cmz/tests/two_groups.rs

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

use cmz::{cmz_basepoints, cmz_group_init};
use curve25519_dalek::ristretto::RistrettoPoint;
use group::Group;
use sha2::Sha512;

#[test]
fn two_groups_coexist() {
    let ristretto_a = RistrettoPoint::hash_from_bytes::<Sha512>(b"CMZ Generator A");
    let p256_a = p256::ProjectivePoint::generator() * p256::Scalar::from(42u64);

    cmz_group_init::<RistrettoPoint>(ristretto_a);
    cmz_group_init::<p256::ProjectivePoint>(p256_a);

    // Each group must read 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);
}