&mut self, other: S)
+    fn mul_assign<S: Into<<Self::Scalar as PrimeField>::Repr>>(&mut self, other: S) {
-    {
         let tmp = Fr::from_repr(other.into()).unwrap();
 
         <Fr as Field>::mul_assign(self, &tmp);
@@ -419,8 +419,7 @@ impl CurveAffine for Fr {
         <Fr as Field>::negate(self);
     }
 
-    fn mul<S: Into<<Self::Scalar as PrimeField>::Repr>>(&self, other: S) -> Self::Projective
+    fn mul<S: Into<<Self::Scalar as PrimeField>::Repr>>(&self, other: S) -> Self::Projective {
-    {
         let mut res = *self;
         let tmp = Fr::from_repr(other.into()).unwrap();
 

bellman/src/groth16/tests/mod.rs

@@ -6,86 +6,82 @@ use self::dummy_engine::*;
 
 use std::marker::PhantomData;
 
-use ::{
+use crate::{Circuit, ConstraintSystem, SynthesisError};
-    Circuit,
-    ConstraintSystem,
-    SynthesisError
-};
 
-use super::{
+use super::{create_proof, generate_parameters, prepare_verifying_key, verify_proof};
-    generate_parameters,
-    prepare_verifying_key,
-    create_proof,
-    verify_proof
-};
 
 struct XORDemo<E: Engine> {
     a: Option<bool>,
     b: Option<bool>,
-    _marker: PhantomData<E>
+    _marker: PhantomData<E>,
 }
 
 impl<E: Engine> Circuit<E> for XORDemo<E> {
-    fn synthesize<CS: ConstraintSystem<E>>(
+    fn synthesize<CS: ConstraintSystem<E>>(self, cs: &mut CS) -> Result<(), SynthesisError> {
-        self,
+        let a_var = cs.alloc(
-        cs: &mut CS
+            || "a",
-    ) -> Result<(), SynthesisError>
+            || {
-    {
+                if self.a.is_some() {
-        let a_var = cs.alloc(|| "a", || {
+                    if self.a.unwrap() {
-            if self.a.is_some() {
+                        Ok(E::Fr::one())
-                if self.a.unwrap() {
+                    } else {
-                    Ok(E::Fr::one())
+                        Ok(E::Fr::zero())
+                    }
                 } else {
-                    Ok(E::Fr::zero())
+                    Err(SynthesisError::AssignmentMissing)
                 }
-            } else {
+            },
-                Err(SynthesisError::AssignmentMissing)
+        )?;
-            }
-        })?;
 
         cs.enforce(
             || "a_boolean_constraint",
             |lc| lc + CS::one() - a_var,
             |lc| lc + a_var,
-            |lc| lc
+            |lc| lc,
         );
 
-        let b_var = cs.alloc(|| "b", || {
+        let b_var = cs.alloc(
-            if self.b.is_some() {
+            || "b",
-                if self.b.unwrap() {
+            || {
-                    Ok(E::Fr::one())
+                if self.b.is_some() {
+                    if self.b.unwrap() {
+                        Ok(E::Fr::one())
+                    } else {
+                        Ok(E::Fr::zero())
+                    }
                 } else {
-                    Ok(E::Fr::zero())
+                    Err(SynthesisError::AssignmentMissing)
                 }
-            } else {
+            },
-                Err(SynthesisError::AssignmentMissing)
+        )?;
-            }
-        })?;
 
         cs.enforce(
             || "b_boolean_constraint",
             |lc| lc + CS::one() - b_var,
             |lc| lc + b_var,
-            |lc| lc
+            |lc| lc,
         );
 
-        let c_var = cs.alloc_input(|| "c", || {
+        let c_var = cs.alloc_input(
-            if self.a.is_some() && self.b.is_some() {
+            || "c",
-                if self.a.unwrap() ^ self.b.unwrap() {
+            || {
-                    Ok(E::Fr::one())
+                if self.a.is_some() && self.b.is_some() {
+                    if self.a.unwrap() ^ self.b.unwrap() {
+                        Ok(E::Fr::one())
+                    } else {
+                        Ok(E::Fr::zero())
+                    }
                 } else {
-                    Ok(E::Fr::zero())
+                    Err(SynthesisError::AssignmentMissing)
                 }
-            } else {
+            },
-                Err(SynthesisError::AssignmentMissing)
+        )?;
-            }
-        })?;
 
         cs.enforce(
             || "c_xor_constraint",
             |lc| lc + a_var + a_var,
             |lc| lc + b_var,
-            |lc| lc + a_var + b_var - c_var
+            |lc| lc + a_var + b_var - c_var,
         );
 
         Ok(())
@@ -106,19 +102,10 @@ fn test_xordemo() {
         let c = XORDemo::<DummyEngine> {
             a: None,
             b: None,
-            _marker: PhantomData
+            _marker: PhantomData,
         };
 
-        generate_parameters(
+        generate_parameters(c, g1, g2, alpha, beta, gamma, delta, tau).unwrap()
-            c,
-            g1,
-            g2,
-            alpha,
-            beta,
-            gamma,
-            delta,
-            tau
-        ).unwrap()
     };
 
     // This will synthesize the constraint system:
@@ -226,32 +213,35 @@ fn test_xordemo() {
     59158
     */
 
-    let u_i = [59158, 48317, 21767, 10402].iter().map(|e| {
+    let u_i = [59158, 48317, 21767, 10402]
-        Fr::from_str(&format!("{}", e)).unwrap()
+        .iter()
-    }).collect::<Vec<Fr>>();
+        .map(|e| Fr::from_str(&format!("{}", e)).unwrap())
-    let v_i = [0, 0, 60619, 30791].iter().map(|e| {
+        .collect::<Vec<Fr>>();
-        Fr::from_str(&format!("{}", e)).unwrap()
+    let v_i = [0, 0, 60619, 30791]
-    }).collect::<Vec<Fr>>();
+        .iter()
-    let w_i = [0, 23320, 41193, 41193].iter().map(|e| {
+        .map(|e| Fr::from_str(&format!("{}", e)).unwrap())
-        Fr::from_str(&format!("{}", e)).unwrap()
+        .collect::<Vec<Fr>>();
-    }).collect::<Vec<Fr>>();
+    let w_i = [0, 23320, 41193, 41193]
+        .iter()
+        .map(|e| Fr::from_str(&format!("{}", e)).unwrap())
+        .collect::<Vec<Fr>>();
 
-    for (u, a) in u_i.iter()
+    for (u, a) in u_i.iter().zip(&params.a[..]) {
-                     .zip(&params.a[..])
-    {
         assert_eq!(u, a);
     }
 
-    for (v, b) in v_i.iter()
+    for (v, b) in v_i
-                     .filter(|&&e| e != Fr::zero())
+        .iter()
-                     .zip(&params.b_g1[..])
+        .filter(|&&e| e != Fr::zero())
+        .zip(&params.b_g1[..])
     {
         assert_eq!(v, b);
     }
 
-    for (v, b) in v_i.iter()
+    for (v, b) in v_i
-                     .filter(|&&e| e != Fr::zero())
+        .iter()
-                     .zip(&params.b_g2[..])
+        .filter(|&&e| e != Fr::zero())
+        .zip(&params.b_g2[..])
     {
         assert_eq!(v, b);
     }
@@ -296,15 +286,10 @@ fn test_xordemo() {
         let c = XORDemo {
             a: Some(true),
             b: Some(false),
-            _marker: PhantomData
+            _marker: PhantomData,
         };
 
-        create_proof(
+        create_proof(c, &params, r, s).unwrap()
-            c,
-            &params,
-            r,
-            s
-        ).unwrap()
     };
 
     // A(x) =
@@ -320,7 +305,7 @@ fn test_xordemo() {
         expected_a.add_assign(&u_i[0]); // a_0 = 1
         expected_a.add_assign(&u_i[1]); // a_1 = 1
         expected_a.add_assign(&u_i[2]); // a_2 = 1
-        // a_3 = 0
+                                        // a_3 = 0
         assert_eq!(proof.a, expected_a);
     }
 
@@ -337,7 +322,7 @@ fn test_xordemo() {
         expected_b.add_assign(&v_i[0]); // a_0 = 1
         expected_b.add_assign(&v_i[1]); // a_1 = 1
         expected_b.add_assign(&v_i[2]); // a_2 = 1
-        // a_3 = 0
+                                        // a_3 = 0
         assert_eq!(proof.b, expected_b);
     }
 
@@ -378,7 +363,10 @@ fn test_xordemo() {
         expected_c.add_assign(&params.l[0]);
 
         // H query answer
-        for (i, coeff) in [5040, 11763, 10755, 63633, 128, 9747, 8739].iter().enumerate() {
+        for (i, coeff) in [5040, 11763, 10755, 63633, 128, 9747, 8739]
+            .iter()
+            .enumerate()
+        {
             let coeff = Fr::from_str(&format!("{}", coeff)).unwrap();
 
             let mut tmp = params.h[i];
@@ -389,9 +377,5 @@ fn test_xordemo() {
         assert_eq!(expected_c, proof.c);
     }
 
-    assert!(verify_proof(
+    assert!(verify_proof(&pvk, &proof, &[Fr::one()]).unwrap());
-        &pvk,
-        &proof,
-        &[Fr::one()]
-    ).unwrap());
 }

bellman/src/groth16/verifier.rs

@@ -2,20 +2,11 @@ use ff::PrimeField;
 use group::{CurveAffine, CurveProjective};
 use pairing::{Engine, PairingCurveAffine};
 
-use super::{
+use super::{PreparedVerifyingKey, Proof, VerifyingKey};
-    Proof,
-    VerifyingKey,
-    PreparedVerifyingKey
-};
 
-use ::{
+use crate::SynthesisError;
-    SynthesisError
-};
 
-pub fn prepare_verifying_key<E: Engine>(
+pub fn prepare_verifying_key<E: Engine>(vk: &VerifyingKey<E>) -> PreparedVerifyingKey<E> {
-    vk: &VerifyingKey<E>
-) -> PreparedVerifyingKey<E>
-{
     let mut gamma = vk.gamma_g2;
     gamma.negate();
     let mut delta = vk.delta_g2;
@@ -25,16 +16,15 @@ pub fn prepare_verifying_key<E: Engine>(
         alpha_g1_beta_g2: E::pairing(vk.alpha_g1, vk.beta_g2),
         neg_gamma_g2: gamma.prepare(),
         neg_delta_g2: delta.prepare(),
-        ic: vk.ic.clone()
+        ic: vk.ic.clone(),
     }
 }
 
 pub fn verify_proof<'a, E: Engine>(
     pvk: &'a PreparedVerifyingKey<E>,
     proof: &Proof<E>,
-    public_inputs: &[E::Fr]
+    public_inputs: &[E::Fr],
-) -> Result<bool, SynthesisError>
+) -> Result<bool, SynthesisError> {
-{
     if (public_inputs.len() + 1) != pvk.ic.len() {
         return Err(SynthesisError::MalformedVerifyingKey);
     }
@@ -53,11 +43,14 @@ pub fn verify_proof<'a, E: Engine>(
     // A * B + inputs * (-gamma) + C * (-delta) = alpha * beta
     // which allows us to do a single final exponentiation.
 
-    Ok(E::final_exponentiation(
+    Ok(E::final_exponentiation(&E::miller_loop(
-        &E::miller_loop([
+        [
             (&proof.a.prepare(), &proof.b.prepare()),
             (&acc.into_affine().prepare(), &pvk.neg_gamma_g2),
-            (&proof.c.prepare(), &pvk.neg_delta_g2)
+            (&proof.c.prepare(), &pvk.neg_delta_g2),
-        ].into_iter())
+        ]
-    ).unwrap() == pvk.alpha_g1_beta_g2)
+        .iter(),
+    ))
+    .unwrap()
+        == pvk.alpha_g1_beta_g2)
 }

bellman/src/lib.rs

@@ -1,33 +1,154 @@
-extern crate ff;
+//! `bellman` is a crate for building zk-SNARK circuits. It provides circuit
-extern crate group;
+//! traits and and primitive structures, as well as basic gadget implementations
-#[cfg(feature = "pairing")]
+//! such as booleans and number abstractions.
-extern crate pairing;
+//!
-extern crate rand;
+//! # Example circuit
+//!
+//! Say we want to write a circuit that proves we know the preimage to some hash
+//! computed using SHA-256d (calling SHA-256 twice). The preimage must have a
+//! fixed length known in advance (because the circuit parameters will depend on
+//! it), but can otherwise have any value. We take the following strategy:
+//!
+//! - Witness each bit of the preimage.
+//! - Compute `hash = SHA-256d(preimage)` inside the circuit.
+//! - Expose `hash` as a public input using multiscalar packing.
+//!
+//! ```
+//! use bellman::{
+//!     gadgets::{
+//!         boolean::{AllocatedBit, Boolean},
+//!         multipack,
+//!         sha256::sha256,
+//!     },
+//!     groth16, Circuit, ConstraintSystem, SynthesisError,
+//! };
+//! use pairing::{bls12_381::Bls12, Engine};
+//! use rand::rngs::OsRng;
+//! use sha2::{Digest, Sha256};
+//!
+//! /// Our own SHA-256d gadget. Input and output are in little-endian bit order.
+//! fn sha256d<E: Engine, CS: ConstraintSystem<E>>(
+//!     mut cs: CS,
+//!     data: &[Boolean],
+//! ) -> Result<Vec<Boolean>, SynthesisError> {
+//!     // Flip endianness of each input byte
+//!     let input: Vec<_> = data
+//!         .chunks(8)
+//!         .map(|c| c.iter().rev())
+//!         .flatten()
+//!         .cloned()
+//!         .collect();
+//!
+//!     let mid = sha256(cs.namespace(|| "SHA-256(input)"), &input)?;
+//!     let res = sha256(cs.namespace(|| "SHA-256(mid)"), &mid)?;
+//!
+//!     // Flip endianness of each output byte
+//!     Ok(res
+//!         .chunks(8)
+//!         .map(|c| c.iter().rev())
+//!         .flatten()
+//!         .cloned()
+//!         .collect())
+//! }
+//!
+//! struct MyCircuit {
+//!     /// The input to SHA-256d we are proving that we know. Set to `None` when we
+//!     /// are verifying a proof (and do not have the witness data).
+//!     preimage: Option<[u8; 80]>,
+//! }
+//!
+//! impl<E: Engine> Circuit<E> for MyCircuit {
+//!     fn synthesize<CS: ConstraintSystem<E>>(self, cs: &mut CS) -> Result<(), SynthesisError> {
+//!         // Compute the values for the bits of the preimage. If we are verifying a proof,
+//!         // we still need to create the same constraints, so we return an equivalent-size
+//!         // Vec of None (indicating that the value of each bit is unknown).
+//!         let bit_values = if let Some(preimage) = self.preimage {
+//!             preimage
+//!                 .into_iter()
+//!                 .map(|byte| (0..8).map(move |i| (byte >> i) & 1u8 == 1u8))
+//!                 .flatten()
+//!                 .map(|b| Some(b))
+//!                 .collect()
+//!         } else {
+//!             vec![None; 80 * 8]
+//!         };
+//!         assert_eq!(bit_values.len(), 80 * 8);
+//!
+//!         // Witness the bits of the preimage.
+//!         let preimage_bits = bit_values
+//!             .into_iter()
+//!             .enumerate()
+//!             // Allocate each bit.
+//!             .map(|(i, b)| {
+//!                 AllocatedBit::alloc(cs.namespace(|| format!("preimage bit {}", i)), b)
+//!             })
+//!             // Convert the AllocatedBits into Booleans (required for the sha256 gadget).
+//!             .map(|b| b.map(Boolean::from))
+//!             .collect::<Result<Vec<_>, _>>()?;
+//!
+//!         // Compute hash = SHA-256d(preimage).
+//!         let hash = sha256d(cs.namespace(|| "SHA-256d(preimage)"), &preimage_bits)?;
+//!
+//!         // Expose the vector of 32 boolean variables as compact public inputs.
+//!         multipack::pack_into_inputs(cs.namespace(|| "pack hash"), &hash)
+//!     }
+//! }
+//!
+//! // Create parameters for our circuit. In a production deployment these would
+//! // be generated securely using a multiparty computation.
+//! let params = {
+//!     let c = MyCircuit { preimage: None };
+//!     groth16::generate_random_parameters::<Bls12, _, _>(c, &mut OsRng).unwrap()
+//! };
+//!
+//! // Prepare the verification key (for proof verification).
+//! let pvk = groth16::prepare_verifying_key(&params.vk);
+//!
+//! // Pick a preimage and compute its hash.
+//! let preimage = [42; 80];
+//! let hash = Sha256::digest(&Sha256::digest(&preimage));
+//!
+//! // Create an instance of our circuit (with the preimage as a witness).
+//! let c = MyCircuit {
+//!     preimage: Some(preimage),
+//! };
+//!
+//! // Create a Groth16 proof with our parameters.
+//! let proof = groth16::create_random_proof(c, &params, &mut OsRng).unwrap();
+//!
+//! // Pack the hash as inputs for proof verification.
+//! let hash_bits = multipack::bytes_to_bits_le(&hash);
+//! let inputs = multipack::compute_multipacking::<Bls12>(&hash_bits);
+//!
+//! // Check the proof!
+//! assert!(groth16::verify_proof(&pvk, &proof, &inputs).unwrap());
+//! ```
+//!
+//! # Roadmap
+//!
+//! `bellman` is being refactored into a generic proving library. Currently it
+//! is pairing-specific, and different types of proving systems need to be
+//! implemented as sub-modules. After the refactor, `bellman` will be generic
+//! using the [`ff`] and [`group`] crates, while specific proving systems will
+//! be separate crates that pull in the dependencies they require.
 
-extern crate futures;
+// Catch documentation errors caused by code changes.
-extern crate bit_vec;
+#![deny(intra_doc_link_resolution_failure)]
-extern crate byteorder;
 
-#[cfg(feature = "multicore")]
-extern crate crossbeam;
-#[cfg(feature = "multicore")]
-extern crate futures_cpupool;
-#[cfg(feature = "multicore")]
-extern crate num_cpus;
-
-pub mod multicore;
-mod multiexp;
 pub mod domain;
+pub mod gadgets;
 #[cfg(feature = "groth16")]
 pub mod groth16;
+pub mod multicore;
+mod multiexp;
 
 use ff::{Field, ScalarEngine};
 
-use std::ops::{Add, Sub};
-use std::fmt;
 use std::error::Error;
+use std::fmt;
 use std::io;
 use std::marker::PhantomData;
+use std::ops::{Add, Sub};
 
 /// Computations are expressed in terms of arithmetic circuits, in particular
 /// rank-1 quadratic constraint systems. The `Circuit` trait represents a
@@ -35,10 +156,7 @@ use std::marker::PhantomData;
 /// CRS generation and during proving.
 pub trait Circuit<E: ScalarEngine> {
     /// Synthesize the circuit into a rank-1 quadratic constraint system
-    fn synthesize<CS: ConstraintSystem<E>>(
+    fn synthesize<CS: ConstraintSystem<E>>(self, cs: &mut CS) -> Result<(), SynthesisError>;
-        self,
-        cs: &mut CS
-    ) -> Result<(), SynthesisError>;
 }
 
 /// Represents a variable in our constraint system.
@@ -64,7 +182,7 @@ impl Variable {
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub enum Index {
     Input(usize),
-    Aux(usize)
+    Aux(usize),
 }
 
 /// This represents a linear combination of some variables, with coefficients
@@ -97,6 +215,7 @@ impl<E: ScalarEngine> Add<(E::Fr, Variable)> for LinearCombination<E> {
 impl<E: ScalarEngine> Sub<(E::Fr, Variable)> for LinearCombination<E> {
     type Output = LinearCombination<E>;
 
+    #[allow(clippy::suspicious_arithmetic_impl)]
     fn sub(self, (mut coeff, var): (E::Fr, Variable)) -> LinearCombination<E> {
         coeff.negate();
 
@@ -191,7 +310,7 @@ pub enum SynthesisError {
     /// During verification, our verifying key was malformed.
     MalformedVerifyingKey,
     /// During CRS generation, we observed an unconstrained auxiliary variable
-    UnconstrainedVariable
+    UnconstrainedVariable,
 }
 
 impl From<io::Error> for SynthesisError {
@@ -203,21 +322,23 @@ impl From<io::Error> for SynthesisError {
 impl Error for SynthesisError {
     fn description(&self) -> &str {
         match *self {
-            SynthesisError::AssignmentMissing => "an assignment for a variable could not be computed",
+            SynthesisError::AssignmentMissing => {
+                "an assignment for a variable could not be computed"
+            }
             SynthesisError::DivisionByZero => "division by zero",
             SynthesisError::Unsatisfiable => "unsatisfiable constraint system",
             SynthesisError::PolynomialDegreeTooLarge => "polynomial degree is too large",
             SynthesisError::UnexpectedIdentity => "encountered an identity element in the CRS",
             SynthesisError::IoError(_) => "encountered an I/O error",
             SynthesisError::MalformedVerifyingKey => "malformed verifying key",
-            SynthesisError::UnconstrainedVariable => "auxiliary variable was unconstrained"
+            SynthesisError::UnconstrainedVariable => "auxiliary variable was unconstrained",
         }
     }
 }
 
 impl fmt::Display for SynthesisError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
-        if let &SynthesisError::IoError(ref e) = self {
+        if let SynthesisError::IoError(ref e) = *self {
             write!(f, "I/O error: ")?;
             e.fmt(f)
         } else {
@@ -242,40 +363,36 @@ pub trait ConstraintSystem<E: ScalarEngine>: Sized {
     /// determine the assignment of the variable. The given `annotation` function is invoked
     /// in testing contexts in order to derive a unique name for this variable in the current
     /// namespace.
-    fn alloc<F, A, AR>(
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>;
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>;
 
     /// Allocate a public variable in the constraint system. The provided function is used to
     /// determine the assignment of the variable.
-    fn alloc_input<F, A, AR>(
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>;
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>;
 
     /// Enforce that `A` * `B` = `C`. The `annotation` function is invoked in testing contexts
     /// in order to derive a unique name for the constraint in the current namespace.
-    fn enforce<A, AR, LA, LB, LC>(
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
-        &mut self,
+    where
-        annotation: A,
+        A: FnOnce() -> AR,
-        a: LA,
+        AR: Into<String>,
-        b: LB,
+        LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        c: LC
+        LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-    )
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>;
-        where A: FnOnce() -> AR, AR: Into<String>,
-              LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>;
 
     /// Create a new (sub)namespace and enter into it. Not intended
     /// for downstream use; use `namespace` instead.
     fn push_namespace<NR, N>(&mut self, name_fn: N)
-        where NR: Into<String>, N: FnOnce() -> NR;
+    where
+        NR: Into<String>,
+        N: FnOnce() -> NR;
 
     /// Exit out of the existing namespace. Not intended for
     /// downstream use; use `namespace` instead.
@@ -286,11 +403,10 @@ pub trait ConstraintSystem<E: ScalarEngine>: Sized {
     fn get_root(&mut self) -> &mut Self::Root;
 
     /// Begin a namespace for this constraint system.
-    fn namespace<'a, NR, N>(
+    fn namespace<NR, N>(&mut self, name_fn: N) -> Namespace<'_, E, Self::Root>
-        &'a mut self,
+    where
-        name_fn: N
+        NR: Into<String>,
-    ) -> Namespace<'a, E, Self::Root>
+        N: FnOnce() -> NR,
-        where NR: Into<String>, N: FnOnce() -> NR
     {
         self.get_root().push_namespace(name_fn);
 
@@ -300,7 +416,7 @@ pub trait ConstraintSystem<E: ScalarEngine>: Sized {
 
 /// This is a "namespaced" constraint system which borrows a constraint system (pushing
 /// a namespace context) and, when dropped, pops out of the namespace context.
-pub struct Namespace<'a, E: ScalarEngine, CS: ConstraintSystem<E> + 'a>(&'a mut CS, PhantomData<E>);
+pub struct Namespace<'a, E: ScalarEngine, CS: ConstraintSystem<E>>(&'a mut CS, PhantomData<E>);
 
 impl<'cs, E: ScalarEngine, CS: ConstraintSystem<E>> ConstraintSystem<E> for Namespace<'cs, E, CS> {
     type Root = CS::Root;
@@ -309,37 +425,31 @@ impl<'cs, E: ScalarEngine, CS: ConstraintSystem<E>> ConstraintSystem<E> for Name
         CS::one()
     }
 
-    fn alloc<F, A, AR>(
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         self.0.alloc(annotation, f)
     }
 
-    fn alloc_input<F, A, AR>(
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         self.0.alloc_input(annotation, f)
     }
 
-    fn enforce<A, AR, LA, LB, LC>(
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
-        &mut self,
+    where
-        annotation: A,
+        A: FnOnce() -> AR,
-        a: LA,
+        AR: Into<String>,
-        b: LB,
+        LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        c: LC
+        LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-    )
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        where A: FnOnce() -> AR, AR: Into<String>,
-              LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>
     {
         self.0.enforce(annotation, a, b, c)
     }
@@ -349,18 +459,18 @@ impl<'cs, E: ScalarEngine, CS: ConstraintSystem<E>> ConstraintSystem<E> for Name
     // never a root constraint system.
 
     fn push_namespace<NR, N>(&mut self, _: N)
-        where NR: Into<String>, N: FnOnce() -> NR
+    where
+        NR: Into<String>,
+        N: FnOnce() -> NR,
     {
         panic!("only the root's push_namespace should be called");
     }
 
-    fn pop_namespace(&mut self)
+    fn pop_namespace(&mut self) {
-    {
         panic!("only the root's pop_namespace should be called");
     }
 
-    fn get_root(&mut self) -> &mut Self::Root
+    fn get_root(&mut self) -> &mut Self::Root {
-    {
         self.0.get_root()
     }
 }
@@ -380,54 +490,48 @@ impl<'cs, E: ScalarEngine, CS: ConstraintSystem<E>> ConstraintSystem<E> for &'cs
         CS::one()
     }
 
-    fn alloc<F, A, AR>(
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         (**self).alloc(annotation, f)
     }
 
-    fn alloc_input<F, A, AR>(
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
-        &mut self,
+    where
-        annotation: A,
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
-        f: F
+        A: FnOnce() -> AR,
-    ) -> Result<Variable, SynthesisError>
+        AR: Into<String>,
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
     {
         (**self).alloc_input(annotation, f)
     }
 
-    fn enforce<A, AR, LA, LB, LC>(
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
-        &mut self,
+    where
-        annotation: A,
+        A: FnOnce() -> AR,
-        a: LA,
+        AR: Into<String>,
-        b: LB,
+        LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        c: LC
+        LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-    )
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-        where A: FnOnce() -> AR, AR: Into<String>,
-              LA: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LB: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
-              LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>
     {
         (**self).enforce(annotation, a, b, c)
     }
 
     fn push_namespace<NR, N>(&mut self, name_fn: N)
-        where NR: Into<String>, N: FnOnce() -> NR
+    where
+        NR: Into<String>,
+        N: FnOnce() -> NR,
     {
         (**self).push_namespace(name_fn)
     }
 
-    fn pop_namespace(&mut self)
+    fn pop_namespace(&mut self) {
-    {
         (**self).pop_namespace()
     }
 
-    fn get_root(&mut self) -> &mut Self::Root
+    fn get_root(&mut self) -> &mut Self::Root {
-    {
         (**self).get_root()
     }
 }

bellman/src/multicore.rs

@@ -1,20 +1,21 @@
-//! This is an interface for dealing with the kinds of
+//! An interface for dealing with the kinds of parallel computations involved in
-//! parallel computations involved in bellman. It's
+//! `bellman`. It's currently just a thin wrapper around [`CpuPool`] and
-//! currently just a thin wrapper around CpuPool and
+//! [`crossbeam`] but may be extended in the future to allow for various
-//! crossbeam but may be extended in the future to
+//! parallelism strategies.
-//! allow for various parallelism strategies.
+//!
+//! [`CpuPool`]: futures_cpupool::CpuPool
 
 #[cfg(feature = "multicore")]
 mod implementation {
-    use num_cpus;
+    use crossbeam::{self, thread::Scope};
     use futures::{Future, IntoFuture, Poll};
-    use futures_cpupool::{CpuPool, CpuFuture};
+    use futures_cpupool::{CpuFuture, CpuPool};
-    use crossbeam::{self, Scope};
+    use num_cpus;
 
     #[derive(Clone)]
     pub struct Worker {
         cpus: usize,
-        pool: CpuPool
+        pool: CpuPool,
     }
 
     impl Worker {
@@ -23,8 +24,8 @@ mod implementation {
         // CPUs configured.
         pub(crate) fn new_with_cpus(cpus: usize) -> Worker {
             Worker {
-                cpus: cpus,
+                cpus,
-                pool: CpuPool::new(cpus)
+                pool: CpuPool::new(cpus),
             }
         }
 
@@ -36,26 +37,22 @@ mod implementation {
             log2_floor(self.cpus)
         }
 
-        pub fn compute<F, R>(
+        pub fn compute<F, R>(&self, f: F) -> WorkerFuture<R::Item, R::Error>
-            &self, f: F
+        where
-        ) -> WorkerFuture<R::Item, R::Error>
+            F: FnOnce() -> R + Send + 'static,
-            where F: FnOnce() -> R + Send + 'static,
+            R: IntoFuture + 'static,
-                R: IntoFuture + 'static,
+            R::Future: Send + 'static,
-                R::Future: Send + 'static,
+            R::Item: Send + 'static,
-                R::Item: Send + 'static,
+            R::Error: Send + 'static,
-                R::Error: Send + 'static
         {
             WorkerFuture {
-                future: self.pool.spawn_fn(f)
+                future: self.pool.spawn_fn(f),
             }
         }
 
-        pub fn scope<'a, F, R>(
+        pub fn scope<'a, F, R>(&self, elements: usize, f: F) -> R
-            &self,
+        where
-            elements: usize,
+            F: FnOnce(&Scope<'a>, usize) -> R,
-            f: F
-        ) -> R
-            where F: FnOnce(&Scope<'a>, usize) -> R
         {
             let chunk_size = if elements < self.cpus {
                 1
@@ -63,22 +60,21 @@ mod implementation {
                 elements / self.cpus
             };
 
-            crossbeam::scope(|scope| {
+            // TODO: Handle case where threads fail
-                f(scope, chunk_size)
+            crossbeam::scope(|scope| f(scope, chunk_size))
-            })
+                .expect("Threads aren't allowed to fail yet")
         }
     }
 
     pub struct WorkerFuture<T, E> {
-        future: CpuFuture<T, E>
+        future: CpuFuture<T, E>,
     }
 
     impl<T: Send + 'static, E: Send + 'static> Future for WorkerFuture<T, E> {
         type Item = T;
         type Error = E;
 
-        fn poll(&mut self) -> Poll<Self::Item, Self::Error>
+        fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-        {
             self.future.poll()
         }
     }
@@ -88,7 +84,7 @@ mod implementation {
 
         let mut pow = 0;
 
-        while (1 << (pow+1)) <= num {
+        while (1 << (pow + 1)) <= num {
             pow += 1;
         }
 
@@ -159,8 +155,8 @@ mod implementation {
     pub struct DummyScope;
 
     impl DummyScope {
-        pub fn spawn<F: FnOnce()>(&self, f: F) {
+        pub fn spawn<F: FnOnce(&DummyScope)>(&self, f: F) {
-            f();
+            f(self);
         }
     }
 }

bellman/src/multiexp.rs

@@ -1,11 +1,11 @@
-use ff::{Field, PrimeField, PrimeFieldRepr, ScalarEngine};
-use group::{CurveAffine, CurveProjective};
-use std::sync::Arc;
-use std::io;
-use bit_vec::{self, BitVec};
-use std::iter;
-use futures::{Future};
 use super::multicore::Worker;
+use bit_vec::{self, BitVec};
+use ff::{Field, PrimeField, PrimeFieldRepr, ScalarEngine};
+use futures::Future;
+use group::{CurveAffine, CurveProjective};
+use std::io;
+use std::iter;
+use std::sync::Arc;
 
 use super::SynthesisError;
 
@@ -19,7 +19,10 @@ pub trait SourceBuilder<G: CurveAffine>: Send + Sync + 'static + Clone {
 /// A source of bases, like an iterator.
 pub trait Source<G: CurveAffine> {
     /// Parses the element from the source. Fails if the point is at infinity.
-    fn add_assign_mixed(&mut self, to: &mut <G as CurveAffine>::Projective) -> Result<(), SynthesisError>;
+    fn add_assign_mixed(
+        &mut self,
+        to: &mut <G as CurveAffine>::Projective,
+    ) -> Result<(), SynthesisError>;
 
     /// Skips `amt` elements from the source, avoiding deserialization.
     fn skip(&mut self, amt: usize) -> Result<(), SynthesisError>;
@@ -34,13 +37,20 @@ impl<G: CurveAffine> SourceBuilder<G> for (Arc<Vec<G>>, usize) {
 }
 
 impl<G: CurveAffine> Source<G> for (Arc<Vec<G>>, usize) {
-    fn add_assign_mixed(&mut self, to: &mut <G as CurveAffine>::Projective) -> Result<(), SynthesisError> {
+    fn add_assign_mixed(
+        &mut self,
+        to: &mut <G as CurveAffine>::Projective,
+    ) -> Result<(), SynthesisError> {
         if self.0.len() <= self.1 {
-            return Err(io::Error::new(io::ErrorKind::UnexpectedEof, "expected more bases from source").into());
+            return Err(io::Error::new(
+                io::ErrorKind::UnexpectedEof,
+                "expected more bases from source",
+            )
+            .into());
         }
 
         if self.0[self.1].is_zero() {
-            return Err(SynthesisError::UnexpectedIdentity)
+            return Err(SynthesisError::UnexpectedIdentity);
         }
 
         to.add_assign_mixed(&self.0[self.1]);
@@ -52,7 +62,11 @@ impl<G: CurveAffine> Source<G> for (Arc<Vec<G>>, usize) {
 
     fn skip(&mut self, amt: usize) -> Result<(), SynthesisError> {
         if self.0.len() <= self.1 {
-            return Err(io::Error::new(io::ErrorKind::UnexpectedEof, "expected more bases from source").into());
+            return Err(io::Error::new(
+                io::ErrorKind::UnexpectedEof,
+                "expected more bases from source",
+            )
+            .into());
         }
 
         self.1 += amt;
@@ -63,7 +77,7 @@ impl<G: CurveAffine> Source<G> for (Arc<Vec<G>>, usize) {
 
 pub trait QueryDensity {
     /// Returns whether the base exists.
-    type Iter: Iterator<Item=bool>;
+    type Iter: Iterator<Item = bool>;
 
     fn iter(self) -> Self::Iter;
     fn get_query_size(self) -> Option<usize>;
@@ -92,7 +106,7 @@ impl<'a> QueryDensity for &'a FullDensity {
 
 pub struct DensityTracker {
     bv: BitVec,
-    total_density: usize
+    total_density: usize,
 }
 
 impl<'a> QueryDensity for &'a DensityTracker {
@@ -111,7 +125,7 @@ impl DensityTracker {
     pub fn new() -> DensityTracker {
         DensityTracker {
             bv: BitVec::new(),
-            total_density: 0
+            total_density: 0,
         }
     }
 
@@ -138,12 +152,13 @@ fn multiexp_inner<Q, D, G, S>(
     exponents: Arc<Vec<<<G::Engine as ScalarEngine>::Fr as PrimeField>::Repr>>,
     mut skip: u32,
     c: u32,
-    handle_trivial: bool
+    handle_trivial: bool,
-) -> Box<Future<Item=<G as CurveAffine>::Projective, Error=SynthesisError>>
+) -> Box<dyn Future<Item = <G as CurveAffine>::Projective, Error = SynthesisError>>
-    where for<'a> &'a Q: QueryDensity,
+where
-          D: Send + Sync + 'static + Clone + AsRef<Q>,
+    for<'a> &'a Q: QueryDensity,
-          G: CurveAffine,
+    D: Send + Sync + 'static + Clone + AsRef<Q>,
-          S: SourceBuilder<G>
+    G: CurveAffine,
+    S: SourceBuilder<G>,
 {
     // Perform this region of the multiexp
     let this = {
@@ -212,16 +227,24 @@ fn multiexp_inner<Q, D, G, S>(
         // There's another region more significant. Calculate and join it with
         // this region recursively.
         Box::new(
-            this.join(multiexp_inner(pool, bases, density_map, exponents, skip, c, false))
+            this.join(multiexp_inner(
-                .map(move |(this, mut higher)| {
+                pool,
-                    for _ in 0..c {
+                bases,
-                        higher.double();
+                density_map,
-                    }
+                exponents,
+                skip,
+                c,
+                false,
+            ))
+            .map(move |(this, mut higher)| {
+                for _ in 0..c {
+                    higher.double();
+                }
 
-                    higher.add_assign(&this);
+                higher.add_assign(&this);
 
-                    higher
+                higher
-                })
+            }),
         )
     }
 }
@@ -232,12 +255,13 @@ pub fn multiexp<Q, D, G, S>(
     pool: &Worker,
     bases: S,
     density_map: D,
-    exponents: Arc<Vec<<<G::Engine as ScalarEngine>::Fr as PrimeField>::Repr>>
+    exponents: Arc<Vec<<<G::Engine as ScalarEngine>::Fr as PrimeField>::Repr>>,
-) -> Box<Future<Item=<G as CurveAffine>::Projective, Error=SynthesisError>>
+) -> Box<dyn Future<Item = <G as CurveAffine>::Projective, Error = SynthesisError>>
-    where for<'a> &'a Q: QueryDensity,
+where
-          D: Send + Sync + 'static + Clone + AsRef<Q>,
+    for<'a> &'a Q: QueryDensity,
-          G: CurveAffine,
+    D: Send + Sync + 'static + Clone + AsRef<Q>,
-          S: SourceBuilder<G>
+    G: CurveAffine,
+    S: SourceBuilder<G>,
 {
     let c = if exponents.len() < 32 {
         3u32
@@ -260,9 +284,8 @@ pub fn multiexp<Q, D, G, S>(
 fn test_with_bls12() {
     fn naive_multiexp<G: CurveAffine>(
         bases: Arc<Vec<G>>,
-        exponents: Arc<Vec<<G::Scalar as PrimeField>::Repr>>
+        exponents: Arc<Vec<<G::Scalar as PrimeField>::Repr>>,
-    ) -> G::Projective
+    ) -> G::Projective {
-    {
         assert_eq!(bases.len(), exponents.len());
 
         let mut acc = G::Projective::zero();
@@ -274,25 +297,28 @@ fn test_with_bls12() {
         acc
     }
 
