utils/imxtools/sbtools/sbtoelf.c

   1 /***************************************************************************
   2  *             __________               __   ___.
   3  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
   4  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
   5  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
   6  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
   7  *                     \/            \/     \/    \/            \/
   8  * $Id$
   9  *
  10  * Copyright (C) 2010 Bertrik Sikken
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version 2
  15  * of the License, or (at your option) any later version.
  16  *
  17  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
  18  * KIND, either express or implied.
  19  *
  20  ****************************************************************************/
  21
  22 /*
  23  * .sb file parser and chunk extractor
  24  *
  25  * Based on amsinfo, which is
  26  * Copyright © 2008 Rafaël Carré <rafael.carre@gmail.com>
  27  */
  28
  29 #define _ISOC99_SOURCE /* snprintf() */
  30 #include <stdio.h>
  31 #include <errno.h>
  32 #include <stdlib.h>
  33 #include <string.h>
  34 #include <ctype.h>
  35 #include <time.h>
  36 #include <stdarg.h>
  37 #include <strings.h>
  38 #include <getopt.h>
  39
  40 #include "crypto.h"
  41 #include "elf.h"
  42 #include "sb.h"
  43 #include "sb1.h"
  44 #include "misc.h"
  45
  46 /* all blocks are sized as a multiple of 0x1ff */
  47 #define PAD_TO_BOUNDARY(x) (((x) + 0x1ff) & ~0x1ff)
  48
  49 /* If you find a firmware that breaks the known format ^^ */
  50 #define assert(a) do { if(!(a)) { fprintf(stderr,"Assertion \"%s\" failed in %s() line %d!\n\nPlease send us your firmware!\n",#a,__func__,__LINE__); exit(1); } } while(0)
  51
  52 #define crypto_cbc(...) \
  53     do { int ret = crypto_cbc(__VA_ARGS__); \
  54         if(ret != CRYPTO_ERROR_SUCCESS) \
  55             bug("crypto_cbc error: %d\n", ret); \
  56     }while(0)
  57
  58 /* globals */
  59
  60 static char *g_out_prefix;
  61 static bool g_elf_simplify = true;
  62
  63 static void elf_printf(void *user, bool error, const char *fmt, ...)
  64 {
  65     if(!g_debug && !error)
  66         return;
  67     (void) user;
  68     va_list args;
  69     va_start(args, fmt);
  70     vprintf(fmt, args);
  71     va_end(args);
  72 }
  73
  74 static void elf_write(void *user, uint32_t addr, const void *buf, size_t count)
  75 {
  76     FILE *f = user;
  77     fseek(f, addr, SEEK_SET);
  78     fwrite(buf, count, 1, f);
  79 }
  80
  81 static void extract_elf_section(struct elf_params_t *elf, int count, uint32_t id)
  82 {
  83     char name[5];
  84     char *filename = xmalloc(strlen(g_out_prefix) + 32);
  85     sb_fill_section_name(name, id);
  86     sprintf(filename, "%s%s.%d.elf", g_out_prefix, name, count);
  87     if(g_debug)
  88         printf("Write boot section %s to %s\n", name, filename);
  89
  90     FILE *fd = fopen(filename, "wb");
  91     free(filename);
  92
  93     if(fd == NULL)
  94         return;
  95     if(g_elf_simplify)
  96         elf_simplify(elf);
  97     elf_write_file(elf, elf_write, elf_printf, fd);
  98     fclose(fd);
  99 }
 100
 101 static void extract_sb_section(struct sb_section_t *sec)
 102 {
 103     if(sec->is_data)
 104     {
 105         char sec_name[5];
 106         char *filename = xmalloc(strlen(g_out_prefix) + 32);
 107         sb_fill_section_name(sec_name, sec->identifier);
 108         sprintf(filename, "%s%s.bin", g_out_prefix, sec_name);
 109         FILE *fd = fopen(filename, "wb");
 110         if(fd == NULL)
 111             bugp("Cannot open %s for writing\n", filename);
 112         if(g_debug)
 113             printf("Write data section %s to %s\n", sec_name, filename);
 114         free(filename);
 115
 116         for(int j = 0; j < sec->nr_insts; j++)
 117         {
 118             assert(sec->insts[j].inst == SB_INST_DATA);
 119             fwrite(sec->insts[j].data, sec->insts[j].size, 1, fd);
 120         }
 121         fclose(fd);
 122     }
 123
 124     int elf_count = 0;
 125     struct elf_params_t elf;
