Merge branch 'develop' into pending-opcodes

README.md

@@ -32,7 +32,7 @@ Install from Pypi:
 $ pip3 install mythril
 ```
 
-See the [Wiki](https://github.com/ConsenSys/mythril/wiki/Installation-and-Setup) for more detailed instructions. 
+See the [docs](https://mythril-classic.readthedocs.io/en/master/installation.html) for more detailed instructions. 
 
 ## Usage
 
@@ -75,7 +75,7 @@ Caller: [ATTACKER], function: commencekilling(), txdata: 0x7c11da20, value: 0x0
 ```
 
 
-Instructions for using Mythril are found on the [Wiki](https://github.com/ConsenSys/mythril/wiki). 
+Instructions for using Mythril are found on the [docs](https://mythril-classic.readthedocs.io/en/master/). 
 
 For support or general discussions please join the Mythril community on [Discord](https://discord.gg/E3YrVtG).
 

mythril/analysis/modules/ether_thief.py

@@ -1,21 +1,16 @@
 """This module contains the detection code for unauthorized ether
 withdrawal."""
 import logging
-import json
 from copy import copy
 
 from mythril.analysis import solver
 from mythril.analysis.modules.base import DetectionModule
 from mythril.analysis.report import Issue
-from mythril.laser.ethereum.transaction.symbolic import (
-    ATTACKER_ADDRESS,
-    CREATOR_ADDRESS,
-)
+from mythril.laser.ethereum.transaction.symbolic import ATTACKER_ADDRESS
 from mythril.analysis.swc_data import UNPROTECTED_ETHER_WITHDRAWAL
 from mythril.exceptions import UnsatError
-from mythril.laser.ethereum.transaction import ContractCreationTransaction
 from mythril.laser.ethereum.state.global_state import GlobalState
-from mythril.laser.smt import UGT, Sum, symbol_factory, BVAddNoOverflow, If
+from mythril.laser.smt import UGT, symbol_factory, UGE
 
 log = logging.getLogger(__name__)
 
@@ -74,54 +69,40 @@ class EtherThief(DetectionModule):
         :param state:
         :return:
         """
+        state = copy(state)
         instruction = state.get_current_instruction()
 
-        if instruction["opcode"] != "CALL":
-            return []
-
         value = state.mstate.stack[-3]
         target = state.mstate.stack[-2]
 
-        eth_sent_by_attacker = symbol_factory.BitVecVal(0, 256)
-
         constraints = copy(state.mstate.constraints)
 
-        for tx in state.world_state.transaction_sequence:
-            """
-            Constraint: The call value must be greater than the sum of Ether sent by the attacker over all
-            transactions. This prevents false positives caused by legitimate refund functions.
-            Also constrain the addition from overflowing (otherwise the solver produces solutions with
-            ridiculously high call values).
-            """
-            constraints += [
-                BVAddNoOverflow(eth_sent_by_attacker, tx.call_value, signed=False)
-            ]
-            eth_sent_by_attacker = Sum(
-                eth_sent_by_attacker,
-                tx.call_value * If(tx.caller == ATTACKER_ADDRESS, 1, 0),
-            )
-
-            """
-            Constraint: All transactions must originate from regular users (not the creator/owner).
-            This prevents false positives where the owner willingly transfers ownership to another address.
-            """
-
-            if not isinstance(tx, ContractCreationTransaction):
-                constraints += [tx.caller != CREATOR_ADDRESS]
-
         """
         Require that the current transaction is sent by the attacker and
-        that the Ether is sent to the attacker's address.
+        that the Ether sent to the attacker's address is greater than the
+        amount of Ether the attacker sent.
         """
+        attacker_address_bitvec = symbol_factory.BitVecVal(ATTACKER_ADDRESS, 256)
+
+        constraints += [
+            UGE(
+                state.world_state.balances[state.environment.active_account.address],
+                value,
+            )
+        ]
+        state.world_state.balances[attacker_address_bitvec] += value
+        state.world_state.balances[state.environment.active_account.address] -= value
 
