modular_frost/curve/
ed448.rs

1use digest::Digest;
2
3use minimal_ed448::{Scalar, Point};
4pub use minimal_ed448::Ed448;
5pub use ciphersuite::{group::GroupEncoding, Ciphersuite};
6
7use crate::{curve::Curve, algorithm::Hram};
8
9const CONTEXT: &[u8] = b"FROST-ED448-SHAKE256-v1";
10
11impl Curve for Ed448 {
12  const CONTEXT: &'static [u8] = CONTEXT;
13}
14
15// The RFC-8032 Ed448 challenge function.
16#[derive(Copy, Clone)]
17pub(crate) struct Ietf8032Ed448Hram;
18impl Ietf8032Ed448Hram {
19  #[allow(non_snake_case)]
20  pub(crate) fn hram(context: &[u8], R: &Point, A: &Point, m: &[u8]) -> Scalar {
21    Scalar::wide_reduce(
22      <Ed448 as Ciphersuite>::H::digest(
23        [
24          &[b"SigEd448".as_ref(), &[0, u8::try_from(context.len()).unwrap()]].concat(),
25          context,
26          &[R.to_bytes().as_ref(), A.to_bytes().as_ref(), m].concat(),
27        ]
28        .concat(),
29      )
30      .as_ref()
31      .try_into()
32      .unwrap(),
33    )
34  }
35}
36
37/// The challenge function for FROST's Ed448 ciphersuite.
38#[derive(Copy, Clone)]
39pub struct IetfEd448Hram;
40impl Hram<Ed448> for IetfEd448Hram {
41  #[allow(non_snake_case)]
42  fn hram(R: &Point, A: &Point, m: &[u8]) -> Scalar {
43    Ietf8032Ed448Hram::hram(&[], R, A, m)
44  }
45}
modular_frost/curve/ed448.rs

modular_frost/curve/
ed448.rs
