src/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 General Public License as published by
  10   the Free Software Foundation; either version 2 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   General Public License for more details.
  17
  18   You should have received a copy of the GNU 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
  26 #include <libcryptsetup.h>
  27 #include <libudev.h>
  28
  29 #include "log.h"
  30 #include "util.h"
  31 #include "ask-password-api.h"
  32
  33 static const char *opt_type = NULL; /* LUKS1 or PLAIN */
  34 static char *opt_cipher = NULL;
  35 static unsigned opt_key_size = 0;
  36 static char *opt_hash = NULL;
  37 static unsigned opt_tries = 0;
  38 static bool opt_readonly = false;
  39 static bool opt_verify = false;
  40 static usec_t opt_timeout = 0;
  41
  42 /* Options Debian's crypttab knows we don't:
  43
  44     offset=
  45     skip=
  46     precheck=
  47     check=
  48     checkargs=
  49     noearly=
  50     loud=
  51     keyscript=
  52 */
  53
  54 static int parse_one_option(const char *option) {
  55         assert(option);
  56
  57         /* Handled outside of this tool */
  58         if (streq(option, "noauto"))
  59                 return 0;
  60
  61         if (startswith(option, "cipher=")) {
  62                 char *t;
  63
  64                 if (!(t = strdup(option+7)))
  65                         return -ENOMEM;
  66
  67                 free(opt_cipher);
  68                 opt_cipher = t;
  69
  70         } else if (startswith(option, "size=")) {
  71
  72                 if (safe_atou(option+5, &opt_key_size) < 0) {
  73                         log_error("size= parse failure, ignoring.");
  74                         return 0;
  75                 }
  76
  77         } else if (startswith(option, "hash=")) {
  78                 char *t;
  79
  80                 if (!(t = strdup(option+5)))
  81                         return -ENOMEM;
  82
  83                 free(opt_hash);
  84                 opt_hash = t;
  85
  86         } else if (startswith(option, "tries=")) {
  87
  88                 if (safe_atou(option+6, &opt_tries) < 0) {
  89                         log_error("tries= parse failure, ignoring.");
  90                         return 0;
  91                 }
  92
  93         } else if (streq(option, "readonly"))
  94                 opt_readonly = true;
  95         else if (streq(option, "verify"))
  96                 opt_verify = true;
  97         else if (streq(option, "luks"))
  98                 opt_type = CRYPT_LUKS1;
  99         else if (streq(option, "plain") ||
 100                  streq(option, "swap") ||
 101                  streq(option, "tmp"))
 102                 opt_type = CRYPT_PLAIN;
 103         else if (startswith(option, "timeout=")) {
 104
 105                 if (parse_usec(option+8, &opt_timeout) < 0) {
 106                         log_error("timeout= parse failure, ignoring.");
 107                         return 0;
 108                 }
 109
 110         } else
 111                 log_error("Encountered unknown /etc/crypttab option '%s', ignoring.", option);
 112
 113         return 0;
 114 }
 115
 116 static int parse_options(const char *options) {
 117         char *state;
 118         char *w;
 119         size_t l;
 120
 121         assert(options);
 122
 123         FOREACH_WORD_SEPARATOR(w, l, options, ",", state) {
 124                 char *o;
 125                 int r;
 126
 127                 if (!(o = strndup(w, l)))
 128                         return -ENOMEM;
 129
 130                 r = parse_one_option(o);
 131                 free(o);
 132
 133                 if (r < 0)
 134                         return r;
 135         }
 136
 137         return 0;
 138 }
 139
 140 static void log_glue(int level, const char *msg, void *usrptr) {
 141         log_debug("%s", msg);
 142 }
 143
 144 static char *disk_description(const char *path) {
 145         struct udev *udev = NULL;
 146         struct udev_device *device = NULL;
 147         struct stat st;
 148         char *description = NULL;
 149         const char *model;
 150
 151         assert(path);
 152
 153         if (stat(path, &st) < 0)
 154                 return NULL;
 155
 156         if (!S_ISBLK(st.st_mode))
 157                 return NULL;
 158
 159         if (!(udev = udev_new()))
 160                 return NULL;
 161
 162         if (!(device = udev_device_new_from_devnum(udev, 'b', st.st_rdev)))
 163                 goto finish;
 164
 165         if ((model = udev_device_get_property_value(device, "ID_MODEL_FROM_DATABASE")) ||
 166             (model = udev_device_get_property_value(device, "ID_MODEL")))
 167                 description = strdup(model);
 168
 169 finish:
 170         if (device)
 171                 udev_device_unref(device);
 172
 173         if (udev)
 174                 udev_unref(udev);
 175
 176         return description;
 177 }
 178
 179 int main(int argc, char *argv[]) {
 180         int r = EXIT_FAILURE;
 181         struct crypt_device *cd = NULL;
 182         char *password = NULL, *truncated_cipher = NULL;
 183         const char *cipher = NULL, *cipher_mode = NULL, *hash = NULL, *name = NULL;
 184         char *description = NULL;
 185
 186         if (argc < 3) {
