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add chain id into sign bytes to avoid replay attack (#18)
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unclezoro authored Jul 9, 2020
1 parent 8d48b0d commit f4816ee
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Showing 3 changed files with 20 additions and 18 deletions.
25 changes: 13 additions & 12 deletions consensus/parlia/parlia.go
Original file line number Diff line number Diff line change
Expand Up @@ -156,7 +156,7 @@ func isToSystemContract(to common.Address) bool {
}

// ecrecover extracts the Ethereum account address from a signed header.
func ecrecover(header *types.Header, sigCache *lru.ARCCache) (common.Address, error) {
func ecrecover(header *types.Header, sigCache *lru.ARCCache, chainId *big.Int) (common.Address, error) {
// If the signature's already cached, return that
hash := header.Hash()
if address, known := sigCache.Get(hash); known {
Expand All @@ -169,7 +169,7 @@ func ecrecover(header *types.Header, sigCache *lru.ARCCache) (common.Address, er
signature := header.Extra[len(header.Extra)-extraSeal:]

// Recover the public key and the Ethereum address
pubkey, err := crypto.Ecrecover(SealHash(header).Bytes(), signature)
pubkey, err := crypto.Ecrecover(SealHash(header, chainId).Bytes(), signature)
if err != nil {
return common.Address{}, err
}
Expand All @@ -187,9 +187,9 @@ func ecrecover(header *types.Header, sigCache *lru.ARCCache) (common.Address, er
// Note, the method requires the extra data to be at least 65 bytes, otherwise it
// panics. This is done to avoid accidentally using both forms (signature present
// or not), which could be abused to produce different hashes for the same header.
func ParliaRLP(header *types.Header) []byte {
func ParliaRLP(header *types.Header, chainId *big.Int) []byte {
b := new(bytes.Buffer)
encodeSigHeader(b, header)
encodeSigHeader(b, header, chainId)
return b.Bytes()
}

Expand Down Expand Up @@ -498,7 +498,7 @@ func (p *Parlia) snapshot(chain consensus.ChainReader, number uint64, hash commo
headers[i], headers[len(headers)-1-i] = headers[len(headers)-1-i], headers[i]
}

snap, err := snap.apply(headers, chain, parents)
snap, err := snap.apply(headers, chain, parents, p.chainConfig.ChainID)
if err != nil {
return nil, err
}
Expand Down Expand Up @@ -546,7 +546,7 @@ func (p *Parlia) verifySeal(chain consensus.ChainReader, header *types.Header, p
}

// Resolve the authorization key and check against validators
signer, err := ecrecover(header, p.signatures)
signer, err := ecrecover(header, p.signatures, p.chainConfig.ChainID)
if err != nil {
return err
}
Expand Down Expand Up @@ -821,7 +821,7 @@ func (p *Parlia) Seal(chain consensus.ChainReader, block *types.Block, results c
log.Info("Sealing block with", "number", number, "delay", delay, "headerDifficulty", header.Difficulty, "val", val.Hex())

// Sign all the things!
sig, err := signFn(accounts.Account{Address: val}, accounts.MimetypeParlia, ParliaRLP(header))
sig, err := signFn(accounts.Account{Address: val}, accounts.MimetypeParlia, ParliaRLP(header, p.chainConfig.ChainID))
if err != nil {
return err
}
Expand All @@ -839,7 +839,7 @@ func (p *Parlia) Seal(chain consensus.ChainReader, block *types.Block, results c
select {
case results <- block.WithSeal(header):
default:
log.Warn("Sealing result is not read by miner", "sealhash", SealHash(header))
log.Warn("Sealing result is not read by miner", "sealhash", SealHash(header, p.chainConfig.ChainID))
}
}()

Expand Down Expand Up @@ -869,7 +869,7 @@ func CalcDifficulty(snap *Snapshot, signer common.Address) *big.Int {

// SealHash returns the hash of a block prior to it being sealed.
func (p *Parlia) SealHash(header *types.Header) common.Hash {
return SealHash(header)
return SealHash(header, p.chainConfig.ChainID)
}

// APIs implements consensus.Engine, returning the user facing RPC API to query snapshot.
Expand Down Expand Up @@ -1109,15 +1109,16 @@ func (p *Parlia) applyTransaction(

// =========================== utility function ==========================
// SealHash returns the hash of a block prior to it being sealed.
func SealHash(header *types.Header) (hash common.Hash) {
func SealHash(header *types.Header, chainId *big.Int) (hash common.Hash) {
hasher := sha3.NewLegacyKeccak256()
encodeSigHeader(hasher, header)
encodeSigHeader(hasher, header, chainId)
hasher.Sum(hash[:0])
return hash
}

func encodeSigHeader(w io.Writer, header *types.Header) {
func encodeSigHeader(w io.Writer, header *types.Header, chainId *big.Int) {
err := rlp.Encode(w, []interface{}{
chainId,
header.ParentHash,
header.UncleHash,
header.Coinbase,
Expand Down
5 changes: 3 additions & 2 deletions consensus/parlia/snapshot.go
Original file line number Diff line number Diff line change
Expand Up @@ -20,6 +20,7 @@ import (
"bytes"
"encoding/json"
"errors"
"math/big"
"sort"

"github.com/ethereum/go-ethereum/common"
Expand Down Expand Up @@ -123,7 +124,7 @@ func (s *Snapshot) copy() *Snapshot {
return cpy
}

func (s *Snapshot) apply(headers []*types.Header, chain consensus.ChainReader, parents []*types.Header) (*Snapshot, error) {
func (s *Snapshot) apply(headers []*types.Header, chain consensus.ChainReader, parents []*types.Header, chainId *big.Int) (*Snapshot, error) {
// Allow passing in no headers for cleaner code
if len(headers) == 0 {
return s, nil
Expand Down Expand Up @@ -153,7 +154,7 @@ func (s *Snapshot) apply(headers []*types.Header, chain consensus.ChainReader, p
delete(snap.Recents, number-limit)
}
// Resolve the authorization key and check against signers
validator, err := ecrecover(header, s.sigCache)
validator, err := ecrecover(header, s.sigCache, chainId)
if err != nil {
return nil, err
}
Expand Down
8 changes: 4 additions & 4 deletions signer/core/signed_data.go
Original file line number Diff line number Diff line change
Expand Up @@ -285,7 +285,7 @@ func (api *SignerAPI) determineSignatureFormat(ctx context.Context, contentType
header.Extra = newExtra
}
// Get back the rlp data, encoded by us
sighash, parliaRlp, err := parliaHeaderHashAndRlp(header)
sighash, parliaRlp, err := parliaHeaderHashAndRlp(header, api.chainID)
if err != nil {
return nil, useEthereumV, err
}
Expand Down Expand Up @@ -351,13 +351,13 @@ func cliqueHeaderHashAndRlp(header *types.Header) (hash, rlp []byte, err error)
return hash, rlp, err
}

func parliaHeaderHashAndRlp(header *types.Header) (hash, rlp []byte, err error) {
func parliaHeaderHashAndRlp(header *types.Header, chainId *big.Int) (hash, rlp []byte, err error) {
if len(header.Extra) < 65 {
err = fmt.Errorf("clique header extradata too short, %d < 65", len(header.Extra))
return
}
rlp = parlia.ParliaRLP(header)
hash = parlia.SealHash(header).Bytes()
rlp = parlia.ParliaRLP(header, chainId)
hash = parlia.SealHash(header, chainId).Bytes()
return hash, rlp, err
}

Expand Down

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