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

@@ -0,0 +1,19 @@
+language: rust
+rust:
+  - 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

@@ -1,13 +1,14 @@
 [workspace]
 members = [
     "bellman",
+    "ff",
+    "group",
     "librustzcash",
     "pairing",
-    "sapling-crypto",
+    "zcash_client_backend",
+    "zcash_history",
     "zcash_primitives",
     "zcash_proofs",
-    "zcash_wallet",
-    "zip32",
 ]
 
 [profile.release]

LICENSE-MIT

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2017 Zcash Company
+Copyright (c) 2017-2019 Electric Coin Company
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

bellman/Cargo.toml

@@ -1,22 +1,42 @@
 [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"
+blake2s_simd = "0.5"
+ff = { version = "0.5.0", path = "../ff" }
 futures = "0.1"
-futures-cpupool = "0.1"
-num_cpus = "1"
-crossbeam = "0.3"
-pairing = { path = "../pairing" }
+futures-cpupool = { version = "0.1", optional = true }
+group = { version = "0.2.0", path = "../group" }
+num_cpus = { version = "1", optional = true }
+crossbeam = { version = "0.7", 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]
-default = []
+groth16 = ["pairing"]
+multicore = ["futures-cpupool", "crossbeam", "num_cpus"]
+default = ["groth16", "multicore"]
+
+[[test]]
+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

@@ -1,52 +1,50 @@
-//! This module contains an `EvaluationDomain` abstraction for
-//! performing various kinds of polynomial arithmetic on top of
-//! the scalar field.
+//! This module contains an [`EvaluationDomain`] abstraction for performing
+//! various kinds of polynomial arithmetic on top of the scalar field.
 //!
-//! In pairing-based SNARKs like Groth16, we need to calculate
-//! a quotient polynomial over a target polynomial with roots
-//! at distinct points associated with each constraint of the
-//! constraint system. In order to be efficient, we choose these
-//! roots to be the powers of a 2^n root of unity in the field.
-//! This allows us to perform polynomial operations in O(n)
-//! by performing an O(n log n) FFT over such a domain.
+//! In pairing-based SNARKs like [Groth16], we need to calculate a quotient
+//! polynomial over a target polynomial with roots at distinct points associated
+//! with each constraint of the constraint system. In order to be efficient, we
+//! choose these roots to be the powers of a 2<sup>n</sup> root of unity in the
+//! field. This allows us to perform polynomial operations in O(n) by performing
+//! an O(n log n) FFT over such a domain.
+//!
+//! [`EvaluationDomain`]: crate::domain::EvaluationDomain
+//! [Groth16]: https://eprint.iacr.org/2016/260
 
-use pairing::{
-    Engine,
-    Field,
-    PrimeField,
-    CurveProjective
-};
+use ff::{Field, PrimeField, ScalarEngine};
+use group::CurveProjective;
 
-use super::{
-    SynthesisError
-};
+use super::SynthesisError;
 
 use super::multicore::Worker;
 
-pub struct EvaluationDomain<E: Engine, G: Group<E>> {
+pub struct EvaluationDomain<E: ScalarEngine, G: Group<E>> {
     coeffs: Vec<G>,
     exp: u32,
     omega: E::Fr,
     omegainv: E::Fr,
     geninv: E::Fr,
-    minv: E::Fr
+    minv: E::Fr,
 }
 
-impl<E: Engine, G: Group<E>> EvaluationDomain<E, G> {
-    pub fn as_ref(&self) -> &[G] {
+impl<E: ScalarEngine, G: Group<E>> AsRef<[G]> for EvaluationDomain<E, G> {
+    fn as_ref(&self) -> &[G] {
         &self.coeffs
     }
-
-    pub fn as_mut(&mut self) -> &mut [G] {
-        &mut 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 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;
@@ -57,7 +55,7 @@ impl<E: Engine, 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);
             }
         }
 
@@ -71,29 +69,30 @@ impl<E: Engine, G: Group<E>> EvaluationDomain<E, G> {
         coeffs.resize(m, G::group_zero());
 
         Ok(EvaluationDomain {
-            coeffs: coeffs,
-            exp: exp,
-            omega: omega,
+            coeffs,
+            exp,
+            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);
                     }
@@ -102,11 +101,10 @@ impl<E: Engine, 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);
@@ -117,14 +115,12 @@ impl<E: Engine, 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);
@@ -143,13 +139,15 @@ impl<E: Engine, 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)
-    {
-        let i = self.z(&E::Fr::multiplicative_generator()).inverse().unwrap();
+    pub fn divide_by_z_on_coset(&mut self, worker: &Worker) {
+        let i = self
+            .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);
                     }
@@ -163,8 +161,12 @@ impl<E: Engine, 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)) {
-                scope.spawn(move || {
+            for (a, b) in self
+                .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);
                     }
@@ -178,8 +180,12 @@ impl<E: Engine, 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)) {
-                scope.spawn(move || {
+            for (a, b) in self
+                .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);
                     }
@@ -189,7 +195,7 @@ impl<E: Engine, G: Group<E>> EvaluationDomain<E, G> {
     }
 }
 
-pub trait Group<E: Engine>: Sized + Copy + Clone + Send + Sync {
+pub trait Group<E: ScalarEngine>: Sized + Copy + Clone + Send + Sync {
     fn group_zero() -> Self;
     fn group_mul_assign(&mut self, by: &E::Fr);
     fn group_add_assign(&mut self, other: &Self);
@@ -227,23 +233,23 @@ impl<G: CurveProjective> Group<G::Engine> for Point<G> {
     }
 }
 
-pub struct Scalar<E: Engine>(pub E::Fr);
+pub struct Scalar<E: ScalarEngine>(pub E::Fr);
 
-impl<E: Engine> PartialEq for Scalar<E> {
+impl<E: ScalarEngine> PartialEq for Scalar<E> {
     fn eq(&self, other: &Scalar<E>) -> bool {
         self.0 == other.0
     }
 }
 
-impl<E: Engine> Copy for Scalar<E> { }
+impl<E: ScalarEngine> Copy for Scalar<E> {}
 
-impl<E: Engine> Clone for Scalar<E> {
+impl<E: ScalarEngine> Clone for Scalar<E> {
     fn clone(&self) -> Scalar<E> {
         *self
     }
 }
 
-impl<E: Engine> Group<E> for Scalar<E> {
+impl<E: ScalarEngine> Group<E> for Scalar<E> {
     fn group_zero() -> Self {
         Scalar(E::Fr::zero())
     }
@@ -258,8 +264,7 @@ impl<E: Engine> Group<E> for Scalar<E> {
     }
 }
 
-fn best_fft<E: Engine, 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 {
@@ -269,8 +274,7 @@ fn best_fft<E: Engine, T: Group<E>>(a: &mut [T], worker: &Worker, omega: &E::Fr,
     }
 }
 
-fn serial_fft<E: Engine, 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 {
@@ -292,7 +296,7 @@ fn serial_fft<E: Engine, T: Group<E>>(a: &mut [T], omega: &E::Fr, log_n: u32)
 
     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 {
@@ -314,14 +318,13 @@ fn serial_fft<E: Engine, T: Group<E>>(a: &mut [T], omega: &E::Fr, log_n: u32)
     }
 }
 
-fn parallel_fft<E: Engine, T: Group<E>>(
+fn parallel_fft<E: ScalarEngine, T: Group<E>>(
     a: &mut [T],
     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;
@@ -333,18 +336,18 @@ fn parallel_fft<E: Engine, 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);
@@ -361,7 +364,7 @@ fn parallel_fft<E: Engine, 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 {
@@ -375,19 +378,23 @@ fn parallel_fft<E: Engine, T: Group<E>>(
 
 // Test multiplying various (low degree) polynomials together and
 // comparing with naive evaluations.
+#[cfg(feature = "pairing")]
 #[test]
 fn polynomial_arith() {
     use pairing::bls12_381::Bls12;
-    use rand::{self, Rand};
+    use rand_core::RngCore;
 
-    fn test_mul<E: Engine, 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 b: Vec<_> = (0..coeffs_b).map(|_| Scalar::<E>(E::Fr::rand(rng))).collect();
+                let mut a: Vec<_> = (0..coeffs_a)
+                    .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];
@@ -422,13 +429,13 @@ fn polynomial_arith() {
     test_mul::<Bls12, _>(rng);
 }
 
+#[cfg(feature = "pairing")]
 #[test]
 fn fft_composition() {
     use pairing::bls12_381::Bls12;
-    use rand;
+    use rand_core::RngCore;
 
-    fn test_comp<E: Engine, 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 {
@@ -436,7 +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();
@@ -460,21 +467,23 @@ fn fft_composition() {
     test_comp::<Bls12, _>(rng);
 }
 
+#[cfg(feature = "pairing")]
 #[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: Engine, 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();
 

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 pedersen_hash;
+pub mod multieq;
 pub mod multipack;
+pub mod num;
 pub mod sha256;
+pub mod uint32;
 
-pub mod sapling;
-pub mod sprout;
-
-use bellman::{
-    SynthesisError
-};
+use crate::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

@@ -1,21 +1,16 @@
-use pairing::{Engine, Field};
-use super::*;
-use super::num::{
-    AllocatedNum,
-    Num
-};
+//! Window table lookup gadgets.
+
+use ff::{Field, ScalarEngine};
+
 use super::boolean::Boolean;
-use bellman::{
-    ConstraintSystem
-};
+use super::num::{AllocatedNum, Num};
+use super::*;
+use crate::ConstraintSystem;
 
 // Synthesize the constants for each base pattern.
-fn synth<'a, E: Engine, I>(
-    window_size: usize,
-    constants: I,
-    assignment: &mut [E::Fr]
-)
-    where I: IntoIterator<Item=&'a E::Fr>
+fn synth<'a, E: ScalarEngine, I>(window_size: usize, constants: I, assignment: &mut [E::Fr])
+where
+    I: IntoIterator<Item = &'a E::Fr>,
 {
     assert_eq!(assignment.len(), 1 << window_size);
 
@@ -34,19 +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 =
-    match (bits[0].get_value(), bits[1].get_value(), bits[2].get_value()) {
+    let i = match (
+        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 {
@@ -59,25 +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(
-        cs.namespace(|| "x"),
-        || {
-            Ok(coords[*i.get()?].0)
-        }
-    )?;
+    let res_x = AllocatedNum::alloc(cs.namespace(|| "x"), || Ok(coords[*i.get()?].0))?;
 
     // Allocate the y-coordinate resulting from the lookup
-    let res_y = AllocatedNum::alloc(
-        cs.namespace(|| "y"),
-        || {
-            Ok(coords[*i.get()?].1)
-        }
-    )?;
+    let res_y = AllocatedNum::alloc(cs.namespace(|| "y"), || Ok(coords[*i.get()?].1))?;
 
     // Compute the coefficients for the lookup constraints
     let mut x_coeffs = [E::Fr::zero(); 8];
@@ -91,30 +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))
@@ -122,19 +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 =
-    match (bits[0].get_value(), bits[1].get_value()) {
+    let i = match (bits[0].get_value(), bits[1].get_value()) {
         (Some(a_value), Some(b_value)) => {
             let mut tmp = 0;
             if a_value {
@@ -144,22 +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(
-        cs.namespace(|| "y"),
-        || {
+    let y = AllocatedNum::alloc(cs.namespace(|| "y"), || {
         let mut tmp = coords[*i.get()?].1;
         if *bits[2].get_value().get()? {
             tmp.negate();
         }
         Ok(tmp)
-        }
-    )?;
+    })?;
 
     let one = CS::one();
 
@@ -177,16 +171,16 @@ pub fn lookup3_xy_with_conditional_negation<E: Engine, CS>(
         .add_bool_with_coeff(one, &bits[1], x_coeffs[0b10])
         .add_bool_with_coeff(one, &precomp, x_coeffs[0b11]);
 
-    let y_lc = precomp.lc::<E>(one, y_coeffs[0b11]) +
-               &bits[1].lc::<E>(one, y_coeffs[0b10]) +
-               &bits[0].lc::<E>(one, y_coeffs[0b01]) +
-               (y_coeffs[0b00], one);
+    let y_lc = precomp.lc::<E>(one, y_coeffs[0b11])
+        + &bits[1].lc::<E>(one, y_coeffs[0b10])
+        + &bits[0].lc::<E>(one, y_coeffs[0b01])
+        + (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()))
@@ -194,46 +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 ::circuit::boolean::{Boolean, AllocatedBit};
+    use crate::gadgets::boolean::{AllocatedBit, Boolean};
+    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 = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "a"), Some(a_val)).unwrap()
-            );
+            let a_val = rng.next_u32() % 2 != 0;
+            let a = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "a"), Some(a_val)).unwrap());
 
-            let b_val = rng.gen();
-            let b = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "b"), Some(b_val)).unwrap()
-            );
+            let b_val = rng.next_u32() % 2 != 0;
+            let b = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "b"), Some(b_val)).unwrap());
 
-            let c_val = rng.gen();
-            let c = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "c"), Some(c_val)).unwrap()
-            );
+            let c_val = rng.next_u32() % 2 != 0;
+            let c = Boolean::from(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 b_val { index += 2 }
-            if c_val { index += 4 }
+            if a_val {
+                index += 1
+            }
+            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);
@@ -242,53 +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 = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "a"), Some(a_val)).unwrap()
-            );
+            let a_val = rng.next_u32() % 2 != 0;
+            let a = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "a"), Some(a_val)).unwrap());
 
-            let b_val = rng.gen();
-            let b = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "b"), Some(b_val)).unwrap()
-            );
+            let b_val = rng.next_u32() % 2 != 0;
+            let b = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "b"), Some(b_val)).unwrap());
 
-            let c_val = rng.gen();
-            let c = Boolean::from(
-                AllocatedBit::alloc(cs.namespace(|| "c"), Some(c_val)).unwrap()
-            );
+            let c_val = rng.next_u32() % 2 != 0;
+            let c = Boolean::from(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 b_val { index += 2 }
+            if a_val {
+                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

@@ -1,17 +1,8 @@
-use pairing::{
-    Engine,
-    Field,
-    PrimeField
-};
+use ff::{Field, PrimeField, ScalarEngine};
 
-use bellman::{
-    SynthesisError,
-    ConstraintSystem,
-    LinearCombination,
-    Variable
-};
+use crate::{ConstraintSystem, LinearCombination, SynthesisError, Variable};
 
-pub struct MultiEq<E: Engine, CS: ConstraintSystem<E>>{
+pub struct MultiEq<E: ScalarEngine, CS: ConstraintSystem<E>> {
     cs: CS,
     ops: usize,
     bits_used: usize,
@@ -19,19 +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();
@@ -39,7 +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();
@@ -51,9 +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();
@@ -68,7 +57,7 @@ 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();
@@ -76,62 +65,55 @@ impl<E: Engine, CS: ConstraintSystem<E>> Drop for MultiEq<E, CS> {
     }
 }
 
-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>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    where
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
+        A: FnOnce() -> AR,
+        AR: Into<String>,
     {
         self.cs.alloc(annotation, f)
     }
 
-    fn alloc_input<F, A, AR>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    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>(
-        &mut self,
-        annotation: A,
-        a: LA,
-        b: LB,
-        c: LC
-    )
-        where A: FnOnce() -> AR, AR: Into<String>,
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
+    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>
+        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

@@ -1,83 +1,62 @@
-use pairing::{
-    Engine,
-    Field,
-    PrimeField,
-    PrimeFieldRepr,
-    BitIterator
-};
+//! Gadgets representing numbers in the scalar field of the underlying curve.
 
-use bellman::{
-    SynthesisError,
-    ConstraintSystem,
-    LinearCombination,
-    Variable
-};
+use ff::{BitIterator, Field, PrimeField, PrimeFieldRepr, ScalarEngine};
 
-use super::{
-    Assignment
-};
+use crate::{ConstraintSystem, LinearCombination, SynthesisError, Variable};
 
-use super::boolean::{
-    self,
-    Boolean,
-    AllocatedBit
-};
+use super::Assignment;
 
-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> {
-    pub fn alloc<CS, F>(
-        mut cs: CS,
-        value: F,
-    ) -> Result<Self, SynthesisError>
-        where CS: ConstraintSystem<E>,
-              F: FnOnce() -> Result<E::Fr, SynthesisError>
+impl<E: ScalarEngine> AllocatedNum<E> {
+    pub fn alloc<CS, F>(mut cs: CS, value: F) -> Result<Self, 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(
+            || "num",
+            || {
                 let tmp = value()?;
 
                 new_value = Some(tmp);
 
                 Ok(tmp)
-        })?;
+            },
+        )?;
 
         Ok(AllocatedNum {
             value: new_value,
-            variable: var
+            variable: var,
         })
     }
 
-    pub fn inputize<CS>(
-        &self,
-        mut cs: CS
-    ) -> Result<(), SynthesisError>
-        where CS: ConstraintSystem<E>
+    pub fn inputize<CS>(&self, mut cs: CS) -> Result<(), SynthesisError>
+    where
+        CS: ConstraintSystem<E>,
     {
-        let input = cs.alloc_input(
-            || "input variable",
-            || {
-                Ok(*self.value.get()?)
-            }
-        )?;
+        let input = cs.alloc_input(|| "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(())
@@ -88,20 +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>(
-        &self,
-        mut cs: CS
-    ) -> Result<Vec<Boolean>, SynthesisError>
-        where CS: ConstraintSystem<E>
+    pub fn to_bits_le_strict<CS>(&self, mut cs: CS) -> 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,
-                  CS: ConstraintSystem<E>
+        where
+            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
@@ -114,7 +92,7 @@ impl<E: Engine> AllocatedNum<E> {
                     cur = Some(AllocatedBit::and(
                         cs.namespace(|| format!("and {}", i)),
                         cur.as_ref().unwrap(),
-                        v
+                        v,
                     )?);
                 }
             }
@@ -150,15 +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(
-                    cs.namespace(|| format!("bit {}", i)),
-                    a_bit
-                )?;
+                let a_bit = AllocatedBit::alloc(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.
 
@@ -167,7 +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);
                 }
@@ -180,7 +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);
             }
@@ -206,30 +181,20 @@ impl<E: Engine> AllocatedNum<E> {
 
         lc = lc - self.variable;
 
-        cs.enforce(
-            || "unpacking constraint",
-            |lc| lc,
-            |lc| lc,
-            |_| lc
-        );
+        cs.enforce(|| "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>(
-        &self,
-        mut cs: CS
-    ) -> Result<Vec<Boolean>, SynthesisError>
-        where CS: ConstraintSystem<E>
+    pub fn to_bits_le<CS>(&self, mut cs: CS) -> Result<Vec<Boolean>, SynthesisError>
+    where
+        CS: ConstraintSystem<E>,
     {
-        let bits = boolean::field_into_allocated_bits_le(
-            &mut cs,
-            self.value
-        )?;
+        let bits = boolean::field_into_allocated_bits_le(&mut cs, self.value)?;
 
         let mut lc = LinearCombination::zero();
         let mut coeff = E::Fr::one();
@@ -242,86 +207,82 @@ impl<E: Engine> AllocatedNum<E> {
 
         lc = lc - self.variable;
 
-        cs.enforce(
-            || "unpacking constraint",
-            |lc| lc,
-            |lc| lc,
-            |_| lc
-        );
+        cs.enforce(|| "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>(
-        &self,
-        mut cs: CS,
-        other: &Self
-    ) -> Result<Self, SynthesisError>
-        where CS: ConstraintSystem<E>
+    pub fn mul<CS>(&self, mut cs: CS, other: &Self) -> Result<Self, SynthesisError>
+    where
+        CS: ConstraintSystem<E>,
     {
         let mut value = None;
 
-        let var = cs.alloc(|| "product num", || {
+        let var = cs.alloc(
+            || "product num",
+            || {
                 let mut tmp = *self.value.get()?;
                 tmp.mul_assign(other.value.get()?);
 
                 value = Some(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,
-            variable: var
+            value,
+            variable: var,
         })
     }
 
-    pub fn square<CS>(
-        &self,
-        mut cs: CS
-    ) -> Result<Self, SynthesisError>
-        where CS: ConstraintSystem<E>
+    pub fn square<CS>(&self, mut cs: CS) -> Result<Self, SynthesisError>
+    where
+        CS: ConstraintSystem<E>,
     {
         let mut value = None;
 
-        let var = cs.alloc(|| "squared num", || {
+        let var = cs.alloc(
+            || "squared num",
+            || {
                 let mut tmp = *self.value.get()?;
                 tmp.square();
 
                 value = Some(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,
-            variable: var
+            value,
+            variable: var,
         })
     }
 
-    pub fn assert_nonzero<CS>(
-        &self,
-        mut cs: CS
-    ) -> Result<(), SynthesisError>
-        where CS: ConstraintSystem<E>
+    pub fn assert_nonzero<CS>(&self, mut cs: CS) -> Result<(), SynthesisError>
+    where
+        CS: ConstraintSystem<E>,
     {
-        let inv = cs.alloc(|| "ephemeral inverse", || {
+        let inv = cs.alloc(
+            || "ephemeral inverse",
+            || {
                 let tmp = *self.value.get()?;
 
                 if tmp.is_zero() {
@@ -329,7 +290,8 @@ impl<E: Engine> AllocatedNum<E> {
                 } else {
                     Ok(tmp.inverse().unwrap())
                 }
-        })?;
+            },
+        )?;
 
         // Constrain a * inv = 1, which is only valid
         // iff a has a multiplicative inverse, untrue
@@ -338,7 +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(())
@@ -351,44 +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(
-            cs.namespace(|| "conditional reversal result 1"),
-            || {
+        let c = Self::alloc(cs.namespace(|| "conditional reversal result 1"), || {
             if *condition.get_value().get()? {
                 Ok(*b.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(
-            cs.namespace(|| "conditional reversal result 2"),
-            || {
+        let d = Self::alloc(cs.namespace(|| "conditional reversal result 2"), || {
             if *condition.get_value().get()? {
                 Ok(*a.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))
@@ -403,25 +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(),
         }
     }
 
@@ -433,13 +390,7 @@ impl<E: Engine> Num<E> {
         LinearCombination::zero() + (coeff, &self.lc)
     }
 
-    pub fn add_bool_with_coeff(
-        self,
-        one: Variable,
-        bit: &Boolean,
-        coeff: E::Fr
-    ) -> Self
-    {
+    pub fn add_bool_with_coeff(self, one: Variable, bit: &Boolean, coeff: E::Fr) -> Self {
         let newval = match (self.value, bit.get_value()) {
             (Some(mut curval), Some(bval)) => {
                 if bval {
@@ -447,25 +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 bellman::{ConstraintSystem};
+    use crate::ConstraintSystem;
+    use ff::{BitIterator, Field, PrimeField};
     use pairing::bls12_381::{Bls12, Fr};
-    use pairing::{Field, PrimeField, BitIterator};
-    use ::circuit::test::*;
+    use rand_core::SeedableRng;
+    use rand_xorshift::XorShiftRng;
+
     use super::{AllocatedNum, Boolean};
+    use crate::gadgets::test::*;
 
     #[test]
     fn test_allocated_num() {
@@ -494,8 +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 n2 = AllocatedNum::alloc(cs.namespace(|| "b"), || Ok(Fr::from_str("10").unwrap())).unwrap();
+        let n =
+            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());
@@ -507,12 +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 b = AllocatedNum::alloc(cs.namespace(|| "b"), || 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(Fr::random(&mut rng))).unwrap();
             let condition = Boolean::constant(false);
             let (c, d) = AllocatedNum::conditionally_reverse(&mut cs, &a, &b, &condition).unwrap();
 
@@ -525,8 +483,8 @@ mod test {
         {
             let mut cs = TestConstraintSystem::<Bls12>::new();
 
-            let a = AllocatedNum::alloc(cs.namespace(|| "a"), || Ok(rng.gen())).unwrap();
-            let b = AllocatedNum::alloc(cs.namespace(|| "b"), || 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(Fr::random(&mut rng))).unwrap();
             let condition = Boolean::constant(true);
             let (c, d) = AllocatedNum::conditionally_reverse(&mut cs, &a, &b, &condition).unwrap();
 
@@ -565,7 +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());
 
@@ -573,28 +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 {
@@ -602,7 +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;
-use super::multieq::MultiEq;
-use super::boolean::Boolean;
-use bellman::{ConstraintSystem, SynthesisError};
-use pairing::Engine;
+//! Circuits for the [SHA-256] hash function and its internal compression
+//! function.
+//!
+//! [SHA-256]: https://tools.ietf.org/html/rfc6234
 
+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,
-    0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
+    0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, 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(
-        &mut cs,
-        &input,
-        &get_sha256_iv()
-    )?
+    Ok(
+        sha256_compression_function(&mut cs, &input, &get_sha256_iv())?
             .into_iter()
             .flat_map(|e| e.into_bits_be())
-    .collect())
+            .collect(),
+    )
 }
 
-pub fn sha256<E, CS>(
-    mut cs: CS,
-    input: &[Boolean]
-) -> Result<Vec<Boolean>, SynthesisError>
-    where E: Engine, CS: ConstraintSystem<E>
+pub fn sha256<E, CS>(mut cs: CS, input: &[Boolean]) -> Result<Vec<Boolean>, SynthesisError>
+where
+    E: ScalarEngine,
+    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(
-            cs.namespace(|| format!("block {}", i)),
-            block,
-            &cur
-        )?;
+        cur = sha256_compression_function(cs.namespace(|| format!("block {}", i)), block, &cur)?;
     }
 
