crypto/block-luks.c

   1 /*
   2  * QEMU Crypto block device encryption LUKS format
   3  *
   4  * Copyright (c) 2015-2016 Red Hat, Inc.
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library 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 GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  *
  19  */
  20
  21 #include "qemu/osdep.h"
  22 #include "qapi/error.h"
  23 #include "qemu/bswap.h"
  24
  25 #include "block-luks.h"
  26 #include "block-luks-priv.h"
  27
  28 #include "crypto/hash.h"
  29 #include "crypto/afsplit.h"
  30 #include "crypto/pbkdf.h"
  31 #include "crypto/secret.h"
  32 #include "crypto/random.h"
  33 #include "qemu/uuid.h"
  34
  35 #include "qemu/bitmap.h"
  36 #include "qemu/range.h"
  37
  38 /*
  39  * Reference for the LUKS format implemented here is
  40  *
  41  *   docs/on-disk-format.pdf
  42  *
  43  * in 'cryptsetup' package source code
  44  *
  45  * This file implements the 1.2.1 specification, dated
  46  * Oct 16, 2011.
  47  */
  48
  49 typedef struct QCryptoBlockLUKS QCryptoBlockLUKS;
  50
  51 typedef struct QCryptoBlockLUKSNameMap QCryptoBlockLUKSNameMap;
  52 struct QCryptoBlockLUKSNameMap {
  53     const char *name;
  54     int id;
  55 };
  56
  57 typedef struct QCryptoBlockLUKSCipherSizeMap QCryptoBlockLUKSCipherSizeMap;
  58 struct QCryptoBlockLUKSCipherSizeMap {
  59     uint32_t key_bytes;
  60     int id;
  61 };
  62 typedef struct QCryptoBlockLUKSCipherNameMap QCryptoBlockLUKSCipherNameMap;
  63 struct QCryptoBlockLUKSCipherNameMap {
  64     const char *name;
  65     const QCryptoBlockLUKSCipherSizeMap *sizes;
  66 };
  67
  68
  69 static const QCryptoBlockLUKSCipherSizeMap
  70 qcrypto_block_luks_cipher_size_map_aes[] = {
  71     { 16, QCRYPTO_CIPHER_ALGO_AES_128 },
  72     { 24, QCRYPTO_CIPHER_ALGO_AES_192 },
  73     { 32, QCRYPTO_CIPHER_ALGO_AES_256 },
  74     { 0, 0 },
  75 };
  76
  77 static const QCryptoBlockLUKSCipherSizeMap
  78 qcrypto_block_luks_cipher_size_map_cast5[] = {
  79     { 16, QCRYPTO_CIPHER_ALGO_CAST5_128 },
  80     { 0, 0 },
  81 };
  82
  83 static const QCryptoBlockLUKSCipherSizeMap
  84 qcrypto_block_luks_cipher_size_map_serpent[] = {
  85     { 16, QCRYPTO_CIPHER_ALGO_SERPENT_128 },
  86     { 24, QCRYPTO_CIPHER_ALGO_SERPENT_192 },
  87     { 32, QCRYPTO_CIPHER_ALGO_SERPENT_256 },
  88     { 0, 0 },
  89 };
  90
  91 static const QCryptoBlockLUKSCipherSizeMap
  92 qcrypto_block_luks_cipher_size_map_twofish[] = {
  93     { 16, QCRYPTO_CIPHER_ALGO_TWOFISH_128 },
  94     { 24, QCRYPTO_CIPHER_ALGO_TWOFISH_192 },
  95     { 32, QCRYPTO_CIPHER_ALGO_TWOFISH_256 },
  96     { 0, 0 },
  97 };
  98
  99 #ifdef CONFIG_CRYPTO_SM4
 100 static const QCryptoBlockLUKSCipherSizeMap
 101 qcrypto_block_luks_cipher_size_map_sm4[] = {
 102     { 16, QCRYPTO_CIPHER_ALGO_SM4},
 103     { 0, 0 },
 104 };
 105 #endif
 106
 107 static const QCryptoBlockLUKSCipherNameMap
 108 qcrypto_block_luks_cipher_name_map[] = {
 109     { "aes", qcrypto_block_luks_cipher_size_map_aes },
 110     { "cast5", qcrypto_block_luks_cipher_size_map_cast5 },
 111     { "serpent", qcrypto_block_luks_cipher_size_map_serpent },
 112     { "twofish", qcrypto_block_luks_cipher_size_map_twofish },
 113 #ifdef CONFIG_CRYPTO_SM4
 114     { "sm4", qcrypto_block_luks_cipher_size_map_sm4},
 115 #endif
 116 };
 117
 118 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48);
 119 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592);
 120
 121
 122 struct QCryptoBlockLUKS {
 123     QCryptoBlockLUKSHeader header;
 124
 125     /* Main encryption algorithm used for encryption*/
 126     QCryptoCipherAlgo cipher_alg;
 127
 128     /* Mode of encryption for the selected encryption algorithm */
 129     QCryptoCipherMode cipher_mode;
 130
 131     /* Initialization vector generation algorithm */
 132     QCryptoIVGenAlgo ivgen_alg;
 133
 134     /* Hash algorithm used for IV generation*/
 135     QCryptoHashAlgo ivgen_hash_alg;
 136
 137     /*
 138      * Encryption algorithm used for IV generation.
 139      * Usually the same as main encryption algorithm
 140      */
 141     QCryptoCipherAlgo ivgen_cipher_alg;
 142
 143     /* Hash algorithm used in pbkdf2 function */
 144     QCryptoHashAlgo hash_alg;
 145
 146     /* Name of the secret that was used to open the image */
 147     char *secret;
 148 };
 149
 150
 151 static int qcrypto_block_luks_cipher_name_lookup(const char *name,
 152                                                  QCryptoCipherMode mode,
 153                                                  uint32_t key_bytes,
 154                                                  Error **errp)
 155 {
 156     const QCryptoBlockLUKSCipherNameMap *map =
 157         qcrypto_block_luks_cipher_name_map;
 158     size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
 159     size_t i, j;
 160
 161     if (mode == QCRYPTO_CIPHER_MODE_XTS) {
 162         key_bytes /= 2;
 163     }
 164
 165     for (i = 0; i < maplen; i++) {
 166         if (!g_str_equal(map[i].name, name)) {
 167             continue;
 168         }
 169         for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
 170             if (map[i].sizes[j].key_bytes == key_bytes) {
 171                 return map[i].sizes[j].id;
 172             }
 173         }
 174     }
 175
 176     error_setg(errp, "Algorithm '%s' with key size %d bytes not supported",
 177                name, key_bytes);
 178     return 0;
 179 }
 180
 181 static const char *
 182 qcrypto_block_luks_cipher_alg_lookup(QCryptoCipherAlgo alg,
 183                                      Error **errp)
 184 {
 185     const QCryptoBlockLUKSCipherNameMap *map =
 186         qcrypto_block_luks_cipher_name_map;
 187     size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
 188     size_t i, j;
 189     for (i = 0; i < maplen; i++) {
 190         for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
 191             if (map[i].sizes[j].id == alg) {
 192                 return map[i].name;
 193             }
 194         }
 195     }
 196
 197     error_setg(errp, "Algorithm '%s' not supported",
 198                QCryptoCipherAlgo_str(alg));
 199     return NULL;
 200 }
 201
 202 /* XXX replace with qapi_enum_parse() in future, when we can
 203  * make that function emit a more friendly error message */
 204 static int qcrypto_block_luks_name_lookup(const char *name,
 205                                           const QEnumLookup *map,
 206                                           const char *type,
 207                                           Error **errp)
 208 {
 209     int ret = qapi_enum_parse(map, name, -1, NULL);
 210
 211     if (ret < 0) {
 212         error_setg(errp, "%s '%s' not supported", type, name);
 213         return 0;
 214     }
 215     return ret;
 216 }
 217
 218 #define qcrypto_block_luks_cipher_mode_lookup(name, errp)               \
 219     qcrypto_block_luks_name_lookup(name,                                \
 220                                    &QCryptoCipherMode_lookup,           \
 221                                    "Cipher mode",                       \
 222                                    errp)
 223
 224 #define qcrypto_block_luks_hash_name_lookup(name, errp)                 \
 225     qcrypto_block_luks_name_lookup(name,                                \
 226                                    &QCryptoHashAlgo_lookup,        \
 227                                    "Hash algorithm",                    \
 228                                    errp)
 229
 230 #define qcrypto_block_luks_ivgen_name_lookup(name, errp)                \
 231     qcrypto_block_luks_name_lookup(name,                                \
 232                                    &QCryptoIVGenAlgo_lookup,       \
 233                                    "IV generator",                      \
 234                                    errp)
 235
 236
 237 static bool
 238 qcrypto_block_luks_has_format(const uint8_t *buf,
 239                               size_t buf_size)
 240 {
 241     const QCryptoBlockLUKSHeader *luks_header = (const void *)buf;
 242
 243     if (buf_size >= offsetof(QCryptoBlockLUKSHeader, cipher_name) &&
 244         memcmp(luks_header->magic, qcrypto_block_luks_magic,
 245                QCRYPTO_BLOCK_LUKS_MAGIC_LEN) == 0 &&
 246         be16_to_cpu(luks_header->version) == QCRYPTO_BLOCK_LUKS_VERSION) {
 247         return true;
 248     } else {
 249         return false;
 250     }
 251 }
 252
 253
 254 /**
 255  * Deal with a quirk of dm-crypt usage of ESSIV.
