lib/luks1/keymanage.c

   1 /*
   2  * LUKS - Linux Unified Key Setup
   3  *
   4  * Copyright (C) 2004-2006, Clemens Fruhwirth <clemens@endorphin.org>
   5  * Copyright (C) 2009-2012, Red Hat, Inc. All rights reserved.
   6  *
   7  * This program is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License
   9  * version 2 as published by the Free Software Foundation.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19  */
  20
  21 #include <sys/types.h>
  22 #include <sys/stat.h>
  23 #include <netinet/in.h>
  24 #include <fcntl.h>
  25 #include <errno.h>
  26 #include <unistd.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <string.h>
  30 #include <ctype.h>
  31 #include <assert.h>
  32 #include <uuid/uuid.h>
  33
  34 #include "luks.h"
  35 #include "af.h"
  36 #include "pbkdf.h"
  37 #include "internal.h"
  38
  39 #define div_round_up(a,b) ({           \
  40         typeof(a) __a = (a);          \
  41         typeof(b) __b = (b);          \
  42         (__a - 1) / __b + 1;        \
  43 })
  44
  45 static inline int round_up_modulo(int x, int m) {
  46         return div_round_up(x, m) * m;
  47 }
  48
  49 /* Get size of struct luks_phrd with all keyslots material space */
  50 static uint64_t LUKS_device_sectors(size_t keyLen, unsigned int stripes)
  51 {
  52         uint64_t keyslot_sectors, sector;
  53         int i;
  54
  55         keyslot_sectors = div_round_up(keyLen * stripes, SECTOR_SIZE);
  56         sector = round_up_modulo(LUKS_PHDR_SIZE, LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE);
  57
  58         for (i = 0; i < LUKS_NUMKEYS; i++) {
  59                 sector = round_up_modulo(sector, LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE);
  60                 sector += keyslot_sectors;
  61         }
  62
  63         return sector;
  64 }
  65
  66 static int LUKS_check_device_size(const char *device,
  67                                   uint64_t min_sectors,
  68                                   size_t keyLength)
  69 {
  70         uint64_t dev_size, req_sectors;
  71
  72         req_sectors = LUKS_device_sectors(keyLength, LUKS_STRIPES);
  73         if (min_sectors > req_sectors)
  74                 req_sectors = min_sectors;
  75
  76         if(device_size(device, &dev_size)) {
  77                 log_dbg("Cannot get device size for device %s.", device);
  78                 return -EIO;
  79         }
  80
  81         return (req_sectors > (dev_size >> SECTOR_SHIFT));
  82 }
  83
  84 /* Check keyslot to prevent access outside of header and keyslot area */
  85 static int LUKS_check_keyslot_size(const struct luks_phdr *phdr, unsigned int keyIndex)
  86 {
  87         uint32_t secs_per_stripes;
  88
  89         /* First sectors is the header itself */
  90         if (phdr->keyblock[keyIndex].keyMaterialOffset * SECTOR_SIZE < sizeof(*phdr)) {
  91                 log_dbg("Invalid offset %u in keyslot %u.",
  92                         phdr->keyblock[keyIndex].keyMaterialOffset, keyIndex);
  93                 return 1;
  94         }
  95
  96         /* Ignore following check for detached header where offset can be zero. */
  97         if (phdr->payloadOffset == 0)
  98                 return 0;
  99
 100         if (phdr->payloadOffset <= phdr->keyblock[keyIndex].keyMaterialOffset) {
 101                 log_dbg("Invalid offset %u in keyslot %u (beyond data area offset %u).",
 102                         phdr->keyblock[keyIndex].keyMaterialOffset, keyIndex,
 103                         phdr->payloadOffset);
 104                 return 1;
 105         }
 106
 107         secs_per_stripes = div_round_up(phdr->keyBytes * phdr->keyblock[keyIndex].stripes, SECTOR_SIZE);
 108
 109         if (phdr->payloadOffset < (phdr->keyblock[keyIndex].keyMaterialOffset + secs_per_stripes)) {
 110                 log_dbg("Invalid keyslot size %u (offset %u, stripes %u) in "
 111                         "keyslot %u (beyond data area offset %u).",
 112                         secs_per_stripes,
 113                         phdr->keyblock[keyIndex].keyMaterialOffset,
 114                         phdr->keyblock[keyIndex].stripes,
 115                         keyIndex, phdr->payloadOffset);
 116                 return 1;
 117         }
 118
 119         return 0;
 120 }
 121
 122 static const char *dbg_slot_state(crypt_keyslot_info ki)
 123 {
 124         switch(ki) {
 125         case CRYPT_SLOT_INACTIVE:
 126                 return "INACTIVE";
 127         case CRYPT_SLOT_ACTIVE:
 128                 return "ACTIVE";
 129         case CRYPT_SLOT_ACTIVE_LAST:
 130                 return "ACTIVE_LAST";
 131         case CRYPT_SLOT_INVALID:
 132         default:
 133                 return "INVALID";
 134         }
 135 }
 136
 137 int LUKS_hdr_backup(
 138         const char *backup_file,
 139         const char *device,
 140         struct luks_phdr *hdr,
 141         struct crypt_device *ctx)
 142 {
 143         int r = 0, devfd = -1;
 144         ssize_t buffer_size;
 145         char *buffer = NULL;
 146         struct stat st;
 147
 148         if(stat(backup_file, &st) == 0) {
 149                 log_err(ctx, _("Requested file %s already exist.\n"), backup_file);
 150                 return -EINVAL;
 151         }
 152
 153         r = LUKS_read_phdr(device, hdr, 1, 0, ctx);
 154         if (r)
 155                 return r;
 156
