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 "strv.h"
  32 #include "ask-password-api.h"
  33
  34 static const char *opt_type = NULL; /* LUKS1 or PLAIN */
  35 static char *opt_cipher = NULL;
  36 static unsigned opt_key_size = 0;
  37 static char *opt_hash = NULL;
  38 static unsigned opt_tries = 0;
  39 static bool opt_readonly = false;
  40 static bool opt_verify = false;
  41 static usec_t opt_timeout = 0;
  42
  43 /* Options Debian's crypttab knows we don't:
  44
  45     offset=
  46     skip=
  47     precheck=
  48     check=
  49     checkargs=
  50     noearly=
  51     loud=
  52     keyscript=
  53 */
  54
  55 static int parse_one_option(const char *option) {
  56         assert(option);
  57
  58         /* Handled outside of this tool */
  59         if (streq(option, "noauto"))
  60                 return 0;
  61
  62         if (startswith(option, "cipher=")) {
  63                 char *t;
  64
  65                 if (!(t = strdup(option+7)))
  66                         return -ENOMEM;
  67
  68                 free(opt_cipher);
  69                 opt_cipher = t;
  70
  71         } else if (startswith(option, "size=")) {
  72
  73                 if (safe_atou(option+5, &opt_key_size) < 0) {
  74                         log_error("size= parse failure, ignoring.");
  75                         return 0;
  76                 }
  77
  78         } else if (startswith(option, "hash=")) {
  79                 char *t;
  80
  81                 if (!(t = strdup(option+5)))
  82                         return -ENOMEM;
  83
  84                 free(opt_hash);
  85                 opt_hash = t;
  86
  87         } else if (startswith(option, "tries=")) {
  88
  89                 if (safe_atou(option+6, &opt_tries) < 0) {
  90                         log_error("tries= parse failure, ignoring.");
  91                         return 0;
  92                 }
  93
  94         } else if (streq(option, "readonly"))
  95                 opt_readonly = true;
  96         else if (streq(option, "verify"))
  97                 opt_verify = true;
  98         else if (streq(option, "luks"))
  99                 opt_type = CRYPT_LUKS1;
 100         else if (streq(option, "plain") ||
 101                  streq(option, "swap") ||
 102                  streq(option, "tmp"))
 103                 opt_type = CRYPT_PLAIN;
 104         else if (startswith(option, "timeout=")) {
 105
 106                 if (parse_usec(option+8, &opt_timeout) < 0) {
 107                         log_error("timeout= parse failure, ignoring.");
 108                         return 0;
 109                 }
 110
 111         } else
 112                 log_error("Encountered unknown /etc/crypttab option '%s', ignoring.", option);
 113
 114         return 0;
 115 }
 116
 117 static int parse_options(const char *options) {
 118         char *state;
 119         char *w;
 120         size_t l;
 121
 122         assert(options);
 123
 124         FOREACH_WORD_SEPARATOR(w, l, options, ",", state) {
 125                 char *o;
 126                 int r;
 127
 128                 if (!(o = strndup(w, l)))
 129                         return -ENOMEM;
 130
 131                 r = parse_one_option(o);
 132                 free(o);
 133
 134                 if (r < 0)
 135                         return r;
 136         }
 137
 138         return 0;
 139 }
 140
 141 static void log_glue(int level, const char *msg, void *usrptr) {
 142         log_debug("%s", msg);
 143 }
 144
 145 static char *disk_description(const char *path) {
 146         struct udev *udev = NULL;
 147         struct udev_device *device = NULL;
 148         struct stat st;
 149         char *description = NULL;
 150         const char *model;
 151
 152         assert(path);
 153
 154         if (stat(path, &st) < 0)
 155                 return NULL;
 156
 157         if (!S_ISBLK(st.st_mode))
 158                 return NULL;
 159
 160         if (!(udev = udev_new()))
 161                 return NULL;
 162
 163         if (!(device = udev_device_new_from_devnum(udev, 'b', st.st_rdev)))
 164                 goto finish;
 165
 166         if ((model = udev_device_get_property_value(device, "ID_MODEL_FROM_DATABASE")) ||
 167             (model = udev_device_get_property_value(device, "ID_MODEL")))
 168                 description = strdup(model);
 169
 170 finish:
 171         if (device)
 172                 udev_device_unref(device);
 173
 174         if (udev)
 175                 udev_unref(udev);
 176
 177         return description;
 178 }
 179
 180 int main(int argc, char *argv[]) {
 181         int r = EXIT_FAILURE;
 182         struct crypt_device *cd = NULL;
 183         char **passwords = NULL, *truncated_cipher = NULL;
 184         const char *cipher = NULL, *cipher_mode = NULL, *hash = NULL, *name = NULL;
 185         char *description = NULL;
 186
 187         if (argc < 3) {
 188                 log_error("This program requires at least two arguments.");
 189                 return EXIT_FAILURE;
 190         }
 191
 192         log_set_target(LOG_TARGET_AUTO);
 193         log_parse_environment();
 194         log_open();
 195
 196         if (streq(argv[1], "attach")) {
 197                 uint32_t flags = 0;
 198                 int k;
 199                 unsigned try;
 200                 const char *key_file = NULL;
 201                 usec_t until;
 202                 crypt_status_info status;
 203
