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 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 uint8_t *splitkey; 429 size_t splitkeylen; 430 uint8_t *possiblekey; 431 int ret = -1; 432 ssize_t rv; 433 QCryptoCipher *cipher = NULL; 434 uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN]; 435 QCryptoIVGen *ivgen = NULL; 436 size_t niv; 437 438 if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) { 439 return 0; 440 } 441 442 splitkeylen = masterkeylen * slot->stripes; 443 splitkey = g_new0(uint8_t, splitkeylen); 444 possiblekey = g_new0(uint8_t, masterkeylen); 445 446 /* 447 * The user password is used to generate a (possible) 448 * decryption key. This may or may not successfully 449 * decrypt the master key - we just blindly assume 450 * the key is correct and validate the results of 451 * decryption later. 452 */ 453 if (qcrypto_pbkdf2(hash, 454 (const uint8_t *)password, strlen(password), 455 slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN, 456 slot->iterations, 457 possiblekey, masterkeylen, 458 errp) < 0) { 459 goto cleanup; 460 } 461 462 /* 463 * We need to read the master key material from the 464 * LUKS key material header. What we're reading is 465 * not the raw master key, but rather the data after 466 * it has been passed through AFSplit and the result 467 * then encrypted. 468 */ 469 rv = readfunc(block, 470 slot->key_offset * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 471 splitkey, splitkeylen, 472 opaque, 473 errp); 474 if (rv < 0) { 475 goto cleanup; 476 } 477 478 479 /* Setup the cipher/ivgen that we'll use to try to decrypt 480 * the split master key material */ 481 cipher = qcrypto_cipher_new(cipheralg, ciphermode, 482 possiblekey, masterkeylen, 483 errp); 484 if (!cipher) { 485 goto cleanup; 486 } 487 488 niv = qcrypto_cipher_get_iv_len(cipheralg, 489 ciphermode); 490 ivgen = qcrypto_ivgen_new(ivalg, 491 ivcipheralg, 492 ivhash, 493 possiblekey, masterkeylen, 494 errp); 495 if (!ivgen) { 496 goto cleanup; 497 } 498 499 500 /* 501 * The master key needs to be decrypted in the same 502 * way that the block device payload will be decrypted 503 * later. In particular we'll be using the IV generator 504 * to reset the encryption cipher every time the master 505 * key crosses a sector boundary. 506 */ 507 if (qcrypto_block_cipher_decrypt_helper(cipher, 508 niv, 509 ivgen, 510 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 511 0, 512 splitkey, 513 splitkeylen, 514 errp) < 0) { 515 goto cleanup; 516 } 517 518 /* 519 * Now we've decrypted the split master key, join 520 * it back together to get the actual master key. 521 */ 522 if (qcrypto_afsplit_decode(hash, 523 masterkeylen, 524 slot->stripes, 525 splitkey, 526 masterkey, 527 errp) < 0) { 528 goto cleanup; 529 } 530 531 532 /* 533 * We still don't know that the masterkey we got is valid, 534 * because we just blindly assumed the user's password 535 * was correct. This is where we now verify it. We are 536 * creating a hash of the master key using PBKDF and 537 * then comparing that to the hash stored in the key slot 538 * header 539 */ 540 if (qcrypto_pbkdf2(hash, 541 masterkey, masterkeylen, 542 luks->header.master_key_salt, 543 QCRYPTO_BLOCK_LUKS_SALT_LEN, 544 luks->header.master_key_iterations, 545 keydigest, G_N_ELEMENTS(keydigest), 546 errp) < 0) { 547 goto cleanup; 548 } 549 550 if (memcmp(keydigest, luks->header.master_key_digest, 551 QCRYPTO_BLOCK_LUKS_DIGEST_LEN) == 0) { 552 /* Success, we got the right master key */ 553 ret = 1; 554 goto cleanup; 555 } 556 557 /* Fail, user's password was not valid for this key slot, 558 * tell caller to try another slot */ 559 ret = 0; 560 561 cleanup: 562 qcrypto_ivgen_free(ivgen); 563 qcrypto_cipher_free(cipher); 564 