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  * - warn if block_size > PAGE_SIZE
  27  * - configure.in/config.h defaults
  28  */
  29
  30 #include <stdio.h>
  31 #include <stdlib.h>
  32 #include <stdarg.h>
  33 #include <errno.h>
  34 #include <string.h>
  35 #include <popt.h>
  36
  37 #include "cryptsetup.h"
  38
  39 #define PACKAGE_VERITY "veritysetup"
  40
  41 #define MODE_VERIFY     0
  42 #define MODE_CREATE     1
  43 #define MODE_ACTIVATE   2
  44 #define MODE_DUMP       3
  45
  46 static int mode = -1;
  47 static int use_superblock = 1; /* FIXME: no superblock not supported */
  48
  49 static const char *dm_device = NULL;
  50 static const char *data_device = NULL;
  51 static const char *hash_device = NULL;
  52 static const char *hash_algorithm = NULL;
  53 static const char *root_hash = NULL;
  54
  55 static int version = 1;
  56 static int data_block_size = 4096;
  57 static int hash_block_size = 4096;
  58 static char *data_blocks_string = NULL;
  59 static uint64_t data_blocks = 0;
  60 static char *hash_start_string = NULL;
  61 static const char *salt_string = NULL;
  62 static unsigned salt_size = 32;
  63 static uint64_t hash_start = 0;
  64
  65 static int opt_verbose = 0;
  66 static int opt_debug = 0;
  67 static int opt_version_mode = 0;
  68
  69 static int hex_to_bytes(const char *hex, char *result)
  70 {
  71         char buf[3] = "xx\0", *endp;
  72         int i, len;
  73
  74         len = strlen(hex) / 2;
  75         for (i = 0; i < len; i++) {
  76                 memcpy(buf, &hex[i * 2], 2);
  77                 result[i] = strtoul(buf, &endp, 16);
  78                 if (endp != &buf[2])
  79                         return -EINVAL;
  80         }
  81         return i;
  82 }
  83
  84 __attribute__((format(printf, 5, 6)))
  85 static void clogger(struct crypt_device *cd, int level, const char *file,
  86                    int line, const char *format, ...)
  87 {
  88         va_list argp;
  89         char *target = NULL;
  90
  91         va_start(argp, format);
  92
  93         if (vasprintf(&target, format, argp) > 0) {
  94                 if (level >= 0) {
  95                         crypt_log(cd, level, target);
  96 #ifdef CRYPT_DEBUG
  97                 } else if (opt_debug)
  98                         printf("# %s:%d %s\n", file ?: "?", line, target);
  99 #else
 100                 } else if (opt_debug)
 101                         printf("# %s\n", target);
 102 #endif
 103         }
 104
 105         va_end(argp);
 106         free(target);
 107 }
 108
 109 static void _log(int level, const char *msg, void *usrptr __attribute__((unused)))
 110 {
 111         switch(level) {
 112
 113         case CRYPT_LOG_NORMAL:
 114                 fputs(msg, stdout);
 115                 break;
 116         case CRYPT_LOG_VERBOSE:
 117                 if (opt_verbose)
 118                         fputs(msg, stdout);
 119                 break;
 120         case CRYPT_LOG_ERROR:
 121                 fputs(msg, stderr);
 122                 break;
 123         case CRYPT_LOG_DEBUG:
 124                 if (opt_debug)
 125                         printf("# %s\n", msg);
 126                 break;
 127         default:
 128                 fprintf(stderr, "Internal error on logging class for msg: %s", msg);
 129                 break;
 130         }
 131 }
 132
 133 static int action_dump(void)
 134 {
 135         struct crypt_device *cd = NULL;
 136         struct crypt_params_verity params = {};
 137         int r;
 138
 139         if ((r = crypt_init(&cd, hash_device)))
 140                 return r;
 141
 142         params.hash_area_offset = hash_start;
 143         r = crypt_load(cd, CRYPT_VERITY, &params);
 144         if (!r)
 145                 crypt_dump(cd);
 146         crypt_free(cd);
 147         return r;
 148 }
 149
 150 static int action_activate(int verify)
 151 {
 152         struct crypt_device *cd = NULL;
