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 27 #include "crypto/hash.h" 28 #include "crypto/afsplit.h" 29 #include "crypto/pbkdf.h" 30 #include "crypto/secret.h" 31 #include "crypto/random.h" 32 #include "qemu/uuid.h" 33 34 #include "qemu/coroutine.h" 35 36 /* 37 * Reference for the LUKS format implemented here is 38 * 39 * docs/on-disk-format.pdf 40 * 41 * in 'cryptsetup' package source code 42 * 43 * This file implements the 1.2.1 specification, dated 44 * Oct 16, 2011. 45 */ 46 47 typedef struct QCryptoBlockLUKS QCryptoBlockLUKS; 48 typedef struct QCryptoBlockLUKSHeader QCryptoBlockLUKSHeader; 49 typedef struct QCryptoBlockLUKSKeySlot QCryptoBlockLUKSKeySlot; 50 51 52 /* The following constants are all defined by the LUKS spec */ 53 #define QCRYPTO_BLOCK_LUKS_VERSION 1 54 55 #define QCRYPTO_BLOCK_LUKS_MAGIC_LEN 6 56 #define QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN 32 57 #define QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN 32 58 #define QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN 32 59 #define QCRYPTO_BLOCK_LUKS_DIGEST_LEN 20 60 #define QCRYPTO_BLOCK_LUKS_SALT_LEN 32 61 #define QCRYPTO_BLOCK_LUKS_UUID_LEN 40 62 #define QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS 8 63 #define QCRYPTO_BLOCK_LUKS_STRIPES 4000 64 #define QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS 1000 65 #define QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS 1000 66 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET 4096 67 68 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED 0x0000DEAD 69 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED 0x00AC71F3 70 71 #define QCRYPTO_BLOCK_LUKS_SECTOR_SIZE 512LL 72 73 static const char qcrypto_block_luks_magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN] = { 74 'L', 'U', 'K', 'S', 0xBA, 0xBE 75 }; 76 77 typedef struct QCryptoBlockLUKSNameMap QCryptoBlockLUKSNameMap; 78 struct QCryptoBlockLUKSNameMap { 79 const char *name; 80 int id; 81 }; 82 83 typedef struct QCryptoBlockLUKSCipherSizeMap QCryptoBlockLUKSCipherSizeMap; 84 struct QCryptoBlockLUKSCipherSizeMap { 85 uint32_t key_bytes; 86 int id; 87 }; 88 typedef struct QCryptoBlockLUKSCipherNameMap QCryptoBlockLUKSCipherNameMap; 89 struct QCryptoBlockLUKSCipherNameMap { 90 const char *name; 91 const QCryptoBlockLUKSCipherSizeMap *sizes; 92 }; 93 94 95 static const QCryptoBlockLUKSCipherSizeMap 96 qcrypto_block_luks_cipher_size_map_aes[] = { 97 { 16, QCRYPTO_CIPHER_ALG_AES_128 }, 98 { 24, QCRYPTO_CIPHER_ALG_AES_192 }, 99 { 32, QCRYPTO_CIPHER_ALG_AES_256 }, 100 { 0, 0 }, 101 }; 102 103 static const QCryptoBlockLUKSCipherSizeMap 104 qcrypto_block_luks_cipher_size_map_cast5[] = { 105 { 16, QCRYPTO_CIPHER_ALG_CAST5_128 }, 106 { 0, 0 }, 107 }; 108 109 static const QCryptoBlockLUKSCipherSizeMap 110 qcrypto_block_luks_cipher_size_map_serpent[] = { 111 { 16, QCRYPTO_CIPHER_ALG_SERPENT_128 }, 112 { 24, QCRYPTO_CIPHER_ALG_SERPENT_192 }, 113 { 32, QCRYPTO_CIPHER_ALG_SERPENT_256 }, 114 { 0, 0 }, 115 }; 116 117 static const QCryptoBlockLUKSCipherSizeMap 118 qcrypto_block_luks_cipher_size_map_twofish[] = { 119 { 16, QCRYPTO_CIPHER_ALG_TWOFISH_128 }, 120 { 24, QCRYPTO_CIPHER_ALG_TWOFISH_192 }, 121 { 32, QCRYPTO_CIPHER_ALG_TWOFISH_256 }, 122 { 0, 0 }, 123 }; 124 125 static const QCryptoBlockLUKSCipherNameMap 126 qcrypto_block_luks_cipher_name_map[] = { 127 { "aes", qcrypto_block_luks_cipher_size_map_aes }, 128 { "cast5", qcrypto_block_luks_cipher_size_map_cast5 }, 129 { "serpent", qcrypto_block_luks_cipher_size_map_serpent }, 130 { "twofish", qcrypto_block_luks_cipher_size_map_twofish }, 131 }; 132 133 134 /* 135 * This struct is written to disk in big-endian format, 136 * but operated upon in native-endian format. 137 */ 138 struct QCryptoBlockLUKSKeySlot { 139 /* state of keyslot, enabled/disable */ 140 uint32_t active; 141 /* iterations for PBKDF2 */ 142 uint32_t iterations; 143 /* salt for PBKDF2 */ 144 uint8_t salt[QCRYPTO_BLOCK_LUKS_SALT_LEN]; 145 /* start sector of key material */ 146 uint32_t key_offset; 147 /* number of anti-forensic stripes */ 148 uint32_t stripes; 149 }; 150 151 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48); 152 153 154 /* 155 * This struct is written to disk in big-endian format, 156 * but operated upon in native-endian format. 157 */ 158 struct QCryptoBlockLUKSHeader { 159 /* 'L', 'U', 'K', 'S', '0xBA', '0xBE' */ 160 char magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN]; 161 162 /* LUKS version, currently 1 */ 163 uint16_t version; 164 165 /* cipher name specification (aes, etc) */ 166 char cipher_name[QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN]; 167 168 /* cipher mode specification (cbc-plain, xts-essiv:sha256, etc) */ 169 char cipher_mode[QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN]; 170 171 /* hash specification (sha256, etc) */ 172 char hash_spec[QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN]; 173 174 /* start offset of the volume data (in 512 byte sectors) */ 175 uint32_t payload_offset; 176 177 /* Number of key bytes */ 178 uint32_t key_bytes; 179 180 /* master key checksum after PBKDF2 */ 181 uint8_t master_key_digest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN]; 182 183 /* salt for master key PBKDF2 */ 184 uint8_t