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Merge pull request #54 from ebfull/sprout-circuit-minimal

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Sprout circuit implementation
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ebfull 2018-04-02 16:55:09 -06:00 committed by GitHub
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1
Cargo.toml
View File

@ -24,6 +24,7 @@ rev = "7a5b5fc99ae483a0043db7547fb79a6fa44b88a9"
[dev-dependencies]
hex-literal = "0.1"
rust-crypto = "0.2"
[features]
default = ["u128-support"]

464
src/circuit/boolean.rs
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@ -523,6 +523,278 @@ impl Boolean {
}
}
}
/// Computes (a and b) xor ((not a) and c)
pub fn sha256_ch<'a, E, CS>(
mut cs: CS,
a: &'a Self,
b: &'a Self,
c: &'a Self
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
let ch_value = match (a.get_value(), b.get_value(), c.get_value()) {
(Some(a), Some(b), Some(c)) => {
// (a and b) xor ((not a) and c)
Some((a & b) ^ ((!a) & c))
},
_ => None
};
match (a, b, c) {
(&Boolean::Constant(_),
&Boolean::Constant(_),
&Boolean::Constant(_)) => {
// They're all constants, so we can just compute the value.
return Ok(Boolean::Constant(ch_value.expect("they're all constants")));
},
(&Boolean::Constant(false), _, c) => {
// If a is false
// (a and b) xor ((not a) and c)
// equals
// (false) xor (c)
// equals
// c
return Ok(c.clone());
},
(a, &Boolean::Constant(false), c) => {
// If b is false
// (a and b) xor ((not a) and c)
// equals
// ((not a) and c)
return Boolean::and(
cs,
&a.not(),
&c
);
},
(a, b, &Boolean::Constant(false)) => {
// If c is false
// (a and b) xor ((not a) and c)
// equals
// (a and b)
return Boolean::and(
cs,
&a,
&b
);
},
(a, b, &Boolean::Constant(true)) => {
// If c is true
// (a and b) xor ((not a) and c)
// equals
// (a and b) xor (not a)
// equals
// not (a and (not b))
return Ok(Boolean::and(
cs,
&a,
&b.not()
)?.not());
},
(a, &Boolean::Constant(true), c) => {
// If b is true
// (a and b) xor ((not a) and c)
// equals
// a xor ((not a) and c)
// equals
// not ((not a) and (not c))
return Ok(Boolean::and(
cs,
&a.not(),
&c.not()
)?.not());
},
(&Boolean::Constant(true), _, _) => {
// If a is true
// (a and b) xor ((not a) and c)
// equals
// b xor ((not a) and c)
// So we just continue!
},
(&Boolean::Is(_), &Boolean::Is(_), &Boolean::Is(_)) |
(&Boolean::Is(_), &Boolean::Is(_), &Boolean::Not(_)) |
(&Boolean::Is(_), &Boolean::Not(_), &Boolean::Is(_)) |
(&Boolean::Is(_), &Boolean::Not(_), &Boolean::Not(_)) |
(&Boolean::Not(_), &Boolean::Is(_), &Boolean::Is(_)) |
(&Boolean::Not(_), &Boolean::Is(_), &Boolean::Not(_)) |
(&Boolean::Not(_), &Boolean::Not(_), &Boolean::Is(_)) |
(&Boolean::Not(_), &Boolean::Not(_), &Boolean::Not(_))
=> {}
}
let ch = cs.alloc(|| "ch", || {
ch_value.get().map(|v| {
if *v {
E::Fr::one()
} else {
E::Fr::zero()
}
})
})?;
// a(b - c) = ch - c
cs.enforce(
|| "ch computation",
|_| b.lc(CS::one(), E::Fr::one())
- &c.lc(CS::one(), E::Fr::one()),
|_| a.lc(CS::one(), E::Fr::one()),
|lc| lc + ch - &c.lc(CS::one(), E::Fr::one())
);
Ok(AllocatedBit {
value: ch_value,
variable: ch
}.into())
}
/// Computes (a and b) xor (a and c) xor (b and c)
pub fn sha256_maj<'a, E, CS>(
mut cs: CS,
a: &'a Self,
b: &'a Self,
c: &'a Self,
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>
{
let maj_value = match (a.get_value(), b.get_value(), c.get_value()) {
(Some(a), Some(b), Some(c)) => {
// (a and b) xor (a and c) xor (b and c)
Some((a & b) ^ (a & c) ^ (b & c))
},
_ => None
};
match (a, b, c) {
(&Boolean::Constant(_),
&Boolean::Constant(_),
&Boolean::Constant(_)) => {
// They're all constants, so we can just compute the value.
