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  * as published by the Free Software Foundation; either version 2
   9  * of the License, or (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include "cryptsetup.h"
  22
  23 #define PACKAGE_VERITY "veritysetup"
  24
  25 static int use_superblock = 1;
  26
  27 static const char *hash_algorithm = NULL;
  28 static int hash_type = 1;
  29 static int data_block_size = DEFAULT_VERITY_DATA_BLOCK;
  30 static int hash_block_size = DEFAULT_VERITY_HASH_BLOCK;
  31 static uint64_t data_blocks = 0;
  32 static const char *salt_string = NULL;
  33 static uint64_t hash_offset = 0;
  34 static const char *opt_uuid = NULL;
  35
  36 static int opt_version_mode = 0;
  37
  38 static const char **action_argv;
  39 static int action_argc;
  40
  41 static int _prepare_format(struct crypt_params_verity *params,
  42                            const char *data_device,
  43                            uint32_t flags)
  44 {
  45         char *salt = NULL;
  46         int len;
  47
  48         params->hash_name = hash_algorithm ?: DEFAULT_VERITY_HASH;
  49         params->data_device = data_device;
  50
  51         if (salt_string && !strcmp(salt_string, "-")) {
  52                 params->salt_size = 0;
  53                 params->salt = NULL;
  54         } else if (salt_string) {
  55                 len = crypt_hex_to_bytes(salt_string, &salt, 0);
  56                 if (len < 0) {
  57                         log_err(_("Invalid salt string specified.\n"));
  58                         return -EINVAL;
  59                 }
  60                 params->salt_size = len;
  61                 params->salt = salt;
  62         } else {
  63                 params->salt_size = DEFAULT_VERITY_SALT_SIZE;
  64                 params->salt = NULL;
  65         }
  66
  67         params->data_block_size = data_block_size;
  68         params->hash_block_size = hash_block_size;
  69         params->data_size = data_blocks;
  70         params->hash_area_offset = hash_offset;
  71         params->hash_type = hash_type;
  72         params->flags = flags;
  73
  74         return 0;
  75 }
  76
  77 static int action_format(int arg)
  78 {
  79         struct crypt_device *cd = NULL;
  80         struct crypt_params_verity params = {};
  81         uint32_t flags = CRYPT_VERITY_CREATE_HASH;
  82         int r;
  83
  84         /* Try to create hash image if doesn't exist */
  85         r = open(action_argv[1], O_WRONLY | O_EXCL | O_CREAT, S_IRUSR | S_IWUSR);
  86         if (r < 0 && errno != EEXIST) {
  87                 log_err(_("Cannot create hash image %s for writing.\n"), action_argv[1]);
  88                 return -EINVAL;
  89         } else if (r >= 0) {
  90                 log_dbg("Created hash image %s.", action_argv[1]);
  91                 close(r);
  92         }
  93
  94         if ((r = crypt_init(&cd, action_argv[1])))
  95                 goto out;
  96
  97         if (!use_superblock)
  98                 flags |= CRYPT_VERITY_NO_HEADER;
  99
 100         r = _prepare_format(&params, action_argv[0], flags);
 101         if (r < 0)
 102                 goto out;
 103
 104         r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, opt_uuid, NULL, 0, &params);
 105         if (!r)
 106                 crypt_dump(cd);
 107 out:
 108         crypt_free(cd);
 109         free(CONST_CAST(char*)params.salt);
 110         return r;
 111 }
 112
 113 static int _activate(const char *dm_device,
 114                       const char *data_device,
 115                       const char *hash_device,
 116                       const char *root_hash,
 117                       uint32_t flags)
 118 {
 119         struct crypt_device *cd = NULL;
 120         struct crypt_params_verity params = {};
 121         uint32_t activate_flags = CRYPT_ACTIVATE_READONLY;
 122         char *root_hash_bytes = NULL;
 123         ssize_t hash_size;
 124         int r;
 125