-    use rand::{self, Rand};
     use pairing::{bls12_381::Bls12, Engine};
+    use rand;
 
     const SAMPLES: usize = 1 << 14;
 
     let rng = &mut rand::thread_rng();
-    let v = Arc::new((0..SAMPLES).map(|_| <Bls12 as ScalarEngine>::Fr::rand(rng).into_repr()).collect::<Vec<_>>());
+    let v = Arc::new(
-    let g = Arc::new((0..SAMPLES).map(|_| <Bls12 as Engine>::G1::rand(rng).into_affine()).collect::<Vec<_>>());
+        (0..SAMPLES)
+            .map(|_| <Bls12 as ScalarEngine>::Fr::random(rng).into_repr())
+            .collect::<Vec<_>>(),
+    );
+    let g = Arc::new(
+        (0..SAMPLES)
+            .map(|_| <Bls12 as Engine>::G1::random(rng).into_affine())
+            .collect::<Vec<_>>(),
+    );
 
     let naive = naive_multiexp(g.clone(), v.clone());
 
     let pool = Worker::new();
 
-    let fast = multiexp(
+    let fast = multiexp(&pool, (g, 0), FullDensity, v).wait().unwrap();
-        &pool,
-        (g, 0),
-        FullDensity,
-        v
-    ).wait().unwrap();
 
     assert_eq!(naive, fast);
 }

bellman/tests/mimc.rs

@@ -1,44 +1,29 @@
-extern crate bellman;
-extern crate ff;
-extern crate pairing;
-extern crate rand;
-
 // For randomness (during paramgen and proof generation)
-use rand::{thread_rng, Rng};
+use rand::thread_rng;
 
 // For benchmarking
 use std::time::{Duration, Instant};
 
 // Bring in some tools for using pairing-friendly curves
-use ff::Field;
+use ff::{Field, ScalarEngine};
 use pairing::Engine;
 
 // We're going to use the BLS12-381 pairing-friendly elliptic curve.
-use pairing::bls12_381::{
+use pairing::bls12_381::Bls12;
-    Bls12
-};
 
 // We'll use these interfaces to construct our circuit.
-use bellman::{
+use bellman::{Circuit, ConstraintSystem, SynthesisError};
-    Circuit,
-    ConstraintSystem,
-    SynthesisError
-};
 
 // We're going to use the Groth16 proving system.
 use bellman::groth16::{
-    Proof,
+    create_random_proof, generate_random_parameters, prepare_verifying_key, verify_proof, Proof,
-    generate_random_parameters,
-    prepare_verifying_key,
-    create_random_proof,
-    verify_proof,
 };
 
 const MIMC_ROUNDS: usize = 322;
 
 /// This is an implementation of MiMC, specifically a
 /// variant named `LongsightF322p3` for BLS12-381.
-/// See http://eprint.iacr.org/2016/492 for more 
+/// See http://eprint.iacr.org/2016/492 for more
 /// information about this construction.
 ///
 /// ```
@@ -49,12 +34,7 @@ const MIMC_ROUNDS: usize = 322;
 ///     return xL
 /// }
 /// ```
-fn mimc<E: Engine>(
+fn mimc<E: Engine>(mut xl: E::Fr, mut xr: E::Fr, constants: &[E::Fr]) -> E::Fr {
-    mut xl: E::Fr,
-    mut xr: E::Fr,
-    constants: &[E::Fr]
-) -> E::Fr
-{
     assert_eq!(constants.len(), MIMC_ROUNDS);
 
     for i in 0..MIMC_ROUNDS {
@@ -76,80 +56,81 @@ fn mimc<E: Engine>(
 struct MiMCDemo<'a, E: Engine> {
     xl: Option<E::Fr>,
     xr: Option<E::Fr>,
-    constants: &'a [E::Fr]
+    constants: &'a [E::Fr],
 }
 
 /// Our demo circuit implements this `Circuit` trait which
 /// is used during paramgen and proving in order to
 /// synthesize the constraint system.
 impl<'a, E: Engine> Circuit<E> for MiMCDemo<'a, E> {
-    fn synthesize<CS: ConstraintSystem<E>>(
+    fn synthesize<CS: ConstraintSystem<E>>(self, cs: &mut CS) -> Result<(), SynthesisError> {
-        self,
-        cs: &mut CS
-    ) -> Result<(), SynthesisError>
-    {
         assert_eq!(self.constants.len(), MIMC_ROUNDS);
 
         // Allocate the first component of the preimage.
         let mut xl_value = self.xl;
-        let mut xl = cs.alloc(|| "preimage xl", || {
+        let mut xl = cs.alloc(
-            xl_value.ok_or(SynthesisError::AssignmentMissing)
+            || "preimage xl",
-        })?;
+            || xl_value.ok_or(SynthesisError::AssignmentMissing),
+        )?;
 
         // Allocate the second component of the preimage.
         let mut xr_value = self.xr;
-        let mut xr = cs.alloc(|| "preimage xr", || {
+        let mut xr = cs.alloc(
-            xr_value.ok_or(SynthesisError::AssignmentMissing)
+            || "preimage xr",
-        })?;
+            || xr_value.ok_or(SynthesisError::AssignmentMissing),
+        )?;
 
         for i in 0..MIMC_ROUNDS {
             // xL, xR := xR + (xL + Ci)^3, xL
             let cs = &mut cs.namespace(|| format!("round {}", i));
 
             // tmp = (xL + Ci)^2
-            let mut tmp_value = xl_value.map(|mut e| {
+            let tmp_value = xl_value.map(|mut e| {
                 e.add_assign(&self.constants[i]);
                 e.square();
                 e
             });
-            let mut tmp = cs.alloc(|| "tmp", || {
+            let tmp = cs.alloc(
-                tmp_value.ok_or(SynthesisError::AssignmentMissing)
+                || "tmp",
-            })?;
+                || tmp_value.ok_or(SynthesisError::AssignmentMissing),
+            )?;
 
             cs.enforce(
                 || "tmp = (xL + Ci)^2",
                 |lc| lc + xl + (self.constants[i], CS::one()),
                 |lc| lc + xl + (self.constants[i], CS::one()),
-                |lc| lc + tmp
+                |lc| lc + tmp,
             );
 
             // new_xL = xR + (xL + Ci)^3
             // new_xL = xR + tmp * (xL + Ci)
             // new_xL - xR = tmp * (xL + Ci)
-            let mut new_xl_value = xl_value.map(|mut e| {
+            let new_xl_value = xl_value.map(|mut e| {
                 e.add_assign(&self.constants[i]);
                 e.mul_assign(&tmp_value.unwrap());
                 e.add_assign(&xr_value.unwrap());
                 e
             });
 
-            let mut new_xl = if i == (MIMC_ROUNDS-1) {
+            let new_xl = if i == (MIMC_ROUNDS - 1) {
                 // This is the last round, xL is our image and so
                 // we allocate a public input.
-                cs.alloc_input(|| "image", || {
+                cs.alloc_input(
-                    new_xl_value.ok_or(SynthesisError::AssignmentMissing)
+                    || "image",
-                })?
+                    || new_xl_value.ok_or(SynthesisError::AssignmentMissing),
+                )?
             } else {
-                cs.alloc(|| "new_xl", || {
+                cs.alloc(
-                    new_xl_value.ok_or(SynthesisError::AssignmentMissing)
+                    || "new_xl",
-                })?
+                    || new_xl_value.ok_or(SynthesisError::AssignmentMissing),
+                )?
             };
 
             cs.enforce(
                 || "new_xL = xR + (xL + Ci)^3",
                 |lc| lc + tmp,
                 |lc| lc + xl + (self.constants[i], CS::one()),
-                |lc| lc + new_xl - xr
+                |lc| lc + new_xl - xr,
             );
 
             // xR = xL
@@ -172,7 +153,9 @@ fn test_mimc() {
     let rng = &mut thread_rng();
 
     // Generate the MiMC round constants
-    let constants = (0..MIMC_ROUNDS).map(|_| rng.gen()).collect::<Vec<_>>();
+    let constants = (0..MIMC_ROUNDS)
+        .map(|_| <Bls12 as ScalarEngine>::Fr::random(rng))
+        .collect::<Vec<_>>();
 
     println!("Creating parameters...");
 
@@ -181,7 +164,7 @@ fn test_mimc() {
         let c = MiMCDemo::<Bls12> {
             xl: None,
             xr: None,
-            constants: &constants
+            constants: &constants,
         };
 
         generate_random_parameters(c, rng).unwrap()
@@ -203,8 +186,8 @@ fn test_mimc() {
 
     for _ in 0..SAMPLES {
         // Generate a random preimage and compute the image
-        let xl = rng.gen();
+        let xl = <Bls12 as ScalarEngine>::Fr::random(rng);
-        let xr = rng.gen();
+        let xr = <Bls12 as ScalarEngine>::Fr::random(rng);
         let image = mimc::<Bls12>(xl, xr, &constants);
 
         proof_vec.truncate(0);
@@ -216,7 +199,7 @@ fn test_mimc() {
             let c = MiMCDemo {
                 xl: Some(xl),
                 xr: Some(xr),
-                constants: &constants
+                constants: &constants,
             };
 
             // Create a groth16 proof with our parameters.
@@ -230,20 +213,16 @@ fn test_mimc() {
         let start = Instant::now();
         let proof = Proof::read(&proof_vec[..]).unwrap();
         // Check the proof
-        assert!(verify_proof(
+        assert!(verify_proof(&pvk, &proof, &[image]).unwrap());
-            &pvk,
-            &proof,
-            &[image]
-        ).unwrap());
         total_verifying += start.elapsed();
     }
     let proving_avg = total_proving / SAMPLES;
-    let proving_avg = proving_avg.subsec_nanos() as f64 / 1_000_000_000f64
+    let proving_avg =
-                      + (proving_avg.as_secs() as f64);
+        proving_avg.subsec_nanos() as f64 / 1_000_000_000f64 + (proving_avg.as_secs() as f64);
 
     let verifying_avg = total_verifying / SAMPLES;
-    let verifying_avg = verifying_avg.subsec_nanos() as f64 / 1_000_000_000f64
+    let verifying_avg =
-                      + (verifying_avg.as_secs() as f64);
+        verifying_avg.subsec_nanos() as f64 / 1_000_000_000f64 + (verifying_avg.as_secs() as f64);
 
     println!("Average proving time: {:?} seconds", proving_avg);
     println!("Average verifying time: {:?} seconds", verifying_avg);

ff/Cargo.toml

@@ -1,18 +1,23 @@
 [package]
 name = "ff"
-version = "0.4.0"
+version = "0.5.2"
 authors = ["Sean Bowe <ewillbefull@gmail.com>"]
 description = "Library for building and interfacing with finite fields"
+readme = "README.md"
 documentation = "https://docs.rs/ff/"
 homepage = "https://github.com/ebfull/ff"
 license = "MIT/Apache-2.0"
 repository = "https://github.com/ebfull/ff"
+edition = "2018"
 
 [dependencies]
 byteorder = "1"
-rand = "0.4"
+ff_derive = { version = "^0.4.1", path = "ff_derive", optional = true }
-ff_derive = { version = "0.3.0", path = "ff_derive", optional = true }
+rand_core = "0.5"
 
 [features]
 default = []
 derive = ["ff_derive"]
+
+[badges]
+maintenance = { status = "actively-developed" }

ff/README.md

@@ -12,14 +12,18 @@ Add the `ff` crate to your `Cargo.toml`:
 
 ```toml
 [dependencies]
-ff = "0.4"
+ff = "0.5"
 ```
 
-The `ff` crate contains `Field`, `PrimeField`, `PrimeFieldRepr` and `SqrtField` traits. See the **[documentation](https://docs.rs/ff/0.4.0/ff/)** for more.
+The `ff` crate contains `Field`, `PrimeField`, `PrimeFieldRepr` and `SqrtField` traits.
+See the **[documentation](https://docs.rs/ff/)** for more.
 
 ### #![derive(PrimeField)]
 
-If you need an implementation of a prime field, this library also provides a procedural macro that will expand into an efficient implementation of a prime field when supplied with the modulus. `PrimeFieldGenerator` must be an element of Fp of p-1 order, that is also quadratic nonresidue.
+If you need an implementation of a prime field, this library also provides a procedural
+macro that will expand into an efficient implementation of a prime field when supplied
+with the modulus. `PrimeFieldGenerator` must be an element of Fp of p-1 order, that is
+also quadratic nonresidue.
 
 First, enable the `derive` crate feature:
 