master_key_salt[QCRYPTO_BLOCK_LUKS_SALT_LEN]; 185 186 /* iterations for master key PBKDF2 */ 187 uint32_t master_key_iterations; 188 189 /* UUID of the partition in standard ASCII representation */ 190 uint8_t uuid[QCRYPTO_BLOCK_LUKS_UUID_LEN]; 191 192 /* key slots */ 193 QCryptoBlockLUKSKeySlot key_slots[QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS]; 194 }; 195 196 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592); 197 198 199 struct QCryptoBlockLUKS { 200 QCryptoBlockLUKSHeader header; 201 202 /* Cache parsed versions of what's in header fields, 203 * as we can't rely on QCryptoBlock.cipher being 204 * non-NULL */ 205 QCryptoCipherAlgorithm cipher_alg; 206 QCryptoCipherMode cipher_mode; 207 QCryptoIVGenAlgorithm ivgen_alg; 208 QCryptoHashAlgorithm ivgen_hash_alg; 209 QCryptoHashAlgorithm hash_alg; 210 }; 211 212 213 static int qcrypto_block_luks_cipher_name_lookup(const char *name, 214 QCryptoCipherMode mode, 215 uint32_t key_bytes, 216 Error **errp) 217 { 218 const QCryptoBlockLUKSCipherNameMap *map = 219 qcrypto_block_luks_cipher_name_map; 220 size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map); 221 size_t i, j; 222 223 if (mode == QCRYPTO_CIPHER_MODE_XTS) { 224 key_bytes /= 2; 225 } 226 227 for (i = 0; i < maplen; i++) { 228 if (!g_str_equal(map[i].name, name)) { 229 continue; 230 } 231 for (j = 0; j < map[i].sizes[j].key_bytes; j++) { 232 if (map[i].sizes[j].key_bytes == key_bytes) { 233 return map[i].sizes[j].id; 234 } 235 } 236 } 237 238 error_setg(errp, "Algorithm %s with key size %d bytes not supported", 239 name, key_bytes); 240 return 0; 241 } 242 243 static const char * 244 qcrypto_block_luks_cipher_alg_lookup(QCryptoCipherAlgorithm alg, 245 Error **errp) 246 { 247 const QCryptoBlockLUKSCipherNameMap *map = 248 qcrypto_block_luks_cipher_name_map; 249 size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map); 250 size_t i, j; 251 for (i = 0; i < maplen; i++) { 252 for (j = 0; j < map[i].sizes[j].key_bytes; j++) { 253 if (map[i].sizes[j].id == alg) { 254 return map[i].name; 255 } 256 } 257 } 258 259 error_setg(errp, "Algorithm '%s' not supported", 260 QCryptoCipherAlgorithm_str(alg)); 261 return NULL; 262 } 263 264 /* XXX replace with qapi_enum_parse() in future, when we can 265 * make that function emit a more friendly error message */ 266 static int qcrypto_block_luks_name_lookup(const char *name, 267 const QEnumLookup *map, 268 const char *type, 269 Error **errp) 270 { 271 int ret = qapi_enum_parse(map, name, -1, NULL); 272 273 if (ret < 0) { 274 error_setg(errp, "%s %s not supported", type, name); 275 return 0; 276 } 277 return ret; 278 } 279 280 #define qcrypto_block_luks_cipher_mode_lookup(name, errp) \ 281 qcrypto_block_luks_name_lookup(name, \ 282 &QCryptoCipherMode_lookup, \ 283 "Cipher mode", \ 284 errp) 285 286 #define qcrypto_block_luks_hash_name_lookup(name, errp) \ 287 qcrypto_block_luks_name_lookup(name, \ 288 &QCryptoHashAlgorithm_lookup, \ 289 "Hash algorithm", \ 290 errp) 291 292 #define qcrypto_block_luks_ivgen_name_lookup(name, errp) \ 293 qcrypto_block_luks_name_lookup(name, \ 294 &QCryptoIVGenAlgorithm_lookup, \ 295 "IV generator", \ 296 errp) 297 298 299 static bool 300 qcrypto_block_luks_has_format(const uint8_t *buf, 301 size_t buf_size) 302 { 303 const QCryptoBlockLUKSHeader *luks_header = (const void *)buf; 304 305 if (buf_size >= offsetof(QCryptoBlockLUKSHeader, cipher_name) && 306 memcmp(luks_header->magic, qcrypto_block_luks_magic, 307 QCRYPTO_BLOCK_LUKS_MAGIC_LEN) == 0 && 308 be16_to_cpu(luks_header->version) == QCRYPTO_BLOCK_LUKS_VERSION) { 309 return true; 310 } else { 311 return false; 312 } 313 } 314 315 316 /** 317 * Deal with a quirk of dm-crypt usage of ESSIV. 318 * 319 * When calculating ESSIV IVs, the cipher length used by ESSIV 320 * may be different from the cipher length used for the block 321 * encryption, becauses dm-crypt uses the hash digest length 322 * as the key size. ie, if you have AES 128 as the block cipher 323 * and SHA 256 as ESSIV hash, then ESSIV will use AES 256 as 324 * the cipher since that gets a key length matching the digest 325 * size, not AES 128 with truncated digest as might be imagined 326 */ 327 static QCryptoCipherAlgorithm 328 qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm cipher, 329 QCryptoHashAlgorithm hash, 330 Error **errp) 331 { 332 size_t digestlen = qcrypto_hash_digest_len(hash); 333 size_t keylen = qcrypto_cipher_get_key_len(cipher); 334 if (digestlen == keylen) { 335 return cipher; 336 } 337 338 switch (cipher) { 339 case QCRYPTO_CIPHER_ALG_AES_128: 340 case QCRYPTO_CIPHER_ALG_AES_192: 341 case QCRYPTO_CIPHER_ALG_AES_256: 342 if (digestlen == qcrypto_cipher_get_key_len( 343 QCRYPTO_CIPHER_ALG_AES_128)) { 344 return QCRYPTO_CIPHER_ALG_AES_128; 345 } else if (digestlen == qcrypto_cipher_get_key_len( 346 QCRYPTO_CIPHER_ALG_AES_192)) { 347 return QCRYPTO_CIPHER_ALG_AES_192; 348 } else if (digestlen == qcrypto_cipher_get_key_len( 349 QCRYPTO_CIPHER_ALG_AES_256)) { 350 return QCRYPTO_CIPHER_ALG_AES_256; 351 } else { 352 error_setg(errp, "No AES cipher with key size %zu available", 353 digestlen); 354 return 0; 355 } 356 break; 357 case QCRYPTO_CIPHER_ALG_SERPENT_128: 358 case QCRYPTO_CIPHER_ALG_SERPENT_192: 359 case QCRYPTO_CIPHER_ALG_SERPENT_256: 