sha2/sha256/
soft.rs

1#![allow(clippy::many_single_char_names)]
2use crate::consts::BLOCK_LEN;
3use core::convert::TryInto;
4
5#[inline(always)]
6fn shl(v: [u32; 4], o: u32) -> [u32; 4] {
7    [v[0] >> o, v[1] >> o, v[2] >> o, v[3] >> o]
8}
9
10#[inline(always)]
11fn shr(v: [u32; 4], o: u32) -> [u32; 4] {
12    [v[0] << o, v[1] << o, v[2] << o, v[3] << o]
13}
14
15#[inline(always)]
16fn or(a: [u32; 4], b: [u32; 4]) -> [u32; 4] {
17    [a[0] | b[0], a[1] | b[1], a[2] | b[2], a[3] | b[3]]
18}
19
20#[inline(always)]
21fn xor(a: [u32; 4], b: [u32; 4]) -> [u32; 4] {
22    [a[0] ^ b[0], a[1] ^ b[1], a[2] ^ b[2], a[3] ^ b[3]]
23}
24
25#[inline(always)]
26fn add(a: [u32; 4], b: [u32; 4]) -> [u32; 4] {
27    [
28        a[0].wrapping_add(b[0]),
29        a[1].wrapping_add(b[1]),
30        a[2].wrapping_add(b[2]),
31        a[3].wrapping_add(b[3]),
32    ]
33}
34
35fn sha256load(v2: [u32; 4], v3: [u32; 4]) -> [u32; 4] {
36    [v3[3], v2[0], v2[1], v2[2]]
37}
38
39fn sha256swap(v0: [u32; 4]) -> [u32; 4] {
40    [v0[2], v0[3], v0[0], v0[1]]
41}
42
43fn sha256msg1(v0: [u32; 4], v1: [u32; 4]) -> [u32; 4] {
44    // sigma 0 on vectors
45    #[inline]
46    fn sigma0x4(x: [u32; 4]) -> [u32; 4] {
47        let t1 = or(shl(x, 7), shr(x, 25));
48        let t2 = or(shl(x, 18), shr(x, 14));
49        let t3 = shl(x, 3);
50        xor(xor(t1, t2), t3)
51    }
52
53    add(v0, sigma0x4(sha256load(v0, v1)))
54}
55
56fn sha256msg2(v4: [u32; 4], v3: [u32; 4]) -> [u32; 4] {
57    macro_rules! sigma1 {
58        ($a:expr) => {
59            $a.rotate_right(17) ^ $a.rotate_right(19) ^ ($a >> 10)
60        };
61    }
62
63    let [x3, x2, x1, x0] = v4;
64    let [w15, w14, _, _] = v3;
65
66    let w16 = x0.wrapping_add(sigma1!(w14));
67    let w17 = x1.wrapping_add(sigma1!(w15));
68    let w18 = x2.wrapping_add(sigma1!(w16));
69    let w19 = x3.wrapping_add(sigma1!(w17));
70
71    [w19, w18, w17, w16]
72}
73
74fn sha256_digest_round_x2(cdgh: [u32; 4], abef: [u32; 4], wk: [u32; 4]) -> [u32; 4] {
75    macro_rules! big_sigma0 {
76        ($a:expr) => {
77            ($a.rotate_right(2) ^ $a.rotate_right(13) ^ $a.rotate_right(22))
78        };
79    }
80    macro_rules! big_sigma1 {
81        ($a:expr) => {
82            ($a.rotate_right(6) ^ $a.rotate_right(11) ^ $a.rotate_right(25))
83        };
84    }
85    macro_rules! bool3ary_202 {
86        ($a:expr, $b:expr, $c:expr) => {
87            $c ^ ($a & ($b ^ $c))
88        };
89    } // Choose, MD5F, SHA1C
90    macro_rules! bool3ary_232 {
91        ($a:expr, $b:expr, $c:expr) => {
92            ($a & $b) ^ ($a & $c) ^ ($b & $c)
93        };
94    } // Majority, SHA1M
95
96    let [_, _, wk1, wk0] = wk;
97    let [a0, b0, e0, f0] = abef;
98    let [c0, d0, g0, h0] = cdgh;
99
100    // a round
101    let x0 = big_sigma1!(e0)
102        .wrapping_add(bool3ary_202!(e0, f0, g0))
103        .wrapping_add(wk0)
104        .wrapping_add(h0);
105    let y0 = big_sigma0!(a0).wrapping_add(bool3ary_232!(a0, b0, c0));
106    let (a1, b1, c1, d1, e1, f1, g1, h1) = (
107        x0.wrapping_add(y0),
108        a0,
109        b0,
110        c0,
111        x0.wrapping_add(d0),
112        e0,
113        f0,
114        g0,
115    );
116
117    // a round
118    let x1 = big_sigma1!(e1)
119        .wrapping_add(bool3ary_202!(e1, f1, g1))
120        .wrapping_add(wk1)
121        .wrapping_add(h1);
122    let y1 = big_sigma0!(a1).wrapping_add(bool3ary_232!(a1, b1, c1));
123    let (a2, b2, _, _, e2, f2, _, _) = (
