Files
librustzcash/src/circuit/boolean.rs

1027 lines
38 KiB
Rust

use pairing::{
Engine,
Field,
PrimeField,
BitIterator
};
use bellman::{
ConstraintSystem,
SynthesisError,
LinearCombination,
Variable
};
use super::{
Assignment
};
/// Represents a variable in the constraint system which is guaranteed
/// to be either zero or one.
#[derive(Clone)]
pub struct AllocatedBit {
variable: Variable,
value: Option<bool>
}
impl AllocatedBit {
pub fn get_value(&self) -> Option<bool> {
self.value
}
pub fn get_variable(&self) -> Variable {
self.variable
}
/// Allocate a variable in the constraint system which can only be a
/// boolean value. Further, constrain that the boolean is false
/// unless the condition is false.
pub fn alloc_conditionally<E, CS>(
mut cs: CS,
value: Option<bool>,
must_be_false: &AllocatedBit
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
let var = cs.alloc(|| "boolean", || {
if *value.get()? {
Ok(E::Fr::one())
} else {
Ok(E::Fr::zero())
}
})?;
// Constrain: (1 - must_be_false - a) * a = 0
// if must_be_false is true, the equation
// reduces to -a * a = 0, which implies a = 0.
// if must_be_false is false, the equation
// reduces to (1 - a) * a = 0, which is a
// traditional boolean constraint.
cs.enforce(
|| "boolean constraint",
|lc| lc + CS::one() - must_be_false.variable - var,
|lc| lc + var,
|lc| lc
);
Ok(AllocatedBit {
variable: var,
value: value
})
}
/// Allocate a variable in the constraint system which can only be a
/// boolean value.
pub fn alloc<E, CS>(
mut cs: CS,
value: Option<bool>,
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
let var = cs.alloc(|| "boolean", || {
if *value.get()? {
Ok(E::Fr::one())
} else {
Ok(E::Fr::zero())
}
})?;
// Constrain: (1 - a) * a = 0
// This constrains a to be either 0 or 1.
cs.enforce(
|| "boolean constraint",
|lc| lc + CS::one() - var,
|lc| lc + var,
|lc| lc
);
Ok(AllocatedBit {
variable: var,
value: value
})
}
/// Performs an XOR operation over the two operands, returning
/// an `AllocatedBit`.
pub fn xor<E, CS>(
mut cs: CS,
a: &Self,
b: &Self
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
let mut result_value = None;
let result_var = cs.alloc(|| "xor result", || {
if *a.value.get()? ^ *b.value.get()? {
result_value = Some(true);
Ok(E::Fr::one())
} else {
result_value = Some(false);
Ok(E::Fr::zero())
}
})?;
// Constrain (a + a) * (b) = (a + b - c)
// Given that a and b are boolean constrained, if they
// are equal, the only solution for c is 0, and if they
// are different, the only solution for c is 1.
//
// ¬(a ∧ b) ∧ ¬(¬a ∧ ¬b) = c
// (1 - (a * b)) * (1 - ((1 - a) * (1 - b))) = c
// (1 - ab) * (1 - (1 - a - b + ab)) = c
// (1 - ab) * (a + b - ab) = c
// a + b - ab - (a^2)b - (b^2)a + (a^2)(b^2) = c
// a + b - ab - ab - ab + ab = c
// a + b - 2ab = c
// -2a * b = c - a - b
// 2a * b = a + b - c
// (a + a) * b = a + b - c
cs.enforce(
|| "xor constraint",
|lc| lc + a.variable + a.variable,
|lc| lc + b.variable,
|lc| lc + a.variable + b.variable - result_var
);
Ok(AllocatedBit {
variable: result_var,
value: result_value
})
}
/// Performs an AND operation over the two operands, returning
/// an `AllocatedBit`.
pub fn and<E, CS>(
mut cs: CS,
a: &Self,
b: &Self
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
let mut result_value = None;
let result_var = cs.alloc(|| "and result", || {
if *a.value.get()? & *b.value.get()? {
result_value = Some(true);
Ok(E::Fr::one())
} else {
result_value = Some(false);
Ok(E::Fr::zero())
}
})?;
// Constrain (a) * (b) = (c), ensuring c is 1 iff
// a AND b are both 1.