-    Ok(cur.into_iter()
-    .flat_map(|e| e.into_bits_be())
-    .collect())
+    Ok(cur.into_iter().flat_map(|e| e.into_bits_be()).collect())
 }
 
 fn get_sha256_iv() -> Vec<UInt32> {
@@ -81,14 +80,17 @@ 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
+        .chunks(32)
         .map(|e| UInt32::from_bits_be(e))
         .collect::<Vec<_>>();
 
@@ -101,29 +103,17 @@ fn sha256_compression_function<E, CS>(
 
         // 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);
-        s0 = s0.xor(
-            cs.namespace(|| "first xor for s0"),
-            &w[i-15].rotr(18)
-        )?;
-        s0 = s0.xor(
-            cs.namespace(|| "second xor for s0"),
-            &w[i-15].shr(3)
-        )?;
+        s0 = s0.xor(cs.namespace(|| "first xor for s0"), &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);
-        s1 = s1.xor(
-            cs.namespace(|| "first xor for s1"),
-            &w[i-2].rotr(19)
-        )?;
-        s1 = s1.xor(
-            cs.namespace(|| "second xor for s1"),
-            &w[i-2].shr(10)
-        )?;
+        s1 = s1.xor(cs.namespace(|| "first xor for s1"), &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>(
-            self,
-            cs: M,
-            others: &[UInt32]
-        ) -> Result<UInt32, SynthesisError>
-            where E: Engine,
+        fn compute<E, CS, M>(self, cs: M, others: &[UInt32]) -> Result<UInt32, SynthesisError>
+        where
+            E: ScalarEngine,
             CS: ConstraintSystem<E>,
-                  M: ConstraintSystem<E, Root=MultiEq<E, CS>>
+            M: ConstraintSystem<E, Root = MultiEq<E, CS>>,
         {
             Ok(match self {
-                Maybe::Concrete(ref v) => {
-                    return Ok(v.clone())
-                },
+                Maybe::Concrete(ref v) => return Ok(v.clone()),
                 Maybe::Deferred(mut v) => {
-                    v.extend(others.into_iter().cloned());
-                    UInt32::addmany(
-                        cs,
-                        &v
-                    )?
+                    v.extend(others.iter().cloned());
+                    UInt32::addmany(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(
-            cs.namespace(|| "first xor for s1"),
-            &new_e.rotr(11)
-        )?;
-        s1 = s1.xor(
-            cs.namespace(|| "second xor for s1"),
-            &new_e.rotr(25)
-        )?;
+        s1 = s1.xor(cs.namespace(|| "first xor for s1"), &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(
-            cs.namespace(|| "ch"),
-            &new_e,
-            &f,
-            &g
-        )?;
+        let ch = UInt32::sha256_ch(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(
-            cs.namespace(|| "first xor for s0"),
-            &new_a.rotr(13)
-        )?;
-        s0 = s0.xor(
-            cs.namespace(|| "second xor for s0"),
-            &new_a.rotr(22)
-        )?;
+        s0 = s0.xor(cs.namespace(|| "first xor for s0"), &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(
-            cs.namespace(|| "maj"),
-            &new_a,
-            &b,
-            &c
-        )?;
+        let maj = UInt32::sha256_maj(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::{XorShiftRng, SeedableRng, Rng};
+    use rand_core::{RngCore, SeedableRng};
+    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(
-            &mut cs,
-            &input_bits,
-            &iv
-        ).unwrap();
+        let out = sha256_compression_function(&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)
+            .map(|i| {
                 Boolean::from(
                     AllocatedBit::alloc(
                         cs.namespace(|| format!("input bit {}", i)),
-                    Some(rng.gen())
-                ).unwrap()
+                        Some(rng.next_u32() % 2 != 0),
                     )
-        }).collect();
+                    .unwrap(),
+                )
+            })
+            .collect();
 
-        sha256_compression_function(
-            cs.namespace(|| "sha256"),
-            &input_bits,
-            &iv
-        ).unwrap();
+        sha256_compression_function(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 crypto::digest::Digest;
+        use sha2::{Digest, Sha256};
 
-        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];
-            h.result(&mut hash_result[..]);
+            let hash_result = h.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
+                .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

@@ -1,17 +1,8 @@
-use pairing::{
-    Engine,
-    Field,
-    PrimeField,
-    PrimeFieldRepr
-};
+//! Helpers for testing circuit implementations.
 
-use bellman::{
-    LinearCombination,
-    SynthesisError,
-    ConstraintSystem,
-    Variable,
-    Index
-};
+use ff::{Field, PrimeField, PrimeFieldRepr, ScalarEngine};
+
+use crate::{ConstraintSystem, Index, LinearCombination, SynthesisError, Variable};
 
 use std::collections::HashMap;
 use std::fmt::Write;
@@ -20,27 +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)]
@@ -52,7 +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,
         }
     }
 }
@@ -67,19 +58,16 @@ 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>(
-    terms: &[(Variable, E::Fr)],
-) -> BTreeMap<OrderedVariable, E::Fr>
-{
+fn proc_lc<E: ScalarEngine>(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);
     }
 
@@ -98,11 +86,7 @@ fn proc_lc<E: Engine>(
     map
 }
 
-fn hash_lc<E: Engine>(
-    terms: &[(Variable, E::Fr)],
-    h: &mut Blake2s
-)
-{
+fn hash_lc<E: ScalarEngine>(terms: &[(Variable, E::Fr)], h: &mut Blake2sState) {
     let map = proc_lc::<E>(terms);
 
     let mut buf = [0u8; 9 + 32];
@@ -114,7 +98,7 @@ 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);
@@ -127,18 +111,17 @@ fn hash_lc<E: Engine>(
     }
 }
 
-fn eval_lc<E: Engine>(
+fn eval_lc<E: ScalarEngine>(
     terms: &[(Variable, E::Fr)],
     inputs: &[(E::Fr, String)],
-    aux: &[(E::Fr, String)]
-) -> E::Fr
-{
+    aux: &[(E::Fr, String)],
+) -> 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);
@@ -148,17 +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![],
         }
     }
 
@@ -171,9 +157,9 @@ impl<E: Engine> TestConstraintSystem<E> {
             tmp
         };
 
-        let powers_of_two = (0..E::Fr::NUM_BITS).map(|i| {
-            E::Fr::from_str("2").unwrap().pow(&[i as u64])
-        }).collect::<Vec<_>>();
+        let powers_of_two = (0..E::Fr::NUM_BITS)
+            .map(|i| E::Fr::from_str("2").unwrap().pow(&[u64::from(i)]))
+            .collect::<Vec<_>>();
 
         let pp = |s: &mut String, lc: &LinearCombination<E>| {
             write!(s, "(").unwrap();
@@ -200,7 +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();
                     }
@@ -230,7 +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];
 
@@ -263,57 +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)) => {
-                match v.get_unchecked() {
+            Some(&NamedObject::Var(ref v)) => match v.get_unchecked() {
                 Index::Input(index) => self.inputs[index].0 = to,
-                    Index::Aux(index) => self.aux[index].0 = to
-                }
-            }
-            Some(e) => panic!("tried to set path `{}` to value, but `{:?}` already exists there.", path, e),
-            _ => panic!("no variable exists at path: {}", path)
+                Index::Aux(index) => self.aux[index].0 = to,
+            },
+            Some(e) => panic!(
+                "tried to set path `{}` to value, but `{:?}` already exists there.",
+                path, e
+            ),
+            _ => 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);
@@ -321,17 +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)) => {
-                match v.get_unchecked() {
+            Some(&NamedObject::Var(ref v)) => match v.get_unchecked() {
                 Index::Input(index) => self.inputs[index].0,
-                    Index::Aux(index) => self.aux[index].0
-                }
-            }
-            Some(e) => panic!("tried to get value of path `{}`, but `{:?}` exists there (not a variable)", path, e),
-            _ => panic!("no variable exists at path: {}", path)
+                Index::Aux(index) => self.aux[index].0,
+            },
+            Some(e) => panic!(
+                "tried to get value of path `{}`, but `{:?}` exists there (not a variable)",
+                path, e
+            ),
+            _ => panic!("no variable exists at path: {}", path),
         }
     }
 
@@ -352,8 +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 += "/";
         }
@@ -365,15 +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>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    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());
@@ -384,12 +363,11 @@ impl<E: Engine> ConstraintSystem<E> for TestConstraintSystem<E> {
         Ok(var)
     }
 
-    fn alloc_input<F, A, AR>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    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());
@@ -400,17 +378,13 @@ impl<E: Engine> ConstraintSystem<E> for TestConstraintSystem<E> {
         Ok(var)
     }
 
-    fn enforce<A, AR, LA, LB, LC>(
-        &mut self,
-        annotation: A,
-        a: LA,
-        b: LB,
-        c: LC
-    )
-        where A: FnOnce() -> AR, AR: Into<String>,
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
+    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>
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
     {
         let path = compute_path(&self.current_namespace, annotation().into());
         let index = self.constraints.len();
@@ -424,7 +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());
@@ -432,47 +408,43 @@ 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
     }
 }
 
 #[test]
 fn test_cs() {
+    use ff::PrimeField;
     use pairing::bls12_381::{Bls12, Fr};
-    use pairing::PrimeField;
 
     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 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();
+    let a = cs
+        .namespace(|| "a")
+        .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(
-        || "mult",
-        |lc| lc + a,
-        |lc| lc + b,
-        |lc| lc + c
-    );
+    cs.enforce(|| "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(
-        || "eq",
-        |lc| lc + a,
-        |lc| lc + one,
-        |lc| lc + b
-    );
+    cs.enforce(|| "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

@@ -1,19 +1,13 @@
-use pairing::{
-    Engine,
-    Field,
-    PrimeField
-};
+//! Circuit representation of a [`u32`], with helpers for the [`sha256`]
+//! gadgets.
+//!
+//! [`sha256`]: crate::gadgets::sha256
 
-use bellman::{
-    SynthesisError,
-    ConstraintSystem,
-    LinearCombination
-};
+use ff::{Field, PrimeField, ScalarEngine};
 
-use super::boolean::{
-    Boolean,
-    AllocatedBit
-};
+use crate::{ConstraintSystem, LinearCombination, SynthesisError};
+
+use super::boolean::{AllocatedBit, Boolean};
 
 use super::multieq::MultiEq;
 
@@ -23,13 +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;
@@ -44,18 +37,16 @@ impl UInt32 {
         }
 
         UInt32 {
-            bits: bits,
-            value: Some(value)
+            bits,
+            value: Some(value),
         }
     }
 
     /// Allocate a `UInt32` in the constraint system
-    pub fn alloc<E, CS>(
-        mut cs: CS,
-        value: Option<u32>
-    ) -> Result<Self, SynthesisError>
-        where E: Engine,
-              CS: ConstraintSystem<E>
+    pub fn alloc<E, CS>(mut cs: CS, value: Option<u32>) -> Result<Self, SynthesisError>
+    where
+        E: ScalarEngine,
+        CS: ConstraintSystem<E>,
     {
         let values = match value {
             Some(mut val) => {
@@ -67,28 +58,28 @@ impl UInt32 {
                 }
 
                 v
-            },
-            None => vec![None; 32]
+            }
+            None => vec![None; 32],
         };
 
-        let bits = values.into_iter()
+        let bits = values
+            .into_iter()
             .enumerate()
             .map(|(i, v)| {
                 Ok(Boolean::from(AllocatedBit::alloc(
                     cs.namespace(|| format!("allocated bit {}", i)),
-                                v
+                    v,
                 )?))
             })
             .collect::<Result<Vec<_>, SynthesisError>>()?;
 
-        Ok(UInt32 {
-            bits: bits,
-            value: value
-        })
+        Ok(UInt32 { bits, value })
     }
 
-    pub fn into_bits_be(&self) -> Vec<Boolean> {
-        self.bits.iter().rev().cloned().collect()
+    pub fn into_bits_be(self) -> Vec<Boolean> {
+        let mut ret = self.bits;
+        ret.reverse();
+        ret
     }
 
     pub fn from_bits_be(bits: &[Boolean]) -> Self {
@@ -99,28 +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(false) => {},
-                None => { value = None; }
+                Some(true) => {
+                    value.as_mut().map(|v| *v |= 1);
+                }
+                Some(false) => {}
+                None => {
+                    value = None;
+                }
             }
         }
 
         UInt32 {
-            value: value,
-            bits: bits.iter().rev().cloned().collect()
+            value,
+            bits: bits.iter().rev().cloned().collect(),
         }
     }
 
-
     /// Turns this `UInt32` into its little-endian byte order representation.
-    pub fn into_bits(&self) -> Vec<Boolean> {
-        self.bits.clone()
+    pub fn into_bits(self) -> Vec<Boolean> {
+        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();
@@ -129,39 +122,41 @@ impl UInt32 {
         for b in new_bits.iter().rev() {
             value.as_mut().map(|v| *v <<= 1);
 
-            match b {
-                &Boolean::Constant(b) => {
+            match *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::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::Not(ref b) => {
-                    match b.get_value() {
-                        Some(false) => { value.as_mut().map(|v| *v |= 1); },
-                        Some(true) => {},
-                        None => { value = None }
-                    }
-                }
             }
         }
 
         UInt32 {
-            value: value,
-            bits: new_bits
+            value,
+            bits: new_bits,
         }
     }
 
     pub fn rotr(&self, by: usize) -> Self {
         let by = by % 32;
 
-        let new_bits = self.bits.iter()
+        let new_bits = self
+            .bits
+            .iter()
             .skip(by)
             .chain(self.bits.iter())
             .take(32)
@@ -170,7 +165,7 @@ impl UInt32 {
 
         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)),
         }
     }
 
@@ -179,7 +174,8 @@ impl UInt32 {
 
         let fill = Boolean::constant(false);
 
-        let new_bits = self.bits
+        let new_bits = self
+            .bits
             .iter() // The bits are least significant first
             .skip(by) // Skip the bits that will be lost during the shift
             .chain(Some(&fill).into_iter().cycle()) // Rest will be zeros
@@ -189,7 +185,7 @@ impl UInt32 {
 
         UInt32 {
             bits: new_bits,
-            value: self.value.map(|v| v >> by as u32)
+            value: self.value.map(|v| v >> by as u32),
         }
     }
 
@@ -199,21 +195,22 @@ impl UInt32 {
         b: &Self,
         c: &Self,
         tri_fn: F,
-        circuit_fn: U
+        circuit_fn: U,
     ) -> Result<Self, SynthesisError>
-        where E: Engine,
+    where
+        E: ScalarEngine,
         CS: ConstraintSystem<E>,
         F: Fn(u32, u32, u32) -> u32,
-              U: Fn(&mut CS, usize, &Boolean, &Boolean, &Boolean) -> Result<Boolean, SynthesisError>
+        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(tri_fn(a, b, c))
-            },
-            _ => None
+            (Some(a), Some(b), Some(c)) => Some(tri_fn(a, b, c)),
+            _ => None,
         };
 
-        let bits = a.bits.iter()
+        let bits = a
+            .bits
+            .iter()
             .zip(b.bits.iter())
             .zip(c.bits.iter())
             .enumerate()
@@ -221,99 +218,76 @@ impl UInt32 {
             .collect::<Result<_, _>>()?;
 
         Ok(UInt32 {
-            bits: bits,
-            value: new_value
+            bits,
+            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>(
-        cs: CS,
-        a: &Self,
-        b: &Self,
-        c: &Self
-    ) -> Result<Self, SynthesisError>
-        where E: Engine,
-              CS: ConstraintSystem<E>
+    pub fn sha256_maj<E, CS>(cs: CS, a: &Self, b: &Self, c: &Self) -> Result<Self, SynthesisError>
+    where
+        E: ScalarEngine,
+        CS: ConstraintSystem<E>,
     {
-        Self::triop(cs, a, b, c, |a, b, c| (a & b) ^ (a & c) ^ (b & c),
-            |cs, i, a, b, c| {
-                Boolean::sha256_maj(
-                    cs.namespace(|| format!("maj {}", i)),
+        Self::triop(
+            cs,
             a,
             b,
-                    c
-                )
-            }
+            c,
+            |a, b, c| (a & b) ^ (a & c) ^ (b & 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>(
-        cs: CS,
-        a: &Self,
-        b: &Self,
-        c: &Self
-    ) -> Result<Self, SynthesisError>
-        where E: Engine,
-              CS: ConstraintSystem<E>
+    pub fn sha256_ch<E, CS>(cs: CS, a: &Self, b: &Self, c: &Self) -> Result<Self, SynthesisError>
+    where
+        E: ScalarEngine,
+        CS: ConstraintSystem<E>,
     {
-        Self::triop(cs, a, b, c, |a, b, c| (a & b) ^ ((!a) & c),
-            |cs, i, a, b, c| {
-                Boolean::sha256_ch(
-                    cs.namespace(|| format!("ch {}", i)),
+        Self::triop(
+            cs,
             a,
             b,
-                    c
-                )
-            }
+            c,
+            |a, b, c| (a & b) ^ ((!a) & 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>(
-        &self,
-        mut cs: CS,
-        other: &Self
-    ) -> Result<Self, SynthesisError>
-        where E: Engine,
-              CS: ConstraintSystem<E>
+    pub fn xor<E, CS>(&self, mut cs: CS, other: &Self) -> Result<Self, SynthesisError>
+    where
+        E: ScalarEngine,
+        CS: ConstraintSystem<E>,
     {
         let new_value = match (self.value, other.value) {
-            (Some(a), Some(b)) => {
-                Some(a ^ b)
-            },
-            _ => None
+            (Some(a), Some(b)) => Some(a ^ b),
+            _ => None,
         };
 
-        let bits = self.bits.iter()
+        let bits = self
+            .bits
+            .iter()
             .zip(other.bits.iter())
             .enumerate()
-                            .map(|(i, (a, b))| {
-                                Boolean::xor(
-                                    cs.namespace(|| format!("xor of bit {}", i)),
-                                    a,
-                                    b
-                                )
-                            })
+            .map(|(i, (a, b))| Boolean::xor(cs.namespace(|| format!("xor of bit {}", i)), a, b))
             .collect::<Result<_, _>>()?;
 
         Ok(UInt32 {
-            bits: bits,
-            value: new_value
+            bits,
+            value: new_value,
         })
     }
 
     /// Perform modular addition of several `UInt32` objects.
-    pub fn addmany<E, CS, M>(
-        mut cs: M,
-        operands: &[Self]
-    ) -> Result<Self, SynthesisError>
-        where E: Engine,
+    pub fn addmany<E, CS, M>(mut cs: M, operands: &[Self]) -> Result<Self, SynthesisError>
+    where
+        E: ScalarEngine,
         CS: ConstraintSystem<E>,
-              M: ConstraintSystem<E, Root=MultiEq<E, CS>>
+        M: ConstraintSystem<E, Root = MultiEq<E, CS>>,
     {
         // Make some arbitrary bounds for ourselves to avoid overflows
         // in the scalar field
@@ -323,7 +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);
@@ -339,8 +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
@@ -384,7 +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
@@ -405,48 +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 ::circuit::boolean::{Boolean};
-    use super::{UInt32};
-    use pairing::bls12_381::{Bls12};
-    use pairing::{Field};
-    use ::circuit::test::*;
-    use bellman::{ConstraintSystem};
-    use circuit::multieq::MultiEq;
+    use super::UInt32;
+    use crate::gadgets::boolean::Boolean;
+    use crate::gadgets::multieq::MultiEq;
+    use crate::gadgets::test::*;
+    use crate::ConstraintSystem;
+    use ff::Field;
+    use pairing::bls12_381::Bls12;
+    use rand_core::{RngCore, SeedableRng};
+    use rand_xorshift::XorShiftRng;
 
     #[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 {
-                    &Boolean::Constant(bit) => {
+                match *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(false), &Boolean::Constant(false)) => {},
-                    _ => unreachable!()
+                    (&Boolean::Constant(true), &Boolean::Constant(true)) => {}
+                    (&Boolean::Constant(false), &Boolean::Constant(false)) => {}
+                    _ => unreachable!(),
                 }
             }
         }
@@ -454,30 +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 {
-                    &Boolean::Constant(bit) => {
+                match *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(false), &Boolean::Constant(false)) => {},
-                    _ => unreachable!()
+                    (&Boolean::Constant(true), &Boolean::Constant(true)) => {}
+                    (&Boolean::Constant(false), &Boolean::Constant(false)) => {}
+                    _ => unreachable!(),
                 }
             }
         }
@@ -485,14 +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 b: u32 = rng.gen();
-            let c: u32 = rng.gen();
+            let a = rng.next_u32();
+            let b = rng.next_u32();
+            let c = rng.next_u32();
 
             let mut expected = a ^ b ^ c;
 
@@ -508,14 +494,14 @@ mod test {
             assert!(r.value == Some(expected));
 
             for b in r.bits.iter() {
-                match b {
-                    &Boolean::Is(ref b) => {
+                match *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));
                     }
                 }
@@ -527,14 +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 b: u32 = rng.gen();
-            let c: u32 = rng.gen();
+            let a = rng.next_u32();
+            let b = rng.next_u32();
+            let c = rng.next_u32();
 
             let a_bit = UInt32::constant(a);
             let b_bit = UInt32::constant(b);
@@ -544,17 +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 {
-                    &Boolean::Is(_) => panic!(),
-                    &Boolean::Not(_) => panic!(),
-                    &Boolean::Constant(b) => {
+                match *b {
+                    Boolean::Is(_) => panic!(),
+                    Boolean::Not(_) => panic!(),
+                    Boolean::Constant(b) => {
                         assert!(b == (expected & 1 == 1));
                     }
                 }
@@ -566,15 +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 b: u32 = rng.gen();
-            let c: u32 = rng.gen();
-            let d: u32 = rng.gen();
+            let a = rng.next_u32();
+            let b = rng.next_u32();
+            let c = rng.next_u32();
+            let d = rng.next_u32();
 
             let mut expected = (a ^ b).wrapping_add(c).wrapping_add(d);
 
@@ -586,8 +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();
-                r
+                UInt32::addmany(cs.namespace(|| "addition"), &[r, c_bit, d_bit]).unwrap()
             };
 
             assert!(cs.is_satisfied());
@@ -595,16 +587,14 @@ mod test {
             assert!(r.value == Some(expected));
 
             for b in r.bits.iter() {
-                match b {
-                    &Boolean::Is(ref b) => {
+                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(_) => {
-                        unreachable!()
                     }
+                    Boolean::Not(ref b) => {
+                        assert!(!b.get_value().unwrap() == (expected & 1 == 1));
+                    }
+                    Boolean::Constant(_) => unreachable!(),
                 }
 
                 expected >>= 1;
@@ -623,9 +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);
 
@@ -637,11 +630,11 @@ mod test {
 
             let mut tmp = num;
             for b in &b.bits {
-                match b {
-                    &Boolean::Constant(b) => {
+                match *b {
+                    Boolean::Constant(b) => {
                         assert_eq!(b, tmp & 1 == 1);
-                    },
-                    _ => unreachable!()
+                    }
+                    _ => unreachable!(),
                 }
 
                 tmp >>= 1;
@@ -653,15 +646,18 @@ 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 >> i);
+                let b = UInt32::constant(num.wrapping_shr(i as u32));
 
-                assert_eq!(a.value.unwrap(), num >> i);
+                assert_eq!(a.value.unwrap(), num.wrapping_shr(i as u32));
 
                 assert_eq!(a.bits.len(), b.bits.len());
                 for (a, b) in a.bits.iter().zip(b.bits.iter()) {
@@ -673,14 +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 b: u32 = rng.gen();
-            let c: u32 = rng.gen();
+            let a = rng.next_u32();
+            let b = rng.next_u32();
+            let c = rng.next_u32();
 
             let mut expected = (a & b) ^ (a & c) ^ (b & c);
 
@@ -698,10 +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));
                     }
@@ -714,14 +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 b: u32 = rng.gen();
-            let c: u32 = rng.gen();
+            let a = rng.next_u32();
+            let b = rng.next_u32();
+            let c = rng.next_u32();
 
             let mut expected = (a & b) ^ ((!a) & c);
 
@@ -739,10 +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

@@ -1,65 +1,39 @@
-use rand::Rng;
+use rand_core::RngCore;
 
 use std::sync::Arc;
 
-use pairing::{
-    Engine,
-    PrimeField,
-    Field,
-    Wnaf,
-    CurveProjective,
-    CurveAffine
-};
+use ff::{Field, PrimeField};
+use group::{CurveAffine, CurveProjective, Wnaf};
+use pairing::Engine;
 
-use super::{
-    Parameters,
-    VerifyingKey
-};
+use super::{Parameters, VerifyingKey};
 
-use ::{
-    SynthesisError,
-    Circuit,
-    ConstraintSystem,
-    LinearCombination,
-    Variable,
-    Index
-};
+use crate::{Circuit, ConstraintSystem, Index, LinearCombination, SynthesisError, Variable};
 
-use ::domain::{
-    EvaluationDomain,
-    Scalar
-};
+use crate::domain::{EvaluationDomain, Scalar};
 
-use ::multicore::{
-    Worker
-};
+use crate::multicore::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 g2 = rng.gen();
-    let alpha = rng.gen();
-    let beta = rng.gen();
-    let gamma = rng.gen();
-    let delta = rng.gen();
-    let tau = rng.gen();
+    let g1 = E::G1::random(rng);
+    let g2 = E::G2::random(rng);
+    let alpha = E::Fr::random(rng);
+    let beta = E::Fr::random(rng);
+    let gamma = E::Fr::random(rng);
+    let delta = E::Fr::random(rng);
+    let tau = E::Fr::random(rng);
 