 157         buffer_size = hdr->payloadOffset << SECTOR_SHIFT;
 158         buffer = crypt_safe_alloc(buffer_size);
 159         if (!buffer || buffer_size < LUKS_ALIGN_KEYSLOTS) {
 160                 r = -ENOMEM;
 161                 goto out;
 162         }
 163
 164         log_dbg("Storing backup of header (%u bytes) and keyslot area (%u bytes).",
 165                 sizeof(*hdr), buffer_size - LUKS_ALIGN_KEYSLOTS);
 166
 167         devfd = open(device, O_RDONLY | O_DIRECT | O_SYNC);
 168         if(devfd == -1) {
 169                 log_err(ctx, _("Device %s is not a valid LUKS device.\n"), device);
 170                 r = -EINVAL;
 171                 goto out;
 172         }
 173
 174         if(read_blockwise(devfd, buffer, buffer_size) < buffer_size) {
 175                 r = -EIO;
 176                 goto out;
 177         }
 178         close(devfd);
 179
 180         /* Wipe unused area, so backup cannot contain old signatures */
 181         memset(buffer + sizeof(*hdr), 0, LUKS_ALIGN_KEYSLOTS - sizeof(*hdr));
 182
 183         devfd = creat(backup_file, S_IRUSR);
 184         if(devfd == -1) {
 185                 r = -EINVAL;
 186                 goto out;
 187         }
 188         if(write(devfd, buffer, buffer_size) < buffer_size) {
 189                 log_err(ctx, _("Cannot write header backup file %s.\n"), backup_file);
 190                 r = -EIO;
 191                 goto out;
 192         }
 193         close(devfd);
 194
 195         r = 0;
 196 out:
 197         if (devfd != -1)
 198                 close(devfd);
 199         crypt_safe_free(buffer);
 200         return r;
 201 }
 202
 203 int LUKS_hdr_restore(
 204         const char *backup_file,
 205         const char *device,
 206         struct luks_phdr *hdr,
 207         struct crypt_device *ctx)
 208 {
 209         int r = 0, devfd = -1, diff_uuid = 0;
 210         ssize_t buffer_size;
 211         char *buffer = NULL, msg[200];
 212         struct stat st;
 213         struct luks_phdr hdr_file;
 214
 215         if(stat(backup_file, &st) < 0) {
 216                 log_err(ctx, _("Backup file %s doesn't exist.\n"), backup_file);
 217                 return -EINVAL;
 218         }
 219
 220         r = LUKS_read_phdr_backup(backup_file, device, &hdr_file, 0, ctx);
 221         if (!r)
 222                 buffer_size = hdr_file.payloadOffset << SECTOR_SHIFT;
 223
 224         if (r || buffer_size < LUKS_ALIGN_KEYSLOTS) {
 225                 log_err(ctx, _("Backup file doesn't contain valid LUKS header.\n"));
 226                 r = -EINVAL;
 227                 goto out;
 228         }
 229
 230         buffer = crypt_safe_alloc(buffer_size);
 231         if (!buffer) {
 232                 r = -ENOMEM;
 233                 goto out;
 234         }
 235
 236         devfd = open(backup_file, O_RDONLY);
 237         if(devfd == -1) {
 238                 log_err(ctx, _("Cannot open header backup file %s.\n"), backup_file);
 239                 r = -EINVAL;
 240                 goto out;
 241         }
 242
 243         if(read(devfd, buffer, buffer_size) < buffer_size) {
 244                 log_err(ctx, _("Cannot read header backup file %s.\n"), backup_file);
 245                 r = -EIO;
 246                 goto out;
 247         }
 248         close(devfd);
 249
 250         r = LUKS_read_phdr(device, hdr, 0, 0, ctx);
 251         if (r == 0) {
 252                 log_dbg("Device %s already contains LUKS header, checking UUID and offset.", device);
 253                 if(hdr->payloadOffset != hdr_file.payloadOffset ||
 254                    hdr->keyBytes != hdr_file.keyBytes) {
 255                         log_err(ctx, _("Data offset or key size differs on device and backup, restore failed.\n"));
 256                         r = -EINVAL;
 257                         goto out;
 258                 }
 259                 if (memcmp(hdr->uuid, hdr_file.uuid, UUID_STRING_L))
 260                         diff_uuid = 1;
 261         }
 262
 263         if (snprintf(msg, sizeof(msg), _("Device %s %s%s"), device,
 264                  r ? _("does not contain LUKS header. Replacing header can destroy data on that device.") :
 265                      _("already contains LUKS header. Replacing header will destroy existing keyslots."),
 266                      diff_uuid ? _("\nWARNING: real device header has different UUID than backup!") : "") < 0) {
 267                 r = -ENOMEM;
 268                 goto out;
 269         }
 270
 271         if (!crypt_confirm(ctx, msg)) {
 272                 r = -EINVAL;
 273                 goto out;
 274         }
 275
 276         log_dbg("Storing backup of header (%u bytes) and keyslot area (%u bytes) to device %s.",
 277                 sizeof(*hdr), buffer_size - LUKS_ALIGN_KEYSLOTS, device);
 278
 279         devfd = open(device, O_WRONLY | O_DIRECT | O_SYNC);
 280         if(devfd == -1) {
 281                 log_err(ctx, _("Cannot open device %s.\n"), device);
 282                 r = -EINVAL;
 283                 goto out;
 284         }
 285
 286         if(write_blockwise(devfd, buffer, buffer_size) < buffer_size) {
 287                 r = -EIO;
 288                 goto out;
 289         }
 290         close(devfd);
 291
 292         /* Be sure to reload new data */
 293         r = LUKS_read_phdr(device, hdr, 1, 0, ctx);
 294 out:
