sqisign-verify 0.3.0

SQIsign signature verification (no_std, zero allocation, pure Rust)
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

//!
//! Contains the base curve E0, torsion point bases, and other per-level
//! constant data needed by the EC and isogeny layers.
//!
//! Enable the `signing` feature to include quaternion data, endomorphism
//! action matrices, and torsion degree constants needed by the signing path.

use crate::params::SecurityLevel;

pub mod level1;
pub mod level3;
pub mod level5;

/// Level-specific precomputed constants needed by the verification and
/// EC layers. Implemented for each security level marker type.
pub trait LevelPrecomp: SecurityLevel {
    /// Canonical 𝔽p²-encoded bytes for the x-coordinate of the first
    /// generator of the 2ᶠ-torsion basis on E0.
    fn basis_e0_px_bytes() -> &'static [u8];

    /// Canonical 𝔽p²-encoded bytes for the x-coordinate of the second
    /// generator of the 2ᶠ-torsion basis on E0.
    fn basis_e0_qx_bytes() -> &'static [u8];

    /// The odd cofactor (p+1) / 2ᶠ as 64-bit limbs (little-endian).
    fn p_cofactor_for_2f() -> &'static [u64];

    /// Bit-length of the odd cofactor.
    fn p_cofactor_for_2f_bitlength() -> u32;

    /// Exponent f such that the torsion subgroup is ℤ/2ᶠ × ℤ/2ᶠ.
    fn torsion_even_power() -> u32;

    /// 10 precomputed 4×4 basis change matrices for splitting transforms.
    fn splitting_transforms() -> &'static [[[u8; 4]; 4]; 10];

    /// 6 precomputed 4×4 normalization matrices for splitting.
    fn normalization_transforms() -> &'static [[[u8; 4]; 4]; 6];

    /// Character evaluation table for splitting.
    fn chi_eval() -> &'static [[i32; 4]; 4];

    /// Pairs of indices for the 10 possible zero-positions in splitting.
    fn even_index() -> &'static [[i32; 2]; 10];
}

impl LevelPrecomp for crate::params::Level1 {
    fn basis_e0_px_bytes() -> &'static [u8] {
        &level1::BASIS_E0_PX_BYTES
    }
    fn basis_e0_qx_bytes() -> &'static [u8] {
        &level1::BASIS_E0_QX_BYTES
    }
    fn p_cofactor_for_2f() -> &'static [u64] {
        level1::P_COFACTOR_FOR_2F
    }
    fn p_cofactor_for_2f_bitlength() -> u32 {
        level1::P_COFACTOR_FOR_2F_BITLENGTH
    }
    fn torsion_even_power() -> u32 {
        level1::TORSION_EVEN_POWER
    }
    fn splitting_transforms() -> &'static [[[u8; 4]; 4]; 10] {
        &level1::SPLITTING_TRANSFORMS
    }
    fn normalization_transforms() -> &'static [[[u8; 4]; 4]; 6] {
        &level1::NORMALIZATION_TRANSFORMS
    }
    fn chi_eval() -> &'static [[i32; 4]; 4] {
        &level1::CHI_EVAL
    }
    fn even_index() -> &'static [[i32; 2]; 10] {
        &level1::EVEN_INDEX
    }
}

impl LevelPrecomp for crate::params::Level3 {
    fn basis_e0_px_bytes() -> &'static [u8] {
        &level3::BASIS_E0_PX_BYTES
    }
    fn basis_e0_qx_bytes() -> &'static [u8] {
        &level3::BASIS_E0_QX_BYTES
    }
    fn p_cofactor_for_2f() -> &'static [u64] {
        level3::P_COFACTOR_FOR_2F
    }
    fn p_cofactor_for_2f_bitlength() -> u32 {
        level3::P_COFACTOR_FOR_2F_BITLENGTH
    }
    fn torsion_even_power() -> u32 {
        level3::TORSION_EVEN_POWER
    }
    fn splitting_transforms() -> &'static [[[u8; 4]; 4]; 10] {
        &level3::SPLITTING_TRANSFORMS
    }
    fn normalization_transforms() -> &'static [[[u8; 4]; 4]; 6] {
        &level3::NORMALIZATION_TRANSFORMS
    }
    fn chi_eval() -> &'static [[i32; 4]; 4] {
        &level3::CHI_EVAL
    }
    fn even_index() -> &'static [[i32; 2]; 10] {
        &level3::EVEN_INDEX
    }
}

impl LevelPrecomp for crate::params::Level5 {
    fn basis_e0_px_bytes() -> &'static [u8] {
        &level5::BASIS_E0_PX_BYTES
    }
    fn basis_e0_qx_bytes() -> &'static [u8] {
        &level5::BASIS_E0_QX_BYTES
    }
    fn p_cofactor_for_2f() -> &'static [u64] {
        level5::P_COFACTOR_FOR_2F
    }
    fn p_cofactor_for_2f_bitlength() -> u32 {
        level5::P_COFACTOR_FOR_2F_BITLENGTH
    }
    fn torsion_even_power() -> u32 {
        level5::TORSION_EVEN_POWER
    }
    fn splitting_transforms() -> &'static [[[u8; 4]; 4]; 10] {
        &level5::SPLITTING_TRANSFORMS
    }
    fn normalization_transforms() -> &'static [[[u8; 4]; 4]; 6] {
        &level5::NORMALIZATION_TRANSFORMS
    }
    fn chi_eval() -> &'static [[i32; 4]; 4] {
        &level5::CHI_EVAL
    }
    fn even_index() -> &'static [[i32; 2]; 10] {
        &level5::EVEN_INDEX
    }
}