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)
  51 {
  52         uint64_t keyslot_sectors, sector;
  53         int i;
  54
  55         keyslot_sectors = div_round_up(AF_split_size(keyLen, LUKS_STRIPES), SECTOR_SIZE);
  56         sector = 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(struct crypt_device *ctx, size_t keyLength)
  67 {
  68         struct device *device = crypt_metadata_device(ctx);
  69         uint64_t dev_sectors, hdr_sectors;
  70
  71         if (!keyLength)
  72                 return -EINVAL;
  73
  74         if(device_size(device, &dev_sectors)) {
  75                 log_dbg("Cannot get device size for device %s.", device_path(device));
  76                 return -EIO;
  77         }
  78
  79         dev_sectors >>= SECTOR_SHIFT;
  80         hdr_sectors = LUKS_device_sectors(keyLength);
  81         log_dbg("Key length %u, device size %" PRIu64 " sectors, header size %"
  82                 PRIu64 " sectors.",keyLength, dev_sectors, hdr_sectors);
  83
  84         if (hdr_sectors > dev_sectors) {
  85                 log_err(ctx, _("Device %s is too small.\n"), device_path(device));
  86                 return -EINVAL;
  87         }
  88
  89         return 0;
  90 }
  91
  92 /* Check keyslot to prevent access outside of header and keyslot area */
  93 static int LUKS_check_keyslot_size(const struct luks_phdr *phdr, unsigned int keyIndex)
  94 {
  95         uint32_t secs_per_stripes;
  96
  97         /* First sectors is the header itself */
  98         if (phdr->keyblock[keyIndex].keyMaterialOffset * SECTOR_SIZE < sizeof(*phdr)) {
  99                 log_dbg("Invalid offset %u in keyslot %u.",
 100                         phdr->keyblock[keyIndex].keyMaterialOffset, keyIndex);
 101                 return 1;
 102         }
 103
 104         /* Ignore following check for detached header where offset can be zero. */
 105         if (phdr->payloadOffset == 0)
 106                 return 0;
 107
 108         if (phdr->payloadOffset <= phdr->keyblock[keyIndex].keyMaterialOffset) {
 109                 log_dbg("Invalid offset %u in keyslot %u (beyond data area offset %u).",
 110                         phdr->keyblock[keyIndex].keyMaterialOffset, keyIndex,
 111                         phdr->payloadOffset);
 112                 return 1;
 113         }
 114
 115         secs_per_stripes = div_round_up(AF_split_size(phdr->keyBytes, phdr->keyblock[keyIndex].stripes), SECTOR_SIZE);
 116
 117         if (phdr->payloadOffset < (phdr->keyblock[keyIndex].keyMaterialOffset + secs_per_stripes)) {
 118                 log_dbg("Invalid keyslot size %u (offset %u, stripes %u) in "
 119                         "keyslot %u (beyond data area offset %u).",
 120                         secs_per_stripes,
 121                         phdr->keyblock[keyIndex].keyMaterialOffset,
 122                         phdr->keyblock[keyIndex].stripes,
 123                         keyIndex, phdr->payloadOffset);
 124                 return 1;
 125         }
 126
 127         return 0;
 128 }
 129
 130 static const char *dbg_slot_state(crypt_keyslot_info ki)
 131 {
 132         switch(ki) {
 133         case CRYPT_SLOT_INACTIVE:
 134                 return "INACTIVE";
 135         case CRYPT_SLOT_ACTIVE:
 136                 return "ACTIVE";
 137         case CRYPT_SLOT_ACTIVE_LAST:
 138                 return "ACTIVE_LAST";
 139         case CRYPT_SLOT_INVALID:
 140         default:
 141                 return "INVALID";
 142         }
 143 }
 144
 145 int LUKS_hdr_backup(
 146         const char *backup_file,
 147         struct luks_phdr *hdr,
 148         struct crypt_device *ctx)
 149 {
 150         struct device *device = crypt_metadata_device(ctx);
 151         int r = 0, devfd = -1;
 152         ssize_t buffer_size;
 153         char *buffer = NULL;
 154         struct stat st;
 155
 156         if(stat(backup_file, &st) == 0) {
 157                 log_err(ctx, _("Requested file %s already exist.\n"), backup_file);
 158                 return -EINVAL;
 159         }
 160
 161         r = LUKS_read_phdr(hdr, 1, 0, ctx);
 162         if (r)
 163                 return r;
 164
 165         buffer_size = LUKS_device_sectors(hdr->keyBytes) << SECTOR_SHIFT;
 166         buffer = crypt_safe_alloc(buffer_size);
 167         if (!buffer || buffer_size < LUKS_ALIGN_KEYSLOTS) {
 168                 r = -ENOMEM;
 169                 goto out;
 170         }
 171
 172         log_dbg("Storing backup of header (%u bytes) and keyslot area (%u bytes).",
 173                 sizeof(*hdr), buffer_size - LUKS_ALIGN_KEYSLOTS);
 174
 175         devfd = open(device_path(device), O_RDONLY | O_DIRECT | O_SYNC);
 176         if(devfd == -1) {
 177                 log_err(ctx, _("Device %s is not a valid LUKS device.\n"), device_path(device));
 178                 r = -EINVAL;
 179                 goto out;
 180         }
 181
 182         if(read_blockwise(devfd, device_block_size(device), buffer, buffer_size) < buffer_size) {
 183                 r = -EIO;
 184                 goto out;
 185         }
 186         close(devfd);
 187
 188         /* Wipe unused area, so backup cannot contain old signatures */
 189         memset(buffer + sizeof(*hdr), 0, LUKS_ALIGN_KEYSLOTS - sizeof(*hdr));
 190
 191         devfd = creat(backup_file, S_IRUSR);
 192         if(devfd == -1) {
