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
  37 /*
  38  * Reference for the LUKS format implemented here is
  39  *
  40  *   docs/on-disk-format.pdf
  41  *
  42  * in 'cryptsetup' package source code
  43  *
  44  * This file implements the 1.2.1 specification, dated
  45  * Oct 16, 2011.
  46  */
  47
  48 typedef struct QCryptoBlockLUKS QCryptoBlockLUKS;
  49
  50 typedef struct QCryptoBlockLUKSNameMap QCryptoBlockLUKSNameMap;
  51 struct QCryptoBlockLUKSNameMap {
  52     const char *name;
  53     int id;
  54 };
  55
  56 typedef struct QCryptoBlockLUKSCipherSizeMap QCryptoBlockLUKSCipherSizeMap;
  57 struct QCryptoBlockLUKSCipherSizeMap {
  58     uint32_t key_bytes;
  59     int id;
  60 };
  61 typedef struct QCryptoBlockLUKSCipherNameMap QCryptoBlockLUKSCipherNameMap;
  62 struct QCryptoBlockLUKSCipherNameMap {
  63     const char *name;
  64     const QCryptoBlockLUKSCipherSizeMap *sizes;
  65 };
  66
  67
  68 static const QCryptoBlockLUKSCipherSizeMap
  69 qcrypto_block_luks_cipher_size_map_aes[] = {
  70     { 16, QCRYPTO_CIPHER_ALG_AES_128 },
  71     { 24, QCRYPTO_CIPHER_ALG_AES_192 },
  72     { 32, QCRYPTO_CIPHER_ALG_AES_256 },
  73     { 0, 0 },
  74 };
  75
  76 static const QCryptoBlockLUKSCipherSizeMap
  77 qcrypto_block_luks_cipher_size_map_cast5[] = {
  78     { 16, QCRYPTO_CIPHER_ALG_CAST5_128 },
  79     { 0, 0 },
  80 };
  81
  82 static const QCryptoBlockLUKSCipherSizeMap
  83 qcrypto_block_luks_cipher_size_map_serpent[] = {
  84     { 16, QCRYPTO_CIPHER_ALG_SERPENT_128 },
  85     { 24, QCRYPTO_CIPHER_ALG_SERPENT_192 },
  86     { 32, QCRYPTO_CIPHER_ALG_SERPENT_256 },
  87     { 0, 0 },
  88 };
  89
  90 static const QCryptoBlockLUKSCipherSizeMap
  91 qcrypto_block_luks_cipher_size_map_twofish[] = {
  92     { 16, QCRYPTO_CIPHER_ALG_TWOFISH_128 },
  93     { 24, QCRYPTO_CIPHER_ALG_TWOFISH_192 },
  94     { 32, QCRYPTO_CIPHER_ALG_TWOFISH_256 },
  95     { 0, 0 },
  96 };
  97
  98 #ifdef CONFIG_CRYPTO_SM4
  99 static const QCryptoBlockLUKSCipherSizeMap
 100 qcrypto_block_luks_cipher_size_map_sm4[] = {
 101     { 16, QCRYPTO_CIPHER_ALG_SM4},
 102     { 0, 0 },
 103 };
 104 #endif
 105
 106 static const QCryptoBlockLUKSCipherNameMap
 107 qcrypto_block_luks_cipher_name_map[] = {
 108     { "aes", qcrypto_block_luks_cipher_size_map_aes },
 109     { "cast5", qcrypto_block_luks_cipher_size_map_cast5 },
 110     { "serpent", qcrypto_block_luks_cipher_size_map_serpent },
 111     { "twofish", qcrypto_block_luks_cipher_size_map_twofish },
 112 #ifdef CONFIG_CRYPTO_SM4
 113     { "sm4", qcrypto_block_luks_cipher_size_map_sm4},
 114 #endif
 115 };
 116
 117 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48);
 118 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592);
 119
 120
 121 struct QCryptoBlockLUKS {
 122     QCryptoBlockLUKSHeader header;
 123
 124     /* Main encryption algorithm used for encryption*/
 125     QCryptoCipherAlgorithm cipher_alg;
 126
 127     /* Mode of encryption for the selected encryption algorithm */
 128     QCryptoCipherMode cipher_mode;
 129
 130     /* Initialization vector generation algorithm */
 131     QCryptoIVGenAlgorithm ivgen_alg;
 132
 133     /* Hash algorithm used for IV generation*/
 134     QCryptoHashAlgorithm ivgen_hash_alg;
 135
 136     /*
 137      * Encryption algorithm used for IV generation.
 138      * Usually the same as main encryption algorithm
 139      */
 140     QCryptoCipherAlgorithm ivgen_cipher_alg;
 141
 142     /* Hash algorithm used in pbkdf2 function */
 143     QCryptoHashAlgorithm hash_alg;
 144
 145     /* Name of the secret that was used to open the image */
 146     char *secret;
 147 };
 148
 149
 150 static int qcrypto_block_luks_cipher_name_lookup(const char *name,
 151                                                  QCryptoCipherMode mode,
 152                                                  uint32_t key_bytes,
 153                                                  Error **errp)
 154 {
 155     const QCryptoBlockLUKSCipherNameMap *map =
 156         qcrypto_block_luks_cipher_name_map;
 157     size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
 158     size_t i, j;
 159
 160     if (mode == QCRYPTO_CIPHER_MODE_XTS) {
 161         key_bytes /= 2;
 162     }
 163
 164     for (i = 0; i < maplen; i++) {
 165         if (!g_str_equal(map[i].name, name)) {
 166             continue;
 167         }
 168         for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
 169             if (map[i].sizes[j].key_bytes == key_bytes) {
 170                 return map[i].sizes[j].id;
 171             }
 172         }
 173     }
 174
 175     error_setg(errp, "Algorithm '%s' with key size %d bytes not supported",
 176                name, key_bytes);
 177     return 0;
 178 }
 179
 180 static const char *
 181 qcrypto_block_luks_cipher_alg_lookup(QCryptoCipherAlgorithm alg,
 182                                      Error **errp)
 183 {
 184     const QCryptoBlockLUKSCipherNameMap *map =
 185         qcrypto_block_luks_cipher_name_map;
 186     size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
 187     size_t i, j;
 188     for (i = 0; i < maplen; i++) {
 189         for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
 190             if (map[i].sizes[j].id == alg) {
 191                 return map[i].name;
 192             }
 193         }
 194     }
 195
 196     error_setg(errp, "Algorithm '%s' not supported",
 197                QCryptoCipherAlgorithm_str(alg));
 198     return NULL;
 199 }
 200
 201 /* XXX replace with qapi_enum_parse() in future, when we can
 202  * make that function emit a more friendly error message */
 203 static int qcrypto_block_luks_name_lookup(const char *name,
 204                                           const QEnumLookup *map,
 205                                           const char *type,
 206                                           Error **errp)
 207 {
 208     int ret = qapi_enum_parse(map, name, -1, NULL);
 209
 210     if (ret < 0) {
 211         error_setg(errp, "%s '%s' not supported", type, name);
 212         return 0;
 213     }
 214     return ret;
 215 }
 216
 217 #define qcrypto_block_luks_cipher_mode_lookup(name, errp)               \
 218     qcrypto_block_luks_name_lookup(name,                                \
 219                                    &QCryptoCipherMode_lookup,           \
 220                                    "Cipher mode",                       \
 221                                    errp)
 222
 223 #define qcrypto_block_luks_hash_name_lookup(name, errp)                 \
 224     qcrypto_block_luks_name_lookup(name,                                \
 225                                    &QCryptoHashAlgorithm_lookup,        \
 226                                    "Hash algorithm",                    \
 227                                    errp)
 228
 229 #define qcrypto_block_luks_ivgen_name_lookup(name, errp)                \
 230     qcrypto_block_luks_name_lookup(name,                                \
 231                                    &QCryptoIVGenAlgorithm_lookup,       \
 232                                    "IV generator",                      \
 233                                    errp)
 234
 235
 236 static bool
 237 qcrypto_block_luks_has_format(const uint8_t *buf,
 238                               size_t buf_size)
 239 {
 240     const QCryptoBlockLUKSHeader *luks_header = (const void *)buf;
 241
 242     if (buf_size >= offsetof(QCryptoBlockLUKSHeader, cipher_name) &&
 243         memcmp(luks_header->magic, qcrypto_block_luks_magic,
 244                QCRYPTO_BLOCK_LUKS_MAGIC_LEN) == 0 &&
 245         be16_to_cpu(luks_header->version) == QCRYPTO_BLOCK_LUKS_VERSION) {
 246         return true;
 247     } else {
 248         return false;
 249     }
 250 }
 251
 252
 253 /**
 254  * Deal with a quirk of dm-crypt usage of ESSIV.