 126         if ((r = crypt_init(&cd, hash_device)))
 127                 goto out;
 128
 129         if (use_superblock) {
 130                 params.flags = flags;
 131                 params.hash_area_offset = hash_offset;
 132                 r = crypt_load(cd, CRYPT_VERITY, &params);
 133         } else {
 134                 r = _prepare_format(&params, data_device, flags | CRYPT_VERITY_NO_HEADER);
 135                 if (r < 0)
 136                         goto out;
 137                 r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);
 138         }
 139         if (r < 0)
 140                 goto out;
 141         r = crypt_set_data_device(cd, data_device);
 142         if (r < 0)
 143                 goto out;
 144
 145         hash_size = crypt_get_volume_key_size(cd);
 146         if (crypt_hex_to_bytes(root_hash, &root_hash_bytes, 0) != hash_size) {
 147                 log_err(_("Invalid root hash string specified.\n"));
 148                 r = -EINVAL;
 149                 goto out;
 150         }
 151         r = crypt_activate_by_volume_key(cd, dm_device,
 152                                          root_hash_bytes,
 153                                          hash_size,
 154                                          activate_flags);
 155 out:
 156         crypt_free(cd);
 157         free(root_hash_bytes);
 158         free(CONST_CAST(char*)params.salt);
 159         return r;
 160 }
 161
 162 static int action_create(int arg)
 163 {
 164         return _activate(action_argv[0],
 165                          action_argv[1],
 166                          action_argv[2],
 167                          action_argv[3], 0);
 168 }
 169
 170 static int action_verify(int arg)
 171 {
 172         return _activate(NULL,
 173                          action_argv[0],
 174                          action_argv[1],
 175                          action_argv[2],
 176                          CRYPT_VERITY_CHECK_HASH);
 177 }
 178
 179 static int action_remove(int arg)
 180 {
 181         struct crypt_device *cd = NULL;
 182         int r;
 183
 184         r = crypt_init_by_name(&cd, action_argv[0]);
 185         if (r == 0)
 186                 r = crypt_deactivate(cd, action_argv[0]);
 187
 188         crypt_free(cd);
 189         return r;
 190 }
 191
 192 static int action_status(int arg)
 193 {
 194         crypt_status_info ci;
 195         struct crypt_active_device cad;
 196         struct crypt_params_verity vp = {};
 197         struct crypt_device *cd = NULL;
 198         struct stat st;
 199         char *backing_file;
 200         unsigned i, path = 0;
 201         int r = 0;
 202
 203         /* perhaps a path, not a dm device name */
 204         if (strchr(action_argv[0], '/') && !stat(action_argv[0], &st))
 205                 path = 1;
 206
 207         ci = crypt_status(NULL, action_argv[0]);
 208         switch (ci) {
 209         case CRYPT_INVALID:
 210                 r = -EINVAL;
 211                 break;
 212         case CRYPT_INACTIVE:
 213                 if (path)
 214                         log_std("%s is inactive.\n", action_argv[0]);
 215                 else
 216                         log_std("%s/%s is inactive.\n", crypt_get_dir(), action_argv[0]);
 217                 r = -ENODEV;
 218                 break;
 219         case CRYPT_ACTIVE:
 220         case CRYPT_BUSY:
 221                 if (path)
 222                         log_std("%s is active%s.\n", action_argv[0],
 223                                 ci == CRYPT_BUSY ? " and is in use" : "");
 224                 else
 225                         log_std("%s/%s is active%s.\n", crypt_get_dir(), action_argv[0],
 226                                 ci == CRYPT_BUSY ? " and is in use" : "");
 227
 228                 r = crypt_init_by_name_and_header(&cd, action_argv[0], NULL);
 229                 if (r < 0 || !crypt_get_type(cd))
 230                         goto out;
 231
 232                 log_std("  type:        %s\n", crypt_get_type(cd));
