python/tink/daead/_deterministic_aead_key_manager.py

# Copyright 2019 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.

"""Python wrapper of the wrapped C++ Deterministic AEAD key manager."""

from tink import core
from tink.cc.pybind import tink_bindings
from tink.daead import _deterministic_aead
from tink.daead import _deterministic_aead_wrapper


class _DeterministicAeadCcToPyWrapper(_deterministic_aead.DeterministicAead):
  """Transforms C++ DeterministicAead into a Python primitive."""

  def __init__(self, cc_deterministic_aead):
    self._deterministic_aead = cc_deterministic_aead

  @core.use_tink_errors
  def encrypt_deterministically(self, plaintext: bytes,
                                associated_data: bytes) -> bytes:
    return self._deterministic_aead.encrypt_deterministically(
        plaintext, associated_data)

  @core.use_tink_errors
  def decrypt_deterministically(self, ciphertext: bytes,
                                associated_data: bytes) -> bytes:
    return self._deterministic_aead.decrypt_deterministically(
        ciphertext, associated_data)


def register():
  """Registers all deterministic AEAD key managers and the wrapper in the Python Registry."""
  tink_bindings.register()

  type_url = 'type.googleapis.com/google.crypto.tink.AesSivKey'
  key_manager = core.KeyManagerCcToPyWrapper(
      tink_bindings.DeterministicAeadKeyManager.from_cc_registry(type_url),
      _deterministic_aead.DeterministicAead, _DeterministicAeadCcToPyWrapper)
  core.Registry.register_key_manager(key_manager, new_key_allowed=True)
  core.Registry.register_primitive_wrapper(
      _deterministic_aead_wrapper.DeterministicAeadWrapper())