pub fn md5_hex(input: &str) -> String {
let digest = md5(input.as_bytes());
let mut out = String::with_capacity(32);
for b in digest {
out.push_str(&format!("{b:02x}"));
}
out
}
fn md5(input: &[u8]) -> [u8; 16] {
let mut msg = input.to_vec();
let bit_len = (msg.len() as u64) * 8;
msg.push(0x80);
while (msg.len() % 64) != 56 {
msg.push(0);
}
msg.extend_from_slice(&bit_len.to_le_bytes());
let mut a0: u32 = 0x6745_2301;
let mut b0: u32 = 0xefcd_ab89;
let mut c0: u32 = 0x98ba_dcfe;
let mut d0: u32 = 0x1032_5476;
const S: [u32; 64] = [
7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 5, 9, 14, 20, 5, 9, 14, 20, 5,
9, 14, 20, 5, 9, 14, 20, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 6, 10,
15, 21, 6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21,
];
const K: [u32; 64] = [
0xd76a_a478,
0xe8c7_b756,
0x2420_70db,
0xc1bd_ceee,
0xf57c_0faf,
0x4787_c62a,
0xa830_4613,
0xfd46_9501,
0x6980_98d8,
0x8b44_f7af,
0xffff_5bb1,
0x895c_d7be,
0x6b90_1122,
0xfd98_7193,
0xa679_438e,
0x49b4_0821,
0xf61e_2562,
0xc040_b340,
0x265e_5a51,
0xe9b6_c7aa,
0xd62f_105d,
0x0244_1453,
0xd8a1_e681,
0xe7d3_fbc8,
0x21e1_cde6,
0xc337_07d6,
0xf4d5_0d87,
0x455a_14ed,
0xa9e3_e905,
0xfcef_a3f8,
0x676f_02d9,
0x8d2a_4c8a,
0xfffa_3942,
0x8771_f681,
0x6d9d_6122,
0xfde5_380c,
0xa4be_ea44,
0x4bde_cfa9,
0xf6bb_4b60,
0xbebf_bc70,
0x289b_7ec6,
0xeaa1_27fa,
0xd4ef_3085,
0x0488_1d05,
0xd9d4_d039,
0xe6db_99e5,
0x1fa2_7cf8,
0xc4ac_5665,
0xf429_2244,
0x432a_ff97,
0xab94_23a7,
0xfc93_a039,
0x655b_59c3,
0x8f0c_cc92,
0xffef_f47d,
0x8584_5dd1,
0x6fa8_7e4f,
0xfe2c_e6e0,
0xa301_4314,
0x4e08_11a1,
0xf753_7e82,
0xbd3a_f235,
0x2ad7_d2bb,
0xeb86_d391,
];
for chunk in msg.chunks_exact(64) {
let mut m = [0u32; 16];
for (i, bytes) in chunk.chunks_exact(4).enumerate() {
m[i] = u32::from_le_bytes([bytes[0], bytes[1], bytes[2], bytes[3]]);
}
let mut a = a0;
let mut b = b0;
let mut c = c0;
let mut d = d0;
for i in 0..64 {
let (f, g) = if i < 16 {
((b & c) | ((!b) & d), i)
} else if i < 32 {
((d & b) | ((!d) & c), (5 * i + 1) % 16)
} else if i < 48 {
(b ^ c ^ d, (3 * i + 5) % 16)
} else {
(c ^ (b | !d), (7 * i) % 16)
};
let tmp = d;
d = c;
c = b;
b = b.wrapping_add(
a.wrapping_add(f)
.wrapping_add(K[i])
.wrapping_add(m[g])
.rotate_left(S[i]),
);
a = tmp;
}
a0 = a0.wrapping_add(a);
b0 = b0.wrapping_add(b);
c0 = c0.wrapping_add(c);
d0 = d0.wrapping_add(d);
}
let mut out = [0u8; 16];
out[0..4].copy_from_slice(&a0.to_le_bytes());
out[4..8].copy_from_slice(&b0.to_le_bytes());
out[8..12].copy_from_slice(&c0.to_le_bytes());
out[12..16].copy_from_slice(&d0.to_le_bytes());
out
}
#[cfg(test)]
#[path = "md5_tests.rs"]
mod md5_tests;