 233
 234                 r = crypt_get_active_device(cd, action_argv[0], &cad);
 235                 if (r < 0)
 236                         goto out;
 237
 238                 log_std("  status:      %s\n",
 239                         cad.flags & CRYPT_ACTIVATE_CORRUPTED ? "corrupted" : "verified");
 240
 241                 r = crypt_get_verity_info(cd, &vp);
 242                 if (r < 0)
 243                         goto out;
 244
 245                 log_std("  hash type:   %u\n", vp.hash_type);
 246                 log_std("  data block:  %u\n", vp.data_block_size);
 247                 log_std("  hash block:  %u\n", vp.hash_block_size);
 248                 log_std("  hash name:   %s\n", vp.hash_name);
 249                 log_std("  salt:        ");
 250                 if (vp.salt_size)
 251                         for(i = 0; i < vp.salt_size; i++)
 252                                 log_std("%02hhx", (const char)vp.salt[i]);
 253                 else
 254                         log_std("-");
 255                 log_std("\n");
 256
 257                 log_std("  data device: %s\n", vp.data_device);
 258                 if (crypt_loop_device(vp.data_device)) {
 259                         backing_file = crypt_loop_backing_file(vp.data_device);
 260                         log_std("  data loop:   %s\n", backing_file);
 261                         free(backing_file);
 262                 }
 263                 log_std("  size:        %" PRIu64 " sectors\n", cad.size);
 264                 log_std("  mode:        %s\n", cad.flags & CRYPT_ACTIVATE_READONLY ?
 265                                            "readonly" : "read/write");
 266
 267                 log_std("  hash device: %s\n", vp.hash_device);
 268                 if (crypt_loop_device(vp.hash_device)) {
 269                         backing_file = crypt_loop_backing_file(vp.hash_device);
 270                         log_std("  hash loop:   %s\n", backing_file);
 271                         free(backing_file);
 272                 }
 273                 log_std("  hash offset: %" PRIu64 " sectors\n",
 274                         vp.hash_area_offset * vp.hash_block_size / 512);
 275         }
 276 out:
 277         crypt_free(cd);
 278         if (r == -ENOTSUP)
 279                 r = 0;
 280         return r;
 281 }
 282
 283 static int action_dump(int arg)
 284 {
 285         struct crypt_device *cd = NULL;
 286         struct crypt_params_verity params = {};
 287         int r;
 288
 289         if ((r = crypt_init(&cd, action_argv[0])))
 290                 return r;
 291
 292         params.hash_area_offset = hash_offset;
 293         r = crypt_load(cd, CRYPT_VERITY, &params);
 294         if (!r)
 295                 crypt_dump(cd);
 296         crypt_free(cd);
 297         return r;
 298 }
 299
 300 static struct action_type {
 301         const char *type;
 302         int (*handler)(int);
 303         int required_action_argc;
 304         const char *arg_desc;
 305         const char *desc;
 306 } action_types[] = {
 307         { "format",     action_format, 2, N_("<data_device> <hash_device>"),N_("format device") },
 308         { "verify",     action_verify, 3, N_("<data_device> <hash_device> <root_hash>"),N_("verify device") },
 309         { "create",     action_create, 4, N_("<name> <data_device> <hash_device> <root_hash>"),N_("create active device") },
 310         { "remove",     action_remove, 1, N_("<name>"),N_("remove (deactivate) device") },
 311         { "status",     action_status, 1, N_("<name>"),N_("show active device status") },
 312         { "dump",       action_dump,   1, N_("<hash_device>"),N_("show on-disk information") },
 313         { NULL, NULL, 0, NULL, NULL }
 314 };
 315
 316 static void help(poptContext popt_context,
 317                  enum poptCallbackReason reason __attribute__((unused)),
 318                  struct poptOption *key,
 319                  const char *arg __attribute__((unused)),