360 if (digestlen == qcrypto_cipher_get_key_len( 361 QCRYPTO_CIPHER_ALG_SERPENT_128)) { 362 return QCRYPTO_CIPHER_ALG_SERPENT_128; 363 } else if (digestlen == qcrypto_cipher_get_key_len( 364 QCRYPTO_CIPHER_ALG_SERPENT_192)) { 365 return QCRYPTO_CIPHER_ALG_SERPENT_192; 366 } else if (digestlen == qcrypto_cipher_get_key_len( 367 QCRYPTO_CIPHER_ALG_SERPENT_256)) { 368 return QCRYPTO_CIPHER_ALG_SERPENT_256; 369 } else { 370 error_setg(errp, "No Serpent cipher with key size %zu available", 371 digestlen); 372 return 0; 373 } 374 break; 375 case QCRYPTO_CIPHER_ALG_TWOFISH_128: 376 case QCRYPTO_CIPHER_ALG_TWOFISH_192: 377 case QCRYPTO_CIPHER_ALG_TWOFISH_256: 378 if (digestlen == qcrypto_cipher_get_key_len( 379 QCRYPTO_CIPHER_ALG_TWOFISH_128)) { 380 return QCRYPTO_CIPHER_ALG_TWOFISH_128; 381 } else if (digestlen == qcrypto_cipher_get_key_len( 382 QCRYPTO_CIPHER_ALG_TWOFISH_192)) { 383 return QCRYPTO_CIPHER_ALG_TWOFISH_192; 384 } else if (digestlen == qcrypto_cipher_get_key_len( 385 QCRYPTO_CIPHER_ALG_TWOFISH_256)) { 386 return QCRYPTO_CIPHER_ALG_TWOFISH_256; 387 } else { 388 error_setg(errp, "No Twofish cipher with key size %zu available", 389 digestlen); 390 return 0; 391 } 392 break; 393 default: 394 error_setg(errp, "Cipher %s not supported with essiv", 395 QCryptoCipherAlgorithm_str(cipher)); 396 return 0; 397 } 398 } 399 400 /* 401 * Given a key slot, and user password, this will attempt to unlock 402 * the master encryption key from the key slot. 403 * 404 * Returns: 405 * 0 if the key slot is disabled, or key could not be decrypted 406 * with the provided password 407 * 1 if the key slot is enabled, and key decrypted successfully 408 * with the provided password 409 * -1 if a fatal error occurred loading the key 410 */ 411 static int 412 qcrypto_block_luks_load_key(QCryptoBlock *block, 413 QCryptoBlockLUKSKeySlot *slot, 414 const char *password, 415 QCryptoCipherAlgorithm cipheralg, 416 QCryptoCipherMode ciphermode, 417 QCryptoHashAlgorithm hash, 418 QCryptoIVGenAlgorithm ivalg, 419 QCryptoCipherAlgorithm ivcipheralg, 420 QCryptoHashAlgorithm ivhash, 421 uint8_t *masterkey, 422 size_t masterkeylen, 423 QCryptoBlockReadFunc readfunc, 424 void *opaque, 425 Error **errp) 426 { 427 QCryptoBlockLUKS *luks = block->opaque; 428 g_autofree uint8_t *splitkey = NULL; 429 size_t splitkeylen; 430 g_autofree uint8_t *possiblekey = NULL; 431 ssize_t rv; 432 g_autoptr(QCryptoCipher) cipher = NULL; 433 uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN]; 434 g_autoptr(QCryptoIVGen) ivgen = NULL; 435 size_t niv; 436 437 if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) { 438 return 0; 439 } 440 441 splitkeylen = masterkeylen * slot->stripes; 442 splitkey = g_new0(uint8_t, splitkeylen); 443 possiblekey = g_new0(uint8_t, masterkeylen); 444 445 /* 446 * The user password is used to generate a (possible) 447 * decryption key. This may or may not successfully 448 * decrypt the master key - we just blindly assume 449 * the key is correct and validate the results of 450 * decryption later. 451 */ 452 if (qcrypto_pbkdf2(hash, 453 (const uint8_t *)password, strlen(password), 454 slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN, 455 slot->iterations, 456 possiblekey, masterkeylen, 457 errp) < 0) { 458 return -1; 459 } 460 461 /* 462 * We need to read the master key material from the 463 * LUKS key material header. What we're reading is 464 * not the raw master key, but rather the data after 465 * it has been passed through AFSplit and the result 466 * then encrypted. 467 */ 468 rv = readfunc(block, 469 slot->key_offset * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 470 splitkey, splitkeylen, 471 opaque, 472 errp); 473 if (rv < 0) { 474 return -1; 475 } 476 477 478 /* Setup the cipher/ivgen that we'll use to try to decrypt 479 * the split master key material */ 480 cipher = qcrypto_cipher_new(cipheralg, ciphermode, 481 possiblekey, masterkeylen, 482 errp); 483 if (!cipher) { 484 return -1; 485 } 486 487 niv = qcrypto_cipher_get_iv_len(cipheralg, 488 ciphermode); 489 ivgen = qcrypto_ivgen_new(ivalg, 490 ivcipheralg, 491 ivhash, 492 possiblekey, masterkeylen, 493 errp); 494 if (!ivgen) { 495 return -1; 496 } 497 498 499 /* 500 * The master key needs to be decrypted in the same 501 * way that the block device payload will be decrypted 502 * later. In particular we'll be using the IV generator 503 * to reset the encryption cipher every time the master 504 * key crosses a sector boundary. 