 295         if (devfd != -1)
 296                 close(devfd);
 297         crypt_safe_free(buffer);
 298         return r;
 299 }
 300
 301 /* This routine should do some just basic recovery for known problems. */
 302 static int _keyslot_repair(const char *device, struct luks_phdr *phdr, struct crypt_device *ctx)
 303 {
 304         struct luks_phdr temp_phdr;
 305         const unsigned char *sector = (const unsigned char*)phdr;
 306         struct volume_key *vk;
 307         uint64_t PBKDF2_per_sec = 1;
 308         int i, bad, r, need_write = 0;
 309
 310         if (phdr->keyBytes != 16 && phdr->keyBytes != 32) {
 311                 log_err(ctx, _("Non standard key size, manual repair required.\n"));
 312                 return -EINVAL;
 313         }
 314         /* cryptsetup 1.0 did not align to 4k, cannot repair this one */
 315         if (phdr->keyblock[0].keyMaterialOffset < (LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE)) {
 316                 log_err(ctx, _("Non standard keyslots alignment, manual repair required.\n"));
 317                 return -EINVAL;
 318         }
 319
 320         vk = crypt_alloc_volume_key(phdr->keyBytes, NULL);
 321
 322         log_verbose(ctx, _("Repairing keyslots.\n"));
 323
 324         log_dbg("Generating second header with the same parameters for check.");
 325         /* cipherName, cipherMode, hashSpec, uuid are already null terminated */
 326         /* payloadOffset - cannot check */
 327         r = LUKS_generate_phdr(&temp_phdr, vk, phdr->cipherName, phdr->cipherMode,
 328                                phdr->hashSpec,phdr->uuid, LUKS_STRIPES,
 329                                phdr->payloadOffset, 0,
 330                                1, &PBKDF2_per_sec,
 331                                "/dev/null", ctx);
 332         if (r < 0) {
 333                 log_err(ctx, _("Repair failed."));
 334                 goto out;
 335         }
 336
 337         for(i = 0; i < LUKS_NUMKEYS; ++i) {
 338                 if (phdr->keyblock[i].active == LUKS_KEY_ENABLED)  {
 339                         log_dbg("Skipping repair for active keyslot %i.", i);
 340                         continue;
 341                 }
 342
 343                 bad = 0;
 344                 if (phdr->keyblock[i].keyMaterialOffset != temp_phdr.keyblock[i].keyMaterialOffset) {
 345                         log_err(ctx, _("Keyslot %i: offset repaired (%u -> %u).\n"), i,
 346                                 (unsigned)phdr->keyblock[i].keyMaterialOffset,
 347                                 (unsigned)temp_phdr.keyblock[i].keyMaterialOffset);
 348                         phdr->keyblock[i].keyMaterialOffset = temp_phdr.keyblock[i].keyMaterialOffset;
 349                         bad = 1;
 350                 }
 351
 352                 if (phdr->keyblock[i].stripes != temp_phdr.keyblock[i].stripes) {
 353                         log_err(ctx, _("Keyslot %i: stripes repaired (%u -> %u).\n"), i,
 354                                 (unsigned)phdr->keyblock[i].stripes,
 355                                 (unsigned)temp_phdr.keyblock[i].stripes);
 356                         phdr->keyblock[i].stripes = temp_phdr.keyblock[i].stripes;
 357                         bad = 1;
 358                 }
 359
 360                 /* Known case - MSDOS partition table signature */
 361                 if (i == 6 && sector[0x1fe] == 0x55 && sector[0x1ff] == 0xaa) {
 362                         log_err(ctx, _("Keyslot %i: bogus partition signature.\n"), i);
 363                         bad = 1;
 364                 }
 365
 366                 if(bad) {
 367                         log_err(ctx, _("Keyslot %i: salt wiped.\n"), i);
 368                         phdr->keyblock[i].active = LUKS_KEY_DISABLED;
 369                         memset(&phdr->keyblock[i].passwordSalt, 0x00, LUKS_SALTSIZE);
 370                         phdr->keyblock[i].passwordIterations = 0;
 371                 }
 372
 373                 if (bad)
 374                         need_write = 1;
 375         }
 376
 377         if (need_write) {
 378                 log_verbose(ctx, _("Writing LUKS header to disk.\n"));
 379                 r = LUKS_write_phdr(device, phdr, ctx);
 380         }
 381 out:
 382         crypt_free_volume_key(vk);
 383         memset(&temp_phdr, 0, sizeof(temp_phdr));
 384         return r;
 385 }
 386
 387 static int _check_and_convert_hdr(const char *device,
 388                                   struct luks_phdr *hdr,
 389                                   int require_luks_device,
 390                                   int repair,
 391                                   struct crypt_device *ctx)
 392 {
 393         int r = 0;
 394         unsigned int i;
 395         char luksMagic[] = LUKS_MAGIC;
 396
 397         if(memcmp(hdr->magic, luksMagic, LUKS_MAGIC_L)) { /* Check magic */
 398                 log_dbg("LUKS header not detected.");
 399                 if (require_luks_device)
 400                         log_err(ctx, _("Device %s is not a valid LUKS device.\n"), device);
 401                 return -EINVAL;
 402         } else if((hdr->version = ntohs(hdr->version)) != 1) {  /* Convert every uint16/32_t item from network byte order */
 403                 log_err(ctx, _("Unsupported LUKS version %d.\n"), hdr->version);
 404                 return -EINVAL;
 405         }
 406