g_free(splitkey); 565 g_free(possiblekey); 566 return ret; 567 } 568 569 570 /* 571 * Given a user password, this will iterate over all key 572 * slots and try to unlock each active key slot using the 573 * password until it successfully obtains a master key. 574 * 575 * Returns 0 if a key was loaded, -1 if no keys could be loaded 576 */ 577 static int 578 qcrypto_block_luks_find_key(QCryptoBlock *block, 579 const char *password, 580 QCryptoCipherAlgorithm cipheralg, 581 QCryptoCipherMode ciphermode, 582 QCryptoHashAlgorithm hash, 583 QCryptoIVGenAlgorithm ivalg, 584 QCryptoCipherAlgorithm ivcipheralg, 585 QCryptoHashAlgorithm ivhash, 586 uint8_t **masterkey, 587 size_t *masterkeylen, 588 QCryptoBlockReadFunc readfunc, 589 void *opaque, 590 Error **errp) 591 { 592 QCryptoBlockLUKS *luks = block->opaque; 593 size_t i; 594 int rv; 595 596 *masterkey = g_new0(uint8_t, luks->header.key_bytes); 597 *masterkeylen = luks->header.key_bytes; 598 599 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 600 rv = qcrypto_block_luks_load_key(block, 601 &luks->header.key_slots[i], 602 password, 603 cipheralg, 604 ciphermode, 605 hash, 606 ivalg, 607 ivcipheralg, 608 ivhash, 609 *masterkey, 610 *masterkeylen, 611 readfunc, 612 opaque, 613 errp); 614 if (rv < 0) { 615 goto error; 616 } 617 if (rv == 1) { 618 return 0; 619 } 620 } 621 622 error_setg(errp, "Invalid password, cannot unlock any keyslot"); 623 624 error: 625 g_free(*masterkey); 626 *masterkey = NULL; 627 *masterkeylen = 0; 628 return -1; 629 } 630 631 632 static int 633 qcrypto_block_luks_open(QCryptoBlock *block, 634 QCryptoBlockOpenOptions *options, 635 const char *optprefix, 636 QCryptoBlockReadFunc readfunc, 637 void *opaque, 638 unsigned int flags, 639 size_t n_threads, 640 Error **errp) 641 { 642 QCryptoBlockLUKS *luks; 643 Error *local_err = NULL; 644 int ret = 0; 645 size_t i; 646 ssize_t rv; 647 uint8_t *masterkey = NULL; 648 size_t masterkeylen; 649 char *ivgen_name, *ivhash_name; 650 QCryptoCipherMode ciphermode; 651 QCryptoCipherAlgorithm cipheralg; 652 QCryptoIVGenAlgorithm ivalg; 653 QCryptoCipherAlgorithm ivcipheralg; 654 QCryptoHashAlgorithm hash; 655 QCryptoHashAlgorithm ivhash; 656 char *password = NULL; 657 658 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { 659 if (!options->u.luks.key_secret) { 660 error_setg(errp, "Parameter '%skey-secret' is required for cipher", 661 optprefix ? optprefix : ""); 662 return -1; 663 } 664 password = qcrypto_secret_lookup_as_utf8( 665 options->u.luks.key_secret, errp); 666 if (!password) { 667 return -1; 668 } 669 } 670 671 luks = g_new0(QCryptoBlockLUKS, 1); 672 block->opaque = luks; 673 674 /* Read the entire LUKS header, minus the key material from 675 * the underlying device */ 676 rv = readfunc(block, 0, 677 (uint8_t *)&luks->header, 678 sizeof(luks->header), 679 opaque, 680 errp); 681 if (rv < 0) { 682 ret = rv; 683 goto fail; 684 } 685 686 /* The header is always stored in big-endian format, so 687 * convert everything to native */ 688 be16_to_cpus(&luks->header.version); 689 be32_to_cpus(&luks->header.payload_offset); 690 be32_to_cpus(&luks->header.key_bytes); 691 be32_to_cpus(&luks->header.master_key_iterations); 692 693 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 694 be32_to_cpus(&luks->header.key_slots[i].active); 695 be32_to_cpus(&luks->header.key_slots[i].iterations); 696 be32_to_cpus(&luks->header.key_slots[i].key_offset); 697 be32_to_cpus(&luks->header.key_slots[i].stripes); 698 } 699 700 if (memcmp(luks->header.magic, qcrypto_block_luks_magic, 701 QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { 702 error_setg(errp, "Volume is not in LUKS format"); 703 ret = -EINVAL; 704 goto fail; 705 } 706 if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { 707 error_setg(errp, "LUKS version %" PRIu32 " is not supported", 708 luks->header.version); 709 ret = -ENOTSUP; 710 goto fail; 711 } 712 713 /* 714 * The cipher_mode header contains a string that we have 715 * to further parse, of the format 716 * 717 * <cipher-mode>-<iv-generator>[:<iv-hash>] 718 * 719 * eg cbc-essiv:sha256, cbc-plain64 720 */ 721 ivgen_name = strchr(luks->header.cipher_mode, '-'); 722 if (!ivgen_name) { 723 ret = -EINVAL; 724 error_setg(errp, "Unexpected cipher mode string format %s", 725 luks->header.cipher_mode); 726 goto fail; 727 } 728 *ivgen_name = '\0'; 729 ivgen_name++; 730 731 ivhash_name = strchr(ivgen_name, ':'); 732 if (!ivhash_name) { 733 ivhash = 0; 734 } else { 735 *ivhash_name = '\0'; 736 ivhash_name++; 737 738 ivhash = qcrypto_block_luks_hash_name_lookup(ivhash_name, 739 &local_err); 740 if (local_err) { 741 ret = -ENOTSUP; 742 error_propagate(errp, local_err); 743 goto fail; 744 } 745 } 746 747 ciphermode = qcrypto_block_luks_cipher_mode_lookup(luks->header.cipher_mode, 748 &local_err); 749 if (local_err) { 750 ret = -ENOTSUP; 751 error_propagate(errp, local_err); 752 goto fail; 753 } 754 755 cipheralg = qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, 756 ciphermode, 757 luks->header.key_bytes, 758 &local_err); 759 if (local_err) { 760 ret = -ENOTSUP; 761 error_propagate(errp, local_err); 762 goto fail; 763 } 764 765 hash = qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, 766 &local_err); 767 if (local_err) { 768 ret = -ENOTSUP; 769 error_propagate(errp, local_err); 770 goto fail; 771 } 772 773 ivalg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, 774 &local_err); 775 if (local_err) { 776 ret = -ENOTSUP; 777 error_propagate(errp, local_err); 778 goto fail; 779 } 780 781 if (ivalg == QCRYPTO_IVGEN_ALG_ESSIV) { 782 if (!ivhash_name) { 783 ret = -EINVAL; 784 error_setg(errp, "Missing IV generator hash specification"); 785 goto fail; 786 } 787 ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg, 788 ivhash, 789 &local_err); 790 if (local_err) { 791 ret = -ENOTSUP; 792 error_propagate(errp, local_err); 793 goto fail; 794 } 795 } else { 796 /* Note we parsed the ivhash_name earlier in the cipher_mode 797 * spec string even with plain/plain64 ivgens, but we 798 * will ignore it, since it is irrelevant for these ivgens. 799 * This is for compat with dm-crypt which will silently 800 * ignore hash names with these ivgens rather than report 801 * an error about the invalid usage 802 */ 803 ivcipheralg = cipheralg; 804 } 805 806 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { 807 /* Try to find which key slot our password is valid for 808 * and unlock the master key from that slot. 809 */ 810 if (qcrypto_block_luks_find_key(block, 811 password, 812 cipheralg, ciphermode, 813 hash, 814 ivalg, 815 ivcipheralg, 816 ivhash, 817 &masterkey, &masterkeylen, 818 readfunc, opaque, 819 errp) < 0) { 820 ret = -EACCES; 821 goto fail; 822 } 823 824 /* We have a valid master key now, so can setup the 825 * block device payload decryption objects 826 */ 827 block->kdfhash = hash; 828 block->niv = qcrypto_cipher_get_iv_len(cipheralg, 829 ciphermode); 830 block->ivgen = qcrypto_ivgen_new(ivalg, 831 ivcipheralg, 832 ivhash, 833 masterkey, masterkeylen, 834 errp); 835 if (!block->ivgen) { 836 ret = -ENOTSUP; 837 goto fail; 838 } 839 840 ret = qcrypto_block_init_cipher(block, cipheralg, ciphermode, 841 masterkey, masterkeylen, n_threads, 842 errp); 843 if (ret < 0) { 844 ret = -ENOTSUP; 845 goto fail; 846 } 847 } 848 849 block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 850 block->payload_offset = luks->header.payload_offset * 851 block->sector_size; 852 853 luks->cipher_alg = cipheralg; 854 luks->cipher_mode = ciphermode; 855 luks->ivgen_alg = ivalg; 856 luks->ivgen_hash_alg = ivhash; 857 luks->hash_alg = hash; 858 859 g_free(masterkey); 860 g_free(password); 861 862 return 0; 863 864 fail: 865 g_free(masterkey); 866 qcrypto_block_free_cipher(block); 867 qcrypto_ivgen_free(block->ivgen); 868 g_free(luks); 869 g_free(password); 870 return ret; 871 } 872 873 874 static void 875 qcrypto_block_luks_uuid_gen(uint8_t *uuidstr) 876 { 877 QemuUUID uuid; 878 qemu_uuid_generate(&uuid); 879 qemu_uuid_unparse(&uuid, (char *)uuidstr); 880 } 881 882 static int 883 qcrypto_block_luks_create(QCryptoBlock *block, 884 QCryptoBlockCreateOptions *options, 885 const char *optprefix, 886 QCryptoBlockInitFunc initfunc, 887 QCryptoBlockWriteFunc writefunc, 888 void *opaque, 889 Error **errp) 890 { 891 QCryptoBlockLUKS *luks; 892 QCryptoBlockCreateOptionsLUKS luks_opts; 893 Error *local_err = NULL; 894 uint8_t *masterkey = NULL; 895 uint8_t *slotkey = NULL; 896 uint8_t *splitkey = NULL; 897 size_t splitkeylen = 0; 898 size_t i; 899 QCryptoCipher *cipher = NULL; 900 QCryptoIVGen *ivgen = NULL; 901 char *password; 902 const char *cipher_alg; 903 const char *cipher_mode; 904 const char *ivgen_alg; 905 const char *ivgen_hash_alg = NULL; 906 const char *hash_alg; 907 char *cipher_mode_spec = NULL; 908 QCryptoCipherAlgorithm ivcipheralg = 0; 909 uint64_t iters; 910 911 memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts)); 912 if (!luks_opts.has_iter_time) { 913 luks_opts.iter_time = 2000; 914 } 915 if (!luks_opts.has_cipher_alg) { 916 luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256; 917 } 918 if (!luks_opts.has_cipher_mode) { 919 luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS; 920 } 921 if (!luks_opts.has_ivgen_alg) { 922 luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64; 923 } 924 if (!luks_opts.has_hash_alg) { 925 luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256; 926 } 927 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 928 if (!luks_opts.has_ivgen_hash_alg) { 929 luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256; 930 luks_opts.has_ivgen_hash_alg = true; 931 } 932 } 933 /* Note we're allowing ivgen_hash_alg to be set even for 934 * non-essiv iv generators that don't need a hash. It will 935 * be silently ignored, for compatibility with dm-crypt */ 936 937 if (!options->u.luks.key_secret) { 938 error_setg(errp, "Parameter '%skey-secret' is required for cipher", 939 optprefix ? optprefix : ""); 940 return -1; 941 } 942 password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp); 943 if (!password) { 944 return -1; 945 } 946 947 luks = g_new0(QCryptoBlockLUKS, 1); 948 block->opaque = luks; 949 950 memcpy(luks->header.magic, qcrypto_block_luks_magic, 951 QCRYPTO_BLOCK_LUKS_MAGIC_LEN); 952 953 /* We populate the header in native endianness initially and 954 * then convert everything to big endian just before writing 955 * it out to disk 956 */ 957 luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION; 958 qcrypto_block_luks_uuid_gen(luks->header.uuid); 959 960 cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg, 961 errp); 962 if (!cipher_alg) { 963 goto error; 964 } 965 966 cipher_mode = QCryptoCipherMode_str(luks_opts.cipher_mode); 967 ivgen_alg = QCryptoIVGenAlgorithm_str(luks_opts.ivgen_alg); 968 if (luks_opts.has_ivgen_hash_alg) { 969 ivgen_hash_alg = QCryptoHashAlgorithm_str(luks_opts.ivgen_hash_alg); 970 cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg, 971 ivgen_hash_alg); 972 } else { 973 cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg); 974 } 975 hash_alg = QCryptoHashAlgorithm_str(luks_opts.hash_alg); 976 977 978 if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) { 979 error_setg(errp, "Cipher name '%s' is