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 "crypto/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 } QEMU_PACKED; 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 } QEMU_PACKED; 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_lookup[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 char *const *map, 268 size_t maplen, 269 const char *type, 270 Error **errp) 271 { 272 size_t i; 273 for (i = 0; i < maplen; i++) { 274 if (g_str_equal(map[i], name)) { 275 return i; 276 } 277 } 278 279 error_setg(errp, "%s %s not supported", type, name); 280 return 0; 281 } 282 283 #define qcrypto_block_luks_cipher_mode_lookup(name, errp) \ 284 qcrypto_block_luks_name_lookup(name, \ 285 QCryptoCipherMode_lookup, \ 286 QCRYPTO_CIPHER_MODE__MAX, \ 287 "Cipher mode", \ 288 errp) 289 290 #define qcrypto_block_luks_hash_name_lookup(name, errp) \ 291 qcrypto_block_luks_name_lookup(name, \ 292 QCryptoHashAlgorithm_lookup, \ 293 QCRYPTO_HASH_ALG__MAX, \ 294 "Hash algorithm", \ 295 errp) 296 297 #define qcrypto_block_luks_ivgen_name_lookup(name, errp) \ 298 qcrypto_block_luks_name_lookup(name, \ 299 QCryptoIVGenAlgorithm_lookup, \ 300 QCRYPTO_IVGEN_ALG__MAX, \ 301 "IV generator", \ 302 errp) 303 304 305 static bool 306 qcrypto_block_luks_has_format(const uint8_t *buf, 307 size_t buf_size) 308 { 309 const QCryptoBlockLUKSHeader *luks_header = (const void *)buf; 310 311 if (buf_size >= offsetof(QCryptoBlockLUKSHeader, cipher_name) && 312 memcmp(luks_header->magic, qcrypto_block_luks_magic, 313 QCRYPTO_BLOCK_LUKS_MAGIC_LEN) == 0 && 314 be16_to_cpu(luks_header->version) == QCRYPTO_BLOCK_LUKS_VERSION) { 315 return true; 316 } else { 317 return false; 318 } 319 } 320 321 322 /** 323 * Deal with a quirk of dm-crypt usage of ESSIV. 324 * 325 * When calculating ESSIV IVs, the cipher length used by ESSIV 326 * may be different from the cipher length used for the block 327 * encryption, becauses dm-crypt uses the hash digest length 328 * as the key size. ie, if you have AES 128 as the block cipher 329 * and SHA 256 as ESSIV hash, then ESSIV will use AES 256 as 330 * the cipher since that gets a key length matching the digest 331 * size, not AES 128 with truncated digest as might be imagined 332 */ 333 static QCryptoCipherAlgorithm 334 qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm cipher, 335 QCryptoHashAlgorithm hash, 336 Error **errp) 337 { 338 size_t digestlen = qcrypto_hash_digest_len(hash); 339 size_t keylen = qcrypto_cipher_get_key_len(cipher); 340 if (digestlen == keylen) { 341 return cipher; 342 } 343 344 switch (cipher) { 345 case QCRYPTO_CIPHER_ALG_AES_128: 346 case QCRYPTO_CIPHER_ALG_AES_192: 347 case QCRYPTO_CIPHER_ALG_AES_256: 348 if (digestlen == qcrypto_cipher_get_key_len( 349 QCRYPTO_CIPHER_ALG_AES_128)) { 350 return QCRYPTO_CIPHER_ALG_AES_128; 351 } else if (digestlen == qcrypto_cipher_get_key_len( 352 QCRYPTO_CIPHER_ALG_AES_192)) { 353 return QCRYPTO_CIPHER_ALG_AES_192; 354 } else if (digestlen == qcrypto_cipher_get_key_len( 355 QCRYPTO_CIPHER_ALG_AES_256)) { 356 return QCRYPTO_CIPHER_ALG_AES_256; 357 } else { 358 error_setg(errp, "No AES cipher with key size %zu available", 359 digestlen); 360 return 0; 361 } 362 break; 363 case QCRYPTO_CIPHER_ALG_SERPENT_128: 364 case QCRYPTO_CIPHER_ALG_SERPENT_192: 365 case QCRYPTO_CIPHER_ALG_SERPENT_256: 366 if (digestlen == qcrypto_cipher_get_key_len( 367 QCRYPTO_CIPHER_ALG_SERPENT_128)) { 368 return QCRYPTO_CIPHER_ALG_SERPENT_128; 369 } else if (digestlen == qcrypto_cipher_get_key_len( 370 QCRYPTO_CIPHER_ALG_SERPENT_192)) { 371 return QCRYPTO_CIPHER_ALG_SERPENT_192; 372 } else if (digestlen == qcrypto_cipher_get_key_len( 373 QCRYPTO_CIPHER_ALG_SERPENT_256)) { 374 return QCRYPTO_CIPHER_ALG_SERPENT_256; 375 } else { 376 error_setg(errp, "No Serpent cipher with key size %zu available", 377 digestlen); 378 return 0; 379 } 380 break; 381 case QCRYPTO_CIPHER_ALG_TWOFISH_128: 382 case QCRYPTO_CIPHER_ALG_TWOFISH_192: 383 