use crate::BinaryToTextEncoding;
use crate::utils::encoders::{to_base32, to_base64, to_base64url, to_binary_string, to_hex_string};
#[derive(Copy, Clone)]
pub struct Sha256 {
data: [u8; 64],
datalen: usize,
bitlen: u64,
state: [u32; 8],
}
impl Sha256 {
pub fn new() -> Self {
Self {
data: [0; 64],
datalen: 0,
bitlen: 0,
state: [
0x6a09e667,
0xbb67ae85,
0x3c6ef372,
0xa54ff53a,
0x510e527f,
0x9b05688c,
0x1f83d9ab,
0x5be0cd19,
],
}
}
pub fn update(&mut self, data: &[u8]) -> Self {
let mut i = 0usize;
while i < data.len() {
self.data[self.datalen] = data[i];
self.datalen += 1;
if self.datalen == 64 {
self.transform();
self.bitlen += 512;
self.datalen = 0;
}
i += 1;
}
*self
}
pub fn digest(&mut self, encoding: BinaryToTextEncoding) -> String {
let i = self.datalen;
if self.datalen < 56 {
self.data[i] = 0x80;
for j in i+1..56 {
self.data[j] = 0x00;
}
} else {
self.data[i] = 0x80;
for j in i+1..64 {
self.data[j] = 0x00;
}
self.transform();
for j in 0..56 {
self.data[j] = 0x00;
}
}
self.bitlen += self.datalen as u64 * 8;
self.data[63] = self.bitlen as u8;
self.data[62] = (self.bitlen >> 8) as u8;
self.data[61] = (self.bitlen >> 16) as u8;
self.data[60] = (self.bitlen >> 24) as u8;
self.data[59] = (self.bitlen >> 32) as u8;
self.data[58] = (self.bitlen >> 40) as u8;
self.data[57] = (self.bitlen >> 48) as u8;
self.data[56] = (self.bitlen >> 56) as u8;
self.transform();
let mut hash: [u8; 32] = [0; 32];
for i in 0..4 {
hash[i] = (self.state[0] >> (24 - i * 8)) as u8;
hash[i + 4] = (self.state[1] >> (24 - i * 8)) as u8;
hash[i + 8] = (self.state[2] >> (24 - i * 8)) as u8;
hash[i + 12] = (self.state[3] >> (24 - i * 8)) as u8;
hash[i + 16] = (self.state[4] >> (24 - i * 8)) as u8;
hash[i + 20] = (self.state[5] >> (24 - i * 8)) as u8;
hash[i + 24] = (self.state[6] >> (24 - i * 8)) as u8;
hash[i + 28] = (self.state[7] >> (24 - i * 8)) as u8;
}
match encoding {
BinaryToTextEncoding::Base32 => to_base32(&hash),
BinaryToTextEncoding::Base64 => to_base64(&hash),
BinaryToTextEncoding::Base64Url => to_base64url(to_base64(&hash)),
BinaryToTextEncoding::Hex => to_hex_string(&hash),
BinaryToTextEncoding::Binary => to_binary_string(&hash),
}
}
fn transform(&mut self) {
let 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 m: [u32; 64] = [0; 64];
let mut a: u32;
let mut b: u32;
let mut c: u32;
let mut d: u32;
let mut e: u32;
let mut f: u32;
let mut g: u32;
let mut h: u32;
let mut t1: u32;
let mut t2: u32;
for i in 0..16 {
let j = i * 4;
m[i] = ((self.data[j] as u32) << 24) | ((self.data[j + 1] as u32) << 16)
| ((self.data[j + 2] as u32) << 8) | (self.data[j + 3] as u32);
}
for i in 16..64 {
let s0 = self.rotate_right(m[i - 15], 7) ^ self.rotate_right(m[i - 15], 18) ^ (m[i - 15] >> 3);
let s1 = self.rotate_right(m[i - 2], 17) ^ self.rotate_right(m[i - 2], 19) ^ (m[i - 2] >> 10);
m[i] = m[i - 16].wrapping_add(s0).wrapping_add(m[i - 7]).wrapping_add(s1);
}
a = self.state[0];
b = self.state[1];
c = self.state[2];
d = self.state[3];
e = self.state[4];
f = self.state[5];
g = self.state[6];
h = self.state[7];
for i in 0..64 {
let s1 = self.rotate_right(e, 6) ^ self.rotate_right(e, 11) ^ self.rotate_right(e, 25);
let ch = (e & f) ^ (!e & g);
t1 = h.wrapping_add(s1).wrapping_add(ch).wrapping_add(k[i]).wrapping_add(m[i]);
let s0 = self.rotate_right(a, 2) ^ self.rotate_right(a, 13) ^ self.rotate_right(a, 22);
let maj = (a & b) ^ (a & c) ^ (b & c);
t2 = s0.wrapping_add(maj);
h = g;
g = f;
f = e;
e = d.wrapping_add(t1);
d = c;
c = b;
b = a;
a = t1.wrapping_add(t2);
}
self.state[0] = self.state[0].wrapping_add(a);
self.state[1] = self.state[1].wrapping_add(b);
self.state[2] = self.state[2].wrapping_add(c);
self.state[3] = self.state[3].wrapping_add(d);
self.state[4] = self.state[4].wrapping_add(e);
self.state[5] = self.state[5].wrapping_add(f);
self.state[6] = self.state[6].wrapping_add(g);
self.state[7] = self.state[7].wrapping_add(h);
}
fn rotate_right(&mut self, x: u32, n: u32) -> u32 {
(x >> n) | (x << (32 - n))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_sha256() {
let sut = Sha256::new()
.update(b"hello world")
.digest(BinaryToTextEncoding::Hex);
assert_eq!(sut, "b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9");
}
}