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  */
  26
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <stdarg.h>
  30 #include <errno.h>
  31 #include <string.h>
  32 #include <popt.h>
  33 #include <limits.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 version = 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 action_format(int arg)
 121 {
 122         struct crypt_device *cd = NULL;
 123         struct crypt_params_verity params = {};
 124         char salt_bytes[512];
 125         int r;
 126
 127         if ((r = crypt_init(&cd, action_argv[1])))
 128                 goto out;
 129
 130         params.hash_name = hash_algorithm ?: DEFAULT_VERITY_HASH;
 131         params.data_device = action_argv[0];
 132
 133         if (salt_string) {
 134                 params.salt_size = strlen(salt_string) / 2;
 135                 if (hex_to_bytes(salt_string, salt_bytes) != params.salt_size) {
 136                         r = -EINVAL;
 137                         goto out;
 138                 }
 139                 params.salt = salt_bytes;
 140         } else
 141                 params.salt_size = DEFAULT_VERITY_SALT_SIZE;
 142
 143         params.data_block_size = data_block_size;
 144         params.hash_block_size = hash_block_size;
 145         params.data_size = data_blocks;
 146         params.hash_area_offset = hash_start;
 147         params.version = version;
 148         params.flags = CRYPT_VERITY_CREATE_HASH;
 149         if (!use_superblock)
 150                 params.flags |= CRYPT_VERITY_NO_HEADER;
 151
 152         r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);
 153         if (!r)
 154                 crypt_dump(cd);
 155 out:
 156         crypt_free(cd);
 157         return r;
 158 }
 159
 160 static int _activate(const char *dm_device,
 161                       const char *data_device,
 162                       const char *hash_device,
 163                       const char *root_hash,
 164                       uint32_t flags)
 165 {
 166         struct crypt_device *cd = NULL;
 167         struct crypt_params_verity params = {};
 168         uint32_t activate_flags = CRYPT_ACTIVATE_READONLY;
 169         char root_hash_bytes[128];
 170         int r;
 171
 172         if ((r = crypt_init(&cd, hash_device)))
 173                 goto out;
 174
 175         params.flags |= flags;
 176
 177         if (use_superblock) {
 178                 params.hash_area_offset = hash_start;
 179                 r = crypt_load(cd, CRYPT_VERITY, &params);
 180         } else {/*
 181                 params.hash_name = hash_algorithm;
 182                 params.salt = salt_bytes;
 183                 params.salt_size = salt_size;
 184                 params.data_block_size = data_block_size;
 185                 params.hash_block_size = hash_block_size;
 186
 187                 params.data_size = data_blocks * data_block_size / 512;
 188                 params.version = version;
 189                 params.flags |= CRYPT_VERITY_NO_HEADER;
 190                 r = crypt_load(cd, CRYPT_VERITY, &params);
 191                 crypt_format(); */
 192                 r = -EINVAL;
 193                 goto out;
 194         }
 195         if (r < 0)
 196                 goto out;
 197         r = crypt_set_data_device(cd, data_device);
 198         if (r < 0)
 199                 goto out;
 200
 201         if (hex_to_bytes(root_hash, root_hash_bytes) !=
 202             crypt_get_volume_key_size(cd)) {
 203                 r = -EINVAL;
 204                 goto out;
 205         }
 206         r = crypt_activate_by_volume_key(cd, dm_device,
 207                                          root_hash_bytes,
 208                                          crypt_get_volume_key_size(cd),
 209                                          activate_flags);
 210 out:
 211         if (!r)
 212                 crypt_dump(cd);
 213         crypt_free(cd);
 214         return r;
 215 }
 216
 217 static int action_create(int arg)
 218 {
 219         return _activate(action_argv[0],
 220                          action_argv[1],
 221                          action_argv[2],
 222                          action_argv[3], 0);
 223 }
 224
 225 static int action_verify(int arg)
 226 {
 227         return _activate(NULL,
 228                          action_argv[0],
 229                          action_argv[1],
 230                          action_argv[2],
 231                          CRYPT_VERITY_CHECK_HASH);
 232 }
 233
 234 static int action_remove(int arg)
 235 {
 236         struct crypt_device *cd = NULL;
 237         int r;
 238
