Commit 413202e7 by Ned Batchelder

Merged ned/whitelistable-sandbox

parents e685ff71 cab49716
......@@ -470,6 +470,7 @@ class LoncapaProblem(object):
python_path=python_path,
cache=self.system.cache,
slug=self.problem_id,
unsafely=self.system.can_execute_unsafe_code(),
)
except Exception as err:
log.exception("Error while execing script code: " + all_code)
......
......@@ -288,7 +288,14 @@ class LoncapaResponse(object):
}
try:
safe_exec.safe_exec(code, globals_dict, python_path=self.context['python_path'], slug=self.id)
safe_exec.safe_exec(
code,
globals_dict,
python_path=self.context['python_path'],
slug=self.id,
random_seed=self.context['seed'],
unsafely=self.system.can_execute_unsafe_code(),
)
except Exception as err:
msg = 'Error %s in evaluating hint function %s' % (err, hintfn)
msg += "\nSee XML source line %s" % getattr(
......@@ -973,7 +980,14 @@ class CustomResponse(LoncapaResponse):
'ans': ans,
}
globals_dict.update(kwargs)
safe_exec.safe_exec(code, globals_dict, python_path=self.context['python_path'], slug=self.id)
safe_exec.safe_exec(
code,
globals_dict,
python_path=self.context['python_path'],
slug=self.id,
random_seed=self.context['seed'],
unsafely=self.system.can_execute_unsafe_code(),
)
return globals_dict['cfn_return']
return check_function
......@@ -1090,7 +1104,14 @@ class CustomResponse(LoncapaResponse):
# exec the check function
if isinstance(self.code, basestring):
try:
safe_exec.safe_exec(self.code, self.context, cache=self.system.cache, slug=self.id)
safe_exec.safe_exec(
self.code,
self.context,
cache=self.system.cache,
slug=self.id,
random_seed=self.context['seed'],
unsafely=self.system.can_execute_unsafe_code(),
)
except Exception as err:
self._handle_exec_exception(err)
......@@ -1814,7 +1835,14 @@ class SchematicResponse(LoncapaResponse):
]
self.context.update({'submission': submission})
try:
safe_exec.safe_exec(self.code, self.context, cache=self.system.cache, slug=self.id)
safe_exec.safe_exec(
self.code,
self.context,
cache=self.system.cache,
slug=self.id,
random_seed=self.context['seed'],
unsafely=self.system.can_execute_unsafe_code(),
)
except Exception as err:
msg = 'Error %s in evaluating SchematicResponse' % err
raise ResponseError(msg)
......
"""Capa's specialized use of codejail.safe_exec."""
from codejail.safe_exec import safe_exec as codejail_safe_exec
from codejail.safe_exec import not_safe_exec as codejail_not_safe_exec
from codejail.safe_exec import json_safe, SafeExecException
from . import lazymod
from statsd import statsd
......@@ -71,7 +72,7 @@ def update_hash(hasher, obj):
@statsd.timed('capa.safe_exec.time')
def safe_exec(code, globals_dict, random_seed=None, python_path=None, cache=None, slug=None):
def safe_exec(code, globals_dict, random_seed=None, python_path=None, cache=None, slug=None, unsafely=False):
"""
Execute python code safely.
......@@ -90,6 +91,8 @@ def safe_exec(code, globals_dict, random_seed=None, python_path=None, cache=None
`slug` is an arbitrary string, a description that's meaningful to the
caller, that will be used in log messages.
If `unsafely` is true, then the code will actually be executed without sandboxing.
"""
# Check the cache for a previous result.
if cache:
......@@ -111,9 +114,15 @@ def safe_exec(code, globals_dict, random_seed=None, python_path=None, cache=None
# Create the complete code we'll run.
code_prolog = CODE_PROLOG % random_seed
# Decide which code executor to use.
if unsafely:
exec_fn = codejail_not_safe_exec
else:
exec_fn = codejail_safe_exec
# Run the code! Results are side effects in globals_dict.
try:
codejail_safe_exec(
exec_fn(
code_prolog + LAZY_IMPORTS + code, globals_dict,
python_path=python_path, slug=slug,
)
......
"""Test safe_exec.py"""
import hashlib
import os
import os.path
import random
import textwrap
import unittest
from nose.plugins.skip import SkipTest
from capa.safe_exec import safe_exec, update_hash
from codejail.safe_exec import SafeExecException
from codejail.jail_code import is_configured
class TestSafeExec(unittest.TestCase):
......@@ -68,6 +72,24 @@ class TestSafeExec(unittest.TestCase):
self.assertIn("ZeroDivisionError", cm.exception.message)
class TestSafeOrNot(unittest.TestCase):
def test_cant_do_something_forbidden(self):
# Can't test for forbiddenness if CodeJail isn't configured for python.
if not is_configured("python"):
raise SkipTest
g = {}
with self.assertRaises(SafeExecException) as cm:
safe_exec("import os; files = os.listdir('/')", g)
self.assertIn("OSError", cm.exception.message)
self.assertIn("Permission denied", cm.exception.message)
def test_can_do_something_forbidden_if_run_unsafely(self):
g = {}
safe_exec("import os; files = os.listdir('/')", g, unsafely=True)
self.assertEqual(g['files'], os.listdir('/'))
class DictCache(object):
"""A cache implementation over a simple dict, for testing."""
......