 193                 r = -EINVAL;
 194                 goto out;
 195         }
 196         if(write(devfd, buffer, buffer_size) < buffer_size) {
 197                 log_err(ctx, _("Cannot write header backup file %s.\n"), backup_file);
 198                 r = -EIO;
 199                 goto out;
 200         }
 201         close(devfd);
 202
 203         r = 0;
 204 out:
 205         if (devfd != -1)
 206                 close(devfd);
 207         crypt_safe_free(buffer);
 208         return r;
 209 }
 210
 211 int LUKS_hdr_restore(
 212         const char *backup_file,
 213         struct luks_phdr *hdr,
 214         struct crypt_device *ctx)
 215 {
 216         struct device *device = crypt_metadata_device(ctx);
 217         int r = 0, devfd = -1, diff_uuid = 0;
 218         ssize_t buffer_size = 0;
 219         char *buffer = NULL, msg[200];
 220         struct stat st;
 221         struct luks_phdr hdr_file;
 222
 223         if(stat(backup_file, &st) < 0) {
 224                 log_err(ctx, _("Backup file %s doesn't exist.\n"), backup_file);
 225                 return -EINVAL;
 226         }
 227
 228         r = LUKS_read_phdr_backup(backup_file, &hdr_file, 0, ctx);
 229         if (!r)
 230                 buffer_size = LUKS_device_sectors(hdr_file.keyBytes) << SECTOR_SHIFT;
 231
 232         if (r || buffer_size < LUKS_ALIGN_KEYSLOTS) {
 233                 log_err(ctx, _("Backup file doesn't contain valid LUKS header.\n"));
 234                 r = -EINVAL;
 235                 goto out;
 236         }
 237
 238         buffer = crypt_safe_alloc(buffer_size);
 239         if (!buffer) {
 240                 r = -ENOMEM;
 241                 goto out;
 242         }
 243
 244         devfd = open(backup_file, O_RDONLY);
 245         if(devfd == -1) {
 246                 log_err(ctx, _("Cannot open header backup file %s.\n"), backup_file);
 247                 r = -EINVAL;
 248                 goto out;
 249         }
 250
 251         if(read(devfd, buffer, buffer_size) < buffer_size) {
 252                 log_err(ctx, _("Cannot read header backup file %s.\n"), backup_file);
 253                 r = -EIO;
 254                 goto out;
 255         }
 256         close(devfd);
 257
 258         r = LUKS_read_phdr(hdr, 0, 0, ctx);
 259         if (r == 0) {
 260                 log_dbg("Device %s already contains LUKS header, checking UUID and offset.", device_path(device));
 261                 if(hdr->payloadOffset != hdr_file.payloadOffset ||
 262                    hdr->keyBytes != hdr_file.keyBytes) {
 263                         log_err(ctx, _("Data offset or key size differs on device and backup, restore failed.\n"));
 264                         r = -EINVAL;
 265                         goto out;
 266                 }
 267                 if (memcmp(hdr->uuid, hdr_file.uuid, UUID_STRING_L))
 268                         diff_uuid = 1;
 269         }
 270
 271         if (snprintf(msg, sizeof(msg), _("Device %s %s%s"), device_path(device),
 272                  r ? _("does not contain LUKS header. Replacing header can destroy data on that device.") :
 273                      _("already contains LUKS header. Replacing header will destroy existing keyslots."),
 274                      diff_uuid ? _("\nWARNING: real device header has different UUID than backup!") : "") < 0) {
 275                 r = -ENOMEM;
 276                 goto out;
 277         }
 278
 279         if (!crypt_confirm(ctx, msg)) {
 280                 r = -EINVAL;
 281                 goto out;
 282         }
 283
 284         log_dbg("Storing backup of header (%u bytes) and keyslot area (%u bytes) to device %s.",
 285                 sizeof(*hdr), buffer_size - LUKS_ALIGN_KEYSLOTS, device_path(device));
 286
 287         devfd = open(device_path(device), O_WRONLY | O_DIRECT | O_SYNC);
 288         if(devfd == -1) {
 289                 if (errno == EACCES)
 290                         log_err(ctx, _("Cannot write to device %s, permission denied.\n"),
 291                                 device_path(device));
 292                 else
 293                         log_err(ctx, _("Cannot open device %s.\n"), device_path(device));
 294                 r = -EINVAL;
 295                 goto out;
 296         }
 297
 298         if (write_blockwise(devfd, device_block_size(device), buffer, buffer_size) < buffer_size) {
 299                 r = -EIO;
 300                 goto out;
 301         }
 302         close(devfd);
 303
 304         /* Be sure to reload new data */
 305         r = LUKS_read_phdr(hdr, 1, 0, ctx);
 306 out:
 307         if (devfd != -1)
 308                 close(devfd);
 309         crypt_safe_free(buffer);
 310         return r;
 311 }
 312
 313 /* This routine should do some just basic recovery for known problems. */
 314 static int _keyslot_repair(struct luks_phdr *phdr, struct crypt_device *ctx)
 315 {
 316         struct luks_phdr temp_phdr;
 317         const unsigned char *sector = (const unsigned char*)phdr;
 318         struct volume_key *vk;
 319         uint64_t PBKDF2_per_sec = 1;
 320         int i, bad, r, need_write = 0;
 321
 322         if (phdr->keyBytes != 16 && phdr->keyBytes != 32) {
 323                 log_err(ctx, _("Non standard key size, manual repair required.\n"));
 324                 return -EINVAL;
