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 slot->key_offset * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 477 splitkey, splitkeylen, 478 errp, 479 opaque); 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, 0, 680 (uint8_t *)&luks->header, 681 sizeof(luks->header), 682 errp, 683 opaque); 684 if (rv < 0) { 685 ret = rv; 686 goto fail; 687 } 688 689 /* The header is always stored in big-endian format, so 690 * convert everything to native */ 691 be16_to_cpus(&luks->header.version); 692 be32_to_cpus(&luks->header.payload_offset); 693 be32_to_cpus(&luks->header.key_bytes); 694 be32_to_cpus(&luks->header.master_key_iterations); 695 696 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 697 be32_to_cpus(&luks->header.key_slots[i].active); 698 be32_to_cpus(&luks->header.key_slots[i].iterations); 699 be32_to_cpus(&luks->header.key_slots[i].key_offset); 700 be32_to_cpus(&luks->header.key_slots[i].stripes); 701 } 702 703 if (memcmp(luks->header.magic, qcrypto_block_luks_magic, 704 QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { 705 error_setg(errp, "Volume is not in LUKS format"); 706 ret = -EINVAL; 707 goto fail; 708 } 709 if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { 710 error_setg(errp, "LUKS version %" PRIu32 " is not supported", 711 luks->header.version); 712 ret = -ENOTSUP; 713 goto fail; 714 } 715 716 /* 717 * The cipher_mode header contains a string that we have 718 * to further parse, of the format 719 * 720 * <cipher-mode>-<iv-generator>[:<iv-hash>] 721 * 722 * eg cbc-essiv:sha256, cbc-plain64 723 */ 724 ivgen_name = strchr(luks->header.cipher_mode, '-'); 725 if (!ivgen_name) { 726 ret = -EINVAL; 727 error_setg(errp, "Unexpected cipher mode string format %s", 728 luks->header.cipher_mode); 729 goto fail; 730 } 731 *ivgen_name = '\0'; 732 ivgen_name++; 733 734 ivhash_name = strchr(ivgen_name, ':'); 735 if (!ivhash_name) { 736 ivhash = 0; 737 } else { 738 *ivhash_name = '\0'; 739 ivhash_name++; 740 741 ivhash = qcrypto_block_luks_hash_name_lookup(ivhash_name, 742 &local_err); 743 if (local_err) { 744 ret = -ENOTSUP; 745 error_propagate(errp, local_err); 746 goto fail; 747 } 748 } 749 750 ciphermode = qcrypto_block_luks_cipher_mode_lookup(luks->header.cipher_mode, 751 &local_err); 752 if (local_err) { 753 ret = -ENOTSUP; 754 error_propagate(errp, local_err); 755 goto fail; 756 } 757 758 cipheralg = qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, 759 ciphermode, 760 luks->header.key_bytes, 761 &local_err); 762 if (local_err) { 763 ret = -ENOTSUP; 764 error_propagate(errp, local_err); 765 goto fail; 766 } 767 768 hash = qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, 769 &local_err); 770 if (local_err) { 771 ret = -ENOTSUP; 772 error_propagate(errp, local_err); 773 goto fail; 774 } 775 776 ivalg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, 777 &local_err); 778 if (local_err) { 779 ret = -ENOTSUP; 780 error_propagate(errp, local_err); 781 goto fail; 782 } 783 784 if (ivalg == QCRYPTO_IVGEN_ALG_ESSIV) { 785 if (!ivhash_name) { 786 ret = -EINVAL; 787 error_setg(errp, "Missing IV generator hash specification"); 788 goto fail; 789 } 790 ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg, 791 ivhash, 792 &local_err); 793 if (local_err) { 794 ret = -ENOTSUP; 795 error_propagate(errp, local_err); 796 goto fail; 797 } 798 } else { 799 /* Note we parsed the ivhash_name earlier in the cipher_mode 800 * spec string even with plain/plain64 ivgens, but we 801 * will ignore it, since it is irrelevant for these ivgens. 