 256  *
 257  * When calculating ESSIV IVs, the cipher length used by ESSIV
 258  * may be different from the cipher length used for the block
 259  * encryption, because dm-crypt uses the hash digest length
 260  * as the key size. ie, if you have AES 128 as the block cipher
 261  * and SHA 256 as ESSIV hash, then ESSIV will use AES 256 as
 262  * the cipher since that gets a key length matching the digest
 263  * size, not AES 128 with truncated digest as might be imagined
 264  */
 265 static QCryptoCipherAlgo
 266 qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgo cipher,
 267                                 QCryptoHashAlgo hash,
 268                                 Error **errp)
 269 {
 270     size_t digestlen = qcrypto_hash_digest_len(hash);
 271     size_t keylen = qcrypto_cipher_get_key_len(cipher);
 272     if (digestlen == keylen) {
 273         return cipher;
 274     }
 275
 276     switch (cipher) {
 277     case QCRYPTO_CIPHER_ALGO_AES_128:
 278     case QCRYPTO_CIPHER_ALGO_AES_192:
 279     case QCRYPTO_CIPHER_ALGO_AES_256:
 280         if (digestlen == qcrypto_cipher_get_key_len(
 281                 QCRYPTO_CIPHER_ALGO_AES_128)) {
 282             return QCRYPTO_CIPHER_ALGO_AES_128;
 283         } else if (digestlen == qcrypto_cipher_get_key_len(
 284                        QCRYPTO_CIPHER_ALGO_AES_192)) {
 285             return QCRYPTO_CIPHER_ALGO_AES_192;
 286         } else if (digestlen == qcrypto_cipher_get_key_len(
 287                        QCRYPTO_CIPHER_ALGO_AES_256)) {
 288             return QCRYPTO_CIPHER_ALGO_AES_256;
 289         } else {
 290             error_setg(errp, "No AES cipher with key size %zu available",
 291                        digestlen);
 292             return 0;
 293         }
 294         break;
 295     case QCRYPTO_CIPHER_ALGO_SERPENT_128:
 296     case QCRYPTO_CIPHER_ALGO_SERPENT_192:
 297     case QCRYPTO_CIPHER_ALGO_SERPENT_256:
 298         if (digestlen == qcrypto_cipher_get_key_len(
 299                 QCRYPTO_CIPHER_ALGO_SERPENT_128)) {
 300             return QCRYPTO_CIPHER_ALGO_SERPENT_128;
 301         } else if (digestlen == qcrypto_cipher_get_key_len(
 302                        QCRYPTO_CIPHER_ALGO_SERPENT_192)) {
 303             return QCRYPTO_CIPHER_ALGO_SERPENT_192;
 304         } else if (digestlen == qcrypto_cipher_get_key_len(
 305                        QCRYPTO_CIPHER_ALGO_SERPENT_256)) {
 306             return QCRYPTO_CIPHER_ALGO_SERPENT_256;
 307         } else {
 308             error_setg(errp, "No Serpent cipher with key size %zu available",
 309                        digestlen);
 310             return 0;
 311         }
 312         break;
 313     case QCRYPTO_CIPHER_ALGO_TWOFISH_128:
 314     case QCRYPTO_CIPHER_ALGO_TWOFISH_192:
 315     case QCRYPTO_CIPHER_ALGO_TWOFISH_256:
 316         if (digestlen == qcrypto_cipher_get_key_len(
 317                 QCRYPTO_CIPHER_ALGO_TWOFISH_128)) {
 318             return QCRYPTO_CIPHER_ALGO_TWOFISH_128;
 319         } else if (digestlen == qcrypto_cipher_get_key_len(
 320                        QCRYPTO_CIPHER_ALGO_TWOFISH_192)) {
 321             return QCRYPTO_CIPHER_ALGO_TWOFISH_192;
 322         } else if (digestlen == qcrypto_cipher_get_key_len(
 323                        QCRYPTO_CIPHER_ALGO_TWOFISH_256)) {
 324             return QCRYPTO_CIPHER_ALGO_TWOFISH_256;
 325         } else {
 326             error_setg(errp, "No Twofish cipher with key size %zu available",
 327                        digestlen);
 328             return 0;
 329         }
 330         break;
 331     default:
 332         error_setg(errp, "Cipher %s not supported with essiv",
 333                    QCryptoCipherAlgo_str(cipher));
 334         return 0;
 335     }
 336 }
 337
 338 /*
 339  * Returns number of sectors needed to store the key material
 340  * given number of anti forensic stripes
 341  */
 342 static int
 343 qcrypto_block_luks_splitkeylen_sectors(const QCryptoBlockLUKS *luks,
 344                                        unsigned int header_sectors,
 345                                        unsigned int stripes)
 346 {
 347     /*
 348      * This calculation doesn't match that shown in the spec,
 349      * but instead follows the cryptsetup implementation.
 350      */
 351
 352     size_t splitkeylen = luks->header.master_key_len * stripes;
 353
 354     /* First align the key material size to block size*/
 355     size_t splitkeylen_sectors =
 356         DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE);
 357
 358     /* Then also align the key material size to the size of the header */
 359     return ROUND_UP(splitkeylen_sectors, header_sectors);
 360 }
 361
 362
 363 void
 364 qcrypto_block_luks_to_disk_endian(QCryptoBlockLUKSHeader *hdr)
 365 {
 366     size_t i;
 367
 368     /*
 369      * Everything on disk uses Big Endian (tm), so flip header fields
 370      * before writing them
 371      */
 372     cpu_to_be16s(&hdr->version);
 373     cpu_to_be32s(&hdr->payload_offset_sector);
 374     cpu_to_be32s(&hdr->master_key_len);
 375     cpu_to_be32s(&hdr->master_key_iterations);
 376
 377     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
 378         cpu_to_be32s(&hdr->key_slots[i].active);
 379         cpu_to_be32s(&hdr->key_slots[i].iterations);
 380         cpu_to_be32s(&hdr->key_slots[i].key_offset_sector);
 381         cpu_to_be32s(&hdr->key_slots[i].stripes);
 382     }
 383 }
 384
 385 void
 386 qcrypto_block_luks_from_disk_endian(QCryptoBlockLUKSHeader *hdr)
 387 {
 388     size_t i;
 389
 390     /*
 391      * The header is always stored in big-endian format, so
 392      * convert everything to native
 393      */
 394     be16_to_cpus(&hdr->version);
 395     be32_to_cpus(&hdr->payload_offset_sector);
 396     be32_to_cpus(&hdr->master_key_len);
 397     be32_to_cpus(&hdr->master_key_iterations);
 398
 399     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
 400         be32_to_cpus(&hdr->key_slots[i].active);
 401         be32_to_cpus(&hdr->key_slots[i].iterations);
 402         be32_to_cpus(&hdr->key_slots[i].key_offset_sector);
 403         be32_to_cpus(&hdr->key_slots[i].stripes);
 404     }
 405 }
 406
 407 /*
 408  * Stores the main LUKS header, taking care of endianness
 409  */
 410 static int
 411 qcrypto_block_luks_store_header(QCryptoBlock *block,
 412                                 QCryptoBlockWriteFunc writefunc,
 413                                 void *opaque,
 414                                 Error **errp)
 415 {
 416     const QCryptoBlockLUKS *luks = block->opaque;
 417     Error *local_err = NULL;
 418     g_autofree QCryptoBlockLUKSHeader *hdr_copy = NULL;
 419
 420     /* Create a copy of the header */
 421     hdr_copy = g_new0(QCryptoBlockLUKSHeader, 1);
 422     memcpy(hdr_copy, &luks->header, sizeof(QCryptoBlockLUKSHeader));
 423
 424     qcrypto_block_luks_to_disk_endian(hdr_copy);
 425
 426     /* Write out the partition header and key slot headers */
 427     writefunc(block, 0, (const uint8_t *)hdr_copy, sizeof(*hdr_copy),
 428               opaque, &local_err);
 429
 430     if (local_err) {
 431         error_propagate(errp, local_err);
 432         return -1;
 433     }
 434     return 0;
 435 }
 436
 437 /*
 438  * Loads the main LUKS header, and byteswaps it to native endianness
 439  * And run basic sanity checks on it
 440  */
 441 static int
 442 qcrypto_block_luks_load_header(QCryptoBlock *block,
 443                                 QCryptoBlockReadFunc readfunc,
 444                                 void *opaque,
 445                                 Error **errp)
 446 {
 447     int rv;
 448     QCryptoBlockLUKS *luks = block->opaque;
 449
 450     /*
 451      * Read the entire LUKS header, minus the key material from
 452      * the underlying device
 453      */
 454     rv = readfunc(block, 0,
 455                   (uint8_t *)&luks->header,
 456                   sizeof(luks->header),
 457                   opaque,
 458                   errp);
 459     if (rv < 0) {
 460         return rv;
 461     }
 462
 463     qcrypto_block_luks_from_disk_endian(&luks->header);
 464
 465     return 0;
 466 }
 467
 468 /*
 469  * Does basic sanity checks on the LUKS header
 470  */
 471 static int
 472 qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks,
 473                                 unsigned int flags,