         constraints += [
-            UGT(value, eth_sent_by_attacker),
+            UGT(
+                state.world_state.balances[attacker_address_bitvec],
+                state.world_state.starting_balances[attacker_address_bitvec],
+            ),
             target == ATTACKER_ADDRESS,
             state.current_transaction.caller == ATTACKER_ADDRESS,
         ]
 
         try:
-
             transaction_sequence = solver.get_transaction_sequence(state, constraints)
 
             issue = Issue(

mythril/analysis/solver.py

@@ -95,7 +95,7 @@ def get_transaction_sequence(
     concrete_transactions = []
 
     tx_constraints, minimize = _set_minimisation_constraints(
-        transaction_sequence, constraints.copy(), [], 5000
+        transaction_sequence, constraints.copy(), [], 5000, global_state.world_state
     )
 
     try:
@@ -103,19 +103,23 @@ def get_transaction_sequence(
     except UnsatError:
         raise UnsatError
 
-    min_price_dict = {}  # type: Dict[str, int]
+    # Include creation account in initial state
+    # Note: This contains the code, which should not exist until after the first tx
+    initial_world_state = transaction_sequence[0].world_state
+    initial_accounts = initial_world_state.accounts
+
     for transaction in transaction_sequence:
         concrete_transaction = _get_concrete_transaction(model, transaction)
         concrete_transactions.append(concrete_transaction)
 
-        caller = concrete_transaction["origin"]
-        value = int(concrete_transaction["value"], 16)
-        min_price_dict[caller] = min_price_dict.get(caller, 0) + value
-
-    if isinstance(transaction_sequence[0], ContractCreationTransaction):
-        initial_accounts = transaction_sequence[0].prev_world_state.accounts
-    else:
-        initial_accounts = transaction_sequence[0].world_state.accounts
+    min_price_dict = {}  # type: Dict[str, int]
+    for address in initial_accounts.keys():
+        min_price_dict[address] = model.eval(
+            initial_world_state.starting_balances[
+                symbol_factory.BitVecVal(address, 256)
+            ].raw,
+            model_completion=True,
+        ).as_long()
 
     concrete_initial_state = _get_concrete_state(initial_accounts, min_price_dict)
 
@@ -171,7 +175,7 @@ def _get_concrete_transaction(model: z3.Model, transaction: BaseTransaction):
 
 
 def _set_minimisation_constraints(
-    transaction_sequence, constraints, minimize, max_size
+    transaction_sequence, constraints, minimize, max_size, world_state
 ) -> Tuple[Constraints, tuple]:
     """ Set constraints that minimise key transaction values
 
@@ -192,6 +196,22 @@ def _set_minimisation_constraints(
 
         # Minimize
         minimize.append(transaction.call_data.calldatasize)
-        minimize.append(transaction.call_value)
+
+        constraints.append(
+            UGE(
+                symbol_factory.BitVecVal(1000000000000000000000, 256),
+                world_state.starting_balances[transaction.caller],
+            )
+        )
+
+    for account in world_state.accounts.values():
+        # Lazy way to prevent overflows and to ensure "reasonable" balances
+        # Each account starts with less than 100 ETH
+        constraints.append(
+            UGE(
+                symbol_factory.BitVecVal(100000000000000000000, 256),
+                world_state.starting_balances[account.address],
+            )
+        )
 
     return constraints, tuple(minimize)

mythril/laser/ethereum/call.py

@@ -49,7 +49,11 @@ def get_call_parameters(
 
     callee_account = None
     call_data = get_call_data(global_state, memory_input_offset, memory_input_size)
-    if int(callee_address, 16) >= 5 or int(callee_address, 16) == 0:
+    if (
+        isinstance(callee_address, BitVec)
+        or int(callee_address, 16) >= 5
+        or int(callee_address, 16) == 0
+    ):
         callee_account = get_callee_account(
             global_state, callee_address, dynamic_loader
         )
@@ -84,12 +88,11 @@ def get_callee_address(
     except TypeError:
         log.debug("Symbolic call encountered")
 