505 */ 506 if (qcrypto_block_cipher_decrypt_helper(cipher, 507 niv, 508 ivgen, 509 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 510 0, 511 splitkey, 512 splitkeylen, 513 errp) < 0) { 514 return -1; 515 } 516 517 /* 518 * Now we've decrypted the split master key, join 519 * it back together to get the actual master key. 520 */ 521 if (qcrypto_afsplit_decode(hash, 522 masterkeylen, 523 slot->stripes, 524 splitkey, 525 masterkey, 526 errp) < 0) { 527 return -1; 528 } 529 530 531 /* 532 * We still don't know that the masterkey we got is valid, 533 * because we just blindly assumed the user's password 534 * was correct. This is where we now verify it. We are 535 * creating a hash of the master key using PBKDF and 536 * then comparing that to the hash stored in the key slot 537 * header 538 */ 539 if (qcrypto_pbkdf2(hash, 540 masterkey, masterkeylen, 541 luks->header.master_key_salt, 542 QCRYPTO_BLOCK_LUKS_SALT_LEN, 543 luks->header.master_key_iterations, 544 keydigest, G_N_ELEMENTS(keydigest), 545 errp) < 0) { 546 return -1; 547 } 548 549 if (memcmp(keydigest, luks->header.master_key_digest, 550 QCRYPTO_BLOCK_LUKS_DIGEST_LEN) == 0) { 551 /* Success, we got the right master key */ 552 return 1; 553 } 554 555 /* Fail, user's password was not valid for this key slot, 556 * tell caller to try another slot */ 557 return 0; 558 } 559 560 561 /* 562 * Given a user password, this will iterate over all key 563 * slots and try to unlock each active key slot using the 564 * password until it successfully obtains a master key. 565 * 566 * Returns 0 if a key was loaded, -1 if no keys could be loaded 567 */ 568 static int 569 qcrypto_block_luks_find_key(QCryptoBlock *block, 570 const char *password, 571 QCryptoCipherAlgorithm cipheralg, 572 QCryptoCipherMode ciphermode, 573 QCryptoHashAlgorithm hash, 574 QCryptoIVGenAlgorithm ivalg, 575 QCryptoCipherAlgorithm ivcipheralg, 576 QCryptoHashAlgorithm ivhash, 577 uint8_t **masterkey, 578 size_t *masterkeylen, 579 QCryptoBlockReadFunc readfunc, 580 void *opaque, 581 Error **errp) 582 { 583 QCryptoBlockLUKS *luks = block->opaque; 584 size_t i; 585 int rv; 586 587 *masterkey = g_new0(uint8_t, luks->header.key_bytes); 588 *masterkeylen = luks->header.key_bytes; 589 590 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 591 rv = qcrypto_block_luks_load_key(block, 592 &luks->header.key_slots[i], 593 password, 594 cipheralg, 595 ciphermode, 596 hash, 597 ivalg, 598 ivcipheralg, 599 ivhash, 600 *masterkey, 601 *masterkeylen, 602 readfunc, 603 opaque, 604 errp); 605 if (rv < 0) { 606 goto error; 607 } 608 if (rv == 1) { 609 return 0; 610 } 611 } 612 613 error_setg(errp, "Invalid password, cannot unlock any keyslot"); 614 615 error: 616 g_free(*masterkey); 617 *masterkey = NULL; 618 *masterkeylen = 0; 619 return -1; 620 } 621 622 623 static int 624 qcrypto_block_luks_open(QCryptoBlock *block, 625 QCryptoBlockOpenOptions *options, 626 const char *optprefix, 627 QCryptoBlockReadFunc readfunc, 628 void *opaque, 629 unsigned int flags, 630 size_t n_threads, 631 Error **errp) 632 { 633 QCryptoBlockLUKS *luks; 634 Error *local_err = NULL; 635 int ret = 0; 636 size_t i; 637 ssize_t rv; 638 g_autofree uint8_t *masterkey = NULL; 639 size_t masterkeylen; 640 char *ivgen_name, *ivhash_name; 641 QCryptoCipherMode ciphermode; 642 QCryptoCipherAlgorithm cipheralg; 643 QCryptoIVGenAlgorithm ivalg; 644 QCryptoCipherAlgorithm ivcipheralg; 645 QCryptoHashAlgorithm hash; 646 QCryptoHashAlgorithm ivhash; 647 g_autofree char *password = NULL; 648 649 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { 650 if (!options->u.luks.key_secret) { 651 error_setg(errp, "Parameter '%skey-secret' is required for cipher", 652 optprefix ? optprefix : ""); 653 return -1; 654 } 655 password = qcrypto_secret_lookup_as_utf8( 656 options->u.luks.key_secret, errp); 657 if (!password) { 658 return -1; 659 } 660 } 661 662 luks = g_new0(QCryptoBlockLUKS, 1); 663 block->opaque = luks; 664 665 /* Read the entire LUKS header, minus the key material from 666 * the underlying device */ 667 rv = readfunc(block, 0, 668 (uint8_t *)&luks->header, 669 sizeof(luks->header), 670 opaque, 671 errp); 672 if (rv < 0) { 673 ret = rv; 674 goto fail; 675 } 676 677 /* The header is always stored in big-endian format, so 678 * convert everything to native */ 679 be16_to_cpus(&luks->header.version); 680 be32_to_cpus(&luks->header.payload_offset); 681 be32_to_cpus(&luks->header.key_bytes); 682 be32_to_cpus(&luks->header.master_key_iterations); 683 684 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 685 be32_to_cpus(&luks->header.key_slots[i].active); 686 be32_to_cpus(&luks->header.key_slots[i].iterations); 687 be32_to_cpus(&luks->header.key_slots[i].key_offset); 688 be32_to_cpus(&luks->header.key_slots[i].stripes); 689 } 690 691 if (memcmp(luks->header.magic, qcrypto_block_luks_magic, 692 QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { 693 error_setg(errp, "Volume is not in LUKS format"); 694 ret = -EINVAL; 695 goto fail; 696 } 697 if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { 698 error_setg(errp, "LUKS version %" PRIu32 " is not supported", 699 luks->header.version); 700 ret = -ENOTSUP; 701 goto fail; 702 } 703 704 /* 705 * The cipher_mode header contains a string that we have 706 * to further parse, of the format 707 * 708 * <cipher-mode>-<iv-generator>[:<iv-hash>] 709 * 710 * eg cbc-essiv:sha256, cbc-plain64 711 */ 712 ivgen_name = strchr(luks->header.cipher_mode, '-'); 713 if (!ivgen_name) { 714 ret = -EINVAL; 715 error_setg(errp, "Unexpected cipher mode string format %s", 716 luks->header.cipher_mode); 717 goto fail; 718 } 719 *ivgen_name = '\0'; 720 ivgen_name++; 721 722 ivhash_name = strchr(ivgen_name, ':'); 723 if (!ivhash_name) { 724 ivhash = 0; 725 } else { 726 *ivhash_name = '\0'; 727 ivhash_name++; 728 729 ivhash = qcrypto_block_luks_hash_name_lookup(ivhash_name, 730 &local_err); 731 if (local_err) { 732 ret = -ENOTSUP; 733 error_propagate(errp, local_err); 734 goto fail; 735 } 736 } 737 738 ciphermode = qcrypto_block_luks_cipher_mode_lookup(luks->header.cipher_mode, 739 &local_err); 740 if (local_err) { 741 ret = -ENOTSUP; 742 error_propagate(errp, local_err); 743 goto fail; 744 } 745 746 cipheralg = qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, 747 ciphermode, 748 luks->header.key_bytes, 749 &local_err); 750 if (local_err) { 751 ret = -ENOTSUP; 752 error_propagate(errp, local_err); 753 goto fail; 754 } 755 756 hash = qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, 757 &local_err); 758 if (local_err) { 759 ret = -ENOTSUP; 760 error_propagate(errp, local_err); 761 goto fail; 762 } 763 764 ivalg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, 765 &local_err); 766 if (local_err) { 767 ret = -ENOTSUP; 768 error_propagate(errp, local_err); 769 goto fail; 770 } 771 772 if (ivalg == QCRYPTO_IVGEN_ALG_ESSIV) { 773 if (!ivhash_name) { 774 ret = -EINVAL; 775 error_setg(errp, "Missing IV generator hash specification"); 776 goto fail; 777 } 778 ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg, 779 ivhash, 780 &local_err); 781 if (local_err) { 782 ret = -ENOTSUP; 783 error_propagate(errp, local_err); 784 goto fail; 785 } 786 } else { 787 /* Note we parsed the ivhash_name earlier in the cipher_mode 788 * spec string even with plain/plain64 ivgens, but we 789 * will ignore it, since it is irrelevant for these ivgens. 790 * This is for compat with dm-crypt which will silently 791 * ignore hash names with these ivgens rather than report 792 * an error about the invalid usage 793 */ 794 ivcipheralg = cipheralg; 795 } 796 797 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { 798 /* Try to find which key slot our password is valid for 799 * and unlock the master key from that slot. 800 */ 801 if (qcrypto_block_luks_find_key(block, 802 password, 803 cipheralg, ciphermode, 804 hash, 805 ivalg, 806 ivcipheralg, 807 ivhash, 808 &masterkey, &masterkeylen, 809 readfunc, opaque, 810 errp) < 0) { 811 ret = -EACCES; 812 goto fail; 813 } 814 815 /* We have a valid master key now, so can setup the 816 * block device payload decryption objects 817 */ 818 block->kdfhash = hash; 819 block->niv = qcrypto_cipher_get_iv_len(cipheralg, 820 ciphermode); 821 block->ivgen = qcrypto_ivgen_new(ivalg, 822 ivcipheralg, 823 ivhash, 824 masterkey, masterkeylen, 825 errp); 826 if (!block->ivgen) { 827 ret = -ENOTSUP; 828 goto fail; 829 } 830 831 ret = qcrypto_block_init_cipher(block, cipheralg, ciphermode, 832 masterkey, masterkeylen, n_threads, 833 errp); 834 if (ret < 0) { 835 ret = -ENOTSUP; 836 goto fail; 837 } 838 } 839 840 block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 841 block->payload_offset = luks->header.payload_offset * 842 block->sector_size; 843 844 luks->cipher_alg = cipheralg; 845 luks->cipher_mode = ciphermode; 846 luks->ivgen_alg = ivalg; 847 luks->ivgen_hash_alg = ivhash; 848 luks->hash_alg = hash; 849 850 return 0; 851 852 fail: 853 qcrypto_block_free_cipher(block); 854 qcrypto_ivgen_free(block->ivgen); 855 g_free(luks); 856 return ret; 857 } 858 859 860 static void 861 qcrypto_block_luks_uuid_gen(uint8_t *uuidstr) 862 { 863 QemuUUID uuid; 864 qemu_uuid_generate(&uuid); 865 qemu_uuid_unparse(&uuid, (char *)uuidstr); 866 } 867 868 static int 869 qcrypto_block_luks_create(QCryptoBlock *block, 870 QCryptoBlockCreateOptions *options, 871 const char *optprefix, 872 QCryptoBlockInitFunc initfunc, 873 QCryptoBlockWriteFunc writefunc, 874 void *opaque, 875 Error **errp) 876 { 877 QCryptoBlockLUKS *luks; 878 QCryptoBlockCreateOptionsLUKS luks_opts; 879 Error *local_err = NULL; 880 g_autofree uint8_t *masterkey = NULL; 881 g_autofree uint8_t *slotkey = NULL; 882 g_autofree uint8_t *splitkey = NULL; 883 size_t splitkeylen = 0; 884 size_t i; 885 g_autoptr(QCryptoCipher) cipher = NULL; 886 g_autoptr(QCryptoIVGen) ivgen = NULL; 887 g_autofree char *password = NULL; 888 const char *cipher_alg; 889 const char *cipher_mode; 890 const char *ivgen_alg; 891 const char *ivgen_hash_alg = NULL; 892 const char *hash_alg; 893 g_autofree char *cipher_mode_spec = NULL; 894 QCryptoCipherAlgorithm ivcipheralg = 0; 895 uint64_t iters; 896 897 memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts)); 898 if (!luks_opts.has_iter_time) { 899 luks_opts.iter_time = 2000; 900 } 901 if (!luks_opts.has_cipher_alg) { 902 luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256; 903 } 904 if (!luks_opts.has_cipher_mode) { 905 luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS; 906 } 907 if (!luks_opts.has_ivgen_alg) { 908 luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64; 909 } 910 if (!luks_opts.has_hash_alg) { 911 luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256; 912 } 913 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 914 if (!luks_opts.has_ivgen_hash_alg) { 915 luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256; 916 luks_opts.has_ivgen_hash_alg = true; 917 } 918 } 919 /* Note we're allowing ivgen_hash_alg to be set even for 920 * non-essiv iv generators that don't need a hash. It will 921 * be silently ignored, for compatibility with dm-crypt */ 922 923 if (!options->u.luks.key_secret) { 924 error_setg(errp, "Parameter '%skey-secret' is required for cipher", 925 optprefix ? optprefix : ""); 926 return -1; 927 } 928 password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp); 