The core protocol of WoopChain
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woop/consensus/consensus_v2.go

782 lines
27 KiB

package consensus
import (
"bytes"
"context"
"encoding/hex"
"sync/atomic"
"time"
"github.com/harmony-one/harmony/internal/utils"
"github.com/rs/zerolog"
msg_pb "github.com/harmony-one/harmony/api/proto/message"
"github.com/harmony-one/harmony/block"
"github.com/harmony-one/harmony/consensus/quorum"
"github.com/harmony-one/harmony/core/types"
"github.com/harmony-one/harmony/crypto/bls"
vrf_bls "github.com/harmony-one/harmony/crypto/vrf/bls"
nodeconfig "github.com/harmony-one/harmony/internal/configs/node"
"github.com/harmony-one/harmony/p2p"
"github.com/harmony-one/harmony/shard"
"github.com/harmony-one/vdf/src/vdf_go"
"github.com/pkg/errors"
)
var (
errSenderPubKeyNotLeader = errors.New("sender pubkey doesn't match leader")
errVerifyMessageSignature = errors.New("verify message signature failed")
)
// IsViewChangingMode return true if curernt mode is viewchanging
func (consensus *Consensus) IsViewChangingMode() bool {
return consensus.current.Mode() == ViewChanging
}
// HandleMessageUpdate will update the consensus state according to received message
func (consensus *Consensus) HandleMessageUpdate(ctx context.Context, msg *msg_pb.Message, senderKey *bls.SerializedPublicKey) error {
// when node is in ViewChanging mode, it still accepts normal messages into FBFTLog
// in order to avoid possible trap forever but drop PREPARE and COMMIT
// which are message types specifically for a node acting as leader
// so we just ignore those messages
if consensus.IsViewChangingMode() &&
(msg.Type == msg_pb.MessageType_PREPARE ||
msg.Type == msg_pb.MessageType_COMMIT) {
return nil
}
intendedForValidator, intendedForLeader :=
!consensus.IsLeader(),
consensus.IsLeader()
switch t := msg.Type; true {
// Handle validator intended messages first
case t == msg_pb.MessageType_ANNOUNCE && intendedForValidator:
if !bytes.Equal(senderKey[:], consensus.LeaderPubKey.Bytes[:]) &&
consensus.current.Mode() == Normal && !consensus.IgnoreViewIDCheck.IsSet() {
return errSenderPubKeyNotLeader
}
if !consensus.senderKeySanityChecks(msg, senderKey) {
return errVerifyMessageSignature
}
consensus.onAnnounce(msg)
case t == msg_pb.MessageType_PREPARED && intendedForValidator:
if !bytes.Equal(senderKey[:], consensus.LeaderPubKey.Bytes[:]) &&
consensus.current.Mode() == Normal && !consensus.IgnoreViewIDCheck.IsSet() {
return errSenderPubKeyNotLeader
}
if !consensus.senderKeySanityChecks(msg, senderKey) {
return errVerifyMessageSignature
}
consensus.onPrepared(msg)
case t == msg_pb.MessageType_COMMITTED && intendedForValidator:
if !bytes.Equal(senderKey[:], consensus.LeaderPubKey.Bytes[:]) &&
consensus.current.Mode() == Normal && !consensus.IgnoreViewIDCheck.IsSet() {
return errSenderPubKeyNotLeader
}
if !consensus.senderKeySanityChecks(msg, senderKey) {
return errVerifyMessageSignature
}
consensus.onCommitted(msg)
// Handle leader intended messages now
case t == msg_pb.MessageType_PREPARE && intendedForLeader:
consensus.onPrepare(msg)
case t == msg_pb.MessageType_COMMIT && intendedForLeader:
consensus.onCommit(msg)
// Handle view change messages
case t == msg_pb.MessageType_VIEWCHANGE:
if !consensus.senderKeySanityChecks(msg, senderKey) {
return errVerifyMessageSignature
}
consensus.onViewChange(msg)
case t == msg_pb.MessageType_NEWVIEW:
if !consensus.senderKeySanityChecks(msg, senderKey) {
return errVerifyMessageSignature
}
consensus.onNewView(msg)
}
return nil
}
func (consensus *Consensus) finalCommit() {
consensus.getLogger().Info().
Int64("NumCommits", consensus.Decider.SignersCount(quorum.Commit)).
