| # Copyright 2020 Google LLC |
| # |
| # 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. |
| """Cross-language tests for the Aead primitive. |
| |
| These tests check some basic AEAD properties, and that all implementations can |
| interoperate with each other. |
| """ |
| |
| # Placeholder for import for type annotations |
| from typing import Iterable, Text, Tuple |
| |
| from absl.testing import absltest |
| from absl.testing import parameterized |
| |
| import tink |
| from tink import aead |
| |
| from tink.proto import tink_pb2 |
| from tink.testing import keyset_builder |
| from util import supported_key_types |
| from util import testing_servers |
| |
| SUPPORTED_LANGUAGES = testing_servers.SUPPORTED_LANGUAGES_BY_PRIMITIVE['aead'] |
| |
| |
| def setUpModule(): |
| aead.register() |
| testing_servers.start('aead') |
| |
| |
| def tearDownModule(): |
| testing_servers.stop() |
| |
| |
| # To test all implementations of AEAD, we simply try all availalble default key |
| # templates. |
| # Note that in order to test keys not covered by key templates, the parameter |
| # function would need to be rewritten to yield keyset instead of key template |
| # names. |
| |
| |
| def all_aead_key_template_names() -> Iterable[Text]: |
| """Yields all AEAD key template names.""" |
| for key_type in supported_key_types.AEAD_KEY_TYPES: |
| for key_template_name in supported_key_types.KEY_TEMPLATE_NAMES[key_type]: |
| yield key_template_name |
| |
| |
| class AeadPythonTest(parameterized.TestCase): |
| |
| @parameterized.parameters(all_aead_key_template_names()) |
| def test_encrypt_decrypt(self, key_template_name): |
| supported_langs = supported_key_types.SUPPORTED_LANGUAGES_BY_TEMPLATE_NAME[ |
| key_template_name] |
| self.assertNotEmpty(supported_langs) |
| key_template = supported_key_types.KEY_TEMPLATE[key_template_name] |
| # Take the first supported language to generate the keyset. |
| keyset = testing_servers.new_keyset(supported_langs[0], key_template) |
| supported_aeads = [ |
| testing_servers.aead(lang, keyset) for lang in supported_langs |
| ] |
| unsupported_aeads = [ |
| testing_servers.aead(lang, keyset) |
| for lang in SUPPORTED_LANGUAGES |
| if lang not in supported_langs |
| ] |
| for p in supported_aeads: |
| plaintext = ( |
| b'This is some plaintext message to be encrypted using key_template ' |
| b'%s using %s for encryption.' |
| % (key_template_name.encode('utf8'), p.lang.encode('utf8'))) |
| associated_data = ( |
| b'Some associated data for %s using %s for encryption.' % |
| (key_template_name.encode('utf8'), p.lang.encode('utf8'))) |
| ciphertext = p.encrypt(plaintext, associated_data) |
| for p2 in supported_aeads: |
| output = p2.decrypt(ciphertext, associated_data) |
| self.assertEqual(output, plaintext) |
| for p2 in unsupported_aeads: |
| with self.assertRaises( |
| tink.TinkError, |
| msg='Language %s supports AEAD decrypt with %s unexpectedly' % |
| (p2.lang, key_template_name)): |
| p2.decrypt(ciphertext, associated_data) |
| for p in unsupported_aeads: |
| with self.assertRaises( |
| tink.TinkError, |
| msg='Language %s supports AEAD encrypt with %s unexpectedly' % ( |
| p.lang, key_template_name)): |
| p.encrypt(b'plaintext', b'associated_data') |
| |
| |
| # If the implementations work fine for keysets with single keys, then key |
| # rotation should work if the primitive wrapper is implemented correctly. |
| # These wrappers do not depend on the key type, so it should be fine to always |
| # test with the same key type. Since the AEAD wrapper needs to treat keys |
| # with output prefix RAW differently, we also include such a template for that. |
