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