add signature verification for secp and bls

Signed-off-by: Ignacio Hagopian <jsign.uy@gmail.com>
jsign · Sep 7, 2021 · b4937ff · b4937ff
1 parent 09ca970
commit b4937ff
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Showing 4 changed files with 128 additions and 18 deletions.
diff --git a/bls/bls.go b/bls/bls.go
@@ -26,3 +26,17 @@ func Sign(pk []byte, msg []byte) ([]byte, error) {
 	}
 	return s, nil
 }
+
+// Verify verifies that a message is correctly signed by a public key.
+func Verify(pubkey, msg, sig []byte) bool {
+	point := curve12381.NewGroupG1().Point()
+	if err := point.UnmarshalBinary(pubkey); err != nil {
+		return false
+	}
+	signer := bls.NewSchemeOnG2(curve12381.NewBLS12381Suite())
+	if err := signer.Verify(point, msg, sig); err != nil {
+		return false
+	}
+
+	return true
+}
diff --git a/secp256k1/secp256k1.go b/secp256k1/secp256k1.go
@@ -1,6 +1,7 @@
 package secp256k1
 
 import (
+	"bytes"
 	"fmt"
 
 	"github.com/dchest/blake2b"
@@ -28,6 +29,28 @@ func Sign(pk []byte, msg []byte) ([]byte, error) {
 	return sig, nil
 }
 
+// Verify verifies that a message is correctly signed by a public key.
+func Verify(pubkey, msg, sig []byte) bool {
+	// We need to do the inverse operation of signatures.b
+	recoveryID := sig[64] + 27
+	copy(sig[1:], sig)
+	sig[0] = recoveryID
+
+	msgHash := blake2b.Sum256(msg)
+	vpubkey, _, err := ecdsa.RecoverCompact(sig, msgHash[:])
+	if err != nil {
+		return false
+	}
+	verifAddr, err := address.NewSecp256k1Address(vpubkey.SerializeUncompressed())
+	if err != nil {
+		return false
+	}
+	if !bytes.Equal(verifAddr.Payload(), pubkey) {
+		return false
+	}
+	return true
+}
+
 func GetPubKey(pk []byte) (address.Address, error) {
 	priv := secp256k1.PrivKeyFromBytes(pk)
 	pubkey := priv.PubKey()

diff --git a/wallet/wallet.go b/wallet/wallet.go
@@ -47,6 +47,21 @@ func WalletSign(exportedPK string, msg []byte) (*crypto.Signature, error) {
 	}
 }
 
+func WalletVerify(publicKey address.Address, msg []byte, sig []byte) (bool, error) {
+	var signature crypto.Signature
+	if err := signature.UnmarshalBinary(sig); err != nil {
+		return false, fmt.Errorf("unmarshaling signature: %s", err)
+	}
+	switch publicKey.Protocol() {
+	case address.SECP256K1:
+		return secp256k1.Verify(publicKey.Payload(), msg, signature.Data), nil
+	case address.BLS:
+		return bls.Verify(publicKey.Payload(), msg, signature.Data), nil
+	default:
+		return false, fmt.Errorf("address type not supported")
+	}
+}
+
 func PublicKey(lotusExportedPK string) (address.Address, error) {
 	ki, err := decodeLotusExportedPK(lotusExportedPK)
 	if err != nil {

diff --git a/wallet/wallet_test.go b/wallet/wallet_test.go
@@ -4,26 +4,62 @@ import (
 	"encoding/hex"
 	"testing"
 
+	"github.com/filecoin-project/go-address"
 	"github.com/stretchr/testify/require"
 )
 
+var msg = []byte("DUKE") // 44554b45 in hex.
+
 func TestSecp256k1(t *testing.T) {
 	t.Parallel()
 
+	publicAddr := "f1fib3pv7jua2ockdugtz7viz3cyy6lkhh7rfx3sa"
+
 	// lotus wallet export f1fib3pv7jua2ockdugtz7viz3cyy6lkhh7rfx3sa
-	pk64 := "7b2254797065223a22736563703235366b31222c22507269766174654b6579223a226b35507976337148327349586343595a58594f5775453149326e32554539436861556b6c4e36695a5763453d227d"
+	privateKeyHex := "7b2254797065223a22736563703235366b31222c22507269766174654b6579223a226b35507976337148327349586343595a58594f5775453149326e32554539436861556b6c4e36695a5763453d227d"
+
+	// lotus wallet sign f1fib3pv7jua2ockdugtz7viz3cyy6lkhh7rfx3sa 44554b45
+	hexSignature := "0103bff286f1371c1a4ce8e33c29d6a20eeb53f17970190d12c5a1c0fc4be9a56e766250d5a82dda2179fa90ae297696d1dfaa9eea8f2f833da0cf87b927294eb700"
 
 	t.Run("sign", func(t *testing.T) {
 		t.Parallel()
 
-		lotusFormatSig := testSign(t, pk64)
+		sig, err := WalletSign(privateKeyHex, msg)
+		require.NoError(t, err)
+		sigm, err := sig.MarshalBinary()
+		require.NoError(t, err)
+		genHexSignature := hex.EncodeToString(sigm)
+
+		require.Equal(t, hexSignature, genHexSignature)
+	})
+
+	t.Run("verify", func(t *testing.T) {
+		t.Parallel()
+
+		// Check that signature verification succeeds with correct: signature, message, and public key.
+		sig, err := hex.DecodeString(hexSignature)
+		require.NoError(t, err)
+		addr, err := address.NewFromString(publicAddr)
+		require.NoError(t, err)
+		okSig, err := WalletVerify(addr, msg, sig)
+		require.NoError(t, err)
+		require.True(t, okSig)
+
+		// Check that signature verification fails with incorrect message.
+		okSig, err = WalletVerify(addr, []byte("DUKEZ"), sig)
+		require.NoError(t, err)
+		require.False(t, okSig)
 