 187                 log_error("This program requires at least two arguments.");
 188                 return EXIT_FAILURE;
 189         }
 190
 191         log_set_target(LOG_TARGET_AUTO);
 192         log_parse_environment();
 193         log_open();
 194
 195         if (streq(argv[1], "attach")) {
 196                 uint32_t flags = 0;
 197                 int k;
 198                 unsigned try;
 199                 const char *key_file = NULL;
 200                 usec_t until;
 201                 crypt_status_info status;
 202
 203                 if (argc < 4) {
 204                         log_error("attach requires at least two arguments.");
 205                         goto finish;
 206                 }
 207
 208                 if (argc >= 5 &&
 209                     argv[4][0] &&
 210                     !streq(argv[4], "-") &&
 211                     !streq(argv[4], "none")) {
 212
 213                         if (!path_is_absolute(argv[4]))
 214                                 log_error("Password file path %s is not absolute. Ignoring.", argv[4]);
 215                         else
 216                                 key_file = argv[4];
 217                 }
 218
 219                 if (argc >= 6 && argv[5][0] && !streq(argv[5], "-"))
 220                         parse_options(argv[5]);
 221
 222                 /* A delicious drop of snake oil */
 223                 mlockall(MCL_FUTURE);
 224
 225                 description = disk_description(argv[3]);
 226                 name = description ? description : argv[2];
 227
 228                 if ((k = crypt_init(&cd, argv[3]))) {
 229                         log_error("crypt_init() failed: %s", strerror(-k));
 230                         goto finish;
 231                 }
 232
 233                 crypt_set_log_callback(cd, log_glue, NULL);
 234
 235                 status = crypt_status(cd, argv[2]);
 236                 if (status == CRYPT_ACTIVE || status == CRYPT_BUSY) {
 237                         log_info("Volume %s already active.", argv[2]);
 238                         r = EXIT_SUCCESS;
 239                         goto finish;
 240                 }
 241
 242                 if (opt_readonly)
 243                         flags |= CRYPT_ACTIVATE_READONLY;
 244
 245                 until = now(CLOCK_MONOTONIC) + (opt_timeout > 0 ? opt_timeout : 60 * USEC_PER_SEC);
 246
 247                 opt_tries = opt_tries > 0 ? opt_tries : 3;
 248                 opt_key_size = (opt_key_size > 0 ? opt_key_size : 256);
 249                 hash = opt_hash ? opt_hash : "ripemd160";
 250
 251                 if (opt_cipher) {
 252                         size_t l;
 253
 254                         l = strcspn(opt_cipher, "-");
 255
 256                         if (!(truncated_cipher = strndup(opt_cipher, l))) {
 257                                 log_error("Out of memory");
 258                                 goto finish;
 259                         }
 260
 261                         cipher = truncated_cipher;
 262                         cipher_mode = opt_cipher[l] ? opt_cipher+l+1 : "plain";
 263                 } else {
 264                         cipher = "aes";
 265                         cipher_mode = "cbc-essiv:sha256";
 266                 }
 267
 268                 for (try = 0; try < opt_tries; try++) {
 269                         bool pass_volume_key = false;
 270
 271                         free(password);
 272                         password = NULL;
 273
 274                         if (!key_file) {
 275                                 char *text;
 276
 277                                 if (asprintf(&text, "Please enter passphrase for disk %s!", name) < 0) {
 278                                         log_error("Out of memory");
 279                                         goto finish;
 280                                 }
 281
 282                                 k = ask_password_auto(text, "drive-harddisk", until, &password);
 283                                 free(text);
 284
 285                                 if (k < 0) {
 286                                         log_error("Failed to query password: %s", strerror(-k));
 287                                         goto finish;
 288                                 }
 289
 290                                 if (opt_verify) {
 291                                         char *password2 = NULL;
 292
 293                                         if (asprintf(&text, "Please enter passphrase for disk %s! (verification)", name) < 0) {
 294                                                 log_error("Out of memory");
 295                                                 goto finish;
 296                                         }
 297
 298                                         k = ask_password_auto(text, "drive-harddisk", until, &password2);
 299                                         free(text);
 300
 301                                         if (k < 0) {
 302                                                 log_error("Failed to query verification password: %s", strerror(-k));
 303                                                 goto finish;
 304                                         }
 305
 306                                         if (!streq(password, password2)) {
