python/tink/mac/_mac_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._mac_key_templates."""

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

from absl.testing import absltest
from tink.proto import common_pb2
from tink.proto import hmac_pb2
from tink.proto import tink_pb2
from tink import mac


class MacKeyTemplatesTest(absltest.TestCase):

  def test_hmac_sha256_128bittag(self):
    template = mac.mac_key_templates.HMAC_SHA256_128BITTAG
    self.assertEqual('type.googleapis.com/google.crypto.tink.HmacKey',
                     template.type_url)
    self.assertEqual(tink_pb2.TINK, template.output_prefix_type)
    key_format = hmac_pb2.HmacKeyFormat()
    key_format.ParseFromString(template.value)
    self.assertEqual(32, key_format.key_size)
    self.assertEqual(16, key_format.params.tag_size)
    self.assertEqual(common_pb2.SHA256, key_format.params.hash)

  def test_hmac_sha256_256bittag(self):
    template = mac.mac_key_templates.HMAC_SHA256_256BITTAG
    self.assertEqual('type.googleapis.com/google.crypto.tink.HmacKey',
                     template.type_url)
    self.assertEqual(tink_pb2.TINK, template.output_prefix_type)
    key_format = hmac_pb2.HmacKeyFormat()
    key_format.ParseFromString(template.value)
    self.assertEqual(32, key_format.key_size)
    self.assertEqual(32, key_format.params.tag_size)
    self.assertEqual(common_pb2.SHA256, key_format.params.hash)

  def test_hmac_sha512_256bittag(self):
    template = mac.mac_key_templates.HMAC_SHA512_256BITTAG
    self.assertEqual('type.googleapis.com/google.crypto.tink.HmacKey',
                     template.type_url)
    self.assertEqual(tink_pb2.TINK, template.output_prefix_type)
    key_format = hmac_pb2.HmacKeyFormat()
    key_format.ParseFromString(template.value)
    self.assertEqual(64, key_format.key_size)
    self.assertEqual(32, key_format.params.tag_size)
    self.assertEqual(common_pb2.SHA512, key_format.params.hash)

  def test_hmac_sha512_512bittag(self):
    template = mac.mac_key_templates.HMAC_SHA512_512BITTAG
    self.assertEqual('type.googleapis.com/google.crypto.tink.HmacKey',
                     template.type_url)
    self.assertEqual(tink_pb2.TINK, template.output_prefix_type)
    key_format = hmac_pb2.HmacKeyFormat()
    key_format.ParseFromString(template.value)
    self.assertEqual(64, key_format.key_size)
    self.assertEqual(64, key_format.params.tag_size)
    self.assertEqual(common_pb2.SHA512, key_format.params.hash)

  def test_create_hmac_key_template(self):
    # Intentionally using "weird" or invalid values for parameters,
    # to test that the function correctly puts them in the resulting template.
    template = mac.mac_key_templates.create_hmac_key_template(
        key_size=42, tag_size=24, hash_type=common_pb2.SHA512)
    self.assertEqual('type.googleapis.com/google.crypto.tink.HmacKey',
                     template.type_url)
    self.assertEqual(tink_pb2.TINK, template.output_prefix_type)
    key_format = hmac_pb2.HmacKeyFormat()
    key_format.ParseFromString(template.value)
    self.assertEqual(42, key_format.key_size)
    self.assertEqual(24, key_format.params.tag_size)
    self.assertEqual(common_pb2.SHA512, key_format.params.hash)


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