def test_concrete_call_symbolic_to():
# arrange
address = "0x10"
active_account = Account(address)
active_account.code = Disassembly("00")
environment = Environment(active_account, None, None, None, None, None)
state = GlobalState(None, environment, None)
state.mstate.memory = ["placeholder", "calldata_bling_0"]
node = Node("example")
node.contract_name = "the contract name"
node.function_name = "the function name"
to = Variable("calldata_3", VarType.SYMBOLIC)
meminstart = Variable(1, VarType.CONCRETE)
call = Call(node, state, None, None, to, None)
# act
issues = _concrete_call(call, state, address, meminstart)
# assert
issue = issues[0]
assert issue.address == address
assert issue.contract == node.contract_name
assert issue.function == node.function_name
assert issue.title == "Call data forwarded with delegatecall()"
assert issue.type == "Informational"
assert (
issue.description
== "This contract forwards its call data via DELEGATECALL in its fallback function."
" This means that any function in the called contract can be executed."
" Note that the callee contract will have access to the storage of the "
"calling contract.\n DELEGATECALL target: calldata_3"
)
def sym_exec(self, main_address):
logging.debug("Starting LASER execution")
# Initialize the execution environment
environment = Environment(
self.accounts[main_address],
BitVec("caller", 256),
[],
BitVec("gasprice", 256),
BitVec("callvalue", 256),
BitVec("origin", 256),
calldata_type=CalldataType.SYMBOLIC,
)
# TODO: contact name fix
initial_node = Node(environment.active_account.contract_name)
self.nodes[initial_node.uid] = initial_node
global_state = GlobalState(self.accounts, environment, initial_node)
initial_node.states.append(global_state)
# Empty the work_list before starting an execution
self.work_list.append(global_state)
self._sym_exec()
logging.info("Execution complete")
logging.info("%d nodes, %d edges, %d total states", len(self.nodes),
len(self.edges), self.total_states)
def test_delegate_call(sym_mock, concrete_mock, curr_instruction):
# arrange
# sym_mock = mocker.patch.object(delegatecall, "_symbolic_call")
# concrete_mock = mocker.patch.object(delegatecall, "_concrete_call")
sym_mock.return_value = []
concrete_mock.return_value = []
curr_instruction.return_value = {"address": "0x10"}
active_account = Account("0x10")
active_account.code = Disassembly("00")
environment = Environment(active_account, None, None, None, None, None)
state = GlobalState(None, environment, Node)
state.mstate.memory = ["placeholder", "calldata_bling_0"]
state.mstate.stack = [1, 2, 3]
assert state.get_current_instruction() == {"address": "0x10"}
node = Node("example")
node.contract_name = "the contract name"
node.function_name = "fallback"
to = Variable("storage_1", VarType.SYMBOLIC)
call = Call(node, state, None, "DELEGATECALL", to, None)
statespace = MagicMock()
statespace.calls = [call]
# act
execute(statespace)
# assert
assert concrete_mock.call_count == 1
assert sym_mock.call_count == 1
def sym_exec(self, main_address):
logging.debug("Starting LASER execution")
self.time = datetime.now()
# Initialize the execution environment
environment = Environment(
self.accounts[main_address],
BitVec("caller", 256),
[],
BitVec("gasprice", 256),
BitVec("callvalue", 256),
BitVec("origin", 256),
calldata_type=CalldataType.SYMBOLIC,
)
self.instructions_covered = [
False for _ in environment.code.instruction_list
]
initial_node = Node(environment.active_account.contract_name)
self.nodes[initial_node.uid] = initial_node
global_state = GlobalState(self.accounts, environment, initial_node)
global_state.environment.active_function_name = "fallback()"
initial_node.states.append(global_state)
# Empty the work_list before starting an execution
self.work_list.append(global_state)
self._sym_exec()
logging.info("Execution complete")
logging.info("Achieved {0:.3g}% coverage".format(self.coverage))
logging.info("%d nodes, %d edges, %d total states", len(self.nodes),
len(self.edges), self.total_states)
def run(self, open_world_states: list, evm):
""" Runs this transaction on the evm starting from the open world states """
# Consume the open states
open_states = open_world_states[:]
del open_world_states[:]
for open_world_state in open_states:
# Initialize the execution environment
environment = Environment(
open_world_state[self.callee_address],
self.caller,
[],
self.gas_price,
self.call_value,
self.origin,
calldata_type=CalldataType.SYMBOLIC,
)
new_node = Node(environment.active_account.contract_name)
evm.instructions_covered = [False for _ in environment.code.instruction_list]
evm.nodes[new_node.uid] = new_node
if open_world_state.node:
evm.edges.append(Edge(open_world_state.node.uid, new_node.uid, edge_type=JumpType.Transaction, condition=None))
global_state = GlobalState(open_world_state.accounts, environment, new_node)
global_state.environment.active_function_name = 'fallback'
new_node.states.append(global_state)
evm.work_list.append(global_state)
evm.exec()
logging.info("Execution complete")
logging.info("Achieved {0:.3g}% coverage".format(evm.coverage))
def get_constr_glbstate(contract, address):
mstate = MachineState(gas=10000000)
minimal_const_byte_len = get_minimal_constructor_param_encoding_len(abi_json_to_abi(contract.abi))
