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  * - audit alloc errors / error path
  23  * - change command names (cryptsetup style)
  24  * - extend superblock (UUID)
  25  * - add api tests
  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
  35 #include "cryptsetup.h"
  36
  37 #define PACKAGE_VERITY "veritysetup"
  38
  39 #define MODE_VERIFY     0
  40 #define MODE_CREATE     1
  41 #define MODE_ACTIVATE   2
  42 #define MODE_DUMP       3
  43 #define MODE_STATUS     4
  44
  45 static int mode = -1;
  46 static int use_superblock = 1; /* FIXME: no superblock not supported */
  47
  48 static const char *dm_device = NULL;
  49 static const char *data_device = NULL;
  50 static const char *hash_device = NULL;
  51 static const char *hash_algorithm = NULL;
  52 static const char *root_hash = NULL;
  53
  54 static int version = 1;
  55 static int data_block_size = DEFAULT_VERITY_DATA_BLOCK;
  56 static int hash_block_size = DEFAULT_VERITY_HASH_BLOCK;
  57 static char *data_blocks_string = NULL;
  58 static uint64_t data_blocks = 0;
  59 static char *hash_start_string = NULL;
  60 static const char *salt_string = NULL;
  61 static unsigned salt_size = DEFAULT_VERITY_SALT_SIZE;
  62 static uint64_t hash_start = 0;
  63
  64 static int opt_verbose = 0;
  65 static int opt_debug = 0;
  66 static int opt_version_mode = 0;
  67
  68 static int hex_to_bytes(const char *hex, char *result)
  69 {
  70         char buf[3] = "xx\0", *endp;
  71         int i, len;
  72
  73         len = strlen(hex) / 2;
  74         for (i = 0; i < len; i++) {
  75                 memcpy(buf, &hex[i * 2], 2);
  76                 result[i] = strtoul(buf, &endp, 16);
  77                 if (endp != &buf[2])
  78                         return -EINVAL;
  79         }
  80         return i;
  81 }
  82
  83 __attribute__((format(printf, 5, 6)))
  84 static void clogger(struct crypt_device *cd, int level, const char *file,
  85                    int line, const char *format, ...)
  86 {
  87         va_list argp;
  88         char *target = NULL;
  89
  90         va_start(argp, format);
  91
  92         if (vasprintf(&target, format, argp) > 0) {
  93                 if (level >= 0) {
  94                         crypt_log(cd, level, target);
  95 #ifdef CRYPT_DEBUG
  96                 } else if (opt_debug)
  97                         printf("# %s:%d %s\n", file ?: "?", line, target);
  98 #else
  99                 } else if (opt_debug)
 100                         printf("# %s\n", target);
 101 #endif
 102         }
 103
 104         va_end(argp);
 105         free(target);
 106 }
 107
 108 static void _log(int level, const char *msg, void *usrptr __attribute__((unused)))
 109 {
 110         switch(level) {
 111
 112         case CRYPT_LOG_NORMAL:
 113                 fputs(msg, stdout);
 114                 break;
 115         case CRYPT_LOG_VERBOSE:
 116                 if (opt_verbose)
 117                         fputs(msg, stdout);
 118                 break;
 119         case CRYPT_LOG_ERROR:
 120                 fputs(msg, stderr);
 121                 break;
 122         case CRYPT_LOG_DEBUG:
 123                 if (opt_debug)
 124                         printf("# %s\n", msg);
 125                 break;
 126         default:
 127                 fprintf(stderr, "Internal error on logging class for msg: %s", msg);
 128                 break;
 129         }
 130 }
 131
 132 static int action_dump(void)
 133 {
 134         struct crypt_device *cd = NULL;
 135         struct crypt_params_verity params = {};
 136         int r;
 137
 138         if ((r = crypt_init(&cd, hash_device)))
 139                 return r;
 140
 141         params.hash_area_offset = hash_start;
 142         r = crypt_load(cd, CRYPT_VERITY, &params);
 143         if (!r)
 144                 crypt_dump(cd);
 145         crypt_free(cd);
 146         return r;
 147 }
 148
 149 static int action_status(void)
 150 {
 151         struct crypt_device *cd = NULL;
 152         int r;
 153
 154         r = crypt_init_by_name_and_header(&cd, dm_device, NULL);
 155         if (!r)
