protocol/bbft.go

   1 package protocol
   2
   3 import (
   4         "encoding/hex"
   5         "fmt"
   6
   7         "github.com/golang/groupcache/lru"
   8         log "github.com/sirupsen/logrus"
   9
  10         "github.com/vapor/crypto/ed25519"
  11         "github.com/vapor/crypto/ed25519/chainkd"
  12         "github.com/vapor/errors"
  13         "github.com/vapor/event"
  14         "github.com/vapor/protocol/bc"
  15         "github.com/vapor/protocol/bc/types"
  16         "github.com/vapor/protocol/state"
  17 )
  18
  19 const (
  20         maxSignatureCacheSize = 10000
  21 )
  22
  23 var (
  24         errVotingOperationOverFlow = errors.New("voting operation result overflow")
  25         errDoubleSignBlock         = errors.New("the consensus is double sign in same height of different block")
  26         errInvalidSignature        = errors.New("the signature of block is invalid")
  27 )
  28
  29 type bbft struct {
  30         consensusNodeManager *consensusNodeManager
  31         orphanManage         *OrphanManage
  32         signatureCache       *lru.Cache
  33         eventDispatcher      *event.Dispatcher
  34 }
  35
  36 func newBbft(store Store, blockIndex *state.BlockIndex, orphanManage *OrphanManage, eventDispatcher *event.Dispatcher) *bbft {
  37         return &bbft{
  38                 orphanManage:         orphanManage,
  39                 consensusNodeManager: newConsensusNodeManager(store, blockIndex),
  40                 signatureCache:       lru.New(maxSignatureCacheSize),
  41                 eventDispatcher:      eventDispatcher,
  42         }
  43 }
  44
  45 // IsConsensusPubkey determine whether a public key is a consensus node at a specified height
  46 func (b *bbft) IsConsensusPubkey(blockHash *bc.Hash, pubkey []byte) (bool, error) {
  47         node, err := b.consensusNodeManager.getConsensusNode(blockHash, hex.EncodeToString(pubkey))
  48         if err != nil && err != errNotFoundConsensusNode {
  49                 return false, err
  50         }
  51         return node != nil, nil
  52 }
  53
  54 func (b *bbft) isIrreversible(block *types.Block) bool {
  55         signNum, err := b.validateSign(block)
  56         if err != nil {
  57                 return false
  58         }
  59
  60         return signNum > (numOfConsensusNode * 2 / 3)
  61 }
  62
  63 // NextLeaderTime returns the start time of the specified public key as the next leader node
  64 func (b *bbft) NextLeaderTimeRange(pubkey []byte, bestBlockHash *bc.Hash) (uint64, uint64, error) {
  65         return b.consensusNodeManager.nextLeaderTimeRange(pubkey, bestBlockHash)
  66 }
  67
  68 func (b *bbft) ApplyBlock(voteResultMap map[uint64]*state.VoteResult, block *types.Block) (err error) {
  69         return b.consensusNodeManager.applyBlock(voteResultMap, block)
  70 }
  71
  72 func (b *bbft) DetachBlock(voteResultMap map[uint64]*state.VoteResult, block *types.Block) error {
  73         return b.consensusNodeManager.detachBlock(voteResultMap, block)
  74 }
  75
  76 // ProcessBlockSignature process the received block signature messages
  77 // return once a block become irreversible, whether it's height greater than best block height
  78 // if so, the chain module must update status
  79 func (b *bbft) ProcessBlockSignature(signature, pubkey []byte, blockHeight uint64, blockHash *bc.Hash) (bool, error) {
  80         consensusNode, err := b.consensusNodeManager.getConsensusNode(blockHash, hex.EncodeToString(pubkey))
  81         if err != nil {
  82                 return false, err
  83         }
  84
  85         if !ed25519.Verify(ed25519.PublicKey(pubkey), blockHash.Bytes(), signature) {
  86                 return false, errInvalidSignature
  87         }
  88
  89         isDoubleSign, err := b.checkDoubleSign(consensusNode.order, blockHeight, *blockHash)
  90         if err != nil {
  91                 return false, err
  92         }
  93
  94         if isDoubleSign {
  95                 log.WithFields(log.Fields{"module": logModule, "blockHash": blockHash.String(), "pubkey": pubkey}).Warn("the consensus node double sign the same height of different block")
  96                 return false, errDoubleSignBlock
  97         }
  98
  99         orphanBlock, ok := b.orphanManage.Get(blockHash)
 100         if ok {
 101                 orphanBlock.Witness[consensusNode.order] = signature
 102                 return false, nil
 103         }
 104
 105         block, err := b.consensusNodeManager.store.GetBlock(blockHash)
 106         if err != nil {
 107                 // block is not exist, save the signature
 108                 key := fmt.Sprintf("%s:%s", blockHash.String(), hex.EncodeToString(pubkey))
 109                 b.signatureCache.Add(key, signature)
 110                 return false, err
 111         }
 112
 113         if err := b.updateBlockSignature(block, consensusNode.order, signature); err != nil {
 114                 return false, err
 115         }
 116
 117         return b.isIrreversible(block) && blockHeight > b.consensusNodeManager.blockIndex.BestNode().Height, nil
 118 }
 119
 120 // ValidateBlock verify whether the block is valid
 121 func (b *bbft) ValidateBlock(block *types.Block) error {
 122         signNum, err := b.validateSign(block)
 123         if err != nil {
 124                 return err
 125         }
 126
 127         if signNum == 0 {
 128                 return errors.New("no valid signature")
 129         }
 130         return nil
 131 }
 132
 133 // validateSign verify the signatures of block, and return the number of correct signature