 126     elf_init(&elf);
 127
 128     for(int i = 0; i < sec->nr_insts; i++)
 129     {
 130         struct sb_inst_t *inst = &sec->insts[i];
 131         switch(inst->inst)
 132         {
 133             case SB_INST_LOAD:
 134                 elf_add_load_section(&elf, inst->addr, inst->size, inst->data);
 135                 break;
 136             case SB_INST_FILL:
 137                 elf_add_fill_section(&elf, inst->addr, inst->size, inst->pattern);
 138                 break;
 139             case SB_INST_CALL:
 140             case SB_INST_JUMP:
 141                 elf_set_start_addr(&elf, inst->addr);
 142                 extract_elf_section(&elf, elf_count++, sec->identifier);
 143                 elf_release(&elf);
 144                 elf_init(&elf);
 145                 break;
 146             default:
 147                 /* ignore mode and nop */
 148                 break;
 149         }
 150     }
 151
 152     if(!elf_is_empty(&elf))
 153         extract_elf_section(&elf, elf_count, sec->identifier);
 154     elf_release(&elf);
 155 }
 156
 157 static void extract_sb_file(struct sb_file_t *file)
 158 {
 159     for(int i = 0; i < file->nr_sections; i++)
 160         extract_sb_section(&file->sections[i]);
 161 }
 162
 163 static void extract_elf(struct elf_params_t *elf, int count)
 164 {
 165     char *filename = xmalloc(strlen(g_out_prefix) + 32);
 166     sprintf(filename, "%s.%d.elf", g_out_prefix, count);
 167     if(g_debug)
 168         printf("Write boot content to %s\n", filename);
 169
 170     FILE *fd = fopen(filename, "wb");
 171     free(filename);
 172
 173     if(fd == NULL)
 174         return;
 175     if(g_elf_simplify)
 176         elf_simplify(elf);
 177     elf_write_file(elf, elf_write, elf_printf, fd);
 178     fclose(fd);
 179 }
 180
 181 static void extract_sb1_file(struct sb1_file_t *file)
 182 {
 183     int elf_count = 0;
 184     struct elf_params_t elf;
 185     elf_init(&elf);
 186
 187     for(int i = 0; i < file->nr_insts; i++)
 188     {
 189         struct sb1_inst_t *inst = &file->insts[i];
 190         switch(inst->cmd)
 191         {
 192             case SB1_INST_LOAD:
 193                 elf_add_load_section(&elf, inst->addr, inst->size, inst->data);
 194                 break;
 195             case SB1_INST_FILL:
 196                 elf_add_fill_section(&elf, inst->addr, inst->size, inst->pattern);
 197                 break;
 198             case SB1_INST_CALL:
 199             case SB1_INST_JUMP:
 200                 elf_set_start_addr(&elf, inst->addr);
 201                 extract_elf(&elf, elf_count++);
 202                 elf_release(&elf);
 203                 elf_init(&elf);
 204                 break;
 205             default:
 206                 /* ignore mode and nop */
 207                 break;
 208         }
 209     }
 210
 211     if(!elf_is_empty(&elf))
 212         extract_elf(&elf, elf_count);
 213     elf_release(&elf);
 214 }
 215
 216 static void usage(void)
 217 {
 218     printf("Usage: sbtoelf [options] sb-file\n");
 219     printf("Options:\n");
 220     printf("  -?/--help\tDisplay this message\n");
 221     printf("  -o <prefix>\tEnable output and set prefix\n");
 222     printf("  -d/--debug\tEnable debug output*\n");
 223     printf("  -k <file>\tAdd key file\n");
 224     printf("  -z\t\tAdd zero key\n");
 225     printf("  -r\t\tUse raw command mode\n");
 226     printf("  -a/--add-key <key>\tAdd single key (hex or usbotp)\n");
 227     printf("  -n/--no-color\tDisable output colors\n");
 228     printf("  -l/--loopback <file>\tProduce sb file out of extracted description*\n");
 229     printf("  -f/--force\tForce reading even without a key*\n");
 230     printf("  -1/--v1\tForce to read file as a version 1 file\n");
 231     printf("  -2/--v2\tForce to read file as a version 2 file\n");
 232     printf("  -s/--no-simpl\tPrevent elf files from being simplified*\n");
 233     printf("  -x\t\tUse default sb1 key\n");
 234     printf("Options marked with a * are for debug purpose only\n");
 235     exit(1);
 236 }
 237
 238 static void sb_printf(void *user, bool error, color_t c, const char *fmt, ...)