case QCRYPTO_CIPHER_ALG_TWOFISH_256: 384 if (digestlen == qcrypto_cipher_get_key_len( 385 QCRYPTO_CIPHER_ALG_TWOFISH_128)) { 386 return QCRYPTO_CIPHER_ALG_TWOFISH_128; 387 } else if (digestlen == qcrypto_cipher_get_key_len( 388 QCRYPTO_CIPHER_ALG_TWOFISH_192)) { 389 return QCRYPTO_CIPHER_ALG_TWOFISH_192; 390 } else if (digestlen == qcrypto_cipher_get_key_len( 391 QCRYPTO_CIPHER_ALG_TWOFISH_256)) { 392 return QCRYPTO_CIPHER_ALG_TWOFISH_256; 393 } else { 394 error_setg(errp, "No Twofish cipher with key size %zu available", 395 digestlen); 396 return 0; 397 } 398 break; 399 default: 400 error_setg(errp, "Cipher %s not supported with essiv", 401 QCryptoCipherAlgorithm_lookup[cipher]); 402 return 0; 403 } 404 } 405 406 /* 407 * Given a key slot, and user password, this will attempt to unlock 408 * the master encryption key from the key slot. 409 * 410 * Returns: 411 * 0 if the key slot is disabled, or key could not be decrypted 412 * with the provided password 413 * 1 if the key slot is enabled, and key decrypted successfully 414 * with the provided password 415 * -1 if a fatal error occurred loading the key 416 */ 417 static int 418 qcrypto_block_luks_load_key(QCryptoBlock *block, 419 QCryptoBlockLUKSKeySlot *slot, 420 const char *password, 421 QCryptoCipherAlgorithm cipheralg, 422 QCryptoCipherMode ciphermode, 423 QCryptoHashAlgorithm hash, 424 QCryptoIVGenAlgorithm ivalg, 425 QCryptoCipherAlgorithm ivcipheralg, 426 QCryptoHashAlgorithm ivhash, 427 uint8_t *masterkey, 428 size_t masterkeylen, 429 QCryptoBlockReadFunc readfunc, 430 void *opaque, 431 Error **errp) 432 { 433 QCryptoBlockLUKS *luks = block->opaque; 434 uint8_t *splitkey; 435 size_t splitkeylen; 436 uint8_t *possiblekey; 437 int ret = -1; 438 ssize_t rv; 439 QCryptoCipher *cipher = NULL; 440 uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN]; 441 QCryptoIVGen *ivgen = NULL; 442 size_t niv; 443 444 if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) { 445 return 0; 446 } 447 448 splitkeylen = masterkeylen * slot->stripes; 449 splitkey = g_new0(uint8_t, splitkeylen); 450 possiblekey = g_new0(uint8_t, masterkeylen); 451 452 /* 453 * The user password is used to generate a (possible) 454 * decryption key. This may or may not successfully 455 * decrypt the master key - we just blindly assume 456 * the key is correct and validate the results of 457 * decryption later. 458 */ 459 if (qcrypto_pbkdf2(hash, 460 (const uint8_t *)password, strlen(password), 461 slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN, 462 slot->iterations, 463 possiblekey, masterkeylen, 464 errp) < 0) { 465 goto cleanup; 466 } 467 468 /* 469 * We need to read the master key material from the 470 * LUKS key material header. What we're reading is 471 * not the raw master key, but rather the data after 472 * it has been passed through AFSplit and the result 473 * then encrypted. 474 */ 475 rv = readfunc(block, 476 opaque, 477 slot->key_offset * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 478 splitkey, splitkeylen, 479 errp); 480 if (rv < 0) { 481 goto cleanup; 482 } 483 484 485 /* Setup the cipher/ivgen that we'll use to try to decrypt 486 * the split master key material */ 487 cipher = qcrypto_cipher_new(cipheralg, ciphermode, 488 possiblekey, masterkeylen, 489 errp); 490 if (!cipher) { 491 goto cleanup; 492 } 493 494 niv = qcrypto_cipher_get_iv_len(cipheralg, 495 ciphermode); 496 ivgen = qcrypto_ivgen_new(ivalg, 497 ivcipheralg, 498 ivhash, 499 possiblekey, masterkeylen, 500 errp); 501 if (!ivgen) { 502 goto cleanup; 503 } 504 505 506 /* 507 * The master key needs to be decrypted in the same 508 * way that the block device payload will be decrypted 509 * later. In particular we'll be using the IV generator 510 * to reset the encryption cipher every time the master 511 * key crosses a sector boundary. 