 474                                 Error **errp)
 475 {
 476     size_t i, j;
 477
 478     unsigned int header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
 479         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
 480     bool detached = flags & QCRYPTO_BLOCK_OPEN_DETACHED;
 481
 482     if (memcmp(luks->header.magic, qcrypto_block_luks_magic,
 483                QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) {
 484         error_setg(errp, "Volume is not in LUKS format");
 485         return -1;
 486     }
 487
 488     if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) {
 489         error_setg(errp, "LUKS version %" PRIu32 " is not supported",
 490                    luks->header.version);
 491         return -1;
 492     }
 493
 494     if (!memchr(luks->header.cipher_name, '\0',
 495                 sizeof(luks->header.cipher_name))) {
 496         error_setg(errp, "LUKS header cipher name is not NUL terminated");
 497         return -1;
 498     }
 499
 500     if (!memchr(luks->header.cipher_mode, '\0',
 501                 sizeof(luks->header.cipher_mode))) {
 502         error_setg(errp, "LUKS header cipher mode is not NUL terminated");
 503         return -1;
 504     }
 505
 506     if (!memchr(luks->header.hash_spec, '\0',
 507                 sizeof(luks->header.hash_spec))) {
 508         error_setg(errp, "LUKS header hash spec is not NUL terminated");
 509         return -1;
 510     }
 511
 512     if (!detached && luks->header.payload_offset_sector <
 513         DIV_ROUND_UP(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET,
 514                      QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) {
 515         error_setg(errp, "LUKS payload is overlapping with the header");
 516         return -1;
 517     }
 518
 519     if (luks->header.master_key_iterations == 0) {
 520         error_setg(errp, "LUKS key iteration count is zero");
 521         return -1;
 522     }
 523
 524     /* Check all keyslots for corruption  */
 525     for (i = 0 ; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; i++) {
 526
 527         const QCryptoBlockLUKSKeySlot *slot1 = &luks->header.key_slots[i];
 528         unsigned int start1 = slot1->key_offset_sector;
 529         unsigned int len1 =
 530             qcrypto_block_luks_splitkeylen_sectors(luks,
 531                                                    header_sectors,
 532                                                    slot1->stripes);
 533
 534         if (slot1->stripes != QCRYPTO_BLOCK_LUKS_STRIPES) {
 535             error_setg(errp, "Keyslot %zu is corrupted (stripes %d != %d)",
 536                        i, slot1->stripes, QCRYPTO_BLOCK_LUKS_STRIPES);
 537             return -1;
 538         }
 539
 540         if (slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED &&
 541             slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) {
 542             error_setg(errp,
 543                        "Keyslot %zu state (active/disable) is corrupted", i);
 544             return -1;
 545         }
 546
 547         if (slot1->active == QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED &&
 548             slot1->iterations == 0) {
 549             error_setg(errp, "Keyslot %zu iteration count is zero", i);
 550             return -1;
 551         }
 552
 553         if (start1 < DIV_ROUND_UP(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET,
 554                                   QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) {
 555             error_setg(errp,
 556                        "Keyslot %zu is overlapping with the LUKS header",
 557                        i);
 558             return -1;
 559         }
 560
 561         if (!detached && start1 + len1 > luks->header.payload_offset_sector) {
 562             error_setg(errp,
 563                        "Keyslot %zu is overlapping with the encrypted payload",
 564                        i);
 565             return -1;
 566         }
 567
 568         for (j = i + 1 ; j < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; j++) {
 569             const QCryptoBlockLUKSKeySlot *slot2 = &luks->header.key_slots[j];
 570             unsigned int start2 = slot2->key_offset_sector;
 571             unsigned int len2 =
 572                 qcrypto_block_luks_splitkeylen_sectors(luks,
 573                                                        header_sectors,
 574                                                        slot2->stripes);
 575
 576             if (ranges_overlap(start1, len1, start2, len2)) {
 577                 error_setg(errp,
 578                            "Keyslots %zu and %zu are overlapping in the header",
 579                            i, j);
 580                 return -1;
 581             }
 582         }
 583
 584     }
 585     return 0;
 586 }
 587
 588 /*
 589  * Parses the crypto parameters that are stored in the LUKS header
 590  */
 591
 592 static int
 593 qcrypto_block_luks_parse_header(QCryptoBlockLUKS *luks, Error **errp)
 594 {
 595     g_autofree char *cipher_mode = g_strdup(luks->header.cipher_mode);
 596     char *ivgen_name, *ivhash_name;
 597     Error *local_err = NULL;
 598
 599     /*
 600      * The cipher_mode header contains a string that we have
 601      * to further parse, of the format
 602      *
 603      *    <cipher-mode>-<iv-generator>[:<iv-hash>]
 604      *
 605      * eg  cbc-essiv:sha256, cbc-plain64
 606      */
 607     ivgen_name = strchr(cipher_mode, '-');
 608     if (!ivgen_name) {
 609         error_setg(errp, "Unexpected cipher mode string format '%s'",
 610                    luks->header.cipher_mode);
 611         return -1;
 612     }
 613     *ivgen_name = '\0';
 614     ivgen_name++;
 615
 616     ivhash_name = strchr(ivgen_name, ':');
 617     if (!ivhash_name) {
 618         luks->ivgen_hash_alg = 0;
 619     } else {
 620         *ivhash_name = '\0';
 621         ivhash_name++;
 622
 623         luks->ivgen_hash_alg = qcrypto_block_luks_hash_name_lookup(ivhash_name,
 624                                                                    &local_err);
 625         if (local_err) {
 626             error_propagate(errp, local_err);
 627             return -1;
 628         }
 629     }
 630
 631     luks->cipher_mode = qcrypto_block_luks_cipher_mode_lookup(cipher_mode,
 632                                                               &local_err);
 633     if (local_err) {
 634         error_propagate(errp, local_err);
 635         return -1;
 636     }
 637
 638     luks->cipher_alg =
 639             qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name,
 640                                                   luks->cipher_mode,
 641                                                   luks->header.master_key_len,
 642                                                   &local_err);
 643     if (local_err) {
 644         error_propagate(errp, local_err);
 645         return -1;
 646     }
 647
 648     luks->hash_alg =
 649             qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec,
 650                                                 &local_err);
 651     if (local_err) {
 652         error_propagate(errp, local_err);
 653         return -1;
 654     }
 655
 656     luks->ivgen_alg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name,
 657                                                            &local_err);
 658     if (local_err) {
 659         error_propagate(errp, local_err);
 660         return -1;
 661     }
 662
 663     if (luks->ivgen_alg == QCRYPTO_IV_GEN_ALGO_ESSIV) {
 664         if (!ivhash_name) {
 665             error_setg(errp, "Missing IV generator hash specification");
 666             return -1;
 667         }
 668         luks->ivgen_cipher_alg =
 669                 qcrypto_block_luks_essiv_cipher(luks->cipher_alg,
 670                                                 luks->ivgen_hash_alg,
 671                                                 &local_err);
 672         if (local_err) {
 673             error_propagate(errp, local_err);
 674             return -1;
 675         }
 676     } else {
 677
 678         /*
 679          * Note we parsed the ivhash_name earlier in the cipher_mode
 680          * spec string even with plain/plain64 ivgens, but we
 681          * will ignore it, since it is irrelevant for these ivgens.