 255  *
 256  * When calculating ESSIV IVs, the cipher length used by ESSIV
 257  * may be different from the cipher length used for the block
 258  * encryption, because dm-crypt uses the hash digest length
 259  * as the key size. ie, if you have AES 128 as the block cipher
 260  * and SHA 256 as ESSIV hash, then ESSIV will use AES 256 as
 261  * the cipher since that gets a key length matching the digest
 262  * size, not AES 128 with truncated digest as might be imagined
 263  */
 264 static QCryptoCipherAlgorithm
 265 qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm cipher,
 266                                 QCryptoHashAlgorithm hash,
 267                                 Error **errp)
 268 {
 269     size_t digestlen = qcrypto_hash_digest_len(hash);
 270     size_t keylen = qcrypto_cipher_get_key_len(cipher);
 271     if (digestlen == keylen) {
 272         return cipher;
 273     }
 274
 275     switch (cipher) {
 276     case QCRYPTO_CIPHER_ALG_AES_128:
 277     case QCRYPTO_CIPHER_ALG_AES_192:
 278     case QCRYPTO_CIPHER_ALG_AES_256:
 279         if (digestlen == qcrypto_cipher_get_key_len(
 280                 QCRYPTO_CIPHER_ALG_AES_128)) {
 281             return QCRYPTO_CIPHER_ALG_AES_128;
 282         } else if (digestlen == qcrypto_cipher_get_key_len(
 283                        QCRYPTO_CIPHER_ALG_AES_192)) {
 284             return QCRYPTO_CIPHER_ALG_AES_192;
 285         } else if (digestlen == qcrypto_cipher_get_key_len(
 286                        QCRYPTO_CIPHER_ALG_AES_256)) {
 287             return QCRYPTO_CIPHER_ALG_AES_256;
 288         } else {
 289             error_setg(errp, "No AES cipher with key size %zu available",
 290                        digestlen);
 291             return 0;
 292         }
 293         break;
 294     case QCRYPTO_CIPHER_ALG_SERPENT_128:
 295     case QCRYPTO_CIPHER_ALG_SERPENT_192:
 296     case QCRYPTO_CIPHER_ALG_SERPENT_256:
 297         if (digestlen == qcrypto_cipher_get_key_len(
 298                 QCRYPTO_CIPHER_ALG_SERPENT_128)) {
 299             return QCRYPTO_CIPHER_ALG_SERPENT_128;
 300         } else if (digestlen == qcrypto_cipher_get_key_len(
 301                        QCRYPTO_CIPHER_ALG_SERPENT_192)) {
 302             return QCRYPTO_CIPHER_ALG_SERPENT_192;
 303         } else if (digestlen == qcrypto_cipher_get_key_len(
 304                        QCRYPTO_CIPHER_ALG_SERPENT_256)) {
 305             return QCRYPTO_CIPHER_ALG_SERPENT_256;
 306         } else {
 307             error_setg(errp, "No Serpent cipher with key size %zu available",
 308                        digestlen);
 309             return 0;
 310         }
 311         break;
 312     case QCRYPTO_CIPHER_ALG_TWOFISH_128:
 313     case QCRYPTO_CIPHER_ALG_TWOFISH_192:
 314     case QCRYPTO_CIPHER_ALG_TWOFISH_256:
 315         if (digestlen == qcrypto_cipher_get_key_len(
 316                 QCRYPTO_CIPHER_ALG_TWOFISH_128)) {
 317             return QCRYPTO_CIPHER_ALG_TWOFISH_128;
 318         } else if (digestlen == qcrypto_cipher_get_key_len(
 319                        QCRYPTO_CIPHER_ALG_TWOFISH_192)) {
 320             return QCRYPTO_CIPHER_ALG_TWOFISH_192;
 321         } else if (digestlen == qcrypto_cipher_get_key_len(
 322                        QCRYPTO_CIPHER_ALG_TWOFISH_256)) {
 323             return QCRYPTO_CIPHER_ALG_TWOFISH_256;
 324         } else {
 325             error_setg(errp, "No Twofish cipher with key size %zu available",
 326                        digestlen);
 327             return 0;
 328         }
 329         break;
 330     default:
 331         error_setg(errp, "Cipher %s not supported with essiv",
 332                    QCryptoCipherAlgorithm_str(cipher));
 333         return 0;
 334     }
 335 }
 336
 337 /*
 338  * Returns number of sectors needed to store the key material
 339  * given number of anti forensic stripes
 340  */
 341 static int
 342 qcrypto_block_luks_splitkeylen_sectors(const QCryptoBlockLUKS *luks,
 343                                        unsigned int header_sectors,
 344                                        unsigned int stripes)
 345 {
 346     /*
 347      * This calculation doesn't match that shown in the spec,
 348      * but instead follows the cryptsetup implementation.
 349      */
 350
 351     size_t splitkeylen = luks->header.master_key_len * stripes;
 352
 353     /* First align the key material size to block size*/
 354     size_t splitkeylen_sectors =
 355         DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE);
 356
 357     /* Then also align the key material size to the size of the header */
 358     return ROUND_UP(splitkeylen_sectors, header_sectors);
 359 }
 360
 361
 362 void
 363 qcrypto_block_luks_to_disk_endian(QCryptoBlockLUKSHeader *hdr)
 364 {
 365     size_t i;
 366
 367     /*
 368      * Everything on disk uses Big Endian (tm), so flip header fields
 369      * before writing them
 370      */
 371     cpu_to_be16s(&hdr->version);
 372     cpu_to_be32s(&hdr->payload_offset_sector);
 373     cpu_to_be32s(&hdr->master_key_len);
 374     cpu_to_be32s(&hdr->master_key_iterations);
 375
 376     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
 377         cpu_to_be32s(&hdr->key_slots[i].active);
 378         cpu_to_be32s(&hdr->key_slots[i].iterations);
 379         cpu_to_be32s(&hdr->key_slots[i].key_offset_sector);
 380         cpu_to_be32s(&hdr->key_slots[i].stripes);
 381     }
 382 }
 383
 384 void
 385 qcrypto_block_luks_from_disk_endian(QCryptoBlockLUKSHeader *hdr)
 386 {
 387     size_t i;
 388
 389     /*
 390      * The header is always stored in big-endian format, so
 391      * convert everything to native
 392      */
 393     be16_to_cpus(&hdr->version);
 394     be32_to_cpus(&hdr->payload_offset_sector);
 395     be32_to_cpus(&hdr->master_key_len);
 396     be32_to_cpus(&hdr->master_key_iterations);
 397
 398     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
 399         be32_to_cpus(&hdr->key_slots[i].active);
 400         be32_to_cpus(&hdr->key_slots[i].iterations);
 401         be32_to_cpus(&hdr->key_slots[i].key_offset_sector);
 402         be32_to_cpus(&hdr->key_slots[i].stripes);
 403     }
 404 }
 405
 406 /*
 407  * Stores the main LUKS header, taking care of endianness
 408  */
 409 static int
 410 qcrypto_block_luks_store_header(QCryptoBlock *block,
 411                                 QCryptoBlockWriteFunc writefunc,
 412                                 void *opaque,
 413                                 Error **errp)
 414 {
 415     const QCryptoBlockLUKS *luks = block->opaque;
 416     Error *local_err = NULL;
 417     g_autofree QCryptoBlockLUKSHeader *hdr_copy = NULL;
 418
 419     /* Create a copy of the header */
 420     hdr_copy = g_new0(QCryptoBlockLUKSHeader, 1);
 421     memcpy(hdr_copy, &luks->header, sizeof(QCryptoBlockLUKSHeader));
 422
 423     qcrypto_block_luks_to_disk_endian(hdr_copy);
 424
 425     /* Write out the partition header and key slot headers */
 426     writefunc(block, 0, (const uint8_t *)hdr_copy, sizeof(*hdr_copy),
 427               opaque, &local_err);
 428
 429     if (local_err) {
 430         error_propagate(errp, local_err);
 431         return -1;
 432     }
 433     return 0;
 434 }
 435
 436 /*
 437  * Loads the main LUKS header, and byteswaps it to native endianness
 438  * And run basic sanity checks on it
 439  */
 440 static int
 441 qcrypto_block_luks_load_header(QCryptoBlock *block,
 442                                 QCryptoBlockReadFunc readfunc,
 443                                 void *opaque,
 444                                 Error **errp)
 445 {
 446     int rv;
 447     QCryptoBlockLUKS *luks = block->opaque;
 448
 449     /*
 450      * Read the entire LUKS header, minus the key material from
 451      * the underlying device
 452      */
 453     rv = readfunc(block, 0,
 454                   (uint8_t *)&luks->header,
 455                   sizeof(luks->header),
 456                   opaque,
 457                   errp);
 458     if (rv < 0) {
 459         return rv;
 460     }
 461
 462     qcrypto_block_luks_from_disk_endian(&luks->header);
 463
 464     return 0;
 465 }
 466
 467 /*
 468  * Does basic sanity checks on the LUKS header
 469  */
 470 static int
 471 qcrypto_block_luks_check_header(const QCryptoBlockLUKS *luks,
 472                                 unsigned int flags,
