accounts, core, crypto, internal: use canonical sigs internally

This commit is contained in:
Péter Szilágyi 2016-12-16 14:18:18 +02:00
parent 0fac8cba47
commit b746cd7d31
No known key found for this signature in database
GPG key ID: E9AE538CEDF8293D
9 changed files with 58 additions and 153 deletions

View file

@ -52,7 +52,7 @@ func NewKeyedTransactor(key *ecdsa.PrivateKey) *TransactOpts {
if address != keyAddr {
return nil, errors.New("not authorized to sign this account")
}
signature, err := crypto.SignEthereum(signer.Hash(tx).Bytes(), key)
signature, err := crypto.Sign(signer.Hash(tx).Bytes(), key)
if err != nil {
return nil, err
}

View file

@ -136,13 +136,12 @@ func (am *Manager) DeleteAccount(a Account, passphrase string) error {
return err
}
// Sign calculates a ECDSA signature for the given hash.
// Note, Ethereum signatures have a particular format as described in the
// yellow paper. Use the SignEthereum function to calculate a signature
// in Ethereum format.
// Sign calculates a ECDSA signature for the given hash. The produced signature
// is in the canonical secp256k1 format (V = 0 or 1).
func (am *Manager) Sign(addr common.Address, hash []byte) ([]byte, error) {
am.mu.RLock()
defer am.mu.RUnlock()
unlockedKey, found := am.unlocked[addr]
if !found {
return nil, ErrLocked
@ -150,28 +149,16 @@ func (am *Manager) Sign(addr common.Address, hash []byte) ([]byte, error) {
return crypto.Sign(hash, unlockedKey.PrivateKey)
}
// SignEthereum calculates a ECDSA signature for the given hash.
// The signature has the format as described in the Ethereum yellow paper.
func (am *Manager) SignEthereum(addr common.Address, hash []byte) ([]byte, error) {
am.mu.RLock()
defer am.mu.RUnlock()
unlockedKey, found := am.unlocked[addr]
if !found {
return nil, ErrLocked
}
return crypto.SignEthereum(hash, unlockedKey.PrivateKey)
}
// SignWithPassphrase signs hash if the private key matching the given
// address can be decrypted with the given passphrase.
// SignWithPassphrase signs hash if the private key matching the given address
// can be decrypted with the given passphrase. The produced signature is in the
// canonical secp256k1 format (V = 0 or 1).
func (am *Manager) SignWithPassphrase(addr common.Address, passphrase string, hash []byte) (signature []byte, err error) {
_, key, err := am.getDecryptedKey(Account{Address: addr}, passphrase)
if err != nil {
return nil, err
}
defer zeroKey(key.PrivateKey)
return crypto.SignEthereum(hash, key.PrivateKey)
return crypto.Sign(hash, key.PrivateKey)
}
// Unlock unlocks the given account indefinitely.

View file

@ -53,7 +53,7 @@ func TestBlockEncoding(t *testing.T) {
tx1 := NewTransaction(0, common.HexToAddress("095e7baea6a6c7c4c2dfeb977efac326af552d87"), big.NewInt(10), big.NewInt(50000), big.NewInt(10), nil)
tx1, _ = tx1.WithSignature(HomesteadSigner{}, common.Hex2Bytes("9bea4c4daac7c7c52e093e6a4c35dbbcf8856f1af7b059ba20253e70848d094f8a8fae537ce25ed8cb5af9adac3f141af69bd515bd2ba031522df09b97dd72b11b"))
tx1, _ = tx1.WithSignature(HomesteadSigner{}, common.Hex2Bytes("9bea4c4daac7c7c52e093e6a4c35dbbcf8856f1af7b059ba20253e70848d094f8a8fae537ce25ed8cb5af9adac3f141af69bd515bd2ba031522df09b97dd72b100"))
fmt.Println(block.Transactions()[0].Hash())
fmt.Println(tx1.data)
fmt.Println(tx1.Hash())

