protocol/bbft.go

   1 package protocol
   2
   3 import (
   4         "encoding/hex"
   5         "fmt"
   6
   7         log "github.com/sirupsen/logrus"
   8
   9         "github.com/vapor/config"
  10         "github.com/vapor/errors"
  11         "github.com/vapor/event"
  12         "github.com/vapor/protocol/bc"
  13         "github.com/vapor/protocol/bc/types"
  14         "github.com/vapor/protocol/state"
  15 )
  16
  17 const (
  18         maxSignatureCacheSize = 10000
  19 )
  20
  21 var (
  22         errVotingOperationOverFlow = errors.New("voting operation result overflow")
  23         errDoubleSignBlock         = errors.New("the consensus is double sign in same height of different block")
  24         errInvalidSignature        = errors.New("the signature of block is invalid")
  25         errSignForkChain           = errors.New("can not sign fork before the irreversible block")
  26 )
  27
  28 func signCacheKey(blockHash, pubkey string) string {
  29         return fmt.Sprintf("%s:%s", blockHash, pubkey)
  30 }
  31
  32 func (c *Chain) isIrreversible(blockNode *state.BlockNode) bool {
  33         consensusNodes, err := c.consensusNodeManager.getConsensusNodes(blockNode.Parent)
  34         if err != nil {
  35                 return false
  36         }
  37
  38         signCount := 0
  39         for i := 0; i < len(consensusNodes); i++ {
  40                 if blockNode.BlockWitness[i] != nil {
  41                         signCount++
  42                 }
  43         }
  44
  45         return signCount > len(consensusNodes)*2/3
  46 }
  47
  48 // GetVoteResultByHash return vote result by block hash
  49 func (c *Chain) GetVoteResultByHash(blockHash *bc.Hash) (*state.VoteResult, error) {
  50         blockNode, err := c.store.GetBlockNode(blockHash)
  51         if err != nil {
  52                 return nil, err
  53         }
  54         return c.consensusNodeManager.getVoteResult(state.CalcVoteSeq(blockNode.Height), blockNode)
  55 }
  56
  57 // IsBlocker returns whether the consensus node is a blocker at the specified time
  58 func (c *Chain) IsBlocker(prevBlockHash *bc.Hash, pubKey string, timeStamp uint64) (bool, error) {
  59         xPub, err := c.consensusNodeManager.getBlocker(prevBlockHash, timeStamp)
  60         if err != nil {
  61                 return false, err
  62         }
  63         return xPub == pubKey, nil
  64 }
  65
  66 // GetBlock return blocker by specified timestamp
  67 func (c *Chain) GetBlocker(prevBlockHash *bc.Hash, timestamp uint64) (string, error) {
  68         return c.consensusNodeManager.getBlocker(prevBlockHash, timestamp)
  69 }
  70
  71 // ProcessBlockSignature process the received block signature messages
  72 // return whether a block become irreversible, if so, the chain module must update status
  73 func (c *Chain) ProcessBlockSignature(signature, xPub []byte, blockHash *bc.Hash) error {
  74         xpubStr := hex.EncodeToString(xPub[:])
  75         blockNode, err := c.store.GetBlockNode(blockHash)
  76         if err != nil {
  77                 return err
  78         }
  79
  80         // save the signature if the block is not exist
  81         if blockNode == nil {
  82                 cacheKey := signCacheKey(blockHash.String(), xpubStr)
  83                 c.signatureCache.Add(cacheKey, signature)
  84                 return nil
  85         }
  86
  87         consensusNode, err := c.consensusNodeManager.getConsensusNode(blockNode.Parent, xpubStr)
  88         if err != nil {
  89                 return err
  90         }
  91
  92         if blockNode.BlockWitness[int64(consensusNode.Order)] != nil {
  93                 return nil
  94         }
  95
  96         c.cond.L.Lock()
  97         defer c.cond.L.Unlock()
  98         if err := c.checkNodeSign(blockNode.BlockHeader(), consensusNode, signature); err != nil {
  99                 return err
 100         }
 101
 102         if err := c.updateBlockSignature(blockNode, consensusNode.Order, signature); err != nil {
 103                 return err
 104         }
 105         return c.eventDispatcher.Post(event.BlockSignatureEvent{BlockHash: *blockHash, Signature: signature, XPub: xPub})
 106 }
 107
 108 // validateSign verify the signatures of block, and return the number of correct signature
 109 // if some signature is invalid, they will be reset to nil
 110 // if the block has not the signature of blocker, it will return error
 111 func (c *Chain) validateSign(block *types.Block) error {
 112         consensusNodeMap, err := c.consensusNodeManager.getConsensusNodes(&block.PreviousBlockHash)
 113         if err != nil {
 114                 return err
 115         }
 116
 117         hasBlockerSign := false
 118         blockHash := block.Hash()
 119         for pubKey, node := range consensusNodeMap {
 120                 if len(block.Witness) <= int(node.Order) {
 121                         continue
 122                 }
 123
 124                 if block.Get(node.Order) == nil {
 125                         cachekey := signCacheKey(blockHash.String(), pubKey)
 126                         if signature, ok := c.signatureCache.Get(cachekey); ok {
 127                                 block.Set(node.Order, signature.([]byte))
 128                         } else {
 129                                 continue
 130                         }
 131                 }
 132