 134 // if some signature is invalid, they will be reset to nil
 135 // if the block has not the signature of blocker, it will return error
 136 func (b *bbft) validateSign(block *types.Block) (uint64, error) {
 137         var correctSignNum uint64
 138         blockHash := block.Hash()
 139         consensusNodeMap, err := b.consensusNodeManager.getConsensusNodesByVoteResult(&blockHash)
 140         if err != nil {
 141                 return 0, err
 142         }
 143
 144         hasBlockerSign := false
 145         for pubkey, node := range consensusNodeMap {
 146                 if len(block.Witness) <= int(node.order) {
 147                         continue
 148                 }
 149
 150                 blockHash := block.Hash()
 151                 if block.Witness[node.order] == nil {
 152                         key := fmt.Sprintf("%s:%s", blockHash.String(), pubkey)
 153                         signature, ok := b.signatureCache.Get(key)
 154                         if ok {
 155                                 block.Witness[node.order] = signature.([]byte)
 156                         }
 157                 }
 158
 159                 if ed25519.Verify(ed25519.PublicKey(pubkey), blockHash.Bytes(), block.Witness[node.order]) {
 160                         isDoubleSign, err := b.checkDoubleSign(node.order, block.Height, block.Hash())
 161                         if err != nil {
 162                                 return 0, err
 163                         }
 164
 165                         if isDoubleSign {
 166                                 log.WithFields(log.Fields{"module": logModule, "blockHash": blockHash.String(), "pubkey": pubkey}).Warn("the consensus node double sign the same height of different block")
 167                                 // Consensus node is signed twice with the same block height, discard the signature
 168                                 block.Witness[node.order] = nil
 169                         } else {
 170                                 correctSignNum++
 171                                 isBlocker, err := b.consensusNodeManager.isBlocker(&blockHash, pubkey)
 172                                 if err != nil {
 173                                         return 0, err
 174                                 }
 175                                 if isBlocker {
 176                                         hasBlockerSign = true
 177                                 }
 178                         }
 179                 } else {
 180                         // discard the invalid signature
 181                         block.Witness[node.order] = nil
 182                 }
 183         }
 184         if !hasBlockerSign {
 185                 return 0, errors.New("the block has no signature of the blocker")
 186         }
 187         return correctSignNum, nil
 188 }
 189
 190 func (b *bbft) checkDoubleSign(nodeOrder, blockHeight uint64, blockHash bc.Hash) (bool, error) {
 191         blockNodes := b.consensusNodeManager.blockIndex.NodesByHeight(blockHeight)
 192         for _, blockNode := range blockNodes {
 193                 if blockNode.Hash == blockHash {
 194                         continue
 195                 }
 196                 if ok, err := blockNode.BlockWitness.Test(uint32(nodeOrder)); err != nil && ok {
 197                         block, err := b.consensusNodeManager.store.GetBlock(&blockHash)
 198                         if err != nil {
 199                                 return false, err
 200                         }
 201
 202                         // reset nil to discard signature
 203                         if err := b.updateBlockSignature(block, nodeOrder, nil); err != nil {
 204                                 return false, err
 205                         }
 206
 207                         return true, nil
 208                 }
 209         }
 210         return false, nil
 211 }
 212
 213 // SignBlock signing the block if current node is consensus node
 214 func (b *bbft) SignBlock(block *types.Block) ([]byte, error) {
 215         var xprv chainkd.XPrv
 216         xpub := [64]byte(xprv.XPub())
 217         blockHash := block.Hash()
 218         node, err := b.consensusNodeManager.getConsensusNode(&blockHash, hex.EncodeToString(xpub[:]))
 219         if err != nil && err != errNotFoundConsensusNode {
 220                 return nil, err
 221         }
 222
 223         if node == nil {
 224                 return nil, nil
 225         }
 226
 227         signature := xprv.Sign(block.Hash().Bytes())
 228         block.Witness[node.order] = signature
 229         return signature, nil
 230 }
 231
 232 func (b *bbft) updateBlockSignature(block *types.Block, nodeOrder uint64, signature []byte) error {
 233         blockHash := block.Hash()
 234         blockNode := b.consensusNodeManager.blockIndex.GetNode(&blockHash)
 235
 236         if len(signature) != 0 {
 237                 if err := blockNode.BlockWitness.Set(uint32(nodeOrder)); err != nil {
 238                         return err
 239                 }
 240         } else {
 241                 if err := blockNode.BlockWitness.Clean(uint32(nodeOrder)); err != nil {
 242                         return err
 243                 }
 244         }
 245
 246         block.Witness[nodeOrder] = signature
 247         txStatus, err := b.consensusNodeManager.store.GetTransactionStatus(&blockHash)
 248         if err != nil {
 249                 return err
 250         }
 251
 252         return b.consensusNodeManager.store.SaveBlock(block, txStatus)
 253 }