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  * - extend superblock (UUID)
  22  * - add api tests
  23  * - report in-kernel status outside libcryptsetup (extend api)
  24  */
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <stdarg.h>
  29 #include <errno.h>
  30 #include <string.h>
  31 #include <inttypes.h>
  32 #include <popt.h>
  33 #include <limits.h>
  34 #include <sys/stat.h>
  35
  36 #include "cryptsetup.h"
  37
  38 #define PACKAGE_VERITY "veritysetup"
  39
  40 static int use_superblock = 1; /* FIXME: no superblock not supported */
  41
  42 static const char *hash_algorithm = NULL;
  43 static int version = 1;
  44 static int data_block_size = DEFAULT_VERITY_DATA_BLOCK;
  45 static int hash_block_size = DEFAULT_VERITY_HASH_BLOCK;
  46 static uint64_t data_blocks = 0;
  47 static const char *salt_string = NULL;
  48 static uint64_t hash_start = 0;
  49
  50 static int opt_verbose = 0;
  51 static int opt_debug = 0;
  52 static int opt_version_mode = 0;
  53
  54 static const char **action_argv;
  55 static int action_argc;
  56
  57 static int hex_to_bytes(const char *hex, char *result)
  58 {
  59         char buf[3] = "xx\0", *endp;
  60         int i, len;
  61
  62         len = strlen(hex) / 2;
  63         for (i = 0; i < len; i++) {
  64                 memcpy(buf, &hex[i * 2], 2);
  65                 result[i] = strtoul(buf, &endp, 16);
  66                 if (endp != &buf[2])
  67                         return -EINVAL;
  68         }
  69         return i;
  70 }
  71
  72 __attribute__((format(printf, 5, 6)))
  73 static void clogger(struct crypt_device *cd, int level, const char *file,
  74                    int line, const char *format, ...)
  75 {
  76         va_list argp;
  77         char *target = NULL;
  78
  79         va_start(argp, format);
  80
  81         if (vasprintf(&target, format, argp) > 0) {
  82                 if (level >= 0) {
  83                         crypt_log(cd, level, target);
  84 #ifdef CRYPT_DEBUG
  85                 } else if (opt_debug)
  86                         printf("# %s:%d %s\n", file ?: "?", line, target);
  87 #else
  88                 } else if (opt_debug)
  89                         printf("# %s\n", target);
  90 #endif
  91         }
  92
  93         va_end(argp);
  94         free(target);
  95 }
  96
  97 static void _log(int level, const char *msg, void *usrptr __attribute__((unused)))
  98 {
  99         switch(level) {
 100
 101         case CRYPT_LOG_NORMAL:
 102                 fputs(msg, stdout);
 103                 break;
 104         case CRYPT_LOG_VERBOSE:
 105                 if (opt_verbose)
 106                         fputs(msg, stdout);
 107                 break;
 108         case CRYPT_LOG_ERROR:
 109                 fputs(msg, stderr);
 110                 break;
 111         case CRYPT_LOG_DEBUG:
 112                 if (opt_debug)
 113                         printf("# %s\n", msg);
 114                 break;
 115         default:
 116                 fprintf(stderr, "Internal error on logging class for msg: %s", msg);
 117                 break;
 118         }
 119 }
 120
 121 static int _prepare_format(struct crypt_params_verity *params,
 122                            const char *data_device,
 123                            uint32_t flags)
 124 {
 125         static char salt_bytes[512];
 126
 127         params->hash_name = hash_algorithm ?: DEFAULT_VERITY_HASH;
 128         params->data_device = data_device;
 129
 130         if (salt_string && !strcmp(salt_string, "-")) {
 131                 params->salt_size = 0;
 132                 params->salt = NULL;
 133         } else if (salt_string) {
 134                 params->salt_size = strlen(salt_string) / 2;
 135                 if (hex_to_bytes(salt_string, salt_bytes) != params->salt_size)
 136                         return -EINVAL;
 137                 params->salt = salt_bytes;
 138         } else
 139                 params->salt_size = DEFAULT_VERITY_SALT_SIZE;
 140
 141         params->data_block_size = data_block_size;
 142         params->hash_block_size = hash_block_size;
 143         params->data_size = data_blocks;
 144         params->hash_area_offset = hash_start;
 145         params->version = version;
 146         params->flags = flags;
 147
 148         return 0;
 149 }
 150
 151 static int action_format(int arg)
 152 {
 153         struct crypt_device *cd = NULL;
 154         struct crypt_params_verity params = {};
 155         uint32_t flags = CRYPT_VERITY_CREATE_HASH;
 156         int r;
 157
 158         if ((r = crypt_init(&cd, action_argv[1])))
