diff --git a/core/vm/address.go b/core/vm/address.go index 215f4bc8f..0b3a95dd0 100644 --- a/core/vm/address.go +++ b/core/vm/address.go @@ -3,8 +3,8 @@ package vm import ( "math/big" - "github.com/ethereum/go-ethereum/crypto" "github.com/ethereum/go-ethereum/common" + "github.com/ethereum/go-ethereum/crypto" ) type Address interface { @@ -61,15 +61,32 @@ func ripemd160Func(in []byte) []byte { return common.LeftPadBytes(crypto.Ripemd160(in), 32) } +const ecRecoverInputLength = 128 + func ecrecoverFunc(in []byte) []byte { - // In case of an invalid sig. Defaults to return nil - defer func() { recover() }() + // "in" is (hash, v, r, s), each 32 bytes + // but for ecrecover we want (r, s, v) + if len(in) < ecRecoverInputLength { + return nil + } - hash := in[:32] - v := common.BigD(in[32:64]).Bytes()[0] - 27 - sig := append(in[64:], v) + // Treat V as a 256bit integer + v := new(big.Int).Sub(common.Bytes2Big(in[32:64]), big.NewInt(27)) + // Ethereum requires V to be either 0 or 1 => (27 || 28) + if !(v.Cmp(Zero) == 0 || v.Cmp(One) == 0) { + return nil + } + + // v needs to be moved to the end + rsv := append(in[64:128], byte(v.Uint64())) + pubKey := crypto.Ecrecover(in[:32], rsv) + // make sure the public key is a valid one + if pubKey == nil || len(pubKey) != 65 { + return nil + } - return common.LeftPadBytes(crypto.Sha3(crypto.Ecrecover(append(hash, sig...))[1:])[12:], 32) + // the first byte of pubkey is bitcoin heritage + return common.LeftPadBytes(crypto.Sha3(pubKey[1:])[12:], 32) } func memCpy(in []byte) []byte { diff --git a/crypto/crypto.go b/crypto/crypto.go index 442942c6c..9a1559fbf 100644 --- a/crypto/crypto.go +++ b/crypto/crypto.go @@ -68,13 +68,8 @@ func Ripemd160(data []byte) []byte { return ripemd.Sum(nil) } -func Ecrecover(data []byte) []byte { - var in = struct { - hash []byte - sig []byte - }{data[:32], data[32:]} - - r, _ := secp256k1.RecoverPubkey(in.hash, in.sig) +func Ecrecover(hash, sig []byte) []byte { + r, _ := secp256k1.RecoverPubkey(hash, sig) return r } @@ -151,9 +146,12 @@ func GenerateKey() (*ecdsa.PrivateKey, error) { } func SigToPub(hash, sig []byte) *ecdsa.PublicKey { - s := Ecrecover(append(hash, sig...)) - x, y := elliptic.Unmarshal(S256(), s) + s := Ecrecover(hash, sig) + if s == nil || len(s) != 65 { + return nil + } + x, y := elliptic.Unmarshal(S256(), s) return &ecdsa.PublicKey{S256(), x, y} }