 407         hdr->hashSpec[LUKS_HASHSPEC_L - 1] = '\0';
 408         if (PBKDF2_HMAC_ready(hdr->hashSpec) < 0) {
 409                 log_err(ctx, _("Requested LUKS hash %s is not supported.\n"), hdr->hashSpec);
 410                 return -EINVAL;
 411         }
 412
 413         /* Header detected */
 414         hdr->payloadOffset      = ntohl(hdr->payloadOffset);
 415         hdr->keyBytes           = ntohl(hdr->keyBytes);
 416         hdr->mkDigestIterations = ntohl(hdr->mkDigestIterations);
 417
 418         for(i = 0; i < LUKS_NUMKEYS; ++i) {
 419                 hdr->keyblock[i].active             = ntohl(hdr->keyblock[i].active);
 420                 hdr->keyblock[i].passwordIterations = ntohl(hdr->keyblock[i].passwordIterations);
 421                 hdr->keyblock[i].keyMaterialOffset  = ntohl(hdr->keyblock[i].keyMaterialOffset);
 422                 hdr->keyblock[i].stripes            = ntohl(hdr->keyblock[i].stripes);
 423                 if (LUKS_check_keyslot_size(hdr, i)) {
 424                         log_err(ctx, _("LUKS keyslot %u is invalid.\n"), i);
 425                         r = -EINVAL;
 426                 }
 427         }
 428
 429         /* Avoid unterminated strings */
 430         hdr->cipherName[LUKS_CIPHERNAME_L - 1] = '\0';
 431         hdr->cipherMode[LUKS_CIPHERMODE_L - 1] = '\0';
 432         hdr->uuid[UUID_STRING_L - 1] = '\0';
 433
 434         if (repair) {
 435                 if (r == -EINVAL)
 436                         r = _keyslot_repair(device, hdr, ctx);
 437                 else
 438                         log_verbose(ctx, _("No known problems detected for LUKS header.\n"));
 439         }
 440
 441         return r;
 442 }
 443
 444 static void _to_lower(char *str, unsigned max_len)
 445 {
 446         for(; *str && max_len; str++, max_len--)
 447                 if (isupper(*str))
 448                         *str = tolower(*str);
 449 }
 450
 451 static void LUKS_fix_header_compatible(struct luks_phdr *header)
 452 {
 453         /* Old cryptsetup expects "sha1", gcrypt allows case insensistive names,
 454          * so always convert hash to lower case in header */
 455         _to_lower(header->hashSpec, LUKS_HASHSPEC_L);
 456 }
 457
 458 int LUKS_read_phdr_backup(const char *backup_file,
 459                           const char *device,
 460                           struct luks_phdr *hdr,
 461                           int require_luks_device,
 462                           struct crypt_device *ctx)
 463 {
 464         ssize_t hdr_size = sizeof(struct luks_phdr);
 465         int devfd = 0, r = 0;
 466
 467         log_dbg("Reading LUKS header of size %d from backup file %s",
 468                 (int)hdr_size, backup_file);
 469
 470         devfd = open(backup_file, O_RDONLY);
 471         if(-1 == devfd) {
 472                 log_err(ctx, _("Cannot open file %s.\n"), device);
 473                 return -EINVAL;
 474         }
 475
 476         if (read(devfd, hdr, hdr_size) < hdr_size)
 477                 r = -EIO;
 478         else {
 479                 LUKS_fix_header_compatible(hdr);
 480                 r = _check_and_convert_hdr(backup_file, hdr,
 481                                            require_luks_device, 0, ctx);
 482         }
 483
 484         close(devfd);
 485         return r;
 486 }
 487
 488 int LUKS_read_phdr(const char *device,
 489                    struct luks_phdr *hdr,
 490                    int require_luks_device,
 491                    int repair,
 492                    struct crypt_device *ctx)
 493 {
 494         ssize_t hdr_size = sizeof(struct luks_phdr);
 495         int devfd = 0, r = 0;
 496
 497         if (repair && !require_luks_device)
 498                 return -EINVAL;
 499
 500         log_dbg("Reading LUKS header of size %d from device %s",
 501                 hdr_size, device);
 502
 503         devfd = open(device,O_RDONLY | O_DIRECT | O_SYNC);
 504         if(-1 == devfd) {
 505                 log_err(ctx, _("Cannot open device %s.\n"), device);
 506                 return -EINVAL;
 507         }
 508
 509         if (read_blockwise(devfd, hdr, hdr_size) < hdr_size)
 510                 r = -EIO;
 511         else
 512                 r = _check_and_convert_hdr(device, hdr, require_luks_device,
 513                                            repair, ctx);
 514
 515         close(devfd);
 516         return r;
 517 }
 518
 519 int LUKS_write_phdr(const char *device,
 520                     struct luks_phdr *hdr,
 521                     struct crypt_device *ctx)
 522 {
 523         ssize_t hdr_size = sizeof(struct luks_phdr);
 524         int devfd = 0;
 525         unsigned int i;
 526         struct luks_phdr convHdr;
 527         int r;
 528
 529         log_dbg("Updating LUKS header of size %d on device %s",
 530                 sizeof(struct luks_phdr), device);
 531
 532         if (LUKS_check_device_size(device, hdr->payloadOffset, hdr->keyBytes)) {
 533                 log_err(ctx, _("Device %s is too small.\n"), device);
 534                 return -EINVAL;
 535         }
 536
 537         devfd = open(device,O_RDWR | O_DIRECT | O_SYNC);
 538         if(-1 == devfd) {
 539                 log_err(ctx, _("Cannot open device %s.\n"), device);
 540                 return -EINVAL;
 541         }
 542
 543         memcpy(&convHdr, hdr, hdr_size);