Msg("[finalCommit] Finalizing Consensus")
beforeCatchupNum := consensus.blockNum
leaderPriKey, err := consensus.GetConsensusLeaderPrivateKey()
if err != nil {
consensus.getLogger().Error().Err(err).Msg("[finalCommit] leader not found")
return
}
// Construct committed message
network, err := consensus.construct(msg_pb.MessageType_COMMITTED, nil, []*bls.PrivateKeyWrapper{leaderPriKey})
if err != nil {
consensus.getLogger().Warn().Err(err).
Msg("[finalCommit] Unable to construct Committed message")
return
}
msgToSend, FBFTMsg :=
network.Bytes,
network.FBFTMsg
commitSigAndBitmap := FBFTMsg.Payload
consensus.FBFTLog.AddMessage(FBFTMsg)
// find correct block content
curBlockHash := consensus.blockHash
block := consensus.FBFTLog.GetBlockByHash(curBlockHash)
if block == nil {
consensus.getLogger().Warn().
Str("blockHash", hex.EncodeToString(curBlockHash[:])).
Msg("[finalCommit] Cannot find block by hash")
return
}
block.SetCurrentCommitSig(commitSigAndBitmap)
consensus.commitBlock(block, FBFTMsg)
if consensus.blockNum-beforeCatchupNum != 1 {
consensus.getLogger().Warn().
Uint64("beforeCatchupBlockNum", beforeCatchupNum).
Msg("[finalCommit] Leader cannot provide the correct block for committed message")
return
}
// if leader successfully finalizes the block, send committed message to validators
// TODO: once leader rotation is implemented, leader who is about to be switched out
// needs to send the committed message immediately so the next leader can
// have the full commit signatures for new block
// For now, the leader don't need to send immediately as the committed sig will be
// included in the next block and sent in next prepared message. Unless the node
// won't be the leader anymore or it's the last block of the epoch (no pipelining).
sendImmediately := false
if !consensus.IsLeader() || block.IsLastBlockInEpoch() {
sendImmediately = true
}
if err := consensus.msgSender.SendWithRetry(
block.NumberU64(),
msg_pb.MessageType_COMMITTED, []nodeconfig.GroupID{
nodeconfig.NewGroupIDByShardID(nodeconfig.ShardID(consensus.ShardID)),
},
p2p.ConstructMessage(msgToSend), sendImmediately); err != nil {
consensus.getLogger().Warn().Err(err).Msg("[finalCommit] Cannot send committed message")
} else {
consensus.getLogger().Info().
Hex("blockHash", curBlockHash[:]).
Uint64("blockNum", consensus.blockNum).
Msg("[finalCommit] Sent Committed Message")
}
// Dump new block into level db
// In current code, we add signatures in block in tryCatchup, the block dump to explorer does not contains signatures
// but since explorer doesn't need signatures, it should be fine
// in future, we will move signatures to next block
//explorer.GetStorageInstance(consensus.leader.IP, consensus.leader.Port, true).Dump(block, beforeCatchupNum)
if consensus.consensusTimeout[timeoutBootstrap].IsActive() {
consensus.consensusTimeout[timeoutBootstrap].Stop()
consensus.getLogger().Info().Msg("[finalCommit] Start consensus timer; stop bootstrap timer only once")
} else {
consensus.getLogger().Info().Msg("[finalCommit] Start consensus timer")
}
consensus.consensusTimeout[timeoutConsensus].Start()
consensus.getLogger().Info().
Uint64("blockNum", block.NumberU64()).
Uint64("epochNum", block.Epoch().Uint64()).
Uint64("ViewId", block.Header().ViewID().Uint64()).
Str("blockHash", block.Hash().String()).
Int("numTxns", len(block.Transactions())).
Int("numStakingTxns", len(block.StakingTransactions())).
Msg("HOORAY!!!!!!! CONSENSUS REACHED!!!!!!!")
// Sleep to wait for the full block time
consensus.getLogger().Info().Msg("[finalCommit] Waiting for Block Time")
<-time.After(time.Until(consensus.NextBlockDue))
// Update time due for next block
consensus.NextBlockDue = time.Now().Add(consensus.BlockPeriod)
// Send commit sig/bitmap to finish the new block proposal
go func() {
select {
case consensus.CommitSigChannel <- commitSigAndBitmap:
case <-time.After(6 * time.Second):
utils.Logger().Error().Err(err).Msg("[finalCommit] channel not received after 6s for commitSigAndBitmap")
}
}()
}
// BlockCommitSigs returns the byte array of aggregated
// commit signature and bitmap signed on the block
func (consensus *Consensus) BlockCommitSigs(blockNum uint64) ([]byte, error) {
if consensus.blockNum <= 1 {
return nil, nil
}
lastCommits, err := consensus.Blockchain.ReadCommitSig(blockNum)
if err != nil ||
len(lastCommits) < bls.BLSSignatureSizeInBytes {
msgs := consensus.FBFTLog.GetMessagesByTypeSeq(
msg_pb.MessageType_COMMITTED, blockNum,
)
if len(msgs) != 1 {
consensus.getLogger().Error().
