python/hybrid/hybrid_decrypt_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 CLIF-wrapped C++ Hybrid En- and Decryption key manager."""

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

from typing import Text

from tink.cc.python import hybrid_decrypt as cc_hybrid_decrypt
from tink.python.cc.clif import cc_key_manager
from tink.python.core import key_manager
from tink.python.core import tink_error
from tink.python.hybrid import hybrid_decrypt


class _HybridDecryptCcToPyWrapper(hybrid_decrypt.HybridDecrypt):
  """Transforms cliffed C++ HybridDecrypt primitive into a Python primitive."""

  def __init__(self, cc_primitive: cc_hybrid_decrypt.HybridDecrypt):
    self._hybrid_decrypt = cc_primitive

  @tink_error.use_tink_errors
  def decrypt(self, ciphertext: bytes, context_info: bytes) -> bytes:
    return self._hybrid_decrypt.decrypt(ciphertext, context_info)


def from_cc_registry(
    type_url: Text) -> key_manager.KeyManager[hybrid_decrypt.HybridDecrypt]:
  return key_manager.PrivateKeyManagerCcToPyWrapper(
      cc_key_manager.HybridDecryptKeyManager.from_cc_registry(type_url),
      hybrid_decrypt.HybridDecrypt, _HybridDecryptCcToPyWrapper)