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  * - support device without superblock
  22  * - extend superblock (UUID)
  23  * - add api tests
  24  * - salt string "-"
  25  * - man page
  26  */
  27
  28 #include <stdio.h>
  29 #include <stdlib.h>
  30 #include <stdarg.h>
  31 #include <errno.h>
  32 #include <string.h>
  33 #include <popt.h>
  34 #include <limits.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 action_format(int arg)
 122 {
 123         struct crypt_device *cd = NULL;
 124         struct crypt_params_verity params = {};
 125         char salt_bytes[512];
 126         int r;
 127
 128         if ((r = crypt_init(&cd, action_argv[1])))
 129                 goto out;
 130
 131         params.hash_name = hash_algorithm ?: DEFAULT_VERITY_HASH;
 132         params.data_device = action_argv[0];
 133
 134         if (salt_string) {
 135                 params.salt_size = strlen(salt_string) / 2;
 136                 if (hex_to_bytes(salt_string, salt_bytes) != params.salt_size) {
 137                         r = -EINVAL;
 138                         goto out;
 139                 }
 140                 params.salt = salt_bytes;
 141         } else
 142                 params.salt_size = DEFAULT_VERITY_SALT_SIZE;
 143
 144         params.data_block_size = data_block_size;
 145         params.hash_block_size = hash_block_size;
 146         params.data_size = data_blocks;
 147         params.hash_area_offset = hash_start;
 148         params.version = version;
 149         params.flags = CRYPT_VERITY_CREATE_HASH;
 150         if (!use_superblock)
 151                 params.flags |= CRYPT_VERITY_NO_HEADER;
 152
 153         r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);
 154         if (!r)
 155                 crypt_dump(cd);
 156 out:
 157         crypt_free(cd);
 158         return r;
 159 }
 160
 161 static int _activate(const char *dm_device,
 162                       const char *data_device,
 163                       const char *hash_device,
 164                       const char *root_hash,
 165                       uint32_t flags)
 166 {
 167         struct crypt_device *cd = NULL;
 168         struct crypt_params_verity params = {};
 169         uint32_t activate_flags = CRYPT_ACTIVATE_READONLY;
 170         char root_hash_bytes[128];
 171         int r;
 172
 173         if ((r = crypt_init(&cd, hash_device)))
 174                 goto out;
 175
 176         params.flags |= flags;
 177
 178         if (use_superblock) {
 179                 params.hash_area_offset = hash_start;
 180                 r = crypt_load(cd, CRYPT_VERITY, &params);
 181         } else {/*
 182                 params.hash_name = hash_algorithm;
 183                 params.salt = salt_bytes;
 184                 params.salt_size = salt_size;
 185                 params.data_block_size = data_block_size;
 186                 params.hash_block_size = hash_block_size;
 187
 188                 params.data_size = data_blocks * data_block_size / 512;
 189                 params.version = version;
 190                 params.flags |= CRYPT_VERITY_NO_HEADER;
 191                 r = crypt_load(cd, CRYPT_VERITY, &params);
 192                 crypt_format(); */
 193                 r = -EINVAL;
 194                 goto out;
 195         }
 196         if (r < 0)
 197                 goto out;
 198         r = crypt_set_data_device(cd, data_device);
 199         if (r < 0)
 200                 goto out;
 201
 202         if (hex_to_bytes(root_hash, root_hash_bytes) !=
 203             crypt_get_volume_key_size(cd)) {
 204                 r = -EINVAL;
 205                 goto out;
 206         }
 207         r = crypt_activate_by_volume_key(cd, dm_device,
 208                                          root_hash_bytes,
 209                                          crypt_get_volume_key_size(cd),
 210                                          activate_flags);
 211 out:
 212         if (!r)
 213                 crypt_dump(cd);
 214         crypt_free(cd);
 215         return r;
 216 }
 217
 218 static int action_create(int arg)
 219 {
 220         return _activate(action_argv[0],
