src/veritysetup.c

   1 /*
   2  * veritysetup - setup cryptographic volumes for dm-verity
   3  *
   4  * Copyright (C) 2012, Red Hat, Inc. All rights reserved.
   5  *
   6  * This program is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU General Public License
   8  * version 2 as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13  * GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this program; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  18  */
  19
  20 /* TODO:
  21  * - init_by_name()
  22  * - unify units / uint64 etc
  23  * - check translations
  24  * - support device without superblock
  25  * - audit alloc errors / error path
  26  * - change command names (cryptsetup style)
  27  * - extend superblock (UUID)
  28  * - warn if block_size > PAGE_SIZE
  29  */
  30
  31 #include <stdio.h>
  32 #include <stdlib.h>
  33 #include <stdarg.h>
  34 #include <errno.h>
  35 #include <string.h>
  36 #include <popt.h>
  37
  38 #include "cryptsetup.h"
  39
  40 #define PACKAGE_VERITY "veritysetup"
  41
  42 #define MODE_VERIFY     0
  43 #define MODE_CREATE     1
  44 #define MODE_ACTIVATE   2
  45 #define MODE_DUMP       3
  46
  47 static int mode = -1;
  48 static int use_superblock = 1; /* FIXME: no superblock not supported */
  49
  50 static const char *dm_device = NULL;
  51 static const char *data_device = NULL;
  52 static const char *hash_device = NULL;
  53 static const char *hash_algorithm = NULL;
  54 static const char *root_hash = NULL;
  55
  56 static int version = 1;
  57 static int data_block_size = 4096;
  58 static int hash_block_size = 4096;
  59 static char *data_blocks_string = NULL;
  60 static long long data_blocks = 0;
  61 static char *hash_start_string = NULL;
  62 static const char *salt_string = NULL;
  63
  64 static unsigned salt_size = 32;
  65
  66 static off_t superblock_position = 0;
  67
  68 static int opt_verbose = 0;
  69 static int opt_debug = 0;
  70 static int opt_version_mode = 0;
  71
  72 static int hex_to_bytes(const char *hex, char *result)
  73 {
  74         char buf[3] = "xx\0", *endp;
  75         int i, len;
  76
  77         len = strlen(hex) / 2;
  78         for (i = 0; i < len; i++) {
  79                 memcpy(buf, &hex[i * 2], 2);
  80                 result[i] = strtoul(buf, &endp, 16);
  81                 if (endp != &buf[2])
  82                         return -EINVAL;
  83         }
  84         return i;
  85 }
  86
  87 __attribute__((format(printf, 5, 6)))
  88 static void clogger(struct crypt_device *cd, int level, const char *file,
  89                    int line, const char *format, ...)
  90 {
  91         va_list argp;
  92         char *target = NULL;
  93
  94         va_start(argp, format);
  95
  96         if (vasprintf(&target, format, argp) > 0) {
  97                 if (level >= 0) {
  98                         crypt_log(cd, level, target);
  99 #ifdef CRYPT_DEBUG
 100                 } else if (opt_debug)
 101                         printf("# %s:%d %s\n", file ?: "?", line, target);
 102 #else
 103                 } else if (opt_debug)
 104                         printf("# %s\n", target);
 105 #endif
 106         }
 107
 108         va_end(argp);
 109         free(target);
 110 }
 111
 112 static void _log(int level, const char *msg, void *usrptr __attribute__((unused)))
 113 {
 114         switch(level) {
 115
 116         case CRYPT_LOG_NORMAL:
 117                 fputs(msg, stdout);
 118                 break;
 119         case CRYPT_LOG_VERBOSE:
 120                 if (opt_verbose)
 121                         fputs(msg, stdout);
 122                 break;
 123         case CRYPT_LOG_ERROR:
 124                 fputs(msg, stderr);
 125                 break;
 126         case CRYPT_LOG_DEBUG:
 127                 if (opt_debug)
 128                         printf("# %s\n", msg);
 129                 break;
 130         default:
 131                 fprintf(stderr, "Internal error on logging class for msg: %s", msg);
 132                 break;
 133         }
 134 }
 135
 136 static int action_dump(void)
 137 {
 138         struct crypt_device *cd = NULL;
 139         struct crypt_params_verity params = {};
 140         int r;
 141
 142         if ((r = crypt_init(&cd, hash_device)))
 143                 return r;
 144
 145         params.hash_area_offset = superblock_position;
 146         r = crypt_load(cd, CRYPT_VERITY, &params);
 147         if (!r)