 159                 goto out;
 160
 161         if (!use_superblock)
 162                 flags |= CRYPT_VERITY_NO_HEADER;
 163
 164         r = _prepare_format(&params, action_argv[0], flags);
 165         if (r < 0)
 166                 goto out;
 167
 168         r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);
 169         if (!r)
 170                 crypt_dump(cd);
 171 out:
 172         crypt_free(cd);
 173         return r;
 174 }
 175
 176 static int _activate(const char *dm_device,
 177                       const char *data_device,
 178                       const char *hash_device,
 179                       const char *root_hash,
 180                       uint32_t flags)
 181 {
 182         struct crypt_device *cd = NULL;
 183         struct crypt_params_verity params = {};
 184         uint32_t activate_flags = CRYPT_ACTIVATE_READONLY;
 185         char root_hash_bytes[128];
 186         int r;
 187
 188         if ((r = crypt_init(&cd, hash_device)))
 189                 goto out;
 190
 191         if (use_superblock) {
 192                 params.flags = flags;
 193                 params.hash_area_offset = hash_start;
 194                 r = crypt_load(cd, CRYPT_VERITY, &params);
 195         } else {
 196                 r = _prepare_format(&params, data_device, flags | CRYPT_VERITY_NO_HEADER);
 197                 if (r < 0)
 198                         goto out;
 199                 r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);
 200         }
 201         if (r < 0)
 202                 goto out;
 203         r = crypt_set_data_device(cd, data_device);
 204         if (r < 0)
 205                 goto out;
 206
 207         if (hex_to_bytes(root_hash, root_hash_bytes) !=
 208             crypt_get_volume_key_size(cd)) {
 209                 r = -EINVAL;
 210                 goto out;
 211         }
 212         r = crypt_activate_by_volume_key(cd, dm_device,
 213                                          root_hash_bytes,
 214                                          crypt_get_volume_key_size(cd),
 215                                          activate_flags);
 216 out:
 217         crypt_free(cd);
 218         return r;
 219 }
 220
 221 static int action_create(int arg)
 222 {
 223         return _activate(action_argv[0],
 224                          action_argv[1],
 225                          action_argv[2],
 226                          action_argv[3], 0);
 227 }
 228
 229 static int action_verify(int arg)
 230 {
 231         return _activate(NULL,
 232                          action_argv[0],
 233                          action_argv[1],
 234                          action_argv[2],
 235                          CRYPT_VERITY_CHECK_HASH);
 236 }
 237
 238 static int action_remove(int arg)
 239 {
 240         struct crypt_device *cd = NULL;
 241         int r;
 242
 243         r = crypt_init_by_name(&cd, action_argv[0]);
 244         if (r == 0)
 245                 r = crypt_deactivate(cd, action_argv[0]);
 246
 247         crypt_free(cd);
 248         return r;
 249 }
 250
 251 static int action_status(int arg)
 252 {
 253         crypt_status_info ci;
 254         struct crypt_active_device cad;
 255         struct crypt_params_verity vp = {};
 256         struct crypt_device *cd = NULL;
 257         struct stat st;
 258         char *backing_file;
 259         int i, path = 0, r = 0;
 260
 261         /* perhaps a path, not a dm device name */
 262         if (strchr(action_argv[0], '/') && !stat(action_argv[0], &st))
 263                 path = 1;
 264
 265         ci = crypt_status(NULL, action_argv[0]);
 266         switch (ci) {
 267         case CRYPT_INVALID:
 268                 r = -EINVAL;
 269                 break;
 270         case CRYPT_INACTIVE:
 271                 if (path)
 272                         log_std("%s is inactive.\n", action_argv[0]);
 273                 else
 274                         log_std("%s/%s is inactive.\n", crypt_get_dir(), action_argv[0]);
 275                 r = -ENODEV;
 276                 break;
 277         case CRYPT_ACTIVE:
 278         case CRYPT_BUSY:
 279                 if (path)
 280                         log_std("%s is active%s.\n", action_argv[0],
 281                                 ci == CRYPT_BUSY ? " and is in use" : "");
 282                 else
 283                         log_std("%s/%s is active%s.\n", crypt_get_dir(), action_argv[0],
 284                                 ci == CRYPT_BUSY ? " and is in use" : "");
 285
 286                 r = crypt_init_by_name_and_header(&cd, action_argv[0], NULL);
 287                 if (r < 0 || !crypt_get_type(cd))