-        # TODO: This is broken. Now it should be Storage[(\d+)].
-        match = re.search(r"storage_(\d+)", str(simplify(symbolic_to_address)))
+        match = re.search(r"Storage\[(\d+)\]", str(simplify(symbolic_to_address)))
         log.debug("CALL to: " + str(simplify(symbolic_to_address)))
 
         if match is None or dynamic_loader is None:
-            raise ValueError()
+            return symbolic_to_address
 
         index = int(match.group(1))
         log.debug("Dynamic contract address at storage index {}".format(index))
@@ -100,9 +103,8 @@ def get_callee_address(
                 "0x{:040X}".format(environment.active_account.address.value), index
             )
         # TODO: verify whether this happens or not
-        except Exception:
-            log.debug("Error accessing contract storage.")
-            raise ValueError
+        except:
+            return symbolic_to_address
 
         # testrpc simply returns the address, geth response is more elaborate.
         if not re.match(r"^0x[0-9a-f]{40}$", callee_address):
@@ -112,7 +114,9 @@ def get_callee_address(
 
 
 def get_callee_account(
-    global_state: GlobalState, callee_address: str, dynamic_loader: DynLoader
+    global_state: GlobalState,
+    callee_address: Union[str, BitVec],
+    dynamic_loader: DynLoader,
 ):
     """Gets the callees account from the global_state.
 
@@ -123,6 +127,12 @@ def get_callee_account(
     """
     accounts = global_state.accounts
 
+    if isinstance(callee_address, BitVec):
+        if callee_address.symbolic:
+            return Account(callee_address, balances=global_state.world_state.balances)
+        else:
+            callee_address = hex(callee_address.value)[2:]
+
     try:
         return global_state.accounts[int(callee_address, 16)]
     except KeyError:
@@ -209,12 +219,12 @@ def get_call_data(
 
 def native_call(
     global_state: GlobalState,
-    callee_address: str,
+    callee_address: Union[str, BitVec],
     call_data: BaseCalldata,
     memory_out_offset: Union[int, Expression],
     memory_out_size: Union[int, Expression],
-) -> Optional[List[GlobalState]]:
-    if not 0 < int(callee_address, 16) < 5:
+) -> Union[List[GlobalState], None]:
+    if isinstance(callee_address, BitVec) or not 0 < int(callee_address, 16) < 5:
         return None
 
     log.debug("Native contract called: " + callee_address)

mythril/laser/ethereum/instructions.py

@@ -25,6 +25,7 @@ from mythril.laser.smt import (
     Bool,
     Not,
     LShR,
+    UGE,
 )
 from mythril.laser.smt import symbol_factory
 
@@ -56,6 +57,30 @@ TT256 = 2 ** 256
 TT256M1 = 2 ** 256 - 1
 
 
+def transfer_ether(
+    global_state: GlobalState,
+    sender: BitVec,
+    receiver: BitVec,
+    value: Union[int, BitVec],
+):
+    """
+    Perform an Ether transfer between two accounts
+
+    :param global_state: The global state in which the Ether transfer occurs
+    :param sender: The sender of the Ether
+    :param receiver: The recipient of the Ether
+    :param value: The amount of Ether to send
+    :return:
+    """
+    value = value if isinstance(value, BitVec) else symbol_factory.BitVecVal(value, 256)
+
+    global_state.mstate.constraints.append(
+        UGE(global_state.world_state.balances[sender], value)
+    )
+    global_state.world_state.balances[receiver] += value
+    global_state.world_state.balances[sender] -= value
+
+
 class StateTransition(object):
     """Decorator that handles global state copy and original return.
 