 473                                 Error **errp)
 474 {
 475     size_t i, j;
 476
 477     unsigned int header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
 478         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
 479     bool detached = flags & QCRYPTO_BLOCK_OPEN_DETACHED;
 480
 481     if (memcmp(luks->header.magic, qcrypto_block_luks_magic,
 482                QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) {
 483         error_setg(errp, "Volume is not in LUKS format");
 484         return -1;
 485     }
 486
 487     if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) {
 488         error_setg(errp, "LUKS version %" PRIu32 " is not supported",
 489                    luks->header.version);
 490         return -1;
 491     }
 492
 493     if (!memchr(luks->header.cipher_name, '\0',
 494                 sizeof(luks->header.cipher_name))) {
 495         error_setg(errp, "LUKS header cipher name is not NUL terminated");
 496         return -1;
 497     }
 498
 499     if (!memchr(luks->header.cipher_mode, '\0',
 500                 sizeof(luks->header.cipher_mode))) {
 501         error_setg(errp, "LUKS header cipher mode is not NUL terminated");
 502         return -1;
 503     }
 504
 505     if (!memchr(luks->header.hash_spec, '\0',
 506                 sizeof(luks->header.hash_spec))) {
 507         error_setg(errp, "LUKS header hash spec is not NUL terminated");
 508         return -1;
 509     }
 510
 511     if (!detached && luks->header.payload_offset_sector <
 512         DIV_ROUND_UP(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET,
 513                      QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) {
 514         error_setg(errp, "LUKS payload is overlapping with the header");
 515         return -1;
 516     }
 517
 518     if (luks->header.master_key_iterations == 0) {
 519         error_setg(errp, "LUKS key iteration count is zero");
 520         return -1;
 521     }
 522
 523     /* Check all keyslots for corruption  */
 524     for (i = 0 ; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; i++) {
 525
 526         const QCryptoBlockLUKSKeySlot *slot1 = &luks->header.key_slots[i];
 527         unsigned int start1 = slot1->key_offset_sector;
 528         unsigned int len1 =
 529             qcrypto_block_luks_splitkeylen_sectors(luks,
 530                                                    header_sectors,
 531                                                    slot1->stripes);
 532
 533         if (slot1->stripes != QCRYPTO_BLOCK_LUKS_STRIPES) {
 534             error_setg(errp, "Keyslot %zu is corrupted (stripes %d != %d)",
 535                        i, slot1->stripes, QCRYPTO_BLOCK_LUKS_STRIPES);
 536             return -1;
 537         }
 538
 539         if (slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED &&
 540             slot1->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) {
 541             error_setg(errp,
 542                        "Keyslot %zu state (active/disable) is corrupted", i);
 543             return -1;
 544         }
 545
 546         if (slot1->active == QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED &&
 547             slot1->iterations == 0) {
 548             error_setg(errp, "Keyslot %zu iteration count is zero", i);
 549             return -1;
 550         }
 551
 552         if (start1 < DIV_ROUND_UP(QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET,
 553                                   QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) {
 554             error_setg(errp,
 555                        "Keyslot %zu is overlapping with the LUKS header",
 556                        i);
 557             return -1;
 558         }
 559
 560         if (!detached && start1 + len1 > luks->header.payload_offset_sector) {
 561             error_setg(errp,
 562                        "Keyslot %zu is overlapping with the encrypted payload",
 563                        i);
 564             return -1;
 565         }
 566
 567         for (j = i + 1 ; j < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS ; j++) {
 568             const QCryptoBlockLUKSKeySlot *slot2 = &luks->header.key_slots[j];
 569             unsigned int start2 = slot2->key_offset_sector;
 570             unsigned int len2 =
 571                 qcrypto_block_luks_splitkeylen_sectors(luks,
 572                                                        header_sectors,
 573                                                        slot2->stripes);
 574
 575             if (start1 + len1 > start2 && start2 + len2 > start1) {
 576                 error_setg(errp,
 577                            "Keyslots %zu and %zu are overlapping in the header",
 578                            i, j);
 579                 return -1;
 580             }
 581         }
 582
 583     }
 584     return 0;
 585 }
 586
 587 /*
 588  * Parses the crypto parameters that are stored in the LUKS header
 589  */
 590
 591 static int
 592 qcrypto_block_luks_parse_header(QCryptoBlockLUKS *luks, Error **errp)
 593 {
 594     g_autofree char *cipher_mode = g_strdup(luks->header.cipher_mode);
 595     char *ivgen_name, *ivhash_name;
 596     Error *local_err = NULL;
 597
 598     /*
 599      * The cipher_mode header contains a string that we have
 600      * to further parse, of the format
 601      *
 602      *    <cipher-mode>-<iv-generator>[:<iv-hash>]
 603      *
 604      * eg  cbc-essiv:sha256, cbc-plain64
 605      */
 606     ivgen_name = strchr(cipher_mode, '-');
 607     if (!ivgen_name) {
 608         error_setg(errp, "Unexpected cipher mode string format '%s'",
 609                    luks->header.cipher_mode);
 610         return -1;
 611     }
 612     *ivgen_name = '\0';
 613     ivgen_name++;
 614
 615     ivhash_name = strchr(ivgen_name, ':');
 616     if (!ivhash_name) {
 617         luks->ivgen_hash_alg = 0;
 618     } else {
 619         *ivhash_name = '\0';
 620         ivhash_name++;
 621
 622         luks->ivgen_hash_alg = qcrypto_block_luks_hash_name_lookup(ivhash_name,
 623                                                                    &local_err);
 624         if (local_err) {
 625             error_propagate(errp, local_err);
 626             return -1;
 627         }
 628     }
 629
 630     luks->cipher_mode = qcrypto_block_luks_cipher_mode_lookup(cipher_mode,
 631                                                               &local_err);
 632     if (local_err) {
 633         error_propagate(errp, local_err);
 634         return -1;
 635     }
 636
 637     luks->cipher_alg =
 638             qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name,
 639                                                   luks->cipher_mode,
 640                                                   luks->header.master_key_len,
 641                                                   &local_err);
 642     if (local_err) {
 643         error_propagate(errp, local_err);
 644         return -1;
 645     }
 646
 647     luks->hash_alg =
 648             qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec,
 649                                                 &local_err);
 650     if (local_err) {
 651         error_propagate(errp, local_err);
 652         return -1;
 653     }
 654
 655     luks->ivgen_alg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name,
 656                                                            &local_err);
 657     if (local_err) {
 658         error_propagate(errp, local_err);
 659         return -1;
 660     }
 661
 662     if (luks->ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
 663         if (!ivhash_name) {
 664             error_setg(errp, "Missing IV generator hash specification");
 665             return -1;
 666         }
 667         luks->ivgen_cipher_alg =
 668                 qcrypto_block_luks_essiv_cipher(luks->cipher_alg,
 669                                                 luks->ivgen_hash_alg,
 670                                                 &local_err);
 671         if (local_err) {
 672             error_propagate(errp, local_err);
 673             return -1;
 674         }
 675     } else {
 676
 677         /*
 678          * Note we parsed the ivhash_name earlier in the cipher_mode
 679          * spec string even with plain/plain64 ivgens, but we
 680          * will ignore it, since it is irrelevant for these ivgens.
