Merge pull request #1425 from hyperledger/stub-opcodes

Implement CHAINID and DIFFICULTY opcodes

Author: seanyoung

crypto/signature.go

@@ -118,7 +118,7 @@ func (sig *Signature) String() string {
 }
 
 func GetEthChainID(chainID string) *big.Int {
-	return new(big.Int).SetBytes([]byte(chainID))
+	return new(big.Int).SetBytes(Keccak256([]byte(chainID)))
 }
 
 func GetEthSignatureRecoveryID(chainID string, parity *big.Int) *big.Int {

execution/engine/blockchain.go

@@ -12,6 +12,8 @@ type TestBlockchain struct {
 	BlockTime   time.Time
 }
 
+var _ Blockchain = (*TestBlockchain)(nil)
+
 func (b *TestBlockchain) LastBlockHeight() uint64 {
 	return b.BlockHeight
 }
@@ -28,3 +30,7 @@ func (b *TestBlockchain) BlockHash(height uint64) ([]byte, error) {
 	binary.BigEndian.PutUint64(bs[24:], height)
 	return bs, nil
 }
+
+func (V *TestBlockchain) ChainID() string {
+	return "TestChain"
+}

execution/engine/callable.go

@@ -12,6 +12,7 @@ type Blockchain interface {
 	LastBlockHeight() uint64
 	LastBlockTime() time.Time
 	BlockHash(height uint64) ([]byte, error)
+	ChainID() string
 }
 
 type CallParams struct {

execution/evm/asm/opcodes.go

@@ -71,8 +71,9 @@ const (
 	COINBASE
 	TIMESTAMP
 	BLOCKHEIGHT
-	DIFFICULTY_DEPRECATED
+	DIFFICULTY
 	GASLIMIT
+	CHAINID
 )
 
 const (
@@ -236,12 +237,13 @@ var opCodeNames = map[OpCode]string{
 	EXTCODEHASH:         "EXTCODEHASH",
 
 	// 0x40 range - block operations
-	BLOCKHASH:             "BLOCKHASH",
-	COINBASE:              "COINBASE",
-	TIMESTAMP:             "TIMESTAMP",
-	BLOCKHEIGHT:           "BLOCKHEIGHT",
-	DIFFICULTY_DEPRECATED: "DIFFICULTY_DEPRECATED",
-	GASLIMIT:              "GASLIMIT",
+	BLOCKHASH:   "BLOCKHASH",
+	COINBASE:    "COINBASE",
+	TIMESTAMP:   "TIMESTAMP",
+	BLOCKHEIGHT: "BLOCKHEIGHT",
+	DIFFICULTY:  "DIFFICULTY",
+	GASLIMIT:    "GASLIMIT",
+	CHAINID:     "CHAINID",
 
 	// 0x50 range - 'storage' and execution
 	POP:      "POP",

execution/evm/contract.go

@@ -478,10 +478,20 @@ func (c *Contract) execute(st engine.State, params engine.CallParams) ([]byte, e
 			stack.Push64(number)
 			c.debugf(" => %d\n", number)
 
+		case DIFFICULTY: // 0x44
+			// ~ hashes per solution - by convention we'll use unity since there are no misses if you are proposer
+			stack.Push(One256)
+			c.debugf(" => %v\n", One256)
+
 		case GASLIMIT: // 0x45
 			stack.PushBigInt(params.Gas)
 			c.debugf(" => %v\n", *params.Gas)
 
+		case CHAINID: // 0x46
+			id := crypto.GetEthChainID(st.Blockchain.ChainID())
+			stack.PushBigInt(id)
+			c.debugf(" => %X\n", id)
+
 		case POP: // 0x50
 			popped := stack.Pop()
 			c.debugf(" => 0x%v\n", popped)

execution/wasm/contract.go

@@ -84,13 +84,7 @@ func (ctx *context) ResolveFunc(module, field string) lifeExec.FunctionImport {
 	}
 
 	switch field {
-	case "call":
-		fallthrough
-	case "callCode":
-		fallthrough
-	case "callDelegate":
-		fallthrough
-	case "callStatic":
+	case "call", "callCode", "callDelegate", "callStatic":
 		return func(vm *lifeExec.VirtualMachine) int64 {
 			gasLimit := big.NewInt(vm.GetCurrentFrame().Locals[0])
 			addressPtr := uint32(vm.GetCurrentFrame().Locals[1])