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-rw-r--r--core/vm/contracts.go102
1 files changed, 102 insertions, 0 deletions
diff --git a/core/vm/contracts.go b/core/vm/contracts.go
new file mode 100644
index 000000000..90e356b1d
--- /dev/null
+++ b/core/vm/contracts.go
@@ -0,0 +1,102 @@
+package vm
+
+import (
+ "math/big"
+
+ "github.com/ethereum/go-ethereum/common"
+ "github.com/ethereum/go-ethereum/crypto"
+ "github.com/ethereum/go-ethereum/logger"
+ "github.com/ethereum/go-ethereum/logger/glog"
+ "github.com/ethereum/go-ethereum/params"
+)
+
+type Address interface {
+ Call(in []byte) []byte
+}
+
+type PrecompiledAccount struct {
+ Gas func(l int) *big.Int
+ fn func(in []byte) []byte
+}
+
+func (self PrecompiledAccount) Call(in []byte) []byte {
+ return self.fn(in)
+}
+
+var Precompiled = PrecompiledContracts()
+
+// XXX Could set directly. Testing requires resetting and setting of pre compiled contracts.
+func PrecompiledContracts() map[string]*PrecompiledAccount {
+ return map[string]*PrecompiledAccount{
+ // ECRECOVER
+ string(common.LeftPadBytes([]byte{1}, 20)): &PrecompiledAccount{func(l int) *big.Int {
+ return params.EcrecoverGas
+ }, ecrecoverFunc},
+
+ // SHA256
+ string(common.LeftPadBytes([]byte{2}, 20)): &PrecompiledAccount{func(l int) *big.Int {
+ n := big.NewInt(int64(l+31) / 32)
+ n.Mul(n, params.Sha256WordGas)
+ return n.Add(n, params.Sha256Gas)
+ }, sha256Func},
+
+ // RIPEMD160
+ string(common.LeftPadBytes([]byte{3}, 20)): &PrecompiledAccount{func(l int) *big.Int {
+ n := big.NewInt(int64(l+31) / 32)
+ n.Mul(n, params.Ripemd160WordGas)
+ return n.Add(n, params.Ripemd160Gas)
+ }, ripemd160Func},
+
+ string(common.LeftPadBytes([]byte{4}, 20)): &PrecompiledAccount{func(l int) *big.Int {
+ n := big.NewInt(int64(l+31) / 32)
+ n.Mul(n, params.IdentityWordGas)
+
+ return n.Add(n, params.IdentityGas)
+ }, memCpy},
+ }
+}
+
+func sha256Func(in []byte) []byte {
+ return crypto.Sha256(in)
+}
+
+func ripemd160Func(in []byte) []byte {
+ return common.LeftPadBytes(crypto.Ripemd160(in), 32)
+}
+
+const ecRecoverInputLength = 128
+
+func ecrecoverFunc(in []byte) []byte {
+ in = common.RightPadBytes(in, 128)
+ // "in" is (hash, v, r, s), each 32 bytes
+ // but for ecrecover we want (r, s, v)
+
+ r := common.BytesToBig(in[64:96])
+ s := common.BytesToBig(in[96:128])
+ // Treat V as a 256bit integer
+ vbig := common.Bytes2Big(in[32:64])
+ v := byte(vbig.Uint64())
+
+ if !crypto.ValidateSignatureValues(v, r, s) {
+ glog.V(logger.Error).Infof("EC RECOVER FAIL: v, r or s value invalid")
+ return nil
+ }
+
+ // v needs to be at the end and normalized for libsecp256k1
+ vbignormal := new(big.Int).Sub(vbig, big.NewInt(27))
+ vnormal := byte(vbignormal.Uint64())
+ rsv := append(in[64:128], vnormal)
+ pubKey, err := crypto.Ecrecover(in[:32], rsv)
+ // make sure the public key is a valid one
+ if err != nil {
+ glog.V(logger.Error).Infof("EC RECOVER FAIL: ", err)
+ return nil
+ }
+
+ // the first byte of pubkey is bitcoin heritage
+ return common.LeftPadBytes(crypto.Sha3(pubKey[1:])[12:], 32)
+}
+
+func memCpy(in []byte) []byte {
+ return in
+}