-    generate_parameters::<E, C>(
-        circuit,
-        g1,
-        g2,
-        alpha,
-        beta,
-        gamma,
-        delta,
-        tau
-    )
+    generate_parameters::<E, C>(circuit, g1, g2, alpha, beta, gamma, delta, tau)
 }
 
 /// This is our assembly structure that we'll use to synthesize the
@@ -73,18 +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>(
-        &mut self,
-        _: A,
-        _: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc<F, A, AR>(&mut self, _: A, _: F) -> Result<Variable, SynthesisError>
+    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.
@@ -99,12 +72,11 @@ impl<E: Engine> ConstraintSystem<E> for KeypairAssembly<E> {
         Ok(Variable(Index::Aux(index)))
     }
 
-    fn alloc_input<F, A, AR>(
-        &mut self,
-        _: A,
-        _: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc_input<F, A, AR>(&mut self, _: A, _: F) -> Result<Variable, SynthesisError>
+    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.
@@ -119,48 +91,59 @@ impl<E: Engine> ConstraintSystem<E> for KeypairAssembly<E> {
         Ok(Variable(Index::Input(index)))
     }
 
-    fn enforce<A, AR, LA, LB, LC>(
-        &mut self,
-        _: A,
-        a: LA,
-        b: LB,
-        c: LC
-    )
-        where A: FnOnce() -> AR, AR: Into<String>,
+    fn enforce<A, AR, LA, LB, LC>(&mut self, _: A, a: LA, b: LB, c: LC)
+    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>
+        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(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);
+        eval(
+            a(LinearCombination::zero()),
+            &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.
     }
 
@@ -178,9 +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,
@@ -191,7 +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
@@ -203,11 +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(|| "",
-            |lc| lc + Variable(Index::Input(i)),
-            |lc| lc,
-            |lc| lc,
-        );
+        assembly.enforce(|| "", |lc| lc + Variable(Index::Input(i)), |lc| lc, |lc| lc);
     }
 
     // Create bases for blind evaluation of polynomials at tau
@@ -245,9 +226,8 @@ 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()
-                {
-                    scope.spawn(move || {
+                for (i, powers_of_tau) in powers_of_tau.chunks_mut(chunk).enumerate() {
+                    scope.spawn(move |_scope| {
                         let mut current_tau_power = tau.pow(&[(i * chunk) as u64]);
 
                         for p in powers_of_tau {
@@ -265,14 +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);
@@ -325,9 +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());
@@ -338,7 +318,8 @@ 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
+                .chunks_mut(chunk)
                 .zip(b_g1.chunks_mut(chunk))
                 .zip(b_g2.chunks_mut(chunk))
                 .zip(ext.chunks_mut(chunk))
@@ -349,8 +330,9 @@ pub fn generate_parameters<E, C>(
                 let mut g1_wnaf = g1_wnaf.shared();
                 let mut g2_wnaf = g2_wnaf.shared();
 
-                scope.spawn(move || {
-                    for ((((((a, b_g1), b_g2), ext), at), bt), ct) in a.iter_mut()
+                scope.spawn(move |_scope| {
+                    for ((((((a, b_g1), b_g2), ext), at), bt), ct) in a
+                        .iter_mut()
                         .zip(b_g1.iter_mut())
                         .zip(b_g2.iter_mut())
                         .zip(ext.iter_mut())
@@ -360,9 +342,8 @@ pub fn generate_parameters<E, C>(
                     {
                         fn eval_at_tau<E: Engine>(
                             powers_of_tau: &[Scalar<E>],
-                            p: &[(E::Fr, usize)]
-                        ) -> E::Fr
-                        {
+                            p: &[(E::Fr, usize)],
+                        ) -> E::Fr {
                             let mut acc = E::Fr::zero();
 
                             for &(ref coeff, index) in p {
@@ -427,10 +408,10 @@ pub fn generate_parameters<E, C>(
         &gamma_inverse,
         &alpha,
         &beta,
-        &worker
+        &worker,
     );
 
-    // Evaluate for auxillary variables.
+    // Evaluate for auxiliary variables.
     eval(
         &g1_wnaf,
         &g2_wnaf,
@@ -445,7 +426,7 @@ pub fn generate_parameters<E, C>(
         &delta_inverse,
         &alpha,
         &beta,
-        &worker
+        &worker,
     );
 
     // Don't allow any elements be unconstrained, so that
@@ -466,17 +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()),
-        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())
+        a: Arc::new(
+            a.into_iter()
+                .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 @@
-use pairing::{
-    Engine,
-    CurveAffine,
-    EncodedPoint
-};
+//! The [Groth16] proving system.
+//!
+//! [Groth16]: https://eprint.iacr.org/2016/260
 
-use ::{
-    SynthesisError
-};
+use group::{CurveAffine, EncodedPoint};
+use pairing::{Engine, PairingCurveAffine};
 
-use multiexp::SourceBuilder;
+use crate::SynthesisError;
+
+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.b == other.b &&
-        self.c == other.c
+        self.a == other.a && self.b == other.b && self.c == other.c
     }
 }
 
 impl<E: Engine> Proof<E> {
-    pub fn write<W: Write>(
-        &self,
-        mut writer: W
-    ) -> io::Result<()>
-    {
+    pub fn write<W: Write>(&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())?;
@@ -52,10 +45,7 @@ impl<E: Engine> Proof<E> {
         Ok(())
     }
 
-    pub fn read<R: Read>(
-        mut reader: R
-    ) -> io::Result<Self>
-    {
+    pub fn read<R: Read>(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();
 
@@ -63,37 +53,48 @@ impl<E: Engine> Proof<E> {
         let a = g1_repr
             .into_affine()
             .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-                .and_then(|e| if e.is_zero() {
-                    Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+            .and_then(|e| {
+                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()
             .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-                .and_then(|e| if e.is_zero() {
-                    Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+            .and_then(|e| {
+                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()
             .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-                .and_then(|e| if e.is_zero() {
-                    Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+            .and_then(|e| {
+                if e.is_zero() {
+                    Err(io::Error::new(
+                        io::ErrorKind::InvalidData,
+                        "point at infinity",
+                    ))
                 } else {
                     Ok(e)
+                }
             })?;
 
-        Ok(Proof {
-            a: a,
-            b: b,
-            c: c
-        })
+        Ok(Proof { a, b, 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.beta_g1 == other.beta_g1 &&
-        self.beta_g2 == other.beta_g2 &&
-        self.gamma_g2 == other.gamma_g2 &&
-        self.delta_g1 == other.delta_g1 &&
-        self.delta_g2 == other.delta_g2 &&
-        self.ic == other.ic
+        self.alpha_g1 == other.alpha_g1
+            && self.beta_g1 == other.beta_g1
+            && self.beta_g2 == other.beta_g2
+            && self.gamma_g2 == other.gamma_g2
+            && self.delta_g1 == other.delta_g1
+            && self.delta_g2 == other.delta_g2
+            && self.ic == other.ic
     }
 }
 
 impl<E: Engine> VerifyingKey<E> {
-    pub fn write<W: Write>(
-        &self,
-        mut writer: W
-    ) -> io::Result<()>
-    {
+    pub fn write<W: Write>(&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>(
-        mut reader: R
-    ) -> io::Result<Self>
-    {
+    pub fn read<R: Read>(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;
 
@@ -191,23 +197,28 @@ impl<E: Engine> VerifyingKey<E> {
             let g1 = g1_repr
                 .into_affine()
                 .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-                     .and_then(|e| if e.is_zero() {
-                         Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+                .and_then(|e| {
+                    if e.is_zero() {
+                        Err(io::Error::new(
+                            io::ErrorKind::InvalidData,
+                            "point at infinity",
+                        ))
                     } else {
                         Ok(e)
+                    }
                 })?;
 
             ic.push(g1);
         }
 
         Ok(VerifyingKey {
-            alpha_g1: alpha_g1,
-            beta_g1: beta_g1,
-            beta_g2: beta_g2,
-            gamma_g2: gamma_g2,
-            delta_g1: delta_g1,
-            delta_g2: delta_g2,
-            ic: ic
+            alpha_g1,
+            beta_g1,
+            beta_g2,
+            gamma_g2,
+            delta_g1,
+            delta_g2,
+            ic,
         })
     }
 }
@@ -221,7 +232,7 @@ pub struct Parameters<E: Engine> {
     pub h: Arc<Vec<E::G1Affine>>,
 
     // Elements of the form (beta * u_i(tau) + alpha v_i(tau) + w_i(tau)) / delta
-    // for all auxillary inputs. Variables can never be unconstrained, so this
+    // for all auxiliary inputs. Variables can never be unconstrained, so this
     // never contains points at infinity.
     pub l: 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.h == other.h &&
-        self.l == other.l &&
-        self.a == other.a &&
-        self.b_g1 == other.b_g1 &&
-        self.b_g2 == other.b_g2
+        self.vk == other.vk
+            && self.h == other.h
+            && self.l == other.l
+            && self.a == other.a
+            && self.b_g1 == other.b_g1
+            && self.b_g2 == other.b_g2
     }
 }
 
 impl<E: Engine> Parameters<E> {
-    pub fn write<W: Write>(
-        &self,
-        mut writer: W
-    ) -> io::Result<()>
-    {
+    pub fn write<W: Write>(&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>(
-        mut reader: R,
-        checked: bool
-    ) -> io::Result<Self>
-    {
+    pub fn read<R: Read>(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
-                .into_affine()
+                repr.into_affine()
             } else {
-                repr
-                .into_affine_unchecked()
+                repr.into_affine_unchecked()
             }
             .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-            .and_then(|e| if e.is_zero() {
-                Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+            .and_then(|e| {
+                if e.is_zero() {
+                    Err(io::Error::new(
+                        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
-                .into_affine()
+                repr.into_affine()
             } else {
-                repr
-                .into_affine_unchecked()
+                repr.into_affine_unchecked()
             }
             .map_err(|e| io::Error::new(io::ErrorKind::InvalidData, e))
-            .and_then(|e| if e.is_zero() {
-                Err(io::Error::new(io::ErrorKind::InvalidData, "point at infinity"))
+            .and_then(|e| {
+                if e.is_zero() {
+                    Err(io::Error::new(
+                        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),
         })
     }
 }
@@ -385,43 +394,34 @@ pub struct PreparedVerifyingKey<E: Engine> {
     /// Pairing result of alpha*beta
     alpha_g1_beta_g2: E::Fqk,
     /// -gamma in G2
-    neg_gamma_g2: <E::G2Affine as CurveAffine>::Prepared,
+    neg_gamma_g2: <E::G2Affine as PairingCurveAffine>::Prepared,
     /// -delta in G2
-    neg_delta_g2: <E::G2Affine as CurveAffine>::Prepared,
+    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(
-        &mut self,
-        num_ic: usize
-    ) -> 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_vk(&mut self, num_ic: usize) -> 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(
-        &mut self,
-        _: usize
-    ) -> Result<VerifyingKey<E>, SynthesisError>
-    {
+    fn get_vk(&mut self, _: usize) -> Result<VerifyingKey<E>, SynthesisError> {
         Ok(self.vk.clone())
     }
 
-    fn get_h(
-        &mut self,
-        _: usize
-    ) -> Result<Self::G1Builder, SynthesisError>
-    {
+    fn get_h(&mut self, _: usize) -> Result<Self::G1Builder, SynthesisError> {
         Ok((self.h.clone(), 0))
     }
 
-    fn get_l(
-        &mut self,
-        _: usize
-    ) -> Result<Self::G1Builder, SynthesisError>
-    {
+    fn get_l(&mut self, _: usize) -> Result<Self::G1Builder, SynthesisError> {
         Ok((self.l.clone(), 0))
     }
 
     fn get_a(
         &mut self,
         num_inputs: usize,
-        _: usize
-    ) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>
-    {
+        _: usize,
+    ) -> 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
-    ) -> Result<(Self::G1Builder, Self::G1Builder), SynthesisError>
-    {
+        _: usize,
+    ) -> 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
-    ) -> Result<(Self::G2Builder, Self::G2Builder), SynthesisError>
-    {
+        _: usize,
+    ) -> 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 rand::{Rand, thread_rng};
-    use pairing::{Field};
+    use ff::Field;
     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
-            ) -> Result<(), SynthesisError>
-            {
+                cs: &mut CS,
+            ) -> 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(
+                    || "c",
+                    || {
                         let mut a = self.a.ok_or(SynthesisError::AssignmentMissing)?;
                         let b = self.b.ok_or(SynthesisError::AssignmentMissing)?;
 
                         a.mul_assign(&b);
                         Ok(a)
-                })?;
+                    },
+                )?;
 
-                cs.enforce(
-                    || "a*b=c",
-                    |lc| lc + a,
-                    |lc| lc + b,
-                    |lc| lc + c
-                );
+                cs.enforce(|| "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, _, _>(
-            MySillyCircuit { a: None, b: None },
-            rng
-        ).unwrap();
+        let params =
+            generate_random_parameters::<Bls12, _, _>(MySillyCircuit { a: None, b: None }, rng)
+                .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 b = Fr::rand(rng);
+            let a = Fr::random(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
-            ).unwrap();
+                rng,
+            )
+            .unwrap();
 
             let mut v = vec![];
             proof.write(&mut v).unwrap();

bellman/src/groth16/prover.rs

@@ -1,54 +1,30 @@
-use rand::Rng;
+use rand_core::RngCore;
 
 use std::sync::Arc;
 
 use futures::Future;
 
-use pairing::{
-    Engine,
-    PrimeField,
-    Field,
-    CurveProjective,
-    CurveAffine
-};
+use ff::{Field, PrimeField};
+use group::{CurveAffine, CurveProjective};
+use pairing::Engine;
 
-use super::{
-    ParameterSource,
-    Proof
-};
+use super::{ParameterSource, Proof};
 
-use ::{
-    SynthesisError,
-    Circuit,
-    ConstraintSystem,
-    LinearCombination,
-    Variable,
-    Index
-};
+use crate::{Circuit, ConstraintSystem, Index, LinearCombination, SynthesisError, Variable};
 
-use ::domain::{
-    EvaluationDomain,
-    Scalar
-};
+use crate::domain::{EvaluationDomain, Scalar};
 
-use ::multiexp::{
-    DensityTracker,
-    FullDensity,
-    multiexp
-};
+use crate::multiexp::{multiexp, DensityTracker, FullDensity};
 
-use ::multicore::{
-    Worker
-};
+use crate::multicore::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]
-) -> E::Fr
-{
+    aux_assignment: &[E::Fr],
+) -> E::Fr {
     let mut acc = E::Fr::zero();
 
     for &(index, coeff) in lc.0.iter() {
@@ -60,7 +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 {
@@ -93,18 +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>(
-        &mut self,
-        _: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc<F, A, AR>(&mut self, _: A, f: F) -> Result<Variable, SynthesisError>
+    where
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
+        A: FnOnce() -> AR,
+        AR: Into<String>,
     {
         self.aux_assignment.push(f()?);
         self.a_aux_density.add_element();
@@ -113,12 +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>(
-        &mut self,
-        _: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc_input<F, A, AR>(&mut self, _: A, f: F) -> Result<Variable, SynthesisError>
+    where
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
+        A: FnOnce() -> AR,
+        AR: Into<String>,
     {
         self.input_assignment.push(f()?);
         self.b_input_density.add_element();
@@ -126,17 +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>(
-        &mut self,
-        _: A,
-        a: LA,
-        b: LB,
-        c: LC
-    )
-        where A: FnOnce() -> AR, AR: Into<String>,
+    fn enforce<A, AR, LA, LB, LC>(&mut self, _: A, a: LA, b: LB, c: LC)
+    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>
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
     {
         let a = a(LinearCombination::zero());
         let b = b(LinearCombination::zero());
@@ -150,14 +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,
@@ -168,18 +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.
     }
 
@@ -191,12 +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 s = rng.gen();
+    let r = E::Fr::random(rng);
+    let s = E::Fr::random(rng);
 
     create_proof::<E, C, P>(circuit, params, r, s)
 }
@@ -205,9 +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(),
@@ -217,7 +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()))?;
@@ -225,11 +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(|| "",
-            |lc| lc + Variable(Index::Input(i)),
-            |lc| lc,
-            |lc| lc,
-        );
+        prover.enforce(|| "", |lc| lc + Variable(Index::Input(i)), |lc| lc, |lc| lc);
     }
 
     let worker = Worker::new();
@@ -263,31 +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 aux_assignment = Arc::new(prover.aux_assignment.into_iter().map(|s| s.into_repr()).collect::<Vec<_>>());
+    let input_assignment = Arc::new(
+        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_aux = multiexp(&worker, a_aux_source, Arc::new(prover.a_aux_density), aux_assignment.clone());
+    let a_inputs = multiexp(
+        &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_aux = multiexp(&worker, b_g1_aux_source, b_aux_density.clone(), aux_assignment.clone());
+    let b_g1_inputs = multiexp(
+        &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() {
@@ -329,6 +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

@@ -1,20 +1,13 @@
-use pairing::{
-    Engine,
-    PrimeField,
-    PrimeFieldRepr,
-    Field,
+use ff::{
+    Field, LegendreSymbol, PrimeField, PrimeFieldDecodingError, PrimeFieldRepr, ScalarEngine,
     SqrtField,
-    LegendreSymbol,
-    CurveProjective,
-    CurveAffine,
-    PrimeFieldDecodingError,
-    GroupDecodingError,
-    EncodedPoint
 };
+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);
@@ -23,18 +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)
     }
 
-impl Field for Fr {
     fn zero() -> Self {
         Fr(Wrapping(0))
     }
@@ -90,9 +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 }
-        else if s == <Fr as Field>::one() { LegendreSymbol::QuadraticResidue }
-        else { LegendreSymbol::QuadraticNonResidue }
+        if s == <Fr as Field>::zero() {
+            LegendreSymbol::Zero
+        } else if s == <Fr as Field>::one() {
+            LegendreSymbol::QuadraticResidue
+        } else {
+            LegendreSymbol::QuadraticNonResidue
+        }
     }
 
     fn sqrt(&self) -> Option<Self> {
@@ -153,14 +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])
     }
 }
@@ -263,8 +252,11 @@ impl PrimeField for Fr {
 #[derive(Clone)]
 pub struct DummyEngine;
 
-impl Engine for DummyEngine {
+impl ScalarEngine for DummyEngine {
     type Fr = Fr;
+}
+
+impl Engine for DummyEngine {
     type G1 = Fr;
     type G1Affine = Fr;
     type G2 = Fr;
@@ -276,10 +268,13 @@ impl Engine for DummyEngine {
     type Fqk = Fr;
 
     fn miller_loop<'a, I>(i: I) -> Self::Fqk
-        where I: IntoIterator<Item=&'a (
-                                    &'a <Self::G1Affine as CurveAffine>::Prepared,
-                                    &'a <Self::G2Affine as CurveAffine>::Prepared
-                               )>
+    where
+        I: IntoIterator<
+            Item = &'a (
+                &'a <Self::G1Affine as PairingCurveAffine>::Prepared,
+                &'a <Self::G2Affine as PairingCurveAffine>::Prepared,
+            ),
+        >,
     {
         let mut acc = <Fr as Field>::zero();
 
@@ -293,8 +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)
     }
 }
@@ -305,6 +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()
     }
@@ -317,9 +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
@@ -341,8 +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);
@@ -401,11 +396,8 @@ impl EncodedPoint for FakePoint {
 }
 
 impl CurveAffine for Fr {
-    type Pair = Fr;
-    type PairingResult = Fr;
     type Compressed = FakePoint;
     type Uncompressed = FakePoint;
-    type Prepared = Fr;
     type Projective = Fr;
     type Base = Fr;
     type Scalar = Fr;
@@ -427,8 +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();
 
@@ -437,6 +428,16 @@ impl CurveAffine for Fr {
         res
     }
 
+    fn into_projective(&self) -> Self::Projective {
+        *self
+    }
+}
+
+impl PairingCurveAffine for Fr {
+    type Prepared = Fr;
+    type Pair = Fr;
+    type PairingResult = Fr;
+
     fn prepare(&self) -> Self::Prepared {
         *self
     }
@@ -444,8 +445,4 @@ impl CurveAffine for Fr {
     fn pairing_with(&self, other: &Self::Pair) -> Self::PairingResult {
         self.mul(*other)
     }
-
-    fn into_projective(&self) -> Self::Projective {
-        *self
-    }
 }

bellman/src/groth16/tests/mod.rs

@@ -1,40 +1,26 @@
-use pairing::{
-    Engine,
-    Field,
-    PrimeField
-};
+use ff::{Field, PrimeField};
+use pairing::Engine;
 
 mod dummy_engine;
 use self::dummy_engine::*;
 
 use std::marker::PhantomData;
 
-use ::{
-    Circuit,
-    ConstraintSystem,
-    SynthesisError
-};
+use crate::{Circuit, ConstraintSystem, SynthesisError};
 
-use super::{
-    generate_parameters,
-    prepare_verifying_key,
-    create_proof,
-    verify_proof
-};
+use super::{create_proof, generate_parameters, prepare_verifying_key, 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>>(
-        self,
-        cs: &mut CS
-    ) -> Result<(), SynthesisError>
-    {
-        let a_var = cs.alloc(|| "a", || {
+    fn synthesize<CS: ConstraintSystem<E>>(self, cs: &mut CS) -> Result<(), SynthesisError> {
+        let a_var = cs.alloc(
+            || "a",
+            || {
                 if self.a.is_some() {
                     if self.a.unwrap() {
                         Ok(E::Fr::one())
@@ -44,16 +30,19 @@ impl<E: Engine> Circuit<E> for XORDemo<E> {
                 } 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(
+            || "b",
+            || {
                 if self.b.is_some() {
                     if self.b.unwrap() {
                         Ok(E::Fr::one())
@@ -63,16 +52,19 @@ impl<E: Engine> Circuit<E> for XORDemo<E> {
                 } 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(
+            || "c",
+            || {
                 if self.a.is_some() && self.b.is_some() {
                     if self.a.unwrap() ^ self.b.unwrap() {
                         Ok(E::Fr::one())
@@ -82,13 +74,14 @@ impl<E: Engine> Circuit<E> for XORDemo<E> {
                 } 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(())
@@ -109,19 +102,10 @@ fn test_xordemo() {
         let c = XORDemo::<DummyEngine> {
             a: None,
             b: None,
-            _marker: PhantomData
+            _marker: PhantomData,
         };
 
-        generate_parameters(
-            c,
-            g1,
-            g2,
-            alpha,
-            beta,
-            gamma,
-            delta,
-            tau
-        ).unwrap()
+        generate_parameters(c, g1, g2, alpha, beta, gamma, delta, tau).unwrap()
     };
 
     // This will synthesize the constraint system:
@@ -229,30 +213,33 @@ fn test_xordemo() {
     59158
     */
 
-    let u_i = [59158, 48317, 21767, 10402].iter().map(|e| {
-        Fr::from_str(&format!("{}", e)).unwrap()
-    }).collect::<Vec<Fr>>();
-    let v_i = [0, 0, 60619, 30791].iter().map(|e| {
-        Fr::from_str(&format!("{}", e)).unwrap()
-    }).collect::<Vec<Fr>>();
-    let w_i = [0, 23320, 41193, 41193].iter().map(|e| {
-        Fr::from_str(&format!("{}", e)).unwrap()
-    }).collect::<Vec<Fr>>();
+    let u_i = [59158, 48317, 21767, 10402]
+        .iter()
+        .map(|e| Fr::from_str(&format!("{}", e)).unwrap())
+        .collect::<Vec<Fr>>();
+    let v_i = [0, 0, 60619, 30791]
+        .iter()
+        .map(|e| Fr::from_str(&format!("{}", e)).unwrap())
+        .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()
-                     .zip(&params.a[..])
-    {
+    for (u, a) in u_i.iter().zip(&params.a[..]) {
         assert_eq!(u, a);
     }
 
-    for (v, b) in v_i.iter()
+    for (v, b) in v_i
+        .iter()
         .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
+        .iter()
         .filter(|&&e| e != Fr::zero())
         .zip(&params.b_g2[..])
     {
@@ -299,15 +286,10 @@ fn test_xordemo() {
         let c = XORDemo {
             a: Some(true),
             b: Some(false),
-            _marker: PhantomData
+            _marker: PhantomData,
         };
 
-        create_proof(
-            c,
-            &params,
-            r,
-            s
-        ).unwrap()
+        create_proof(c, &params, r, s).unwrap()
     };
 
     // A(x) =
@@ -381,7 +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];
@@ -392,9 +377,5 @@ fn test_xordemo() {
         assert_eq!(expected_c, proof.c);
     }
 
-    assert!(verify_proof(
-        &pvk,
-        &proof,
-        &[Fr::one()]
-    ).unwrap());
+    assert!(verify_proof(&pvk, &proof, &[Fr::one()]).unwrap());
 }

bellman/src/groth16/verifier.rs

@@ -1,24 +1,12 @@
-use pairing::{
-    Engine,
-    CurveProjective,
-    CurveAffine,
-    PrimeField
-};
+use ff::PrimeField;
+use group::{CurveAffine, CurveProjective};
+use pairing::{Engine, PairingCurveAffine};
 
-use super::{
-    Proof,
-    VerifyingKey,
-    PreparedVerifyingKey
-};
+use super::{PreparedVerifyingKey, Proof, VerifyingKey};
 
-use ::{
-    SynthesisError
-};
+use crate::SynthesisError;
 
-pub fn prepare_verifying_key<E: Engine>(
-    vk: &VerifyingKey<E>
-) -> PreparedVerifyingKey<E>
-{
+pub fn prepare_verifying_key<E: Engine>(vk: &VerifyingKey<E>) -> PreparedVerifyingKey<E> {
     let mut gamma = vk.gamma_g2;
     gamma.negate();
     let mut delta = vk.delta_g2;
@@ -28,16 +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]
-) -> Result<bool, SynthesisError>
-{
+    public_inputs: &[E::Fr],
+) -> Result<bool, SynthesisError> {
     if (public_inputs.len() + 1) != pvk.ic.len() {
         return Err(SynthesisError::MalformedVerifyingKey);
     }
@@ -56,11 +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(
-        &E::miller_loop([
+    Ok(E::final_exponentiation(&E::miller_loop(
+        [
             (&proof.a.prepare(), &proof.b.prepare()),
             (&acc.into_affine().prepare(), &pvk.neg_gamma_g2),
-            (&proof.c.prepare(), &pvk.neg_delta_g2)
-        ].into_iter())
-    ).unwrap() == pvk.alpha_g1_beta_g2)
+            (&proof.c.prepare(), &pvk.neg_delta_g2),
+        ]
+        .iter(),
+    ))
+    .unwrap()
+        == pvk.alpha_g1_beta_g2)
 }

bellman/src/lib.rs

@@ -1,35 +1,162 @@
-extern crate pairing;
-extern crate rand;
-extern crate num_cpus;
-extern crate futures;
-extern crate futures_cpupool;
-extern crate bit_vec;
-extern crate crossbeam;
-extern crate byteorder;
+//! `bellman` is a crate for building zk-SNARK circuits. It provides circuit
+//! traits and and primitive structures, as well as basic gadget implementations
+//! such as booleans and number abstractions.
+//!
+//! # 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.
 