cs.enforce(
|| "and constraint",
|lc| lc + a.variable,
|lc| lc + b.variable,
|lc| lc + result_var
);
Ok(AllocatedBit {
variable: result_var,
value: result_value
})
}
/// Calculates `a AND (NOT b)`.
pub fn and_not<E, CS>(
mut cs: CS,
a: &Self,
b: &Self
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
let mut result_value = None;
let result_var = cs.alloc(|| "and not result", || {
if *a.value.get()? & !*b.value.get()? {
result_value = Some(true);
Ok(E::Fr::one())
} else {
result_value = Some(false);
Ok(E::Fr::zero())
}
})?;
// Constrain (a) * (1 - b) = (c), ensuring c is 1 iff
// a is true and b is false, and otherwise c is 0.
cs.enforce(
|| "and not constraint",
|lc| lc + a.variable,
|lc| lc + CS::one() - b.variable,
|lc| lc + result_var
);
Ok(AllocatedBit {
variable: result_var,
value: result_value
})
}
/// Calculates `(NOT a) AND (NOT b)`.
pub fn nor<E, CS>(
mut cs: CS,
a: &Self,
b: &Self
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
let mut result_value = None;
let result_var = cs.alloc(|| "nor result", || {
if !*a.value.get()? & !*b.value.get()? {
result_value = Some(true);
Ok(E::Fr::one())
} else {
result_value = Some(false);
Ok(E::Fr::zero())
}
})?;
// Constrain (1 - a) * (1 - b) = (c), ensuring c is 1 iff
// a and b are both false, and otherwise c is 0.
cs.enforce(
|| "nor constraint",
|lc| lc + CS::one() - a.variable,
|lc| lc + CS::one() - b.variable,
|lc| lc + result_var
);
Ok(AllocatedBit {
variable: result_var,
value: result_value
})
}
}
pub fn u64_into_boolean_vec_le<E: Engine, CS: ConstraintSystem<E>>(
mut cs: CS,
value: Option<u64>
) -> Result<Vec<Boolean>, SynthesisError>
{
let values = match value {
Some(ref value) => {
let mut tmp = Vec::with_capacity(64);
for i in 0..64 {
tmp.push(Some(*value >> i & 1 == 1));
}
tmp
},
None => {
vec![None; 64]
}
};
let bits = values.into_iter().enumerate().map(|(i, b)| {
Ok(Boolean::from(AllocatedBit::alloc(
cs.namespace(|| format!("bit {}", i)),
b
)?))
}).collect::<Result<Vec<_>, SynthesisError>>()?;
Ok(bits)
}
pub fn field_into_allocated_bits_be<E: Engine, CS: ConstraintSystem<E>, F: PrimeField>(
mut cs: CS,
value: Option<F>
) -> Result<Vec<AllocatedBit>, SynthesisError>
{
let values = match value {
Some(ref value) => {
let mut field_char = BitIterator::new(F::char());
let mut tmp = Vec::with_capacity(F::NUM_BITS as usize);
let mut found_one = false;
for b in BitIterator::new(value.into_repr()) {
// Skip leading bits
found_one |= field_char.next().unwrap();
if !found_one {
continue;
}
tmp.push(Some(b));
}
assert_eq!(tmp.len(), F::NUM_BITS as usize);
tmp
},
None => {
vec![None; F::NUM_BITS as usize]
}
};
let bits = values.into_iter().enumerate().map(|(i, b)| {
AllocatedBit::alloc(
cs.namespace(|| format!("bit {}", i)),
b
)
}).collect::<Result<Vec<_>, SynthesisError>>()?;
Ok(bits)
}
/// This is a boolean value which may be either a constant or
/// an interpretation of an `AllocatedBit`.