View file

@ -199,7 +199,7 @@ func (tx *Transaction) UnmarshalJSON(input []byte) error {
var V byte
if isProtectedV((*big.Int)(dec.V)) {
V = normaliseV(NewEIP155Signer(deriveChainId((*big.Int)(dec.V))), (*big.Int)(dec.V))
V = byte((new(big.Int).Sub((*big.Int)(dec.V), deriveChainId((*big.Int)(dec.V))).Uint64()) - 35 + 27)
} else {
V = byte(((*big.Int)(dec.V)).Uint64())
}
@ -272,51 +272,6 @@ func (tx *Transaction) Size() common.StorageSize {
return common.StorageSize(c)
}
/*
// From returns the address derived from the signature (V, R, S) using secp256k1
// elliptic curve and an error if it failed deriving or upon an incorrect
// signature.
//
// From Uses the homestead consensus rules to determine whether the signature is
// valid.
//
// From caches the address, allowing it to be used regardless of
// Frontier / Homestead. however, the first time called it runs
// signature validations, so we need two versions. This makes it
// easier to ensure backwards compatibility of things like package rpc
// where eth_getblockbynumber uses tx.From() and needs to work for
// both txs before and after the first homestead block. Signatures
// valid in homestead are a subset of valid ones in Frontier)
func (tx *Transaction) From() (common.Address, error) {
if tx.signer == nil {
return common.Address{}, errNoSigner
}
if from := tx.from.Load(); from != nil {
return from.(common.Address), nil
}
pubkey, err := tx.signer.PublicKey(tx)
if err != nil {
return common.Address{}, err
}
var addr common.Address
copy(addr[:], crypto.Keccak256(pubkey[1:])[12:])
tx.from.Store(addr)
return addr, nil
}
// SignatureValues returns the ECDSA signature values contained in the transaction.
func (tx *Transaction) SignatureValues() (v byte, r *big.Int, s *big.Int, err error) {
if tx.signer == nil {
return 0, nil, nil,errNoSigner
}
return normaliseV(tx.signer, tx.data.V), new(big.Int).Set(tx.data.R),new(big.Int).Set(tx.data.S), nil
}
*/
// AsMessage returns the transaction as a core.Message.
//
// AsMessage requires a signer to derive the sender.