124        x1.wrapping_add(y1),
125        a1,
126        b1,
127        c1,
128        x1.wrapping_add(d1),
129        e1,
130        f1,
131        g1,
132    );
133
134    [a2, b2, e2, f2]
135}
136
137fn schedule(v0: [u32; 4], v1: [u32; 4], v2: [u32; 4], v3: [u32; 4]) -> [u32; 4] {
138    let t1 = sha256msg1(v0, v1);
139    let t2 = sha256load(v2, v3);
140    let t3 = add(t1, t2);
141    sha256msg2(t3, v3)
142}
143
144macro_rules! rounds4 {
145    ($abef:ident, $cdgh:ident, $rest:expr, $i:expr) => {{
146        let t1 = add($rest, crate::consts::K32X4[$i]);
147        $cdgh = sha256_digest_round_x2($cdgh, $abef, t1);
148        let t2 = sha256swap(t1);
149        $abef = sha256_digest_round_x2($abef, $cdgh, t2);
150    }};
151}
152
153macro_rules! schedule_rounds4 {
154    (
155        $abef:ident, $cdgh:ident,
156        $w0:expr, $w1:expr, $w2:expr, $w3:expr, $w4:expr,
157        $i: expr
158    ) => {{
159        $w4 = schedule($w0, $w1, $w2, $w3);
160        rounds4!($abef, $cdgh, $w4, $i);
161    }};
162}
163
164/// Process a block with the SHA-256 algorithm.
165fn sha256_digest_block_u32(state: &mut [u32; 8], block: &[u32; 16]) {
166    let mut abef = [state[0], state[1], state[4], state[5]];
167    let mut cdgh = [state[2], state[3], state[6], state[7]];
168
169    // Rounds 0..64
170    let mut w0 = [block[3], block[2], block[1], block[0]];
171    let mut w1 = [block[7], block[6], block[5], block[4]];
172    let mut w2 = [block[11], block[10], block[9], block[8]];
173    let mut w3 = [block[15], block[14], block[13], block[12]];
174    let mut w4;
175
176    rounds4!(abef, cdgh, w0, 0);
177    rounds4!(abef, cdgh, w1, 1);
178    rounds4!(abef, cdgh, w2, 2);
179    rounds4!(abef, cdgh, w3, 3);
180    schedule_rounds4!(abef, cdgh, w0, w1, w2, w3, w4, 4);
181    schedule_rounds4!(abef, cdgh, w1, w2, w3, w4, w0, 5);
182    schedule_rounds4!(abef, cdgh, w2, w3, w4, w0, w1, 6);
183    schedule_rounds4!(abef, cdgh, w3, w4, w0, w1, w2, 7);
184    schedule_rounds4!(abef, cdgh, w4, w0, w1, w2, w3, 8);
185    schedule_rounds4!(abef, cdgh, w0, w1, w2, w3, w4, 9);
186    schedule_rounds4!(abef, cdgh, w1, w2, w3, w4, w0, 10);
187    schedule_rounds4!(abef, cdgh, w2, w3, w4, w0, w1, 11);
188    schedule_rounds4!(abef, cdgh, w3, w4, w0, w1, w2, 12);
189    schedule_rounds4!(abef, cdgh, w4, w0, w1, w2, w3, 13);
190    schedule_rounds4!(abef, cdgh, w0, w1, w2, w3, w4, 14);
191    schedule_rounds4!(abef, cdgh, w1, w2, w3, w4, w0, 15);
192
193    let [a, b, e, f] = abef;
194    let [c, d, g, h] = cdgh;
195
196    state[0] = state[0].wrapping_add(a);
197    state[1] = state[1].wrapping_add(b);
198    state[2] = state[2].wrapping_add(c);
199    state[3] = state[3].wrapping_add(d);
200    state[4] = state[4].wrapping_add(e);
201    state[5] = state[5].wrapping_add(f);
202    state[6] = state[6].wrapping_add(g);
203    state[7] = state[7].wrapping_add(h);
204}
205
206pub fn compress(state: &mut [u32; 8], blocks: &[[u8; 64]]) {
207    let mut block_u32 = [0u32; BLOCK_LEN];
208    // since LLVM can't properly use aliasing yet it will make
209    // unnecessary state stores without this copy
210    let mut state_cpy = *state;
211    for block in blocks {
212        for (o, chunk) in block_u32.iter_mut().zip(block.chunks_exact(4)) {
213            *o = u32::from_be_bytes(chunk.try_into().unwrap());
214        }
215        sha256_digest_block_u32(&mut state_cpy, &block_u32);
216    }
217    *state = state_cpy;
218}
sha2/sha256/soft.rs

sha2/sha256/
soft.rs