 153         struct crypt_params_verity params = {};
 154         uint32_t activate_flags = CRYPT_ACTIVATE_READONLY;
 155         char root_hash_bytes[128];
 156         int r;
 157
 158         if ((r = crypt_init(&cd, hash_device)))
 159                 goto out;
 160
 161         if (verify)
 162                 params.flags |= CRYPT_VERITY_CHECK_HASH;
 163
 164         if (use_superblock) {
 165                 params.hash_area_offset = hash_start;
 166                 r = crypt_load(cd, CRYPT_VERITY, &params);
 167         } else {/*
 168                 params.hash_name = hash_algorithm;
 169                 params.salt = salt_bytes;
 170                 params.salt_size = salt_size;
 171                 params.data_block_size = data_block_size;
 172                 params.hash_block_size = hash_block_size;
 173
 174                 params.data_size = data_blocks * data_block_size / 512;
 175                 params.version = version;
 176                 params.flags |= CRYPT_VERITY_NO_HEADER;
 177                 r = crypt_load(cd, CRYPT_VERITY, &params);
 178                 crypt_format(); */
 179                 r = -EINVAL;
 180                 goto out;
 181         }
 182         if (r < 0)
 183                 goto out;
 184         r = crypt_set_data_device(cd, data_device);
 185         if (r < 0)
 186                 goto out;
 187
 188         if (hex_to_bytes(root_hash, root_hash_bytes) !=
 189             crypt_get_volume_key_size(cd)) {
 190                 r = -EINVAL;
 191                 goto out;
 192         }
 193         r = crypt_activate_by_volume_key(cd, dm_device, root_hash_bytes,
 194                                          crypt_get_volume_key_size(cd),
 195                                          activate_flags);
 196 out:
 197         if (!r)
 198                 crypt_dump(cd);
 199         crypt_free(cd);
 200         return r;
 201 }
 202
 203 static int action_create(void)
 204 {
 205         struct crypt_device *cd = NULL;
 206         struct crypt_params_verity params = {};
 207         char salt_bytes[512];
 208         int r;
 209
 210         if ((r = crypt_init(&cd, hash_device)))
 211                 goto out;
 212
 213         params.hash_name = hash_algorithm ?: "sha256";
 214         params.data_device = data_device;
 215
 216         if (salt_string) {
 217                 if (hex_to_bytes(salt_string, salt_bytes) != salt_size) {
 218                         r = -EINVAL;
 219                         goto out;
 220                 }
 221                 params.salt = salt_bytes;
 222         }
 223
 224         params.salt_size = salt_size;
 225         params.data_block_size = data_block_size;
 226         params.hash_block_size = hash_block_size;
 227         params.data_size = data_blocks;
 228         params.hash_area_offset = hash_start;
 229         params.version = version;
 230         params.flags = CRYPT_VERITY_CREATE_HASH;
 231         if (!use_superblock)
 232                 params.flags |= CRYPT_VERITY_NO_HEADER;
 233
 234         r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);
 235         if (!r)
 236                 crypt_dump(cd);
 237 out:
 238         crypt_free(cd);
 239         return r;
 240 }
 241
 242 static __attribute__ ((noreturn)) void usage(poptContext popt_context,
 243                                              int exitcode, const char *error,
 244                                              const char *more)
 245 {
 246         poptPrintUsage(popt_context, stderr, 0);
 247         if (error)
 248                 log_err("%s: %s\n", more, error);
 249         poptFreeContext(popt_context);
 250         exit(exitcode);
 251 }
 252
 253 static void help(poptContext popt_context,
 254                  enum poptCallbackReason reason __attribute__((unused)),
 255                  struct poptOption *key,
 256                  const char *arg __attribute__((unused)),
