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

525 lines
18 KiB

package consensus
import (
"bytes"
"encoding/binary"
"encoding/gob"
"encoding/hex"
"errors"
"time"
"github.com/ethereum/go-ethereum/rlp"
"github.com/harmony-one/harmony/core/types"
"github.com/harmony-one/harmony/profiler"
"github.com/dedis/kyber"
"github.com/dedis/kyber/sign/schnorr"
"github.com/harmony-one/harmony/blockchain"
"github.com/harmony-one/harmony/crypto"
"github.com/harmony-one/harmony/log"
"github.com/harmony-one/harmony/p2p"
proto_consensus "github.com/harmony-one/harmony/proto/consensus"
)
const (
waitForEnoughValidators = 300
)
var (
startTime time.Time
)
// WaitForNewBlock 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
if !consensus.HasEnoughValidators() {
consensus.Log.Debug("Not enough validators", "# Validators", len(consensus.PublicKeys))
time.Sleep(waitForEnoughValidators * time.Millisecond)
}
// TODO: think about potential race condition
startTime = time.Now()
consensus.Log.Debug("STARTING CONSENSUS", "consensus", consensus, "startTime", startTime)
for consensus.state == Finished {
// time.Sleep(500 * time.Millisecond)
consensus.ResetState()
consensus.startConsensus(&newBlock)
break
}
}
}
// WaitForNewBlockAccount waits for the next new block to run consensus on
func (consensus *Consensus) WaitForNewBlockAccount(blockChannel chan *types.Block) {
consensus.Log.Debug("Waiting for block", "consensus", consensus)
for { // keep waiting for new blocks
newBlock := <-blockChannel
// TODO: think about potential race condition
if !consensus.HasEnoughValidators() {
consensus.Log.Debug("Not enough validators", "# Validators", len(consensus.PublicKeys))
time.Sleep(waitForEnoughValidators * time.Millisecond)
}
startTime = time.Now()
consensus.Log.Debug("STARTING CONSENSUS", "consensus", consensus, "startTime", startTime)
for consensus.state == Finished {
// time.Sleep(500 * time.Millisecond)
data, err := rlp.EncodeToBytes(newBlock)
if err == nil {
consensus.Log.Debug("Sample tx", "tx", newBlock.Transactions()[0])
consensus.ResetState()
consensus.startConsensus(&blockchain.Block{Hash: newBlock.Hash(), AccountBlock: data})
} else {
consensus.Log.Error("Failed encoding the block with RLP")
}
break
}
}
}
// ProcessMessageLeader dispatches consensus message 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.StartConsensus:
consensus.processStartConsensusMessage(payload)
case proto_consensus.Commit:
consensus.processCommitMessage(payload, ChallengeDone)
case proto_consensus.Response:
consensus.processResponseMessage(payload, CollectiveSigDone)
case proto_consensus.FinalCommit:
consensus.processCommitMessage(payload, FinalChallengeDone)
case proto_consensus.FinalResponse:
consensus.processResponseMessage(payload, Finished)
default:
consensus.Log.Error("Unexpected message type", "msgType", msgType, "consensus", consensus)
}
}
// processStartConsensusMessage is the handler for message which triggers consensus process.
func (consensus *Consensus) processStartConsensusMessage(payload []byte) {
// TODO: remove these method after testnet
tx := blockchain.NewCoinbaseTX([20]byte{0}, "y", 0)
consensus.startConsensus(blockchain.NewGenesisBlock(tx, 0))
}
// startConsensus 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[:])
consensus.Log.Debug("Start encoding block")
// prepare message and broadcast to validators
byteBuffer := bytes.NewBuffer([]byte{})
encoder := gob.NewEncoder(byteBuffer)
encoder.Encode(newBlock)
consensus.blockHeader = byteBuffer.Bytes()
consensus.Log.Debug("Stop encoding block")
msgToSend := consensus.constructAnnounceMessage()
p2p.BroadcastMessageFromLeader(consensus.GetValidatorPeers(), msgToSend)
// Set state to AnnounceDone
consensus.state = AnnounceDone
consensus.commitByLeader(true)
}
// commitByLeader commits to the message itself before receiving others commits
func (consensus *Consensus) commitByLeader(firstRound bool) {
// Generate leader's own commitment
secret, commitment := crypto.Commit(crypto.Ed25519Curve)
consensus.secret[consensus.consensusID] = secret
if firstRound {
(*consensus.commitments)[consensus.nodeID] = commitment
consensus.bitmap.SetKey(consensus.pubKey, true)
} else {
(*consensus.finalCommitments)[consensus.nodeID] = commitment
consensus.finalBitmap.SetKey(consensus.pubKey, true)
}
}
// processCommitMessage processes the commit message sent from validators
func (consensus *Consensus) processCommitMessage(payload []byte, targetState State) {
// 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
v, ok := consensus.validators.Load(validatorID)
if !ok {
consensus.Log.Warn("Received message from unrecognized validator", "validatorID", validatorID, "consensus", consensus)
return
}
value, ok := v.(p2p.Peer)
if !ok {
