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  * - configure.in/config.h defaults
  27  */
  28
  29 #include <stdio.h>
  30 #include <stdlib.h>
  31 #include <stdarg.h>
  32 #include <errno.h>
  33 #include <string.h>
  34 #include <popt.h>
  35
  36 #include "cryptsetup.h"
  37
  38 #define PACKAGE_VERITY "veritysetup"
  39
  40 #define MODE_VERIFY     0
  41 #define MODE_CREATE     1
  42 #define MODE_ACTIVATE   2
  43 #define MODE_DUMP       3
  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 = 4096;
  56 static int hash_block_size = 4096;
  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 = 32;
  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_activate(int verify)
 150 {
 151         struct crypt_device *cd = NULL;
 152         struct crypt_params_verity params = {};
 153         uint32_t activate_flags = CRYPT_ACTIVATE_READONLY;
 154         char root_hash_bytes[128];
 155         int r;
 156
 157         if ((r = crypt_init(&cd, hash_device)))
 158                 goto out;
 159
 160         if (verify)
 161                 params.flags |= CRYPT_VERITY_CHECK_HASH;
 162
 163         if (use_superblock) {
 164                 params.hash_area_offset = hash_start;
 165                 r = crypt_load(cd, CRYPT_VERITY, &params);
 166         } else {/*
 167                 params.hash_name = hash_algorithm;
 168                 params.salt = salt_bytes;
 169                 params.salt_size = salt_size;
 170                 params.data_block_size = data_block_size;
 171                 params.hash_block_size = hash_block_size;
 172
 173                 params.data_size = data_blocks * data_block_size / 512;
 174                 params.version = version;
 175                 params.flags |= CRYPT_VERITY_NO_HEADER;
 176                 r = crypt_load(cd, CRYPT_VERITY, &params);
 177                 crypt_format(); */
 178                 r = -EINVAL;
 179                 goto out;
 180         }
 181         if (r < 0)
 182                 goto out;
 183         r = crypt_set_data_device(cd, data_device);
 184         if (r < 0)
 185                 goto out;
 186
 187         if (hex_to_bytes(root_hash, root_hash_bytes) !=
 188             crypt_get_volume_key_size(cd)) {
 189                 r = -EINVAL;
 190                 goto out;
 191         }
 192         r = crypt_activate_by_volume_key(cd, dm_device, root_hash_bytes,
 193                                          crypt_get_volume_key_size(cd),
 194                                          activate_flags);
 195 out:
 196         if (!r)
 197                 crypt_dump(cd);
 198         crypt_free(cd);
 199         return r;
 200 }
 201
 202 static int action_create(void)
 203 {
 204         struct crypt_device *cd = NULL;
 205         struct crypt_params_verity params = {};
 206         char salt_bytes[512];
 207         int r;
 208
 209         if ((r = crypt_init(&cd, hash_device)))
 210                 goto out;
 211
 212         params.hash_name = hash_algorithm ?: "sha256";
 213         params.data_device = data_device;
 214
 215         if (salt_string) {
 216                 if (hex_to_bytes(salt_string, salt_bytes) != salt_size) {
 217                         r = -EINVAL;
 218                         goto out;
 219                 }
 220                 params.salt = salt_bytes;
 221         }
 222
 223         params.salt_size = salt_size;
 224         params.data_block_size = data_block_size;
 225         params.hash_block_size = hash_block_size;
 226         params.data_size = data_blocks;
 227         params.hash_area_offset = hash_start;
 228         params.version = version;
 229         params.flags = CRYPT_VERITY_CREATE_HASH;
 230         if (!use_superblock)
 231                 params.flags |= CRYPT_VERITY_NO_HEADER;
 232
 233         r = crypt_format(cd, CRYPT_VERITY, NULL, NULL, NULL, NULL, 0, &params);
 234         if (!r)
 235                 crypt_dump(cd);
 236 out:
 237         crypt_free(cd);
 238         return r;
 239 }
 240
 241 static __attribute__ ((noreturn)) void usage(poptContext popt_context,
 242                                              int exitcode, const char *error,
