Use schnorr signature for signing the messages

consensus/consensus.go

@@ -8,6 +8,7 @@ import (
 	"harmony-benchmark/crypto"
 	"harmony-benchmark/log"
 	"harmony-benchmark/p2p"
+	"kyber/sign/schnorr"
 	"regexp"
 	"strconv"
 	"sync"
@@ -145,6 +146,14 @@ func NewConsensus(ip, port, ShardID string, peers []p2p.Peer, leader p2p.Peer) *
 	return &consensus
 }
 
+func (consensus *Consensus) signMessage(message []byte) []byte {
+	signature, err := schnorr.Sign(crypto.Ed25519Curve, consensus.priKey, message)
+	if err != nil {
+		panic("Failed to sign message with Schnorr signature.")
+	}
+	return signature
+}
+
 // Reset the state of the consensus
 func (consensus *Consensus) ResetState() {
 	consensus.state = FINISHED

consensus/consensus_leader.go

@@ -2,7 +2,6 @@ package consensus
 
 import (
 	"bytes"
-	"crypto/sha256"
 	"encoding/binary"
 	"encoding/gob"
 	"github.com/dedis/kyber"
@@ -115,18 +114,12 @@ func (consensus *Consensus) constructAnnounceMessage() []byte {
 	buffer.Write(fourBytes)
 
 	// 64 byte of signature on previous data
-	signature := signMessage(buffer.Bytes())
+	signature := consensus.signMessage(buffer.Bytes())
 	buffer.Write(signature)
 
 	return proto_consensus.ConstructConsensusMessage(proto_consensus.ANNOUNCE, buffer.Bytes())
 }
 
-func signMessage(message []byte) []byte {
-	// TODO: implement real ECC signature
-	mockSignature := sha256.Sum256(message)
-	return append(mockSignature[:], mockSignature[:]...)
-}
-
 // Processes the commit message sent from validators
 func (consensus *Consensus) processCommitMessage(payload []byte) {
 	//#### Read payload data
@@ -225,7 +218,7 @@ func (consensus *Consensus) constructChallengeMessage() []byte {
 	buffer.Write(getChallenge(aggCommitment, consensus.bitmap.AggregatePublic, buffer.Bytes()[:36])) // message contains consensus id and block hash for now.
 
 	// 64 byte of signature on previous data
-	signature := signMessage(buffer.Bytes())
+	signature := consensus.signMessage(buffer.Bytes())
 	buffer.Write(signature)
 
 	return proto_consensus.ConstructConsensusMessage(proto_consensus.CHALLENGE, buffer.Bytes())

consensus/consensus_validator.go

@@ -163,7 +163,7 @@ func (consensus *Consensus) constructCommitMessage() (secret kyber.Scalar, commi
 	commitment.MarshalTo(buffer)
 
 	// 64 byte of signature on previous data
-	signature := signMessage(buffer.Bytes())
+	signature := consensus.signMessage(buffer.Bytes())
 	buffer.Write(signature)
 
 	return secret, proto_consensus.ConstructConsensusMessage(proto_consensus.COMMIT, buffer.Bytes())
@@ -322,7 +322,7 @@ func (consensus *Consensus) constructResponseMessage() []byte {
 	buffer.Write(response)
 
 	// 64 byte of signature on previous data
-	signature := signMessage(buffer.Bytes())
+	signature := consensus.signMessage(buffer.Bytes())
 	buffer.Write(signature)
 
 	return proto_consensus.ConstructConsensusMessage(proto_consensus.RESPONSE, buffer.Bytes())