View file

@ -53,7 +53,7 @@ func MakeSigner(config *params.ChainConfig, blockNumber *big.Int) Signer {
// SignECDSA signs the transaction using the given signer and private key
func SignECDSA(s Signer, tx *Transaction, prv *ecdsa.PrivateKey) (*Transaction, error) {
h := s.Hash(tx)
sig, err := crypto.SignEthereum(h[:], prv)
sig, err := crypto.Sign(h[:], prv)
if err != nil {
return nil, err
}
@ -91,11 +91,6 @@ func Sender(signer Signer, tx *Transaction) (common.Address, error) {
return addr, nil
}
// SignatureValues returns the ECDSA signature values contained in the transaction.
func SignatureValues(signer Signer, tx *Transaction) (v byte, r *big.Int, s *big.Int) {
return normaliseV(signer, tx.data.V), new(big.Int).Set(tx.data.R), new(big.Int).Set(tx.data.S)
}
type Signer interface {
// Hash returns the rlp encoded hash for signatures
Hash(tx *Transaction) common.Hash
@ -143,7 +138,7 @@ func (s EIP155Signer) PublicKey(tx *Transaction) ([]byte, error) {
return nil, ErrInvalidChainId
}
V := normaliseV(s, tx.data.V)
V := byte((new(big.Int).Sub(tx.data.V, s.chainIdMul).Uint64()) - 35 + 27)
if !crypto.ValidateSignatureValues(V, tx.data.R, tx.data.S, true) {
return nil, ErrInvalidSig
}
@ -168,7 +163,7 @@ func (s EIP155Signer) PublicKey(tx *Transaction) ([]byte, error) {
}
// WithSignature returns a new transaction with the given signature.
// This signature needs to be formatted as described in the yellow paper (v+27).
// This signature needs to be in the canonical secp256k1 form (v = 0 or 1).
func (s EIP155Signer) WithSignature(tx *Transaction, sig []byte) (*Transaction, error) {
if len(sig) != 65 {
panic(fmt.Sprintf("wrong size for snature: got %d, want 65", len(sig)))
@ -179,7 +174,7 @@ func (s EIP155Signer) WithSignature(tx *Transaction, sig []byte) (*Transaction,
cpy.data.S = new(big.Int).SetBytes(sig[32:64])
cpy.data.V = new(big.Int).SetBytes([]byte{sig[64]})
if s.chainId.BitLen() > 0 {
cpy.data.V = big.NewInt(int64(sig[64] - 27 + 35))
cpy.data.V = big.NewInt(int64(sig[64] + 35))
cpy.data.V.Add(cpy.data.V, s.chainIdMul)
}
return cpy, nil
@ -201,7 +196,7 @@ func (s EIP155Signer) Hash(tx *Transaction) common.Hash {
func (s EIP155Signer) SigECDSA(tx *Transaction, prv *ecdsa.PrivateKey) (*Transaction, error) {
h := s.Hash(tx)
sig, err := crypto.SignEthereum(h[:], prv)
sig, err := crypto.Sign(h[:], prv)
if err != nil {
return nil, err
}
@ -218,7 +213,7 @@ func (s HomesteadSigner) Equal(s2 Signer) bool {
}
// WithSignature returns a new transaction with the given snature.
// This snature needs to be formatted as described in the yellow paper (v+27).
// This signature needs to be in the canonical secp256k1 form (v = 0 or 1).
func (hs HomesteadSigner) WithSignature(tx *Transaction, sig []byte) (*Transaction, error) {
if len(sig) != 65 {
panic(fmt.Sprintf("wrong size for snature: got %d, want 65", len(sig)))
@ -226,13 +221,13 @@ func (hs HomesteadSigner) WithSignature(tx *Transaction, sig []byte) (*Transacti
cpy := &Transaction{data: tx.data}
cpy.data.R = new(big.Int).SetBytes(sig[:32])
cpy.data.S = new(big.Int).SetBytes(sig[32:64])
cpy.data.V = new(big.Int).SetBytes([]byte{sig[64]})
cpy.data.V = new(big.Int).SetBytes([]byte{sig[64] + 27})
return cpy, nil
}
func (hs HomesteadSigner) SignECDSA(tx *Transaction, prv *ecdsa.PrivateKey) (*Transaction, error) {
h := hs.Hash(tx)
sig, err := crypto.SignEthereum(h[:], prv)
sig, err := crypto.Sign(h[:], prv)
if err != nil {
return nil, err
}
@ -274,7 +269,7 @@ func (s FrontierSigner) Equal(s2 Signer) bool {
}
// WithSignature returns a new transaction with the given snature.
// This snature needs to be formatted as described in the yellow paper (v+27).
// This signature needs to be in the canonical secp256k1 form (v = 0 or 1).
func (fs FrontierSigner) WithSignature(tx *Transaction, sig []byte) (*Transaction, error) {
if len(sig) != 65 {
panic(fmt.Sprintf("wrong size for snature: got %d, want 65", len(sig)))
@ -282,13 +277,13 @@ func (fs FrontierSigner) WithSignature(tx *Transaction, sig []byte) (*Transactio
cpy := &Transaction{data: tx.data}
cpy.data.R = new(big.Int).SetBytes(sig[:32])
cpy.data.S = new(big.Int).SetBytes(sig[32:64])
cpy.data.V = new(big.Int).SetBytes([]byte{sig[64]})
cpy.data.V = new(big.Int).SetBytes([]byte{sig[64] + 27})
return cpy, nil
}
func (fs FrontierSigner) SignECDSA(tx *Transaction, prv *ecdsa.PrivateKey) (*Transaction, error) {
h := fs.Hash(tx)
sig, err := crypto.SignEthereum(h[:], prv)
sig, err := crypto.Sign(h[:], prv)
if err != nil {
return nil, err
}
@ -336,18 +331,6 @@ func (fs FrontierSigner) PublicKey(tx *Transaction) ([]byte, error) {
return pub, nil
}
// normaliseV returns the Ethereum version of the V parameter
func normaliseV(s Signer, v *big.Int) byte {
if s, ok := s.(EIP155Signer); ok {
stdV := v.BitLen() <= 8 && (v.Uint64() == 27 || v.Uint64() == 28)
if s.chainId.BitLen() > 0 && !stdV {
nv := byte((new(big.Int).Sub(v, s.chainIdMul).Uint64()) - 35 + 27)
return nv
}
}
return byte(v.Uint64())
}
// deriveChainId derives the chain id from the given v parameter
func deriveChainId(v *big.Int) *big.Int {
if v.BitLen() <= 64 {