512 */ 513 if (qcrypto_block_decrypt_helper(cipher, 514 niv, 515 ivgen, 516 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 517 0, 518 splitkey, 519 splitkeylen, 520 errp) < 0) { 521 goto cleanup; 522 } 523 524 /* 525 * Now we've decrypted the split master key, join 526 * it back together to get the actual master key. 527 */ 528 if (qcrypto_afsplit_decode(hash, 529 masterkeylen, 530 slot->stripes, 531 splitkey, 532 masterkey, 533 errp) < 0) { 534 goto cleanup; 535 } 536 537 538 /* 539 * We still don't know that the masterkey we got is valid, 540 * because we just blindly assumed the user's password 541 * was correct. This is where we now verify it. We are 542 * creating a hash of the master key using PBKDF and 543 * then comparing that to the hash stored in the key slot 544 * header 545 */ 546 if (qcrypto_pbkdf2(hash, 547 masterkey, masterkeylen, 548 luks->header.master_key_salt, 549 QCRYPTO_BLOCK_LUKS_SALT_LEN, 550 luks->header.master_key_iterations, 551 keydigest, G_N_ELEMENTS(keydigest), 552 errp) < 0) { 553 goto cleanup; 554 } 555 556 if (memcmp(keydigest, luks->header.master_key_digest, 557 QCRYPTO_BLOCK_LUKS_DIGEST_LEN) == 0) { 558 /* Success, we got the right master key */ 559 ret = 1; 560 goto cleanup; 561 } 562 563 /* Fail, user's password was not valid for this key slot, 564 * tell caller to try another slot */ 565 ret = 0; 566 567 cleanup: 568 qcrypto_ivgen_free(ivgen); 569 qcrypto_cipher_free(cipher); 570 g_free(splitkey); 571 g_free(possiblekey); 572 return ret; 573 } 574 575 576 /* 577 * Given a user password, this will iterate over all key 578 * slots and try to unlock each active key slot using the 579 * password until it successfully obtains a master key. 580 * 581 * Returns 0 if a key was loaded, -1 if no keys could be loaded 582 */ 583 static int 584 qcrypto_block_luks_find_key(QCryptoBlock *block, 585 const char *password, 586 QCryptoCipherAlgorithm cipheralg, 587 QCryptoCipherMode ciphermode, 588 QCryptoHashAlgorithm hash, 589 QCryptoIVGenAlgorithm ivalg, 590 QCryptoCipherAlgorithm ivcipheralg, 591 QCryptoHashAlgorithm ivhash, 592 uint8_t **masterkey, 593 size_t *masterkeylen, 594 QCryptoBlockReadFunc readfunc, 595 void *opaque, 596 Error **errp) 597 { 598 QCryptoBlockLUKS *luks = block->opaque; 599 size_t i; 600 int rv; 601 602 *masterkey = g_new0(uint8_t, luks->header.key_bytes); 603 *masterkeylen = luks->header.key_bytes; 604 605 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 606 rv = qcrypto_block_luks_load_key(block, 607 &luks->header.key_slots[i], 608 password, 609 cipheralg, 610 ciphermode, 611 hash, 612 ivalg, 613 ivcipheralg, 614 ivhash, 615 *masterkey, 616 *masterkeylen, 617 readfunc, 618 opaque, 619 errp); 620 if (rv < 0) { 621 goto error; 622 } 623 if (rv == 1) { 624 return 0; 625 } 626 } 627 628 error_setg(errp, "Invalid password, cannot unlock any keyslot"); 629 630 error: 631 g_free(*masterkey); 632 *masterkey = NULL; 633 *masterkeylen = 0; 634 return -1; 635 } 636 637 638 static int 639 qcrypto_block_luks_open(QCryptoBlock *block, 640 QCryptoBlockOpenOptions *options, 641 QCryptoBlockReadFunc readfunc, 642 void *opaque, 643 unsigned int flags, 644 Error **errp) 645 { 646 QCryptoBlockLUKS *luks; 647 Error *local_err = NULL; 648 int ret = 0; 649 size_t i; 650 ssize_t rv; 651 uint8_t *masterkey = NULL; 652 size_t masterkeylen; 653 char *ivgen_name, *ivhash_name; 654 QCryptoCipherMode ciphermode; 655 QCryptoCipherAlgorithm cipheralg; 656 QCryptoIVGenAlgorithm ivalg; 657 QCryptoCipherAlgorithm ivcipheralg; 658 QCryptoHashAlgorithm hash; 659 QCryptoHashAlgorithm ivhash; 660 char *password = NULL; 661 662 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { 663 if (!options->u.luks.key_secret) { 664 error_setg(errp, "Parameter 'key-secret' is required for cipher"); 665 return -1; 666 } 667 password = qcrypto_secret_lookup_as_utf8( 668 options->u.luks.key_secret, errp); 669 if (!password) { 670 return -1; 671 } 672 } 673 674 luks = g_new0(QCryptoBlockLUKS, 1); 675 block->opaque = luks; 676 677 /* Read the entire LUKS header, minus the key material from 