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Remove sinsemilla_s_generators() function. 

Co-authored-by: Jack Grigg <jack@electriccoin.co>
This commit is contained in:
therealyingtong 2021-08-12 20:52:37 +08:00
parent a9e96eb0a4
commit 92a7e20d30
2 changed files with 13 additions and 19 deletions
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5
src/primitives/sinsemilla.rs
View File

@ -13,7 +13,7 @@ use self::addition::IncompletePoint;
mod constants;
mod sinsemilla_s;
pub use constants::*;
pub use sinsemilla_s::*;
pub(crate) use sinsemilla_s::*;
pub(crate) fn lebs2ip_k(bits: &[bool]) -> u32 {
assert!(bits.len() == K);
@ -120,7 +120,8 @@ impl HashDomain {
.chunks(K)
.fold(IncompletePoint::from(self.Q), |acc, chunk| {
let (S_x, S_y) = SINSEMILLA_S[lebs2ip_k(chunk) as usize];
acc + pallas::Affine::from_xy(S_x, S_y).unwrap().to_curve() + acc
let S_chunk = pallas::Affine::from_xy(S_x, S_y).unwrap().to_curve();
(acc + S_chunk) + acc
})
}

27
src/primitives/sinsemilla/constants.rs
View File

@ -1,7 +1,4 @@
//! Sinsemilla generators
use group::Curve;
use halo2::arithmetic::{CurveAffine, CurveExt};
use pasta_curves::pallas;
/// Number of bits of each message piece in $\mathsf{SinsemillaHashToPoint}$
pub const K: usize = 10;
@ -62,15 +59,6 @@ pub const Q_MERKLE_CRH: ([u8; 32], [u8; 32]) = (
/// SWU hash-to-curve personalization for Sinsemilla $S$ generators.
pub const S_PERSONALIZATION: &str = "z.cash:SinsemillaS";
/// Creates the Sinsemilla S generators used in each round of the Sinsemilla hash
pub fn sinsemilla_s_generators() -> impl Iterator<Item = (pallas::Base, pallas::Base)> {
let hasher = pallas::Point::hash_to_curve(S_PERSONALIZATION);
(0..(1u32 << K)).map(move |j| {
let point = hasher(&j.to_le_bytes()).to_affine().coordinates().unwrap();
(*point.x(), *point.y())
})
}
#[cfg(test)]
mod tests {
use super::super::{CommitDomain, HashDomain};
@ -79,16 +67,21 @@ mod tests {
COMMIT_IVK_PERSONALIZATION, MERKLE_CRH_PERSONALIZATION, NOTE_COMMITMENT_PERSONALIZATION,
};
use group::Curve;
use halo2::arithmetic::FieldExt;
use halo2::arithmetic::{CurveAffine, CurveExt, FieldExt};
use halo2::pasta::pallas;
#[test]
fn sinsemilla_s() {
use super::super::sinsemilla_s::SINSEMILLA_S;
let sinsemilla_s: Vec<_> = sinsemilla_s_generators().collect();
assert_eq!(sinsemilla_s.len(), SINSEMILLA_S.len());
for (expected, actual) in sinsemilla_s.iter().zip(&SINSEMILLA_S[..]) {
assert_eq!(expected, actual);
let hasher = pallas::Point::hash_to_curve(S_PERSONALIZATION);
for j in 0..(1u32 << K) {
let computed = {
let point = hasher(&j.to_le_bytes()).to_affine().coordinates().unwrap();
(*point.x(), *point.y())
};
let actual = SINSEMILLA_S[j as usize];
assert_eq!(computed, actual);
}
}