@@ -41,13 +45,16 @@ extern crate ff;
 struct Fp(FpRepr);
 ```
 
-And that's it! `Fp` now implements `Field` and `PrimeField`. `Fp` will also implement `SqrtField` if supported. The library implements `FpRepr` itself and derives `PrimeFieldRepr` for it.
+And that's it! `Fp` now implements `Field` and `PrimeField`. `Fp` will also implement
+`SqrtField` if supported. The library implements `FpRepr` itself and derives
+`PrimeFieldRepr` for it.
 
 ## License
 
 Licensed under either of
 
- * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
+   http://www.apache.org/licenses/LICENSE-2.0)
  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 
 at your option.

ff/ff_derive/Cargo.toml

@@ -1,12 +1,13 @@
 [package]
 name = "ff_derive"
-version = "0.3.0"
+version = "0.4.1"
 authors = ["Sean Bowe <ewillbefull@gmail.com>"]
 description = "Procedural macro library used to build custom prime field implementations"
 documentation = "https://docs.rs/ff/"
 homepage = "https://github.com/ebfull/ff"
 license = "MIT/Apache-2.0"
 repository = "https://github.com/ebfull/ff"
+edition = "2018"
 
 [lib]
 proc-macro = true
@@ -15,6 +16,9 @@ proc-macro = true
 num-bigint = "0.2"
 num-traits = "0.2"
 num-integer = "0.1"
-proc-macro2 = "0.4"
+proc-macro2 = "1"
-quote = "0.6"
+quote = "1"
-syn = "0.14"
+syn = "1"
+
+[badges]
+maintenance = { status = "passively-maintained" }

ff/ff_derive/src/lib.rs

@@ -2,17 +2,11 @@
 
 extern crate proc_macro;
 extern crate proc_macro2;
-extern crate syn;
-#[macro_use]
-extern crate quote;
-
-extern crate num_bigint;
-extern crate num_integer;
-extern crate num_traits;
 
 use num_bigint::BigUint;
 use num_integer::Integer;
 use num_traits::{One, ToPrimitive, Zero};
+use quote::quote;
 use quote::TokenStreamExt;
 use std::str::FromStr;
 
@@ -52,13 +46,8 @@ pub fn prime_field(input: proc_macro::TokenStream) -> proc_macro::TokenStream {
 
     let mut gen = proc_macro2::TokenStream::new();
 
-    let (constants_impl, sqrt_impl) = prime_field_constants_and_sqrt(
+    let (constants_impl, sqrt_impl) =
-        &ast.ident,
+        prime_field_constants_and_sqrt(&ast.ident, &repr_ident, modulus, limbs, generator);
-        &repr_ident,
-        modulus,
-        limbs,
-        generator,
-    );
 
     gen.extend(constants_impl);
     gen.extend(prime_field_repr_impl(&repr_ident, limbs));
@@ -96,10 +85,10 @@ fn fetch_wrapped_ident(body: &syn::Data) -> Option<syn::Ident> {
 /// Fetch an attribute string from the derived struct.
 fn fetch_attr(name: &str, attrs: &[syn::Attribute]) -> Option<String> {
     for attr in attrs {
-        if let Some(meta) = attr.interpret_meta() {
+        if let Ok(meta) = attr.parse_meta() {
             match meta {
                 syn::Meta::NameValue(nv) => {
-                    if nv.ident.to_string() == name {
+                    if nv.path.get_ident().map(|i| i.to_string()) == Some(name.to_string()) {
                         match nv.lit {
                             syn::Lit::Str(ref s) => return Some(s.value()),
                             _ => {
@@ -127,27 +116,20 @@ fn prime_field_repr_impl(repr: &syn::Ident, limbs: usize) -> proc_macro2::TokenS
         impl ::std::fmt::Debug for #repr
         {
             fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
-                try!(write!(f, "0x"));
+                write!(f, "0x")?;
                 for i in self.0.iter().rev() {
-                    try!(write!(f, "{:016x}", *i));
+                    write!(f, "{:016x}", *i)?;
                 }
 
                 Ok(())
             }
         }
 
-        impl ::rand::Rand for #repr {
-            #[inline(always)]
-            fn rand<R: ::rand::Rng>(rng: &mut R) -> Self {
-                #repr(rng.gen())
-            }
-        }
-
         impl ::std::fmt::Display for #repr {
             fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
-                try!(write!(f, "0x"));
+                write!(f, "0x")?;
                 for i in self.0.iter().rev() {
-                    try!(write!(f, "{:016x}", *i));
+                    write!(f, "{:016x}", *i)?;
                 }
 
                 Ok(())
@@ -366,7 +348,8 @@ fn biguint_num_bits(mut v: BigUint) -> u32 {
 fn exp(base: BigUint, exp: &BigUint, modulus: &BigUint) -> BigUint {
     let mut ret = BigUint::one();
 
-    for i in exp.to_bytes_be()
+    for i in exp
+        .to_bytes_be()
         .into_iter()
         .flat_map(|x| (0..8).rev().map(move |i| (x >> i).is_odd()))
     {
@@ -387,11 +370,13 @@ fn test_exp() {
             &BigUint::from_str("5489673498567349856734895").unwrap(),
             &BigUint::from_str(
                 "52435875175126190479447740508185965837690552500527637822603658699938581184513"
-            ).unwrap()
+            )
+            .unwrap()
         ),
         BigUint::from_str(
             "4371221214068404307866768905142520595925044802278091865033317963560480051536"
-        ).unwrap()
+        )
+        .unwrap()
     );
 }
 
@@ -430,7 +415,7 @@ fn prime_field_constants_and_sqrt(
 
     let mod_minus_1_over_2 =
         biguint_to_u64_vec((&modulus - BigUint::from_str("1").unwrap()) >> 1, limbs);
-    let legendre_impl = quote!{
+    let legendre_impl = quote! {
         fn legendre(&self) -> ::ff::LegendreSymbol {
             // s = self^((modulus - 1) // 2)
             let s = self.pow(#mod_minus_1_over_2);
@@ -452,7 +437,7 @@ fn prime_field_constants_and_sqrt(
             // Compute -R as (m - r)
             let rneg = biguint_to_u64_vec(&modulus - &r, limbs);
 
-            quote!{
+            quote! {
                 impl ::ff::SqrtField for #name {
                     #legendre_impl
 
@@ -479,7 +464,7 @@ fn prime_field_constants_and_sqrt(
             let t_plus_1_over_2 = biguint_to_u64_vec((&t + BigUint::one()) >> 1, limbs);
             let t = biguint_to_u64_vec(t.clone(), limbs);
 
-            quote!{
+            quote! {
                 impl ::ff::SqrtField for #name {
                     #legendre_impl
 
@@ -526,7 +511,7 @@ fn prime_field_constants_and_sqrt(
                 }
             }
         } else {
-            quote!{}
+            quote! {}
         };
 
     // Compute R^2 mod m
@@ -543,36 +528,39 @@ fn prime_field_constants_and_sqrt(
     }
     inv = inv.wrapping_neg();
 
-    (quote! {
+    (
-        /// This is the modulus m of the prime field
+        quote! {
-        const MODULUS: #repr = #repr([#(#modulus,)*]);
+            /// This is the modulus m of the prime field
+            const MODULUS: #repr = #repr([#(#modulus,)*]);
 
-        /// The number of bits needed to represent the modulus.
+            /// The number of bits needed to represent the modulus.
-        const MODULUS_BITS: u32 = #modulus_num_bits;
+            const MODULUS_BITS: u32 = #modulus_num_bits;
 
-        /// The number of bits that must be shaved from the beginning of
+            /// The number of bits that must be shaved from the beginning of
-        /// the representation when randomly sampling.
+            /// the representation when randomly sampling.
-        const REPR_SHAVE_BITS: u32 = #repr_shave_bits;
+            const REPR_SHAVE_BITS: u32 = #repr_shave_bits;
 
-        /// 2^{limbs*64} mod m
+            /// 2^{limbs*64} mod m
-        const R: #repr = #repr(#r);
+            const R: #repr = #repr(#r);
 
-        /// 2^{limbs*64*2} mod m
+            /// 2^{limbs*64*2} mod m
-        const R2: #repr = #repr(#r2);
+            const R2: #repr = #repr(#r2);
 
-        /// -(m^{-1} mod m) mod m
+            /// -(m^{-1} mod m) mod m
-        const INV: u64 = #inv;
+            const INV: u64 = #inv;
 
-        /// Multiplicative generator of `MODULUS` - 1 order, also quadratic
+            /// Multiplicative generator of `MODULUS` - 1 order, also quadratic
-        /// nonresidue.
+            /// nonresidue.
-        const GENERATOR: #repr = #repr(#generator);
+            const GENERATOR: #repr = #repr(#generator);
 
-        /// 2^s * t = MODULUS - 1 with t odd
+            /// 2^s * t = MODULUS - 1 with t odd
-        const S: u32 = #s;
+            const S: u32 = #s;
 
-        /// 2^s root of unity computed by GENERATOR^t
+            /// 2^s root of unity computed by GENERATOR^t
-        const ROOT_OF_UNITY: #repr = #repr(#root_of_unity);
+            const ROOT_OF_UNITY: #repr = #repr(#root_of_unity);
-    }, sqrt_impl)
+        },
+        sqrt_impl,
+    )
 }
 
 /// Implement PrimeField for the derived type.
@@ -592,9 +580,9 @@ fn prime_field_impl(
     mont_paramlist.append_separated(
         (0..(limbs * 2)).map(|i| (i, get_temp(i))).map(|(i, x)| {
             if i != 0 {
-                quote!{mut #x: u64}
+                quote! {mut #x: u64}
             } else {
-                quote!{#x: u64}
+                quote! {#x: u64}
             }
         }),
         proc_macro2::Punct::new(',', proc_macro2::Spacing::Alone),
@@ -607,7 +595,7 @@ fn prime_field_impl(
         for i in 0..limbs {
             {
                 let temp = get_temp(i);
-                gen.extend(quote!{
+                gen.extend(quote! {
                     let k = #temp.wrapping_mul(INV);
                     let mut carry = 0;
                     ::ff::mac_with_carry(#temp, k, MODULUS.0[0], &mut carry);
@@ -616,7 +604,7 @@ fn prime_field_impl(
 
             for j in 1..limbs {
                 let temp = get_temp(i + j);
-                gen.extend(quote!{
+                gen.extend(quote! {
                     #temp = ::ff::mac_with_carry(#temp, k, MODULUS.0[#j], &mut carry);
                 });
             }
@@ -624,17 +612,17 @@ fn prime_field_impl(
             let temp = get_temp(i + limbs);
 
             if i == 0 {
-                gen.extend(quote!{
+                gen.extend(quote! {
                     #temp = ::ff::adc(#temp, 0, &mut carry);
                 });
             } else {
-                gen.extend(quote!{
+                gen.extend(quote! {
                     #temp = ::ff::adc(#temp, carry2, &mut carry);
                 });
             }
 
             if i != (limbs - 1) {
-                gen.extend(quote!{
+                gen.extend(quote! {
                     let carry2 = carry;
                 });
             }
@@ -643,7 +631,7 @@ fn prime_field_impl(
         for i in 0..limbs {
             let temp = get_temp(limbs + i);
 
-            gen.extend(quote!{
+            gen.extend(quote! {
                 (self.0).0[#i] = #temp;
             });
         }
@@ -655,14 +643,14 @@ fn prime_field_impl(
         let mut gen = proc_macro2::TokenStream::new();
 
         for i in 0..(limbs - 1) {
-            gen.extend(quote!{
+            gen.extend(quote! {
                 let mut carry = 0;
             });
 
             for j in (i + 1)..limbs {
                 let temp = get_temp(i + j);
                 if i == 0 {
-                    gen.extend(quote!{
+                    gen.extend(quote! {
                         let #temp = ::ff::mac_with_carry(0, (#a.0).0[#i], (#a.0).0[#j], &mut carry);
                     });
                 } else {
@@ -674,7 +662,7 @@ fn prime_field_impl(
 
             let temp = get_temp(i + limbs);
 
-            gen.extend(quote!{
+            gen.extend(quote! {
                 let #temp = carry;
             });
         }
@@ -684,21 +672,21 @@ fn prime_field_impl(
             let temp1 = get_temp(limbs * 2 - i - 1);
 
             if i == 1 {
-                gen.extend(quote!{
+                gen.extend(quote! {
                     let #temp0 = #temp1 >> 63;
                 });
             } else if i == (limbs * 2 - 1) {
-                gen.extend(quote!{
+                gen.extend(quote! {
                     let #temp0 = #temp0 << 1;
                 });
             } else {
-                gen.extend(quote!{
+                gen.extend(quote! {
                     let #temp0 = (#temp0 << 1) | (#temp1 >> 63);
                 });
             }
         }
 
-        gen.extend(quote!{
+        gen.extend(quote! {
             let mut carry = 0;
         });
 
@@ -706,7 +694,7 @@ fn prime_field_impl(
             let temp0 = get_temp(i * 2);
             let temp1 = get_temp(i * 2 + 1);
             if i == 0 {
-                gen.extend(quote!{
+                gen.extend(quote! {
                     let #temp0 = ::ff::mac_with_carry(0, (#a.0).0[#i], (#a.0).0[#i], &mut carry);
                 });
             } else {
@@ -715,7 +703,7 @@ fn prime_field_impl(
                 });
             }
 
-            gen.extend(quote!{
+            gen.extend(quote! {
                 let #temp1 = ::ff::adc(#temp1, 0, &mut carry);
             });
         }
@@ -726,7 +714,7 @@ fn prime_field_impl(
             proc_macro2::Punct::new(',', proc_macro2::Spacing::Alone),
         );
 
-        gen.extend(quote!{
+        gen.extend(quote! {
             self.mont_reduce(#mont_calling);
         });
 
@@ -741,7 +729,7 @@ fn prime_field_impl(
         let mut gen = proc_macro2::TokenStream::new();
 
         for i in 0..limbs {
-            gen.extend(quote!{
+            gen.extend(quote! {
                 let mut carry = 0;
             });
 
@@ -749,7 +737,7 @@ fn prime_field_impl(
                 let temp = get_temp(i + j);
 
                 if i == 0 {
-                    gen.extend(quote!{
+                    gen.extend(quote! {
                         let #temp = ::ff::mac_with_carry(0, (#a.0).0[#i], (#b.0).0[#j], &mut carry);
                     });
                 } else {
@@ -761,7 +749,7 @@ fn prime_field_impl(
 
             let temp = get_temp(i + limbs);
 
-            gen.extend(quote!{
+            gen.extend(quote! {
                 let #temp = carry;
             });
         }
@@ -772,29 +760,29 @@ fn prime_field_impl(
             proc_macro2::Punct::new(',', proc_macro2::Spacing::Alone),
         );
 
-        gen.extend(quote!{
+        gen.extend(quote! {
             self.mont_reduce(#mont_calling);
         });
 
         gen
     }
 
-    let squaring_impl = sqr_impl(quote!{self}, limbs);
+    let squaring_impl = sqr_impl(quote! {self}, limbs);
-    let multiply_impl = mul_impl(quote!{self}, quote!{other}, limbs);
+    let multiply_impl = mul_impl(quote! {self}, quote! {other}, limbs);
     let montgomery_impl = mont_impl(limbs);
 
     // (self.0).0[0], (self.0).0[1], ..., 0, 0, 0, 0, ...
     let mut into_repr_params = proc_macro2::TokenStream::new();
     into_repr_params.append_separated(
         (0..limbs)
-            .map(|i| quote!{ (self.0).0[#i] })
+            .map(|i| quote! { (self.0).0[#i] })
-            .chain((0..limbs).map(|_| quote!{0})),
+            .chain((0..limbs).map(|_| quote! {0})),
         proc_macro2::Punct::new(',', proc_macro2::Spacing::Alone),
     );
 
     let top_limb_index = limbs - 1;
 
-    quote!{
+    quote! {
         impl ::std::marker::Copy for #name { }
 
         impl ::std::clone::Clone for #name {
@@ -839,22 +827,6 @@ fn prime_field_impl(
             }
         }
 
-        impl ::rand::Rand for #name {
-            /// Computes a uniformly random element using rejection sampling.
-            fn rand<R: ::rand::Rng>(rng: &mut R) -> Self {
-                loop {
-                    let mut tmp = #name(#repr::rand(rng));
-
-                    // Mask away the unused bits at the beginning.
-                    tmp.0.as_mut()[#top_limb_index] &= 0xffffffffffffffff >> REPR_SHAVE_BITS;
-
-                    if tmp.is_valid() {
-                        return tmp
-                    }
-                }
-            }
-        }
-
         impl From<#name> for #repr {
             fn from(e: #name) -> #repr {
                 e.into_repr()
@@ -904,6 +876,26 @@ fn prime_field_impl(
         }
 
         impl ::ff::Field for #name {
+            /// Computes a uniformly random element using rejection sampling.
+            fn random<R: ::rand_core::RngCore + ?std::marker::Sized>(rng: &mut R) -> Self {
+                loop {
+                    let mut tmp = {
+                        let mut repr = [0u64; #limbs];
+                        for i in 0..#limbs {
+                            repr[i] = rng.next_u64();
+                        }
+                        #name(#repr(repr))
+                    };
+
+                    // Mask away the unused most-significant bits.
+                    tmp.0.as_mut()[#top_limb_index] &= 0xffffffffffffffff >> REPR_SHAVE_BITS;
+
+                    if tmp.is_valid() {
+                        return tmp
+                    }
+                }
+            }
+
             #[inline]
             fn zero() -> Self {
                 #name(#repr::from(0))

ff/src/lib.rs

@@ -1,23 +1,24 @@
+//! This crate provides traits for working with finite fields.
+
+// Catch documentation errors caused by code changes.
+#![deny(intra_doc_link_resolution_failure)]
 #![allow(unused_imports)]
 
-extern crate byteorder;
-extern crate rand;
-
-#[cfg(feature = "derive")]
-#[macro_use]
-extern crate ff_derive;
-
 #[cfg(feature = "derive")]
 pub use ff_derive::*;
 
+use rand_core::RngCore;
 use std::error::Error;
 use std::fmt;
 use std::io::{self, Read, Write};
 
 /// This trait represents an element of a field.
 pub trait Field:
-    Sized + Eq + Copy + Clone + Send + Sync + fmt::Debug + fmt::Display + 'static + rand::Rand
+    Sized + Eq + Copy + Clone + Send + Sync + fmt::Debug + fmt::Display + 'static
 {
+    /// Returns an element chosen uniformly at random using a user-provided RNG.
+    fn random<R: RngCore + ?std::marker::Sized>(rng: &mut R) -> Self;
+
     /// Returns the zero element of the field, the additive identity.
     fn zero() -> Self;
 
@@ -100,7 +101,6 @@ pub trait PrimeFieldRepr:
     + fmt::Debug
     + fmt::Display
     + 'static
-    + rand::Rand
     + AsRef<[u64]>
     + AsMut<[u64]>
     + From<u64>
@@ -207,7 +207,7 @@ impl Error for PrimeFieldDecodingError {
 }
 
 impl fmt::Display for PrimeFieldDecodingError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
         match *self {
             PrimeFieldDecodingError::NotInField(ref repr) => {
                 write!(f, "{} is not an element of the field", repr)
@@ -263,7 +263,7 @@ pub trait PrimeField: Field {
     }
 
     /// Convert this prime field element into a biginteger representation.
-    fn from_repr(Self::Repr) -> Result<Self, PrimeFieldDecodingError>;
+    fn from_repr(_: Self::Repr) -> Result<Self, PrimeFieldDecodingError>;
 
     /// Convert a biginteger representation into a prime field element, if
     /// the number is an element of the field.

group/Cargo.toml

@@ -1,17 +1,23 @@
 [package]
 name = "group"
-version = "0.1.0"
+version = "0.2.0"
 authors = [
     "Sean Bowe <ewillbefull@gmail.com>",
     "Jack Grigg <jack@z.cash>",
 ]
+readme = "README.md"
 license = "MIT/Apache-2.0"
 
 description = "Elliptic curve group traits and utilities"
 documentation = "https://docs.rs/group/"
 homepage = "https://github.com/ebfull/group"
 repository = "https://github.com/ebfull/group"
+edition = "2018"
 
 [dependencies]
-ff = { path = "../ff" }
+ff = { version = "0.5.0", path = "../ff" }
-rand = "0.4"
+rand = "0.7"
+rand_xorshift = "0.2"
+
+[badges]
+maintenance = { status = "actively-developed" }

group/README.md

@@ -1,10 +1,13 @@
 # group [![Crates.io](https://img.shields.io/crates/v/group.svg)](https://crates.io/crates/group) #
 
+`group` is a crate for working with groups over elliptic curves.
+
 ## License
 
 Licensed under either of
 
- * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
+   http://www.apache.org/licenses/LICENSE-2.0)
  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 
 at your option.

group/src/lib.rs

@@ -1,7 +1,8 @@
-extern crate ff;
+// Catch documentation errors caused by code changes.
-extern crate rand;
+#![deny(intra_doc_link_resolution_failure)]
 
 use ff::{PrimeField, PrimeFieldDecodingError, ScalarEngine, SqrtField};
+use rand::RngCore;
 use std::error::Error;
 use std::fmt;
 
@@ -13,23 +14,16 @@ pub use self::wnaf::Wnaf;
 /// Projective representation of an elliptic curve point guaranteed to be
 /// in the correct prime order subgroup.
 pub trait CurveProjective:
-    PartialEq
+    PartialEq + Eq + Sized + Copy + Clone + Send + Sync + fmt::Debug + fmt::Display + 'static
-    + Eq
-    + Sized
-    + Copy
-    + Clone
-    + Send
-    + Sync
-    + fmt::Debug
-    + fmt::Display
-    + rand::Rand
-    + 'static
 {
     type Engine: ScalarEngine<Fr = Self::Scalar>;
     type Scalar: PrimeField + SqrtField;
     type Base: SqrtField;
     type Affine: CurveAffine<Projective = Self, Scalar = Self::Scalar>;
 
+    /// Returns an element chosen uniformly at random using a user-provided RNG.
+    fn random<R: RngCore>(rng: &mut R) -> Self;
+
     /// Returns the additive identity.
     fn zero() -> Self;
 
@@ -185,7 +179,7 @@ impl Error for GroupDecodingError {
 }
 
 impl fmt::Display for GroupDecodingError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
         match *self {
             GroupDecodingError::CoordinateDecodingError(description, ref err) => {
                 write!(f, "{} decoding error: {}", description, err)

group/src/tests/mod.rs

@@ -1,9 +1,14 @@
-use rand::{Rand, Rng, SeedableRng, XorShiftRng};
+use ff::{Field, PrimeField};
+use rand::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
-use {CurveAffine, CurveProjective, EncodedPoint};
+use crate::{CurveAffine, CurveProjective, EncodedPoint};
 
 pub fn curve_tests<G: CurveProjective>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     // Negation edge case with zero.
     {
@@ -21,7 +26,7 @@ pub fn curve_tests<G: CurveProjective>() {
 
     // Addition edge cases with zero
     {
-        let mut r = G::rand(&mut rng);
+        let mut r = G::random(&mut rng);
         let rcopy = r;
         r.add_assign(&G::zero());
         assert_eq!(r, rcopy);
@@ -45,9 +50,10 @@ pub fn curve_tests<G: CurveProjective>() {
 
     // Transformations
     {
-        let a = G::rand(&mut rng);
+        let a = G::random(&mut rng);
         let b = a.into_affine().into_projective();
-        let c = a.into_affine()
+        let c = a
+            .into_affine()
             .into_projective()
             .into_affine()
             .into_projective();
@@ -65,11 +71,12 @@ pub fn curve_tests<G: CurveProjective>() {
 }
 
 fn random_wnaf_tests<G: CurveProjective>() {
-    use ff::PrimeField;
+    use crate::wnaf::*;
 
-    use wnaf::*;
+    let mut rng = XorShiftRng::from_seed([
-
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        0xe5,
+    ]);
 
     {
         let mut table = vec![];
@@ -77,8 +84,8 @@ fn random_wnaf_tests<G: CurveProjective>() {
 
         for w in 2..14 {
             for _ in 0..100 {
-                let g = G::rand(&mut rng);
+                let g = G::random(&mut rng);
-                let s = G::Scalar::rand(&mut rng).into_repr();
+                let s = G::Scalar::random(&mut rng).into_repr();
                 let mut g1 = g;
                 g1.mul_assign(s);
 
@@ -95,8 +102,8 @@ fn random_wnaf_tests<G: CurveProjective>() {
         fn only_compiles_if_send<S: Send>(_: &S) {}
 
         for _ in 0..100 {
-            let g = G::rand(&mut rng);
+            let g = G::random(&mut rng);
-            let s = G::Scalar::rand(&mut rng).into_repr();
+            let s = G::Scalar::random(&mut rng).into_repr();
             let mut g1 = g;
             g1.mul_assign(s);
 
@@ -129,7 +136,8 @@ fn random_wnaf_tests<G: CurveProjective>() {
                 let mut wnaf = Wnaf::new();
                 {
                     // Populate the vectors.
-                    wnaf.base(rng.gen(), 1).scalar(rng.gen());
+                    wnaf.base(G::random(&mut rng), 1)
+                        .scalar(G::Scalar::random(&mut rng).into_repr());
                 }
                 wnaf.base(g, 1).scalar(s)
             };
@@ -137,7 +145,8 @@ fn random_wnaf_tests<G: CurveProjective>() {
                 let mut wnaf = Wnaf::new();
                 {
                     // Populate the vectors.
-                    wnaf.base(rng.gen(), 1).scalar(rng.gen());
+                    wnaf.base(G::random(&mut rng), 1)
+                        .scalar(G::Scalar::random(&mut rng).into_repr());
                 }
                 wnaf.scalar(s).base(g)
             };
@@ -145,7 +154,8 @@ fn random_wnaf_tests<G: CurveProjective>() {
                 let mut wnaf = Wnaf::new();
                 {
                     // Populate the vectors.
-                    wnaf.base(rng.gen(), 1).scalar(rng.gen());
+                    wnaf.base(G::random(&mut rng), 1)
+                        .scalar(G::Scalar::random(&mut rng).into_repr());
                 }
                 let mut shared = wnaf.base(g, 1).shared();
 
@@ -157,7 +167,8 @@ fn random_wnaf_tests<G: CurveProjective>() {
                 let mut wnaf = Wnaf::new();
                 {
                     // Populate the vectors.
-                    wnaf.base(rng.gen(), 1).scalar(rng.gen());
+                    wnaf.base(G::random(&mut rng), 1)
+                        .scalar(G::Scalar::random(&mut rng).into_repr());
                 }
                 let mut shared = wnaf.scalar(s).shared();
 
@@ -179,14 +190,15 @@ fn random_wnaf_tests<G: CurveProjective>() {
 }
 
 fn random_negation_tests<G: CurveProjective>() {
-    use ff::Field;
+    let mut rng = XorShiftRng::from_seed([
-
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let r = G::rand(&mut rng);
+        let r = G::random(&mut rng);
 
-        let s = G::Scalar::rand(&mut rng);
+        let s = G::Scalar::random(&mut rng);
         let mut sneg = s;
         sneg.negate();
 
@@ -210,11 +222,14 @@ fn random_negation_tests<G: CurveProjective>() {
 }
 
 fn random_doubling_tests<G: CurveProjective>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let mut a = G::rand(&mut rng);
+        let mut a = G::random(&mut rng);
-        let mut b = G::rand(&mut rng);
+        let mut b = G::random(&mut rng);
 
         // 2(a + b)
         let mut tmp1 = a;
@@ -237,15 +252,18 @@ fn random_doubling_tests<G: CurveProjective>() {
 }
 
 fn random_multiplication_tests<G: CurveProjective>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let mut a = G::rand(&mut rng);
+        let mut a = G::random(&mut rng);
-        let mut b = G::rand(&mut rng);
+        let mut b = G::random(&mut rng);
         let a_affine = a.into_affine();
         let b_affine = b.into_affine();
 
-        let s = G::Scalar::rand(&mut rng);
+        let s = G::Scalar::random(&mut rng);
 
         // s ( a + b )
         let mut tmp1 = a;
@@ -269,12 +287,15 @@ fn random_multiplication_tests<G: CurveProjective>() {
 }
 
 fn random_addition_tests<G: CurveProjective>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let a = G::rand(&mut rng);
+        let a = G::random(&mut rng);
-        let b = G::rand(&mut rng);
+        let b = G::random(&mut rng);
-        let c = G::rand(&mut rng);
+        let c = G::random(&mut rng);
         let a_affine = a.into_affine();
         let b_affine = b.into_affine();
         let c_affine = c.into_affine();
@@ -347,10 +368,13 @@ fn random_addition_tests<G: CurveProjective>() {
 }
 
 fn random_transformation_tests<G: CurveProjective>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let g = G::rand(&mut rng);
+        let g = G::random(&mut rng);
         let g_affine = g.into_affine();
         let g_projective = g_affine.into_projective();
         assert_eq!(g, g_projective);
@@ -358,24 +382,25 @@ fn random_transformation_tests<G: CurveProjective>() {
 
     // Batch normalization
     for _ in 0..10 {
-        let mut v = (0..1000).map(|_| G::rand(&mut rng)).collect::<Vec<_>>();
+        let mut v = (0..1000).map(|_| G::random(&mut rng)).collect::<Vec<_>>();
 
         for i in &v {
             assert!(!i.is_normalized());
         }
 
-        use rand::distributions::{IndependentSample, Range};
+        use rand::distributions::{Distribution, Uniform};
-        let between = Range::new(0, 1000);
+        let between = Uniform::new(0, 1000);
         // Sprinkle in some normalized points
         for _ in 0..5 {
-            v[between.ind_sample(&mut rng)] = G::zero();
+            v[between.sample(&mut rng)] = G::zero();
         }
         for _ in 0..5 {
-            let s = between.ind_sample(&mut rng);
+            let s = between.sample(&mut rng);
             v[s] = v[s].into_affine().into_projective();
         }
 
-        let expected_v = v.iter()
+        let expected_v = v
+            .iter()
             .map(|v| v.into_affine().into_projective())
             .collect::<Vec<_>>();
         G::batch_normalization(&mut v);
@@ -389,7 +414,10 @@ fn random_transformation_tests<G: CurveProjective>() {
 }
 
 fn random_encoding_tests<G: CurveAffine>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     assert_eq!(
         G::zero().into_uncompressed().into_affine().unwrap(),
@@ -402,7 +430,7 @@ fn random_encoding_tests<G: CurveAffine>() {
     );
 
     for _ in 0..1000 {
-        let mut r = G::Projective::rand(&mut rng).into_affine();
+        let mut r = G::Projective::random(&mut rng).into_affine();
 
         let uncompressed = r.into_uncompressed();
         let de_uncompressed = uncompressed.into_affine().unwrap();

librustzcash/Cargo.toml

@@ -1,12 +1,18 @@
 [package]
 name = "librustzcash"
-version = "0.1.0"
+description = "Rust FFI used by the zcashd binary. Not an official API."
+version = "0.2.0"
 authors = [
     "Sean Bowe <ewillbefull@gmail.com>",
     "Jack Grigg <jack@z.cash>",
     "Jay Graber <jay@z.cash>",
     "Simon Liu <simon@z.cash>"
-    ]
+]
+homepage = "https://github.com/zcash/librustzcash"
+repository = "https://github.com/zcash/librustzcash"
+readme = "README.md"
+license = "MIT OR Apache-2.0"
+edition = "2018"
 
 [lib]
 name = "rustzcash"
@@ -14,18 +20,17 @@ path = "src/rustzcash.rs"
 crate-type = ["staticlib"]
 
 [dependencies]
-bellman = { path = "../bellman" }
+bellman = { version = "0.2.0", path = "../bellman" }
-ff = { path = "../ff" }
+blake2b_simd = "0.5"
+blake2s_simd = "0.5"
+ff = { version = "0.5.0", path = "../ff" }
 libc = "0.2"
-pairing = { path = "../pairing" }
+pairing = { version = "0.15.0", path = "../pairing" }
 lazy_static = "1"
-byteorder = "1"
+rand_core = "0.5.1"
-rand = "0.4"
+zcash_history = { version = "0.0.1", path = "../zcash_history" }
-sapling-crypto = { path = "../sapling-crypto" }
+zcash_primitives = { version = "0.1.0", path = "../zcash_primitives" }
-zcash_primitives = { path = "../zcash_primitives" }
+zcash_proofs = { version = "0.1.0", path = "../zcash_proofs" }
-zcash_proofs = { path = "../zcash_proofs" }
-zip32 = { path = "../zip32" }
 
-[dependencies.blake2-rfc]
+[badges]
-git = "https://github.com/gtank/blake2-rfc"
+maintenance = { status = "deprecated" }
-rev = "7a5b5fc99ae483a0043db7547fb79a6fa44b88a9"

librustzcash/README.md

@@ -1,12 +1,17 @@
 # librustzcash
 
-This repository contains librustzcash, a static library for Zcash code assets written in Rust.
+`librustzcash` is an FFI library crate that exposes the Zcash Rust components to
+the `zcashd` full node.
+
+The FFI API does not have any stability guarantees, and will change as required
+by `zcashd`.
 
 ## License
 
 Licensed under either of
 
- * Apache License, Version 2.0, ([LICENSE-APACHE](../LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * Apache License, Version 2.0, ([LICENSE-APACHE](../LICENSE-APACHE) or
+   http://www.apache.org/licenses/LICENSE-2.0)
  * MIT license ([LICENSE-MIT](../LICENSE-MIT) or http://opensource.org/licenses/MIT)
 
 at your option.

librustzcash/include/librustzcash.h

@@ -112,8 +112,7 @@ extern "C" {
     bool librustzcash_sapling_output_proof(
         void *ctx,
         const unsigned char *esk,
-        const unsigned char *diversifier,
+        const unsigned char *payment_address,
-        const unsigned char *pk_d,
         const unsigned char *rcm,
         const uint64_t value,
         unsigned char *cv,
@@ -308,6 +307,33 @@ extern "C" {
         unsigned char *j_ret,
         unsigned char *addr_ret
     );
+
+    uint32_t librustzcash_mmr_append(
+        uint32_t cbranch,
+        uint32_t t_len,
+        const uint32_t *ni_ptr,
+        const unsigned char *n_ptr,
+        size_t p_len,
+        const unsigned char *nn_ptr,
+        unsigned char *rt_ret,
+        unsigned char *buf_ret
+    );
+
+    uint32_t librustzcash_mmr_delete(
+        uint32_t cbranch,
+        uint32_t t_len,
+        const uint32_t *ni_ptr,
+        const unsigned char *n_ptr,
+        size_t p_len,
+        size_t e_len,
+        unsigned char *rt_ret
+    );
+
+    uint32_t librustzcash_mmr_hash_node(
+        uint32_t cbranch,
+        const unsigned char *n_ptr,
+        unsigned char *h_ret
+    );
 }
 
 #endif // LIBRUSTZCASH_INCLUDE_H_

librustzcash/src/tests/key_agreement.rs

@@ -1,10 +1,10 @@
 use ff::{PrimeField, PrimeFieldRepr};
 use pairing::bls12_381::Bls12;
-use rand::{OsRng, Rng};
+use rand_core::{OsRng, RngCore};
-use sapling_crypto::jubjub::{edwards, JubjubBls12};
+use zcash_primitives::jubjub::{edwards, JubjubBls12};
-use sapling_crypto::primitives::{Diversifier, ViewingKey};
+use zcash_primitives::primitives::{Diversifier, ViewingKey};
 
-use {
+use crate::{
     librustzcash_sapling_generate_r, librustzcash_sapling_ka_agree,
     librustzcash_sapling_ka_derivepublic,
 };
@@ -12,7 +12,7 @@ use {
 #[test]
 fn test_key_agreement() {
     let params = JubjubBls12::new();
-    let mut rng = OsRng::new().unwrap();
+    let mut rng = OsRng;
 
     // Create random viewing key
     let vk = ViewingKey::<Bls12> {
@@ -22,7 +22,9 @@ fn test_key_agreement() {
 
     // Create a random address with the viewing key
     let addr = loop {
-        match vk.into_payment_address(Diversifier(rng.gen()), &params) {
+        let mut d = [0; 11];
+        rng.fill_bytes(&mut d);
+        match vk.to_payment_address(Diversifier(d), &params) {
             Some(a) => break a,
             None => {}
         }
@@ -44,7 +46,7 @@ fn test_key_agreement() {
 
     // Serialize pk_d for the call to librustzcash_sapling_ka_agree
     let mut addr_pk_d = [0u8; 32];
-    addr.pk_d.write(&mut addr_pk_d[..]).unwrap();
+    addr.pk_d().write(&mut addr_pk_d[..]).unwrap();
 
     assert!(librustzcash_sapling_ka_agree(
         &addr_pk_d,
@@ -56,7 +58,7 @@ fn test_key_agreement() {
     // using the diversifier and esk.
     let mut epk = [0u8; 32];
     assert!(librustzcash_sapling_ka_derivepublic(
-        &addr.diversifier.0,
+        &addr.diversifier().0,
         &esk,
         &mut epk
     ));

librustzcash/src/tests/key_components.rs

@@ -1,13 +1,13 @@
 use ff::{PrimeField, PrimeFieldRepr};
 use pairing::bls12_381::Bls12;
-use sapling_crypto::{
+use zcash_primitives::{
     jubjub::{fs::FsRepr, FixedGenerators, JubjubEngine, JubjubParams},
     primitives::{Diversifier, ProofGenerationKey},
 };
 
 use super::JUBJUB;
 
-use {
+use crate::{
     librustzcash_ask_to_ak, librustzcash_check_diversifier, librustzcash_crh_ivk,
     librustzcash_ivk_to_pkd, librustzcash_nsk_to_nk,
 };
@@ -28,6 +28,8 @@ fn key_components() {
         note_v: u64,
         note_r: [u8; 32],
         note_cm: [u8; 32],
+        note_pos: u64,
+        note_nf: [u8; 32],
     };
 
     // From https://github.com/zcash-hackworks/zcash-test-vectors/blob/master/sapling_key_components.py
@@ -87,6 +89,12 @@ fn key_components() {
                 0x18, 0x50, 0xc9, 0xfe, 0xd4, 0x4f, 0xce, 0x08, 0x06, 0x27, 0x8f, 0x08, 0x3e, 0xf2,
                 0xdd, 0x07, 0x64, 0x39,
             ],
+            note_pos: 0,
+            note_nf: [
+                0x44, 0xfa, 0xd6, 0x56, 0x4f, 0xfd, 0xec, 0x9f, 0xa1, 0x9c, 0x43, 0xa2, 0x8f, 0x86,
+                0x1d, 0x5e, 0xbf, 0x60, 0x23, 0x46, 0x00, 0x7d, 0xe7, 0x62, 0x67, 0xd9, 0x75, 0x27,
+                0x47, 0xab, 0x40, 0x63,
+            ],
         },
         TestVector {
             sk: [
@@ -143,6 +151,12 @@ fn key_components() {
                 0x89, 0xe1, 0x0e, 0x26, 0x6b, 0xcf, 0xa3, 0x1c, 0x31, 0xb2, 0x9a, 0x53, 0xae, 0x72,
                 0xca, 0xd4, 0x69, 0x50,
             ],
+            note_pos: 763714296,
+            note_nf: [
+                0x67, 0x9e, 0xb0, 0xc3, 0xa7, 0x57, 0xe2, 0xae, 0x83, 0xcd, 0xb4, 0x2a, 0x1a, 0xb2,
+                0x59, 0xd7, 0x83, 0x88, 0x31, 0x54, 0x19, 0xad, 0xc7, 0x1d, 0x2e, 0x37, 0x63, 0x17,
+                0x4c, 0x2e, 0x9d, 0x93,
+            ],
         },
         TestVector {
             sk: [
@@ -199,6 +213,12 @@ fn key_components() {
                 0xb7, 0x40, 0x82, 0x96, 0x66, 0x17, 0x70, 0xb1, 0x01, 0xb0, 0xaa, 0x87, 0x83, 0x9f,
                 0x4e, 0x55, 0xf1, 0x51,
             ],
+            note_pos: 1527428592,
+            note_nf: [
+                0xe9, 0x8f, 0x6a, 0x8f, 0x34, 0xff, 0x49, 0x80, 0x59, 0xb3, 0xc7, 0x31, 0xb9, 0x1f,
+                0x45, 0x11, 0x08, 0xc4, 0x95, 0x4d, 0x91, 0x94, 0x84, 0x36, 0x1c, 0xf9, 0xb4, 0x8f,
+                0x59, 0xae, 0x1d, 0x14,
+            ],
         },
         TestVector {
             sk: [
@@ -255,6 +275,12 @@ fn key_components() {
                 0xbd, 0x10, 0x5d, 0x88, 0x39, 0x21, 0x2e, 0x0d, 0x16, 0x44, 0xb9, 0xd5, 0x5c, 0xaa,
                 0x60, 0xd1, 0x9b, 0x6c,
             ],
+            note_pos: 2291142888,
+            note_nf: [
+                0x55, 0x47, 0xaa, 0x12, 0xff, 0x80, 0xa6, 0xb3, 0x30, 0x4e, 0x3b, 0x05, 0x86, 0x56,
+                0x47, 0x2a, 0xbd, 0x2c, 0x81, 0x83, 0xb5, 0x9d, 0x07, 0x37, 0xb9, 0x3c, 0xee, 0x75,
+                0x8b, 0xec, 0x47, 0xa1,
+            ],
         },
         TestVector {
             sk: [
@@ -311,6 +337,12 @@ fn key_components() {
                 0xcf, 0x1e, 0x67, 0x15, 0xbf, 0xe7, 0x0b, 0x63, 0x2d, 0x04, 0x4b, 0x26, 0xfb, 0x2b,
                 0xc7, 0x1b, 0x7f, 0x36,
             ],
+            note_pos: 3054857184,
+            note_nf: [
+                0x8a, 0x9a, 0xbd, 0xa3, 0xd4, 0xef, 0x85, 0xca, 0xf2, 0x2b, 0xfa, 0xf2, 0xc4, 0x8f,
+                0x62, 0x38, 0x2a, 0x73, 0xa1, 0x62, 0x4e, 0xb8, 0xeb, 0x2b, 0xd0, 0x0d, 0x27, 0x03,
+                0x01, 0xbf, 0x3d, 0x13,
+            ],
         },
         TestVector {
             sk: [
@@ -367,6 +399,12 @@ fn key_components() {
                 0x1d, 0x74, 0xc5, 0xbc, 0xf2, 0xe1, 0xef, 0x95, 0x66, 0x90, 0x44, 0x73, 0x01, 0x69,
                 0xde, 0x1a, 0x5b, 0x4c,
             ],
+            note_pos: 3818571480,
+            note_nf: [
+                0x33, 0x2a, 0xd9, 0x9e, 0xb9, 0xe9, 0x77, 0xeb, 0x62, 0x7a, 0x12, 0x2d, 0xbf, 0xb2,
+                0xf2, 0x5f, 0xe5, 0x88, 0xe5, 0x97, 0x75, 0x3e, 0xc5, 0x58, 0x0f, 0xf2, 0xbe, 0x20,
+                0xb6, 0xc9, 0xa7, 0xe1,
+            ],
         },
         TestVector {
             sk: [
@@ -423,6 +461,12 @@ fn key_components() {
                 0x90, 0xb6, 0xe0, 0xf2, 0xf4, 0xbf, 0x4e, 0xc4, 0xa0, 0xdb, 0x5b, 0xbc, 0xcb, 0x5b,
                 0x78, 0x3a, 0x1e, 0x55,
             ],
+            note_pos: 287318480,
+            note_nf: [
+                0xfc, 0x74, 0xcd, 0x0e, 0x4b, 0xe0, 0x49, 0x57, 0xb1, 0x96, 0xcf, 0x87, 0x34, 0xae,
+                0x99, 0x23, 0x96, 0xaf, 0x4c, 0xfa, 0x8f, 0xec, 0xbb, 0x86, 0xf9, 0x61, 0xe6, 0xb4,
+                0x07, 0xd5, 0x1e, 0x11,
