The core protocol of WoopChain
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woop/consensus/consensus_leader.go

379 lines
12 KiB

package consensus
import (
"bytes"
"encoding/binary"
"encoding/gob"
"github.com/dedis/kyber"
"github.com/dedis/kyber/sign/schnorr"
"harmony-benchmark/blockchain"
"harmony-benchmark/crypto"
"harmony-benchmark/log"
"harmony-benchmark/p2p"
proto_consensus "harmony-benchmark/proto/consensus"
"time"
)
var (
startTime time.Time
)
// Waits for the next new block to run consensus on
func (consensus *Consensus) WaitForNewBlock(blockChannel chan blockchain.Block) {
consensus.Log.Debug("Waiting for block", "consensus", consensus)
for { // keep waiting for new blocks
newBlock := <-blockChannel
// TODO: think about potential race condition
startTime = time.Now()
consensus.Log.Info("STARTING CONSENSUS", "consensus", consensus, "startTime", startTime)
for consensus.state == FINISHED {
time.Sleep(500 * time.Millisecond)
consensus.startConsensus(&newBlock)
break
}
}
}
// Consensus message dispatcher for the leader
func (consensus *Consensus) ProcessMessageLeader(message []byte) {
msgType, err := proto_consensus.GetConsensusMessageType(message)
if err != nil {
consensus.Log.Error("Failed to get consensus message type.", "err", err, "consensus", consensus)
}
payload, err := proto_consensus.GetConsensusMessagePayload(message)
if err != nil {
consensus.Log.Error("Failed to get consensus message payload.", "err", err, "consensus", consensus)
}
switch msgType {
case proto_consensus.ANNOUNCE:
consensus.Log.Error("Unexpected message type", "msgType", msgType, "consensus", consensus)
case proto_consensus.COMMIT:
consensus.processCommitMessage(payload)
case proto_consensus.CHALLENGE:
consensus.Log.Error("Unexpected message type", "msgType", msgType, "consensus", consensus)
case proto_consensus.RESPONSE:
consensus.processResponseMessage(payload)
case proto_consensus.START_CONSENSUS:
consensus.processStartConsensusMessage(payload)
default:
consensus.Log.Error("Unexpected message type", "msgType", msgType, "consensus", consensus)
}
}
// Handler for message which triggers consensus process
func (consensus *Consensus) processStartConsensusMessage(payload []byte) {
tx := blockchain.NewCoinbaseTX("x", "y", 0)
consensus.startConsensus(blockchain.NewGenesisBlock(tx, 0))
}
// Starts a new consensus for a block by broadcast a announce message to the validators
func (consensus *Consensus) startConsensus(newBlock *blockchain.Block) {
// Copy over block hash and block header data
copy(consensus.blockHash[:], newBlock.Hash[:])
// prepare message and broadcast to validators
byteBuffer := bytes.NewBuffer([]byte{})
encoder := gob.NewEncoder(byteBuffer)
encoder.Encode(newBlock)
consensus.blockHeader = byteBuffer.Bytes()
msgToSend := consensus.constructAnnounceMessage()
p2p.BroadcastMessage(consensus.getValidatorPeers(), msgToSend)
// Set state to ANNOUNCE_DONE
consensus.state = ANNOUNCE_DONE
// Generate leader's own commitment
secret, commitment := crypto.Commit(crypto.Ed25519Curve)
consensus.secret = secret
consensus.commitments[consensus.nodeId] = commitment
consensus.bitmap.SetKey(consensus.pubKey, true)
}
// Constructs the announce message
func (consensus *Consensus) constructAnnounceMessage() []byte {
buffer := bytes.NewBuffer([]byte{})
// 4 byte consensus id
fourBytes := make([]byte, 4)
binary.BigEndian.PutUint32(fourBytes, consensus.consensusId)
buffer.Write(fourBytes)
// 32 byte block hash
buffer.Write(consensus.blockHash[:])
// 2 byte leader id
twoBytes := make([]byte, 2)