consensus.Log.Warn("Invalid 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.Equal(blockHash, consensus.blockHash[:]) {
consensus.Log.Warn("Received Commit with wrong blockHash", "myConsensusId", consensus.consensusID, "theirConsensusId", consensusID, "consensus", consensus)
return
}
commitments := consensus.commitments // targetState == ChallengeDone
bitmap := consensus.bitmap
if targetState == FinalChallengeDone {
commitments = consensus.finalCommitments
bitmap = consensus.finalBitmap
}
// proceed only when the message is not received before
_, ok = (*commitments)[validatorID]
shouldProcess := !ok
if len((*commitments)) >= ((len(consensus.PublicKeys)*2)/3 + 1) {
shouldProcess = false
}
if shouldProcess {
point := crypto.Ed25519Curve.Point()
point.UnmarshalBinary(commitment)
(*commitments)[validatorID] = point
consensus.Log.Debug("Received new commit message", "num", len(*commitments), "validatorID", validatorID)
// Set the bitmap indicate this validate signed. TODO: figure out how to resolve the inconsistency of validators from commit and response messages
bitmap.SetKey(value.PubKey, true)
}
if !shouldProcess {
consensus.Log.Debug("Received new commit message", "validatorID", validatorID)
return
}
if len((*commitments)) >= ((len(consensus.PublicKeys)*2)/3+1) && consensus.state < targetState {
consensus.Log.Debug("Enough commitments received with signatures", "num", len(*commitments), "state", consensus.state)
// Broadcast challenge
msgTypeToSend := proto_consensus.Challenge // targetState == ChallengeDone
if targetState == FinalChallengeDone {
msgTypeToSend = proto_consensus.FinalChallenge
}
msgToSend, challengeScalar, aggCommitment := consensus.constructChallengeMessage(msgTypeToSend)
bytes, err := challengeScalar.MarshalBinary()
if err != nil {
log.Error("Failed to serialize challenge")
}
if msgTypeToSend == proto_consensus.Challenge {
copy(consensus.challenge[:], bytes)
consensus.aggregatedCommitment = aggCommitment
} else if msgTypeToSend == proto_consensus.FinalChallenge {
copy(consensus.finalChallenge[:], bytes)
consensus.aggregatedFinalCommitment = aggCommitment
}
// Add leader's response
consensus.responseByLeader(challengeScalar, targetState == ChallengeDone)
// Broadcast challenge message
p2p.BroadcastMessageFromLeader(consensus.GetValidatorPeers(), msgToSend)
// Set state to targetState (ChallengeDone or FinalChallengeDone)
consensus.state = targetState
}
}
// Leader commit to the message itself before receiving others commits
func (consensus *Consensus) responseByLeader(challenge kyber.Scalar, firstRound bool) {
// Generate leader's own commitment
response, err := crypto.Response(crypto.Ed25519Curve, consensus.priKey, consensus.secret[consensus.consensusID], challenge)
if err == nil {
if firstRound {
(*consensus.responses)[consensus.nodeID] = response
consensus.bitmap.SetKey(consensus.pubKey, true)
} else {
(*consensus.finalResponses)[consensus.nodeID] = response
consensus.finalBitmap.SetKey(consensus.pubKey, true)
}
} else {
log.Warn("Failed to generate response", "err", err)
}
}
// Processes the response message sent from validators
func (consensus *Consensus) processResponseMessage(payload []byte, targetState State) {
//#### 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()
defer consensus.mutex.Unlock()
// 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.Equal(blockHash, consensus.blockHash[:]) {
consensus.Log.Warn("Received Response with wrong blockHash", "myConsensusId", consensus.consensusID, "theirConsensusId", consensusID, "consensus", consensus)
return
}
// Verify signature
v, ok := consensus.validators.Load(validatorID)
if !ok {
consensus.Log.Warn("Received message from unrecognized validator", "validatorID", validatorID, "consensus", consensus)
return
}
value, ok := v.(p2p.Peer)
if !ok {
consensus.Log.Warn("Invalid 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
}
commitments := consensus.commitments // targetState == CollectiveSigDone
responses := consensus.responses
bitmap := consensus.bitmap
if targetState == Finished {
commitments = consensus.finalCommitments
responses = consensus.finalResponses
bitmap = consensus.finalBitmap
}
// proceed only when the message is not received before
_, ok = (*responses)[validatorID]
shouldProcess = shouldProcess && !ok
if len((*responses)) >= ((len(consensus.PublicKeys)*2)/3 + 1) {
shouldProcess = false
}
if shouldProcess {
// verify the response matches the received commit
responseScalar := crypto.Ed25519Curve.Scalar()
responseScalar.UnmarshalBinary(response)
err := consensus.verifyResponse(commitments, responseScalar, validatorID)
if err != nil {
consensus.Log.Warn("Failed to verify the response", "error", err)
shouldProcess = false
} else {
(*responses)[validatorID] = responseScalar