 320                  void *data __attribute__((unused)))
 321 {
 322         struct action_type *action;
 323
 324         if (key->shortName == '?') {
 325                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 326                 poptPrintHelp(popt_context, stdout, 0);
 327                 log_std(_("\n"
 328                          "<action> is one of:\n"));
 329                 for(action = action_types; action->type; action++)
 330                         log_std("\t%s %s - %s\n", action->type, _(action->arg_desc), _(action->desc));
 331                 log_std(_("\n"
 332                          "<name> is the device to create under %s\n"
 333                          "<data_device> is the data device\n"
 334                          "<hash_device> is the device containing verification data\n"
 335                          "<root_hash> hash of the root node on <hash_device>\n"),
 336                         crypt_get_dir());
 337
 338                 log_std(_("\nDefault compiled-in dm-verity parameters:\n"
 339                          "\tHash: %s, Data block (bytes): %u, "
 340                          "Hash block (bytes): %u, Salt size: %u, Hash format: %u\n"),
 341                         DEFAULT_VERITY_HASH, DEFAULT_VERITY_DATA_BLOCK,
 342                         DEFAULT_VERITY_HASH_BLOCK, DEFAULT_VERITY_SALT_SIZE,
 343                         1);
 344                 exit(EXIT_SUCCESS);
 345         } else
 346                 usage(popt_context, EXIT_SUCCESS, NULL, NULL);
 347 }
 348
 349 static int run_action(struct action_type *action)
 350 {
 351         int r;
 352
 353         log_dbg("Running command %s.", action->type);
 354
 355         r = action->handler(0);
 356
 357         show_status(r);
 358         return translate_errno(r);
 359 }
 360
 361 int main(int argc, const char **argv)
 362 {
 363         static char *popt_tmp;
 364         static const char *null_action_argv[] = {NULL};
 365         static struct poptOption popt_help_options[] = {
 366                 { NULL,    '\0', POPT_ARG_CALLBACK, help, 0, NULL,                         NULL },
 367                 { "help",  '?',  POPT_ARG_NONE,     NULL, 0, N_("Show this help message"), NULL },
 368                 { "usage", '\0', POPT_ARG_NONE,     NULL, 0, N_("Display brief usage"),    NULL },
 369                 POPT_TABLEEND
 370         };
 371         static struct poptOption popt_options[] = {
 372                 { NULL,              '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, N_("Help options:"), NULL },
 373                 { "version",         '\0', POPT_ARG_NONE, &opt_version_mode, 0, N_("Print package version"), NULL },
 374                 { "verbose",         'v',  POPT_ARG_NONE, &opt_verbose,      0, N_("Shows more detailed error messages"), NULL },
 375                 { "debug",           '\0', POPT_ARG_NONE, &opt_debug,        0, N_("Show debug messages"), NULL },
 376                 { "no-superblock",   0,    POPT_ARG_VAL,  &use_superblock,   0, N_("Do not use verity superblock"), NULL },
 377                 { "format",          0,    POPT_ARG_INT,  &hash_type,        0, N_("Format type (1 - normal, 0 - original Chrome OS)"), N_("number") },
 378                 { "data-block-size", 0,    POPT_ARG_INT,  &data_block_size,  0, N_("Block size on the data device"), N_("bytes") },
 379                 { "hash-block-size", 0,    POPT_ARG_INT,  &hash_block_size,  0, N_("Block size on the hash device"), N_("bytes") },
 380                 { "data-blocks",     0,    POPT_ARG_STRING, &popt_tmp,       1, N_("The number of blocks in the data file"), N_("blocks") },
 381                 { "hash-offset",     0,    POPT_ARG_STRING, &popt_tmp,       2, N_("Starting offset on the hash device"), N_("bytes") },
 382                 { "hash",            'h',  POPT_ARG_STRING, &hash_algorithm, 0, N_("Hash algorithm"), N_("string") },
 383                 { "salt",            's',  POPT_ARG_STRING, &salt_string,    0, N_("Salt"), N_("hex string") },