#[derive(Clone)]
pub enum Boolean {
/// Existential view of the boolean variable
Is(AllocatedBit),
/// Negated view of the boolean variable
Not(AllocatedBit),
/// Constant (not an allocated variable)
Constant(bool)
}
impl Boolean {
pub fn enforce_equal<E, CS>(
mut cs: CS,
a: &Self,
b: &Self
) -> Result<(), SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
let c = Self::xor(&mut cs, a, b)?;
match c {
Boolean::Constant(false) => {
Ok(())
},
Boolean::Constant(true) => {
Err(SynthesisError::Unsatisfiable)
},
Boolean::Is(ref res) => {
cs.enforce(
|| "enforce equals zero",
|lc| lc,
|lc| lc,
|lc| lc + res.get_variable()
);
Ok(())
},
Boolean::Not(ref res) => {
cs.enforce(
|| "enforce equals one",
|lc| lc,
|lc| lc,
|lc| lc + CS::one() - res.get_variable()
);
Ok(())
},
}
}
pub fn get_value(&self) -> Option<bool> {
match self {
&Boolean::Constant(c) => Some(c),
&Boolean::Is(ref v) => v.get_value(),
&Boolean::Not(ref v) => v.get_value().map(|b| !b)
}
}
pub fn lc<E: Engine>(
&self,
one: Variable,
coeff: E::Fr
) -> LinearCombination<E>
{
match self {
&Boolean::Constant(c) => {
if c {
LinearCombination::<E>::zero() + (coeff, one)
} else {
LinearCombination::<E>::zero()
}
},
&Boolean::Is(ref v) => {
LinearCombination::<E>::zero() + (coeff, v.get_variable())
},
&Boolean::Not(ref v) => {
LinearCombination::<E>::zero() + (coeff, one) - (coeff, v.get_variable())
}
}
}
/// Construct a boolean from a known constant
pub fn constant(b: bool) -> Self {
Boolean::Constant(b)
}
/// Return a negated interpretation of this boolean.
pub fn not(&self) -> Self {
match self {
&Boolean::Constant(c) => Boolean::Constant(!c),
&Boolean::Is(ref v) => Boolean::Not(v.clone()),
&Boolean::Not(ref v) => Boolean::Is(v.clone())
}
}
/// Perform XOR over two boolean operands
pub fn xor<'a, E, CS>(
cs: CS,
a: &'a Self,
b: &'a Self
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
match (a, b) {
(&Boolean::Constant(false), x) | (x, &Boolean::Constant(false)) => Ok(x.clone()),
(&Boolean::Constant(true), x) | (x, &Boolean::Constant(true)) => Ok(x.not()),
// a XOR (NOT b) = NOT(a XOR b)
(is @ &Boolean::Is(_), not @ &Boolean::Not(_)) | (not @ &Boolean::Not(_), is @ &Boolean::Is(_)) => {
Ok(Boolean::xor(
cs,
is,
&not.not()
)?.not())
},
// a XOR b = (NOT a) XOR (NOT b)
(&Boolean::Is(ref a), &Boolean::Is(ref b)) | (&Boolean::Not(ref a), &Boolean::Not(ref b)) => {
Ok(Boolean::Is(AllocatedBit::xor(cs, a, b)?))
}
}
}
/// Perform AND over two boolean operands
pub fn and<'a, E, CS>(
cs: CS,
a: &'a Self,
b: &'a Self
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
match (a, b) {
// false AND x is always false
(&Boolean::Constant(false), _) | (_, &Boolean::Constant(false)) => Ok(Boolean::Constant(false)),
// true AND x is always x
(&Boolean::Constant(true), x) | (x, &Boolean::Constant(true)) => Ok(x.clone()),
// a AND (NOT b)
(&Boolean::Is(ref is), &Boolean::Not(ref not)) | (&Boolean::Not(ref not), &Boolean::Is(ref is)) => {
Ok(Boolean::Is(AllocatedBit::and_not(cs, is, not)?))
},
// (NOT a) AND (NOT b) = a NOR b
(&Boolean::Not(ref a), &Boolean::Not(ref b)) => {
Ok(Boolean::Is(AllocatedBit::nor(cs, a, b)?))
},
// a AND b
(&Boolean::Is(ref a), &Boolean::Is(ref b)) => {
Ok(Boolean::Is(AllocatedBit::and(cs, a, b)?))