too long for LUKS header", 980 cipher_alg); 981 goto error; 982 } 983 if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) { 984 error_setg(errp, "Cipher mode '%s' is too long for LUKS header", 985 cipher_mode_spec); 986 goto error; 987 } 988 if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) { 989 error_setg(errp, "Hash name '%s' is too long for LUKS header", 990 hash_alg); 991 goto error; 992 } 993 994 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 995 ivcipheralg = qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg, 996 luks_opts.ivgen_hash_alg, 997 &local_err); 998 if (local_err) { 999 error_propagate(errp, local_err); 1000 goto error; 1001 } 1002 } else { 1003 ivcipheralg = luks_opts.cipher_alg; 1004 } 1005 1006 strcpy(luks->header.cipher_name, cipher_alg); 1007 strcpy(luks->header.cipher_mode, cipher_mode_spec); 1008 strcpy(luks->header.hash_spec, hash_alg); 1009 1010 luks->header.key_bytes = qcrypto_cipher_get_key_len(luks_opts.cipher_alg); 1011 if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) { 1012 luks->header.key_bytes *= 2; 1013 } 1014 1015 /* Generate the salt used for hashing the master key 1016 * with PBKDF later 1017 */ 1018 if (qcrypto_random_bytes(luks->header.master_key_salt, 1019 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1020 errp) < 0) { 1021 goto error; 1022 } 1023 1024 /* Generate random master key */ 1025 masterkey = g_new0(uint8_t, luks->header.key_bytes); 1026 if (qcrypto_random_bytes(masterkey, 1027 luks->header.key_bytes, errp) < 0) { 1028 goto error; 1029 } 1030 1031 1032 /* Setup the block device payload encryption objects */ 1033 if (qcrypto_block_init_cipher(block, luks_opts.cipher_alg, 1034 luks_opts.cipher_mode, masterkey, 1035 luks->header.key_bytes, 1, errp) < 0) { 1036 goto error; 1037 } 1038 1039 block->kdfhash = luks_opts.hash_alg; 1040 block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg, 1041 luks_opts.cipher_mode); 1042 block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1043 ivcipheralg, 1044 luks_opts.ivgen_hash_alg, 1045 masterkey, luks->header.key_bytes, 1046 errp); 1047 1048 if (!block->ivgen) { 1049 goto error; 1050 } 1051 1052 1053 /* Determine how many iterations we need to hash the master 1054 * key, in order to have 1 second of compute time used 1055 */ 1056 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1057 masterkey, luks->header.key_bytes, 1058 luks->header.master_key_salt, 1059 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1060 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1061 &local_err); 1062 if (local_err) { 1063 error_propagate(errp, local_err); 1064 goto error; 1065 } 1066 1067 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1068 error_setg_errno(errp, ERANGE, 1069 "PBKDF iterations %llu too large to scale", 1070 (unsigned long long)iters); 1071 goto error; 1072 } 1073 1074 /* iter_time was in millis, but count_iters reported for secs */ 1075 iters = iters * luks_opts.iter_time / 1000; 1076 1077 /* Why /= 8 ? That matches cryptsetup, but there's no 1078 * explanation why they chose /= 8... Probably so that 1079 * if all 8 keyslots are active we only spend 1 second 1080 * in total time to check all keys */ 1081 iters /= 8; 1082 if (iters > UINT32_MAX) { 1083 error_setg_errno(errp, ERANGE, 1084 "PBKDF iterations %llu larger than %u", 1085 (unsigned long long)iters, UINT32_MAX); 1086 goto error; 1087 } 1088 iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS); 1089 luks->header.master_key_iterations = iters; 1090 1091 /* Hash the master key, saving the result in the LUKS 1092 * header. This hash is used when opening the encrypted 1093 * device to verify that the user password unlocked a 1094 * valid master key 1095 */ 1096 