 156                 r = crypt_dump(cd);
 157         crypt_free(cd);
 158         return r;
 159 }
 160
 161 static int action_activate(int verify)
 162 {
 163         struct crypt_device *cd = NULL;
 164         struct crypt_params_verity params = {};
 165         uint32_t activate_flags = CRYPT_ACTIVATE_READONLY;
 166         char root_hash_bytes[128];
 167         int r;
 168
 169         if ((r = crypt_init(&cd, hash_device)))
 170                 goto out;
 171
 172         if (verify)
 173                 params.flags |= CRYPT_VERITY_CHECK_HASH;
 174
 175         if (use_superblock) {
 176                 params.hash_area_offset = hash_start;
 177                 r = crypt_load(cd, CRYPT_VERITY, &params);
 178         } else {/*
 179                 params.hash_name = hash_algorithm;
 180                 params.salt = salt_bytes;
 181                 params.salt_size = salt_size;
 182                 params.data_block_size = data_block_size;
 183                 params.hash_block_size = hash_block_size;
 184
 185                 params.data_size = data_blocks * data_block_size / 512;
 186                 params.version = version;
 187                 params.flags |= CRYPT_VERITY_NO_HEADER;
 188                 r = crypt_load(cd, CRYPT_VERITY, &params);
 189                 crypt_format(); */
 190                 r = -EINVAL;
 191                 goto out;
 192         }
 193         if (r < 0)
 194                 goto out;
 195         r = crypt_set_data_device(cd, data_device);
 196         if (r < 0)
 197                 goto out;
 198
 199         if (hex_to_bytes(root_hash, root_hash_bytes) !=
 200             crypt_get_volume_key_size(cd)) {
 201                 r = -EINVAL;
 202                 goto out;
 203         }
 204         r = crypt_activate_by_volume_key(cd, dm_device, root_hash_bytes,
 205                                          crypt_get_volume_key_size(cd),
 206                                          activate_flags);
 207 out:
 208         if (!r)
 209                 crypt_dump(cd);
 210         crypt_free(cd);
 211         return r;
 212 }
 213
 214 static int action_create(void)
 215 {
 216         struct crypt_device *cd = NULL;
 217         struct crypt_params_verity params = {};
 218         char salt_bytes[512];
 219         int r;
 220
 221         if ((r = crypt_init(&cd, hash_device)))
 222                 goto out;
 223
 224         params.hash_name = hash_algorithm ?: DEFAULT_VERITY_HASH;
 225         params.data_device = data_device;
 226
 227         if (salt_string) {
 228                 if (hex_to_bytes(salt_string, salt_bytes) != salt_size) {
 229                         r = -EINVAL;
 230                         goto out;
 231                 }
 232                 params.salt = salt_bytes;
 233         }
 234
 235         params.salt_size = salt_size;
 236         params.data_block_size = data_block_size;
 237         params.hash_block_size = hash_block_size;
 238         params.data_size = data_blocks;
 239         params.hash_area_offset = hash_start;
 240         params.version = version;
 241         params.flags = CRYPT_VERITY_CREATE_HASH;
 242         if (!use_superblock)
 243                 params.flags |= CRYPT_VERITY_NO_HEADER;
 244
 245         r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);
 246         if (!r)
 247                 crypt_dump(cd);
 248 out:
 249         crypt_free(cd);
 250         return r;
 251 }
 252
 253 static __attribute__ ((noreturn)) void usage(poptContext popt_context,
 254                                              int exitcode, const char *error,
 255                                              const char *more)
 256 {
 257         poptPrintUsage(popt_context, stderr, 0);
 258         if (error)
 259                 log_err("%s: %s\n", more, error);
 260         poptFreeContext(popt_context);
 261         exit(exitcode);
 262 }
 263
 264 static void help(poptContext popt_context,
 265                  enum poptCallbackReason reason __attribute__((unused)),
 266                  struct poptOption *key,
 267                  const char *arg __attribute__((unused)),
