Update BabyJubJub EdDSA to last circomlib version

- Update BabyJubJub EdDSA signature to last circomlib version (Poseidon
usage)
- Remove panic on hash error inside verification, to avoid panic due
field overflow of BabyJubJub signature verification

babyjub/eddsa.go

@@ -177,6 +177,24 @@ func (s *SignatureComp) Decompress() (*Signature, error) {
 	return new(Signature).Decompress(*s)
 }
 
+// Scan implements Scanner for database/sql.
+func (s *SignatureComp) Scan(src interface{}) error {
+	srcB, ok := src.([]byte)
+	if !ok {
+		return fmt.Errorf("can't scan %T into Signature", src)
+	}
+	if len(srcB) != 64 {
+		return fmt.Errorf("can't scan []byte of len %d into Signature, want %d", len(srcB), 64)
+	}
+	copy(s[:], srcB[:])
+	return nil
+}
+
+// Value implements valuer for database/sql.
+func (s SignatureComp) Value() (driver.Value, error) {
+	return s[:], nil
+}
+
 // Scan implements Scanner for database/sql.
 func (s *Signature) Scan(src interface{}) error {
 	srcB, ok := src.([]byte)
@@ -229,7 +247,7 @@ func (p *PublicKey) VerifyMimc7(msg *big.Int, sig *Signature) bool {
 	hmInput := []*big.Int{sig.R8.X, sig.R8.Y, p.X, p.Y, msg}
 	hm, err := mimc7.Hash(hmInput, nil) // hm = H1(8*R.x, 8*R.y, A.x, A.y, msg)
 	if err != nil {
-		panic(err)
+		return false
 	}
 
 	left := NewPoint().Mul(sig.S, B8) // left = s * 8 * B
@@ -255,7 +273,7 @@ func (k *PrivateKey) SignPoseidon(msg *big.Int) *Signature {
 	R8 := NewPoint().Mul(r, B8) // R8 = r * 8 * B
 	A := k.Public().Point()
 
-	hmInput := []*big.Int{R8.X, R8.Y, A.X, A.Y, msg, big.NewInt(int64(0))}
+	hmInput := []*big.Int{R8.X, R8.Y, A.X, A.Y, msg}
 	hm, err := poseidon.Hash(hmInput) // hm = H1(8*R.x, 8*R.y, A.x, A.y, msg)
 	if err != nil {
 		panic(err)
@@ -272,10 +290,10 @@ func (k *PrivateKey) SignPoseidon(msg *big.Int) *Signature {
 // VerifyPoseidon verifies the signature of a message encoded as a big.Int in Zq
 // using blake-512 hash for buffer hashing and Poseidon for big.Int hashing.
 func (p *PublicKey) VerifyPoseidon(msg *big.Int, sig *Signature) bool {
-	hmInput := []*big.Int{sig.R8.X, sig.R8.Y, p.X, p.Y, msg, big.NewInt(int64(0))}
+	hmInput := []*big.Int{sig.R8.X, sig.R8.Y, p.X, p.Y, msg}
 	hm, err := poseidon.Hash(hmInput) // hm = H1(8*R.x, 8*R.y, A.x, A.y, msg)
 	if err != nil {
-		panic(err)
+		return false
 	}
 
 	left := NewPoint().Mul(sig.S, B8) // left = s * 8 * B

babyjub/eddsa_test.go

@@ -96,7 +96,7 @@ func TestSignVerifyPoseidon(t *testing.T) {
 		"15383486972088797283337779941324724402501462225528836549661220478783371668959",
 		sig.R8.Y.String())
 	assert.Equal(t,
-		"1662463587877312619203503803508234533733252768380479199263194005796068211378",
+		"1398758333392199195742243841591064350253744445503462896781493968760929513778",
 		sig.S.String())
 
 	ok := pk.VerifyPoseidon(msg, sig)
@@ -108,7 +108,7 @@ func TestSignVerifyPoseidon(t *testing.T) {
 
 	assert.Equal(t, ""+
 		"dfedb4315d3f2eb4de2d3c510d7a987dcab67089c8ace06308827bf5bcbe02a2"+
-		"b23a1f04909fc088dec7e4835d85a326f7c0d0b2a3d0232d84448ca7c9ebac03",
+		"32f16b0f2f4c4e1169aa59685637e1429b6581a9531d058d65f4ab224eab1703",
 		hex.EncodeToString(sigBuf[:]))
 
 	ok = pk.VerifyPoseidon(msg, sig2)
@@ -135,6 +135,17 @@ func TestCompressDecompress(t *testing.T) {
 	}
 }
 
+func TestSignatureCompScannerValuer(t *testing.T) {
+	privK := NewRandPrivKey()
+	var value driver.Valuer //nolint:gosimple this is done to ensure interface compability
+	value = privK.SignPoseidon(big.NewInt(674238462)).Compress()
+	scan := privK.SignPoseidon(big.NewInt(1)).Compress()
+	fromDB, err := value.Value()
+	assert.Nil(t, err)
+	assert.Nil(t, scan.Scan(fromDB))
+	assert.Equal(t, value, scan)
+}
+
 func TestSignatureScannerValuer(t *testing.T) {
 	privK := NewRandPrivKey()
 	var value driver.Valuer
@@ -142,8 +153,8 @@ func TestSignatureScannerValuer(t *testing.T) {
 	value = privK.SignPoseidon(big.NewInt(674238462))
 	scan = privK.SignPoseidon(big.NewInt(1))
 	fromDB, err := value.Value()
-	assert.NoError(t, err)
-	assert.NoError(t, scan.Scan(fromDB))
+	assert.Nil(t, err)
+	assert.Nil(t, scan.Scan(fromDB))
 	assert.Equal(t, value, scan)
 }
 
@@ -157,8 +168,8 @@ func TestPubKeyScannerValuer(t *testing.T) {
 	value = pubKValue
 	scan = pubKScan
 	fromDB, err := value.Value()
-	assert.NoError(t, err)
-	assert.NoError(t, scan.Scan(fromDB))
+	assert.Nil(t, err)
+	assert.Nil(t, scan.Scan(fromDB))
 	assert.Equal(t, value, scan)
 }
 

go.sum

@@ -126,6 +126,7 @@ github.com/steakknife/bloomfilter v0.0.0-20180922174646-6819c0d2a570 h1:gIlAHnH1
 github.com/steakknife/bloomfilter v0.0.0-20180922174646-6819c0d2a570/go.mod h1:8OR4w3TdeIHIh1g6EMY5p0gVNOovcWC+1vpc7naMuAw=
 github.com/steakknife/hamming v0.0.0-20180906055917-c99c65617cd3 h1:njlZPzLwU639dk2kqnCPPv+wNjq7Xb6EfUxe/oX0/NM=
 github.com/steakknife/hamming v0.0.0-20180906055917-c99c65617cd3/go.mod h1:hpGUWaI9xL8pRQCTXQgocU38Qw1g0Us7n5PxxTwTCYU=
+github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.2.2/go.mod h1:a8OnRcib4nhh0OaRAV+Yts87kKdq0PP7pXfy6kDkUVs=
 github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=