 682          * This is for compat with dm-crypt which will silently
 683          * ignore hash names with these ivgens rather than report
 684          * an error about the invalid usage
 685          */
 686         luks->ivgen_cipher_alg = luks->cipher_alg;
 687     }
 688     return 0;
 689 }
 690
 691 /*
 692  * Given a key slot,  user password, and the master key,
 693  * will store the encrypted master key there, and update the
 694  * in-memory header. User must then write the in-memory header
 695  *
 696  * Returns:
 697  *    0 if the keyslot was written successfully
 698  *      with the provided password
 699  *   -1 if a fatal error occurred while storing the key
 700  */
 701 static int
 702 qcrypto_block_luks_store_key(QCryptoBlock *block,
 703                              unsigned int slot_idx,
 704                              const char *password,
 705                              uint8_t *masterkey,
 706                              uint64_t iter_time,
 707                              QCryptoBlockWriteFunc writefunc,
 708                              void *opaque,
 709                              Error **errp)
 710 {
 711     QCryptoBlockLUKS *luks = block->opaque;
 712     QCryptoBlockLUKSKeySlot *slot;
 713     g_autofree uint8_t *splitkey = NULL;
 714     size_t splitkeylen;
 715     g_autofree uint8_t *slotkey = NULL;
 716     g_autoptr(QCryptoCipher) cipher = NULL;
 717     g_autoptr(QCryptoIVGen) ivgen = NULL;
 718     Error *local_err = NULL;
 719     uint64_t iters;
 720     int ret = -1;
 721
 722     assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
 723     slot = &luks->header.key_slots[slot_idx];
 724     splitkeylen = luks->header.master_key_len * slot->stripes;
 725
 726     if (qcrypto_random_bytes(slot->salt,
 727                              QCRYPTO_BLOCK_LUKS_SALT_LEN,
 728                              errp) < 0) {
 729         goto cleanup;
 730     }
 731
 732     /*
 733      * Determine how many iterations are required to
 734      * hash the user password while consuming 1 second of compute
 735      * time
 736      */
 737     iters = qcrypto_pbkdf2_count_iters(luks->hash_alg,
 738                                        (uint8_t *)password, strlen(password),
 739                                        slot->salt,
 740                                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
 741                                        luks->header.master_key_len,
 742                                        &local_err);
 743     if (local_err) {
 744         error_propagate(errp, local_err);
 745         goto cleanup;
 746     }
 747
 748     if (iters > (ULLONG_MAX / iter_time)) {
 749         error_setg_errno(errp, ERANGE,
 750                          "PBKDF iterations %llu too large to scale",
 751                          (unsigned long long)iters);
 752         goto cleanup;
 753     }
 754
 755     /* iter_time was in millis, but count_iters reported for secs */
 756     iters = iters * iter_time / 1000;
 757
 758     if (iters > UINT32_MAX) {
 759         error_setg_errno(errp, ERANGE,
 760                          "PBKDF iterations %llu larger than %u",
 761                          (unsigned long long)iters, UINT32_MAX);
 762         goto cleanup;
 763     }
 764
 765     slot->iterations =
 766         MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS);
 767
 768
 769     /*
 770      * Generate a key that we'll use to encrypt the master
 771      * key, from the user's password
 772      */
 773     slotkey = g_new0(uint8_t, luks->header.master_key_len);
 774     if (qcrypto_pbkdf2(luks->hash_alg,
 775                        (uint8_t *)password, strlen(password),
 776                        slot->salt,
 777                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
 778                        slot->iterations,
 779                        slotkey, luks->header.master_key_len,
 780                        errp) < 0) {
 781         goto cleanup;
 782     }
 783
 784
 785     /*
 786      * Setup the encryption objects needed to encrypt the
 787      * master key material
 788      */
 789     cipher = qcrypto_cipher_new(luks->cipher_alg,
 790                                 luks->cipher_mode,
 791                                 slotkey, luks->header.master_key_len,
 792                                 errp);
 793     if (!cipher) {
 794         goto cleanup;
 795     }
 796
 797     ivgen = qcrypto_ivgen_new(luks->ivgen_alg,
 798                               luks->ivgen_cipher_alg,
 799                               luks->ivgen_hash_alg,
 800                               slotkey, luks->header.master_key_len,
 801                               errp);
 802     if (!ivgen) {
 803         goto cleanup;
 804     }
 805
 806     /*
 807      * Before storing the master key, we need to vastly
 808      * increase its size, as protection against forensic
 809      * disk data recovery
 810      */
 811     splitkey = g_new0(uint8_t, splitkeylen);
 812
 813     if (qcrypto_afsplit_encode(luks->hash_alg,
 814                                luks->header.master_key_len,
 815                                slot->stripes,
 816                                masterkey,
 817                                splitkey,
 818                                errp) < 0) {
 819         goto cleanup;
 820     }
 821
 822     /*
 823      * Now we encrypt the split master key with the key generated
 824      * from the user's password, before storing it
 825      */
 826     if (qcrypto_block_cipher_encrypt_helper(cipher, block->niv, ivgen,
 827                                             QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
 828                                             0,
 829                                             splitkey,
 830                                             splitkeylen,
 831                                             errp) < 0) {
 832         goto cleanup;
 833     }
 834
 835     /* Write out the slot's master key material. */
 836     if (writefunc(block,
 837                   slot->key_offset_sector *
 838                   QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
 839                   splitkey, splitkeylen,
 840                   opaque,
 841                   errp) < 0) {
 842         goto cleanup;
 843     }
 844
 845     slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED;
 846
 847     if (qcrypto_block_luks_store_header(block,  writefunc, opaque, errp) < 0) {
 848         goto cleanup;
 849     }
 850
 851     ret = 0;
 852
 853 cleanup:
 854     if (slotkey) {
 855         memset(slotkey, 0, luks->header.master_key_len);
 856     }
 857     if (splitkey) {
 858         memset(splitkey, 0, splitkeylen);
 859     }
 860     return ret;
 861 }
 862
 863 /*
 864  * Given a key slot, and user password, this will attempt to unlock
 865  * the master encryption key from the key slot.
 866  *
 867  * Returns:
 868  *    0 if the key slot is disabled, or key could not be decrypted
 869  *      with the provided password
 870  *    1 if the key slot is enabled, and key decrypted successfully
 871  *      with the provided password
 872  *   -1 if a fatal error occurred loading the key
 873  */
 874 static int
 875 qcrypto_block_luks_load_key(QCryptoBlock *block,
 876                             size_t slot_idx,
 877                             const char *password,
 878                             uint8_t *masterkey,
 879                             QCryptoBlockReadFunc readfunc,
 880                             void *opaque,
 881                             Error **errp)
 882 {
 883     QCryptoBlockLUKS *luks = block->opaque;
 884     const QCryptoBlockLUKSKeySlot *slot;
 885     g_autofree uint8_t *splitkey = NULL;
 886     size_t splitkeylen;
 887     g_autofree uint8_t *possiblekey = NULL;
 888     int rv;
 889     g_autoptr(QCryptoCipher) cipher = NULL;
 890     uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN];
 891     g_autoptr(QCryptoIVGen) ivgen = NULL;
 892     size_t niv;
 893
 894     assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
 895     slot = &luks->header.key_slots[slot_idx];
 896     if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) {
 897         return 0;
 898     }
 899
 900     splitkeylen = luks->header.master_key_len * slot->stripes;
 901     splitkey = g_new0(uint8_t, splitkeylen);
 902     possiblekey = g_new0(uint8_t, luks->header.master_key_len);
 903
 904     /*
 905      * The user password is used to generate a (possible)
 906      * decryption key. This may or may not successfully
 907      * decrypt the master key - we just blindly assume
 908      * the key is correct and validate the results of
 909      * decryption later.
 910      */
 911     if (qcrypto_pbkdf2(luks->hash_alg,
 912                        (const uint8_t *)password, strlen(password),
 913                        slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN,
 914                        slot->iterations,
 915                        possiblekey, luks->header.master_key_len,
 916                        errp) < 0) {
 917         return -1;
 918     }
 919
 920     /*
 921      * We need to read the master key material from the
 922      * LUKS key material header. What we're reading is
 923      * not the raw master key, but rather the data after
 924      * it has been passed through AFSplit and the result
 925      * then encrypted.
 926      */
 927     rv = readfunc(block,
 928                   slot->key_offset_sector * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
 929                   splitkey, splitkeylen,
 930                   opaque,
 931                   errp);
 932     if (rv < 0) {
 933         return -1;
 934     }
 935
 936
 937     /* Setup the cipher/ivgen that we'll use to try to decrypt
 938      * the split master key material */
 939     cipher = qcrypto_cipher_new(luks->cipher_alg,
 940                                 luks->cipher_mode,
 941                                 possiblekey,
 942                                 luks->header.master_key_len,
 943                                 errp);
 944     if (!cipher) {
 945         return -1;
 946     }
 947
 948     niv = qcrypto_cipher_get_iv_len(luks->cipher_alg,
 949                                     luks->cipher_mode);
 950
 951     ivgen = qcrypto_ivgen_new(luks->ivgen_alg,
 952                               luks->ivgen_cipher_alg,
 953                               luks->ivgen_hash_alg,
 954                               possiblekey,
 955                               luks->header.master_key_len,
 956                               errp);
 957     if (!ivgen) {
 958         return -1;
 959     }
 960
 961
 962     /*
 963      * The master key needs to be decrypted in the same
 964      * way that the block device payload will be decrypted
 965      * later. In particular we'll be using the IV generator
 966      * to reset the encryption cipher every time the master
 967      * key crosses a sector boundary.