-		// lotus wallet sign f1fib3pv7jua2ockdugtz7viz3cyy6lkhh7rfx3sa 44554b45
-		require.Equal(t, "0103bff286f1371c1a4ce8e33c29d6a20eeb53f17970190d12c5a1c0fc4be9a56e766250d5a82dda2179fa90ae297696d1dfaa9eea8f2f833da0cf87b927294eb700", lotusFormatSig)
+		// Check that signature verification fails with incorrect public key.
+		wrongAddr, err := address.NewFromString("f1fib3pv7jua2ockdugtz7viz3cyy6lkhh7rfx3sb")
+		require.NoError(t, err)
+		okSig, err = WalletVerify(wrongAddr, msg, sig)
+		require.NoError(t, err)
+		require.False(t, okSig)
 	})
 
 	t.Run("gen-pubkey", func(t *testing.T) {
-		addr, err := PublicKey(pk64)
+		addr, err := PublicKey(privateKeyHex)
 		require.NoError(t, err)
 		require.Equal(t, "f1fib3pv7jua2ockdugtz7viz3cyy6lkhh7rfx3sa", addr.String())
 	})
@@ -32,27 +68,49 @@ func TestSecp256k1(t *testing.T) {
 func TestBLSSign(t *testing.T) {
 	t.Parallel()
 
+	publicAddr := "f3rpskqryflc2sqzzzu7j2q6fecrkdkv4p2avpf4kyk5u754he7g6cr2rbpmif7pam5oxbme2oyzot4ry3d74q"
+
 	// lotus wallet export f3rpskqryflc2sqzzzu7j2q6fecrkdkv4p2avpf4kyk5u754he7g6cr2rbpmif7pam5oxbme2oyzot4ry3d74q
-	pk64 := "7b2254797065223a22626c73222c22507269766174654b6579223a226862702f794666527439514c43716b6d566171415752436f50556777314b776971716e73684e49704e57513d227d"
+	privateKeyHex := "7b2254797065223a22626c73222c22507269766174654b6579223a226862702f794666527439514c43716b6d566171415752436f50556777314b776971716e73684e49704e57513d227d"
+
+	// lotus wallet sign f3rpskqryflc2sqzzzu7j2q6fecrkdkv4p2avpf4kyk5u754he7g6cr2rbpmif7pam5oxbme2oyzot4ry3d74q 44554b45
+	hexSignature := "0280cef41af956cf6855725a5af0d8d956ea41f6da2688cc1f436a7ea5ebd15d96ba384746b819c0836c53a54d6d30b0a70b528204e9da92f833031e7a4776f57bad83e033ea0235bad0f8a5337a4eb66870fc0429175ed63f91203ec1b65c6e31"
 
 	t.Run("sign", func(t *testing.T) {
 		t.Parallel()
 
-		lotusFormatSig := testSign(t, pk64)
+		sig, err := WalletSign(privateKeyHex, msg)
+		require.NoError(t, err)
+		sigm, err := sig.MarshalBinary()
+		require.NoError(t, err)
+		genHexSignature := hex.EncodeToString(sigm)
 
-		// lotus wallet sign f3rpskqryflc2sqzzzu7j2q6fecrkdkv4p2avpf4kyk5u754he7g6cr2rbpmif7pam5oxbme2oyzot4ry3d74q 44554b45
-		require.Equal(t, "0280cef41af956cf6855725a5af0d8d956ea41f6da2688cc1f436a7ea5ebd15d96ba384746b819c0836c53a54d6d30b0a70b528204e9da92f833031e7a4776f57bad83e033ea0235bad0f8a5337a4eb66870fc0429175ed63f91203ec1b65c6e31", lotusFormatSig)
+		require.Equal(t, hexSignature, genHexSignature)
 	})
-}
 
-func testSign(t *testing.T, lotusExportedPK string) string {
-	t.Helper()
-	msg := []byte("DUKE")
+	t.Run("verify", func(t *testing.T) {
+		t.Parallel()
+
+		// Check that signature verification succeeds with correct: signature, message, and public key.
+		sig, err := hex.DecodeString(hexSignature)
+		require.NoError(t, err)
+		addr, err := address.NewFromString(publicAddr)
+		require.NoError(t, err)
+		okSig, err := WalletVerify(addr, msg, sig)
+		require.NoError(t, err)
+		require.True(t, okSig)
+
+		// Check that signature verification fails with incorrect message.
+		okSig, err = WalletVerify(addr, []byte("DUKEZ"), sig)
+		require.NoError(t, err)
+		require.False(t, okSig)
 
-	sig, err := WalletSign(lotusExportedPK, msg)
-	require.NoError(t, err)
+		// Check that signature verification fails with incorrect public key.
+		wrongAddr, err := address.NewFromString("f3wmv7nhiqosmlr6mis2mr4xzupdhe3rtvw5ntis4x6yru7jhm35pfla2pkwgwfa3t62kdmoylssczmf74yika")
+		require.NoError(t, err)
+		okSig, err = WalletVerify(wrongAddr, msg, sig)
+		require.NoError(t, err)
+		require.False(t, okSig)
 
-	sigm, err := sig.MarshalBinary()
-	require.NoError(t, err)
-	return hex.EncodeToString(sigm)
+	})
 }