 544         memset(&convHdr._padding, 0, sizeof(convHdr._padding));
 545
 546         /* Convert every uint16/32_t item to network byte order */
 547         convHdr.version            = htons(hdr->version);
 548         convHdr.payloadOffset      = htonl(hdr->payloadOffset);
 549         convHdr.keyBytes           = htonl(hdr->keyBytes);
 550         convHdr.mkDigestIterations = htonl(hdr->mkDigestIterations);
 551         for(i = 0; i < LUKS_NUMKEYS; ++i) {
 552                 convHdr.keyblock[i].active             = htonl(hdr->keyblock[i].active);
 553                 convHdr.keyblock[i].passwordIterations = htonl(hdr->keyblock[i].passwordIterations);
 554                 convHdr.keyblock[i].keyMaterialOffset  = htonl(hdr->keyblock[i].keyMaterialOffset);
 555                 convHdr.keyblock[i].stripes            = htonl(hdr->keyblock[i].stripes);
 556         }
 557
 558         r = write_blockwise(devfd, &convHdr, hdr_size) < hdr_size ? -EIO : 0;
 559         if (r)
 560                 log_err(ctx, _("Error during update of LUKS header on device %s.\n"), device);
 561         close(devfd);
 562
 563         /* Re-read header from disk to be sure that in-memory and on-disk data are the same. */
 564         if (!r) {
 565                 r = LUKS_read_phdr(device, hdr, 1, 0, ctx);
 566                 if (r)
 567                         log_err(ctx, _("Error re-reading LUKS header after update on device %s.\n"), device);
 568         }
 569
 570         return r;
 571 }
 572
 573 static int LUKS_PBKDF2_performance_check(const char *hashSpec,
 574                                          uint64_t *PBKDF2_per_sec,
 575                                          struct crypt_device *ctx)
 576 {
 577         if (!*PBKDF2_per_sec) {
 578                 if (PBKDF2_performance_check(hashSpec, PBKDF2_per_sec) < 0) {
 579                         log_err(ctx, _("Not compatible PBKDF2 options (using hash algorithm %s).\n"), hashSpec);
 580                         return -EINVAL;
 581                 }
 582                 log_dbg("PBKDF2: %" PRIu64 " iterations per second using hash %s.", *PBKDF2_per_sec, hashSpec);
 583         }
 584
 585         return 0;
 586 }
 587
 588 int LUKS_generate_phdr(struct luks_phdr *header,
 589                        const struct volume_key *vk,
 590                        const char *cipherName, const char *cipherMode, const char *hashSpec,
 591                        const char *uuid, unsigned int stripes,
 592                        unsigned int alignPayload,
 593                        unsigned int alignOffset,
 594                        uint32_t iteration_time_ms,
 595                        uint64_t *PBKDF2_per_sec,
 596                        const char *metadata_device,
 597                        struct crypt_device *ctx)
 598 {
 599         unsigned int i=0;
 600         unsigned int blocksPerStripeSet = div_round_up(vk->keylength*stripes,SECTOR_SIZE);
 601         int r;
 602         uuid_t partitionUuid;
 603         int currentSector;
 604         char luksMagic[] = LUKS_MAGIC;
 605
 606         /* For separate metadata device allow zero alignment */
 607         if (alignPayload == 0 && !metadata_device)
 608                 alignPayload = DEFAULT_DISK_ALIGNMENT / SECTOR_SIZE;
 609
 610         if (PBKDF2_HMAC_ready(hashSpec) < 0) {
 611                 log_err(ctx, _("Requested LUKS hash %s is not supported.\n"), hashSpec);
 612                 return -EINVAL;
 613         }
 614
 615         if (uuid && uuid_parse(uuid, partitionUuid) == -1) {
 616                 log_err(ctx, _("Wrong LUKS UUID format provided.\n"));
 617                 return -EINVAL;
 618         }
 619         if (!uuid)
 620                 uuid_generate(partitionUuid);
 621
 622         memset(header,0,sizeof(struct luks_phdr));
 623
 624         /* Set Magic */
 625         memcpy(header->magic,luksMagic,LUKS_MAGIC_L);
 626         header->version=1;
 627         strncpy(header->cipherName,cipherName,LUKS_CIPHERNAME_L);
 628         strncpy(header->cipherMode,cipherMode,LUKS_CIPHERMODE_L);
 629         strncpy(header->hashSpec,hashSpec,LUKS_HASHSPEC_L);
 630
 631         header->keyBytes=vk->keylength;
 632
 633         LUKS_fix_header_compatible(header);
 634
 635         log_dbg("Generating LUKS header version %d using hash %s, %s, %s, MK %d bytes",
 636                 header->version, header->hashSpec ,header->cipherName, header->cipherMode,
 637                 header->keyBytes);
 638
 639         r = crypt_random_get(ctx, header->mkDigestSalt, LUKS_SALTSIZE, CRYPT_RND_SALT);
 640         if(r < 0) {
 641                 log_err(ctx,  _("Cannot create LUKS header: reading random salt failed.\n"));
 642                 return r;
 643         }
 644
 645         if ((r = LUKS_PBKDF2_performance_check(header->hashSpec, PBKDF2_per_sec, ctx)))
 646                 return r;
 647
 648         /* Compute master key digest */
 649         iteration_time_ms /= 8;
 650         header->mkDigestIterations = at_least((uint32_t)(*PBKDF2_per_sec/1024) * iteration_time_ms,
 651                                               LUKS_MKD_ITERATIONS_MIN);
 652
 653         r = PBKDF2_HMAC(header->hashSpec,vk->key,vk->keylength,
 654                         header->mkDigestSalt,LUKS_SALTSIZE,
 655                         header->mkDigestIterations,
 656                         header->mkDigest,LUKS_DIGESTSIZE);
 657         if(r < 0) {