 148                 crypt_dump(cd);
 149         crypt_free(cd);
 150         return r;
 151 }
 152
 153 static int action_activate(int verify)
 154 {
 155         struct crypt_device *cd = NULL;
 156         struct crypt_params_verity params = {};
 157         uint32_t activate_flags = CRYPT_ACTIVATE_READONLY;
 158         char root_hash_bytes[128];
 159         int r;
 160
 161         if ((r = crypt_init(&cd, hash_device)))
 162                 goto out;
 163
 164         if (verify)
 165                 params.flags |= CRYPT_VERITY_CHECK_HASH;
 166
 167         if (use_superblock) {
 168                 params.hash_area_offset = superblock_position;
 169                 r = crypt_load(cd, CRYPT_VERITY, &params);
 170         } else {/*
 171                 params.hash_name = hash_algorithm;
 172                 params.salt = salt_bytes;
 173                 params.salt_size = salt_size;
 174                 params.data_block_size = data_block_size;
 175                 params.hash_block_size = hash_block_size;
 176
 177                 params.data_size = data_blocks * data_block_size / 512;
 178                 params.version = version;
 179                 params.flags |= CRYPT_VERITY_NO_HEADER;
 180                 r = crypt_load(cd, CRYPT_VERITY, &params);
 181                 crypt_format(); */
 182                 r = -EINVAL;
 183                 goto out;
 184         }
 185         if (r < 0)
 186                 goto out;
 187         r = crypt_set_data_device(cd, data_device);
 188         if (r < 0)
 189                 goto out;
 190
 191         if (hex_to_bytes(root_hash, root_hash_bytes) !=
 192             crypt_get_volume_key_size(cd)) {
 193                 r = -EINVAL;
 194                 goto out;
 195         }
 196         r = crypt_activate_by_volume_key(cd, dm_device, root_hash_bytes,
 197                                          crypt_get_volume_key_size(cd),
 198                                          activate_flags);
 199 out:
 200         if (!r)
 201                 crypt_dump(cd);
 202         crypt_free(cd);
 203         return r;
 204 }
 205
 206 static int action_create(void)
 207 {
 208         struct crypt_device *cd = NULL;
 209         struct crypt_params_verity params = {};
 210         char salt_bytes[512];
 211         int r;
 212
 213         if ((r = crypt_init(&cd, hash_device)))
 214                 goto out;
 215
 216         params.hash_name = hash_algorithm;
 217         params.data_device = data_device;
 218
 219         if (salt_string) {
 220                 if (hex_to_bytes(salt_string, salt_bytes) != salt_size) {
 221                         r = -EINVAL;
 222                         goto out;
 223                 }
 224                 params.salt = salt_bytes;
 225         }
 226
 227         params.salt_size = salt_size;
 228         params.data_block_size = data_block_size;
 229         params.hash_block_size = hash_block_size;
 230         params.data_size = data_blocks;
 231         params.hash_area_offset = superblock_position;
 232         params.version = version;
 233         params.flags = CRYPT_VERITY_CREATE_HASH;
 234         if (!use_superblock)
 235                 params.flags |= CRYPT_VERITY_NO_HEADER;
 236
 237         r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);
 238         if (!r)
 239                 crypt_dump(cd);
 240 out:
 241         crypt_free(cd);
 242         return r;
 243 }
 244
 245 static __attribute__ ((noreturn)) void usage(poptContext popt_context,
 246                                              int exitcode, const char *error,
 247                                              const char *more)
 248 {
 249         poptPrintUsage(popt_context, stderr, 0);
 250         if (error)
 251                 log_err("%s: %s\n", more, error);
 252         poptFreeContext(popt_context);
 253         exit(exitcode);
 254 }
 255
 256 static void help(poptContext popt_context,
 257                  enum poptCallbackReason reason __attribute__((unused)),
 258                  struct poptOption *key,
 259                  const char *arg __attribute__((unused)),
 260                  void *data __attribute__((unused)))
 261 {
 262         if (key->shortName == '?') {
 263                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 264                 poptPrintHelp(popt_context, stdout, 0);
 265                 exit(EXIT_SUCCESS);
 266         } else
 267                 usage(popt_context, EXIT_SUCCESS, NULL, NULL);