 268                  void *data __attribute__((unused)))
 269 {
 270         if (key->shortName == '?') {
 271                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 272                 poptPrintHelp(popt_context, stdout, 0);
 273                 exit(EXIT_SUCCESS);
 274         } else
 275                 usage(popt_context, EXIT_SUCCESS, NULL, NULL);
 276 }
 277
 278 static void _dbg_version_and_cmd(int argc, const char **argv)
 279 {
 280         int i;
 281
 282         log_std("# %s %s processing \"", PACKAGE_VERITY, PACKAGE_VERSION);
 283         for (i = 0; i < argc; i++) {
 284                 if (i)
 285                         log_std(" ");
 286                 log_std("%s", argv[i]);
 287         }
 288         log_std("\"\n");
 289 }
 290
 291 int main(int argc, const char **argv)
 292 {
 293         static struct poptOption popt_help_options[] = {
 294                 { NULL,    '\0', POPT_ARG_CALLBACK, help, 0, NULL,                         NULL },
 295                 { "help",  '?',  POPT_ARG_NONE,     NULL, 0, N_("Show this help message"), NULL },
 296                 { "usage", '\0', POPT_ARG_NONE,     NULL, 0, N_("Display brief usage"),    NULL },
 297                 POPT_TABLEEND
 298         };
 299         static struct poptOption popt_options[] = {
 300                 { NULL,                '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, N_("Help options:"), NULL },
 301                 { "version",           '\0', POPT_ARG_NONE, &opt_version_mode,          0, N_("Print package version"), NULL },
 302                 { "verbose",            0 /*v*/,  POPT_ARG_NONE, &opt_verbose,               0, N_("Shows more detailed error messages"), NULL },
 303                 { "debug",             '\0', POPT_ARG_NONE, &opt_debug,                 0, N_("Show debug messages"), NULL },
 304                 { "create",             'c',    POPT_ARG_VAL, &mode, MODE_CREATE, "Create hash", NULL },
 305                 { "verify",             'v',    POPT_ARG_VAL, &mode, MODE_VERIFY, "Verify integrity", NULL },
 306                 { "activate",           'a',    POPT_ARG_VAL, &mode, MODE_ACTIVATE, "Activate the device", NULL },
 307                 { "dump",               'd',    POPT_ARG_VAL, &mode, MODE_DUMP, "Dump the device", NULL },
 308                 { "status",             's',    POPT_ARG_VAL, &mode, MODE_STATUS, "Status active device", NULL },
 309                 { "no-superblock",      0,      POPT_ARG_VAL, &use_superblock, 0, "Do not create/use superblock" },
 310                 { "format",             0,      POPT_ARG_INT, &version, 0, "Format version (1 - normal format, 0 - original Chromium OS format)", "number" },
 311                 { "data-block-size",    0,      POPT_ARG_INT, &data_block_size, 0, "Block size on the data device", "bytes" },
 312                 { "hash-block-size",    0,      POPT_ARG_INT, &hash_block_size, 0, "Block size on the hash device", "bytes" },
 313                 { "data-blocks",        0,      POPT_ARG_STRING, &data_blocks_string, 0, "The number of blocks in the data file", "blocks" },
 314                 { "hash-start",         0,      POPT_ARG_STRING, &hash_start_string, 0, "Starting block on the hash device", "512-byte sectors" },
 315                 { "algorithm",          0,      POPT_ARG_STRING, &hash_algorithm, 0, "Hash algorithm (default sha256)", "string" },
 316                 { "salt",               0,      POPT_ARG_STRING, &salt_string, 0, "Salt", "hex string" },
 317                 POPT_TABLEEND
 318         };
 319         poptContext popt_context;
 320         int r;
 321         char *end;
 322
 323         crypt_set_log_callback(NULL, _log, NULL);
 324
 325         setlocale(LC_ALL, "");
 326         bindtextdomain(PACKAGE, LOCALEDIR);
 327         textdomain(PACKAGE);
 328
 329         popt_context = poptGetContext("verity", argc, argv, popt_options, 0);
 330
 331         poptSetOtherOptionHelp(popt_context, "[-c|-v|-a|-d] [<device name> if activating] <data device> <hash device> [<root hash> if activating or verifying] [OPTION...]");