+// Catch documentation errors caused by code changes.
+#![deny(intra_doc_link_resolution_failure)]
+
+pub mod domain;
+pub mod gadgets;
+#[cfg(feature = "groth16")]
+pub mod groth16;
 pub mod multicore;
 mod multiexp;
-pub mod domain;
-pub mod groth16;
 
-use pairing::{Engine, Field};
+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
 /// circuit that can be synthesized. The `synthesize` method is called during
 /// CRS generation and during proving.
-pub trait Circuit<E: Engine> {
+pub trait Circuit<E: ScalarEngine> {
     /// Synthesize the circuit into a rank-1 quadratic constraint system
-    fn synthesize<CS: ConstraintSystem<E>>(
-        self,
-        cs: &mut CS
-    ) -> Result<(), SynthesisError>;
+    fn synthesize<CS: ConstraintSystem<E>>(self, cs: &mut CS) -> Result<(), SynthesisError>;
 }
 
 /// Represents a variable in our constraint system.
@@ -51,31 +178,31 @@ impl Variable {
 }
 
 /// Represents the index of either an input variable or
-/// auxillary variable.
+/// auxiliary 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
 /// in the scalar field of a pairing-friendly elliptic curve group.
 #[derive(Clone)]
-pub struct LinearCombination<E: Engine>(Vec<(Variable, E::Fr)>);
+pub struct LinearCombination<E: ScalarEngine>(Vec<(Variable, E::Fr)>);
 
-impl<E: Engine> AsRef<[(Variable, E::Fr)]> for LinearCombination<E> {
+impl<E: ScalarEngine> AsRef<[(Variable, E::Fr)]> for LinearCombination<E> {
     fn as_ref(&self) -> &[(Variable, E::Fr)] {
         &self.0
     }
 }
 
-impl<E: Engine> LinearCombination<E> {
+impl<E: ScalarEngine> LinearCombination<E> {
     pub fn zero() -> LinearCombination<E> {
         LinearCombination(vec![])
     }
 }
 
-impl<E: Engine> Add<(E::Fr, Variable)> for LinearCombination<E> {
+impl<E: ScalarEngine> Add<(E::Fr, Variable)> for LinearCombination<E> {
     type Output = LinearCombination<E>;
 
     fn add(mut self, (coeff, var): (E::Fr, Variable)) -> LinearCombination<E> {
@@ -85,9 +212,10 @@ impl<E: Engine> Add<(E::Fr, Variable)> for LinearCombination<E> {
     }
 }
 
-impl<E: Engine> Sub<(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();
 
@@ -95,7 +223,7 @@ impl<E: Engine> Sub<(E::Fr, Variable)> for LinearCombination<E> {
     }
 }
 
-impl<E: Engine> Add<Variable> for LinearCombination<E> {
+impl<E: ScalarEngine> Add<Variable> for LinearCombination<E> {
     type Output = LinearCombination<E>;
 
     fn add(self, other: Variable) -> LinearCombination<E> {
@@ -103,7 +231,7 @@ impl<E: Engine> Add<Variable> for LinearCombination<E> {
     }
 }
 
-impl<E: Engine> Sub<Variable> for LinearCombination<E> {
+impl<E: ScalarEngine> Sub<Variable> for LinearCombination<E> {
     type Output = LinearCombination<E>;
 
     fn sub(self, other: Variable) -> LinearCombination<E> {
@@ -111,7 +239,7 @@ impl<E: Engine> Sub<Variable> for LinearCombination<E> {
     }
 }
 
-impl<'a, E: Engine> Add<&'a LinearCombination<E>> for LinearCombination<E> {
+impl<'a, E: ScalarEngine> Add<&'a LinearCombination<E>> for LinearCombination<E> {
     type Output = LinearCombination<E>;
 
     fn add(mut self, other: &'a LinearCombination<E>) -> LinearCombination<E> {
@@ -123,7 +251,7 @@ impl<'a, E: Engine> Add<&'a LinearCombination<E>> for LinearCombination<E> {
     }
 }
 
-impl<'a, E: Engine> Sub<&'a LinearCombination<E>> for LinearCombination<E> {
+impl<'a, E: ScalarEngine> Sub<&'a LinearCombination<E>> for LinearCombination<E> {
     type Output = LinearCombination<E>;
 
     fn sub(mut self, other: &'a LinearCombination<E>) -> LinearCombination<E> {
@@ -135,7 +263,7 @@ impl<'a, E: Engine> Sub<&'a LinearCombination<E>> for LinearCombination<E> {
     }
 }
 
-impl<'a, E: Engine> Add<(E::Fr, &'a LinearCombination<E>)> for LinearCombination<E> {
+impl<'a, E: ScalarEngine> Add<(E::Fr, &'a LinearCombination<E>)> for LinearCombination<E> {
     type Output = LinearCombination<E>;
 
     fn add(mut self, (coeff, other): (E::Fr, &'a LinearCombination<E>)) -> LinearCombination<E> {
@@ -149,7 +277,7 @@ impl<'a, E: Engine> Add<(E::Fr, &'a LinearCombination<E>)> for LinearCombination
     }
 }
 
-impl<'a, E: Engine> Sub<(E::Fr, &'a LinearCombination<E>)> for LinearCombination<E> {
+impl<'a, E: ScalarEngine> Sub<(E::Fr, &'a LinearCombination<E>)> for LinearCombination<E> {
     type Output = LinearCombination<E>;
 
     fn sub(mut self, (coeff, other): (E::Fr, &'a LinearCombination<E>)) -> LinearCombination<E> {
@@ -181,8 +309,8 @@ pub enum SynthesisError {
     IoError(io::Error),
     /// During verification, our verifying key was malformed.
     MalformedVerifyingKey,
-    /// During CRS generation, we observed an unconstrained auxillary variable
-    UnconstrainedVariable
+    /// During CRS generation, we observed an unconstrained auxiliary variable
+    UnconstrainedVariable,
 }
 
 impl From<io::Error> for SynthesisError {
@@ -194,21 +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 => "auxillary variable was unconstrained"
+            SynthesisError::UnconstrainedVariable => "auxiliary variable was unconstrained",
         }
     }
 }
 
 impl fmt::Display for SynthesisError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        if let &SynthesisError::IoError(ref e) = self {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+        if let SynthesisError::IoError(ref e) = *self {
             write!(f, "I/O error: ")?;
             e.fmt(f)
         } else {
@@ -219,7 +349,7 @@ impl fmt::Display for SynthesisError {
 
 /// Represents a constraint system which can have new variables
 /// allocated and constrains between them formed.
-pub trait ConstraintSystem<E: Engine>: Sized {
+pub trait ConstraintSystem<E: ScalarEngine>: Sized {
     /// Represents the type of the "root" of this constraint system
     /// so that nested namespaces can minimize indirection.
     type Root: ConstraintSystem<E>;
@@ -233,32 +363,26 @@ pub trait ConstraintSystem<E: Engine>: 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>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>;
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    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>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>;
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    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>(
-        &mut self,
-        annotation: A,
-        a: LA,
-        b: LB,
-        c: LC
-    )
-        where A: FnOnce() -> AR, AR: Into<String>,
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
+    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>;
@@ -266,7 +390,9 @@ pub trait ConstraintSystem<E: Engine>: Sized {
     /// 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.
@@ -277,11 +403,10 @@ pub trait ConstraintSystem<E: Engine>: Sized {
     fn get_root(&mut self) -> &mut Self::Root;
 
     /// Begin a namespace for this constraint system.
-    fn namespace<'a, NR, N>(
-        &'a mut self,
-        name_fn: N
-    ) -> Namespace<'a, E, Self::Root>
-        where NR: Into<String>, N: FnOnce() -> NR
+    fn namespace<NR, N>(&mut self, name_fn: N) -> Namespace<'_, E, Self::Root>
+    where
+        NR: Into<String>,
+        N: FnOnce() -> NR,
     {
         self.get_root().push_namespace(name_fn);
 
@@ -291,46 +416,40 @@ pub trait ConstraintSystem<E: Engine>: 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: Engine, 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: Engine, CS: ConstraintSystem<E>> ConstraintSystem<E> for Namespace<'cs, E, CS> {
+impl<'cs, E: ScalarEngine, CS: ConstraintSystem<E>> ConstraintSystem<E> for Namespace<'cs, E, CS> {
     type Root = CS::Root;
 
     fn one() -> Variable {
         CS::one()
     }
 
-    fn alloc<F, A, AR>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    where
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
+        A: FnOnce() -> AR,
+        AR: Into<String>,
     {
         self.0.alloc(annotation, f)
     }
 
-    fn alloc_input<F, A, AR>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    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>(
-        &mut self,
-        annotation: A,
-        a: LA,
-        b: LB,
-        c: LC
-    )
-        where A: FnOnce() -> AR, AR: Into<String>,
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
+    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>
+        LC: FnOnce(LinearCombination<E>) -> LinearCombination<E>,
     {
         self.0.enforce(annotation, a, b, c)
     }
@@ -340,23 +459,23 @@ impl<'cs, E: Engine, CS: ConstraintSystem<E>> ConstraintSystem<E> for Namespace<
     // 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()
     }
 }
 
-impl<'a, E: Engine, CS: ConstraintSystem<E>> Drop for Namespace<'a, E, CS> {
+impl<'a, E: ScalarEngine, CS: ConstraintSystem<E>> Drop for Namespace<'a, E, CS> {
     fn drop(&mut self) {
         self.get_root().pop_namespace()
     }
@@ -364,61 +483,55 @@ impl<'a, E: Engine, CS: ConstraintSystem<E>> Drop for Namespace<'a, E, CS> {
 
 /// Convenience implementation of ConstraintSystem<E> for mutable references to
 /// constraint systems.
-impl<'cs, E: Engine, CS: ConstraintSystem<E>> ConstraintSystem<E> for &'cs mut CS {
+impl<'cs, E: ScalarEngine, CS: ConstraintSystem<E>> ConstraintSystem<E> for &'cs mut CS {
     type Root = CS::Root;
 
     fn one() -> Variable {
         CS::one()
     }
 
-    fn alloc<F, A, AR>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    where
+        F: FnOnce() -> Result<E::Fr, SynthesisError>,
+        A: FnOnce() -> AR,
+        AR: Into<String>,
     {
         (**self).alloc(annotation, f)
     }
 
-    fn alloc_input<F, A, AR>(
-        &mut self,
-        annotation: A,
-        f: F
-    ) -> Result<Variable, SynthesisError>
-        where F: FnOnce() -> Result<E::Fr, SynthesisError>, A: FnOnce() -> AR, AR: Into<String>
+    fn alloc_input<F, A, AR>(&mut self, annotation: A, f: F) -> Result<Variable, SynthesisError>
+    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>(
-        &mut self,
-        annotation: A,
-        a: LA,
-        b: LB,
-        c: LC
-    )
-        where A: FnOnce() -> AR, AR: Into<String>,
+    fn enforce<A, AR, LA, LB, LC>(&mut self, annotation: A, a: LA, b: LB, c: LC)
+    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>
+        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

@@ -1,18 +1,21 @@
-//! This is an interface for dealing with the kinds of
-//! parallel computations involved in bellman. It's
-//! currently just a thin wrapper around CpuPool and
-//! crossbeam but may be extended in the future to
-//! allow for various parallelism strategies.
+//! An interface for dealing with the kinds of parallel computations involved in
+//! `bellman`. It's currently just a thin wrapper around [`CpuPool`] and
+//! [`crossbeam`] but may be extended in the future to allow for various
+//! parallelism strategies.
+//!
+//! [`CpuPool`]: futures_cpupool::CpuPool
 
-use num_cpus;
+#[cfg(feature = "multicore")]
+mod implementation {
+    use crossbeam::{self, thread::Scope};
     use futures::{Future, IntoFuture, Poll};
-use futures_cpupool::{CpuPool, CpuFuture};
-use crossbeam::{self, Scope};
+    use futures_cpupool::{CpuFuture, CpuPool};
+    use num_cpus;
 
     #[derive(Clone)]
     pub struct Worker {
         cpus: usize,
-    pool: CpuPool
+        pool: CpuPool,
     }
 
     impl Worker {
@@ -21,8 +24,8 @@ impl Worker {
         // CPUs configured.
         pub(crate) fn new_with_cpus(cpus: usize) -> Worker {
             Worker {
-            cpus: cpus,
-            pool: CpuPool::new(cpus)
+                cpus,
+                pool: CpuPool::new(cpus),
             }
         }
 
@@ -34,26 +37,22 @@ impl Worker {
             log2_floor(self.cpus)
         }
 
-    pub fn compute<F, R>(
-        &self, f: F
-    ) -> WorkerFuture<R::Item, R::Error>
-        where F: FnOnce() -> R + Send + 'static,
+        pub fn compute<F, R>(&self, f: F) -> WorkerFuture<R::Item, R::Error>
+        where
+            F: FnOnce() -> R + Send + 'static,
             R: IntoFuture + 'static,
             R::Future: 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>(
-        &self,
-        elements: usize,
-        f: F
-    ) -> R
-        where F: FnOnce(&Scope<'a>, usize) -> R
+        pub fn scope<'a, F, R>(&self, elements: usize, f: F) -> R
+        where
+            F: FnOnce(&Scope<'a>, usize) -> R,
         {
             let chunk_size = if elements < self.cpus {
                 1
@@ -61,22 +60,21 @@ impl Worker {
                 elements / self.cpus
             };
 
-        crossbeam::scope(|scope| {
-            f(scope, chunk_size)
-        })
+            // TODO: Handle case where threads fail
+            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()
         }
     }
@@ -104,3 +102,63 @@ fn test_log2_floor() {
         assert_eq!(log2_floor(7), 2);
         assert_eq!(log2_floor(8), 3);
     }
+}
+
+#[cfg(not(feature = "multicore"))]
+mod implementation {
+    use futures::{future, Future, IntoFuture, Poll};
+
+    #[derive(Clone)]
+    pub struct Worker;
+
+    impl Worker {
+        pub fn new() -> Worker {
+            Worker
+        }
+
+        pub fn log_num_cpus(&self) -> u32 {
+            0
+        }
+
+        pub fn compute<F, R>(&self, f: F) -> R::Future
+        where
+            F: FnOnce() -> R + Send + 'static,
+            R: IntoFuture + 'static,
+            R::Future: Send + 'static,
+            R::Item: Send + 'static,
+            R::Error: Send + 'static,
+        {
+            f().into_future()
+        }
+
+        pub fn scope<F, R>(&self, elements: usize, f: F) -> R
+        where
+            F: FnOnce(&DummyScope, usize) -> R,
+        {
+            f(&DummyScope, elements)
+        }
+    }
+
+    pub struct WorkerFuture<T, E> {
+        future: future::FutureResult<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> {
+            self.future.poll()
+        }
+    }
+
+    pub struct DummyScope;
+
+    impl DummyScope {
+        pub fn spawn<F: FnOnce(&DummyScope)>(&self, f: F) {
+            f(self);
+        }
+    }
+}
+
+pub use self::implementation::*;

bellman/src/multiexp.rs

@@ -1,17 +1,11 @@
-use pairing::{
-    CurveAffine,
-    CurveProjective,
-    Engine,
-    PrimeField,
-    Field,
-    PrimeFieldRepr
-};
-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;
 
@@ -25,7 +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>;
@@ -40,13 +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]);
@@ -58,7 +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;
@@ -98,7 +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 {
@@ -117,7 +125,7 @@ impl DensityTracker {
     pub fn new() -> DensityTracker {
         DensityTracker {
             bv: BitVec::new(),
-            total_density: 0
+            total_density: 0,
         }
     }
 
@@ -141,15 +149,16 @@ fn multiexp_inner<Q, D, G, S>(
     pool: &Worker,
     bases: S,
     density_map: D,
-    exponents: Arc<Vec<<<G::Engine as Engine>::Fr as PrimeField>::Repr>>,
+    exponents: Arc<Vec<<<G::Engine as ScalarEngine>::Fr as PrimeField>::Repr>>,
     mut skip: u32,
     c: u32,
-    handle_trivial: bool
-) -> Box<Future<Item=<G as CurveAffine>::Projective, Error=SynthesisError>>
-    where for<'a> &'a Q: QueryDensity,
+    handle_trivial: bool,
+) -> Box<dyn Future<Item = <G as CurveAffine>::Projective, Error = SynthesisError>>
+where
+    for<'a> &'a Q: QueryDensity,
     D: Send + Sync + 'static + Clone + AsRef<Q>,
     G: CurveAffine,
-          S: SourceBuilder<G>
+    S: SourceBuilder<G>,
 {
     // Perform this region of the multiexp
     let this = {
@@ -167,8 +176,8 @@ fn multiexp_inner<Q, D, G, S>(
             // Create space for the buckets
             let mut buckets = vec![<G as CurveAffine>::Projective::zero(); (1 << c) - 1];
 
-            let zero = <G::Engine as Engine>::Fr::zero().into_repr();
-            let one = <G::Engine as Engine>::Fr::one().into_repr();
+            let zero = <G::Engine as ScalarEngine>::Fr::zero().into_repr();
+            let one = <G::Engine as ScalarEngine>::Fr::one().into_repr();
 
             // Sort the bases into buckets
             for (&exp, density) in exponents.iter().zip(density_map.as_ref().iter()) {
@@ -211,14 +220,22 @@ fn multiexp_inner<Q, D, G, S>(
 
     skip += c;
 
-    if skip >= <G::Engine as Engine>::Fr::NUM_BITS {
+    if skip >= <G::Engine as ScalarEngine>::Fr::NUM_BITS {
         // There isn't another region.
         Box::new(this)
     } else {
         // 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(
+                pool,
+                bases,
+                density_map,
+                exponents,
+                skip,
+                c,
+                false,
+            ))
             .map(move |(this, mut higher)| {
                 for _ in 0..c {
                     higher.double();
@@ -227,7 +244,7 @@ fn multiexp_inner<Q, D, G, S>(
                 higher.add_assign(&this);
 
                 higher
-                })
+            }),
         )
     }
 }
@@ -238,12 +255,13 @@ pub fn multiexp<Q, D, G, S>(
     pool: &Worker,
     bases: S,
     density_map: D,
-    exponents: Arc<Vec<<<G::Engine as Engine>::Fr as PrimeField>::Repr>>
-) -> Box<Future<Item=<G as CurveAffine>::Projective, Error=SynthesisError>>
-    where for<'a> &'a Q: QueryDensity,
+    exponents: Arc<Vec<<<G::Engine as ScalarEngine>::Fr as PrimeField>::Repr>>,
+) -> Box<dyn Future<Item = <G as CurveAffine>::Projective, Error = SynthesisError>>
+where
+    for<'a> &'a Q: QueryDensity,
     D: Send + Sync + 'static + Clone + AsRef<Q>,
     G: CurveAffine,
-          S: SourceBuilder<G>
+    S: SourceBuilder<G>,
 {
     let c = if exponents.len() < 32 {
         3u32
@@ -261,13 +279,13 @@ pub fn multiexp<Q, D, G, S>(
     multiexp_inner(pool, bases, density_map, exponents, 0, c, true)
 }
 
+#[cfg(feature = "pairing")]
 #[test]
 fn test_with_bls12() {
     fn naive_multiexp<G: CurveAffine>(
         bases: Arc<Vec<G>>,
-        exponents: Arc<Vec<<G::Scalar as PrimeField>::Repr>>
-    ) -> G::Projective
-    {
+        exponents: Arc<Vec<<G::Scalar as PrimeField>::Repr>>,
+    ) -> G::Projective {
         assert_eq!(bases.len(), exponents.len());
 
         let mut acc = G::Projective::zero();
@@ -279,25 +297,28 @@ fn test_with_bls12() {
         acc
     }
 
-    use rand::{self, Rand};
-    use pairing::bls12_381::Bls12;
+    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 Engine>::Fr::rand(rng).into_repr()).collect::<Vec<_>>());
-    let g = Arc::new((0..SAMPLES).map(|_| <Bls12 as Engine>::G1::rand(rng).into_affine()).collect::<Vec<_>>());
+    let v = Arc::new(
+        (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(
-        &pool,
-        (g, 0),
-        FullDensity,
-        v
-    ).wait().unwrap();
+    let fast = multiexp(&pool, (g, 0), FullDensity, v).wait().unwrap();
 
     assert_eq!(naive, fast);
 }

bellman/tests/mimc.rs

@@ -1,38 +1,22 @@
-extern crate bellman;
-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 pairing::{
-    Engine,
-    Field
-};
+use ff::{Field, ScalarEngine};
+use pairing::Engine;
 
 // We're going to use the BLS12-381 pairing-friendly elliptic curve.
-use pairing::bls12_381::{
-    Bls12
-};
+use pairing::bls12_381::Bls12;
 
 // We'll use these interfaces to construct our circuit.
-use bellman::{
-    Circuit,
-    ConstraintSystem,
-    SynthesisError
-};
+use bellman::{Circuit, ConstraintSystem, SynthesisError};
 
 // We're going to use the Groth16 proving system.
 use bellman::groth16::{
-    Proof,
-    generate_random_parameters,
-    prepare_verifying_key,
-    create_random_proof,
-    verify_proof,
+    create_random_proof, generate_random_parameters, prepare_verifying_key, verify_proof, Proof,
 };
 
 const MIMC_ROUNDS: usize = 322;
@@ -50,12 +34,7 @@ const MIMC_ROUNDS: usize = 322;
 ///     return xL
 /// }
 /// ```
-fn mimc<E: Engine>(
-    mut xl: E::Fr,
-    mut xr: E::Fr,
-    constants: &[E::Fr]
-) -> E::Fr
-{
+fn mimc<E: Engine>(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 {
@@ -77,80 +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>>(
-        self,
-        cs: &mut CS
-    ) -> Result<(), SynthesisError>
-    {
+    fn synthesize<CS: ConstraintSystem<E>>(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", || {
-            xl_value.ok_or(SynthesisError::AssignmentMissing)
-        })?;
+        let mut xl = cs.alloc(
+            || "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", || {
-            xr_value.ok_or(SynthesisError::AssignmentMissing)
-        })?;
+        let mut xr = cs.alloc(
+            || "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", || {
-                tmp_value.ok_or(SynthesisError::AssignmentMissing)
-            })?;
+            let tmp = cs.alloc(
+                || "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", || {
-                    new_xl_value.ok_or(SynthesisError::AssignmentMissing)
-                })?
+                cs.alloc_input(
+                    || "image",
+                    || new_xl_value.ok_or(SynthesisError::AssignmentMissing),
+                )?
             } else {
-                cs.alloc(|| "new_xl", || {
-                    new_xl_value.ok_or(SynthesisError::AssignmentMissing)
-                })?
+                cs.alloc(
+                    || "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
@@ -173,7 +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...");
 
@@ -182,7 +164,7 @@ fn test_mimc() {
         let c = MiMCDemo::<Bls12> {
             xl: None,
             xr: None,
-            constants: &constants
+            constants: &constants,
         };
 
         generate_random_parameters(c, rng).unwrap()
@@ -204,8 +186,8 @@ fn test_mimc() {
 
     for _ in 0..SAMPLES {
         // Generate a random preimage and compute the image
-        let xl = rng.gen();
-        let xr = rng.gen();
+        let xl = <Bls12 as ScalarEngine>::Fr::random(rng);
+        let xr = <Bls12 as ScalarEngine>::Fr::random(rng);
         let image = mimc::<Bls12>(xl, xr, &constants);
 
         proof_vec.truncate(0);
@@ -217,7 +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.
@@ -231,20 +213,16 @@ fn test_mimc() {
         let start = Instant::now();
         let proof = Proof::read(&proof_vec[..]).unwrap();
         // Check the proof
-        assert!(verify_proof(
-            &pvk,
-            &proof,
-            &[image]
-        ).unwrap());
+        assert!(verify_proof(&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
-                      + (proving_avg.as_secs() as f64);
+    let proving_avg =
+        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
-                      + (verifying_avg.as_secs() as f64);
+    let verifying_avg =
+        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/.gitignore