return Ok(Boolean::Constant(maj_value.expect("they're all constants")));
},
(&Boolean::Constant(false), b, c) => {
// If a is false,
// (a and b) xor (a and c) xor (b and c)
// equals
// (b and c)
return Boolean::and(
cs,
b,
c
);
},
(a, &Boolean::Constant(false), c) => {
// If b is false,
// (a and b) xor (a and c) xor (b and c)
// equals
// (a and c)
return Boolean::and(
cs,
a,
c
);
},
(a, b, &Boolean::Constant(false)) => {
// If c is false,
// (a and b) xor (a and c) xor (b and c)
// equals
// (a and b)
return Boolean::and(
cs,
a,
b
);
},
(a, b, &Boolean::Constant(true)) => {
// If c is true,
// (a and b) xor (a and c) xor (b and c)
// equals
// (a and b) xor (a) xor (b)
// equals
// not ((not a) and (not b))
return Ok(Boolean::and(
cs,
&a.not(),
&b.not()
)?.not());
},
(a, &Boolean::Constant(true), c) => {
// If b is true,
// (a and b) xor (a and c) xor (b and c)
// equals
// (a) xor (a and c) xor (c)
return Ok(Boolean::and(
cs,
&a.not(),
&c.not()
)?.not());
},
(&Boolean::Constant(true), b, c) => {
// If a is true,
// (a and b) xor (a and c) xor (b and c)
// equals
// (b) xor (c) xor (b and c)
return Ok(Boolean::and(
cs,
&b.not(),
&c.not()
)?.not());
},
(&Boolean::Is(_), &Boolean::Is(_), &Boolean::Is(_)) |
(&Boolean::Is(_), &Boolean::Is(_), &Boolean::Not(_)) |
(&Boolean::Is(_), &Boolean::Not(_), &Boolean::Is(_)) |
(&Boolean::Is(_), &Boolean::Not(_), &Boolean::Not(_)) |
(&Boolean::Not(_), &Boolean::Is(_), &Boolean::Is(_)) |
(&Boolean::Not(_), &Boolean::Is(_), &Boolean::Not(_)) |
(&Boolean::Not(_), &Boolean::Not(_), &Boolean::Is(_)) |
(&Boolean::Not(_), &Boolean::Not(_), &Boolean::Not(_))
=> {}
}
let maj = cs.alloc(|| "maj", || {
maj_value.get().map(|v| {
if *v {
E::Fr::one()
} else {
E::Fr::zero()
}
})
})?;
// ¬(¬a ∧ ¬b) ∧ ¬(¬a ∧ ¬c) ∧ ¬(¬b ∧ ¬c)
// (1 - ((1 - a) * (1 - b))) * (1 - ((1 - a) * (1 - c))) * (1 - ((1 - b) * (1 - c)))
// (a + b - ab) * (a + c - ac) * (b + c - bc)
// -2abc + ab + ac + bc
// a (-2bc + b + c) + bc
//
// (b) * (c) = (bc)
// (2bc - b - c) * (a) = bc - maj
let bc = Self::and(
cs.namespace(|| "b and c"),
b,
c
)?;
cs.enforce(
|| "maj computation",
|_| bc.lc(CS::one(), E::Fr::one())
+ &bc.lc(CS::one(), E::Fr::one())
- &b.lc(CS::one(), E::Fr::one())
- &c.lc(CS::one(), E::Fr::one()),
|_| a.lc(CS::one(), E::Fr::one()),
|_| bc.lc(CS::one(), E::Fr::one()) - maj
);
Ok(AllocatedBit {
value: maj_value,
variable: maj
}.into())
}
}
impl From<AllocatedBit> for Boolean {
@ -797,6 +1069,31 @@ mod test {
NegatedAllocatedFalse
}
impl OperandType {
fn is_constant(&self) -> bool {
match *self {
OperandType::True => true,
OperandType::False => true,
OperandType::AllocatedTrue => false,
OperandType::AllocatedFalse => false,
OperandType::NegatedAllocatedTrue => false,
OperandType::NegatedAllocatedFalse => false
}
}
fn val(&self) -> bool {
match *self {
OperandType::True => true,
OperandType::False => false,
OperandType::AllocatedTrue => true,
OperandType::AllocatedFalse => false,
OperandType::NegatedAllocatedTrue => false,
OperandType::NegatedAllocatedFalse => true
}
}
}
#[test]
fn test_boolean_xor() {
let variants = [
@ -1115,4 +1412,171 @@ mod test {
assert_eq!(bits[254 - 20].value.unwrap(), true);
assert_eq!(bits[254 - 23].value.unwrap(), true);
}
#[test]
fn test_boolean_sha256_ch() {
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() {
for third_operand in variants.iter().cloned() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let a;
let b;
let c;
// ch = (a and b) xor ((not a) and c)
let expected = (first_operand.val() & second_operand.val()) ^
((!first_operand.val()) & third_operand.val());
{
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");
c = dyn_construct(third_operand, "c");
}
let maj = Boolean::sha256_ch(&mut cs, &a, &b, &c).unwrap();
assert!(cs.is_satisfied());
assert_eq!(maj.get_value().unwrap(), expected);
if first_operand.is_constant() ||
second_operand.is_constant() ||
third_operand.is_constant()
{
if first_operand.is_constant() &&
second_operand.is_constant() &&
third_operand.is_constant()
{
assert_eq!(cs.num_constraints(), 0);
}
}
else
{
assert_eq!(cs.get("ch"), {
if expected {
Fr::one()
} else {
Fr::zero()
}
});
cs.set("ch", {
if expected {
Fr::zero()
} else {
Fr::one()
}
});
assert_eq!(cs.which_is_unsatisfied().unwrap(), "ch computation");
}
}
}
}
}
#[test]
fn test_boolean_sha256_maj() {
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() {
for third_operand in variants.iter().cloned() {
let mut cs = TestConstraintSystem::<Bls12>::new();
let a;
let b;
let c;
// maj = (a and b) xor (a and c) xor (b and c)
let expected = (first_operand.val() & second_operand.val()) ^
(first_operand.val() & third_operand.val()) ^
(second_operand.val() & third_operand.val());
{
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");
c = dyn_construct(third_operand, "c");
}
let maj = Boolean::sha256_maj(&mut cs, &a, &b, &c).unwrap();
assert!(cs.is_satisfied());
assert_eq!(maj.get_value().unwrap(), expected);
if first_operand.is_constant() ||
second_operand.is_constant() ||
third_operand.is_constant()
{
if first_operand.is_constant() &&
second_operand.is_constant() &&
third_operand.is_constant()
{
assert_eq!(cs.num_constraints(), 0);
}
}
else
{
assert_eq!(cs.get("maj"), {
if expected {
Fr::one()
} else {
Fr::zero()
}
});
cs.set("maj", {
if expected {
Fr::zero()
} else {
Fr::one()
}
});
assert_eq!(cs.which_is_unsatisfied().unwrap(), "maj computation");
}
}
}
}
}
}

2
src/circuit/mod.rs
View File

@ -10,8 +10,10 @@ pub mod lookup;
pub mod ecc;
pub mod pedersen_hash;
pub mod multipack;
pub mod sha256;
pub mod sapling;
pub mod sprout;
use bellman::{
SynthesisError

417
src/circuit/sha256.rs Normal file
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@ -0,0 +1,417 @@
use super::uint32::UInt32;
use super::multieq::MultiEq;
use super::boolean::Boolean;
use bellman::{ConstraintSystem, SynthesisError};
use pairing::Engine;
const ROUND_CONSTANTS: [u32; 64] = [
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
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
];
const IV: [u32; 8] = [
0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19
];
pub fn sha256_block_no_padding<E, CS>(
mut cs: CS,
input: &[Boolean]
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
assert_eq!(input.len(), 512);
Ok(sha256_compression_function(
&mut cs,
&input,
&get_sha256_iv()
)?