 221                          action_argv[1],
 222                          action_argv[2],
 223                          action_argv[3], 0);
 224 }
 225
 226 static int action_verify(int arg)
 227 {
 228         return _activate(NULL,
 229                          action_argv[0],
 230                          action_argv[1],
 231                          action_argv[2],
 232                          CRYPT_VERITY_CHECK_HASH);
 233 }
 234
 235 static int action_remove(int arg)
 236 {
 237         struct crypt_device *cd = NULL;
 238         int r;
 239
 240         r = crypt_init_by_name(&cd, action_argv[0]);
 241         if (r == 0)
 242                 r = crypt_deactivate(cd, action_argv[0]);
 243
 244         crypt_free(cd);
 245         return r;
 246 }
 247
 248 static int action_status(int arg)
 249 {
 250         struct crypt_device *cd = NULL;
 251         int r;
 252
 253         r = crypt_init_by_name_and_header(&cd, action_argv[0], NULL);
 254         if (!r)
 255                 r = crypt_dump(cd);
 256         crypt_free(cd);
 257         return r;
 258 }
 259
 260 static int action_dump(int arg)
 261 {
 262         struct crypt_device *cd = NULL;
 263         struct crypt_params_verity params = {};
 264         int r;
 265
 266         if ((r = crypt_init(&cd, action_argv[0])))
 267                 return r;
 268
 269         params.hash_area_offset = hash_start;
 270         r = crypt_load(cd, CRYPT_VERITY, &params);
 271         if (!r)
 272                 crypt_dump(cd);
 273         crypt_free(cd);
 274         return r;
 275 }
 276
 277 static __attribute__ ((noreturn)) void usage(poptContext popt_context,
 278                                              int exitcode, const char *error,
 279                                              const char *more)
 280 {
 281         poptPrintUsage(popt_context, stderr, 0);
 282         if (error)
 283                 log_err("%s: %s\n", more, error);
 284         poptFreeContext(popt_context);
 285         exit(exitcode);
 286 }
 287
 288 static void _dbg_version_and_cmd(int argc, const char **argv)
 289 {
 290         int i;
 291
 292         log_std("# %s %s processing \"", PACKAGE_VERITY, PACKAGE_VERSION);
 293         for (i = 0; i < argc; i++) {
 294                 if (i)
 295                         log_std(" ");
 296                 log_std("%s", argv[i]);
 297         }
 298         log_std("\"\n");
 299 }
 300
 301 static struct action_type {
 302         const char *type;
 303         int (*handler)(int);
 304         int required_action_argc;
 305         const char *arg_desc;
 306         const char *desc;
 307 } action_types[] = {
 308         { "format",     action_format, 2, N_("<data_device> <hash_device>"),N_("format device") },
 309         { "verify",     action_verify, 3, N_("<data_device> <hash_device> <root_hash>"),N_("verify device") },
 310         { "create",     action_create, 4, N_("<name> <data_device> <hash_device> <root_hash>"),N_("create active device") },
 311         { "remove",     action_remove, 1, N_("<name>"),N_("remove (deactivate) device") },
 312         { "status",     action_status, 1, N_("<name>"),N_("show active device status") },
 313         { "dump",       action_dump,   1, N_("<hash_device>"),N_("show on-disk information") },
 314         { NULL, NULL, 0, NULL, NULL }
 315 };
 316
 317 static void help(poptContext popt_context,
 318                  enum poptCallbackReason reason __attribute__((unused)),
 319                  struct poptOption *key,
 320                  const char *arg __attribute__((unused)),
 321                  void *data __attribute__((unused)))
 322 {
 323         struct action_type *action;
 324
 325         if (key->shortName == '?') {
 326                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 327                 poptPrintHelp(popt_context, stdout, 0);
 328                 log_std(_("\n"
 329                          "<action> is one of:\n"));
 330                 for(action = action_types; action->type; action++)
 331                         log_std("\t%s %s - %s\n", action->type, _(action->arg_desc), _(action->desc));
 332                 log_std(_("\n"