}
}
}
}
impl From<AllocatedBit> for Boolean {
fn from(b: AllocatedBit) -> Boolean {
Boolean::Is(b)
}
}
#[cfg(test)]
mod test {
use bellman::{ConstraintSystem};
use pairing::bls12_381::{Bls12, Fr};
use pairing::{Field, PrimeField};
use ::circuit::test::*;
use super::{
AllocatedBit,
Boolean,
field_into_allocated_bits_be,
u64_into_boolean_vec_le
};
#[test]
fn test_allocated_bit() {
let mut cs = TestConstraintSystem::<Bls12>::new();
AllocatedBit::alloc(&mut cs, Some(true)).unwrap();
assert!(cs.get("boolean") == Fr::one());
assert!(cs.is_satisfied());
cs.set("boolean", Fr::zero());
assert!(cs.is_satisfied());
cs.set("boolean", Fr::from_str("2").unwrap());
assert!(!cs.is_satisfied());
assert!(cs.which_is_unsatisfied() == Some("boolean constraint"));
}
#[test]
fn test_xor() {
for a_val in [false, true].iter() {
for b_val in [false, true].iter() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let a = AllocatedBit::alloc(cs.namespace(|| "a"), Some(*a_val)).unwrap();
let b = AllocatedBit::alloc(cs.namespace(|| "b"), Some(*b_val)).unwrap();
let c = AllocatedBit::xor(&mut cs, &a, &b).unwrap();
assert_eq!(c.value.unwrap(), *a_val ^ *b_val);
assert!(cs.is_satisfied());
assert!(cs.get("a/boolean") == if *a_val { Field::one() } else { Field::zero() });
assert!(cs.get("b/boolean") == if *b_val { Field::one() } else { Field::zero() });
assert!(cs.get("xor result") == if *a_val ^ *b_val { Field::one() } else { Field::zero() });
// Invert the result and check if the constraint system is still satisfied
cs.set("xor result", if *a_val ^ *b_val { Field::zero() } else { Field::one() });
assert!(!cs.is_satisfied());
}
}
}
#[test]
fn test_and() {
for a_val in [false, true].iter() {
for b_val in [false, true].iter() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let a = AllocatedBit::alloc(cs.namespace(|| "a"), Some(*a_val)).unwrap();
let b = AllocatedBit::alloc(cs.namespace(|| "b"), Some(*b_val)).unwrap();
let c = AllocatedBit::and(&mut cs, &a, &b).unwrap();
assert_eq!(c.value.unwrap(), *a_val & *b_val);
assert!(cs.is_satisfied());
assert!(cs.get("a/boolean") == if *a_val { Field::one() } else { Field::zero() });
assert!(cs.get("b/boolean") == if *b_val { Field::one() } else { Field::zero() });
assert!(cs.get("and result") == if *a_val & *b_val { Field::one() } else { Field::zero() });
// Invert the result and check if the constraint system is still satisfied
cs.set("and result", if *a_val & *b_val { Field::zero() } else { Field::one() });
assert!(!cs.is_satisfied());
}
}
}
#[test]
fn test_and_not() {
for a_val in [false, true].iter() {
for b_val in [false, true].iter() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let a = AllocatedBit::alloc(cs.namespace(|| "a"), Some(*a_val)).unwrap();
let b = AllocatedBit::alloc(cs.namespace(|| "b"), Some(*b_val)).unwrap();
let c = AllocatedBit::and_not(&mut cs, &a, &b).unwrap();
assert_eq!(c.value.unwrap(), *a_val & !*b_val);
assert!(cs.is_satisfied());
assert!(cs.get("a/boolean") == if *a_val { Field::one() } else { Field::zero() });
assert!(cs.get("b/boolean") == if *b_val { Field::one() } else { Field::zero() });
assert!(cs.get("and not result") == if *a_val & !*b_val { Field::one() } else { Field::zero() });
// Invert the result and check if the constraint system is still satisfied
cs.set("and not result", if *a_val & !*b_val { Field::zero() } else { Field::one() });
assert!(!cs.is_satisfied());
}
}
}
#[test]
fn test_nor() {
for a_val in [false, true].iter() {
for b_val in [false, true].iter() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let a = AllocatedBit::alloc(cs.namespace(|| "a"), Some(*a_val)).unwrap();
let b = AllocatedBit::alloc(cs.namespace(|| "b"), Some(*b_val)).unwrap();
let c = AllocatedBit::nor(&mut cs, &a, &b).unwrap();
assert_eq!(c.value.unwrap(), !*a_val & !*b_val);
assert!(cs.is_satisfied());
assert!(cs.get("a/boolean") == if *a_val { Field::one() } else { Field::zero() });
assert!(cs.get("b/boolean") == if *b_val { Field::one() } else { Field::zero() });
assert!(cs.get("nor result") == if !*a_val & !*b_val { Field::one() } else { Field::zero() });
// Invert the result and check if the constraint system is still satisfied
cs.set("nor result", if !*a_val & !*b_val { Field::zero() } else { Field::one() });
assert!(!cs.is_satisfied());
}
}
}
#[test]
fn test_enforce_equal() {
for a_bool in [false, true].iter().cloned() {
for b_bool in [false, true].iter().cloned() {
