From 581c8d7b018448a7a6fd419357ae00e48572a1a4 Mon Sep 17 00:00:00 2001 From: Eric N Date: Wed, 18 Sep 2019 13:31:23 -0700 Subject: [PATCH] Refactor code --- mythril/laser/ethereum/instructions.py | 109 ++++-------------- .../transaction/transaction_models.py | 3 + 2 files changed, 27 insertions(+), 85 deletions(-) diff --git a/mythril/laser/ethereum/instructions.py b/mythril/laser/ethereum/instructions.py index b7709343..70467da3 100644 --- a/mythril/laser/ethereum/instructions.py +++ b/mythril/laser/ethereum/instructions.py @@ -787,7 +787,7 @@ class Instruction: return [global_state] @staticmethod - def _calldata_copy_helper(global_state, state, mstart, dstart, size): + def _calldata_copy_helper(global_state, mstate, mstart, dstart, size): environment = global_state.environment try: @@ -811,11 +811,11 @@ class Instruction: size = cast(int, size) if size > 0: try: - state.mem_extend(mstart, size) + mstate.mem_extend(mstart, size) except TypeError as e: log.debug("Memory allocation error: {}".format(e)) - state.mem_extend(mstart, 1) - state.memory[mstart] = global_state.new_bitvec( + mstate.mem_extend(mstart, 1) + mstate.memory[mstart] = global_state.new_bitvec( "calldata_" + str(environment.active_account.contract_name) + "[" @@ -840,12 +840,12 @@ class Instruction: else simplify(cast(BitVec, i_data) + 1) ) for i in range(len(new_memory)): - state.memory[i + mstart] = new_memory[i] + mstate.memory[i + mstart] = new_memory[i] except IndexError: log.debug("Exception copying calldata to memory") - state.memory[mstart] = global_state.new_bitvec( + mstate.memory[mstart] = global_state.new_bitvec( "calldata_" + str(environment.active_account.contract_name) + "[" @@ -1039,34 +1039,6 @@ class Instruction: global_state.mstate.stack.append(global_state.environment.gasprice) return [global_state] - @staticmethod - def _handle_symbolic_args( - global_state: GlobalState, concrete_memory_offset: int - ) -> None: - """ - In contract creation transaction with dynamic arguments(like arrays, maps) solidity will try to - execute CODECOPY with code size as len(with_args) - len(without_args) which in our case - would be 0, hence we are writing 10 symbol words onto the memory on the assumption that - no one would use 10 array/map arguments for constructor. - :param global_state: The global state - :param concrete_memory_offset: The memory offset on which symbols should be written - """ - no_of_words = ceil( - min(len(global_state.environment.code.bytecode) / 2, 320) / 32 - ) - global_state.mstate.mem_extend(concrete_memory_offset, 32 * no_of_words) - for i in range(no_of_words): - global_state.mstate.memory.write_word_at( - concrete_memory_offset + i * 32, - global_state.new_bitvec( - "code_{}({})".format( - concrete_memory_offset + i * 32, - global_state.environment.active_account.contract_name, - ), - 256, - ), - ) - @StateTransition() def codecopy_(self, global_state: GlobalState) -> List[GlobalState]: """ @@ -1088,17 +1060,17 @@ class Instruction: # Treat creation code after the expected disassembly as calldata. # This is a slightly hacky way to ensure that symbolic constructor # arguments work correctly. + mstate = global_state.mstate offset = code_offset - code_size - log.warning("Doing hacky thing offset: {} size: {}".format(offset, size)) + log.debug("Copying from code offset: {} with size: {}".format(offset, size)) if isinstance(global_state.environment.calldata, SymbolicCalldata): if code_offset >= code_size: return self._calldata_copy_helper( - global_state, global_state.mstate, memory_offset, offset, size + global_state, mstate, memory_offset, offset, size ) else: # Copy from both code and calldata appropriately. - state = global_state.mstate environment = global_state.environment concrete_memory_offset = helper.get_concrete_int(memory_offset) concrete_code_offset = helper.get_concrete_int(code_offset) @@ -1124,47 +1096,21 @@ class Instruction: calldata_copy_size if calldata_copy_size >= 0 else 0 ) - try: - global_state.mstate.mem_extend( - concrete_memory_offset, concrete_size + calldata_copy_size - ) - except TypeError: - global_state.mstate.mem_extend(concrete_memory_offset, 1) - global_state.mstate.memory[ - concrete_memory_offset - ] = global_state.new_bitvec( - "code({})".format( - global_state.environment.active_account.contract_name - ), - 8, - ) - return [global_state] - for i in range(concrete_size): - if i < code_copy_size: - # copy from code - global_state.mstate.memory[concrete_memory_offset + i] = int( - code[ - 2 - * (code_copy_offset + i) : 2 - * (code_copy_offset + i + 1) - ], - 16, - ) - elif i < code_copy_size + calldata_copy_size: - # copy from calldata - global_state.mstate.memory[ - concrete_memory_offset + i - ] = calldata[calldata_copy_offset + i - code_copy_size] - else: - global_state.mstate.memory[ - concrete_memory_offset + i - ] = global_state.new_bitvec( - "code({})".format( - global_state.environment.active_account.contract_name - ), - 8, - ) - return [global_state] + [global_state] = self._code_copy_helper( + code=global_state.environment.code.bytecode, + memory_offset=memory_offset, + code_offset=code_copy_offset, + size=code_copy_size, + op="CODECOPY", + global_state=global_state, + ) + return self._calldata_copy_helper( + global_state=global_state, + mstate=mstate, + mstart=memory_offset + code_copy_size, + dstart=calldata_copy_offset, + size=calldata_copy_size, + ) return self._code_copy_helper( code=global_state.environment.code.bytecode, @@ -1254,13 +1200,6 @@ class Instruction: if code[0:2] == "0x": code = code[2:] - if concrete_size == 0 and isinstance( - global_state.current_transaction, ContractCreationTransaction - ): - if concrete_code_offset >= len(code) // 2: - Instruction._handle_symbolic_args(global_state, concrete_memory_offset) - return [global_state] - for i in range(concrete_size): if 2 * (concrete_code_offset + i + 1) <= len(code): global_state.mstate.memory[concrete_memory_offset + i] = int( diff --git a/mythril/laser/ethereum/transaction/transaction_models.py b/mythril/laser/ethereum/transaction/transaction_models.py index 06019646..b36cc61d 100644 --- a/mythril/laser/ethereum/transaction/transaction_models.py +++ b/mythril/laser/ethereum/transaction/transaction_models.py @@ -198,6 +198,9 @@ class ContractCreationTransaction(BaseTransaction): contract_address=None, ) -> None: self.prev_world_state = deepcopy(world_state) + contract_address = ( + contract_address if isinstance(contract_address, int) else None + ) callee_account = world_state.create_account( 0, concrete_storage=True, creator=caller.value, address=contract_address )