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chore: update to ff v0.13
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@jonathanpwang
jonathanpwang committed Jan 2, 2024
1 parent fbdb4e2 commit a9b016f
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Showing 2 changed files with 66 additions and 38 deletions.
41 changes: 30 additions & 11 deletions src/ed25519/fq.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,7 @@ use core::convert::TryInto;
use core::fmt;
use core::ops::{Add, Mul, Neg, Sub};

use ff::PrimeField;
use ff::{FromUniformBytes, PrimeField, WithSmallOrderMulGroup};
use rand::RngCore;
use serde::{Deserialize, Serialize};
use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};
Expand Down Expand Up @@ -45,6 +45,10 @@ const MODULUS_LIMBS_32: [u32; 8] = [
/// Constant representing the modulus as static str
const MODULUS_STR: &str = "0x7fffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffed";

/// Obtained with:
/// `sage: GF(57896044618658097711785492504343953926634992332820282019728792003956564819949).primitive_element()`
const MULTIPLICATIVE_GENERATOR: Fq = Fq::from_raw([0x02, 0x0, 0x0, 0x0]);

/// INV = -(p^{-1} mod 2^64) mod 2^64
const INV: u64 = 0x86bca1af286bca1b;

Expand Down Expand Up @@ -83,7 +87,7 @@ const ROOT_OF_UNITY_INV: Fq = Fq::zero();
use crate::{
field_arithmetic, field_common, field_specific, impl_add_binop_specify_output,
impl_binops_additive, impl_binops_additive_specify_output, impl_binops_multiplicative,
impl_binops_multiplicative_mixed, impl_sub_binop_specify_output,
impl_binops_multiplicative_mixed, impl_from_u64, impl_sub_binop_specify_output, impl_sum_prod,
};
impl_binops_additive!(Fq, Fq);
impl_binops_multiplicative!(Fq, Fq);
Expand All @@ -101,6 +105,8 @@ field_common!(
R3
);
field_arithmetic!(Fq, MODULUS, INV, dense);
impl_sum_prod!(Fq);
impl_from_u64!(Fq, R2);

impl Fq {
pub const fn size() -> usize {
Expand Down Expand Up @@ -201,8 +207,8 @@ impl ff::PrimeField for Fq {
const CAPACITY: u32 = 255;
const MODULUS: &'static str = MODULUS_STR;
const MULTIPLICATIVE_GENERATOR: Self = MULTIPLICATIVE_GENERATOR;
const ROOT_OF_UNITY: Self = ROOT_OF_UNITY;
const ROOT_OF_UNITY_INV: Self = ROOT_OF_UNITY_INV;
const ROOT_OF_UNITY: Self = todo!();
const ROOT_OF_UNITY_INV: Self = todo!();
const TWO_INV: Self = TWO_INV;
const DELTA: Self = DELTA;
const S: u32 = 1;
Expand All @@ -216,7 +222,7 @@ impl ff::PrimeField for Fq {
tmp.0[3] = u64::from_le_bytes(repr[24..32].try_into().unwrap());

// Try to subtract the modulus
let (_, borrow) = tmp.0[0].overflowing_sub(MODULUS.0[0]);
let (_, borrow) = sbb(tmp.0[0], MODULUS.0[0], 0);
let (_, borrow) = sbb(tmp.0[1], MODULUS.0[1], borrow);
let (_, borrow) = sbb(tmp.0[2], MODULUS.0[2], borrow);
let (_, borrow) = sbb(tmp.0[3], MODULUS.0[3], borrow);
Expand All @@ -236,7 +242,7 @@ impl ff::PrimeField for Fq {
fn to_repr(&self) -> Self::Repr {
// Turn into canonical form by computing
// (a.R) / R = a
let tmp = Fq::montgomery_reduce_short(self.0[0], self.0[1], self.0[2], self.0[3]);
let tmp = Fq::montgomery_reduce_short(&self.0);

let mut res = [0; 32];
res[0..8].copy_from_slice(&tmp.0[0].to_le_bytes());
Expand All @@ -250,14 +256,27 @@ impl ff::PrimeField for Fq {
fn is_odd(&self) -> Choice {
Choice::from(self.to_repr()[0] & 1)
}
}

fn multiplicative_generator() -> Self {
unimplemented!();
impl FromUniformBytes<64> for Fq {
/// Converts a 512-bit little endian integer into
/// an `Fq` by reducing by the modulus.
fn from_uniform_bytes(bytes: &[u8; 64]) -> Self {
Self::from_u512([
u64::from_le_bytes(bytes[0..8].try_into().unwrap()),
u64::from_le_bytes(bytes[8..16].try_into().unwrap()),
u64::from_le_bytes(bytes[16..24].try_into().unwrap()),
u64::from_le_bytes(bytes[24..32].try_into().unwrap()),
u64::from_le_bytes(bytes[32..40].try_into().unwrap()),
u64::from_le_bytes(bytes[40..48].try_into().unwrap()),
u64::from_le_bytes(bytes[48..56].try_into().unwrap()),
u64::from_le_bytes(bytes[56..64].try_into().unwrap()),
])
}
}

fn root_of_unity() -> Self {
unimplemented!();
}
impl WithSmallOrderMulGroup<3> for Fq {
const ZETA: Self = todo!();
}

#[cfg(test)]
Expand Down
63 changes: 36 additions & 27 deletions src/ed25519/fr.rs
View file
Original file line number Diff line number Diff line change
Expand Up @@ -2,15 +2,13 @@ use core::convert::TryInto;
use core::fmt;
use core::ops::{Add, Mul, Neg, Sub};

use ff::PrimeField;
use ff::{FromUniformBytes, PrimeField, WithSmallOrderMulGroup};
use rand::RngCore;
use serde::{Deserialize, Serialize};
use subtle::{Choice, ConditionallySelectable, ConstantTimeEq, CtOption};

use crate::arithmetic::{adc, mac, macx, sbb};

use pasta_curves::arithmetic::{FieldExt, Group, SqrtRatio};

