secp256kfun 0.12.1

A mid-level secp256k1 library optimized for fun!
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
136
137
138
139
140
141
142
143
144
145

#![cfg(all(feature = "libsecp_compat", feature = "alloc", feature = "proptest"))]
#![allow(non_snake_case)]
#[cfg(not(target_arch = "wasm32"))]
mod against_c_lib {
    use proptest::prelude::*;
    use secp256k1::{All, PublicKey, Secp256k1, SecretKey};
    use secp256kfun::{G, Point, Scalar, g, marker::*, op::double_mul, s, secp256k1};

    lazy_static::lazy_static! {
        static ref SECP: Secp256k1<All> = Secp256k1::new();
    }

    proptest! {
        #[test]
        fn point_multiplication(s1 in any::<[u8;32]>(), s2 in any::<[u8;32]>()) {

            // Multiply a generator by scalar for both libraries and test equality
            let (point_1, secp_pk_1) = {
                let point_1 = g!({ Scalar::<Secret, Zero>::from_bytes_mod_order(s1) } * G)
                    .normalize().non_zero()
                    .unwrap();

                let secp_pk_1 =
                    PublicKey::from_secret_key(&*SECP, &SecretKey::from_slice(&s1).unwrap());

                prop_assert_eq!(
                    &point_1.to_bytes_uncompressed()[..],
                    &secp_pk_1.serialize_uncompressed()[..]
                );
                (point_1, secp_pk_1)
            };

            // Multiply the resulting points by another scalar and test equality
            {
                let point_2 = g!({ Scalar::<Secret, Zero>::from_bytes_mod_order(s2) } * point_1)
                    .normalize().non_zero()
                    .unwrap();
                let secp_pk_2 = {
                    let scalar = secp256k1::Scalar::from_be_bytes(s2).unwrap();
                    secp_pk_1.mul_tweak(&SECP, &scalar).unwrap()
                };
                prop_assert_eq!(
                    &point_2.to_bytes_uncompressed()[..],
                    &secp_pk_2.serialize_uncompressed()[..]
                );
            }
        }

        #[test]
        fn vartime_double_mul(scalar_H in any::<[u8;32]>(), y in any::<[u8;32]>(), x in any::<[u8;32]>()) {
            let result = {
                let H = g!({ Scalar::<Secret, Zero>::from_bytes_mod_order(scalar_H) } * G);
                double_mul(
                    Scalar::<Secret, Zero>::from_bytes_mod_order(x).public(),
                    G,
                    Scalar::<Secret, Zero>::from_bytes_mod_order(y).public(),
                    H,
                )
                    .normalize().non_zero()
                    .unwrap()
            };

            let result_secp = {
                let H = PublicKey::from_secret_key(&*SECP, &SecretKey::from_slice(&scalar_H).unwrap());
                let x_G = PublicKey::from_secret_key(&*SECP, &SecretKey::from_slice(&x).unwrap());
                let scalar = secp256k1::Scalar::from_be_bytes(y).unwrap();
                let y_H = H.mul_tweak(&*SECP, &scalar).unwrap();
                x_G.combine(&y_H).unwrap()
            };

            prop_assert_eq!(
                &result.to_bytes_uncompressed()[..],
                &result_secp.serialize_uncompressed()[..]
            )
        }

        #[test]
        fn point_addition(scalar_1 in any::<[u8;32]>()) {
            let secp_pk_1 =
                PublicKey::from_secret_key(&*SECP, &SecretKey::from_slice(&scalar_1).unwrap());
            let point_1 = g!({ Scalar::<Secret, Zero>::from_bytes_mod_order(scalar_1) } * G);


            prop_assert_eq!(
                (g!(point_1 + point_1))
                    .normalize().non_zero()
                    .unwrap()
                    .to_bytes_uncompressed(),
                secp_pk_1
                    .combine(&secp_pk_1)
                    .unwrap()
                    .serialize_uncompressed()
            );
        }

        #[test]
        fn scalar_ops(bytes_1 in any::<[u8;32]>(), bytes_2 in any::<[u8;32]>()) {
            let scalar_1 = Scalar::<Secret, Zero>::from_bytes_mod_order(bytes_1);
            let scalar_2 = Scalar::<Secret, Zero>::from_bytes_mod_order(bytes_2);
            let sk_1 = &SecretKey::from_slice(&bytes_1).unwrap();

            prop_assert_eq!(&scalar_1.to_bytes()[..], &sk_1[..]);

            prop_assert_eq!(
                &(s!(scalar_1 + scalar_2)).to_bytes()[..],
                &{
                    let res = sk_1;
                    let scalar = secp256k1::Scalar::from_be_bytes(bytes_2).unwrap();
                    res.add_tweak(&scalar).unwrap()
                }[..]
            );

            prop_assert_eq!(
                &(s!(scalar_1 * scalar_2)).to_bytes()[..],
                &{
                    let scalar = secp256k1::Scalar::from_be_bytes(bytes_2).unwrap();
                    sk_1.mul_tweak(&scalar).unwrap()
                }[..]
            )
        }

        #[test]
        fn scalar_negation(bytes in any::<[u8;32]>()) {
            let sk = SecretKey::from_slice(&bytes).unwrap().negate();
            let scalar = Scalar::<Secret, Zero>::from_bytes_mod_order(bytes);
            prop_assert_eq!(&(-scalar).to_bytes()[..], &sk[..]);
        }

        #[test]
        fn point_ord(point1 in any::<Point>(), point2 in any::<Point>()) {
            prop_assert_eq!(
                point1.cmp(&point2),
                PublicKey::from(point1).cmp(&PublicKey::from(point2))
            );
        }

        #[test]
        fn scalar_ord(scalar1 in any::<Scalar<Public, Zero>>(), scalar2 in any::<Scalar<Public,Zero>>()) {
            prop_assert_eq!(
                scalar1.cmp(&scalar2),
                secp256k1::Scalar::from(scalar1).cmp(&secp256k1::Scalar::from(scalar2))
            );
        }
    }
}