src/cryptsetup/cryptsetup.c

   1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
   2
   3 /***
   4   This file is part of systemd.
   5
   6   Copyright 2010 Lennart Poettering
   7
   8   systemd is free software; you can redistribute it and/or modify it
   9   under the terms of the GNU Lesser General Public License as published by
  10   the Free Software Foundation; either version 2.1 of the License, or
  11   (at your option) any later version.
  12
  13   systemd is distributed in the hope that it will be useful, but
  14   WITHOUT ANY WARRANTY; without even the implied warranty of
  15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16   Lesser General Public License for more details.
  17
  18   You should have received a copy of the GNU Lesser General Public License
  19   along with systemd; If not, see <http://www.gnu.org/licenses/>.
  20 ***/
  21
  22 #include <string.h>
  23 #include <errno.h>
  24 #include <sys/mman.h>
  25 #include <mntent.h>
  26
  27 #include <libcryptsetup.h>
  28 #include <libudev.h>
  29
  30 #include "log.h"
  31 #include "util.h"
  32 #include "path-util.h"
  33 #include "strv.h"
  34 #include "ask-password-api.h"
  35 #include "def.h"
  36
  37 static const char *opt_type = NULL; /* LUKS1 or PLAIN */
  38 static char *opt_cipher = NULL;
  39 static unsigned opt_key_size = 0;
  40 static unsigned opt_keyfile_size = 0;
  41 static unsigned opt_keyfile_offset = 0;
  42 static char *opt_hash = NULL;
  43 static unsigned opt_tries = 0;
  44 static bool opt_readonly = false;
  45 static bool opt_verify = false;
  46 static bool opt_discards = false;
  47 static usec_t opt_timeout = DEFAULT_TIMEOUT_USEC;
  48
  49 /* Options Debian's crypttab knows we don't:
  50
  51     offset=
  52     skip=
  53     precheck=
  54     check=
  55     checkargs=
  56     noearly=
  57     loud=
  58     keyscript=
  59 */
  60
  61 static int parse_one_option(const char *option) {
  62         assert(option);
  63
  64         /* Handled outside of this tool */
  65         if (streq(option, "noauto") || streq(option, "nofail"))
  66                 return 0;
  67
  68         if (startswith(option, "cipher=")) {
  69                 char *t;
  70
  71                 t = strdup(option+7);
  72                 if (!t)
  73                         return -ENOMEM;
  74
  75                 free(opt_cipher);
  76                 opt_cipher = t;
  77
  78         } else if (startswith(option, "size=")) {
  79
  80                 if (safe_atou(option+5, &opt_key_size) < 0) {
  81                         log_error("size= parse failure, ignoring.");
  82                         return 0;
  83                 }
  84
  85         } else if (startswith(option, "keyfile-size=")) {
  86
  87                 if (safe_atou(option+13, &opt_keyfile_size) < 0) {
  88                         log_error("keyfile-size= parse failure, ignoring.");
  89                         return 0;
  90                 }
  91
  92         } else if (startswith(option, "keyfile-offset=")) {
  93
  94                 if (safe_atou(option+15, &opt_keyfile_offset) < 0) {
  95                         log_error("keyfile-offset= parse failure, ignoring.");
  96                         return 0;
  97                 }
  98
  99         } else if (startswith(option, "hash=")) {
 100                 char *t;
 101
 102                 t = strdup(option+5);
 103                 if (!t)
 104                         return -ENOMEM;
 105
 106                 free(opt_hash);
 107                 opt_hash = t;
 108
 109         } else if (startswith(option, "tries=")) {
 110
 111                 if (safe_atou(option+6, &opt_tries) < 0) {
 112                         log_error("tries= parse failure, ignoring.");
 113                         return 0;
 114                 }
 115
 116         } else if (streq(option, "readonly") || streq(option, "read-only"))
 117                 opt_readonly = true;
 118         else if (streq(option, "verify"))
 119                 opt_verify = true;
 120         else if (streq(option, "allow-discards"))
 121                 opt_discards = true;
 122         else if (streq(option, "luks"))
 123                 opt_type = CRYPT_LUKS1;
 124         else if (streq(option, "plain") ||
 125                  streq(option, "swap") ||
 126                  streq(option, "tmp"))
 127                 opt_type = CRYPT_PLAIN;
 128         else if (startswith(option, "timeout=")) {
 129
 130                 if (parse_sec(option+8, &opt_timeout) < 0) {
 131                         log_error("timeout= parse failure, ignoring.");
 132                         return 0;
 133                 }
 134
 135         } else if (!streq(option, "none"))
 136                 log_error("Encountered unknown /etc/crypttab option '%s', ignoring.", option);
 137
 138         return 0;
 139 }
 140
 141 static int parse_options(const char *options) {
 142         char *state, *w;
 143         size_t l;
 144         int r;
 145
 146         assert(options);
 147
 148         FOREACH_WORD_SEPARATOR(w, l, options, ",", state) {
 149                 _cleanup_free_ char *o;
 150
 151                 o = strndup(w, l);
 152                 if (!o)
 153                         return -ENOMEM;
 154                 r = parse_one_option(o);
 155                 if (r < 0)
 156                         return r;
 157         }
 158
 159         return 0;
 160 }
 161
 162 static void log_glue(int level, const char *msg, void *usrptr) {
 163         log_debug("%s", msg);
 164 }
 165
 166 static char *disk_description(const char *path) {