.into_iter()
.flat_map(|e| e.into_bits_be())
.collect())
}
pub fn sha256<E, CS>(
mut cs: CS,
input: &[Boolean]
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
assert!(input.len() % 8 == 0);
let mut padded = input.to_vec();
let plen = padded.len() as u64;
// append a single '1' bit
padded.push(Boolean::constant(true));
// append K '0' bits, where K is the minimum number >= 0 such that L + 1 + K + 64 is a multiple of 512
while (padded.len() + 64) % 512 != 0 {
padded.push(Boolean::constant(false));
}
// append L as a 64-bit big-endian integer, making the total post-processed length a multiple of 512 bits
for b in (0..64).rev().map(|i| (plen >> i) & 1 == 1) {
padded.push(Boolean::constant(b));
}
assert!(padded.len() % 512 == 0);
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
)?;
}
Ok(cur.into_iter()
.flat_map(|e| e.into_bits_be())
.collect())
}
fn get_sha256_iv() -> Vec<UInt32> {
IV.iter().map(|&v| UInt32::constant(v)).collect()
}
fn sha256_compression_function<E, CS>(
cs: CS,
input: &[Boolean],
current_hash_value: &[UInt32]
) -> Result<Vec<UInt32>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
assert_eq!(input.len(), 512);
assert_eq!(current_hash_value.len(), 8);
let mut w = input.chunks(32)
.map(|e| UInt32::from_bits_be(e))
.collect::<Vec<_>>();
// We can save some constraints by combining some of
// the constraints in different u32 additions
let mut cs = MultiEq::new(cs);
for i in 16..64 {
let cs = &mut cs.namespace(|| format!("w extension {}", i));
// s0 := (w[i-15] rightrotate 7) xor (w[i-15] rightrotate 18) xor (w[i-15] rightshift 3)
let mut s0 = w[i-15].rotr(7);
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)
)?;
let tmp = UInt32::addmany(
cs.namespace(|| "computation of w[i]"),
&[w[i-16].clone(), s0, w[i-7].clone(), s1]
)?;
// w[i] := w[i-16] + s0 + w[i-7] + s1
w.push(tmp);
}
assert_eq!(w.len(), 64);
enum Maybe {
Deferred(Vec<UInt32>),
Concrete(UInt32)
}
impl Maybe {
fn compute<E, CS, M>(
self,
cs: M,
others: &[UInt32]
) -> Result<UInt32, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>,
M: ConstraintSystem<E, Root=MultiEq<E, CS>>
{
Ok(match self {
Maybe::Concrete(ref v) => {
return Ok(v.clone())
},
Maybe::Deferred(mut v) => {
v.extend(others.into_iter().cloned());
UInt32::addmany(
cs,
&v
)?
}
})
}
}
let mut a = Maybe::Concrete(current_hash_value[0].clone());
let mut b = current_hash_value[1].clone();
let mut c = current_hash_value[2].clone();
let mut d = current_hash_value[3].clone();
let mut e = Maybe::Concrete(current_hash_value[4].clone());
let mut f = current_hash_value[5].clone();
let mut g = current_hash_value[6].clone();
let mut h = current_hash_value[7].clone();
for i in 0..64 {
let cs = &mut cs.namespace(|| format!("compression round {}", i));
// 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)
)?;
// ch := (e and f) xor ((not e) and g)
let ch = UInt32::sha256_ch(
cs.namespace(|| "ch"),
&new_e,
&f,
&g
)?;
// temp1 := h + S1 + ch + k[i] + w[i]
let temp1 = vec![
h.clone(),
s1,
ch,
UInt32::constant(ROUND_CONSTANTS[i]),
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)
)?;
// maj := (a and b) xor (a and c) xor (b and c)
let maj = UInt32::sha256_maj(
cs.namespace(|| "maj"),
&new_a,
&b,
&c
)?;
// temp2 := S0 + maj
let temp2 = vec![s0, maj];
/*
h := g
g := f
f := e
e := d + temp1
d := c
c := b
b := a
a := temp1 + temp2
*/
h = g;
g = f;
f = new_e;
e = Maybe::Deferred(temp1.iter().cloned().chain(Some(d)).collect::<Vec<_>>());
d = c;
c = b;
b = new_a;
a = Maybe::Deferred(temp1.iter().cloned().chain(temp2.iter().cloned()).collect::<Vec<_>>());
}
/*
Add the compressed chunk to the current hash value:
h0 := h0 + a
h1 := h1 + b
h2 := h2 + c
h3 := h3 + d
h4 := h4 + e
h5 := h5 + f
h6 := h6 + g
h7 := h7 + h
*/
let h0 = a.compute(
cs.namespace(|| "deferred h0 computation"),
&[current_hash_value[0].clone()]
)?;
let h1 = UInt32::addmany(
cs.namespace(|| "new h1"),
&[current_hash_value[1].clone(), b]
)?;
let h2 = UInt32::addmany(
cs.namespace(|| "new h2"),
&[current_hash_value[2].clone(), c]
)?;
let h3 = UInt32::addmany(
cs.namespace(|| "new h3"),
&[current_hash_value[3].clone(), d]
)?;
let h4 = e.compute(
cs.namespace(|| "deferred h4 computation"),
&[current_hash_value[4].clone()]
)?;
let h5 = UInt32::addmany(
cs.namespace(|| "new h5"),
&[current_hash_value[5].clone(), f]
)?;
let h6 = UInt32::addmany(
cs.namespace(|| "new h6"),
&[current_hash_value[6].clone(), g]
)?;
let h7 = UInt32::addmany(
cs.namespace(|| "new h7"),
&[current_hash_value[7].clone(), h]
)?;
Ok(vec![h0, h1, h2, h3, h4, h5, h6, h7])
}
#[cfg(test)]
mod test {
use super::*;
use circuit::boolean::AllocatedBit;
use pairing::bls12_381::Bls12;
use circuit::test::TestConstraintSystem;
use rand::{XorShiftRng, SeedableRng, Rng};
#[test]