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

ff/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "ff"
+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"
+ff_derive = { version = "^0.4.1", path = "ff_derive", optional = true }
+rand_core = "0.5"
+
+[features]
+default = []
+derive = ["ff_derive"]
+
+[badges]
+maintenance = { status = "actively-developed" }

ff/LICENSE-MIT

@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2017 Zcash Company
+Copyright (c) 2017 Sean Bowe
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

ff/README.md

@@ -0,0 +1,67 @@
+# ff
+
+`ff` is a finite field library written in pure Rust, with no `unsafe{}` code.
+
+## Disclaimers
+
+* This library does not provide constant-time guarantees.
+
+## Usage
+
+Add the `ff` crate to your `Cargo.toml`:
+
+```toml
+[dependencies]
+ff = "0.5"
+```
+
+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.
+
+First, enable the `derive` crate feature:
+
+```toml
+[dependencies]
+ff = { version = "0.4", features = ["derive"] }
+```
+
+And then use the macro like so:
+
+```rust
+extern crate rand;
+#[macro_use]
+extern crate ff;
+
+#[derive(PrimeField)]
+#[PrimeFieldModulus = "52435875175126190479447740508185965837690552500527637822603658699938581184513"]
+#[PrimeFieldGenerator = "7"]
+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.
+
+## 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.

ff/ff_derive/Cargo.toml

@@ -0,0 +1,24 @@
+[package]
+name = "ff_derive"
+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
+
+[dependencies]
+num-bigint = "0.2"
+num-traits = "0.2"
+num-integer = "0.1"
+proc-macro2 = "1"
+quote = "1"
+syn = "1"
+
+[badges]
+maintenance = { status = "passively-maintained" }

ff/src/lib.rs

@@ -0,0 +1,393 @@
+//! 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)]
+
+#[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
+{
+    /// 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;
+
+    /// Returns the one element of the field, the multiplicative identity.
+    fn one() -> Self;
+
+    /// Returns true iff this element is zero.
+    fn is_zero(&self) -> bool;
+
+    /// Squares this element.
+    fn square(&mut self);
+
+    /// Doubles this element.
+    fn double(&mut self);
+
+    /// Negates this element.
+    fn negate(&mut self);
+
+    /// Adds another element to this element.
+    fn add_assign(&mut self, other: &Self);
+
+    /// Subtracts another element from this element.
+    fn sub_assign(&mut self, other: &Self);
+
+    /// Multiplies another element by this element.
+    fn mul_assign(&mut self, other: &Self);
+
+    /// Computes the multiplicative inverse of this element, if nonzero.
+    fn inverse(&self) -> Option<Self>;
+
+    /// Exponentiates this element by a power of the base prime modulus via
+    /// the Frobenius automorphism.
+    fn frobenius_map(&mut self, power: usize);
+
+    /// Exponentiates this element by a number represented with `u64` limbs,
+    /// least significant digit first.
+    fn pow<S: AsRef<[u64]>>(&self, exp: S) -> Self {
+        let mut res = Self::one();
+
+        let mut found_one = false;
+
+        for i in BitIterator::new(exp) {
+            if found_one {
+                res.square();
+            } else {
+                found_one = i;
+            }
+
+            if i {
+                res.mul_assign(self);
+            }
+        }
+
+        res
+    }
+}
+
+/// This trait represents an element of a field that has a square root operation described for it.
+pub trait SqrtField: Field {
+    /// Returns the Legendre symbol of the field element.
+    fn legendre(&self) -> LegendreSymbol;
+
+    /// Returns the square root of the field element, if it is
+    /// quadratic residue.
+    fn sqrt(&self) -> Option<Self>;
+}
+
+/// This trait represents a wrapper around a biginteger which can encode any element of a particular
+/// prime field. It is a smart wrapper around a sequence of `u64` limbs, least-significant digit
+/// first.
+pub trait PrimeFieldRepr:
+    Sized
+    + Copy
+    + Clone
+    + Eq
+    + Ord
+    + Send
+    + Sync
+    + Default
+    + fmt::Debug
+    + fmt::Display
+    + 'static
+    + AsRef<[u64]>
+    + AsMut<[u64]>
+    + From<u64>
+{
+    /// Subtract another represetation from this one.
+    fn sub_noborrow(&mut self, other: &Self);
+
+    /// Add another representation to this one.
+    fn add_nocarry(&mut self, other: &Self);
+
+    /// Compute the number of bits needed to encode this number. Always a
+    /// multiple of 64.
+    fn num_bits(&self) -> u32;
+
+    /// Returns true iff this number is zero.
+    fn is_zero(&self) -> bool;
+
+    /// Returns true iff this number is odd.
+    fn is_odd(&self) -> bool;
+
+    /// Returns true iff this number is even.
+    fn is_even(&self) -> bool;
+
+    /// Performs a rightwise bitshift of this number, effectively dividing
+    /// it by 2.
+    fn div2(&mut self);
+
+    /// Performs a rightwise bitshift of this number by some amount.
+    fn shr(&mut self, amt: u32);
+
+    /// Performs a leftwise bitshift of this number, effectively multiplying
+    /// it by 2. Overflow is ignored.
+    fn mul2(&mut self);
+
+    /// Performs a leftwise bitshift of this number by some amount.
+    fn shl(&mut self, amt: u32);
+
+    /// Writes this `PrimeFieldRepr` as a big endian integer.
+    fn write_be<W: Write>(&self, mut writer: W) -> io::Result<()> {
+        use byteorder::{BigEndian, WriteBytesExt};
+
+        for digit in self.as_ref().iter().rev() {
+            writer.write_u64::<BigEndian>(*digit)?;
+        }
+
+        Ok(())
+    }
+
+    /// Reads a big endian integer into this representation.
+    fn read_be<R: Read>(&mut self, mut reader: R) -> io::Result<()> {
+        use byteorder::{BigEndian, ReadBytesExt};
+
+        for digit in self.as_mut().iter_mut().rev() {
+            *digit = reader.read_u64::<BigEndian>()?;
+        }
+
+        Ok(())
+    }
+
+    /// Writes this `PrimeFieldRepr` as a little endian integer.
+    fn write_le<W: Write>(&self, mut writer: W) -> io::Result<()> {
+        use byteorder::{LittleEndian, WriteBytesExt};
+
+        for digit in self.as_ref().iter() {
+            writer.write_u64::<LittleEndian>(*digit)?;
+        }
+
+        Ok(())
+    }
+
+    /// Reads a little endian integer into this representation.
+    fn read_le<R: Read>(&mut self, mut reader: R) -> io::Result<()> {
+        use byteorder::{LittleEndian, ReadBytesExt};
+
+        for digit in self.as_mut().iter_mut() {
+            *digit = reader.read_u64::<LittleEndian>()?;
+        }
+
+        Ok(())
+    }
+}
+
+#[derive(Debug, PartialEq)]
+pub enum LegendreSymbol {
+    Zero = 0,
+    QuadraticResidue = 1,
+    QuadraticNonResidue = -1,
+}
+
+/// An error that may occur when trying to interpret a `PrimeFieldRepr` as a
+/// `PrimeField` element.
+#[derive(Debug)]
+pub enum PrimeFieldDecodingError {
+    /// The encoded value is not in the field
+    NotInField(String),
+}
+
+impl Error for PrimeFieldDecodingError {
+    fn description(&self) -> &str {
+        match *self {
+            PrimeFieldDecodingError::NotInField(..) => "not an element of the field",
+        }
+    }
+}
+
+impl fmt::Display for PrimeFieldDecodingError {
+    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)
+            }
+        }
+    }
+}
+
+/// This represents an element of a prime field.
+pub trait PrimeField: Field {
+    /// The prime field can be converted back and forth into this biginteger
+    /// representation.
+    type Repr: PrimeFieldRepr + From<Self>;
+
+    /// Interpret a string of numbers as a (congruent) prime field element.
+    /// Does not accept unnecessary leading zeroes or a blank string.
+    fn from_str(s: &str) -> Option<Self> {
+        if s.is_empty() {
+            return None;
+        }
+
+        if s == "0" {
+            return Some(Self::zero());
+        }
+
+        let mut res = Self::zero();
+
+        let ten = Self::from_repr(Self::Repr::from(10)).unwrap();
+
+        let mut first_digit = true;
+
+        for c in s.chars() {
+            match c.to_digit(10) {
+                Some(c) => {
+                    if first_digit {
+                        if c == 0 {
+                            return None;
+                        }
+
+                        first_digit = false;
+                    }
+
+                    res.mul_assign(&ten);
+                    res.add_assign(&Self::from_repr(Self::Repr::from(u64::from(c))).unwrap());
+                }
+                None => {
+                    return None;
+                }
+            }
+        }
+
+        Some(res)
+    }
+
+    /// Convert this prime field element into a biginteger representation.
+    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.
+    fn into_repr(&self) -> Self::Repr;
+
+    /// Returns the field characteristic; the modulus.
+    fn char() -> Self::Repr;
+
+    /// How many bits are needed to represent an element of this field.
+    const NUM_BITS: u32;
+
+    /// How many bits of information can be reliably stored in the field element.
+    const CAPACITY: u32;
+
+    /// Returns the multiplicative generator of `char()` - 1 order. This element
+    /// must also be quadratic nonresidue.
+    fn multiplicative_generator() -> Self;
+
+    /// 2^s * t = `char()` - 1 with t odd.
+    const S: u32;
+
+    /// Returns the 2^s root of unity computed by exponentiating the `multiplicative_generator()`
+    /// by t.
+    fn root_of_unity() -> Self;
+}
+
+/// An "engine" is a collection of types (fields, elliptic curve groups, etc.)
+/// with well-defined relationships. Specific relationships (for example, a
+/// pairing-friendly curve) can be defined in a subtrait.
+pub trait ScalarEngine: Sized + 'static + Clone {
+    /// This is the scalar field of the engine's groups.
+    type Fr: PrimeField + SqrtField;
+}
+
+#[derive(Debug)]
+pub struct BitIterator<E> {
+    t: E,
+    n: usize,
+}
+
+impl<E: AsRef<[u64]>> BitIterator<E> {
+    pub fn new(t: E) -> Self {
+        let n = t.as_ref().len() * 64;
+
+        BitIterator { t, n }
+    }
+}
+
+impl<E: AsRef<[u64]>> Iterator for BitIterator<E> {
+    type Item = bool;
+
+    fn next(&mut self) -> Option<bool> {
+        if self.n == 0 {
+            None
+        } else {
+            self.n -= 1;
+            let part = self.n / 64;
+            let bit = self.n - (64 * part);
+
+            Some(self.t.as_ref()[part] & (1 << bit) > 0)
+        }
+    }
+}
+
+#[test]
+fn test_bit_iterator() {
+    let mut a = BitIterator::new([0xa953d79b83f6ab59, 0x6dea2059e200bd39]);
+    let expected = "01101101111010100010000001011001111000100000000010111101001110011010100101010011110101111001101110000011111101101010101101011001";
+
+    for e in expected.chars() {
+        assert!(a.next().unwrap() == (e == '1'));
+    }
+
+    assert!(a.next().is_none());
+
+    let expected = "1010010101111110101010000101101011101000011101110101001000011001100100100011011010001011011011010001011011101100110100111011010010110001000011110100110001100110011101101000101100011100100100100100001010011101010111110011101011000011101000111011011101011001";
+
+    let mut a = BitIterator::new([
+        0x429d5f3ac3a3b759,
+        0xb10f4c66768b1c92,
+        0x92368b6d16ecd3b4,
+        0xa57ea85ae8775219,
+    ]);
+
+    for e in expected.chars() {
+        assert!(a.next().unwrap() == (e == '1'));
+    }
+
+    assert!(a.next().is_none());
+}
+
+pub use self::arith_impl::*;
+
+mod arith_impl {
+    /// Calculate a - b - borrow, returning the result and modifying
+    /// the borrow value.
+    #[inline(always)]
+    pub fn sbb(a: u64, b: u64, borrow: &mut u64) -> u64 {
+        let tmp = (1u128 << 64) + u128::from(a) - u128::from(b) - u128::from(*borrow);
+
+        *borrow = if tmp >> 64 == 0 { 1 } else { 0 };
+
+        tmp as u64
+    }
+
+    /// Calculate a + b + carry, returning the sum and modifying the
+    /// carry value.
+    #[inline(always)]
+    pub fn adc(a: u64, b: u64, carry: &mut u64) -> u64 {
+        let tmp = u128::from(a) + u128::from(b) + u128::from(*carry);
+
+        *carry = (tmp >> 64) as u64;
+
+        tmp as u64
+    }
+
+    /// Calculate a + (b * c) + carry, returning the least significant digit
+    /// and setting carry to the most significant digit.
+    #[inline(always)]
+    pub fn mac_with_carry(a: u64, b: u64, c: u64, carry: &mut u64) -> u64 {
+        let tmp = (u128::from(a)) + u128::from(b) * u128::from(c) + u128::from(*carry);
+
+        *carry = (tmp >> 64) as u64;
+
+        tmp as u64
+    }
+}

group/COPYRIGHT

@@ -1,7 +1,7 @@
-Copyrights in the "zip32" library are retained by their contributors. No
-copyright assignment is required to contribute to the "zip32" library.
+Copyrights in the "group" library are retained by their contributors. No
+copyright assignment is required to contribute to the "group" library.
 
-The "zip32" library is licensed under either of
+The "group" 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)

group/Cargo.toml

@@ -0,0 +1,23 @@
+[package]
+name = "group"
+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 = { version = "0.5.0", path = "../ff" }
+rand = "0.7"
+rand_xorshift = "0.2"
+
+[badges]
+maintenance = { status = "actively-developed" }

group/README.md

@@ -1,10 +1,13 @@
-# zip32 [![Crates.io](https://img.shields.io/crates/v/zip32.svg)](https://crates.io/crates/zip32) #
+# 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

@@ -0,0 +1,190 @@
+// Catch documentation errors caused by code changes.
+#![deny(intra_doc_link_resolution_failure)]
+
+use ff::{PrimeField, PrimeFieldDecodingError, ScalarEngine, SqrtField};
+use rand::RngCore;
+use std::error::Error;
+use std::fmt;
+
+pub mod tests;
+
+mod wnaf;
+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 + Eq + Sized + Copy + Clone + Send + Sync + fmt::Debug + fmt::Display + '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;
+
+    /// Returns a fixed generator of unknown exponent.
+    fn one() -> Self;
+
+    /// Determines if this point is the point at infinity.
+    fn is_zero(&self) -> bool;
+
+    /// Normalizes a slice of projective elements so that
+    /// conversion to affine is cheap.
+    fn batch_normalization(v: &mut [Self]);
+
+    /// Checks if the point is already "normalized" so that
+    /// cheap affine conversion is possible.
+    fn is_normalized(&self) -> bool;
+
+    /// Doubles this element.
+    fn double(&mut self);
+
+    /// Adds another element to this element.
+    fn add_assign(&mut self, other: &Self);
+
+    /// Subtracts another element from this element.
+    fn sub_assign(&mut self, other: &Self) {
+        let mut tmp = *other;
+        tmp.negate();
+        self.add_assign(&tmp);
+    }
+
+    /// Adds an affine element to this element.
+    fn add_assign_mixed(&mut self, other: &Self::Affine);
+
+    /// Negates this element.
+    fn negate(&mut self);
+
+    /// Performs scalar multiplication of this element.
+    fn mul_assign<S: Into<<Self::Scalar as PrimeField>::Repr>>(&mut self, other: S);
+
+    /// Converts this element into its affine representation.
+    fn into_affine(&self) -> Self::Affine;
+
+    /// Recommends a wNAF window table size given a scalar. Always returns a number
+    /// between 2 and 22, inclusive.
+    fn recommended_wnaf_for_scalar(scalar: <Self::Scalar as PrimeField>::Repr) -> usize;
+
+    /// Recommends a wNAF window size given the number of scalars you intend to multiply
+    /// a base by. Always returns a number between 2 and 22, inclusive.
+    fn recommended_wnaf_for_num_scalars(num_scalars: usize) -> usize;
+}
+
+/// Affine representation of an elliptic curve point guaranteed to be
+/// in the correct prime order subgroup.
+pub trait CurveAffine:
+    Copy + Clone + Sized + Send + Sync + fmt::Debug + fmt::Display + PartialEq + Eq + 'static
+{
+    type Engine: ScalarEngine<Fr = Self::Scalar>;
+    type Scalar: PrimeField + SqrtField;
+    type Base: SqrtField;
+    type Projective: CurveProjective<Affine = Self, Scalar = Self::Scalar>;
+    type Uncompressed: EncodedPoint<Affine = Self>;
+    type Compressed: EncodedPoint<Affine = Self>;
+
+    /// Returns the additive identity.
+    fn zero() -> Self;
+
+    /// Returns a fixed generator of unknown exponent.
+    fn one() -> Self;
+
+    /// Determines if this point represents the point at infinity; the
+    /// additive identity.
+    fn is_zero(&self) -> bool;
+
+    /// Negates this element.
+    fn negate(&mut self);
+
+    /// Performs scalar multiplication of this element with mixed addition.
+    fn mul<S: Into<<Self::Scalar as PrimeField>::Repr>>(&self, other: S) -> Self::Projective;
+
+    /// Converts this element into its affine representation.
+    fn into_projective(&self) -> Self::Projective;
+
+    /// Converts this element into its compressed encoding, so long as it's not
+    /// the point at infinity.
+    fn into_compressed(&self) -> Self::Compressed {
+        <Self::Compressed as EncodedPoint>::from_affine(*self)
+    }
+
+    /// Converts this element into its uncompressed encoding, so long as it's not
+    /// the point at infinity.
+    fn into_uncompressed(&self) -> Self::Uncompressed {
+        <Self::Uncompressed as EncodedPoint>::from_affine(*self)
+    }
+}
+
+/// An encoded elliptic curve point, which should essentially wrap a `[u8; N]`.
+pub trait EncodedPoint:
+    Sized + Send + Sync + AsRef<[u8]> + AsMut<[u8]> + Clone + Copy + 'static
+{
+    type Affine: CurveAffine;
+
+    /// Creates an empty representation.
+    fn empty() -> Self;
+
+    /// Returns the number of bytes consumed by this representation.
+    fn size() -> usize;
+
+    /// Converts an `EncodedPoint` into a `CurveAffine` element,
+    /// if the encoding represents a valid element.
+    fn into_affine(&self) -> Result<Self::Affine, GroupDecodingError>;
+
+    /// Converts an `EncodedPoint` into a `CurveAffine` element,
+    /// without guaranteeing that the encoding represents a valid
+    /// element. This is useful when the caller knows the encoding is
+    /// valid already.
+    ///
+    /// If the encoding is invalid, this can break API invariants,
+    /// so caution is strongly encouraged.
+    fn into_affine_unchecked(&self) -> Result<Self::Affine, GroupDecodingError>;
+
+    /// Creates an `EncodedPoint` from an affine point, as long as the
+    /// point is not the point at infinity.
+    fn from_affine(affine: Self::Affine) -> Self;
+}
+
+/// An error that may occur when trying to decode an `EncodedPoint`.
+#[derive(Debug)]
+pub enum GroupDecodingError {
+    /// The coordinate(s) do not lie on the curve.
+    NotOnCurve,
+    /// The element is not part of the r-order subgroup.
+    NotInSubgroup,
+    /// One of the coordinates could not be decoded
+    CoordinateDecodingError(&'static str, PrimeFieldDecodingError),
+    /// The compression mode of the encoded element was not as expected
+    UnexpectedCompressionMode,
+    /// The encoding contained bits that should not have been set
+    UnexpectedInformation,
+}
+
+impl Error for GroupDecodingError {
+    fn description(&self) -> &str {
+        match *self {
+            GroupDecodingError::NotOnCurve => "coordinate(s) do not lie on the curve",
+            GroupDecodingError::NotInSubgroup => "the element is not part of an r-order subgroup",
+            GroupDecodingError::CoordinateDecodingError(..) => "coordinate(s) could not be decoded",
+            GroupDecodingError::UnexpectedCompressionMode => {
+                "encoding has unexpected compression mode"
+            }
+            GroupDecodingError::UnexpectedInformation => "encoding has unexpected information",
+        }
+    }
+}
+
+impl fmt::Display for GroupDecodingError {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> Result<(), fmt::Error> {
+        match *self {
+            GroupDecodingError::CoordinateDecodingError(description, ref err) => {
+                write!(f, "{} decoding error: {}", description, err)
+            }
+            _ => write!(f, "{}", self.description()),
+        }
+    }
+}

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, Field};
+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);
@@ -45,7 +50,7 @@ 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()
@@ -66,10 +71,12 @@ pub fn curve_tests<G: CurveProjective>() {
 }
 
 fn random_wnaf_tests<G: CurveProjective>() {
-    use wnaf::*;
-    use PrimeField;
+    use crate::wnaf::*;
 
-    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 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 s = G::Scalar::rand(&mut rng).into_repr();
+                let g = G::random(&mut rng);
+                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 s = G::Scalar::rand(&mut rng).into_repr();
+            let g = G::random(&mut rng);
+            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();
 
@@ -179,12 +190,15 @@ fn random_wnaf_tests<G: CurveProjective>() {
 }
 
 fn random_negation_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 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();
 
@@ -208,11 +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 b = G::rand(&mut rng);
+        let mut a = G::random(&mut rng);
+        let mut b = G::random(&mut rng);
 
         // 2(a + b)
         let mut tmp1 = a;
@@ -235,15 +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 b = G::rand(&mut rng);
+        let mut a = G::random(&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;
@@ -267,12 +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 b = G::rand(&mut rng);
-        let c = G::rand(&mut rng);
+        let a = G::random(&mut rng);
+        let b = G::random(&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();
@@ -345,10 +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);
@@ -356,20 +382,20 @@ 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};
-        let between = Range::new(0, 1000);
+        use rand::distributions::{Distribution, Uniform};
+        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();
         }
 
@@ -388,7 +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(),
@@ -401,7 +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();

group/src/wnaf.rs

@@ -1,4 +1,6 @@
-use super::{CurveProjective, PrimeField, PrimeFieldRepr};
+use ff::{PrimeField, PrimeFieldRepr};
+
+use super::CurveProjective;
 
 /// Replaces the contents of `table` with a w-NAF window table for the given window size.
 pub(crate) fn wnaf_table<G: CurveProjective>(table: &mut Vec<G>, mut base: G, window: usize) {

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"
@@ -14,15 +20,17 @@ path = "src/rustzcash.rs"
 crate-type = ["staticlib"]
 
 [dependencies]
-bellman = { path = "../bellman" }
+bellman = { version = "0.2.0", path = "../bellman" }
+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 = "0.4"
-sapling-crypto = { path = "../sapling-crypto" }
-zip32 = { path = "../zip32" }
+rand_core = "0.5.1"
+zcash_history = { version = "0.0.1", path = "../zcash_history" }
+zcash_primitives = { version = "0.1.0", path = "../zcash_primitives" }
+zcash_proofs = { version = "0.1.0", path = "../zcash_proofs" }
 
-[dependencies.blake2-rfc]
-git = "https://github.com/gtank/blake2-rfc"
-rev = "7a5b5fc99ae483a0043db7547fb79a6fa44b88a9"
+[badges]
+maintenance = { status = "deprecated" }

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

@@ -4,6 +4,12 @@
 #include <stdint.h>
 
 extern "C" {
+#ifdef WIN32
+    typedef uint16_t codeunit;
+#else
+    typedef uint8_t codeunit;
+#endif
+
     void librustzcash_to_scalar(const unsigned char *input, unsigned char *result);
 
     void librustzcash_ask_to_ak(const unsigned char *ask, unsigned char *result);
@@ -19,11 +25,14 @@ extern "C" {
     /// Loads the zk-SNARK parameters into memory and saves
     /// paths as necessary. Only called once.
     void librustzcash_init_zksnark_params(
-        const char* spend_path,
+        const codeunit* spend_path,
+        size_t spend_path_len,
         const char* spend_hash,
-        const char* output_path,
+        const codeunit* output_path,
+        size_t output_path_len,
         const char* output_hash,
-        const char* sprout_path,
+        const codeunit* sprout_path,
+        size_t sprout_path_len,
         const char* sprout_hash
     );
 
@@ -103,8 +112,7 @@ extern "C" {
     bool librustzcash_sapling_output_proof(
         void *ctx,
         const unsigned char *esk,
-        const unsigned char *diversifier,
-        const unsigned char *pk_d,
+        const unsigned char *payment_address,
         const unsigned char *rcm,
         const uint64_t value,
         unsigned char *cv,
@@ -299,6 +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 pairing::{PrimeField, PrimeFieldRepr};
-use rand::{OsRng, Rng};
-use sapling_crypto::jubjub::{edwards, JubjubBls12};
-use sapling_crypto::primitives::{Diversifier, ViewingKey};
+use rand_core::{OsRng, RngCore};
+use zcash_primitives::jubjub::{edwards, JubjubBls12};
+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

@@ -1,12 +1,13 @@
-use pairing::{bls12_381::Bls12, PrimeField, PrimeFieldRepr};
-use sapling_crypto::{
+use ff::{PrimeField, PrimeFieldRepr};
+use pairing::bls12_381::Bls12;
+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,
 };
@@ -27,6 +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
@@ -86,6 +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: [
@@ -142,6 +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: [
@@ -198,6 +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: [
@@ -254,6 +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: [
@@ -310,6 +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: [
@@ -366,6 +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: [
@@ -422,6 +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: [
@@ -478,6 +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: [
@@ -534,6 +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: [
@@ -590,6 +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,
+            ],
         },
     ];
 
@@ -615,7 +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();
@@ -641,10 +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);
         }
         {
@@ -662,5 +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 librustzcash_sapling_compute_nf;
+use crate::librustzcash_sapling_compute_cm;
+use crate::librustzcash_sapling_compute_nf;
 
 #[test]
 fn notes() {

librustzcash/src/tests/signatures.rs

@@ -1,8 +1,7 @@
-use pairing::{bls12_381::Bls12, PrimeField, PrimeFieldRepr};
-use sapling_crypto::{
-    jubjub::{FixedGenerators, JubjubEngine},
-    redjubjub::{PrivateKey, PublicKey, Signature},
-};
+use ff::{PrimeField, PrimeFieldRepr};
+use pairing::bls12_381::Bls12;
+use zcash_primitives::jubjub::{FixedGenerators, JubjubEngine};
+use zcash_primitives::redjubjub::{PrivateKey, PublicKey, Signature};
 
 use super::JUBJUB;
 

pairing/Cargo.toml

@@ -2,22 +2,33 @@
 name = "pairing"
 
 # Remember to change version string in README.md.
-version = "0.14.2"
-authors = ["Sean Bowe <ewillbefull@gmail.com>"]
+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"
-clippy = { version = "0.0.200", optional = true }
+ff = { version = "^0.5.2", path = "../ff", features = ["derive"] }
+group = { version = "0.2.0", path = "../group" }
+rand_core = "0.5"
+
+[dev-dependencies]
+rand_xorshift = "0.2"
 
 [features]
 unstable-features = ["expose-arith"]
 expose-arith = []
-u128-support = []
 default = []
+
+[badges]
+maintenance = { status = "actively-developed" }

pairing/README.md

@@ -1,28 +1,32 @@
 # 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/)
 
 Bring the `pairing` crate into your project just as you normally would.
 