 658                 log_err(ctx,  _("Cannot create LUKS header: header digest failed (using hash %s).\n"),
 659                         header->hashSpec);
 660                 return r;
 661         }
 662
 663         currentSector = round_up_modulo(LUKS_PHDR_SIZE, LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE);
 664         for(i = 0; i < LUKS_NUMKEYS; ++i) {
 665                 header->keyblock[i].active = LUKS_KEY_DISABLED;
 666                 header->keyblock[i].keyMaterialOffset = currentSector;
 667                 header->keyblock[i].stripes = stripes;
 668                 currentSector = round_up_modulo(currentSector + blocksPerStripeSet,
 669                                                 LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE);
 670         }
 671
 672         if (metadata_device) {
 673                 /* for separate metadata device use alignPayload directly */
 674                 header->payloadOffset = alignPayload;
 675         } else {
 676                 /* alignOffset - offset from natural device alignment provided by topology info */
 677                 currentSector = round_up_modulo(currentSector, alignPayload);
 678                 header->payloadOffset = currentSector + alignOffset;
 679         }
 680
 681         uuid_unparse(partitionUuid, header->uuid);
 682
 683         log_dbg("Data offset %d, UUID %s, digest iterations %" PRIu32,
 684                 header->payloadOffset, header->uuid, header->mkDigestIterations);
 685
 686         return 0;
 687 }
 688
 689 int LUKS_hdr_uuid_set(
 690         const char *device,
 691         struct luks_phdr *hdr,
 692         const char *uuid,
 693         struct crypt_device *ctx)
 694 {
 695         uuid_t partitionUuid;
 696
 697         if (uuid && uuid_parse(uuid, partitionUuid) == -1) {
 698                 log_err(ctx, _("Wrong LUKS UUID format provided.\n"));
 699                 return -EINVAL;
 700         }
 701         if (!uuid)
 702                 uuid_generate(partitionUuid);
 703
 704         uuid_unparse(partitionUuid, hdr->uuid);
 705
 706         return LUKS_write_phdr(device, hdr, ctx);
 707 }
 708
 709 int LUKS_set_key(const char *device, unsigned int keyIndex,
 710                  const char *password, size_t passwordLen,
 711                  struct luks_phdr *hdr, struct volume_key *vk,
 712                  uint32_t iteration_time_ms,
 713                  uint64_t *PBKDF2_per_sec,
 714                  struct crypt_device *ctx)
 715 {
 716         struct volume_key *derived_key;
 717         char *AfKey = NULL;
 718         unsigned int AFEKSize;
 719         uint64_t PBKDF2_temp;
 720         int r;
 721
 722         if(hdr->keyblock[keyIndex].active != LUKS_KEY_DISABLED) {
 723                 log_err(ctx,  _("Key slot %d active, purge first.\n"), keyIndex);
 724                 return -EINVAL;
 725         }
 726
 727         if(hdr->keyblock[keyIndex].stripes < LUKS_STRIPES) {
 728                 log_err(ctx, _("Key slot %d material includes too few stripes. Header manipulation?\n"),
 729                         keyIndex);
 730                  return -EINVAL;
 731         }
 732
 733         log_dbg("Calculating data for key slot %d", keyIndex);
 734
 735         if ((r = LUKS_PBKDF2_performance_check(hdr->hashSpec, PBKDF2_per_sec, ctx)))
 736                 return r;
 737
 738         /*
 739          * Avoid floating point operation
 740          * Final iteration count is at least LUKS_SLOT_ITERATIONS_MIN
 741          */
 742         PBKDF2_temp = (*PBKDF2_per_sec / 2) * (uint64_t)iteration_time_ms;
 743         PBKDF2_temp /= 1024;
 744         if (PBKDF2_temp > UINT32_MAX)
 745                 PBKDF2_temp = UINT32_MAX;
 746         hdr->keyblock[keyIndex].passwordIterations = at_least((uint32_t)PBKDF2_temp,
 747                                                               LUKS_SLOT_ITERATIONS_MIN);
 748
 749         log_dbg("Key slot %d use %d password iterations.", keyIndex, hdr->keyblock[keyIndex].passwordIterations);
 750
 751         derived_key = crypt_alloc_volume_key(hdr->keyBytes, NULL);
 752         if (!derived_key)
 753                 return -ENOMEM;
 754
 755         r = crypt_random_get(ctx, hdr->keyblock[keyIndex].passwordSalt,
 756                        LUKS_SALTSIZE, CRYPT_RND_SALT);
 757         if (r < 0)
 758                 return r;
 759
 760         r = PBKDF2_HMAC(hdr->hashSpec, password,passwordLen,
 761                         hdr->keyblock[keyIndex].passwordSalt,LUKS_SALTSIZE,
 762                         hdr->keyblock[keyIndex].passwordIterations,
 763                         derived_key->key, hdr->keyBytes);
 764         if (r < 0)
 765                 goto out;
 766
 767         /*
 768          * AF splitting, the masterkey stored in vk->key is split to AfKey
 769          */
 770         assert(vk->keylength == hdr->keyBytes);
 771         AFEKSize = hdr->keyblock[keyIndex].stripes*vk->keylength;
 772         AfKey = crypt_safe_alloc(AFEKSize);
 773         if (!AfKey) {
 774                 r = -ENOMEM;
 775                 goto out;
 776         }
 777
 778         log_dbg("Using hash %s for AF in key slot %d, %d stripes",
 779                 hdr->hashSpec, keyIndex, hdr->keyblock[keyIndex].stripes);
 780         r = AF_split(vk->key,AfKey,vk->keylength,hdr->keyblock[keyIndex].stripes,hdr->hashSpec);