fn test_blank_hash() {
let iv = get_sha256_iv();
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_bits: Vec<_> = out.into_iter().flat_map(|e| e.into_bits_be()).collect();
assert!(cs.is_satisfied());
assert_eq!(cs.num_constraints(), 0);
let expected = hex!("e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855");
let mut out = out_bits.into_iter();
for b in expected.into_iter() {
for i in (0..8).rev() {
let c = out.next().unwrap().get_value().unwrap();
assert_eq!(c, (b >> i) & 1u8 == 1u8);
}
}
}
#[test]
fn test_full_block() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
let iv = get_sha256_iv();
let mut cs = TestConstraintSystem::<Bls12>::new();
let input_bits: Vec<_> = (0..512).map(|i| {
Boolean::from(
AllocatedBit::alloc(
cs.namespace(|| format!("input bit {}", i)),
Some(rng.gen())
).unwrap()
)
}).collect();
sha256_compression_function(
cs.namespace(|| "sha256"),
&input_bits,
&iv
).unwrap();
assert!(cs.is_satisfied());
assert_eq!(cs.num_constraints() - 512, 25840);
}
#[test]
fn test_against_vectors() {
use crypto::sha2::Sha256;
use crypto::digest::Digest;
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 = Sha256::new();
let data: Vec<u8> = (0..input_len).map(|_| rng.gen()).collect();
h.input(&data);
let mut hash_result = [0u8; 32];
h.result(&mut hash_result[..]);
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).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());
}
}
let r = sha256(&mut cs, &input_bits).unwrap();
assert!(cs.is_satisfied());
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);
}
}
}
}
}
}

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src/circuit/sprout/commitment.rs Normal file
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use pairing::{Engine};
use bellman::{ConstraintSystem, SynthesisError};
use circuit::sha256::{
sha256
};
use circuit::boolean::{
Boolean
};
pub fn note_comm<E, CS>(
cs: CS,
a_pk: &[Boolean],
value: &[Boolean],
rho: &[Boolean],
r: &[Boolean]
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
assert_eq!(a_pk.len(), 256);
assert_eq!(value.len(), 64);
assert_eq!(rho.len(), 256);
assert_eq!(r.len(), 256);
let mut image = vec![];
image.push(Boolean::constant(true));
image.push(Boolean::constant(false));
image.push(Boolean::constant(true));
image.push(Boolean::constant(true));
image.push(Boolean::constant(false));
image.push(Boolean::constant(false));
image.push(Boolean::constant(false));
image.push(Boolean::constant(false));
image.extend(a_pk.iter().cloned());
image.extend(value.iter().cloned());
image.extend(rho.iter().cloned());
image.extend(r.iter().cloned());
sha256(
cs,
&image
)
}

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use pairing::{Engine};
use bellman::{ConstraintSystem, SynthesisError};
use circuit::sha256::{
sha256_block_no_padding
};
use circuit::boolean::{
AllocatedBit,
Boolean
};
use super::*;
use super::prfs::*;
use super::commitment::note_comm;
pub struct InputNote {
pub nf: Vec<Boolean>,
pub mac: Vec<Boolean>,
}
impl InputNote {
pub fn compute<E, CS>(
mut cs: CS,
a_sk: Option<SpendingKey>,
rho: Option<UniqueRandomness>,
r: Option<CommitmentRandomness>,
value: &NoteValue,
h_sig: &[Boolean],
nonce: bool,
auth_path: [Option<([u8; 32], bool)>; TREE_DEPTH],
rt: &[Boolean]
) -> Result<InputNote, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
let a_sk = witness_u252(
cs.namespace(|| "a_sk"),
a_sk.as_ref().map(|a_sk| &a_sk.0[..])
)?;
let rho = witness_u256(
cs.namespace(|| "rho"),
rho.as_ref().map(|rho| &rho.0[..])
)?;
let r = witness_u256(
cs.namespace(|| "r"),
r.as_ref().map(|r| &r.0[..])
)?;
let a_pk = prf_a_pk(
cs.namespace(|| "a_pk computation"),
&a_sk
)?;
let nf = prf_nf(
cs.namespace(|| "nf computation"),
&a_sk,
&rho
)?;
let mac = prf_pk(
cs.namespace(|| "mac computation"),
&a_sk,
h_sig,
nonce
)?;
let cm = note_comm(
cs.namespace(|| "cm computation"),
&a_pk,
&value.bits_le(),
&rho,
&r
)?;
// Witness into the merkle tree
let mut cur = cm.clone();
for (i, layer) in auth_path.into_iter().enumerate() {
let cs = &mut cs.namespace(|| format!("layer {}", i));
let cur_is_right = AllocatedBit::alloc(
cs.namespace(|| "cur is right"),
layer.as_ref().map(|&(_, p)| p)
)?;
let lhs = cur;
let rhs = witness_u256(
cs.namespace(|| "sibling"),
layer.as_ref().map(|&(ref sibling, _)| &sibling[..])
)?;
// Conditionally swap if cur is right
let preimage = conditionally_swap_u256(
cs.namespace(|| "conditional swap"),
&lhs[..],
&rhs[..],
&cur_is_right
)?;
cur = sha256_block_no_padding(
cs.namespace(|| "hash of this layer"),
&preimage
)?;
}
// enforce must be true if the value is nonzero
let enforce = AllocatedBit::alloc(
cs.namespace(|| "enforce"),
value.get_value().map(|n| n != 0)
)?;
// value * (1 - enforce) = 0
// If `value` is zero, `enforce` _can_ be zero.