678 * the underlying device */ 679 rv = readfunc(block, opaque, 0, 680 (uint8_t *)&luks->header, 681 sizeof(luks->header), 682 errp); 683 if (rv < 0) { 684 ret = rv; 685 goto fail; 686 } 687 688 /* The header is always stored in big-endian format, so 689 * convert everything to native */ 690 be16_to_cpus(&luks->header.version); 691 be32_to_cpus(&luks->header.payload_offset); 692 be32_to_cpus(&luks->header.key_bytes); 693 be32_to_cpus(&luks->header.master_key_iterations); 694 695 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 696 be32_to_cpus(&luks->header.key_slots[i].active); 697 be32_to_cpus(&luks->header.key_slots[i].iterations); 698 be32_to_cpus(&luks->header.key_slots[i].key_offset); 699 be32_to_cpus(&luks->header.key_slots[i].stripes); 700 } 701 702 if (memcmp(luks->header.magic, qcrypto_block_luks_magic, 703 QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { 704 error_setg(errp, "Volume is not in LUKS format"); 705 ret = -EINVAL; 706 goto fail; 707 } 708 if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { 709 error_setg(errp, "LUKS version %" PRIu32 " is not supported", 710 luks->header.version); 711 ret = -ENOTSUP; 712 goto fail; 713 } 714 715 /* 716 * The cipher_mode header contains a string that we have 717 * to further parse, of the format 718 * 719 * <cipher-mode>-<iv-generator>[:<iv-hash>] 720 * 721 * eg cbc-essiv:sha256, cbc-plain64 722 */ 723 ivgen_name = strchr(luks->header.cipher_mode, '-'); 724 if (!ivgen_name) { 725 ret = -EINVAL; 726 error_setg(errp, "Unexpected cipher mode string format %s", 727 luks->header.cipher_mode); 728 goto fail; 729 } 730 *ivgen_name = '\0'; 731 ivgen_name++; 732 733 ivhash_name = strchr(ivgen_name, ':'); 734 if (!ivhash_name) { 735 ivhash = 0; 736 } else { 737 *ivhash_name = '\0'; 738 ivhash_name++; 739 740 ivhash = qcrypto_block_luks_hash_name_lookup(ivhash_name, 741 &local_err); 742 if (local_err) { 743 ret = -ENOTSUP; 744 error_propagate(errp, local_err); 745 goto fail; 746 } 747 } 748 749 ciphermode = qcrypto_block_luks_cipher_mode_lookup(luks->header.cipher_mode, 750 &local_err); 751 if (local_err) { 752 ret = -ENOTSUP; 753 error_propagate(errp, local_err); 754 goto fail; 755 } 756 757 cipheralg = qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, 758 ciphermode, 759 luks->header.key_bytes, 760 &local_err); 761 if (local_err) { 762 ret = -ENOTSUP; 763 error_propagate(errp, local_err); 764 goto fail; 765 } 766 767 hash = qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, 768 &local_err); 769 if (local_err) { 770 ret = -ENOTSUP; 771 error_propagate(errp, local_err); 772 goto fail; 773 } 774 775 ivalg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, 776 &local_err); 777 if (local_err) { 778 ret = -ENOTSUP; 779 error_propagate(errp, local_err); 780 goto fail; 781 } 782 783 if (ivalg == QCRYPTO_IVGEN_ALG_ESSIV) { 784 if (!ivhash_name) { 785 ret = -EINVAL; 786 error_setg(errp, "Missing IV generator hash specification"); 787 goto fail; 788 } 789 ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg, 790 ivhash, 791 &local_err); 792 if (local_err) { 793 ret = -ENOTSUP; 794 error_propagate(errp, local_err); 795 goto fail; 796 } 797 } else { 798 /* Note we parsed the ivhash_name earlier in the cipher_mode 799 * spec string even with plain/plain64 ivgens, but we 800 * will ignore it, since it is irrelevant for these ivgens. 