 167
 168         static const char name_fields[] = {
 169                 "ID_PART_ENTRY_NAME\0"
 170                 "DM_NAME\0"
 171                 "ID_MODEL_FROM_DATABASE\0"
 172                 "ID_MODEL\0"
 173         };
 174
 175         struct udev *udev = NULL;
 176         struct udev_device *device = NULL;
 177         struct stat st;
 178         char *description = NULL;
 179         const char *i;
 180
 181         assert(path);
 182
 183         if (stat(path, &st) < 0)
 184                 return NULL;
 185
 186         if (!S_ISBLK(st.st_mode))
 187                 return NULL;
 188
 189         udev = udev_new();
 190         if (!udev)
 191                 return NULL;
 192
 193         device = udev_device_new_from_devnum(udev, 'b', st.st_rdev);
 194         if (!device)
 195                 goto finish;
 196
 197         NULSTR_FOREACH(i, name_fields) {
 198                 const char *name;
 199
 200                 name = udev_device_get_property_value(device, i);
 201                 if (!isempty(name)) {
 202                         description = strdup(name);
 203                         break;
 204                 }
 205         }
 206
 207 finish:
 208         if (device)
 209                 udev_device_unref(device);
 210
 211         if (udev)
 212                 udev_unref(udev);
 213
 214         return description;
 215 }
 216
 217 static char *disk_mount_point(const char *label) {
 218         char *mp = NULL, *device = NULL;
 219         FILE *f = NULL;
 220         struct mntent *m;
 221
 222         /* Yeah, we don't support native systemd unit files here for now */
 223
 224         if (asprintf(&device, "/dev/mapper/%s", label) < 0)
 225                 goto finish;
 226
 227         f = setmntent("/etc/fstab", "r");
 228         if (!f)
 229                 goto finish;
 230
 231         while ((m = getmntent(f)))
 232                 if (path_equal(m->mnt_fsname, device)) {
 233                         mp = strdup(m->mnt_dir);
 234                         break;
 235                 }
 236
 237 finish:
 238         if (f)
 239                 endmntent(f);
 240
 241         free(device);
 242
 243         return mp;
 244 }
 245
 246 static int help(void) {
 247
 248         printf("%s attach VOLUME SOURCEDEVICE [PASSWORD] [OPTIONS]\n"
 249                "%s detach VOLUME\n\n"
 250                "Attaches or detaches an encrypted block device.\n",
 251                program_invocation_short_name,
 252                program_invocation_short_name);
 253
 254         return 0;
 255 }
 256
 257 int main(int argc, char *argv[]) {
 258         int r = EXIT_FAILURE;
 259         struct crypt_device *cd = NULL;
 260         char **passwords = NULL, *truncated_cipher = NULL;
 261         const char *cipher = NULL, *cipher_mode = NULL, *hash = NULL, *name = NULL;
 262         char *description = NULL, *name_buffer = NULL, *mount_point = NULL;
 263
 264         if (argc <= 1) {
 265                 help();
 266                 return EXIT_SUCCESS;
 267         }
 268
 269         if (argc < 3) {
 270                 log_error("This program requires at least two arguments.");
 271                 return EXIT_FAILURE;
 272         }
 273
 274         log_set_target(LOG_TARGET_AUTO);
 275         log_parse_environment();
 276         log_open();
 277
 278         umask(0022);
 279
 280         if (streq(argv[1], "attach")) {
 281                 uint32_t flags = 0;
 282                 int k;
 283                 unsigned try;
 284                 const char *key_file = NULL;
 285                 usec_t until;
 286                 crypt_status_info status;
 287
 288                 /* Arguments: systemd-cryptsetup attach VOLUME SOURCE-DEVICE [PASSWORD] [OPTIONS] */
 289
 290                 if (argc < 4) {
 291                         log_error("attach requires at least two arguments.");
 292                         goto finish;
 293                 }
 294
 295                 if (argc >= 5 &&
 296                     argv[4][0] &&
 297                     !streq(argv[4], "-") &&
 298                     !streq(argv[4], "none")) {
 299
 300                         if (!path_is_absolute(argv[4]))
 301                                 log_error("Password file path %s is not absolute. Ignoring.", argv[4]);
 302                         else
 303                                 key_file = argv[4];
 304                 }
 305
 306                 if (argc >= 6 && argv[5][0] && !streq(argv[5], "-")) {
 307                         if (parse_options(argv[5]) < 0)
 308                                 goto finish;
 309                 }
 310
 311                 /* A delicious drop of snake oil */
 312                 mlockall(MCL_FUTURE);
 313
 314                 description = disk_description(argv[3]);
 315                 mount_point = disk_mount_point(argv[2]);
 316
 317                 if (description && streq(argv[2], description)) {
 318                         /* If the description string is simply the
 319                          * volume name, then let's not show this
 320                          * twice */
 321                         free(description);
 322                         description = NULL;
 323                 }
 324
 325                 if (mount_point && description)
 326                         asprintf(&name_buffer, "%s (%s) on %s", description, argv[2], mount_point);
 327                 else if (mount_point)
 328                         asprintf(&name_buffer, "%s on %s", argv[2], mount_point);
