cmz/tests/two_groups.rs

//! Basepoint derivation is keyed by group type, so two groups can coexist.

use cmz::{cmz_basepoints, cmz_generator_a, cmz_group_init};
use curve25519_dalek::ristretto::RistrettoPoint;
use group::{Group, GroupEncoding};

const RISTRETTO_A_ENCODING: &[u8] = &[
    0x8e, 0x65, 0xa3, 0x1d, 0xc2, 0x60, 0x08, 0xdf, 0xbc, 0xd9, 0xf6, 0xef, 0xbd, 0x57, 0xf7, 0xcb,
    0xb2, 0xb3, 0x98, 0x72, 0xf6, 0xfd, 0x32, 0x73, 0x6a, 0x00, 0x7a, 0x08, 0xc2, 0x1e, 0x47, 0x18,
];
const P256_A_ENCODING: &[u8] = &[
    0x02, 0x73, 0xe5, 0x71, 0x95, 0x24, 0x34, 0xf0, 0xd5, 0xac, 0xaa, 0xe0, 0xfc, 0xe7, 0x35, 0x7c,
    0x45, 0xb2, 0x73, 0xbd, 0x8e, 0x30, 0x4e, 0xe1, 0xac, 0xd9, 0xf2, 0x43, 0xf3, 0x0b, 0x96, 0x18,
    0x9e,
];

#[test]
fn two_groups_coexist() {
    let ristretto_a = cmz_generator_a::<RistrettoPoint>();
    let p256_a = cmz_generator_a::<p256::ProjectivePoint>();

    assert_eq!(&ristretto_a.to_bytes()[..], RISTRETTO_A_ENCODING);
    assert_eq!(&p256_a.to_bytes()[..], P256_A_ENCODING);

    // Each group is initialized automatically and reads back its own
    // basepoints, not the other's.
    assert_eq!(cmz_basepoints::<RistrettoPoint>().A(), ristretto_a);
    assert_eq!(
        cmz_basepoints::<RistrettoPoint>().B(),
        RistrettoPoint::generator()
    );
    assert_eq!(cmz_basepoints::<p256::ProjectivePoint>().A(), p256_a);
    assert_eq!(
        cmz_basepoints::<p256::ProjectivePoint>().B(),
        p256::ProjectivePoint::generator()
    );

    // Re-initializing keeps the first value, per cmz_group_init's contract.
    cmz_group_init::<RistrettoPoint>(RistrettoPoint::generator());
    assert_eq!(cmz_basepoints::<RistrettoPoint>().A(), ristretto_a);
}