# better would be to append symbolic params to the bytecode such that the codecopy instruction that copies the
# params into memory takes care of placing them onto the memory with the respective size.
for i in range(int(minimal_const_byte_len / 32)):
mstate.mem_extend(128 + 32 * i, 32)
mstate.memory.insert(128 + 32 * i, BitVec('calldata_' + contract.name + '[' + str(i * 32)+ "]", 256))
# Todo Replace pure placement of enough symbolic 32 Byte-words with placement of symbolic variables that contain
# the name of the solidity variables
accounts = {address: Account(address, contract.disassembly, contract_name=contract.name)}
environment = Environment(
accounts[address],
BitVec("caller", 256),
[],
BitVec("gasprice", 256),
BitVec("callvalue", 256),
BitVec("origin", 256),
calldata_type=CalldataType.SYMBOLIC,
)
# Todo find source for account info, maybe the std statespace?
return GlobalState(accounts, environment, None, mstate)
def initial_global_state(self):
# Initialize the execution environment
environment = Environment(
self.callee_account,
self.caller,
self.call_data,
self.gas_price,
self.call_value,
self.origin,
self.code,
calldata_type=self.call_data_type,
)
if hasattr(self, "code_extension"):
environment.code_extension = self.code_extension
global_state = GlobalState(self.world_state, environment, None)
global_state.environment.active_function_name = 'constructor'
return global_state
def get_t_indexed_environment(active_account, index):
# Initialize the execution environment
environment = Environment(
active_account,
BitVec("caller_"+str(index), 256),
[],
BitVec("gasprice_"+str(index), 256),
BitVec("callvalue_"+str(index), 256),
BitVec("origin_"+str(index), 256),
calldata_type=CalldataType.SYMBOLIC,
)
return environment
def test_codecopy_concrete():
# Arrange
active_account = Account("0x0", code=Disassembly("60606040"))
environment = Environment(active_account, None, None, None, None, None)
og_state = GlobalState(None, environment, None, MachineState(gas=10000000))
og_state.mstate.stack = [2, 2, 2]
instruction = Instruction("codecopy", dynamic_loader=None)
# Act
new_state = instruction.evaluate(og_state)[0]
# Assert
assert new_state.mstate.memory[2] == 96
assert new_state.mstate.memory[3] == 64
def initial_global_state(self):
# Initialize the execution environment
environment = Environment(self.callee_account,
self.caller,
self.call_data,
self.gas_price,
self.call_value,
self.origin,
code=self.code or self.callee_account.code,
calldata_type=self.call_data_type,
can_write=self.can_write)
global_state = GlobalState(self.world_state, environment, None)
global_state.environment.active_function_name = 'fallback'
return global_state
def initial_global_state(self):
# Initialize the execution environment
environment = Environment(
self.callee_account,
self.caller,
self.call_data,
self.gas_price,
self.call_value,
self.origin,
self.code,
calldata_type=self.call_data_type,
)
global_state = GlobalState(self.world_state, environment, None)
global_state.environment.active_function_name = "constructor"
global_state.mstate.constraints.extend(
global_state.environment.calldata.constraints)
return global_state
def test_symbolic_call_storage_to(mocker):
# arrange
address = "0x10"
active_account = Account(address)
active_account.code = Disassembly("00")
environment = Environment(active_account, None, None, None, None, None)
state = GlobalState(None, environment, None)
state.mstate.memory = ["placeholder", "calldata_bling_0"]
node = Node("example")
node.contract_name = "the contract name"
node.function_name = "the function name"
to = Variable("storage_1", VarType.SYMBOLIC)
call = Call(node, state, None, "Type: ", to, None)
mocker.patch.object(SymExecWrapper, "__init__", lambda x, y: None)
statespace = SymExecWrapper(1)
mocker.patch.object(statespace, "find_storage_write")
statespace.find_storage_write.return_value = "Function name"
# act
issues = _symbolic_call(call, state, address, statespace)
# assert
issue = issues[0]
assert issue.address == address
assert issue.contract == node.contract_name
assert issue.function == node.function_name
assert issue.title == "Type: to a user-supplied address"
assert issue.type == "Informational"
assert (
issue.description
== "This contract delegates execution to a contract address in storage slot 1."