 239         r = crypt_init_by_name(&cd, action_argv[0]);
 240         if (r == 0)
 241                 r = crypt_deactivate(cd, action_argv[0]);
 242
 243         crypt_free(cd);
 244         return r;
 245 }
 246
 247 static int action_status(int arg)
 248 {
 249         struct crypt_device *cd = NULL;
 250         int r;
 251
 252         r = crypt_init_by_name_and_header(&cd, action_argv[0], NULL);
 253         if (!r)
 254                 r = crypt_dump(cd);
 255         crypt_free(cd);
 256         return r;
 257 }
 258
 259 static int action_dump(int arg)
 260 {
 261         struct crypt_device *cd = NULL;
 262         struct crypt_params_verity params = {};
 263         int r;
 264
 265         if ((r = crypt_init(&cd, action_argv[0])))
 266                 return r;
 267
 268         params.hash_area_offset = hash_start;
 269         r = crypt_load(cd, CRYPT_VERITY, &params);
 270         if (!r)
 271                 crypt_dump(cd);
 272         crypt_free(cd);
 273         return r;
 274 }
 275
 276 static __attribute__ ((noreturn)) void usage(poptContext popt_context,
 277                                              int exitcode, const char *error,
 278                                              const char *more)
 279 {
 280         poptPrintUsage(popt_context, stderr, 0);
 281         if (error)
 282                 log_err("%s: %s\n", more, error);
 283         poptFreeContext(popt_context);
 284         exit(exitcode);
 285 }
 286
 287 static void _dbg_version_and_cmd(int argc, const char **argv)
 288 {
 289         int i;
 290
 291         log_std("# %s %s processing \"", PACKAGE_VERITY, PACKAGE_VERSION);
 292         for (i = 0; i < argc; i++) {
 293                 if (i)
 294                         log_std(" ");
 295                 log_std("%s", argv[i]);
 296         }
 297         log_std("\"\n");
 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 void show_status(int errcode)
 350 {
 351         char error[256], *error_;
 352
 353         if(!opt_verbose)
 354                 return;
 355
 356         if(!errcode) {
 357                 log_std(_("Command successful.\n"));
 358                 return;
 359         }
 360
 361         crypt_get_error(error, sizeof(error));
 362
 363         if (!error[0]) {
 364                 error_ = strerror_r(-errcode, error, sizeof(error));
 365                 if (error_ != error) {
 366                         strncpy(error, error_, sizeof(error));
 367                         error[sizeof(error) - 1] = '\0';
 368                 }
 369         }
 370
 371         log_err(_("Command failed with code %i"), -errcode);
 372         if (*error)
 373                 log_err(": %s\n", error);
 374         else
 375                 log_err(".\n");
 376 }
 377
 378 static int run_action(struct action_type *action)
 379 {
 380         int r;
 381
 382         log_dbg("Running command %s.", action->type);
 383
 384         r = action->handler(0);
 385
 386         show_status(r);
 387
 388         /* Translate exit code to simple codes */
 389         switch (r) {
 390         case 0:         r = EXIT_SUCCESS; break;
 391         case -EEXIST:
 392         case -EBUSY:    r = 5; break;
 393         case -ENOTBLK:
 394         case -ENODEV:   r = 4; break;
 395         case -ENOMEM:   r = 3; break;
 396         case -EPERM:    r = 2; break;
 397         case -EINVAL:
 398         case -ENOENT:
 399         case -ENOSYS:
 400         default:        r = EXIT_FAILURE;
 401         }
 402         return r;
 403 }
 404
 405 int main(int argc, const char **argv)
 406 {
 407         static char *popt_tmp;
 408         static struct poptOption popt_help_options[] = {
 409                 { NULL,    '\0', POPT_ARG_CALLBACK, help, 0, NULL,                         NULL },
 410                 { "help",  '?',  POPT_ARG_NONE,     NULL, 0, N_("Show this help message"), NULL },
 411                 { "usage", '\0', POPT_ARG_NONE,     NULL, 0, N_("Display brief usage"),    NULL },
 412                 POPT_TABLEEND
 413         };
 414         static struct poptOption popt_options[] = {
 415                 { NULL,              '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, N_("Help options:"), NULL },
 416                 { "version",         '\0', POPT_ARG_NONE, &opt_version_mode, 0, N_("Print package version"), NULL },
 417                 { "verbose",         'v',  POPT_ARG_NONE, &opt_verbose,      0, N_("Shows more detailed error messages"), NULL },
 418                 { "debug",           '\0', POPT_ARG_NONE, &opt_debug,        0, N_("Show debug messages"), NULL },
