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