tools/firmware-utils/src/buffalo-enc.c

   1 /*
   2  * Copyright (C) 2009-2011 Gabor Juhos <juhosg@openwrt.org>
   3  *
   4  * This program is free software; you can redistribute it and/or modify it
   5  * under the terms of the GNU General Public License version 2 as published
   6  * by the Free Software Foundation.
   7  *
   8  */
   9
  10 #include <stdio.h>
  11 #include <stdlib.h>
  12 #include <stdint.h>
  13 #include <string.h>
  14 #include <libgen.h>
  15 #include <getopt.h>     /* for getopt() */
  16 #include <stdarg.h>
  17
  18 #include "buffalo-lib.h"
  19
  20 #define ERR(fmt, args...) do { \
  21         fflush(0); \
  22         fprintf(stderr, "[%s] *** error: " fmt "\n", \
  23                         progname, ## args ); \
  24 } while (0)
  25
  26 static char *progname;
  27 static char *ifname;
  28 static char *ofname;
  29 static char *crypt_key = "Buffalo";
  30 static char *magic = "start";
  31 static int longstate;
  32 static unsigned char seed = 'O';
  33
  34 static char *product;
  35 static char *version;
  36 static int do_decrypt;
  37
  38 void usage(int status)
  39 {
  40         FILE *stream = (status != EXIT_SUCCESS) ? stderr : stdout;
  41
  42         fprintf(stream, "Usage: %s [OPTIONS...]\n", progname);
  43         fprintf(stream,
  44 "\n"
  45 "Options:\n"
  46 "  -d              decrypt instead of encrypt\n"
  47 "  -i <file>       read input from the file <file>\n"
  48 "  -o <file>       write output to the file <file>\n"
  49 "  -l              use longstate {en,de}cryption method\n"
  50 "  -k <key>        use <key> for encryption (default: Buffalo)\n"
  51 "  -m <magic>      set magic to <magic>\n"
  52 "  -p <product>    set product name to <product>\n"
  53 "  -v <version>    set version to <version>\n"
  54 "  -h              show this screen\n"
  55         );
  56
  57         exit(status);
  58 }
  59
  60 static int decrypt_file(void)
  61 {
  62         struct enc_param ep;
  63         ssize_t src_len;
  64         unsigned char *buf = NULL;
  65         int err;
  66         int ret = -1;
  67
  68         src_len = get_file_size(ifname);
  69         if (src_len < 0) {
  70                 ERR("unable to get size of '%s'", ifname);
  71                 goto out;
  72         }
  73
  74         buf = malloc(src_len);
  75         if (buf == NULL) {
  76                 ERR("no memory for the buffer");
  77                 goto out;
  78         }
  79
  80         err = read_file_to_buf(ifname, buf, src_len);
  81         if (err) {
  82                 ERR("unable to read from file '%s'", ifname);
  83                 goto out;
  84         }
  85
  86         memset(&ep, '\0', sizeof(ep));
  87         ep.key = (unsigned char *) crypt_key;
  88
  89         err = decrypt_buf(&ep, buf, src_len);
  90         if (err) {
  91                 ERR("unable to decrypt '%s'", ifname);
  92                 goto out;
  93         }
  94
  95         printf("Magic\t\t: '%s'\n", ep.magic);
  96         printf("Seed\t\t: 0x%02x\n", ep.seed);
  97         printf("Product\t\t: '%s'\n", ep.product);
  98         printf("Version\t\t: '%s'\n", ep.version);
  99         printf("Data len\t: %u\n", ep.datalen);
 100         printf("Checksum\t: 0x%08x\n", ep.csum);
 101
 102         err = write_buf_to_file(ofname, buf, ep.datalen);
 103         if (err) {
 104                 ERR("unable to write to file '%s'", ofname);
 105                 goto out;
 106         }
 107
 108         ret = 0;
 109
 110 out:
 111         free(buf);
 112         return ret;
 113 }
 114
 115 static int encrypt_file(void)
 116 {
 117         struct enc_param ep;
 118         ssize_t src_len;
 119         unsigned char *buf;
 120         uint32_t hdrlen;
 121         ssize_t totlen = 0;
 122         int err;
 123         int ret = -1;
 124
 125         src_len = get_file_size(ifname);
 126         if (src_len < 0) {
 127                 ERR("unable to get size of '%s'", ifname);
 128                 goto out;
 129         }
 130
 131         totlen = enc_compute_buf_len(product, version, src_len);
 132         hdrlen = enc_compute_header_len(product, version);
 133
 134         buf = malloc(totlen);
 135         if (buf == NULL) {
 136                 ERR("no memory for the buffer");
 137                 goto out;
 138         }
 139
 140         err = read_file_to_buf(ifname, &buf[hdrlen], src_len);
 141         if (err) {
 142                 ERR("unable to read from file '%s'", ofname);
 143                 goto free_buf;
 144         }
 145
 146         memset(&ep, '\0', sizeof(ep));
 147         ep.key = (unsigned char *) crypt_key;