 288                         goto out;
 289
 290                 log_std("  type:        %s\n", crypt_get_type(cd));
 291
 292                 r = crypt_get_active_device(cd, action_argv[0], &cad);
 293                 if (r < 0)
 294                         goto out;
 295
 296                 log_std("  status:      %s\n",
 297                         cad.flags & CRYPT_ACTIVATE_CORRUPTED ? "corrupted" : "verified");
 298
 299                 r = crypt_get_verity_info(cd, &vp);
 300                 if (r < 0)
 301                         goto out;
 302
 303                 log_std("  version:     %u\n", vp.version);
 304                 log_std("  data block:  %u\n", vp.data_block_size);
 305                 log_std("  hash block:  %u\n", vp.hash_block_size);
 306                 log_std("  hash name:   %s\n", vp.hash_name);
 307                 log_std("  salt:        ");
 308                 if (vp.salt_size)
 309                         for(i = 0; i < vp.salt_size; i++)
 310                                 log_std("%02hhx", (const char)vp.salt[i]);
 311                 else
 312                         log_std("-");
 313                 log_std("\n");
 314
 315                 log_std("  data device: %s\n", vp.data_device);
 316                 if (crypt_loop_device(vp.data_device)) {
 317                         backing_file = crypt_loop_backing_file(vp.data_device);
 318                         log_std("  data loop:   %s\n", backing_file);
 319                         free(backing_file);
 320                 }
 321                 log_std("  size:        %" PRIu64 " sectors\n", cad.size);
 322                 log_std("  mode:        %s\n", cad.flags & CRYPT_ACTIVATE_READONLY ?
 323                                            "readonly" : "read/write");
 324
 325                 log_std("  hash device: %s\n", vp.hash_device);
 326                 if (crypt_loop_device(vp.hash_device)) {
 327                         backing_file = crypt_loop_backing_file(vp.hash_device);
 328                         log_std("  hash loop:   %s\n", backing_file);
 329                         free(backing_file);
 330                 }
 331                 log_std("  hash offset: %" PRIu64 " sectors\n",
 332                         vp.hash_area_offset * vp.hash_block_size / 512);
 333         }
 334 out:
 335         crypt_free(cd);
 336         if (r == -ENOTSUP)
 337                 r = 0;
 338         return r;
 339 }
 340
 341 static int action_dump(int arg)
 342 {
 343         struct crypt_device *cd = NULL;
 344         struct crypt_params_verity params = {};
 345         int r;
 346
 347         if ((r = crypt_init(&cd, action_argv[0])))
 348                 return r;
 349
 350         params.hash_area_offset = hash_start;
 351         r = crypt_load(cd, CRYPT_VERITY, &params);
 352         if (!r)
 353                 crypt_dump(cd);
 354         crypt_free(cd);
 355         return r;
 356 }
 357
 358 static __attribute__ ((noreturn)) void usage(poptContext popt_context,
 359                                              int exitcode, const char *error,
 360                                              const char *more)
 361 {
 362         poptPrintUsage(popt_context, stderr, 0);
 363         if (error)
 364                 log_err("%s: %s\n", more, error);
 365         poptFreeContext(popt_context);
 366         exit(exitcode);
 367 }
 368
 369 static void _dbg_version_and_cmd(int argc, const char **argv)
 370 {
 371         int i;
 372
 373         log_std("# %s %s processing \"", PACKAGE_VERITY, PACKAGE_VERSION);
 374         for (i = 0; i < argc; i++) {
 375                 if (i)
 376                         log_std(" ");
 377                 log_std("%s", argv[i]);
 378         }
 379         log_std("\"\n");
 380 }
 381
 382 static struct action_type {
 383         const char *type;
 384         int (*handler)(int);
 385         int required_action_argc;
 386         const char *arg_desc;
 387         const char *desc;
 388 } action_types[] = {
 389         { "format",     action_format, 2, N_("<data_device> <hash_device>"),N_("format device") },
 390         { "verify",     action_verify, 3, N_("<data_device> <hash_device> <root_hash>"),N_("verify device") },
 391         { "create",     action_create, 4, N_("<name> <data_device> <hash_device> <root_hash>"),N_("create active device") },
 392         { "remove",     action_remove, 1, N_("<name>"),N_("remove (deactivate) device") },
 393         { "status",     action_status, 1, N_("<name>"),N_("show active device status") },
 394         { "dump",       action_dump,   1, N_("<hash_device>"),N_("show on-disk information") },
