sha2/sha256/soft/
unroll.rs

1use crate::consts::K32;
2
3#[rustfmt::skip]
4macro_rules! repeat64 {
5    ($i:ident, $b:block) => {
6        let $i = 0; $b; let $i = 1; $b; let $i = 2; $b; let $i = 3; $b;
7        let $i = 4; $b; let $i = 5; $b; let $i = 6; $b; let $i = 7; $b;
8        let $i = 8; $b; let $i = 9; $b; let $i = 10; $b; let $i = 11; $b;
9        let $i = 12; $b; let $i = 13; $b; let $i = 14; $b; let $i = 15; $b;
10        let $i = 16; $b; let $i = 17; $b; let $i = 18; $b; let $i = 19; $b;
11        let $i = 20; $b; let $i = 21; $b; let $i = 22; $b; let $i = 23; $b;
12        let $i = 24; $b; let $i = 25; $b; let $i = 26; $b; let $i = 27; $b;
13        let $i = 28; $b; let $i = 29; $b; let $i = 30; $b; let $i = 31; $b;
14        let $i = 32; $b; let $i = 33; $b; let $i = 34; $b; let $i = 35; $b;
15        let $i = 36; $b; let $i = 37; $b; let $i = 38; $b; let $i = 39; $b;
16        let $i = 40; $b; let $i = 41; $b; let $i = 42; $b; let $i = 43; $b;
17        let $i = 44; $b; let $i = 45; $b; let $i = 46; $b; let $i = 47; $b;
18        let $i = 48; $b; let $i = 49; $b; let $i = 50; $b; let $i = 51; $b;
19        let $i = 52; $b; let $i = 53; $b; let $i = 54; $b; let $i = 55; $b;
20        let $i = 56; $b; let $i = 57; $b; let $i = 58; $b; let $i = 59; $b;
21        let $i = 60; $b; let $i = 61; $b; let $i = 62; $b; let $i = 63; $b;
22    };
23}
24
25/// Read round constant
26fn rk(i: usize) -> u32 {
27    // `read_volatile` forces compiler to read round constants from the static
28    // instead of inlining them, which improves codegen and performance on some platforms.
29    // On x86 targets 32-bit constants can be encoded using immediate argument on the `add`
30    // instruction, so it's more efficient to inline them.
31    cfg_if::cfg_if! {
32        if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
33            use core::ptr::read as r;
34        } else {
35            use core::ptr::read_volatile as r;
36        }
37    }
38
39    unsafe {
40        let p = K32.as_ptr().add(i);
41        r(p)
42    }
43}
44
45/// Process a block with the SHA-256 algorithm.
46fn compress_block(state: &mut [u32; 8], block: &[u8; 64]) {
47    let mut block = super::to_u32s(block);
48    let [mut a, mut b, mut c, mut d, mut e, mut f, mut g, mut h] = *state;
49
50    repeat64!(i, {
51        let w = if i < 16 {
52            block[i]
53        } else {
54            let w15 = block[(i - 15) % 16];
55            let s0 = (w15.rotate_right(7)) ^ (w15.rotate_right(18)) ^ (w15 >> 3);
56            let w2 = block[(i - 2) % 16];
57            let s1 = (w2.rotate_right(17)) ^ (w2.rotate_right(19)) ^ (w2 >> 10);
58            block[i % 16] = block[i % 16]
59                .wrapping_add(s0)
60                .wrapping_add(block[(i - 7) % 16])
61                .wrapping_add(s1);
62            block[i % 16]
63        };
64
65        let s1 = e.rotate_right(6) ^ e.rotate_right(11) ^ e.rotate_right(25);
66        let ch = (e & f) ^ ((!e) & g);
67        let t1 = s1
68            .wrapping_add(ch)
69            .wrapping_add(rk(i))
70            .wrapping_add(w)
71            .wrapping_add(h);
72        let s0 = a.rotate_right(2) ^ a.rotate_right(13) ^ a.rotate_right(22);
73        let maj = (a & b) ^ (a & c) ^ (b & c);
74        let t2 = s0.wrapping_add(maj);
75
76        h = g;
77        g = f;
78        f = e;
79        e = d.wrapping_add(t1);
80        d = c;
81        c = b;
82        b = a;
83        a = t1.wrapping_add(t2);
84    });
85
86    state[0] = state[0].wrapping_add(a);
87    state[1] = state[1].wrapping_add(b);
88    state[2] = state[2].wrapping_add(c);
89    state[3] = state[3].wrapping_add(d);
90    state[4] = state[4].wrapping_add(e);
91    state[5] = state[5].wrapping_add(f);
92    state[6] = state[6].wrapping_add(g);
93    state[7] = state[7].wrapping_add(h);
94}
95
96pub(in super::super) fn compress(state: &mut [u32; 8], blocks: &[[u8; 64]]) {
97    for block in blocks {
98        compress_block(state, block);
99    }
100}
sha2/sha256/soft/unroll.rs

sha2/sha256/soft/
unroll.rs