 148         ep.seed = seed;
 149         ep.longstate = longstate;
 150         ep.csum = buffalo_csum(src_len, &buf[hdrlen], src_len);
 151         ep.datalen = src_len;
 152         strcpy((char *) ep.magic, magic);
 153         strcpy((char *) ep.product, product);
 154         strcpy((char *) ep.version, version);
 155
 156         err = encrypt_buf(&ep, buf, &buf[hdrlen]);
 157         if (err) {
 158                 ERR("invalid input file");
 159                 goto free_buf;
 160         }
 161
 162         err = write_buf_to_file(ofname, buf, totlen);
 163         if (err) {
 164                 ERR("unable to write to file '%s'", ofname);
 165                 goto free_buf;
 166         }
 167
 168         ret = 0;
 169
 170 free_buf:
 171         free(buf);
 172 out:
 173         return ret;
 174 }
 175
 176 static int check_params(void)
 177 {
 178         int ret = -1;
 179
 180         if (ifname == NULL) {
 181                 ERR("no input file specified");
 182                 goto out;
 183         }
 184
 185         if (ofname == NULL) {
 186                 ERR("no output file specified");
 187                 goto out;
 188         }
 189
 190         if (crypt_key == NULL) {
 191                 ERR("no key specified");
 192                 goto out;
 193         } else if (strlen(crypt_key) > BCRYPT_MAX_KEYLEN) {
 194                 ERR("key '%s' is too long", crypt_key);
 195                 goto out;
 196         }
 197
 198         if (strlen(magic) != (ENC_MAGIC_LEN - 1)) {
 199                 ERR("length of magic must be %d", ENC_MAGIC_LEN - 1);
 200                 goto out;
 201         }
 202
 203         if (!do_decrypt) {
 204                 if (product == NULL) {
 205                         ERR("no product specified");
 206                         goto out;
 207                 }
 208
 209                 if (version == NULL) {
 210                         ERR("no version specified");
 211                         goto out;
 212                 }
 213
 214                 if (strlen(product) > (ENC_PRODUCT_LEN - 1)) {
 215                         ERR("product name '%s' is too long", product);
 216                         goto out;
 217                 }
 218
 219                 if (strlen(version) > (ENC_VERSION_LEN - 1)) {
 220                         ERR("version '%s' is too long", version);
 221                         goto out;
 222                 }
 223         }
 224
 225         ret = 0;
 226
 227 out:
 228         return ret;
 229 }
 230
 231 int main(int argc, char *argv[])
 232 {
 233         int res = EXIT_FAILURE;
 234         int err;
 235
 236         progname = basename(argv[0]);
 237
 238         while ( 1 ) {
 239                 int c;
 240
 241                 c = getopt(argc, argv, "adi:m:o:hp:v:k:r:s:");
 242                 if (c == -1)
 243                         break;
 244
 245                 switch (c) {
 246                 case 'd':
 247                         do_decrypt = 1;
 248                         break;
 249                 case 'i':
 250                         ifname = optarg;
 251                         break;
 252                 case 'l':
 253                         longstate = 1;
 254                         break;
 255                 case 'm':
 256                         magic = optarg;
 257                         break;
 258                 case 'o':
 259                         ofname = optarg;
 260                         break;
 261                 case 'p':
 262                         product = optarg;
 263                         break;
 264                 case 'v':
 265                         version = optarg;
 266                         break;
 267                 case 'k':
 268                         crypt_key = optarg;
 269                         break;
 270                 case 's':
 271                         seed = strtoul(optarg, NULL, 16);
 272                         break;
 273                 case 'h':
 274                         usage(EXIT_SUCCESS);
 275                         break;
 276                 default:
 277                         usage(EXIT_FAILURE);
 278                         break;
 279                 }
 280         }
 281
 282         err = check_params();
 283         if (err)
 284                 goto out;
 285
 286         if (do_decrypt)
 287                 err = decrypt_file();
 288         else
 289                 err = encrypt_file();
 290
 291         if (err)
 292                 goto out;
 293
 294         res = EXIT_SUCCESS;
 295
 296 out:
 297         return res;
 298 }