802 * This is for compat with dm-crypt which will silently 803 * ignore hash names with these ivgens rather than report 804 * an error about the invalid usage 805 */ 806 ivcipheralg = cipheralg; 807 } 808 809 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { 810 /* Try to find which key slot our password is valid for 811 * and unlock the master key from that slot. 812 */ 813 if (qcrypto_block_luks_find_key(block, 814 password, 815 cipheralg, ciphermode, 816 hash, 817 ivalg, 818 ivcipheralg, 819 ivhash, 820 &masterkey, &masterkeylen, 821 readfunc, opaque, 822 errp) < 0) { 823 ret = -EACCES; 824 goto fail; 825 } 826 827 /* We have a valid master key now, so can setup the 828 * block device payload decryption objects 829 */ 830 block->kdfhash = hash; 831 block->niv = qcrypto_cipher_get_iv_len(cipheralg, 832 ciphermode); 833 block->ivgen = qcrypto_ivgen_new(ivalg, 834 ivcipheralg, 835 ivhash, 836 masterkey, masterkeylen, 837 errp); 838 if (!block->ivgen) { 839 ret = -ENOTSUP; 840 goto fail; 841 } 842 843 block->cipher = qcrypto_cipher_new(cipheralg, 844 ciphermode, 845 masterkey, masterkeylen, 846 errp); 847 if (!block->cipher) { 848 ret = -ENOTSUP; 849 goto fail; 850 } 851 } 852 853 block->payload_offset = luks->header.payload_offset * 854 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 855 856 luks->cipher_alg = cipheralg; 857 luks->cipher_mode = ciphermode; 858 luks->ivgen_alg = ivalg; 859 luks->ivgen_hash_alg = ivhash; 860 luks->hash_alg = hash; 861 862 g_free(masterkey); 863 g_free(password); 864 865 return 0; 866 867 fail: 868 g_free(masterkey); 869 qcrypto_cipher_free(block->cipher); 870 qcrypto_ivgen_free(block->ivgen); 871 g_free(luks); 872 g_free(password); 873 return ret; 874 } 875 876 877 static void 878 qcrypto_block_luks_uuid_gen(uint8_t *uuidstr) 879 { 880 QemuUUID uuid; 881 qemu_uuid_generate(&uuid); 882 qemu_uuid_unparse(&uuid, (char *)uuidstr); 883 } 884 885 static int 886 qcrypto_block_luks_create(QCryptoBlock *block, 887 QCryptoBlockCreateOptions *options, 888 QCryptoBlockInitFunc initfunc, 889 QCryptoBlockWriteFunc writefunc, 890 void *opaque, 891 Error **errp) 892 { 893 QCryptoBlockLUKS *luks; 894 QCryptoBlockCreateOptionsLUKS luks_opts; 895 Error *local_err = NULL; 896 uint8_t *masterkey = NULL; 897 uint8_t *slotkey = NULL; 898 uint8_t *splitkey = NULL; 899 size_t splitkeylen = 0; 900 size_t i; 901 QCryptoCipher *cipher = NULL; 902 QCryptoIVGen *ivgen = NULL; 903 char *password; 904 const char *cipher_alg; 905 const char *cipher_mode; 906 const char *ivgen_alg; 907 const char *ivgen_hash_alg = NULL; 908 const char *hash_alg; 909 char *cipher_mode_spec = NULL; 910 QCryptoCipherAlgorithm ivcipheralg = 0; 911 uint64_t iters; 912 913 memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts)); 914 if (!luks_opts.has_iter_time) { 915 luks_opts.iter_time = 2000; 916 } 917 if (!luks_opts.has_cipher_alg) { 918 luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256; 919 } 920 if (!luks_opts.has_cipher_mode) { 921 luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS; 922 } 923 if (!luks_opts.has_ivgen_alg) { 924 luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64; 925 } 926 if (!luks_opts.has_hash_alg) { 927 luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256; 928 } 929 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 930 if (!luks_opts.has_ivgen_hash_alg) { 931 luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256; 932 luks_opts.has_ivgen_hash_alg = true; 933 } 934 } 935 /* Note we're allowing ivgen_hash_alg to be set even for 936 * non-essiv iv generators that don't need a hash. It will 937 * be silently ignored, for compatibility with dm-crypt */ 938 939 if (!options->u.luks.key_secret) { 940 error_setg(errp, "Parameter 'key-secret' is required for cipher"); 941 return -1; 942 } 943 password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp); 944 if (!password) { 945 return -1; 946 } 947 948 luks = g_new0(QCryptoBlockLUKS, 1); 949 block->opaque = luks; 950 951 memcpy(luks->header.magic, qcrypto_block_luks_magic, 952 QCRYPTO_BLOCK_LUKS_MAGIC_LEN); 953 954 /* We populate the header in native endianness initially and 955 * then convert everything to big endian just before writing 956 * it out to disk 957 */ 958 luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION; 