 257                  void *data __attribute__((unused)))
 258 {
 259         if (key->shortName == '?') {
 260                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 261                 poptPrintHelp(popt_context, stdout, 0);
 262                 exit(EXIT_SUCCESS);
 263         } else
 264                 usage(popt_context, EXIT_SUCCESS, NULL, NULL);
 265 }
 266
 267 static void _dbg_version_and_cmd(int argc, const char **argv)
 268 {
 269         int i;
 270
 271         log_std("# %s %s processing \"", PACKAGE_VERITY, PACKAGE_VERSION);
 272         for (i = 0; i < argc; i++) {
 273                 if (i)
 274                         log_std(" ");
 275                 log_std("%s", argv[i]);
 276         }
 277         log_std("\"\n");
 278 }
 279
 280 int main(int argc, const char **argv)
 281 {
 282         static struct poptOption popt_help_options[] = {
 283                 { NULL,    '\0', POPT_ARG_CALLBACK, help, 0, NULL,                         NULL },
 284                 { "help",  '?',  POPT_ARG_NONE,     NULL, 0, N_("Show this help message"), NULL },
 285                 { "usage", '\0', POPT_ARG_NONE,     NULL, 0, N_("Display brief usage"),    NULL },
 286                 POPT_TABLEEND
 287         };
 288         static struct poptOption popt_options[] = {
 289                 { NULL,                '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, N_("Help options:"), NULL },
 290                 { "version",           '\0', POPT_ARG_NONE, &opt_version_mode,          0, N_("Print package version"), NULL },
 291                 { "verbose",            0 /*v*/,  POPT_ARG_NONE, &opt_verbose,               0, N_("Shows more detailed error messages"), NULL },
 292                 { "debug",             '\0', POPT_ARG_NONE, &opt_debug,                 0, N_("Show debug messages"), NULL },
 293                 { "create",             'c',    POPT_ARG_VAL, &mode, MODE_CREATE, "Create hash", NULL },
 294                 { "verify",             'v',    POPT_ARG_VAL, &mode, MODE_VERIFY, "Verify integrity", NULL },
 295                 { "activate",           'a',    POPT_ARG_VAL, &mode, MODE_ACTIVATE, "Activate the device", NULL },
 296                 { "dump",               'd',    POPT_ARG_VAL, &mode, MODE_DUMP, "Dump the device", NULL },
 297                 { "no-superblock",      0,      POPT_ARG_VAL, &use_superblock, 0, "Do not create/use superblock" },
 298                 { "format",             0,      POPT_ARG_INT, &version, 0, "Format version (1 - normal format, 0 - original Chromium OS format)", "number" },
 299                 { "data-block-size",    0,      POPT_ARG_INT, &data_block_size, 0, "Block size on the data device", "bytes" },
 300                 { "hash-block-size",    0,      POPT_ARG_INT, &hash_block_size, 0, "Block size on the hash device", "bytes" },
 301                 { "data-blocks",        0,      POPT_ARG_STRING, &data_blocks_string, 0, "The number of blocks in the data file", "blocks" },
 302                 { "hash-start",         0,      POPT_ARG_STRING, &hash_start_string, 0, "Starting block on the hash device", "512-byte sectors" },
 303                 { "algorithm",          0,      POPT_ARG_STRING, &hash_algorithm, 0, "Hash algorithm (default sha256)", "string" },
 304                 { "salt",               0,      POPT_ARG_STRING, &salt_string, 0, "Salt", "hex string" },
 305                 POPT_TABLEEND
 306         };
 307         poptContext popt_context;
 308         int r;
 309         char *end;
 310
 311         crypt_set_log_callback(NULL, _log, NULL);
 312
 313         setlocale(LC_ALL, "");
 314         bindtextdomain(PACKAGE, LOCALEDIR);
 315         textdomain(PACKAGE);
 316
 317         popt_context = poptGetContext("verity", argc, argv, popt_options, 0);
 318
 319         poptSetOtherOptionHelp(popt_context, "[-c|-v|-a|-d] [<device name> if activating] <data device> <hash device> [<root hash> if activating or verifying] [OPTION...]");