+            ],
         },
         TestVector {
             sk: [
@@ -479,6 +523,12 @@ fn key_components() {
                 0x60, 0xa0, 0x06, 0xf8, 0x2b, 0xb7, 0xad, 0xcd, 0x75, 0x22, 0x3f, 0xa8, 0x59, 0x36,
                 0xf7, 0x8c, 0x2b, 0x23,
             ],
+            note_pos: 1051032776,
+            note_nf: [
+                0xd2, 0xe8, 0x87, 0xbd, 0x85, 0x4a, 0x80, 0x2b, 0xce, 0x85, 0x70, 0x53, 0x02, 0x0f,
+                0x5d, 0x3e, 0x7c, 0x8a, 0xe5, 0x26, 0x7c, 0x5b, 0x65, 0x83, 0xb3, 0xd2, 0x12, 0xcc,
+                0x8b, 0xb6, 0x98, 0x90,
+            ],
         },
         TestVector {
             sk: [
@@ -535,6 +585,12 @@ fn key_components() {
                 0x23, 0x36, 0xc2, 0xa0, 0x5a, 0x08, 0x03, 0x23, 0x9b, 0x5b, 0x88, 0xfd, 0x92, 0x07,
                 0x8f, 0xea, 0x4d, 0x04,
             ],
+            note_pos: 1814747072,
+            note_nf: [
+                0xa8, 0x2f, 0x17, 0x50, 0xcc, 0x5b, 0x2b, 0xee, 0x64, 0x9a, 0x36, 0x5c, 0x04, 0x20,
+                0xed, 0x87, 0x07, 0x5b, 0x88, 0x71, 0xfd, 0xa4, 0xa7, 0xf5, 0x84, 0x0d, 0x6b, 0xbe,
+                0xb1, 0x7c, 0xd6, 0x20,
+            ],
         },
         TestVector {
             sk: [
@@ -591,6 +647,12 @@ fn key_components() {
                 0x64, 0x41, 0x9b, 0x0e, 0x55, 0x0a, 0xbb, 0xcb, 0x8e, 0x2b, 0xcb, 0xda, 0x8b, 0x63,
                 0xe4, 0x1d, 0xeb, 0x37,
             ],
+            note_pos: 2578461368,
+            note_nf: [
+                0x65, 0x36, 0x74, 0x87, 0x3b, 0x3c, 0x67, 0x0c, 0x58, 0x85, 0x84, 0x73, 0xe7, 0xfe,
+                0x72, 0x19, 0x72, 0xfb, 0x96, 0xe2, 0x15, 0xb8, 0x73, 0x77, 0xa1, 0x7c, 0xa3, 0x71,
+                0x0d, 0x93, 0xc9, 0xe9,
+            ],
         },
     ];
 
@@ -616,7 +678,7 @@ fn key_components() {
         }
 
         let pgk = ProofGenerationKey { ak, nsk };
-        let fvk = pgk.into_viewing_key(&JUBJUB);
+        let fvk = pgk.to_viewing_key(&JUBJUB);
         {
             let mut vec = Vec::new();
             fvk.nk.write(&mut vec).unwrap();
@@ -642,10 +704,10 @@ fn key_components() {
         let diversifier = Diversifier(tv.default_d);
         assert!(librustzcash_check_diversifier(&tv.default_d));
 
-        let addr = fvk.into_payment_address(diversifier, &JUBJUB).unwrap();
+        let addr = fvk.to_payment_address(diversifier, &JUBJUB).unwrap();
         {
             let mut vec = Vec::new();
-            addr.pk_d.write(&mut vec).unwrap();
+            addr.pk_d().write(&mut vec).unwrap();
             assert_eq!(&vec, &tv.default_pk_d);
         }
         {
@@ -663,5 +725,7 @@ fn key_components() {
             note.cm(&JUBJUB).into_repr().write_le(&mut vec).unwrap();
             assert_eq!(&vec, &tv.note_cm);
         }
+
+        assert_eq!(note.nf(&fvk, tv.note_pos, &JUBJUB), tv.note_nf);
     }
 }

librustzcash/src/tests/mmr.rs

@@ -0,0 +1,225 @@
+use zcash_history::{Entry, EntryLink, NodeData};
+
+use crate::{librustzcash_mmr_append, librustzcash_mmr_delete};
+
+const NODE_DATA_16L: &[u8] = include_bytes!("./res/tree16.dat");
+const NODE_DATA_1023L: &[u8] = include_bytes!("./res/tree1023.dat");
+
+struct TreeView {
+    peaks: Vec<(u32, Entry)>,
+    extra: Vec<(u32, Entry)>,
+}
+
+fn draft(into: &mut Vec<(u32, Entry)>, nodes: &[NodeData], peak_pos: usize, h: u32) {
+    let node_data = nodes[peak_pos - 1].clone();
+    let peak: Entry = match h {
+        0 => node_data.into(),
+        _ => Entry::new(
+            node_data,
+            EntryLink::Stored((peak_pos - (1 << h) - 1) as u32),
+            EntryLink::Stored((peak_pos - 2) as u32),
+        ),
+    };
+
+    into.push(((peak_pos - 1) as u32, peak));
+}
+
+fn prepare_tree(nodes: &[NodeData]) -> TreeView {
+    assert!(!nodes.is_empty());
+
+    // integer log2 of (nodes.len()+1), -1
+    let mut h = (32 - ((nodes.len() + 1) as u32).leading_zeros() - 1) - 1;
+    let mut peak_pos = (1 << (h + 1)) - 1;
+    let mut peaks = Vec::new();
+
+    // used later
+    let mut last_peak_pos = 0;
+    let mut last_peak_h = 0;
+
+    loop {
+        if peak_pos > nodes.len() {
+            // left child, -2^h
+            peak_pos -= 1 << h;
+            h -= 1;
+        }
+
+        if peak_pos <= nodes.len() {
+            draft(&mut peaks, nodes, peak_pos, h);
+
+            // save to be used in next loop
+            last_peak_pos = peak_pos;
+            last_peak_h = h;
+
+            // right sibling
+            peak_pos += (1 << (h + 1)) - 1;
+        }
+
+        if h == 0 {
+            break;
+        }
+    }
+
+    // for deletion, everything on the right slope of the last peak should be pre-loaded
+    let mut extra = Vec::new();
+    let mut h = last_peak_h;
+    let mut peak_pos = last_peak_pos;
+
+    while h > 0 {
+        let left_pos = peak_pos - (1 << h);
+        let right_pos = peak_pos - 1;
+        h -= 1;
+
+        // drafting left child
+        draft(&mut extra, nodes, left_pos, h);
+
+        // drafting right child
+        draft(&mut extra, nodes, right_pos, h);
+
+        // continuing on right slope
+        peak_pos = right_pos;
+    }
+
+    TreeView { peaks, extra }
+}
+
+fn preload_tree_append(nodes: &[NodeData]) -> (Vec<u32>, Vec<[u8; zcash_history::MAX_ENTRY_SIZE]>) {
+    assert!(!nodes.is_empty());
+
+    let tree_view = prepare_tree(nodes);
+
+    let mut indices = Vec::new();
+    let mut bytes = Vec::new();
+
+    for (idx, entry) in tree_view.peaks.into_iter() {
+        let mut buf = [0u8; zcash_history::MAX_ENTRY_SIZE];
+        entry
+            .write(&mut &mut buf[..])
+            .expect("Cannot fail if enough buffer length");
+        indices.push(idx);
+        bytes.push(buf);
+    }
+
+    (indices, bytes)
+}
+
+// also returns number of peaks
+fn preload_tree_delete(
+    nodes: &[NodeData],
+) -> (Vec<u32>, Vec<[u8; zcash_history::MAX_ENTRY_SIZE]>, usize) {
+    assert!(!nodes.is_empty());
+
+    let tree_view = prepare_tree(nodes);
+
+    let mut indices = Vec::new();
+    let mut bytes = Vec::new();
+
+    let peak_count = tree_view.peaks.len();
+
+    for (idx, entry) in tree_view
+        .peaks
+        .into_iter()
+        .chain(tree_view.extra.into_iter())
+    {
+        let mut buf = [0u8; zcash_history::MAX_ENTRY_SIZE];
+        entry
+            .write(&mut &mut buf[..])
+            .expect("Cannot fail if enough buffer length");
+        indices.push(idx);
+        bytes.push(buf);
+    }
+
+    (indices, bytes, peak_count)
+}
+
+fn load_nodes(bytes: &'static [u8]) -> Vec<NodeData> {
+    let mut res = Vec::new();
+    let mut cursor = std::io::Cursor::new(bytes);
+    while (cursor.position() as usize) < bytes.len() {
+        let node_data = zcash_history::NodeData::read(0, &mut cursor)
+            .expect("Statically checked to be correct");
+        res.push(node_data);
+    }
+
+    res
+}
+
+#[test]
+fn append() {
+    let nodes = load_nodes(NODE_DATA_16L);
+    let (indices, peaks) = preload_tree_append(&nodes);
+
+    let mut rt_ret = [0u8; 32];
+
+    let mut buf_ret = Vec::<[u8; zcash_history::MAX_NODE_DATA_SIZE]>::with_capacity(32);
+
+    let mut new_node_data = [0u8; zcash_history::MAX_NODE_DATA_SIZE];
+    let new_node = NodeData {
+        consensus_branch_id: 0,
+        subtree_commitment: [0u8; 32],
+        start_time: 101,
+        end_time: 110,
+        start_target: 190,
+        end_target: 200,
+        start_sapling_root: [0u8; 32],
+        end_sapling_root: [0u8; 32],
+        subtree_total_work: Default::default(),
+        start_height: 10,
+        end_height: 10,
+        sapling_tx: 13,
+    };
+    new_node
+        .write(&mut &mut new_node_data[..])
+        .expect("Failed to write node data");
+
+    let result = librustzcash_mmr_append(
+        0,
+        nodes.len() as u32,
+        indices.as_ptr(),
+        peaks.as_ptr(),
+        peaks.len(),
+        &new_node_data,
+        &mut rt_ret,
+        buf_ret.as_mut_ptr(),
+    );
+
+    unsafe {
+        buf_ret.set_len(result as usize);
+    }
+
+    assert_eq!(result, 2);
+
+    let new_node_1 =
+        NodeData::from_bytes(0, &buf_ret[0][..]).expect("Failed to reconstruct return node #1");
+
+    let new_node_2 =
+        NodeData::from_bytes(0, &buf_ret[1][..]).expect("Failed to reconstruct return node #2");
+
+    assert_eq!(new_node_1.start_height, 10);
+    assert_eq!(new_node_1.end_height, 10);
+
+    // this is combined new node (which is `new_node_1`) + the one which was there before (for block #9)
+    assert_eq!(new_node_2.start_height, 9);
+    assert_eq!(new_node_2.end_height, 10);
+    assert_eq!(new_node_2.sapling_tx, 27);
+}
+
+#[test]
+fn delete() {
+    let nodes = load_nodes(NODE_DATA_1023L);
+    let (indices, nodes, peak_count) = preload_tree_delete(&nodes);
+
+    let mut rt_ret = [0u8; 32];
+
+    let result = librustzcash_mmr_delete(
+        0,
+        nodes.len() as u32,
+        indices.as_ptr(),
+        nodes.as_ptr(),
+        peak_count,
+        indices.len() - peak_count,
+        &mut rt_ret,
+    );
+
+    // Deleting from full tree of 9 height would result in cascade deleting of 10 nodes
+    assert_eq!(result, 10);
+}

librustzcash/src/tests/mod.rs

@@ -1,9 +1,10 @@
-use sapling_crypto::jubjub::{FixedGenerators, JubjubParams};
+use zcash_primitives::jubjub::{FixedGenerators, JubjubParams};
 
 use super::JUBJUB;
 
 mod key_agreement;
 mod key_components;
+mod mmr;
 mod notes;
 mod signatures;
 

librustzcash/src/tests/notes.rs

@@ -1,5 +1,5 @@
-use librustzcash_sapling_compute_cm;
+use crate::librustzcash_sapling_compute_cm;
-use librustzcash_sapling_compute_nf;
+use crate::librustzcash_sapling_compute_nf;
 
 #[test]
 fn notes() {

librustzcash/src/tests/signatures.rs

@@ -1,9 +1,7 @@
 use ff::{PrimeField, PrimeFieldRepr};
 use pairing::bls12_381::Bls12;
-use sapling_crypto::{
+use zcash_primitives::jubjub::{FixedGenerators, JubjubEngine};
-    jubjub::{FixedGenerators, JubjubEngine},
+use zcash_primitives::redjubjub::{PrivateKey, PublicKey, Signature};
-    redjubjub::{PrivateKey, PublicKey, Signature},
-};
 
 use super::JUBJUB;
 

pairing/Cargo.toml

@@ -2,25 +2,33 @@
 name = "pairing"
 
 # Remember to change version string in README.md.
-version = "0.14.2"
+version = "0.15.1"
 authors = [
     "Sean Bowe <ewillbefull@gmail.com>",
     "Jack Grigg <jack@z.cash>",
 ]
+readme = "README.md"
 license = "MIT/Apache-2.0"
 
 description = "Pairing-friendly elliptic curve library"
 documentation = "https://docs.rs/pairing/"
 homepage = "https://github.com/ebfull/pairing"
 repository = "https://github.com/ebfull/pairing"
+edition ="2018"
 
 [dependencies]
-rand = "0.4"
 byteorder = "1"
-ff = { path = "../ff", features = ["derive"] }
+ff = { version = "^0.5.2", path = "../ff", features = ["derive"] }
-group = { path = "../group" }
+group = { version = "0.2.0", path = "../group" }
+rand_core = "0.5"
+
+[dev-dependencies]
+rand_xorshift = "0.2"
 
 [features]
 unstable-features = ["expose-arith"]
 expose-arith = []
 default = []
+
+[badges]
+maintenance = { status = "actively-developed" }

pairing/README.md

@@ -1,6 +1,16 @@
 # pairing [![Crates.io](https://img.shields.io/crates/v/pairing.svg)](https://crates.io/crates/pairing) #
 
-This is a Rust crate for using pairing-friendly elliptic curves. Currently, only the [BLS12-381](https://z.cash/blog/new-snark-curve.html) construction is implemented.
+`pairing` is a crate for using pairing-friendly elliptic curves.
+
+Currently, only the [BLS12-381](https://z.cash/blog/new-snark-curve.html)
+construction is implemented.
+
+## Roadmap
+
+`pairing` is being refactored into a generic library for working with
+pairing-friendly curves. After the refactor, `pairing` will provide basic traits
+for pairing-friendly elliptic curve constructions, while specific curves will be
+in separate crates.
 
 ## [Documentation](https://docs.rs/pairing/)
 
@@ -8,13 +18,15 @@ Bring the `pairing` crate into your project just as you normally would.
 
 ## Security Warnings
 
-This library does not make any guarantees about constant-time operations, memory access patterns, or resistance to side-channel attacks.
+This library does not make any guarantees about constant-time operations, memory
+access patterns, or resistance to side-channel attacks.
 
 ## License
 
 Licensed under either of
 
- * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
+   http://www.apache.org/licenses/LICENSE-2.0)
  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 
 at your option.

pairing/benches/bls12_381/ec.rs

@@ -1,6 +1,8 @@
 mod g1 {
-    use rand::{Rand, SeedableRng, XorShiftRng};
+    use rand_core::SeedableRng;
+    use rand_xorshift::XorShiftRng;
 
+    use ff::Field;
     use group::CurveProjective;
     use pairing::bls12_381::*;
 
@@ -8,10 +10,13 @@ mod g1 {
     fn bench_g1_mul_assign(b: &mut ::test::Bencher) {
         const SAMPLES: usize = 1000;
 
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         let v: Vec<(G1, Fr)> = (0..SAMPLES)
-            .map(|_| (G1::rand(&mut rng), Fr::rand(&mut rng)))
+            .map(|_| (G1::random(&mut rng), Fr::random(&mut rng)))
             .collect();
 
         let mut count = 0;
@@ -27,10 +32,13 @@ mod g1 {
     fn bench_g1_add_assign(b: &mut ::test::Bencher) {
         const SAMPLES: usize = 1000;
 
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         let v: Vec<(G1, G1)> = (0..SAMPLES)
-            .map(|_| (G1::rand(&mut rng), G1::rand(&mut rng)))
+            .map(|_| (G1::random(&mut rng), G1::random(&mut rng)))
             .collect();
 
         let mut count = 0;
@@ -46,10 +54,13 @@ mod g1 {
     fn bench_g1_add_assign_mixed(b: &mut ::test::Bencher) {
         const SAMPLES: usize = 1000;
 
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         let v: Vec<(G1, G1Affine)> = (0..SAMPLES)
-            .map(|_| (G1::rand(&mut rng), G1::rand(&mut rng).into()))
+            .map(|_| (G1::random(&mut rng), G1::random(&mut rng).into()))
             .collect();
 
         let mut count = 0;
@@ -63,8 +74,10 @@ mod g1 {
 }
 
 mod g2 {
-    use rand::{Rand, SeedableRng, XorShiftRng};
+    use rand_core::SeedableRng;
+    use rand_xorshift::XorShiftRng;
 
+    use ff::Field;
     use group::CurveProjective;
     use pairing::bls12_381::*;
 
@@ -72,10 +85,13 @@ mod g2 {
     fn bench_g2_mul_assign(b: &mut ::test::Bencher) {
         const SAMPLES: usize = 1000;
 
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         let v: Vec<(G2, Fr)> = (0..SAMPLES)
-            .map(|_| (G2::rand(&mut rng), Fr::rand(&mut rng)))
+            .map(|_| (G2::random(&mut rng), Fr::random(&mut rng)))
             .collect();
 
         let mut count = 0;
@@ -91,10 +107,13 @@ mod g2 {
     fn bench_g2_add_assign(b: &mut ::test::Bencher) {
         const SAMPLES: usize = 1000;
 
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         let v: Vec<(G2, G2)> = (0..SAMPLES)
-            .map(|_| (G2::rand(&mut rng), G2::rand(&mut rng)))
+            .map(|_| (G2::random(&mut rng), G2::random(&mut rng)))
             .collect();
 
         let mut count = 0;
@@ -110,10 +129,13 @@ mod g2 {
     fn bench_g2_add_assign_mixed(b: &mut ::test::Bencher) {
         const SAMPLES: usize = 1000;
 
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         let v: Vec<(G2, G2Affine)> = (0..SAMPLES)
-            .map(|_| (G2::rand(&mut rng), G2::rand(&mut rng).into()))
+            .map(|_| (G2::random(&mut rng), G2::random(&mut rng).into()))
             .collect();
 
         let mut count = 0;

pairing/benches/bls12_381/fq.rs

@@ -1,4 +1,5 @@
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
 use ff::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 use pairing::bls12_381::*;
@@ -7,12 +8,15 @@ use pairing::bls12_381::*;
 fn bench_fq_repr_add_nocarry(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(FqRepr, FqRepr)> = (0..SAMPLES)
         .map(|_| {
-            let mut tmp1 = FqRepr::rand(&mut rng);
+            let mut tmp1 = Fq::random(&mut rng).into_repr();
-            let mut tmp2 = FqRepr::rand(&mut rng);
+            let mut tmp2 = Fq::random(&mut rng).into_repr();
             // Shave a few bits off to avoid overflow.
             for _ in 0..3 {
                 tmp1.div2();
@@ -35,11 +39,14 @@ fn bench_fq_repr_add_nocarry(b: &mut ::test::Bencher) {
 fn bench_fq_repr_sub_noborrow(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(FqRepr, FqRepr)> = (0..SAMPLES)
         .map(|_| {
-            let tmp1 = FqRepr::rand(&mut rng);
+            let tmp1 = Fq::random(&mut rng).into_repr();
             let mut tmp2 = tmp1;
             // Ensure tmp2 is smaller than tmp1.
             for _ in 0..10 {
@@ -62,9 +69,14 @@ fn bench_fq_repr_sub_noborrow(b: &mut ::test::Bencher) {
 fn bench_fq_repr_num_bits(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<FqRepr> = (0..SAMPLES).map(|_| FqRepr::rand(&mut rng)).collect();
+    let v: Vec<FqRepr> = (0..SAMPLES)
+        .map(|_| Fq::random(&mut rng).into_repr())
+        .collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -78,9 +90,14 @@ fn bench_fq_repr_num_bits(b: &mut ::test::Bencher) {
 fn bench_fq_repr_mul2(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<FqRepr> = (0..SAMPLES).map(|_| FqRepr::rand(&mut rng)).collect();
+    let v: Vec<FqRepr> = (0..SAMPLES)
+        .map(|_| Fq::random(&mut rng).into_repr())
+        .collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -95,9 +112,14 @@ fn bench_fq_repr_mul2(b: &mut ::test::Bencher) {
 fn bench_fq_repr_div2(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<FqRepr> = (0..SAMPLES).map(|_| FqRepr::rand(&mut rng)).collect();
+    let v: Vec<FqRepr> = (0..SAMPLES)
+        .map(|_| Fq::random(&mut rng).into_repr())
+        .collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -112,10 +134,13 @@ fn bench_fq_repr_div2(b: &mut ::test::Bencher) {
 fn bench_fq_add_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fq, Fq)> = (0..SAMPLES)
-        .map(|_| (Fq::rand(&mut rng), Fq::rand(&mut rng)))
+        .map(|_| (Fq::random(&mut rng), Fq::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -131,10 +156,13 @@ fn bench_fq_add_assign(b: &mut ::test::Bencher) {
 fn bench_fq_sub_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fq, Fq)> = (0..SAMPLES)
-        .map(|_| (Fq::rand(&mut rng), Fq::rand(&mut rng)))
+        .map(|_| (Fq::random(&mut rng), Fq::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -150,10 +178,13 @@ fn bench_fq_sub_assign(b: &mut ::test::Bencher) {
 fn bench_fq_mul_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fq, Fq)> = (0..SAMPLES)
-        .map(|_| (Fq::rand(&mut rng), Fq::rand(&mut rng)))
+        .map(|_| (Fq::random(&mut rng), Fq::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -169,9 +200,12 @@ fn bench_fq_mul_assign(b: &mut ::test::Bencher) {
 fn bench_fq_square(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fq> = (0..SAMPLES).map(|_| Fq::rand(&mut rng)).collect();
+    let v: Vec<Fq> = (0..SAMPLES).map(|_| Fq::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -186,9 +220,12 @@ fn bench_fq_square(b: &mut ::test::Bencher) {
 fn bench_fq_inverse(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fq> = (0..SAMPLES).map(|_| Fq::rand(&mut rng)).collect();
+    let v: Vec<Fq> = (0..SAMPLES).map(|_| Fq::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -201,9 +238,12 @@ fn bench_fq_inverse(b: &mut ::test::Bencher) {
 fn bench_fq_negate(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fq> = (0..SAMPLES).map(|_| Fq::rand(&mut rng)).collect();
+    let v: Vec<Fq> = (0..SAMPLES).map(|_| Fq::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -218,11 +258,14 @@ fn bench_fq_negate(b: &mut ::test::Bencher) {
 fn bench_fq_sqrt(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<Fq> = (0..SAMPLES)
         .map(|_| {
-            let mut tmp = Fq::rand(&mut rng);
+            let mut tmp = Fq::random(&mut rng);
             tmp.square();
             tmp
         })
@@ -239,9 +282,12 @@ fn bench_fq_sqrt(b: &mut ::test::Bencher) {
 fn bench_fq_into_repr(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fq> = (0..SAMPLES).map(|_| Fq::rand(&mut rng)).collect();
+    let v: Vec<Fq> = (0..SAMPLES).map(|_| Fq::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -254,10 +300,13 @@ fn bench_fq_into_repr(b: &mut ::test::Bencher) {
 fn bench_fq_from_repr(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<FqRepr> = (0..SAMPLES)
-        .map(|_| Fq::rand(&mut rng).into_repr())
+        .map(|_| Fq::random(&mut rng).into_repr())
         .collect();
 
     let mut count = 0;

pairing/benches/bls12_381/fq12.rs

@@ -1,4 +1,5 @@
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
 use ff::Field;
 use pairing::bls12_381::*;
@@ -7,10 +8,13 @@ use pairing::bls12_381::*;
 fn bench_fq12_add_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fq12, Fq12)> = (0..SAMPLES)
-        .map(|_| (Fq12::rand(&mut rng), Fq12::rand(&mut rng)))
+        .map(|_| (Fq12::random(&mut rng), Fq12::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -26,10 +30,13 @@ fn bench_fq12_add_assign(b: &mut ::test::Bencher) {
 fn bench_fq12_sub_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fq12, Fq12)> = (0..SAMPLES)
-        .map(|_| (Fq12::rand(&mut rng), Fq12::rand(&mut rng)))
+        .map(|_| (Fq12::random(&mut rng), Fq12::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -45,10 +52,13 @@ fn bench_fq12_sub_assign(b: &mut ::test::Bencher) {
 fn bench_fq12_mul_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fq12, Fq12)> = (0..SAMPLES)
-        .map(|_| (Fq12::rand(&mut rng), Fq12::rand(&mut rng)))
+        .map(|_| (Fq12::random(&mut rng), Fq12::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -64,9 +74,12 @@ fn bench_fq12_mul_assign(b: &mut ::test::Bencher) {
 fn bench_fq12_squaring(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fq12> = (0..SAMPLES).map(|_| Fq12::rand(&mut rng)).collect();
+    let v: Vec<Fq12> = (0..SAMPLES).map(|_| Fq12::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -81,9 +94,12 @@ fn bench_fq12_squaring(b: &mut ::test::Bencher) {
 fn bench_fq12_inverse(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fq12> = (0..SAMPLES).map(|_| Fq12::rand(&mut rng)).collect();
+    let v: Vec<Fq12> = (0..SAMPLES).map(|_| Fq12::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {

pairing/benches/bls12_381/fq2.rs

@@ -1,4 +1,5 @@
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
 use ff::{Field, SqrtField};
 use pairing::bls12_381::*;
@@ -7,10 +8,13 @@ use pairing::bls12_381::*;
 fn bench_fq2_add_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fq2, Fq2)> = (0..SAMPLES)
-        .map(|_| (Fq2::rand(&mut rng), Fq2::rand(&mut rng)))
+        .map(|_| (Fq2::random(&mut rng), Fq2::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -26,10 +30,13 @@ fn bench_fq2_add_assign(b: &mut ::test::Bencher) {
 fn bench_fq2_sub_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fq2, Fq2)> = (0..SAMPLES)
-        .map(|_| (Fq2::rand(&mut rng), Fq2::rand(&mut rng)))
+        .map(|_| (Fq2::random(&mut rng), Fq2::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -45,10 +52,13 @@ fn bench_fq2_sub_assign(b: &mut ::test::Bencher) {
 fn bench_fq2_mul_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fq2, Fq2)> = (0..SAMPLES)
-        .map(|_| (Fq2::rand(&mut rng), Fq2::rand(&mut rng)))
+        .map(|_| (Fq2::random(&mut rng), Fq2::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -64,9 +74,12 @@ fn bench_fq2_mul_assign(b: &mut ::test::Bencher) {
 fn bench_fq2_squaring(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fq2> = (0..SAMPLES).map(|_| Fq2::rand(&mut rng)).collect();
+    let v: Vec<Fq2> = (0..SAMPLES).map(|_| Fq2::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -81,9 +94,12 @@ fn bench_fq2_squaring(b: &mut ::test::Bencher) {
 fn bench_fq2_inverse(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fq2> = (0..SAMPLES).map(|_| Fq2::rand(&mut rng)).collect();
+    let v: Vec<Fq2> = (0..SAMPLES).map(|_| Fq2::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -97,9 +113,12 @@ fn bench_fq2_inverse(b: &mut ::test::Bencher) {
 fn bench_fq2_sqrt(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fq2> = (0..SAMPLES).map(|_| Fq2::rand(&mut rng)).collect();
+    let v: Vec<Fq2> = (0..SAMPLES).map(|_| Fq2::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {

pairing/benches/bls12_381/fr.rs

@@ -1,4 +1,5 @@
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
 use ff::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 use pairing::bls12_381::*;
@@ -7,12 +8,15 @@ use pairing::bls12_381::*;
 fn bench_fr_repr_add_nocarry(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(FrRepr, FrRepr)> = (0..SAMPLES)
         .map(|_| {
-            let mut tmp1 = FrRepr::rand(&mut rng);
+            let mut tmp1 = Fr::random(&mut rng).into_repr();
-            let mut tmp2 = FrRepr::rand(&mut rng);
+            let mut tmp2 = Fr::random(&mut rng).into_repr();
             // Shave a few bits off to avoid overflow.
             for _ in 0..3 {
                 tmp1.div2();
@@ -35,11 +39,14 @@ fn bench_fr_repr_add_nocarry(b: &mut ::test::Bencher) {
 fn bench_fr_repr_sub_noborrow(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(FrRepr, FrRepr)> = (0..SAMPLES)
         .map(|_| {
-            let tmp1 = FrRepr::rand(&mut rng);
+            let tmp1 = Fr::random(&mut rng).into_repr();
             let mut tmp2 = tmp1;
             // Ensure tmp2 is smaller than tmp1.
             for _ in 0..10 {
@@ -62,9 +69,14 @@ fn bench_fr_repr_sub_noborrow(b: &mut ::test::Bencher) {
 fn bench_fr_repr_num_bits(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<FrRepr> = (0..SAMPLES).map(|_| FrRepr::rand(&mut rng)).collect();
+    let v: Vec<FrRepr> = (0..SAMPLES)
+        .map(|_| Fr::random(&mut rng).into_repr())
+        .collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -78,9 +90,14 @@ fn bench_fr_repr_num_bits(b: &mut ::test::Bencher) {
 fn bench_fr_repr_mul2(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<FrRepr> = (0..SAMPLES).map(|_| FrRepr::rand(&mut rng)).collect();
+    let v: Vec<FrRepr> = (0..SAMPLES)
+        .map(|_| Fr::random(&mut rng).into_repr())
+        .collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -95,9 +112,14 @@ fn bench_fr_repr_mul2(b: &mut ::test::Bencher) {
 fn bench_fr_repr_div2(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<FrRepr> = (0..SAMPLES).map(|_| FrRepr::rand(&mut rng)).collect();
+    let v: Vec<FrRepr> = (0..SAMPLES)
+        .map(|_| Fr::random(&mut rng).into_repr())
+        .collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -112,10 +134,13 @@ fn bench_fr_repr_div2(b: &mut ::test::Bencher) {
 fn bench_fr_add_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fr, Fr)> = (0..SAMPLES)
-        .map(|_| (Fr::rand(&mut rng), Fr::rand(&mut rng)))
+        .map(|_| (Fr::random(&mut rng), Fr::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -131,10 +156,13 @@ fn bench_fr_add_assign(b: &mut ::test::Bencher) {
 fn bench_fr_sub_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fr, Fr)> = (0..SAMPLES)
-        .map(|_| (Fr::rand(&mut rng), Fr::rand(&mut rng)))
+        .map(|_| (Fr::random(&mut rng), Fr::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -150,10 +178,13 @@ fn bench_fr_sub_assign(b: &mut ::test::Bencher) {
 fn bench_fr_mul_assign(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(Fr, Fr)> = (0..SAMPLES)
-        .map(|_| (Fr::rand(&mut rng), Fr::rand(&mut rng)))
+        .map(|_| (Fr::random(&mut rng), Fr::random(&mut rng)))
         .collect();
 
     let mut count = 0;
@@ -169,9 +200,12 @@ fn bench_fr_mul_assign(b: &mut ::test::Bencher) {
 fn bench_fr_square(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fr> = (0..SAMPLES).map(|_| Fr::rand(&mut rng)).collect();
+    let v: Vec<Fr> = (0..SAMPLES).map(|_| Fr::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -186,9 +220,12 @@ fn bench_fr_square(b: &mut ::test::Bencher) {
 fn bench_fr_inverse(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fr> = (0..SAMPLES).map(|_| Fr::rand(&mut rng)).collect();
+    let v: Vec<Fr> = (0..SAMPLES).map(|_| Fr::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -201,9 +238,12 @@ fn bench_fr_inverse(b: &mut ::test::Bencher) {
 fn bench_fr_negate(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fr> = (0..SAMPLES).map(|_| Fr::rand(&mut rng)).collect();
+    let v: Vec<Fr> = (0..SAMPLES).map(|_| Fr::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -218,11 +258,14 @@ fn bench_fr_negate(b: &mut ::test::Bencher) {
 fn bench_fr_sqrt(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<Fr> = (0..SAMPLES)
         .map(|_| {
-            let mut tmp = Fr::rand(&mut rng);
+            let mut tmp = Fr::random(&mut rng);
             tmp.square();
             tmp
         })
@@ -239,9 +282,12 @@ fn bench_fr_sqrt(b: &mut ::test::Bencher) {
 fn bench_fr_into_repr(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<Fr> = (0..SAMPLES).map(|_| Fr::rand(&mut rng)).collect();
+    let v: Vec<Fr> = (0..SAMPLES).map(|_| Fr::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -254,10 +300,13 @@ fn bench_fr_into_repr(b: &mut ::test::Bencher) {
 fn bench_fr_from_repr(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<FrRepr> = (0..SAMPLES)
-        .map(|_| Fr::rand(&mut rng).into_repr())
+        .map(|_| Fr::random(&mut rng).into_repr())
         .collect();
 
     let mut count = 0;

pairing/benches/bls12_381/mod.rs

@@ -4,8 +4,10 @@ mod fq12;
 mod fq2;
 mod fr;
 
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
+use group::CurveProjective;
 use pairing::bls12_381::*;
 use pairing::{Engine, PairingCurveAffine};
 
@@ -13,9 +15,12 @@ use pairing::{Engine, PairingCurveAffine};
 fn bench_pairing_g1_preparation(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<G1> = (0..SAMPLES).map(|_| G1::rand(&mut rng)).collect();
+    let v: Vec<G1> = (0..SAMPLES).map(|_| G1::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -29,9 +34,12 @@ fn bench_pairing_g1_preparation(b: &mut ::test::Bencher) {
 fn bench_pairing_g2_preparation(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
-    let v: Vec<G2> = (0..SAMPLES).map(|_| G2::rand(&mut rng)).collect();
+    let v: Vec<G2> = (0..SAMPLES).map(|_| G2::random(&mut rng)).collect();
 
     let mut count = 0;
     b.iter(|| {
@@ -45,13 +53,16 @@ fn bench_pairing_g2_preparation(b: &mut ::test::Bencher) {
 fn bench_pairing_miller_loop(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(G1Prepared, G2Prepared)> = (0..SAMPLES)
         .map(|_| {
             (
-                G1Affine::from(G1::rand(&mut rng)).prepare(),
+                G1Affine::from(G1::random(&mut rng)).prepare(),
-                G2Affine::from(G2::rand(&mut rng)).prepare(),
+                G2Affine::from(G2::random(&mut rng)).prepare(),
             )
         })
         .collect();
@@ -68,13 +79,16 @@ fn bench_pairing_miller_loop(b: &mut ::test::Bencher) {
 fn bench_pairing_final_exponentiation(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<Fq12> = (0..SAMPLES)
         .map(|_| {
             (
-                G1Affine::from(G1::rand(&mut rng)).prepare(),
+                G1Affine::from(G1::random(&mut rng)).prepare(),
-                G2Affine::from(G2::rand(&mut rng)).prepare(),
+                G2Affine::from(G2::random(&mut rng)).prepare(),
             )
         })
         .map(|(ref p, ref q)| Bls12::miller_loop(&[(p, q)]))
@@ -92,10 +106,13 @@ fn bench_pairing_final_exponentiation(b: &mut ::test::Bencher) {
 fn bench_pairing_full(b: &mut ::test::Bencher) {
     const SAMPLES: usize = 1000;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let v: Vec<(G1, G2)> = (0..SAMPLES)
-        .map(|_| (G1::rand(&mut rng), G2::rand(&mut rng)))
+        .map(|_| (G1::random(&mut rng), G2::random(&mut rng)))
         .collect();
 
     let mut count = 0;

pairing/benches/pairing_benches.rs

@@ -3,7 +3,8 @@
 extern crate ff;
 extern crate group;
 extern crate pairing;
-extern crate rand;
+extern crate rand_core;
+extern crate rand_xorshift;
 extern crate test;
 
 mod bls12_381;

pairing/src/bls12_381/ec.rs

@@ -14,12 +14,11 @@ macro_rules! curve_impl {
         pub struct $affine {
             pub(crate) x: $basefield,
             pub(crate) y: $basefield,
-            pub(crate) infinity: bool
+            pub(crate) infinity: bool,
         }
 
-        impl ::std::fmt::Display for $affine
+        impl ::std::fmt::Display for $affine {
-        {
+            fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
-            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
                 if self.infinity {
                     write!(f, "{}(Infinity)", $name)
                 } else {
@@ -30,14 +29,13 @@ macro_rules! curve_impl {
 
         #[derive(Copy, Clone, Debug, Eq)]
         pub struct $projective {
-           pub(crate) x: $basefield,
+            pub(crate) x: $basefield,
-           pub(crate) y: $basefield,
+            pub(crate) y: $basefield,
-           pub(crate) z: $basefield
+            pub(crate) z: $basefield,
         }
 
-        impl ::std::fmt::Display for $projective
+        impl ::std::fmt::Display for $projective {
-        {
+            fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
-            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
                 write!(f, "{}", self.into_affine())
             }
         }
@@ -89,7 +87,9 @@ macro_rules! curve_impl {
                 let mut res = $projective::zero();
                 for i in bits {
                     res.double();
-                    if i { res.add_assign_mixed(self) }
+                    if i {
+                        res.add_assign_mixed(self)
+                    }
                 }
                 res
             }
@@ -112,12 +112,8 @@ macro_rules! curve_impl {
 
                     $affine {
                         x: x,
-                        y: if (y < negy) ^ greatest {
+                        y: if (y < negy) ^ greatest { y } else { negy },
-                            y
+                        infinity: false,
-                        } else {
-                            negy
-                        },
-                        infinity: false
                     }
                 })
             }
@@ -156,7 +152,7 @@ macro_rules! curve_impl {
                 $affine {
                     x: $basefield::zero(),
                     y: $basefield::one(),
-                    infinity: true
+                    infinity: true,
                 }
             }
 
@@ -182,7 +178,6 @@ macro_rules! curve_impl {
             fn into_projective(&self) -> $projective {
                 (*self).into()
             }
-
         }
 
         impl PairingCurveAffine for $affine {
@@ -197,14 +192,18 @@ macro_rules! curve_impl {
             fn pairing_with(&self, other: &Self::Pair) -> Self::PairingResult {
                 self.perform_pairing(other)
             }
-
         }
 
-        impl Rand for $projective {
+        impl CurveProjective for $projective {
-            fn rand<R: Rng>(rng: &mut R) -> Self {
+            type Engine = Bls12;
+            type Scalar = $scalarfield;
+            type Base = $basefield;
+            type Affine = $affine;
+
+            fn random<R: RngCore + ?std::marker::Sized>(rng: &mut R) -> Self {
                 loop {
-                    let x = rng.gen();
+                    let x = $basefield::random(rng);
-                    let greatest = rng.gen();
+                    let greatest = rng.next_u32() % 2 != 0;
 
                     if let Some(p) = $affine::get_point_from_x(x, greatest) {
                         let p = p.scale_by_cofactor();
@@ -215,13 +214,6 @@ macro_rules! curve_impl {
                     }
                 }
             }
-        }
-
-        impl CurveProjective for $projective {
-            type Engine = Bls12;
-            type Scalar = $scalarfield;
-            type Base = $basefield;
-            type Affine = $affine;
 
             // The point at infinity is always represented by
             // Z = 0.
@@ -229,7 +221,7 @@ macro_rules! curve_impl {
                 $projective {
                     x: $basefield::zero(),
                     y: $basefield::one(),
-                    z: $basefield::zero()
+                    z: $basefield::zero(),
                 }
             }
 
@@ -247,8 +239,7 @@ macro_rules! curve_impl {
                 self.is_zero() || self.z == $basefield::one()
             }
 
-            fn batch_normalization(v: &mut [Self])
+            fn batch_normalization(v: &mut [Self]) {
-            {
                 // Montgomery’s Trick and Fast Implementation of Masked AES
                 // Genelle, Prouff and Quisquater
                 // Section 3.2
@@ -256,9 +247,10 @@ macro_rules! curve_impl {
                 // First pass: compute [a, ab, abc, ...]
                 let mut prod = Vec::with_capacity(v.len());
                 let mut tmp = $basefield::one();
-                for g in v.iter_mut()
+                for g in v
-                          // Ignore normalized elements
+                    .iter_mut()
-                          .filter(|g| !g.is_normalized())
+                    // Ignore normalized elements
+                    .filter(|g| !g.is_normalized())
                 {
                     tmp.mul_assign(&g.z);
                     prod.push(tmp);
@@ -268,13 +260,19 @@ macro_rules! curve_impl {
                 tmp = tmp.inverse().unwrap(); // Guaranteed to be nonzero.
 
                 // Second pass: iterate backwards to compute inverses
-                for (g, s) in v.iter_mut()
+                for (g, s) in v
-                               // Backwards
+                    .iter_mut()
-                               .rev()
+                    // Backwards
-                               // Ignore normalized elements
+                    .rev()
-                               .filter(|g| !g.is_normalized())
+                    // Ignore normalized elements
-                               // Backwards, skip last element, fill in one for last term.
+                    .filter(|g| !g.is_normalized())
-                               .zip(prod.into_iter().rev().skip(1).chain(Some($basefield::one())))
+                    // Backwards, skip last element, fill in one for last term.
+                    .zip(
+                        prod.into_iter()
+                            .rev()
+                            .skip(1)
+                            .chain(Some($basefield::one())),
+                    )
                 {
                     // tmp := tmp * g.z; g.z := tmp * s = 1/z
                     let mut newtmp = tmp;
@@ -285,9 +283,7 @@ macro_rules! curve_impl {
                 }
 
                 // Perform affine transformations
-                for g in v.iter_mut()
+                for g in v.iter_mut().filter(|g| !g.is_normalized()) {
-                          .filter(|g| !g.is_normalized())
-                {
                     let mut z = g.z; // 1/z
                     z.square(); // 1/z^2
                     g.x.mul_assign(&z); // x/z^2
@@ -540,8 +536,7 @@ macro_rules! curve_impl {
 
                 let mut found_one = false;
 
-                for i in BitIterator::new(other.into())