View file

@ -47,7 +47,7 @@ var (
common.FromHex("5544"),
).WithSignature(
HomesteadSigner{},
common.Hex2Bytes("98ff921201554726367d2be8c804a7ff89ccf285ebc57dff8ae4c44b9c19ac4a8887321be575c8095f789dd4c743dfe42c1820f9231f98a962b210e3ac2452a31c"),
common.Hex2Bytes("98ff921201554726367d2be8c804a7ff89ccf285ebc57dff8ae4c44b9c19ac4a8887321be575c8095f789dd4c743dfe42c1820f9231f98a962b210e3ac2452a301"),
)
)

View file

@ -199,14 +199,15 @@ func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error) {
}
// Sign calculates an ECDSA signature.
//
// This function is susceptible to choosen plaintext attacks that can leak
// information about the private key that is used for signing. Callers must
// be aware that the given hash cannot be choosen by an adversery. Common
// solution is to hash any input before calculating the signature.
//
// Note: the calculated signature is not Ethereum compliant. The yellow paper
// dictates Ethereum singature to have a V value with and offset of 27 v in [27,28].
// Use SignEthereum to get an Ethereum compliant signature.
// The produced signature is in the canonical secp256k1 format (V = 0 or 1),
// which can be transformed into the proper Ethereum signature accoring to
// the yellow paper within the transaction signer.
func Sign(data []byte, prv *ecdsa.PrivateKey) (sig []byte, err error) {
if len(data) != 32 {
return nil, fmt.Errorf("hash is required to be exactly 32 bytes (%d)", len(data))
@ -218,20 +219,6 @@ func Sign(data []byte, prv *ecdsa.PrivateKey) (sig []byte, err error) {
return
}
// SignEthereum calculates an Ethereum ECDSA signature.
// This function is susceptible to choosen plaintext attacks that can leak
// information about the private key that is used for signing. Callers must
// be aware that the given hash cannot be freely choosen by an adversery.
// Common solution is to hash the message before calculating the signature.
func SignEthereum(data []byte, prv *ecdsa.PrivateKey) ([]byte, error) {
sig, err := Sign(data, prv)
if err != nil {
return nil, err
}
sig[64] += 27 // as described in the yellow paper
return sig, err
}
func Encrypt(pub *ecdsa.PublicKey, message []byte) ([]byte, error) {
return ecies.Encrypt(rand.Reader, ecies.ImportECDSAPublic(pub), message, nil, nil)
}

View file

@ -80,22 +80,15 @@ func Test0Key(t *testing.T) {
}
}
func testSign(signfn func([]byte, *ecdsa.PrivateKey) ([]byte, error), t *testing.T) {
func TestSign(t *testing.T) {
key, _ := HexToECDSA(testPrivHex)
addr := common.HexToAddress(testAddrHex)
msg := Keccak256([]byte("foo"))
sig, err := signfn(msg, key)
sig, err := Sign(msg, key)
if err != nil {
t.Errorf("Sign error: %s", err)
}
// signfn can return a recover id of either [0,1] or [27,28].
// In the latter case its an Ethereum signature, adjust recover id.
if sig[64] == 27 || sig[64] == 28 {
sig[64] -= 27
}
recoveredPub, err := Ecrecover(msg, sig)
if err != nil {
t.Errorf("ECRecover error: %s", err)
@ -117,34 +110,15 @@ func testSign(signfn func([]byte, *ecdsa.PrivateKey) ([]byte, error), t *testing
}
}
func TestSign(t *testing.T) {
testSign(Sign, t)
}
func TestSignEthereum(t *testing.T) {
testSign(SignEthereum, t)
}
func testInvalidSign(signfn func([]byte, *ecdsa.PrivateKey) ([]byte, error), t *testing.T) {
_, err := signfn(make([]byte, 1), nil)
if err == nil {
func TestInvalidSign(t *testing.T) {
if _, err := Sign(make([]byte, 1), nil); err == nil {
t.Errorf("expected sign with hash 1 byte to error")
}
_, err = signfn(make([]byte, 33), nil)
if err == nil {
if _, err := Sign(make([]byte, 33), nil); err == nil {
t.Errorf("expected sign with hash 33 byte to error")
}
}
func TestInvalidSign(t *testing.T) {
testInvalidSign(Sign, t)
}
func TestInvalidSignEthereum(t *testing.T) {
testInvalidSign(SignEthereum, t)
}
func TestNewContractAddress(t *testing.T) {
key, _ := HexToECDSA(testPrivHex)
addr := common.HexToAddress(testAddrHex)