 320
 321         if (argc <= 1) {
 322                 poptPrintHelp(popt_context, stdout, 0);
 323                 exit(1);
 324         }
 325
 326         r = poptGetNextOpt(popt_context);
 327         if (r < -1)
 328                 usage(popt_context, EXIT_FAILURE, poptStrerror(r),
 329                       poptBadOption(popt_context, POPT_BADOPTION_NOALIAS));
 330         if (opt_version_mode) {
 331                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 332                 poptFreeContext(popt_context);
 333                 exit(EXIT_SUCCESS);
 334         }
 335
 336         if (mode < 0)
 337                 usage(popt_context, EXIT_FAILURE, _("Unknown action."),
 338                       poptGetInvocationName(popt_context));
 339
 340         if (mode == MODE_ACTIVATE) {
 341                 dm_device = poptGetArg(popt_context);
 342                 if (!dm_device || !*dm_device)
 343                         usage(popt_context, EXIT_FAILURE,
 344                               _("Missing activation device name."),
 345                               poptGetInvocationName(popt_context));
 346         }
 347
 348         data_device = poptGetArg(popt_context);
 349         if (!data_device)
 350                 usage(popt_context, EXIT_FAILURE, _("Missing data device name."),
 351                       poptGetInvocationName(popt_context));
 352
 353         hash_device = poptGetArg(popt_context);
 354         if (!hash_device)
 355                 usage(popt_context, EXIT_FAILURE, _("Missing hash device name."),
 356                       poptGetInvocationName(popt_context));
 357
 358         if (mode == MODE_ACTIVATE || mode == MODE_VERIFY) {
 359                 root_hash = poptGetArg(popt_context);
 360                 if (!root_hash)
 361                 usage(popt_context, EXIT_FAILURE, _("Root hash not specified."),
 362                       poptGetInvocationName(popt_context));
 363         }
 364
 365         if (data_blocks_string) {
 366                 data_blocks = strtoll(data_blocks_string, &end, 10);
 367                 if (!*data_blocks_string || *end)
 368                         usage(popt_context, EXIT_FAILURE,
 369                               _("Invalid number of data blocks."),
 370                               poptGetInvocationName(popt_context));
 371         }
 372
 373         /* hash start */
 374         if (hash_start_string) {
 375                 hash_start = strtoll(hash_start_string, &end, 10);
 376                 if (!*hash_start_string || *end)
 377                         usage(popt_context, EXIT_FAILURE,
 378                               _("Invalid hash device offset."),
 379                               poptGetInvocationName(popt_context));
 380                 hash_start *= 512;
 381         }
 382
 383         if (salt_string || !use_superblock) {
 384                 if (!salt_string || !strcmp(salt_string, "-"))
 385                         salt_string = "";
 386                 salt_size = strlen(salt_string) / 2;
 387         }
 388
 389         if (opt_debug) {
 390                 opt_verbose = 1;
 391                 crypt_set_debug_level(-1);
 392                 _dbg_version_and_cmd(argc, argv);
 393         }
 394
 395         switch (mode) {
 396                 case MODE_ACTIVATE:
 397                         r = action_activate(0);
 398                         break;
 399                 case MODE_VERIFY:
 400                         r = action_activate(1);
 401                         break;
 402                 case MODE_CREATE:
 403                         r = action_create();
 404                         break;
 405                 case MODE_DUMP:
 406                         r = action_dump();
 407                         break;
 408         }
 409
 410         poptFreeContext(popt_context);
 411         return r;
 412 }