 968      */
 969     if (qcrypto_block_cipher_decrypt_helper(cipher,
 970                                             niv,
 971                                             ivgen,
 972                                             QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
 973                                             0,
 974                                             splitkey,
 975                                             splitkeylen,
 976                                             errp) < 0) {
 977         return -1;
 978     }
 979
 980     /*
 981      * Now we've decrypted the split master key, join
 982      * it back together to get the actual master key.
 983      */
 984     if (qcrypto_afsplit_decode(luks->hash_alg,
 985                                luks->header.master_key_len,
 986                                slot->stripes,
 987                                splitkey,
 988                                masterkey,
 989                                errp) < 0) {
 990         return -1;
 991     }
 992
 993
 994     /*
 995      * We still don't know that the masterkey we got is valid,
 996      * because we just blindly assumed the user's password
 997      * was correct. This is where we now verify it. We are
 998      * creating a hash of the master key using PBKDF and
 999      * then comparing that to the hash stored in the key slot
1000      * header
1001      */
1002     if (qcrypto_pbkdf2(luks->hash_alg,
1003                        masterkey,
1004                        luks->header.master_key_len,
1005                        luks->header.master_key_salt,
1006                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
1007                        luks->header.master_key_iterations,
1008                        keydigest,
1009                        G_N_ELEMENTS(keydigest),
1010                        errp) < 0) {
1011         return -1;
1012     }
1013
1014     if (memcmp(keydigest, luks->header.master_key_digest,
1015                QCRYPTO_BLOCK_LUKS_DIGEST_LEN) == 0) {
1016         /* Success, we got the right master key */
1017         return 1;
1018     }
1019
1020     /* Fail, user's password was not valid for this key slot,
1021      * tell caller to try another slot */
1022     return 0;
1023 }
1024
1025
1026 /*
1027  * Given a user password, this will iterate over all key
1028  * slots and try to unlock each active key slot using the
1029  * password until it successfully obtains a master key.
1030  *
1031  * Returns 0 if a key was loaded, -1 if no keys could be loaded
1032  */
1033 static int
1034 qcrypto_block_luks_find_key(QCryptoBlock *block,
1035                             const char *password,
1036                             uint8_t *masterkey,
1037                             QCryptoBlockReadFunc readfunc,
1038                             void *opaque,
1039                             Error **errp)
1040 {
1041     size_t i;
1042     int rv;
1043
1044     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1045         rv = qcrypto_block_luks_load_key(block,
1046                                          i,
1047                                          password,
1048                                          masterkey,
1049                                          readfunc,
1050                                          opaque,
1051                                          errp);
1052         if (rv < 0) {
1053             goto error;
1054         }
1055         if (rv == 1) {
1056             return 0;
1057         }
1058     }
1059
1060     error_setg(errp, "Invalid password, cannot unlock any keyslot");
1061  error:
1062     return -1;
1063 }
1064
1065 /*
1066  * Returns true if a slot i is marked as active
1067  * (contains encrypted copy of the master key)
1068  */
1069 static bool
1070 qcrypto_block_luks_slot_active(const QCryptoBlockLUKS *luks,
1071                                unsigned int slot_idx)
1072 {
1073     uint32_t val;
1074
1075     assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
1076     val = luks->header.key_slots[slot_idx].active;
1077     return val == QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED;
1078 }
1079
1080 /*
1081  * Returns the number of slots that are marked as active
1082  * (slots that contain encrypted copy of the master key)
1083  */
1084 static unsigned int
1085 qcrypto_block_luks_count_active_slots(const QCryptoBlockLUKS *luks)
1086 {
1087     size_t i = 0;
1088     unsigned int ret = 0;
1089
1090     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1091         if (qcrypto_block_luks_slot_active(luks, i)) {
1092             ret++;
1093         }
1094     }
1095     return ret;
1096 }
1097
1098 /*
1099  * Finds first key slot which is not active
1100  * Returns the key slot index, or -1 if it doesn't exist
1101  */
1102 static int
1103 qcrypto_block_luks_find_free_keyslot(const QCryptoBlockLUKS *luks)
1104 {
1105     size_t i;
1106
1107     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1108         if (!qcrypto_block_luks_slot_active(luks, i)) {
1109             return i;
1110         }
1111     }
1112     return -1;
1113 }
1114
1115 /*
1116  * Erases an keyslot given its index
1117  * Returns:
1118  *    0 if the keyslot was erased successfully
1119  *   -1 if a error occurred while erasing the keyslot
1120  *
1121  */
1122 static int
1123 qcrypto_block_luks_erase_key(QCryptoBlock *block,
1124                              unsigned int slot_idx,
1125                              QCryptoBlockWriteFunc writefunc,
1126                              void *opaque,
1127                              Error **errp)
1128 {
1129     QCryptoBlockLUKS *luks = block->opaque;
1130     QCryptoBlockLUKSKeySlot *slot;
1131     g_autofree uint8_t *garbagesplitkey = NULL;
1132     size_t splitkeylen;
1133     size_t i;
1134     Error *local_err = NULL;
1135     int ret;
1136
1137     assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
1138     slot = &luks->header.key_slots[slot_idx];
1139
1140     splitkeylen = luks->header.master_key_len * slot->stripes;
1141     assert(splitkeylen > 0);
1142
1143     garbagesplitkey = g_new0(uint8_t, splitkeylen);
1144
1145     /* Reset the key slot header */
1146     memset(slot->salt, 0, QCRYPTO_BLOCK_LUKS_SALT_LEN);
1147     slot->iterations = 0;
1148     slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
1149
1150     ret = qcrypto_block_luks_store_header(block, writefunc,
1151                                           opaque, &local_err);
1152
1153     if (ret < 0) {
1154         error_propagate(errp, local_err);
1155     }
1156     /*
1157      * Now try to erase the key material, even if the header
1158      * update failed
1159      */
1160     for (i = 0; i < QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS; i++) {
1161         if (qcrypto_random_bytes(garbagesplitkey,
1162                                  splitkeylen, &local_err) < 0) {
1163             /*
1164              * If we failed to get the random data, still write
1165              * at least zeros to the key slot at least once
1166              */
1167             error_propagate(errp, local_err);
1168
1169             if (i > 0) {
1170                 return -1;
1171             }
1172         }
1173         if (writefunc(block,
1174                       slot->key_offset_sector * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1175                       garbagesplitkey,
1176                       splitkeylen,
1177                       opaque,
1178                       &local_err) < 0) {
1179             error_propagate(errp, local_err);
1180             return -1;
1181         }
1182     }
1183     return ret;
1184 }
1185
1186 static int
1187 qcrypto_block_luks_open(QCryptoBlock *block,
1188                         QCryptoBlockOpenOptions *options,
1189                         const char *optprefix,
1190                         QCryptoBlockReadFunc readfunc,
1191                         void *opaque,
1192                         unsigned int flags,
1193                         Error **errp)
1194 {
1195     QCryptoBlockLUKS *luks = NULL;
1196     g_autofree uint8_t *masterkey = NULL;
1197     g_autofree char *password = NULL;
1198
1199     if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
1200         if (!options->u.luks.key_secret) {
1201             error_setg(errp, "Parameter '%skey-secret' is required for cipher",
1202                        optprefix ? optprefix : "");
1203             return -1;
1204         }
1205         password = qcrypto_secret_lookup_as_utf8(
1206             options->u.luks.key_secret, errp);
1207         if (!password) {
1208             return -1;
1209         }
1210     }
1211
1212     luks = g_new0(QCryptoBlockLUKS, 1);
1213     block->opaque = luks;
1214     luks->secret = g_strdup(options->u.luks.key_secret);
1215
1216     if (qcrypto_block_luks_load_header(block, readfunc, opaque, errp) < 0) {
1217         goto fail;
1218     }
1219
1220     if (qcrypto_block_luks_check_header(luks, flags, errp) < 0) {
1221         goto fail;
1222     }
1223
1224     if (qcrypto_block_luks_parse_header(luks, errp) < 0) {
1225         goto fail;
1226     }
1227
1228     if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
1229         /* Try to find which key slot our password is valid for
1230          * and unlock the master key from that slot.
