Security analysis tool for EVM bytecode. Supports smart contracts built for Ethereum, Hedera, Quorum, Vechain, Roostock, Tron and other EVM-compatible blockchains.
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mythril/tests/analysis/test_delegatecall.py

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from mythril.analysis.modules.delegatecall import (
execute,
_concrete_call,
_symbolic_call,
)
from mythril.analysis.ops import Call, Variable, VarType
from mythril.analysis.symbolic import SymExecWrapper
from mythril.laser.ethereum.cfg import Node
from mythril.laser.ethereum.state import GlobalState, Environment, Account
import pytest
from unittest.mock import MagicMock, patch
import pytest_mock
from mythril.disassembler.disassembly import Disassembly
def test_concrete_call():
# 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(1, VarType.CONCRETE)
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: 0x1"
)
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 test_concrete_call_not_calldata():
# arrange
state = GlobalState(None, None, None)
state.mstate.memory = ["placeholder", "not_calldata"]
meminstart = Variable(1, VarType.CONCRETE)
# act
issues = _concrete_call(None, state, None, meminstart)
# assert
assert issues == []
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_symbolic_call_calldata_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("calldata", 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 obtained from calldata. "
"Be aware that the called contract gets unrestricted access to this contract's state."
)
@patch("mythril.laser.ethereum.state.GlobalState.get_current_instruction")
@patch("mythril.analysis.modules.delegatecall._concrete_call")
@patch("mythril.analysis.modules.delegatecall._symbolic_call")
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
@patch("mythril.analysis.modules.delegatecall._concrete_call")
@patch("mythril.analysis.modules.delegatecall._symbolic_call")
def test_delegate_call_not_delegate(sym_mock, concrete_mock):
# 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 = []
node = Node("example")
node.function_name = "fallback"
to = Variable("storage_1", VarType.SYMBOLIC)
call = Call(node, None, None, "NOT_DELEGATECALL", to, None)
statespace = MagicMock()
statespace.calls = [call]
# act
issues = execute(statespace)
# assert
assert issues == []
assert concrete_mock.call_count == 0
assert sym_mock.call_count == 0
@patch("mythril.analysis.modules.delegatecall._concrete_call")
@patch("mythril.analysis.modules.delegatecall._symbolic_call")
def test_delegate_call_not_fallback(sym_mock, concrete_mock):
# 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 = []
node = Node("example")
node.function_name = "not_fallback"
to = Variable("storage_1", VarType.SYMBOLIC)
call = Call(node, None, None, "DELEGATECALL", to, None)
statespace = MagicMock()
statespace.calls = [call]
# act
issues = execute(statespace)
# assert
assert issues == []
assert concrete_mock.call_count == 0
assert sym_mock.call_count == 0