From eeefb784f24c37d5f56a421e1ccc911cace9385e Mon Sep 17 00:00:00 2001 From: "Bryan D. Payne" Date: Fri, 7 Jun 2013 09:34:25 -0700 Subject: [PATCH] Fix memcache encryption middleware This fixes lp1175367 and lp1175368 by redesigning the memcache crypt middleware to not do dangerous things. It is forward compatible, but will invalidate any existing ephemeral encrypted or signed memcache entries. Change-Id: Ice8724949a48bfad3b8b7c41b5f50a18a9ad9f42 Signed-off-by: Bryan D. Payne --- doc/source/middlewarearchitecture.rst | 37 ++-- keystoneclient/middleware/auth_token.py | 131 ++++++------- keystoneclient/middleware/memcache_crypt.py | 197 ++++++++++++-------- tests/test_auth_token_middleware.py | 89 ++------- tests/test_memcache_crypt.py | 96 ++++++---- 5 files changed, 277 insertions(+), 273 deletions(-) diff --git a/doc/source/middlewarearchitecture.rst b/doc/source/middlewarearchitecture.rst index 803fbd905..894d40dd9 100644 --- a/doc/source/middlewarearchitecture.rst +++ b/doc/source/middlewarearchitecture.rst @@ -1,5 +1,5 @@ .. - Copyright 2011-2012 OpenStack, LLC + Copyright 2011-2013 OpenStack, LLC All Rights Reserved. Licensed under the Apache License, Version 2.0 (the "License"); you may @@ -188,7 +188,8 @@ Configuration Options the timeout when validating token by http). * ``auth_port``: (optional, default `35357`) the port used to validate tokens * ``auth_protocol``: (optional, default `https`) -* ``auth_uri``: (optional, defaults to `auth_protocol`://`auth_host`:`auth_port`) +* ``auth_uri``: (optional, defaults to + `auth_protocol`://`auth_host`:`auth_port`) * ``certfile``: (required, if Keystone server requires client cert) * ``keyfile``: (required, if Keystone server requires client cert) This can be the same as the certfile if the certfile includes the private key. @@ -232,22 +233,24 @@ Memcache Protection =================== When using memcached, we are storing user tokens and token validation -information into the cache as raw data. Which means anyone who have access -to the memcache servers can read and modify data stored there. To mitigate -this risk, ``auth_token`` middleware provides an option to either encrypt -or authenticate the token data stored in the cache. - -* ``memcache_security_strategy``: (optional) if defined, indicate whether token - data should be encrypted or authenticated. Acceptable values are ``ENCRYPT`` - or ``MAC``. If ``ENCRYPT``, token data is encrypted in the cache. If - ``MAC``, token data is authenticated (with HMAC) in the cache. If its value - is neither ``MAC`` nor ``ENCRYPT``, ``auth_token`` will raise an exception - on initialization. +information into the cache as raw data. Which means that anyone who +has access to the memcache servers can read and modify data stored +there. To mitigate this risk, ``auth_token`` middleware provides an +option to authenticate and optionally encrypt the token data stored in +the cache. + +* ``memcache_security_strategy``: (optional) if defined, indicate + whether token data should be authenticated or authenticated and + encrypted. Acceptable values are ``MAC`` or ``ENCRYPT``. If ``MAC``, + token data is authenticated (with HMAC) in the cache. If + ``ENCRYPT``, token data is encrypted and authenticated in the + cache. If the value is not one of these options or empty, + ``auth_token`` will raise an exception on initialization. * ``memcache_secret_key``: (optional, mandatory if - ``memcache_security_strategy`` is defined) if defined, - a random string to be used for key derivation. If - ``memcache_security_strategy`` is defined and ``memcache_secret_key`` is - absent, ``auth_token`` will raise an exception on