929 if (!password) { 930 return -1; 931 } 932 933 luks = g_new0(QCryptoBlockLUKS, 1); 934 block->opaque = luks; 935 936 memcpy(luks->header.magic, qcrypto_block_luks_magic, 937 QCRYPTO_BLOCK_LUKS_MAGIC_LEN); 938 939 /* We populate the header in native endianness initially and 940 * then convert everything to big endian just before writing 941 * it out to disk 942 */ 943 luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION; 944 qcrypto_block_luks_uuid_gen(luks->header.uuid); 945 946 cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg, 947 errp); 948 if (!cipher_alg) { 949 goto error; 950 } 951 952 cipher_mode = QCryptoCipherMode_str(luks_opts.cipher_mode); 953 ivgen_alg = QCryptoIVGenAlgorithm_str(luks_opts.ivgen_alg); 954 if (luks_opts.has_ivgen_hash_alg) { 955 ivgen_hash_alg = QCryptoHashAlgorithm_str(luks_opts.ivgen_hash_alg); 956 cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg, 957 ivgen_hash_alg); 958 } else { 959 cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg); 960 } 961 hash_alg = QCryptoHashAlgorithm_str(luks_opts.hash_alg); 962 963 964 if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) { 965 error_setg(errp, "Cipher name '%s' is too long for LUKS header", 966 cipher_alg); 967 goto error; 968 } 969 if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) { 970 error_setg(errp, "Cipher mode '%s' is too long for LUKS header", 971 cipher_mode_spec); 972 goto error; 973 } 974 if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) { 975 error_setg(errp, "Hash name '%s' is too long for LUKS header", 976 hash_alg); 977 goto error; 978 } 979 980 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 981 ivcipheralg = qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg, 982 luks_opts.ivgen_hash_alg, 983 &local_err); 984 if (local_err) { 985 error_propagate(errp, local_err); 986 goto error; 987 } 988 } else { 989 ivcipheralg = luks_opts.cipher_alg; 990 } 991 992 strcpy(luks->header.cipher_name, cipher_alg); 993 strcpy(luks->header.cipher_mode, cipher_mode_spec); 994 strcpy(luks->header.hash_spec, hash_alg); 995 996 luks->header.key_bytes = qcrypto_cipher_get_key_len(luks_opts.cipher_alg); 997 if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) { 998 luks->header.key_bytes *= 2; 999 } 1000 1001 /* Generate the salt used for hashing the master key 1002 * with PBKDF later 1003 */ 1004 if (qcrypto_random_bytes(luks->header.master_key_salt, 1005 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1006 errp) < 0) { 1007 goto error; 1008 } 1009 1010 /* Generate random master key */ 1011 masterkey = g_new0(uint8_t, luks->header.key_bytes); 1012 if (qcrypto_random_bytes(masterkey, 1013 luks->header.key_bytes, errp) < 0) { 1014 goto error; 1015 } 1016 1017 1018 /* Setup the block device payload encryption objects */ 1019 if (qcrypto_block_init_cipher(block, luks_opts.cipher_alg, 1020 luks_opts.cipher_mode, masterkey, 1021 luks->header.key_bytes, 1, errp) < 0) { 1022 goto error; 1023 } 1024 1025 block->kdfhash = luks_opts.hash_alg; 1026 block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg, 1027 luks_opts.cipher_mode); 1028 block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1029 ivcipheralg, 1030 luks_opts.ivgen_hash_alg, 1031 masterkey, luks->header.key_bytes, 1032 errp); 1033 1034 if (!block->ivgen) { 1035 goto error; 1036 } 1037 1038 1039 /* Determine how many iterations we need to hash the master 1040 * key, in order to have 1 second of compute time used 1041 */ 1042 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1043 masterkey, luks->header.key_bytes, 1044 luks->header.master_key_salt, 1045 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1046 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1047 &local_err); 1048 if (local_err) { 1049 error_propagate(errp, local_err); 1050 goto error; 1051 } 1052 1053 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1054 error_setg_errno(errp, ERANGE, 1055 "PBKDF iterations %llu too large to scale", 1056 (unsigned long long)iters); 1057 goto error; 1058 } 1059 1060 /* iter_time was in millis, but count_iters reported for secs */ 1061 iters = iters * luks_opts.iter_time / 1000; 1062 1063 /* Why /= 8 ? That matches cryptsetup, but there's no 1064 * explanation why they chose /= 8... Probably so that 1065 * if all 8 keyslots are active we only spend 1 second 1066 * in total time to check all keys */ 1067 iters /= 8; 1068 if (iters > UINT32_MAX) { 1069 error_setg_errno(errp, ERANGE, 1070 "PBKDF iterations %llu larger than %u", 1071 (unsigned long long)iters, UINT32_MAX); 1072 goto error; 1073 } 1074 iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS); 1075 luks->header.master_key_iterations = iters; 1076 1077 /* Hash the master key, saving the result in the LUKS 1078 * header. This hash is used when opening the encrypted 1079 * device to verify that the user password unlocked a 1080 * valid master key 1081 */ 1082 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1083 masterkey, luks->header.key_bytes, 1084 luks->header.master_key_salt, 1085 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1086 luks->header.master_key_iterations, 1087 luks->header.master_key_digest, 1088 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1089 errp) < 0) { 1090 goto error; 1091 } 1092 1093 1094 /* Although LUKS has multiple key slots, we're just going 1095 * to use the first key slot */ 1096 splitkeylen = luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRIPES; 1097 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1098 luks->header.key_slots[i].active = i == 0 ? 