 681          * This is for compat with dm-crypt which will silently
 682          * ignore hash names with these ivgens rather than report
 683          * an error about the invalid usage
 684          */
 685         luks->ivgen_cipher_alg = luks->cipher_alg;
 686     }
 687     return 0;
 688 }
 689
 690 /*
 691  * Given a key slot,  user password, and the master key,
 692  * will store the encrypted master key there, and update the
 693  * in-memory header. User must then write the in-memory header
 694  *
 695  * Returns:
 696  *    0 if the keyslot was written successfully
 697  *      with the provided password
 698  *   -1 if a fatal error occurred while storing the key
 699  */
 700 static int
 701 qcrypto_block_luks_store_key(QCryptoBlock *block,
 702                              unsigned int slot_idx,
 703                              const char *password,
 704                              uint8_t *masterkey,
 705                              uint64_t iter_time,
 706                              QCryptoBlockWriteFunc writefunc,
 707                              void *opaque,
 708                              Error **errp)
 709 {
 710     QCryptoBlockLUKS *luks = block->opaque;
 711     QCryptoBlockLUKSKeySlot *slot;
 712     g_autofree uint8_t *splitkey = NULL;
 713     size_t splitkeylen;
 714     g_autofree uint8_t *slotkey = NULL;
 715     g_autoptr(QCryptoCipher) cipher = NULL;
 716     g_autoptr(QCryptoIVGen) ivgen = NULL;
 717     Error *local_err = NULL;
 718     uint64_t iters;
 719     int ret = -1;
 720
 721     assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
 722     slot = &luks->header.key_slots[slot_idx];
 723     splitkeylen = luks->header.master_key_len * slot->stripes;
 724
 725     if (qcrypto_random_bytes(slot->salt,
 726                              QCRYPTO_BLOCK_LUKS_SALT_LEN,
 727                              errp) < 0) {
 728         goto cleanup;
 729     }
 730
 731     /*
 732      * Determine how many iterations are required to
 733      * hash the user password while consuming 1 second of compute
 734      * time
 735      */
 736     iters = qcrypto_pbkdf2_count_iters(luks->hash_alg,
 737                                        (uint8_t *)password, strlen(password),
 738                                        slot->salt,
 739                                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
 740                                        luks->header.master_key_len,
 741                                        &local_err);
 742     if (local_err) {
 743         error_propagate(errp, local_err);
 744         goto cleanup;
 745     }
 746
 747     if (iters > (ULLONG_MAX / iter_time)) {
 748         error_setg_errno(errp, ERANGE,
 749                          "PBKDF iterations %llu too large to scale",
 750                          (unsigned long long)iters);
 751         goto cleanup;
 752     }
 753
 754     /* iter_time was in millis, but count_iters reported for secs */
 755     iters = iters * iter_time / 1000;
 756
 757     if (iters > UINT32_MAX) {
 758         error_setg_errno(errp, ERANGE,
 759                          "PBKDF iterations %llu larger than %u",
 760                          (unsigned long long)iters, UINT32_MAX);
 761         goto cleanup;
 762     }
 763
 764     slot->iterations =
 765         MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS);
 766
 767
 768     /*
 769      * Generate a key that we'll use to encrypt the master
 770      * key, from the user's password
 771      */
 772     slotkey = g_new0(uint8_t, luks->header.master_key_len);
 773     if (qcrypto_pbkdf2(luks->hash_alg,
 774                        (uint8_t *)password, strlen(password),
 775                        slot->salt,
 776                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
 777                        slot->iterations,
 778                        slotkey, luks->header.master_key_len,
 779                        errp) < 0) {
 780         goto cleanup;
 781     }
 782
 783
 784     /*
 785      * Setup the encryption objects needed to encrypt the
 786      * master key material
 787      */
 788     cipher = qcrypto_cipher_new(luks->cipher_alg,
 789                                 luks->cipher_mode,
 790                                 slotkey, luks->header.master_key_len,
 791                                 errp);
 792     if (!cipher) {
 793         goto cleanup;
 794     }
 795
 796     ivgen = qcrypto_ivgen_new(luks->ivgen_alg,
 797                               luks->ivgen_cipher_alg,
 798                               luks->ivgen_hash_alg,
 799                               slotkey, luks->header.master_key_len,
 800                               errp);
 801     if (!ivgen) {
 802         goto cleanup;
 803     }
 804
 805     /*
 806      * Before storing the master key, we need to vastly
 807      * increase its size, as protection against forensic
 808      * disk data recovery
 809      */
 810     splitkey = g_new0(uint8_t, splitkeylen);
 811
 812     if (qcrypto_afsplit_encode(luks->hash_alg,
 813                                luks->header.master_key_len,
 814                                slot->stripes,
 815                                masterkey,
 816                                splitkey,
 817                                errp) < 0) {
 818         goto cleanup;
 819     }
 820
 821     /*
 822      * Now we encrypt the split master key with the key generated
 823      * from the user's password, before storing it
 824      */
 825     if (qcrypto_block_cipher_encrypt_helper(cipher, block->niv, ivgen,
 826                                             QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
 827                                             0,
 828                                             splitkey,
 829                                             splitkeylen,
 830                                             errp) < 0) {
 831         goto cleanup;
 832     }
 833
 834     /* Write out the slot's master key material. */
 835     if (writefunc(block,
 836                   slot->key_offset_sector *
 837                   QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
 838                   splitkey, splitkeylen,
 839                   opaque,
 840                   errp) < 0) {
 841         goto cleanup;
 842     }
 843
 844     slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED;
 845
 846     if (qcrypto_block_luks_store_header(block,  writefunc, opaque, errp) < 0) {
 847         goto cleanup;
 848     }
 849
 850     ret = 0;
 851
 852 cleanup:
 853     if (slotkey) {
 854         memset(slotkey, 0, luks->header.master_key_len);
 855     }
 856     if (splitkey) {
 857         memset(splitkey, 0, splitkeylen);
 858     }
 859     return ret;
 860 }
 861
 862 /*
 863  * Given a key slot, and user password, this will attempt to unlock
 864  * the master encryption key from the key slot.
 865  *
 866  * Returns:
 867  *    0 if the key slot is disabled, or key could not be decrypted
 868  *      with the provided password
 869  *    1 if the key slot is enabled, and key decrypted successfully
 870  *      with the provided password
 871  *   -1 if a fatal error occurred loading the key
 872  */
 873 static int
 874 qcrypto_block_luks_load_key(QCryptoBlock *block,
 875                             size_t slot_idx,
 876                             const char *password,
 877                             uint8_t *masterkey,
 878                             QCryptoBlockReadFunc readfunc,
 879                             void *opaque,
 880                             Error **errp)
 881 {
 882     QCryptoBlockLUKS *luks = block->opaque;
 883     const QCryptoBlockLUKSKeySlot *slot;
 884     g_autofree uint8_t *splitkey = NULL;
 885     size_t splitkeylen;
 886     g_autofree uint8_t *possiblekey = NULL;
 887     int rv;
 888     g_autoptr(QCryptoCipher) cipher = NULL;
 889     uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN];
 890     g_autoptr(QCryptoIVGen) ivgen = NULL;
 891     size_t niv;
 892
 893     assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
 894     slot = &luks->header.key_slots[slot_idx];
 895     if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) {
 896         return 0;
 897     }
 898
 899     splitkeylen = luks->header.master_key_len * slot->stripes;
 900     splitkey = g_new0(uint8_t, splitkeylen);
 901     possiblekey = g_new0(uint8_t, luks->header.master_key_len);
 902
 903     /*
 904      * The user password is used to generate a (possible)
 905      * decryption key. This may or may not successfully
 906      * decrypt the master key - we just blindly assume
 907      * the key is correct and validate the results of
 908      * decryption later.
 909      */
 910     if (qcrypto_pbkdf2(luks->hash_alg,
 911                        (const uint8_t *)password, strlen(password),
 912                        slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN,
 913                        slot->iterations,
 914                        possiblekey, luks->header.master_key_len,
 915                        errp) < 0) {
 916         return -1;
 917     }
 918
 919     /*
 920      * We need to read the master key material from the
 921      * LUKS key material header. What we're reading is
 922      * not the raw master key, but rather the data after
 923      * it has been passed through AFSplit and the result
 924      * then encrypted.