@@ -842,7 +867,11 @@ class Instruction:
         """
         state = global_state.mstate
         address = state.stack.pop()
-        state.stack.append(global_state.new_bitvec("balance_at_" + str(address), 256))
+
+        balance = global_state.world_state.balances[
+            global_state.environment.active_account.address
+        ]
+        state.stack.append(balance)
         return [global_state]
 
     @StateTransition()
@@ -1629,7 +1658,7 @@ class Instruction:
         transfer_amount = global_state.environment.active_account.balance()
         # Often the target of the suicide instruction will be symbolic
         # If it isn't then we'll transfer the balance to the indicated contract
-        global_state.world_state[target].add_balance(transfer_amount)
+        global_state.world_state.balances[target] += transfer_amount
 
         global_state.environment.active_account = deepcopy(
             global_state.environment.active_account
@@ -1703,6 +1732,10 @@ class Instruction:
 
             if callee_account is not None and callee_account.code.bytecode == "":
                 log.debug("The call is related to ether transfer between accounts")
+                sender = environment.active_account.address
+                receiver = callee_account.address
+                transfer_ether(global_state, sender, receiver, value)
+
                 global_state.mstate.stack.append(
                     global_state.new_bitvec("retval_" + str(instr["address"]), 256)
                 )
@@ -1818,6 +1851,18 @@ class Instruction:
             callee_address, callee_account, call_data, value, gas, _, _ = get_call_parameters(
                 global_state, self.dynamic_loader, True
             )
+
+            if callee_account is not None and callee_account.code.bytecode == "":
+                log.debug("The call is related to ether transfer between accounts")
+                sender = global_state.environment.active_account.address
+                receiver = callee_account.address
+                transfer_ether(global_state, sender, receiver, value)
+
+                global_state.mstate.stack.append(
+                    global_state.new_bitvec("retval_" + str(instr["address"]), 256)
+                )
+                return [global_state]
+
         except ValueError as e:
             log.debug(
                 "Could not determine required parameters for call, putting fresh symbol on the stack. \n{}".format(
@@ -1921,6 +1966,18 @@ class Instruction:
             callee_address, callee_account, call_data, value, gas, _, _ = get_call_parameters(
                 global_state, self.dynamic_loader
             )
+
+            if callee_account is not None and callee_account.code.bytecode == "":
+                log.debug("The call is related to ether transfer between accounts")
+                sender = environment.active_account.address
+                receiver = callee_account.address
+                transfer_ether(global_state, sender, receiver, value)
+
+                global_state.mstate.stack.append(
+                    global_state.new_bitvec("retval_" + str(instr["address"]), 256)
+                )
+                return [global_state]
+
         except ValueError as e:
             log.debug(
                 "Could not determine required parameters for call, putting fresh symbol on the stack. \n{}".format(
@@ -2022,6 +2079,18 @@ class Instruction:
             callee_address, callee_account, call_data, value, gas, memory_out_offset, memory_out_size = get_call_parameters(
                 global_state, self.dynamic_loader
             )
+
+            if callee_account is not None and callee_account.code.bytecode == "":
+                log.debug("The call is related to ether transfer between accounts")
+                sender = global_state.environment.active_account.address
+                receiver = callee_account.address
+                transfer_ether(global_state, sender, receiver, value)
+
+                global_state.mstate.stack.append(
+                    global_state.new_bitvec("retval_" + str(instr["address"]), 256)
+                )
+                return [global_state]
+
         except ValueError as e:
             log.debug(
                 "Could not determine required parameters for call, putting fresh symbol on the stack. \n{}".format(

mythril/laser/ethereum/state/world_state.py

@@ -27,6 +27,7 @@ class WorldState:
         """
         self._accounts = {}  # type: Dict[int, Account]
         self.balances = Array("balance", 256, 256)
+        self.starting_balances = copy(self.balances)
 