 329                 else if (description)
 330                         asprintf(&name_buffer, "%s (%s)", description, argv[2]);
 331
 332                 name = name_buffer ? name_buffer : argv[2];
 333
 334                 k = crypt_init(&cd, argv[3]);
 335                 if (k) {
 336                         log_error("crypt_init() failed: %s", strerror(-k));
 337                         goto finish;
 338                 }
 339
 340                 crypt_set_log_callback(cd, log_glue, NULL);
 341
 342                 status = crypt_status(cd, argv[2]);
 343                 if (status == CRYPT_ACTIVE || status == CRYPT_BUSY) {
 344                         log_info("Volume %s already active.", argv[2]);
 345                         r = EXIT_SUCCESS;
 346                         goto finish;
 347                 }
 348
 349                 if (opt_readonly)
 350                         flags |= CRYPT_ACTIVATE_READONLY;
 351
 352                 if (opt_discards)
 353                         flags |= CRYPT_ACTIVATE_ALLOW_DISCARDS;
 354
 355                 if (opt_timeout > 0)
 356                         until = now(CLOCK_MONOTONIC) + opt_timeout;
 357                 else
 358                         until = 0;
 359
 360                 opt_tries = opt_tries > 0 ? opt_tries : 3;
 361                 opt_key_size = (opt_key_size > 0 ? opt_key_size : 256);
 362                 if (opt_hash) {
 363                         /* plain isn't a real hash type. it just means "use no hash" */
 364                         if (!streq(opt_hash, "plain"))
 365                                 hash = opt_hash;
 366                 } else
 367                         hash = "ripemd160";
 368
 369                 if (opt_cipher) {
 370                         size_t l;
 371
 372                         l = strcspn(opt_cipher, "-");
 373                         truncated_cipher = strndup(opt_cipher, l);
 374
 375                         if (!truncated_cipher) {
 376                                 log_oom();
 377                                 goto finish;
 378                         }
 379
 380                         cipher = truncated_cipher;
 381                         cipher_mode = opt_cipher[l] ? opt_cipher+l+1 : "plain";
 382                 } else {
 383                         cipher = "aes";
 384                         cipher_mode = "cbc-essiv:sha256";
 385                 }
 386
 387                 for (try = 0; try < opt_tries; try++) {
 388                         bool pass_volume_key = false;
 389
 390                         strv_free(passwords);
 391                         passwords = NULL;
 392
 393                         if (!key_file) {
 394                                 char *text, **p;
 395
 396                                 if (asprintf(&text, "Please enter passphrase for disk %s!", name) < 0) {
 397                                         log_oom();
 398                                         goto finish;
 399                                 }
 400
 401                                 k = ask_password_auto(text, "drive-harddisk", until, try == 0 && !opt_verify, &passwords);
 402                                 free(text);
 403
 404                                 if (k < 0) {
 405                                         log_error("Failed to query password: %s", strerror(-k));
 406                                         goto finish;
 407                                 }
 408
 409                                 if (opt_verify) {
 410                                         char **passwords2 = NULL;
 411
 412                                         assert(strv_length(passwords) == 1);
 413
 414                                         if (asprintf(&text, "Please enter passphrase for disk %s! (verification)", name) < 0) {
 415                                                 log_oom();
 416                                                 goto finish;
 417                                         }
 418
 419                                         k = ask_password_auto(text, "drive-harddisk", until, false, &passwords2);
 420                                         free(text);
 421
 422                                         if (k < 0) {
 423                                                 log_error("Failed to query verification password: %s", strerror(-k));
 424                                                 goto finish;
 425                                         }
 426
 427                                         assert(strv_length(passwords2) == 1);
 428
 429                                         if (!streq(passwords[0], passwords2[0])) {
 430                                                 log_warning("Passwords did not match, retrying.");
 431                                                 strv_free(passwords2);
 432                                                 continue;
 433                                         }
 434
 435                                         strv_free(passwords2);
 436                                 }
 437
 438                                 strv_uniq(passwords);
 439
 440                                 STRV_FOREACH(p, passwords) {
 441                                         char *c;
 442
 443                                         if (strlen(*p)+1 >= opt_key_size)
 444                                                 continue;
 445
 446                                         /* Pad password if necessary */
 447                                         if (!(c = new(char, opt_key_size))) {
 448                                                 log_oom();
