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