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1097 masterkey, luks->header.key_bytes, 1098 luks->header.master_key_salt, 1099 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1100 luks->header.master_key_iterations, 1101 luks->header.master_key_digest, 1102 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1103 errp) < 0) { 1104 goto error; 1105 } 1106 1107 1108 /* Although LUKS has multiple key slots, we're just going 1109 * to use the first key slot */ 1110 splitkeylen = luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRIPES; 1111 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1112 luks->header.key_slots[i].active = i == 0 ? 1113 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED : 1114 QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; 1115 luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES; 1116 1117 /* This calculation doesn't match that shown in the spec, 1118 * but instead follows the cryptsetup implementation. 1119 */ 1120 luks->header.key_slots[i].key_offset = 1121 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1122 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1123 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1124 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1125 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i); 1126 } 1127 1128 if (qcrypto_random_bytes(luks->header.key_slots[0].salt, 1129 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1130 errp) < 0) { 1131 goto error; 1132 } 1133 1134 /* Again we determine how many iterations are required to 1135 * hash the user password while consuming 1 second of compute 1136 * time */ 1137 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1138 (uint8_t *)password, strlen(password), 1139 luks->header.key_slots[0].salt, 1140 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1141 luks->header.key_bytes, 1142 &local_err); 1143 if (local_err) { 1144 error_propagate(errp, local_err); 1145 goto error; 1146 } 1147 1148 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1149 error_setg_errno(errp, ERANGE, 1150 "PBKDF iterations %llu too large to scale", 1151 (unsigned long long)iters); 1152 goto error; 1153 } 1154 1155 /* iter_time was in millis, but count_iters reported for secs */ 1156 iters = iters * luks_opts.iter_time / 1000; 1157 1158 if (iters > UINT32_MAX) { 1159 error_setg_errno(errp, ERANGE, 1160 "PBKDF iterations %llu larger than %u", 1161 (unsigned long long)iters, UINT32_MAX); 1162 goto error; 1163 } 1164 1165 luks->header.key_slots[0].iterations = 1166 MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS); 1167 1168 1169 /* Generate a key that we'll use to encrypt the master 1170 * key, from the user's password 1171 */ 1172 slotkey = g_new0(uint8_t, luks->header.key_bytes); 1173 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1174 (uint8_t *)password, strlen(password), 1175 luks->header.key_slots[0].salt, 1176 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1177 luks->header.key_slots[0].iterations, 1178 slotkey, luks->header.key_bytes, 1179 errp) < 0) { 1180 goto error; 1181 } 1182 1183 1184 /* Setup the encryption objects needed to encrypt the 1185 * master key material 1186 */ 1187 cipher = qcrypto_cipher_new(luks_opts.cipher_alg, 1188 luks_opts.cipher_mode, 1189 slotkey, luks->header.key_bytes, 1190 errp); 1191 if (!cipher) { 1192 goto error; 1193 } 1194 1195 ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1196 ivcipheralg, 1197 luks_opts.ivgen_hash_alg, 1198 slotkey, luks->header.key_bytes, 1199 errp); 1200 if (!ivgen) { 1201 goto error; 1202 } 1203 1204 /* Before storing the master key, we need to vastly 1205 * increase its size, as protection against forensic 1206 * disk data recovery */ 1207 splitkey = g_new0(uint8_t, splitkeylen); 1208 1209 if (qcrypto_afsplit_encode(luks_opts.hash_alg, 1210 luks->header.key_bytes, 1211 luks->header.key_slots[0].stripes, 1212 masterkey, 1213 splitkey, 1214 errp) < 0) { 1215 goto error; 1216 } 1217 1218 /* Now we encrypt the split master key with the key generated 1219 * from the user's password, before storing it */ 1220 if (qcrypto_block_cipher_encrypt_helper(cipher, block->niv, ivgen, 1221 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1222 0, 1223 splitkey, 1224 splitkeylen, 1225 errp) < 0) { 1226 goto error; 1227 } 1228 1229 1230 /* The total size of the LUKS headers is the partition header + key 1231 * slot headers, rounded up to the nearest sector, combined with 1232 * the size of each master key material region, also rounded up 1233 * to the nearest sector */ 1234 luks->header.payload_offset = 1235 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1236 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1237 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1238 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1239 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * 1240 QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); 1241 1242 block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1243 block->payload_offset = luks->header.payload_offset * 1244 block->sector_size; 1245 1246 /* Reserve header space to match payload offset */ 1247 initfunc(block, block->payload_offset, opaque, &local_err); 1248 if (local_err) { 1249 error_propagate(errp, local_err); 1250 goto error; 1251 } 1252 1253 /* Everything on disk uses Big Endian, so flip header fields 1254 * before writing them */ 1255 cpu_to_be16s(&luks->header.version); 1256 cpu_to_be32s(&luks->header.payload_offset); 1257 cpu_to_be32s(&luks->header.key_bytes); 1258 cpu_to_be32s(&luks->header.master_key_iterations); 1259 1260 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1261 cpu_to_be32s(&luks->header.key_slots[i].active); 1262 cpu_to_be32s(&luks->header.key_slots[i].iterations); 1263 cpu_to_be32s(&luks->header.key_slots[i].key_offset); 1264 cpu_to_be32s(&luks->header.key_slots[i].stripes); 1265 } 1266 1267 1268 /* Write out the partition header and key slot headers */ 1269 writefunc(block, 0, 1270 (const uint8_t *)&luks->header, 1271 sizeof(luks->header), 1272 opaque, 1273 &local_err); 1274 1275 /* Delay checking local_err until we've byte-swapped */ 1276 1277 /* Byte swap the header back to native, in case we need 1278 * to read it again later */ 1279 be16_to_cpus(&luks->header.version); 1280 be32_to_cpus(&luks->header.payload_offset); 1281 be32_to_cpus(&luks->header.key_bytes); 1282 be32_to_cpus(&luks->header.master_key_iterations); 1283 1284 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1285 be32_to_cpus(&luks->header.key_slots[i].active); 1286 be32_to_cpus(&luks->header.key_slots[i].iterations); 1287 be32_to_cpus(&luks->header.key_slots[i].key_offset); 1288 be32_to_cpus(&luks->header.key_slots[i].stripes); 1289 } 1290 1291 if (local_err) { 1292 error_propagate(errp, local_err); 1293 goto error; 1294 } 1295 1296 /* Write out the master key material, starting at the 1297 * sector immediately following the partition header. */ 1298 if (writefunc(block, 1299 luks->header.key_slots[0].key_offset * 1300 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1301 splitkey, splitkeylen, 1302 opaque, 1303 errp) != splitkeylen) { 1304 goto error; 1305 } 1306 1307 luks->cipher_alg = luks_opts.cipher_alg; 1308 luks->cipher_mode = luks_opts.cipher_mode; 1309 luks->ivgen_alg = luks_opts.ivgen_alg; 1310 luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg; 1311 luks->hash_alg = luks_opts.hash_alg; 1312 1313 memset(masterkey, 0, luks->header.key_bytes); 1314 