1231          */
1232
1233         masterkey = g_new0(uint8_t, luks->header.master_key_len);
1234
1235         if (qcrypto_block_luks_find_key(block,
1236                                         password,
1237                                         masterkey,
1238                                         readfunc, opaque,
1239                                         errp) < 0) {
1240             goto fail;
1241         }
1242
1243         /* We have a valid master key now, so can setup the
1244          * block device payload decryption objects
1245          */
1246         block->kdfhash = luks->hash_alg;
1247         block->niv = qcrypto_cipher_get_iv_len(luks->cipher_alg,
1248                                                luks->cipher_mode);
1249
1250         block->ivgen = qcrypto_ivgen_new(luks->ivgen_alg,
1251                                          luks->ivgen_cipher_alg,
1252                                          luks->ivgen_hash_alg,
1253                                          masterkey,
1254                                          luks->header.master_key_len,
1255                                          errp);
1256         if (!block->ivgen) {
1257             goto fail;
1258         }
1259
1260         if (qcrypto_block_init_cipher(block,
1261                                       luks->cipher_alg,
1262                                       luks->cipher_mode,
1263                                       masterkey,
1264                                       luks->header.master_key_len,
1265                                       errp) < 0) {
1266             goto fail;
1267         }
1268     }
1269
1270     block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1271     block->payload_offset = luks->header.payload_offset_sector *
1272         block->sector_size;
1273     block->detached_header = (block->payload_offset == 0) ? true : false;
1274
1275     return 0;
1276
1277  fail:
1278     qcrypto_block_free_cipher(block);
1279     qcrypto_ivgen_free(block->ivgen);
1280     g_free(luks->secret);
1281     g_free(luks);
1282     return -1;
1283 }
1284
1285
1286 static void
1287 qcrypto_block_luks_uuid_gen(uint8_t *uuidstr)
1288 {
1289     QemuUUID uuid;
1290     qemu_uuid_generate(&uuid);
1291     qemu_uuid_unparse(&uuid, (char *)uuidstr);
1292 }
1293
1294 static int
1295 qcrypto_block_luks_create(QCryptoBlock *block,
1296                           QCryptoBlockCreateOptions *options,
1297                           const char *optprefix,
1298                           QCryptoBlockInitFunc initfunc,
1299                           QCryptoBlockWriteFunc writefunc,
1300                           void *opaque,
1301                           Error **errp)
1302 {
1303     QCryptoBlockLUKS *luks;
1304     QCryptoBlockCreateOptionsLUKS luks_opts;
1305     Error *local_err = NULL;
1306     g_autofree uint8_t *masterkey = NULL;
1307     size_t header_sectors;
1308     size_t split_key_sectors;
1309     size_t i;
1310     g_autofree char *password = NULL;
1311     const char *cipher_alg;
1312     const char *cipher_mode;
1313     const char *ivgen_alg;
1314     const char *ivgen_hash_alg = NULL;
1315     const char *hash_alg;
1316     g_autofree char *cipher_mode_spec = NULL;
1317     uint64_t iters;
1318     uint64_t detached_header_size;
1319
1320     memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts));
1321     if (!luks_opts.has_iter_time) {
1322         luks_opts.iter_time = QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS;
1323     }
1324     if (!luks_opts.has_cipher_alg) {
1325         luks_opts.cipher_alg = QCRYPTO_CIPHER_ALGO_AES_256;
1326     }
1327     if (!luks_opts.has_cipher_mode) {
1328         luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS;
1329     }
1330     if (!luks_opts.has_ivgen_alg) {
1331         luks_opts.ivgen_alg = QCRYPTO_IV_GEN_ALGO_PLAIN64;
1332     }
1333     if (!luks_opts.has_hash_alg) {
1334         luks_opts.hash_alg = QCRYPTO_HASH_ALGO_SHA256;
1335     }
1336     if (luks_opts.ivgen_alg == QCRYPTO_IV_GEN_ALGO_ESSIV) {
1337         if (!luks_opts.has_ivgen_hash_alg) {
1338             luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALGO_SHA256;
1339             luks_opts.has_ivgen_hash_alg = true;
1340         }
1341     }
1342
1343     luks = g_new0(QCryptoBlockLUKS, 1);
1344     block->opaque = luks;
1345
1346     luks->cipher_alg = luks_opts.cipher_alg;
1347     luks->cipher_mode = luks_opts.cipher_mode;
1348     luks->ivgen_alg = luks_opts.ivgen_alg;
1349     luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg;
1350     luks->hash_alg = luks_opts.hash_alg;
1351
1352
1353     /* Note we're allowing ivgen_hash_alg to be set even for
1354      * non-essiv iv generators that don't need a hash. It will
1355      * be silently ignored, for compatibility with dm-crypt */
1356
1357     if (!options->u.luks.key_secret) {
1358         error_setg(errp, "Parameter '%skey-secret' is required for cipher",
1359                    optprefix ? optprefix : "");
1360         goto error;
1361     }
1362     luks->secret = g_strdup(options->u.luks.key_secret);
1363
1364     password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp);
1365     if (!password) {
1366         goto error;
1367     }
1368
1369
1370     memcpy(luks->header.magic, qcrypto_block_luks_magic,
1371            QCRYPTO_BLOCK_LUKS_MAGIC_LEN);
1372
1373     /* We populate the header in native endianness initially and
1374      * then convert everything to big endian just before writing
1375      * it out to disk
1376      */
1377     luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION;
1378     qcrypto_block_luks_uuid_gen(luks->header.uuid);
1379
1380     cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg,
1381                                                       errp);
1382     if (!cipher_alg) {
1383         goto error;
1384     }
1385
1386     cipher_mode = QCryptoCipherMode_str(luks_opts.cipher_mode);
1387     ivgen_alg = QCryptoIVGenAlgo_str(luks_opts.ivgen_alg);
1388     if (luks_opts.has_ivgen_hash_alg) {
1389         ivgen_hash_alg = QCryptoHashAlgo_str(luks_opts.ivgen_hash_alg);
1390         cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg,
1391                                            ivgen_hash_alg);
1392     } else {
1393         cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg);
1394     }
1395     hash_alg = QCryptoHashAlgo_str(luks_opts.hash_alg);
1396
1397
1398     if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) {
1399         error_setg(errp, "Cipher name '%s' is too long for LUKS header",
1400                    cipher_alg);
1401         goto error;
1402     }
1403     if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) {
1404         error_setg(errp, "Cipher mode '%s' is too long for LUKS header",
1405                    cipher_mode_spec);
1406         goto error;
1407     }
1408     if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) {
1409         error_setg(errp, "Hash name '%s' is too long for LUKS header",
1410                    hash_alg);
1411         goto error;
1412     }
1413
1414     if (luks_opts.ivgen_alg == QCRYPTO_IV_GEN_ALGO_ESSIV) {
1415         luks->ivgen_cipher_alg =
1416                 qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg,
1417                                                 luks_opts.ivgen_hash_alg,
1418                                                 &local_err);
1419         if (local_err) {
1420             error_propagate(errp, local_err);
1421             goto error;
1422         }
1423     } else {
1424         luks->ivgen_cipher_alg = luks_opts.cipher_alg;
1425     }
1426
1427     strcpy(luks->header.cipher_name, cipher_alg);
1428     strcpy(luks->header.cipher_mode, cipher_mode_spec);
1429     strcpy(luks->header.hash_spec, hash_alg);
1430
1431     luks->header.master_key_len =
1432         qcrypto_cipher_get_key_len(luks_opts.cipher_alg);
1433
1434     if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) {
1435         luks->header.master_key_len *= 2;
1436     }
1437
1438     /* Generate the salt used for hashing the master key
1439      * with PBKDF later
1440      */
1441     if (qcrypto_random_bytes(luks->header.master_key_salt,
1442                              QCRYPTO_BLOCK_LUKS_SALT_LEN,
1443                              errp) < 0) {
1444         goto error;
1445     }
1446
1447     /* Generate random master key */
1448     masterkey = g_new0(uint8_t, luks->header.master_key_len);
1449     if (qcrypto_random_bytes(masterkey,
1450                              luks->header.master_key_len, errp) < 0) {
1451         goto error;
1452     }
1453
1454
1455     /* Setup the block device payload encryption objects */
1456     if (qcrypto_block_init_cipher(block, luks_opts.cipher_alg,
1457                                   luks_opts.cipher_mode, masterkey,
1458                                   luks->header.master_key_len, errp) < 0) {
1459         goto error;
1460     }
1461
1462     block->kdfhash = luks_opts.hash_alg;
1463     block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg,
1464                                            luks_opts.cipher_mode);
1465     block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg,
1466                                      luks->ivgen_cipher_alg,
1467                                      luks_opts.ivgen_hash_alg,
1468                                      masterkey, luks->header.master_key_len,
1469                                      errp);
1470
1471     if (!block->ivgen) {
1472         goto error;
1473     }
1474
1475
1476     /* Determine how many iterations we need to hash the master
1477      * key, in order to have 1 second of compute time used
1478      */
1479     iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg,
1480                                        masterkey, luks->header.master_key_len,
1481                                        luks->header.master_key_salt,
1482                                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
1483                                        QCRYPTO_BLOCK_LUKS_DIGEST_LEN,
1484                                        &local_err);