 781         if (r < 0)
 782                 goto out;
 783
 784         log_dbg("Updating key slot %d [0x%04x] area on device %s.", keyIndex,
 785                 hdr->keyblock[keyIndex].keyMaterialOffset << 9, device);
 786         /* Encryption via dm */
 787         r = LUKS_encrypt_to_storage(AfKey,
 788                                     AFEKSize,
 789                                     hdr,
 790                                     derived_key,
 791                                     device,
 792                                     hdr->keyblock[keyIndex].keyMaterialOffset,
 793                                     ctx);
 794         if (r < 0) {
 795                 log_err(ctx, _("Failed to write to key storage.\n"));
 796                 goto out;
 797         }
 798
 799         /* Mark the key as active in phdr */
 800         r = LUKS_keyslot_set(hdr, (int)keyIndex, 1);
 801         if (r < 0)
 802                 goto out;
 803
 804         r = LUKS_write_phdr(device, hdr, ctx);
 805         if (r < 0)
 806                 goto out;
 807
 808         r = 0;
 809 out:
 810         crypt_safe_free(AfKey);
 811         crypt_free_volume_key(derived_key);
 812         return r;
 813 }
 814
 815 /* Check whether a volume key is invalid. */
 816 int LUKS_verify_volume_key(const struct luks_phdr *hdr,
 817                            const struct volume_key *vk)
 818 {
 819         char checkHashBuf[LUKS_DIGESTSIZE];
 820
 821         if (PBKDF2_HMAC(hdr->hashSpec, vk->key, vk->keylength,
 822                         hdr->mkDigestSalt, LUKS_SALTSIZE,
 823                         hdr->mkDigestIterations, checkHashBuf,
 824                         LUKS_DIGESTSIZE) < 0)
 825                 return -EINVAL;
 826
 827         if (memcmp(checkHashBuf, hdr->mkDigest, LUKS_DIGESTSIZE))
 828                 return -EPERM;
 829
 830         return 0;
 831 }
 832
 833 /* Try to open a particular key slot */
 834 static int LUKS_open_key(const char *device,
 835                   unsigned int keyIndex,
 836                   const char *password,
 837                   size_t passwordLen,
 838                   struct luks_phdr *hdr,
 839                   struct volume_key *vk,
 840                   struct crypt_device *ctx)
 841 {
 842         crypt_keyslot_info ki = LUKS_keyslot_info(hdr, keyIndex);
 843         struct volume_key *derived_key;
 844         char *AfKey;
 845         size_t AFEKSize;
 846         int r;
 847
 848         log_dbg("Trying to open key slot %d [%s].", keyIndex,
 849                 dbg_slot_state(ki));
 850
 851         if (ki < CRYPT_SLOT_ACTIVE)
 852                 return -ENOENT;
 853
 854         derived_key = crypt_alloc_volume_key(hdr->keyBytes, NULL);
 855         if (!derived_key)
 856                 return -ENOMEM;
 857
 858         assert(vk->keylength == hdr->keyBytes);
 859         AFEKSize = hdr->keyblock[keyIndex].stripes*vk->keylength;
 860         AfKey = crypt_safe_alloc(AFEKSize);
 861         if (!AfKey)
 862                 return -ENOMEM;
 863
 864         r = PBKDF2_HMAC(hdr->hashSpec, password,passwordLen,
 865                         hdr->keyblock[keyIndex].passwordSalt,LUKS_SALTSIZE,
 866                         hdr->keyblock[keyIndex].passwordIterations,
 867                         derived_key->key, hdr->keyBytes);
 868         if (r < 0)
 869                 goto out;
 870
 871         log_dbg("Reading key slot %d area.", keyIndex);
 872         r = LUKS_decrypt_from_storage(AfKey,
 873                                       AFEKSize,
 874                                       hdr,
 875                                       derived_key,
 876                                       device,
 877                                       hdr->keyblock[keyIndex].keyMaterialOffset,
 878                                       ctx);
 879         if (r < 0) {
 880                 log_err(ctx, _("Failed to read from key storage.\n"));
 881                 goto out;
 882         }
 883
 884         r = AF_merge(AfKey,vk->key,vk->keylength,hdr->keyblock[keyIndex].stripes,hdr->hashSpec);
 885         if (r < 0)
 886                 goto out;
 887
 888         r = LUKS_verify_volume_key(hdr, vk);
 889         if (!r)
 890                 log_verbose(ctx, _("Key slot %d unlocked.\n"), keyIndex);
 891 out:
 892         crypt_safe_free(AfKey);
 893         crypt_free_volume_key(derived_key);
 894         return r;
 895 }
 896
 897 int LUKS_open_key_with_hdr(const char *device,
 898                            int keyIndex,
 899                            const char *password,
 900                            size_t passwordLen,
 901                            struct luks_phdr *hdr,
 902                            struct volume_key **vk,
 903                            struct crypt_device *ctx)
 904 {
 905         unsigned int i;
 906         int r;
 907
 908         *vk = crypt_alloc_volume_key(hdr->keyBytes, NULL);
 909
 910         if (keyIndex >= 0) {
 911                 r = LUKS_open_key(device, keyIndex, password, passwordLen, hdr, *vk, ctx);
 912                 return (r < 0) ? r : keyIndex;
 913         }
 914
 915         for(i = 0; i < LUKS_NUMKEYS; i++) {
 916                 r = LUKS_open_key(device, i, password, passwordLen, hdr, *vk, ctx);
 917                 if(r == 0)
 918                         return i;
 919