Int("numCommittedMsg", len(msgs)).
Msg("GetLastCommitSig failed with wrong number of committed message")
return nil, errors.Errorf(
"GetLastCommitSig failed with wrong number of committed message %d", len(msgs),
)
}
lastCommits = msgs[0].Payload
}
return lastCommits, nil
}
// Start waits for the next new block and run consensus
func (consensus *Consensus) Start(
blockChannel chan *types.Block, stopChan, stoppedChan, startChannel chan struct{},
) {
go func() {
toStart := make(chan struct{}, 1)
isInitialLeader := consensus.IsLeader()
if isInitialLeader {
consensus.getLogger().Info().Time("time", time.Now()).Msg("[ConsensusMainLoop] Waiting for consensus start")
// send a signal to indicate it's ready to run consensus
// this signal is consumed by node object to create a new block and in turn trigger a new consensus on it
go func() {
<-startChannel
toStart <- struct{}{}
consensus.getLogger().Info().Time("time", time.Now()).Msg("[ConsensusMainLoop] Send ReadySignal")
consensus.ReadySignal <- SyncProposal
}()
}
consensus.getLogger().Info().Time("time", time.Now()).Msg("[ConsensusMainLoop] Consensus started")
defer close(stoppedChan)
ticker := time.NewTicker(3 * time.Second)
defer ticker.Stop()
consensus.consensusTimeout[timeoutBootstrap].Start()
consensus.getLogger().Info().Msg("[ConsensusMainLoop] Start bootstrap timeout (only once)")
vdfInProgress := false
// Set up next block due time.
consensus.NextBlockDue = time.Now().Add(consensus.BlockPeriod)
start := false
for {
select {
case <-toStart:
start = true
case <-ticker.C:
consensus.getLogger().Debug().Msg("[ConsensusMainLoop] Ticker")
if !start && isInitialLeader {
continue
}
for k, v := range consensus.consensusTimeout {
if consensus.current.Mode() == Syncing ||
consensus.current.Mode() == Listening {
v.Stop()
}
if !v.CheckExpire() {
continue
}
if k != timeoutViewChange {
consensus.getLogger().Warn().Msg("[ConsensusMainLoop] Ops Consensus Timeout!!!")
consensus.startViewChange()
break
} else {
consensus.getLogger().Warn().Msg("[ConsensusMainLoop] Ops View Change Timeout!!!")
consensus.startViewChange()
break
}
}
case <-consensus.syncReadyChan:
consensus.getLogger().Info().Msg("[ConsensusMainLoop] syncReadyChan")
consensus.SetBlockNum(consensus.Blockchain.CurrentHeader().Number().Uint64() + 1)
consensus.SetViewIDs(consensus.Blockchain.CurrentHeader().ViewID().Uint64() + 1)
mode := consensus.UpdateConsensusInformation()
consensus.current.SetMode(mode)
consensus.getLogger().Info().Str("Mode", mode.String()).Msg("Node is IN SYNC")
case <-consensus.syncNotReadyChan:
consensus.getLogger().Info().Msg("[ConsensusMainLoop] syncNotReadyChan")
consensus.SetBlockNum(consensus.Blockchain.CurrentHeader().Number().Uint64() + 1)
consensus.current.SetMode(Syncing)
consensus.getLogger().Info().Msg("[ConsensusMainLoop] Node is OUT OF SYNC")
case newBlock := <-blockChannel:
consensus.getLogger().Info().
Uint64("MsgBlockNum", newBlock.NumberU64()).
Msg("[ConsensusMainLoop] Received Proposed New Block!")
//VRF/VDF is only generated in the beacon chain
if consensus.NeedsRandomNumberGeneration(newBlock.Header().Epoch()) {
// generate VRF if the current block has a new leader
if !consensus.Blockchain.IsSameLeaderAsPreviousBlock(newBlock) {
vrfBlockNumbers, err := consensus.Blockchain.ReadEpochVrfBlockNums(newBlock.Header().Epoch())
if err != nil {
consensus.getLogger().Info().