 133                 if err := c.checkNodeSign(&block.BlockHeader, node, block.Get(node.Order)); err == errDoubleSignBlock {
 134                         log.WithFields(log.Fields{"module": logModule, "blockHash": blockHash.String(), "pubKey": pubKey}).Warn("the consensus node double sign the same height of different block")
 135                         block.Delete(node.Order)
 136                         continue
 137                 } else if err != nil {
 138                         return err
 139                 }
 140
 141                 isBlocker, err := c.IsBlocker(&block.PreviousBlockHash, pubKey, block.Timestamp)
 142                 if err != nil {
 143                         return err
 144                 }
 145
 146                 if isBlocker {
 147                         hasBlockerSign = true
 148                 }
 149
 150         }
 151
 152         if !hasBlockerSign {
 153                 return errors.New("the block has no signature of the blocker")
 154         }
 155         return nil
 156 }
 157
 158 func (c *Chain) checkNodeSign(bh *types.BlockHeader, consensusNode *state.ConsensusNode, signature []byte) error {
 159         if !consensusNode.XPub.Verify(bh.Hash().Bytes(), signature) {
 160                 return errInvalidSignature
 161         }
 162
 163         blockHashes, err := c.consensusNodeManager.store.GetBlockHashesByHeight(bh.Height)
 164         if err != nil {
 165                 return err
 166         }
 167
 168         for _, blockHash := range blockHashes {
 169                 if *blockHash == bh.Hash() {
 170                         continue
 171                 }
 172
 173                 blockNode, err := c.store.GetBlockNode(blockHash)
 174                 if err != nil {
 175                         return err
 176                 }
 177
 178                 consensusNode, err := c.consensusNodeManager.getConsensusNode(blockNode.Parent, consensusNode.XPub.String())
 179                 if err != nil && err != errNotFoundConsensusNode {
 180                         return err
 181                 }
 182
 183                 if err == errNotFoundConsensusNode {
 184                         continue
 185                 }
 186
 187                 if blockNode.BlockWitness[consensusNode.Order] != nil {
 188                         return errDoubleSignBlock
 189                 }
 190         }
 191         return nil
 192 }
 193
 194 // SignBlock signing the block if current node is consensus node
 195 func (c *Chain) SignBlock(block *types.Block) ([]byte, error) {
 196         xprv := config.CommonConfig.PrivateKey()
 197         xpubStr := xprv.XPub().String()
 198         node, err := c.consensusNodeManager.getConsensusNode(&block.PreviousBlockHash, xpubStr)
 199         if err == errNotFoundConsensusNode {
 200                 return nil, nil
 201         } else if err != nil {
 202                 return nil, err
 203         }
 204
 205         c.cond.L.Lock()
 206         defer c.cond.L.Unlock()
 207         //check double sign in same block height
 208         blockHashes, err := c.consensusNodeManager.store.GetBlockHashesByHeight(block.Height)
 209         if err != nil {
 210                 return nil, err
 211         }
 212
 213         for _, hash := range blockHashes {
 214                 blockNode, err := c.consensusNodeManager.store.GetBlockNode(hash)
 215                 if err != nil {
 216                         return nil, err
 217                 }
 218
 219                 // Has already signed the same height block
 220                 if blockNode.BlockWitness[int64(node.Order)] != nil {
 221                         return nil, nil
 222                 }
 223         }
 224
 225         blockNode, err := c.store.GetBlockNode(&block.PreviousBlockHash)
 226         if err != nil {
 227                 return nil, err
 228         }
 229
 230         for {
 231                 if blockNode.Height <= c.bestIrreversibleNode.Height {
 232                         return nil, errSignForkChain
 233                 }
 234
 235                 if _, err := c.store.GetBlockHashByHeight(block.Height); err != nil {
 236                         break
 237                 }
 238
 239                 blockNode, err = c.store.GetBlockNode(blockNode.Parent)
 240                 if err != nil {
 241                         return nil, err
 242                 }
 243         }
 244
 245         signature := block.Get(node.Order)
 246         if len(signature) == 0 {
 247                 signature = xprv.Sign(block.Hash().Bytes())
 248                 block.Set(node.Order, signature)
 249         }
 250         return signature, nil
 251 }
 252
 253 func (c *Chain) updateBlockSignature(blockNode *state.BlockNode, nodeOrder uint64, signature []byte) error {
 254         blockHeader, err := c.store.GetBlockHeader(&blockNode.Hash)
 255         if err != nil {
 256                 return err
 257         }
 258
 259         blockHeader.Set(nodeOrder, signature)
 260
 261         if err := c.store.SaveBlockHeader(blockHeader); err != nil {
 262                 return err
 263         }
 264
 265         if c.isIrreversible(blockNode) && blockNode.Height > c.bestIrreversibleNode.Height {
 266                 if err := c.store.SaveChainStatus(c.bestNode, blockNode, state.NewUtxoViewpoint(), []*state.VoteResult{}); err != nil {
 267                         return err
 268                 }
 269
 270                 c.bestIrreversibleNode = blockNode
 271         }
 272         return nil
 273 }