mirror of https://github.com/ConsenSys/mythril
Nikhil Parasaram
6 years ago
commit
4346565ab8
@ -0,0 +1,104 @@ |
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from typing import Union |
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from z3 import BitVecRef, Extract, BitVecVal, If, BoolRef, Z3Exception, simplify, Concat |
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from mythril.laser.ethereum import util |
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class Memory: |
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def __init__(self): |
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self._memory = [] |
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def __len__(self): |
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return len(self._memory) |
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def extend(self, size): |
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self._memory.extend(bytearray(size)) |
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def get_word_at(self, index: int) -> Union[int, BitVecRef]: |
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""" |
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Access a word from a specified memory index |
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:param index: integer representing the index to access |
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:return: 32 byte word at the specified index |
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""" |
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try: |
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return util.concrete_int_from_bytes( |
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bytes([util.get_concrete_int(b) for b in self[index : index + 32]]), 0 |
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) |
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except TypeError: |
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result = simplify( |
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Concat( |
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[ |
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b if isinstance(b, BitVecRef) else BitVecVal(b, 8) |
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for b in self[index : index + 32] |
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] |
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) |
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) |
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assert result.size() == 256 |
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return result |
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|
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def write_word_at( |
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self, index: int, value: Union[int, BitVecRef, bool, BoolRef] |
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) -> None: |
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""" |
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Writes a 32 byte word to memory at the specified index` |
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:param index: index to write to |
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:param value: the value to write to memory |
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""" |
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try: |
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# Attempt to concretize value |
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if isinstance(value, bool): |
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_bytes = ( |
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int(1).to_bytes(32, byteorder="big") |
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if value |
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else int(0).to_bytes(32, byteorder="big") |
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) |
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else: |
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_bytes = util.concrete_int_to_bytes(value) |
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assert len(_bytes) == 32 |
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self[index : index + 32] = _bytes |
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except (Z3Exception, AttributeError): # BitVector or BoolRef |
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if isinstance(value, BoolRef): |
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value_to_write = If(value, BitVecVal(1, 256), BitVecVal(0, 256)) |
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else: |
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value_to_write = value |
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assert value_to_write.size() == 256 |
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for i in range(0, value_to_write.size(), 8): |
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self[index + 31 - (i // 8)] = Extract(i + 7, i, value_to_write) |
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def __getitem__(self, item: Union[int, slice]) -> Union[BitVecRef, int, list]: |
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if isinstance(item, slice): |
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start, step, stop = item.start, item.step, item.stop |
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if start is None: |
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start = 0 |
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if stop is None: # 2**256 is just a bit too big |
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raise IndexError("Invalid Memory Slice") |
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if step is None: |
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step = 1 |
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return [self[i] for i in range(start, stop, step)] |
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try: |
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return self._memory[item] |
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except IndexError: |
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return 0 |
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def __setitem__(self, key: Union[int, slice], value: Union[BitVecRef, int, list]): |
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if isinstance(key, slice): |
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start, step, stop = key.start, key.step, key.stop |
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if start is None: |
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start = 0 |
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if stop is None: |
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raise IndexError("Invalid Memory Slice") |
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if step is None: |
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step = 1 |
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for i in range(0, stop - start, step): |
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self[start + i] = value[i] |
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else: |
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if isinstance(value, int): |
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assert 0 <= value <= 0xFF |
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if isinstance(value, BitVecRef): |
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assert value.size() == 8 |
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self._memory[key] = value |
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@ -1 +1,66 @@ |
