Files
serai/processor/ethereum/src/key_gen.rs
Luke Parker a141deaf36 Smash the singular Ciphersuite trait into multiple
This helps identify where the various functionalities are used, or rather, not
used. The `Ciphersuite` trait present in `patches/ciphersuite`, facilitating
the entire FCMP++ tree, only requires the markers _and_ canonical point
decoding. I've opened a PR to upstream such a trait into `group`
(https://github.com/zkcrypto/group/pull/68).

`WrappedGroup` is still justified for as long as `Group::generator` exists.
Moving `::generator()` to its own trait, on an independent structure (upstream)
would be massively appreciated. @tarcieri also wanted to update from
`fn generator()` to `const GENERATOR`, which would encourage further discussion
on https://github.com/zkcrypto/group/issues/32 and
https://github.com/zkcrypto/group/issues/45, which have been stagnant.

The `Id` trait is occasionally used yet really should be first off the chopping
block.

Finally, `WithPreferredHash` is only actually used around a third of the time,
which more than justifies it being a separate trait.

---

Updates `dalek_ff_group::Scalar` to directly re-export
`curve25519_dalek::Scalar`, as without issue. `dalek_ff_group::RistrettoPoint`
also could be replaced with an export of `curve25519_dalek::RistrettoPoint`,
yet the coordinator relies on how we implemented `Hash` on it for the hell of
it so it isn't worth it at this time. `dalek_ff_group::EdwardsPoint` can't be
replaced for an re-export of `curve25519_dalek::SubgroupPoint` as it doesn't
implement `zeroize`, `subtle` traits within a released, non-yanked version.
Relevance to https://github.com/serai-dex/serai/issues/201 and
https://github.com/dalek-cryptography/curve25519-dalek/issues/811#issuecomment-3247732746.

Also updates the `Ristretto` ciphersuite to prefer `Blake2b-512` over
`SHA2-512`. In order to maintain compliance with FROST's IETF standard,
`modular-frost` defines its own ciphersuite for Ristretto which still uses
`SHA2-512`.
2025-09-03 13:50:20 -04:00

32 lines
939 B
Rust

use ciphersuite::*;
use dkg::{ThresholdKeys, Curves, Secp256k1};
use ethereum_schnorr::PublicKey;
pub(crate) struct KeyGenParams;
impl key_gen::KeyGenParams for KeyGenParams {
const ID: &'static str = "Ethereum";
type ExternalNetworkCiphersuite = Secp256k1;
fn tweak_keys(
keys: &mut ThresholdKeys<<Self::ExternalNetworkCiphersuite as Curves>::ToweringCurve>,
) {
while PublicKey::new(keys.group_key()).is_none() {
*keys = keys.clone().offset(<<Secp256k1 as Curves>::ToweringCurve as WrappedGroup>::F::ONE);
}
}
fn encode_key(
key: <<Self::ExternalNetworkCiphersuite as Curves>::ToweringCurve as WrappedGroup>::G,
) -> Vec<u8> {
PublicKey::new(key).unwrap().eth_repr().to_vec()
}
fn decode_key(
key: &[u8],
) -> Option<<<Self::ExternalNetworkCiphersuite as Curves>::ToweringCurve as WrappedGroup>::G> {
PublicKey::from_eth_repr(key.try_into().ok()?).map(|key| key.point())
}
}