package vm import ( "math/big" "github.com/ethereum/go-ethereum/crypto" "github.com/ethereum/go-ethereum/ethutil" ) type Address interface { Call(in []byte) []byte } type PrecompiledAddress struct { Gas func(l int) *big.Int fn func(in []byte) []byte } func (self PrecompiledAddress) Call(in []byte) []byte { return self.fn(in) } var Precompiled = map[uint64]*PrecompiledAddress{ 1: &PrecompiledAddress{func(l int) *big.Int { return GasEcrecover }, ecrecoverFunc}, 2: &PrecompiledAddress{func(l int) *big.Int { n := big.NewInt(int64(l+31)/32 + 1) n.Mul(n, GasSha256) return n }, sha256Func}, 3: &PrecompiledAddress{func(l int) *big.Int { n := big.NewInt(int64(l+31)/32 + 1) n.Mul(n, GasRipemd) return n }, ripemd160Func}, } func sha256Func(in []byte) []byte { return crypto.Sha256(in) } func ripemd160Func(in []byte) []byte { return ethutil.LeftPadBytes(crypto.Ripemd160(in), 32) } func ecrecoverFunc(in []byte) []byte { // In case of an invalid sig. Defaults to return nil defer func() { recover() }() hash := in[:32] v := ethutil.BigD(in[32:64]).Bytes()[0] - 27 sig := append(in[64:], v) return ethutil.LeftPadBytes(crypto.Sha3(crypto.Ecrecover(append(hash, sig...))[1:])[12:], 32) }