core: Add dkg test (#119)

2 files changed, 16 insertions, 0 deletions

diff --git a/crypto/dkg/dkg.go b/crypto/dkg/dkg.go
index 4e21d45..df01078 100644
--- a/crypto/dkg/dkg.go
+++ b/crypto/dkg/dkg.go
@@ -304,6 +304,9 @@ func (prv *PrivateKey) Bytes() []byte {
 // VerifySignature checks that the given public key created signature over hash.
 func (pub PublicKey) VerifySignature(
 	hash common.Hash, signature crypto.Signature) bool {
+	if len(signature) == 0 {
+		return false
+	}
 	var sig bls.Sign
 	if err := sig.Deserialize(signature[:]); err != nil {
 		fmt.Println(err)
diff --git a/crypto/dkg/dkg_test.go b/crypto/dkg/dkg_test.go
index 8e8ce79..badb0ce 100644
--- a/crypto/dkg/dkg_test.go
+++ b/crypto/dkg/dkg_test.go
@@ -277,6 +277,19 @@ func (s *DKGTestSuite) TestDKGProtocol() {
 	s.True(groupPK.VerifySignature(hash, recoverSig2))
 }
 
+func (s *DKGTestSuite) TestSignature() {
+	prvKey := NewPrivateKey()
+	pubKey := prvKey.PublicKey()
+	hash := crypto.Keccak256Hash([]byte("🛫"))
+	sig, err := prvKey.Sign(hash)
+	s.Require().NoError(err)
+	s.True(pubKey.VerifySignature(hash, sig))
+	sig[0]++
+	s.False(pubKey.VerifySignature(hash, sig))
+	sig = crypto.Signature{}
+	s.False(pubKey.VerifySignature(hash, sig))
+}
+
 func TestDKG(t *testing.T) {
 	suite.Run(t, new(DKGTestSuite))
 }