 239 {
 240     (void) user;
 241     (void) error;
 242     va_list args;
 243     va_start(args, fmt);
 244     color(c);
 245     vprintf(fmt, args);
 246     va_end(args);
 247 }
 248
 249 static struct crypto_key_t g_zero_key =
 250 {
 251     .method = CRYPTO_KEY,
 252     .u.key = {0}
 253 };
 254
 255
 256
 257 enum sb_version_guess_t
 258 {
 259     SB_VERSION_1,
 260     SB_VERSION_2,
 261     SB_VERSION_UNK,
 262 };
 263
 264 enum sb_version_guess_t guess_sb_version(const char *filename)
 265 {
 266 #define ret(x) do { fclose(f); return x; } while(0)
 267     FILE *f = fopen(filename, "rb");
 268     if(f == NULL)
 269         bugp("Cannot open file for reading\n");
 270     // check signature
 271     uint8_t sig[4];
 272     if(fseek(f, 20, SEEK_SET))
 273         ret(SB_VERSION_UNK);
 274     if(fread(sig, 4, 1, f) != 1)
 275         ret(SB_VERSION_UNK);
 276     if(memcmp(sig, "STMP", 4) != 0)
 277         ret(SB_VERSION_UNK);
 278     // check header size (v1)
 279     uint32_t hdr_size;
 280     if(fseek(f, 8, SEEK_SET))
 281         ret(SB_VERSION_UNK);
 282     if(fread(&hdr_size, 4, 1, f) != 1)
 283         ret(SB_VERSION_UNK);
 284     if(hdr_size == 0x34)
 285         ret(SB_VERSION_1);
 286     // check header params relationship
 287     struct
 288     {
 289         uint16_t nr_keys; /* Number of encryption keys */
 290         uint16_t key_dict_off; /* Offset to key dictionary (in blocks) */
 291         uint16_t header_size; /* In blocks */
 292         uint16_t nr_sections; /* Number of sections */
 293         uint16_t sec_hdr_size; /* Section header size (in blocks) */
 294     } __attribute__((packed)) u;
 295     if(fseek(f, 0x28, SEEK_SET))
 296         ret(SB_VERSION_UNK);
 297     if(fread(&u, sizeof(u), 1, f) != 1)
 298         ret(SB_VERSION_UNK);
 299     if(u.sec_hdr_size == 1 && u.header_size == 6 && u.key_dict_off == u.header_size + u.nr_sections)
 300         ret(SB_VERSION_2);
 301     ret(SB_VERSION_UNK);
 302 #undef ret
 303 }
 304
 305 int main(int argc, char **argv)
 306 {
 307     bool raw_mode = false;
 308     const char *loopback = NULL;
 309     bool force_sb1 = false;
 310     bool force_sb2 = false;
 311
 312     while(1)
 313     {
 314         static struct option long_options[] =
 315         {
 316             {"help", no_argument, 0, '?'},
 317             {"debug", no_argument, 0, 'd'},
 318             {"add-key", required_argument, 0, 'a'},
 319             {"no-color", no_argument, 0, 'n'},
 320             {"loopback", required_argument, 0, 'l'},
 321             {"force", no_argument, 0, 'f'},
 322             {"v1", no_argument, 0, '1'},
 323             {"v2", no_argument, 0, '2'},
 324             {"no-simpl", no_argument, 0, 's'},
 325             {0, 0, 0, 0}
 326         };
 327
 328         int c = getopt_long(argc, argv, "?do:k:zra:nl:f12xs", long_options, NULL);
 329         if(c == -1)
 330             break;
 331         switch(c)
 332         {
 333             case -1:
 334                 break;
 335             case 'l':
 336                 if(loopback)
 337                     bug("Only one loopback file can be specified !\n");
 338                 loopback = optarg;
 339                 break;
 340             case 'n':
 341                 enable_color(false);
 342                 break;
 343             case 'd':
 344                 g_debug = true;
 345                 break;
 346             case '?':
 347                 usage();
 348                 break;
 349             case 'o':
 350                 g_out_prefix = optarg;
 351                 break;
 352             case 'f':
 353                 g_force = true;
 354                 break;
 355             case 'k':
 356             {
 357                 if(!add_keys_from_file(optarg))