801 * This is for compat with dm-crypt which will silently 802 * ignore hash names with these ivgens rather than report 803 * an error about the invalid usage 804 */ 805 ivcipheralg = cipheralg; 806 } 807 808 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { 809 /* Try to find which key slot our password is valid for 810 * and unlock the master key from that slot. 811 */ 812 if (qcrypto_block_luks_find_key(block, 813 password, 814 cipheralg, ciphermode, 815 hash, 816 ivalg, 817 ivcipheralg, 818 ivhash, 819 &masterkey, &masterkeylen, 820 readfunc, opaque, 821 errp) < 0) { 822 ret = -EACCES; 823 goto fail; 824 } 825 826 /* We have a valid master key now, so can setup the 827 * block device payload decryption objects 828 */ 829 block->kdfhash = hash; 830 block->niv = qcrypto_cipher_get_iv_len(cipheralg, 831 ciphermode); 832 block->ivgen = qcrypto_ivgen_new(ivalg, 833 ivcipheralg, 834 ivhash, 835 masterkey, masterkeylen, 836 errp); 837 if (!block->ivgen) { 838 ret = -ENOTSUP; 839 goto fail; 840 } 841 842 block->cipher = qcrypto_cipher_new(cipheralg, 843 ciphermode, 844 masterkey, masterkeylen, 845 errp); 846 if (!block->cipher) { 847 ret = -ENOTSUP; 848 goto fail; 849 } 850 } 851 852 block->payload_offset = luks->header.payload_offset * 853 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 854 855 luks->cipher_alg = cipheralg; 856 luks->cipher_mode = ciphermode; 857 luks->ivgen_alg = ivalg; 858 luks->ivgen_hash_alg = ivhash; 859 luks->hash_alg = hash; 860 861 g_free(masterkey); 862 g_free(password); 863 864 return 0; 865 866 fail: 867 g_free(masterkey); 868 qcrypto_cipher_free(block->cipher); 869 qcrypto_ivgen_free(block->ivgen); 870 g_free(luks); 871 g_free(password); 872 return ret; 873 } 874 875 876 static void 877 qcrypto_block_luks_uuid_gen(uint8_t *uuidstr) 878 { 879 QemuUUID uuid; 880 qemu_uuid_generate(&uuid); 881 qemu_uuid_unparse(&uuid, (char *)uuidstr); 882 } 883 884 static int 885 qcrypto_block_luks_create(QCryptoBlock *block, 886 QCryptoBlockCreateOptions *options, 887 QCryptoBlockInitFunc initfunc, 888 QCryptoBlockWriteFunc writefunc, 889 void *opaque, 890 Error **errp) 891 { 892 QCryptoBlockLUKS *luks; 893 QCryptoBlockCreateOptionsLUKS luks_opts; 894 Error *local_err = NULL; 895 uint8_t *masterkey = NULL; 896 uint8_t *slotkey = NULL; 897 uint8_t *splitkey = NULL; 898 size_t splitkeylen = 0; 899 size_t i; 900 QCryptoCipher *cipher = NULL; 901 QCryptoIVGen *ivgen = NULL; 902 char *password; 903 const char *cipher_alg; 904 const char *cipher_mode; 905 const char *ivgen_alg; 906 const char *ivgen_hash_alg = NULL; 907 const char *hash_alg; 908 char *cipher_mode_spec = NULL; 909 QCryptoCipherAlgorithm ivcipheralg = 0; 910 uint64_t iters; 911 912 memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts)); 913 if (!luks_opts.has_iter_time) { 914 luks_opts.iter_time = 2000; 915 } 916 if (!luks_opts.has_cipher_alg) { 917 luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256; 918 } 919 if (!luks_opts.has_cipher_mode) { 920 luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS; 921 } 922 if (!luks_opts.has_ivgen_alg) { 923 luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64; 924 } 925 if (!luks_opts.has_hash_alg) { 926 luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256; 927 } 928 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 929 if (!luks_opts.has_ivgen_hash_alg) { 930 luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256; 931 luks_opts.has_ivgen_hash_alg = true; 932 } 933 } 934 /* Note we're allowing ivgen_hash_alg to be set even for 935 * non-essiv iv generators that don't need a hash. It will 936 * be silently ignored, for compatibility with dm-crypt */ 937 938 if (!options->u.luks.key_secret) { 939 error_setg(errp, "Parameter 'key-secret' is required for cipher"); 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_lookup[luks_opts.cipher_mode]; 967 ivgen_alg = QCryptoIVGenAlgorithm_lookup[luks_opts.ivgen_alg]; 968 if (luks_opts.has_ivgen_hash_alg) { 969 ivgen_hash_alg = QCryptoHashAlgorithm_lookup[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_lookup[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 block->cipher = qcrypto_cipher_new(luks_opts.cipher_alg, 1034 luks_opts.cipher_mode, 1035 masterkey, luks->header.key_bytes, 1036 errp); 1037 if (!block->cipher) { 1038 goto error; 1039 } 1040 1041 block->kdfhash = luks_opts.hash_alg; 1042 block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg, 1043 luks_opts.cipher_mode); 1044 block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1045 