Uint64("MsgBlockNum", newBlock.NumberU64()).
Uint64("Epoch", newBlock.Header().Epoch().Uint64()).
Msg("[ConsensusMainLoop] no VRF block number from local db")
}
//check if VRF is already generated for the current block
vrfAlreadyGenerated := false
for _, v := range vrfBlockNumbers {
if v == newBlock.NumberU64() {
consensus.getLogger().Info().
Uint64("MsgBlockNum", newBlock.NumberU64()).
Uint64("Epoch", newBlock.Header().Epoch().Uint64()).
Msg("[ConsensusMainLoop] VRF is already generated for this block")
vrfAlreadyGenerated = true
break
}
}
if !vrfAlreadyGenerated {
//generate a new VRF for the current block
vrfBlockNumbers := consensus.GenerateVrfAndProof(newBlock, vrfBlockNumbers)
//generate a new VDF for the current epoch if there are enough VRFs in the current epoch
//note that >= instead of == is used, because it is possible the current leader
//can commit this block, go offline without finishing VDF
if (!vdfInProgress) && len(vrfBlockNumbers) >= consensus.VdfSeedSize() {
//check local database to see if there's a VDF generated for this epoch
//generate a VDF if no blocknum is available
_, err := consensus.Blockchain.ReadEpochVdfBlockNum(newBlock.Header().Epoch())
if err != nil {
consensus.GenerateVdfAndProof(newBlock, vrfBlockNumbers)
vdfInProgress = true
}
}
}
}
vdfOutput, seed, err := consensus.GetNextRnd()
if err == nil {
vdfInProgress = false
// Verify the randomness
vdfObject := vdf_go.New(shard.Schedule.VdfDifficulty(), seed)
if !vdfObject.Verify(vdfOutput) {
consensus.getLogger().Warn().
Uint64("MsgBlockNum", newBlock.NumberU64()).
Uint64("Epoch", newBlock.Header().Epoch().Uint64()).
Msg("[ConsensusMainLoop] failed to verify the VDF output")
} else {
//write the VDF only if VDF has not been generated
_, err := consensus.Blockchain.ReadEpochVdfBlockNum(newBlock.Header().Epoch())
if err == nil {
consensus.getLogger().Info().
Uint64("MsgBlockNum", newBlock.NumberU64()).
Uint64("Epoch", newBlock.Header().Epoch().Uint64()).
Msg("[ConsensusMainLoop] VDF has already been generated previously")
} else {
consensus.getLogger().Info().
Uint64("MsgBlockNum", newBlock.NumberU64()).
Uint64("Epoch", newBlock.Header().Epoch().Uint64()).
Msg("[ConsensusMainLoop] Generated a new VDF")
newBlock.AddVdf(vdfOutput[:])
}
}
}
}
startTime = time.Now()
consensus.msgSender.Reset(newBlock.NumberU64())
consensus.getLogger().Info().
Int("numTxs", len(newBlock.Transactions())).
Int("numStakingTxs", len(newBlock.StakingTransactions())).
Time("startTime", startTime).
Int64("publicKeys", consensus.Decider.ParticipantsCount()).
Msg("[ConsensusMainLoop] STARTING CONSENSUS")
consensus.announce(newBlock)
case viewID := <-consensus.commitFinishChan:
consensus.getLogger().Info().Msg("[ConsensusMainLoop] commitFinishChan")
// Only Leader execute this condition
func() {
consensus.mutex.Lock()
defer consensus.mutex.Unlock()
if viewID == consensus.GetCurBlockViewID() {
consensus.finalCommit()
}
}()
case <-stopChan:
consensus.getLogger().Info().Msg("[ConsensusMainLoop] stopChan")
return
}
}
consensus.getLogger().Info().Msg("[ConsensusMainLoop] Ended.")
}()
}
// LastMileBlockIter is the iterator to iterate over the last mile blocks in consensus cache.