for a_neg in [false, true].iter().cloned() {
for b_neg in [false, true].iter().cloned() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let mut a = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "a"), Some(a_bool)).unwrap());
let mut b = Boolean::from(AllocatedBit::alloc(cs.namespace(|| "b"), Some(b_bool)).unwrap());
if a_neg {
a = a.not();
}
if b_neg {
b = b.not();
}
Boolean::enforce_equal(&mut cs, &a, &b).unwrap();
assert_eq!(
cs.is_satisfied(),
(a_bool ^ a_neg) == (b_bool ^ b_neg)
);
}
}
}
}
}
#[test]
fn test_boolean_negation() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let mut b = Boolean::from(AllocatedBit::alloc(&mut cs, Some(true)).unwrap());
match b {
Boolean::Is(_) => {},
_ => panic!("unexpected value")
}
b = b.not();
match b {
Boolean::Not(_) => {},
_ => panic!("unexpected value")
}
b = b.not();
match b {
Boolean::Is(_) => {},
_ => panic!("unexpected value")
}
b = Boolean::constant(true);
match b {
Boolean::Constant(true) => {},
_ => panic!("unexpected value")
}
b = b.not();
match b {
Boolean::Constant(false) => {},
_ => panic!("unexpected value")
}
b = b.not();
match b {
Boolean::Constant(true) => {},
_ => panic!("unexpected value")
}
}
#[derive(Copy, Clone, Debug)]
enum OperandType {
True,
False,
AllocatedTrue,
AllocatedFalse,
NegatedAllocatedTrue,
NegatedAllocatedFalse
}
#[test]
fn test_boolean_xor() {
let variants = [
OperandType::True,
OperandType::False,
OperandType::AllocatedTrue,
OperandType::AllocatedFalse,
OperandType::NegatedAllocatedTrue,
OperandType::NegatedAllocatedFalse
];
for first_operand in variants.iter().cloned() {
for second_operand in variants.iter().cloned() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let a;
let b;
{
let mut dyn_construct = |operand, name| {
let cs = cs.namespace(|| name);
match operand {
OperandType::True => Boolean::constant(true),
OperandType::False => Boolean::constant(false),
OperandType::AllocatedTrue => Boolean::from(AllocatedBit::alloc(cs, Some(true)).unwrap()),
OperandType::AllocatedFalse => Boolean::from(AllocatedBit::alloc(cs, Some(false)).unwrap()),
OperandType::NegatedAllocatedTrue => Boolean::from(AllocatedBit::alloc(cs, Some(true)).unwrap()).not(),
OperandType::NegatedAllocatedFalse => Boolean::from(AllocatedBit::alloc(cs, Some(false)).unwrap()).not(),
}
};
a = dyn_construct(first_operand, "a");
b = dyn_construct(second_operand, "b");
}
let c = Boolean::xor(&mut cs, &a, &b).unwrap();
assert!(cs.is_satisfied());
match (first_operand, second_operand, c) {
(OperandType::True, OperandType::True, Boolean::Constant(false)) => {},
(OperandType::True, OperandType::False, Boolean::Constant(true)) => {},
(OperandType::True, OperandType::AllocatedTrue, Boolean::Not(_)) => {},
(OperandType::True, OperandType::AllocatedFalse, Boolean::Not(_)) => {},
(OperandType::True, OperandType::NegatedAllocatedTrue, Boolean::Is(_)) => {},
(OperandType::True, OperandType::NegatedAllocatedFalse, Boolean::Is(_)) => {},
(OperandType::False, OperandType::True, Boolean::Constant(true)) => {},
(OperandType::False, OperandType::False, Boolean::Constant(false)) => {},
(OperandType::False, OperandType::AllocatedTrue, Boolean::Is(_)) => {},
(OperandType::False, OperandType::AllocatedFalse, Boolean::Is(_)) => {},
(OperandType::False, OperandType::NegatedAllocatedTrue, Boolean::Not(_)) => {},
(OperandType::False, OperandType::NegatedAllocatedFalse, Boolean::Not(_)) => {},
(OperandType::AllocatedTrue, OperandType::True, Boolean::Not(_)) => {},
(OperandType::AllocatedTrue, OperandType::False, Boolean::Is(_)) => {},
(OperandType::AllocatedTrue, OperandType::AllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("xor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::AllocatedTrue, OperandType::AllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("xor result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::AllocatedTrue, OperandType::NegatedAllocatedTrue, Boolean::Not(ref v)) => {
assert!(cs.get("xor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::AllocatedTrue, OperandType::NegatedAllocatedFalse, Boolean::Not(ref v)) => {
assert!(cs.get("xor result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::AllocatedFalse, OperandType::True, Boolean::Not(_)) => {},
(OperandType::AllocatedFalse, OperandType::False, Boolean::Is(_)) => {},
