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.Hash)
  34         if err != nil {
  35                 return false
  36         }
  37
  38         signCount := 0
  39         for i := 0; i < len(consensusNodes); i++ {
  40                 if ok, _ := blockNode.BlockWitness.Test(uint32(i)); ok {
  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 := c.index.GetNode(blockHash)
  51         return c.consensusNodeManager.getVoteResult(state.CalcVoteSeq(blockNode.Height), blockNode)
  52 }
  53
  54 // IsBlocker returns whether the consensus node is a blocker at the specified time
  55 func (c *Chain) IsBlocker(prevBlockHash *bc.Hash, pubkey string, timeStamp uint64) (bool, error) {
  56         return c.consensusNodeManager.isBlocker(prevBlockHash, pubkey, timeStamp)
  57 }
  58
  59 // ProcessBlockSignature process the received block signature messages
  60 // return whether a block become irreversible, if so, the chain module must update status
  61 func (c *Chain) ProcessBlockSignature(signature, xPub []byte, blockHash *bc.Hash) error {
  62         xpubStr := hex.EncodeToString(xPub[:])
  63         blockNode := c.index.GetNode(blockHash)
  64         // save the signature if the block is not exist
  65         if blockNode == nil {
  66                 cacheKey := signCacheKey(blockHash.String(), xpubStr)
  67                 c.signatureCache.Add(cacheKey, signature)
  68                 return nil
  69         }
  70
  71         consensusNode, err := c.consensusNodeManager.getConsensusNode(&blockNode.Parent.Hash, xpubStr)
  72         if err != nil {
  73                 return err
  74         }
  75
  76         if exist, _ := blockNode.BlockWitness.Test(uint32(consensusNode.Order)); exist {
  77                 return nil
  78         }
  79
  80         c.cond.L.Lock()
  81         defer c.cond.L.Unlock()
  82         if err := c.checkNodeSign(blockNode.BlockHeader(), consensusNode, signature); err != nil {
  83                 return err
  84         }
  85
  86         if err := c.updateBlockSignature(blockNode, consensusNode.Order, signature); err != nil {
  87                 return err
  88         }
  89         return c.eventDispatcher.Post(event.BlockSignatureEvent{BlockHash: *blockHash, Signature: signature, XPub: xPub})
  90 }
  91
  92 // validateSign verify the signatures of block, and return the number of correct signature
  93 // if some signature is invalid, they will be reset to nil
  94 // if the block has not the signature of blocker, it will return error
  95 func (c *Chain) validateSign(block *types.Block) error {
  96         consensusNodeMap, err := c.consensusNodeManager.getConsensusNodes(&block.PreviousBlockHash)
  97         if err != nil {
  98                 return err
  99         }
 100
 101         hasBlockerSign := false
 102         blockHash := block.Hash()
 103         for pubKey, node := range consensusNodeMap {
 104                 if len(block.Witness) <= int(node.Order) {
 105                         continue
 106                 }
 107
 108                 if block.Witness[node.Order] == nil {
 109                         cachekey := signCacheKey(blockHash.String(), pubKey)
 110                         if signature, ok := c.signatureCache.Get(cachekey); ok {
 111                                 block.Witness[node.Order] = signature.([]byte)
 112                         } else {
 113                                 continue
 114                         }
 115                 }
 116
 117                 if err := c.checkNodeSign(&block.BlockHeader, node, block.Witness[node.Order]); err == errDoubleSignBlock {
 118                         log.WithFields(log.Fields{"module": logModule, "blockHash": blockHash.String(), "pubKey": pubKey}).Warn("the consensus node double sign the same height of different block")
 119                         block.Witness[node.Order] = nil
 120                         continue
 121                 } else if err != nil {
 122                         return err
 123                 }
 124
 125                 isBlocker, err := c.consensusNodeManager.isBlocker(&block.PreviousBlockHash, pubKey, block.Timestamp)
 126                 if err != nil {
 127                         return err