 449                                                 goto finish;
 450                                         }
 451
 452                                         strncpy(c, *p, opt_key_size);
 453                                         free(*p);
 454                                         *p = c;
 455                                 }
 456                         }
 457
 458                         k = 0;
 459
 460                         if (!opt_type || streq(opt_type, CRYPT_LUKS1))
 461                                 k = crypt_load(cd, CRYPT_LUKS1, NULL);
 462
 463                         if ((!opt_type && k < 0) || streq_ptr(opt_type, CRYPT_PLAIN)) {
 464                                 struct crypt_params_plain params;
 465
 466                                 zero(params);
 467                                 params.hash = hash;
 468
 469                                 /* for CRYPT_PLAIN limit reads
 470                                 * from keyfile to key length, and
 471                                 * ignore keyfile-size */
 472                                 opt_keyfile_size = opt_key_size / 8;
 473
 474                                 /* In contrast to what the name
 475                                  * crypt_setup() might suggest this
 476                                  * doesn't actually format anything,
 477                                  * it just configures encryption
 478                                  * parameters when used for plain
 479                                  * mode. */
 480                                 k = crypt_format(cd, CRYPT_PLAIN,
 481                                                  cipher,
 482                                                  cipher_mode,
 483                                                  NULL,
 484                                                  NULL,
 485                                                  opt_keyfile_size,
 486                                                  &params);
 487
 488                                 /* hash == NULL implies the user passed "plain" */
 489                                 pass_volume_key = (hash == NULL);
 490                         }
 491
 492                         if (k < 0) {
 493                                 log_error("Loading of cryptographic parameters failed: %s", strerror(-k));
 494                                 goto finish;
 495                         }
 496
 497                         log_info("Set cipher %s, mode %s, key size %i bits for device %s.",
 498                                  crypt_get_cipher(cd),
 499                                  crypt_get_cipher_mode(cd),
 500                                  crypt_get_volume_key_size(cd)*8,
 501                                  argv[3]);
 502
 503                         if (key_file)
 504                                 k = crypt_activate_by_keyfile_offset(cd, argv[2], CRYPT_ANY_SLOT, key_file, opt_keyfile_size,
 505                                             opt_keyfile_offset, flags);
 506                         else {
 507                                 char **p;
 508
 509                                 STRV_FOREACH(p, passwords) {
 510
 511                                         if (pass_volume_key)
 512                                                 k = crypt_activate_by_volume_key(cd, argv[2], *p, opt_key_size, flags);
 513                                         else
 514                                                 k = crypt_activate_by_passphrase(cd, argv[2], CRYPT_ANY_SLOT, *p, strlen(*p), flags);
 515
 516                                         if (k >= 0)
 517                                                 break;
 518                                 }
 519                         }
 520
 521                         if (k >= 0)
 522                                 break;
 523
 524                         if (k != -EPERM) {
 525                                 log_error("Failed to activate: %s", strerror(-k));
 526                                 goto finish;
 527                         }
 528
 529                         log_warning("Invalid passphrase.");
 530                 }
 531
 532                 if (try >= opt_tries) {
 533                         log_error("Too many attempts.");
 534                         r = EXIT_FAILURE;
 535                         goto finish;
 536                 }
 537
 538         } else if (streq(argv[1], "detach")) {
 539                 int k;
 540
 541                 k = crypt_init_by_name(&cd, argv[2]);
 542                 if (k) {
 543                         log_error("crypt_init() failed: %s", strerror(-k));
 544                         goto finish;
 545                 }
 546
 547                 crypt_set_log_callback(cd, log_glue, NULL);
 548
 549                 k = crypt_deactivate(cd, argv[2]);
 550                 if (k < 0) {
 551                         log_error("Failed to deactivate: %s", strerror(-k));
 552                         goto finish;
 553                 }
 554
 555         } else {
 556                 log_error("Unknown verb %s.", argv[1]);
 557                 goto finish;
 558         }
 559
 560         r = EXIT_SUCCESS;
 561
 562 finish:
 563
 564         if (cd)
 565                 crypt_free(cd);
 566
 567         free(opt_cipher);
 568         free(opt_hash);
 569
 570         free(truncated_cipher);
 571
 572         strv_free(passwords);
 573
 574         free(description);
 575         free(mount_point);
 576         free(name_buffer);
 577
 578         return r;
 579 }