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