def _generate_initial_material()

in src/dynamodb_encryption_sdk/material_providers/aws_kms.py [0:0]

• 19 lines of code
• 4 McCabe index (conditional complexity)

    def _generate_initial_material(self, encryption_context):
        # type: (EncryptionContext) -> Tuple[bytes, bytes]
        """Generate the initial cryptographic material for use with HKDF.

        :param EncryptionContext encryption_context: Encryption context providing information about request
        :returns: Plaintext and ciphertext of initial cryptographic material
        :rtype: bytes and bytes
        """
        key_id = self._select_key_id(encryption_context)
        self._validate_key_id(key_id, encryption_context)
        key_length = 256 // 8
        kms_encryption_context = self._kms_encryption_context(
            encryption_context=encryption_context,
            encryption_description=self._content_key_info.description,
            signing_description=self._signing_key_info.description,
        )
        kms_params = dict(KeyId=key_id, NumberOfBytes=key_length, EncryptionContext=kms_encryption_context)
        if self._grant_tokens:
            kms_params["GrantTokens"] = self._grant_tokens
        # Catch any boto3 errors and normalize to expected WrappingError
        try:
            response = self._client(key_id).generate_data_key(**kms_params)
            return response["Plaintext"], response["CiphertextBlob"]
        except (botocore.exceptions.ClientError, KeyError):
            message = "Failed to generate materials using AWS KMS"
            _LOGGER.exception(message)
            raise WrappingError(message)