 384                 { "uuid",            '\0', POPT_ARG_STRING, &opt_uuid,       0, N_("UUID for device to use."), NULL },
 385                 POPT_TABLEEND
 386         };
 387
 388         poptContext popt_context;
 389         struct action_type *action;
 390         const char *aname;
 391         int r;
 392
 393         crypt_set_log_callback(NULL, tool_log, NULL);
 394
 395         setlocale(LC_ALL, "");
 396         bindtextdomain(PACKAGE, LOCALEDIR);
 397         textdomain(PACKAGE);
 398
 399         popt_context = poptGetContext("verity", argc, argv, popt_options, 0);
 400         poptSetOtherOptionHelp(popt_context,
 401                                _("[OPTION...] <action> <action-specific>"));
 402
 403         while((r = poptGetNextOpt(popt_context)) > 0) {
 404                 unsigned long long ull_value;
 405                 char *endp;
 406
 407                 errno = 0;
 408                 ull_value = strtoull(popt_tmp, &endp, 10);
 409                 if (*endp || !*popt_tmp || !isdigit(*popt_tmp) ||
 410                     (errno == ERANGE && ull_value == ULLONG_MAX) ||
 411                     (errno != 0 && ull_value == 0))
 412                         r = POPT_ERROR_BADNUMBER;
 413
 414                 switch(r) {
 415                         case 1:
 416                                 data_blocks = ull_value;
 417                                 break;
 418                         case 2:
 419                                 hash_offset = ull_value;
 420                                 break;
 421                 }
 422
 423                 if (r < 0)
 424                         break;
 425         }
 426
 427         if (r < -1)
 428                 usage(popt_context, EXIT_FAILURE, poptStrerror(r),
 429                       poptBadOption(popt_context, POPT_BADOPTION_NOALIAS));
 430
 431         if (opt_version_mode) {
 432                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 433                 poptFreeContext(popt_context);
 434                 exit(EXIT_SUCCESS);
 435         }
 436
 437         if (!(aname = poptGetArg(popt_context)))
 438                 usage(popt_context, EXIT_FAILURE, _("Argument <action> missing."),
 439                       poptGetInvocationName(popt_context));
 440         for(action = action_types; action->type; action++)
 441                 if (strcmp(action->type, aname) == 0)
 442                         break;
 443         if (!action->type)
 444                 usage(popt_context, EXIT_FAILURE, _("Unknown action."),
 445                       poptGetInvocationName(popt_context));
 446
 447         action_argc = 0;
 448         action_argv = poptGetArgs(popt_context);
 449         /* Make return values of poptGetArgs more consistent in case of remaining argc = 0 */
 450         if(!action_argv)
 451                 action_argv = null_action_argv;
 452
 453         /* Count args, somewhat unnice, change? */
 454         while(action_argv[action_argc] != NULL)
 455                 action_argc++;
 456
 457         if(action_argc < action->required_action_argc) {
 458                 char buf[128];
 459                 snprintf(buf, 128,_("%s: requires %s as arguments"), action->type, action->arg_desc);
 460                 usage(popt_context, EXIT_FAILURE, buf,
 461                       poptGetInvocationName(popt_context));
 462         }
 463
 464         if (data_block_size < 0 || hash_block_size < 0 || hash_type < 0) {
 465                 usage(popt_context, EXIT_FAILURE,
 466                       _("Negative number for option not permitted."),
 467                       poptGetInvocationName(popt_context));
 468         }
 469
 470         if (opt_debug) {
 471                 opt_verbose = 1;
 472                 crypt_set_debug_level(-1);
 473                 dbg_version_and_cmd(argc, argv);
 474         }
 475
 476         r = run_action(action);
 477         poptFreeContext(popt_context);
 478         return r;
 479 }