// If `value` is nonzero, `enforce` _must_ be one.
cs.enforce(
|| "enforce validity",
|_| value.lc(),
|lc| lc + CS::one() - enforce.get_variable(),
|lc| lc
);
assert_eq!(cur.len(), rt.len());
// Check that the anchor (exposed as a public input)
// is equal to the merkle tree root that we calculated
// for this note
for (i, (cur, rt)) in cur.into_iter().zip(rt.iter()).enumerate() {
// (cur - rt) * enforce = 0
// if enforce is zero, cur and rt can be different
// if enforce is one, they must be equal
cs.enforce(
|| format!("conditionally enforce correct root for bit {}", i),
|_| cur.lc(CS::one(), E::Fr::one()) - &rt.lc(CS::one(), E::Fr::one()),
|lc| lc + enforce.get_variable(),
|lc| lc
);
}
Ok(InputNote {
mac: mac,
nf: nf
})
}
}
/// Swaps two 256-bit blobs conditionally, returning the
/// 512-bit concatenation.
pub fn conditionally_swap_u256<E, CS>(
mut cs: CS,
lhs: &[Boolean],
rhs: &[Boolean],
condition: &AllocatedBit
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>,
{
assert_eq!(lhs.len(), 256);
assert_eq!(rhs.len(), 256);
let mut new_lhs = vec![];
let mut new_rhs = vec![];
for (i, (lhs, rhs)) in lhs.iter().zip(rhs.iter()).enumerate() {
let cs = &mut cs.namespace(|| format!("bit {}", i));
let x = Boolean::from(AllocatedBit::alloc(
cs.namespace(|| "x"),
condition.get_value().and_then(|v| {
if v {
rhs.get_value()
} else {
lhs.get_value()
}
})
)?);
// x = (1-condition)lhs + (condition)rhs
// x = lhs - lhs(condition) + rhs(condition)
// x - lhs = condition (rhs - lhs)
// if condition is zero, we don't swap, so
// x - lhs = 0
// x = lhs
// if condition is one, we do swap, so
// x - lhs = rhs - lhs
// x = rhs
cs.enforce(
|| "conditional swap for x",
|lc| lc + &rhs.lc(CS::one(), E::Fr::one())
- &lhs.lc(CS::one(), E::Fr::one()),
|lc| lc + condition.get_variable(),
|lc| lc + &x.lc(CS::one(), E::Fr::one())
- &lhs.lc(CS::one(), E::Fr::one())
);
let y = Boolean::from(AllocatedBit::alloc(
cs.namespace(|| "y"),
condition.get_value().and_then(|v| {
if v {
lhs.get_value()
} else {
rhs.get_value()
}
})
)?);
// y = (1-condition)rhs + (condition)lhs
// y - rhs = condition (lhs - rhs)
cs.enforce(
|| "conditional swap for y",
|lc| lc + &lhs.lc(CS::one(), E::Fr::one())
- &rhs.lc(CS::one(), E::Fr::one()),
|lc| lc + condition.get_variable(),
|lc| lc + &y.lc(CS::one(), E::Fr::one())
- &rhs.lc(CS::one(), E::Fr::one())
);
new_lhs.push(x);
new_rhs.push(y);
}
let mut f = new_lhs;
f.extend(new_rhs);
assert_eq!(f.len(), 512);
Ok(f)
}

488
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use pairing::{Engine, Field};
use bellman::{ConstraintSystem, SynthesisError, Circuit, LinearCombination};
use circuit::boolean::{
AllocatedBit,
Boolean
};
use circuit::multipack::pack_into_inputs;
mod prfs;
mod commitment;
mod input;
mod output;
use self::input::*;
use self::output::*;
pub const TREE_DEPTH: usize = 29;
pub struct SpendingKey(pub [u8; 32]);
pub struct PayingKey(pub [u8; 32]);
pub struct UniqueRandomness(pub [u8; 32]);
pub struct CommitmentRandomness(pub [u8; 32]);
pub struct JoinSplit {
pub vpub_old: Option<u64>,
pub vpub_new: Option<u64>,
pub h_sig: Option<[u8; 32]>,
pub phi: Option<[u8; 32]>,
pub inputs: Vec<JSInput>,
pub outputs: Vec<JSOutput>,
pub rt: Option<[u8; 32]>,
}
pub struct JSInput {
pub value: Option<u64>,
pub a_sk: Option<SpendingKey>,
pub rho: Option<UniqueRandomness>,
pub r: Option<CommitmentRandomness>,
pub auth_path: [Option<([u8; 32], bool)>; TREE_DEPTH]
}
pub struct JSOutput {
pub value: Option<u64>,
pub a_pk: Option<PayingKey>,
pub r: Option<CommitmentRandomness>
}
impl<E: Engine> Circuit<E> for JoinSplit {
fn synthesize<CS: ConstraintSystem<E>>(
self,
cs: &mut CS
) -> Result<(), SynthesisError>
{
assert_eq!(self.inputs.len(), 2);
assert_eq!(self.outputs.len(), 2);
// vpub_old is the value entering the
// JoinSplit from the "outside" value
// pool
let vpub_old = NoteValue::new(
cs.namespace(|| "vpub_old"),
self.vpub_old
)?;
// vpub_new is the value leaving the
// JoinSplit into the "outside" value
// pool
let vpub_new = NoteValue::new(
cs.namespace(|| "vpub_new"),
self.vpub_new
)?;
// The left hand side of the balance equation
// vpub_old + inputs[0].value + inputs[1].value
let mut lhs = vpub_old.lc();
// The right hand side of the balance equation
// vpub_old + inputs[0].value + inputs[1].value
let mut rhs = vpub_new.lc();
// Witness rt (merkle tree root)
let rt = witness_u256(
cs.namespace(|| "rt"),
self.rt.as_ref().map(|v| &v[..])
).unwrap();
// Witness h_sig
let h_sig = witness_u256(
cs.namespace(|| "h_sig"),
self.h_sig.as_ref().map(|v| &v[..])
).unwrap();
// Witness phi
let phi = witness_u252(
cs.namespace(|| "phi"),
self.phi.as_ref().map(|v| &v[..])
