Merge pull request #1718 from WeiLoy/feature-mainnet-launch

Limit the length of the Extra field in the block header
PlatONnetwork · Mar 5, 2021 · 62b9a90 · 62b9a90
2 parents 983c60c + 6592d2d
commit 62b9a90
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Showing 4 changed files with 23 additions and 4 deletions.
diff --git a/consensus/cbft/cbft.go b/consensus/cbft/cbft.go
@@ -648,6 +648,11 @@ func (cbft *Cbft) VerifyHeader(chain consensus.ChainReader, header *types.Header
 		return fmt.Errorf("verify header fail, missing signature, number:%d, hash:%s", header.Number.Uint64(), header.Hash().String())
 	}
 
+	if header.IsInvalid() {
+		cbft.log.Error("Verify header fail, Extra field is too long", "number", header.Number, "hash", header.CacheHash())
+		return fmt.Errorf("verify header fail, Extra field is too long, number:%d, hash:%s", header.Number.Uint64(), header.CacheHash().String())
+	}
+
 	if err := cbft.validatorPool.VerifyHeader(header); err != nil {
 		cbft.log.Error("Verify header fail", "number", header.Number, "hash", header.Hash(), "err", err)
 		return fmt.Errorf("verify header fail, number:%d, hash:%s, err:%s", header.Number.Uint64(), header.Hash().String(), err.Error())

diff --git a/consensus/sign.go b/consensus/sign.go
@@ -56,7 +56,7 @@ func SigHash(header *types.Header) (hash common.Hash) {
 		header.GasLimit,
 		header.GasUsed,
 		header.Time,
-		header.Extra[:len(header.Extra)-65], // Yes, this will panic if extra is too short
+		header.ExtraData(),
 		header.Nonce,
 	})
 	hasher.Sum(hash[:0])
@@ -74,7 +74,7 @@ func Ecrecover(header *types.Header, sigcache *lru.ARCCache) (common.Address, er
 	if len(header.Extra) < ExtraSeal {
 		return common.Address{}, ErrMissingSignature
 	}
-	signature := header.Extra[len(header.Extra)-ExtraSeal:]
+	signature := header.Signature()
 
 	// Recover the public key and the Ethereum address
 	pubkey, err := crypto.Ecrecover(SigHash(header).Bytes(), signature)

diff --git a/core/genesis.go b/core/genesis.go
@@ -501,7 +501,7 @@ func DefaultGenesisBlock() *Genesis {
 		Config:    params.MainnetChainConfig,
 		Nonce:     hexutil.MustDecode("0x024c6378c176ef6c717cd37a74c612c9abd615d13873ff6651e3d352b31cb0b2e1"),
 		Timestamp: 0,
-		ExtraData: hexutil.MustDecode("0xd782070186706c61746f6e86676f312e3131856c696e757800000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000"),
+		ExtraData: []byte("Let us compute"),
 		GasLimit:  params.GenesisGasLimit,
 		Alloc: map[common.Address]GenesisAccount{
 			vm.RewardManagerPoolAddr: {Balance: rewardMgrPoolIssue},

diff --git a/core/types/block.go b/core/types/block.go
@@ -40,6 +40,8 @@ import (
 
 var (
 	EmptyRootHash = DeriveSha(Transactions{})
+	// Extra field in the block header, maximum length
+	ExtraMaxSize = 97
 )
 
 // BlockNonce is an 81-byte vrf proof containing random numbers
@@ -180,7 +182,19 @@ func (h *Header) Signature() []byte {
 	if len(h.Extra) < 32 {
 		return []byte{}
 	}
-	return h.Extra[32:]
+	return h.Extra[32:97]
+}
+
+func (h *Header) ExtraData() []byte {
+	if len(h.Extra) < 32 {
+		return []byte{}
+	}
+	return h.Extra[:32]
+}
+
+// Check whether the Extra field exceeds the limit size
+func (h *Header) IsInvalid() bool {
+	return len(h.Extra) > ExtraMaxSize
 }
 
 // hasherPool holds Keccak hashers.