(OperandType::AllocatedFalse, OperandType::AllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("xor result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::AllocatedFalse, OperandType::AllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("xor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::AllocatedFalse, OperandType::NegatedAllocatedTrue, Boolean::Not(ref v)) => {
assert!(cs.get("xor result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::AllocatedFalse, OperandType::NegatedAllocatedFalse, Boolean::Not(ref v)) => {
assert!(cs.get("xor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedTrue, OperandType::True, Boolean::Is(_)) => {},
(OperandType::NegatedAllocatedTrue, OperandType::False, Boolean::Not(_)) => {},
(OperandType::NegatedAllocatedTrue, OperandType::AllocatedTrue, Boolean::Not(ref v)) => {
assert!(cs.get("xor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedTrue, OperandType::AllocatedFalse, Boolean::Not(ref v)) => {
assert!(cs.get("xor result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::NegatedAllocatedTrue, OperandType::NegatedAllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("xor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedTrue, OperandType::NegatedAllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("xor result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::NegatedAllocatedFalse, OperandType::True, Boolean::Is(_)) => {},
(OperandType::NegatedAllocatedFalse, OperandType::False, Boolean::Not(_)) => {},
(OperandType::NegatedAllocatedFalse, OperandType::AllocatedTrue, Boolean::Not(ref v)) => {
assert!(cs.get("xor result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::NegatedAllocatedFalse, OperandType::AllocatedFalse, Boolean::Not(ref v)) => {
assert!(cs.get("xor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedFalse, OperandType::NegatedAllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("xor result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::NegatedAllocatedFalse, OperandType::NegatedAllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("xor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
_ => panic!("this should never be encountered")
}
}
}
}
#[test]
fn test_boolean_and() {
let variants = [
OperandType::True,
OperandType::False,
OperandType::AllocatedTrue,
OperandType::AllocatedFalse,
OperandType::NegatedAllocatedTrue,
OperandType::NegatedAllocatedFalse
];
for first_operand in variants.iter().cloned() {
for second_operand in variants.iter().cloned() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let a;
let b;
{
let mut dyn_construct = |operand, name| {
let cs = cs.namespace(|| name);
match operand {
OperandType::True => Boolean::constant(true),
OperandType::False => Boolean::constant(false),
OperandType::AllocatedTrue => Boolean::from(AllocatedBit::alloc(cs, Some(true)).unwrap()),
OperandType::AllocatedFalse => Boolean::from(AllocatedBit::alloc(cs, Some(false)).unwrap()),
OperandType::NegatedAllocatedTrue => Boolean::from(AllocatedBit::alloc(cs, Some(true)).unwrap()).not(),
OperandType::NegatedAllocatedFalse => Boolean::from(AllocatedBit::alloc(cs, Some(false)).unwrap()).not(),
}
};
a = dyn_construct(first_operand, "a");
b = dyn_construct(second_operand, "b");
}
let c = Boolean::and(&mut cs, &a, &b).unwrap();
assert!(cs.is_satisfied());
match (first_operand, second_operand, c) {
(OperandType::True, OperandType::True, Boolean::Constant(true)) => {},
(OperandType::True, OperandType::False, Boolean::Constant(false)) => {},
(OperandType::True, OperandType::AllocatedTrue, Boolean::Is(_)) => {},
(OperandType::True, OperandType::AllocatedFalse, Boolean::Is(_)) => {},
(OperandType::True, OperandType::NegatedAllocatedTrue, Boolean::Not(_)) => {},
(OperandType::True, OperandType::NegatedAllocatedFalse, Boolean::Not(_)) => {},
(OperandType::False, OperandType::True, Boolean::Constant(false)) => {},
(OperandType::False, OperandType::False, Boolean::Constant(false)) => {},
(OperandType::False, OperandType::AllocatedTrue, Boolean::Constant(false)) => {},
(OperandType::False, OperandType::AllocatedFalse, Boolean::Constant(false)) => {},
(OperandType::False, OperandType::NegatedAllocatedTrue, Boolean::Constant(false)) => {},
(OperandType::False, OperandType::NegatedAllocatedFalse, Boolean::Constant(false)) => {},
(OperandType::AllocatedTrue, OperandType::True, Boolean::Is(_)) => {},
(OperandType::AllocatedTrue, OperandType::False, Boolean::Constant(false)) => {},