 243                                              const char *more)
 244 {
 245         poptPrintUsage(popt_context, stderr, 0);
 246         if (error)
 247                 log_err("%s: %s\n", more, error);
 248         poptFreeContext(popt_context);
 249         exit(exitcode);
 250 }
 251
 252 static void help(poptContext popt_context,
 253                  enum poptCallbackReason reason __attribute__((unused)),
 254                  struct poptOption *key,
 255                  const char *arg __attribute__((unused)),
 256                  void *data __attribute__((unused)))
 257 {
 258         if (key->shortName == '?') {
 259                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 260                 poptPrintHelp(popt_context, stdout, 0);
 261                 exit(EXIT_SUCCESS);
 262         } else
 263                 usage(popt_context, EXIT_SUCCESS, NULL, NULL);
 264 }
 265
 266 static void _dbg_version_and_cmd(int argc, const char **argv)
 267 {
 268         int i;
 269
 270         log_std("# %s %s processing \"", PACKAGE_VERITY, PACKAGE_VERSION);
 271         for (i = 0; i < argc; i++) {
 272                 if (i)
 273                         log_std(" ");
 274                 log_std("%s", argv[i]);
 275         }
 276         log_std("\"\n");
 277 }
 278
 279 int main(int argc, const char **argv)
 280 {
 281         static struct poptOption popt_help_options[] = {
 282                 { NULL,    '\0', POPT_ARG_CALLBACK, help, 0, NULL,                         NULL },
 283                 { "help",  '?',  POPT_ARG_NONE,     NULL, 0, N_("Show this help message"), NULL },
 284                 { "usage", '\0', POPT_ARG_NONE,     NULL, 0, N_("Display brief usage"),    NULL },
 285                 POPT_TABLEEND
 286         };
 287         static struct poptOption popt_options[] = {
 288                 { NULL,                '\0', POPT_ARG_INCLUDE_TABLE, popt_help_options, 0, N_("Help options:"), NULL },
 289                 { "version",           '\0', POPT_ARG_NONE, &opt_version_mode,          0, N_("Print package version"), NULL },
 290                 { "verbose",            0 /*v*/,  POPT_ARG_NONE, &opt_verbose,               0, N_("Shows more detailed error messages"), NULL },
 291                 { "debug",             '\0', POPT_ARG_NONE, &opt_debug,                 0, N_("Show debug messages"), NULL },
 292                 { "create",             'c',    POPT_ARG_VAL, &mode, MODE_CREATE, "Create hash", NULL },
 293                 { "verify",             'v',    POPT_ARG_VAL, &mode, MODE_VERIFY, "Verify integrity", NULL },
 294                 { "activate",           'a',    POPT_ARG_VAL, &mode, MODE_ACTIVATE, "Activate the device", NULL },
 295                 { "dump",               'd',    POPT_ARG_VAL, &mode, MODE_DUMP, "Dump the device", NULL },
 296                 { "no-superblock",      0,      POPT_ARG_VAL, &use_superblock, 0, "Do not create/use superblock" },
 297                 { "format",             0,      POPT_ARG_INT, &version, 0, "Format version (1 - normal format, 0 - original Chromium OS format)", "number" },
 298                 { "data-block-size",    0,      POPT_ARG_INT, &data_block_size, 0, "Block size on the data device", "bytes" },
 299                 { "hash-block-size",    0,      POPT_ARG_INT, &hash_block_size, 0, "Block size on the hash device", "bytes" },
 300                 { "data-blocks",        0,      POPT_ARG_STRING, &data_blocks_string, 0, "The number of blocks in the data file", "blocks" },
 301                 { "hash-start",         0,      POPT_ARG_STRING, &hash_start_string, 0, "Starting block on the hash device", "512-byte sectors" },
 302                 { "algorithm",          0,      POPT_ARG_STRING, &hash_algorithm, 0, "Hash algorithm (default sha256)", "string" },
 303                 { "salt",               0,      POPT_ARG_STRING, &salt_string, 0, "Salt", "hex string" },
 304                 POPT_TABLEEND
 305         };
 306         poptContext popt_context;
 307         int r;
 308         char *end;
 309
 310         crypt_set_log_callback(NULL, _log, NULL);
 311
 312         setlocale(LC_ALL, "");
 313         bindtextdomain(PACKAGE, LOCALEDIR);