 332
 333         if (argc <= 1) {
 334                 poptPrintHelp(popt_context, stdout, 0);
 335                 exit(1);
 336         }
 337
 338         r = poptGetNextOpt(popt_context);
 339         if (r < -1)
 340                 usage(popt_context, EXIT_FAILURE, poptStrerror(r),
 341                       poptBadOption(popt_context, POPT_BADOPTION_NOALIAS));
 342         if (opt_version_mode) {
 343                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 344                 poptFreeContext(popt_context);
 345                 exit(EXIT_SUCCESS);
 346         }
 347
 348         if (mode < 0)
 349                 usage(popt_context, EXIT_FAILURE, _("Unknown action."),
 350                       poptGetInvocationName(popt_context));
 351
 352         if (mode == MODE_ACTIVATE || mode == MODE_STATUS) {
 353                 dm_device = poptGetArg(popt_context);
 354                 if (!dm_device || !*dm_device)
 355                         usage(popt_context, EXIT_FAILURE,
 356                               _("Missing activation device name."),
 357                               poptGetInvocationName(popt_context));
 358         }
 359
 360         if (mode == MODE_STATUS)
 361                 goto run; //FIXME
 362
 363         data_device = poptGetArg(popt_context);
 364         if (!data_device)
 365                 usage(popt_context, EXIT_FAILURE, _("Missing data device name."),
 366                       poptGetInvocationName(popt_context));
 367
 368         hash_device = poptGetArg(popt_context);
 369         if (!hash_device)
 370                 usage(popt_context, EXIT_FAILURE, _("Missing hash device name."),
 371                       poptGetInvocationName(popt_context));
 372
 373         if (mode == MODE_ACTIVATE || mode == MODE_VERIFY) {
 374                 root_hash = poptGetArg(popt_context);
 375                 if (!root_hash)
 376                 usage(popt_context, EXIT_FAILURE, _("Root hash not specified."),
 377                       poptGetInvocationName(popt_context));
 378         }
 379
 380         if (data_blocks_string) {
 381                 data_blocks = strtoll(data_blocks_string, &end, 10);
 382                 if (!*data_blocks_string || *end)
 383                         usage(popt_context, EXIT_FAILURE,
 384                               _("Invalid number of data blocks."),
 385                               poptGetInvocationName(popt_context));
 386         }
 387
 388         /* hash start */
 389         if (hash_start_string) {
 390                 hash_start = strtoll(hash_start_string, &end, 10);
 391                 if (!*hash_start_string || *end)
 392                         usage(popt_context, EXIT_FAILURE,
 393                               _("Invalid hash device offset."),
 394                               poptGetInvocationName(popt_context));
 395                 hash_start *= 512;
 396         }
 397
 398         if (salt_string || !use_superblock) {
 399                 if (!salt_string || !strcmp(salt_string, "-"))
 400                         salt_string = "";
 401                 salt_size = strlen(salt_string) / 2;
 402         }
 403 run:
 404         if (opt_debug) {
 405                 opt_verbose = 1;
 406                 crypt_set_debug_level(-1);
 407                 _dbg_version_and_cmd(argc, argv);
 408         }
 409
 410         switch (mode) {
 411                 case MODE_ACTIVATE:
 412                         r = action_activate(0);
 413                         break;
 414                 case MODE_VERIFY:
 415                         r = action_activate(1);
 416                         break;
 417                 case MODE_CREATE:
 418                         r = action_create();
 419                         break;
 420                 case MODE_DUMP:
 421                         r = action_dump();
 422                         break;
 423                 case MODE_STATUS:
 424                         r = action_status();
 425                         break;
 426         }
 427
 428         poptFreeContext(popt_context);
 429         return r;
 430 }