internal/ethapi: fix hex handling for eth_sign, personal_{sign,recover}

This commit is contained in:
Felix Lange 2016-12-16 11:19:03 +01:00
parent 38827dd9ca
commit 3e4a04f34d
1 changed files with 14 additions and 29 deletions

View File

@ -28,6 +28,7 @@ import (
"github.com/ethereum/ethash"
"github.com/ethereum/go-ethereum/accounts"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/core"
"github.com/ethereum/go-ethereum/core/types"
"github.com/ethereum/go-ethereum/core/vm"
@ -289,14 +290,14 @@ func (s *PrivateAccountAPI) SendTransaction(ctx context.Context, args SendTxArgs
}
// signHash is a helper function that calculates a hash for the given message that can be
// safely used to calculate a signature from. The hash is calulcated with:
// keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
func signHash(message string) []byte {
data := common.FromHex(message)
// Give context to the signed message. This prevents an adversery to sign a tx.
// It has no cryptographic purpose.
// safely used to calculate a signature from.
//
// The hash is calulcated as
// keccak256("\x19Ethereum Signed Message:\n"${message length}${message}).
//
// This gives context to the signed message and prevents signing of transactions.
func signHash(data []byte) []byte {
msg := fmt.Sprintf("\x19Ethereum Signed Message:\n%d%s", len(data), data)
// Always hash, this prevents choosen plaintext attacks that can extract key information
return crypto.Keccak256([]byte(msg))
}
@ -306,13 +307,8 @@ func signHash(message string) []byte {
// The key used to calculate the signature is decrypted with the given password.
//
// https://github.com/ethereum/go-ethereum/wiki/Management-APIs#personal_sign
func (s *PrivateAccountAPI) Sign(ctx context.Context, message string, addr common.Address, passwd string) (string, error) {
hash := signHash(message)
signature, err := s.b.AccountManager().SignWithPassphrase(addr, passwd, hash)
if err != nil {
return "0x", err
}
return common.ToHex(signature), nil
func (s *PrivateAccountAPI) Sign(ctx context.Context, data hexutil.Bytes, addr common.Address, passwd string) (hexutil.Bytes, error) {
return s.b.AccountManager().SignWithPassphrase(addr, passwd, signHash(data))
}
// EcRecover returns the address for the account that was used to create the signature.
@ -322,29 +318,20 @@ func (s *PrivateAccountAPI) Sign(ctx context.Context, message string, addr commo
// addr = ecrecover(hash, signature)
//
// https://github.com/ethereum/go-ethereum/wiki/Management-APIs#personal_ecRecover
func (s *PrivateAccountAPI) EcRecover(ctx context.Context, message string, signature string) (common.Address, error) {
var (
hash = signHash(message)
sig = common.FromHex(signature)
)
func (s *PrivateAccountAPI) EcRecover(ctx context.Context, data, sig hexutil.Bytes) (common.Address, error) {
if len(sig) != 65 {
return common.Address{}, fmt.Errorf("signature must be 65 bytes long")
}
// see crypto.Ecrecover description
if sig[64] == 27 || sig[64] == 28 {
sig[64] -= 27
}
rpk, err := crypto.Ecrecover(hash, sig)
rpk, err := crypto.Ecrecover(signHash(data), sig)
if err != nil {
return common.Address{}, err
}
pubKey := crypto.ToECDSAPub(rpk)
recoveredAddr := crypto.PubkeyToAddress(*pubKey)
return recoveredAddr, nil
}
@ -1116,10 +1103,8 @@ func (s *PublicTransactionPoolAPI) SendRawTransaction(ctx context.Context, encod
// The account associated with addr must be unlocked.
//
// https://github.com/ethereum/wiki/wiki/JSON-RPC#eth_sign
func (s *PublicTransactionPoolAPI) Sign(addr common.Address, message string) (string, error) {
hash := signHash(message)
signature, err := s.b.AccountManager().SignEthereum(addr, hash)
return common.ToHex(signature), err
func (s *PublicTransactionPoolAPI) Sign(addr common.Address, data hexutil.Bytes) (hexutil.Bytes, error) {
return s.b.AccountManager().SignEthereum(addr, signHash(data))
}
// SignTransactionArgs represents the arguments to sign a transaction.