         self.node = None  # type: Optional['Node']
         self.transaction_sequence = transaction_sequence or []
@@ -60,6 +61,7 @@ class WorldState:
             annotations=new_annotations,
         )
         new_world_state.balances = copy(self.balances)
+        new_world_state.starting_balances = copy(self.starting_balances)
         for account in self._accounts.values():
             new_world_state.put_account(copy(account))
         new_world_state.node = self.node
@@ -115,7 +117,7 @@ class WorldState:
             concrete_storage=concrete_storage,
         )
         if balance:
-            new_account.set_balance(symbol_factory.BitVecVal(balance, 256))
+            new_account.add_balance(symbol_factory.BitVecVal(balance, 256))
 
         self.put_account(new_account)
         return new_account

mythril/laser/ethereum/transaction/transaction_models.py

@@ -4,7 +4,7 @@ execution."""
 import array
 from copy import deepcopy
 from z3 import ExprRef
-from typing import Union, Optional, cast
+from typing import Union, Optional
 
 from mythril.laser.ethereum.state.calldata import ConcreteCalldata
 from mythril.laser.ethereum.state.account import Account
@@ -12,8 +12,10 @@ from mythril.laser.ethereum.state.calldata import BaseCalldata, SymbolicCalldata
 from mythril.laser.ethereum.state.environment import Environment
 from mythril.laser.ethereum.state.global_state import GlobalState
 from mythril.laser.ethereum.state.world_state import WorldState
-from mythril.disassembler.disassembly import Disassembly
-from mythril.laser.smt import symbol_factory
+from mythril.laser.smt import symbol_factory, UGE, BitVec
+import logging
+
+log = logging.getLogger(__name__)
 
 _next_transaction_id = 0
 
@@ -115,10 +117,17 @@ class BaseTransaction:
 
         sender = environment.sender
         receiver = environment.active_account.address
-        value = environment.callvalue
+        value = (
+            environment.callvalue
+            if isinstance(environment.callvalue, BitVec)
+            else symbol_factory.BitVecVal(environment.callvalue, 256)
+        )
 
-        global_state.world_state.balances[sender] -= value
+        global_state.mstate.constraints.append(
+            UGE(global_state.world_state.balances[sender], value)
+        )
         global_state.world_state.balances[receiver] += value
+        global_state.world_state.balances[sender] -= value
 
         return global_state
 
@@ -180,7 +189,6 @@ class ContractCreationTransaction(BaseTransaction):
             0, concrete_storage=True, creator=caller.value
         )
         callee_account.contract_name = contract_name
-        # TODO: set correct balance for new account
         super().__init__(
             world_state=world_state,
             callee_account=callee_account,

tests/laser/evm_testsuite/VMTests/vmSystemOperations/suicide0.json

@@ -47,7 +47,7 @@
                 }
             },
             "0xcd1722f3947def4cf144679da39c4c32bdc35681" : {
-                "balance" : "0x17",
+                "balance" : "0x0186a0",
                 "code" : "0x6000355415600957005b60203560003555",
                 "nonce" : "0x00",
                 "storage" : {

tests/laser/evm_testsuite/VMTests/vmSystemOperations/suicideNotExistingAccount.json

@@ -54,7 +54,7 @@
                 }
             },
             "0xcd1722f3947def4cf144679da39c4c32bdc35681" : {
-                "balance" : "0x17",
+                "balance" : "0x0186a0",
                 "code" : "0x6000355415600957005b60203560003555",
                 "nonce" : "0x00",
                 "storage" : {

tests/laser/evm_testsuite/VMTests/vmSystemOperations/suicideSendEtherToMe.json

@@ -47,7 +47,7 @@
                 }
             },
             "0xcd1722f3947def4cf144679da39c4c32bdc35681" : {
-                "balance" : "0x17",
+                "balance" : "0x0186a0",
                 "code" : "0x6000355415600957005b60203560003555",
                 "nonce" : "0x00",
                 "storage" : {