ring/digest/
sha1.rs

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1// Copyright 2015-2025 Brian Smith.
2// Copyright 2016 Simon Sapin.
3//
4// Permission to use, copy, modify, and/or distribute this software for any
5// purpose with or without fee is hereby granted, provided that the above
6// copyright notice and this permission notice appear in all copies.
7//
8// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
9// WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
10// MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
11// SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
12// WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
13// OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
14// CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
15
16use super::{
17    sha2::{
18        fallback::{ch, maj, Word},
19        State32,
20    },
21    BlockLen, OutputLen,
22};
23use crate::polyfill::slice::{self, AsChunks};
24use core::{mem::size_of, num::Wrapping};
25
26pub(super) const BLOCK_LEN: BlockLen = BlockLen::_512;
27pub const CHAINING_LEN: usize = 160 / 8;
28pub(super) const OUTPUT_LEN: OutputLen = OutputLen::_160;
29const CHAINING_WORDS: usize = CHAINING_LEN / 4;
30
31type W32 = Wrapping<u32>;
32
33// FIPS 180-4 4.1.1
34#[inline]
35fn parity(x: W32, y: W32, z: W32) -> W32 {
36    x ^ y ^ z
37}
38
39type State = [W32; CHAINING_WORDS];
40const ROUNDS: usize = 80;
41
42pub fn sha1_block_data_order(state: &mut State32, data: AsChunks<u8, { BLOCK_LEN.into() }>) {
43    // The unwrap won't fail because `CHAINING_WORDS` is smaller than the
44    // length.
45    let state: &mut State = (&mut state[..CHAINING_WORDS]).try_into().unwrap();
46    // SAFETY: The caller guarantees that this is called with data pointing to `num`
47    // `BLOCK_LEN`-long blocks.
48    *state = block_data_order(*state, data)
49}
50
51#[inline]
52#[rustfmt::skip]
53fn block_data_order(
54    mut H: [W32; CHAINING_WORDS],
55    M: AsChunks<u8, { BLOCK_LEN.into() }>,
56) -> [W32; CHAINING_WORDS]
57{
58    for M in M {
59        let (M, remainder): (AsChunks<u8, {size_of::<W32>()}>, &[u8]) = slice::as_chunks(M);
60        debug_assert!(remainder.is_empty());
61
62        // FIPS 180-4 6.1.2 Step 1
63        let mut W: [W32; ROUNDS] = [W32::ZERO; ROUNDS];
64        W.iter_mut().zip(M).for_each(|(Wt, Mt)| {
65            *Wt = W32::from_be_bytes(*Mt);
66        });
67        for t in 16..ROUNDS {
68            let wt = W[t - 3] ^ W[t - 8] ^ W[t - 14] ^ W[t - 16];
69            W[t] = rotl(wt, 1);
70        }
71
72        // FIPS 180-4 6.1.2 Step 2
73        let [a, b, c, d, e] = H;
74
75        // FIPS 180-4 6.1.2 Step 3 with constants and functions from FIPS 180-4 {4.1.1, 4.2.1}
76        let (a, b, c, d, e) = step3(a, b, c, d, e, &W, 0, Wrapping(0x5a827999), ch);
77        let (a, b, c, d, e) = step3(a, b, c, d, e, &W, 20, Wrapping(0x6ed9eba1), parity);
78        let (a, b, c, d, e) = step3(a, b, c, d, e, &W, 40, Wrapping(0x8f1bbcdc), maj);
79        let (a, b, c, d, e) = step3(a, b, c, d, e, &W, 60, Wrapping(0xca62c1d6), parity);
80
81        // FIPS 180-4 6.1.2 Step 4
82        H[0] += a;
83        H[1] += b;
84        H[2] += c;
85        H[3] += d;
86        H[4] += e;
87    }
88
89    H
90}
91
92#[inline(always)]
93fn step3(
94    mut a: W32,
95    mut b: W32,
96    mut c: W32,
97    mut d: W32,
98    mut e: W32,
99    W: &[W32; 80],
100    t: usize,
101    k: W32,
102    f: impl Fn(W32, W32, W32) -> W32,
103) -> (W32, W32, W32, W32, W32) {
104    let W = &W[t..(t + 20)];
105    for W_t in W.iter() {
106        let T = rotl(a, 5) + f(b, c, d) + e + k + W_t;
107        e = d;
108        d = c;
109        c = rotl(b, 30);
110        b = a;
111        a = T;
112    }
113    (a, b, c, d, e)
114}
115
116#[inline(always)]
117fn rotl(x: W32, n: u32) -> W32 {
118    Wrapping(x.0.rotate_left(n))
119}
ring/digest/sha1.rs

ring/digest/
sha1.rs