1485     if (local_err) {
1486         error_propagate(errp, local_err);
1487         goto error;
1488     }
1489
1490     if (iters > (ULLONG_MAX / luks_opts.iter_time)) {
1491         error_setg_errno(errp, ERANGE,
1492                          "PBKDF iterations %llu too large to scale",
1493                          (unsigned long long)iters);
1494         goto error;
1495     }
1496
1497     /* iter_time was in millis, but count_iters reported for secs */
1498     iters = iters * luks_opts.iter_time / 1000;
1499
1500     /* Why /= 8 ?  That matches cryptsetup, but there's no
1501      * explanation why they chose /= 8... Probably so that
1502      * if all 8 keyslots are active we only spend 1 second
1503      * in total time to check all keys */
1504     iters /= 8;
1505     if (iters > UINT32_MAX) {
1506         error_setg_errno(errp, ERANGE,
1507                          "PBKDF iterations %llu larger than %u",
1508                          (unsigned long long)iters, UINT32_MAX);
1509         goto error;
1510     }
1511     iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS);
1512     luks->header.master_key_iterations = iters;
1513
1514     /* Hash the master key, saving the result in the LUKS
1515      * header. This hash is used when opening the encrypted
1516      * device to verify that the user password unlocked a
1517      * valid master key
1518      */
1519     if (qcrypto_pbkdf2(luks_opts.hash_alg,
1520                        masterkey, luks->header.master_key_len,
1521                        luks->header.master_key_salt,
1522                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
1523                        luks->header.master_key_iterations,
1524                        luks->header.master_key_digest,
1525                        QCRYPTO_BLOCK_LUKS_DIGEST_LEN,
1526                        errp) < 0) {
1527         goto error;
1528     }
1529
1530     /* start with the sector that follows the header*/
1531     header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1532         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1533
1534     split_key_sectors =
1535         qcrypto_block_luks_splitkeylen_sectors(luks,
1536                                                header_sectors,
1537                                                QCRYPTO_BLOCK_LUKS_STRIPES);
1538
1539     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1540         QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i];
1541         slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
1542
1543         slot->key_offset_sector = header_sectors + i * split_key_sectors;
1544         slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES;
1545     }
1546
1547     if (block->detached_header) {
1548         /*
1549          * For a detached LUKS header image, set the payload_offset_sector
1550          * to 0 to specify the starting point for read/write
1551          */
1552         luks->header.payload_offset_sector = 0;
1553     } else {
1554         /*
1555          * The total size of the LUKS headers is the partition header + key
1556          * slot headers, rounded up to the nearest sector, combined with
1557          * the size of each master key material region, also rounded up
1558          * to the nearest sector
1559          */
1560         luks->header.payload_offset_sector = header_sectors +
1561                 QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS * split_key_sectors;
1562     }
1563
1564     block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1565     block->payload_offset = luks->header.payload_offset_sector *
1566         block->sector_size;
1567     detached_header_size =
1568         (header_sectors + QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS *
1569          split_key_sectors) * block->sector_size;
1570
1571     /* Reserve header space to match payload offset */
1572     initfunc(block, detached_header_size, opaque, &local_err);
1573     if (local_err) {
1574         error_propagate(errp, local_err);
1575         goto error;
1576     }
1577
1578
1579     /* populate the slot 0 with the password encrypted master key*/
1580     /* This will also store the header */
1581     if (qcrypto_block_luks_store_key(block,
1582                                      0,
1583                                      password,
1584                                      masterkey,
1585                                      luks_opts.iter_time,
1586                                      writefunc,
1587                                      opaque,
1588                                      errp) < 0) {
1589         goto error;
1590     }
1591
1592     memset(masterkey, 0, luks->header.master_key_len);
1593
1594     return 0;
1595
1596  error:
1597     if (masterkey) {
1598         memset(masterkey, 0, luks->header.master_key_len);
1599     }
1600
1601     qcrypto_block_free_cipher(block);
1602     qcrypto_ivgen_free(block->ivgen);
1603
1604     g_free(luks->secret);
1605     g_free(luks);
1606     return -1;
1607 }
1608
1609 static int
1610 qcrypto_block_luks_amend_add_keyslot(QCryptoBlock *block,
1611                                      QCryptoBlockReadFunc readfunc,
1612                                      QCryptoBlockWriteFunc writefunc,
1613                                      void *opaque,
1614                                      QCryptoBlockAmendOptionsLUKS *opts_luks,
1615                                      bool force,
1616                                      Error **errp)
1617 {
1618     QCryptoBlockLUKS *luks = block->opaque;
1619     uint64_t iter_time = opts_luks->has_iter_time ?
1620                          opts_luks->iter_time :
1621                          QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS;
1622     int keyslot;
1623     g_autofree char *old_password = NULL;
1624     g_autofree char *new_password = NULL;
1625     g_autofree uint8_t *master_key = NULL;
1626
1627     char *secret = opts_luks->secret ?: luks->secret;
1628
1629     if (!opts_luks->new_secret) {
1630         error_setg(errp, "'new-secret' is required to activate a keyslot");
1631         return -1;
1632     }
1633     if (opts_luks->old_secret) {
1634         error_setg(errp,
1635                    "'old-secret' must not be given when activating keyslots");
1636         return -1;
1637     }
1638
1639     if (opts_luks->has_keyslot) {
1640         keyslot = opts_luks->keyslot;
1641         if (keyslot < 0 || keyslot >= QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS) {
1642             error_setg(errp,
1643                        "Invalid keyslot %u specified, must be between 0 and %u",
1644                        keyslot, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS - 1);
1645             return -1;
1646         }
1647     } else {
1648         keyslot = qcrypto_block_luks_find_free_keyslot(luks);
1649         if (keyslot == -1) {
1650             error_setg(errp,
1651                        "Can't add a keyslot - all keyslots are in use");
1652             return -1;
1653         }
1654     }
1655
1656     if (!force && qcrypto_block_luks_slot_active(luks, keyslot)) {
1657         error_setg(errp,
1658                    "Refusing to overwrite active keyslot %i - "
1659                    "please erase it first",
1660                    keyslot);
1661         return -1;
1662     }
1663
1664     /* Locate the password that will be used to retrieve the master key */
1665     old_password = qcrypto_secret_lookup_as_utf8(secret, errp);
1666     if (!old_password) {
1667         return -1;
1668     }
1669
1670     /* Retrieve the master key */
1671     master_key = g_new0(uint8_t, luks->header.master_key_len);
1672
1673     if (qcrypto_block_luks_find_key(block, old_password, master_key,
1674                                     readfunc, opaque, errp) < 0) {
1675         error_append_hint(errp, "Failed to retrieve the master key");
1676         return -1;
1677     }
1678
1679     /* Locate the new password*/
1680     new_password = qcrypto_secret_lookup_as_utf8(opts_luks->new_secret, errp);
1681     if (!new_password) {
1682         return -1;
1683     }
1684
1685     /* Now set the new keyslots */
1686     if (qcrypto_block_luks_store_key(block, keyslot, new_password, master_key,
1687                                      iter_time, writefunc, opaque, errp)) {
1688         error_append_hint(errp, "Failed to write to keyslot %i", keyslot);
1689         return -1;
1690     }
1691     return 0;
1692 }
1693
1694 static int
1695 qcrypto_block_luks_amend_erase_keyslots(QCryptoBlock *block,
1696                                         QCryptoBlockReadFunc readfunc,
1697                                         QCryptoBlockWriteFunc writefunc,
1698                                         void *opaque,
1699                                         QCryptoBlockAmendOptionsLUKS *opts_luks,
1700                                         bool force,
1701                                         Error **errp)
1702 {
1703     QCryptoBlockLUKS *luks = block->opaque;
1704     g_autofree uint8_t *tmpkey = NULL;
1705     g_autofree char *old_password = NULL;
1706
1707     if (opts_luks->new_secret) {
1708         error_setg(errp,
1709                    "'new-secret' must not be given when erasing keyslots");
1710         return -1;
1711     }
1712     if (opts_luks->has_iter_time) {
1713         error_setg(errp,
1714                    "'iter-time' must not be given when erasing keyslots");
1715         return -1;
1716     }
1717     if (opts_luks->secret) {
1718         error_setg(errp,
1719                    "'secret' must not be given when erasing keyslots");
1720         return -1;
1721     }
1722
1723     /* Load the old password if given */
1724     if (opts_luks->old_secret) {
1725         old_password = qcrypto_secret_lookup_as_utf8(opts_luks->old_secret,
1726                                                      errp);
1727         if (!old_password) {
1728             return -1;
1729         }
1730
1731         /*
1732          * Allocate a temporary key buffer that we will need when
1733          * checking if slot matches the given old password