 204                 if (argc < 4) {
 205                         log_error("attach requires at least two arguments.");
 206                         goto finish;
 207                 }
 208
 209                 if (argc >= 5 &&
 210                     argv[4][0] &&
 211                     !streq(argv[4], "-") &&
 212                     !streq(argv[4], "none")) {
 213
 214                         if (!path_is_absolute(argv[4]))
 215                                 log_error("Password file path %s is not absolute. Ignoring.", argv[4]);
 216                         else
 217                                 key_file = argv[4];
 218                 }
 219
 220                 if (argc >= 6 && argv[5][0] && !streq(argv[5], "-"))
 221                         parse_options(argv[5]);
 222
 223                 /* A delicious drop of snake oil */
 224                 mlockall(MCL_FUTURE);
 225
 226                 description = disk_description(argv[3]);
 227                 name = description ? description : argv[2];
 228
 229                 if ((k = crypt_init(&cd, argv[3]))) {
 230                         log_error("crypt_init() failed: %s", strerror(-k));
 231                         goto finish;
 232                 }
 233
 234                 crypt_set_log_callback(cd, log_glue, NULL);
 235
 236                 status = crypt_status(cd, argv[2]);
 237                 if (status == CRYPT_ACTIVE || status == CRYPT_BUSY) {
 238                         log_info("Volume %s already active.", argv[2]);
 239                         r = EXIT_SUCCESS;
 240                         goto finish;
 241                 }
 242
 243                 if (opt_readonly)
 244                         flags |= CRYPT_ACTIVATE_READONLY;
 245
 246                 until = now(CLOCK_MONOTONIC) + (opt_timeout > 0 ? opt_timeout : 60 * USEC_PER_SEC);
 247
 248                 opt_tries = opt_tries > 0 ? opt_tries : 3;
 249                 opt_key_size = (opt_key_size > 0 ? opt_key_size : 256);
 250                 hash = opt_hash ? opt_hash : "ripemd160";
 251
 252                 if (opt_cipher) {
 253                         size_t l;
 254
 255                         l = strcspn(opt_cipher, "-");
 256
 257                         if (!(truncated_cipher = strndup(opt_cipher, l))) {
 258                                 log_error("Out of memory");
 259                                 goto finish;
 260                         }
 261
 262                         cipher = truncated_cipher;
 263                         cipher_mode = opt_cipher[l] ? opt_cipher+l+1 : "plain";
 264                 } else {
 265                         cipher = "aes";
 266                         cipher_mode = "cbc-essiv:sha256";
 267                 }
 268
 269                 for (try = 0; try < opt_tries; try++) {
 270                         bool pass_volume_key = false;
 271
 272                         strv_free(passwords);
 273                         passwords = NULL;
 274
 275                         if (!key_file) {
 276                                 char *text;
 277                                 char **p;
 278
 279                                 if (asprintf(&text, "Please enter passphrase for disk %s!", name) < 0) {
 280                                         log_error("Out of memory");
 281                                         goto finish;
 282                                 }
 283
 284                                 k = ask_password_auto(text, "drive-harddisk", until, try == 0 && !opt_verify, &passwords);
 285                                 free(text);
 286
 287                                 if (k < 0) {
 288                                         log_error("Failed to query password: %s", strerror(-k));
 289                                         goto finish;
 290                                 }
 291
 292                                 if (opt_verify) {
 293                                         char **passwords2 = NULL;
 294
 295                                         assert(strv_length(passwords) == 1);
 296
 297                                         if (asprintf(&text, "Please enter passphrase for disk %s! (verification)", name) < 0) {
 298                                                 log_error("Out of memory");
 299                                                 goto finish;
 300                                         }
 301
 302                                         k = ask_password_auto(text, "drive-harddisk", until, false, &passwords2);
 303                                         free(text);
 304
 305                                         if (k < 0) {
 306                                                 log_error("Failed to query verification password: %s", strerror(-k));
 307                                                 goto finish;
 308                                         }
 309
 310                                         assert(strv_length(passwords2) == 1);
 311
 312                                         if (!streq(passwords[0], passwords2[0])) {
 313                                                 log_warning("Passwords did not match, retrying.");
 314                                                 strv_free(passwords2);
 315                                                 continue;
 316                                         }
 317
 318                                         strv_free(passwords2);
 319                                 }
 320