 325         }
 326         /* cryptsetup 1.0 did not align to 4k, cannot repair this one */
 327         if (phdr->keyblock[0].keyMaterialOffset < (LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE)) {
 328                 log_err(ctx, _("Non standard keyslots alignment, manual repair required.\n"));
 329                 return -EINVAL;
 330         }
 331
 332         vk = crypt_alloc_volume_key(phdr->keyBytes, NULL);
 333
 334         log_verbose(ctx, _("Repairing keyslots.\n"));
 335
 336         log_dbg("Generating second header with the same parameters for check.");
 337         /* cipherName, cipherMode, hashSpec, uuid are already null terminated */
 338         /* payloadOffset - cannot check */
 339         r = LUKS_generate_phdr(&temp_phdr, vk, phdr->cipherName, phdr->cipherMode,
 340                                phdr->hashSpec,phdr->uuid, LUKS_STRIPES,
 341                                phdr->payloadOffset, 0,
 342                                1, &PBKDF2_per_sec,
 343                                1, ctx);
 344         if (r < 0) {
 345                 log_err(ctx, _("Repair failed."));
 346                 goto out;
 347         }
 348
 349         for(i = 0; i < LUKS_NUMKEYS; ++i) {
 350                 if (phdr->keyblock[i].active == LUKS_KEY_ENABLED)  {
 351                         log_dbg("Skipping repair for active keyslot %i.", i);
 352                         continue;
 353                 }
 354
 355                 bad = 0;
 356                 if (phdr->keyblock[i].keyMaterialOffset != temp_phdr.keyblock[i].keyMaterialOffset) {
 357                         log_err(ctx, _("Keyslot %i: offset repaired (%u -> %u).\n"), i,
 358                                 (unsigned)phdr->keyblock[i].keyMaterialOffset,
 359                                 (unsigned)temp_phdr.keyblock[i].keyMaterialOffset);
 360                         phdr->keyblock[i].keyMaterialOffset = temp_phdr.keyblock[i].keyMaterialOffset;
 361                         bad = 1;
 362                 }
 363
 364                 if (phdr->keyblock[i].stripes != temp_phdr.keyblock[i].stripes) {
 365                         log_err(ctx, _("Keyslot %i: stripes repaired (%u -> %u).\n"), i,
 366                                 (unsigned)phdr->keyblock[i].stripes,
 367                                 (unsigned)temp_phdr.keyblock[i].stripes);
 368                         phdr->keyblock[i].stripes = temp_phdr.keyblock[i].stripes;
 369                         bad = 1;
 370                 }
 371
 372                 /* Known case - MSDOS partition table signature */
 373                 if (i == 6 && sector[0x1fe] == 0x55 && sector[0x1ff] == 0xaa) {
 374                         log_err(ctx, _("Keyslot %i: bogus partition signature.\n"), i);
 375                         bad = 1;
 376                 }
 377
 378                 if(bad) {
 379                         log_err(ctx, _("Keyslot %i: salt wiped.\n"), i);
 380                         phdr->keyblock[i].active = LUKS_KEY_DISABLED;
 381                         memset(&phdr->keyblock[i].passwordSalt, 0x00, LUKS_SALTSIZE);
 382                         phdr->keyblock[i].passwordIterations = 0;
 383                 }
 384
 385                 if (bad)
 386                         need_write = 1;
 387         }
 388
 389         if (need_write) {
 390                 log_verbose(ctx, _("Writing LUKS header to disk.\n"));
 391                 r = LUKS_write_phdr(phdr, ctx);
 392         }
 393 out:
 394         crypt_free_volume_key(vk);
 395         memset(&temp_phdr, 0, sizeof(temp_phdr));
 396         return r;
 397 }
 398
 399 static int _check_and_convert_hdr(const char *device,
 400                                   struct luks_phdr *hdr,
 401                                   int require_luks_device,
 402                                   int repair,
 403                                   struct crypt_device *ctx)
 404 {
 405         int r = 0;
 406         unsigned int i;
 407         char luksMagic[] = LUKS_MAGIC;
 408
 409         if(memcmp(hdr->magic, luksMagic, LUKS_MAGIC_L)) { /* Check magic */
 410                 log_dbg("LUKS header not detected.");
 411                 if (require_luks_device)
 412                         log_err(ctx, _("Device %s is not a valid LUKS device.\n"), device);
 413                 return -EINVAL;
 414         } else if((hdr->version = ntohs(hdr->version)) != 1) {  /* Convert every uint16/32_t item from network byte order */
 415                 log_err(ctx, _("Unsupported LUKS version %d.\n"), hdr->version);
 416                 return -EINVAL;
 417         }
 418
 419         hdr->hashSpec[LUKS_HASHSPEC_L - 1] = '\0';
 420         if (PBKDF2_HMAC_ready(hdr->hashSpec) < 0) {
 421                 log_err(ctx, _("Requested LUKS hash %s is not supported.\n"), hdr->hashSpec);
 422                 return -EINVAL;
 423         }
 424
 425         /* Header detected */
 426         hdr->payloadOffset      = ntohl(hdr->payloadOffset);
 427         hdr->keyBytes           = ntohl(hdr->keyBytes);
 428         hdr->mkDigestIterations = ntohl(hdr->mkDigestIterations);
 429
 430         for(i = 0; i < LUKS_NUMKEYS; ++i) {
 431                 hdr->keyblock[i].active             = ntohl(hdr->keyblock[i].active);
 432                 hdr->keyblock[i].passwordIterations = ntohl(hdr->keyblock[i].passwordIterations);