-If you're using a supported platform and the nightly Rust compiler, you can enable the `u128-support` feature for faster arithmetic.
-
-```toml
-[dependencies.pairing]
-version = "0.14"
-features = ["u128-support"]
-```
-
 ## 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

@@ -1,17 +1,22 @@
 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::*;
-    use pairing::CurveProjective;
 
     #[bench]
     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;
@@ -63,19 +74,24 @@ 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::*;
-    use pairing::CurveProjective;
 
     #[bench]
     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

@@ -1,18 +1,22 @@
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
+use ff::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 use pairing::bls12_381::*;
-use pairing::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 
 #[bench]
 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 tmp2 = FqRepr::rand(&mut rng);
+            let mut tmp1 = Fq::random(&mut rng).into_repr();
+            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

@@ -1,16 +1,20 @@
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
+use ff::Field;
 use pairing::bls12_381::*;
-use pairing::Field;
 
 #[bench]
 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

@@ -1,16 +1,20 @@
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
+use ff::{Field, SqrtField};
 use pairing::bls12_381::*;
-use pairing::{Field, SqrtField};
 
 #[bench]
 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

@@ -1,18 +1,22 @@
-use rand::{Rand, SeedableRng, XorShiftRng};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
+use ff::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 use pairing::bls12_381::*;
-use pairing::{Field, PrimeField, PrimeFieldRepr, SqrtField};
 
 #[bench]
 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 tmp2 = FrRepr::rand(&mut rng);
+            let mut tmp1 = Fr::random(&mut rng).into_repr();
+            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

@@ -4,18 +4,23 @@ 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::{CurveAffine, Engine};
+use pairing::{Engine, PairingCurveAffine};
 
 #[bench]
 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(),
-                G2Affine::from(G2::rand(&mut rng)).prepare(),
+                G1Affine::from(G1::random(&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(),
-                G2Affine::from(G2::rand(&mut rng)).prepare(),
+                G1Affine::from(G1::random(&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

@@ -1,7 +1,10 @@
 #![feature(test)]
 
+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
-        {
-            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        impl ::std::fmt::Display for $affine {
+            fn fmt(&self, f: &mut ::std::fmt::Formatter<'_>) -> ::std::fmt::Result {
                 if self.infinity {
                     write!(f, "{}(Infinity)", $name)
                 } else {
@@ -32,12 +31,11 @@ macro_rules! curve_impl {
         pub struct $projective {
             pub(crate) x: $basefield,
             pub(crate) y: $basefield,
-           pub(crate) z: $basefield
+            pub(crate) z: $basefield,
         }
 
-        impl ::std::fmt::Display for $projective
-        {
-            fn fmt(&self, f: &mut ::std::fmt::Formatter) -> ::std::fmt::Result {
+        impl ::std::fmt::Display for $projective {
+            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
-                        } else {
-                            negy
-                        },
-                        infinity: false
+                        y: if (y < negy) ^ greatest { y } else { negy },
+                        infinity: false,
                     }
                 })
             }
@@ -148,18 +144,15 @@ macro_rules! curve_impl {
             type Engine = Bls12;
             type Scalar = $scalarfield;
             type Base = $basefield;
-            type Prepared = $prepared;
             type Projective = $projective;
             type Uncompressed = $uncompressed;
             type Compressed = $compressed;
-            type Pair = $pairing;
-            type PairingResult = Fq12;
 
             fn zero() -> Self {
                 $affine {
                     x: $basefield::zero(),
                     y: $basefield::one(),
-                    infinity: true
+                    infinity: true,
                 }
             }
 
@@ -182,6 +175,16 @@ macro_rules! curve_impl {
                 }
             }
 
+            fn into_projective(&self) -> $projective {
+                (*self).into()
+            }
+        }
+
+        impl PairingCurveAffine for $affine {
+            type Prepared = $prepared;
+            type Pair = $pairing;
+            type PairingResult = Fq12;
+
             fn prepare(&self) -> Self::Prepared {
                 $prepared::from_affine(*self)
             }
@@ -189,18 +192,18 @@ macro_rules! curve_impl {
             fn pairing_with(&self, other: &Self::Pair) -> Self::PairingResult {
                 self.perform_pairing(other)
             }
-
-            fn into_projective(&self) -> $projective {
-                (*self).into()
         }
 
-        }
+        impl CurveProjective for $projective {
+            type Engine = Bls12;
+            type Scalar = $scalarfield;
+            type Base = $basefield;
+            type Affine = $affine;
 
-        impl Rand for $projective {
-            fn rand<R: Rng>(rng: &mut R) -> Self {
+            fn random<R: RngCore + ?std::marker::Sized>(rng: &mut R) -> Self {
                 loop {
-                    let x = rng.gen();
-                    let greatest = rng.gen();
+                    let x = $basefield::random(rng);
+                    let greatest = rng.next_u32() % 2 != 0;
 
                     if let Some(p) = $affine::get_point_from_x(x, greatest) {
                         let p = p.scale_by_cofactor();
@@ -211,13 +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.
@@ -225,7 +221,7 @@ macro_rules! curve_impl {
                 $projective {
                     x: $basefield::zero(),
                     y: $basefield::one(),
-                    z: $basefield::zero()
+                    z: $basefield::zero(),
                 }
             }
 
@@ -243,8 +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
@@ -252,7 +247,8 @@ 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
+                    .iter_mut()
                     // Ignore normalized elements
                     .filter(|g| !g.is_normalized())
                 {
@@ -264,13 +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
+                    .iter_mut()
                     // Backwards
                     .rev()
                     // Ignore normalized elements
                     .filter(|g| !g.is_normalized())
                     // Backwards, skip last element, fill in one for last term.
-                               .zip(prod.into_iter().rev().skip(1).chain(Some($basefield::one())))
+                    .zip(
+                        prod.into_iter()
+                            .rev()
+                            .skip(1)
+                            .chain(Some($basefield::one())),
+                    )
                 {
                     // tmp := tmp * g.z; g.z := tmp * s = 1/z
                     let mut newtmp = tmp;
@@ -281,9 +283,7 @@ macro_rules! curve_impl {
                 }
 
                 // Perform affine transformations
-                for g in v.iter_mut()
-                          .filter(|g| !g.is_normalized())
-                {
+                for g in v.iter_mut().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
@@ -536,8 +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 {
@@ -575,7 +574,7 @@ macro_rules! curve_impl {
                     $projective {
                         x: p.x,
                         y: p.y,
-                        z: $basefield::one()
+                        z: $basefield::one(),
                     }
                 }
             }
@@ -592,7 +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.
@@ -612,23 +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 rand::{Rand, Rng};
+    use crate::{Engine, PairingCurveAffine};
+    use ff::{BitIterator, Field, PrimeField, PrimeFieldRepr, SqrtField};
+    use group::{CurveAffine, CurveProjective, EncodedPoint, GroupDecodingError};
+    use rand_core::RngCore;
     use std::fmt;
-    use {
-        BitIterator, CurveAffine, CurveProjective, EncodedPoint, Engine, Field, GroupDecodingError,
-        PrimeField, PrimeFieldRepr, SqrtField,
-    };
 
     curve_impl!(
         "G1",
@@ -658,7 +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)
         }
     }
@@ -768,7 +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)
         }
     }
@@ -936,7 +934,7 @@ pub mod g1 {
 
     #[test]
     fn g1_generator() {
-        use SqrtField;
+        use crate::SqrtField;
 
         let mut x = Fq::zero();
         let mut i = 0;
@@ -954,7 +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,
                 };
@@ -989,7 +987,8 @@ pub mod g1 {
                     0x9fe83b1b4a5d648d,
                     0xf583cc5a508f6a40,
                     0xc3ad2aefde0bb13,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0x60aa6f9552f03aae,
                     0xecd01d5181300d35,
@@ -997,7 +996,8 @@ pub mod g1 {
                     0xe760f57922998c9d,
                     0x953703f5795a39e5,
                     0xfe3ae0922df702c,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             };
             assert!(!p.is_on_curve());
@@ -1014,7 +1014,8 @@ pub mod g1 {
                     0xea034ee2928b30a8,
                     0xbd8833dc7c79a7f7,
                     0xe45c9f0c0438675,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0x3b450eb1ab7b5dad,
                     0xa65cb81e975e8675,
@@ -1022,7 +1023,8 @@ pub mod g1 {
                     0x753ddf21a2601d20,
                     0x532d0b640bd3ff8b,
                     0x118d2c543f031102,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             };
             assert!(!p.is_on_curve());
@@ -1040,7 +1042,8 @@ pub mod g1 {
                     0xf35de9ce0d6b4e84,
                     0x265bddd23d1dec54,
                     0x12a8778088458308,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0x8a22defa0d526256,
                     0xc57ca55456fcb9ae,
@@ -1048,7 +1051,8 @@ pub mod g1 {
                     0x921beef89d4f29df,
                     0x5b6fda44ad85fa78,
                     0xed74ab9f302cbe0,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             };
             assert!(p.is_on_curve());
@@ -1066,7 +1070,8 @@ pub mod g1 {
                 0x485e77d50a5df10d,
                 0x4c6fcac4b55fd479,
                 0x86ed4d9906fb064,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0xd25ee6461538c65,
                 0x9f3bbb2ecd3719b9,
@@ -1074,7 +1079,8 @@ pub mod g1 {
                 0xcefca68333c35288,
                 0x570c8005f8573fa6,
                 0x152ca696fe034442,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             z: Fq::one(),
         };
 
@@ -1086,7 +1092,8 @@ pub mod g1 {
                 0x5f44314ec5e3fb03,
                 0x24e8538737c6e675,
                 0x8abd623a594fba8,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0x6b0528f088bb7044,
                 0x2fdeb5c82917ff9e,
@@ -1094,7 +1101,8 @@ pub mod g1 {
                 0xd65104c6f95a872a,
                 0x1f2998a5a9c61253,
                 0xe74846154a9e44,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             z: Fq::one(),
         });
 
@@ -1110,7 +1118,8 @@ pub mod g1 {
                     0xc4f9a52a428e23bb,
                     0xd178b28dd4f407ef,
                     0x17fb8905e9183c69
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0xd0de9d65292b7710,
                     0xf6a05f2bcf1d9ca7,
@@ -1118,7 +1127,8 @@ pub mod g1 {
                     0xeec8d1a5b7466c58,
                     0x4bc362649dce6376,
                     0x430cbdc5455b00a
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             }
         );
@@ -1134,7 +1144,8 @@ pub mod g1 {
                 0x485e77d50a5df10d,
                 0x4c6fcac4b55fd479,
                 0x86ed4d9906fb064,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0xd25ee6461538c65,
                 0x9f3bbb2ecd3719b9,
@@ -1142,7 +1153,8 @@ pub mod g1 {
                 0xcefca68333c35288,
                 0x570c8005f8573fa6,
                 0x152ca696fe034442,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             z: Fq::one(),
         };
 
@@ -1160,7 +1172,8 @@ pub mod g1 {
                     0x4b914c16687dcde0,
                     0x66c8baf177d20533,
                     0xaf960cff3d83833
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 y: Fq::from_repr(FqRepr([
                     0x3f0675695f5177a8,
                     0x2b6d82ae178a1ba0,
@@ -1168,7 +1181,8 @@ pub mod g1 {
                     0x1771a65b60572f4e,
                     0x8b547c1313b27555,
                     0x135075589a687b1e
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 infinity: false,
             }
         );
@@ -1191,7 +1205,8 @@ pub mod g1 {
                 0x71ffa8021531705,
                 0x7418d484386d267,
                 0xd5108d8ff1fbd6,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0xa776ccbfe9981766,
                 0x255632964ff40f4a,
@@ -1199,7 +1214,8 @@ pub mod g1 {
                 0x520f74773e74c8c3,
                 0x484c8fc982008f0,
                 0xee2c3d922008cc6,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             infinity: false,
         };
 
@@ -1211,7 +1227,8 @@ pub mod g1 {
                 0xc6e05201e5f83991,
                 0xf7c75910816f207c,
                 0x18d4043e78103106,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0xa776ccbfe9981766,
                 0x255632964ff40f4a,
@@ -1219,7 +1236,8 @@ pub mod g1 {
                 0x520f74773e74c8c3,
                 0x484c8fc982008f0,
                 0xee2c3d922008cc6,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             infinity: false,
         };
 
@@ -1234,7 +1252,8 @@ pub mod g1 {
                 0x9676ff02ec39c227,
                 0x4c12c15d7e55b9f3,
                 0x57fd1e317db9bd,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             y: Fq::from_repr(FqRepr([
                 0x1288334016679345,
                 0xf955cd68615ff0b5,
@@ -1242,7 +1261,8 @@ pub mod g1 {
                 0x1267d70db51049fb,
                 0x4696deb9ab2ba3e7,
                 0xb1e4e11177f59d4,
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             infinity: false,
         };
 
@@ -1263,19 +1283,19 @@ pub mod g1 {
 
     #[test]
     fn g1_curve_tests() {
-        ::tests::curve::curve_tests::<G1>();
+        use group::tests::curve_tests;
+        curve_tests::<G1>();
     }
 }
 
 pub mod g2 {
     use super::super::{Bls12, Fq, Fq12, Fq2, FqRepr, Fr, FrRepr};
     use super::g1::G1Affine;
-    use rand::{Rand, Rng};
+    use crate::{Engine, PairingCurveAffine};
+    use ff::{BitIterator, Field, PrimeField, PrimeFieldRepr, SqrtField};
+    use group::{CurveAffine, CurveProjective, EncodedPoint, GroupDecodingError};
+    use rand_core::RngCore;
     use std::fmt;
-    use {
-        BitIterator, CurveAffine, CurveProjective, EncodedPoint, Engine, Field, GroupDecodingError,
-        PrimeField, PrimeFieldRepr, SqrtField,
-    };
 
     curve_impl!(
         "G2",
@@ -1305,7 +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)
         }
     }
@@ -1431,7 +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)
         }
     }
@@ -1620,7 +1640,7 @@ pub mod g2 {
 
     #[test]
     fn g2_generator() {
-        use SqrtField;
+        use crate::SqrtField;
 
         let mut x = Fq2::zero();
         let mut i = 0;
@@ -1636,7 +1656,7 @@ pub mod g2 {
                 negy.negate();
 
                 let p = G2Affine {
-                    x: x,
+                    x,
                     y: if y < negy { y } else { negy },
                     infinity: false,
                 };
@@ -1672,7 +1692,8 @@ pub mod g2 {
                         0x7a17a004747e3dbe,
                         0xcc65406a7c2e5a73,
                         0x10b8c03d64db4d0c,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0xd30e70fe2f029778,
                         0xda30772df0f5212e,
@@ -1680,7 +1701,8 @@ pub mod g2 {
                         0xfb777e5b9b568608,
                         0x789bac1fec71a2b9,
                         0x1342f02e2da54405,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -1690,7 +1712,8 @@ pub mod g2 {
                         0x663015d9410eb608,
                         0x78e82a79d829a544,
                         0x40a00545bb3c1e,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x4709802348e79377,
                         0xb5ac4dc9204bcfbd,
@@ -1698,7 +1721,8 @@ pub mod g2 {
                         0x15008b1dc399e8df,
                         0x68128fd0548a3829,
                         0x16a613db5c873aaa,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             };
@@ -1717,7 +1741,8 @@ pub mod g2 {
                         0x41abba710d6c692c,
                         0xffcc4b2b62ce8484,
                         0x6993ec01b8934ed,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0xb94e92d5f874e26,
                         0x44516408bc115d95,
@@ -1725,7 +1750,8 @@ pub mod g2 {
                         0xa5a0c2b7131f3555,
                         0x83800965822367e7,
                         0x10cf1d3ad8d90bfa,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -1735,7 +1761,8 @@ pub mod g2 {
                         0x5a9171720e73eb51,
                         0x38eb4fd8d658adb7,
                         0xb649051bbc1164d,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x9225814253d7df75,
                         0xc196c2513477f887,
@@ -1743,7 +1770,8 @@ pub mod g2 {
                         0x55f2b8efad953e04,
                         0x7379345eda55265e,
                         0x377f2e6208fd4cb,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             };
@@ -1763,7 +1791,8 @@ pub mod g2 {
                         0x2199bc19c48c393d,
                         0x4a151b732a6075bf,
                         0x17762a3b9108c4a7,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x26f461e944bbd3d1,
                         0x298f3189a9cf6ed6,
@@ -1771,7 +1800,8 @@ pub mod g2 {
                         0x7e147f3f9e6e241,
                         0x72a9b63583963fff,
                         0x158b0083c000462,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -1781,7 +1811,8 @@ pub mod g2 {
                         0x68cad19430706b4d,
                         0x3ccfb97b924dcea8,
                         0x1660f93434588f8d,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0xaaed3985b6dcb9c7,
                         0xc1e985d6d898d9f4,
@@ -1789,7 +1820,8 @@ pub mod g2 {
                         0x3940a2dbb914b529,
                         0xbeb88137cf34f3e7,
                         0x1699ee577c61b694,
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             };
@@ -1809,7 +1841,8 @@ pub mod g2 {
                     0x72556c999f3707ac,
                     0x4617f2e6774e9711,
                     0x100b2fe5bffe030b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0x7a33555977ec608,
                     0xe23039d1fe9c0881,
@@ -1817,7 +1850,8 @@ pub mod g2 {
                     0x4637c4f417667e2e,
                     0x93ebe7c3e41f6acc,
                     0xde884f89a9a371b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             y: Fq2 {
                 c0: Fq::from_repr(FqRepr([
@@ -1827,7 +1861,8 @@ pub mod g2 {
                     0x25fd427b4122f231,
                     0xd83112aace35cae,
                     0x191b2432407cbb7f,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0xf68ae82fe97662f5,
                     0xe986057068b50b7d,
@@ -1835,7 +1870,8 @@ pub mod g2 {
                     0x9eaa6d19de569196,
                     0xf6a03d31e2ec2183,
                     0x3bdafaf7ca9b39b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             z: Fq2::one(),
         };
@@ -1849,7 +1885,8 @@ pub mod g2 {
                     0x8e73a96b329ad190,
                     0x27c546f75ee1f3ab,
                     0xa33d27add5e7e82,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0x93b1ebcd54870dfe,
                     0xf1578300e1342e11,
@@ -1857,7 +1894,8 @@ pub mod g2 {
                     0x2089faf462438296,
                     0x828e5848cd48ea66,
                     0x141ecbac1deb038b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             y: Fq2 {
                 c0: Fq::from_repr(FqRepr([
@@ -1867,7 +1905,8 @@ pub mod g2 {
                     0x2767032fc37cc31d,
                     0xd5ee2aba84fd10fe,
                     0x16576ccd3dd0a4e8,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0x4da9b6f6a96d1dd2,
                     0x9657f7da77f1650e,
@@ -1875,7 +1914,8 @@ pub mod g2 {
                     0x31898db63f87363a,
                     0xabab040ddbd097cc,
                     0x11ad236b9ba02990,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             z: Fq2::one(),
         });
@@ -1893,7 +1933,8 @@ pub mod g2 {
                         0xf1273e6406eef9cc,
                         0xababd760ff05cb92,
                         0xd7c20456617e89
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0xd1a50b8572cbd2b8,
                         0x238f0ac6119d07df,
@@ -1901,7 +1942,8 @@ pub mod g2 {
                         0x8b203284c51edf6b,
                         0xc8a0b730bbb21f5e,
                         0x1a3b59d29a31274
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -1911,7 +1953,8 @@ pub mod g2 {
                         0x64528ab3863633dc,
                         0x159384333d7cba97,
                         0x4cb84741f3cafe8
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x242af0dc3640e1a4,
                         0xe90a73ad65c66919,
@@ -1919,7 +1962,8 @@ pub mod g2 {
                         0x38528f92b689644d,
                         0xb6884deec59fb21f,
                         0x3c075d3ec52ba90
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             }
@@ -1937,7 +1981,8 @@ pub mod g2 {
                     0x72556c999f3707ac,
                     0x4617f2e6774e9711,
                     0x100b2fe5bffe030b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0x7a33555977ec608,
                     0xe23039d1fe9c0881,
@@ -1945,7 +1990,8 @@ pub mod g2 {
                     0x4637c4f417667e2e,
                     0x93ebe7c3e41f6acc,
                     0xde884f89a9a371b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             y: Fq2 {
                 c0: Fq::from_repr(FqRepr([
@@ -1955,7 +2001,8 @@ pub mod g2 {
                     0x25fd427b4122f231,
                     0xd83112aace35cae,
                     0x191b2432407cbb7f,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
                 c1: Fq::from_repr(FqRepr([
                     0xf68ae82fe97662f5,
                     0xe986057068b50b7d,
@@ -1963,7 +2010,8 @@ pub mod g2 {
                     0x9eaa6d19de569196,
                     0xf6a03d31e2ec2183,
                     0x3bdafaf7ca9b39b,
-                ])).unwrap(),
+                ]))
+                .unwrap(),
             },
             z: Fq2::one(),
         };
@@ -1983,7 +2031,8 @@ pub mod g2 {
                         0xbcedcfce1e52d986,
                         0x9755d4a3926e9862,
                         0x18bab73760fd8024
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x4e7c5e0a2ae5b99e,
                         0x96e582a27f028961,
@@ -1991,7 +2040,8 @@ pub mod g2 {
                         0xeb0cf5e610ef4fe7,
                         0x7b4c2bae8db6e70b,
                         0xf136e43909fca0
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 y: Fq2 {
                     c0: Fq::from_repr(FqRepr([
@@ -2001,7 +2051,8 @@ pub mod g2 {
                         0xa5a2a51f7fde787b,
                         0x8b92866bc6384188,
                         0x81a53fe531d64ef
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                     c1: Fq::from_repr(FqRepr([
                         0x4c5d607666239b34,
                         0xeddb5f48304d14b3,
@@ -2009,7 +2060,8 @@ pub mod g2 {
                         0xb271f52f12ead742,
                         0x244e6c2015c83348,
                         0x19e2deae6eb9b441
-                    ])).unwrap(),
+                    ]))
+                    .unwrap(),
                 },
                 infinity: false,
             }
@@ -2018,7 +2070,8 @@ pub mod g2 {
 
     #[test]
     fn g2_curve_tests() {
-        ::tests::curve::curve_tests::<G2>();
+        use group::tests::curve_tests;
+        curve_tests::<G2>();
     }
 }
 

pairing/src/bls12_381/fq12.rs

@@ -1,8 +1,8 @@
 use super::fq::FROBENIUS_COEFF_FQ12_C1;
 use super::fq2::Fq2;
 use super::fq6::Fq6;
-use rand::{Rand, Rng};
-use Field;
+use ff::Field;
+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 c1 = Fq2::rand(&mut rng);
-        let c5 = Fq2::rand(&mut rng);
-        let mut a = Fq12::rand(&mut rng);
+        let c0 = Fq2::random(&mut rng);
+        let c1 = Fq2::random(&mut rng);
+        let c5 = Fq2::random(&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,
-                c1: c1,
+                c0,
+                c1,
                 c2: Fq2::zero(),
             },
             c1: Fq6 {
@@ -182,8 +185,8 @@ fn test_fq12_mul_by_014() {
 
 #[test]
 fn fq12_field_tests() {
-    use PrimeField;
+    use ff::PrimeField;
 
-    ::tests::field::random_field_tests::<Fq12>();
-    ::tests::field::random_frobenius_tests::<Fq12, _>(super::fq::Fq::char(), 13);
+    crate::tests::field::random_field_tests::<Fq12>();
+    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 rand::{Rand, Rng};
-use {Field, SqrtField};
+use super::fq::{Fq, FROBENIUS_COEFF_FQ2_C1, NEGATIVE_ONE};
+use ff::{Field, SqrtField};
+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 {
-    fn rand<R: Rng>(rng: &mut R) -> Self {
+impl Field for Fq2 {
+    fn random<R: RngCore + ?std::marker::Sized>(rng: &mut R) -> Self {
         Fq2 {
-            c0: rng.gen(),
-            c1: rng.gen(),
-        }
+            c0: Fq::random(rng),
+            c1: Fq::random(rng),
         }
     }
 