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{"error": null, "issues": [{"address": 618, "contract": "Unknown", "debug": "<DEBUG-DATA>", "description": "The function `_function_0x141f32ff` uses callcode. Callcode does not persist sender or value over the call. Use delegatecall instead.", "function": "_function_0x141f32ff", "max_gas_used": 1141, "min_gas_used": 389, "swc-id": "111", "title": "Use of callcode", "type": "Warning"}, {"address": 626, "contract": "Unknown", "debug": "<DEBUG-DATA>", "description": "The return value of an external call is not checked. Note that execution continue even if the called contract throws.", "function": "_function_0x141f32ff", "max_gas_used": 35856, "min_gas_used": 1104, "swc-id": "104", "title": "Unchecked CALL return value", "type": "Informational"}, {"address": 857, "contract": "Unknown", "debug": "<DEBUG-DATA>", "description": "The return value of an external call is not checked. Note that execution continue even if the called contract throws.", "function": "_function_0x9b58bc26", "max_gas_used": 35919, "min_gas_used": 1167, "swc-id": "104", "title": "Unchecked CALL return value", "type": "Informational"}, {"address": 1038, "contract": "Unknown", "debug": "<DEBUG-DATA>", "description": "The contract executes a function call with high gas to a user-supplied address. Note that the callee can contain arbitrary code and may re-enter any function in this contract. Review the business logic carefully to prevent unanticipated effects on the contract state.", "function": "_function_0xeea4c864", "max_gas_used": 1229, "min_gas_used": 477, "swc-id": "107", "title": "External call to user-supplied address", "type": "Warning"}, {"address": 1046, "contract": "Unknown", "debug": "<DEBUG-DATA>", "description": "The return value of an external call is not checked. Note that execution continue even if the called contract throws.", "function": "_function_0xeea4c864", "max_gas_used": 35944, "min_gas_used": 1192, "swc-id": "104", "title": "Unchecked CALL return value", "type": "Informational"}], "success": true} |
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{ |
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"error": null, |
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"issues": [ |
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{ |
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"address": 618, |
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"contract": "Unknown", |
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"debug": "<DEBUG-DATA>", |
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"description": "The function `_function_0x141f32ff` uses callcode. Callcode does not persist sender or value over the call. Use delegatecall instead.", |
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"function": "_function_0x141f32ff", |
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"max_gas_used": 1141, |
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"min_gas_used": 389, |
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"swc-id": "111", |
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"title": "Use of callcode", |
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"type": "Warning" |
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}, |
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{ |
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"address": 626, |
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"contract": "Unknown", |
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"debug": "<DEBUG-DATA>", |
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"description": "The return value of an external call is not checked. Note that execution continue even if the called contract throws.", |
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"function": "_function_0x141f32ff", |
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"max_gas_used": 35856, |
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"min_gas_used": 1104, |
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"swc-id": "104", |
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"title": "Unchecked CALL return value", |
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"type": "Informational" |
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}, |
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{ |
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"address": 857, |
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"contract": "Unknown", |
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"debug": "<DEBUG-DATA>", |
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"description": "The return value of an external call is not checked. Note that execution continue even if the called contract throws.", |
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"function": "_function_0x9b58bc26", |
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"max_gas_used": 35913, |
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"min_gas_used": 1161, |
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"swc-id": "104", |
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"title": "Unchecked CALL return value", |
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"type": "Informational" |
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}, |
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{ |
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"address": 1038, |
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"contract": "Unknown", |
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"debug": "<DEBUG-DATA>", |
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"description": "The contract executes a function call with high gas to a user-supplied address. Note that the callee can contain arbitrary code and may re-enter any function in this contract. Review the business logic carefully to prevent unanticipated effects on the contract state.", |
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"function": "_function_0xeea4c864", |
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"max_gas_used": 1223, |
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"min_gas_used": 471, |
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"swc-id": "107", |
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"title": "External call to user-supplied address", |
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"type": "Warning" |
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}, |
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{ |
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"address": 1046, |
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"contract": "Unknown", |
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"debug": "<DEBUG-DATA>", |
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"description": "The return value of an external call is not checked. Note that execution continue even if the called contract throws.", |
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"function": "_function_0xeea4c864", |
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"max_gas_used": 35938, |
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"min_gas_used": 1186, |
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"swc-id": "104", |
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"title": "Unchecked CALL return value", |
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"type": "Informational" |
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} |
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], |
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"success": true |
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} |
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|
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