From ae6a4fcc7a707e419463c47e191afe54def26764 Mon Sep 17 00:00:00 2001 From: Campbell Barton Date: Tue, 12 Jul 2022 16:05:15 +1000 Subject: Tests: add test to ensure restricted py-driver execution is working Add internal function (only used for testing at the moment) `_bpy._driver_secure_code_test`. Add test `script_pyapi_bpy_driver_secure_eval` to serves two purposes: - Ensure expressions that should be insecure remain so when upgrading Python or making any changes in this area. - Ensure new versions of Python don't introduce new byte-codes that prevent existing expressions from being executed (happened when upgrading from 3.7, see [0]). [0]: dfa52017638abdf59791e5588c439d3a558a191d --- tests/python/CMakeLists.txt | 5 + tests/python/bl_pyapi_bpy_driver_secure_eval.py | 220 ++++++++++++++++++++++++ 2 files changed, 225 insertions(+) create mode 100644 tests/python/bl_pyapi_bpy_driver_secure_eval.py (limited to 'tests') diff --git a/tests/python/CMakeLists.txt b/tests/python/CMakeLists.txt index 38c3fc4389a..d95f2cd2644 100644 --- a/tests/python/CMakeLists.txt +++ b/tests/python/CMakeLists.txt @@ -101,6 +101,11 @@ add_blender_test( --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_mathutils.py ) +add_blender_test( + script_pyapi_bpy_driver_secure_eval + --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_bpy_driver_secure_eval.py +) + add_blender_test( script_pyapi_idprop --python ${CMAKE_CURRENT_LIST_DIR}/bl_pyapi_idprop.py diff --git a/tests/python/bl_pyapi_bpy_driver_secure_eval.py b/tests/python/bl_pyapi_bpy_driver_secure_eval.py new file mode 100644 index 00000000000..953dbcd5381 --- /dev/null +++ b/tests/python/bl_pyapi_bpy_driver_secure_eval.py @@ -0,0 +1,220 @@ +# SPDX-License-Identifier: GPL-2.0-or-later + +# ./blender.bin --background -noaudio --python tests/python/bl_pyapi_bpy_driver_secure_eval.py -- --verbose +import bpy +import unittest +import builtins +from types import ModuleType + + +# ----------------------------------------------------------------------------- +# Mock Environment + + +expect_unreachable_msg = "This function should _NEVER_ run!" +# Internal check, to ensure this actually runs as expected. +expect_unreachable_count = 0 + + +def expect_os_unreachable(): + global expect_unreachable_count + expect_unreachable_count += 1 + raise Exception(expect_unreachable_msg) + + +__import__("os").expect_os_unreachable = expect_os_unreachable + + +expect_open_unreachable_count = 0 + + +def open_expect_unreachable(*args, **kwargs): + global expect_open_unreachable_count + expect_open_unreachable_count += 1 + raise Exception(expect_unreachable_msg) + + +mock_builtins = {**builtins.__dict__, **{"open": open_expect_unreachable}} + + +# ----------------------------------------------------------------------------- +# Utility Functions + + +def is_expression_secure(expr_str, verbose): + """ + Return (ok, code) where ok is true if expr_str is considered secure. + """ + # Internal function only for testing (not part of the public API). + from _bpy import _driver_secure_code_test + expr_code = compile(expr_str, "", 'eval') + ok = _driver_secure_code_test(expr_code, verbose=verbose) + return ok, expr_code + + +# ----------------------------------------------------------------------------- +# Tests (Accept) + + +class _TestExprMixIn: + """ + Sub-classes must define: + - expressions_expect_secure: boolean, the expected secure state. + - expressions: A sequence of expressions that must evaluate in the driver name-space. + + Optionally: + - expressions_expect_unreachable: + A boolean, when true, it's expected each expression should call + ``expect_os_unreachable`` or ``expect_open_unreachable``. + """ + + # Sub-class may override. + expressions_expect_unreachable = False + + def assertSecure(self, expect_secure, expr_str): + is_secure, expr_code = is_expression_secure( + expr_str, + # Only verbose when secure as this is will result in an failure, + # in that case it's useful to know which op-codes caused the test to unexpectedly fail. + verbose=expect_secure, + ) + if is_secure != expect_secure: + raise self.failureException( + "Expression \"%s\" was expected to be %s" % + (expr_str, "secure" if expect_secure else "insecure")) + # NOTE: executing is not essential, it's just better to ensure the expressions make sense. + try: + exec( + expr_code, + {"__builtins__": mock_builtins}, + {**bpy.app.driver_namespace, **{"__builtins__": mock_builtins}}, + ) + # exec(expr_code, {}, bpy.app.driver_namespace) + ex = None + except BaseException as ex_test: + ex = ex_test + + if self.expressions_expect_unreachable: + if ex and ex.args == (expect_unreachable_msg,): + ex = None + elif not ex: + raise self.failureException("Expression \"%s\" failed to run `os.expect_os_unreachable`" % (expr_str,)) + else: + # An unknown exception was raised, use the exception below. + pass + + if ex: + raise self.failureException("Expression \"%s\" failed to evaluate with error: %r" % (expr_str, ex)) + + def test_expr(self): + expect_secure = self.expressions_expect_secure + for expr_str in self.expressions: + self.assertSecure(expect_secure, expr_str) + + +class TestExprMixIn_Accept(_TestExprMixIn): + expressions_expect_secure = True + + +class TestExprMixIn_Reject(_TestExprMixIn): + expressions_expect_secure = False + + +class TestAcceptLiteralNumbers(unittest.TestCase, TestExprMixIn_Accept): + expressions = ("1", "1_1", "1.1", "1j", "0x1", "0o1", "0b1") + + +class TestAcceptLiteralStrings(unittest.TestCase, TestExprMixIn_Accept): + expressions = ("''", "'_'", "r''", "r'_'", "'''_'''") + + +class TestAcceptSequencesEmpty(unittest.TestCase, TestExprMixIn_Accept): + expressions = ("()", "[]", "{}", "[[]]", "(())") + + +class TestAcceptSequencesSimple(unittest.TestCase, TestExprMixIn_Accept): + expressions = ("('', '')", "['', '_']", "{'', '_'}", "{'': '_'}") + + +class TestAcceptSequencesExpand(unittest.TestCase, TestExprMixIn_Accept): + expressions = ("(*('', '_'),)", "[*(), *[]]", "{*{1, 2}}") + + +class TestAcceptSequencesComplex(unittest.TestCase, TestExprMixIn_Accept): + expressions = ("[1, 2, 3][-1:0:-1][0]", "1 in (1, 2)", "False if 1 in {1, 2} else True") + + +class TestAcceptMathOperators(unittest.TestCase, TestExprMixIn_Accept): + expressions = ("4 / 4", "4 * 4", "4 // 4", "2 ** 2", "4 ^ -1", "4 & 1", "4 % 1") + + +class TestAcceptMathFunctionsSimple(unittest.TestCase, TestExprMixIn_Accept): + expressions = ("sin(pi)", "degrees(pi / 2)", "clamp(4, 0, 1)") + + +class TestAcceptMathFunctionsComplex(unittest.TestCase, TestExprMixIn_Accept): + expressions = ("-(sin(pi) ** 2) / 2", "floor(22 / 7)", "ceil(pi + 1)") + + +# ----------------------------------------------------------------------------- +# Tests (Reject) + +class TestRejectLiteralFStrings(unittest.TestCase, TestExprMixIn_Reject): + # F-String's are not supported as `BUILD_STRING` op-code is disabled, + # while it may be safe to enable that needs to be double-checked. + # Further it doesn't seem useful for typical math expressions used in drivers. + expressions = ("f''", "f'{1}'", "f'{\"_\"}'") + + +class TestRejectModuleAccess(unittest.TestCase, TestExprMixIn_Reject): + # Each of these commands _must_ run `expect_os_unreachable`, + # and must also be rejected as insecure - otherwise we have problems. + expressions_expect_unreachable = True + expressions = ( + "__import__('os').expect_os_unreachable()", + "exec(\"__import__('os').expect_os_unreachable()\")", + "(globals().update(__import__('os').__dict__), expect_os_unreachable())", + ) + + # Ensure the functions are actually called. + def setUp(self): + self._count = expect_unreachable_count + + def tearDown(self): + count_actual = expect_unreachable_count - self._count + count_expect = len(self.expressions) + if count_actual != count_expect: + raise Exception( + "Expected 'os.expect_os_unreachable' to be called %d times but was called %d times" % + (count_expect, count_actual), + ) + + +class TestRejectOpenAccess(unittest.TestCase, TestExprMixIn_Reject): + # Each of these commands _must_ run `expect_open_unreachable`, + # and must also be rejected as insecure - otherwise we have problems. + expressions_expect_unreachable = True + expressions = ( + "open('file.txt', 'r')", + "exec(\"open('file.txt', 'r')\")", + "(globals().update({'fake_open': __builtins__['open']}), fake_open())", + ) + + # Ensure the functions are actually called. + def setUp(self): + self._count = expect_open_unreachable_count + + def tearDown(self): + count_actual = expect_open_unreachable_count - self._count + count_expect = len(self.expressions) + if count_actual != count_expect: + raise Exception( + "Expected 'open' to be called %d times but was called %d times" % + (count_expect, count_actual), + ) + + +if __name__ == '__main__': + import sys + sys.argv = [__file__] + (sys.argv[sys.argv.index("--") + 1:] if "--" in sys.argv else []) + unittest.main() -- cgit v1.2.3