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                 goto out;
  92
  93         printf("Magic\t\t: '%s'\n", ep.magic);
  94         printf("Seed\t\t: 0x%02x\n", ep.seed);
  95         printf("Product\t\t: '%s'\n", ep.product);
  96         printf("Version\t\t: '%s'\n", ep.version);
  97         printf("Data len\t: %u\n", ep.datalen);
  98         printf("Checksum\t: 0x%08x\n", ep.csum);
  99
 100         err = write_buf_to_file(ofname, buf, ep.datalen);
 101         if (err) {
 102                 ERR("unable to write to file '%s'", ofname);
 103                 goto out;
 104         }
 105
 106         ret = 0;
 107
 108 out:
 109         free(buf);
 110         return ret;
 111 }
 112
 113 static int encrypt_file(void)
 114 {
 115         struct enc_param ep;
 116         ssize_t src_len;
 117         unsigned char *buf;
 118         uint32_t hdrlen;
 119         ssize_t totlen = 0;
 120         int err;
 121         int ret = -1;
 122
 123         src_len = get_file_size(ifname);
 124         if (src_len < 0) {
 125                 ERR("unable to get size of '%s'", ifname);
 126                 goto out;
 127         }
 128
 129         totlen = enc_compute_buf_len(product, version, src_len);
 130         hdrlen = enc_compute_header_len(product, version);
 131
 132         buf = malloc(totlen);
 133         if (buf == NULL) {
 134                 ERR("no memory for the buffer");
 135                 goto out;
 136         }
 137
 138         err = read_file_to_buf(ifname, &buf[hdrlen], src_len);
 139         if (err) {
 140                 ERR("unable to read from file '%s'", ofname);
 141                 goto free_buf;
 142         }
 143
 144         memset(&ep, '\0', sizeof(ep));
 145         ep.key = (unsigned char *) crypt_key;
 146         ep.seed = seed;
 147         ep.longstate = longstate;
 148         ep.csum = buffalo_csum(src_len, &buf[hdrlen], src_len);
 149         ep.datalen = src_len;
 150         strcpy((char *) ep.magic, magic);
 151         strcpy((char *) ep.product, product);
 152         strcpy((char *) ep.version, version);
 153
 154         err = encrypt_buf(&ep, buf, &buf[hdrlen]);
 155         if (err) {
 156                 ERR("invalid input file");
 157                 goto free_buf;
 158         }
 159
 160         err = write_buf_to_file(ofname, buf, totlen);
 161         if (err) {
 162                 ERR("unable to write to file '%s'", ofname);
 163                 goto free_buf;
 164         }
 165
 166         ret = 0;
 167
 168 free_buf:
 169         free(buf);
 170 out:
 171         return ret;
 172 }
 173
 174 static int check_params(void)
 175 {
 176         int ret = -1;
 177
 178         if (ifname == NULL) {
 179                 ERR("no input file specified");
 180                 goto out;
 181         }
 182
 183         if (ofname == NULL) {
 184                 ERR("no output file specified");
 185                 goto out;
 186         }
 187
 188         if (crypt_key == NULL) {
 189                 ERR("no key specified");
 190                 goto out;
 191         } else if (strlen(crypt_key) > BCRYPT_MAX_KEYLEN) {
 192                 ERR("key '%s' is too long", crypt_key);
 193                 goto out;
 194         }
 195
 196         if (strlen(magic) != (ENC_MAGIC_LEN - 1)) {
 197                 ERR("length of magic must be %d", ENC_MAGIC_LEN - 1);
 198                 goto out;
 199         }
 200
 201         if (!do_decrypt) {
 202                 if (product == NULL) {
 203                         ERR("no product specified");
 204                         goto out;
 205                 }
 206
 207                 if (version == NULL) {
 208                         ERR("no version specified");
 209                         goto out;
 210                 }
 211
 212                 if (strlen(product) > (ENC_PRODUCT_LEN - 1)) {
 213                         ERR("product name '%s' is too long", product);
 214                         goto out;
 215                 }
 216
 217                 if (strlen(version) > (ENC_VERSION_LEN - 1)) {
 218                         ERR("version '%s' is too long", version);
 219                         goto out;
 220                 }
 221         }
 222
 223         ret = 0;
 224
 225 out:
 226         return ret;
 227 }
 228
 229 int main(int argc, char *argv[])
 230 {
 231         int res = EXIT_FAILURE;
 232         int err;
 233
 234         progname = basename(argv[0]);
 235
 236         while ( 1 ) {
 237                 int c;
 238
 239                 c = getopt(argc, argv, "adi:m:o:hp:v:k:r:s:");
 240                 if (c == -1)
 241                         break;
 242
 243                 switch (c) {
 244                 case 'd':
 245                         do_decrypt = 1;
 246                         break;
 247                 case 'i':
 248                         ifname = optarg;
 249                         break;
 250                 case 'l':
 251                         longstate = 1;
 252                         break;
 253                 case 'm':
 254                         magic = optarg;
 255                         break;
 256                 case 'o':
 257                         ofname = optarg;
 258                         break;
 259                 case 'p':
 260                         product = optarg;
 261                         break;
 262                 case 'v':
 263                         version = optarg;
 264                         break;
 265                 case 'k':
 266                         crypt_key = optarg;
 267                         break;
 268                 case 's':
 269                         seed = strtoul(optarg, NULL, 16);
 270                         break;
 271                 case 'h':
 272                         usage(EXIT_SUCCESS);
 273                         break;
 274                 default:
 275                         usage(EXIT_FAILURE);
 276                         break;
 277                 }
 278         }
 279
 280         err = check_params();
 281         if (err)
 282                 goto out;
 283
 284         if (do_decrypt)
 285                 err = decrypt_file();
 286         else
 287                 err = encrypt_file();
 288
 289         if (err)
 290                 goto out;
 291
 292         res = EXIT_SUCCESS;
 293
 294 out:
 295         return res;
 296 }