 433                 hdr->keyblock[i].keyMaterialOffset  = ntohl(hdr->keyblock[i].keyMaterialOffset);
 434                 hdr->keyblock[i].stripes            = ntohl(hdr->keyblock[i].stripes);
 435                 if (LUKS_check_keyslot_size(hdr, i)) {
 436                         log_err(ctx, _("LUKS keyslot %u is invalid.\n"), i);
 437                         r = -EINVAL;
 438                 }
 439         }
 440
 441         /* Avoid unterminated strings */
 442         hdr->cipherName[LUKS_CIPHERNAME_L - 1] = '\0';
 443         hdr->cipherMode[LUKS_CIPHERMODE_L - 1] = '\0';
 444         hdr->uuid[UUID_STRING_L - 1] = '\0';
 445
 446         if (repair) {
 447                 if (r == -EINVAL)
 448                         r = _keyslot_repair(hdr, ctx);
 449                 else
 450                         log_verbose(ctx, _("No known problems detected for LUKS header.\n"));
 451         }
 452
 453         return r;
 454 }
 455
 456 static void _to_lower(char *str, unsigned max_len)
 457 {
 458         for(; *str && max_len; str++, max_len--)
 459                 if (isupper(*str))
 460                         *str = tolower(*str);
 461 }
 462
 463 static void LUKS_fix_header_compatible(struct luks_phdr *header)
 464 {
 465         /* Old cryptsetup expects "sha1", gcrypt allows case insensistive names,
 466          * so always convert hash to lower case in header */
 467         _to_lower(header->hashSpec, LUKS_HASHSPEC_L);
 468 }
 469
 470 int LUKS_read_phdr_backup(const char *backup_file,
 471                           struct luks_phdr *hdr,
 472                           int require_luks_device,
 473                           struct crypt_device *ctx)
 474 {
 475         ssize_t hdr_size = sizeof(struct luks_phdr);
 476         int devfd = 0, r = 0;
 477
 478         log_dbg("Reading LUKS header of size %d from backup file %s",
 479                 (int)hdr_size, backup_file);
 480
 481         devfd = open(backup_file, O_RDONLY);
 482         if(-1 == devfd) {
 483                 log_err(ctx, _("Cannot open file %s.\n"), backup_file);
 484                 return -EINVAL;
 485         }
 486
 487         if (read(devfd, hdr, hdr_size) < hdr_size)
 488                 r = -EIO;
 489         else {
 490                 LUKS_fix_header_compatible(hdr);
 491                 r = _check_and_convert_hdr(backup_file, hdr,
 492                                            require_luks_device, 0, ctx);
 493         }
 494
 495         close(devfd);
 496         return r;
 497 }
 498
 499 int LUKS_read_phdr(struct luks_phdr *hdr,
 500                    int require_luks_device,
 501                    int repair,
 502                    struct crypt_device *ctx)
 503 {
 504         struct device *device = crypt_metadata_device(ctx);
 505         ssize_t hdr_size = sizeof(struct luks_phdr);
 506         int devfd = 0, r = 0;
 507
 508         /* LUKS header starts at offset 0, first keyslot on LUKS_ALIGN_KEYSLOTS */
 509         assert(sizeof(struct luks_phdr) <= LUKS_ALIGN_KEYSLOTS);
 510
 511         /* Stripes count cannot be changed without additional code fixes yet */
 512         assert(LUKS_STRIPES == 4000);
 513
 514         if (repair && !require_luks_device)
 515                 return -EINVAL;
 516
 517         log_dbg("Reading LUKS header of size %d from device %s",
 518                 hdr_size, device_path(device));
 519
 520         devfd = open(device_path(device), O_RDONLY | O_DIRECT | O_SYNC);
 521         if (devfd == -1) {
 522                 log_err(ctx, _("Cannot open device %s.\n"), device_path(device));
 523                 return -EINVAL;
 524         }
 525
 526         if (read_blockwise(devfd, device_block_size(device), hdr, hdr_size) < hdr_size)
 527                 r = -EIO;
 528         else
 529                 r = _check_and_convert_hdr(device_path(device), hdr, require_luks_device,
 530                                            repair, ctx);
 531
 532         if (!r)
 533                 r = LUKS_check_device_size(ctx, hdr->keyBytes);
 534
 535         close(devfd);
 536         return r;
 537 }
 538
 539 int LUKS_write_phdr(struct luks_phdr *hdr,
 540                     struct crypt_device *ctx)
 541 {
 542         struct device *device = crypt_metadata_device(ctx);
 543         ssize_t hdr_size = sizeof(struct luks_phdr);
 544         int devfd = 0;
 545         unsigned int i;
 546         struct luks_phdr convHdr;
 547         int r;
 548
 549         log_dbg("Updating LUKS header of size %d on device %s",
 550                 sizeof(struct luks_phdr), device_path(device));
 551
 552         r = LUKS_check_device_size(ctx, hdr->keyBytes);
 553         if (r)
 554                 return r;
 555
 556         devfd = open(device_path(device), O_RDWR | O_DIRECT | O_SYNC);
 557         if(-1 == devfd) {
 558                 if (errno == EACCES)
 559                         log_err(ctx, _("Cannot write to device %s, permission denied.\n"),
 560                                 device_path(device));
 561                 else
 562                         log_err(ctx, _("Cannot open device %s.\n"), device_path(device));
 563                 return -EINVAL;
 564         }
 565
 566         memcpy(&convHdr, hdr, hdr_size);
 567         memset(&convHdr._padding, 0, sizeof(convHdr._padding));
 568