ivcipheralg, 1046 luks_opts.ivgen_hash_alg, 1047 masterkey, luks->header.key_bytes, 1048 errp); 1049 1050 if (!block->ivgen) { 1051 goto error; 1052 } 1053 1054 1055 /* Determine how many iterations we need to hash the master 1056 * key, in order to have 1 second of compute time used 1057 */ 1058 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1059 masterkey, luks->header.key_bytes, 1060 luks->header.master_key_salt, 1061 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1062 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1063 &local_err); 1064 if (local_err) { 1065 error_propagate(errp, local_err); 1066 goto error; 1067 } 1068 1069 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1070 error_setg_errno(errp, ERANGE, 1071 "PBKDF iterations %llu too large to scale", 1072 (unsigned long long)iters); 1073 goto error; 1074 } 1075 1076 /* iter_time was in millis, but count_iters reported for secs */ 1077 iters = iters * luks_opts.iter_time / 1000; 1078 1079 /* Why /= 8 ? That matches cryptsetup, but there's no 1080 * explanation why they chose /= 8... Probably so that 1081 * if all 8 keyslots are active we only spend 1 second 1082 * in total time to check all keys */ 1083 iters /= 8; 1084 if (iters > UINT32_MAX) { 1085 error_setg_errno(errp, ERANGE, 1086 "PBKDF iterations %llu larger than %u", 1087 (unsigned long long)iters, UINT32_MAX); 1088 goto error; 1089 } 1090 iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS); 1091 luks->header.master_key_iterations = iters; 1092 1093 /* Hash the master key, saving the result in the LUKS 1094 * header. This hash is used when opening the encrypted 1095 * device to verify that the user password unlocked a 1096 * valid master key 1097 */ 1098 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1099 masterkey, luks->header.key_bytes, 1100 luks->header.master_key_salt, 1101 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1102 luks->header.master_key_iterations, 1103 luks->header.master_key_digest, 1104 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1105 errp) < 0) { 1106 goto error; 1107 } 1108 1109 1110 /* Although LUKS has multiple key slots, we're just going 1111 * to use the first key slot */ 1112 splitkeylen = luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRIPES; 1113 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1114 luks->header.key_slots[i].active = i == 0 ? 1115 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED : 1116 QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; 1117 luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES; 1118 1119 /* This calculation doesn't match that shown in the spec, 1120 * but instead follows the cryptsetup implementation. 1121 */ 1122 luks->header.key_slots[i].key_offset = 1123 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1124 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1125 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1126 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1127 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i); 1128 } 1129 1130 if (qcrypto_random_bytes(luks->header.key_slots[0].salt, 1131 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1132 errp) < 0) { 1133 goto error; 1134 } 1135 1136 /* Again we determine how many iterations are required to 1137 * hash the user password while consuming 1 second of compute 1138 * time */ 1139 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1140 (uint8_t *)password, strlen(password), 1141 luks->header.key_slots[0].salt, 1142 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1143 luks->header.key_bytes, 1144 &local_err); 1145 if (local_err) { 1146 error_propagate(errp, local_err); 1147 goto error; 1148 } 1149 1150 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1151 error_setg_errno(errp, ERANGE, 1152 "PBKDF iterations %llu too large to scale", 1153 (unsigned long long)iters); 1154 goto error; 1155 } 1156 1157 /* iter_time was in