+                for i in BitIterator::new(other.into()) {
-                {
                     if found_one {
                         res.double();
                     } else {
@@ -579,7 +574,7 @@ macro_rules! curve_impl {
                     $projective {
                         x: p.x,
                         y: p.y,
-                        z: $basefield::one()
+                        z: $basefield::one(),
                     }
                 }
             }
@@ -596,7 +591,7 @@ macro_rules! curve_impl {
                     $affine {
                         x: p.x,
                         y: p.y,
-                        infinity: false
+                        infinity: false,
                     }
                 } else {
                     // Z is nonzero, so it must have an inverse in a field.
@@ -616,22 +611,22 @@ macro_rules! curve_impl {
                     $affine {
                         x: x,
                         y: y,
-                        infinity: false
+                        infinity: false,
                     }
                 }
             }
         }
-    }
+    };
 }
 
 pub mod g1 {
     use super::super::{Bls12, Fq, Fq12, FqRepr, Fr, FrRepr};
     use super::g2::G2Affine;
+    use crate::{Engine, PairingCurveAffine};
     use ff::{BitIterator, Field, PrimeField, PrimeFieldRepr, SqrtField};
     use group::{CurveAffine, CurveProjective, EncodedPoint, GroupDecodingError};
-    use rand::{Rand, Rng};
+    use rand_core::RngCore;
     use std::fmt;
-    use {Engine, PairingCurveAffine};
 
     curve_impl!(
         "G1",
@@ -661,7 +656,7 @@ pub mod g1 {
     }
 
     impl fmt::Debug for G1Uncompressed {
-        fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
             self.0[..].fmt(formatter)
         }
     }
@@ -771,7 +766,7 @@ pub mod g1 {
     }
 
     impl fmt::Debug for G1Compressed {
-        fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
             self.0[..].fmt(formatter)
         }
     }
@@ -939,7 +934,7 @@ pub mod g1 {
 
     #[test]
     fn g1_generator() {
-        use SqrtField;
+        use crate::SqrtField;
 
         let mut x = Fq::zero();
         let mut i = 0;
@@ -957,7 +952,7 @@ pub mod g1 {
                 let negyrepr = negy.into_repr();
 
                 let p = G1Affine {
-                    x: x,
+                    x,
                     y: if yrepr < negyrepr { y } else { negy },
                     infinity: false,
                 };
@@ -992,7 +987,8 @@ pub mod g1 {
                     0x9fe83b1b4a5d648d,
                     0xf583cc5a508f6a40,
                     0xc3ad2aefde0bb13,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0x60aa6f9552f03aae,
                     0xecd01d5181300d35,
@@ -1000,7 +996,8 @@ pub mod g1 {
                     0xe760f57922998c9d,
                     0x953703f5795a39e5,
                     0xfe3ae0922df702c,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             };
             assert!(!p.is_on_curve());
@@ -1017,7 +1014,8 @@ pub mod g1 {
                     0xea034ee2928b30a8,
                     0xbd8833dc7c79a7f7,
                     0xe45c9f0c0438675,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0x3b450eb1ab7b5dad,
                     0xa65cb81e975e8675,
@@ -1025,7 +1023,8 @@ pub mod g1 {
                     0x753ddf21a2601d20,
                     0x532d0b640bd3ff8b,
                     0x118d2c543f031102,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             };
             assert!(!p.is_on_curve());
@@ -1043,7 +1042,8 @@ pub mod g1 {
                     0xf35de9ce0d6b4e84,
                     0x265bddd23d1dec54,
                     0x12a8778088458308,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0x8a22defa0d526256,
                     0xc57ca55456fcb9ae,
@@ -1051,7 +1051,8 @@ pub mod g1 {
                     0x921beef89d4f29df,
                     0x5b6fda44ad85fa78,
                     0xed74ab9f302cbe0,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             };
             assert!(p.is_on_curve());
@@ -1069,7 +1070,8 @@ pub mod g1 {
                 0x485e77d50a5df10d,
                 0x4c6fcac4b55fd479,
                 0x86ed4d9906fb064,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0xd25ee6461538c65,
                 0x9f3bbb2ecd3719b9,
@@ -1077,7 +1079,8 @@ pub mod g1 {
                 0xcefca68333c35288,
                 0x570c8005f8573fa6,
                 0x152ca696fe034442,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             z: Fq::one(),
         };
 
@@ -1089,7 +1092,8 @@ pub mod g1 {
                 0x5f44314ec5e3fb03,
                 0x24e8538737c6e675,
                 0x8abd623a594fba8,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0x6b0528f088bb7044,
                 0x2fdeb5c82917ff9e,
@@ -1097,7 +1101,8 @@ pub mod g1 {
                 0xd65104c6f95a872a,
                 0x1f2998a5a9c61253,
                 0xe74846154a9e44,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             z: Fq::one(),
         });
 
@@ -1113,7 +1118,8 @@ pub mod g1 {
                     0xc4f9a52a428e23bb,
                     0xd178b28dd4f407ef,
                     0x17fb8905e9183c69
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0xd0de9d65292b7710,
                     0xf6a05f2bcf1d9ca7,
@@ -1121,7 +1127,8 @@ pub mod g1 {
                     0xeec8d1a5b7466c58,
                     0x4bc362649dce6376,
                     0x430cbdc5455b00a
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             }
         );
@@ -1137,7 +1144,8 @@ pub mod g1 {
                 0x485e77d50a5df10d,
                 0x4c6fcac4b55fd479,
                 0x86ed4d9906fb064,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0xd25ee6461538c65,
                 0x9f3bbb2ecd3719b9,
@@ -1145,7 +1153,8 @@ pub mod g1 {
                 0xcefca68333c35288,
                 0x570c8005f8573fa6,
                 0x152ca696fe034442,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             z: Fq::one(),
         };
 
@@ -1163,7 +1172,8 @@ pub mod g1 {
                     0x4b914c16687dcde0,
                     0x66c8baf177d20533,
                     0xaf960cff3d83833
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0x3f0675695f5177a8,
                     0x2b6d82ae178a1ba0,
@@ -1171,7 +1181,8 @@ pub mod g1 {
                     0x1771a65b60572f4e,
                     0x8b547c1313b27555,
                     0x135075589a687b1e
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             }
         );
@@ -1194,7 +1205,8 @@ pub mod g1 {
                 0x71ffa8021531705,
                 0x7418d484386d267,
                 0xd5108d8ff1fbd6,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0xa776ccbfe9981766,
                 0x255632964ff40f4a,
@@ -1202,7 +1214,8 @@ pub mod g1 {
                 0x520f74773e74c8c3,
                 0x484c8fc982008f0,
                 0xee2c3d922008cc6,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             infinity: false,
         };
 
@@ -1214,7 +1227,8 @@ pub mod g1 {
                 0xc6e05201e5f83991,
                 0xf7c75910816f207c,
                 0x18d4043e78103106,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0xa776ccbfe9981766,
                 0x255632964ff40f4a,
@@ -1222,7 +1236,8 @@ pub mod g1 {
                 0x520f74773e74c8c3,
                 0x484c8fc982008f0,
                 0xee2c3d922008cc6,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             infinity: false,
         };
 
@@ -1237,7 +1252,8 @@ pub mod g1 {
                 0x9676ff02ec39c227,
                 0x4c12c15d7e55b9f3,
                 0x57fd1e317db9bd,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0x1288334016679345,
                 0xf955cd68615ff0b5,
@@ -1245,7 +1261,8 @@ pub mod g1 {
                 0x1267d70db51049fb,
                 0x4696deb9ab2ba3e7,
                 0xb1e4e11177f59d4,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             infinity: false,
         };
 
@@ -1274,11 +1291,11 @@ pub mod g1 {
 pub mod g2 {
     use super::super::{Bls12, Fq, Fq12, Fq2, FqRepr, Fr, FrRepr};
     use super::g1::G1Affine;
+    use crate::{Engine, PairingCurveAffine};
     use ff::{BitIterator, Field, PrimeField, PrimeFieldRepr, SqrtField};
     use group::{CurveAffine, CurveProjective, EncodedPoint, GroupDecodingError};
-    use rand::{Rand, Rng};
+    use rand_core::RngCore;
     use std::fmt;
-    use {Engine, PairingCurveAffine};
 
     curve_impl!(
         "G2",
@@ -1308,7 +1325,7 @@ pub mod g2 {
     }
 
     impl fmt::Debug for G2Uncompressed {
-        fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
             self.0[..].fmt(formatter)
         }
     }
@@ -1434,7 +1451,7 @@ pub mod g2 {
     }
 
     impl fmt::Debug for G2Compressed {
-        fn fmt(&self, formatter: &mut fmt::Formatter) -> Result<(), fmt::Error> {
+        fn fmt(&self, formatter: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
             self.0[..].fmt(formatter)
         }
     }
@@ -1623,7 +1640,7 @@ pub mod g2 {
 
     #[test]
     fn g2_generator() {
-        use SqrtField;
+        use crate::SqrtField;
 
         let mut x = Fq2::zero();
         let mut i = 0;
@@ -1639,7 +1656,7 @@ pub mod g2 {
                 negy.negate();
 
                 let p = G2Affine {
-                    x: x,
+                    x,
                     y: if y < negy { y } else { negy },
                     infinity: false,
                 };
@@ -1675,7 +1692,8 @@ pub mod g2 {
                         0x7a17a004747e3dbe,
                         0xcc65406a7c2e5a73,
                         0x10b8c03d64db4d0c,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0xd30e70fe2f029778,
                         0xda30772df0f5212e,
@@ -1683,7 +1701,8 @@ pub mod g2 {
                         0xfb777e5b9b568608,
                         0x789bac1fec71a2b9,
                         0x1342f02e2da54405,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -1693,7 +1712,8 @@ pub mod g2 {
                         0x663015d9410eb608,
                         0x78e82a79d829a544,
                         0x40a00545bb3c1e,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x4709802348e79377,
                         0xb5ac4dc9204bcfbd,
@@ -1701,7 +1721,8 @@ pub mod g2 {
                         0x15008b1dc399e8df,
                         0x68128fd0548a3829,
                         0x16a613db5c873aaa,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             };
@@ -1720,7 +1741,8 @@ pub mod g2 {
                         0x41abba710d6c692c,
                         0xffcc4b2b62ce8484,
                         0x6993ec01b8934ed,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0xb94e92d5f874e26,
                         0x44516408bc115d95,
@@ -1728,7 +1750,8 @@ pub mod g2 {
                         0xa5a0c2b7131f3555,
                         0x83800965822367e7,
                         0x10cf1d3ad8d90bfa,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -1738,7 +1761,8 @@ pub mod g2 {
                         0x5a9171720e73eb51,
                         0x38eb4fd8d658adb7,
                         0xb649051bbc1164d,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x9225814253d7df75,
                         0xc196c2513477f887,
@@ -1746,7 +1770,8 @@ pub mod g2 {
                         0x55f2b8efad953e04,
                         0x7379345eda55265e,
                         0x377f2e6208fd4cb,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             };
@@ -1766,7 +1791,8 @@ pub mod g2 {
                         0x2199bc19c48c393d,
                         0x4a151b732a6075bf,
                         0x17762a3b9108c4a7,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x26f461e944bbd3d1,
                         0x298f3189a9cf6ed6,
@@ -1774,7 +1800,8 @@ pub mod g2 {
                         0x7e147f3f9e6e241,
                         0x72a9b63583963fff,
                         0x158b0083c000462,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -1784,7 +1811,8 @@ pub mod g2 {
                         0x68cad19430706b4d,
                         0x3ccfb97b924dcea8,
                         0x1660f93434588f8d,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0xaaed3985b6dcb9c7,
                         0xc1e985d6d898d9f4,
@@ -1792,7 +1820,8 @@ pub mod g2 {
                         0x3940a2dbb914b529,
                         0xbeb88137cf34f3e7,
                         0x1699ee577c61b694,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             };
@@ -1812,7 +1841,8 @@ pub mod g2 {
                     0x72556c999f3707ac,
                     0x4617f2e6774e9711,
                     0x100b2fe5bffe030b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0x7a33555977ec608,
                     0xe23039d1fe9c0881,
@@ -1820,7 +1850,8 @@ pub mod g2 {
                     0x4637c4f417667e2e,
                     0x93ebe7c3e41f6acc,
                     0xde884f89a9a371b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             y: Fq2 {
                 c0: Fq::from_repr(FqRepr([
@@ -1830,7 +1861,8 @@ pub mod g2 {
                     0x25fd427b4122f231,
                     0xd83112aace35cae,
                     0x191b2432407cbb7f,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0xf68ae82fe97662f5,
                     0xe986057068b50b7d,
@@ -1838,7 +1870,8 @@ pub mod g2 {
                     0x9eaa6d19de569196,
                     0xf6a03d31e2ec2183,
                     0x3bdafaf7ca9b39b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             z: Fq2::one(),
         };
@@ -1852,7 +1885,8 @@ pub mod g2 {
                     0x8e73a96b329ad190,
                     0x27c546f75ee1f3ab,
                     0xa33d27add5e7e82,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0x93b1ebcd54870dfe,
                     0xf1578300e1342e11,
@@ -1860,7 +1894,8 @@ pub mod g2 {
                     0x2089faf462438296,
                     0x828e5848cd48ea66,
                     0x141ecbac1deb038b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             y: Fq2 {
                 c0: Fq::from_repr(FqRepr([
@@ -1870,7 +1905,8 @@ pub mod g2 {
                     0x2767032fc37cc31d,
                     0xd5ee2aba84fd10fe,
                     0x16576ccd3dd0a4e8,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0x4da9b6f6a96d1dd2,
                     0x9657f7da77f1650e,
@@ -1878,7 +1914,8 @@ pub mod g2 {
                     0x31898db63f87363a,
                     0xabab040ddbd097cc,
                     0x11ad236b9ba02990,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             z: Fq2::one(),
         });
@@ -1896,7 +1933,8 @@ pub mod g2 {
                         0xf1273e6406eef9cc,
                         0xababd760ff05cb92,
                         0xd7c20456617e89
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0xd1a50b8572cbd2b8,
                         0x238f0ac6119d07df,
@@ -1904,7 +1942,8 @@ pub mod g2 {
                         0x8b203284c51edf6b,
                         0xc8a0b730bbb21f5e,
                         0x1a3b59d29a31274
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -1914,7 +1953,8 @@ pub mod g2 {
                         0x64528ab3863633dc,
                         0x159384333d7cba97,
                         0x4cb84741f3cafe8
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x242af0dc3640e1a4,
                         0xe90a73ad65c66919,
@@ -1922,7 +1962,8 @@ pub mod g2 {
                         0x38528f92b689644d,
                         0xb6884deec59fb21f,
                         0x3c075d3ec52ba90
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             }
@@ -1940,7 +1981,8 @@ pub mod g2 {
                     0x72556c999f3707ac,
                     0x4617f2e6774e9711,
                     0x100b2fe5bffe030b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0x7a33555977ec608,
                     0xe23039d1fe9c0881,
@@ -1948,7 +1990,8 @@ pub mod g2 {
                     0x4637c4f417667e2e,
                     0x93ebe7c3e41f6acc,
                     0xde884f89a9a371b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             y: Fq2 {
                 c0: Fq::from_repr(FqRepr([
@@ -1958,7 +2001,8 @@ pub mod g2 {
                     0x25fd427b4122f231,
                     0xd83112aace35cae,
                     0x191b2432407cbb7f,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0xf68ae82fe97662f5,
                     0xe986057068b50b7d,
@@ -1966,7 +2010,8 @@ pub mod g2 {
                     0x9eaa6d19de569196,
                     0xf6a03d31e2ec2183,
                     0x3bdafaf7ca9b39b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             z: Fq2::one(),
         };
@@ -1986,7 +2031,8 @@ pub mod g2 {
                         0xbcedcfce1e52d986,
                         0x9755d4a3926e9862,
                         0x18bab73760fd8024
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x4e7c5e0a2ae5b99e,
                         0x96e582a27f028961,
@@ -1994,7 +2040,8 @@ pub mod g2 {
                         0xeb0cf5e610ef4fe7,
                         0x7b4c2bae8db6e70b,
                         0xf136e43909fca0
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -2004,7 +2051,8 @@ pub mod g2 {
                         0xa5a2a51f7fde787b,
                         0x8b92866bc6384188,
                         0x81a53fe531d64ef
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x4c5d607666239b34,
                         0xeddb5f48304d14b3,
@@ -2012,7 +2060,8 @@ pub mod g2 {
                         0xb271f52f12ead742,
                         0x244e6c2015c83348,
                         0x19e2deae6eb9b441
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             }

pairing/src/bls12_381/fq.rs

@@ -1173,7 +1173,9 @@ fn test_neg_one() {
 }
 
 #[cfg(test)]
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+#[cfg(test)]
+use rand_xorshift::XorShiftRng;
 
 #[test]
 fn test_fq_repr_ordering() {
@@ -1396,7 +1398,10 @@ fn test_fq_repr_num_bits() {
 
 #[test]
 fn test_fq_repr_sub_noborrow() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let mut t = FqRepr([
         0x827a4a08041ebd9,
@@ -1426,7 +1431,7 @@ fn test_fq_repr_sub_noborrow() {
     );
 
     for _ in 0..1000 {
-        let mut a = FqRepr::rand(&mut rng);
+        let mut a = Fq::random(&mut rng).into_repr();
         a.0[5] >>= 30;
         let mut b = a;
         for _ in 0..10 {
@@ -1483,7 +1488,10 @@ fn test_fq_repr_sub_noborrow() {
 
 #[test]
 fn test_fq_repr_add_nocarry() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let mut t = FqRepr([
         0x827a4a08041ebd9,
@@ -1514,9 +1522,9 @@ fn test_fq_repr_add_nocarry() {
 
     // Test for the associativity of addition.
     for _ in 0..1000 {
-        let mut a = FqRepr::rand(&mut rng);
+        let mut a = Fq::random(&mut rng).into_repr();
-        let mut b = FqRepr::rand(&mut rng);
+        let mut b = Fq::random(&mut rng).into_repr();
-        let mut c = FqRepr::rand(&mut rng);
+        let mut c = Fq::random(&mut rng).into_repr();
 
         // Unset the first few bits, so that overflow won't occur.
         a.0[5] >>= 3;
@@ -1574,31 +1582,32 @@ fn test_fq_is_valid() {
     a.0.sub_noborrow(&FqRepr::from(1));
     assert!(a.is_valid());
     assert!(Fq(FqRepr::from(0)).is_valid());
-    assert!(
+    assert!(Fq(FqRepr([
-        Fq(FqRepr([
+        0xdf4671abd14dab3e,
-            0xdf4671abd14dab3e,
+        0xe2dc0c9f534fbd33,
-            0xe2dc0c9f534fbd33,
+        0x31ca6c880cc444a6,
-            0x31ca6c880cc444a6,
+        0x257a67e70ef33359,
-            0x257a67e70ef33359,
+        0xf9b29e493f899b36,
-            0xf9b29e493f899b36,
+        0x17c8be1800b9f059
-            0x17c8be1800b9f059
+    ]))
-        ])).is_valid()
+    .is_valid());
-    );
+    assert!(!Fq(FqRepr([
-    assert!(
+        0xffffffffffffffff,
-        !Fq(FqRepr([
+        0xffffffffffffffff,
-            0xffffffffffffffff,
+        0xffffffffffffffff,
-            0xffffffffffffffff,
+        0xffffffffffffffff,
-            0xffffffffffffffff,
+        0xffffffffffffffff,
-            0xffffffffffffffff,
+        0xffffffffffffffff
-            0xffffffffffffffff,
+    ]))
-            0xffffffffffffffff
+    .is_valid());
-        ])).is_valid()
-    );
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
         assert!(a.is_valid());
     }
 }
@@ -1708,13 +1717,16 @@ fn test_fq_add_assign() {
 
     // Test associativity
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Generate a, b, c and ensure (a + b) + c == a + (b + c).
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
-        let b = Fq::rand(&mut rng);
+        let b = Fq::random(&mut rng);
-        let c = Fq::rand(&mut rng);
+        let c = Fq::random(&mut rng);
 
         let mut tmp1 = a;
         tmp1.add_assign(&b);
@@ -1818,12 +1830,15 @@ fn test_fq_sub_assign() {
         );
     }
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Ensure that (a - b) + (b - a) = 0.
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
-        let b = Fq::rand(&mut rng);
+        let b = Fq::random(&mut rng);
 
         let mut tmp1 = a;
         tmp1.sub_assign(&b);
@@ -1865,13 +1880,16 @@ fn test_fq_mul_assign() {
         ]))
     );
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000000 {
         // Ensure that (a * b) * c = a * (b * c)
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
-        let b = Fq::rand(&mut rng);
+        let b = Fq::random(&mut rng);
-        let c = Fq::rand(&mut rng);
+        let c = Fq::random(&mut rng);
 
         let mut tmp1 = a;
         tmp1.mul_assign(&b);
@@ -1887,10 +1905,10 @@ fn test_fq_mul_assign() {
     for _ in 0..1000000 {
         // Ensure that r * (a + b + c) = r*a + r*b + r*c
 
-        let r = Fq::rand(&mut rng);
+        let r = Fq::random(&mut rng);
-        let mut a = Fq::rand(&mut rng);
+        let mut a = Fq::random(&mut rng);
-        let mut b = Fq::rand(&mut rng);
+        let mut b = Fq::random(&mut rng);
-        let mut c = Fq::rand(&mut rng);
+        let mut c = Fq::random(&mut rng);
 
         let mut tmp1 = a;
         tmp1.add_assign(&b);
@@ -1929,14 +1947,18 @@ fn test_fq_squaring() {
             0xdc05c659b4e15b27,
             0x79361e5a802c6a23,
             0x24bcbe5d51b9a6f
-        ])).unwrap()
+        ]))
+        .unwrap()
     );
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000000 {
         // Ensure that (a * a) = a^2
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
 
         let mut tmp = a;
         tmp.square();
@@ -1952,13 +1974,16 @@ fn test_fq_squaring() {
 fn test_fq_inverse() {
     assert!(Fq::zero().inverse().is_none());
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let one = Fq::one();
 
     for _ in 0..1000 {
         // Ensure that a * a^-1 = 1
-        let mut a = Fq::rand(&mut rng);
+        let mut a = Fq::random(&mut rng);
         let ainv = a.inverse().unwrap();
         a.mul_assign(&ainv);
         assert_eq!(a, one);
@@ -1967,11 +1992,14 @@ fn test_fq_inverse() {
 
 #[test]
 fn test_fq_double() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Ensure doubling a is equivalent to adding a to itself.
-        let mut a = Fq::rand(&mut rng);
+        let mut a = Fq::random(&mut rng);
         let mut b = a;
         b.add_assign(&a);
         a.double();
@@ -1988,11 +2016,14 @@ fn test_fq_negate() {
         assert!(a.is_zero());
     }
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Ensure (a - (-a)) = 0.
-        let mut a = Fq::rand(&mut rng);
+        let mut a = Fq::random(&mut rng);
         let mut b = a;
         b.negate();
         a.add_assign(&b);
@@ -2003,12 +2034,15 @@ fn test_fq_negate() {
 
 #[test]
 fn test_fq_pow() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for i in 0..1000 {
         // Exponentiate by various small numbers and ensure it consists with repeated
         // multiplication.
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
         let target = a.pow(&[i]);
         let mut c = Fq::one();
         for _ in 0..i {
@@ -2019,7 +2053,7 @@ fn test_fq_pow() {
 
     for _ in 0..1000 {
         // Exponentiating by the modulus should have no effect in a prime field.
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
 
         assert_eq!(a, a.pow(Fq::char()));
     }
@@ -2029,13 +2063,16 @@ fn test_fq_pow() {
 fn test_fq_sqrt() {
     use ff::SqrtField;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     assert_eq!(Fq::zero().sqrt().unwrap(), Fq::zero());
 
     for _ in 0..1000 {
         // Ensure sqrt(a^2) = a or -a
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
         let mut nega = a;
         nega.negate();
         let mut b = a;
@@ -2048,7 +2085,7 @@ fn test_fq_sqrt() {
 
     for _ in 0..1000 {
         // Ensure sqrt(a)^2 = a for random a
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
 
         if let Some(mut tmp) = a.sqrt() {
             tmp.square();
@@ -2061,16 +2098,15 @@ fn test_fq_sqrt() {
 #[test]
 fn test_fq_from_into_repr() {
     // q + 1 should not be in the field
-    assert!(
+    assert!(Fq::from_repr(FqRepr([
-        Fq::from_repr(FqRepr([
+        0xb9feffffffffaaac,
-            0xb9feffffffffaaac,
+        0x1eabfffeb153ffff,
-            0x1eabfffeb153ffff,
+        0x6730d2a0f6b0f624,
-            0x6730d2a0f6b0f624,
+        0x64774b84f38512bf,
-            0x64774b84f38512bf,
+        0x4b1ba7b6434bacd7,
-            0x4b1ba7b6434bacd7,
+        0x1a0111ea397fe69a
-            0x1a0111ea397fe69a
+    ]))
-        ])).is_err()
+    .is_err());
-    );
 
     // q should not be in the field
     assert!(Fq::from_repr(Fq::char()).is_err());
@@ -2108,11 +2144,14 @@ fn test_fq_from_into_repr() {
     // Zero should be in the field.
     assert!(Fq::from_repr(FqRepr::from(0)).unwrap().is_zero());
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Try to turn Fq elements into representations and back again, and compare.
-        let a = Fq::rand(&mut rng);
+        let a = Fq::random(&mut rng);
         let a_repr = a.into_repr();
         let b_repr = FqRepr::from(a);
         assert_eq!(a_repr, b_repr);
@@ -2186,10 +2225,10 @@ fn test_fq_root_of_unity() {
 
 #[test]
 fn fq_field_tests() {
-    ::tests::field::random_field_tests::<Fq>();
+    crate::tests::field::random_field_tests::<Fq>();
-    ::tests::field::random_sqrt_tests::<Fq>();
+    crate::tests::field::random_sqrt_tests::<Fq>();
-    ::tests::field::random_frobenius_tests::<Fq, _>(Fq::char(), 13);
+    crate::tests::field::random_frobenius_tests::<Fq, _>(Fq::char(), 13);
-    ::tests::field::from_str_tests::<Fq>();
+    crate::tests::field::from_str_tests::<Fq>();
 }
 
 #[test]
@@ -2205,7 +2244,7 @@ fn test_fq_ordering() {
 
 #[test]
 fn fq_repr_tests() {
-    ::tests::repr::random_repr_tests::<FqRepr>();
+    crate::tests::repr::random_repr_tests::<Fq>();
 }
 
 #[test]

pairing/src/bls12_381/fq12.rs

@@ -2,7 +2,7 @@ use super::fq::FROBENIUS_COEFF_FQ12_C1;
 use super::fq2::Fq2;
 use super::fq6::Fq6;
 use ff::Field;
-use rand::{Rand, Rng};
+use rand_core::RngCore;
 
 /// An element of Fq12, represented by c0 + c1 * w.
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
@@ -12,20 +12,11 @@ pub struct Fq12 {
 }
 
 impl ::std::fmt::Display for Fq12 {
-    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
         write!(f, "Fq12({} + {} * w)", self.c0, self.c1)
     }
 }
 
-impl Rand for Fq12 {
-    fn rand<R: Rng>(rng: &mut R) -> Self {
-        Fq12 {
-            c0: rng.gen(),
-            c1: rng.gen(),
-        }
-    }
-}
-
 impl Fq12 {
     pub fn conjugate(&mut self) {
         self.c1.negate();
@@ -49,6 +40,13 @@ impl Fq12 {
 }
 
 impl Field for Fq12 {
+    fn random<R: RngCore + ?std::marker::Sized>(rng: &mut R) -> Self {
+        Fq12 {
+            c0: Fq6::random(rng),
+            c1: Fq6::random(rng),
+        }
+    }
+
     fn zero() -> Self {
         Fq12 {
             c0: Fq6::zero(),
@@ -149,24 +147,29 @@ impl Field for Fq12 {
 }
 
 #[cfg(test)]
-use rand::{SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+#[cfg(test)]
+use rand_xorshift::XorShiftRng;
 
 #[test]
 fn test_fq12_mul_by_014() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let c0 = Fq2::rand(&mut rng);
+        let c0 = Fq2::random(&mut rng);
-        let c1 = Fq2::rand(&mut rng);
+        let c1 = Fq2::random(&mut rng);
-        let c5 = Fq2::rand(&mut rng);
+        let c5 = Fq2::random(&mut rng);
-        let mut a = Fq12::rand(&mut rng);
+        let mut a = Fq12::random(&mut rng);
         let mut b = a;
 
         a.mul_by_014(&c0, &c1, &c5);
         b.mul_assign(&Fq12 {
             c0: Fq6 {
-                c0: c0,
+                c0,
-                c1: c1,
+                c1,
                 c2: Fq2::zero(),
             },
             c1: Fq6 {
@@ -184,6 +187,6 @@ fn test_fq12_mul_by_014() {
 fn fq12_field_tests() {
     use ff::PrimeField;
 
-    ::tests::field::random_field_tests::<Fq12>();
+    crate::tests::field::random_field_tests::<Fq12>();
-    ::tests::field::random_frobenius_tests::<Fq12, _>(super::fq::Fq::char(), 13);
+    crate::tests::field::random_frobenius_tests::<Fq12, _>(super::fq::Fq::char(), 13);
 }

pairing/src/bls12_381/fq2.rs

@@ -1,6 +1,6 @@
-use super::fq::{FROBENIUS_COEFF_FQ2_C1, Fq, NEGATIVE_ONE};
+use super::fq::{Fq, FROBENIUS_COEFF_FQ2_C1, NEGATIVE_ONE};
 use ff::{Field, SqrtField};
-use rand::{Rand, Rng};
+use rand_core::RngCore;
 
 use std::cmp::Ordering;
 
@@ -12,7 +12,7 @@ pub struct Fq2 {
 }
 
 impl ::std::fmt::Display for Fq2 {
-    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
         write!(f, "Fq2({} + {} * u)", self.c0, self.c1)
     }
 }
@@ -56,16 +56,14 @@ impl Fq2 {
     }
 }
 
-impl Rand for Fq2 {
+impl Field for Fq2 {
-    fn rand<R: Rng>(rng: &mut R) -> Self {
+    fn random<R: RngCore + ?std::marker::Sized>(rng: &mut R) -> Self {
         Fq2 {
-            c0: rng.gen(),
+            c0: Fq::random(rng),
-            c1: rng.gen(),
+            c1: Fq::random(rng),
         }
     }
-}
 
-impl Field for Fq2 {
     fn zero() -> Self {
         Fq2 {
             c0: Fq::zero(),
@@ -263,12 +261,11 @@ fn test_fq2_basics() {
     );
     assert!(Fq2::zero().is_zero());
     assert!(!Fq2::one().is_zero());
-    assert!(
+    assert!(!Fq2 {
-        !Fq2 {
+        c0: Fq::zero(),
-            c0: Fq::zero(),
+        c1: Fq::one(),
-            c1: Fq::one(),
+    }
-        }.is_zero()
+    .is_zero());
-    );
 }
 
 #[test]
@@ -311,7 +308,8 @@ fn test_fq2_squaring() {
             0xf7f295a94e58ae7c,
             0x41b76dcc1c3fbe5e,
             0x7080c5fa1d8e042,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x38f473b3c870a4ab,
             0x6ad3291177c8c7e5,
@@ -319,7 +317,8 @@ fn test_fq2_squaring() {
             0xbfb99020604137a0,
             0xfc58a7b7be815407,
             0x10d1615e75250a21,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.square();
     assert_eq!(
@@ -332,7 +331,8 @@ fn test_fq2_squaring() {
                 0xcb674157618da176,
                 0x4cf17b5893c3d327,
                 0x7eac81369c43361
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xc1579cf58e980cf8,
                 0xa23eb7e12dd54d98,
@@ -340,7 +340,8 @@ fn test_fq2_squaring() {
                 0x38d0d7275a9689e1,
                 0x739c983042779a65,
                 0x1542a61c8a8db994
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -358,7 +359,8 @@ fn test_fq2_mul() {
             0x9ee53e7e84d7532e,
             0x1c202d8ed97afb45,
             0x51d3f9253e2516f,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0xa7348a8b511aedcf,
             0x143c215d8176b319,
@@ -366,7 +368,8 @@ fn test_fq2_mul() {
             0x9533e4a9a5158be,
             0x7a5e1ecb676d65f9,
             0x180c3ee46656b008,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.mul_assign(&Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -376,7 +379,8 @@ fn test_fq2_mul() {
             0xcd460f9f0c23e430,
             0x6c9110292bfa409,
             0x2c93a72eb8af83e,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x4b1c3f936d8992d4,
             0x1d2a72916dba4c8a,
@@ -384,7 +388,8 @@ fn test_fq2_mul() {
             0x57a06d3135a752ae,
             0x634cd3c6c565096d,
             0x19e17334d4e93558,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     });
     assert_eq!(
         a,
@@ -396,7 +401,8 @@ fn test_fq2_mul() {
                 0x5511fe4d84ee5f78,
                 0x5310a202d92f9963,
                 0x1751afbe166e5399
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x84af0e1bd630117a,
                 0x6c63cd4da2c2aa7,
@@ -404,7 +410,8 @@ fn test_fq2_mul() {
                 0xc975106579c275ee,
                 0x33a9ac82ce4c5083,
                 0x1ef1a36c201589d
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -424,7 +431,8 @@ fn test_fq2_inverse() {
             0x9ee53e7e84d7532e,
             0x1c202d8ed97afb45,
             0x51d3f9253e2516f,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0xa7348a8b511aedcf,
             0x143c215d8176b319,
@@ -432,7 +440,8 @@ fn test_fq2_inverse() {
             0x9533e4a9a5158be,
             0x7a5e1ecb676d65f9,
             0x180c3ee46656b008,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     let a = a.inverse().unwrap();
     assert_eq!(
@@ -445,7 +454,8 @@ fn test_fq2_inverse() {
                 0xdfba703293941c30,
                 0xa6c3d8f9586f2636,
                 0x1351ef01941b70c4
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x8c39fd76a8312cb4,
                 0x15d7b6b95defbff0,
@@ -453,7 +463,8 @@ fn test_fq2_inverse() {
                 0xcbf651a0f367afb2,
                 0xdf4e54f0d3ef15a6,
                 0x103bdf241afb0019
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -471,7 +482,8 @@ fn test_fq2_addition() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -479,7 +491,8 @@ fn test_fq2_addition() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.add_assign(&Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -489,7 +502,8 @@ fn test_fq2_addition() {
             0x3b88899a42a6318f,
             0x986a4a62fa82a49d,
             0x13ce433fa26027f5,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x66323bf80b58b9b9,
             0xa1379b6facf6e596,
@@ -497,7 +511,8 @@ fn test_fq2_addition() {
             0x2236f55246d0d44d,
             0x4c8c1800eb104566,
             0x11d6e20e986c2085,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     });
     assert_eq!(
         a,
@@ -509,7 +524,8 @@ fn test_fq2_addition() {
                 0xf4ef57d604b6bca2,
                 0x65309427b3d5d090,
                 0x14c715d5553f01d2
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xfdb032e7d9079a94,
                 0x35a2809d15468d83,
@@ -517,7 +533,8 @@ fn test_fq2_addition() {
                 0xd62fa51334f560fa,
                 0x9ad265eb46e01984,
                 0x1303f3465112c8bc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -535,7 +552,8 @@ fn test_fq2_subtraction() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -543,7 +561,8 @@ fn test_fq2_subtraction() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.sub_assign(&Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -553,7 +572,8 @@ fn test_fq2_subtraction() {
             0x3b88899a42a6318f,
             0x986a4a62fa82a49d,
             0x13ce433fa26027f5,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x66323bf80b58b9b9,
             0xa1379b6facf6e596,
@@ -561,7 +581,8 @@ fn test_fq2_subtraction() {
             0x2236f55246d0d44d,
             0x4c8c1800eb104566,
             0x11d6e20e986c2085,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     });
     assert_eq!(
         a,
@@ -573,7 +594,8 @@ fn test_fq2_subtraction() {
                 0xe255902672ef6c43,
                 0x7f77a718021c342d,
                 0x72ba14049fe9881
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xeb4abaf7c255d1cd,
                 0x11df49bc6cacc256,
@@ -581,7 +603,8 @@ fn test_fq2_subtraction() {
                 0xf63905f39ad8cb1f,
                 0x4cd5dd9fb40b3b8f,
                 0x957411359ba6e4c
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -599,7 +622,8 @@ fn test_fq2_negation() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -607,7 +631,8 @@ fn test_fq2_negation() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.negate();
     assert_eq!(
@@ -620,7 +645,8 @@ fn test_fq2_negation() {
                 0xab107d49317487ab,
                 0x7e555df189f880e3,
                 0x19083f5486a10cbd
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x228109103250c9d0,
                 0x8a411ad149045812,
@@ -628,7 +654,8 @@ fn test_fq2_negation() {
                 0xb07e9bc405608611,
                 0xfcd559cbe77bd8b8,
                 0x18d400b280d93e62
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -646,7 +673,8 @@ fn test_fq2_doubling() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -654,7 +682,8 @@ fn test_fq2_doubling() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.double();
     assert_eq!(
@@ -667,7 +696,8 @@ fn test_fq2_doubling() {
                 0x72cd9c7784211627,
                 0x998c938972a657e7,
                 0x1f1a52b65bdb3b9
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x2efbeddf9b5dc1b6,
                 0x28d5ca5ad09f4fdb,
@@ -675,7 +705,8 @@ fn test_fq2_doubling() {
                 0x67f15f81dc49195b,
                 0x9c8c9bd4b79fa83d,
                 0x25a226f714d506e
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -693,7 +724,8 @@ fn test_fq2_frobenius_map() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -701,7 +733,8 @@ fn test_fq2_frobenius_map() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.frobenius_map(0);
     assert_eq!(
@@ -714,7 +747,8 @@ fn test_fq2_frobenius_map() {
                 0xb966ce3bc2108b13,
                 0xccc649c4b9532bf3,
                 0xf8d295b2ded9dc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x977df6efcdaee0db,
                 0x946ae52d684fa7ed,
@@ -722,7 +756,8 @@ fn test_fq2_frobenius_map() {
                 0xb3f8afc0ee248cad,
                 0x4e464dea5bcfd41e,
                 0x12d1137b8a6a837
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
     a.frobenius_map(1);
@@ -736,7 +771,8 @@ fn test_fq2_frobenius_map() {
                 0xb966ce3bc2108b13,
                 0xccc649c4b9532bf3,
                 0xf8d295b2ded9dc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x228109103250c9d0,
                 0x8a411ad149045812,
@@ -744,7 +780,8 @@ fn test_fq2_frobenius_map() {
                 0xb07e9bc405608611,
                 0xfcd559cbe77bd8b8,
                 0x18d400b280d93e62
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
     a.frobenius_map(1);
@@ -758,7 +795,8 @@ fn test_fq2_frobenius_map() {
                 0xb966ce3bc2108b13,
                 0xccc649c4b9532bf3,
                 0xf8d295b2ded9dc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x977df6efcdaee0db,
                 0x946ae52d684fa7ed,
@@ -766,7 +804,8 @@ fn test_fq2_frobenius_map() {
                 0xb3f8afc0ee248cad,