| KEY_ROTATION_TEMPLATES = [ |
| aead.aead_key_templates.AES128_CTR_HMAC_SHA256, |
| keyset_builder.raw_template(aead.aead_key_templates.AES128_CTR_HMAC_SHA256) |
| ] |
| |
| |
| def key_rotation_test_cases( |
| ) -> Iterable[Tuple[Text, Text, tink_pb2.KeyTemplate, tink_pb2.KeyTemplate]]: |
| for enc_lang in SUPPORTED_LANGUAGES: |
| for dec_lang in SUPPORTED_LANGUAGES: |
| for old_key_tmpl in KEY_ROTATION_TEMPLATES: |
| for new_key_tmpl in KEY_ROTATION_TEMPLATES: |
| yield (enc_lang, dec_lang, old_key_tmpl, new_key_tmpl) |
| |
| |
| class AeadKeyRotationTest(parameterized.TestCase): |
| |
| @parameterized.parameters(key_rotation_test_cases()) |
| def test_key_rotation(self, enc_lang, dec_lang, old_key_tmpl, new_key_tmpl): |
| # Do a key rotation from an old key generated from old_key_tmpl to a new |
| # key generated from new_key_tmpl. Encryption and decryption are done |
| # in languages enc_lang and dec_lang. |
| builder = keyset_builder.new_keyset_builder() |
| older_key_id = builder.add_new_key(old_key_tmpl) |
| builder.set_primary_key(older_key_id) |
| enc_aead1 = testing_servers.aead(enc_lang, builder.keyset()) |
| dec_aead1 = testing_servers.aead(dec_lang, builder.keyset()) |
| newer_key_id = builder.add_new_key(new_key_tmpl) |
| enc_aead2 = testing_servers.aead(enc_lang, builder.keyset()) |
| dec_aead2 = testing_servers.aead(dec_lang, builder.keyset()) |
| |
| builder.set_primary_key(newer_key_id) |
| enc_aead3 = testing_servers.aead(enc_lang, builder.keyset()) |
| dec_aead3 = testing_servers.aead(dec_lang, builder.keyset()) |
| |
| builder.disable_key(older_key_id) |
| enc_aead4 = testing_servers.aead(enc_lang, builder.keyset()) |
| dec_aead4 = testing_servers.aead(dec_lang, builder.keyset()) |
| |
| self.assertNotEqual(older_key_id, newer_key_id) |
| # 1 encrypts with the older key. So 1, 2 and 3 can decrypt it, but not 4. |
| ciphertext1 = enc_aead1.encrypt(b'plaintext', b'ad') |
| self.assertEqual(dec_aead1.decrypt(ciphertext1, b'ad'), b'plaintext') |
| self.assertEqual(dec_aead2.decrypt(ciphertext1, b'ad'), b'plaintext') |
| self.assertEqual(dec_aead3.decrypt(ciphertext1, b'ad'), b'plaintext') |
| with self.assertRaises(tink.TinkError): |
| _ = dec_aead4.decrypt(ciphertext1, b'ad') |
| |
| # 2 encrypts with the older key. So 1, 2 and 3 can decrypt it, but not 4. |
| ciphertext2 = enc_aead2.encrypt(b'plaintext', b'ad') |
| self.assertEqual(dec_aead1.decrypt(ciphertext2, b'ad'), b'plaintext') |
| self.assertEqual(dec_aead2.decrypt(ciphertext2, b'ad'), b'plaintext') |
| self.assertEqual(dec_aead3.decrypt(ciphertext2, b'ad'), b'plaintext') |
| with self.assertRaises(tink.TinkError): |
| _ = dec_aead4.decrypt(ciphertext2, b'ad') |
| |
| # 3 encrypts with the newer key. So 2, 3 and 4 can decrypt it, but not 1. |
| ciphertext3 = enc_aead3.encrypt(b'plaintext', b'ad') |
| with self.assertRaises(tink.TinkError): |
| _ = dec_aead1.decrypt(ciphertext3, b'ad') |
| self.assertEqual(dec_aead2.decrypt(ciphertext3, b'ad'), b'plaintext') |
| self.assertEqual(dec_aead3.decrypt(ciphertext3, b'ad'), b'plaintext') |
| self.assertEqual(dec_aead4.decrypt(ciphertext3, b'ad'), b'plaintext') |
| |
| # 4 encrypts with the newer key. So 2, 3 and 4 can decrypt it, but not 1. |
| ciphertext4 = enc_aead4.encrypt(b'plaintext', b'ad') |
| with self.assertRaises(tink.TinkError): |
| _ = dec_aead1.decrypt(ciphertext4, b'ad') |
| self.assertEqual(dec_aead2.decrypt(ciphertext4, b'ad'), b'plaintext') |
| self.assertEqual(dec_aead3.decrypt(ciphertext4, b'ad'), b'plaintext') |
| self.assertEqual(dec_aead4.decrypt(ciphertext4, b'ad'), b'plaintext') |
| |
| if __name__ == '__main__': |
| absltest.main() |