def _content_key_from_material_description()

in src/dynamodb_encryption_sdk/materials/wrapped.py [0:0]

• 17 lines of code
• 2 McCabe index (conditional complexity)

    def _content_key_from_material_description(self):
        """Load the content key from material description and unwrap it for use.

        :returns: Unwrapped content key
        :rtype: DelegatedKey
        """
        if self._unwrapping_key is None:
            raise UnwrappingError(
                "Cryptographic materials cannot be loaded from material description: no unwrapping key"
            )

        wrapping_algorithm = self.material_description.get(
            MaterialDescriptionKeys.CONTENT_KEY_WRAPPING_ALGORITHM.value, self._unwrapping_key.algorithm
        )
        wrapped_key = base64.b64decode(self.material_description[MaterialDescriptionKeys.WRAPPED_DATA_KEY.value])
        content_key_algorithm = self._content_key_algorithm.split("/", 1)[0]
        return self._unwrapping_key.unwrap(
            algorithm=wrapping_algorithm,
            wrapped_key=wrapped_key,
            wrapped_key_algorithm=content_key_algorithm,
            wrapped_key_type=EncryptionKeyType.SYMMETRIC,
            additional_associated_data=None,
        )