diff options
| -rw-r--r-- | nova/api/ec2/__init__.py | 70 | ||||
| -rw-r--r-- | nova/fakememcache.py | 50 | ||||
| -rw-r--r-- | nova/tests/middleware_unittest.py | 82 | ||||
| -rw-r--r-- | run_tests.py | 1 |
4 files changed, 202 insertions, 1 deletions
diff --git a/nova/api/ec2/__init__.py b/nova/api/ec2/__init__.py index a6ee16c33..19eb666cd 100644 --- a/nova/api/ec2/__init__.py +++ b/nova/api/ec2/__init__.py @@ -22,12 +22,13 @@ Starting point for routing EC2 requests. import logging import routes +import time import webob import webob.dec import webob.exc -from nova import exception from nova import context +from nova import exception from nova import flags from nova import wsgi from nova.api.ec2 import apirequest @@ -37,6 +38,16 @@ from nova.auth import manager FLAGS = flags.FLAGS +flags.DEFINE_boolean('use_lockout', False, + 'Whether or not to use lockout middleware.') +flags.DEFINE_integer('lockout_attempts', 5, + 'Number of failed auths before lockout.') +flags.DEFINE_integer('lockout_minutes', 15, + 'Number of minutes to lockout if triggered.') +flags.DEFINE_list('lockout_memcached_servers', None, + 'Memcached servers or None for in process cache.') + + _log = logging.getLogger("api") _log.setLevel(logging.DEBUG) @@ -47,6 +58,63 @@ class API(wsgi.Middleware): def __init__(self): self.application = Authenticate(Router(Authorizer(Executor()))) + if FLAGS.use_lockout: + self.application = Lockout(self.application) + + +class Lockout(wsgi.Middleware): + """Only allow x failed auths in a y minute period. + + x = lockout_attempts flag + y = lockout_timeout flag + + Uses memcached if lockout_memcached_servers flag is set, otherwise it + uses a very simple in-proccess cache. Due to the simplicity of + the implementation, the timeout window is reset with every failed + request, so it actually blocks if there are x failed logins with no + more than y minutes between any two failures. + + There is a possible race condition where simultaneous requests could + sneak in before the lockout hits, but this is extremely rare and would + only result in a couple of extra failed attempts.""" + + def __init__(self, application, time_fn=time.time): + """The middleware can use a custom time function for testing.""" + self.time_fn = time_fn + if FLAGS.lockout_memcached_servers: + import memcache + else: + from nova import fakememcache as memcache + self.mc = memcache.Client(FLAGS.lockout_memcached_servers, debug=0) + super(Lockout, self).__init__(application) + + @webob.dec.wsgify + def __call__(self, req): + access_key = req.params['AWSAccessKeyId'] + failures_key = "%s-failures" % access_key + last_key = "%s-last" % access_key + now = self.time_fn() + timeout = now - FLAGS.lockout_minutes * 60 + # NOTE(vish): To use incr, failures has to be a string. + failures = int(self.mc.get(failures_key) or 0) + last = self.mc.get(last_key) + if (failures and failures >= FLAGS.lockout_attempts + and last > timeout): + self.mc.set(last_key, now) + detail = "Too many failed authentications." + raise webob.exc.HTTPForbidden(detail=detail) + res = req.get_response(self.application) + if res.status_int == 403: + if last > timeout: + failures = int(self.mc.incr(failures_key)) + if failures >= FLAGS.lockout_attempts: + _log.warn('Access key %s has had %d failed authentications' + ' and will be locked out for %d minutes.' % + (access_key, failures, FLAGS.lockout_minutes)) + else: + self.mc.set(failures_key, '1') + self.mc.set(last_key, now) + return res class Authenticate(wsgi.Middleware): diff --git a/nova/fakememcache.py b/nova/fakememcache.py new file mode 100644 index 000000000..0b2e3b6c1 --- /dev/null +++ b/nova/fakememcache.py @@ -0,0 +1,50 @@ +# vim: tabstop=4 shiftwidth=4 softtabstop=4 + +# Copyright 2010 United States Government as represented by the +# Administrator of the National Aeronautics and Space Administration. +# All Rights Reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); you may +# not use this file except in compliance with the License. You may obtain +# a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT +# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the +# License for the specific language governing permissions and limitations +# under the License. + +"""Super simple fake memcache client.""" + + +class Client(object): + """Replicates a tiny subset of memcached client interface.""" + __cache = {} + + def __init__(self, *args, **kwargs): + """Ignores all constructor params.""" + pass + + def get(self, key): + """Retrieves the value for a key or None.""" + return self.