-impl Field for Fq2 {
     fn zero() -> Self {
         Fq2 {
             c0: Fq::zero(),
@@ -160,7 +158,7 @@ impl Field for Fq2 {
 }
 
 impl SqrtField for Fq2 {
-    fn legendre(&self) -> ::LegendreSymbol {
+    fn legendre(&self) -> ::ff::LegendreSymbol {
         self.norm().legendre()
     }
 
@@ -266,13 +264,14 @@ fn test_fq2_basics() {
     assert!(!Fq2 {
         c0: Fq::zero(),
         c1: Fq::one(),
-    }.is_zero());
+    }
+    .is_zero());
 }
 
 #[test]
 fn test_fq2_squaring() {
     use super::fq::FqRepr;
-    use PrimeField;
+    use ff::PrimeField;
 
     let mut a = Fq2 {
         c0: Fq::one(),
@@ -309,7 +308,8 @@ fn test_fq2_squaring() {
             0xf7f295a94e58ae7c,
             0x41b76dcc1c3fbe5e,
             0x7080c5fa1d8e042,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x38f473b3c870a4ab,
             0x6ad3291177c8c7e5,
@@ -317,7 +317,8 @@ fn test_fq2_squaring() {
             0xbfb99020604137a0,
             0xfc58a7b7be815407,
             0x10d1615e75250a21,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.square();
     assert_eq!(
@@ -330,7 +331,8 @@ fn test_fq2_squaring() {
                 0xcb674157618da176,
                 0x4cf17b5893c3d327,
                 0x7eac81369c43361
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xc1579cf58e980cf8,
                 0xa23eb7e12dd54d98,
@@ -338,7 +340,8 @@ fn test_fq2_squaring() {
                 0x38d0d7275a9689e1,
                 0x739c983042779a65,
                 0x1542a61c8a8db994
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -346,7 +349,7 @@ fn test_fq2_squaring() {
 #[test]
 fn test_fq2_mul() {
     use super::fq::FqRepr;
-    use PrimeField;
+    use ff::PrimeField;
 
     let mut a = Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -356,7 +359,8 @@ fn test_fq2_mul() {
             0x9ee53e7e84d7532e,
             0x1c202d8ed97afb45,
             0x51d3f9253e2516f,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0xa7348a8b511aedcf,
             0x143c215d8176b319,
@@ -364,7 +368,8 @@ fn test_fq2_mul() {
             0x9533e4a9a5158be,
             0x7a5e1ecb676d65f9,
             0x180c3ee46656b008,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.mul_assign(&Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -374,7 +379,8 @@ fn test_fq2_mul() {
             0xcd460f9f0c23e430,
             0x6c9110292bfa409,
             0x2c93a72eb8af83e,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x4b1c3f936d8992d4,
             0x1d2a72916dba4c8a,
@@ -382,7 +388,8 @@ fn test_fq2_mul() {
             0x57a06d3135a752ae,
             0x634cd3c6c565096d,
             0x19e17334d4e93558,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     });
     assert_eq!(
         a,
@@ -394,7 +401,8 @@ fn test_fq2_mul() {
                 0x5511fe4d84ee5f78,
                 0x5310a202d92f9963,
                 0x1751afbe166e5399
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x84af0e1bd630117a,
                 0x6c63cd4da2c2aa7,
@@ -402,7 +410,8 @@ fn test_fq2_mul() {
                 0xc975106579c275ee,
                 0x33a9ac82ce4c5083,
                 0x1ef1a36c201589d
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -410,7 +419,7 @@ fn test_fq2_mul() {
 #[test]
 fn test_fq2_inverse() {
     use super::fq::FqRepr;
-    use PrimeField;
+    use ff::PrimeField;
 
     assert!(Fq2::zero().inverse().is_none());
 
@@ -422,7 +431,8 @@ fn test_fq2_inverse() {
             0x9ee53e7e84d7532e,
             0x1c202d8ed97afb45,
             0x51d3f9253e2516f,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0xa7348a8b511aedcf,
             0x143c215d8176b319,
@@ -430,7 +440,8 @@ fn test_fq2_inverse() {
             0x9533e4a9a5158be,
             0x7a5e1ecb676d65f9,
             0x180c3ee46656b008,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     let a = a.inverse().unwrap();
     assert_eq!(
@@ -443,7 +454,8 @@ fn test_fq2_inverse() {
                 0xdfba703293941c30,
                 0xa6c3d8f9586f2636,
                 0x1351ef01941b70c4
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x8c39fd76a8312cb4,
                 0x15d7b6b95defbff0,
@@ -451,7 +463,8 @@ fn test_fq2_inverse() {
                 0xcbf651a0f367afb2,
                 0xdf4e54f0d3ef15a6,
                 0x103bdf241afb0019
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -459,7 +472,7 @@ fn test_fq2_inverse() {
 #[test]
 fn test_fq2_addition() {
     use super::fq::FqRepr;
-    use PrimeField;
+    use ff::PrimeField;
 
     let mut a = Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -469,7 +482,8 @@ fn test_fq2_addition() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -477,7 +491,8 @@ fn test_fq2_addition() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.add_assign(&Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -487,7 +502,8 @@ fn test_fq2_addition() {
             0x3b88899a42a6318f,
             0x986a4a62fa82a49d,
             0x13ce433fa26027f5,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x66323bf80b58b9b9,
             0xa1379b6facf6e596,
@@ -495,7 +511,8 @@ fn test_fq2_addition() {
             0x2236f55246d0d44d,
             0x4c8c1800eb104566,
             0x11d6e20e986c2085,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     });
     assert_eq!(
         a,
@@ -507,7 +524,8 @@ fn test_fq2_addition() {
                 0xf4ef57d604b6bca2,
                 0x65309427b3d5d090,
                 0x14c715d5553f01d2
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xfdb032e7d9079a94,
                 0x35a2809d15468d83,
@@ -515,7 +533,8 @@ fn test_fq2_addition() {
                 0xd62fa51334f560fa,
                 0x9ad265eb46e01984,
                 0x1303f3465112c8bc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -523,7 +542,7 @@ fn test_fq2_addition() {
 #[test]
 fn test_fq2_subtraction() {
     use super::fq::FqRepr;
-    use PrimeField;
+    use ff::PrimeField;
 
     let mut a = Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -533,7 +552,8 @@ fn test_fq2_subtraction() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -541,7 +561,8 @@ fn test_fq2_subtraction() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.sub_assign(&Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -551,7 +572,8 @@ fn test_fq2_subtraction() {
             0x3b88899a42a6318f,
             0x986a4a62fa82a49d,
             0x13ce433fa26027f5,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x66323bf80b58b9b9,
             0xa1379b6facf6e596,
@@ -559,7 +581,8 @@ fn test_fq2_subtraction() {
             0x2236f55246d0d44d,
             0x4c8c1800eb104566,
             0x11d6e20e986c2085,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     });
     assert_eq!(
         a,
@@ -571,7 +594,8 @@ fn test_fq2_subtraction() {
                 0xe255902672ef6c43,
                 0x7f77a718021c342d,
                 0x72ba14049fe9881
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xeb4abaf7c255d1cd,
                 0x11df49bc6cacc256,
@@ -579,7 +603,8 @@ fn test_fq2_subtraction() {
                 0xf63905f39ad8cb1f,
                 0x4cd5dd9fb40b3b8f,
                 0x957411359ba6e4c
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -587,7 +612,7 @@ fn test_fq2_subtraction() {
 #[test]
 fn test_fq2_negation() {
     use super::fq::FqRepr;
-    use PrimeField;
+    use ff::PrimeField;
 
     let mut a = Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -597,7 +622,8 @@ fn test_fq2_negation() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -605,7 +631,8 @@ fn test_fq2_negation() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.negate();
     assert_eq!(
@@ -618,7 +645,8 @@ fn test_fq2_negation() {
                 0xab107d49317487ab,
                 0x7e555df189f880e3,
                 0x19083f5486a10cbd
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x228109103250c9d0,
                 0x8a411ad149045812,
@@ -626,7 +654,8 @@ fn test_fq2_negation() {
                 0xb07e9bc405608611,
                 0xfcd559cbe77bd8b8,
                 0x18d400b280d93e62
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -634,7 +663,7 @@ fn test_fq2_negation() {
 #[test]
 fn test_fq2_doubling() {
     use super::fq::FqRepr;
-    use PrimeField;
+    use ff::PrimeField;
 
     let mut a = Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -644,7 +673,8 @@ fn test_fq2_doubling() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -652,7 +682,8 @@ fn test_fq2_doubling() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.double();
     assert_eq!(
@@ -665,7 +696,8 @@ fn test_fq2_doubling() {
                 0x72cd9c7784211627,
                 0x998c938972a657e7,
                 0x1f1a52b65bdb3b9
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x2efbeddf9b5dc1b6,
                 0x28d5ca5ad09f4fdb,
@@ -673,7 +705,8 @@ fn test_fq2_doubling() {
                 0x67f15f81dc49195b,
                 0x9c8c9bd4b79fa83d,
                 0x25a226f714d506e
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -681,7 +714,7 @@ fn test_fq2_doubling() {
 #[test]
 fn test_fq2_frobenius_map() {
     use super::fq::FqRepr;
-    use PrimeField;
+    use ff::PrimeField;
 
     let mut a = Fq2 {
         c0: Fq::from_repr(FqRepr([
@@ -691,7 +724,8 @@ fn test_fq2_frobenius_map() {
             0xb966ce3bc2108b13,
             0xccc649c4b9532bf3,
             0xf8d295b2ded9dc,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
         c1: Fq::from_repr(FqRepr([
             0x977df6efcdaee0db,
             0x946ae52d684fa7ed,
@@ -699,7 +733,8 @@ fn test_fq2_frobenius_map() {
             0xb3f8afc0ee248cad,
             0x4e464dea5bcfd41e,
             0x12d1137b8a6a837,
-        ])).unwrap(),
+        ]))
+        .unwrap(),
     };
     a.frobenius_map(0);
     assert_eq!(
@@ -712,7 +747,8 @@ fn test_fq2_frobenius_map() {
                 0xb966ce3bc2108b13,
                 0xccc649c4b9532bf3,
                 0xf8d295b2ded9dc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x977df6efcdaee0db,
                 0x946ae52d684fa7ed,
@@ -720,7 +756,8 @@ fn test_fq2_frobenius_map() {
                 0xb3f8afc0ee248cad,
                 0x4e464dea5bcfd41e,
                 0x12d1137b8a6a837
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
     a.frobenius_map(1);
@@ -734,7 +771,8 @@ fn test_fq2_frobenius_map() {
                 0xb966ce3bc2108b13,
                 0xccc649c4b9532bf3,
                 0xf8d295b2ded9dc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x228109103250c9d0,
                 0x8a411ad149045812,
@@ -742,7 +780,8 @@ fn test_fq2_frobenius_map() {
                 0xb07e9bc405608611,
                 0xfcd559cbe77bd8b8,
                 0x18d400b280d93e62
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
     a.frobenius_map(1);
@@ -756,7 +795,8 @@ fn test_fq2_frobenius_map() {
                 0xb966ce3bc2108b13,
                 0xccc649c4b9532bf3,
                 0xf8d295b2ded9dc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x977df6efcdaee0db,
                 0x946ae52d684fa7ed,
@@ -764,7 +804,8 @@ fn test_fq2_frobenius_map() {
                 0xb3f8afc0ee248cad,
                 0x4e464dea5bcfd41e,
                 0x12d1137b8a6a837
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
     a.frobenius_map(2);
@@ -778,7 +819,8 @@ fn test_fq2_frobenius_map() {
                 0xb966ce3bc2108b13,
                 0xccc649c4b9532bf3,
                 0xf8d295b2ded9dc
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0x977df6efcdaee0db,
                 0x946ae52d684fa7ed,
@@ -786,7 +828,8 @@ fn test_fq2_frobenius_map() {
                 0xb3f8afc0ee248cad,
                 0x4e464dea5bcfd41e,
                 0x12d1137b8a6a837
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
@@ -794,7 +837,7 @@ fn test_fq2_frobenius_map() {
 #[test]
 fn test_fq2_sqrt() {
     use super::fq::FqRepr;
-    use PrimeField;
+    use ff::PrimeField;
 
     assert_eq!(
         Fq2 {
@@ -805,7 +848,8 @@ fn test_fq2_sqrt() {
                 0xdb4a116b5bf74aa1,
                 0x1e58b2159dfe10e2,
                 0x7ca7da1f13606ac
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xfa8de88b7516d2c3,
                 0x371a75ed14f41629,
@@ -813,8 +857,10 @@ fn test_fq2_sqrt() {
                 0x212611bca4e99121,
                 0x8ee5394d77afb3d,
                 0xec92336650e49d5
-            ])).unwrap(),
-        }.sqrt()
+            ]))
+            .unwrap(),
+        }
+        .sqrt()
         .unwrap(),
         Fq2 {
             c0: Fq::from_repr(FqRepr([
@@ -824,7 +870,8 @@ fn test_fq2_sqrt() {
                 0x8d7f1f723d02c1d3,
                 0x881b3e01b611c070,
                 0x10f6963bbad2ebc5
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::from_repr(FqRepr([
                 0xc099534fc209e752,
                 0x7670594665676447,
@@ -832,7 +879,8 @@ fn test_fq2_sqrt() {
                 0x6b852aeaf2afcb1b,
                 0xa4c93b08105d71a9,
                 0x8d7cfff94216330
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 
@@ -845,9 +893,11 @@ fn test_fq2_sqrt() {
                 0x64774b84f38512bf,
                 0x4b1ba7b6434bacd7,
                 0x1a0111ea397fe69a
-            ])).unwrap(),
+            ]))
+            .unwrap(),
             c1: Fq::zero(),
-        }.sqrt()
+        }
+        .sqrt()
         .unwrap(),
         Fq2 {
             c0: Fq::zero(),
@@ -858,14 +908,15 @@ fn test_fq2_sqrt() {
                 0x64774b84f38512bf,
                 0x4b1ba7b6434bacd7,
                 0x1a0111ea397fe69a
-            ])).unwrap(),
+            ]))
+            .unwrap(),
         }
     );
 }
 
 #[test]
 fn test_fq2_legendre() {
-    use LegendreSymbol::*;
+    use ff::LegendreSymbol::*;
 
     assert_eq!(Zero, Fq2::zero().legendre());
     // i^2 = -1
@@ -877,11 +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(),
@@ -889,7 +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);
@@ -900,9 +956,9 @@ fn test_fq2_mul_nonresidue() {
 
 #[test]
 fn fq2_field_tests() {
-    use PrimeField;
+    use ff::PrimeField;
 
-    ::tests::field::random_field_tests::<Fq2>();
-    ::tests::field::random_sqrt_tests::<Fq2>();
-    ::tests::field::random_frobenius_tests::<Fq2, _>(super::fq::Fq::char(), 13);
+    crate::tests::field::random_field_tests::<Fq2>();
+    crate::tests::field::random_sqrt_tests::<Fq2>();
+    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 rand::{Rand, Rng};
-use Field;
+use ff::Field;
+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 mut a = Fq6::rand(&mut rng);
+        let c1 = Fq2::random(&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 c1 = Fq2::rand(&mut rng);
-        let mut a = Fq6::rand(&mut rng);
+        let c0 = Fq2::random(&mut rng);
+        let c1 = Fq2::random(&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,
-            c1: c1,
+            c0,
+            c1,
             c2: Fq2::zero(),
         });
 
@@ -367,8 +376,8 @@ fn test_fq6_mul_by_01() {
 
 #[test]
 fn fq6_field_tests() {
-    use PrimeField;
+    use ff::PrimeField;
 
-    ::tests::field::random_field_tests::<Fq6>();
-    ::tests::field::random_frobenius_tests::<Fq6, _>(super::fq::Fq::char(), 13);
+    crate::tests::field::random_field_tests::<Fq6>();
+    crate::tests::field::random_frobenius_tests::<Fq6, _>(super::fq::Fq::char(), 13);
 }

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,
-    G2Uncompressed,
+    G1Affine, G1Compressed, G1Prepared, G1Uncompressed, G2Affine, G2Compressed, G2Prepared,
+    G2Uncompressed, G1, G2,
 };
 pub use self::fq::{Fq, FqRepr};
 pub use self::fq12::Fq12;
@@ -18,7 +21,10 @@ pub use self::fq2::Fq2;
 pub use self::fq6::Fq6;
 pub use self::fr::{Fr, FrRepr};
 
-use super::{BitIterator, CurveAffine, Engine, Field};
+use super::{Engine, PairingCurveAffine};
+
+use ff::{BitIterator, Field, ScalarEngine};
+use group::CurveAffine;
 
 // The BLS parameter x for BLS12-381 is -0xd201000000010000
 const BLS_X: u64 = 0xd201000000010000;
@@ -27,8 +33,11 @@ const BLS_X_IS_NEGATIVE: bool = true;
 #[derive(Clone, Debug)]
 pub struct Bls12;
 
-impl Engine for Bls12 {
+impl ScalarEngine for Bls12 {
     type Fr = Fr;
+}
+
+impl Engine for Bls12 {
     type G1 = G1;
     type G1Affine = G1Affine;
     type G2 = G2;
@@ -41,8 +50,8 @@ impl Engine for Bls12 {
     where
         I: IntoIterator<
             Item = &'a (
-                &'a <Self::G1Affine as CurveAffine>::Prepared,
-                &'a <Self::G2Affine as CurveAffine>::Prepared,
+                &'a <Self::G1Affine as PairingCurveAffine>::Prepared,
+                &'a <Self::G2Affine as PairingCurveAffine>::Prepared,
             ),
         >,
     {
@@ -360,5 +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

@@ -1,5 +1,8 @@
+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

@@ -1,59 +1,49 @@
+//! 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 `clippy` feature is
-// provided, it is enabled and all compiler warnings are prohibited.
-#![cfg_attr(feature = "clippy", deny(warnings))]
-#![cfg_attr(feature = "clippy", feature(plugin))]
-#![cfg_attr(feature = "clippy", plugin(clippy))]
-#![cfg_attr(feature = "clippy", allow(inline_always))]
-#![cfg_attr(feature = "clippy", allow(too_many_arguments))]
-#![cfg_attr(feature = "clippy", allow(unreadable_literal))]
-#![cfg_attr(feature = "clippy", allow(many_single_char_names))]
-#![cfg_attr(feature = "clippy", allow(new_without_default_derive))]
-#![cfg_attr(feature = "clippy", allow(write_literal))]
+// 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(clippy::inline_always))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::too_many_arguments))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::unreadable_literal))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::many_single_char_names))]
+#![cfg_attr(feature = "cargo-clippy", allow(clippy::new_without_default))]
+#![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 rand;
-
 #[cfg(test)]
 pub mod tests;
 
 pub mod bls12_381;
 
-mod wnaf;
-pub use self::wnaf::Wnaf;
-
-use std::error::Error;
-use std::fmt;
-use std::io::{self, Read, Write};
+use ff::{Field, PrimeField, ScalarEngine, SqrtField};
+use group::{CurveAffine, CurveProjective};
 
 /// An "engine" is a collection of types (fields, elliptic curve groups, etc.)
 /// with well-defined relationships. In particular, the G1/G2 curve groups are
 /// of prime order `r`, and are equipped with a bilinear pairing function.
-pub trait Engine: Sized + 'static + Clone {
-    /// This is the scalar field of the G1/G2 groups.
-    type Fr: PrimeField + SqrtField;
-
+pub trait Engine: ScalarEngine {
     /// The projective representation of an element in G1.
     type G1: CurveProjective<
             Engine = Self,
             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: CurveAffine<
+    type G1Affine: PairingCurveAffine<
             Engine = Self,
             Base = Self::Fq,
             Scalar = Self::Fr,
             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<
@@ -61,19 +51,17 @@ pub trait Engine: Sized + 'static + Clone {
             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: CurveAffine<
+    type G2Affine: PairingCurveAffine<
             Engine = Self,
             Base = Self::Fqe,
             Scalar = Self::Fr,
             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;
@@ -89,13 +77,13 @@ pub trait Engine: Sized + 'static + Clone {
     where
         I: IntoIterator<
             Item = &'a (
-                &'a <Self::G1Affine as CurveAffine>::Prepared,
-                &'a <Self::G2Affine as CurveAffine>::Prepared,
+                &'a <Self::G1Affine as PairingCurveAffine>::Prepared,
+                &'a <Self::G2Affine as PairingCurveAffine>::Prepared,
             ),
         >;
 
     /// 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
@@ -104,655 +92,22 @@ pub trait Engine: Sized + 'static + Clone {
         G2: Into<Self::G2Affine>,
     {
         Self::final_exponentiation(&Self::miller_loop(
-            [(&(p.into().prepare()), &(q.into().prepare()))].into_iter(),
-        )).unwrap()
+            [(&(p.into().prepare()), &(q.into().prepare()))].iter(),
+        ))
+        .unwrap()
     }
 }
 
-/// Projective representation of an elliptic curve point guaranteed to be
-/// in the correct prime order subgroup.
-pub trait CurveProjective:
-    PartialEq
-    + Eq
-    + Sized
-    + Copy
-    + Clone
-    + Send
-    + Sync
-    + fmt::Debug
-    + fmt::Display
-    + rand::Rand
-    + 'static
-{
-    type Engine: Engine<Fr = Self::Scalar>;
-    type Scalar: PrimeField + SqrtField;
-    type Base: SqrtField;
-    type Affine: CurveAffine<Projective = Self, Scalar = Self::Scalar>;
-
-    /// Returns the additive identity.
-    fn zero() -> Self;
-
-    /// Returns a fixed generator of unknown exponent.
-    fn one() -> Self;
-
-    /// Determines if this point is the point at infinity.
-    fn is_zero(&self) -> bool;
-
-    /// Normalizes a slice of projective elements so that
-    /// conversion to affine is cheap.
-    fn batch_normalization(v: &mut [Self]);
-
-    /// Checks if the point is already "normalized" so that
-    /// cheap affine conversion is possible.
-    fn is_normalized(&self) -> bool;
-
-    /// Doubles this element.
-    fn double(&mut self);
-
-    /// Adds another element to this element.
-    fn add_assign(&mut self, other: &Self);
-
-    /// Subtracts another element from this element.
-    fn sub_assign(&mut self, other: &Self) {
-        let mut tmp = *other;
-        tmp.negate();
-        self.add_assign(&tmp);
-    }
-
-    /// Adds an affine element to this element.
-    fn add_assign_mixed(&mut self, other: &Self::Affine);
-
-    /// Negates this element.
-    fn negate(&mut self);
-
-    /// Performs scalar multiplication of this element.
-    fn mul_assign<S: Into<<Self::Scalar as PrimeField>::Repr>>(&mut self, other: S);
-
-    /// Converts this element into its affine representation.
-    fn into_affine(&self) -> Self::Affine;
-
-    /// Recommends a wNAF window table size given a scalar. Always returns a number
-    /// between 2 and 22, inclusive.
-    fn recommended_wnaf_for_scalar(scalar: <Self::Scalar as PrimeField>::Repr) -> usize;
-
-    /// Recommends a wNAF window size given the number of scalars you intend to multiply
-    /// a base by. Always returns a number between 2 and 22, inclusive.
-    fn recommended_wnaf_for_num_scalars(num_scalars: usize) -> usize;
-}
-
-/// Affine representation of an elliptic curve point guaranteed to be
-/// in the correct prime order subgroup.
-pub trait CurveAffine:
-    Copy + Clone + Sized + Send + Sync + fmt::Debug + fmt::Display + PartialEq + Eq + 'static
-{
-    type Engine: Engine<Fr = Self::Scalar>;
-    type Scalar: PrimeField + SqrtField;
-    type Base: SqrtField;
-    type Projective: CurveProjective<Affine = Self, Scalar = Self::Scalar>;
+/// Affine representation of an elliptic curve point that can be used
+/// to perform pairings.
+pub trait PairingCurveAffine: CurveAffine {
     type Prepared: Clone + Send + Sync + 'static;
-    type Uncompressed: EncodedPoint<Affine = Self>;
-    type Compressed: EncodedPoint<Affine = Self>;
-    type Pair: CurveAffine<Pair = Self>;
+    type Pair: PairingCurveAffine<Pair = Self>;
     type PairingResult: Field;
 
-    /// Returns the additive identity.
-    fn zero() -> Self;
-
-    /// Returns a fixed generator of unknown exponent.
-    fn one() -> Self;
-
-    /// Determines if this point represents the point at infinity; the
-    /// additive identity.
-    fn is_zero(&self) -> bool;
-
-    /// Negates this element.
-    fn negate(&mut self);
-
-    /// Performs scalar multiplication of this element with mixed addition.
-    fn mul<S: Into<<Self::Scalar as PrimeField>::Repr>>(&self, other: S) -> Self::Projective;
-
     /// Prepares this element for pairing purposes.
     fn prepare(&self) -> Self::Prepared;
 