1099 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED : 1100 QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; 1101 luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES; 1102 1103 /* This calculation doesn't match that shown in the spec, 1104 * but instead follows the cryptsetup implementation. 1105 */ 1106 luks->header.key_slots[i].key_offset = 1107 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1108 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1109 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1110 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1111 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i); 1112 } 1113 1114 if (qcrypto_random_bytes(luks->header.key_slots[0].salt, 1115 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1116 errp) < 0) { 1117 goto error; 1118 } 1119 1120 /* Again we determine how many iterations are required to 1121 * hash the user password while consuming 1 second of compute 1122 * time */ 1123 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1124 (uint8_t *)password, strlen(password), 1125 luks->header.key_slots[0].salt, 1126 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1127 luks->header.key_bytes, 1128 &local_err); 1129 if (local_err) { 1130 error_propagate(errp, local_err); 1131 goto error; 1132 } 1133 1134 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1135 error_setg_errno(errp, ERANGE, 1136 "PBKDF iterations %llu too large to scale", 1137 (unsigned long long)iters); 1138 goto error; 1139 } 1140 1141 /* iter_time was in millis, but count_iters reported for secs */ 1142 iters = iters * luks_opts.iter_time / 1000; 1143 1144 if (iters > UINT32_MAX) { 1145 error_setg_errno(errp, ERANGE, 1146 "PBKDF iterations %llu larger than %u", 1147 (unsigned long long)iters, UINT32_MAX); 1148 goto error; 1149 } 1150 1151 luks->header.key_slots[0].iterations = 1152 MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS); 1153 1154 1155 /* Generate a key that we'll use to encrypt the master 1156 * key, from the user's password 1157 */ 1158 slotkey = g_new0(uint8_t, luks->header.key_bytes); 1159 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1160 (uint8_t *)password, strlen(password), 1161 luks->header.key_slots[0].salt, 1162 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1163 luks->header.key_slots[0].iterations, 1164 slotkey, luks->header.key_bytes, 1165 errp) < 0) { 1166 goto error; 1167 } 1168 1169 1170 /* Setup the encryption objects needed to encrypt the 1171 * master key material 1172 */ 1173 cipher = qcrypto_cipher_new(luks_opts.cipher_alg, 1174 luks_opts.cipher_mode, 1175 slotkey, luks->header.key_bytes, 1176 errp); 1177 if (!cipher) { 1178 goto error; 1179 } 1180 1181 ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1182 ivcipheralg, 1183 luks_opts.ivgen_hash_alg, 1184 slotkey, luks->header.key_bytes, 1185 errp); 1186 if (!ivgen) { 1187 goto error; 1188 } 1189 1190 /* Before storing the master key, we need to vastly 1191 * increase its size, as protection against forensic 1192 * disk data recovery */ 1193 splitkey = g_new0(uint8_t, splitkeylen); 1194 1195 if (qcrypto_afsplit_encode(luks_opts.hash_alg, 1196 luks->header.key_bytes, 1197 luks->header.key_slots[0].stripes, 1198 masterkey, 1199 splitkey, 1200 errp) < 0) { 1201 goto error; 1202 } 1203 1204 /* Now we encrypt the split master key with the key generated 1205 * from the user's password, before storing it */ 1206 if (qcrypto_block_cipher_encrypt_helper(cipher, block->niv, ivgen, 1207 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1208 0, 1209 splitkey, 1210 splitkeylen, 1211 errp) < 0) { 1212 goto error; 1213 } 1214 1215 1216 /* The total size of the LUKS headers is the partition header + key 1217 * slot headers, rounded up to the nearest sector, combined with 1218 * the size of each master key material region, also rounded up 1219 * to the nearest sector */ 1220 luks->header.payload_offset = 1221 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1222 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1223 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1224 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1225 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * 1226 QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); 1227 1228 block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1229 block->payload_offset = luks->header.payload_offset * 1230 block->sector_size; 1231 1232 /* Reserve header space to match payload offset */ 1233 initfunc(block, block->payload_offset, opaque, &local_err); 1234 if (local_err) { 1235 error_propagate(errp, local_err); 1236 goto error; 1237 } 1238 1239 /* Everything on disk uses Big Endian, so flip header fields 1240 * before writing them */ 1241 cpu_to_be16s(&luks->header.version); 1242 cpu_to_be32s(&luks->header.payload_offset); 1243 cpu_to_be32s(&luks->header.key_bytes); 1244 cpu_to_be32s(&luks->header.master_key_iterations); 