add helper func to get signature without prefix, and handle signature…

… index errors

oracle/reactor.go

@@ -133,7 +133,11 @@ func (oracleR *Reactor) Receive(e p2p.Envelope) {
 	switch msg := e.Message.(type) {
 	case *oracleproto.GossipedVotes:
 		// get account and sign type of oracle votes
-		accountType, signType := utils.GetAccountSignTypeFromSignature(msg.Signature)
+		accountType, signType, err := utils.GetAccountSignTypeFromSignature(msg.Signature)
+		if err != nil {
+			logrus.Errorf("unable to get account and sign type from signature: %v", msg.Signature)
+			return
+		}
 		var pubKey crypto.PubKey
 
 		// get pubkey based on sign type
@@ -183,7 +187,11 @@ func (oracleR *Reactor) Receive(e p2p.Envelope) {
 
 		// verify sig of incoming gossip vote, throw if verification fails
 		// signature starts from index 2 onwards due to the account and sign type prefix bytes
-		if success := pubKey.VerifySignature(types.OracleVoteSignBytes(oracleR.ConsensusState.GetState().ChainID, msg), msg.Signature[2:]); !success {
+		signatureWithoutPrefix, err := utils.GetSignatureWithoutPrefix(msg.Signature)
+		if err != nil {
+			logrus.Errorf("unable to get signature without prefix, invalid signature: %v", msg.Signature)
+		}
+		if success := pubKey.VerifySignature(types.OracleVoteSignBytes(oracleR.ConsensusState.GetState().ChainID, msg), signatureWithoutPrefix); !success {
 			logrus.Errorf("failed signature verification for validator: %v, skipping gossip", pubKey.Address().String())
 			return
 		}

oracle/service/utils/utils.go

@@ -10,8 +10,11 @@ import (
 // index 0: accountType (if votes are signed by main val or oracle delegate)
 // index 1: signType (type of key used: ed25519/sr25519/secp256k1)
 
-func GetAccountSignTypeFromSignature(signature []byte) (accountType []byte, signType []byte) {
-	return []byte{signature[0]}, []byte{signature[1]}
+func GetAccountSignTypeFromSignature(signature []byte) (accountType []byte, signType []byte, err error) {
+	if len(signature) < 2 {
+		return nil, nil, fmt.Errorf("GetAccountSignTypeFromSignature: invalid signature: %v", signature)
+	}
+	return []byte{signature[0]}, []byte{signature[1]}, nil
 }
 
 func FormSignaturePrefix(isSubAccount bool, signType string) ([]byte, error) {
@@ -36,3 +39,11 @@ func FormSignaturePrefix(isSubAccount bool, signType string) ([]byte, error) {
 
 	return sigPrefix, nil
 }
+
+func GetSignatureWithoutPrefix(prefixedSig []byte) ([]byte, error) {
+	if len(prefixedSig) < 2 {
+		return nil, fmt.Errorf("GetSignature: invalid signature: %v", prefixedSig)
+	}
+
+	return prefixedSig[2:], nil
+}

privval/signer_client_test.go

@@ -11,7 +11,7 @@ import (
 	"github.com/cometbft/cometbft/crypto"
 	"github.com/cometbft/cometbft/crypto/tmhash"
 	cmtrand "github.com/cometbft/cometbft/libs/rand"
-	oracletypes "github.com/cometbft/cometbft/oracle/service/types"
+	"github.com/cometbft/cometbft/oracle/service/utils"
 	cryptoproto "github.com/cometbft/cometbft/proto/tendermint/crypto"
 	oracleproto "github.com/cometbft/cometbft/proto/tendermint/oracle"
 	privvalproto "github.com/cometbft/cometbft/proto/tendermint/privval"
@@ -247,18 +247,20 @@ func TestSignerOracleVote(t *testing.T) {
 			}
 		})
 
-		sigPrefix := []byte{}
-		sigPrefix = append(sigPrefix, oracletypes.MainAccountSigPrefix...)
-		sigPrefix = append(sigPrefix, oracletypes.Ed25519SignType...)
+		sigPrefix, err := utils.FormSignaturePrefix(false, "ed25519")
+		assert.Equal(t, err, nil)
 
 		require.NoError(t, tc.mockPV.SignOracleVote(tc.chainID, want, sigPrefix))
 		require.NoError(t, tc.signerClient.SignOracleVote(tc.chainID, have, sigPrefix))
 
 		assert.Equal(t, want.Signature, have.Signature)
 
+		signatureWithoutPrefix, err := utils.GetSignatureWithoutPrefix(have.Signature)
+		assert.Equal(t, err, nil)
+
 		// test verify sig with pv and signing client signatures
-		require.True(t, pvPubKey.VerifySignature(types.OracleVoteSignBytes(tc.chainID, want), want.Signature[2:]))
-		require.True(t, scPubKey.VerifySignature(types.OracleVoteSignBytes(tc.chainID, have), have.Signature[2:]))
+		require.True(t, pvPubKey.VerifySignature(types.OracleVoteSignBytes(tc.chainID, want), signatureWithoutPrefix))
+		require.True(t, scPubKey.VerifySignature(types.OracleVoteSignBytes(tc.chainID, have), signatureWithoutPrefix))
 	}
 }