libcrux-sha3 0.0.6

Libcrux SHA-3 implementation
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

use super::*;

use libcrux_intrinsics::arm64::_uint64x2_t;

#[inline]
pub(crate) fn keccak2<const RATE: usize, const DELIM: u8>(
    data: &[&[u8]; 2],
    out0: &mut [u8],
    out1: &mut [u8],
) {
    #[cfg(not(eurydice))]
    debug_assert!(out0.len() == out1.len());
    #[cfg(not(eurydice))]
    debug_assert!(data[0].len() == data[1].len());

    let mut s = KeccakState::<2, _uint64x2_t>::new();
    let data_len = data[0].len();
    for i in 0..data_len / RATE {
        s.absorb_block::<RATE>(data, i * RATE);
    }
    let rem = data_len % RATE;
    s.absorb_final::<RATE, DELIM>(data, data_len - rem, rem);

    let outlen = out0.len();
    let blocks = outlen / RATE;
    let last = outlen - (outlen % RATE);

    if blocks == 0 {
        s.squeeze2::<RATE>(out0, out1, 0, outlen);
    } else {
        s.squeeze2::<RATE>(out0, out1, 0, RATE);
        for i in 1..blocks {
            s.keccakf1600();
            s.squeeze2::<RATE>(out0, out1, i * RATE, RATE);
        }
        if last < outlen {
            s.keccakf1600();
            s.squeeze2::<RATE>(out0, out1, last, outlen - last);
        }
    }
}

impl KeccakState<2, _uint64x2_t> {
    #[inline(always)]
    pub(crate) fn squeeze_next_block<const RATE: usize>(
        &mut self,
        out0: &mut [u8],
        out1: &mut [u8],
        start: usize,
    ) {
        self.keccakf1600();
        self.squeeze2::<RATE>(out0, out1, start, RATE);
    }

    /// Write out the first block of Keccak output.
    ///
    /// This function MUST NOT be called after any of the other `squeeze_*`
    /// functions have been called, since that would result in a duplicate output
    /// block.
    pub(crate) fn squeeze_first_block<const RATE: usize>(&self, out0: &mut [u8], out1: &mut [u8]) {
        self.squeeze2::<RATE>(out0, out1, 0, RATE);
    }

    #[inline(always)]
    pub(crate) fn squeeze_first_three_blocks<const RATE: usize>(
        &mut self,
        out0: &mut [u8],
        out1: &mut [u8],
    ) {
        self.squeeze2::<RATE>(out0, out1, 0, RATE);

        self.keccakf1600();
        self.squeeze2::<RATE>(out0, out1, RATE, RATE);

        self.keccakf1600();
        self.squeeze2::<RATE>(out0, out1, 2 * RATE, RATE);
    }

    #[inline(always)]
    pub(crate) fn squeeze_first_five_blocks<const RATE: usize>(
        &mut self,
        out0: &mut [u8],
        out1: &mut [u8],
    ) {
        self.squeeze2::<RATE>(out0, out1, 0, RATE);

        self.keccakf1600();
        self.squeeze2::<RATE>(out0, out1, RATE, RATE);

        self.keccakf1600();
        self.squeeze2::<RATE>(out0, out1, 2 * RATE, RATE);

        self.keccakf1600();
        self.squeeze2::<RATE>(out0, out1, 3 * RATE, RATE);

        self.keccakf1600();
        self.squeeze2::<RATE>(out0, out1, 4 * RATE, RATE);
    }
}