 569         /* Convert every uint16/32_t item to network byte order */
 570         convHdr.version            = htons(hdr->version);
 571         convHdr.payloadOffset      = htonl(hdr->payloadOffset);
 572         convHdr.keyBytes           = htonl(hdr->keyBytes);
 573         convHdr.mkDigestIterations = htonl(hdr->mkDigestIterations);
 574         for(i = 0; i < LUKS_NUMKEYS; ++i) {
 575                 convHdr.keyblock[i].active             = htonl(hdr->keyblock[i].active);
 576                 convHdr.keyblock[i].passwordIterations = htonl(hdr->keyblock[i].passwordIterations);
 577                 convHdr.keyblock[i].keyMaterialOffset  = htonl(hdr->keyblock[i].keyMaterialOffset);
 578                 convHdr.keyblock[i].stripes            = htonl(hdr->keyblock[i].stripes);
 579         }
 580
 581         r = write_blockwise(devfd, device_block_size(device), &convHdr, hdr_size) < hdr_size ? -EIO : 0;
 582         if (r)
 583                 log_err(ctx, _("Error during update of LUKS header on device %s.\n"), device_path(device));
 584         close(devfd);
 585
 586         /* Re-read header from disk to be sure that in-memory and on-disk data are the same. */
 587         if (!r) {
 588                 r = LUKS_read_phdr(hdr, 1, 0, ctx);
 589                 if (r)
 590                         log_err(ctx, _("Error re-reading LUKS header after update on device %s.\n"),
 591                                 device_path(device));
 592         }
 593
 594         return r;
 595 }
 596
 597 static int LUKS_PBKDF2_performance_check(const char *hashSpec,
 598                                          uint64_t *PBKDF2_per_sec,
 599                                          struct crypt_device *ctx)
 600 {
 601         if (!*PBKDF2_per_sec) {
 602                 if (PBKDF2_performance_check(hashSpec, PBKDF2_per_sec) < 0) {
 603                         log_err(ctx, _("Not compatible PBKDF2 options (using hash algorithm %s).\n"), hashSpec);
 604                         return -EINVAL;
 605                 }
 606                 log_dbg("PBKDF2: %" PRIu64 " iterations per second using hash %s.", *PBKDF2_per_sec, hashSpec);
 607         }
 608
 609         return 0;
 610 }
 611
 612 int LUKS_generate_phdr(struct luks_phdr *header,
 613                        const struct volume_key *vk,
 614                        const char *cipherName, const char *cipherMode, const char *hashSpec,
 615                        const char *uuid, unsigned int stripes,
 616                        unsigned int alignPayload,
 617                        unsigned int alignOffset,
 618                        uint32_t iteration_time_ms,
 619                        uint64_t *PBKDF2_per_sec,
 620                        int detached_metadata_device,
 621                        struct crypt_device *ctx)
 622 {
 623         unsigned int i=0;
 624         unsigned int blocksPerStripeSet = div_round_up(AF_split_size(vk->keylength, stripes),SECTOR_SIZE);
 625         int r;
 626         uuid_t partitionUuid;
 627         int currentSector;
 628         char luksMagic[] = LUKS_MAGIC;
 629
 630         /* For separate metadata device allow zero alignment */
 631         if (alignPayload == 0 && !detached_metadata_device)
 632                 alignPayload = DEFAULT_DISK_ALIGNMENT / SECTOR_SIZE;
 633
 634         if (PBKDF2_HMAC_ready(hashSpec) < 0) {
 635                 log_err(ctx, _("Requested LUKS hash %s is not supported.\n"), hashSpec);
 636                 return -EINVAL;
 637         }
 638
 639         if (uuid && uuid_parse(uuid, partitionUuid) == -1) {
 640                 log_err(ctx, _("Wrong LUKS UUID format provided.\n"));
 641                 return -EINVAL;
 642         }
 643         if (!uuid)
 644                 uuid_generate(partitionUuid);
 645
 646         memset(header,0,sizeof(struct luks_phdr));
 647
 648         /* Set Magic */
 649         memcpy(header->magic,luksMagic,LUKS_MAGIC_L);
 650         header->version=1;
 651         strncpy(header->cipherName,cipherName,LUKS_CIPHERNAME_L);
 652         strncpy(header->cipherMode,cipherMode,LUKS_CIPHERMODE_L);
 653         strncpy(header->hashSpec,hashSpec,LUKS_HASHSPEC_L);
 654
 655         header->keyBytes=vk->keylength;
 656
 657         LUKS_fix_header_compatible(header);
 658
 659         log_dbg("Generating LUKS header version %d using hash %s, %s, %s, MK %d bytes",
 660                 header->version, header->hashSpec ,header->cipherName, header->cipherMode,
 661                 header->keyBytes);
 662
 663         r = crypt_random_get(ctx, header->mkDigestSalt, LUKS_SALTSIZE, CRYPT_RND_SALT);
 664         if(r < 0) {
 665                 log_err(ctx,  _("Cannot create LUKS header: reading random salt failed.\n"));
 666                 return r;
 667         }
 668
 669         if ((r = LUKS_PBKDF2_performance_check(header->hashSpec, PBKDF2_per_sec, ctx)))
 670                 return r;
 671
 672         /* Compute master key digest */
 673         iteration_time_ms /= 8;
 674         header->mkDigestIterations = at_least((uint32_t)(*PBKDF2_per_sec/1024) * iteration_time_ms,
 675                                               LUKS_MKD_ITERATIONS_MIN);
 676
 677         r = PBKDF2_HMAC(header->hashSpec,vk->key,vk->keylength,
 678                         header->mkDigestSalt,LUKS_SALTSIZE,
 679                         header->mkDigestIterations,