 920                 /* Do not retry for errors that are no -EPERM or -ENOENT,
 921                    former meaning password wrong, latter key slot inactive */
 922                 if ((r != -EPERM) && (r != -ENOENT))
 923                         return r;
 924         }
 925         /* Warning, early returns above */
 926         log_err(ctx, _("No key available with this passphrase.\n"));
 927         return -EPERM;
 928 }
 929
 930 int LUKS_del_key(const char *device,
 931                  unsigned int keyIndex,
 932                  struct luks_phdr *hdr,
 933                  struct crypt_device *ctx)
 934 {
 935         unsigned int startOffset, endOffset, stripesLen;
 936         int r;
 937
 938         r = LUKS_read_phdr(device, hdr, 1, 0, ctx);
 939         if (r)
 940                 return r;
 941
 942         r = LUKS_keyslot_set(hdr, keyIndex, 0);
 943         if (r) {
 944                 log_err(ctx, _("Key slot %d is invalid, please select keyslot between 0 and %d.\n"),
 945                         keyIndex, LUKS_NUMKEYS - 1);
 946                 return r;
 947         }
 948
 949         /* secure deletion of key material */
 950         startOffset = hdr->keyblock[keyIndex].keyMaterialOffset;
 951         stripesLen = hdr->keyBytes * hdr->keyblock[keyIndex].stripes;
 952         endOffset = startOffset + div_round_up(stripesLen, SECTOR_SIZE);
 953
 954         r = crypt_wipe(device, startOffset * SECTOR_SIZE,
 955                        (endOffset - startOffset) * SECTOR_SIZE,
 956                        CRYPT_WIPE_DISK, 0);
 957         if (r) {
 958                 log_err(ctx, _("Cannot wipe device %s.\n"), device);
 959                 return r;
 960         }
 961
 962         /* Wipe keyslot info */
 963         memset(&hdr->keyblock[keyIndex].passwordSalt, 0, LUKS_SALTSIZE);
 964         hdr->keyblock[keyIndex].passwordIterations = 0;
 965
 966         r = LUKS_write_phdr(device, hdr, ctx);
 967
 968         return r;
 969 }
 970
 971 crypt_keyslot_info LUKS_keyslot_info(struct luks_phdr *hdr, int keyslot)
 972 {
 973         int i;
 974
 975         if(keyslot >= LUKS_NUMKEYS || keyslot < 0)
 976                 return CRYPT_SLOT_INVALID;
 977
 978         if (hdr->keyblock[keyslot].active == LUKS_KEY_DISABLED)
 979                 return CRYPT_SLOT_INACTIVE;
 980
 981         if (hdr->keyblock[keyslot].active != LUKS_KEY_ENABLED)
 982                 return CRYPT_SLOT_INVALID;
 983
 984         for(i = 0; i < LUKS_NUMKEYS; i++)
 985                 if(i != keyslot && hdr->keyblock[i].active == LUKS_KEY_ENABLED)
 986                         return CRYPT_SLOT_ACTIVE;
 987
 988         return CRYPT_SLOT_ACTIVE_LAST;
 989 }
 990
 991 int LUKS_keyslot_find_empty(struct luks_phdr *hdr)
 992 {
 993         int i;
 994
 995         for (i = 0; i < LUKS_NUMKEYS; i++)
 996                 if(hdr->keyblock[i].active == LUKS_KEY_DISABLED)
 997                         break;
 998
 999         if (i == LUKS_NUMKEYS)
1000                 return -EINVAL;
1001
1002         return i;
1003 }
1004
1005 int LUKS_keyslot_active_count(struct luks_phdr *hdr)
1006 {
1007         int i, num = 0;
1008
1009         for (i = 0; i < LUKS_NUMKEYS; i++)
1010                 if(hdr->keyblock[i].active == LUKS_KEY_ENABLED)
1011                         num++;
1012
1013         return num;
1014 }
1015
1016 int LUKS_keyslot_set(struct luks_phdr *hdr, int keyslot, int enable)
1017 {
1018         crypt_keyslot_info ki = LUKS_keyslot_info(hdr, keyslot);
1019
1020         if (ki == CRYPT_SLOT_INVALID)
1021                 return -EINVAL;
1022
1023         hdr->keyblock[keyslot].active = enable ? LUKS_KEY_ENABLED : LUKS_KEY_DISABLED;
1024         log_dbg("Key slot %d was %s in LUKS header.", keyslot, enable ? "enabled" : "disabled");
1025         return 0;
1026 }
1027
1028 int LUKS1_activate(struct crypt_device *cd,
1029                    const char *name,
1030                    struct volume_key *vk,
1031                    uint32_t flags)
1032 {
1033         int r;
1034         char *dm_cipher = NULL;
1035         enum devcheck device_check;
1036         struct crypt_dm_active_device dmd = {
1037                 .target = DM_CRYPT,
1038                 .uuid   = crypt_get_uuid(cd),
1039                 .flags  = flags,
1040                 .size   = 0,
1041                 .data_device = crypt_get_device_name(cd),
1042                 .u.crypt = {
1043                         .cipher = NULL,
1044                         .vk     = vk,
1045                         .offset = crypt_get_data_offset(cd),
1046                         .iv_offset = 0,
1047                 }
1048         };
1049
1050         if (dmd.flags & CRYPT_ACTIVATE_SHARED)
1051                 device_check = DEV_SHARED;
1052         else
1053                 device_check = DEV_EXCL;
1054
1055         r = device_check_and_adjust(cd, dmd.data_device, device_check,
1056                                     &dmd.size, &dmd.u.crypt.offset,
1057                                     &dmd.flags);
1058         if (r)
1059                 return r;
1060
1061         r = asprintf(&dm_cipher, "%s-%s", crypt_get_cipher(cd), crypt_get_cipher_mode(cd));
1062         if (r < 0)
1063                 return -ENOMEM;
1064
1065         dmd.u.crypt.cipher = dm_cipher;
1066         r = dm_create_device(name, CRYPT_LUKS1, &dmd, 0);
1067
1068         free(dm_cipher);
1069         return r;
1070 }