 419                 { "no-superblock",   0,    POPT_ARG_VAL,  &use_superblock,   0, N_("Do not use verity superblock"), NULL },
 420                 { "format",          0,    POPT_ARG_INT,  &version,          0, N_("Format type (1 - normal, 0 - original Chromium OS)"), N_("number") },
 421                 { "data-block-size", 0,    POPT_ARG_INT,  &data_block_size,  0, N_("Block size on the data device"), N_("bytes") },
 422                 { "hash-block-size", 0,    POPT_ARG_INT,  &hash_block_size,  0, N_("Block size on the hash device"), N_("bytes") },
 423                 { "data-blocks",     0,    POPT_ARG_STRING, &popt_tmp,       1, N_("The number of blocks in the data file"), N_("blocks") },
 424                 { "hash-start",      0,    POPT_ARG_STRING, &popt_tmp,       2, N_("Starting block on the hash device"), N_("512-byte sectors") },
 425                 { "hash",            'h',  POPT_ARG_STRING, &hash_algorithm, 0, N_("Hash algorithm"), N_("string") },
 426                 { "salt",            's',  POPT_ARG_STRING, &salt_string,    0, N_("Salt"), N_("hex string") },
 427                 POPT_TABLEEND
 428         };
 429
 430         poptContext popt_context;
 431         struct action_type *action;
 432         const char *aname, *null_action_argv[] = {NULL};
 433         int r;
 434
 435         crypt_set_log_callback(NULL, _log, NULL);
 436
 437         setlocale(LC_ALL, "");
 438         bindtextdomain(PACKAGE, LOCALEDIR);
 439         textdomain(PACKAGE);
 440
 441         popt_context = poptGetContext("verity", argc, argv, popt_options, 0);
 442         poptSetOtherOptionHelp(popt_context,
 443                                N_("[OPTION...] <action> <action-specific>"));
 444
 445         while((r = poptGetNextOpt(popt_context)) > 0) {
 446                 unsigned long long ull_value;
 447                 char *endp;
 448
 449                 errno = 0;
 450                 ull_value = strtoull(popt_tmp, &endp, 0);
 451                 if (*endp || !*popt_tmp ||
 452                     (errno == ERANGE && ull_value == ULLONG_MAX) ||
 453                     (errno != 0 && ull_value == 0))
 454                         r = POPT_ERROR_BADNUMBER;
 455
 456                 switch(r) {
 457                         case 1:
 458                                 data_blocks = ull_value;
 459                                 break;
 460                         case 2:
 461                                 hash_start = ull_value * 512;
 462                                 break;
 463                 }
 464
 465                 if (r < 0)
 466                         break;
 467         }
 468
 469         if (r < -1)
 470                 usage(popt_context, EXIT_FAILURE, poptStrerror(r),
 471                       poptBadOption(popt_context, POPT_BADOPTION_NOALIAS));
 472
 473         if (opt_version_mode) {
 474                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 475                 poptFreeContext(popt_context);
 476                 exit(EXIT_SUCCESS);
 477         }
 478
 479         if (!(aname = poptGetArg(popt_context)))
 480                 usage(popt_context, EXIT_FAILURE, _("Argument <action> missing."),
 481                       poptGetInvocationName(popt_context));
 482         for(action = action_types; action->type; action++)
 483                 if (strcmp(action->type, aname) == 0)
 484                         break;
 485         if (!action->type)
 486                 usage(popt_context, EXIT_FAILURE, _("Unknown action."),
 487                       poptGetInvocationName(popt_context));
 488
 489         action_argc = 0;
 490         action_argv = poptGetArgs(popt_context);
 491         /* Make return values of poptGetArgs more consistent in case of remaining argc = 0 */
 492         if(!action_argv)
 493                 action_argv = null_action_argv;
 494
 495         /* Count args, somewhat unnice, change? */
 496         while(action_argv[action_argc] != NULL)
 497                 action_argc++;
 498
 499         if(action_argc < action->required_action_argc) {
 500                 char buf[128];
 501                 snprintf(buf, 128,_("%s: requires %s as arguments"), action->type, action->arg_desc);
 502                 usage(popt_context, EXIT_FAILURE, buf,
 503                       poptGetInvocationName(popt_context));
 504         }
 505
 506         if (opt_debug) {
 507                 opt_verbose = 1;
 508                 crypt_set_debug_level(-1);
 509                 _dbg_version_and_cmd(argc, argv);
 510         }
 511
 512         r = run_action(action);
 513         poptFreeContext(popt_context);
 514         return r;
 515 }