                 0x4e464dea5bcfd41e,
                 0x12d1137b8a6a837
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
     a.frobenius_map(2);
@@ -780,7 +819,8 @@ fn test_fq2_frobenius_map() {
                 0xb966ce3bc2108b13,
                 0xccc649c4b9532bf3,
                 0xf8d295b2ded9dc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x977df6efcdaee0db,
                 0x946ae52d684fa7ed,
@@ -788,7 +828,8 @@ fn test_fq2_frobenius_map() {
                 0xb3f8afc0ee248cad,
                 0x4e464dea5bcfd41e,
                 0x12d1137b8a6a837
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -807,7 +848,8 @@ fn test_fq2_sqrt() {
                 0xdb4a116b5bf74aa1,
                 0x1e58b2159dfe10e2,
                 0x7ca7da1f13606ac
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xfa8de88b7516d2c3,
                 0x371a75ed14f41629,
@@ -815,9 +857,11 @@ fn test_fq2_sqrt() {
                 0x212611bca4e99121,
                 0x8ee5394d77afb3d,
                 0xec92336650e49d5
-            ])).unwrap(),
+            ]))
-        }.sqrt()
             .unwrap(),
+        }
+        .sqrt()
+        .unwrap(),
         Fq2 {
             c0: Fq::from_repr(FqRepr([
                 0x40b299b2704258c5,
@@ -826,7 +870,8 @@ fn test_fq2_sqrt() {
                 0x8d7f1f723d02c1d3,
                 0x881b3e01b611c070,
                 0x10f6963bbad2ebc5
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xc099534fc209e752,
                 0x7670594665676447,
@@ -834,7 +879,8 @@ fn test_fq2_sqrt() {
                 0x6b852aeaf2afcb1b,
                 0xa4c93b08105d71a9,
                 0x8d7cfff94216330
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 
@@ -847,10 +893,12 @@ fn test_fq2_sqrt() {
                 0x64774b84f38512bf,
                 0x4b1ba7b6434bacd7,
                 0x1a0111ea397fe69a
-            ])).unwrap(),
+            ]))
-            c1: Fq::zero(),
-        }.sqrt()
             .unwrap(),
+            c1: Fq::zero(),
+        }
+        .sqrt()
+        .unwrap(),
         Fq2 {
             c0: Fq::zero(),
             c1: Fq::from_repr(FqRepr([
@@ -860,7 +908,8 @@ fn test_fq2_sqrt() {
                 0x64774b84f38512bf,
                 0x4b1ba7b6434bacd7,
                 0x1a0111ea397fe69a
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -879,11 +928,16 @@ fn test_fq2_legendre() {
 }
 
 #[cfg(test)]
-use rand::{SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+#[cfg(test)]
+use rand_xorshift::XorShiftRng;
 
 #[test]
 fn test_fq2_mul_nonresidue() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let nqr = Fq2 {
         c0: Fq::one(),
@@ -891,7 +945,7 @@ fn test_fq2_mul_nonresidue() {
     };
 
     for _ in 0..1000 {
-        let mut a = Fq2::rand(&mut rng);
+        let mut a = Fq2::random(&mut rng);
         let mut b = a;
         a.mul_by_nonresidue();
         b.mul_assign(&nqr);
@@ -904,7 +958,7 @@ fn test_fq2_mul_nonresidue() {
 fn fq2_field_tests() {
     use ff::PrimeField;
 
-    ::tests::field::random_field_tests::<Fq2>();
+    crate::tests::field::random_field_tests::<Fq2>();
-    ::tests::field::random_sqrt_tests::<Fq2>();
+    crate::tests::field::random_sqrt_tests::<Fq2>();
-    ::tests::field::random_frobenius_tests::<Fq2, _>(super::fq::Fq::char(), 13);
+    crate::tests::field::random_frobenius_tests::<Fq2, _>(super::fq::Fq::char(), 13);
 }

pairing/src/bls12_381/fq6.rs

@@ -1,7 +1,7 @@
 use super::fq::{FROBENIUS_COEFF_FQ6_C1, FROBENIUS_COEFF_FQ6_C2};
 use super::fq2::Fq2;
 use ff::Field;
-use rand::{Rand, Rng};
+use rand_core::RngCore;
 
 /// An element of Fq6, represented by c0 + c1 * v + c2 * v^(2).
 #[derive(Copy, Clone, Debug, Eq, PartialEq)]
@@ -12,21 +12,11 @@ pub struct Fq6 {
 }
 
 impl ::std::fmt::Display for Fq6 {
-    fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+    fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
         write!(f, "Fq6({} + {} * v, {} * v^2)", self.c0, self.c1, self.c2)
     }
 }
 
-impl Rand for Fq6 {
-    fn rand<R: Rng>(rng: &mut R) -> Self {
-        Fq6 {
-            c0: rng.gen(),
-            c1: rng.gen(),
-            c2: rng.gen(),
-        }
-    }
-}
-
 impl Fq6 {
     /// Multiply by quadratic nonresidue v.
     pub fn mul_by_nonresidue(&mut self) {
@@ -110,6 +100,14 @@ impl Fq6 {
 }
 
 impl Field for Fq6 {
+    fn random<R: RngCore + ?std::marker::Sized>(rng: &mut R) -> Self {
+        Fq6 {
+            c0: Fq2::random(rng),
+            c1: Fq2::random(rng),
+            c2: Fq2::random(rng),
+        }
+    }
+
     fn zero() -> Self {
         Fq6 {
             c0: Fq2::zero(),
@@ -302,11 +300,16 @@ impl Field for Fq6 {
 }
 
 #[cfg(test)]
-use rand::{SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+#[cfg(test)]
+use rand_xorshift::XorShiftRng;
 
 #[test]
 fn test_fq6_mul_nonresidue() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let nqr = Fq6 {
         c0: Fq2::zero(),
@@ -315,7 +318,7 @@ fn test_fq6_mul_nonresidue() {
     };
 
     for _ in 0..1000 {
-        let mut a = Fq6::rand(&mut rng);
+        let mut a = Fq6::random(&mut rng);
         let mut b = a;
         a.mul_by_nonresidue();
         b.mul_assign(&nqr);
@@ -326,17 +329,20 @@ fn test_fq6_mul_nonresidue() {
 
 #[test]
 fn test_fq6_mul_by_1() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let c1 = Fq2::rand(&mut rng);
+        let c1 = Fq2::random(&mut rng);
-        let mut a = Fq6::rand(&mut rng);
+        let mut a = Fq6::random(&mut rng);
         let mut b = a;
 
         a.mul_by_1(&c1);
         b.mul_assign(&Fq6 {
             c0: Fq2::zero(),
-            c1: c1,
+            c1,
             c2: Fq2::zero(),
         });
 
@@ -346,18 +352,21 @@ fn test_fq6_mul_by_1() {
 
 #[test]
 fn test_fq6_mul_by_01() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let c0 = Fq2::rand(&mut rng);
+        let c0 = Fq2::random(&mut rng);
-        let c1 = Fq2::rand(&mut rng);
+        let c1 = Fq2::random(&mut rng);
-        let mut a = Fq6::rand(&mut rng);
+        let mut a = Fq6::random(&mut rng);
         let mut b = a;
 
         a.mul_by_01(&c0, &c1);
         b.mul_assign(&Fq6 {
-            c0: c0,
+            c0,
-            c1: c1,
+            c1,
             c2: Fq2::zero(),
         });
 
@@ -369,6 +378,6 @@ fn test_fq6_mul_by_01() {
 fn fq6_field_tests() {
     use ff::PrimeField;
 
-    ::tests::field::random_field_tests::<Fq6>();
+    crate::tests::field::random_field_tests::<Fq6>();
-    ::tests::field::random_frobenius_tests::<Fq6, _>(super::fq::Fq::char(), 13);
+    crate::tests::field::random_frobenius_tests::<Fq6, _>(super::fq::Fq::char(), 13);
 }

pairing/src/bls12_381/fr.rs

@@ -6,7 +6,9 @@ use ff::{Field, PrimeField, PrimeFieldDecodingError, PrimeFieldRepr};
 pub struct Fr(FrRepr);
 
 #[cfg(test)]
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+#[cfg(test)]
+use rand_xorshift::XorShiftRng;
 
 #[test]
 fn test_fr_repr_ordering() {
@@ -197,7 +199,10 @@ fn test_fr_repr_num_bits() {
 
 #[test]
 fn test_fr_repr_sub_noborrow() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let mut t = FrRepr([
         0x8e62a7e85264e2c3,
@@ -221,7 +226,7 @@ fn test_fr_repr_sub_noborrow() {
     );
 
     for _ in 0..1000 {
-        let mut a = FrRepr::rand(&mut rng);
+        let mut a = Fr::random(&mut rng).into_repr();
         a.0[3] >>= 30;
         let mut b = a;
         for _ in 0..10 {
@@ -296,7 +301,10 @@ fn test_fr_legendre() {
 
 #[test]
 fn test_fr_repr_add_nocarry() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let mut t = FrRepr([
         0xd64f669809cbc6a4,
@@ -322,9 +330,9 @@ fn test_fr_repr_add_nocarry() {
 
     // Test for the associativity of addition.
     for _ in 0..1000 {
-        let mut a = FrRepr::rand(&mut rng);
+        let mut a = Fr::random(&mut rng).into_repr();
-        let mut b = FrRepr::rand(&mut rng);
+        let mut b = Fr::random(&mut rng).into_repr();
-        let mut c = FrRepr::rand(&mut rng);
+        let mut c = Fr::random(&mut rng).into_repr();
 
         // Unset the first few bits, so that overflow won't occur.
         a.0[3] >>= 3;
@@ -380,27 +388,28 @@ fn test_fr_is_valid() {
     a.0.sub_noborrow(&FrRepr::from(1));
     assert!(a.is_valid());
     assert!(Fr(FrRepr::from(0)).is_valid());
-    assert!(
+    assert!(Fr(FrRepr([
-        Fr(FrRepr([
+        0xffffffff00000000,
-            0xffffffff00000000,
+        0x53bda402fffe5bfe,
-            0x53bda402fffe5bfe,
+        0x3339d80809a1d805,
-            0x3339d80809a1d805,
+        0x73eda753299d7d48
-            0x73eda753299d7d48
+    ]))
-        ])).is_valid()
+    .is_valid());
-    );
+    assert!(!Fr(FrRepr([
-    assert!(
+        0xffffffffffffffff,
-        !Fr(FrRepr([
+        0xffffffffffffffff,
-            0xffffffffffffffff,
+        0xffffffffffffffff,
-            0xffffffffffffffff,
+        0xffffffffffffffff
-            0xffffffffffffffff,
+    ]))
-            0xffffffffffffffff
+    .is_valid());
-        ])).is_valid()
-    );
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
         assert!(a.is_valid());
     }
 }
@@ -492,13 +501,16 @@ fn test_fr_add_assign() {
 
     // Test associativity
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Generate a, b, c and ensure (a + b) + c == a + (b + c).
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
-        let b = Fr::rand(&mut rng);
+        let b = Fr::random(&mut rng);
-        let c = Fr::rand(&mut rng);
+        let c = Fr::random(&mut rng);
 
         let mut tmp1 = a;
         tmp1.add_assign(&b);
@@ -586,12 +598,15 @@ fn test_fr_sub_assign() {
         );
     }
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Ensure that (a - b) + (b - a) = 0.
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
-        let b = Fr::rand(&mut rng);
+        let b = Fr::random(&mut rng);
 
         let mut tmp1 = a;
         tmp1.sub_assign(&b);
@@ -627,13 +642,16 @@ fn test_fr_mul_assign() {
         ]))
     );
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000000 {
         // Ensure that (a * b) * c = a * (b * c)
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
-        let b = Fr::rand(&mut rng);
+        let b = Fr::random(&mut rng);
-        let c = Fr::rand(&mut rng);
+        let c = Fr::random(&mut rng);
 
         let mut tmp1 = a;
         tmp1.mul_assign(&b);
@@ -649,10 +667,10 @@ fn test_fr_mul_assign() {
     for _ in 0..1000000 {
         // Ensure that r * (a + b + c) = r*a + r*b + r*c
 
-        let r = Fr::rand(&mut rng);
+        let r = Fr::random(&mut rng);
-        let mut a = Fr::rand(&mut rng);
+        let mut a = Fr::random(&mut rng);
-        let mut b = Fr::rand(&mut rng);
+        let mut b = Fr::random(&mut rng);
-        let mut c = Fr::rand(&mut rng);
+        let mut c = Fr::random(&mut rng);
 
         let mut tmp1 = a;
         tmp1.add_assign(&b);
@@ -687,14 +705,18 @@ fn test_fr_squaring() {
             0xb79a310579e76ec2,
             0xac1da8d0a9af4e5f,
             0x13f629c49bf23e97
-        ])).unwrap()
+        ]))
+        .unwrap()
     );
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000000 {
         // Ensure that (a * a) = a^2
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
 
         let mut tmp = a;
         tmp.square();
@@ -710,13 +732,16 @@ fn test_fr_squaring() {
 fn test_fr_inverse() {
     assert!(Fr::zero().inverse().is_none());
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     let one = Fr::one();
 
     for _ in 0..1000 {
         // Ensure that a * a^-1 = 1
-        let mut a = Fr::rand(&mut rng);
+        let mut a = Fr::random(&mut rng);
         let ainv = a.inverse().unwrap();
         a.mul_assign(&ainv);
         assert_eq!(a, one);
@@ -725,11 +750,14 @@ fn test_fr_inverse() {
 
 #[test]
 fn test_fr_double() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Ensure doubling a is equivalent to adding a to itself.
-        let mut a = Fr::rand(&mut rng);
+        let mut a = Fr::random(&mut rng);
         let mut b = a;
         b.add_assign(&a);
         a.double();
@@ -746,11 +774,14 @@ fn test_fr_negate() {
         assert!(a.is_zero());
     }
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Ensure (a - (-a)) = 0.
-        let mut a = Fr::rand(&mut rng);
+        let mut a = Fr::random(&mut rng);
         let mut b = a;
         b.negate();
         a.add_assign(&b);
@@ -761,12 +792,15 @@ fn test_fr_negate() {
 
 #[test]
 fn test_fr_pow() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for i in 0..1000 {
         // Exponentiate by various small numbers and ensure it consists with repeated
         // multiplication.
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
         let target = a.pow(&[i]);
         let mut c = Fr::one();
         for _ in 0..i {
@@ -777,7 +811,7 @@ fn test_fr_pow() {
 
     for _ in 0..1000 {
         // Exponentiating by the modulus should have no effect in a prime field.
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
 
         assert_eq!(a, a.pow(Fr::char()));
     }
@@ -787,13 +821,16 @@ fn test_fr_pow() {
 fn test_fr_sqrt() {
     use ff::SqrtField;
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     assert_eq!(Fr::zero().sqrt().unwrap(), Fr::zero());
 
     for _ in 0..1000 {
         // Ensure sqrt(a^2) = a or -a
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
         let mut nega = a;
         nega.negate();
         let mut b = a;
@@ -806,7 +843,7 @@ fn test_fr_sqrt() {
 
     for _ in 0..1000 {
         // Ensure sqrt(a)^2 = a for random a
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
 
         if let Some(mut tmp) = a.sqrt() {
             tmp.square();
@@ -819,14 +856,13 @@ fn test_fr_sqrt() {
 #[test]
 fn test_fr_from_into_repr() {
     // r + 1 should not be in the field
-    assert!(
+    assert!(Fr::from_repr(FrRepr([
-        Fr::from_repr(FrRepr([
+        0xffffffff00000002,
-            0xffffffff00000002,
+        0x53bda402fffe5bfe,
-            0x53bda402fffe5bfe,
+        0x3339d80809a1d805,
-            0x3339d80809a1d805,
+        0x73eda753299d7d48
-            0x73eda753299d7d48
+    ]))
-        ])).is_err()
+    .is_err());
-    );
 
     // r should not be in the field
     assert!(Fr::from_repr(Fr::char()).is_err());
@@ -858,11 +894,14 @@ fn test_fr_from_into_repr() {
     // Zero should be in the field.
     assert!(Fr::from_repr(FrRepr::from(0)).unwrap().is_zero());
 
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
         // Try to turn Fr elements into representations and back again, and compare.
-        let a = Fr::rand(&mut rng);
+        let a = Fr::random(&mut rng);
         let a_repr = a.into_repr();
         let b_repr = FrRepr::from(a);
         assert_eq!(a_repr, b_repr);
@@ -926,7 +965,8 @@ fn test_fr_display() {
                 0x185ec8eb3f5b5aee,
                 0x684499ffe4b9dd99,
                 0x7c9bba7afb68faa
-            ])).unwrap()
+            ]))
+            .unwrap()
         ),
         "Fr(0x07c9bba7afb68faa684499ffe4b9dd99185ec8eb3f5b5aeec3cae746a3b5ecc7)".to_string()
     );
@@ -938,7 +978,8 @@ fn test_fr_display() {
                 0xb0ad10817df79b6a,
                 0xd034a80a2b74132b,
                 0x41cf9a1336f50719
-            ])).unwrap()
+            ]))
+            .unwrap()
         ),
         "Fr(0x41cf9a1336f50719d034a80a2b74132bb0ad10817df79b6a44c71298ff198106)".to_string()
     );
@@ -974,13 +1015,13 @@ fn test_fr_root_of_unity() {
 
 #[test]
 fn fr_field_tests() {
-    ::tests::field::random_field_tests::<Fr>();
+    crate::tests::field::random_field_tests::<Fr>();
-    ::tests::field::random_sqrt_tests::<Fr>();
+    crate::tests::field::random_sqrt_tests::<Fr>();
-    ::tests::field::random_frobenius_tests::<Fr, _>(Fr::char(), 13);
+    crate::tests::field::random_frobenius_tests::<Fr, _>(Fr::char(), 13);
-    ::tests::field::from_str_tests::<Fr>();
+    crate::tests::field::from_str_tests::<Fr>();
 }
 
 #[test]
 fn fr_repr_tests() {
-    ::tests::repr::random_repr_tests::<FrRepr>();
+    crate::tests::repr::random_repr_tests::<Fr>();
 }

pairing/src/bls12_381/mod.rs

@@ -1,3 +1,6 @@
+//! An implementation of the BLS12-381 pairing-friendly elliptic curve
+//! construction.
+
 mod ec;
 mod fq;
 mod fq12;
@@ -9,8 +12,8 @@ mod fr;
 mod tests;
 
 pub use self::ec::{
-    G1, G1Affine, G1Compressed, G1Prepared, G1Uncompressed, G2, G2Affine, G2Compressed, G2Prepared,
+    G1Affine, G1Compressed, G1Prepared, G1Uncompressed, G2Affine, G2Compressed, G2Prepared,
-    G2Uncompressed,
+    G2Uncompressed, G1, G2,
 };
 pub use self::fq::{Fq, FqRepr};
 pub use self::fq12::Fq12;
@@ -366,5 +369,5 @@ impl G2Prepared {
 
 #[test]
 fn bls12_engine_tests() {
-    ::tests::engine::engine_tests::<Bls12>();
+    crate::tests::engine::engine_tests::<Bls12>();
 }

pairing/src/bls12_381/tests/mod.rs

@@ -2,7 +2,7 @@ use ff::PrimeFieldRepr;
 use group::{CurveAffine, CurveProjective, EncodedPoint, GroupDecodingError};
 
 use super::*;
-use *;
+use crate::*;
 
 #[test]
 fn test_pairing_result_against_relic() {

pairing/src/lib.rs

@@ -1,21 +1,20 @@
+//! A library for working with pairing-friendly curves.
+
 // `clippy` is a code linting tool for improving code quality by catching
 // common mistakes or strange code patterns. If the `cargo-clippy` feature
 // is provided, all compiler warnings are prohibited.
 #![cfg_attr(feature = "cargo-clippy", deny(warnings))]
-#![cfg_attr(feature = "cargo-clippy", allow(inline_always))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::inline_always))]
-#![cfg_attr(feature = "cargo-clippy", allow(too_many_arguments))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::too_many_arguments))]
-#![cfg_attr(feature = "cargo-clippy", allow(unreadable_literal))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::unreadable_literal))]
-#![cfg_attr(feature = "cargo-clippy", allow(many_single_char_names))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::many_single_char_names))]
-#![cfg_attr(feature = "cargo-clippy", allow(new_without_default_derive))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::new_without_default))]
-#![cfg_attr(feature = "cargo-clippy", allow(write_literal))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::write_literal))]
+// Catch documentation errors caused by code changes.
+#![deny(intra_doc_link_resolution_failure)]
 // Force public structures to implement Debug
 #![deny(missing_debug_implementations)]
 
-extern crate byteorder;
-extern crate ff;
-extern crate group;
-extern crate rand;
-
 #[cfg(test)]
 pub mod tests;
 
@@ -34,8 +33,7 @@ pub trait Engine: ScalarEngine {
             Base = Self::Fq,
             Scalar = Self::Fr,
             Affine = Self::G1Affine,
-        >
+        > + From<Self::G1Affine>;
-        + From<Self::G1Affine>;
 
     /// The affine representation of an element in G1.
     type G1Affine: PairingCurveAffine<
@@ -45,8 +43,7 @@ pub trait Engine: ScalarEngine {
             Projective = Self::G1,
             Pair = Self::G2Affine,
             PairingResult = Self::Fqk,
-        >
+        > + From<Self::G1>;
-        + From<Self::G1>;
 
     /// The projective representation of an element in G2.
     type G2: CurveProjective<
@@ -54,8 +51,7 @@ pub trait Engine: ScalarEngine {
             Base = Self::Fqe,
             Scalar = Self::Fr,
             Affine = Self::G2Affine,
-        >
+        > + From<Self::G2Affine>;
-        + From<Self::G2Affine>;
 
     /// The affine representation of an element in G2.
     type G2Affine: PairingCurveAffine<
@@ -65,8 +61,7 @@ pub trait Engine: ScalarEngine {
             Projective = Self::G2,
             Pair = Self::G1Affine,
             PairingResult = Self::Fqk,
-        >
+        > + From<Self::G2>;
-        + From<Self::G2>;
 
     /// The base field that hosts G1.
     type Fq: PrimeField + SqrtField;
@@ -88,7 +83,7 @@ pub trait Engine: ScalarEngine {
         >;
 
     /// Perform final exponentiation of the result of a miller loop.
-    fn final_exponentiation(&Self::Fqk) -> Option<Self::Fqk>;
+    fn final_exponentiation(_: &Self::Fqk) -> Option<Self::Fqk>;
 
     /// Performs a complete pairing operation `(p, q)`.
     fn pairing<G1, G2>(p: G1, q: G2) -> Self::Fqk
@@ -97,8 +92,9 @@ pub trait Engine: ScalarEngine {
         G2: Into<Self::G2Affine>,
     {
         Self::final_exponentiation(&Self::miller_loop(
-            [(&(p.into().prepare()), &(q.into().prepare()))].into_iter(),
+            [(&(p.into().prepare()), &(q.into().prepare()))].iter(),
-        )).unwrap()
+        ))
+        .unwrap()
     }
 }
 

pairing/src/tests/engine.rs

@@ -1,14 +1,18 @@
 use group::{CurveAffine, CurveProjective};
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
-use {Engine, Field, PairingCurveAffine, PrimeField};
+use crate::{Engine, Field, PairingCurveAffine, PrimeField};
 
 pub fn engine_tests<E: Engine>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..10 {
-        let a = E::G1::rand(&mut rng).into_affine();
+        let a = E::G1::random(&mut rng).into_affine();
-        let b = E::G2::rand(&mut rng).into_affine();
+        let b = E::G2::random(&mut rng).into_affine();
 
         assert!(a.pairing_with(&b) == b.pairing_with(&a));
         assert!(a.pairing_with(&b) == E::pairing(a, b));
@@ -18,10 +22,10 @@ pub fn engine_tests<E: Engine>() {
         let z1 = E::G1Affine::zero().prepare();
         let z2 = E::G2Affine::zero().prepare();
 
-        let a = E::G1::rand(&mut rng).into_affine().prepare();
+        let a = E::G1::random(&mut rng).into_affine().prepare();
-        let b = E::G2::rand(&mut rng).into_affine().prepare();
+        let b = E::G2::random(&mut rng).into_affine().prepare();
-        let c = E::G1::rand(&mut rng).into_affine().prepare();
+        let c = E::G1::random(&mut rng).into_affine().prepare();
-        let d = E::G2::rand(&mut rng).into_affine().prepare();
+        let d = E::G2::random(&mut rng).into_affine().prepare();
 
         assert_eq!(
             E::Fqk::one(),
@@ -49,12 +53,15 @@ pub fn engine_tests<E: Engine>() {
 }
 
 fn random_miller_loop_tests<E: Engine>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     // Exercise the miller loop for a reduced pairing
     for _ in 0..1000 {
-        let a = E::G1::rand(&mut rng);
+        let a = E::G1::random(&mut rng);
-        let b = E::G2::rand(&mut rng);
+        let b = E::G2::random(&mut rng);
 
         let p2 = E::pairing(a, b);
 
@@ -68,10 +75,10 @@ fn random_miller_loop_tests<E: Engine>() {
 
     // Exercise a double miller loop
     for _ in 0..1000 {
-        let a = E::G1::rand(&mut rng);
+        let a = E::G1::random(&mut rng);
-        let b = E::G2::rand(&mut rng);
+        let b = E::G2::random(&mut rng);
-        let c = E::G1::rand(&mut rng);
+        let c = E::G1::random(&mut rng);
-        let d = E::G2::rand(&mut rng);
+        let d = E::G2::random(&mut rng);
 
         let ab = E::pairing(a, b);
         let cd = E::pairing(c, d);
@@ -92,14 +99,17 @@ fn random_miller_loop_tests<E: Engine>() {
 }
 
 fn random_bilinearity_tests<E: Engine>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let a = E::G1::rand(&mut rng);
+        let a = E::G1::random(&mut rng);
-        let b = E::G2::rand(&mut rng);
+        let b = E::G2::random(&mut rng);
 
-        let c = E::Fr::rand(&mut rng);
+        let c = E::Fr::random(&mut rng);
-        let d = E::Fr::rand(&mut rng);
+        let d = E::Fr::random(&mut rng);
 
         let mut ac = a;
         ac.mul_assign(c);

pairing/src/tests/field.rs

@@ -1,12 +1,16 @@
 use ff::{Field, LegendreSymbol, PrimeField, SqrtField};
-use rand::{Rng, SeedableRng, XorShiftRng};
+use rand_core::{RngCore, SeedableRng};
+use rand_xorshift::XorShiftRng;
 
 pub fn random_frobenius_tests<F: Field, C: AsRef<[u64]>>(characteristic: C, maxpower: usize) {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..100 {
         for i in 0..(maxpower + 1) {
-            let mut a = F::rand(&mut rng);
+            let mut a = F::random(&mut rng);
             let mut b = a;
 
             for _ in 0..i {
@@ -20,10 +24,13 @@ pub fn random_frobenius_tests<F: Field, C: AsRef<[u64]>>(characteristic: C, maxp
 }
 
 pub fn random_sqrt_tests<F: SqrtField>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..10000 {
-        let a = F::rand(&mut rng);
+        let a = F::random(&mut rng);
         let mut b = a;
         b.square();
         assert_eq!(b.legendre(), LegendreSymbol::QuadraticResidue);
@@ -54,7 +61,10 @@ pub fn random_sqrt_tests<F: SqrtField>() {
 }
 
 pub fn random_field_tests<F: Field>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     random_multiplication_tests::<F, _>(&mut rng);
     random_addition_tests::<F, _>(&mut rng);
@@ -76,14 +86,14 @@ pub fn random_field_tests<F: Field>() {
 
     // Multiplication by zero
     {
-        let mut a = F::rand(&mut rng);
+        let mut a = F::random(&mut rng);
         a.mul_assign(&F::zero());
         assert!(a.is_zero());
     }
 
     // Addition by zero
     {
-        let mut a = F::rand(&mut rng);
+        let mut a = F::random(&mut rng);
         let copy = a;
         a.add_assign(&F::zero());
         assert_eq!(a, copy);
@@ -106,10 +116,13 @@ pub fn from_str_tests<F: PrimeField>() {
     }
 
     {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+        let mut rng = XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
 
         for _ in 0..1000 {
-            let n: u64 = rng.gen();
+            let n = rng.next_u64();
 
             let a = F::from_str(&format!("{}", n)).unwrap();
             let b = F::from_repr(n.into()).unwrap();
@@ -124,11 +137,11 @@ pub fn from_str_tests<F: PrimeField>() {
     assert!(F::from_str("00000000000").is_none());
 }
 
-fn random_multiplication_tests<F: Field, R: Rng>(rng: &mut R) {
+fn random_multiplication_tests<F: Field, R: RngCore>(rng: &mut R) {
     for _ in 0..10000 {
-        let a = F::rand(rng);
+        let a = F::random(rng);
-        let b = F::rand(rng);
+        let b = F::random(rng);
-        let c = F::rand(rng);
+        let c = F::random(rng);
 
         let mut t0 = a; // (a * b) * c
         t0.mul_assign(&b);
@@ -147,11 +160,11 @@ fn random_multiplication_tests<F: Field, R: Rng>(rng: &mut R) {
     }
 }
 
-fn random_addition_tests<F: Field, R: Rng>(rng: &mut R) {
+fn random_addition_tests<F: Field, R: RngCore>(rng: &mut R) {
     for _ in 0..10000 {
-        let a = F::rand(rng);
+        let a = F::random(rng);
-        let b = F::rand(rng);
+        let b = F::random(rng);
-        let c = F::rand(rng);
+        let c = F::random(rng);
 
         let mut t0 = a; // (a + b) + c
         t0.add_assign(&b);
@@ -170,10 +183,10 @@ fn random_addition_tests<F: Field, R: Rng>(rng: &mut R) {
     }
 }
 
-fn random_subtraction_tests<F: Field, R: Rng>(rng: &mut R) {
+fn random_subtraction_tests<F: Field, R: RngCore>(rng: &mut R) {
     for _ in 0..10000 {
-        let a = F::rand(rng);
+        let b = F::random(rng);
-        let b = F::rand(rng);
+        let a = F::random(rng);
 
         let mut t0 = a; // (a - b)
         t0.sub_assign(&b);
@@ -188,9 +201,9 @@ fn random_subtraction_tests<F: Field, R: Rng>(rng: &mut R) {
     }
 }
 
-fn random_negation_tests<F: Field, R: Rng>(rng: &mut R) {
+fn random_negation_tests<F: Field, R: RngCore>(rng: &mut R) {
     for _ in 0..10000 {
-        let a = F::rand(rng);
+        let a = F::random(rng);
         let mut b = a;
         b.negate();
         b.add_assign(&a);
@@ -199,9 +212,9 @@ fn random_negation_tests<F: Field, R: Rng>(rng: &mut R) {
     }
 }
 
-fn random_doubling_tests<F: Field, R: Rng>(rng: &mut R) {
+fn random_doubling_tests<F: Field, R: RngCore>(rng: &mut R) {
     for _ in 0..10000 {
-        let mut a = F::rand(rng);
+        let mut a = F::random(rng);
         let mut b = a;
         a.add_assign(&b);
         b.double();
@@ -210,9 +223,9 @@ fn random_doubling_tests<F: Field, R: Rng>(rng: &mut R) {
     }
 }
 
-fn random_squaring_tests<F: Field, R: Rng>(rng: &mut R) {
+fn random_squaring_tests<F: Field, R: RngCore>(rng: &mut R) {
     for _ in 0..10000 {
-        let mut a = F::rand(rng);
+        let mut a = F::random(rng);
         let mut b = a;
         a.mul_assign(&b);
         b.square();
@@ -221,11 +234,11 @@ fn random_squaring_tests<F: Field, R: Rng>(rng: &mut R) {
     }
 }
 
-fn random_inversion_tests<F: Field, R: Rng>(rng: &mut R) {
+fn random_inversion_tests<F: Field, R: RngCore>(rng: &mut R) {
     assert!(F::zero().inverse().is_none());
 
     for _ in 0..10000 {
-        let mut a = F::rand(rng);
+        let mut a = F::random(rng);
         let b = a.inverse().unwrap(); // probablistically nonzero
         a.mul_assign(&b);
 
@@ -233,14 +246,14 @@ fn random_inversion_tests<F: Field, R: Rng>(rng: &mut R) {
     }
 }
 
-fn random_expansion_tests<F: Field, R: Rng>(rng: &mut R) {
+fn random_expansion_tests<F: Field, R: RngCore>(rng: &mut R) {
     for _ in 0..10000 {
         // Compare (a + b)(c + d) and (a*c + b*c + a*d + b*d)
 
-        let a = F::rand(rng);
+        let a = F::random(rng);
-        let b = F::rand(rng);
+        let b = F::random(rng);
-        let c = F::rand(rng);
+        let c = F::random(rng);
-        let d = F::rand(rng);
+        let d = F::random(rng);
 
         let mut t0 = a;
         t0.add_assign(&b);

pairing/src/tests/repr.rs

@@ -1,21 +1,25 @@
-use ff::PrimeFieldRepr;
+use ff::{PrimeField, PrimeFieldRepr};
-use rand::{SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
-pub fn random_repr_tests<R: PrimeFieldRepr>() {
+pub fn random_repr_tests<P: PrimeField>() {
-    random_encoding_tests::<R>();
+    random_encoding_tests::<P>();
-    random_shl_tests::<R>();
+    random_shl_tests::<P>();
-    random_shr_tests::<R>();
+    random_shr_tests::<P>();
 }
 
-fn random_encoding_tests<R: PrimeFieldRepr>() {
+fn random_encoding_tests<P: PrimeField>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..1000 {
-        let r = R::rand(&mut rng);
+        let r = P::random(&mut rng).into_repr();
 
         // Big endian
         {
-            let mut rdecoded = R::default();
+            let mut rdecoded = <P as PrimeField>::Repr::default();
 
             let mut v: Vec<u8> = vec![];
             r.write_be(&mut v).unwrap();
@@ -26,7 +30,7 @@ fn random_encoding_tests<R: PrimeFieldRepr>() {
 
         // Little endian
         {
-            let mut rdecoded = R::default();
+            let mut rdecoded = <P as PrimeField>::Repr::default();
 
             let mut v: Vec<u8> = vec![];
             r.write_le(&mut v).unwrap();
@@ -36,8 +40,8 @@ fn random_encoding_tests<R: PrimeFieldRepr>() {
         }
 
         {
-            let mut rdecoded_le = R::default();
+            let mut rdecoded_le = <P as PrimeField>::Repr::default();
-            let mut rdecoded_be_flip = R::default();
+            let mut rdecoded_be_flip = <P as PrimeField>::Repr::default();
 
             let mut v: Vec<u8> = vec![];
             r.write_le(&mut v).unwrap();
@@ -55,11 +59,14 @@ fn random_encoding_tests<R: PrimeFieldRepr>() {
     }
 }
 
-fn random_shl_tests<R: PrimeFieldRepr>() {
+fn random_shl_tests<P: PrimeField>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..100 {
-        let r = R::rand(&mut rng);
+        let r = P::random(&mut rng).into_repr();
 
         for shift in 0..(r.num_bits() + 1) {
             let mut r1 = r;
@@ -76,11 +83,14 @@ fn random_shl_tests<R: PrimeFieldRepr>() {
     }
 }
 
-fn random_shr_tests<R: PrimeFieldRepr>() {
+fn random_shr_tests<P: PrimeField>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+    let mut rng = XorShiftRng::from_seed([
+        0x59, 0x62, 0xbe, 0x5d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06, 0xbc,
+        0xe5,
+    ]);
 
     for _ in 0..100 {
-        let r = R::rand(&mut rng);
+        let r = P::random(&mut rng).into_repr();
 
         for shift in 0..(r.num_bits() + 1) {
             let mut r1 = r;

sapling-crypto/.gitignore

@@ -1,3 +0,0 @@
-/target/
-**/*.rs.bk
-Cargo.lock

sapling-crypto/COPYRIGHT

@@ -1,14 +0,0 @@
-Copyrights in the "sapling-crypto" library are retained by their contributors. No
-copyright assignment is required to contribute to the "sapling-crypto" library.
-
-The "sapling-crypto" library is licensed under either of
-
- * Apache License, Version 2.0, (see ./LICENSE-APACHE or http://www.apache.org/licenses/LICENSE-2.0)
- * MIT license (see ./LICENSE-MIT or http://opensource.org/licenses/MIT)
-
-at your option.
-
-Unless you explicitly state otherwise, any contribution intentionally
-submitted for inclusion in the work by you, as defined in the Apache-2.0
-license, shall be dual licensed as above, without any additional terms or
-conditions.

sapling-crypto/Cargo.toml

@@ -1,28 +0,0 @@
-[package]
-authors = ["Sean Bowe <sean@z.cash>"]
-description = "Cryptographic library for Zcash Sapling"
-documentation = "https://github.com/zcash-hackworks/sapling"
-homepage = "https://github.com/zcash-hackworks/sapling"
-license = "MIT/Apache-2.0"
-name = "sapling-crypto"
-repository = "https://github.com/zcash-hackworks/sapling"
-version = "0.0.1"
-
-[dependencies.pairing]
-path = "../pairing"
-features = ["expose-arith"]
-
-[dependencies]
-bellman = { path = "../bellman" }
-ff = { path = "../ff" }
-rand = "0.4"
-digest = "0.7"
-byteorder = "1"
-
-[dependencies.blake2-rfc]
-git = "https://github.com/gtank/blake2-rfc"
-rev = "7a5b5fc99ae483a0043db7547fb79a6fa44b88a9"
-
-[dev-dependencies]
-hex-literal = "0.1"
-rust-crypto = "0.2"

sapling-crypto/LICENSE-MIT

@@ -1,23 +0,0 @@
-Permission is hereby granted, free of charge, to any
-person obtaining a copy of this software and associated
-documentation files (the "Software"), to deal in the
-Software without restriction, including without
-limitation the rights to use, copy, modify, merge,
-publish, distribute, sublicense, and/or sell copies of
-the Software, and to permit persons to whom the Software
-is furnished to do so, subject to the following
-conditions:
-
-The above copyright notice and this permission notice
-shall be included in all copies or substantial portions
-of the Software.
-
-THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF
-ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
-TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
-PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT
-SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
-CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
-OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR
-IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-DEALINGS IN THE SOFTWARE.

sapling-crypto/README.md

@@ -1,23 +0,0 @@
-# sapling-crypto
-
-This repository contains a (work-in-progress) implementation of Zcash's "Sapling" cryptography.
-
-## Security Warnings
-
-This library is currently under development and has not been reviewed.
-
-## License
-
-Licensed under either of
-
- * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
- * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
-
-at your option.
-
-### Contribution
-
-Unless you explicitly state otherwise, any contribution intentionally
-submitted for inclusion in the work by you, as defined in the Apache-2.0
-license, shall be dual licensed as above, without any additional terms or
-conditions.

sapling-crypto/benches/pedersen_hash.rs

@@ -1,23 +0,0 @@
-#![feature(test)]
-
-extern crate rand;
-extern crate test;
-extern crate pairing;
-extern crate sapling_crypto;
-
-use rand::{Rand, thread_rng};
-use pairing::bls12_381::Bls12;
-use sapling_crypto::jubjub::JubjubBls12;
-use sapling_crypto::pedersen_hash::{pedersen_hash, Personalization};
-
-#[bench]
-fn bench_pedersen_hash(b: &mut test::Bencher) {
-    let params = JubjubBls12::new();
-    let rng = &mut thread_rng();
-    let bits = (0..510).map(|_| bool::rand(rng)).collect::<Vec<_>>();
-    let personalization = Personalization::MerkleTree(31);
-
-    b.iter(|| {
-        pedersen_hash::<Bls12, _>(personalization, bits.clone(), &params)
-    });
-}

sapling-crypto/examples/bench.rs

@@ -1,102 +0,0 @@
-extern crate sapling_crypto;
-extern crate bellman;
-extern crate rand;
-extern crate pairing;
-
-use std::time::{Duration, Instant};
-use sapling_crypto::jubjub::{
-    JubjubBls12,
-    edwards,
-    fs,
-};
-use sapling_crypto::circuit::sapling::{
-    Spend
-};
-use sapling_crypto::primitives::{
-    Diversifier,
-    ProofGenerationKey,
-    ValueCommitment
-};
-use bellman::groth16::*;
-use rand::{XorShiftRng, SeedableRng, Rng};
-use pairing::bls12_381::{Bls12, Fr};
-
-const TREE_DEPTH: usize = 32;
-
-fn main() {
-    let jubjub_params = &JubjubBls12::new();
-    let rng = &mut XorShiftRng::from_seed([0x3dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
-
-    println!("Creating sample parameters...");
-    let groth_params = generate_random_parameters::<Bls12, _, _>(
-        Spend {
-            params: jubjub_params,
-            value_commitment: None,
-            proof_generation_key: None,
-            payment_address: None,
-            commitment_randomness: None,
-            ar: None,
-            auth_path: vec![None; TREE_DEPTH],
-            anchor: None
-        },
-        rng
-    ).unwrap();
-
-    const SAMPLES: u32 = 50;
-
-    let mut total_time = Duration::new(0, 0);
-    for _ in 0..SAMPLES {
-        let value_commitment = ValueCommitment {
-            value: 1,
-            randomness: rng.gen()
-        };
-
-        let nsk: fs::Fs = rng.gen();
-        let ak = edwards::Point::rand(rng, jubjub_params).mul_by_cofactor(jubjub_params);
-
-        let proof_generation_key = ProofGenerationKey {
-            ak: ak.clone(),
-            nsk: nsk.clone()
-        };
-
-        let viewing_key = proof_generation_key.into_viewing_key(jubjub_params);
-
-        let payment_address;
-
-        loop {
-            let diversifier = Diversifier(rng.gen());
-
-            if let Some(p) = viewing_key.into_payment_address(
-                diversifier,
-                jubjub_params
-            )
-            {
-                payment_address = p;
-                break;
-            }
-        }
-
-        let commitment_randomness: fs::Fs = rng.gen();
-        let auth_path = vec![Some((rng.gen(), rng.gen())); TREE_DEPTH];
-        let ar: fs::Fs = rng.gen();
-        let anchor: Fr = rng.gen();
-
-        let start = Instant::now();
-        let _ = create_random_proof(Spend {
-            params: jubjub_params,
-            value_commitment: Some(value_commitment),
-            proof_generation_key: Some(proof_generation_key),
-            payment_address: Some(payment_address),
-            commitment_randomness: Some(commitment_randomness),
-            ar: Some(ar),
-            auth_path: auth_path,
-            anchor: Some(anchor)
-        }, &groth_params, rng).unwrap();
-        total_time += start.elapsed();
-    }
-    let avg = total_time / SAMPLES;
-    let avg = avg.subsec_nanos() as f64 / 1_000_000_000f64
-              + (avg.as_secs() as f64);
-
-    println!("Average proving time (in seconds): {}", avg);
-}

sapling-crypto/src/circuit/blake2s.rs

@@ -1,438 +0,0 @@
-use pairing::{
-    Engine,
-};
-
-use bellman::{
-    SynthesisError,
-    ConstraintSystem
-};
-
-use super::boolean::{
-    Boolean
-};
-
-use super::uint32::{
-    UInt32
-};
-
-use super::multieq::MultiEq;
-
-/*
-2.1.  Parameters
