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