g_free(masterkey); 1315 memset(slotkey, 0, luks->header.key_bytes); 1316 g_free(slotkey); 1317 g_free(splitkey); 1318 g_free(password); 1319 g_free(cipher_mode_spec); 1320 1321 qcrypto_ivgen_free(ivgen); 1322 qcrypto_cipher_free(cipher); 1323 1324 return 0; 1325 1326 error: 1327 if (masterkey) { 1328 memset(masterkey, 0, luks->header.key_bytes); 1329 } 1330 g_free(masterkey); 1331 if (slotkey) { 1332 memset(slotkey, 0, luks->header.key_bytes); 1333 } 1334 g_free(slotkey); 1335 g_free(splitkey); 1336 g_free(password); 1337 g_free(cipher_mode_spec); 1338 1339 qcrypto_ivgen_free(ivgen); 1340 qcrypto_cipher_free(cipher); 1341 1342 qcrypto_block_free_cipher(block); 1343 qcrypto_ivgen_free(block->ivgen); 1344 1345 g_free(luks); 1346 return -1; 1347 } 1348 1349 1350 static int qcrypto_block_luks_get_info(QCryptoBlock *block, 1351 QCryptoBlockInfo *info, 1352 Error **errp) 1353 { 1354 QCryptoBlockLUKS *luks = block->opaque; 1355 QCryptoBlockInfoLUKSSlot *slot; 1356 QCryptoBlockInfoLUKSSlotList *slots = NULL, **prev = &info->u.luks.slots; 1357 size_t i; 1358 1359 info->u.luks.cipher_alg = luks->cipher_alg; 1360 info->u.luks.cipher_mode = luks->cipher_mode; 1361 info->u.luks.ivgen_alg = luks->ivgen_alg; 1362 if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 1363 info->u.luks.has_ivgen_hash_alg = true; 1364 info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg; 1365 } 1366 info->u.luks.hash_alg = luks->hash_alg; 1367 info->u.luks.payload_offset = block->payload_offset; 1368 info->u.luks.master_key_iters = luks->header.master_key_iterations; 1369 info->u.luks.uuid = g_strndup((const char *)luks->header.uuid, 1370 sizeof(luks->header.uuid)); 1371 1372 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1373 slots = g_new0(QCryptoBlockInfoLUKSSlotList, 1); 1374 *prev = slots; 1375 1376 slots->value = slot = g_new0(QCryptoBlockInfoLUKSSlot, 1); 1377 slot->active = luks->header.key_slots[i].active == 1378 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; 1379 slot->key_offset = luks->header.key_slots[i].key_offset 1380 * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1381 if (slot->active) { 1382 slot->has_iters = true; 1383 slot->iters = luks->header.key_slots[i].iterations; 1384 slot->has_stripes = true; 1385 slot->stripes = luks->header.key_slots[i].stripes; 1386 } 1387 1388 prev = &slots->next; 1389 } 1390 1391 return 0; 1392 } 1393 1394 1395 static void qcrypto_block_luks_cleanup(QCryptoBlock *block) 1396 { 1397 g_free(block->opaque); 1398 } 1399 1400 1401 static int 1402 qcrypto_block_luks_decrypt(QCryptoBlock *block, 1403 uint64_t offset, 1404 uint8_t *buf, 1405 size_t len, 1406 Error **errp) 1407 { 1408 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); 1409 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); 1410 return qcrypto_block_decrypt_helper(block, 1411 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1412 offset, buf, len, errp); 1413 } 1414 1415 1416 static int 1417 qcrypto_block_luks_encrypt(QCryptoBlock *block, 1418 uint64_t offset, 1419 uint8_t *buf, 1420 size_t len, 1421 Error **errp) 1422 { 1423 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); 1424 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)); 1425 return qcrypto_block_encrypt_helper(block, 1426 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1427 offset, buf, len, errp); 1428 } 1429 1430 1431 const QCryptoBlockDriver qcrypto_block_driver_luks = { 1432 .open = qcrypto_block_luks_open, 1433 .create = qcrypto_block_luks_create, 1434 .get_info = qcrypto_block_luks_get_info, 1435 .cleanup = qcrypto_block_luks_cleanup, 1436 .decrypt = qcrypto_block_luks_decrypt, 1437 .encrypt = qcrypto_block_luks_encrypt, 1438 .has_format = qcrypto_block_luks_has_format, 1439 }; 1440