 925      */
 926     rv = readfunc(block,
 927                   slot->key_offset_sector * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
 928                   splitkey, splitkeylen,
 929                   opaque,
 930                   errp);
 931     if (rv < 0) {
 932         return -1;
 933     }
 934
 935
 936     /* Setup the cipher/ivgen that we'll use to try to decrypt
 937      * the split master key material */
 938     cipher = qcrypto_cipher_new(luks->cipher_alg,
 939                                 luks->cipher_mode,
 940                                 possiblekey,
 941                                 luks->header.master_key_len,
 942                                 errp);
 943     if (!cipher) {
 944         return -1;
 945     }
 946
 947     niv = qcrypto_cipher_get_iv_len(luks->cipher_alg,
 948                                     luks->cipher_mode);
 949
 950     ivgen = qcrypto_ivgen_new(luks->ivgen_alg,
 951                               luks->ivgen_cipher_alg,
 952                               luks->ivgen_hash_alg,
 953                               possiblekey,
 954                               luks->header.master_key_len,
 955                               errp);
 956     if (!ivgen) {
 957         return -1;
 958     }
 959
 960
 961     /*
 962      * The master key needs to be decrypted in the same
 963      * way that the block device payload will be decrypted
 964      * later. In particular we'll be using the IV generator
 965      * to reset the encryption cipher every time the master
 966      * key crosses a sector boundary.
 967      */
 968     if (qcrypto_block_cipher_decrypt_helper(cipher,
 969                                             niv,
 970                                             ivgen,
 971                                             QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
 972                                             0,
 973                                             splitkey,
 974                                             splitkeylen,
 975                                             errp) < 0) {
 976         return -1;
 977     }
 978
 979     /*
 980      * Now we've decrypted the split master key, join
 981      * it back together to get the actual master key.
 982      */
 983     if (qcrypto_afsplit_decode(luks->hash_alg,
 984                                luks->header.master_key_len,
 985                                slot->stripes,
 986                                splitkey,
 987                                masterkey,
 988                                errp) < 0) {
 989         return -1;
 990     }
 991
 992
 993     /*
 994      * We still don't know that the masterkey we got is valid,
 995      * because we just blindly assumed the user's password
 996      * was correct. This is where we now verify it. We are
 997      * creating a hash of the master key using PBKDF and
 998      * then comparing that to the hash stored in the key slot
 999      * header
1000      */
1001     if (qcrypto_pbkdf2(luks->hash_alg,
1002                        masterkey,
1003                        luks->header.master_key_len,
1004                        luks->header.master_key_salt,
1005                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
1006                        luks->header.master_key_iterations,
1007                        keydigest,
1008                        G_N_ELEMENTS(keydigest),
1009                        errp) < 0) {
1010         return -1;
1011     }
1012
1013     if (memcmp(keydigest, luks->header.master_key_digest,
1014                QCRYPTO_BLOCK_LUKS_DIGEST_LEN) == 0) {
1015         /* Success, we got the right master key */
1016         return 1;
1017     }
1018
1019     /* Fail, user's password was not valid for this key slot,
1020      * tell caller to try another slot */
1021     return 0;
1022 }
1023
1024
1025 /*
1026  * Given a user password, this will iterate over all key
1027  * slots and try to unlock each active key slot using the
1028  * password until it successfully obtains a master key.
1029  *
1030  * Returns 0 if a key was loaded, -1 if no keys could be loaded
1031  */
1032 static int
1033 qcrypto_block_luks_find_key(QCryptoBlock *block,
1034                             const char *password,
1035                             uint8_t *masterkey,
1036                             QCryptoBlockReadFunc readfunc,
1037                             void *opaque,
1038                             Error **errp)
1039 {
1040     size_t i;
1041     int rv;
1042
1043     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1044         rv = qcrypto_block_luks_load_key(block,
1045                                          i,
1046                                          password,
1047                                          masterkey,
1048                                          readfunc,
1049                                          opaque,
1050                                          errp);
1051         if (rv < 0) {
1052             goto error;
1053         }
1054         if (rv == 1) {
1055             return 0;
1056         }
1057     }
1058
1059     error_setg(errp, "Invalid password, cannot unlock any keyslot");
1060  error:
1061     return -1;
1062 }
1063
1064 /*
1065  * Returns true if a slot i is marked as active
1066  * (contains encrypted copy of the master key)
1067  */
1068 static bool
1069 qcrypto_block_luks_slot_active(const QCryptoBlockLUKS *luks,
1070                                unsigned int slot_idx)
1071 {
1072     uint32_t val;
1073
1074     assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
1075     val = luks->header.key_slots[slot_idx].active;
1076     return val == QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED;
1077 }
1078
1079 /*
1080  * Returns the number of slots that are marked as active
1081  * (slots that contain encrypted copy of the master key)
1082  */
1083 static unsigned int
1084 qcrypto_block_luks_count_active_slots(const QCryptoBlockLUKS *luks)
1085 {
1086     size_t i = 0;
1087     unsigned int ret = 0;
1088
1089     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1090         if (qcrypto_block_luks_slot_active(luks, i)) {
1091             ret++;
1092         }
1093     }
1094     return ret;
1095 }
1096
1097 /*
1098  * Finds first key slot which is not active
1099  * Returns the key slot index, or -1 if it doesn't exist
1100  */
1101 static int
1102 qcrypto_block_luks_find_free_keyslot(const QCryptoBlockLUKS *luks)
1103 {
1104     size_t i;
1105
1106     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1107         if (!qcrypto_block_luks_slot_active(luks, i)) {
1108             return i;
1109         }
1110     }
1111     return -1;
1112 }
1113
1114 /*
1115  * Erases an keyslot given its index
1116  * Returns:
1117  *    0 if the keyslot was erased successfully
1118  *   -1 if a error occurred while erasing the keyslot
1119  *
1120  */
1121 static int
1122 qcrypto_block_luks_erase_key(QCryptoBlock *block,
1123                              unsigned int slot_idx,
1124                              QCryptoBlockWriteFunc writefunc,
1125                              void *opaque,
1126                              Error **errp)
1127 {
1128     QCryptoBlockLUKS *luks = block->opaque;
1129     QCryptoBlockLUKSKeySlot *slot;
1130     g_autofree uint8_t *garbagesplitkey = NULL;
1131     size_t splitkeylen;
1132     size_t i;
1133     Error *local_err = NULL;
1134     int ret;
1135
1136     assert(slot_idx < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
1137     slot = &luks->header.key_slots[slot_idx];
1138
1139     splitkeylen = luks->header.master_key_len * slot->stripes;
1140     assert(splitkeylen > 0);
1141
1142     garbagesplitkey = g_new0(uint8_t, splitkeylen);
1143
1144     /* Reset the key slot header */
1145     memset(slot->salt, 0, QCRYPTO_BLOCK_LUKS_SALT_LEN);
1146     slot->iterations = 0;
1147     slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
1148
1149     ret = qcrypto_block_luks_store_header(block, writefunc,
1150                                           opaque, &local_err);
1151
1152     if (ret < 0) {
1153         error_propagate(errp, local_err);
1154     }
1155     /*
1156      * Now try to erase the key material, even if the header
1157      * update failed
1158      */
1159     for (i = 0; i < QCRYPTO_BLOCK_LUKS_ERASE_ITERATIONS; i++) {
1160         if (qcrypto_random_bytes(garbagesplitkey,
1161                                  splitkeylen, &local_err) < 0) {
1162             /*
1163              * If we failed to get the random data, still write
1164              * at least zeros to the key slot at least once
1165              */
1166             error_propagate(errp, local_err);
1167
1168             if (i > 0) {
1169                 return -1;
1170             }
1171         }
1172         if (writefunc(block,
1173                       slot->key_offset_sector * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1174                       garbagesplitkey,
1175                       splitkeylen,
1176                       opaque,
1177                       &local_err) < 0) {
1178             error_propagate(errp, local_err);
1179             return -1;
1180         }
1181     }
1182     return ret;
1183 }
1184
1185 static int
1186 qcrypto_block_luks_open(QCryptoBlock *block,
1187                         QCryptoBlockOpenOptions *options,
1188                         const char *optprefix,
1189                         QCryptoBlockReadFunc readfunc,
1190                         void *opaque,
1191                         unsigned int flags,
1192                         size_t n_threads,
