1package blindsecp256k1
 2
 3import (
 4	"math/big"
 5	"testing"
 6
 7	"github.com/ethereum/go-ethereum/crypto"
 8	"github.com/stretchr/testify/assert"
 9	"github.com/stretchr/testify/require"
10)
11
12func TestFlow(t *testing.T) {
13	// signer: create new signer key pair
14	sk := NewPrivateKey()
15	signerPubK := sk.Public()
16
17	// signer: when user requests new R parameter to blind a new msg,
18	// create new signerR (public) with its secret k
19	k, signerR := NewRequestParameters()
20
21	// user: blinds the msg using signer's R
22	msg := new(big.Int).SetBytes([]byte("test"))
23	msgBlinded, userSecretData, err := Blind(msg, signerR)
24	require.Nil(t, err)
25
26	// signer: signs the blinded message using its private key & secret k
27	sBlind, err := sk.BlindSign(msgBlinded, k)
28	require.Nil(t, err)
29
30	// user: unblinds the blinded signature
31	sig := Unblind(sBlind, userSecretData)
32	sigB := sig.Bytes()
33	sig2, err := NewSignatureFromBytes(sigB)
34	assert.Nil(t, err)
35	assert.Equal(t, sig, sig2)
36
37	// signature can be verified with signer PublicKey
38	verified := Verify(msg, sig, signerPubK)
39	assert.True(t, verified)
40}
41
42func TestHashMOddBytes(t *testing.T) {
43	// This test is made with same values than
44	// https://github.com/arnaucube/blindsecp256k1-js to ensure
45	// compatibility
46	mStr := "3024162961766929396601888431330224482373544644288322432261208139289299439809"
47	m, ok := new(big.Int).SetString(mStr, 10)
48	require.True(t, ok)
49	mBytes := m.Bytes()
50
51	hBytes := crypto.Keccak256(mBytes[3:])
52	h := new(big.Int).SetBytes(hBytes)
53	assert.Equal(t,
54		"57523339312508913023232057765773019244858443678197951618720342803494056599369",
55		h.String())
56
57	hBytes = crypto.Keccak256(append(mBytes, []byte{0x12, 0x34}...))
58	h = new(big.Int).SetBytes(hBytes)
59	assert.Equal(t,
60		"9697834584560956691445940439424778243200861871421750951058436814122640359156",
61		h.String())
62}
63
64// func newBigIntWithBitLen(n int) *big.Int {
65//         b := make([]byte, n/8)
66//         for i := 0; i < len(b); i++ {
67//                 b[i] = 255
68//         }
69//         bi := new(big.Int).SetBytes(b[:])
70//         return bi
71// }
72//
73// func TestMinBigIntBytesLen(t *testing.T) {
74//         k := big.NewInt(1)
75//         sk := PrivateKey(*k)
76//
77//         mBlinded := newBigIntWithBitLen(MinBigIntBytesLen)
78//         require.Equal(t, MinBigIntBytesLen, mBlinded.BitLen())
79//         _, err := sk.BlindSign(mBlinded, k)
80//         assert.Nil(t, err)
81//
82//         mBlinded = new(big.Int).Div(mBlinded, big.NewInt(2))
83//         require.Equal(t, MinBigIntBytesLen-1, mBlinded.BitLen())
84//         _, err = sk.BlindSign(mBlinded, k)
85//         assert.Equal(t, "mBlinded too small", err.Error())
86// }