).unwrap();
let mut input_notes = vec![];
let mut lhs_total = self.vpub_old;
// Iterate over the JoinSplit inputs
for (i, input) in self.inputs.into_iter().enumerate() {
let cs = &mut cs.namespace(|| format!("input {}", i));
// Accumulate the value of the left hand side
if let Some(value) = input.value {
lhs_total = lhs_total.map(|v| v.wrapping_add(value));
}
// Allocate the value of the note
let value = NoteValue::new(
cs.namespace(|| "value"),
input.value
)?;
// Compute the nonce (for PRF inputs) which is false
// for the first input, and true for the second input.
let nonce = match i {
0 => false,
1 => true,
_ => unreachable!()
};
// Perform input note computations
input_notes.push(InputNote::compute(
cs.namespace(|| "note"),
input.a_sk,
input.rho,
input.r,
&value,
&h_sig,
nonce,
input.auth_path,
&rt
)?);
// Add the note value to the left hand side of
// the balance equation
lhs = lhs + &value.lc();
}
// Rebind lhs so that it isn't mutable anymore
let lhs = lhs;
// See zcash/zcash/issues/854
{
// Expected sum of the left hand side of the balance
// equation, expressed as a 64-bit unsigned integer
let lhs_total = NoteValue::new(
cs.namespace(|| "total value of left hand side"),
lhs_total
)?;
// Enforce that the left hand side can be expressed as a 64-bit
// integer
cs.enforce(
|| "left hand side can be expressed as a 64-bit unsigned integer",
|_| lhs.clone(),
|lc| lc + CS::one(),
|_| lhs_total.lc()
);
}
let mut output_notes = vec![];
// Iterate over the JoinSplit outputs
for (i, output) in self.outputs.into_iter().enumerate() {
let cs = &mut cs.namespace(|| format!("output {}", i));
let value = NoteValue::new(
cs.namespace(|| "value"),
output.value
)?;
// Compute the nonce (for PRF inputs) which is false
// for the first output, and true for the second output.
let nonce = match i {
0 => false,
1 => true,
_ => unreachable!()
};
// Perform output note computations
output_notes.push(OutputNote::compute(
cs.namespace(|| "note"),
output.a_pk,
&value,
output.r,
&phi,
&h_sig,
nonce
)?);
// Add the note value to the right hand side of
// the balance equation
rhs = rhs + &value.lc();
}
// Enforce that balance is equal
cs.enforce(
|| "balance equation",
|_| lhs.clone(),
|lc| lc + CS::one(),
|_| rhs
);
let mut public_inputs = vec![];
public_inputs.extend(rt);
public_inputs.extend(h_sig);
for note in input_notes {
public_inputs.extend(note.nf);
public_inputs.extend(note.mac);
}
for note in output_notes {
public_inputs.extend(note.cm);
}
public_inputs.extend(vpub_old.bits_le());
public_inputs.extend(vpub_new.bits_le());
pack_into_inputs(cs.namespace(|| "input packing"), &public_inputs)
}
}
pub struct NoteValue {
value: Option<u64>,
// Least significant digit first
bits: Vec<AllocatedBit>
}
impl NoteValue {
fn new<E, CS>(
mut cs: CS,
value: Option<u64>
) -> Result<NoteValue, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>,
{
let mut values;
match value {
Some(mut val) => {
values = vec![];
for _ in 0..64 {
values.push(Some(val & 1 == 1));
val >>= 1;
}
},
None => {
values = vec![None; 64];
}
}
let mut bits = vec![];
for (i, value) in values.into_iter().enumerate() {
bits.push(
AllocatedBit::alloc(
cs.namespace(|| format!("bit {}", i)),
value
)?
);
}
Ok(NoteValue {
value: value,
bits: bits
})
}
/// Encodes the bits of the value into little-endian
/// byte order.
fn bits_le(&self) -> Vec<Boolean> {
self.bits.chunks(8)
.flat_map(|v| v.iter().rev())
.cloned()
.map(|e| Boolean::from(e))
.collect()
}
/// Computes this value as a linear combination of
/// its bits.
fn lc<E: Engine>(&self) -> LinearCombination<E> {
let mut tmp = LinearCombination::zero();
let mut coeff = E::Fr::one();
for b in &self.bits {
tmp = tmp + (coeff, b.get_variable());
coeff.double();
}
tmp
}
fn get_value(&self) -> Option<u64> {
self.value
}
}
/// Witnesses some bytes in the constraint system,
/// skipping the first `skip_bits`.