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                                       n_threads,
1266                                       errp) < 0) {
1267             goto fail;
1268         }
1269     }
1270
1271     block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1272     block->payload_offset = luks->header.payload_offset_sector *
1273         block->sector_size;
1274     block->detached_header = (block->payload_offset == 0) ? true : false;
1275
1276     return 0;
1277
1278  fail:
1279     qcrypto_block_free_cipher(block);
1280     qcrypto_ivgen_free(block->ivgen);
1281     g_free(luks->secret);
1282     g_free(luks);
1283     return -1;
1284 }
1285
1286
1287 static void
1288 qcrypto_block_luks_uuid_gen(uint8_t *uuidstr)
1289 {
1290     QemuUUID uuid;
1291     qemu_uuid_generate(&uuid);
1292     qemu_uuid_unparse(&uuid, (char *)uuidstr);
1293 }
1294
1295 static int
1296 qcrypto_block_luks_create(QCryptoBlock *block,
1297                           QCryptoBlockCreateOptions *options,
1298                           const char *optprefix,
1299                           QCryptoBlockInitFunc initfunc,
1300                           QCryptoBlockWriteFunc writefunc,
1301                           void *opaque,
1302                           Error **errp)
1303 {
1304     QCryptoBlockLUKS *luks;
1305     QCryptoBlockCreateOptionsLUKS luks_opts;
1306     Error *local_err = NULL;
1307     g_autofree uint8_t *masterkey = NULL;
1308     size_t header_sectors;
1309     size_t split_key_sectors;
1310     size_t i;
1311     g_autofree char *password = NULL;
1312     const char *cipher_alg;
1313     const char *cipher_mode;
1314     const char *ivgen_alg;
1315     const char *ivgen_hash_alg = NULL;
1316     const char *hash_alg;
1317     g_autofree char *cipher_mode_spec = NULL;
1318     uint64_t iters;
1319     uint64_t detached_header_size;
1320
1321     memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts));
1322     if (!luks_opts.has_iter_time) {
1323         luks_opts.iter_time = QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS;
1324     }
1325     if (!luks_opts.has_cipher_alg) {
1326         luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256;
1327     }
1328     if (!luks_opts.has_cipher_mode) {
1329         luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS;
1330     }
1331     if (!luks_opts.has_ivgen_alg) {
1332         luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64;
1333     }
1334     if (!luks_opts.has_hash_alg) {
1335         luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256;
1336     }
1337     if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
1338         if (!luks_opts.has_ivgen_hash_alg) {
1339             luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256;
1340             luks_opts.has_ivgen_hash_alg = true;
1341         }
1342     }
1343
1344     luks = g_new0(QCryptoBlockLUKS, 1);
1345     block->opaque = luks;
1346
1347     luks->cipher_alg = luks_opts.cipher_alg;
1348     luks->cipher_mode = luks_opts.cipher_mode;
1349     luks->ivgen_alg = luks_opts.ivgen_alg;
1350     luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg;
1351     luks->hash_alg = luks_opts.hash_alg;
1352
1353
1354     /* Note we're allowing ivgen_hash_alg to be set even for
1355      * non-essiv iv generators that don't need a hash. It will
1356      * be silently ignored, for compatibility with dm-crypt */
1357
1358     if (!options->u.luks.key_secret) {
1359         error_setg(errp, "Parameter '%skey-secret' is required for cipher",
1360                    optprefix ? optprefix : "");
1361         goto error;
1362     }
1363     luks->secret = g_strdup(options->u.luks.key_secret);
1364
1365     password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp);
1366     if (!password) {
1367         goto error;
1368     }
1369
1370
1371     memcpy(luks->header.magic, qcrypto_block_luks_magic,
1372            QCRYPTO_BLOCK_LUKS_MAGIC_LEN);
1373
1374     /* We populate the header in native endianness initially and
1375      * then convert everything to big endian just before writing
1376      * it out to disk
1377      */
1378     luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION;
1379     qcrypto_block_luks_uuid_gen(luks->header.uuid);
1380
1381     cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg,
1382                                                       errp);
1383     if (!cipher_alg) {
1384         goto error;
1385     }
1386
1387     cipher_mode = QCryptoCipherMode_str(luks_opts.cipher_mode);
1388     ivgen_alg = QCryptoIVGenAlgorithm_str(luks_opts.ivgen_alg);
1389     if (luks_opts.has_ivgen_hash_alg) {
1390         ivgen_hash_alg = QCryptoHashAlgorithm_str(luks_opts.ivgen_hash_alg);
1391         cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg,
1392                                            ivgen_hash_alg);
1393     } else {
1394         cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg);
1395     }
1396     hash_alg = QCryptoHashAlgorithm_str(luks_opts.hash_alg);
1397
1398
1399     if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) {
1400         error_setg(errp, "Cipher name '%s' is too long for LUKS header",
1401                    cipher_alg);
1402         goto error;
1403     }
1404     if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) {
1405         error_setg(errp, "Cipher mode '%s' is too long for LUKS header",
1406                    cipher_mode_spec);
1407         goto error;
1408     }
1409     if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) {
1410         error_setg(errp, "Hash name '%s' is too long for LUKS header",
1411                    hash_alg);
1412         goto error;
1413     }
1414
1415     if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
1416         luks->ivgen_cipher_alg =
1417                 qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg,
1418                                                 luks_opts.ivgen_hash_alg,
1419                                                 &local_err);
1420         if (local_err) {
1421             error_propagate(errp, local_err);
1422             goto error;
1423         }
1424     } else {
1425         luks->ivgen_cipher_alg = luks_opts.cipher_alg;
1426     }
1427
1428     strcpy(luks->header.cipher_name, cipher_alg);
1429     strcpy(luks->header.cipher_mode, cipher_mode_spec);
1430     strcpy(luks->header.hash_spec, hash_alg);
1431
1432     luks->header.master_key_len =
1433         qcrypto_cipher_get_key_len(luks_opts.cipher_alg);
1434
1435     if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) {
1436         luks->header.master_key_len *= 2;
1437     }
1438
1439     /* Generate the salt used for hashing the master key
1440      * with PBKDF later
1441      */
1442     if (qcrypto_random_bytes(luks->header.master_key_salt,
1443                              QCRYPTO_BLOCK_LUKS_SALT_LEN,
1444                              errp) < 0) {
1445         goto error;
1446     }
1447
1448     /* Generate random master key */
1449     masterkey = g_new0(uint8_t, luks->header.master_key_len);
1450     if (qcrypto_random_bytes(masterkey,
1451                              luks->header.master_key_len, errp) < 0) {
1452         goto error;
1453     }
1454
1455
1456     /* Setup the block device payload encryption objects */
1457     if (qcrypto_block_init_cipher(block, luks_opts.cipher_alg,
1458                                   luks_opts.cipher_mode, masterkey,
1459                                   luks->header.master_key_len, 1, errp) < 0) {
1460         goto error;
1461     }
1462
1463     block->kdfhash = luks_opts.hash_alg;
1464     block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg,
1465                                            luks_opts.cipher_mode);
1466     block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg,
1467                                      luks->ivgen_cipher_alg,
1468                                      luks_opts.ivgen_hash_alg,
1469                                      masterkey, luks->header.master_key_len,
1470                                      errp);
1471
1472     if (!block->ivgen) {
1473         goto error;
1474     }
1475
1476
1477     /* Determine how many iterations we need to hash the master
1478      * key, in order to have 1 second of compute time used
1479      */
1480     iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg,
1481                                        masterkey, luks->header.master_key_len,
1482                                        luks->header.master_key_salt,
1483                                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
1484                                        QCRYPTO_BLOCK_LUKS_DIGEST_LEN,
1485                                        &local_err);
1486     if (local_err) {
1487         error_propagate(errp, local_err);
1488         goto error;
1489     }
1490
1491     if (iters > (ULLONG_MAX / luks_opts.iter_time)) {
1492         error_setg_errno(errp, ERANGE,
1493                          "PBKDF iterations %llu too large to scale",
1494                          (unsigned long long)iters);
1495         goto error;
1496     }
1497
1498     /* iter_time was in millis, but count_iters reported for secs */
1499     iters = iters * luks_opts.iter_time / 1000;
1500
1501     /* Why /= 8 ?  That matches cryptsetup, but there's no
1502      * explanation why they chose /= 8... Probably so that
1503      * if all 8 keyslots are active we only spend 1 second
1504      * in total time to check all keys */
1505     iters /= 8;
1506     if (iters > UINT32_MAX) {
1507         error_setg_errno(errp, ERANGE,
1508                          "PBKDF iterations %llu larger than %u",
