vm makeover

vm/native.go

@@ -0,0 +1,90 @@
+package vm
+
+import (
+	"code.google.com/p/go.crypto/ripemd160"
+	"crypto/sha256"
+	"github.com/tendermint/tendermint/vm/secp256k1"
+	"github.com/tendermint/tendermint/vm/sha3"
+
+	. "github.com/tendermint/tendermint/common"
+)
+
+var nativeContracts = make(map[Word]NativeContract)
+
+func init() {
+	nativeContracts[Uint64ToWord(1)] = ecrecoverFunc
+	nativeContracts[Uint64ToWord(2)] = sha256Func
+	nativeContracts[Uint64ToWord(3)] = ripemd160Func
+	nativeContracts[Uint64ToWord(4)] = identityFunc
+}
+
+//-----------------------------------------------------------------------------
+
+type NativeContract func(input []byte, gas *uint64) (output []byte, err error)
+
+func ecrecoverFunc(input []byte, gas *uint64) (output []byte, err error) {
+	// Deduct gas
+	gasRequired := GasEcRecover
+	if *gas < gasRequired {
+		return nil, ErrInsufficientGas
+	} else {
+		*gas -= gasRequired
+	}
+	// Recover
+	hash := input[:32]
+	v := byte(input[32] - 27) // ignore input[33:64], v is small.
+	sig := append(input[64:], v)
+
+	recovered, err := secp256k1.RecoverPubkey(hash, sig)
+	if err != nil {
+		return nil, err
+	}
+	hashed := sha3.Sha3(recovered[1:])
+	return RightPadBytes(hashed, 32), nil
+}
+
+func sha256Func(input []byte, gas *uint64) (output []byte, err error) {
+	// Deduct gas
+	gasRequired := uint64((len(input)+31)/32)*GasSha256Word + GasSha256Base
+	if *gas < gasRequired {
+		return nil, ErrInsufficientGas
+	} else {
+		*gas -= gasRequired
+	}
+	// Hash
+	hasher := sha256.New()
+	_, err = hasher.Write(input)
+	if err != nil {
+		panic(err)
+	}
+	return hasher.Sum(nil), nil
+}
+
+func ripemd160Func(input []byte, gas *uint64) (output []byte, err error) {
+	// Deduct gas
+	gasRequired := uint64((len(input)+31)/32)*GasRipemd160Word + GasRipemd160Base
+	if *gas < gasRequired {
+		return nil, ErrInsufficientGas
+	} else {
+		*gas -= gasRequired
+	}
+	// Hash
+	hasher := ripemd160.New()
+	_, err = hasher.Write(input)
+	if err != nil {
+		panic(err)
+	}
+	return RightPadBytes(hasher.Sum(nil), 32), nil
+}
+
+func identityFunc(input []byte, gas *uint64) (output []byte, err error) {
+	// Deduct gas
+	gasRequired := uint64((len(input)+31)/32)*GasIdentityWord + GasIdentityBase
+	if *gas < gasRequired {
+		return nil, ErrInsufficientGas
+	} else {
+		*gas -= gasRequired
+	}
+	// Return identity
+	return input, nil
+}