binary.BigEndian.PutUint16(twoBytes, consensus.nodeId)
buffer.Write(twoBytes)
// n byte of block header
buffer.Write(consensus.blockHeader)
// 64 byte of signature on previous data
signature := consensus.signMessage(buffer.Bytes())
buffer.Write(signature)
return proto_consensus.ConstructConsensusMessage(proto_consensus.ANNOUNCE, buffer.Bytes())
}
// Processes the commit message sent from validators
func (consensus *Consensus) processCommitMessage(payload []byte) {
// Read payload data
offset := 0
// 4 byte consensus id
consensusId := binary.BigEndian.Uint32(payload[offset : offset+4])
offset += 4
// 32 byte block hash
blockHash := payload[offset : offset+32]
offset += 32
// 2 byte validator id
validatorId := binary.BigEndian.Uint16(payload[offset : offset+2])
offset += 2
// 32 byte commit
commitment := payload[offset : offset+32]
offset += 32
// 64 byte of signature on all above data
signature := payload[offset : offset+64]
offset += 64
// Verify signature
value, ok := consensus.validators[validatorId]
if !ok {
consensus.Log.Warn("Received message from unrecognized validator", "validatorId", validatorId, "consensus", consensus)
return
}
if schnorr.Verify(crypto.Ed25519Curve, value.PubKey, payload[:offset-64], signature) != nil {
consensus.Log.Warn("Received message with invalid signature", "validatorKey", consensus.leader.PubKey, "consensus", consensus)
return
}
// check consensus Id
consensus.mutex.Lock()
defer consensus.mutex.Unlock()
if consensusId != consensus.consensusId {
consensus.Log.Warn("Received COMMIT with wrong consensus Id", "myConsensusId", consensus.consensusId, "theirConsensusId", consensusId, "consensus", consensus)
return
}
if bytes.Compare(blockHash, consensus.blockHash[:]) != 0 {
consensus.Log.Warn("Received COMMIT with wrong blockHash", "myConsensusId", consensus.consensusId, "theirConsensusId", consensusId, "consensus", consensus)
return
}
// proceed only when the message is not received before
_, ok = consensus.commitments[validatorId]
shouldProcess := !ok
if shouldProcess {
point := crypto.Ed25519Curve.Point()
point.UnmarshalBinary(commitment)
consensus.commitments[validatorId] = point
}
if !shouldProcess {
return
}
if len(consensus.commitments) >= (2*(len(consensus.validators)+1))/3+1 && consensus.state < CHALLENGE_DONE {
consensus.Log.Debug("Enough commitments received with signatures", "numOfSignatures", len(consensus.commitments))
// Broadcast challenge
msgToSend := consensus.constructChallengeMessage()
p2p.BroadcastMessage(consensus.getValidatorPeers(), msgToSend)
// Set state to CHALLENGE_DONE
consensus.state = CHALLENGE_DONE
}
}
// Construct the challenge message
func (consensus *Consensus) constructChallengeMessage() []byte {
buffer := bytes.NewBuffer([]byte{})
// 4 byte consensus id
fourBytes := make([]byte, 4)
binary.BigEndian.PutUint32(fourBytes, consensus.consensusId)
buffer.Write(fourBytes)
// 32 byte block hash
buffer.Write(consensus.blockHash[:])
// 2 byte leader id
twoBytes := make([]byte, 2)
binary.BigEndian.PutUint16(twoBytes, consensus.nodeId)
buffer.Write(twoBytes)
// 33 byte aggregated commit
commitments := make([]kyber.Point, 0)
for _, val := range consensus.commitments {
commitments = append(commitments, val)
}
aggCommitment, aggCommitmentBytes := getAggregatedCommit(commitments)
buffer.Write(aggCommitmentBytes)
// 33 byte aggregated key
buffer.Write(getAggregatedKey(consensus.bitmap))
// 32 byte challenge
buffer.Write(getChallenge(aggCommitment, consensus.bitmap.AggregatePublic, buffer.Bytes()[:36])) // message contains consensus id and block hash for now.
