1
2
3
4
5 package elliptic
6
7 import (
8 "math/big"
9 "testing"
10 )
11
12 type scalarMultTest struct {
13 k string
14 xIn, yIn string
15 xOut, yOut string
16 }
17
18 var p256MultTests = []scalarMultTest{
19 {
20 "2a265f8bcbdcaf94d58519141e578124cb40d64a501fba9c11847b28965bc737",
21 "023819813ac969847059028ea88a1f30dfbcde03fc791d3a252c6b41211882ea",
22 "f93e4ae433cc12cf2a43fc0ef26400c0e125508224cdb649380f25479148a4ad",
23 "4d4de80f1534850d261075997e3049321a0864082d24a917863366c0724f5ae3",
24 "a22d2b7f7818a3563e0f7a76c9bf0921ac55e06e2e4d11795b233824b1db8cc0",
25 },
26 {
27 "313f72ff9fe811bf573176231b286a3bdb6f1b14e05c40146590727a71c3bccd",
28 "cc11887b2d66cbae8f4d306627192522932146b42f01d3c6f92bd5c8ba739b06",
29 "a2f08a029cd06b46183085bae9248b0ed15b70280c7ef13a457f5af382426031",
30 "831c3f6b5f762d2f461901577af41354ac5f228c2591f84f8a6e51e2e3f17991",
31 "93f90934cd0ef2c698cc471c60a93524e87ab31ca2412252337f364513e43684",
32 },
33 }
34
35 func TestP256BaseMult(t *testing.T) {
36 p256 := P256()
37 p256Generic := genericParamsForCurve(p256)
38
39 scalars := make([]*big.Int, 0, len(p224BaseMultTests)+1)
40 for _, e := range p224BaseMultTests {
41 k, _ := new(big.Int).SetString(e.k, 10)
42 scalars = append(scalars, k)
43 }
44 k := new(big.Int).SetInt64(1)
45 k.Lsh(k, 500)
46 scalars = append(scalars, k)
47
48 for i, k := range scalars {
49 x, y := p256.ScalarBaseMult(k.Bytes())
50 x2, y2 := p256Generic.ScalarBaseMult(k.Bytes())
51 if x.Cmp(x2) != 0 || y.Cmp(y2) != 0 {
52 t.Errorf("#%d: got (%x, %x), want (%x, %x)", i, x, y, x2, y2)
53 }
54
55 if testing.Short() && i > 5 {
56 break
57 }
58 }
59 }
60
61 func TestP256Mult(t *testing.T) {
62 p256 := P256()
63 for i, e := range p256MultTests {
64 x, _ := new(big.Int).SetString(e.xIn, 16)
65 y, _ := new(big.Int).SetString(e.yIn, 16)
66 k, _ := new(big.Int).SetString(e.k, 16)
67 expectedX, _ := new(big.Int).SetString(e.xOut, 16)
68 expectedY, _ := new(big.Int).SetString(e.yOut, 16)
69
70 xx, yy := p256.ScalarMult(x, y, k.Bytes())
71 if xx.Cmp(expectedX) != 0 || yy.Cmp(expectedY) != 0 {
72 t.Errorf("#%d: got (%x, %x), want (%x, %x)", i, xx, yy, expectedX, expectedY)
73 }
74 }
75 }
76
77 type synthCombinedMult struct {
78 Curve
79 }
80
81 func (s synthCombinedMult) CombinedMult(bigX, bigY *big.Int, baseScalar, scalar []byte) (x, y *big.Int) {
82 x1, y1 := s.ScalarBaseMult(baseScalar)
83 x2, y2 := s.ScalarMult(bigX, bigY, scalar)
84 return s.Add(x1, y1, x2, y2)
85 }
86
87 func TestP256CombinedMult(t *testing.T) {
88 type combinedMult interface {
89 Curve
90 CombinedMult(bigX, bigY *big.Int, baseScalar, scalar []byte) (x, y *big.Int)
91 }
92
93 p256, ok := P256().(combinedMult)
94 if !ok {
95 p256 = &synthCombinedMult{P256()}
96 }
97
98 gx := p256.Params().Gx
99 gy := p256.Params().Gy
100
101 zero := make([]byte, 32)
102 one := make([]byte, 32)
103 one[31] = 1
104 two := make([]byte, 32)
105 two[31] = 2
106
107
108 x, y := p256.CombinedMult(gx, gy, zero, zero)
109 if x.Sign() != 0 || y.Sign() != 0 {
110 t.Errorf("0×G + 0×G = (%d, %d), should be ∞", x, y)
111 }
112
113
114 x, y = p256.CombinedMult(gx, gy, one, zero)
115 if x.Cmp(gx) != 0 || y.Cmp(gy) != 0 {
116 t.Errorf("1×G + 0×G = (%d, %d), should be (%d, %d)", x, y, gx, gy)
117 }
118
119
120 x, y = p256.CombinedMult(gx, gy, zero, one)
121 if x.Cmp(gx) != 0 || y.Cmp(gy) != 0 {
122 t.Errorf("0×G + 1×G = (%d, %d), should be (%d, %d)", x, y, gx, gy)
123 }
124
125
126 x, y = p256.CombinedMult(gx, gy, one, one)
127 ggx, ggy := p256.ScalarBaseMult(two)
128 if x.Cmp(ggx) != 0 || y.Cmp(ggy) != 0 {
129 t.Errorf("1×G + 1×G = (%d, %d), should be (%d, %d)", x, y, ggx, ggy)
130 }
131
132 minusOne := new(big.Int).Sub(p256.Params().N, big.NewInt(1))
133
134 x, y = p256.CombinedMult(gx, gy, one, minusOne.Bytes())
135 if x.Sign() != 0 || y.Sign() != 0 {
136 t.Errorf("1×G + (-1)×G = (%d, %d), should be ∞", x, y)
137 }
138 }
139
140 func TestIssue52075(t *testing.T) {
141 Gx, Gy := P256().Params().Gx, P256().Params().Gy
142 scalar := make([]byte, 33)
143 scalar[32] = 1
144 x, y := P256().ScalarBaseMult(scalar)
145 if x.Cmp(Gx) != 0 || y.Cmp(Gy) != 0 {
146 t.Errorf("unexpected output (%v,%v)", x, y)
147 }
148 x, y = P256().ScalarMult(Gx, Gy, scalar)
149 if x.Cmp(Gx) != 0 || y.Cmp(Gy) != 0 {
150 t.Errorf("unexpected output (%v,%v)", x, y)
151 }
152 }
153
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