// All blocks returned are guaranteed to pass the verification.
type LastMileBlockIter struct {
blockCandidates []*types.Block
fbftLog FBFTLog
verify func(*types.Block) error
curIndex int
logger *zerolog.Logger
}
// GetLastMileBlockIter get the iterator of the last mile blocks starting from number bnStart
func (consensus *Consensus) GetLastMileBlockIter(bnStart uint64) (*LastMileBlockIter, error) {
consensus.mutex.Lock()
defer consensus.mutex.Unlock()
if consensus.BlockVerifier == nil {
return nil, errors.New("consensus haven't initialized yet")
}
blocks, _, err := consensus.getLastMileBlocksAndMsg(bnStart)
if err != nil {
return nil, err
}
return &LastMileBlockIter{
blockCandidates: blocks,
verify: consensus.BlockVerifier,
curIndex: 0,
logger: consensus.getLogger(),
}, nil
}
// Next iterate to the next last mile block
func (iter *LastMileBlockIter) Next() *types.Block {
if iter.curIndex >= len(iter.blockCandidates) {
return nil
}
block := iter.blockCandidates[iter.curIndex]
iter.curIndex++
if !iter.fbftLog.IsBlockVerified(block) {
if err := iter.verify(block); err != nil {
iter.logger.Debug().Err(err).Msg("block verification failed in consensus last mile block")
return nil
}
iter.fbftLog.MarkBlockVerified(block)
}
return block
}
func (consensus *Consensus) getLastMileBlocksAndMsg(bnStart uint64) ([]*types.Block, []*FBFTMessage, error) {
var (
blocks []*types.Block
msgs []*FBFTMessage
)
for blockNum := bnStart; ; blockNum++ {
blk, msg, err := consensus.FBFTLog.GetCommittedBlockAndMsgsFromNumber(blockNum, consensus.getLogger())
if err != nil {
if err == errFBFTLogNotFound {
break
}
return nil, nil, err
}
blocks = append(blocks, blk)
msgs = append(msgs, msg)
}
return blocks, msgs, nil
}
// preCommitAndPropose commit the current block with 67% commit signatures and start
// proposing new block which will wait on the full commit signatures to finish
func (consensus *Consensus) preCommitAndPropose(blk *types.Block) error {
if blk == nil {
return errors.New("block to pre-commit is nil")
}
leaderPriKey, err := consensus.GetConsensusLeaderPrivateKey()
if err != nil {
return err
}
consensus.mutex.Lock()
network, err := consensus.construct(msg_pb.MessageType_COMMITTED, nil, []*bls.PrivateKeyWrapper{leaderPriKey})
consensus.mutex.Unlock()
if err != nil {
return errors.Wrap(err, "[preCommitAndPropose] Unable to construct Committed message")
}
msgToSend, FBFTMsg :=
network.Bytes,
network.FBFTMsg
consensus.FBFTLog.AddMessage(FBFTMsg)
blk.SetCurrentCommitSig(FBFTMsg.Payload)
if err := consensus.OnConsensusDone(blk); err != nil {
consensus.getLogger().Error().Err(err).Msg("[preCommitAndPropose] Failed to add block to chain")
return err
}
// If it's not the epoch block, do pipelining and send committed message to validators now at 67% committed.
if !blk.IsLastBlockInEpoch() {
if err := consensus.msgSender.SendWithRetry(
blk.NumberU64(),
msg_pb.MessageType_COMMITTED, []nodeconfig.GroupID{
nodeconfig.NewGroupIDByShardID(nodeconfig.ShardID(consensus.ShardID)),
},
p2p.ConstructMessage(msgToSend), true); err != nil {
consensus.getLogger().Warn().Err(err).Msg("[preCommitAndPropose] Cannot send committed message")
} else {
consensus.getLogger().Info().
Str("blockHash", blk.Hash().Hex()).
Uint64("blockNum", consensus.blockNum).
Msg("[preCommitAndPropose] Sent Committed Message")
}
}
// Send signal to Node to propose the new block for consensus
consensus.getLogger().Warn().Err(err).Msg("[preCommitAndPropose] sending block proposal signal")
consensus.ReadySignal <- AsyncProposal
return nil
}
// tryCatchup add the last mile block in PBFT log memory cache to blockchain.