 680                         header->mkDigest,LUKS_DIGESTSIZE);
 681         if(r < 0) {
 682                 log_err(ctx,  _("Cannot create LUKS header: header digest failed (using hash %s).\n"),
 683                         header->hashSpec);
 684                 return r;
 685         }
 686
 687         currentSector = LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE;
 688         for(i = 0; i < LUKS_NUMKEYS; ++i) {
 689                 header->keyblock[i].active = LUKS_KEY_DISABLED;
 690                 header->keyblock[i].keyMaterialOffset = currentSector;
 691                 header->keyblock[i].stripes = stripes;
 692                 currentSector = round_up_modulo(currentSector + blocksPerStripeSet,
 693                                                 LUKS_ALIGN_KEYSLOTS / SECTOR_SIZE);
 694         }
 695
 696         if (detached_metadata_device) {
 697                 /* for separate metadata device use alignPayload directly */
 698                 header->payloadOffset = alignPayload;
 699         } else {
 700                 /* alignOffset - offset from natural device alignment provided by topology info */
 701                 currentSector = round_up_modulo(currentSector, alignPayload);
 702                 header->payloadOffset = currentSector + alignOffset;
 703         }
 704
 705         uuid_unparse(partitionUuid, header->uuid);
 706
 707         log_dbg("Data offset %d, UUID %s, digest iterations %" PRIu32,
 708                 header->payloadOffset, header->uuid, header->mkDigestIterations);
 709
 710         return 0;
 711 }
 712
 713 int LUKS_hdr_uuid_set(
 714         struct luks_phdr *hdr,
 715         const char *uuid,
 716         struct crypt_device *ctx)
 717 {
 718         uuid_t partitionUuid;
 719
 720         if (uuid && uuid_parse(uuid, partitionUuid) == -1) {
 721                 log_err(ctx, _("Wrong LUKS UUID format provided.\n"));
 722                 return -EINVAL;
 723         }
 724         if (!uuid)
 725                 uuid_generate(partitionUuid);
 726
 727         uuid_unparse(partitionUuid, hdr->uuid);
 728
 729         return LUKS_write_phdr(hdr, ctx);
 730 }
 731
 732 int LUKS_set_key(unsigned int keyIndex,
 733                  const char *password, size_t passwordLen,
 734                  struct luks_phdr *hdr, struct volume_key *vk,
 735                  uint32_t iteration_time_ms,
 736                  uint64_t *PBKDF2_per_sec,
 737                  struct crypt_device *ctx)
 738 {
 739         struct volume_key *derived_key;
 740         char *AfKey = NULL;
 741         size_t AFEKSize;
 742         uint64_t PBKDF2_temp;
 743         int r;
 744
 745         if(hdr->keyblock[keyIndex].active != LUKS_KEY_DISABLED) {
 746                 log_err(ctx,  _("Key slot %d active, purge first.\n"), keyIndex);
 747                 return -EINVAL;
 748         }
 749
 750         /* LUKS keyslot has always at least 4000 stripes accoding to specification */
 751         if(hdr->keyblock[keyIndex].stripes < 4000) {
 752                 log_err(ctx, _("Key slot %d material includes too few stripes. Header manipulation?\n"),
 753                         keyIndex);
 754                  return -EINVAL;
 755         }
 756
 757         log_dbg("Calculating data for key slot %d", keyIndex);
 758
 759         if ((r = LUKS_PBKDF2_performance_check(hdr->hashSpec, PBKDF2_per_sec, ctx)))
 760                 return r;
 761
 762         /*
 763          * Avoid floating point operation
 764          * Final iteration count is at least LUKS_SLOT_ITERATIONS_MIN
 765          */
 766         PBKDF2_temp = (*PBKDF2_per_sec / 2) * (uint64_t)iteration_time_ms;
 767         PBKDF2_temp /= 1024;
 768         if (PBKDF2_temp > UINT32_MAX)
 769                 PBKDF2_temp = UINT32_MAX;
 770         hdr->keyblock[keyIndex].passwordIterations = at_least((uint32_t)PBKDF2_temp,
 771                                                               LUKS_SLOT_ITERATIONS_MIN);
 772
 773         log_dbg("Key slot %d use %d password iterations.", keyIndex, hdr->keyblock[keyIndex].passwordIterations);
 774
 775         derived_key = crypt_alloc_volume_key(hdr->keyBytes, NULL);
 776         if (!derived_key)
 777                 return -ENOMEM;
 778
 779         r = crypt_random_get(ctx, hdr->keyblock[keyIndex].passwordSalt,
 780                        LUKS_SALTSIZE, CRYPT_RND_SALT);
 781         if (r < 0)
 782                 return r;
 783
 784         r = PBKDF2_HMAC(hdr->hashSpec, password,passwordLen,
 785                         hdr->keyblock[keyIndex].passwordSalt,LUKS_SALTSIZE,
 786                         hdr->keyblock[keyIndex].passwordIterations,
 787                         derived_key->key, hdr->keyBytes);
 788         if (r < 0)
 789                 goto out;
 790
 791         /*
 792          * AF splitting, the masterkey stored in vk->key is split to AfKey
 793          */
 794         assert(vk->keylength == hdr->keyBytes);
 795         AFEKSize = AF_split_size(vk->keylength, hdr->keyblock[keyIndex].stripes);
 796         AfKey = crypt_safe_alloc(AFEKSize);
 797         if (!AfKey) {
 798                 r = -ENOMEM;
 799                 goto out;
 800         }
 801
 802         log_dbg("Using hash %s for AF in key slot %d, %d stripes",
 803                 hdr->hashSpec, keyIndex, hdr->keyblock[keyIndex].stripes);