 333                          "<name> is the device to create under %s\n"
 334                          "<data_device> is the data device\n"
 335                          "<hash_device> is the device containing verification data\n"
 336                          "<root_hash> hash of the root node on <hash_device>\n"),
 337                         crypt_get_dir());
 338
 339                 log_std(_("\nDefault compiled-in dm-verity parameters:\n"
 340                          "\tHash: %s, Data block (bytes): %u, "
 341                          "Hash block (bytes): %u, Salt size: %u, Hash format: %u\n"),
 342                         DEFAULT_VERITY_HASH, DEFAULT_VERITY_DATA_BLOCK,
 343                         DEFAULT_VERITY_HASH_BLOCK, DEFAULT_VERITY_SALT_SIZE,
 344                         1);
 345                 exit(EXIT_SUCCESS);
 346         } else
 347                 usage(popt_context, EXIT_SUCCESS, NULL, NULL);
 348 }
 349
 350 static void show_status(int errcode)
 351 {
 352         char error[256], *error_;
 353
 354         if(!opt_verbose)
 355                 return;
 356
 357         if(!errcode) {
 358                 log_std(_("Command successful.\n"));
 359                 return;
 360         }
 361
 362         crypt_get_error(error, sizeof(error));
 363
 364         if (!error[0]) {
 365                 error_ = strerror_r(-errcode, error, sizeof(error));
 366                 if (error_ != error) {
 367                         strncpy(error, error_, sizeof(error));
 368                         error[sizeof(error) - 1] = '\0';
 369                 }
 370         }
 371
 372         log_err(_("Command failed with code %i"), -errcode);
 373         if (*error)
 374                 log_err(": %s\n", error);
 375         else
 376                 log_err(".\n");
 377 }
 378
 379 static int run_action(struct action_type *action)
 380 {
 381         int r;
 382
 383         log_dbg("Running command %s.", action->type);
 384
 385         r = action->handler(0);
 386
 387         show_status(r);
 388
 389         /* Translate exit code to simple codes */
 390         switch (r) {
 391         case 0:         r = EXIT_SUCCESS; break;
 392         case -EEXIST:
 393         case -EBUSY:    r = 5; break;
 394         case -ENOTBLK:
 395         case -ENODEV:   r = 4; break;
 396         case -ENOMEM:   r = 3; break;
 397         case -EPERM:    r = 2; break;
 398         case -EINVAL:
 399         case -ENOENT:
 400         case -ENOSYS:
 401         default:        r = EXIT_FAILURE;
 402         }
 403         return r;
 404 }
 405
 406 int main(int argc, const char **argv)
 407 {
 408         static char *popt_tmp;
 409         static struct poptOption popt_help_options[] = {
 410                 { NULL,    '\0', POPT_ARG_CALLBACK, help, 0, NULL,                         NULL },
 411                 { "help",  '?',  POPT_ARG_NONE,     NULL, 0, N_("Show this help message"), NULL },
 412                 { "usage", '\0', POPT_ARG_NONE,     NULL, 0, N_("Display brief usage"),    NULL },
 413                 POPT_TABLEEND
 414         };
 415         static struct poptOption popt_options[] = {
 416                 { NULL,              '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, N_("Help options:"), NULL },
 417                 { "version",         '\0', POPT_ARG_NONE, &opt_version_mode, 0, N_("Print package version"), NULL },
 418                 { "verbose",         'v',  POPT_ARG_NONE, &opt_verbose,      0, N_("Shows more detailed error messages"), NULL },
 419                 { "debug",           '\0', POPT_ARG_NONE, &opt_debug,        0, N_("Show debug messages"), NULL },
 420                 { "no-superblock",   0,    POPT_ARG_VAL,  &use_superblock,   0, N_("Do not use verity superblock"), NULL },
 421                 { "format",          0,    POPT_ARG_INT,  &version,          0, N_("Format type (1 - normal, 0 - original Chromium OS)"), N_("number") },
 422                 { "data-block-size", 0,    POPT_ARG_INT,  &data_block_size,  0, N_("Block size on the data device"), N_("bytes") },
 423                 { "hash-block-size", 0,    POPT_ARG_INT,  &hash_block_size,  0, N_("Block size on the hash device"), N_("bytes") },
