def _create_decrypt_materials_request()

in src/aws_encryption_sdk/streaming_client.py [0:0]

• 21 lines of code
• 5 McCabe index (conditional complexity)

    def _create_decrypt_materials_request(self, header):
        """
        Create a DecryptionMaterialsRequest based on whether
        the StreamDecryptor was provided encryption_context on decrypt
        (i.e. expects to use a CMM from the MPL).
        """
        # If encryption_context is provided on decrypt,
        # pass it to the DecryptionMaterialsRequest as reproduced_encryption_context
        if hasattr(self.config, "encryption_context") \
                and self.config.encryption_context is not None:
            if (_HAS_MPL
                    and isinstance(self.config.materials_manager, CryptoMaterialsManagerFromMPL)):
                return DecryptionMaterialsRequest(
                    encrypted_data_keys=header.encrypted_data_keys,
                    algorithm=header.algorithm,
                    encryption_context=header.encryption_context,
                    commitment_policy=self.config.commitment_policy,
                    reproduced_encryption_context=self.config.encryption_context
                )
            else:
                raise TypeError("encryption_context on decrypt is only supported for CMMs and keyrings "
                                "from the aws-cryptographic-material-providers library.")
        return DecryptionMaterialsRequest(
            encrypted_data_keys=header.encrypted_data_keys,
            algorithm=header.algorithm,
            encryption_context=header.encryption_context,
            commitment_policy=self.config.commitment_policy,
        )