 804         r = AF_split(vk->key,AfKey,vk->keylength,hdr->keyblock[keyIndex].stripes,hdr->hashSpec);
 805         if (r < 0)
 806                 goto out;
 807
 808         log_dbg("Updating key slot %d [0x%04x] area.", keyIndex,
 809                 hdr->keyblock[keyIndex].keyMaterialOffset << 9);
 810         /* Encryption via dm */
 811         r = LUKS_encrypt_to_storage(AfKey,
 812                                     AFEKSize,
 813                                     hdr,
 814                                     derived_key,
 815                                     hdr->keyblock[keyIndex].keyMaterialOffset,
 816                                     ctx);
 817         if (r < 0)
 818                 goto out;
 819
 820         /* Mark the key as active in phdr */
 821         r = LUKS_keyslot_set(hdr, (int)keyIndex, 1);
 822         if (r < 0)
 823                 goto out;
 824
 825         r = LUKS_write_phdr(hdr, ctx);
 826         if (r < 0)
 827                 goto out;
 828
 829         r = 0;
 830 out:
 831         crypt_safe_free(AfKey);
 832         crypt_free_volume_key(derived_key);
 833         return r;
 834 }
 835
 836 /* Check whether a volume key is invalid. */
 837 int LUKS_verify_volume_key(const struct luks_phdr *hdr,
 838                            const struct volume_key *vk)
 839 {
 840         char checkHashBuf[LUKS_DIGESTSIZE];
 841
 842         if (PBKDF2_HMAC(hdr->hashSpec, vk->key, vk->keylength,
 843                         hdr->mkDigestSalt, LUKS_SALTSIZE,
 844                         hdr->mkDigestIterations, checkHashBuf,
 845                         LUKS_DIGESTSIZE) < 0)
 846                 return -EINVAL;
 847
 848         if (memcmp(checkHashBuf, hdr->mkDigest, LUKS_DIGESTSIZE))
 849                 return -EPERM;
 850
 851         return 0;
 852 }
 853
 854 /* Try to open a particular key slot */
 855 static int LUKS_open_key(unsigned int keyIndex,
 856                   const char *password,
 857                   size_t passwordLen,
 858                   struct luks_phdr *hdr,
 859                   struct volume_key *vk,
 860                   struct crypt_device *ctx)
 861 {
 862         crypt_keyslot_info ki = LUKS_keyslot_info(hdr, keyIndex);
 863         struct volume_key *derived_key;
 864         char *AfKey;
 865         size_t AFEKSize;
 866         int r;
 867
 868         log_dbg("Trying to open key slot %d [%s].", keyIndex,
 869                 dbg_slot_state(ki));
 870
 871         if (ki < CRYPT_SLOT_ACTIVE)
 872                 return -ENOENT;
 873
 874         derived_key = crypt_alloc_volume_key(hdr->keyBytes, NULL);
 875         if (!derived_key)
 876                 return -ENOMEM;
 877
 878         assert(vk->keylength == hdr->keyBytes);
 879         AFEKSize = AF_split_size(vk->keylength, hdr->keyblock[keyIndex].stripes);
 880         AfKey = crypt_safe_alloc(AFEKSize);
 881         if (!AfKey)
 882                 return -ENOMEM;
 883
 884         r = PBKDF2_HMAC(hdr->hashSpec, password,passwordLen,
 885                         hdr->keyblock[keyIndex].passwordSalt,LUKS_SALTSIZE,
 886                         hdr->keyblock[keyIndex].passwordIterations,
 887                         derived_key->key, hdr->keyBytes);
 888         if (r < 0)
 889                 goto out;
 890
 891         log_dbg("Reading key slot %d area.", keyIndex);
 892         r = LUKS_decrypt_from_storage(AfKey,
 893                                       AFEKSize,
 894                                       hdr,
 895                                       derived_key,
 896                                       hdr->keyblock[keyIndex].keyMaterialOffset,
 897                                       ctx);
 898         if (r < 0)
 899                 goto out;
 900
 901         r = AF_merge(AfKey,vk->key,vk->keylength,hdr->keyblock[keyIndex].stripes,hdr->hashSpec);
 902         if (r < 0)
 903                 goto out;
 904
 905         r = LUKS_verify_volume_key(hdr, vk);
 906         if (!r)
 907                 log_verbose(ctx, _("Key slot %d unlocked.\n"), keyIndex);
 908 out:
 909         crypt_safe_free(AfKey);
 910         crypt_free_volume_key(derived_key);
 911         return r;
 912 }
 913
 914 int LUKS_open_key_with_hdr(int keyIndex,
 915                            const char *password,
 916                            size_t passwordLen,
 917                            struct luks_phdr *hdr,
 918                            struct volume_key **vk,
 919                            struct crypt_device *ctx)
 920 {
 921         unsigned int i;
 922         int r;
 923
 924         *vk = crypt_alloc_volume_key(hdr->keyBytes, NULL);
 925
 926         if (keyIndex >= 0) {
 927                 r = LUKS_open_key(keyIndex, password, passwordLen, hdr, *vk, ctx);
 928                 return (r < 0) ? r : keyIndex;
 929         }
 930
 931         for(i = 0; i < LUKS_NUMKEYS; i++) {
 932                 r = LUKS_open_key(i, password, passwordLen, hdr, *vk, ctx);
 933                 if(r == 0)
 934                         return i;
 935
 936                 /* Do not retry for errors that are no -EPERM or -ENOENT,
 937                    former meaning password wrong, latter key slot inactive */
 938                 if ((r != -EPERM) && (r != -ENOENT))
 939                         return r;
 940         }
 941         /* Warning, early returns above */
