cthash 0.9.0

const fn implementation of hash functions including MD4, MD5, SHA-1, SHA-2, SHA-3, Keccak
Documentation 
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135

use crate::block_api::eager_split_pad;

/// Compute MD4 digest.
/// # Examples
/// ```
/// use cthash::md4;
/// const H: [u8; 16] = md4(b"data");
/// ```
pub const fn md4(input: &[u8]) -> [u8; 16] {
    let mut state = [0x67452301u32, 0xefcdab89, 0x98badcfe, 0x10325476];

    md4_pad_and_run(input, &mut state);

    let mut out = [0u8; 16];
    let mut i = 0;
    while i < 4 {
        out.as_chunks_mut().0[i] = state[i].to_le_bytes();
        i += 1;
    }
    out
}

#[inline(always)]
const fn md4_pad_and_run(input: &[u8], state: &mut [u32; 4]) {
    let mut b0 = [0; _];
    let mut b1 = [0; _];
    let bit_len = ((input.len() as u64) * 8).to_le_bytes();
    let (blocks, pad_two_blocks) = eager_split_pad(input, &bit_len, 0x80, &mut b0, &mut b1);

    let mut i = 0;
    while i < blocks.len() {
        compress(state, &blocks[i]);
        i += 1;
    }

    if pad_two_blocks {
        compress(state, &b0);
        compress(state, &b1);
    } else {
        compress(state, &b0);
    }
}

const fn compress(h: &mut [u32; 4], block: &[u8; 64]) {
    const K1: u32 = 0x5a827999;
    const K2: u32 = 0x6ed9eba1;

    #[inline(always)]
    const fn round1(a: u32, b: u32, c: u32, d: u32, k: u32, s: u32) -> u32 {
        let t = a.wrapping_add(b & c | !b & d).wrapping_add(k);
        t.rotate_left(s)
    }
    #[inline(always)]
    const fn round2(a: u32, b: u32, c: u32, d: u32, k: u32, s: u32) -> u32 {
        let t = a.wrapping_add(b & c | b & d | c & d).wrapping_add(k).wrapping_add(K1);
        t.rotate_left(s)
    }
    #[inline(always)]
    const fn round3(a: u32, b: u32, c: u32, d: u32, k: u32, s: u32) -> u32 {
        let t = a.wrapping_add(b ^ c ^ d).wrapping_add(k).wrapping_add(K2);
        t.rotate_left(s)
    }

    let mut data = [0u32; 16];
    let mut i = 0;
    let (w_words, _rem) = block.as_chunks();
    while i < 16 {
        data[i] = u32::from_le_bytes(w_words[i]);
        i += 1;
    }

    let mut a = h[0];
    let mut b = h[1];
    let mut c = h[2];
    let mut d = h[3];

    // Round 1
    a = round1(a, b, c, d, data[0], 3);
    d = round1(d, a, b, c, data[1], 7);
    c = round1(c, d, a, b, data[2], 11);
    b = round1(b, c, d, a, data[3], 19);
    a = round1(a, b, c, d, data[4], 3);
    d = round1(d, a, b, c, data[5], 7);
    c = round1(c, d, a, b, data[6], 11);
    b = round1(b, c, d, a, data[7], 19);
    a = round1(a, b, c, d, data[8], 3);
    d = round1(d, a, b, c, data[9], 7);
    c = round1(c, d, a, b, data[10], 11);
    b = round1(b, c, d, a, data[11], 19);
    a = round1(a, b, c, d, data[12], 3);
    d = round1(d, a, b, c, data[13], 7);
    c = round1(c, d, a, b, data[14], 11);
    b = round1(b, c, d, a, data[15], 19);

    // Round 2
    a = round2(a, b, c, d, data[0], 3);
    d = round2(d, a, b, c, data[4], 5);
    c = round2(c, d, a, b, data[8], 9);
    b = round2(b, c, d, a, data[12], 13);
    a = round2(a, b, c, d, data[1], 3);
    d = round2(d, a, b, c, data[5], 5);
    c = round2(c, d, a, b, data[9], 9);
    b = round2(b, c, d, a, data[13], 13);
    a = round2(a, b, c, d, data[2], 3);
    d = round2(d, a, b, c, data[6], 5);
    c = round2(c, d, a, b, data[10], 9);
    b = round2(b, c, d, a, data[14], 13);
    a = round2(a, b, c, d, data[3], 3);
    d = round2(d, a, b, c, data[7], 5);
    c = round2(c, d, a, b, data[11], 9);
    b = round2(b, c, d, a, data[15], 13);

    // Round 3
    a = round3(a, b, c, d, data[0], 3);
    d = round3(d, a, b, c, data[8], 9);
    c = round3(c, d, a, b, data[4], 11);
    b = round3(b, c, d, a, data[12], 15);
    a = round3(a, b, c, d, data[2], 3);
    d = round3(d, a, b, c, data[10], 9);
    c = round3(c, d, a, b, data[6], 11);
    b = round3(b, c, d, a, data[14], 15);
    a = round3(a, b, c, d, data[1], 3);
    d = round3(d, a, b, c, data[9], 9);
    c = round3(c, d, a, b, data[5], 11);
    b = round3(b, c, d, a, data[13], 15);
    a = round3(a, b, c, d, data[3], 3);
    d = round3(d, a, b, c, data[11], 9);
    c = round3(c, d, a, b, data[7], 11);
    b = round3(b, c, d, a, data[15], 15);

    h[0] = h[0].wrapping_add(a);
    h[1] = h[1].wrapping_add(b);
    h[2] = h[2].wrapping_add(c);
    h[3] = h[3].wrapping_add(d);
}