use crate::types::{byte, int};
pub const Size: int = 32;
pub const BlockSize: int = 64;
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,
];
pub struct Digest {
state: [u32; 8],
buf: Vec<byte>,
len: u64,
}
#[allow(non_snake_case)]
pub fn New() -> Digest {
Digest {
state: [
0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19,
],
buf: Vec::with_capacity(64),
len: 0,
}
}
impl Digest {
pub fn Write(&mut self, p: &[byte]) -> (int, crate::errors::error) {
self.len = self.len.wrapping_add(p.len() as u64);
self.buf.extend_from_slice(p);
while self.buf.len() >= 64 {
let block: [u8; 64] = self.buf[..64].try_into().unwrap();
process(&mut self.state, &block);
self.buf.drain(..64);
}
(p.len() as int, crate::errors::nil)
}
pub fn Sum(&self, b: &[byte]) -> Vec<byte> {
let mut state = self.state;
let mut buf = self.buf.clone();
let bit_len = self.len.wrapping_mul(8);
buf.push(0x80);
while buf.len() % 64 != 56 {
buf.push(0);
}
buf.extend_from_slice(&bit_len.to_be_bytes());
let mut i = 0;
while i < buf.len() {
let block: [u8; 64] = buf[i..i + 64].try_into().unwrap();
process(&mut state, &block);
i += 64;
}
let mut out = b.to_vec();
for v in state.iter() {
out.extend_from_slice(&v.to_be_bytes());
}
out
}
pub fn Reset(&mut self) {
self.state = [
0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19,
];
self.buf.clear();
self.len = 0;
}
}
#[allow(non_snake_case)]
pub fn Sum256(data: &[byte]) -> [byte; 32] {
let mut h = New();
h.Write(data);
let v = h.Sum(&[]);
let mut out = [0u8; 32];
out.copy_from_slice(&v);
out
}
fn process(state: &mut [u32; 8], block: &[u8; 64]) {
let mut w = [0u32; 64];
for i in 0..16 {
w[i] = u32::from_be_bytes([
block[i * 4], block[i * 4 + 1], block[i * 4 + 2], block[i * 4 + 3]
]);
}
for i in 16..64 {
let s0 = w[i - 15].rotate_right(7) ^ w[i - 15].rotate_right(18) ^ (w[i - 15] >> 3);
let s1 = w[i - 2].rotate_right(17) ^ w[i - 2].rotate_right(19) ^ (w[i - 2] >> 10);
w[i] = w[i - 16].wrapping_add(s0).wrapping_add(w[i - 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 i in 0..64 {
let s1 = e.rotate_right(6) ^ e.rotate_right(11) ^ e.rotate_right(25);
let ch = (e & f) ^ (!e & g);
let t1 = h.wrapping_add(s1).wrapping_add(ch).wrapping_add(K[i]).wrapping_add(w[i]);
let s0 = a.rotate_right(2) ^ a.rotate_right(13) ^ a.rotate_right(22);
let mj = (a & b) ^ (a & c) ^ (b & c);
let t2 = s0.wrapping_add(mj);
h = g;
g = f;
f = e;
e = d.wrapping_add(t1);
d = c;
c = b;
b = a;
a = t1.wrapping_add(t2);
}
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);
}
#[cfg(test)]
mod tests {
use super::*;
fn hex(b: &[u8]) -> String {
b.iter().map(|x| format!("{:02x}", x)).collect()
}
#[test]
fn sha256_empty() {
let h = Sum256(b"");
assert_eq!(
hex(&h),
"e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855"
);
}
#[test]
fn sha256_abc() {
let h = Sum256(b"abc");
assert_eq!(
hex(&h),
"ba7816bf8f01cfea414140de5dae2223b00361a396177a9cb410ff61f20015ad"
);
}
#[test]
fn sha256_long_message() {
let msg = b"The quick brown fox jumps over the lazy dog";
let h = Sum256(msg);
assert_eq!(
hex(&h),
"d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592"
);
}
#[test]
fn sha256_streaming_equals_single() {
let mut a = New();
a.Write(b"hello ");
a.Write(b"world");
let out_a = a.Sum(&[]);
let out_b = Sum256(b"hello world").to_vec();
assert_eq!(out_a, out_b);
}
}