Files
rosenpass/ciphers/src/subtle/rust_crypto/blake2b.rs
2025-04-03 16:15:03 +02:00

45 lines
1.6 KiB
Rust

use zeroize::Zeroizing;
use blake2::digest::crypto_common::generic_array::GenericArray;
use blake2::digest::crypto_common::typenum::U32;
use blake2::digest::{FixedOutput, Mac};
use blake2::Blake2bMac;
use rosenpass_cipher_traits::primitives::KeyedHash;
use rosenpass_to::{ops::copy_slice, To};
pub use rosenpass_cipher_traits::algorithms::keyed_hash_blake2b::{HASH_LEN, KEY_LEN};
/// Specify that the used implementation of BLAKE2b is the MAC version of BLAKE2b
/// with output and key length of 32 bytes (see [Blake2bMac]).
type Impl = Blake2bMac<U32>;
/// Hashes the given `data` with the [Blake2bMac] hash function under the given `key`.
/// The both the length of the output the length of the key 32 bytes (or 256 bits).
pub struct Blake2b;
impl KeyedHash<KEY_LEN, HASH_LEN> for Blake2b {
type Error = anyhow::Error;
fn keyed_hash(
key: &[u8; KEY_LEN],
data: &[u8],
out: &mut [u8; HASH_LEN],
) -> Result<(), Self::Error> {
let mut h = Impl::new_from_slice(key)?;
h.update(data);
// Jesus christ, blake2 crate, your usage of GenericArray might be nice and fancy,
// but it introduces a ton of complexity. This cost me half an hour just to figure
// out the right way to use the imports while allowing for zeroization.
// An API based on slices might actually be simpler.
let mut tmp = Zeroizing::new([0u8; HASH_LEN]);
let tmp = GenericArray::from_mut_slice(tmp.as_mut());
h.finalize_into(tmp);
copy_slice(tmp.as_ref()).to(out);
Ok(())
}
}
impl rosenpass_cipher_traits::algorithms::KeyedHashBlake2b for Blake2b {}