func (consensus *Consensus) tryCatchup() error {
// TODO: change this to a more systematic symbol
if consensus.BlockVerifier == nil {
return errors.New("consensus haven't finished initialization")
}
initBN := consensus.blockNum
defer consensus.postCatchup(initBN)
blks, msgs, err := consensus.getLastMileBlocksAndMsg(initBN)
if err != nil {
return errors.Wrapf(err, "[TryCatchup] Failed to get last mile blocks: %v", err)
}
for i := range blks {
blk, msg := blks[i], msgs[i]
if blk == nil {
return nil
}
blk.SetCurrentCommitSig(msg.Payload)
if !consensus.FBFTLog.IsBlockVerified(blk) {
if err := consensus.BlockVerifier(blk); err != nil {
consensus.getLogger().Err(err).Msg("[TryCatchup] failed block verifier")
return err
}
consensus.FBFTLog.MarkBlockVerified(blk)
}
consensus.getLogger().Info().Msg("[TryCatchup] Adding block to chain")
if err := consensus.commitBlock(blk, msgs[i]); err != nil {
consensus.getLogger().Error().Err(err).Msg("[TryCatchup] Failed to add block to chain")
return err
}
select {
case consensus.VerifiedNewBlock <- blk:
default:
consensus.getLogger().Info().
Str("blockHash", blk.Hash().String()).
Msg("[TryCatchup] consensus verified block send to chan failed")
continue
}
}
return nil
}
func (consensus *Consensus) commitBlock(blk *types.Block, committedMsg *FBFTMessage) error {
if consensus.Blockchain.CurrentBlock().NumberU64() < blk.NumberU64() {
if err := consensus.OnConsensusDone(blk); err != nil {
return err
}
}
if !committedMsg.HasSingleSender() {
consensus.getLogger().Error().Msg("[TryCatchup] Leader message can not have multiple sender keys")
return errIncorrectSender
}
consensus.SetupForNewConsensus(blk, committedMsg)
return nil
}
func (consensus *Consensus) SetupForNewConsensus(blk *types.Block, committedMsg *FBFTMessage) {
atomic.AddUint64(&consensus.blockNum, 1)
consensus.SetViewIDs(committedMsg.ViewID + 1)
consensus.LeaderPubKey = committedMsg.SenderPubkeys[0]
// Update consensus keys at last so the change of leader status doesn't mess up normal flow
if blk.IsLastBlockInEpoch() {
consensus.SetMode(consensus.UpdateConsensusInformation())
}
consensus.ResetState()
}
func (consensus *Consensus) postCatchup(initBN uint64) {
if initBN < consensus.blockNum {
consensus.getLogger().Info().
Uint64("From", initBN).
Uint64("To", consensus.blockNum).
Msg("[TryCatchup] Caught up!")
consensus.switchPhase("TryCatchup", FBFTAnnounce)
}
// catch up and skip from view change trap
if initBN < consensus.blockNum && consensus.IsViewChangingMode() {
consensus.current.SetMode(Normal)
consensus.consensusTimeout[timeoutViewChange].Stop()
}
// clean up old log
consensus.FBFTLog.PruneCacheBeforeBlock(consensus.blockNum)
}
// GenerateVrfAndProof generates new VRF/Proof from hash of previous block
func (consensus *Consensus) GenerateVrfAndProof(newBlock *types.Block, vrfBlockNumbers []uint64) []uint64 {
key, err := consensus.GetConsensusLeaderPrivateKey()
if err != nil {
consensus.getLogger().Error().
Err(err).
Msg("[GenerateVrfAndProof] VRF generation error")
return vrfBlockNumbers
}
sk := vrf_bls.NewVRFSigner(key.Pri)
blockHash := [32]byte{}
previousHeader := consensus.Blockchain.GetHeaderByNumber(
newBlock.NumberU64() - 1,
)
if previousHeader == nil {
return vrfBlockNumbers
}
previousHash := previousHeader.Hash()
copy(blockHash[:], previousHash[:])
vrf, proof := sk.Evaluate(blockHash[:])
newBlock.AddVrf(append(vrf[:], proof...))
consensus.getLogger().Info().
Uint64("MsgBlockNum", newBlock.NumberU64()).
Uint64("Epoch", newBlock.Header().Epoch().Uint64()).
Int("Num of VRF", len(vrfBlockNumbers)).
Msg("[ConsensusMainLoop] Leader generated a VRF")
return vrfBlockNumbers
}
// ValidateVrfAndProof validates a VRF/Proof from hash of previous block
func (consensus *Consensus) ValidateVrfAndProof(headerObj *block.Header) bool {
vrfPk := vrf_bls.NewVRFVerifier(consensus.LeaderPubKey.Object)
var blockHash [32]byte
previousHeader := consensus.Blockchain.GetHeaderByNumber(
headerObj.Number().Uint64() - 1,
)
if previousHeader == nil {
return false
}
previousHash := previousHeader.Hash()
copy(blockHash[:], previousHash[:])
vrfProof := [96]byte{}
copy(vrfProof[:], headerObj.Vrf()[32:])
hash, err := vrfPk.ProofToHash(blockHash[:], vrfProof[:])
if err != nil {
consensus.getLogger().Warn().