 314         textdomain(PACKAGE);
 315
 316         popt_context = poptGetContext("verity", argc, argv, popt_options, 0);
 317
 318         poptSetOtherOptionHelp(popt_context, "[-c|-v|-a|-d] [<device name> if activating] <data device> <hash device> [<root hash> if activating or verifying] [OPTION...]");
 319
 320         if (argc <= 1) {
 321                 poptPrintHelp(popt_context, stdout, 0);
 322                 exit(1);
 323         }
 324
 325         r = poptGetNextOpt(popt_context);
 326         if (r < -1)
 327                 usage(popt_context, EXIT_FAILURE, poptStrerror(r),
 328                       poptBadOption(popt_context, POPT_BADOPTION_NOALIAS));
 329         if (opt_version_mode) {
 330                 log_std("%s %s\n", PACKAGE_VERITY, PACKAGE_VERSION);
 331                 poptFreeContext(popt_context);
 332                 exit(EXIT_SUCCESS);
 333         }
 334
 335         if (mode < 0)
 336                 usage(popt_context, EXIT_FAILURE, _("Unknown action."),
 337                       poptGetInvocationName(popt_context));
 338
 339         if (mode == MODE_ACTIVATE) {
 340                 dm_device = poptGetArg(popt_context);
 341                 if (!dm_device || !*dm_device)
 342                         usage(popt_context, EXIT_FAILURE,
 343                               _("Missing activation device name."),
 344                               poptGetInvocationName(popt_context));
 345         }
 346
 347         data_device = poptGetArg(popt_context);
 348         if (!data_device)
 349                 usage(popt_context, EXIT_FAILURE, _("Missing data device name."),
 350                       poptGetInvocationName(popt_context));
 351
 352         hash_device = poptGetArg(popt_context);
 353         if (!hash_device)
 354                 usage(popt_context, EXIT_FAILURE, _("Missing hash device name."),
 355                       poptGetInvocationName(popt_context));
 356
 357         if (mode == MODE_ACTIVATE || mode == MODE_VERIFY) {
 358                 root_hash = poptGetArg(popt_context);
 359                 if (!root_hash)
 360                 usage(popt_context, EXIT_FAILURE, _("Root hash not specified."),
 361                       poptGetInvocationName(popt_context));
 362         }
 363
 364         if (data_blocks_string) {
 365                 data_blocks = strtoll(data_blocks_string, &end, 10);
 366                 if (!*data_blocks_string || *end)
 367                         usage(popt_context, EXIT_FAILURE,
 368                               _("Invalid number of data blocks."),
 369                               poptGetInvocationName(popt_context));
 370         }
 371
 372         /* hash start */
 373         if (hash_start_string) {
 374                 hash_start = strtoll(hash_start_string, &end, 10);
 375                 if (!*hash_start_string || *end)
 376                         usage(popt_context, EXIT_FAILURE,
 377                               _("Invalid hash device offset."),
 378                               poptGetInvocationName(popt_context));
 379                 hash_start *= 512;
 380         }
 381
 382         if (salt_string || !use_superblock) {
 383                 if (!salt_string || !strcmp(salt_string, "-"))
 384                         salt_string = "";
 385                 salt_size = strlen(salt_string) / 2;
 386         }
 387
 388         if (opt_debug) {
 389                 opt_verbose = 1;
 390                 crypt_set_debug_level(-1);
 391                 _dbg_version_and_cmd(argc, argv);
 392         }
 393
 394         switch (mode) {
 395                 case MODE_ACTIVATE:
 396                         r = action_activate(0);
 397                         break;
 398                 case MODE_VERIFY:
 399                         r = action_activate(1);
 400                         break;
 401                 case MODE_CREATE:
 402                         r = action_create();
 403                         break;
 404                 case MODE_DUMP:
 405                         r = action_dump();
 406                         break;
 407         }
 408
 409         poptFreeContext(popt_context);
 410         return r;
 411 }