959 qcrypto_block_luks_uuid_gen(luks->header.uuid); 960 961 cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg, 962 errp); 963 if (!cipher_alg) { 964 goto error; 965 } 966 967 cipher_mode = QCryptoCipherMode_lookup[luks_opts.cipher_mode]; 968 ivgen_alg = QCryptoIVGenAlgorithm_lookup[luks_opts.ivgen_alg]; 969 if (luks_opts.has_ivgen_hash_alg) { 970 ivgen_hash_alg = QCryptoHashAlgorithm_lookup[luks_opts.ivgen_hash_alg]; 971 cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg, 972 ivgen_hash_alg); 973 } else { 974 cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg); 975 } 976 hash_alg = QCryptoHashAlgorithm_lookup[luks_opts.hash_alg]; 977 978 979 if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) { 980 error_setg(errp, "Cipher name '%s' is too long for LUKS header", 981 cipher_alg); 982 goto error; 983 } 984 if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) { 985 error_setg(errp, "Cipher mode '%s' is too long for LUKS header", 986 cipher_mode_spec); 987 goto error; 988 } 989 if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) { 990 error_setg(errp, "Hash name '%s' is too long for LUKS header", 991 hash_alg); 992 goto error; 993 } 994 995 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 996 ivcipheralg = qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg, 997 luks_opts.ivgen_hash_alg, 998 &local_err); 999 if (local_err) { 1000 error_propagate(errp, local_err); 1001 goto error; 1002 } 1003 } else { 1004 ivcipheralg = luks_opts.cipher_alg; 1005 } 1006 1007 strcpy(luks->header.cipher_name, cipher_alg); 1008 strcpy(luks->header.cipher_mode, cipher_mode_spec); 1009 strcpy(luks->header.hash_spec, hash_alg); 1010 1011 luks->header.key_bytes = qcrypto_cipher_get_key_len(luks_opts.cipher_alg); 1012 if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) { 1013 luks->header.key_bytes *= 2; 1014 } 1015 1016 /* Generate the salt used for hashing the master key 1017 * with PBKDF later 1018 */ 1019 if (qcrypto_random_bytes(luks->header.master_key_salt, 1020 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1021 errp) < 0) { 1022 goto error; 1023 } 1024 1025 /* Generate random master key */ 1026 masterkey = g_new0(uint8_t, luks->header.key_bytes); 1027 if (qcrypto_random_bytes(masterkey, 1028 luks->header.key_bytes, errp) < 0) { 1029 goto error; 1030 } 1031 1032 1033 /* Setup the block device payload encryption objects */ 1034 block->cipher = qcrypto_cipher_new(luks_opts.cipher_alg, 1035 luks_opts.cipher_mode, 1036 masterkey, luks->header.key_bytes, 1037 errp); 1038 if (!block->cipher) { 1039 goto error; 1040 } 1041 1042 block->kdfhash = luks_opts.hash_alg; 1043 block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg, 1044 luks_opts.cipher_mode); 1045 block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1046 ivcipheralg, 1047 luks_opts.ivgen_hash_alg, 1048 masterkey, luks->header.key_bytes, 1049 errp); 1050 1051 if (!block->ivgen) { 1052 goto error; 1053 } 1054 1055 1056 /* Determine how many iterations we need to hash the master 1057 * key, in order to have 1 second of compute time used 1058 */ 1059 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1060 masterkey, luks->header.key_bytes, 1061 luks->header.master_key_salt, 1062 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1063 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1064 &local_err); 1065 if (local_err) { 1066 error_propagate(errp, local_err); 1067 goto error; 1068 } 1069 1070 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1071 error_setg_errno(errp, ERANGE, 1072 "PBKDF iterations %llu too large to scale", 1073 (unsigned long long)iters); 1074 goto error; 1075 } 1076 1077 /* iter_time was in millis, but count_iters reported for secs */ 1078 iters = iters * luks_opts.iter_time / 1000; 1079 1080 /* Why /= 8 ? That matches cryptsetup, but there's no 1081 * explanation why they chose /= 8... Probably so