crypto: add btcec fallback for sign/recover without cgo (#3680)

* vendor: add github.com/btcsuite/btcd/btcec

* crypto: add btcec fallback for sign/recover without cgo

This commit adds a non-cgo fallback implementation of secp256k1
operations.

* crypto, core/vm: remove wrappers for sha256, ripemd160
This commit is contained in:
Felix Lange
2017-02-18 09:24:12 +01:00
committed by Jeffrey Wilcke
parent bf21549faa
commit 9b0af51386
32 changed files with 3929 additions and 224 deletions

View File

@@ -20,22 +20,21 @@ import (
"crypto/ecdsa"
"crypto/elliptic"
"crypto/rand"
"crypto/sha256"
"fmt"
"encoding/hex"
"errors"
"io"
"io/ioutil"
"math/big"
"os"
"encoding/hex"
"errors"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto/ecies"
"github.com/ethereum/go-ethereum/crypto/secp256k1"
"github.com/ethereum/go-ethereum/crypto/sha3"
"github.com/ethereum/go-ethereum/rlp"
"golang.org/x/crypto/ripemd160"
)
var (
secp256k1_N, _ = new(big.Int).SetString("fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141", 16)
secp256k1_halfN = new(big.Int).Div(secp256k1_N, big.NewInt(2))
)
func Keccak256(data ...[]byte) []byte {
@@ -56,7 +55,6 @@ func Keccak256Hash(data ...[]byte) (h common.Hash) {
}
// Deprecated: For backward compatibility as other packages depend on these
func Sha3(data ...[]byte) []byte { return Keccak256(data...) }
func Sha3Hash(data ...[]byte) common.Hash { return Keccak256Hash(data...) }
// Creates an ethereum address given the bytes and the nonce
@@ -65,39 +63,16 @@ func CreateAddress(b common.Address, nonce uint64) common.Address {
return common.BytesToAddress(Keccak256(data)[12:])
}
func Sha256(data []byte) []byte {
hash := sha256.Sum256(data)
return hash[:]
}
func Ripemd160(data []byte) []byte {
ripemd := ripemd160.New()
ripemd.Write(data)
return ripemd.Sum(nil)
}
// Ecrecover returns the public key for the private key that was used to
// calculate the signature.
//
// Note: secp256k1 expects the recover id to be either 0, 1. Ethereum
// signatures have a recover id with an offset of 27. Callers must take
// this into account and if "recovering" from an Ethereum signature adjust.
func Ecrecover(hash, sig []byte) ([]byte, error) {
return secp256k1.RecoverPubkey(hash, sig)
}
// New methods using proper ecdsa keys from the stdlib
// ToECDSA creates a private key with the given D value.
func ToECDSA(prv []byte) *ecdsa.PrivateKey {
if len(prv) == 0 {
return nil
}
priv := new(ecdsa.PrivateKey)
priv.PublicKey.Curve = secp256k1.S256()
priv.PublicKey.Curve = S256()
priv.D = common.BigD(prv)
priv.PublicKey.X, priv.PublicKey.Y = secp256k1.S256().ScalarBaseMult(prv)
priv.PublicKey.X, priv.PublicKey.Y = priv.PublicKey.Curve.ScalarBaseMult(prv)
return priv
}
@@ -112,15 +87,15 @@ func ToECDSAPub(pub []byte) *ecdsa.PublicKey {
if len(pub) == 0 {
return nil
}
x, y := elliptic.Unmarshal(secp256k1.S256(), pub)
return &ecdsa.PublicKey{Curve: secp256k1.S256(), X: x, Y: y}
x, y := elliptic.Unmarshal(S256(), pub)
return &ecdsa.PublicKey{Curve: S256(), X: x, Y: y}
}
func FromECDSAPub(pub *ecdsa.PublicKey) []byte {
if pub == nil || pub.X == nil || pub.Y == nil {
return nil
}
return elliptic.Marshal(secp256k1.S256(), pub.X, pub.Y)
return elliptic.Marshal(S256(), pub.X, pub.Y)
}
// HexToECDSA parses a secp256k1 private key.
@@ -164,7 +139,7 @@ func SaveECDSA(file string, key *ecdsa.PrivateKey) error {
}
func GenerateKey() (*ecdsa.PrivateKey, error) {
return ecdsa.GenerateKey(secp256k1.S256(), rand.Reader)
return ecdsa.GenerateKey(S256(), rand.Reader)
}
// ValidateSignatureValues verifies whether the signature values are valid with
@@ -175,49 +150,11 @@ func ValidateSignatureValues(v byte, r, s *big.Int, homestead bool) bool {
}
// reject upper range of s values (ECDSA malleability)
// see discussion in secp256k1/libsecp256k1/include/secp256k1.h
if homestead && s.Cmp(secp256k1.HalfN) > 0 {
if homestead && s.Cmp(secp256k1_halfN) > 0 {
return false
}
// Frontier: allow s to be in full N range
return r.Cmp(secp256k1.N) < 0 && s.Cmp(secp256k1.N) < 0 && (v == 0 || v == 1)
}
func SigToPub(hash, sig []byte) (*ecdsa.PublicKey, error) {
s, err := Ecrecover(hash, sig)
if err != nil {
return nil, err
}
x, y := elliptic.Unmarshal(secp256k1.S256(), s)
return &ecdsa.PublicKey{Curve: secp256k1.S256(), X: x, Y: y}, nil
}
// Sign calculates an ECDSA signature.
//
// This function is susceptible to chosen 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 chosen by an adversery. Common
// solution is to hash any input before calculating the signature.
//
// The produced signature is in the [R || S || V] format where V is 0 or 1.
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))
}
seckey := common.LeftPadBytes(prv.D.Bytes(), prv.Params().BitSize/8)
defer zeroBytes(seckey)
sig, err = secp256k1.Sign(data, seckey)
return
}
func Encrypt(pub *ecdsa.PublicKey, message []byte) ([]byte, error) {
return ecies.Encrypt(rand.Reader, ecies.ImportECDSAPublic(pub), message, nil, nil)
}
func Decrypt(prv *ecdsa.PrivateKey, ct []byte) ([]byte, error) {
key := ecies.ImportECDSA(prv)
return key.Decrypt(rand.Reader, ct, nil, nil)
return r.Cmp(secp256k1_N) < 0 && s.Cmp(secp256k1_N) < 0 && (v == 0 || v == 1)
}
func PubkeyToAddress(p ecdsa.PublicKey) common.Address {