fn witness_bits<E, CS>(
mut cs: CS,
value: Option<&[u8]>,
num_bits: usize,
skip_bits: usize
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>,
{
let bit_values = if let Some(value) = value {
let mut tmp = vec![];
for b in value.iter()
.flat_map(|&m| (0..8).rev().map(move |i| m >> i & 1 == 1))
.skip(skip_bits)
{
tmp.push(Some(b));
}
tmp
} else {
vec![None; num_bits]
};
assert_eq!(bit_values.len(), num_bits);
let mut bits = vec![];
for (i, value) in bit_values.into_iter().enumerate() {
bits.push(Boolean::from(AllocatedBit::alloc(
cs.namespace(|| format!("bit {}", i)),
value
)?));
}
Ok(bits)
}
fn witness_u256<E, CS>(
cs: CS,
value: Option<&[u8]>,
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>,
{
witness_bits(cs, value, 256, 0)
}
fn witness_u252<E, CS>(
cs: CS,
value: Option<&[u8]>,
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>,
{
witness_bits(cs, value, 252, 4)
}
#[test]
fn test_sprout_constraints() {
use pairing::bls12_381::{Bls12};
use ::circuit::test::*;
use byteorder::{WriteBytesExt, ReadBytesExt, LittleEndian};
let test_vector = include_bytes!("test_vectors.dat");
let mut test_vector = &test_vector[..];
fn get_u256<R: ReadBytesExt>(mut reader: R) -> [u8; 32] {
let mut result = [0u8; 32];
for i in 0..32 {
result[i] = reader.read_u8().unwrap();
}
result
}
while test_vector.len() != 0 {
let mut cs = TestConstraintSystem::<Bls12>::new();
let phi = Some(get_u256(&mut test_vector));
let rt = Some(get_u256(&mut test_vector));
let h_sig = Some(get_u256(&mut test_vector));
let mut inputs = vec![];
for _ in 0..2 {
test_vector.read_u8().unwrap();
let mut auth_path = [None; TREE_DEPTH];
for i in (0..TREE_DEPTH).rev() {
test_vector.read_u8().unwrap();
let sibling = get_u256(&mut test_vector);
auth_path[i] = Some((sibling, false));
}
let mut position = test_vector.read_u64::<LittleEndian>().unwrap();
for i in 0..TREE_DEPTH {
auth_path[i].as_mut().map(|p| {
p.1 = (position & 1) == 1
});
position >>= 1;
}
// a_pk
let _ = Some(SpendingKey(get_u256(&mut test_vector)));
let value = Some(test_vector.read_u64::<LittleEndian>().unwrap());
let rho = Some(UniqueRandomness(get_u256(&mut test_vector)));
let r = Some(CommitmentRandomness(get_u256(&mut test_vector)));
let a_sk = Some(SpendingKey(get_u256(&mut test_vector)));
inputs.push(
JSInput {
value: value,
a_sk: a_sk,
rho: rho,
r: r,
auth_path: auth_path
}
);
}
let mut outputs = vec![];
for _ in 0..2 {
let a_pk = Some(PayingKey(get_u256(&mut test_vector)));
let value = Some(test_vector.read_u64::<LittleEndian>().unwrap());
get_u256(&mut test_vector);
let r = Some(CommitmentRandomness(get_u256(&mut test_vector)));
outputs.push(
JSOutput {
value: value,
a_pk: a_pk,
r: r
}
);
}
let vpub_old = Some(test_vector.read_u64::<LittleEndian>().unwrap());
let vpub_new = Some(test_vector.read_u64::<LittleEndian>().unwrap());
let nf1 = get_u256(&mut test_vector);
let nf2 = get_u256(&mut test_vector);
let cm1 = get_u256(&mut test_vector);
let cm2 = get_u256(&mut test_vector);
let mac1 = get_u256(&mut test_vector);
let mac2 = get_u256(&mut test_vector);
let js = JoinSplit {
vpub_old: vpub_old,
vpub_new: vpub_new,
h_sig: h_sig,
phi: phi,
inputs: inputs,
outputs: outputs,
rt: rt
};
js.synthesize(&mut cs).unwrap();
if let Some(s) = cs.which_is_unsatisfied() {
panic!("{:?}", s);
}
assert!(cs.is_satisfied());
assert_eq!(cs.num_constraints(), 1989085);
assert_eq!(cs.num_inputs(), 10);
assert_eq!(cs.hash(), "1a228d3c6377130d1778c7885811dc8b8864049cb5af8aff7e6cd46c5bc4b84c");
let mut expected_inputs = vec![];
expected_inputs.extend(rt.unwrap().to_vec());
expected_inputs.extend(h_sig.unwrap().to_vec());
expected_inputs.extend(nf1.to_vec());
expected_inputs.extend(mac1.to_vec());
expected_inputs.extend(nf2.to_vec());
expected_inputs.extend(mac2.to_vec());
expected_inputs.extend(cm1.to_vec());
expected_inputs.extend(cm2.to_vec());
expected_inputs.write_u64::<LittleEndian>(vpub_old.unwrap()).unwrap();
expected_inputs.write_u64::<LittleEndian>(vpub_new.unwrap()).unwrap();
use circuit::multipack;
let expected_inputs = multipack::bytes_to_bits(&expected_inputs);
let expected_inputs = multipack::compute_multipacking::<Bls12>(&expected_inputs);
assert!(cs.verify(&expected_inputs));
}
}

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use pairing::{Engine};
use bellman::{ConstraintSystem, SynthesisError};
use circuit::boolean::{Boolean};
use super::*;
use super::prfs::*;
use super::commitment::note_comm;
pub struct OutputNote {
pub cm: Vec<Boolean>
}
impl OutputNote {
pub fn compute<'a, E, CS>(
mut cs: CS,
a_pk: Option<PayingKey>,
value: &NoteValue,
r: Option<CommitmentRandomness>,
phi: &[Boolean],
h_sig: &[Boolean],
nonce: bool
) -> Result<Self, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>,
{
let rho = prf_rho(
cs.namespace(|| "rho"),
phi,
h_sig,
nonce
)?;
let a_pk = witness_u256(
cs.namespace(|| "a_pk"),
a_pk.as_ref().map(|a_pk| &a_pk.0[..])
)?;
let r = witness_u256(
cs.namespace(|| "r"),
r.as_ref().map(|r| &r.0[..])