(OperandType::AllocatedTrue, OperandType::AllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("and result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::AllocatedTrue, OperandType::AllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("and result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::AllocatedTrue, OperandType::NegatedAllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("and not result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::AllocatedTrue, OperandType::NegatedAllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("and not result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::AllocatedFalse, OperandType::True, Boolean::Is(_)) => {},
(OperandType::AllocatedFalse, OperandType::False, Boolean::Constant(false)) => {},
(OperandType::AllocatedFalse, OperandType::AllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("and result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::AllocatedFalse, OperandType::AllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("and result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::AllocatedFalse, OperandType::NegatedAllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("and not result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::AllocatedFalse, OperandType::NegatedAllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("and not result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedTrue, OperandType::True, Boolean::Not(_)) => {},
(OperandType::NegatedAllocatedTrue, OperandType::False, Boolean::Constant(false)) => {},
(OperandType::NegatedAllocatedTrue, OperandType::AllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("and not result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedTrue, OperandType::AllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("and not result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedTrue, OperandType::NegatedAllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("nor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedTrue, OperandType::NegatedAllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("nor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedFalse, OperandType::True, Boolean::Not(_)) => {},
(OperandType::NegatedAllocatedFalse, OperandType::False, Boolean::Constant(false)) => {},
(OperandType::NegatedAllocatedFalse, OperandType::AllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("and not result") == Field::one());
assert_eq!(v.value, Some(true));
},
(OperandType::NegatedAllocatedFalse, OperandType::AllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("and not result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedFalse, OperandType::NegatedAllocatedTrue, Boolean::Is(ref v)) => {
assert!(cs.get("nor result") == Field::zero());
assert_eq!(v.value, Some(false));
},
(OperandType::NegatedAllocatedFalse, OperandType::NegatedAllocatedFalse, Boolean::Is(ref v)) => {
assert!(cs.get("nor result") == Field::one());
assert_eq!(v.value, Some(true));
},
_ => {
panic!("unexpected behavior at {:?} AND {:?}", first_operand, second_operand);
}
}
}
}
}
#[test]
fn test_u64_into_boolean_vec_le() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let bits = u64_into_boolean_vec_le(&mut cs, Some(17234652694787248421)).unwrap();
assert!(cs.is_satisfied());
assert_eq!(bits.len(), 64);
assert_eq!(bits[63 - 0].get_value().unwrap(), true);
assert_eq!(bits[63 - 1].get_value().unwrap(), true);
assert_eq!(bits[63 - 2].get_value().unwrap(), true);
assert_eq!(bits[63 - 3].get_value().unwrap(), false);
assert_eq!(bits[63 - 4].get_value().unwrap(), true);
assert_eq!(bits[63 - 5].get_value().unwrap(), true);
assert_eq!(bits[63 - 20].get_value().unwrap(), true);
assert_eq!(bits[63 - 21].get_value().unwrap(), false);
assert_eq!(bits[63 - 22].get_value().unwrap(), false);
}
#[test]
fn test_field_into_allocated_bits_be() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let r = Fr::from_str("9147677615426976802526883532204139322118074541891858454835346926874644257775").unwrap();
let bits = field_into_allocated_bits_be(&mut cs, Some(r)).unwrap();
assert!(cs.is_satisfied());
assert_eq!(bits.len(), 255);
assert_eq!(bits[0].value.unwrap(), false);
assert_eq!(bits[1].value.unwrap(), false);
assert_eq!(bits[2].value.unwrap(), true);
assert_eq!(bits[3].value.unwrap(), false);
assert_eq!(bits[4].value.unwrap(), true);
assert_eq!(bits[5].value.unwrap(), false);
assert_eq!(bits[20].value.unwrap(), true);
assert_eq!(bits[23].value.unwrap(), true);
}
}