1734          */
1735         tmpkey = g_new0(uint8_t, luks->header.master_key_len);
1736     }
1737
1738     /* Erase an explicitly given keyslot */
1739     if (opts_luks->has_keyslot) {
1740         int keyslot = opts_luks->keyslot;
1741
1742         if (keyslot < 0 || keyslot >= QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS) {
1743             error_setg(errp,
1744                        "Invalid keyslot %i specified, must be between 0 and %i",
1745                        keyslot, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS - 1);
1746             return -1;
1747         }
1748
1749         if (opts_luks->old_secret) {
1750             int rv = qcrypto_block_luks_load_key(block,
1751                                                  keyslot,
1752                                                  old_password,
1753                                                  tmpkey,
1754                                                  readfunc,
1755                                                  opaque,
1756                                                  errp);
1757             if (rv == -1) {
1758                 return -1;
1759             } else if (rv == 0) {
1760                 error_setg(errp,
1761                            "Given keyslot %i doesn't contain the given "
1762                            "old password for erase operation",
1763                            keyslot);
1764                 return -1;
1765             }
1766         }
1767
1768         if (!force && !qcrypto_block_luks_slot_active(luks, keyslot)) {
1769             error_setg(errp,
1770                        "Given keyslot %i is already erased (inactive) ",
1771                        keyslot);
1772             return -1;
1773         }
1774
1775         if (!force && qcrypto_block_luks_count_active_slots(luks) == 1) {
1776             error_setg(errp,
1777                        "Attempt to erase the only active keyslot %i "
1778                        "which will erase all the data in the image "
1779                        "irreversibly - refusing operation",
1780                        keyslot);
1781             return -1;
1782         }
1783
1784         if (qcrypto_block_luks_erase_key(block, keyslot,
1785                                          writefunc, opaque, errp)) {
1786             error_append_hint(errp, "Failed to erase keyslot %i", keyslot);
1787             return -1;
1788         }
1789
1790     /* Erase all keyslots that match the given old password */
1791     } else if (opts_luks->old_secret) {
1792
1793         unsigned long slots_to_erase_bitmap = 0;
1794         size_t i;
1795         int slot_count;
1796
1797         assert(QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS <=
1798                sizeof(slots_to_erase_bitmap) * 8);
1799
1800         for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1801             int rv = qcrypto_block_luks_load_key(block,
1802                                                  i,
1803                                                  old_password,
1804                                                  tmpkey,
1805                                                  readfunc,
1806                                                  opaque,
1807                                                  errp);
1808             if (rv == -1) {
1809                 return -1;
1810             } else if (rv == 1) {
1811                 bitmap_set(&slots_to_erase_bitmap, i, 1);
1812             }
1813         }
1814
1815         slot_count = bitmap_count_one(&slots_to_erase_bitmap,
1816                                       QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
1817         if (slot_count == 0) {
1818             error_setg(errp,
1819                        "No keyslots match given (old) password for erase operation");
1820             return -1;
1821         }
1822
1823         if (!force &&
1824             slot_count == qcrypto_block_luks_count_active_slots(luks)) {
1825             error_setg(errp,
1826                        "All the active keyslots match the (old) password that "
1827                        "was given and erasing them will erase all the data in "
1828                        "the image irreversibly - refusing operation");
1829             return -1;
1830         }
1831
1832         /* Now apply the update */
1833         for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1834             if (!test_bit(i, &slots_to_erase_bitmap)) {
1835                 continue;
1836             }
1837             if (qcrypto_block_luks_erase_key(block, i, writefunc,
1838                 opaque, errp)) {
1839                 error_append_hint(errp, "Failed to erase keyslot %zu", i);
1840                 return -1;
1841             }
1842         }
1843     } else {
1844         error_setg(errp,
1845                    "To erase keyslot(s), either explicit keyslot index "
1846                    "or the password currently contained in them must be given");
1847         return -1;
1848     }
1849     return 0;
1850 }
1851
1852 static int
1853 qcrypto_block_luks_amend_options(QCryptoBlock *block,
1854                                  QCryptoBlockReadFunc readfunc,
1855                                  QCryptoBlockWriteFunc writefunc,
1856                                  void *opaque,
1857                                  QCryptoBlockAmendOptions *options,
1858                                  bool force,
1859                                  Error **errp)
1860 {
1861     QCryptoBlockAmendOptionsLUKS *opts_luks = &options->u.luks;
1862
1863     switch (opts_luks->state) {
1864     case QCRYPTO_BLOCK_LUKS_KEYSLOT_STATE_ACTIVE:
1865         return qcrypto_block_luks_amend_add_keyslot(block, readfunc,
1866                                                     writefunc, opaque,
1867                                                     opts_luks, force, errp);
1868     case QCRYPTO_BLOCK_LUKS_KEYSLOT_STATE_INACTIVE:
1869         return qcrypto_block_luks_amend_erase_keyslots(block, readfunc,
1870                                                        writefunc, opaque,
1871                                                        opts_luks, force, errp);
1872     default:
1873         g_assert_not_reached();
1874     }
1875 }
1876
1877 static int qcrypto_block_luks_get_info(QCryptoBlock *block,
1878                                        QCryptoBlockInfo *info,
1879                                        Error **errp)
1880 {
1881     QCryptoBlockLUKS *luks = block->opaque;
1882     QCryptoBlockInfoLUKSSlot *slot;
1883     QCryptoBlockInfoLUKSSlotList **tail = &info->u.luks.slots;
1884     size_t i;
1885
1886     info->u.luks.cipher_alg = luks->cipher_alg;
1887     info->u.luks.cipher_mode = luks->cipher_mode;
1888     info->u.luks.ivgen_alg = luks->ivgen_alg;
1889     if (info->u.luks.ivgen_alg == QCRYPTO_IV_GEN_ALGO_ESSIV) {
1890         info->u.luks.has_ivgen_hash_alg = true;
1891         info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg;
1892     }
1893     info->u.luks.hash_alg = luks->hash_alg;
1894     info->u.luks.payload_offset = block->payload_offset;
1895     info->u.luks.master_key_iters = luks->header.master_key_iterations;
1896     info->u.luks.uuid = g_strndup((const char *)luks->header.uuid,
1897                                   sizeof(luks->header.uuid));
1898     info->u.luks.detached_header = block->detached_header;
1899
1900     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1901         slot = g_new0(QCryptoBlockInfoLUKSSlot, 1);
1902         slot->active = luks->header.key_slots[i].active ==
1903             QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED;
1904         slot->key_offset = luks->header.key_slots[i].key_offset_sector
1905              * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1906         if (slot->active) {
1907             slot->has_iters = true;
1908             slot->iters = luks->header.key_slots[i].iterations;
1909             slot->has_stripes = true;
1910             slot->stripes = luks->header.key_slots[i].stripes;
1911         }
1912
1913         QAPI_LIST_APPEND(tail, slot);
1914     }
1915
1916     return 0;
1917 }
1918
1919
1920 static void qcrypto_block_luks_cleanup(QCryptoBlock *block)
1921 {
1922     QCryptoBlockLUKS *luks = block->opaque;
1923     if (luks) {
1924         g_free(luks->secret);
1925         g_free(luks);
1926     }
1927 }
1928
1929
1930 static int
1931 qcrypto_block_luks_decrypt(QCryptoBlock *block,
1932                            uint64_t offset,
1933                            uint8_t *buf,
1934                            size_t len,
1935                            Error **errp)
1936 {
1937     assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1938     assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1939     return qcrypto_block_decrypt_helper(block,
1940                                         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1941                                         offset, buf, len, errp);
1942 }
1943
1944
1945 static int
1946 qcrypto_block_luks_encrypt(QCryptoBlock *block,
1947                            uint64_t offset,
1948                            uint8_t *buf,
1949                            size_t len,
1950                            Error **errp)
1951 {
1952     assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1953     assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1954     return qcrypto_block_encrypt_helper(block,
1955                                         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1956                                         offset, buf, len, errp);
1957 }
1958
1959
1960 const QCryptoBlockDriver qcrypto_block_driver_luks = {
1961     .open = qcrypto_block_luks_open,
1962     .create = qcrypto_block_luks_create,
1963     .amend = qcrypto_block_luks_amend_options,
1964     .get_info = qcrypto_block_luks_get_info,
1965     .cleanup = qcrypto_block_luks_cleanup,
1966     .decrypt = qcrypto_block_luks_decrypt,
1967     .encrypt = qcrypto_block_luks_encrypt,
1968     .has_format = qcrypto_block_luks_has_format,
1969 };