1509                          (unsigned long long)iters, UINT32_MAX);
1510         goto error;
1511     }
1512     iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS);
1513     luks->header.master_key_iterations = iters;
1514
1515     /* Hash the master key, saving the result in the LUKS
1516      * header. This hash is used when opening the encrypted
1517      * device to verify that the user password unlocked a
1518      * valid master key
1519      */
1520     if (qcrypto_pbkdf2(luks_opts.hash_alg,
1521                        masterkey, luks->header.master_key_len,
1522                        luks->header.master_key_salt,
1523                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
1524                        luks->header.master_key_iterations,
1525                        luks->header.master_key_digest,
1526                        QCRYPTO_BLOCK_LUKS_DIGEST_LEN,
1527                        errp) < 0) {
1528         goto error;
1529     }
1530
1531     /* start with the sector that follows the header*/
1532     header_sectors = QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1533         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1534
1535     split_key_sectors =
1536         qcrypto_block_luks_splitkeylen_sectors(luks,
1537                                                header_sectors,
1538                                                QCRYPTO_BLOCK_LUKS_STRIPES);
1539
1540     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1541         QCryptoBlockLUKSKeySlot *slot = &luks->header.key_slots[i];
1542         slot->active = QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
1543
1544         slot->key_offset_sector = header_sectors + i * split_key_sectors;
1545         slot->stripes = QCRYPTO_BLOCK_LUKS_STRIPES;
1546     }
1547
1548     if (block->detached_header) {
1549         /*
1550          * For a detached LUKS header image, set the payload_offset_sector
1551          * to 0 to specify the starting point for read/write
1552          */
1553         luks->header.payload_offset_sector = 0;
1554     } else {
1555         /*
1556          * The total size of the LUKS headers is the partition header + key
1557          * slot headers, rounded up to the nearest sector, combined with
1558          * the size of each master key material region, also rounded up
1559          * to the nearest sector
1560          */
1561         luks->header.payload_offset_sector = header_sectors +
1562                 QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS * split_key_sectors;
1563     }
1564
1565     block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1566     block->payload_offset = luks->header.payload_offset_sector *
1567         block->sector_size;
1568     detached_header_size =
1569         (header_sectors + QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS *
1570          split_key_sectors) * block->sector_size;
1571
1572     /* Reserve header space to match payload offset */
1573     initfunc(block, detached_header_size, opaque, &local_err);
1574     if (local_err) {
1575         error_propagate(errp, local_err);
1576         goto error;
1577     }
1578
1579
1580     /* populate the slot 0 with the password encrypted master key*/
1581     /* This will also store the header */
1582     if (qcrypto_block_luks_store_key(block,
1583                                      0,
1584                                      password,
1585                                      masterkey,
1586                                      luks_opts.iter_time,
1587                                      writefunc,
1588                                      opaque,
1589                                      errp) < 0) {
1590         goto error;
1591     }
1592
1593     memset(masterkey, 0, luks->header.master_key_len);
1594
1595     return 0;
1596
1597  error:
1598     if (masterkey) {
1599         memset(masterkey, 0, luks->header.master_key_len);
1600     }
1601
1602     qcrypto_block_free_cipher(block);
1603     qcrypto_ivgen_free(block->ivgen);
1604
1605     g_free(luks->secret);
1606     g_free(luks);
1607     return -1;
1608 }
1609
1610 static int
1611 qcrypto_block_luks_amend_add_keyslot(QCryptoBlock *block,
1612                                      QCryptoBlockReadFunc readfunc,
1613                                      QCryptoBlockWriteFunc writefunc,
1614                                      void *opaque,
1615                                      QCryptoBlockAmendOptionsLUKS *opts_luks,
1616                                      bool force,
1617                                      Error **errp)
1618 {
1619     QCryptoBlockLUKS *luks = block->opaque;
1620     uint64_t iter_time = opts_luks->has_iter_time ?
1621                          opts_luks->iter_time :
1622                          QCRYPTO_BLOCK_LUKS_DEFAULT_ITER_TIME_MS;
1623     int keyslot;
1624     g_autofree char *old_password = NULL;
1625     g_autofree char *new_password = NULL;
1626     g_autofree uint8_t *master_key = NULL;
1627
1628     char *secret = opts_luks->secret ?: luks->secret;
1629
1630     if (!opts_luks->new_secret) {
1631         error_setg(errp, "'new-secret' is required to activate a keyslot");
1632         return -1;
1633     }
1634     if (opts_luks->old_secret) {
1635         error_setg(errp,
1636                    "'old-secret' must not be given when activating keyslots");
1637         return -1;
1638     }
1639
1640     if (opts_luks->has_keyslot) {
1641         keyslot = opts_luks->keyslot;
1642         if (keyslot < 0 || keyslot >= QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS) {
1643             error_setg(errp,
1644                        "Invalid keyslot %u specified, must be between 0 and %u",
1645                        keyslot, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS - 1);
1646             return -1;
1647         }
1648     } else {
1649         keyslot = qcrypto_block_luks_find_free_keyslot(luks);
1650         if (keyslot == -1) {
1651             error_setg(errp,
1652                        "Can't add a keyslot - all keyslots are in use");
1653             return -1;
1654         }
1655     }
1656
1657     if (!force && qcrypto_block_luks_slot_active(luks, keyslot)) {
1658         error_setg(errp,
1659                    "Refusing to overwrite active keyslot %i - "
1660                    "please erase it first",
1661                    keyslot);
1662         return -1;
1663     }
1664
1665     /* Locate the password that will be used to retrieve the master key */
1666     old_password = qcrypto_secret_lookup_as_utf8(secret, errp);
1667     if (!old_password) {
1668         return -1;
1669     }
1670
1671     /* Retrieve the master key */
1672     master_key = g_new0(uint8_t, luks->header.master_key_len);
1673
1674     if (qcrypto_block_luks_find_key(block, old_password, master_key,
1675                                     readfunc, opaque, errp) < 0) {
1676         error_append_hint(errp, "Failed to retrieve the master key");
1677         return -1;
1678     }
1679
1680     /* Locate the new password*/
1681     new_password = qcrypto_secret_lookup_as_utf8(opts_luks->new_secret, errp);
1682     if (!new_password) {
1683         return -1;
1684     }
1685
1686     /* Now set the new keyslots */
1687     if (qcrypto_block_luks_store_key(block, keyslot, new_password, master_key,
1688                                      iter_time, writefunc, opaque, errp)) {
1689         error_append_hint(errp, "Failed to write to keyslot %i", keyslot);
1690         return -1;
1691     }
1692     return 0;
1693 }
1694
1695 static int
1696 qcrypto_block_luks_amend_erase_keyslots(QCryptoBlock *block,
1697                                         QCryptoBlockReadFunc readfunc,
1698                                         QCryptoBlockWriteFunc writefunc,
1699                                         void *opaque,
1700                                         QCryptoBlockAmendOptionsLUKS *opts_luks,
1701                                         bool force,
1702                                         Error **errp)
1703 {
1704     QCryptoBlockLUKS *luks = block->opaque;
1705     g_autofree uint8_t *tmpkey = NULL;
1706     g_autofree char *old_password = NULL;
1707
1708     if (opts_luks->new_secret) {
1709         error_setg(errp,
1710                    "'new-secret' must not be given when erasing keyslots");
1711         return -1;
1712     }
1713     if (opts_luks->has_iter_time) {
1714         error_setg(errp,
1715                    "'iter-time' must not be given when erasing keyslots");
1716         return -1;
1717     }
1718     if (opts_luks->secret) {
1719         error_setg(errp,
1720                    "'secret' must not be given when erasing keyslots");
1721         return -1;
1722     }
1723
1724     /* Load the old password if given */
1725     if (opts_luks->old_secret) {
1726         old_password = qcrypto_secret_lookup_as_utf8(opts_luks->old_secret,
1727                                                      errp);
1728         if (!old_password) {
1729             return -1;
1730         }
1731
1732         /*
1733          * Allocate a temporary key buffer that we will need when
1734          * checking if slot matches the given old password
1735          */
1736         tmpkey = g_new0(uint8_t, luks->header.master_key_len);
1737     }
1738
1739     /* Erase an explicitly given keyslot */
1740     if (opts_luks->has_keyslot) {
1741         int keyslot = opts_luks->keyslot;
1742
1743         if (keyslot < 0 || keyslot >= QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS) {
1744             error_setg(errp,
1745                        "Invalid keyslot %i specified, must be between 0 and %i",