initialization. + ``memcache_security_strategy`` is defined) this string is used for + key derivation. If ``memcache_security_strategy`` is defined and + ``memcache_secret_key`` is absent, ``auth_token`` will raise an + exception on initialization. Exchanging User Information =========================== diff --git a/keystoneclient/middleware/auth_token.py b/keystoneclient/middleware/auth_token.py index 7e3012cb8..e50f723c8 100644 --- a/keystoneclient/middleware/auth_token.py +++ b/keystoneclient/middleware/auth_token.py @@ -222,6 +222,7 @@ CONF.register_opts(opts, group='keystone_authtoken') LIST_OF_VERSIONS_TO_ATTEMPT = ['v2.0', 'v3.0'] +CACHE_KEY_TEMPLATE = 'tokens/%s' def will_expire_soon(expiry): @@ -847,91 +848,81 @@ def _get_header(self, env, key, default=None): env_key = self._header_to_env_var(key) return env.get(env_key, default) - def _protect_cache_value(self, token, data): - """ Encrypt or sign data if necessary. """ - try: - if self._memcache_security_strategy == 'ENCRYPT': - return memcache_crypt.encrypt_data(token, - self._memcache_secret_key, - data) - elif self._memcache_security_strategy == 'MAC': - return memcache_crypt.sign_data(token, data) - else: - return data - except: - msg = 'Failed to encrypt/sign cache data.' - self.LOG.exception(msg) - return data - - def _unprotect_cache_value(self, token, data): - """ Decrypt or verify signed data if necessary. """ - if data is None: - return data - - try: - if self._memcache_security_strategy == 'ENCRYPT': - return memcache_crypt.decrypt_data(token, - self._memcache_secret_key, - data) - elif self._memcache_security_strategy == 'MAC': - return memcache_crypt.verify_signed_data(token, data) - else: - return data - except: - msg = 'Failed to decrypt/verify cache data.' - self.LOG.exception(msg) - # this should have the same effect as data not found in cache - return None - - def _get_cache_key(self, token): - """ Return the cache key. - - Do not use clear token as key if memcache protection is on. - - """ - htoken = token - if self._memcache_security_strategy in ('ENCRYPT', 'MAC'): - derv_token = token + self._memcache_secret_key - htoken = memcache_crypt.hash_data(derv_token) - return 'tokens/%s' % htoken - - def _cache_get(self, token): + def _cache_get(self, token, ignore_expires=False): """Return token information from cache. If token is invalid raise InvalidUserToken return token only if fresh (not expired). """ + if self._cache and token: - key = self._get_cache_key(token) - cached = self._cache.get(key) - cached = self._unprotect_cache_value(token, cached) + if self._memcache_security_strategy is None: + key = CACHE_KEY_TEMPLATE % token + serialized = self._cache.get(key) + else: + keys = memcache_crypt.derive_keys( + token, + self._memcache_secret_key, + self._memcache_security_strategy) + cache_key = CACHE_KEY_TEMPLATE % ( + memcache_crypt.get_cache_key(keys)) + raw_cached = self._cache.get(cache_key) + try: + # unprotect_data will return None if raw_cached is None + serialized = memcache_crypt.unprotect_data(keys, + raw_cached) + except Exception: + msg = 'Failed to decrypt/verify cache data' + self.LOG.exception(msg) + # this should have the same effect as data not + # found in cache + serialized = None + + if serialized is None: + return None + + # Note that 'invalid' and (data, expires) are the only + # valid types of serialized cache entries, so there is not + # a collision with json.loads(serialized) == None. + cached = json.loads(serialized) if cached == 'invalid': self.LOG.debug('Cached Token %s is marked unauthorized', token) raise InvalidUserToken('Token authorization failed') - if cached: - data, expires = cached - if time.time() < float(expires): - self.LOG.debug('Returning