 268 }
 269
 270 static void _dbg_version_and_cmd(int argc, const char **argv)
 271 {
 272         int i;
 273
 274         log_std("# %s %s processing \"", PACKAGE_VERITY, PACKAGE_VERSION);
 275         for (i = 0; i < argc; i++) {
 276                 if (i)
 277                         log_std(" ");
 278                 log_std("%s", argv[i]);
 279         }
 280         log_std("\"\n");
 281 }
 282
 283 int main(int argc, const char **argv)
 284 {
 285         static struct poptOption popt_help_options[] = {
 286                 { NULL,    '\0', POPT_ARG_CALLBACK, help, 0, NULL,                         NULL },
 287                 { "help",  '?',  POPT_ARG_NONE,     NULL, 0, N_("Show this help message"), NULL },
 288                 { "usage", '\0', POPT_ARG_NONE,     NULL, 0, N_("Display brief usage"),    NULL },
 289                 POPT_TABLEEND
 290         };
 291         static struct poptOption popt_options[] = {
 292                 { NULL,                '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, N_("Help options:"), NULL },
 293                 { "version",           '\0', POPT_ARG_NONE, &opt_version_mode,          0, N_("Print package version"), NULL },
 294                 { "verbose",            0 /*v*/,  POPT_ARG_NONE, &opt_verbose,               0, N_("Shows more detailed error messages"), NULL },
 295                 { "debug",             '\0', POPT_ARG_NONE, &opt_debug,                 0, N_("Show debug messages"), NULL },
 296                 { "create",             'c',    POPT_ARG_VAL, &mode, MODE_CREATE, "Create hash", NULL },
 297                 { "verify",             'v',    POPT_ARG_VAL, &mode, MODE_VERIFY, "Verify integrity", NULL },
 298                 { "activate",           'a',    POPT_ARG_VAL, &mode, MODE_ACTIVATE, "Activate the device", NULL },
 299                 { "dump",               'd',    POPT_ARG_VAL, &mode, MODE_DUMP, "Dump the device", NULL },
 300                 { "no-superblock",      0,      POPT_ARG_VAL, &use_superblock, 0, "Do not create/use superblock" },
 301                 { "format",             0,      POPT_ARG_INT, &version, 0, "Format version (1 - normal format, 0 - original Chromium OS format)", "number" },
 302                 { "data-block-size",    0,      POPT_ARG_INT, &data_block_size, 0, "Block size on the data device", "bytes" },
 303                 { "hash-block-size",    0,      POPT_ARG_INT, &hash_block_size, 0, "Block size on the hash device", "bytes" },
 304                 { "data-blocks",        0,      POPT_ARG_STRING, &data_blocks_string, 0, "The number of blocks in the data file", "blocks" },
 305                 { "hash-start",         0,      POPT_ARG_STRING, &hash_start_string, 0, "Starting block on the hash device", "512-byte sectors" },
 306                 { "algorithm",          0,      POPT_ARG_STRING, &hash_algorithm, 0, "Hash algorithm (default sha256)", "string" },
 307                 { "salt",               0,      POPT_ARG_STRING, &salt_string, 0, "Salt", "hex string" },
 308                 POPT_TABLEEND
 309         };
 310         poptContext popt_context;
 311         int r;
 312         char *end;
 313         static long long hash_start = 0;
 314
 315         crypt_set_log_callback(NULL, _log, NULL);
 316
 317         setlocale(LC_ALL, "");
 318         bindtextdomain(PACKAGE, LOCALEDIR);
 319         textdomain(PACKAGE);
 320
 321         popt_context = poptGetContext("verity", argc, argv, popt_options, 0);
 322
 323         poptSetOtherOptionHelp(popt_context, "[-c|-v|-a|-d] [<device name> if activating] <data device> <hash device> [<root hash> if activating or verifying] [OPTION...]");
 324
 325         if (argc <= 1) {
 326                 poptPrintHelp(popt_context, stdout, 0);
 327                 exit(1);
 328         }
 329
 330         r = poptGetNextOpt(popt_context);
 331         if (r < -1)
 332                 usage(popt_context, EXIT_FAILURE, poptStrerror(r),
 333                       poptBadOption(popt_context, POPT_BADOPTION_NOALIAS));
 334         if (opt_version_mode) {
 335                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 336                 poptFreeContext(popt_context);
 337                 exit(EXIT_SUCCESS);
 338         }
 339
 340         if (mode < 0)
 341                 usage(popt_context, EXIT_FAILURE, _("Unknown action."),
 342                       poptGetInvocationName(popt_context));
 343