 395         { NULL, NULL, 0, NULL, NULL }
 396 };
 397
 398 static void help(poptContext popt_context,
 399                  enum poptCallbackReason reason __attribute__((unused)),
 400                  struct poptOption *key,
 401                  const char *arg __attribute__((unused)),
 402                  void *data __attribute__((unused)))
 403 {
 404         struct action_type *action;
 405
 406         if (key->shortName == '?') {
 407                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 408                 poptPrintHelp(popt_context, stdout, 0);
 409                 log_std(_("\n"
 410                          "<action> is one of:\n"));
 411                 for(action = action_types; action->type; action++)
 412                         log_std("\t%s %s - %s\n", action->type, _(action->arg_desc), _(action->desc));
 413                 log_std(_("\n"
 414                          "<name> is the device to create under %s\n"
 415                          "<data_device> is the data device\n"
 416                          "<hash_device> is the device containing verification data\n"
 417                          "<root_hash> hash of the root node on <hash_device>\n"),
 418                         crypt_get_dir());
 419
 420                 log_std(_("\nDefault compiled-in dm-verity parameters:\n"
 421                          "\tHash: %s, Data block (bytes): %u, "
 422                          "Hash block (bytes): %u, Salt size: %u, Hash format: %u\n"),
 423                         DEFAULT_VERITY_HASH, DEFAULT_VERITY_DATA_BLOCK,
 424                         DEFAULT_VERITY_HASH_BLOCK, DEFAULT_VERITY_SALT_SIZE,
 425                         1);
 426                 exit(EXIT_SUCCESS);
 427         } else
 428                 usage(popt_context, EXIT_SUCCESS, NULL, NULL);
 429 }
 430
 431 static void show_status(int errcode)
 432 {
 433         char error[256], *error_;
 434
 435         if(!opt_verbose)
 436                 return;
 437
 438         if(!errcode) {
 439                 log_std(_("Command successful.\n"));
 440                 return;
 441         }
 442
 443         crypt_get_error(error, sizeof(error));
 444
 445         if (!error[0]) {
 446                 error_ = strerror_r(-errcode, error, sizeof(error));
 447                 if (error_ != error) {
 448                         strncpy(error, error_, sizeof(error));
 449                         error[sizeof(error) - 1] = '\0';
 450                 }
 451         }
 452
 453         log_err(_("Command failed with code %i"), -errcode);
 454         if (*error)
 455                 log_err(": %s\n", error);
 456         else
 457                 log_err(".\n");
 458 }
 459
 460 static int run_action(struct action_type *action)
 461 {
 462         int r;
 463
 464         log_dbg("Running command %s.", action->type);
 465
 466         r = action->handler(0);
 467
 468         show_status(r);
 469
 470         /* Translate exit code to simple codes */
 471         switch (r) {
 472         case 0:         r = EXIT_SUCCESS; break;
 473         case -EEXIST:
 474         case -EBUSY:    r = 5; break;
 475         case -ENOTBLK:
 476         case -ENODEV:   r = 4; break;
 477         case -ENOMEM:   r = 3; break;
 478         case -EPERM:    r = 2; break;
 479         case -EINVAL:
 480         case -ENOENT:
 481         case -ENOSYS:
 482         default:        r = EXIT_FAILURE;
 483         }
 484         return r;
 485 }
 486
 487 int main(int argc, const char **argv)
 488 {
 489         static char *popt_tmp;
 490         static struct poptOption popt_help_options[] = {
 491                 { NULL,    '\0', POPT_ARG_CALLBACK, help, 0, NULL,                         NULL },
 492                 { "help",  '?',  POPT_ARG_NONE,     NULL, 0, N_("Show this help message"), NULL },
 493                 { "usage", '\0', POPT_ARG_NONE,     NULL, 0, N_("Display brief usage"),    NULL },
 494                 POPT_TABLEEND
 495         };
 496         static struct poptOption popt_options[] = {
 497                 { NULL,              '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, N_("Help options:"), NULL },
 498                 { "version",         '\0', POPT_ARG_NONE, &opt_version_mode, 0, N_("Print package version"), NULL },
 499                 { "verbose",         'v',  POPT_ARG_NONE, &opt_verbose,      0, N_("Shows more detailed error messages"), NULL },
 500                 { "debug",           '\0', POPT_ARG_NONE, &opt_debug,        0, N_("Show debug messages"), NULL },