 942         log_err(ctx, _("No key available with this passphrase.\n"));
 943         return -EPERM;
 944 }
 945
 946 int LUKS_del_key(unsigned int keyIndex,
 947                  struct luks_phdr *hdr,
 948                  struct crypt_device *ctx)
 949 {
 950         struct device *device = crypt_metadata_device(ctx);
 951         unsigned int startOffset, endOffset;
 952         int r;
 953
 954         r = LUKS_read_phdr(hdr, 1, 0, ctx);
 955         if (r)
 956                 return r;
 957
 958         r = LUKS_keyslot_set(hdr, keyIndex, 0);
 959         if (r) {
 960                 log_err(ctx, _("Key slot %d is invalid, please select keyslot between 0 and %d.\n"),
 961                         keyIndex, LUKS_NUMKEYS - 1);
 962                 return r;
 963         }
 964
 965         /* secure deletion of key material */
 966         startOffset = hdr->keyblock[keyIndex].keyMaterialOffset;
 967         endOffset = startOffset + div_round_up(AF_split_size(hdr->keyBytes, hdr->keyblock[keyIndex].stripes), SECTOR_SIZE);
 968
 969         r = crypt_wipe(device, startOffset * SECTOR_SIZE,
 970                        (endOffset - startOffset) * SECTOR_SIZE,
 971                        CRYPT_WIPE_DISK, 0);
 972         if (r) {
 973                 if (r == -EACCES) {
 974                         log_err(ctx, _("Cannot write to device %s, permission denied.\n"),
 975                                 device_path(device));
 976                         r = -EINVAL;
 977                 } else
 978                         log_err(ctx, _("Cannot wipe device %s.\n"),
 979                                 device_path(device));
 980                 return r;
 981         }
 982
 983         /* Wipe keyslot info */
 984         memset(&hdr->keyblock[keyIndex].passwordSalt, 0, LUKS_SALTSIZE);
 985         hdr->keyblock[keyIndex].passwordIterations = 0;
 986
 987         r = LUKS_write_phdr(hdr, ctx);
 988
 989         return r;
 990 }
 991
 992 crypt_keyslot_info LUKS_keyslot_info(struct luks_phdr *hdr, int keyslot)
 993 {
 994         int i;
 995
 996         if(keyslot >= LUKS_NUMKEYS || keyslot < 0)
 997                 return CRYPT_SLOT_INVALID;
 998
 999         if (hdr->keyblock[keyslot].active == LUKS_KEY_DISABLED)
1000                 return CRYPT_SLOT_INACTIVE;
1001
1002         if (hdr->keyblock[keyslot].active != LUKS_KEY_ENABLED)
1003                 return CRYPT_SLOT_INVALID;
1004
1005         for(i = 0; i < LUKS_NUMKEYS; i++)
1006                 if(i != keyslot && hdr->keyblock[i].active == LUKS_KEY_ENABLED)
1007                         return CRYPT_SLOT_ACTIVE;
1008
1009         return CRYPT_SLOT_ACTIVE_LAST;
1010 }
1011
1012 int LUKS_keyslot_find_empty(struct luks_phdr *hdr)
1013 {
1014         int i;
1015
1016         for (i = 0; i < LUKS_NUMKEYS; i++)
1017                 if(hdr->keyblock[i].active == LUKS_KEY_DISABLED)
1018                         break;
1019
1020         if (i == LUKS_NUMKEYS)
1021                 return -EINVAL;
1022
1023         return i;
1024 }
1025
1026 int LUKS_keyslot_active_count(struct luks_phdr *hdr)
1027 {
1028         int i, num = 0;
1029
1030         for (i = 0; i < LUKS_NUMKEYS; i++)
1031                 if(hdr->keyblock[i].active == LUKS_KEY_ENABLED)
1032                         num++;
1033
1034         return num;
1035 }
1036
1037 int LUKS_keyslot_set(struct luks_phdr *hdr, int keyslot, int enable)
1038 {
1039         crypt_keyslot_info ki = LUKS_keyslot_info(hdr, keyslot);
1040
1041         if (ki == CRYPT_SLOT_INVALID)
1042                 return -EINVAL;
1043
1044         hdr->keyblock[keyslot].active = enable ? LUKS_KEY_ENABLED : LUKS_KEY_DISABLED;
1045         log_dbg("Key slot %d was %s in LUKS header.", keyslot, enable ? "enabled" : "disabled");
1046         return 0;
1047 }
1048
1049 int LUKS1_activate(struct crypt_device *cd,
1050                    const char *name,
1051                    struct volume_key *vk,
1052                    uint32_t flags)
1053 {
1054         int r;
1055         char *dm_cipher = NULL;
1056         enum devcheck device_check;
1057         struct crypt_dm_active_device dmd = {
1058                 .target = DM_CRYPT,
1059                 .uuid   = crypt_get_uuid(cd),
1060                 .flags  = flags,
1061                 .size   = 0,
1062                 .data_device = crypt_data_device(cd),
1063                 .u.crypt = {
1064                         .cipher = NULL,
1065                         .vk     = vk,
1066                         .offset = crypt_get_data_offset(cd),
1067                         .iv_offset = 0,
1068                 }
1069         };
1070
1071         if (dmd.flags & CRYPT_ACTIVATE_SHARED)
1072                 device_check = DEV_SHARED;
1073         else
1074                 device_check = DEV_EXCL;
1075
1076         r = device_block_adjust(cd, dmd.data_device, device_check,
1077                                  dmd.u.crypt.offset, &dmd.size, &dmd.flags);
1078         if (r)
1079                 return r;
1080
1081         r = asprintf(&dm_cipher, "%s-%s", crypt_get_cipher(cd), crypt_get_cipher_mode(cd));
1082         if (r < 0)
1083                 return -ENOMEM;
1084
1085         dmd.u.crypt.cipher = dm_cipher;
1086         r = dm_create_device(cd, name, CRYPT_LUKS1, &dmd, 0);
1087
1088         free(dm_cipher);
1089         return r;
1090 }