)?;
let cm = note_comm(
cs.namespace(|| "cm computation"),
&a_pk,
&value.bits_le(),
&rho,
&r
)?;
Ok(OutputNote {
cm: cm
})
}
}

79
src/circuit/sprout/prfs.rs Normal file
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@ -0,0 +1,79 @@
use pairing::{Engine};
use bellman::{ConstraintSystem, SynthesisError};
use circuit::sha256::{
sha256_block_no_padding
};
use circuit::boolean::{
Boolean
};
fn prf<E, CS>(
cs: CS,
a: bool,
b: bool,
c: bool,
d: bool,
x: &[Boolean],
y: &[Boolean]
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
assert_eq!(x.len(), 252);
assert_eq!(y.len(), 256);
let mut image = vec![];
image.push(Boolean::constant(a));
image.push(Boolean::constant(b));
image.push(Boolean::constant(c));
image.push(Boolean::constant(d));
image.extend(x.iter().cloned());
image.extend(y.iter().cloned());
assert_eq!(image.len(), 512);
sha256_block_no_padding(
cs,
&image
)
}
pub fn prf_a_pk<E, CS>(
cs: CS,
a_sk: &[Boolean]
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
prf(cs, true, true, false, false, a_sk, &(0..256).map(|_| Boolean::constant(false)).collect::<Vec<_>>())
}
pub fn prf_nf<E, CS>(
cs: CS,
a_sk: &[Boolean],
rho: &[Boolean]
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
prf(cs, true, true, true, false, a_sk, rho)
}
pub fn prf_pk<E, CS>(
cs: CS,
a_sk: &[Boolean],
h_sig: &[Boolean],
nonce: bool
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
prf(cs, false, nonce, false, false, a_sk, h_sig)
}
pub fn prf_rho<E, CS>(
cs: CS,
phi: &[Boolean],
h_sig: &[Boolean],
nonce: bool
) -> Result<Vec<Boolean>, SynthesisError>
where E: Engine, CS: ConstraintSystem<E>
{
prf(cs, false, nonce, true, false, phi, h_sig)
}

BIN
src/circuit/sprout/test_vectors.dat Normal file
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257
src/circuit/uint32.rs
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@ -87,6 +87,31 @@ impl UInt32 {
})
}
pub fn into_bits_be(&self) -> Vec<Boolean> {
self.bits.iter().rev().cloned().collect()
}
pub fn from_bits_be(bits: &[Boolean]) -> Self {
assert_eq!(bits.len(), 32);
let mut value = Some(0u32);
for b in bits {
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; }
}
}
UInt32 {
value: 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.chunks(8)
@ -155,6 +180,104 @@ impl UInt32 {
}
}
pub fn shr(&self, by: usize) -> Self {
let by = by % 32;
let fill = Boolean::constant(false);
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
.take(32) // Only 32 bits needed!
.cloned()
.collect();
UInt32 {
bits: new_bits,
value: self.value.map(|v| v >> by as u32)
}
}
fn triop<E, CS, F, U>(
mut cs: CS,
a: &Self,
b: &Self,
c: &Self,
tri_fn: F,
circuit_fn: U
) -> Result<Self, SynthesisError>
where E: Engine,
CS: ConstraintSystem<E>,
F: Fn(u32, u32, u32) -> u32,
U: Fn(&mut CS, usize, &Boolean, &Boolean, &Boolean) -> Result<Boolean, SynthesisError>
{
let new_value = match (a.value, b.value, c.value) {
(Some(a), Some(b), Some(c)) => {
Some(tri_fn(a, b, c))
},
_ => None
};
let bits = a.bits.iter()
.zip(b.bits.iter())
.zip(c.bits.iter())
.enumerate()
.map(|(i, ((a, b), c))| circuit_fn(&mut cs, i, a, b, c))
.collect::<Result<_, _>>()?;
Ok(UInt32 {
bits: 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>
{
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)),
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>
{
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)),
a,
b,
c
)
}
)
}
/// XOR this `UInt32` with another `UInt32`
pub fn xor<E, CS>(
&self,
@ -304,6 +427,37 @@ mod test {
use bellman::{ConstraintSystem};
use circuit::multieq::MultiEq;
#[test]
fn test_uint32_from_bits_be() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0653]);
for _ in 0..1000 {
let mut v = (0..32).map(|_| Boolean::constant(rng.gen())).collect::<Vec<_>>();
let b = UInt32::from_bits_be(&v);
for (i, bit) in b.bits.iter().enumerate() {
match bit {
&Boolean::Constant(bit) => {
assert!(bit == ((b.value.unwrap() >> i) & 1 == 1));
},
_ => unreachable!()
}
}
let expected_to_be_same = b.into_bits_be();
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!()
}
}
}
}
#[test]
fn test_uint32_from_bits() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0653]);
@ -483,6 +637,7 @@ mod test {
for i in 0..32 {
let b = a.rotr(i);
assert_eq!(a.bits.len(), b.bits.len());
assert!(b.value.unwrap() == num);
@ -501,4 +656,106 @@ mod test {
num = num.rotate_right(1);
}
}
#[test]
fn test_uint32_shr() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0654]);
for _ in 0..50 {
for i in 0..60 {
let num = rng.gen();
let a = UInt32::constant(num).shr(i);
let b = UInt32::constant(num >> i);
assert_eq!(a.value.unwrap(), num >> i);
assert_eq!(a.bits.len(), b.bits.len());
for (a, b) in a.bits.iter().zip(b.bits.iter()) {
assert_eq!(a.get_value().unwrap(), b.get_value().unwrap());
}
}
}
}
#[test]
fn test_uint32_sha256_maj() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0653]);
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 mut expected = (a & b) ^ (a & c) ^ (b & c);
let a_bit = UInt32::alloc(cs.namespace(|| "a_bit"), Some(a)).unwrap();
let b_bit = UInt32::constant(b);
let c_bit = UInt32::alloc(cs.namespace(|| "c_bit"), Some(c)).unwrap();
let r = UInt32::sha256_maj(&mut cs, &a_bit, &b_bit, &c_bit).unwrap();
assert!(cs.is_satisfied());
assert!(r.value == Some(expected));
for b in r.bits.iter() {
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));
}
}
expected >>= 1;
}
}
}
#[test]
fn test_uint32_sha256_ch() {
let mut rng = XorShiftRng::from_seed([0x5dbe6259, 0x8d313d76, 0x3237db17, 0xe5bc0653]);
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 mut expected = (a & b) ^ ((!a) & c);
let a_bit = UInt32::alloc(cs.namespace(|| "a_bit"), Some(a)).unwrap();
let b_bit = UInt32::constant(b);
let c_bit = UInt32::alloc(cs.namespace(|| "c_bit"), Some(c)).unwrap();
let r = UInt32::sha256_ch(&mut cs, &a_bit, &b_bit, &c_bit).unwrap();
assert!(cs.is_satisfied());
assert!(r.value == Some(expected));
for b in r.bits.iter() {
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));
}
}
expected >>= 1;
}
}
}
}

3
src/lib.rs
View File

@ -9,6 +9,9 @@ extern crate byteorder;
#[macro_use]
extern crate hex_literal;
#[cfg(test)]
extern crate crypto;
pub mod jubjub;
pub mod group_hash;
pub mod circuit;