 501                 { "no-superblock",   0,    POPT_ARG_VAL,  &use_superblock,   0, N_("Do not use verity superblock"), NULL },
 502                 { "format",          0,    POPT_ARG_INT,  &version,          0, N_("Format type (1 - normal, 0 - original Chromium OS)"), N_("number") },
 503                 { "data-block-size", 0,    POPT_ARG_INT,  &data_block_size,  0, N_("Block size on the data device"), N_("bytes") },
 504                 { "hash-block-size", 0,    POPT_ARG_INT,  &hash_block_size,  0, N_("Block size on the hash device"), N_("bytes") },
 505                 { "data-blocks",     0,    POPT_ARG_STRING, &popt_tmp,       1, N_("The number of blocks in the data file"), N_("blocks") },
 506                 { "hash-start",      0,    POPT_ARG_STRING, &popt_tmp,       2, N_("Starting block on the hash device"), N_("512-byte sectors") },
 507                 { "hash",            'h',  POPT_ARG_STRING, &hash_algorithm, 0, N_("Hash algorithm"), N_("string") },
 508                 { "salt",            's',  POPT_ARG_STRING, &salt_string,    0, N_("Salt"), N_("hex string") },
 509                 POPT_TABLEEND
 510         };
 511
 512         poptContext popt_context;
 513         struct action_type *action;
 514         const char *aname, *null_action_argv[] = {NULL};
 515         int r;
 516
 517         crypt_set_log_callback(NULL, _log, NULL);
 518
 519         setlocale(LC_ALL, "");
 520         bindtextdomain(PACKAGE, LOCALEDIR);
 521         textdomain(PACKAGE);
 522
 523         popt_context = poptGetContext("verity", argc, argv, popt_options, 0);
 524         poptSetOtherOptionHelp(popt_context,
 525                                N_("[OPTION...] <action> <action-specific>"));
 526
 527         while((r = poptGetNextOpt(popt_context)) > 0) {
 528                 unsigned long long ull_value;
 529                 char *endp;
 530
 531                 errno = 0;
 532                 ull_value = strtoull(popt_tmp, &endp, 0);
 533                 if (*endp || !*popt_tmp ||
 534                     (errno == ERANGE && ull_value == ULLONG_MAX) ||
 535                     (errno != 0 && ull_value == 0))
 536                         r = POPT_ERROR_BADNUMBER;
 537
 538                 switch(r) {
 539                         case 1:
 540                                 data_blocks = ull_value;
 541                                 break;
 542                         case 2:
 543                                 hash_start = ull_value * 512;
 544                                 break;
 545                 }
 546
 547                 if (r < 0)
 548                         break;
 549         }
 550
 551         if (r < -1)
 552                 usage(popt_context, EXIT_FAILURE, poptStrerror(r),
 553                       poptBadOption(popt_context, POPT_BADOPTION_NOALIAS));
 554
 555         if (opt_version_mode) {
 556                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 557                 poptFreeContext(popt_context);
 558                 exit(EXIT_SUCCESS);
 559         }
 560
 561         if (!(aname = poptGetArg(popt_context)))
 562                 usage(popt_context, EXIT_FAILURE, _("Argument <action> missing."),
 563                       poptGetInvocationName(popt_context));
 564         for(action = action_types; action->type; action++)
 565                 if (strcmp(action->type, aname) == 0)
 566                         break;
 567         if (!action->type)
 568                 usage(popt_context, EXIT_FAILURE, _("Unknown action."),
 569                       poptGetInvocationName(popt_context));
 570
 571         action_argc = 0;
 572         action_argv = poptGetArgs(popt_context);
 573         /* Make return values of poptGetArgs more consistent in case of remaining argc = 0 */
 574         if(!action_argv)
 575                 action_argv = null_action_argv;
 576
 577         /* Count args, somewhat unnice, change? */
 578         while(action_argv[action_argc] != NULL)
 579                 action_argc++;
 580
 581         if(action_argc < action->required_action_argc) {
 582                 char buf[128];
 583                 snprintf(buf, 128,_("%s: requires %s as arguments"), action->type, action->arg_desc);
 584                 usage(popt_context, EXIT_FAILURE, buf,
 585                       poptGetInvocationName(popt_context));
 586         }
 587
 588         if (opt_debug) {
 589                 opt_verbose = 1;
 590                 crypt_set_debug_level(-1);
 591                 _dbg_version_and_cmd(argc, argv);
 592         }
 593
 594         r = run_action(action);
 595         poptFreeContext(popt_context);
 596         return r;
 597 }