rust-bitcoin-unsafe-fast/hashes/src/sha512/mod.rs

130 lines
3.5 KiB
Rust

// SPDX-License-Identifier: CC0-1.0
//! SHA512 implementation.
#[cfg(bench)]
mod benches;
mod crypto;
#[cfg(bench)]
mod tests;
use core::cmp;
use crate::{incomplete_block_len, HashEngine as _};
crate::internal_macros::general_hash_type! {
512,
false,
"Output of the SHA512 hash function."
}
#[cfg(not(hashes_fuzz))]
pub(crate) fn from_engine(mut e: HashEngine) -> Hash {
// pad buffer with a single 1-bit then all 0s, until there are exactly 16 bytes remaining
let n_bytes_hashed = e.bytes_hashed;
let zeroes = [0; BLOCK_SIZE - 16];
e.input(&[0x80]);
if incomplete_block_len(&e) > zeroes.len() {
e.input(&zeroes);
}
let pad_length = zeroes.len() - incomplete_block_len(&e);
e.input(&zeroes[..pad_length]);
debug_assert_eq!(incomplete_block_len(&e), zeroes.len());
e.input(&[0; 8]);
e.input(&(8 * n_bytes_hashed).to_be_bytes());
debug_assert_eq!(incomplete_block_len(&e), 0);
Hash(e.midstate())
}
#[cfg(hashes_fuzz)]
pub(crate) fn from_engine(e: HashEngine) -> Hash {
let mut hash = e.midstate();
hash[0] ^= 0xff; // Make this distinct from SHA-256
Hash(hash)
}
pub(crate) const BLOCK_SIZE: usize = 128;
/// Engine to compute SHA512 hash function.
#[derive(Debug, Clone)]
pub struct HashEngine {
h: [u64; 8],
bytes_hashed: u64,
buffer: [u8; BLOCK_SIZE],
}
impl HashEngine {
/// Constructs a new SHA512 hash engine.
#[rustfmt::skip]
pub const fn new() -> Self {
Self {
h: [
0x6a09e667f3bcc908, 0xbb67ae8584caa73b, 0x3c6ef372fe94f82b, 0xa54ff53a5f1d36f1,
0x510e527fade682d1, 0x9b05688c2b3e6c1f, 0x1f83d9abfb41bd6b, 0x5be0cd19137e2179,
],
bytes_hashed: 0,
buffer: [0; BLOCK_SIZE],
}
}
}
impl Default for HashEngine {
fn default() -> Self { Self::new() }
}
impl HashEngine {
#[cfg(not(hashes_fuzz))]
pub(crate) fn midstate(&self) -> [u8; 64] {
let mut ret = [0; 64];
for (val, ret_bytes) in self.h.iter().zip(ret.chunks_exact_mut(8)) {
ret_bytes.copy_from_slice(&val.to_be_bytes());
}
ret
}
#[cfg(hashes_fuzz)]
pub(crate) fn midstate(&self) -> [u8; 64] {
let mut ret = [0; 64];
ret.copy_from_slice(&self.buffer[..64]);
ret
}
/// Constructs a new hash engine suitable for use constructing a `sha512_256::HashEngine`.
#[rustfmt::skip]
pub(crate) const fn sha512_256() -> Self {
HashEngine {
h: [
0x22312194fc2bf72c, 0x9f555fa3c84c64c2, 0x2393b86b6f53b151, 0x963877195940eabd,
0x96283ee2a88effe3, 0xbe5e1e2553863992, 0x2b0199fc2c85b8aa, 0x0eb72ddc81c52ca2,
],
bytes_hashed: 0,
buffer: [0; BLOCK_SIZE],
}
}
/// Constructs a new hash engine suitable for constructing a `sha384::HashEngine`.
#[rustfmt::skip]
pub(crate) const fn sha384() -> Self {
HashEngine {
h: [
0xcbbb9d5dc1059ed8, 0x629a292a367cd507, 0x9159015a3070dd17, 0x152fecd8f70e5939,
0x67332667ffc00b31, 0x8eb44a8768581511, 0xdb0c2e0d64f98fa7, 0x47b5481dbefa4fa4,
],
bytes_hashed: 0,
buffer: [0; BLOCK_SIZE],
}
}
}
impl crate::HashEngine for HashEngine {
type Hash = Hash;
const BLOCK_SIZE: usize = 128;
fn n_bytes_hashed(&self) -> u64 { self.bytes_hashed }
crate::internal_macros::engine_input_impl!();
fn finalize(self) -> Self::Hash { Hash::from_engine(self) }
}