consensus.aggregatedCommitment = aggCommitment
// 64 byte of signature on previous data
signature := consensus.signMessage(buffer.Bytes())
buffer.Write(signature)
return proto_consensus.ConstructConsensusMessage(proto_consensus.CHALLENGE, buffer.Bytes())
}
func getAggregatedCommit(commitments []kyber.Point) (commitment kyber.Point, bytes []byte) {
aggCommitment := crypto.AggregateCommitmentsOnly(crypto.Ed25519Curve, commitments)
bytes, err := aggCommitment.MarshalBinary()
if err != nil {
panic("Failed to deserialize the aggregated commitment")
}
return aggCommitment, append(bytes[:], byte(0))
}
func getAggregatedKey(bitmap *crypto.Mask) []byte {
bytes, err := bitmap.AggregatePublic.MarshalBinary()
if err != nil {
panic("Failed to deserialize the aggregated key")
}
return append(bytes[:], byte(0))
}
func getChallenge(aggCommitment, aggKey kyber.Point, message []byte) []byte {
challenge, err := crypto.Challenge(crypto.Ed25519Curve, aggCommitment, aggKey, message)
if err != nil {
log.Error("Failed to generate challenge")
}
bytes, err := challenge.MarshalBinary()
if err != nil {
log.Error("Failed to serialize challenge")
}
return bytes
}
// Processes the response message sent from validators
func (consensus *Consensus) processResponseMessage(payload []byte) {
//#### Read payload data
offset := 0
// 4 byte consensus id
consensusId := binary.BigEndian.Uint32(payload[offset : offset+4])
offset += 4
// 32 byte block hash
blockHash := payload[offset : offset+32]
offset += 32
// 2 byte validator id
validatorId := binary.BigEndian.Uint16(payload[offset : offset+2])
offset += 2
// 32 byte response
response := payload[offset : offset+32]
offset += 32
// 64 byte of signature on previous data
signature := payload[offset : offset+64]
offset += 64
//#### END: Read payload data
shouldProcess := true
consensus.mutex.Lock()
// check consensus Id
if consensusId != consensus.consensusId {
shouldProcess = false
consensus.Log.Warn("Received RESPONSE with wrong consensus Id", "myConsensusId", consensus.consensusId, "theirConsensusId", consensusId, "consensus", consensus)
}
if bytes.Compare(blockHash, consensus.blockHash[:]) != 0 {
consensus.Log.Warn("Received RESPONSE with wrong blockHash", "myConsensusId", consensus.consensusId, "theirConsensusId", consensusId, "consensus", consensus)
return
}
// Verify signature
value, ok := consensus.validators[validatorId]
if !ok {
consensus.Log.Warn("Received message from unrecognized validator", "validatorId", validatorId, "consensus", consensus)
return
}
if schnorr.Verify(crypto.Ed25519Curve, value.PubKey, payload[:offset-64], signature) != nil {
consensus.Log.Warn("Received message with invalid signature", "validatorKey", consensus.leader.PubKey, "consensus", consensus)
return
}
// proceed only when the message is not received before
_, ok = consensus.responses[validatorId]
shouldProcess = shouldProcess && !ok
if shouldProcess {
scalar := crypto.Ed25519Curve.Scalar()
scalar.UnmarshalBinary(response)
consensus.responses[validatorId] = scalar
}
consensus.mutex.Unlock()
if !shouldProcess {
return
}
//consensus.Log.Debug("RECEIVED RESPONSE", "consensusId", consensusId)
if len(consensus.responses) >= (2*len(consensus.validators))/3+1 && consensus.state != FINISHED {
consensus.mutex.Lock()
if len(consensus.responses) >= (2*len(consensus.validators))/3+1 && consensus.state != FINISHED {
// Aggregate responses
responses := make([]kyber.Scalar, 0)
for _, val := range consensus.responses {
responses = append(responses, val)
}
aggResponse, err := crypto.AggregateResponses(crypto.Ed25519Curve, responses)
if err != nil {
log.Error("Failed to aggregate responses")
return
}
collectiveSign, err := crypto.Sign(crypto.Ed25519Curve, consensus.aggregatedCommitment, aggResponse, consensus.bitmap)
if err != nil {
log.Error("Failed to create collective signature")
return
}
_ = collectiveSign // TODO: put the collective signature into block and broadcast
consensus.Log.Debug("Consensus reached with signatures.", "numOfSignatures", len(consensus.responses))
// Reset state to FINISHED, and clear other data.
consensus.ResetState()
consensus.consensusId++
consensus.Log.Debug("HOORAY!!! CONSENSUS REACHED!!!", "consensusId", consensus.consensusId)
// TODO: reconstruct the whole block from header and transactions
// For now, we used the stored whole block already stored in consensus.blockHeader
txDecoder := gob.NewDecoder(bytes.NewReader(consensus.blockHeader))
var blockHeaderObj blockchain.Block
err = txDecoder.Decode(&blockHeaderObj)
if err != nil {
consensus.Log.Debug("failed to construct the new block after consensus")
}
consensus.OnConsensusDone(&blockHeaderObj)
// TODO: @ricl these logic are irrelevant to consensus, move them to another file, say profiler.
endTime := time.Now()
timeElapsed := endTime.Sub(startTime)
numOfTxs := blockHeaderObj.NumTransactions
consensus.Log.Info("TPS Report",
"numOfTXs", numOfTxs,
"startTime", startTime,
"endTime", endTime,
"timeElapsed", timeElapsed,
"TPS", float64(numOfTxs)/timeElapsed.Seconds(),
"consensus", consensus)
// Send signal to Node so the new block can be added and new round of consensus can be triggered
consensus.ReadySignal <- 1
}
consensus.mutex.Unlock()
}
}