 321                                 STRV_FOREACH(p, passwords) {
 322                                         char *c;
 323
 324                                         if (strlen(*p)+1 >= opt_key_size)
 325                                                 continue;
 326
 327                                         /* Pad password if necessary */
 328                                         if (!(c = new(char, opt_key_size))) {
 329                                                 log_error("Out of memory.");
 330                                                 goto finish;
 331                                         }
 332
 333                                         strncpy(c, *p, opt_key_size);
 334                                         free(*p);
 335                                         *p = c;
 336                                 }
 337                         }
 338
 339                         if (!opt_type || streq(opt_type, CRYPT_LUKS1))
 340                                 k = crypt_load(cd, CRYPT_LUKS1, NULL);
 341
 342                         if ((!opt_type && k < 0) || streq_ptr(opt_type, CRYPT_PLAIN)) {
 343                                 struct crypt_params_plain params;
 344
 345                                 zero(params);
 346                                 params.hash = hash;
 347
 348                                 /* In contrast to what the name
 349                                  * crypt_setup() might suggest this
 350                                  * doesn't actually format anything,
 351                                  * it just configures encryption
 352                                  * parameters when used for plain
 353                                  * mode. */
 354                                 k = crypt_format(cd, CRYPT_PLAIN,
 355                                                  cipher,
 356                                                  cipher_mode,
 357                                                  NULL,
 358                                                  NULL,
 359                                                  opt_key_size / 8,
 360                                                  &params);
 361
 362                                 pass_volume_key = streq(hash, "plain");
 363                         }
 364
 365                         if (k < 0) {
 366                                 log_error("Loading of cryptographic parameters failed: %s", strerror(-k));
 367                                 goto finish;
 368                         }
 369
 370                         log_info("Set cipher %s, mode %s, key size %i bits for device %s.",
 371                                  crypt_get_cipher(cd),
 372                                  crypt_get_cipher_mode(cd),
 373                                  crypt_get_volume_key_size(cd)*8,
 374                                  argv[3]);
 375
 376                         if (key_file)
 377                                 k = crypt_activate_by_keyfile(cd, argv[2], CRYPT_ANY_SLOT, key_file, opt_key_size, flags);
 378                         else {
 379                                 char **p;
 380
 381                                 STRV_FOREACH(p, passwords) {
 382
 383                                         if (pass_volume_key)
 384                                                 k = crypt_activate_by_volume_key(cd, argv[2], *p, opt_key_size, flags);
 385                                         else
 386                                                 k = crypt_activate_by_passphrase(cd, argv[2], CRYPT_ANY_SLOT, *p, strlen(*p), flags);
 387
 388                                         if (k >= 0)
 389                                                 break;
 390                                 }
 391                         }
 392
 393                         if (k >= 0)
 394                                 break;
 395
 396                         if (k != -EPERM) {
 397                                 log_error("Failed to activate: %s", strerror(-k));
 398                                 goto finish;
 399                         }
 400
 401                         log_warning("Invalid passphrase.");
 402                 }
 403
 404                 if (try >= opt_tries) {
 405                         log_error("Too many attempts.");
 406                         r = EXIT_FAILURE;
 407                         goto finish;
 408                 }
 409
 410         } else if (streq(argv[1], "detach")) {
 411                 int k;
 412
 413                 if ((k = crypt_init_by_name(&cd, argv[2]))) {
 414                         log_error("crypt_init() failed: %s", strerror(-k));
 415                         goto finish;
 416                 }
 417
 418                 crypt_set_log_callback(cd, log_glue, NULL);
 419
 420                 if ((k = crypt_deactivate(cd, argv[2])) < 0) {
 421                         log_error("Failed to deactivate: %s", strerror(-k));
 422                         goto finish;
 423                 }
 424
 425         } else {
 426                 log_error("Unknown verb %s.", argv[1]);
 427                 goto finish;
 428         }
 429
 430         r = EXIT_SUCCESS;
 431
 432 finish:
 433
 434         if (cd)
 435                 crypt_free(cd);
 436
 437         free(opt_cipher);
 438         free(opt_hash);
 439
 440         free(truncated_cipher);
 441
 442         strv_free(passwords);
 443
 444         free(description);
 445
 446         return r;
 447 }