 128                 }
 129
 130                 if isBlocker {
 131                         hasBlockerSign = true
 132                 }
 133
 134         }
 135
 136         if !hasBlockerSign {
 137                 return errors.New("the block has no signature of the blocker")
 138         }
 139         return nil
 140 }
 141
 142 func (c *Chain) checkNodeSign(bh *types.BlockHeader, consensusNode *state.ConsensusNode, signature []byte) error {
 143         if !consensusNode.XPub.Verify(bh.Hash().Bytes(), signature) {
 144                 return errInvalidSignature
 145         }
 146
 147         blockNodes := c.consensusNodeManager.blockIndex.NodesByHeight(bh.Height)
 148         for _, blockNode := range blockNodes {
 149                 if blockNode.Hash == bh.Hash() {
 150                         continue
 151                 }
 152
 153                 consensusNode, err := c.consensusNodeManager.getConsensusNode(&blockNode.Parent.Hash, consensusNode.XPub.String())
 154                 if err != nil && err != errNotFoundConsensusNode {
 155                         return err
 156                 }
 157
 158                 if err == errNotFoundConsensusNode {
 159                         continue
 160                 }
 161
 162                 if ok, err := blockNode.BlockWitness.Test(uint32(consensusNode.Order)); err == nil && ok {
 163                         return errDoubleSignBlock
 164                 }
 165         }
 166         return nil
 167 }
 168
 169 // SignBlock signing the block if current node is consensus node
 170 func (c *Chain) SignBlock(block *types.Block) ([]byte, error) {
 171         xprv := config.CommonConfig.PrivateKey()
 172         xpubStr := xprv.XPub().String()
 173         node, err := c.consensusNodeManager.getConsensusNode(&block.PreviousBlockHash, xpubStr)
 174         if err == errNotFoundConsensusNode {
 175                 return nil, nil
 176         } else if err != nil {
 177                 return nil, err
 178         }
 179
 180         c.cond.L.Lock()
 181         defer c.cond.L.Unlock()
 182         //check double sign in same block height
 183         blockNodes := c.consensusNodeManager.blockIndex.NodesByHeight(block.Height)
 184         for _, blockNode := range blockNodes {
 185                 // Has already signed the same height block
 186                 if ok, err := blockNode.BlockWitness.Test(uint32(node.Order)); err == nil && ok {
 187                         return nil, nil
 188                 }
 189         }
 190
 191         for blockNode := c.index.GetNode(&block.PreviousBlockHash); !c.index.InMainchain(blockNode.Hash); blockNode = blockNode.Parent {
 192                 if blockNode.Height <= c.bestIrreversibleNode.Height {
 193                         return nil, errSignForkChain
 194                 }
 195         }
 196
 197         signature := block.Witness[node.Order]
 198         if len(signature) == 0 {
 199                 signature = xprv.Sign(block.Hash().Bytes())
 200                 block.Witness[node.Order] = signature
 201         }
 202         return signature, nil
 203 }
 204
 205 func (c *Chain) updateBlockSignature(blockNode *state.BlockNode, nodeOrder uint64, signature []byte) error {
 206         if err := blockNode.BlockWitness.Set(uint32(nodeOrder)); err != nil {
 207                 return err
 208         }
 209
 210         block, err := c.store.GetBlock(&blockNode.Hash)
 211         if err != nil {
 212                 return err
 213         }
 214
 215         block.Witness[nodeOrder] = signature
 216         txStatus, err := c.store.GetTransactionStatus(&blockNode.Hash)
 217         if err != nil {
 218                 return err
 219         }
 220
 221         if err := c.store.SaveBlock(block, txStatus); err != nil {
 222                 return err
 223         }
 224
 225         if c.isIrreversible(blockNode) && blockNode.Height > c.bestIrreversibleNode.Height {
 226                 if err := c.store.SaveChainStatus(c.bestNode, blockNode, state.NewUtxoViewpoint(), []*state.VoteResult{}); err != nil {
 227                         return err
 228                 }
 229
 230                 c.bestIrreversibleNode = blockNode
 231         }
 232         return nil
 233 }