-   The following table summarizes various parameters and their ranges:
-                            | BLAKE2b          | BLAKE2s          |
-              --------------+------------------+------------------+
-               Bits in word | w = 64           | w = 32           |
-               Rounds in F  | r = 12           | r = 10           |
-               Block bytes  | bb = 128         | bb = 64          |
-               Hash bytes   | 1 <= nn <= 64    | 1 <= nn <= 32    |
-               Key bytes    | 0 <= kk <= 64    | 0 <= kk <= 32    |
-               Input bytes  | 0 <= ll < 2**128 | 0 <= ll < 2**64  |
-              --------------+------------------+------------------+
-               G Rotation   | (R1, R2, R3, R4) | (R1, R2, R3, R4) |
-                constants = | (32, 24, 16, 63) | (16, 12,  8,  7) |
-              --------------+------------------+------------------+
-*/
-
-const R1: usize = 16;
-const R2: usize = 12;
-const R3: usize = 8;
-const R4: usize = 7;
-
-/*
-          Round   |  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 |
-        ----------+-------------------------------------------------+
-         SIGMA[0] |  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 |
-         SIGMA[1] | 14 10  4  8  9 15 13  6  1 12  0  2 11  7  5  3 |
-         SIGMA[2] | 11  8 12  0  5  2 15 13 10 14  3  6  7  1  9  4 |
-         SIGMA[3] |  7  9  3  1 13 12 11 14  2  6  5 10  4  0 15  8 |
-         SIGMA[4] |  9  0  5  7  2  4 10 15 14  1 11 12  6  8  3 13 |
-         SIGMA[5] |  2 12  6 10  0 11  8  3  4 13  7  5 15 14  1  9 |
-         SIGMA[6] | 12  5  1 15 14 13  4 10  0  7  6  3  9  2  8 11 |
-         SIGMA[7] | 13 11  7 14 12  1  3  9  5  0 15  4  8  6  2 10 |
-         SIGMA[8] |  6 15 14  9 11  3  0  8 12  2 13  7  1  4 10  5 |
-         SIGMA[9] | 10  2  8  4  7  6  1  5 15 11  9 14  3 12 13  0 |
-        ----------+-------------------------------------------------+
-*/
-
-const SIGMA: [[usize; 16]; 10] = [
-    [0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15],
-    [14, 10, 4, 8, 9, 15, 13, 6, 1, 12, 0, 2, 11, 7, 5, 3],
-    [11, 8, 12, 0, 5, 2, 15, 13, 10, 14, 3, 6, 7, 1, 9, 4],
-    [7, 9, 3, 1, 13, 12, 11, 14, 2, 6, 5, 10, 4, 0, 15, 8],
-    [9, 0, 5, 7, 2, 4, 10, 15, 14, 1, 11, 12, 6, 8, 3, 13],
-    [2, 12, 6, 10, 0, 11, 8, 3, 4, 13, 7, 5, 15, 14, 1, 9],
-    [12, 5, 1, 15, 14, 13, 4, 10, 0, 7, 6, 3, 9, 2, 8, 11],
-    [13, 11, 7, 14, 12, 1, 3, 9, 5, 0, 15, 4, 8, 6, 2, 10],
-    [6, 15, 14, 9, 11, 3, 0, 8, 12, 2, 13, 7, 1, 4, 10, 5],
-    [10, 2, 8, 4, 7, 6, 1, 5, 15, 11, 9, 14, 3, 12, 13, 0]
-];
-
-/*
-3.1.  Mixing Function G
-   The G primitive function mixes two input words, "x" and "y", into
-   four words indexed by "a", "b", "c", and "d" in the working vector
-   v[0..15].  The full modified vector is returned.  The rotation
-   constants (R1, R2, R3, R4) are given in Section 2.1.
-       FUNCTION G( v[0..15], a, b, c, d, x, y )
-       |
-       |   v[a] := (v[a] + v[b] + x) mod 2**w
-       |   v[d] := (v[d] ^ v[a]) >>> R1
-       |   v[c] := (v[c] + v[d])     mod 2**w
-       |   v[b] := (v[b] ^ v[c]) >>> R2
-       |   v[a] := (v[a] + v[b] + y) mod 2**w
-       |   v[d] := (v[d] ^ v[a]) >>> R3
-       |   v[c] := (v[c] + v[d])     mod 2**w
-       |   v[b] := (v[b] ^ v[c]) >>> R4
-       |
-       |   RETURN v[0..15]
-       |
-       END FUNCTION.
-*/
-
-fn mixing_g<E: Engine, CS: ConstraintSystem<E>, M>(
-    mut cs: M,
-    v: &mut [UInt32],
-    a: usize,
-    b: usize,
-    c: usize,
-    d: usize,
-    x: &UInt32,
-    y: &UInt32
-) -> Result<(), SynthesisError>
-    where M: ConstraintSystem<E, Root=MultiEq<E, CS>>
-{
-    v[a] = UInt32::addmany(cs.namespace(|| "mixing step 1"), &[v[a].clone(), v[b].clone(), x.clone()])?;
-    v[d] = v[d].xor(cs.namespace(|| "mixing step 2"), &v[a])?.rotr(R1);
-    v[c] = UInt32::addmany(cs.namespace(|| "mixing step 3"), &[v[c].clone(), v[d].clone()])?;
-    v[b] = v[b].xor(cs.namespace(|| "mixing step 4"), &v[c])?.rotr(R2);
-    v[a] = UInt32::addmany(cs.namespace(|| "mixing step 5"), &[v[a].clone(), v[b].clone(), y.clone()])?;
-    v[d] = v[d].xor(cs.namespace(|| "mixing step 6"), &v[a])?.rotr(R3);
-    v[c] = UInt32::addmany(cs.namespace(|| "mixing step 7"), &[v[c].clone(), v[d].clone()])?;
-    v[b] = v[b].xor(cs.namespace(|| "mixing step 8"), &v[c])?.rotr(R4);
-
-    Ok(())
-}
-
-/*
-3.2.  Compression Function F
-   Compression function F takes as an argument the state vector "h",
-   message block vector "m" (last block is padded with zeros to full
-   block size, if required), 2w-bit offset counter "t", and final block
-   indicator flag "f".  Local vector v[0..15] is used in processing.  F
-   returns a new state vector.  The number of rounds, "r", is 12 for
-   BLAKE2b and 10 for BLAKE2s.  Rounds are numbered from 0 to r - 1.
-       FUNCTION F( h[0..7], m[0..15], t, f )
-       |
-       |      // Initialize local work vector v[0..15]
-       |      v[0..7] := h[0..7]              // First half from state.
-       |      v[8..15] := IV[0..7]            // Second half from IV.
-       |
-       |      v[12] := v[12] ^ (t mod 2**w)   // Low word of the offset.
-       |      v[13] := v[13] ^ (t >> w)       // High word.
-       |
-       |      IF f = TRUE THEN                // last block flag?
-       |      |   v[14] := v[14] ^ 0xFF..FF   // Invert all bits.
-       |      END IF.
-       |
-       |      // Cryptographic mixing
-       |      FOR i = 0 TO r - 1 DO           // Ten or twelve rounds.
-       |      |
-       |      |   // Message word selection permutation for this round.
-       |      |   s[0..15] := SIGMA[i mod 10][0..15]
-       |      |
-       |      |   v := G( v, 0, 4,  8, 12, m[s[ 0]], m[s[ 1]] )
-       |      |   v := G( v, 1, 5,  9, 13, m[s[ 2]], m[s[ 3]] )
-       |      |   v := G( v, 2, 6, 10, 14, m[s[ 4]], m[s[ 5]] )
-       |      |   v := G( v, 3, 7, 11, 15, m[s[ 6]], m[s[ 7]] )
-       |      |
-       |      |   v := G( v, 0, 5, 10, 15, m[s[ 8]], m[s[ 9]] )
-       |      |   v := G( v, 1, 6, 11, 12, m[s[10]], m[s[11]] )
-       |      |   v := G( v, 2, 7,  8, 13, m[s[12]], m[s[13]] )
-       |      |   v := G( v, 3, 4,  9, 14, m[s[14]], m[s[15]] )
-       |      |
-       |      END FOR
-       |
-       |      FOR i = 0 TO 7 DO               // XOR the two halves.
-       |      |   h[i] := h[i] ^ v[i] ^ v[i + 8]
-       |      END FOR.
-       |
-       |      RETURN h[0..7]                  // New state.
-       |
-       END FUNCTION.
-*/
-
-
-fn blake2s_compression<E: Engine, CS: ConstraintSystem<E>>(
-    mut cs: CS,
-    h: &mut [UInt32],
-    m: &[UInt32],
-    t: u64,
-    f: bool
-) -> Result<(), SynthesisError>
-{
-    assert_eq!(h.len(), 8);
-    assert_eq!(m.len(), 16);
-
-    /*
-    static const uint32_t blake2s_iv[8] =
-    {
-        0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A,
-        0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19
-    };
-    */
-
-    let mut v = Vec::with_capacity(16);
-    v.extend_from_slice(h);
-    v.push(UInt32::constant(0x6A09E667));
-    v.push(UInt32::constant(0xBB67AE85));
-    v.push(UInt32::constant(0x3C6EF372));
-    v.push(UInt32::constant(0xA54FF53A));
-    v.push(UInt32::constant(0x510E527F));
-    v.push(UInt32::constant(0x9B05688C));
-    v.push(UInt32::constant(0x1F83D9AB));
-    v.push(UInt32::constant(0x5BE0CD19));
-
-    assert_eq!(v.len(), 16);
-
-    v[12] = v[12].xor(cs.namespace(|| "first xor"), &UInt32::constant(t as u32))?;
-    v[13] = v[13].xor(cs.namespace(|| "second xor"), &UInt32::constant((t >> 32) as u32))?;
-
-    if f {
-        v[14] = v[14].xor(cs.namespace(|| "third xor"), &UInt32::constant(u32::max_value()))?;
-    }
-
-    {
-        let mut cs = MultiEq::new(&mut cs);
-
-        for i in 0..10 {
-            let mut cs = cs.namespace(|| format!("round {}", i));
-
-            let s = SIGMA[i % 10];
-
-            mixing_g(cs.namespace(|| "mixing invocation 1"), &mut v, 0, 4,  8, 12, &m[s[ 0]], &m[s[ 1]])?;
-            mixing_g(cs.namespace(|| "mixing invocation 2"), &mut v, 1, 5,  9, 13, &m[s[ 2]], &m[s[ 3]])?;
-            mixing_g(cs.namespace(|| "mixing invocation 3"), &mut v, 2, 6, 10, 14, &m[s[ 4]], &m[s[ 5]])?;
-            mixing_g(cs.namespace(|| "mixing invocation 4"), &mut v, 3, 7, 11, 15, &m[s[ 6]], &m[s[ 7]])?;
-
-            mixing_g(cs.namespace(|| "mixing invocation 5"), &mut v, 0, 5, 10, 15, &m[s[ 8]], &m[s[ 9]])?;
-            mixing_g(cs.namespace(|| "mixing invocation 6"), &mut v, 1, 6, 11, 12, &m[s[10]], &m[s[11]])?;
-            mixing_g(cs.namespace(|| "mixing invocation 7"), &mut v, 2, 7,  8, 13, &m[s[12]], &m[s[13]])?;
-            mixing_g(cs.namespace(|| "mixing invocation 8"), &mut v, 3, 4,  9, 14, &m[s[14]], &m[s[15]])?;
-        }
-    }
-
-    for i in 0..8 {
-        let mut cs = cs.namespace(|| format!("h[{i}] ^ v[{i}] ^ v[{i} + 8]", i=i));
-
-        h[i] = h[i].xor(cs.namespace(|| "first xor"), &v[i])?;
-        h[i] = h[i].xor(cs.namespace(|| "second xor"), &v[i + 8])?;
-    }
-
-    Ok(())
-}
-
-/*
-        FUNCTION BLAKE2( d[0..dd-1], ll, kk, nn )
-        |
-        |     h[0..7] := IV[0..7]          // Initialization Vector.
-        |
-        |     // Parameter block p[0]
-        |     h[0] := h[0] ^ 0x01010000 ^ (kk << 8) ^ nn
-        |
-        |     // Process padded key and data blocks
-        |     IF dd > 1 THEN
-        |     |       FOR i = 0 TO dd - 2 DO
-        |     |       |       h := F( h, d[i], (i + 1) * bb, FALSE )
-        |     |       END FOR.
-        |     END IF.
-        |
-        |     // Final block.
-        |     IF kk = 0 THEN
-        |     |       h := F( h, d[dd - 1], ll, TRUE )
-        |     ELSE
-        |     |       h := F( h, d[dd - 1], ll + bb, TRUE )
-        |     END IF.
-        |
-        |     RETURN first "nn" bytes from little-endian word array h[].
-        |
-        END FUNCTION.
-*/
-
-pub fn blake2s<E: Engine, CS: ConstraintSystem<E>>(
-    mut cs: CS,
-    input: &[Boolean],
-    personalization: &[u8]
-) -> Result<Vec<Boolean>, SynthesisError>
-{
-    use byteorder::{ByteOrder, LittleEndian};
-
-    assert_eq!(personalization.len(), 8);
-    assert!(input.len() % 8 == 0);
-
-    let mut h = Vec::with_capacity(8);
-    h.push(UInt32::constant(0x6A09E667 ^ 0x01010000 ^ 32));
-    h.push(UInt32::constant(0xBB67AE85));
-    h.push(UInt32::constant(0x3C6EF372));
-    h.push(UInt32::constant(0xA54FF53A));
-    h.push(UInt32::constant(0x510E527F));
-    h.push(UInt32::constant(0x9B05688C));
-
-    // Personalization is stored here
-    h.push(UInt32::constant(0x1F83D9AB ^ LittleEndian::read_u32(&personalization[0..4])));
-    h.push(UInt32::constant(0x5BE0CD19 ^ LittleEndian::read_u32(&personalization[4..8])));
-
-    let mut blocks: Vec<Vec<UInt32>> = vec![];
-
-    for block in input.chunks(512) {
-        let mut this_block = Vec::with_capacity(16);
-        for word in block.chunks(32) {
-            let mut tmp = word.to_vec();
-            while tmp.len() < 32 {
-                tmp.push(Boolean::constant(false));
-            }
-            this_block.push(UInt32::from_bits(&tmp));
-        }
-        while this_block.len() < 16 {
-            this_block.push(UInt32::constant(0));
-        }
-        blocks.push(this_block);
-    }
-
-    if blocks.len() == 0 {
-        blocks.push((0..16).map(|_| UInt32::constant(0)).collect());
-    }
-
-    for (i, block) in blocks[0..blocks.len() - 1].iter().enumerate() {
-        let cs = cs.namespace(|| format!("block {}", i));
-
-        blake2s_compression(cs, &mut h, block, ((i as u64) + 1) * 64, false)?;
-    }
-
-    {
-        let cs = cs.namespace(|| "final block");
-
-        blake2s_compression(cs, &mut h, &blocks[blocks.len() - 1], (input.len() / 8) as u64, true)?;
-    }
-
-    Ok(h.iter().flat_map(|b| b.into_bits()).collect())
-}
-
-#[cfg(test)]
-mod test {
-    use rand::{XorShiftRng, SeedableRng, Rng};
-    use pairing::bls12_381::{Bls12};
-    use ::circuit::boolean::{Boolean, AllocatedBit};
-    use ::circuit::test::TestConstraintSystem;
-    use super::blake2s;
-    use bellman::{ConstraintSystem};
-    use blake2_rfc::blake2s::Blake2s;
-
-    #[test]
-    fn test_blank_hash() {
-        let mut cs = TestConstraintSystem::<Bls12>::new();
-        let input_bits = vec![];
-        let out = blake2s(&mut cs, &input_bits, b"12345678").unwrap();
-        assert!(cs.is_satisfied());
-        assert_eq!(cs.num_constraints(), 0);
-
-        // >>> import blake2s from hashlib
-        // >>> h = blake2s(digest_size=32, person=b'12345678')
-        // >>> h.hexdigest()
-        let expected = hex!("c59f682376d137f3f255e671e207d1f2374ebe504e9314208a52d9f88d69e8c8");
-
-        let mut out = out.into_iter();
-        for b in expected.into_iter() {
-            for i in 0..8 {
-                let c = out.next().unwrap().get_value().unwrap();
-
-                assert_eq!(c, (b >> i) & 1u8 == 1u8);
-            }
-        }
-    }
-
-    #[test]
-    fn test_blake2s_constraints() {
-        let mut cs = TestConstraintSystem::<Bls12>::new();
-        let input_bits: Vec<_> = (0..512).map(|i| AllocatedBit::alloc(cs.namespace(|| format!("input bit {}", i)), Some(true)).unwrap().into()).collect();
-        blake2s(&mut cs, &input_bits, b"12345678").unwrap();
-        assert!(cs.is_satisfied());
-        assert_eq!(cs.num_constraints(), 21518);
-    }
-
-    #[test]
-    fn test_blake2s_precomp_constraints() {
-        // Test that 512 fixed leading bits (constants)
-        // doesn't result in more constraints.
-
-        let mut cs = TestConstraintSystem::<Bls12>::new();
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
-        let input_bits: Vec<_> = (0..512)
-          .map(|_| Boolean::constant(rng.gen()))
-          .chain((0..512)
-                        .map(|i| AllocatedBit::alloc(cs.namespace(|| format!("input bit {}", i)), Some(true)).unwrap().into()))
-          .collect();
-        blake2s(&mut cs, &input_bits, b"12345678").unwrap();
-        assert!(cs.is_satisfied());
-        assert_eq!(cs.num_constraints(), 21518);
-    }
-
-    #[test]
-    fn test_blake2s_constant_constraints() {
-        let mut cs = TestConstraintSystem::<Bls12>::new();
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
-        let input_bits: Vec<_> = (0..512).map(|_| Boolean::constant(rng.gen())).collect();
-        blake2s(&mut cs, &input_bits, b"12345678").unwrap();
-        assert_eq!(cs.num_constraints(), 0);
-    }
-
-    #[test]
-    fn test_blake2s() {
-        let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
-
-        for input_len in (0..32).chain((32..256).filter(|a| a % 8 == 0))
-        {
-            let mut h = Blake2s::with_params(32, &[], &[], b"12345678");
-
-            let data: Vec<u8> = (0..input_len).map(|_| rng.gen()).collect();
-
-            h.update(&data);
-
-            let hash_result = h.finalize();
-
-            let mut cs = TestConstraintSystem::<Bls12>::new();
-
-            let mut input_bits = vec![];
-
-            for (byte_i, input_byte) in data.into_iter().enumerate() {
-                for bit_i in 0..8 {
-                    let cs = cs.namespace(|| format!("input bit {} {}", byte_i, bit_i));
-
-                    input_bits.push(AllocatedBit::alloc(cs, Some((input_byte >> bit_i) & 1u8 == 1u8)).unwrap().into());
-                }
-            }
-
-            let r = blake2s(&mut cs, &input_bits, b"12345678").unwrap();
-
-            assert!(cs.is_satisfied());
-
-            let mut s = hash_result.as_ref().iter()
-                                            .flat_map(|&byte| (0..8).map(move |i| (byte >> i) & 1u8 == 1u8));
-
-            for b in r {
-                match b {
-                    Boolean::Is(b) => {
-                        assert!(s.next().unwrap() == b.get_value().unwrap());
-                    },
-                    Boolean::Not(b) => {
-                        assert!(s.next().unwrap() != b.get_value().unwrap());
-                    },
-                    Boolean::Constant(b) => {
-                        assert!(input_len == 0);
-                        assert!(s.next().unwrap() == b);
-                    }
-                }
-            }
-        }
-    }
-}

sapling-crypto/src/circuit/multipack.rs

@@ -1,114 +0,0 @@
-use ff::{Field, PrimeField};
-use pairing::Engine;
-use bellman::{ConstraintSystem, SynthesisError};
-use super::boolean::{Boolean};
-use super::num::Num;
-use super::Assignment;
-
-/// Takes a sequence of booleans and exposes them as compact
-/// public inputs
-pub fn pack_into_inputs<E, CS>(
-    mut cs: CS,
-    bits: &[Boolean]
-) -> Result<(), SynthesisError>
-    where E: Engine, CS: ConstraintSystem<E>
-{
-    for (i, bits) in bits.chunks(E::Fr::CAPACITY as usize).enumerate()
-    {
-        let mut num = Num::<E>::zero();
-        let mut coeff = E::Fr::one();
-        for bit in bits {
-            num = num.add_bool_with_coeff(CS::one(), bit, coeff);
-
-            coeff.double();
-        }
-
-        let input = cs.alloc_input(|| format!("input {}", i), || {
-            Ok(*num.get_value().get()?)
-        })?;
-
-        // num * 1 = input
-        cs.enforce(
-            || format!("packing constraint {}", i),
-            |_| num.lc(E::Fr::one()),
-            |lc| lc + CS::one(),
-            |lc| lc + input
-        );
-    }
-
-    Ok(())
-}
-
-pub fn bytes_to_bits(bytes: &[u8]) -> Vec<bool>
-{
-    bytes.iter()
-         .flat_map(|&v| (0..8).rev().map(move |i| (v >> i) & 1 == 1))
-         .collect()
-}
-
-pub fn bytes_to_bits_le(bytes: &[u8]) -> Vec<bool>
-{
-    bytes.iter()
-         .flat_map(|&v| (0..8).map(move |i| (v >> i) & 1 == 1))
-         .collect()
-}
-
-pub fn compute_multipacking<E: Engine>(
-    bits: &[bool]
-) -> Vec<E::Fr>
-{
-    let mut result = vec![];
-
-    for bits in bits.chunks(E::Fr::CAPACITY as usize)
-    {
-        let mut cur = E::Fr::zero();
-        let mut coeff = E::Fr::one();
-
-        for bit in bits {
-            if *bit {
-                cur.add_assign(&coeff);
-            }
-
-            coeff.double();
-        }
-
-        result.push(cur);
-    }
-
-    result
-}
-
-#[test]
-fn test_multipacking() {
-    use rand::{SeedableRng, Rng, XorShiftRng};
-    use bellman::{ConstraintSystem};
-    use pairing::bls12_381::{Bls12};
-    use ::circuit::test::*;
-    use super::boolean::{AllocatedBit, Boolean};
-
-    let mut rng = XorShiftRng::from_seed([0x3dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
-
-    for num_bits in 0..1500 {
-        let mut cs = TestConstraintSystem::<Bls12>::new();
-
-        let bits: Vec<bool> = (0..num_bits).map(|_| rng.gen()).collect();
-
-        let circuit_bits = bits.iter().enumerate()
-                               .map(|(i, &b)| {
-                                   Boolean::from(
-                                     AllocatedBit::alloc(
-                                        cs.namespace(|| format!("bit {}", i)),
-                                        Some(b)
-                                     ).unwrap()
-                                   )
-                               })
-                               .collect::<Vec<_>>();
-
-        let expected_inputs = compute_multipacking::<Bls12>(&bits);
-
-        pack_into_inputs(cs.namespace(|| "pack"), &circuit_bits).unwrap();
-
-        assert!(cs.is_satisfied());
-        assert!(cs.verify(&expected_inputs));
-    }
-}

sapling-crypto/src/circuit/pedersen_hash.rs

@@ -1,194 +0,0 @@
-use super::*;
-use super::ecc::{
-    MontgomeryPoint,
-    EdwardsPoint
-};
-use super::boolean::Boolean;
-use ::jubjub::*;
-use bellman::{
-    ConstraintSystem
-};
-use super::lookup::*;
-pub use pedersen_hash::Personalization;
-
-impl Personalization {
-    fn get_constant_bools(&self) -> Vec<Boolean> {
-        self.get_bits()
-        .into_iter()
-        .map(|e| Boolean::constant(e))
-        .collect()
-    }
-}
-
-pub fn pedersen_hash<E: JubjubEngine, CS>(
-    mut cs: CS,
-    personalization: Personalization,
-    bits: &[Boolean],
-    params: &E::Params
-) -> Result<EdwardsPoint<E>, SynthesisError>
-    where CS: ConstraintSystem<E>
-{
-    let personalization = personalization.get_constant_bools();
-    assert_eq!(personalization.len(), 6);
-
-    let mut edwards_result = None;
-    let mut bits = personalization.iter().chain(bits.iter());
-    let mut segment_generators = params.pedersen_circuit_generators().iter();
-    let boolean_false = Boolean::constant(false);
-
-    let mut segment_i = 0;
-    loop {
-        let mut segment_result = None;
-        let mut segment_windows = &segment_generators.next()
-                                                     .expect("enough segments")[..];
-
-        let mut window_i = 0;
-        while let Some(a) = bits.next() {
-            let b = bits.next().unwrap_or(&boolean_false);
-            let c = bits.next().unwrap_or(&boolean_false);
-
-            let tmp = lookup3_xy_with_conditional_negation(
-                cs.namespace(|| format!("segment {}, window {}", segment_i, window_i)),
-                &[a.clone(), b.clone(), c.clone()],
-                &segment_windows[0]
-            )?;
-
-            let tmp = MontgomeryPoint::interpret_unchecked(tmp.0, tmp.1);
-
-            match segment_result {
-                None => {
-                    segment_result = Some(tmp);
-                },
-                Some(ref mut segment_result) => {
-                    *segment_result = tmp.add(
-                        cs.namespace(|| format!("addition of segment {}, window {}", segment_i, window_i)),
-                        segment_result,
-                        params
-                    )?;
-                }
-            }
-
-            segment_windows = &segment_windows[1..];
-
-            if segment_windows.len() == 0 {
-                break;
-            }
-
-            window_i += 1;
-        }
-
-        match segment_result {
-            Some(segment_result) => {
-                // Convert this segment into twisted Edwards form.
-                let segment_result = segment_result.into_edwards(
-                    cs.namespace(|| format!("conversion of segment {} into edwards", segment_i)),
-                    params
-                )?;
-
-                match edwards_result {
-                    Some(ref mut edwards_result) => {
-                        *edwards_result = segment_result.add(
-                            cs.namespace(|| format!("addition of segment {} to accumulator", segment_i)),
-                            edwards_result,
-                            params
-                        )?;
-                    },
-                    None => {
-                        edwards_result = Some(segment_result);
-                    }
-                }
-            },
-            None => {
-                // We didn't process any new bits.
-                break;
-            }
-        }
-
-        segment_i += 1;
-    }
-
-    Ok(edwards_result.unwrap())
-}
-
-#[cfg(test)]
-mod test {
-    use rand::{SeedableRng, Rng, XorShiftRng};
-    use super::*;
-    use ::circuit::test::*;
-    use ::circuit::boolean::{Boolean, AllocatedBit};
-    use ff::PrimeField;
-    use pairing::bls12_381::{Bls12, Fr};
-
-    #[test]
-    fn test_pedersen_hash_constraints() {
-        let mut rng = XorShiftRng::from_seed([0x3dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
-        let params = &JubjubBls12::new();
-        let mut cs = TestConstraintSystem::<Bls12>::new();
-
-        let input: Vec<bool> = (0..(Fr::NUM_BITS * 2)).map(|_| rng.gen()).collect();
-
-        let input_bools: Vec<Boolean> = input.iter().enumerate().map(|(i, b)| {
-            Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| format!("input {}", i)), Some(*b)).unwrap()
-            )
-        }).collect();
-
-        pedersen_hash(
-            cs.namespace(|| "pedersen hash"),
-            Personalization::NoteCommitment,
-            &input_bools,
-            params
-        ).unwrap();
-
-        assert!(cs.is_satisfied());
-        assert_eq!(cs.num_constraints(), 1377);
-    }
-
-    #[test]
-    fn test_pedersen_hash() {
-        let mut rng = XorShiftRng::from_seed([0x3dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
-        let params = &JubjubBls12::new();
-
-        for length in 0..751 {
-            for _ in 0..5 {
-                let mut input: Vec<bool> = (0..length).map(|_| rng.gen()).collect();
-
-                let mut cs = TestConstraintSystem::<Bls12>::new();
-
-                let input_bools: Vec<Boolean> = input.iter().enumerate().map(|(i, b)| {
-                    Boolean::from(
-                        AllocatedBit::alloc(cs.namespace(|| format!("input {}", i)), Some(*b)).unwrap()
-                    )
-                }).collect();
-
-                let res = pedersen_hash(
-                    cs.namespace(|| "pedersen hash"),
-                    Personalization::MerkleTree(1),
-                    &input_bools,
-                    params
-                ).unwrap();
-
-                assert!(cs.is_satisfied());
-
-                let expected = ::pedersen_hash::pedersen_hash::<Bls12, _>(
-                    Personalization::MerkleTree(1),
-                    input.clone().into_iter(),
-                    params
-                ).into_xy();
-
-                assert_eq!(res.get_x().get_value().unwrap(), expected.0);
-                assert_eq!(res.get_y().get_value().unwrap(), expected.1);
-
-                // Test against the output of a different personalization
-                let unexpected = ::pedersen_hash::pedersen_hash::<Bls12, _>(
-                    Personalization::MerkleTree(0),
-                    input.into_iter(),
-                    params
-                ).into_xy();
-
-                assert!(res.get_x().get_value().unwrap() != unexpected.0);
-                assert!(res.get_y().get_value().unwrap() != unexpected.1);
-            }
-        }
-    }
-}

sapling-crypto/src/group_hash.rs

@@ -1,46 +0,0 @@
-use jubjub::{
-    JubjubEngine,
-    PrimeOrder,
-    edwards
-};
-
-use ff::{
-    PrimeField
-};
-
-use blake2_rfc::blake2s::Blake2s;
-use constants;
-
-/// Produces a random point in the Jubjub curve.
-/// The point is guaranteed to be prime order
-/// and not the identity.
-pub fn group_hash<E: JubjubEngine>(
-    tag: &[u8],
-    personalization: &[u8],
-    params: &E::Params
-) -> Option<edwards::Point<E, PrimeOrder>>
-{
-    assert_eq!(personalization.len(), 8);
-
-    // Check to see that scalar field is 255 bits
-    assert!(E::Fr::NUM_BITS == 255);
-
-    let mut h = Blake2s::with_params(32, &[], &[], personalization);
-    h.update(constants::GH_FIRST_BLOCK);
-    h.update(tag);
-    let h = h.finalize().as_ref().to_vec();
-    assert!(h.len() == 32);
-
-    match edwards::Point::<E, _>::read(&h[..], params) {
-        Ok(p) => {
-            let p = p.mul_by_cofactor(params);
-
-            if p != edwards::Point::zero() {
-                Some(p)
-            } else {
-                None
-            }
-        },
-        Err(_) => None
-    }
-}

sapling-crypto/src/lib.rs

@@ -1,23 +0,0 @@
-extern crate pairing;
-extern crate bellman;
-extern crate blake2_rfc;
-extern crate digest;
-extern crate ff;
-extern crate rand;
-extern crate byteorder;
-
-#[cfg(test)]
-#[macro_use]
-extern crate hex_literal;
-
-#[cfg(test)]
-extern crate crypto;
-
-pub mod jubjub;
-pub mod group_hash;
-pub mod circuit;
-pub mod pedersen_hash;
-pub mod primitives;
-pub mod constants;
-pub mod redjubjub;
-pub mod util;

sapling-crypto/src/primitives/mod.rs

@@ -1,271 +0,0 @@
-use ff::{Field, PrimeField, PrimeFieldRepr};
-
-use constants;
-
-use group_hash::group_hash;
-
-use pedersen_hash::{
-    pedersen_hash,
-    Personalization
-};
-
-use byteorder::{
-    LittleEndian,
-    WriteBytesExt
-};
-
-use jubjub::{
-    JubjubEngine,
-    JubjubParams,
-    edwards,
-    PrimeOrder,
-    FixedGenerators
-};
-
-use blake2_rfc::blake2s::Blake2s;
-
-#[derive(Clone)]
-pub struct ValueCommitment<E: JubjubEngine> {
-    pub value: u64,
-    pub randomness: E::Fs
-}
-
-impl<E: JubjubEngine> ValueCommitment<E> {
-    pub fn cm(
-        &self,
-        params: &E::Params
-    ) -> edwards::Point<E, PrimeOrder>
-    {
-        params.generator(FixedGenerators::ValueCommitmentValue)
-              .mul(self.value, params)
-              .add(
-                  &params.generator(FixedGenerators::ValueCommitmentRandomness)
-                  .mul(self.randomness, params),
-                  params
-              )
-    }
-}
-
-#[derive(Clone)]
-pub struct ProofGenerationKey<E: JubjubEngine> {
-    pub ak: edwards::Point<E, PrimeOrder>,
-    pub nsk: E::Fs
-}
-
-impl<E: JubjubEngine> ProofGenerationKey<E> {
-    pub fn into_viewing_key(&self, params: &E::Params) -> ViewingKey<E> {
-        ViewingKey {
-            ak: self.ak.clone(),
-            nk: params.generator(FixedGenerators::ProofGenerationKey)
-                      .mul(self.nsk, params)
-        }
-    }
-}
-
-#[derive(Debug)]
-pub struct ViewingKey<E: JubjubEngine> {
-    pub ak: edwards::Point<E, PrimeOrder>,
-    pub nk: edwards::Point<E, PrimeOrder>
-}
-
-impl<E: JubjubEngine> ViewingKey<E> {
-    pub fn rk(
-        &self,
-        ar: E::Fs,
-        params: &E::Params
-    ) -> edwards::Point<E, PrimeOrder> {
-        self.ak.add(
-            &params.generator(FixedGenerators::SpendingKeyGenerator)
-                   .mul(ar, params),
-            params
-        )
-    }
-
-    pub fn ivk(&self) -> E::Fs {
-        let mut preimage = [0; 64];
-
-        self.ak.write(&mut preimage[0..32]).unwrap();
-        self.nk.write(&mut preimage[32..64]).unwrap();
-
-        let mut h = Blake2s::with_params(32, &[], &[], constants::CRH_IVK_PERSONALIZATION);
-        h.update(&preimage);
-        let mut h = h.finalize().as_ref().to_vec();
-
-        // Drop the most significant five bits, so it can be interpreted as a scalar.
-        h[31] &= 0b0000_0111;
-
-        let mut e = <E::Fs as PrimeField>::Repr::default();
-        e.read_le(&h[..]).unwrap();
-
-        E::Fs::from_repr(e).expect("should be a valid scalar")
-    }
-
-    pub fn into_payment_address(
-        &self,
-        diversifier: Diversifier,
-        params: &E::Params
-    ) -> Option<PaymentAddress<E>>
-    {
-        diversifier.g_d(params).map(|g_d| {
-            let pk_d = g_d.mul(self.ivk(), params);
-
-            PaymentAddress {
-                pk_d: pk_d,
-                diversifier: diversifier
-            }
-        })
-    }
-}
-
-#[derive(Copy, Clone, Debug, PartialEq)]
-pub struct Diversifier(pub [u8; 11]);
-
-impl Diversifier {
-    pub fn g_d<E: JubjubEngine>(
-        &self,
-        params: &E::Params
-    ) -> Option<edwards::Point<E, PrimeOrder>>
-    {
-        group_hash::<E>(&self.0, constants::KEY_DIVERSIFICATION_PERSONALIZATION, params)
-    }
-}
-
-#[derive(Clone, Debug)]
-pub struct PaymentAddress<E: JubjubEngine> {
-    pub pk_d: edwards::Point<E, PrimeOrder>,
-    pub diversifier: Diversifier
-}
-
-impl<E: JubjubEngine> PartialEq for PaymentAddress<E> {
-    fn eq(&self, other: &Self) -> bool {
-        self.pk_d == other.pk_d && self.diversifier == other.diversifier
-    }
-}
-
-impl<E: JubjubEngine> PaymentAddress<E> {
-    pub fn g_d(
-        &self,
-        params: &E::Params
-    ) -> Option<edwards::Point<E, PrimeOrder>>
-    {
-        self.diversifier.g_d(params)
-    }
-
-    pub fn create_note(
-        &self,
-        value: u64,
-        randomness: E::Fs,
-        params: &E::Params
-    ) -> Option<Note<E>>
-    {
-        self.g_d(params).map(|g_d| {
-            Note {
-                value: value,
-                r: randomness,
-                g_d: g_d,
-                pk_d: self.pk_d.clone()
-            }
-        })
-    }
-}
-
-#[derive(Clone, Debug)]
-pub struct Note<E: JubjubEngine> {
-    /// The value of the note
-    pub value: u64,
-    /// The diversified base of the address, GH(d)
-    pub g_d: edwards::Point<E, PrimeOrder>,
-    /// The public key of the address, g_d^ivk
-    pub pk_d: edwards::Point<E, PrimeOrder>,
-    /// The commitment randomness
-    pub r: E::Fs
-}
-
-impl<E: JubjubEngine> PartialEq for Note<E> {
-    fn eq(&self, other: &Self) -> bool {
-        self.value == other.value
-            && self.g_d == other.g_d
-            && self.pk_d == other.pk_d
-            && self.r == other.r
-    }
-}
-
-impl<E: JubjubEngine> Note<E> {
-    pub fn uncommitted() -> E::Fr {
-        // The smallest u-coordinate that is not on the curve
-        // is one.
-        // TODO: This should be relocated to JubjubEngine as
-        // it's specific to the curve we're using, not all
-        // twisted edwards curves.
-        E::Fr::one()
-    }
-
-    /// Computes the note commitment, returning the full point.
-    fn cm_full_point(&self, params: &E::Params) -> edwards::Point<E, PrimeOrder>
-    {
-        // Calculate the note contents, as bytes
-        let mut note_contents = vec![];
-
-        // Writing the value in little endian
-        (&mut note_contents).write_u64::<LittleEndian>(self.value).unwrap();
-
-        // Write g_d
-        self.g_d.write(&mut note_contents).unwrap();
-
-        // Write pk_d
-        self.pk_d.write(&mut note_contents).unwrap();
-
-        assert_eq!(note_contents.len(), 32 + 32 + 8);
-
-        // Compute the Pedersen hash of the note contents
-        let hash_of_contents = pedersen_hash(
-            Personalization::NoteCommitment,
-            note_contents.into_iter()
-                         .flat_map(|byte| {
-                            (0..8).map(move |i| ((byte >> i) & 1) == 1)
-                         }),
-            params
-        );
-
-        // Compute final commitment
-        params.generator(FixedGenerators::NoteCommitmentRandomness)
-              .mul(self.r, params)
-              .add(&hash_of_contents, params)
-    }
-
-    /// Computes the nullifier given the viewing key and
-    /// note position
-    pub fn nf(
-        &self,
-        viewing_key: &ViewingKey<E>,
-        position: u64,
-        params: &E::Params
-    ) -> Vec<u8>
-    {
-        // Compute rho = cm + position.G
-        let rho = self
-            .cm_full_point(params)
-            .add(
-                &params.generator(FixedGenerators::NullifierPosition)
-                       .mul(position, params),
-                params
-            );
-
-        // Compute nf = BLAKE2s(nk | rho)
-        let mut nf_preimage = [0u8; 64];
-        viewing_key.nk.write(&mut nf_preimage[0..32]).unwrap();
-        rho.write(&mut nf_preimage[32..64]).unwrap();
-        let mut h = Blake2s::with_params(32, &[], &[], constants::PRF_NF_PERSONALIZATION);
-        h.update(&nf_preimage);
-        
-        h.finalize().as_ref().to_vec()
-    }
-
-    /// Computes the note commitment
-    pub fn cm(&self, params: &E::Params) -> E::Fr
-    {
-        // The commitment is in the prime order subgroup, so mapping the
-        // commitment to the x-coordinate is an injective encoding.
-        self.cm_full_point(params).into_xy().0
-    }
-}

zcash_client_backend/.gitignore

@@ -0,0 +1,2 @@
+# Protobufs
+src/proto/

zcash_client_backend/Cargo.toml

@@ -0,0 +1,31 @@
+[package]
+name = "zcash_client_backend"
+description = "APIs for creating shielded Zcash light clients"
+version = "0.1.0"
+authors = [
+    "Jack Grigg <jack@z.cash>",
+]
+homepage = "https://github.com/zcash/librustzcash"
+repository = "https://github.com/zcash/librustzcash"
+readme = "README.md"
+license = "MIT OR Apache-2.0"
+edition = "2018"
+
+[dependencies]
+bech32 = "0.7"
+ff = { version = "0.5.0", path = "../ff" }
+hex = "0.3"
+pairing = { version = "0.15.0", path = "../pairing" }
+protobuf = "2"
+subtle = "2"
+zcash_primitives = { version = "0.1.0", path = "../zcash_primitives" }
+
+[build-dependencies]
+protobuf-codegen-pure = "2"
+
+[dev-dependencies]
+rand_core = "0.5"
+rand_xorshift = "0.2"
+
+[badges]
+maintenance = { status = "actively-developed" }

zcash_client_backend/README.md

@@ -1,12 +1,14 @@
-# zcash_wallet
+# zcash_client_backend
 
-This library contains Rust structs and traits for creating shielded Zcash wallets.
+This library contains Rust structs and traits for creating shielded Zcash light
+clients.
 
 ## License
 
 Licensed under either of
 
- * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
+ * Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
+   http://www.apache.org/licenses/LICENSE-2.0)
  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
 
 at your option.

zcash_client_backend/build.rs

@@ -0,0 +1,11 @@
+use protobuf_codegen_pure;
+
+fn main() {
+    protobuf_codegen_pure::run(protobuf_codegen_pure::Args {
+        out_dir: "src/proto",
+        input: &["proto/compact_formats.proto"],
+        includes: &["proto"],
+        customize: Default::default(),
+    })
+    .expect("protoc");
+}

zcash_client_backend/proto/compact_formats.proto

@@ -0,0 +1,48 @@
+syntax = "proto3";
+package cash.z.wallet.sdk.rpc;
+option go_package = "walletrpc";
+
+// Remember that proto3 fields are all optional. A field that is not present will be set to its zero value.
+// bytes fields of hashes are in canonical little-endian format.
+
+// CompactBlock is a packaging of ONLY the data from a block that's needed to:
+//   1. Detect a payment to your shielded Sapling address
+//   2. Detect a spend of your shielded Sapling notes
+//   3. Update your witnesses to generate new Sapling spend proofs.
+message CompactBlock {
+    uint32 protoVersion = 1; // the version of this wire format, for storage
+    uint64 height = 2; // the height of this block
+    bytes hash = 3;
+    bytes prevHash = 4;
+    uint32 time = 5;
+    bytes header = 6; // (hash, prevHash, and time) OR (full header)
+    repeated CompactTx vtx = 7; // compact transactions from this block
+}
+
+message CompactTx {
+    // Index and hash will allow the receiver to call out to chain
+    // explorers or other data structures to retrieve more information
+    // about this transaction.
+    uint64 index = 1;
+    bytes hash = 2;
+
+    // The transaction fee: present if server can provide. In the case of a
+    // stateless server and a transaction with transparent inputs, this will be
+    // unset because the calculation requires reference to prior transactions.
+    // in a pure-Sapling context, the fee will be calculable as:
+    //    valueBalance + (sum(vPubNew) - sum(vPubOld) - sum(tOut))
+    uint32 fee = 3;
+
+    repeated CompactSpend spends = 4;
+    repeated CompactOutput outputs = 5;
+}
+
+message CompactSpend {
+    bytes nf = 1;
+}
+
+message CompactOutput {
+    bytes cmu = 1;
+    bytes epk = 2;
+    bytes ciphertext = 3;
+}

zcash_client_backend/src/constants.rs

@@ -0,0 +1,5 @@
+//! Zcash global and per-network constants.
+
+pub mod mainnet;
+pub mod regtest;
+pub mod testnet;

zcash_client_backend/src/constants/mainnet.rs

@@ -0,0 +1,30 @@
+//! Constants for the Zcash main network.
+
+/// The mainnet coin type for ZEC, as defined by [SLIP 44].
+///
+/// [SLIP 44]: https://github.com/satoshilabs/slips/blob/master/slip-0044.md
+pub const COIN_TYPE: u32 = 133;
+
+/// The HRP for a Bech32-encoded mainnet [`ExtendedSpendingKey`].
+///
+/// Defined in [ZIP 32].
+///
