wtx 0.44.3

A collection of different transport implementations and related tools focused primarily on web technologies.
Documentation
#[cfg(feature = "crypto-aws-lc-rs")]
mod aws_lc_rs;
pub(crate) mod global;
#[cfg(feature = "crypto-graviola")]
mod graviola;
#[cfg(feature = "p256")]
mod p256;
#[cfg(feature = "p384")]
mod p384;
#[cfg(feature = "crypto-ring")]
mod ring;
#[cfg(feature = "x25519-dalek")]
mod x25519_dalek;

use crate::{misc::DefaultArray, rng::CryptoRng};
use core::marker::PhantomData;

/// Temporary single-use secret key.
pub trait Agreement: Sized {
  /// Ephemeral secret key
  type EphemeralSecretKey;
  /// Public key
  type PublicKey: AsRef<[u8]>;
  /// Shared secret
  type SharedSecret: AsRef<[u8]>;

  /// Generates a symmetric cryptographic key.
  fn diffie_hellman(
    esk: Self::EphemeralSecretKey,
    other_participant_pk: &[u8],
  ) -> crate::Result<Self::SharedSecret>;

  /// New random ephemeral secret key
  fn ephemeral_secret_key<RNG>(rng: &mut RNG) -> crate::Result<Self::EphemeralSecretKey>
  where
    RNG: CryptoRng;

  /// Associated public key of an ephemeral secret
  fn public_key(esk: &Self::EphemeralSecretKey) -> crate::Result<Self::PublicKey>;
}

/// Stub [`Agreement`] implementation used when no backend is enabled.
#[derive(Clone, Copy, Debug, Default, PartialEq)]
pub struct AgreementStub<ESK, PK, SS>(PhantomData<(ESK, PK, SS)>);

impl<ESK, PK, SS> Agreement for AgreementStub<ESK, PK, SS>
where
  ESK: Default,
  PK: AsRef<[u8]> + DefaultArray,
  SS: AsRef<[u8]> + DefaultArray,
{
  type EphemeralSecretKey = ESK;
  type PublicKey = PK;
  type SharedSecret = SS;

  #[inline]
  fn diffie_hellman(_: Self::EphemeralSecretKey, _: &[u8]) -> crate::Result<Self::SharedSecret> {
    Ok(Self::SharedSecret::default_array())
  }

  #[inline]
  fn ephemeral_secret_key<RNG>(_: &mut RNG) -> crate::Result<Self::EphemeralSecretKey>
  where
    RNG: CryptoRng,
  {
    Ok(Self::EphemeralSecretKey::default())
  }

  #[inline]
  fn public_key(_: &Self::EphemeralSecretKey) -> crate::Result<Self::PublicKey> {
    Ok(Self::PublicKey::default_array())
  }
}