tools: Add firmware authenticated encryption tool

Add firmware authenticated encryption tool which utilizes OpenSSL
library to encrypt firmwares using a key provided via cmdline. Currently
this tool supports AES-GCM as an authenticated encryption algorithm.

Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
Change-Id: I60e296af1b98f1912a19d5f91066be7ea85836e4
diff --git a/tools/encrypt_fw/include/cmd_opt.h b/tools/encrypt_fw/include/cmd_opt.h
new file mode 100644
index 0000000..bd7d31f
--- /dev/null
+++ b/tools/encrypt_fw/include/cmd_opt.h
@@ -0,0 +1,32 @@
+/*
+ * Copyright (c) 2015, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2019, Linaro Limited. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef CMD_OPT_H
+#define CMD_OPT_H
+
+#include <getopt.h>
+
+#define CMD_OPT_MAX_NUM			64
+
+/* Supported long command line option types */
+enum {
+	CMD_OPT_FW
+};
+
+/* Structure to define a command line option */
+typedef struct cmd_opt_s {
+	struct option long_opt;
+	const char *help_msg;
+} cmd_opt_t;
+
+/* Exported API*/
+void cmd_opt_add(const cmd_opt_t *cmd_opt);
+const struct option *cmd_opt_get_array(void);
+const char *cmd_opt_get_name(int idx);
+const char *cmd_opt_get_help_msg(int idx);
+
+#endif /* CMD_OPT_H */