pub(super) fn sha256_digest(input: &[u8]) -> [u8; 32] {
const K: [u32; 64] = [
0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, 0x3956c25b, 0x59f111f1, 0x923f82a4,
0xab1c5ed5, 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, 0x72be5d74, 0x80deb1fe,
0x9bdc06a7, 0xc19bf174, 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, 0x2de92c6f,
0x4a7484aa, 0x5cb0a9dc, 0x76f988da, 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc,
0x53380d13, 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, 0xa2bfe8a1, 0xa81a664b,
0xc24b8b70, 0xc76c51a3, 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, 0x19a4c116,
0x1e376c08, 0x2748774c, 0x34b0bcb5, 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, 0x90befffa, 0xa4506ceb, 0xbef9a3f7,
0xc67178f2,
];
let mut state = [
0x6a09e667u32,
0xbb67ae85,
0x3c6ef372,
0xa54ff53a,
0x510e527f,
0x9b05688c,
0x1f83d9ab,
0x5be0cd19,
];
let mut message = input.to_vec();
let bit_len = (message.len() as u64) * 8;
message.push(0x80);
while (message.len() % 64) != 56 {
message.push(0);
}
message.extend_from_slice(&bit_len.to_be_bytes());
for chunk in message.chunks_exact(64) {
let mut words = [0u32; 64];
for (index, block) in chunk.chunks_exact(4).enumerate().take(16) {
words[index] = u32::from_be_bytes([block[0], block[1], block[2], block[3]]);
}
for index in 16..64 {
let s0 = words[index - 15].rotate_right(7)
^ words[index - 15].rotate_right(18)
^ (words[index - 15] >> 3);
let s1 = words[index - 2].rotate_right(17)
^ words[index - 2].rotate_right(19)
^ (words[index - 2] >> 10);
words[index] = words[index - 16]
.wrapping_add(s0)
.wrapping_add(words[index - 7])
.wrapping_add(s1);
}
let mut a = state[0];
let mut b = state[1];
let mut c = state[2];
let mut d = state[3];
let mut e = state[4];
let mut f = state[5];
let mut g = state[6];
let mut h = state[7];
for index in 0..64 {
let s1 = e.rotate_right(6) ^ e.rotate_right(11) ^ e.rotate_right(25);
let ch = (e & f) ^ ((!e) & g);
let temp1 = h
.wrapping_add(s1)
.wrapping_add(ch)
.wrapping_add(K[index])
.wrapping_add(words[index]);
let s0 = a.rotate_right(2) ^ a.rotate_right(13) ^ a.rotate_right(22);
let maj = (a & b) ^ (a & c) ^ (b & c);
let temp2 = s0.wrapping_add(maj);
h = g;
g = f;
f = e;
e = d.wrapping_add(temp1);
d = c;
c = b;
b = a;
a = temp1.wrapping_add(temp2);
}
state[0] = state[0].wrapping_add(a);
state[1] = state[1].wrapping_add(b);
state[2] = state[2].wrapping_add(c);
state[3] = state[3].wrapping_add(d);
state[4] = state[4].wrapping_add(e);
state[5] = state[5].wrapping_add(f);
state[6] = state[6].wrapping_add(g);
state[7] = state[7].wrapping_add(h);
}
let mut digest = [0u8; 32];
for (index, word) in state.iter().enumerate() {
digest[index * 4..index * 4 + 4].copy_from_slice(&word.to_be_bytes());
}
digest
}