 344         if (mode == MODE_ACTIVATE) {
 345                 dm_device = poptGetArg(popt_context);
 346                 if (!dm_device || !*dm_device)
 347                         usage(popt_context, EXIT_FAILURE,
 348                               _("Missing activation device name."),
 349                               poptGetInvocationName(popt_context));
 350         }
 351
 352         data_device = poptGetArg(popt_context);
 353         if (!data_device)
 354                 usage(popt_context, EXIT_FAILURE, _("Missing data device name."),
 355                       poptGetInvocationName(popt_context));
 356
 357         hash_device = poptGetArg(popt_context);
 358         if (!hash_device)
 359                 usage(popt_context, EXIT_FAILURE, _("Missing hash device name."),
 360                       poptGetInvocationName(popt_context));
 361
 362         if (mode == MODE_ACTIVATE || mode == MODE_VERIFY) {
 363                 root_hash = poptGetArg(popt_context);
 364                 if (!root_hash)
 365                 usage(popt_context, EXIT_FAILURE, _("Root hash not specified."),
 366                       poptGetInvocationName(popt_context));
 367         }
 368
 369         if (data_blocks_string) {
 370                 data_blocks = strtoll(data_blocks_string, &end, 10);
 371                 if (!*data_blocks_string || *end)
 372                         usage(popt_context, EXIT_FAILURE,
 373                               _("Invalid number of data blocks."),
 374                               poptGetInvocationName(popt_context));
 375         }
 376
 377         /* hash start */
 378         if (hash_start_string) {
 379                 hash_start = strtoll(hash_start_string, &end, 10);
 380                 if (!*hash_start_string || *end)
 381                         usage(popt_context, EXIT_FAILURE,
 382                               _("Invalid hash device offset."),
 383                               poptGetInvocationName(popt_context));
 384         }
 385
 386         if (hash_start < 0 ||
 387            (unsigned long long)hash_start * 512 / 512 != hash_start ||
 388            (off_t)(hash_start * 512) < 0 ||
 389            (off_t)(hash_start * 512) != hash_start * 512)
 390                 usage(popt_context, EXIT_FAILURE,
 391                       _("Invalid hash device offset."),
 392                       poptGetInvocationName(popt_context));
 393
 394         if (use_superblock)
 395                 superblock_position = hash_start * 512;
 396
 397         if (salt_string || !use_superblock) {
 398                 if (!salt_string || !strcmp(salt_string, "-"))
 399                         salt_string = "";
 400                 salt_size = strlen(salt_string) / 2;
 401         }
 402
 403         if (data_block_size < 512 || (data_block_size & (data_block_size - 1)) || data_block_size >= 1U << 31)
 404                 usage(popt_context, EXIT_FAILURE, _("Invalid data block size."),
 405                       poptGetInvocationName(popt_context));
 406
 407         if (hash_block_size < 512 || (hash_block_size & (hash_block_size - 1)) || hash_block_size >= 1U << 31)
 408                 usage(popt_context, EXIT_FAILURE, _("Invalid hash block size."),
 409                       poptGetInvocationName(popt_context));
 410
 411         if (data_blocks < 0 || (off_t)data_blocks < 0 || (off_t)data_blocks != data_blocks)
 412                 usage(popt_context, EXIT_FAILURE, _("Invalid number of data blocks."),
 413                       poptGetInvocationName(popt_context));
 414
 415         if (!hash_algorithm)
 416                 hash_algorithm = "sha256";
 417
 418         if (opt_debug) {
 419                 opt_verbose = 1;
 420                 crypt_set_debug_level(-1);
 421                 _dbg_version_and_cmd(argc, argv);
 422         }
 423
 424         switch (mode) {
 425                 case MODE_ACTIVATE:
 426                         r = action_activate(0);
 427                         break;
 428                 case MODE_VERIFY:
 429                         r = action_activate(1);
 430                         break;
 431                 case MODE_CREATE:
 432                         r = action_create();
 433                         break;
 434                 case MODE_DUMP:
 435                         r = action_dump();
 436                         break;
 437         }
 438
 439         poptFreeContext(popt_context);
 440         return r;
 441 }