 358                     bug("Cannot add keys from %s\n", optarg);
 359                 break;
 360             }
 361             case 'z':
 362                 add_keys(&g_zero_key, 1);
 363                 break;
 364             case 'x':
 365             {
 366                 struct crypto_key_t key;
 367                 sb1_get_default_key(&key);
 368                 add_keys(&key, 1);
 369                 break;
 370             }
 371             case 'r':
 372                 raw_mode = true;
 373                 break;
 374             case 'a':
 375             {
 376                 struct crypto_key_t key;
 377                 char *s = optarg;
 378                 if(!parse_key(&s, &key))
 379                     bug("Invalid key specified as argument\n");
 380                 if(*s != 0)
 381                     bug("Trailing characters after key specified as argument\n");
 382                 add_keys(&key, 1);
 383                 break;
 384             }
 385             case '1':
 386                 force_sb1 = true;
 387                 break;
 388             case '2':
 389                 force_sb2 = true;
 390                 break;
 391             case 's':
 392                 g_elf_simplify = false;
 393                 break;
 394             default:
 395                 abort();
 396         }
 397     }
 398
 399     if(force_sb1 && force_sb2)
 400         bug("You cannot force both version 1 and 2\n");
 401
 402     if(argc - optind != 1)
 403     {
 404         usage();
 405         return 1;
 406     }
 407
 408     const char *sb_filename = argv[optind];
 409
 410     enum sb_version_guess_t ver = guess_sb_version(sb_filename);
 411
 412     if(force_sb2 || ver == SB_VERSION_2)
 413     {
 414         enum sb_error_t err;
 415         struct sb_file_t *file = sb_read_file(sb_filename, raw_mode, NULL, sb_printf, &err);
 416         if(file == NULL)
 417         {
 418             color(OFF);
 419             printf("SB read failed: %d\n", err);
 420             return 1;
 421         }
 422
 423         color(OFF);
 424         if(g_out_prefix)
 425             extract_sb_file(file);
 426         if(g_debug)
 427         {
 428             color(GREY);
 429             printf("[Debug output]\n");
 430             sb_dump(file, NULL, sb_printf);
 431         }
 432         if(loopback)
 433         {
 434             /* sb_read_file will fill real key and IV but we don't want to override
 435             * them when looping back otherwise the output will be inconsistent and
 436             * garbage */
 437             file->override_real_key = false;
 438             file->override_crypto_iv = false;
 439             sb_write_file(file, loopback);
 440         }
 441         sb_free(file);
 442     }
 443     else if(force_sb1 || ver == SB_VERSION_1)
 444     {
 445         enum sb1_error_t err;
 446         struct sb1_file_t *file = sb1_read_file(sb_filename, NULL, sb_printf, &err);
 447         if(file == NULL)
 448         {
 449             color(OFF);
 450             printf("SB read failed: %d\n", err);
 451             return 1;
 452         }
 453
 454         color(OFF);
 455         if(g_out_prefix)
 456             extract_sb1_file(file);
 457         if(g_debug)
 458         {
 459             color(GREY);
 460             printf("[Debug output]\n");
 461             sb1_dump(file, NULL, sb_printf);
 462         }
 463         if(loopback)
 464             sb1_write_file(file, loopback);
 465
 466         sb1_free(file);
 467     }
 468     else
 469     {
 470         color(OFF);
 471         printf("Cannot guess file type, are you sure it's a valid image ?\n");
 472         return 1;
 473     }
 474     clear_keys();
 475
 476     return 0;
 477 }