consensus.Log.Debug("Received new response message", "num", len(*responses), "validatorID", validatorID)
// Set the bitmap indicate this validate signed. TODO: figure out how to resolve the inconsistency of validators from commit and response messages
bitmap.SetKey(value.PubKey, true)
}
}
if !shouldProcess {
consensus.Log.Debug("Received new response message", "validatorID", validatorID)
return
}
if len(*responses) >= ((len(consensus.PublicKeys)*2)/3+1) && consensus.state != targetState {
if len(*responses) >= ((len(consensus.PublicKeys)*2)/3+1) && consensus.state != targetState {
consensus.Log.Debug("Enough responses received with signatures", "num", len(*responses), "state", consensus.state)
// Aggregate responses
responseScalars := []kyber.Scalar{}
for _, val := range *responses {
responseScalars = append(responseScalars, val)
}
aggregatedResponse, err := crypto.AggregateResponses(crypto.Ed25519Curve, responseScalars)
if err != nil {
log.Error("Failed to aggregate responses")
return
}
aggregatedCommitment := consensus.aggregatedCommitment
if targetState == Finished {
aggregatedCommitment = consensus.aggregatedFinalCommitment
}
collectiveSigAndBitmap, err := crypto.Sign(crypto.Ed25519Curve, aggregatedCommitment, aggregatedResponse, bitmap)
if err != nil {
log.Error("Failed to create collective signature")
return
}
log.Info("CollectiveSig and Bitmap created.", "size", len(collectiveSigAndBitmap))
collectiveSig := [64]byte{}
copy(collectiveSig[:], collectiveSigAndBitmap[:64])
bitmap := collectiveSigAndBitmap[64:]
// Set state to CollectiveSigDone or Finished
consensus.state = targetState
if consensus.state != Finished {
// Start the second round of Cosi
msgToSend := consensus.constructCollectiveSigMessage(collectiveSig, bitmap)
p2p.BroadcastMessageFromLeader(consensus.GetValidatorPeers(), msgToSend)
consensus.commitByLeader(false)
} else {
consensus.Log.Debug("Consensus reached with signatures.", "numOfSignatures", len(*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")
}
// Sign the block
copy(blockHeaderObj.Signature[:], collectiveSig[:])
copy(blockHeaderObj.Bitmap[:], bitmap)
consensus.OnConsensusDone(&blockHeaderObj)
consensus.reportMetrics(blockHeaderObj)
// Send signal to Node so the new block can be added and new round of consensus can be triggered
consensus.ReadySignal <- struct{}{}
}
}
}
}
func (consensus *Consensus) verifyResponse(commitments *map[uint16]kyber.Point, response kyber.Scalar, validatorID uint16) error {
if response.Equal(crypto.Ed25519Curve.Scalar()) {
return errors.New("response is zero valued")
}
_, ok := (*commitments)[validatorID]
if !ok {
return errors.New("no commit is received for the validator")
}
// TODO(RJ): enable the actual check
//challenge := crypto.Ed25519Curve.Scalar()
//challenge.UnmarshalBinary(consensus.challenge[:])
//
//// compute Q = sG + r*pubKey
//sG := crypto.Ed25519Curve.Point().Mul(response, nil)
//r_pubKey := crypto.Ed25519Curve.Point().Mul(challenge, consensus.validators[validatorID].PubKey)
//Q := crypto.Ed25519Curve.Point().Add(sG, r_pubKey)
//
//if !Q.Equal(commit) {
// return errors.New("recreated commit doesn't match the received one")
//}
return nil
}
func (consensus *Consensus) reportMetrics(block blockchain.Block) {
if block.IsStateBlock() { // Skip state block stats
return
}
endTime := time.Now()
timeElapsed := endTime.Sub(startTime)
numOfTxs := int(block.NumTransactions)
if block.AccountBlock != nil {
accountBlock := new(types.Block)
rlp.DecodeBytes(block.AccountBlock, accountBlock)
numOfTxs = len(accountBlock.Transactions())
}
tps := float64(numOfTxs) / timeElapsed.Seconds()
consensus.Log.Info("TPS Report",
"numOfTXs", numOfTxs,
"startTime", startTime,
"endTime", endTime,
"timeElapsed", timeElapsed,
"TPS", tps,
"consensus", consensus)
// Post metrics
profiler := profiler.GetProfiler()
if profiler.MetricsReportURL == "" {
return
}
txHashes := []string{}
for i, end := 0, len(block.TransactionIds); i < 3 && i < end; i++ {
txHashes = append(txHashes, hex.EncodeToString(block.TransactionIds[end-1-i][:]))
}
metrics := map[string]interface{}{
"key": consensus.pubKey.String(),
"tps": tps,
"txCount": numOfTxs,
"nodeCount": len(consensus.PublicKeys) + 1,
"latestBlockHash": hex.EncodeToString(consensus.blockHash[:]),
"latestTxHashes": txHashes,
"blockLatency": int(timeElapsed / time.Millisecond),
}
profiler.LogMetrics(metrics)
}
// HasEnoughValidators checks the number of publicKeys to determine
// if the shard has enough validators
// FIXME (HAR-82): we need epoch support or a better way to determine
// when to initiate the consensus
func (consensus *Consensus) HasEnoughValidators() bool {
if len(consensus.PublicKeys) < consensus.MinPeers {
return false
}
return true
}