 424                 { "data-blocks",     0,    POPT_ARG_STRING, &popt_tmp,       1, N_("The number of blocks in the data file"), N_("blocks") },
 425                 { "hash-start",      0,    POPT_ARG_STRING, &popt_tmp,       2, N_("Starting block on the hash device"), N_("512-byte sectors") },
 426                 { "algorithm",       'h',  POPT_ARG_STRING, &hash_algorithm, 0, N_("Hash algorithm"), N_("string") },
 427                 { "salt",            's',  POPT_ARG_STRING, &salt_string,    0, N_("Salt"), N_("hex string") },
 428                 POPT_TABLEEND
 429         };
 430
 431         poptContext popt_context;
 432         struct action_type *action;
 433         const char *aname, *null_action_argv[] = {NULL};
 434         int r;
 435
 436         crypt_set_log_callback(NULL, _log, NULL);
 437
 438         setlocale(LC_ALL, "");
 439         bindtextdomain(PACKAGE, LOCALEDIR);
 440         textdomain(PACKAGE);
 441
 442         popt_context = poptGetContext("verity", argc, argv, popt_options, 0);
 443         poptSetOtherOptionHelp(popt_context,
 444                                N_("[OPTION...] <action> <action-specific>"));
 445
 446         while((r = poptGetNextOpt(popt_context)) > 0) {
 447                 unsigned long long ull_value;
 448                 char *endp;
 449
 450                 errno = 0;
 451                 ull_value = strtoull(popt_tmp, &endp, 0);
 452                 if (*endp || !*popt_tmp ||
 453                     (errno == ERANGE && ull_value == ULLONG_MAX) ||
 454                     (errno != 0 && ull_value == 0))
 455                         r = POPT_ERROR_BADNUMBER;
 456
 457                 switch(r) {
 458                         case 1:
 459                                 data_blocks = ull_value;
 460                                 break;
 461                         case 2:
 462                                 hash_start = ull_value * 512;
 463                                 break;
 464                 }
 465
 466                 if (r < 0)
 467                         break;
 468         }
 469
 470         if (r < -1)
 471                 usage(popt_context, EXIT_FAILURE, poptStrerror(r),
 472                       poptBadOption(popt_context, POPT_BADOPTION_NOALIAS));
 473
 474         if (opt_version_mode) {
 475                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 476                 poptFreeContext(popt_context);
 477                 exit(EXIT_SUCCESS);
 478         }
 479
 480         if (!(aname = poptGetArg(popt_context)))
 481                 usage(popt_context, EXIT_FAILURE, _("Argument <action> missing."),
 482                       poptGetInvocationName(popt_context));
 483         for(action = action_types; action->type; action++)
 484                 if (strcmp(action->type, aname) == 0)
 485                         break;
 486         if (!action->type)
 487                 usage(popt_context, EXIT_FAILURE, _("Unknown action."),
 488                       poptGetInvocationName(popt_context));
 489
 490         action_argc = 0;
 491         action_argv = poptGetArgs(popt_context);
 492         /* Make return values of poptGetArgs more consistent in case of remaining argc = 0 */
 493         if(!action_argv)
 494                 action_argv = null_action_argv;
 495
 496         /* Count args, somewhat unnice, change? */
 497         while(action_argv[action_argc] != NULL)
 498                 action_argc++;
 499
 500         if(action_argc < action->required_action_argc) {
 501                 char buf[128];
 502                 snprintf(buf, 128,_("%s: requires %s as arguments"), action->type, action->arg_desc);
 503                 usage(popt_context, EXIT_FAILURE, buf,
 504                       poptGetInvocationName(popt_context));
 505         }
 506
 507         if (opt_debug) {
 508                 opt_verbose = 1;
 509                 crypt_set_debug_level(-1);
 510                 _dbg_version_and_cmd(argc, argv);
 511         }
 512
 513         r = run_action(action);
 514         poptFreeContext(popt_context);
 515         return r;
 516 }