that 1082 * if all 8 keyslots are active we only spend 1 second 1083 * in total time to check all keys */ 1084 iters /= 8; 1085 if (iters > UINT32_MAX) { 1086 error_setg_errno(errp, ERANGE, 1087 "PBKDF iterations %llu larger than %u", 1088 (unsigned long long)iters, UINT32_MAX); 1089 goto error; 1090 } 1091 iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS); 1092 luks->header.master_key_iterations = iters; 1093 1094 /* Hash the master key, saving the result in the LUKS 1095 * header. This hash is used when opening the encrypted 1096 * device to verify that the user password unlocked a 1097 * valid master key 1098 */ 1099 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1100 masterkey, luks->header.key_bytes, 1101 luks->header.master_key_salt, 1102 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1103 luks->header.master_key_iterations, 1104 luks->header.master_key_digest, 1105 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1106 errp) < 0) { 1107 goto error; 1108 } 1109 1110 1111 /* Although LUKS has multiple key slots, we're just going 1112 * to use the first key slot */ 1113 splitkeylen = luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRIPES; 1114 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1115 luks->header.key_slots[i].active = i == 0 ? 1116 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED : 1117 QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; 1118 luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES; 1119 1120 /* This calculation doesn't match that shown in the spec, 1121 * but instead follows the cryptsetup implementation. 1122 */ 1123 luks->header.key_slots[i].key_offset = 1124 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1125 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1126 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1127 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1128 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i); 1129 } 1130 1131 if (qcrypto_random_bytes(luks->header.key_slots[0].salt, 1132 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1133 errp) < 0) { 1134 goto error; 1135 } 1136 1137 /* Again we determine how many iterations are required to 1138 * hash the user password while consuming 1 second of compute 1139 * time */ 1140 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1141 (uint8_t *)password, strlen(password), 1142 luks->header.key_slots[0].salt, 1143 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1144 luks->header.key_bytes, 1145 &local_err); 1146 if (local_err) { 1147 error_propagate(errp, local_err); 1148 goto error; 1149 } 1150 1151 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1152 error_setg_errno(errp, ERANGE, 1153 "PBKDF iterations %llu too large to scale", 1154 (unsigned long long)iters); 1155 goto error; 1156 } 1157 1158 /* iter_time was in millis, but count_iters reported for secs */ 1159 iters = iters * luks_opts.iter_time / 1000; 1160 1161 if (iters > UINT32_MAX) { 1162 error_setg_errno(errp, ERANGE, 1163 "PBKDF iterations %llu larger than %u", 1164 (unsigned long long)iters, UINT32_MAX); 1165 goto error; 1166 } 1167 1168 luks->header.key_slots[0].iterations = 1169 MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS); 1170 1171 1172 /* Generate a key that we'll use to encrypt the master 1173 * key, from the user's password 1174 */ 1175 slotkey = g_new0(uint8_t, luks->header.key_bytes); 1176 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1177 (uint8_t *)password, strlen(password), 1178 luks->header.key_slots[0].salt, 1179 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1180 luks->header.key_slots[0].iterations, 1181 slotkey, luks->header.key_bytes, 1182 errp) < 0) { 1183 goto error; 1184 } 1185 1186 1187 /* Setup the encryption objects needed to encrypt the 1188 * master key material 1189 */ 1190 cipher = qcrypto_cipher_new(luks_opts.cipher_alg, 1191 luks_opts.cipher_mode, 