Err(err).
Str("MsgBlockNum", headerObj.Number().String()).
Msg("[OnAnnounce] VRF verification error")
return false
}
if !bytes.Equal(hash[:], headerObj.Vrf()[:32]) {
consensus.getLogger().Warn().
Str("MsgBlockNum", headerObj.Number().String()).
Msg("[OnAnnounce] VRF proof is not valid")
return false
}
vrfBlockNumbers, _ := consensus.Blockchain.ReadEpochVrfBlockNums(
headerObj.Epoch(),
)
consensus.getLogger().Info().
Str("MsgBlockNum", headerObj.Number().String()).
Int("Number of VRF", len(vrfBlockNumbers)).
Msg("[OnAnnounce] validated a new VRF")
return true
}
// GenerateVdfAndProof generates new VDF/Proof from VRFs in the current epoch
func (consensus *Consensus) GenerateVdfAndProof(newBlock *types.Block, vrfBlockNumbers []uint64) {
//derive VDF seed from VRFs generated in the current epoch
seed := [32]byte{}
for i := 0; i < consensus.VdfSeedSize(); i++ {
previousVrf := consensus.Blockchain.GetVrfByNumber(vrfBlockNumbers[i])
for j := 0; j < len(seed); j++ {
seed[j] = seed[j] ^ previousVrf[j]
}
}
consensus.getLogger().Info().
Uint64("MsgBlockNum", newBlock.NumberU64()).
Uint64("Epoch", newBlock.Header().Epoch().Uint64()).
Int("Num of VRF", len(vrfBlockNumbers)).
Msg("[ConsensusMainLoop] VDF computation started")
// TODO ek – limit concurrency
go func() {
vdf := vdf_go.New(shard.Schedule.VdfDifficulty(), seed)
outputChannel := vdf.GetOutputChannel()
start := time.Now()
vdf.Execute()
duration := time.Since(start)
consensus.getLogger().Info().
Dur("duration", duration).
Msg("[ConsensusMainLoop] VDF computation finished")
output := <-outputChannel
// The first 516 bytes are the VDF+proof and the last 32 bytes are XORed VRF as seed
rndBytes := [548]byte{}
copy(rndBytes[:516], output[:])
copy(rndBytes[516:], seed[:])
consensus.RndChannel <- rndBytes
}()
}
// ValidateVdfAndProof validates the VDF/proof in the current epoch
func (consensus *Consensus) ValidateVdfAndProof(headerObj *block.Header) bool {
vrfBlockNumbers, err := consensus.Blockchain.ReadEpochVrfBlockNums(headerObj.Epoch())
if err != nil {
consensus.getLogger().Error().Err(err).
Str("MsgBlockNum", headerObj.Number().String()).
Msg("[OnAnnounce] failed to read VRF block numbers for VDF computation")
}
//extra check to make sure there's no index out of range error
//it can happen if epoch is messed up, i.e. VDF ouput is generated in the next epoch
if consensus.VdfSeedSize() > len(vrfBlockNumbers) {
return false
}
seed := [32]byte{}
for i := 0; i < consensus.VdfSeedSize(); i++ {
previousVrf := consensus.Blockchain.GetVrfByNumber(vrfBlockNumbers[i])
for j := 0; j < len(seed); j++ {
seed[j] = seed[j] ^ previousVrf[j]
}
}
vdfObject := vdf_go.New(shard.Schedule.VdfDifficulty(), seed)
vdfOutput := [516]byte{}
copy(vdfOutput[:], headerObj.Vdf())
if vdfObject.Verify(vdfOutput) {
consensus.getLogger().Info().
Str("MsgBlockNum", headerObj.Number().String()).
Int("Num of VRF", consensus.VdfSeedSize()).
Msg("[OnAnnounce] validated a new VDF")
} else {
consensus.getLogger().Warn().
Str("MsgBlockNum", headerObj.Number().String()).
Uint64("Epoch", headerObj.Epoch().Uint64()).
Int("Num of VRF", consensus.VdfSeedSize()).
Msg("[OnAnnounce] VDF proof is not valid")
return false
}
return true
}