SIGHASH opcode

evm/logic/context.py

@@ -189,3 +189,7 @@ def returndatacopy(computation):
     value = computation.return_data[returndata_start_position: returndata_start_position + size]
 
     computation.memory.write(mem_start_position, size, value)
+
+
+def sighash(computation):
+    computation.stack.push(computation.msg.sig_hash)

evm/mnemonics.py

@@ -49,6 +49,7 @@
 EXTCODECOPY = 'EXTCODECOPY'
 RETURNDATASIZE = 'RETURNDATASIZE'
 RETURNDATACOPY = 'RETURNDATACOPY'
+SIGHASH = 'SIGHASH'
 #
 # Block Information
 #

evm/opcode_values.py

@@ -55,6 +55,7 @@
 EXTCODECOPY = 0x3c
 RETURNDATASIZE = 0x3d
 RETURNDATACOPY = 0x3e
+SIGHASH = 0x3f
 
 
 #

evm/rlp/transactions.py

@@ -165,6 +165,11 @@ class BaseShardingTransaction(rlp.Serializable):
     def hash(self):
         return keccak(rlp.encode(self))
 
+    @property
+    def sig_hash(self):
+        sedes = self.__class__.exclude('data')
+        return keccak(rlp.encode(self, sedes))
+
     #
     # Validation
     #

evm/validation.py

@@ -251,3 +251,8 @@ def validate_transaction_access_list(access_list, title="Access List"):
 def validate_access_list(access_list):
     for entry in access_list:
         validate_is_bytes(entry, "Access prefix")
+
+
+def validate_sig_hash(sig_hash, title="Sig Hash"):
+    validate_is_bytes(sig_hash, title)
+    validate_length(sig_hash, 32, title)

evm/vm/forks/sharding/__init__.py

@@ -30,6 +30,7 @@
 from .computation import ShardingComputation
 from .validation import validate_sharding_transaction
 from .blocks import ShardingBlock
+from .opcodes import SHARDING_OPCODES
 
 
 def _execute_sharding_transaction(vm, transaction):
@@ -80,6 +81,7 @@ def _execute_sharding_transaction(vm, transaction):
         gas=message_gas,
         gas_price=transaction.gas_price,
         to=transaction.to,
+        sig_hash=transaction.sig_hash,
         sender=ENTRY_POINT,
         value=0,
         data=data,
@@ -170,4 +172,6 @@ def _execute_sharding_transaction(vm, transaction):
     # Method overrides
     validate_transaction=validate_sharding_transaction,
     execute_transaction=_execute_sharding_transaction,
+    # opcodes
+    opcodes=SHARDING_OPCODES,
 )

evm/vm/forks/sharding/opcodes.py

@@ -0,0 +1,27 @@
+import copy
+from cytoolz import merge
+
+from evm import opcode_values
+from evm import mnemonics
+
+from evm.opcode import as_opcode
+from evm.logic import (
+    context,
+)
+
+from evm.vm.forks.byzantium import BYZANTIUM_OPCODES
+
+
+NEW_OPCODES = {
+    opcode_values.SIGHASH: as_opcode(
+        logic_fn=context.sighash,
+        mnemonic=mnemonics.SIGHASH,
+        gas_cost=0,
+    ),
+}
+
+
+SHARDING_OPCODES = merge(
+    copy.deepcopy(BYZANTIUM_OPCODES),
+    NEW_OPCODES
+)

evm/vm/message.py

@@ -11,6 +11,7 @@
     validate_uint256,
     validate_is_boolean,
     validate_access_list,
+    validate_sig_hash,
 )
 
 
@@ -148,6 +149,7 @@ def __init__(self,
                  gas,
                  gas_price,
                  to,
+                 sig_hash,
                  sender,
                  value,
                  data,
@@ -178,6 +180,32 @@ def __init__(self,
         validate_is_boolean(is_create, title="Message.is_create")
         self.is_create = is_create
 
+        validate_sig_hash(sig_hash, title="Message.sig_hash")
+        self.sig_hash = sig_hash
+
         if access_list is not None:
             validate_access_list(access_list)
         self.access_list = access_list
+
+    def prepare_child_message(self,
+                              gas,
+                              to,
+                              value,
+                              data,
+                              code,
+                              **kwargs):
+        kwargs.setdefault('sender', self.msg.storage_address)
+
+        child_message = ShardingMessage(
+            gas=gas,
+            gas_price=self.msg.gas_price,
+            origin=self.msg.origin,
+            sig_hash=self.msg.sig_hash,
+            to=to,
+            value=value,
+            data=data,
+            code=code,
+            depth=self.msg.depth + 1,
+            **kwargs
+        )
+        return child_message