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/src/main.c b/tools/encrypt_fw/src/main.c
new file mode 100644
index 0000000..39b7af7
--- /dev/null
+++ b/tools/encrypt_fw/src/main.c
@@ -0,0 +1,224 @@
+/*
+ * Copyright (c) 2019, Linaro Limited. All rights reserved.
+ * Author: Sumit Garg <sumit.garg@linaro.org>
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <assert.h>
+#include <ctype.h>
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdbool.h>
+
+#include <openssl/conf.h>
+
+#include "cmd_opt.h"
+#include "debug.h"
+#include "encrypt.h"
+#include "firmware_encrypted.h"
+
+#define NUM_ELEM(x) ((sizeof(x)) / (sizeof(x[0])))
+#define HELP_OPT_MAX_LEN 128
+
+/* Global options */
+
+/* Info messages created in the Makefile */
+extern const char build_msg[];
+
+static char *key_algs_str[] = {
+ [KEY_ALG_GCM] = "gcm",
+};
+
+static void print_help(const char *cmd, const struct option *long_opt)
+{
+ int rem, i = 0;
+ const struct option *opt;
+ char line[HELP_OPT_MAX_LEN];
+ char *p;
+
+ assert(cmd != NULL);
+ assert(long_opt != NULL);
+
+ printf("\n\n");
+ printf("The firmware encryption tool loads the binary image and\n"
+ "outputs encrypted binary image using an encryption key\n"
+ "provided as an input hex string.\n");
+ printf("\n");
+ printf("Usage:\n");
+ printf("\t%s [OPTIONS]\n\n", cmd);
+
+ printf("Available options:\n");
+ opt = long_opt;
+ while (opt->name) {
+ p = line;
+ rem = HELP_OPT_MAX_LEN;
+ if (isalpha(opt->val)) {
+ /* Short format */
+ sprintf(p, "-%c,", (char)opt->val);
+ p += 3;
+ rem -= 3;
+ }
+ snprintf(p, rem, "--%s %s", opt->name,
+ (opt->has_arg == required_argument) ? "<arg>" : "");
+ printf("\t%-32s %s\n", line, cmd_opt_get_help_msg(i));
+ opt++;
+ i++;
+ }
+ printf("\n");
+}
+
+static int get_key_alg(const char *key_alg_str)
+{
+ int i;
+
+ for (i = 0 ; i < NUM_ELEM(key_algs_str) ; i++) {
+ if (strcmp(key_alg_str, key_algs_str[i]) == 0) {
+ return i;
+ }
+ }
+
+ return -1;
+}
+
+static void parse_fw_enc_status_flag(const char *arg,
+ unsigned short *fw_enc_status)
+{
+ unsigned long flag;
+ char *endptr;
+
+ flag = strtoul(arg, &endptr, 16);
+ if (*endptr != '\0' || flag > FW_ENC_WITH_BSSK) {
+ ERROR("Invalid fw_enc_status flag '%s'\n", arg);
+ exit(1);
+ }
+
+ *fw_enc_status = flag & FW_ENC_STATUS_FLAG_MASK;
+}
+
+/* Common command line options */
+static const cmd_opt_t common_cmd_opt[] = {
+ {
+ { "help", no_argument, NULL, 'h' },
+ "Print this message and exit"
+ },
+ {
+ { "fw-enc-status", required_argument, NULL, 'f' },
+ "Firmware encryption status flag (with SSK=0 or BSSK=1)."
+ },
+ {
+ { "key-alg", required_argument, NULL, 'a' },
+ "Encryption key algorithm: 'gcm' (default)"
+ },
+ {
+ { "key", required_argument, NULL, 'k' },
+ "Encryption key (for supported algorithm)."
+ },
+ {
+ { "nonce", required_argument, NULL, 'n' },
+ "Nonce or Initialization Vector (for supported algorithm)."
+ },
+ {
+ { "in", required_argument, NULL, 'i' },
+ "Input filename to be encrypted."
+ },
+ {
+ { "out", required_argument, NULL, 'o' },
+ "Encrypted output filename."
+ },
+};
+
+int main(int argc, char *argv[])
+{
+ int i, key_alg, ret;
+ int c, opt_idx = 0;
+ const struct option *cmd_opt;
+ char *key = NULL;
+ char *nonce = NULL;
+ char *in_fn = NULL;
+ char *out_fn = NULL;
+ unsigned short fw_enc_status = 0;
+
+ NOTICE("Firmware Encryption Tool: %s\n", build_msg);
+
+ /* Set default options */
+ key_alg = KEY_ALG_GCM;
+
+ /* Add common command line options */
+ for (i = 0; i < NUM_ELEM(common_cmd_opt); i++) {
+ cmd_opt_add(&common_cmd_opt[i]);
+ }
+
+ /* Get the command line options populated during the initialization */
+ cmd_opt = cmd_opt_get_array();
+
+ while (1) {
+ /* getopt_long stores the option index here. */
+ c = getopt_long(argc, argv, "a:f:hi:k:n:o:", cmd_opt, &opt_idx);
+
+ /* Detect the end of the options. */
+ if (c == -1) {
+ break;
+ }
+
+ switch (c) {
+ case 'a':
+ key_alg = get_key_alg(optarg);
+ if (key_alg < 0) {
+ ERROR("Invalid key algorithm '%s'\n", optarg);
+ exit(1);
+ }
+ break;
+ case 'f':
+ parse_fw_enc_status_flag(optarg, &fw_enc_status);
+ break;
+ case 'k':
+ key = optarg;
+ break;
+ case 'i':
+ in_fn = optarg;
+ break;
+ case 'o':
+ out_fn = optarg;
+ break;
+ case 'n':
+ nonce = optarg;
+ break;
+ case 'h':
+ print_help(argv[0], cmd_opt);
+ exit(0);
+ case '?':
+ default:
+ print_help(argv[0], cmd_opt);
+ exit(1);
+ }
+ }
+
+ if (!key) {
+ ERROR("Key must not be NULL\n");
+ exit(1);
+ }
+
+ if (!nonce) {
+ ERROR("Nonce must not be NULL\n");
+ exit(1);
+ }
+
+ if (!in_fn) {
+ ERROR("Input filename must not be NULL\n");
+ exit(1);
+ }
+
+ if (!out_fn) {
+ ERROR("Output filename must not be NULL\n");
+ exit(1);
+ }
+
+ ret = encrypt_file(fw_enc_status, key_alg, key, nonce, in_fn, out_fn);
+
+ CRYPTO_cleanup_all_ex_data();
+
+ return ret;
+}