Source code for dynamodb_encryption_sdk.material_providers.static

# Copyright 2018, Inc. or its affiliates. All Rights Reserved.
# Licensed under the Apache License, Version 2.0 (the "License"). You
# may not use this file except in compliance with the License. A copy of
# the License is located at
# or in the "license" file accompanying this file. This file is
# ANY KIND, either express or implied. See the License for the specific
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"""Cryptographic materials provider for use with pre-configured encryption and decryption materials."""
import attr

from dynamodb_encryption_sdk.materials import CryptographicMaterials  # noqa pylint: disable=unused-import
from dynamodb_encryption_sdk.materials import DecryptionMaterials, EncryptionMaterials
from dynamodb_encryption_sdk.structures import EncryptionContext  # noqa pylint: disable=unused-import

from . import CryptographicMaterialsProvider

try:  # Python 3.5.0 and 3.5.1 have incompatible typing modules
    from typing import Optional  # noqa pylint: disable=unused-import
except ImportError:  # pragma: no cover
    # We only actually need these imports when running the mypy checks

__all__ = ("StaticCryptographicMaterialsProvider",)

[docs]@attr.s(init=False) class StaticCryptographicMaterialsProvider(CryptographicMaterialsProvider): """Manually combine encryption and decryption materials for use as a cryptographic materials provider. :param DecryptionMaterials decryption_materials: Decryption materials to provide (optional) :param EncryptionMaterials encryption_materials: Encryption materials to provide (optional) """ _decryption_materials = attr.ib( validator=attr.validators.optional(attr.validators.instance_of(DecryptionMaterials)), default=None ) _encryption_materials = attr.ib( validator=attr.validators.optional(attr.validators.instance_of(EncryptionMaterials)), default=None ) def __init__( self, decryption_materials=None, # type: Optional[DecryptionMaterials] encryption_materials=None, # type: Optional[EncryptionMaterials] ): # noqa=D107 # type: (...) -> None # Workaround pending resolution of attrs/mypy interaction. # # self._decryption_materials = decryption_materials self._encryption_materials = encryption_materials attr.validate(self)
[docs] def decryption_materials(self, encryption_context): # type: (EncryptionContext) -> CryptographicMaterials """Return the static decryption materials. :param EncryptionContext encryption_context: Encryption context for request (not used by :class:`StaticCryptographicMaterialsProvider`) :raises AttributeError: if no decryption materials are available """ if self._decryption_materials is None: return super(StaticCryptographicMaterialsProvider, self).decryption_materials(encryption_context) return self._decryption_materials
[docs] def encryption_materials(self, encryption_context): # type: (EncryptionContext) -> CryptographicMaterials """Return the static encryption materials. :param EncryptionContext encryption_context: Encryption context for request (not used by :class:`StaticCryptographicMaterialsProvider`) :raises AttributeError: if no encryption materials are available """ if self._encryption_materials is None: return super(StaticCryptographicMaterialsProvider, self).encryption_materials(encryption_context) return self._encryption_materials