cached token %s', token) - return data - else: - self.LOG.debug('Cached Token %s seems expired', token) - - def _cache_store(self, token, data, expires=None): - """ Store value into memcache. """ - key = self._get_cache_key(token) - data = self._protect_cache_value(token, data) - data_to_store = data - if expires: - data_to_store = (data, expires) + + data, expires = cached + if ignore_expires or time.time() < float(expires): + self.LOG.debug('Returning cached token %s', token) + return data + else: + self.LOG.debug('Cached Token %s seems expired', token) + + def _cache_store(self, token, data): + """ Store value into memcache. + + data may be the string 'invalid' or a tuple like (data, expires) + + """ + serialized_data = json.dumps(data) + if self._memcache_security_strategy is None: + cache_key = CACHE_KEY_TEMPLATE % token + data_to_store = serialized_data + else: + keys = memcache_crypt.derive_keys( + token, + self._memcache_secret_key, + self._memcache_security_strategy) + cache_key = CACHE_KEY_TEMPLATE % memcache_crypt.get_cache_key(keys) + data_to_store = memcache_crypt.protect_data(keys, serialized_data) + # we need to special-case set() because of the incompatibility between # Swift MemcacheRing and python-memcached. See # https://bugs.launchpad.net/swift/+bug/1095730 if self._use_keystone_cache: - self._cache.set(key, + self._cache.set(cache_key, data_to_store, time=self.token_cache_time) else: - self._cache.set(key, + self._cache.set(cache_key, data_to_store, timeout=self.token_cache_time) @@ -959,7 +950,7 @@ def _cache_put(self, token, data, expires): """ if self._cache: self.LOG.debug('Storing %s token in memcache', token) - self._cache_store(token, data, expires) + self._cache_store(token, (data, expires)) def _cache_store_invalid(self, token): """Store invalid token in cache.""" diff --git a/keystoneclient/middleware/memcache_crypt.py b/keystoneclient/middleware/memcache_crypt.py index 91e261da0..6cadf3ab9 100755 --- a/keystoneclient/middleware/memcache_crypt.py +++ b/keystoneclient/middleware/memcache_crypt.py @@ -1,6 +1,6 @@ # vim: tabstop=4 shiftwidth=4 softtabstop=4 -# Copyright 2010-2012 OpenStack LLC +# Copyright 2010-2013 OpenStack LLC # # Licensed under the Apache License, Version 2.0 (the "License"); # you may not use this file except in compliance with the License. @@ -18,33 +18,34 @@ """ Utilities for memcache encryption and integrity check. -Data is serialized before been encrypted or MACed. Encryption have a -dependency on the pycrypto. If pycrypto is not available, -CryptoUnabailableError will be raised. +Data should be serialized before entering these functions. Encryption +has a dependency on the pycrypto. If pycrypto is not available, +CryptoUnavailableError will be raised. -Encrypted data stored in memcache are prefixed with '{ENCRYPT:AES256}'. - -MACed data stored in memcache are prefixed with '{MAC:SHA1}'. +This module will not be called unless signing or encryption is enabled +in the config. It will always validate signatures, and will decrypt +data if encryption is enabled. It is not valid to mix protection +modes. """ import base64 import functools import hashlib -import json +import hmac +import math import os -# make sure pycrypt is available +# make sure pycrypto is available try: from Crypto.Cipher import AES except ImportError: AES = None - -# prefix marker indicating data is HMACed (signed by a secret key) -MAC_MARKER = '{MAC:SHA1}' -# prefix marker indicating data is encrypted -ENCRYPT_MARKER = '{ENCRYPT:AES256}' +HASH_FUNCTION = hashlib.sha384 +DIGEST_LENGTH = HASH_FUNCTION().digest_size +DIGEST_SPLIT = DIGEST_LENGTH // 3 +DIGEST_LENGTH_B64 = 4 * int(math.ceil(DIGEST_LENGTH / 3.0)) class InvalidMacError(Exception): @@ -81,77 +82,121 @@ def wrapper(*args, **kwds): return wrapper -def generate_aes_key(token, secret): - """ Generates and returns a 256 bit AES key, based on sha256 hash. """ - return hashlib.sha256(token + secret).digest() - - -def compute_mac(token, serialized_data): - """ Computes and returns the base64 encoded MAC. """ - return hash_data(serialized_data + token) +def constant_time_compare(first, second): + """ Returns True if both string inputs are equal, otherwise False + This function should take a constant amount of time regardless of + how many characters in the strings match. -def hash_data(data): - """ Return the base64 encoded SHA1 hash of the data. """ - return base64.b64encode(hashlib.sha1(data).digest()) - - -def sign_data(token, data): - """ MAC the data using SHA1. """ - mac_data = {} - mac_data['serialized_data'] = json.dumps(data) - mac = compute_mac(token, mac_data['serialized_data']) - mac_data['mac'] = mac - md = MAC_MARKER + base64.b64encode(json.dumps(mac_data)) - return md + """ + if len(first) != len(second): + return False + result = 0 + for x, y in zip(first, second): + result |= ord(x) ^ ord(y) + return result == 0 + + +def derive_keys(token, secret, strategy): + """ Derives keys for MAC and ENCRYPTION from the user-provided + secret. The resulting keys should be passed to the protect and + unprotect functions. + + As suggested by NIST Special Publication 800-108, this uses the + first 128 bits from the sha384 KDF for the obscured cache key + value, the second 128 bits for the message authentication key and + the remaining 128 bits for the encryption key. + + This approach is faster than computing a separate hmac as the KDF + for each desired key. + """ + digest = hmac.new(secret, token + strategy, HASH_FUNCTION).digest() + return {'CACHE_KEY': digest[:DIGEST_SPLIT], + 'MAC': digest[DIGEST_SPLIT: 2 * DIGEST_SPLIT], + 'ENCRYPTION': digest[2 * DIGEST_SPLIT:], + 'strategy': strategy} -def verify_signed_data(token, data): - """ Verify data integrity by ensuring MAC is valid. """ - if data.startswith(MAC_MARKER): - try: - data = data[len(MAC_MARKER):] - mac_data = json.loads(base64.b64decode(data)) - mac = compute_mac(token, mac_data['serialized_data']) - if mac != mac_data['mac']: - raise InvalidMacError('invalid MAC; expect=%s, actual=%s' % - (mac_data['mac'], mac)) - return json.loads(mac_data['serialized_data']) - except: - raise InvalidMacError('invalid MAC; data appeared to be corrupted') - else: - # doesn't appear to be MACed data - return data +def sign_data(key, data): + """ Sign the data using the defined function and the derived key""" + mac = hmac.new(key, data, HASH_FUNCTION).digest() + return base64.b64encode(mac) @assert_crypto_availability -def encrypt_data(token, secret, data): - """ Encryptes the data with the given secret key. """ +def encrypt_data(key, data): + """ Encrypt the data with the given secret key. + + Padding is n bytes of the value n, where 1 <= n <= blocksize. + """ iv = os.urandom(16) - aes_key = generate_aes_key(token, secret) - cipher = AES.new(aes_key, AES.MODE_CFB, iv) - data = json.dumps(data) - encoded_data = base64.b64encode(iv + cipher.encrypt(data)) - encoded_data = ENCRYPT_MARKER + encoded_data - return encoded_data + cipher = AES.new(key, AES.MODE_CBC, iv) + padding = 16 - len(data) % 16 + return iv + cipher.encrypt(data + chr(padding) * padding) @assert_crypto_availability -def decrypt_data(token, secret, data): +def decrypt_data(key, data): """ Decrypt the data with the given secret key. """ - if data.startswith(ENCRYPT_MARKER): - try: - # encrypted data - encoded_data = data[len(ENCRYPT_MARKER):] - aes_key = generate_aes_key(token, secret) - decoded_data = base64.b64decode(encoded_data) - iv = decoded_data[:16] - encrypted_data = decoded_data[16:] - cipher = AES.new(aes_key, AES.MODE_CFB, iv) - decrypted_data = cipher.decrypt(encrypted_data) - return json.loads(decrypted_data) - except: - raise DecryptError('data appeared to be corrupted') - else: - # doesn't appear to be encrypted data - return data + iv = data[:16] + cipher = AES.new(key, AES.MODE_CBC, iv) + try: + result = cipher.decrypt(data[16:]) + except Exception: + raise DecryptError('Encrypted data appears to be corrupted.') + + # Strip the last n padding bytes where n is the last value in + # the plaintext + padding = ord(result[-1]) + return result[:-1 * padding] + + +def protect_data(keys, data): + """ Given keys and serialized data, returns an appropriately + protected string suitable for storage in the cache. + + """ + if keys['strategy'] == 'ENCRYPT': + data = encrypt_data(keys['ENCRYPTION'], data) + + encoded_data = base64.b64encode(data) + + signature = sign_data(keys['MAC'], encoded_data) + return signature + encoded_data + + +def unprotect_data(keys, signed_data): + """ Given keys and cached string data, verifies the signature, + decrypts if necessary, and returns the original serialized data. + + """ + # cache backends return None when no data is found. We don't mind + # that this particular special value is unsigned. + if signed_data is None: + return None + + # First we calculate the signature + provided_mac = signed_data[:DIGEST_LENGTH_B64] + calculated_mac = sign_data( + keys['MAC'], + signed_data[DIGEST_LENGTH_B64:]) + + # Then verify that it matches the provided value + if not constant_time_compare(provided_mac, calculated_mac): + raise InvalidMacError('Invalid MAC; data appears to be corrupted.') + + data = base64.b64decode(signed_data[DIGEST_LENGTH_B64:]) + + # then if necessary decrypt the data + if keys['strategy'] == 'ENCRYPT': + data = decrypt_data(keys['ENCRYPTION'], data) + + return data + + +def get_cache_key(keys): + """ Given keys generated by derive_keys(), returns a base64 + encoded value suitable for use as a cache key in memcached. + + """ + return base64.b64encode(keys['CACHE_KEY']) diff --git a/tests/test_auth_token_middleware.py b/tests/test_auth_token_middleware.py index 06054d088..a4285043c 100644 --- a/tests/test_auth_token_middleware.py +++ b/tests/test_auth_token_middleware.py @@ -28,7 +28,6 @@ from keystoneclient.common import cms from keystoneclient import utils from keystoneclient.middleware import auth_token -from keystoneclient.middleware import memcache_crypt from keystoneclient.openstack.common import memorycache from keystoneclient.openstack.common import jsonutils from keystoneclient.openstack.common import timeutils @@ -1013,9 +1012,7 @@ def test_request_blank_token(self): def _get_cached_token(self, token): token_id = cms.cms_hash_token(token) # NOTE(vish): example tokens are expired so skip the expiration check. - key = self.middleware._get_cache_key(token_id) - cached = self.middleware._cache.get(key) - return self.middleware._unprotect_cache_value(token, cached) + return self.middleware._cache_get(token_id, ignore_expires=True) def test_memcache(self): req = webob.Request.blank('/') @@ -1036,7 +1033,8 @@ def test_memcache_set_invalid(self): token = 'invalid-token' req.headers['X-Auth-Token'] = token self.middleware(req.environ, self.start_fake_response) - self.assertEqual(self._get_cached_token(token), "invalid") + self.assertRaises(auth_token.InvalidUserToken, + self._get_cached_token, token) def test_memcache_set_expired(self): token_cache_time = 