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/config"
  11         "github.com/vapor/crypto/ed25519"
  12         "github.com/vapor/crypto/ed25519/chainkd"
  13         "github.com/vapor/errors"
  14         "github.com/vapor/event"
  15         "github.com/vapor/protocol/bc"
  16         "github.com/vapor/protocol/bc/types"
  17         "github.com/vapor/protocol/state"
  18 )
  19
  20 const (
  21         maxSignatureCacheSize = 10000
  22 )
  23
  24 var (
  25         errVotingOperationOverFlow = errors.New("voting operation result overflow")
  26         errDoubleSignBlock         = errors.New("the consensus is double sign in same height of different block")
  27         errInvalidSignature        = errors.New("the signature of block is invalid")
  28 )
  29
  30 type bbft struct {
  31         consensusNodeManager *consensusNodeManager
  32         orphanManage         *OrphanManage
  33         signatureCache       *lru.Cache
  34         eventDispatcher      *event.Dispatcher
  35 }
  36
  37 func newBbft(store Store, blockIndex *state.BlockIndex, orphanManage *OrphanManage, eventDispatcher *event.Dispatcher) *bbft {
  38         return &bbft{
  39                 orphanManage:         orphanManage,
  40                 consensusNodeManager: newConsensusNodeManager(store, blockIndex),
  41                 signatureCache:       lru.New(maxSignatureCacheSize),
  42                 eventDispatcher:      eventDispatcher,
  43         }
  44 }
  45
  46 func (b *bbft) isIrreversible(block *types.Block) bool {
  47         consensusNodes, err := b.consensusNodeManager.getConsensusNodesByVoteResult(&block.PreviousBlockHash)
  48         if err != nil {
  49                 return false
  50         }
  51
  52         signNum, err := b.validateSign(block)
  53         if err != nil {
  54                 return false
  55         }
  56
  57         return signNum > (uint64(len(consensusNodes)) * 2 / 3)
  58 }
  59
  60 // NextLeaderTime returns the start time of the specified public key as the next leader node
  61 func (b *bbft) NextLeaderTimeRange(pubkey []byte, prevBlockHash *bc.Hash) (uint64, uint64, error) {
  62         return b.consensusNodeManager.nextLeaderTimeRange(pubkey, prevBlockHash)
  63 }
  64
  65 func (b *bbft) ApplyBlock(voteResultMap map[uint64]*state.VoteResult, block *types.Block) (err error) {
  66         return b.consensusNodeManager.applyBlock(voteResultMap, block)
  67 }
  68
  69 func (b *bbft) DetachBlock(voteResultMap map[uint64]*state.VoteResult, block *types.Block) error {
  70         return b.consensusNodeManager.detachBlock(voteResultMap, block)
  71 }
  72
  73 // ProcessBlockSignature process the received block signature messages
  74 // return whether a block become irreversible, if so, the chain module must update status
  75 func (b *bbft) ProcessBlockSignature(signature []byte, xPub [64]byte, blockHeight uint64, blockHash *bc.Hash) (bool, error) {
  76         block, err := b.consensusNodeManager.store.GetBlock(blockHash)
  77         if err != nil {
  78                 // block is not exist, save the signature
  79                 key := fmt.Sprintf("%s:%s", blockHash.String(), hex.EncodeToString(xPub[:]))
  80                 b.signatureCache.Add(key, signature)
  81                 return false, err
  82         }
  83
  84         consensusNode, err := b.consensusNodeManager.getConsensusNode(&block.PreviousBlockHash, hex.EncodeToString(xPub[:]))
  85         if err != nil {
  86                 return false, err
  87         }
  88
  89         if chainkd.XPub(xPub).Verify(blockHash.Bytes(), signature) {
  90                 return false, errInvalidSignature
  91         }
  92
  93         isDoubleSign, err := b.checkDoubleSign(consensusNode.order, blockHeight, *blockHash)
  94         if err != nil {
  95                 return false, err
  96         }
  97
  98         if isDoubleSign {
  99                 log.WithFields(log.Fields{"module": logModule, "blockHash": blockHash.String(), "xPub": hex.EncodeToString(xPub[:])}).Warn("the consensus node double sign the same height of different block")
 100                 return false, errDoubleSignBlock
 101         }
 102