/// This represents an element of $\mathbb{F}_q$ where
///
/// `r = 0x1000000000000000000000000000000014def9dea2f79cd65812631a5cf5d3ed`
Expand Down Expand Up @@ -100,7 +98,7 @@ const ROOT_OF_UNITY_INV: Fr = Fr::zero();
use crate::{
field_arithmetic, field_common, field_specific, impl_add_binop_specify_output,
impl_binops_additive, impl_binops_additive_specify_output, impl_binops_multiplicative,
impl_binops_multiplicative_mixed, impl_sub_binop_specify_output,
impl_binops_multiplicative_mixed, impl_from_u64, impl_sub_binop_specify_output, impl_sum_prod,
};
impl_binops_additive!(Fr, Fr);
impl_binops_multiplicative!(Fr, Fr);
Expand All @@ -118,6 +116,8 @@ field_common!(
R3
);
field_arithmetic!(Fr, MODULUS, INV, dense);
impl_sum_prod!(Fr);
impl_from_u64!(Fr, R2);

impl Fr {
pub const fn size() -> usize {
Expand All @@ -126,6 +126,9 @@ impl Fr {
}

impl ff::Field for Fr {
const ZERO: Self = Self::zero();
const ONE: Self = Self::one();

fn random(mut rng: impl RngCore) -> Self {
Self::from_u512([
rng.next_u64(),
Expand All @@ -139,14 +142,6 @@ impl ff::Field for Fr {
])
}

fn zero() -> Self {
Self::zero()
}

fn one() -> Self {
Self::one()
}

fn double(&self) -> Self {
self.double()
}
Expand Down Expand Up @@ -179,6 +174,10 @@ impl ff::Field for Fr {
CtOption::new(sqrt, choice1 | choice2)
}

fn sqrt_ratio(num: &Self, div: &Self) -> (Choice, Self) {
ff::helpers::sqrt_ratio_generic(num, div)
}

/// Computes the multiplicative inverse of this element,
/// failing if the element is zero.
fn invert(&self) -> CtOption<Self> {
Expand Down Expand Up @@ -216,6 +215,12 @@ impl ff::PrimeField for Fr {

const NUM_BITS: u32 = 256;
const CAPACITY: u32 = 255;
const MODULUS: &'static str = MODULUS_STR;
const MULTIPLICATIVE_GENERATOR: Self = todo!();
const ROOT_OF_UNITY: Self = todo!();
const ROOT_OF_UNITY_INV: Self = ROOT_OF_UNITY_INV;
const TWO_INV: Self = TWO_INV;
const DELTA: Self = DELTA;
const S: u32 = 6;

fn from_repr(repr: Self::Repr) -> CtOption<Self> {
Expand All @@ -227,7 +232,7 @@ impl ff::PrimeField for Fr {
tmp.0[3] = u64::from_le_bytes(repr[24..32].try_into().unwrap());

// Try to subtract the modulus
let (_, borrow) = tmp.0[0].overflowing_sub(MODULUS.0[0]);
let (_, borrow) = sbb(tmp.0[0], MODULUS.0[0], 0);
let (_, borrow) = sbb(tmp.0[1], MODULUS.0[1], borrow);
let (_, borrow) = sbb(tmp.0[2], MODULUS.0[2], borrow);
let (_, borrow) = sbb(tmp.0[3], MODULUS.0[3], borrow);
Expand All @@ -247,7 +252,7 @@ impl ff::PrimeField for Fr {
fn to_repr(&self) -> Self::Repr {
// Turn into canonical form by computing
// (a.R) / R = a
let tmp = Fr::montgomery_reduce_short(self.0[0], self.0[1], self.0[2], self.0[3]);
let tmp = Fr::montgomery_reduce_short(&self.0);

let mut res = [0; 32];
res[0..8].copy_from_slice(&tmp.0[0].to_le_bytes());
Expand All @@ -261,23 +266,27 @@ impl ff::PrimeField for Fr {
fn is_odd(&self) -> Choice {
Choice::from(self.to_repr()[0] & 1)
}
}

fn multiplicative_generator() -> Self {
unimplemented!();
}

fn root_of_unity() -> Self {
unimplemented!();
impl FromUniformBytes<64> for Fr {
/// Converts a 512-bit little endian integer into
/// an `Fq` by reducing by the modulus.
fn from_uniform_bytes(bytes: &[u8; 64]) -> Self {
Self::from_u512([
u64::from_le_bytes(bytes[0..8].try_into().unwrap()),
u64::from_le_bytes(bytes[8..16].try_into().unwrap()),
u64::from_le_bytes(bytes[16..24].try_into().unwrap()),
u64::from_le_bytes(bytes[24..32].try_into().unwrap()),
u64::from_le_bytes(bytes[32..40].try_into().unwrap()),
u64::from_le_bytes(bytes[40..48].try_into().unwrap()),
u64::from_le_bytes(bytes[48..56].try_into().unwrap()),
u64::from_le_bytes(bytes[56..64].try_into().unwrap()),
])
}
}

impl SqrtRatio for Fr {
const T_MINUS1_OVER2: [u64; 4] = [0, 0, 0, 0];

fn get_lower_32(&self) -> u32 {
let tmp = Fr::montgomery_reduce_short(self.0[0], self.0[1], self.0[2], self.0[3]);
tmp.0[0] as u32
}
impl WithSmallOrderMulGroup<3> for Fr {
const ZETA: Self = todo!();
}

#[cfg(test)]
Expand Down

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