millis, but count_iters reported for secs */ 1158 iters = iters * luks_opts.iter_time / 1000; 1159 1160 if (iters > UINT32_MAX) { 1161 error_setg_errno(errp, ERANGE, 1162 "PBKDF iterations %llu larger than %u", 1163 (unsigned long long)iters, UINT32_MAX); 1164 goto error; 1165 } 1166 1167 luks->header.key_slots[0].iterations = 1168 MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS); 1169 1170 1171 /* Generate a key that we'll use to encrypt the master 1172 * key, from the user's password 1173 */ 1174 slotkey = g_new0(uint8_t, luks->header.key_bytes); 1175 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1176 (uint8_t *)password, strlen(password), 1177 luks->header.key_slots[0].salt, 1178 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1179 luks->header.key_slots[0].iterations, 1180 slotkey, luks->header.key_bytes, 1181 errp) < 0) { 1182 goto error; 1183 } 1184 1185 1186 /* Setup the encryption objects needed to encrypt the 1187 * master key material 1188 */ 1189 cipher = qcrypto_cipher_new(luks_opts.cipher_alg, 1190 luks_opts.cipher_mode, 1191 slotkey, luks->header.key_bytes, 1192 errp); 1193 if (!cipher) { 1194 goto error; 1195 } 1196 1197 ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1198 ivcipheralg, 1199 luks_opts.ivgen_hash_alg, 1200 slotkey, luks->header.key_bytes, 1201 errp); 1202 if (!ivgen) { 1203 goto error; 1204 } 1205 1206 /* Before storing the master key, we need to vastly 1207 * increase its size, as protection against forensic 1208 * disk data recovery */ 1209 splitkey = g_new0(uint8_t, splitkeylen); 1210 1211 if (qcrypto_afsplit_encode(luks_opts.hash_alg, 1212 luks->header.key_bytes, 1213 luks->header.key_slots[0].stripes, 1214 masterkey, 1215 splitkey, 1216 errp) < 0) { 1217 goto error; 1218 } 1219 1220 /* Now we encrypt the split master key with the key generated 1221 * from the user's password, before storing it */ 1222 if (qcrypto_block_encrypt_helper(cipher, block->niv, ivgen, 1223 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1224 0, 1225 splitkey, 1226 splitkeylen, 1227 errp) < 0) { 1228 goto error; 1229 } 1230 1231 1232 /* The total size of the LUKS headers is the partition header + key 1233 * slot headers, rounded up to the nearest sector, combined with 1234 * the size of each master key material region, also rounded up 1235 * to the nearest sector */ 1236 luks->header.payload_offset = 1237 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1238 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1239 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1240 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1241 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * 1242 QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); 1243 1244 block->payload_offset = luks->header.payload_offset * 1245 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1246 1247 /* Reserve header space to match payload offset */ 1248 initfunc(block, opaque, block->payload_offset, &local_err); 1249 if (local_err) { 1250 error_propagate(errp, local_err); 1251 goto error; 1252 } 1253 1254 /* Everything on disk uses Big Endian, so flip header fields 1255 * before writing them */ 1256 cpu_to_be16s(&luks->header.version); 1257 cpu_to_be32s(&luks->header.payload_offset); 1258 cpu_to_be32s(&luks->header.key_bytes); 1259 cpu_to_be32s(&luks->header.master_key_iterations); 1260 1261 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1262 cpu_to_be32s(&luks->header.key_slots[i].active); 1263 cpu_to_be32s(&luks->header.key_slots[i].iterations); 1264 cpu_to_be32s(&luks->header.key_slots[i].key_offset); 1265 cpu_to_be32s(&luks->header.key_slots[i].stripes); 1266 } 1267 1268 1269 /* Write out the partition header and key slot headers */ 1270 writefunc(block, opaque, 0, 1271 (const uint8_t *)&luks->header, 1272 sizeof(luks->header), 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, opaque, 1299 luks->header.key_slots[0].key_offset * 1300 