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