......@@ -640,6 +640,23 @@ class StringResponseTest(ResponseTest):
correct_map = problem.grade_answers(input_dict)
self.assertEquals(correct_map.get_hint('1_2_1'), "Hello??")
def test_hint_function_randomization(self):
# The hint function should get the seed from the problem.
problem = self.build_problem(
answer="1",
hintfn="gimme_a_random_hint",
script=textwrap.dedent("""
def gimme_a_random_hint(answer_ids, student_answers, new_cmap, old_cmap):
answer = str(random.randint(0, 1e9))
new_cmap.set_hint_and_mode(answer_ids[0], answer, "always")
""")
)
correct_map = problem.grade_answers({'1_2_1': '2'})
hint = correct_map.get_hint('1_2_1')
r = random.Random(problem.seed)
self.assertEqual(hint, str(r.randint(0, 1e9)))
class CodeResponseTest(ResponseTest):
from response_xml_factory import CodeResponseXMLFactory
......@@ -948,7 +965,6 @@ class CustomResponseTest(ResponseTest):
xml_factory_class = CustomResponseXMLFactory
def test_inline_code(self):
# For inline code, we directly modify global context variables
# 'answers' is a list of answers provided to us
# 'correct' is a list we fill in with True/False
......@@ -961,15 +977,14 @@ class CustomResponseTest(ResponseTest):
self.assert_grade(problem, '0', 'incorrect')
def test_inline_message(self):
# Inline code can update the global messages list
# to pass messages to the CorrectMap for a particular input
# The code can also set the global overall_message (str)
# to pass a message that applies to the whole response
inline_script = textwrap.dedent("""
messages[0] = "Test Message"
overall_message = "Overall message"
""")
messages[0] = "Test Message"
overall_message = "Overall message"
""")
problem = self.build_problem(answer=inline_script)
input_dict = {'1_2_1': '0'}
......@@ -983,8 +998,19 @@ class CustomResponseTest(ResponseTest):
overall_msg = correctmap.get_overall_message()
self.assertEqual(overall_msg, "Overall message")
def test_function_code_single_input(self):
def test_inline_randomization(self):
# Make sure the seed from the problem gets fed into the script execution.
inline_script = """messages[0] = str(random.randint(0, 1e9))"""
problem = self.build_problem(answer=inline_script)
input_dict = {'1_2_1': '0'}
correctmap = problem.grade_answers(input_dict)
input_msg = correctmap.get_msg('1_2_1')
r = random.Random(problem.seed)
self.assertEqual(input_msg, str(r.randint(0, 1e9)))
def test_function_code_single_input(self):
# For function code, we pass in these arguments:
#
# 'expect' is the expect attribute of the <customresponse>
......@@ -1212,6 +1238,29 @@ class CustomResponseTest(ResponseTest):
with self.assertRaises(ResponseError):
problem.grade_answers({'1_2_1': '42'})
def test_setup_randomization(self):
# Ensure that the problem setup script gets the random seed from the problem.
script = textwrap.dedent("""
num = random.randint(0, 1e9)
""")
problem = self.build_problem(script=script)
r = random.Random(problem.seed)
self.assertEqual(r.randint(0, 1e9), problem.context['num'])
def test_check_function_randomization(self):
# The check function should get random-seeded from the problem.
script = textwrap.dedent("""
def check_func(expect, answer_given):
return {'ok': True, 'msg': str(random.randint(0, 1e9))}
""")
problem = self.build_problem(script=script, cfn="check_func", expect="42")
input_dict = {'1_2_1': '42'}
correct_map = problem.grade_answers(input_dict)
msg = correct_map.get_msg('1_2_1')
r = random.Random(problem.seed)
self.assertEqual(msg, str(r.randint(0, 1e9)))
def test_module_imports_inline(self):
'''
Check that the correct modules are available to custom
......@@ -1275,7 +1324,6 @@ class SchematicResponseTest(ResponseTest):
xml_factory_class = SchematicResponseXMLFactory
def test_grade(self):
# Most of the schematic-specific work is handled elsewhere
# (in client-side JavaScript)
# The <schematicresponse> is responsible only for executing the
......@@ -1290,7 +1338,7 @@ class SchematicResponseTest(ResponseTest):
# The actual dictionary would contain schematic information
# sent from the JavaScript simulation
submission_dict = {'test': 'test'}
submission_dict = {'test': 'the_answer'}
input_dict = {'1_2_1': json.dumps(submission_dict)}
correct_map = problem.grade_answers(input_dict)
......@@ -1299,8 +1347,19 @@ class SchematicResponseTest(ResponseTest):
# is what we expect)
self.assertEqual(correct_map.get_correctness('1_2_1'), 'correct')
def test_script_exception(self):
def test_check_function_randomization(self):
# The check function should get a random seed from the problem.
script = "correct = ['correct' if (submission[0]['num'] == random.randint(0, 1e9)) else 'incorrect']"
problem = self.build_problem(answer=script)
r = random.Random(problem.seed)
submission_dict = {'num': r.randint(0, 1e9)}
input_dict = {'1_2_1': json.dumps(submission_dict)}
correct_map = problem.grade_answers(input_dict)
self.assertEqual(correct_map.get_correctness('1_2_1'), 'correct')
def test_script_exception(self):
# Construct a script that will raise an exception
script = "raise Exception('test')"
problem = self.build_problem(answer=script)
......
......@@ -9,5 +9,5 @@
# Our libraries:
-e git+https://github.com/edx/XBlock.git@2144a25d#egg=XBlock
-e git+https://github.com/edx/codejail.git@5fb5fa0#egg=codejail
-e git+https://github.com/edx/codejail.git@0a1b468#egg=codejail
-e git+https://github.com/edx/diff-cover.git@v0.1.1#egg=diff_cover
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