python/tink/streaming_aead/_streaming_aead_key_templates_test.py

# 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.
"""Tests for tink.python.tink.streaming_aead_key_templates."""

from absl.testing import absltest
from absl.testing import parameterized
from tink.proto import aes_ctr_hmac_streaming_pb2
from tink.proto import aes_gcm_hkdf_streaming_pb2
from tink.proto import common_pb2
from tink.proto import tink_pb2
from tink import streaming_aead


class StreamingAeadKeyTemplatesTest(parameterized.TestCase):

  def test_create_aes_gcm_hkdf_streaming_key_template(self):
    # Intentionally using 'weird' or invalid values for parameters,
    # to test that the function correctly puts them in the resulting template.
    template = None
    with self.assertWarns(DeprecationWarning):
      template = (
          streaming_aead.streaming_aead_key_templates
          .create_aes_gcm_hkdf_streaming_key_template(
              aes_key_size=42,
              hash_type=common_pb2.HashType.SHA1,
              derived_key_size=76,
              ciphertext_segment_size=64,
          ))
    self.assertEqual(
        'type.googleapis.com/google.crypto.tink.AesGcmHkdfStreamingKey',
        template.type_url)
    self.assertEqual(tink_pb2.RAW, template.output_prefix_type)
    key_format = aes_gcm_hkdf_streaming_pb2.AesGcmHkdfStreamingKeyFormat()
    key_format.ParseFromString(template.value)
    self.assertEqual(42, key_format.key_size)
    self.assertEqual(common_pb2.HashType.SHA1, key_format.params.hkdf_hash_type)
    self.assertEqual(76, key_format.params.derived_key_size)
    self.assertEqual(64, key_format.params.ciphertext_segment_size)

  def test_create_aes_ctr_hmac_streaming_key_template(self):
    # Intentionally using 'weird' or invalid values for parameters,
    # to test that the function correctly puts them in the resulting template.
    template = None
    with self.assertWarns(DeprecationWarning):
      template = (
          streaming_aead.streaming_aead_key_templates
          .create_aes_ctr_hmac_streaming_key_template(
              aes_key_size=42,
              hkdf_hash_type=common_pb2.HashType.SHA1,
              derived_key_size=76,
              mac_hash_type=common_pb2.HashType.UNKNOWN_HASH,
              tag_size=39,
              ciphertext_segment_size=64,
          ))
    self.assertEqual(
        'type.googleapis.com/google.crypto.tink.AesCtrHmacStreamingKey',
        template.type_url)
    self.assertEqual(tink_pb2.RAW, template.output_prefix_type)
    key_format = aes_ctr_hmac_streaming_pb2.AesCtrHmacStreamingKeyFormat()
    key_format.ParseFromString(template.value)
    self.assertEqual(42, key_format.key_size)
    self.assertEqual(common_pb2.HashType.SHA1, key_format.params.hkdf_hash_type)
    self.assertEqual(76, key_format.params.derived_key_size)
    self.assertEqual(common_pb2.HashType.UNKNOWN_HASH,
                     key_format.params.hmac_params.hash)
    self.assertEqual(39, key_format.params.hmac_params.tag_size)
    self.assertEqual(64, key_format.params.ciphertext_segment_size)


if __name__ == '__main__':
  absltest.main()