 307                                                 log_warning("Passwords did not match, retrying.");
 308                                                 free(password2);
 309                                                 continue;
 310                                         }
 311
 312                                         free(password2);
 313                                 }
 314
 315                                 if (strlen(password)+1 < opt_key_size) {
 316                                         char *c;
 317
 318                                         /* Pad password if necessary */
 319
 320                                         if (!(c = new(char, opt_key_size))) {
 321                                                 log_error("Out of memory.");
 322                                                 goto finish;
 323                                         }
 324
 325                                         strncpy(c, password, opt_key_size);
 326                                         free(password);
 327                                         password = c;
 328                                 }
 329                         }
 330
 331                         if (!opt_type || streq(opt_type, CRYPT_LUKS1))
 332                                 k = crypt_load(cd, CRYPT_LUKS1, NULL);
 333
 334                         if ((!opt_type && k < 0) || streq_ptr(opt_type, CRYPT_PLAIN)) {
 335                                 struct crypt_params_plain params;
 336
 337                                 zero(params);
 338                                 params.hash = hash;
 339
 340                                 /* In contrast to what the name
 341                                  * crypt_setup() might suggest this
 342                                  * doesn't actually format anything,
 343                                  * it just configures encryption
 344                                  * parameters when used for plain
 345                                  * mode. */
 346                                 k = crypt_format(cd, CRYPT_PLAIN,
 347                                                  cipher,
 348                                                  cipher_mode,
 349                                                  NULL,
 350                                                  NULL,
 351                                                  opt_key_size / 8,
 352                                                  &params);
 353
 354                                 pass_volume_key = streq(hash, "plain");
 355                         }
 356
 357                         if (k < 0) {
 358                                 log_error("Loading of cryptographic parameters failed: %s", strerror(-k));
 359                                 goto finish;
 360                         }
 361
 362                         log_info("Set cipher %s, mode %s, key size %i bits for device %s.",
 363                                  crypt_get_cipher(cd),
 364                                  crypt_get_cipher_mode(cd),
 365                                  crypt_get_volume_key_size(cd)*8,
 366                                  argv[3]);
 367
 368                         if (key_file)
 369                                 k = crypt_activate_by_keyfile(cd, argv[2], CRYPT_ANY_SLOT, key_file, opt_key_size, flags);
 370                         else if (pass_volume_key)
 371                                 k = crypt_activate_by_volume_key(cd, argv[2], password, opt_key_size, flags);
 372                         else
 373                                 k = crypt_activate_by_passphrase(cd, argv[2], CRYPT_ANY_SLOT, password, strlen(password), flags);
 374
 375                         if (k >= 0)
 376                                 break;
 377
 378                         if (k != -EPERM) {
 379                                 log_error("Failed to activate: %s", strerror(-k));
 380                                 goto finish;
 381                         }
 382
 383                         log_warning("Invalid passphrase.");
 384                 }
 385
 386                 if (try >= opt_tries) {
 387                         log_error("Too many attempts.");
 388                         r = EXIT_FAILURE;
 389                         goto finish;
 390                 }
 391
 392         } else if (streq(argv[1], "detach")) {
 393                 int k;
 394
 395                 if ((k = crypt_init_by_name(&cd, argv[2]))) {
 396                         log_error("crypt_init() failed: %s", strerror(-k));
 397                         goto finish;
 398                 }
 399
 400                 crypt_set_log_callback(cd, log_glue, NULL);
 401
 402                 if ((k = crypt_deactivate(cd, argv[2])) < 0) {
 403                         log_error("Failed to deactivate: %s", strerror(-k));
 404                         goto finish;
 405                 }
 406
 407         } else {
 408                 log_error("Unknown verb %s.", argv[1]);
 409                 goto finish;
 410         }
 411
 412         r = EXIT_SUCCESS;
 413
 414 finish:
 415
 416         if (cd)
 417                 crypt_free(cd);
 418
 419         free(opt_cipher);
 420         free(opt_hash);
 421
 422         free(truncated_cipher);
 423
 424         free(password);
 425
 426         free(description);
 427
 428         return r;
 429 }