View file

@ -287,11 +287,19 @@ func signHash(data []byte) []byte {
// Sign calculates an Ethereum ECDSA signature for:
// keccack256("\x19Ethereum Signed Message:\n" + len(message) + message))
//
// Note, the produced signature conforms to the secp256k1 curve R, S and V values,
// where the V value will be 27 or 28 for legacy reasons.
//
// 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, data hexutil.Bytes, addr common.Address, passwd string) (hexutil.Bytes, error) {
return s.b.AccountManager().SignWithPassphrase(addr, passwd, signHash(data))
signature, err := s.b.AccountManager().SignWithPassphrase(addr, passwd, signHash(data))
if err != nil {
return nil, err
}
signature[64] += 27 // SignWithPassphrase uses canonical secp256k1 signatures (v = 0 or 1), transform to yellow paper
return signature, nil
}
// EcRecover returns the address for the account that was used to create the signature.
@ -300,15 +308,19 @@ func (s *PrivateAccountAPI) Sign(ctx context.Context, data hexutil.Bytes, addr c
// hash = keccak256("\x19Ethereum Signed Message:\n"${message length}${message})
// addr = ecrecover(hash, signature)
//
// Note, the signature must conform to the secp256k1 curve R, S and V values, where
// the V value must be be 27 or 28 for legacy reasons.
//
// https://github.com/ethereum/go-ethereum/wiki/Management-APIs#personal_ecRecover
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
if sig[64] != 27 && sig[64] != 28 {
return common.Address{}, fmt.Errorf("invalid Ethereum signature (V is not 27 or 28)")
}
sig[64] -= 27 // Transform yellow paper signatures to canonical secp256k1 form
rpk, err := crypto.Ecrecover(signHash(data), sig)
if err != nil {
return common.Address{}, err
@ -964,7 +976,7 @@ func (s *PublicTransactionPoolAPI) GetTransactionReceipt(txHash common.Hash) (ma
func (s *PublicTransactionPoolAPI) sign(addr common.Address, tx *types.Transaction) (*types.Transaction, error) {
signer := types.MakeSigner(s.b.ChainConfig(), s.b.CurrentBlock().Number())
signature, err := s.b.AccountManager().SignEthereum(addr, signer.Hash(tx).Bytes())
signature, err := s.b.AccountManager().Sign(addr, signer.Hash(tx).Bytes())
if err != nil {
return nil, err
}
@ -1046,11 +1058,10 @@ func (s *PublicTransactionPoolAPI) SendTransaction(ctx context.Context, args Sen
}
tx := args.toTransaction()
signer := types.MakeSigner(s.b.ChainConfig(), s.b.CurrentBlock().Number())
signature, err := s.b.AccountManager().SignEthereum(args.From, signer.Hash(tx).Bytes())
signature, err := s.b.AccountManager().Sign(args.From, signer.Hash(tx).Bytes())
if err != nil {
return common.Hash{}, err
}
return submitTransaction(ctx, s.b, tx, signature)
}
@ -1084,11 +1095,19 @@ func (s *PublicTransactionPoolAPI) SendRawTransaction(ctx context.Context, encod
// Sign calculates an ECDSA signature for:
// keccack256("\x19Ethereum Signed Message:\n" + len(message) + message).
//
// Note, the produced signature conforms to the secp256k1 curve R, S and V values,
// where the V value will be 27 or 28 for legacy reasons.
//
// 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, data hexutil.Bytes) (hexutil.Bytes, error) {
return s.b.AccountManager().SignEthereum(addr, signHash(data))
signature, err := s.b.AccountManager().Sign(addr, signHash(data))
if err == nil {
// Sign uses canonical secp256k1 signatures (v = 0 or 1), transform to yellow paper
signature[64] += 27
}
return signature, err
}
// SignTransactionResult represents a RLP encoded signed transaction.