10 @@ -1096,18 +1094,11 @@ def test_encrypt_cache_data(self): 'memcache_secret_key': 'mysecret' } self.set_middleware(conf=conf) - encrypted_data = self.middleware._protect_cache_value( - 'token', TOKEN_RESPONSES[self.token_dict['uuid_token_default']]) - self.assertEqual('{ENCRYPT:AES256}', encrypted_data[:16]) - self.assertEqual( - TOKEN_RESPONSES[self.token_dict['uuid_token_default']], - self.middleware._unprotect_cache_value('token', encrypted_data)) - # should return None if unable to decrypt - self.assertIsNone( - self.middleware._unprotect_cache_value( - 'token', '{ENCRYPT:AES256}corrupted')) - self.assertIsNone( - self.middleware._unprotect_cache_value('mykey', encrypted_data)) + token = 'my_token' + data = ('this_data', 10e100) + self.middleware._init_cache({}) + self.middleware._cache_store(token, data) + self.assertEqual(self.middleware._cache_get(token), data[0]) def test_sign_cache_data(self): conf = { @@ -1119,19 +1110,11 @@ def test_sign_cache_data(self): 'memcache_secret_key': 'mysecret' } self.set_middleware(conf=conf) - signed_data = self.middleware._protect_cache_value( - 'mykey', TOKEN_RESPONSES[self.token_dict['uuid_token_default']]) - expected = '{MAC:SHA1}' - self.assertEqual( - signed_data[:10], - expected) - self.assertEqual( - TOKEN_RESPONSES[self.token_dict['uuid_token_default']], - self.middleware._unprotect_cache_value('mykey', signed_data)) - # should return None on corrupted data - self.assertIsNone( - self.middleware._unprotect_cache_value('mykey', - '{MAC:SHA1}corrupted')) + token = 'my_token' + data = ('this_data', 10e100) + self.middleware._init_cache({}) + self.middleware._cache_store(token, data) + self.assertEqual(self.middleware._cache_get(token), data[0]) def test_no_memcache_protection(self): conf = { @@ -1142,47 +1125,11 @@ def test_no_memcache_protection(self): 'memcache_secret_key': 'mysecret' } self.set_middleware(conf=conf) - data = self.middleware._protect_cache_value('mykey', - 'This is a test!') - self.assertEqual(data, 'This is a test!') - self.assertEqual( - 'This is a test!', - self.middleware._unprotect_cache_value('mykey', data)) - - def test_get_cache_key(self): - conf = { - 'auth_host': 'keystone.example.com', - 'auth_port': 1234, - 'auth_admin_prefix': '/testadmin', - 'memcache_servers': ['localhost:11211'], - 'memcache_secret_key': 'mysecret' - } - self.set_middleware(conf=conf) - self.assertEqual( - 'tokens/mytoken', - self.middleware._get_cache_key('mytoken')) - conf = { - 'auth_host': 'keystone.example.com', - 'auth_port': 1234, - 'auth_admin_prefix': '/testadmin', - 'memcache_servers': ['localhost:11211'], - 'memcache_security_strategy': 'mac', - 'memcache_secret_key': 'mysecret' - } - self.set_middleware(conf=conf) - expected = 'tokens/' + memcache_crypt.hash_data('mytoken' + 'mysecret') - self.assertEqual(self.middleware._get_cache_key('mytoken'), expected) - conf = { - 'auth_host': 'keystone.example.com', - 'auth_port': 1234, - 'auth_admin_prefix': '/testadmin', - 'memcache_servers': ['localhost:11211'], - 'memcache_security_strategy': 'Encrypt', - 'memcache_secret_key': 'abc!' - } - self.set_middleware(conf=conf) - expected = 'tokens/' + memcache_crypt.hash_data('mytoken' + 'abc!') - self.assertEqual(self.middleware._get_cache_key('mytoken'), expected) + token = 'my_token' + data = ('this_data', 10e100) + self.middleware._init_cache({}) + self.middleware._cache_store(token, data) + self.assertEqual(self.middleware._cache_get(token), data[0]) def test_assert_valid_memcache_protection_config(self): # test missing memcache_secret_key diff --git a/tests/test_memcache_crypt.py b/tests/test_memcache_crypt.py index b2281d935..524cd21da 100644 --- a/tests/test_memcache_crypt.py +++ b/tests/test_memcache_crypt.py @@ -4,48 +4,66 @@ class MemcacheCryptPositiveTests(testtools.TestCase): - def test_generate_aes_key(self): - self.assertEqual( - len(memcache_crypt.generate_aes_key('Gimme Da Key', 'hush')), 32) + def _setup_keys(self, strategy): + return memcache_crypt.derive_keys('token', 'secret', strategy) - def test_compute_mac(self): - self.assertEqual( - memcache_crypt.compute_mac('mykey', 'This is a test!'), - 'tREu41yR5tEgeBWIuv9ag4AeKA8=') + def test_constant_time_compare(self): + # make sure it works as a compare, the "constant time" aspect + # isn't appropriate to test in unittests + ctc = memcache_crypt.constant_time_compare + self.assertTrue(ctc('abcd', 'abcd')) + self.assertTrue(ctc('', '')) + self.assertFalse(ctc('abcd', 'efgh')) + self.assertFalse(ctc('abc', 'abcd')) + self.assertFalse(ctc('abc', 'abc\x00')) + self.assertFalse(ctc('', 'abc')) + + def test_derive_keys(self): + keys = memcache_crypt.derive_keys('token', 'secret', 'strategy') + self.assertEqual(len(keys['ENCRYPTION']), + len(keys['CACHE_KEY'])) + self.assertEqual(len(keys['CACHE_KEY']), + len(keys['MAC'])) + self.assertNotEqual(keys['ENCRYPTION'], + keys['MAC']) + self.assertIn('strategy', keys.keys()) + + def test_key_strategy_diff(self): + k1 = self._setup_keys('MAC') + k2 = self._setup_keys('ENCRYPT') + self.assertNotEqual(k1, k2) def test_sign_data(self): - expected = '{MAC:SHA1}eyJtYWMiOiAiM0FrQmdPZHRybGo1RFFESHA1eUxqcDVq' +\ - 'Si9BPSIsICJzZXJpYWxpemVkX2RhdGEiOiAiXCJUaGlzIGlzIGEgdG' +\ - 'VzdCFcIiJ9' - self.assertEqual( - memcache_crypt.sign_data('mykey', 'This is a test!'), - expected) - - def test_verify_signed_data(self): - signed = memcache_crypt.sign_data('mykey', 'Testz') - self.assertEqual( - memcache_crypt.verify_signed_data('mykey', signed), - 'Testz') - self.assertEqual( - memcache_crypt.verify_signed_data('aasSFWE13WER', 'not MACed'), - 'not MACed') - - def test_encrypt_data(self): - expected = '{ENCRYPT:AES256}' - self.assertEqual( - memcache_crypt.encrypt_data('mykey', 'mysecret', - 'This is a test!')[:16], - expected) - - def test_decrypt_data(self): - encrypted = memcache_crypt.encrypt_data('mykey', 'mysecret', 'Testz') - self.assertEqual( - memcache_crypt.decrypt_data('mykey', 'mysecret', encrypted), - 'Testz') - self.assertEqual( - memcache_crypt.decrypt_data('mykey', 'mysecret', - 'Not Encrypted!'), - 'Not Encrypted!') + keys = self._setup_keys('MAC') + sig = memcache_crypt.sign_data(keys['MAC'], 'data') + self.assertEqual(len(sig), memcache_crypt.DIGEST_LENGTH_B64) + + def test_encryption(self): + keys = self._setup_keys('ENCRYPT') + # what you put in is what you get out + for data in ['data', '1234567890123456', '\x00\xFF' * 13 + ] + [chr(x % 256) * x for x in range(768)]: + crypt = memcache_crypt.encrypt_data(keys['ENCRYPTION'], data) + decrypt = memcache_crypt.decrypt_data(keys['ENCRYPTION'], crypt) + self.assertEqual(data, decrypt) + self.assertRaises(memcache_crypt.DecryptError, + memcache_crypt.decrypt_data, + keys['ENCRYPTION'], crypt[:-1]) + + def test_protect_wrappers(self): + data = 'My Pretty Little Data' + for strategy in ['MAC', 'ENCRYPT']: + keys = self._setup_keys(strategy) + protected = memcache_crypt.protect_data(keys, data) + self.assertNotEqual(protected, data) + if strategy == 'ENCRYPT': + self.assertNotIn(data, protected) + unprotected = memcache_crypt.unprotect_data(keys, protected) + self.assertEqual(data, unprotected) + self.assertRaises(memcache_crypt.InvalidMacError, + memcache_crypt.unprotect_data, + keys, protected[:-1]) + self.assertIsNone(memcache_crypt.unprotect_data(keys, None)) def test_no_pycrypt(self): aes = memcache_crypt.AES