Add PrimeFieldBits support to Scalar ()

Co-authored-by: Michael Rosenberg <micro@fastmail.com>
Co-authored-by: pinkforest(she/her) <36498018+pinkforest@users.noreply.github.com>
This commit is contained in:
Luke Parker 2023-09-19 23:21:43 -04:00 committed by GitHub
parent 533b53a0ec
commit 76a8b2a081
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3 changed files with 22 additions and 1 deletions

@ -5,6 +5,10 @@ major series.
## 4.x series
### Unreleased
* Add implementation for `PrimeFieldBits`, behind the `group-bits` feature flag.
### 4.1.1
* Mark `constants::BASEPOINT_ORDER` deprecated from pub API

@ -27,7 +27,7 @@ rustdoc-args = [
"--html-in-header", "docs/assets/rustdoc-include-katex-header.html",
"--cfg", "docsrs",
]
features = ["serde", "rand_core", "digest", "legacy_compatibility", "group"]
features = ["serde", "rand_core", "digest", "legacy_compatibility", "group-bits"]
[dev-dependencies]
sha2 = { version = "0.10", default-features = false }
@ -48,6 +48,7 @@ required-features = ["alloc", "rand_core"]
[dependencies]
cfg-if = "1"
ff = { version = "0.13", default-features = false, optional = true }
group = { version = "0.13", default-features = false, optional = true }
rand_core = { version = "0.6.4", default-features = false, optional = true }
digest = { version = "0.10", default-features = false, optional = true }
@ -67,6 +68,7 @@ alloc = ["zeroize?/alloc"]
precomputed-tables = []
legacy_compatibility = []
group = ["dep:group", "rand_core"]
group-bits = ["group", "ff/bits"]
[target.'cfg(all(not(curve25519_dalek_backend = "fiat"), not(curve25519_dalek_backend = "serial"), target_arch = "x86_64"))'.dependencies]
curve25519-dalek-derive = { version = "0.1", path = "../curve25519-dalek-derive" }

@ -124,6 +124,8 @@ use core::ops::{Sub, SubAssign};
use cfg_if::cfg_if;
#[cfg(feature = "group-bits")]
use group::ff::{FieldBits, PrimeFieldBits};
#[cfg(feature = "group")]
use {
group::ff::{Field, FromUniformBytes, PrimeField},
@ -1321,6 +1323,19 @@ impl PrimeField for Scalar {
};
}
#[cfg(feature = "group-bits")]
impl PrimeFieldBits for Scalar {
type ReprBits = [u8; 32];
fn to_le_bits(&self) -> FieldBits<Self::ReprBits> {
self.to_repr().into()
}
fn char_le_bits() -> FieldBits<Self::ReprBits> {
constants::BASEPOINT_ORDER_PRIVATE.to_bytes().into()
}
}
#[cfg(feature = "group")]
impl FromUniformBytes<64> for Scalar {
fn from_uniform_bytes(bytes: &[u8; 64]) -> Self {