1746                        keyslot, QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS - 1);
1747             return -1;
1748         }
1749
1750         if (opts_luks->old_secret) {
1751             int rv = qcrypto_block_luks_load_key(block,
1752                                                  keyslot,
1753                                                  old_password,
1754                                                  tmpkey,
1755                                                  readfunc,
1756                                                  opaque,
1757                                                  errp);
1758             if (rv == -1) {
1759                 return -1;
1760             } else if (rv == 0) {
1761                 error_setg(errp,
1762                            "Given keyslot %i doesn't contain the given "
1763                            "old password for erase operation",
1764                            keyslot);
1765                 return -1;
1766             }
1767         }
1768
1769         if (!force && !qcrypto_block_luks_slot_active(luks, keyslot)) {
1770             error_setg(errp,
1771                        "Given keyslot %i is already erased (inactive) ",
1772                        keyslot);
1773             return -1;
1774         }
1775
1776         if (!force && qcrypto_block_luks_count_active_slots(luks) == 1) {
1777             error_setg(errp,
1778                        "Attempt to erase the only active keyslot %i "
1779                        "which will erase all the data in the image "
1780                        "irreversibly - refusing operation",
1781                        keyslot);
1782             return -1;
1783         }
1784
1785         if (qcrypto_block_luks_erase_key(block, keyslot,
1786                                          writefunc, opaque, errp)) {
1787             error_append_hint(errp, "Failed to erase keyslot %i", keyslot);
1788             return -1;
1789         }
1790
1791     /* Erase all keyslots that match the given old password */
1792     } else if (opts_luks->old_secret) {
1793
1794         unsigned long slots_to_erase_bitmap = 0;
1795         size_t i;
1796         int slot_count;
1797
1798         assert(QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS <=
1799                sizeof(slots_to_erase_bitmap) * 8);
1800
1801         for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1802             int rv = qcrypto_block_luks_load_key(block,
1803                                                  i,
1804                                                  old_password,
1805                                                  tmpkey,
1806                                                  readfunc,
1807                                                  opaque,
1808                                                  errp);
1809             if (rv == -1) {
1810                 return -1;
1811             } else if (rv == 1) {
1812                 bitmap_set(&slots_to_erase_bitmap, i, 1);
1813             }
1814         }
1815
1816         slot_count = bitmap_count_one(&slots_to_erase_bitmap,
1817                                       QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
1818         if (slot_count == 0) {
1819             error_setg(errp,
1820                        "No keyslots match given (old) password for erase operation");
1821             return -1;
1822         }
1823
1824         if (!force &&
1825             slot_count == qcrypto_block_luks_count_active_slots(luks)) {
1826             error_setg(errp,
1827                        "All the active keyslots match the (old) password that "
1828                        "was given and erasing them will erase all the data in "
1829                        "the image irreversibly - refusing operation");
1830             return -1;
1831         }
1832
1833         /* Now apply the update */
1834         for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1835             if (!test_bit(i, &slots_to_erase_bitmap)) {
1836                 continue;
1837             }
1838             if (qcrypto_block_luks_erase_key(block, i, writefunc,
1839                 opaque, errp)) {
1840                 error_append_hint(errp, "Failed to erase keyslot %zu", i);
1841                 return -1;
1842             }
1843         }
1844     } else {
1845         error_setg(errp,
1846                    "To erase keyslot(s), either explicit keyslot index "
1847                    "or the password currently contained in them must be given");
1848         return -1;
1849     }
1850     return 0;
1851 }
1852
1853 static int
1854 qcrypto_block_luks_amend_options(QCryptoBlock *block,
1855                                  QCryptoBlockReadFunc readfunc,
1856                                  QCryptoBlockWriteFunc writefunc,
1857                                  void *opaque,
1858                                  QCryptoBlockAmendOptions *options,
1859                                  bool force,
1860                                  Error **errp)
1861 {
1862     QCryptoBlockAmendOptionsLUKS *opts_luks = &options->u.luks;
1863
1864     switch (opts_luks->state) {
1865     case Q_CRYPTO_BLOCKLUKS_KEYSLOT_STATE_ACTIVE:
1866         return qcrypto_block_luks_amend_add_keyslot(block, readfunc,
1867                                                     writefunc, opaque,
1868                                                     opts_luks, force, errp);
1869     case Q_CRYPTO_BLOCKLUKS_KEYSLOT_STATE_INACTIVE:
1870         return qcrypto_block_luks_amend_erase_keyslots(block, readfunc,
1871                                                        writefunc, opaque,
1872                                                        opts_luks, force, errp);
1873     default:
1874         g_assert_not_reached();
1875     }
1876 }
1877
1878 static int qcrypto_block_luks_get_info(QCryptoBlock *block,
1879                                        QCryptoBlockInfo *info,
1880                                        Error **errp)
1881 {
1882     QCryptoBlockLUKS *luks = block->opaque;
1883     QCryptoBlockInfoLUKSSlot *slot;
1884     QCryptoBlockInfoLUKSSlotList **tail = &info->u.luks.slots;
1885     size_t i;
1886
1887     info->u.luks.cipher_alg = luks->cipher_alg;
1888     info->u.luks.cipher_mode = luks->cipher_mode;
1889     info->u.luks.ivgen_alg = luks->ivgen_alg;
1890     if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
1891         info->u.luks.has_ivgen_hash_alg = true;
1892         info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg;
1893     }
1894     info->u.luks.hash_alg = luks->hash_alg;
1895     info->u.luks.payload_offset = block->payload_offset;
1896     info->u.luks.master_key_iters = luks->header.master_key_iterations;
1897     info->u.luks.uuid = g_strndup((const char *)luks->header.uuid,
1898                                   sizeof(luks->header.uuid));
1899     info->u.luks.detached_header = block->detached_header;
1900
1901     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1902         slot = g_new0(QCryptoBlockInfoLUKSSlot, 1);
1903         slot->active = luks->header.key_slots[i].active ==
1904             QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED;
1905         slot->key_offset = luks->header.key_slots[i].key_offset_sector
1906              * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1907         if (slot->active) {
1908             slot->has_iters = true;
1909             slot->iters = luks->header.key_slots[i].iterations;
1910             slot->has_stripes = true;
1911             slot->stripes = luks->header.key_slots[i].stripes;
1912         }
1913
1914         QAPI_LIST_APPEND(tail, slot);
1915     }
1916
1917     return 0;
1918 }
1919
1920
1921 static void qcrypto_block_luks_cleanup(QCryptoBlock *block)
1922 {
1923     QCryptoBlockLUKS *luks = block->opaque;
1924     if (luks) {
1925         g_free(luks->secret);
1926         g_free(luks);
1927     }
1928 }
1929
1930
1931 static int
1932 qcrypto_block_luks_decrypt(QCryptoBlock *block,
1933                            uint64_t offset,
1934                            uint8_t *buf,
1935                            size_t len,
1936                            Error **errp)
1937 {
1938     assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1939     assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1940     return qcrypto_block_decrypt_helper(block,
1941                                         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1942                                         offset, buf, len, errp);
1943 }
1944
1945
1946 static int
1947 qcrypto_block_luks_encrypt(QCryptoBlock *block,
1948                            uint64_t offset,
1949                            uint8_t *buf,
1950                            size_t len,
1951                            Error **errp)
1952 {
1953     assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1954     assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1955     return qcrypto_block_encrypt_helper(block,
1956                                         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1957                                         offset, buf, len, errp);
1958 }
1959
1960
1961 const QCryptoBlockDriver qcrypto_block_driver_luks = {
1962     .open = qcrypto_block_luks_open,
1963     .create = qcrypto_block_luks_create,
1964     .amend = qcrypto_block_luks_amend_options,
1965     .get_info = qcrypto_block_luks_get_info,
1966     .cleanup = qcrypto_block_luks_cleanup,
1967     .decrypt = qcrypto_block_luks_decrypt,
1968     .encrypt = qcrypto_block_luks_encrypt,
1969     .has_format = qcrypto_block_luks_has_format,
1970 };