 103         orphanBlock, ok := b.orphanManage.Get(blockHash)
 104         if ok {
 105                 orphanBlock.Witness[consensusNode.order] = signature
 106                 return false, nil
 107         }
 108
 109         if err := b.updateBlockSignature(block, consensusNode.order, signature); err != nil {
 110                 return false, err
 111         }
 112
 113         return b.isIrreversible(block), nil
 114 }
 115
 116 // ValidateBlock verify whether the block is valid
 117 func (b *bbft) ValidateBlock(block *types.Block) error {
 118         signNum, err := b.validateSign(block)
 119         if err != nil {
 120                 return err
 121         }
 122
 123         if signNum == 0 {
 124                 return errors.New("no valid signature")
 125         }
 126         return nil
 127 }
 128
 129 // validateSign verify the signatures of block, and return the number of correct signature
 130 // if some signature is invalid, they will be reset to nil
 131 // if the block has not the signature of blocker, it will return error
 132 func (b *bbft) validateSign(block *types.Block) (uint64, error) {
 133         var correctSignNum uint64
 134         consensusNodeMap, err := b.consensusNodeManager.getConsensusNodesByVoteResult(&block.PreviousBlockHash)
 135         if err != nil {
 136                 return 0, err
 137         }
 138
 139         hasBlockerSign := false
 140         for pubKey, node := range consensusNodeMap {
 141                 if len(block.Witness) <= int(node.order) {
 142                         continue
 143                 }
 144
 145                 blockHash := block.Hash()
 146                 if block.Witness[node.order] == nil {
 147                         key := fmt.Sprintf("%s:%s", blockHash.String(), pubKey)
 148                         signature, ok := b.signatureCache.Get(key)
 149                         if ok {
 150                                 block.Witness[node.order] = signature.([]byte)
 151                         }
 152                 }
 153
 154                 pubKeyBytes, err := hex.DecodeString(pubKey)
 155                 if err != nil {
 156                         return 0, err
 157                 }
 158
 159                 if ed25519.Verify(ed25519.PublicKey(pubKeyBytes[:32]), 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(block, 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         xprv := config.CommonConfig.PrivateKey()
 216         xpub := [64]byte(xprv.XPub())
 217         node, err := b.consensusNodeManager.getConsensusNode(&block.PreviousBlockHash, hex.EncodeToString(xpub[:]))
 218         if err != nil && err != errNotFoundConsensusNode {
 219                 return nil, err
 220         }
 221
 222         if node == nil {
 223                 return nil, nil
 224         }
 225
 226         signature := block.Witness[node.order]
 227         if len(signature) == 0 {
 228                 signature = xprv.Sign(block.Hash().Bytes())
 229                 block.Witness[node.order] = signature
 230         }
 231         return signature, nil
 232 }
 233
 234 func (b *bbft) updateBlockSignature(block *types.Block, nodeOrder uint64, signature []byte) error {
 235         blockHash := block.Hash()
 236         blockNode := b.consensusNodeManager.blockIndex.GetNode(&blockHash)
 237
 238         if len(signature) != 0 {
 239                 if err := blockNode.BlockWitness.Set(uint32(nodeOrder)); err != nil {
 240                         return err
 241                 }
 242         } else {
 243                 if err := blockNode.BlockWitness.Clean(uint32(nodeOrder)); err != nil {
 244                         return err
 245                 }
 246         }
 247
 248         block.Witness[nodeOrder] = signature
 249         txStatus, err := b.consensusNodeManager.store.GetTransactionStatus(&blockHash)
 250         if err != nil {
 251                 return err
 252         }
 253
 254         return b.consensusNodeManager.store.SaveBlock(block, txStatus)
 255 }
 256
 257 // SetBlockIndex set the block index field
 258 func (b *bbft) SetBlockIndex(blockIndex *state.BlockIndex) {
 259         b.consensusNodeManager.blockIndex = blockIndex
 260 }