     /// Perform a pairing
     fn pairing_with(&self, other: &Self::Pair) -> Self::PairingResult;
-
-    /// Converts this element into its affine representation.
-    fn into_projective(&self) -> Self::Projective;
-
-    /// Converts this element into its compressed encoding, so long as it's not
-    /// the point at infinity.
-    fn into_compressed(&self) -> Self::Compressed {
-        <Self::Compressed as EncodedPoint>::from_affine(*self)
-    }
-
-    /// Converts this element into its uncompressed encoding, so long as it's not
-    /// the point at infinity.
-    fn into_uncompressed(&self) -> Self::Uncompressed {
-        <Self::Uncompressed as EncodedPoint>::from_affine(*self)
-    }
-}
-
-/// An encoded elliptic curve point, which should essentially wrap a `[u8; N]`.
-pub trait EncodedPoint:
-    Sized + Send + Sync + AsRef<[u8]> + AsMut<[u8]> + Clone + Copy + 'static
-{
-    type Affine: CurveAffine;
-
-    /// Creates an empty representation.
-    fn empty() -> Self;
-
-    /// Returns the number of bytes consumed by this representation.
-    fn size() -> usize;
-
-    /// Converts an `EncodedPoint` into a `CurveAffine` element,
-    /// if the encoding represents a valid element.
-    fn into_affine(&self) -> Result<Self::Affine, GroupDecodingError>;
-
-    /// Converts an `EncodedPoint` into a `CurveAffine` element,
-    /// without guaranteeing that the encoding represents a valid
-    /// element. This is useful when the caller knows the encoding is
-    /// valid already.
-    ///
-    /// If the encoding is invalid, this can break API invariants,
-    /// so caution is strongly encouraged.
-    fn into_affine_unchecked(&self) -> Result<Self::Affine, GroupDecodingError>;
-
-    /// Creates an `EncodedPoint` from an affine point, as long as the
-    /// point is not the point at infinity.
-    fn from_affine(affine: Self::Affine) -> Self;
-}
-
-/// This trait represents an element of a field.
-pub trait Field:
-    Sized + Eq + Copy + Clone + Send + Sync + fmt::Debug + fmt::Display + 'static + rand::Rand
-{
-    /// Returns the zero element of the field, the additive identity.
-    fn zero() -> Self;
-
-    /// Returns the one element of the field, the multiplicative identity.
-    fn one() -> Self;
-
-    /// Returns true iff this element is zero.
-    fn is_zero(&self) -> bool;
-
-    /// Squares this element.
-    fn square(&mut self);
-
-    /// Doubles this element.
-    fn double(&mut self);
-
-    /// Negates this element.
-    fn negate(&mut self);
-
-    /// Adds another element to this element.
-    fn add_assign(&mut self, other: &Self);
-
-    /// Subtracts another element from this element.
-    fn sub_assign(&mut self, other: &Self);
-
-    /// Multiplies another element by this element.
-    fn mul_assign(&mut self, other: &Self);
-
-    /// Computes the multiplicative inverse of this element, if nonzero.
-    fn inverse(&self) -> Option<Self>;
-
-    /// Exponentiates this element by a power of the base prime modulus via
-    /// the Frobenius automorphism.
-    fn frobenius_map(&mut self, power: usize);
-
-    /// Exponentiates this element by a number represented with `u64` limbs,
-    /// least significant digit first.
-    fn pow<S: AsRef<[u64]>>(&self, exp: S) -> Self {
-        let mut res = Self::one();
-
-        let mut found_one = false;
-
-        for i in BitIterator::new(exp) {
-            if found_one {
-                res.square();
-            } else {
-                found_one = i;
-            }
-
-            if i {
-                res.mul_assign(self);
-            }
-        }
-
-        res
-    }
-}
-
-/// This trait represents an element of a field that has a square root operation described for it.
-pub trait SqrtField: Field {
-    /// Returns the Legendre symbol of the field element.
-    fn legendre(&self) -> LegendreSymbol;
-
-    /// Returns the square root of the field element, if it is
-    /// quadratic residue.
-    fn sqrt(&self) -> Option<Self>;
-}
-
-/// This trait represents a wrapper around a biginteger which can encode any element of a particular
-/// prime field. It is a smart wrapper around a sequence of `u64` limbs, least-significant digit
-/// first.
-pub trait PrimeFieldRepr:
-    Sized
-    + Copy
-    + Clone
-    + Eq
-    + Ord
-    + Send
-    + Sync
-    + Default
-    + fmt::Debug
-    + fmt::Display
-    + 'static
-    + rand::Rand
-    + AsRef<[u64]>
-    + AsMut<[u64]>
-    + From<u64>
-{
-    /// Subtract another represetation from this one.
-    fn sub_noborrow(&mut self, other: &Self);
-
-    /// Add another representation to this one.
-    fn add_nocarry(&mut self, other: &Self);
-
-    /// Compute the number of bits needed to encode this number. Always a
-    /// multiple of 64.
-    fn num_bits(&self) -> u32;
-
-    /// Returns true iff this number is zero.
-    fn is_zero(&self) -> bool;
-
-    /// Returns true iff this number is odd.
-    fn is_odd(&self) -> bool;
-
-    /// Returns true iff this number is even.
-    fn is_even(&self) -> bool;
-
-    /// Performs a rightwise bitshift of this number, effectively dividing
-    /// it by 2.
-    fn div2(&mut self);
-
-    /// Performs a rightwise bitshift of this number by some amount.
-    fn shr(&mut self, amt: u32);
-
-    /// Performs a leftwise bitshift of this number, effectively multiplying
-    /// it by 2. Overflow is ignored.
-    fn mul2(&mut self);
-
-    /// Performs a leftwise bitshift of this number by some amount.
-    fn shl(&mut self, amt: u32);
-
-    /// Writes this `PrimeFieldRepr` as a big endian integer.
-    fn write_be<W: Write>(&self, mut writer: W) -> io::Result<()> {
-        use byteorder::{BigEndian, WriteBytesExt};
-
-        for digit in self.as_ref().iter().rev() {
-            writer.write_u64::<BigEndian>(*digit)?;
-        }
-
-        Ok(())
-    }
-
-    /// Reads a big endian integer into this representation.
-    fn read_be<R: Read>(&mut self, mut reader: R) -> io::Result<()> {
-        use byteorder::{BigEndian, ReadBytesExt};
-
-        for digit in self.as_mut().iter_mut().rev() {
-            *digit = reader.read_u64::<BigEndian>()?;
-        }
-
-        Ok(())
-    }
-
-    /// Writes this `PrimeFieldRepr` as a little endian integer.
-    fn write_le<W: Write>(&self, mut writer: W) -> io::Result<()> {
-        use byteorder::{LittleEndian, WriteBytesExt};
-
-        for digit in self.as_ref().iter() {
-            writer.write_u64::<LittleEndian>(*digit)?;
-        }
-
-        Ok(())
-    }
-
-    /// Reads a little endian integer into this representation.
-    fn read_le<R: Read>(&mut self, mut reader: R) -> io::Result<()> {
-        use byteorder::{LittleEndian, ReadBytesExt};
-
-        for digit in self.as_mut().iter_mut() {
-            *digit = reader.read_u64::<LittleEndian>()?;
-        }
-
-        Ok(())
-    }
-}
-
-#[derive(Debug, PartialEq)]
-pub enum LegendreSymbol {
-    Zero = 0,
-    QuadraticResidue = 1,
-    QuadraticNonResidue = -1,
-}
-
-/// An error that may occur when trying to interpret a `PrimeFieldRepr` as a
-/// `PrimeField` element.
-#[derive(Debug)]
-pub enum PrimeFieldDecodingError {
-    /// The encoded value is not in the field
-    NotInField(String),
-}
-
-impl Error for PrimeFieldDecodingError {
-    fn description(&self) -> &str {
-        match *self {
-            PrimeFieldDecodingError::NotInField(..) => "not an element of the field",
-        }
-    }
-}
-
-impl fmt::Display for PrimeFieldDecodingError {
-    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)
-            }
-        }
-    }
-}
-
-/// An error that may occur when trying to decode an `EncodedPoint`.
-#[derive(Debug)]
-pub enum GroupDecodingError {
-    /// The coordinate(s) do not lie on the curve.
-    NotOnCurve,
-    /// The element is not part of the r-order subgroup.
-    NotInSubgroup,
-    /// One of the coordinates could not be decoded
-    CoordinateDecodingError(&'static str, PrimeFieldDecodingError),
-    /// The compression mode of the encoded element was not as expected
-    UnexpectedCompressionMode,
-    /// The encoding contained bits that should not have been set
-    UnexpectedInformation,
-}
-
-impl Error for GroupDecodingError {
-    fn description(&self) -> &str {
-        match *self {
-            GroupDecodingError::NotOnCurve => "coordinate(s) do not lie on the curve",
-            GroupDecodingError::NotInSubgroup => "the element is not part of an r-order subgroup",
-            GroupDecodingError::CoordinateDecodingError(..) => "coordinate(s) could not be decoded",
-            GroupDecodingError::UnexpectedCompressionMode => {
-                "encoding has unexpected compression mode"
-            }
-            GroupDecodingError::UnexpectedInformation => "encoding has unexpected information",
-        }
-    }
-}
-
-impl fmt::Display for GroupDecodingError {
-    fn fmt(&self, f: &mut fmt::Formatter) -> Result<(), fmt::Error> {
-        match *self {
-            GroupDecodingError::CoordinateDecodingError(description, ref err) => {
-                write!(f, "{} decoding error: {}", description, err)
-            }
-            _ => write!(f, "{}", self.description()),
-        }
-    }
-}
-
-/// This represents an element of a prime field.
-pub trait PrimeField: Field {
-    /// The prime field can be converted back and forth into this biginteger
-    /// representation.
-    type Repr: PrimeFieldRepr + From<Self>;
-
-    /// Interpret a string of numbers as a (congruent) prime field element.
-    /// Does not accept unnecessary leading zeroes or a blank string.
-    fn from_str(s: &str) -> Option<Self> {
-        if s.is_empty() {
-            return None;
-        }
-
-        if s == "0" {
-            return Some(Self::zero());
-        }
-
-        let mut res = Self::zero();
-
-        let ten = Self::from_repr(Self::Repr::from(10)).unwrap();
-
-        let mut first_digit = true;
-
-        for c in s.chars() {
-            match c.to_digit(10) {
-                Some(c) => {
-                    if first_digit {
-                        if c == 0 {
-                            return None;
-                        }
-
-                        first_digit = false;
-                    }
-
-                    res.mul_assign(&ten);
-                    res.add_assign(&Self::from_repr(Self::Repr::from(u64::from(c))).unwrap());
-                }
-                None => {
-                    return None;
-                }
-            }
-        }
-
-        Some(res)
-    }
-
-    /// Convert this prime field element into a biginteger representation.
-    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.
-    fn into_repr(&self) -> Self::Repr;
-
-    /// Returns the field characteristic; the modulus.
-    fn char() -> Self::Repr;
-
-    /// How many bits are needed to represent an element of this field.
-    const NUM_BITS: u32;
-
-    /// How many bits of information can be reliably stored in the field element.
-    const CAPACITY: u32;
-
-    /// Returns the multiplicative generator of `char()` - 1 order. This element
-    /// must also be quadratic nonresidue.
-    fn multiplicative_generator() -> Self;
-
-    /// 2^s * t = `char()` - 1 with t odd.
-    const S: u32;
-
-    /// Returns the 2^s root of unity computed by exponentiating the `multiplicative_generator()`
-    /// by t.
-    fn root_of_unity() -> Self;
-}
-
-#[derive(Debug)]
-pub struct BitIterator<E> {
-    t: E,
-    n: usize,
-}
-
-impl<E: AsRef<[u64]>> BitIterator<E> {
-    pub fn new(t: E) -> Self {
-        let n = t.as_ref().len() * 64;
-
-        BitIterator { t, n }
-    }
-}
-
-impl<E: AsRef<[u64]>> Iterator for BitIterator<E> {
-    type Item = bool;
-
-    fn next(&mut self) -> Option<bool> {
-        if self.n == 0 {
-            None
-        } else {
-            self.n -= 1;
-            let part = self.n / 64;
-            let bit = self.n - (64 * part);
-
-            Some(self.t.as_ref()[part] & (1 << bit) > 0)
-        }
-    }
-}
-
-#[test]
-fn test_bit_iterator() {
-    let mut a = BitIterator::new([0xa953d79b83f6ab59, 0x6dea2059e200bd39]);
-    let expected = "01101101111010100010000001011001111000100000000010111101001110011010100101010011110101111001101110000011111101101010101101011001";
-
-    for e in expected.chars() {
-        assert!(a.next().unwrap() == (e == '1'));
-    }
-
-    assert!(a.next().is_none());
-
-    let expected = "1010010101111110101010000101101011101000011101110101001000011001100100100011011010001011011011010001011011101100110100111011010010110001000011110100110001100110011101101000101100011100100100100100001010011101010111110011101011000011101000111011011101011001";
-
-    let mut a = BitIterator::new([
-        0x429d5f3ac3a3b759,
-        0xb10f4c66768b1c92,
-        0x92368b6d16ecd3b4,
-        0xa57ea85ae8775219,
-    ]);
-
-    for e in expected.chars() {
-        assert!(a.next().unwrap() == (e == '1'));
-    }
-
-    assert!(a.next().is_none());
-}
-
-#[cfg(not(feature = "expose-arith"))]
-use self::arith_impl::*;
-
-#[cfg(feature = "expose-arith")]
-pub use self::arith_impl::*;
-
-#[cfg(feature = "u128-support")]
-mod arith_impl {
-    /// Calculate a - b - borrow, returning the result and modifying
-    /// the borrow value.
-    #[inline(always)]
-    pub fn sbb(a: u64, b: u64, borrow: &mut u64) -> u64 {
-        let tmp = (1u128 << 64) + u128::from(a) - u128::from(b) - u128::from(*borrow);
-
-        *borrow = if tmp >> 64 == 0 { 1 } else { 0 };
-
-        tmp as u64
-    }
-
-    /// Calculate a + b + carry, returning the sum and modifying the
-    /// carry value.
-    #[inline(always)]
-    pub fn adc(a: u64, b: u64, carry: &mut u64) -> u64 {
-        let tmp = u128::from(a) + u128::from(b) + u128::from(*carry);
-
-        *carry = (tmp >> 64) as u64;
-
-        tmp as u64
-    }
-
-    /// Calculate a + (b * c) + carry, returning the least significant digit
-    /// and setting carry to the most significant digit.
-    #[inline(always)]
-    pub fn mac_with_carry(a: u64, b: u64, c: u64, carry: &mut u64) -> u64 {
-        let tmp = (u128::from(a)) + u128::from(b) * u128::from(c) + u128::from(*carry);
-
-        *carry = (tmp >> 64) as u64;
-
-        tmp as u64
-    }
-}
-
-#[cfg(not(feature = "u128-support"))]
-mod arith_impl {
-    #[inline(always)]
-    fn split_u64(i: u64) -> (u64, u64) {
-        (i >> 32, i & 0xFFFFFFFF)
-    }
-
-    #[inline(always)]
-    fn combine_u64(hi: u64, lo: u64) -> u64 {
-        (hi << 32) | lo
-    }
-
-    /// Calculate a - b - borrow, returning the result and modifying
-    /// the borrow value.
-    #[inline(always)]
-    pub fn sbb(a: u64, b: u64, borrow: &mut u64) -> u64 {
-        let (a_hi, a_lo) = split_u64(a);
-        let (b_hi, b_lo) = split_u64(b);
-        let (b, r0) = split_u64((1 << 32) + a_lo - b_lo - *borrow);
-        let (b, r1) = split_u64((1 << 32) + a_hi - b_hi - ((b == 0) as u64));
-
-        *borrow = (b == 0) as u64;
-
-        combine_u64(r1, r0)
-    }
-
-    /// Calculate a + b + carry, returning the sum and modifying the
-    /// carry value.
-    #[inline(always)]
-    pub fn adc(a: u64, b: u64, carry: &mut u64) -> u64 {
-        let (a_hi, a_lo) = split_u64(a);
-        let (b_hi, b_lo) = split_u64(b);
-        let (carry_hi, carry_lo) = split_u64(*carry);
-
-        let (t, r0) = split_u64(a_lo + b_lo + carry_lo);
-        let (t, r1) = split_u64(t + a_hi + b_hi + carry_hi);
-
-        *carry = t;
-
-        combine_u64(r1, r0)
-    }
-
-    /// Calculate a + (b * c) + carry, returning the least significant digit
-    /// and setting carry to the most significant digit.
-    #[inline(always)]
-    pub fn mac_with_carry(a: u64, b: u64, c: u64, carry: &mut u64) -> u64 {
-        /*
-                                [  b_hi  |  b_lo  ]
-                                [  c_hi  |  c_lo  ] *
-        -------------------------------------------
-                                [  b_lo  *  c_lo  ] <-- w
-                       [  b_hi  *  c_lo  ]          <-- x
-                       [  b_lo  *  c_hi  ]          <-- y
-             [   b_hi  *  c_lo  ]                   <-- z
-                                [  a_hi  |  a_lo  ]
-                                [  C_hi  |  C_lo  ]
-        */
-
-        let (a_hi, a_lo) = split_u64(a);
-        let (b_hi, b_lo) = split_u64(b);
-        let (c_hi, c_lo) = split_u64(c);
-        let (carry_hi, carry_lo) = split_u64(*carry);
-
-        let (w_hi, w_lo) = split_u64(b_lo * c_lo);
-        let (x_hi, x_lo) = split_u64(b_hi * c_lo);
-        let (y_hi, y_lo) = split_u64(b_lo * c_hi);
-        let (z_hi, z_lo) = split_u64(b_hi * c_hi);
-
-        let (t, r0) = split_u64(w_lo + a_lo + carry_lo);
-        let (t, r1) = split_u64(t + w_hi + x_lo + y_lo + a_hi + carry_hi);
-        let (t, r2) = split_u64(t + x_hi + y_hi + z_lo);
-        let (_, r3) = split_u64(t + z_hi);
-
-        *carry = combine_u64(r3, r2);
-
-        combine_u64(r1, r0)
-    }
 }

pairing/src/tests/engine.rs

@@ -1,13 +1,18 @@
-use rand::{Rand, SeedableRng, XorShiftRng};
+use group::{CurveAffine, CurveProjective};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
-use {CurveAffine, CurveProjective, Engine, Field, 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 b = E::G2::rand(&mut rng).into_affine();
+        let a = E::G1::random(&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));
@@ -17,10 +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 b = E::G2::rand(&mut rng).into_affine().prepare();
-        let c = E::G1::rand(&mut rng).into_affine().prepare();
-        let d = E::G2::rand(&mut rng).into_affine().prepare();
+        let a = E::G1::random(&mut rng).into_affine().prepare();
+        let b = E::G2::random(&mut rng).into_affine().prepare();
+        let c = E::G1::random(&mut rng).into_affine().prepare();
+        let d = E::G2::random(&mut rng).into_affine().prepare();
 
         assert_eq!(
             E::Fqk::one(),
@@ -48,12 +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 b = E::G2::rand(&mut rng);
+        let a = E::G1::random(&mut rng);
+        let b = E::G2::random(&mut rng);
 
         let p2 = E::pairing(a, b);
 
@@ -67,10 +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 b = E::G2::rand(&mut rng);
-        let c = E::G1::rand(&mut rng);
-        let d = E::G2::rand(&mut rng);
+        let a = E::G1::random(&mut rng);
+        let b = E::G2::random(&mut rng);
+        let c = E::G1::random(&mut rng);
+        let d = E::G2::random(&mut rng);
 
         let ab = E::pairing(a, b);
         let cd = E::pairing(c, d);
@@ -91,14 +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 b = E::G2::rand(&mut rng);
+        let a = E::G1::random(&mut rng);
+        let b = E::G2::random(&mut rng);
 
-        let c = E::Fr::rand(&mut rng);
-        let d = E::Fr::rand(&mut rng);
+        let c = E::Fr::random(&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 rand::{Rng, SeedableRng, XorShiftRng};
-use {Field, LegendreSymbol, PrimeField, SqrtField};
+use ff::{Field, LegendreSymbol, PrimeField, SqrtField};
+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 b = F::rand(rng);
-        let c = F::rand(rng);
+        let a = F::random(rng);
+        let b = F::random(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 b = F::rand(rng);
-        let c = F::rand(rng);
+        let a = F::random(rng);
+        let b = F::random(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::rand(rng);
+        let b = F::random(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 b = F::rand(rng);
-        let c = F::rand(rng);
-        let d = F::rand(rng);
+        let a = F::random(rng);
+        let b = F::random(rng);
+        let c = F::random(rng);
+        let d = F::random(rng);
 
         let mut t0 = a;
         t0.add_assign(&b);

pairing/src/tests/mod.rs

@@ -1,4 +1,3 @@
-pub mod curve;
 pub mod engine;
 pub mod field;
 pub mod repr;

pairing/src/tests/repr.rs

@@ -1,21 +1,25 @@
-use rand::{SeedableRng, XorShiftRng};
-use PrimeFieldRepr;
+use ff::{PrimeField, PrimeFieldRepr};
+use rand_core::SeedableRng;
+use rand_xorshift::XorShiftRng;
 
-pub fn random_repr_tests<R: PrimeFieldRepr>() {
-    random_encoding_tests::<R>();
-    random_shl_tests::<R>();
-    random_shr_tests::<R>();
+pub fn random_repr_tests<P: PrimeField>() {
+    random_encoding_tests::<P>();
+    random_shl_tests::<P>();
+    random_shr_tests::<P>();
 }
 
-fn random_encoding_tests<R: PrimeFieldRepr>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+fn random_encoding_tests<P: PrimeField>() {
+    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_be_flip = R::default();
+            let mut rdecoded_le = <P as PrimeField>::Repr::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>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+fn random_shl_tests<P: PrimeField>() {
+    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>() {
-    let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
+fn random_shr_tests<P: PrimeField>() {
+    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/Cargo.toml

@@ -1,31 +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" }
-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"
-
-[features]
-default = ["u128-support"]
-u128-support = ["pairing/u128-support"]

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

@@ -1,113 +0,0 @@
-use pairing::{Engine, Field, PrimeField};
-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 pairing::bls12_381::{Bls12, Fr};
-    use pairing::PrimeField;
-
-    #[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 pairing::{
-    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

@@ -1,22 +0,0 @@
-extern crate pairing;
-extern crate bellman;
-extern crate blake2_rfc;
-extern crate digest;
-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

@@ -1,258 +0,0 @@
-use pairing::{
-    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)
-        }
-    }
-}
-
-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)]
-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)]
-pub struct PaymentAddress<E: JubjubEngine> {
-    pub pk_d: edwards::Point<E, PrimeOrder>,
-    pub diversifier: 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()
-            }
-        })
-    }
-}
-
-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> 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/LICENSE-APACHE

@@ -0,0 +1,202 @@
+                              Apache License
+                        Version 2.0, January 2004
+                     http://www.apache.org/licenses/
+
+TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
+
+1. Definitions.
+
+   "License" shall mean the terms and conditions for use, reproduction,
+   and distribution as defined by Sections 1 through 9 of this document.
+
+   "Licensor" shall mean the copyright owner or entity authorized by
+   the copyright owner that is granting the License.
+
+   "Legal Entity" shall mean the union of the acting entity and all
+   other entities that control, are controlled by, or are under common
+   control with that entity. For the purposes of this definition,
+   "control" means (i) the power, direct or indirect, to cause the
+   direction or management of such entity, whether by contract or
+   otherwise, or (ii) ownership of fifty percent (50%) or more of the
+   outstanding shares, or (iii) beneficial ownership of such entity.
+
+   "You" (or "Your") shall mean an individual or Legal Entity
+   exercising permissions granted by this License.
+
+   "Source" form shall mean the preferred form for making modifications,
+   including but not limited to software source code, documentation
+   source, and configuration files.
+
+   "Object" form shall mean any form resulting from mechanical
+   transformation or translation of a Source form, including but
+   not limited to compiled object code, generated documentation,
+   and conversions to other media types.
+
+   "Work" shall mean the work of authorship, whether in Source or
+   Object form, made available under the License, as indicated by a
+   copyright notice that is included in or attached to the work
+   (an example is provided in the Appendix below).
+
+   "Derivative Works" shall mean any work, whether in Source or Object
+   form, that is based on (or derived from) the Work and for which the
+   editorial revisions, annotations, elaborations, or other modifications
+   represent, as a whole, an original work of authorship. For the purposes
+   of this License, Derivative Works shall not include works that remain
+   separable from, or merely link (or bind by name) to the interfaces of,
+   the Work and Derivative Works thereof.
+
+   "Contribution" shall mean any work of authorship, including
+   the original version of the Work and any modifications or additions
+   to that Work or Derivative Works thereof, that is intentionally
+   submitted to Licensor for inclusion in the Work by the copyright owner
+   or by an individual or Legal Entity authorized to submit on behalf of
+   the copyright owner. For the purposes of this definition, "submitted"
+   means any form of electronic, verbal, or written communication sent
+   to the Licensor or its representatives, including but not limited to
+   communication on electronic mailing lists, source code control systems,
+   and issue tracking systems that are managed by, or on behalf of, the
+   Licensor for the purpose of discussing and improving the Work, but
+   excluding communication that is conspicuously marked or otherwise
+   designated in writing by the copyright owner as "Not a Contribution."
+
+   "Contributor" shall mean Licensor and any individual or Legal Entity
+   on behalf of whom a Contribution has been received by Licensor and
+   subsequently incorporated within the Work.
+
+2. Grant of Copyright License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   copyright license to reproduce, prepare Derivative Works of,
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+   Work and such Derivative Works in Source or Object form.
+
+3. Grant of Patent License. Subject to the terms and conditions of
+   this License, each Contributor hereby grants to You a perpetual,
+   worldwide, non-exclusive, no-charge, royalty-free, irrevocable
+   (except as stated in this section) patent license to make, have made,
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+   where such license applies only to those patent claims licensable
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+

zcash_client_backend/LICENSE-MIT

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2017-2019 Electric Coin Company
+
+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.

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";