serai/substrate/primitives/src/crypto.rs

use zeroize::Zeroize;
use borsh::{BorshSerialize, BorshDeserialize};

use sp_core::{ConstU32, bounded::BoundedVec};

/// A Ristretto public key.
#[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize, BorshSerialize, BorshDeserialize)]
pub struct Public(pub [u8; 32]);
impl From<sp_core::sr25519::Public> for Public {
  fn from(public: sp_core::sr25519::Public) -> Self {
    Self(public.0)
  }
}
impl From<Public> for sp_core::sr25519::Public {
  fn from(public: Public) -> Self {
    Self::from_raw(public.0)
  }
}

/// A sr25519 signature.
#[derive(Clone, Copy, PartialEq, Eq, Debug, Zeroize, BorshSerialize, BorshDeserialize)]
pub struct Signature(pub [u8; 64]);
impl From<sp_core::sr25519::Signature> for Signature {
  fn from(signature: sp_core::sr25519::Signature) -> Self {
    Self(signature.0)
  }
}
impl From<Signature> for sp_core::sr25519::Signature {
  fn from(signature: Signature) -> Self {
    Self::from_raw(signature.0)
  }
}

/// A key for an external network.
#[derive(Clone, PartialEq, Eq, Debug, BorshSerialize, BorshDeserialize)]
pub struct ExternalKey(
  #[borsh(
    serialize_with = "crate::borsh_serialize_bounded_vec",
    deserialize_with = "crate::borsh_deserialize_bounded_vec"
  )]
  pub BoundedVec<u8, ConstU32<{ Self::MAX_LEN }>>,
);

impl Zeroize for ExternalKey {
  fn zeroize(&mut self) {
    self.0.as_mut().zeroize();
  }
}

impl ExternalKey {
  /// The maximum length for am external key.
  /*
    This support keys up to 96 bytes (such as BLS12-381 G2, which is the largest elliptic-curve
    group element we might reasonably use as a key). This can always be increased if we need to
    adopt a different cryptosystem (one where verification keys are multiple group elements, or
    where group elements do exceed 96 bytes, such as RSA).
  */
  pub const MAX_LEN: u32 = 96;
}

/// The key pair for a validator set.
///
/// This is their Ristretto key, used for publishing data onto Serai, and their key on the external
/// network.
#[derive(Clone, PartialEq, Eq, Debug, Zeroize, BorshSerialize, BorshDeserialize)]
pub struct KeyPair(pub Public, pub ExternalKey);