1245 1246 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1247 cpu_to_be32s(&luks->header.key_slots[i].active); 1248 cpu_to_be32s(&luks->header.key_slots[i].iterations); 1249 cpu_to_be32s(&luks->header.key_slots[i].key_offset); 1250 cpu_to_be32s(&luks->header.key_slots[i].stripes); 1251 } 1252 1253 1254 /* Write out the partition header and key slot headers */ 1255 writefunc(block, 0, 1256 (const uint8_t *)&luks->header, 1257 sizeof(luks->header), 1258 opaque, 1259 &local_err); 1260 1261 /* Delay checking local_err until we've byte-swapped */ 1262 1263 /* Byte swap the header back to native, in case we need 1264 * to read it again later */ 1265 be16_to_cpus(&luks->header.version); 1266 be32_to_cpus(&luks->header.payload_offset); 1267 be32_to_cpus(&luks->header.key_bytes); 1268 be32_to_cpus(&luks->header.master_key_iterations); 1269 1270 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1271 be32_to_cpus(&luks->header.key_slots[i].active); 1272 be32_to_cpus(&luks->header.key_slots[i].iterations); 1273 be32_to_cpus(&luks->header.key_slots[i].key_offset); 1274 be32_to_cpus(&luks->header.key_slots[i].stripes); 1275 } 1276 1277 if (local_err) { 1278 error_propagate(errp, local_err); 1279 goto error; 1280 } 1281 1282 /* Write out the master key material, starting at the 1283 * sector immediately following the partition header. */ 1284 if (writefunc(block, 1285 luks->header.key_slots[0].key_offset * 1286 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1287 splitkey, splitkeylen, 1288 opaque, 1289 errp) != splitkeylen) { 1290 goto error; 1291 } 1292 1293 luks->cipher_alg = luks_opts.cipher_alg; 1294 luks->cipher_mode = luks_opts.cipher_mode; 1295 luks->ivgen_alg = luks_opts.ivgen_alg; 1296 luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg; 1297 luks->hash_alg = luks_opts.hash_alg; 1298 1299 memset(masterkey, 0, luks->header.key_bytes); 1300 memset(slotkey, 0, luks->header.key_bytes); 1301 1302 return 0; 1303 1304 error: 1305 if (masterkey) { 1306 memset(masterkey, 0, luks->header.key_bytes); 1307 } 1308 if (slotkey) { 1309 memset(slotkey, 0, luks->header.key_bytes); 1310 } 1311 1312 qcrypto_block_free_cipher(block); 1313 qcrypto_ivgen_free(block->ivgen); 1314 1315 g_free(luks); 1316 return -1; 1317 } 1318 1319 1320 static int qcrypto_block_luks_get_info(QCryptoBlock *block, 1321 QCryptoBlockInfo *info, 1322 Error **errp) 1323 { 1324 QCryptoBlockLUKS *luks = block->opaque; 1325 QCryptoBlockInfoLUKSSlot *slot; 1326 QCryptoBlockInfoLUKSSlotList *slots = NULL, **prev = &info->u.luks.slots; 1327 size_t i; 1328 1329 info->u.luks.cipher_alg = luks->cipher_alg; 1330 info->u.luks.cipher_mode = luks->cipher_mode; 1331 info->u.luks.ivgen_alg = luks->ivgen_alg; 1332 if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 1333 info->u.luks.has_ivgen_hash_alg = true; 1334 info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg; 1335 } 1336 info->u.luks.hash_alg = luks->hash_alg; 1337 info->u.luks.payload_offset = block->payload_offset; 1338 info->u.luks.master_key_iters = luks->header.master_key_iterations; 1339 info->u.luks.uuid = g_strndup((const char *)luks->header.uuid, 1340 sizeof(luks->header.uuid)); 1341 1342 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1343 slots = g_new0(QCryptoBlockInfoLUKSSlotList, 1); 1344 *prev = slots; 1345 1346 slots->value = slot = g_new0(QCryptoBlockInfoLUKSSlot, 1); 1347 slot->active = luks->header.key_slots[i].active == 1348 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; 1349 slot->key_offset = luks->header.key_slots[i].key_offset 1350 * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1351 if (slot->active) { 1352 slot->has_iters = true; 1353 slot->iters = luks->header.key_slots[i].iterations; 1354 slot->has_stripes = true; 1355 slot->stripes = luks->header.key_slots[i].stripes; 1356 } 1357 1358 prev = &slots->next; 1359 } 1360 1361 return 0; 1362 } 1363 1364 1365 static void qcrypto_block_luks_cleanup(QCryptoBlock *block) 1366 { 1367 g_free(block->opaque); 1368 } 1369 1370 1371 static int 1372 qcrypto_block_luks_decrypt(QCryptoBlock *block, 1373 uint64_t offset, 1374 uint8_t *buf, 1375 size_t len, 1376 Error **errp) 1377 { 1378 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); 1379 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); 1380 return qcrypto_block_decrypt_helper(block, 1381 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1382 offset, buf, len, errp); 1383 } 1384 1385 1386 static int 1387 qcrypto_block_luks_encrypt(QCryptoBlock *block, 1388 uint64_t offset, 1389 uint8_t *buf, 1390 size_t len, 1391 Error **errp) 1392 { 1393 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); 1394 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); 1395 return qcrypto_block_encrypt_helper(block, 1396 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1397 offset, buf, len, errp); 1398 } 1399 1400 1401 const QCryptoBlockDriver qcrypto_block_driver_luks = { 1402 .open = qcrypto_block_luks_open, 1403 .create = qcrypto_block_luks_create, 1404 .get_info = qcrypto_block_luks_get_info, 1405 .cleanup = qcrypto_block_luks_cleanup, 1406 .decrypt = qcrypto_block_luks_decrypt, 1407 .encrypt = qcrypto_block_luks_encrypt, 1408 .has_format = qcrypto_block_luks_has_format, 1409 }; 1410