__cache.get(key, None) + + def set(self, key, value): + """Sets the value for a key.""" + self.__cache[key] = value + return True + + def add(self, key, value): + """Sets the value for a key if it doesn't exist.""" + if key in self.__cache: + return False + return self.set(key, value) + + def incr(self, key, delta=1): + """Increments the value for a key.""" + if not key in self.__cache: + return 0 + self.__cache[key] = str(int(self.__cache[key]) + 1) + return self.__cache[key] diff --git a/nova/tests/middleware_unittest.py b/nova/tests/middleware_unittest.py new file mode 100644 index 000000000..bbbd4a5a7 --- /dev/null +++ b/nova/tests/middleware_unittest.py @@ -0,0 +1,82 @@ +# vim: tabstop=4 shiftwidth=4 softtabstop=4 + +# Copyright 2010 United States Government as represented by the +# Administrator of the National Aeronautics and Space Administration. +# All Rights Reserved. +# +# Licensed under the Apache License, Version 2.0 (the "License"); you may +# not use this file except in compliance with the License. You may obtain +# a copy of the License at +# +# http://www.apache.org/licenses/LICENSE-2.0 +# +# Unless required by applicable law or agreed to in writing, software +# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT +# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the +# License for the specific language governing permissions and limitations +# under the License. + +import webob +import webob.dec +import webob.exc + +from nova.api import ec2 +from nova import flags +from nova import test + + +FLAGS = flags.FLAGS + + +@webob.dec.wsgify +def conditional_forbid(req): + """Helper wsgi app returns 403 if param 'die' is 1.""" + if 'die' in req.params and req.params['die'] == '1': + raise webob.exc.HTTPForbidden() + return 'OK' + + +class LockoutTestCase(test.TrialTestCase): + """Test case for the Lockout middleware.""" + def setUp(self): # pylint: disable-msg=C0103 + self.local_time = 0 + self.lockout = ec2.Lockout(conditional_forbid, + time_fn=self._constant_time) + super(LockoutTestCase, self).setUp() + + def _constant_time(self): + """Helper method to force timeouts.""" + return self.local_time + + def _trigger_lockout(self, access_key): + """Send x failed requests where x = lockout_attempts.""" + for i in xrange(FLAGS.lockout_attempts): + req = webob.Request.blank('/?AWSAccessKeyId=%s&die=1' % access_key) + self.assertEqual(req.get_response(self.lockout).status_int, 403) + + def _is_locked_out(self, access_key): + """Sends a test request to see if key is locked out.""" + req = webob.Request.blank('/?AWSAccessKeyId=%s' % access_key) + return (req.get_response(self.lockout).status_int == 403) + + def _timeout(self): + """Increment time to 1 second past the lockout.""" + self.local_time = 1 + self.local_time + FLAGS.lockout_minutes * 60 + + def test_lockout(self): + self._trigger_lockout('test') + self.assertTrue(self._is_locked_out('test')) + + def test_timeout(self): + self._trigger_lockout('test') + self.assertTrue(self._is_locked_out('test')) + self._timeout() + self.assertFalse(self._is_locked_out('test')) + + def test_multiple_keys(self): + self._trigger_lockout('test1') + self.assertTrue(self._is_locked_out('test1')) + self.assertFalse(self._is_locked_out('test2')) + self._timeout() + self.assertFalse(self._is_locked_out('test1')) + self.assertFalse(self._is_locked_out('test2')) diff --git a/run_tests.py b/run_tests.py index 37a548e4c..a0ef3fd99 100644 --- a/run_tests.py +++ b/run_tests.py @@ -57,6 +57,7 @@ from nova.tests.auth_unittest import * from nova.tests.cloud_unittest import * from nova.tests.compute_unittest import * from nova.tests.flags_unittest import * +from nova.tests.middleware_unittest import * from nova.tests.misc_unittest import * from nova.tests.network_unittest import * from nova.tests.objectstore_unittest import * |