+/// [`ExtendedSpendingKey`]: zcash_primitives::zip32::ExtendedSpendingKey
+/// [ZIP 32]: https://github.com/zcash/zips/blob/master/zip-0032.rst
+pub const HRP_SAPLING_EXTENDED_SPENDING_KEY: &str = "secret-extended-key-main";
+
+/// The HRP for a Bech32-encoded mainnet [`ExtendedFullViewingKey`].
+///
+/// Defined in [ZIP 32].
+///
+/// [`ExtendedFullViewingKey`]: zcash_primitives::zip32::ExtendedFullViewingKey
+/// [ZIP 32]: https://github.com/zcash/zips/blob/master/zip-0032.rst
+pub const HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY: &str = "zxviews";
+
+/// The HRP for a Bech32-encoded mainnet [`PaymentAddress`].
+///
+/// Defined in section 5.6.4 of the [Zcash Protocol Specification].
+///
+/// [`PaymentAddress`]: zcash_primitives::primitives::PaymentAddress
+/// [Zcash Protocol Specification]: https://github.com/zcash/zips/blob/master/protocol/protocol.pdf
+pub const HRP_SAPLING_PAYMENT_ADDRESS: &str = "zs";

zcash_client_backend/src/constants/regtest.rs

@@ -0,0 +1,45 @@
+//! # Regtest constants
+//!
+//! `regtest` is a `zcashd`-specific environment used for local testing. They mostly reuse
+//! the testnet constants.
+//! These constants are defined in [the `zcashd` codebase].
+//! [the `zcashd` codebase]: https://github.com/zcash/zcash/blob/128d863fb8be39ee294fda397c1ce3ba3b889cb2/src/chainparams.cpp#L482-L496
+
+/// The regtest cointype reuses the testnet cointype
+pub const COIN_TYPE: u32 = 1;
+
+/// The HRP for a Bech32-encoded regtest [`ExtendedSpendingKey`].
+///
+/// It is defined in [the `zcashd` codebase].
+///
+/// [`ExtendedSpendingKey`]: zcash_primitives::zip32::ExtendedSpendingKey
+/// [the `zcashd` codebase]: https://github.com/zcash/zcash/blob/128d863fb8be39ee294fda397c1ce3ba3b889cb2/src/chainparams.cpp#L496
+pub const HRP_SAPLING_EXTENDED_SPENDING_KEY: &str = "secret-extended-key-regtest";
+
+/// The HRP for a Bech32-encoded regtest [`ExtendedFullViewingKey`].
+///
+/// It is defined in [the `zcashd` codebase].
+///
+/// [`ExtendedFullViewingKey`]: zcash_primitives::zip32::ExtendedFullViewingKey
+/// [the `zcashd` codebase]: https://github.com/zcash/zcash/blob/128d863fb8be39ee294fda397c1ce3ba3b889cb2/src/chainparams.cpp#L494
+pub const HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY: &str = "zxviewregtestsapling";
+
+/// The HRP for a Bech32-encoded regtest [`PaymentAddress`].
+///
+/// It is defined in [the `zcashd` codebase].
+///
+/// [`PaymentAddress`]: zcash_primitives::primitives::PaymentAddress
+/// [the `zcashd` codebase]: https://github.com/zcash/zcash/blob/128d863fb8be39ee294fda397c1ce3ba3b889cb2/src/chainparams.cpp#L493
+pub const HRP_SAPLING_PAYMENT_ADDRESS: &str = "zregtestsapling";
+
+/// The prefix for a Base58Check-encoded regtest [`TransparentAddress::PublicKey`].
+/// Same as the testnet prefix.
+///
+/// [`TransparentAddress::PublicKey`]: zcash_primitives::legacy::TransparentAddress::PublicKey
+pub const B58_PUBKEY_ADDRESS_PREFIX: [u8; 2] = [0x1d, 0x25];
+
+/// The prefix for a Base58Check-encoded regtest [`TransparentAddress::Script`].
+/// Same as the testnet prefix.
+///
+/// [`TransparentAddress::Script`]: zcash_primitives::legacy::TransparentAddress::Script
+pub const B58_SCRIPT_ADDRESS_PREFIX: [u8; 2] = [0x1c, 0xba];

zcash_client_backend/src/constants/testnet.rs

@@ -0,0 +1,30 @@
+//! Constants for the Zcash test network.
+
+/// The testnet coin type for ZEC, as defined by [SLIP 44].
+///
+/// [SLIP 44]: https://github.com/satoshilabs/slips/blob/master/slip-0044.md
+pub const COIN_TYPE: u32 = 1;
+
+/// The HRP for a Bech32-encoded testnet [`ExtendedSpendingKey`].
+///
+/// Defined in [ZIP 32].
+///
+/// [`ExtendedSpendingKey`]: zcash_primitives::zip32::ExtendedSpendingKey
+/// [ZIP 32]: https://github.com/zcash/zips/blob/master/zip-0032.rst
+pub const HRP_SAPLING_EXTENDED_SPENDING_KEY: &str = "secret-extended-key-test";
+
+/// The HRP for a Bech32-encoded testnet [`ExtendedFullViewingKey`].
+///
+/// Defined in [ZIP 32].
+///
+/// [`ExtendedFullViewingKey`]: zcash_primitives::zip32::ExtendedFullViewingKey
+/// [ZIP 32]: https://github.com/zcash/zips/blob/master/zip-0032.rst
+pub const HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY: &str = "zxviewtestsapling";
+
+/// The HRP for a Bech32-encoded testnet [`PaymentAddress`].
+///
+/// Defined in section 5.6.4 of the [Zcash Protocol Specification].
+///
+/// [`PaymentAddress`]: zcash_primitives::primitives::PaymentAddress
+/// [Zcash Protocol Specification]: https://github.com/zcash/zips/blob/master/protocol/protocol.pdf
+pub const HRP_SAPLING_PAYMENT_ADDRESS: &str = "ztestsapling";

zcash_client_backend/src/decrypt.rs

@@ -0,0 +1,76 @@
+use pairing::bls12_381::Bls12;
+use zcash_primitives::{
+    note_encryption::{try_sapling_note_decryption, try_sapling_output_recovery, Memo},
+    primitives::{Note, PaymentAddress},
+    transaction::Transaction,
+    zip32::ExtendedFullViewingKey,
+    JUBJUB,
+};
+
+/// A decrypted shielded output.
+pub struct DecryptedOutput {
+    /// The index of the output within [`shielded_outputs`].
+    ///
+    /// [`shielded_outputs`]: zcash_primitives::transaction::TransactionData
+    pub index: usize,
+    /// The note within the output.
+    pub note: Note<Bls12>,
+    /// The address the note was sent to.
+    pub to: PaymentAddress<Bls12>,
+    /// The memo included with the note.
+    pub memo: Memo,
+    /// True if this output was recovered using an [`OutgoingViewingKey`], meaning that
+    /// this is a logical output of the transaction.
+    ///
+    /// [`OutgoingViewingKey`]: zcash_primitives::keys::OutgoingViewingKey
+    pub outgoing: bool,
+}
+
+/// Scans a [`Transaction`] for any information that can be decrypted by the set of
+/// [`ExtendedFullViewingKey`]s.
+pub fn decrypt_transaction(
+    tx: &Transaction,
+    extfvks: &[ExtendedFullViewingKey],
+) -> Vec<DecryptedOutput> {
+    let mut decrypted = vec![];
+
+    // Cache IncomingViewingKey calculation
+    let vks: Vec<_> = extfvks
+        .iter()
+        .map(|extfvk| (extfvk.fvk.vk.ivk(), extfvk.fvk.ovk))
+        .collect();
+
+    for (index, output) in tx.shielded_outputs.iter().enumerate() {
+        let epk = match output.ephemeral_key.as_prime_order(&JUBJUB) {
+            Some(p) => p,
+            None => continue,
+        };
+
+        for (ivk, ovk) in &vks {
+            let ((note, to, memo), outgoing) =
+                match try_sapling_note_decryption(ivk, &epk, &output.cmu, &output.enc_ciphertext) {
+                    Some(ret) => (ret, false),
+                    None => match try_sapling_output_recovery(
+                        ovk,
+                        &output.cv,
+                        &output.cmu,
+                        &epk,
+                        &output.enc_ciphertext,
+                        &output.out_ciphertext,
+                    ) {
+                        Some(ret) => (ret, true),
+                        None => continue,
+                    },
+                };
+            decrypted.push(DecryptedOutput {
+                index,
+                note,
+                to,
+                memo,
+                outgoing,
+            })
+        }
+    }
+
+    decrypted
+}

zcash_client_backend/src/encoding.rs

@@ -0,0 +1,347 @@
+//! Encoding and decoding functions for Zcash key and address structs.
+//!
+//! Human-Readable Prefixes (HRPs) for Bech32 encodings are located in the [`constants`]
+//! module.
+//!
+//! [`constants`]: crate::constants
+
+use bech32::{self, Error, FromBase32, ToBase32};
+use pairing::bls12_381::Bls12;
+use std::io::{self, Write};
+use zcash_primitives::{
+    primitives::PaymentAddress,
+    zip32::{ExtendedFullViewingKey, ExtendedSpendingKey},
+    JUBJUB,
+};
+
+fn bech32_encode<F>(hrp: &str, write: F) -> String
+where
+    F: Fn(&mut dyn Write) -> io::Result<()>,
+{
+    let mut data: Vec<u8> = vec![];
+    write(&mut data).expect("Should be able to write to a Vec");
+    bech32::encode(hrp, data.to_base32()).expect("hrp is invalid")
+}
+
+fn bech32_decode<T, F>(hrp: &str, s: &str, read: F) -> Result<Option<T>, Error>
+where
+    F: Fn(Vec<u8>) -> Option<T>,
+{
+    let (decoded_hrp, data) = bech32::decode(s)?;
+    if decoded_hrp == hrp {
+        Vec::<u8>::from_base32(&data).map(|data| read(data))
+    } else {
+        Ok(None)
+    }
+}
+
+/// Writes an [`ExtendedSpendingKey`] as a Bech32-encoded string.
+///
+/// # Examples
+///
+/// ```
+/// use zcash_client_backend::{
+///     constants::testnet::{COIN_TYPE, HRP_SAPLING_EXTENDED_SPENDING_KEY},
+///     encoding::encode_extended_spending_key,
+///     keys::spending_key,
+/// };
+///
+/// let extsk = spending_key(&[0; 32][..], COIN_TYPE, 0);
+/// let encoded = encode_extended_spending_key(HRP_SAPLING_EXTENDED_SPENDING_KEY, &extsk);
+/// ```
+pub fn encode_extended_spending_key(hrp: &str, extsk: &ExtendedSpendingKey) -> String {
+    bech32_encode(hrp, |w| extsk.write(w))
+}
+
+/// Decodes an [`ExtendedSpendingKey`] from a Bech32-encoded string.
+pub fn decode_extended_spending_key(
+    hrp: &str,
+    s: &str,
+) -> Result<Option<ExtendedSpendingKey>, Error> {
+    bech32_decode(hrp, s, |data| ExtendedSpendingKey::read(&data[..]).ok())
+}
+
+/// Writes an [`ExtendedFullViewingKey`] as a Bech32-encoded string.
+///
+/// # Examples
+///
+/// ```
+/// use zcash_client_backend::{
+///     constants::testnet::{COIN_TYPE, HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY},
+///     encoding::encode_extended_full_viewing_key,
+///     keys::spending_key,
+/// };
+/// use zcash_primitives::zip32::ExtendedFullViewingKey;
+///
+/// let extsk = spending_key(&[0; 32][..], COIN_TYPE, 0);
+/// let extfvk = ExtendedFullViewingKey::from(&extsk);
+/// let encoded = encode_extended_full_viewing_key(HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY, &extfvk);
+/// ```
+pub fn encode_extended_full_viewing_key(hrp: &str, extfvk: &ExtendedFullViewingKey) -> String {
+    bech32_encode(hrp, |w| extfvk.write(w))
+}
+
+/// Decodes an [`ExtendedFullViewingKey`] from a Bech32-encoded string.
+pub fn decode_extended_full_viewing_key(
+    hrp: &str,
+    s: &str,
+) -> Result<Option<ExtendedFullViewingKey>, Error> {
+    bech32_decode(hrp, s, |data| ExtendedFullViewingKey::read(&data[..]).ok())
+}
+
+/// Writes a [`PaymentAddress`] as a Bech32-encoded string.
+///
+/// # Examples
+///
+/// ```
+/// use pairing::bls12_381::Bls12;
+/// use rand_core::SeedableRng;
+/// use rand_xorshift::XorShiftRng;
+/// use zcash_client_backend::{
+///     constants::testnet::HRP_SAPLING_PAYMENT_ADDRESS,
+///     encoding::encode_payment_address,
+/// };
+/// use zcash_primitives::{
+///     jubjub::edwards,
+///     primitives::{Diversifier, PaymentAddress},
+///     JUBJUB,
+/// };
+///
+/// let rng = &mut XorShiftRng::from_seed([
+///     0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+///     0xbc, 0xe5,
+/// ]);
+///
+/// let pa = PaymentAddress::from_parts(
+///     Diversifier([0u8; 11]),
+///     edwards::Point::<Bls12, _>::rand(rng, &JUBJUB).mul_by_cofactor(&JUBJUB),
+/// )
+/// .unwrap();
+///
+/// assert_eq!(
+///     encode_payment_address(HRP_SAPLING_PAYMENT_ADDRESS, &pa),
+///     "ztestsapling1qqqqqqqqqqqqqqqqqrjq05nyfku05msvu49mawhg6kr0wwljahypwyk2h88z6975u563j0ym7pe",
+/// );
+/// ```
+pub fn encode_payment_address(hrp: &str, addr: &PaymentAddress<Bls12>) -> String {
+    bech32_encode(hrp, |w| w.write_all(&addr.to_bytes()))
+}
+
+/// Decodes a [`PaymentAddress`] from a Bech32-encoded string.
+///
+/// # Examples
+///
+/// ```
+/// use pairing::bls12_381::Bls12;
+/// use rand_core::SeedableRng;
+/// use rand_xorshift::XorShiftRng;
+/// use zcash_client_backend::{
+///     constants::testnet::HRP_SAPLING_PAYMENT_ADDRESS,
+///     encoding::decode_payment_address,
+/// };
+/// use zcash_primitives::{
+///     jubjub::edwards,
+///     primitives::{Diversifier, PaymentAddress},
+///     JUBJUB,
+/// };
+///
+/// let rng = &mut XorShiftRng::from_seed([
+///     0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+///     0xbc, 0xe5,
+/// ]);
+///
+/// let pa = PaymentAddress::from_parts(
+///     Diversifier([0u8; 11]),
+///     edwards::Point::<Bls12, _>::rand(rng, &JUBJUB).mul_by_cofactor(&JUBJUB),
+/// )
+/// .unwrap();
+///
+/// assert_eq!(
+///     decode_payment_address(
+///         HRP_SAPLING_PAYMENT_ADDRESS,
+///         "ztestsapling1qqqqqqqqqqqqqqqqqrjq05nyfku05msvu49mawhg6kr0wwljahypwyk2h88z6975u563j0ym7pe",
+///     ),
+///     Ok(Some(pa)),
+/// );
+/// ```
+pub fn decode_payment_address(hrp: &str, s: &str) -> Result<Option<PaymentAddress<Bls12>>, Error> {
+    bech32_decode(hrp, s, |data| {
+        if data.len() != 43 {
+            return None;
+        }
+
+        let mut bytes = [0; 43];
+        bytes.copy_from_slice(&data);
+        PaymentAddress::<Bls12>::from_bytes(&bytes, &JUBJUB)
+    })
+}
+
+#[cfg(test)]
+mod tests {
+    use pairing::bls12_381::Bls12;
+    use rand_core::SeedableRng;
+    use rand_xorshift::XorShiftRng;
+    use zcash_primitives::JUBJUB;
+    use zcash_primitives::{
+        jubjub::edwards,
+        primitives::{Diversifier, PaymentAddress},
+        zip32::ExtendedSpendingKey,
+    };
+
+    use super::{
+        decode_extended_full_viewing_key, decode_extended_spending_key, decode_payment_address,
+        encode_extended_full_viewing_key, encode_extended_spending_key, encode_payment_address,
+    };
+    use crate::constants;
+
+    #[test]
+    fn extended_spending_key() {
+        let extsk = ExtendedSpendingKey::master(&[0; 32][..]);
+
+        let encoded_main = "secret-extended-key-main1qqqqqqqqqqqqqq8n3zjjmvhhr854uy3qhpda3ml34haf0x388z5r7h4st4kpsf6qysqws3xh6qmha7gna72fs2n4clnc9zgyd22s658f65pex4exe56qjk5pqj9vfdq7dfdhjc2rs9jdwq0zl99uwycyrxzp86705rk687spn44e2uhm7h0hsagfvkk4n7n6nfer6u57v9cac84t7nl2zth0xpyfeg0w2p2wv2yn6jn923aaz0vdaml07l60ahapk6efchyxwysrvjs87qvlj";
+        let encoded_test = "secret-extended-key-test1qqqqqqqqqqqqqq8n3zjjmvhhr854uy3qhpda3ml34haf0x388z5r7h4st4kpsf6qysqws3xh6qmha7gna72fs2n4clnc9zgyd22s658f65pex4exe56qjk5pqj9vfdq7dfdhjc2rs9jdwq0zl99uwycyrxzp86705rk687spn44e2uhm7h0hsagfvkk4n7n6nfer6u57v9cac84t7nl2zth0xpyfeg0w2p2wv2yn6jn923aaz0vdaml07l60ahapk6efchyxwysrvjsvzyw8j";
+
+        assert_eq!(
+            encode_extended_spending_key(
+                constants::mainnet::HRP_SAPLING_EXTENDED_SPENDING_KEY,
+                &extsk
+            ),
+            encoded_main
+        );
+        assert_eq!(
+            decode_extended_spending_key(
+                constants::mainnet::HRP_SAPLING_EXTENDED_SPENDING_KEY,
+                encoded_main
+            )
+            .unwrap(),
+            Some(extsk.clone())
+        );
+
+        assert_eq!(
+            encode_extended_spending_key(
+                constants::testnet::HRP_SAPLING_EXTENDED_SPENDING_KEY,
+                &extsk
+            ),
+            encoded_test
+        );
+        assert_eq!(
+            decode_extended_spending_key(
+                constants::testnet::HRP_SAPLING_EXTENDED_SPENDING_KEY,
+                encoded_test
+            )
+            .unwrap(),
+            Some(extsk)
+        );
+    }
+
+    #[test]
+    fn extended_full_viewing_key() {
+        let extfvk = (&ExtendedSpendingKey::master(&[0; 32][..])).into();
+
+        let encoded_main = "zxviews1qqqqqqqqqqqqqq8n3zjjmvhhr854uy3qhpda3ml34haf0x388z5r7h4st4kpsf6qy3zw4wc246aw9rlfyg5ndlwvne7mwdq0qe6vxl42pqmcf8pvmmd5slmjxduqa9evgej6wa3th2505xq4nggrxdm93rxk4rpdjt5nmq2vn44e2uhm7h0hsagfvkk4n7n6nfer6u57v9cac84t7nl2zth0xpyfeg0w2p2wv2yn6jn923aaz0vdaml07l60ahapk6efchyxwysrvjsxmansf";
+        let encoded_test = "zxviewtestsapling1qqqqqqqqqqqqqq8n3zjjmvhhr854uy3qhpda3ml34haf0x388z5r7h4st4kpsf6qy3zw4wc246aw9rlfyg5ndlwvne7mwdq0qe6vxl42pqmcf8pvmmd5slmjxduqa9evgej6wa3th2505xq4nggrxdm93rxk4rpdjt5nmq2vn44e2uhm7h0hsagfvkk4n7n6nfer6u57v9cac84t7nl2zth0xpyfeg0w2p2wv2yn6jn923aaz0vdaml07l60ahapk6efchyxwysrvjs8evfkz";
+
+        assert_eq!(
+            encode_extended_full_viewing_key(
+                constants::mainnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY,
+                &extfvk
+            ),
+            encoded_main
+        );
+        assert_eq!(
+            decode_extended_full_viewing_key(
+                constants::mainnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY,
+                encoded_main
+            )
+            .unwrap(),
+            Some(extfvk.clone())
+        );
+
+        assert_eq!(
+            encode_extended_full_viewing_key(
+                constants::testnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY,
+                &extfvk
+            ),
+            encoded_test
+        );
+        assert_eq!(
+            decode_extended_full_viewing_key(
+                constants::testnet::HRP_SAPLING_EXTENDED_FULL_VIEWING_KEY,
+                encoded_test
+            )
+            .unwrap(),
+            Some(extfvk)
+        );
+    }
+
+    #[test]
+    fn payment_address() {
+        let rng = &mut XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
+
+        let addr = PaymentAddress::from_parts(
+            Diversifier([0u8; 11]),
+            edwards::Point::<Bls12, _>::rand(rng, &JUBJUB).mul_by_cofactor(&JUBJUB),
+        )
+        .unwrap();
+
+        let encoded_main =
+            "zs1qqqqqqqqqqqqqqqqqrjq05nyfku05msvu49mawhg6kr0wwljahypwyk2h88z6975u563j8nfaxd";
+        let encoded_test =
+            "ztestsapling1qqqqqqqqqqqqqqqqqrjq05nyfku05msvu49mawhg6kr0wwljahypwyk2h88z6975u563j0ym7pe";
+
+        assert_eq!(
+            encode_payment_address(constants::mainnet::HRP_SAPLING_PAYMENT_ADDRESS, &addr),
+            encoded_main
+        );
+        assert_eq!(
+            decode_payment_address(
+                constants::mainnet::HRP_SAPLING_PAYMENT_ADDRESS,
+                encoded_main
+            )
+            .unwrap(),
+            Some(addr.clone())
+        );
+
+        assert_eq!(
+            encode_payment_address(constants::testnet::HRP_SAPLING_PAYMENT_ADDRESS, &addr),
+            encoded_test
+        );
+        assert_eq!(
+            decode_payment_address(
+                constants::testnet::HRP_SAPLING_PAYMENT_ADDRESS,
+                encoded_test
+            )
+            .unwrap(),
+            Some(addr)
+        );
+    }
+
+    #[test]
+    fn invalid_diversifier() {
+        let rng = &mut XorShiftRng::from_seed([
+            0x59, 0x62, 0xbe, 0x3d, 0x76, 0x3d, 0x31, 0x8d, 0x17, 0xdb, 0x37, 0x32, 0x54, 0x06,
+            0xbc, 0xe5,
+        ]);
+
+        let addr = PaymentAddress::from_parts(
+            Diversifier([1u8; 11]),
+            edwards::Point::<Bls12, _>::rand(rng, &JUBJUB).mul_by_cofactor(&JUBJUB),
+        )
+        .unwrap();
+
+        let encoded_main =
+            encode_payment_address(constants::mainnet::HRP_SAPLING_PAYMENT_ADDRESS, &addr);
+
+        assert_eq!(
+            decode_payment_address(
+                constants::mainnet::HRP_SAPLING_PAYMENT_ADDRESS,
+                &encoded_main
+            )
+            .unwrap(),
+            None
+        );
+    }
+}

zcash_client_backend/src/keys.rs

@@ -0,0 +1,43 @@
+//! Helper functions for managing light client key material.
+
+use zcash_primitives::zip32::{ChildIndex, ExtendedSpendingKey};
+
+/// Derives the ZIP 32 [`ExtendedSpendingKey`] for a given coin type and account from the
+/// given seed.
+///
+/// # Panics
+///
+/// Panics if `seed` is shorter than 32 bytes.
+///
+/// # Examples
+///
+/// ```
+/// use zcash_client_backend::{constants::testnet::COIN_TYPE, keys::spending_key};
+///
+/// let extsk = spending_key(&[0; 32][..], COIN_TYPE, 0);
+/// ```
+pub fn spending_key(seed: &[u8], coin_type: u32, account: u32) -> ExtendedSpendingKey {
+    if seed.len() < 32 {
+        panic!("ZIP 32 seeds MUST be at least 32 bytes");
+    }
+
+    ExtendedSpendingKey::from_path(
+        &ExtendedSpendingKey::master(&seed),
+        &[
+            ChildIndex::Hardened(32),
+            ChildIndex::Hardened(coin_type),
+            ChildIndex::Hardened(account),
+        ],
+    )
+}
+
+#[cfg(test)]
+mod tests {
+    use super::spending_key;
+
+    #[test]
+    #[should_panic]
+    fn spending_key_panics_on_short_seed() {
+        let _ = spending_key(&[0; 31][..], 0, 0);
+    }
+}

zcash_client_backend/src/lib.rs

@@ -0,0 +1,17 @@
+//! *A crate for implementing Zcash light clients.*
+//!
+//! `zcash_client_backend` contains Rust structs and traits for creating shielded Zcash
+//! light clients.
+
+// Catch documentation errors caused by code changes.
+#![deny(intra_doc_link_resolution_failure)]
+
+pub mod constants;
+mod decrypt;
+pub mod encoding;
+pub mod keys;
+pub mod proto;
+pub mod wallet;
+pub mod welding_rig;
+
+pub use decrypt::{decrypt_transaction, DecryptedOutput};

zcash_client_backend/src/proto/mod.rs

@@ -0,0 +1,83 @@
+//! Generated code for handling light client protobuf structs.
+
+use ff::{PrimeField, PrimeFieldRepr};
+use pairing::bls12_381::{Bls12, Fr, FrRepr};
+use zcash_primitives::{
+    block::{BlockHash, BlockHeader},
+    jubjub::{edwards, PrimeOrder},
+    JUBJUB,
+};
+
+pub mod compact_formats;
+
+impl compact_formats::CompactBlock {
+    /// Returns the [`BlockHash`] for this block.
+    ///
+    /// # Panics
+    ///
+    /// This function will panic if [`CompactBlock.header`] is not set and
+    /// [`CompactBlock.hash`] is not exactly 32 bytes.
+    ///
+    /// [`CompactBlock.header`]: #structfield.header
+    /// [`CompactBlock.hash`]: #structfield.hash
+    pub fn hash(&self) -> BlockHash {
+        if let Some(header) = self.header() {
+            header.hash()
+        } else {
+            BlockHash::from_slice(&self.hash)
+        }
+    }
+
+    /// Returns the [`BlockHash`] for this block's parent.
+    ///
+    /// # Panics
+    ///
+    /// This function will panic if [`CompactBlock.header`] is not set and
+    /// [`CompactBlock.prevHash`] is not exactly 32 bytes.
+    ///
+    /// [`CompactBlock.header`]: #structfield.header
+    /// [`CompactBlock.prevHash`]: #structfield.prevHash
+    pub fn prev_hash(&self) -> BlockHash {
+        if let Some(header) = self.header() {
+            header.prev_block
+        } else {
+            BlockHash::from_slice(&self.prevHash)
+        }
+    }
+
+    /// Returns the [`BlockHeader`] for this block if present.
+    ///
+    /// A convenience method that parses [`CompactBlock.header`] if present.
+    ///
+    /// [`CompactBlock.header`]: #structfield.header
+    pub fn header(&self) -> Option<BlockHeader> {
+        if self.header.is_empty() {
+            None
+        } else {
+            BlockHeader::read(&self.header[..]).ok()
+        }
+    }
+}
+
+impl compact_formats::CompactOutput {
+    /// Returns the note commitment for this output.
+    ///
+    /// A convenience method that parses [`CompactOutput.cmu`].
+    ///
+    /// [`CompactOutput.cmu`]: #structfield.cmu
+    pub fn cmu(&self) -> Result<Fr, ()> {
+        let mut repr = FrRepr::default();
+        repr.read_le(&self.cmu[..]).map_err(|_| ())?;
+        Fr::from_repr(repr).map_err(|_| ())
+    }
+
+    /// Returns the ephemeral public key for this output.
+    ///
+    /// A convenience method that parses [`CompactOutput.epk`].
+    ///
+    /// [`CompactOutput.epk`]: #structfield.epk
+    pub fn epk(&self) -> Result<edwards::Point<Bls12, PrimeOrder>, ()> {
+        let p = edwards::Point::<Bls12, _>::read(&self.epk[..], &JUBJUB).map_err(|_| ())?;
+        p.as_prime_order(&JUBJUB).ok_or(())
+    }
+}

zcash_client_backend/src/wallet.rs

@@ -0,0 +1,46 @@
+//! Structs representing transaction data scanned from the block chain by a wallet or
+//! light client.
+
+use pairing::bls12_381::{Bls12, Fr};
+use zcash_primitives::{
+    jubjub::{edwards, PrimeOrder},
+    merkle_tree::IncrementalWitness,
+    primitives::{Note, PaymentAddress},
+    sapling::Node,
+    transaction::TxId,
+};
+
+/// A subset of a [`Transaction`] relevant to wallets and light clients.
+///
+/// [`Transaction`]: zcash_primitives::transaction::Transaction
+pub struct WalletTx {
+    pub txid: TxId,
+    pub index: usize,
+    pub num_spends: usize,
+    pub num_outputs: usize,
+    pub shielded_spends: Vec<WalletShieldedSpend>,
+    pub shielded_outputs: Vec<WalletShieldedOutput>,
+}
+
+/// A subset of a [`SpendDescription`] relevant to wallets and light clients.
+///
+/// [`SpendDescription`]: zcash_primitives::transaction::components::SpendDescription
+pub struct WalletShieldedSpend {
+    pub index: usize,
+    pub nf: Vec<u8>,
+    pub account: usize,
+}
+
+/// A subset of an [`OutputDescription`] relevant to wallets and light clients.
+///
+/// [`OutputDescription`]: zcash_primitives::transaction::components::OutputDescription
+pub struct WalletShieldedOutput {
+    pub index: usize,
+    pub cmu: Fr,
+    pub epk: edwards::Point<Bls12, PrimeOrder>,
+    pub account: usize,
+    pub note: Note<Bls12>,
+    pub to: PaymentAddress<Bls12>,
+    pub is_change: bool,
+    pub witness: IncrementalWitness<Node>,
+}

zcash_client_backend/src/welding_rig.rs

@@ -0,0 +1,397 @@
+//! Tools for scanning a compact representation of the Zcash block chain.
+
+use ff::PrimeField;
+use std::collections::HashSet;
+use subtle::{ConditionallySelectable, ConstantTimeEq, CtOption};
+use zcash_primitives::{
+    jubjub::fs::Fs,
+    merkle_tree::{CommitmentTree, IncrementalWitness},
+    note_encryption::try_sapling_compact_note_decryption,
+    sapling::Node,
+    transaction::TxId,
+    zip32::ExtendedFullViewingKey,
+};
+
+use crate::proto::compact_formats::{CompactBlock, CompactOutput};
+use crate::wallet::{WalletShieldedOutput, WalletShieldedSpend, WalletTx};
+
+/// Scans a [`CompactOutput`] with a set of [`ExtendedFullViewingKey`]s.
+///
+/// Returns a [`WalletShieldedOutput`] and corresponding [`IncrementalWitness`] if this
+/// output belongs to any of the given [`ExtendedFullViewingKey`]s.
+///
+/// The given [`CommitmentTree`] and existing [`IncrementalWitness`]es are incremented
+/// with this output's commitment.
+fn scan_output(
+    (index, output): (usize, CompactOutput),
+    ivks: &[Fs],
+    spent_from_accounts: &HashSet<usize>,
+    tree: &mut CommitmentTree<Node>,
+    existing_witnesses: &mut [&mut IncrementalWitness<Node>],
+    block_witnesses: &mut [&mut IncrementalWitness<Node>],
+    new_witnesses: &mut [&mut IncrementalWitness<Node>],
+) -> Option<WalletShieldedOutput> {
+    let cmu = output.cmu().ok()?;
+    let epk = output.epk().ok()?;
+    let ct = output.ciphertext;
+
+    // Increment tree and witnesses
+    let node = Node::new(cmu.into_repr());
+    for witness in existing_witnesses {
+        witness.append(node).unwrap();
+    }
+    for witness in block_witnesses {
+        witness.append(node).unwrap();
+    }
+    for witness in new_witnesses {
+        witness.append(node).unwrap();
+    }
+    tree.append(node).unwrap();
+
+    for (account, ivk) in ivks.iter().enumerate() {
+        let (note, to) = match try_sapling_compact_note_decryption(ivk, &epk, &cmu, &ct) {
+            Some(ret) => ret,
+            None => continue,
+        };
+
+        // A note is marked as "change" if the account that received it
+        // also spent notes in the same transaction. This will catch,
+        // for instance:
+        // - Change created by spending fractions of notes.
+        // - Notes created by consolidation transactions.
+        // - Notes sent from one account to itself.
+        let is_change = spent_from_accounts.contains(&account);
+
+        return Some(WalletShieldedOutput {
+            index,
+            cmu,
+            epk,
+            account,
+            note,
+            to,
+            is_change,
+            witness: IncrementalWitness::from_tree(tree),
+        });
+    }
+    None
+}
+
+/// Scans a [`CompactBlock`] with a set of [`ExtendedFullViewingKey`]s.
+///
+/// Returns a vector of [`WalletTx`]s belonging to any of the given
+/// [`ExtendedFullViewingKey`]s, and the corresponding new [`IncrementalWitness`]es.
+///
+/// The given [`CommitmentTree`] and existing [`IncrementalWitness`]es are
+/// incremented appropriately.
+pub fn scan_block(
+    block: CompactBlock,
+    extfvks: &[ExtendedFullViewingKey],
+    nullifiers: &[(&[u8], usize)],
+    tree: &mut CommitmentTree<Node>,
+    existing_witnesses: &mut [&mut IncrementalWitness<Node>],
+) -> Vec<WalletTx> {
+    let mut wtxs: Vec<WalletTx> = vec![];
+    let ivks: Vec<_> = extfvks.iter().map(|extfvk| extfvk.fvk.vk.ivk()).collect();
+
+    for tx in block.vtx.into_iter() {
+        let num_spends = tx.spends.len();
+        let num_outputs = tx.outputs.len();
+
+        // Check for spent notes
+        // The only step that is not constant-time is the filter() at the end.
+        let shielded_spends: Vec<_> = tx
+            .spends
+            .into_iter()
+            .enumerate()
+            .map(|(index, spend)| {
+                // Find the first tracked nullifier that matches this spend, and produce
+                // a WalletShieldedSpend if there is a match, in constant time.
+                nullifiers
+                    .iter()
+                    .map(|&(nf, account)| CtOption::new(account as u64, nf.ct_eq(&spend.nf[..])))
+                    .fold(CtOption::new(0, 0.into()), |first, next| {
+                        CtOption::conditional_select(&next, &first, first.is_some())
+                    })
+                    .map(|account| WalletShieldedSpend {
+                        index,
+                        nf: spend.nf,
+                        account: account as usize,
+                    })
+            })
+            .filter(|spend| spend.is_some().into())
+            .map(|spend| spend.unwrap())
+            .collect();
+
+        // Collect the set of accounts that were spent from in this transaction
+        let spent_from_accounts: HashSet<_> =
+            shielded_spends.iter().map(|spend| spend.account).collect();
+
+        // Check for incoming notes while incrementing tree and witnesses
+        let mut shielded_outputs: Vec<WalletShieldedOutput> = vec![];
+        {
+            // Grab mutable references to new witnesses from previous transactions
+            // in this block so that we can update them. Scoped so we don't hold
+            // mutable references to wtxs for too long.
+            let mut block_witnesses: Vec<_> = wtxs
+                .iter_mut()
+                .flat_map(|tx| {
+                    tx.shielded_outputs
+                        .iter_mut()
+                        .map(|output| &mut output.witness)
+                })
+                .collect();
+
+            for to_scan in tx.outputs.into_iter().enumerate() {
+                // Grab mutable references to new witnesses from previous outputs
+                // in this transaction so that we can update them. Scoped so we
+                // don't hold mutable references to shielded_outputs for too long.
+                let mut new_witnesses: Vec<_> = shielded_outputs
+                    .iter_mut()
+                    .map(|output| &mut output.witness)
+                    .collect();
+
+                if let Some(output) = scan_output(
+                    to_scan,
+                    &ivks,
+                    &spent_from_accounts,
+                    tree,
+                    existing_witnesses,
+                    &mut block_witnesses,
+                    &mut new_witnesses,
+                ) {
+                    shielded_outputs.push(output);
+                }
+            }
+        }
+
+        if !(shielded_spends.is_empty() && shielded_outputs.is_empty()) {
+            let mut txid = TxId([0u8; 32]);
+            txid.0.copy_from_slice(&tx.hash);
+            wtxs.push(WalletTx {
+                txid,
+                index: tx.index as usize,
+                num_spends,
+                num_outputs,
+                shielded_spends,
+                shielded_outputs,
+            });
+        }
+    }
+
+    wtxs
+}
+
+#[cfg(test)]
+mod tests {
+    use ff::{Field, PrimeField, PrimeFieldRepr};
+    use pairing::bls12_381::{Bls12, Fr};
+    use rand_core::{OsRng, RngCore};
+    use zcash_primitives::{
+        jubjub::{fs::Fs, FixedGenerators, JubjubParams, ToUniform},
+        merkle_tree::CommitmentTree,
+        note_encryption::{Memo, SaplingNoteEncryption},
+        primitives::Note,
+        transaction::components::Amount,
+        zip32::{ExtendedFullViewingKey, ExtendedSpendingKey},
+        JUBJUB,
+    };
+
+    use super::scan_block;
+    use crate::proto::compact_formats::{CompactBlock, CompactOutput, CompactSpend, CompactTx};
+
+    fn random_compact_tx<R: RngCore>(rng: &mut R) -> CompactTx {
+        let fake_nf = {
+            let mut nf = vec![0; 32];
+            rng.fill_bytes(&mut nf);
+            nf
+        };
+        let fake_cmu = {
+            let fake_cmu = Fr::random(rng);
+            let mut bytes = vec![];
+            fake_cmu.into_repr().write_le(&mut bytes).unwrap();
+            bytes
+        };
+        let fake_epk = {
+            let mut buffer = vec![0; 64];
+            rng.fill_bytes(&mut buffer);
+            let fake_esk = Fs::to_uniform(&buffer[..]);
+            let fake_epk = JUBJUB
+                .generator(FixedGenerators::SpendingKeyGenerator)
+                .mul(fake_esk, &JUBJUB);
+            let mut bytes = vec![];
+            fake_epk.write(&mut bytes).unwrap();
+            bytes
+        };
+        let mut cspend = CompactSpend::new();
+        cspend.set_nf(fake_nf);
+        let mut cout = CompactOutput::new();
+        cout.set_cmu(fake_cmu);
+        cout.set_epk(fake_epk);
+        cout.set_ciphertext(vec![0; 52]);
+        let mut ctx = CompactTx::new();
+        let mut txid = vec![0; 32];
+        rng.fill_bytes(&mut txid);
+        ctx.set_hash(txid);
+        ctx.spends.push(cspend);
+        ctx.outputs.push(cout);
+        ctx
+    }
+
+    /// Create a fake CompactBlock at the given height, with a transaction containing a
+    /// single spend of the given nullifier and a single output paying the given address.
+    /// Returns the CompactBlock.
+    fn fake_compact_block(
+        height: i32,
+        nf: [u8; 32],
+        extfvk: ExtendedFullViewingKey,
+        value: Amount,
+        tx_after: bool,
+    ) -> CompactBlock {
+        let to = extfvk.default_address().unwrap().1;
+
+        // Create a fake Note for the account
+        let mut rng = OsRng;
+        let note = Note {
+            g_d: to.diversifier().g_d::<Bls12>(&JUBJUB).unwrap(),
+            pk_d: to.pk_d().clone(),
+            value: value.into(),
+            r: Fs::random(&mut rng),
+        };
+        let encryptor = SaplingNoteEncryption::new(
+            extfvk.fvk.ovk,
+            note.clone(),
+            to.clone(),
+            Memo::default(),
+            &mut rng,
+        );
+        let mut cmu = vec![];
+        note.cm(&JUBJUB).into_repr().write_le(&mut cmu).unwrap();
+        let mut epk = vec![];
+        encryptor.epk().write(&mut epk).unwrap();
+        let enc_ciphertext = encryptor.encrypt_note_plaintext();
+
+        // Create a fake CompactBlock containing the note
+        let mut cb = CompactBlock::new();
+        cb.set_height(height as u64);
+
+        // Add a random Sapling tx before ours
+        {
+            let mut tx = random_compact_tx(&mut rng);
+            tx.index = cb.vtx.len() as u64;
+            cb.vtx.push(tx);
+        }
+
+        let mut cspend = CompactSpend::new();
+        cspend.set_nf(nf.to_vec());
+        let mut cout = CompactOutput::new();
+        cout.set_cmu(cmu);
+        cout.set_epk(epk);
+        cout.set_ciphertext(enc_ciphertext[..52].to_vec());
+        let mut ctx = CompactTx::new();
+        let mut txid = vec![0; 32];
+        rng.fill_bytes(&mut txid);
+        ctx.set_hash(txid);
+        ctx.spends.push(cspend);
+        ctx.outputs.push(cout);
+        ctx.index = cb.vtx.len() as u64;
+        cb.vtx.push(ctx);
+
+        // Optionally add another random Sapling tx after ours
+        if tx_after {
+            let mut tx = random_compact_tx(&mut rng);
+            tx.index = cb.vtx.len() as u64;
+            cb.vtx.push(tx);
+        }
+
+        cb
+    }
+
+    #[test]
+    fn scan_block_with_my_tx() {
+        let extsk = ExtendedSpendingKey::master(&[]);
+        let extfvk = ExtendedFullViewingKey::from(&extsk);
+
+        let cb = fake_compact_block(
+            1,
+            [0; 32],
+            extfvk.clone(),
+            Amount::from_u64(5).unwrap(),
+            false,
+        );
+        assert_eq!(cb.vtx.len(), 2);
+
+        let mut tree = CommitmentTree::new();
+        let txs = scan_block(cb, &[extfvk], &[], &mut tree, &mut []);
+        assert_eq!(txs.len(), 1);
+
+        let tx = &txs[0];
+        assert_eq!(tx.index, 1);
+        assert_eq!(tx.num_spends, 1);
+        assert_eq!(tx.num_outputs, 1);
+        assert_eq!(tx.shielded_spends.len(), 0);
+        assert_eq!(tx.shielded_outputs.len(), 1);
+        assert_eq!(tx.shielded_outputs[0].index, 0);
+        assert_eq!(tx.shielded_outputs[0].account, 0);
+        assert_eq!(tx.shielded_outputs[0].note.value, 5);
+
+        // Check that the witness root matches
+        assert_eq!(tx.shielded_outputs[0].witness.root(), tree.root());
+    }
+
+    #[test]
+    fn scan_block_with_txs_after_my_tx() {
+        let extsk = ExtendedSpendingKey::master(&[]);
+        let extfvk = ExtendedFullViewingKey::from(&extsk);
+
+        let cb = fake_compact_block(
+            1,
+            [0; 32],
+            extfvk.clone(),
+            Amount::from_u64(5).unwrap(),
+            true,
+        );
+        assert_eq!(cb.vtx.len(), 3);
+
+        let mut tree = CommitmentTree::new();
+        let txs = scan_block(cb, &[extfvk], &[], &mut tree, &mut []);
+        assert_eq!(txs.len(), 1);
+
+        let tx = &txs[0];
+        assert_eq!(tx.index, 1);
+        assert_eq!(tx.num_spends, 1);
+        assert_eq!(tx.num_outputs, 1);
+        assert_eq!(tx.shielded_spends.len(), 0);
+        assert_eq!(tx.shielded_outputs.len(), 1);
+        assert_eq!(tx.shielded_outputs[0].index, 0);
+        assert_eq!(tx.shielded_outputs[0].account, 0);
+        assert_eq!(tx.shielded_outputs[0].note.value, 5);
+
+        // Check that the witness root matches
+        assert_eq!(tx.shielded_outputs[0].witness.root(), tree.root());
+    }
+
+    #[test]
+    fn scan_block_with_my_spend() {
+        let extsk = ExtendedSpendingKey::master(&[]);
+        let extfvk = ExtendedFullViewingKey::from(&extsk);
+        let nf = [7; 32];
+        let account = 12;
+
+        let cb = fake_compact_block(1, nf, extfvk, Amount::from_u64(5).unwrap(), false);
+        assert_eq!(cb.vtx.len(), 2);
+
+        let mut tree = CommitmentTree::new();
+        let txs = scan_block(cb, &[], &[(&nf, account)], &mut tree, &mut []);
+        assert_eq!(txs.len(), 1);
+
+        let tx = &txs[0];
+        assert_eq!(tx.index, 1);
+        assert_eq!(tx.num_spends, 1);
+        assert_eq!(tx.num_outputs, 1);
+        assert_eq!(tx.shielded_spends.len(), 1);
+        assert_eq!(tx.shielded_outputs.len(), 0);
+        assert_eq!(tx.shielded_spends[0].index, 0);
+        assert_eq!(tx.shielded_spends[0].nf, nf);
+        assert_eq!(tx.shielded_spends[0].account, account);
+    }
+}