" This storage slot can be written to by calling the function `Function name`. "
"Be aware that the called contract gets unrestricted access to this contract's state."
)
def test_execute(mocker):
active_account = Account('0x00')
environment = Environment(active_account, None, None, None, None, None)
state_1 = GlobalState(None, environment, None, MachineState(gas=10000000))
state_1.mstate.stack = [1, 2]
mocker.patch.object(state_1, 'get_current_instruction')
state_1.get_current_instruction.return_value = {"opcode": "PUSH"}
state_2 = GlobalState(None, environment, None, MachineState(gas=10000000))
state_2.mstate.stack = [1, 2, 3]
mocker.patch.object(state_2, 'get_current_instruction')
state_2.get_current_instruction.return_value = {"opcode": "ADD"}
node_1 = Node("Test contract")
node_1.states = [state_1, state_2]
state_3 = GlobalState(None, environment, None, MachineState(gas=10000000))
state_3.mstate.stack = [1, 2]
mocker.patch.object(state_3, 'get_current_instruction')
state_3.get_current_instruction.return_value = {"opcode": "ADD"}
node_2 = Node("Test contract")
node_2.states = [state_3]
edge = Edge(node_1.uid, node_2.uid)
statespace = LaserEVM(None)
statespace.edges = [edge]
statespace.nodes[node_1.uid] = node_1
statespace.nodes[node_2.uid] = node_2
# Act
result = TaintRunner.execute(statespace, node_1, state_1, [True, True])
# Assert
print(result)
assert len(result.records) == 3
assert result.records[2].states == []
assert state_3 in result.records[1].states
def call_(self, global_state):
instr = global_state.get_current_instruction()
environment = global_state.environment
try:
callee_address, callee_account, call_data, value, call_data_type, gas, memory_out_offset, memory_out_size = get_call_parameters(
global_state, self.dynamic_loader, True)
except ValueError as e:
logging.info(
"Could not determine required parameters for call, putting fresh symbol on the stack. \n{}"
.format(e))
# TODO: decide what to do in this case
global_state.mstate.stack.append(
BitVec("retval_" + str(instr['address']), 256))
return [global_state]
if 0 < int(callee_address, 16) < 5:
logging.info("Native contract called: " + callee_address)
if call_data == [] and call_data_type == CalldataType.SYMBOLIC:
logging.debug("CALL with symbolic data not supported")
global_state.mstate.stack.append(
BitVec("retval_" + str(instr['address']), 256))
return [global_state]
data = natives.native_contracts(int(callee_address, 16), call_data)
try:
mem_out_start = helper.get_concrete_int(memory_out_offset)
mem_out_sz = memory_out_size.as_long()
except AttributeError:
logging.debug(
"CALL with symbolic start or offset not supported")
global_state.mstate.stack.append(
BitVec("retval_" + str(instr['address']), 256))
return [global_state]
global_state.mstate.mem_extend(mem_out_start, mem_out_sz)
try:
for i in range(min(len(data), mem_out_sz)
): # If more data is used then it's chopped off
global_state.mstate.memory[mem_out_start + i] = data[i]
except:
global_state.mstate.memory[mem_out_start] = BitVec(data, 256)
# TODO: maybe use BitVec here constrained to 1
global_state.mstate.stack.append(
BitVec("retval_" + str(instr['address']), 256))
return [global_state]
global_state.call_stack.append(instr['address'])
callee_environment = Environment(
callee_account,
BitVecVal(int(environment.active_account.address, 16), 256),
call_data,
environment.gasprice,
value,
environment.origin,
calldata_type=call_data_type)
new_global_state = GlobalState(global_state.accounts,
callee_environment, MachineState(gas))
new_global_state.mstate.depth = global_state.mstate.depth + 1
new_global_state.mstate.constraints = copy(
global_state.mstate.constraints)
return [global_state]