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1301 splitkey, splitkeylen, 1302 errp) != splitkeylen) { 1303 goto error; 1304 } 1305 1306 luks->cipher_alg = luks_opts.cipher_alg; 1307 luks->cipher_mode = luks_opts.cipher_mode; 1308 luks->ivgen_alg = luks_opts.ivgen_alg; 1309 luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg; 1310 luks->hash_alg = luks_opts.hash_alg; 1311 1312 memset(masterkey, 0, luks->header.key_bytes); 1313 g_free(masterkey); 1314 memset(slotkey, 0, luks->header.key_bytes); 1315 g_free(slotkey); 1316 g_free(splitkey); 1317 g_free(password); 1318 g_free(cipher_mode_spec); 1319 1320 qcrypto_ivgen_free(ivgen); 1321 qcrypto_cipher_free(cipher); 1322 1323 return 0; 1324 1325 error: 1326 if (masterkey) { 1327 memset(masterkey, 0, luks->header.key_bytes); 1328 } 1329 g_free(masterkey); 1330 if (slotkey) { 1331 memset(slotkey, 0, luks->header.key_bytes); 1332 } 1333 g_free(slotkey); 1334 g_free(splitkey); 1335 g_free(password); 1336 g_free(cipher_mode_spec); 1337 1338 qcrypto_ivgen_free(ivgen); 1339 qcrypto_cipher_free(cipher); 1340 1341 g_free(luks); 1342 return -1; 1343 } 1344 1345 1346 static int qcrypto_block_luks_get_info(QCryptoBlock *block, 1347 QCryptoBlockInfo *info, 1348 Error **errp) 1349 { 1350 QCryptoBlockLUKS *luks = block->opaque; 1351 QCryptoBlockInfoLUKSSlot *slot; 1352 QCryptoBlockInfoLUKSSlotList *slots = NULL, **prev = &info->u.luks.slots; 1353 size_t i; 1354 1355 info->u.luks.cipher_alg = luks->cipher_alg; 1356 info->u.luks.cipher_mode = luks->cipher_mode; 1357 info->u.luks.ivgen_alg = luks->ivgen_alg; 1358 if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 1359 info->u.luks.has_ivgen_hash_alg = true; 1360 info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg; 1361 } 1362 info->u.luks.hash_alg = luks->hash_alg; 1363 info->u.luks.payload_offset = block->payload_offset; 1364 info->u.luks.master_key_iters = luks->header.master_key_iterations; 1365 info->u.luks.uuid = g_strndup((const char *)luks->header.uuid, 1366 sizeof(luks->header.uuid)); 1367 1368 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1369 slots = g_new0(QCryptoBlockInfoLUKSSlotList, 1); 1370 *prev = slots; 1371 1372 slots->value = slot = g_new0(QCryptoBlockInfoLUKSSlot, 1); 1373 slot->active = luks->header.key_slots[i].active == 1374 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; 1375 slot->key_offset = luks->header.key_slots[i].key_offset 1376 * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1377 if (slot->active) { 1378 slot->has_iters = true; 1379 slot->iters = luks->header.key_slots[i].iterations; 1380 slot->has_stripes = true; 1381 slot->stripes = luks->header.key_slots[i].stripes; 1382 } 1383 1384 prev = &slots->next; 1385 } 1386 1387 return 0; 1388 } 1389 1390 1391 static void qcrypto_block_luks_cleanup(QCryptoBlock *block) 1392 { 1393 g_free(block->opaque); 1394 } 1395 1396 1397 static int 1398 qcrypto_block_luks_decrypt(QCryptoBlock *block, 1399 uint64_t startsector, 1400 uint8_t *buf, 1401 size_t len, 1402 Error **errp) 1403 { 1404 return qcrypto_block_decrypt_helper(block->cipher, 1405 block->niv, block->ivgen, 1406 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1407 startsector, buf, len, errp); 1408 } 1409 1410 1411 static int 1412 qcrypto_block_luks_encrypt(QCryptoBlock *block, 1413 uint64_t startsector, 1414 uint8_t *buf, 1415 size_t len, 1416 Error **errp) 1417 { 1418 return qcrypto_block_encrypt_helper(block->cipher, 1419 block->niv, block->ivgen, 1420 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1421 startsector, buf, len, errp); 1422 } 1423 1424 1425 const QCryptoBlockDriver qcrypto_block_driver_luks = { 1426 .open = qcrypto_block_luks_open, 1427 .create = qcrypto_block_luks_create, 1428 .get_info = qcrypto_block_luks_get_info, 1429 .cleanup = qcrypto_block_luks_cleanup, 1430 .decrypt = qcrypto_block_luks_decrypt, 1431 .encrypt = qcrypto_block_luks_encrypt, 1432 .has_format = qcrypto_block_luks_has_format, 1433 }; 1434