1192 slotkey, luks->header.key_bytes, 1193 errp); 1194 if (!cipher) { 1195 goto error; 1196 } 1197 1198 ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1199 ivcipheralg, 1200 luks_opts.ivgen_hash_alg, 1201 slotkey, luks->header.key_bytes, 1202 errp); 1203 if (!ivgen) { 1204 goto error; 1205 } 1206 1207 /* Before storing the master key, we need to vastly 1208 * increase its size, as protection against forensic 1209 * disk data recovery */ 1210 splitkey = g_new0(uint8_t, splitkeylen); 1211 1212 if (qcrypto_afsplit_encode(luks_opts.hash_alg, 1213 luks->header.key_bytes, 1214 luks->header.key_slots[0].stripes, 1215 masterkey, 1216 splitkey, 1217 errp) < 0) { 1218 goto error; 1219 } 1220 1221 /* Now we encrypt the split master key with the key generated 1222 * from the user's password, before storing it */ 1223 if (qcrypto_block_encrypt_helper(cipher, block->niv, ivgen, 1224 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1225 0, 1226 splitkey, 1227 splitkeylen, 1228 errp) < 0) { 1229 goto error; 1230 } 1231 1232 1233 /* The total size of the LUKS headers is the partition header + key 1234 * slot headers, rounded up to the nearest sector, combined with 1235 * the size of each master key material region, also rounded up 1236 * to the nearest sector */ 1237 luks->header.payload_offset = 1238 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1239 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1240 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1241 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1242 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * 1243 QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); 1244 1245 block->payload_offset = luks->header.payload_offset * 1246 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1247 1248 /* Reserve header space to match payload offset */ 1249 initfunc(block, block->payload_offset, &local_err, opaque); 1250 if (local_err) { 1251 error_propagate(errp, local_err); 1252 goto error; 1253 } 1254 1255 /* Everything on disk uses Big Endian, so flip header fields 1256 * before writing them */ 1257 cpu_to_be16s(&luks->header.version); 1258 cpu_to_be32s(&luks->header.payload_offset); 1259 cpu_to_be32s(&luks->header.key_bytes); 1260 cpu_to_be32s(&luks->header.master_key_iterations); 1261 1262 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1263 cpu_to_be32s(&luks->header.key_slots[i].active); 1264 cpu_to_be32s(&luks->header.key_slots[i].iterations); 1265 cpu_to_be32s(&luks->header.key_slots[i].key_offset); 1266 cpu_to_be32s(&luks->header.key_slots[i].stripes); 1267 } 1268 1269 1270 /* Write out the partition header and key slot headers */ 1271 writefunc(block, 0, 1272 (const uint8_t *)&luks->header, 1273 sizeof(luks->header), 1274 &local_err, 1275 opaque); 1276 1277 /* Delay checking local_err until we've byte-swapped */ 1278 1279 /* Byte swap the header back to native, in case we need 1280 * to read it again later */ 1281 be16_to_cpus(&luks->header.version); 1282 be32_to_cpus(&luks->header.payload_offset); 1283 be32_to_cpus(&luks->header.key_bytes); 1284 be32_to_cpus(&luks->header.master_key_iterations); 1285 1286 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1287 be32_to_cpus(&luks->header.key_slots[i].active); 1288 be32_to_cpus(&luks->header.key_slots[i].iterations); 1289 be32_to_cpus(&luks->header.key_slots[i].key_offset); 1290 be32_to_cpus(&luks->header.key_slots[i].stripes); 1291 } 1292 1293 if (local_err) { 1294 error_propagate(errp, local_err); 1295 goto error; 1296 } 1297 1298 /* Write out the master key material, starting at the 1299 * sector immediately following the partition header. */ 1300 if (writefunc(block, 1301 luks->header.key_slots[0].key_offset * 1302 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1303 splitkey, splitkeylen, 1304 errp, 1305 opaque) != splitkeylen) { 1306 goto error; 1307 } 1308 1309 luks->cipher_alg = luks_opts.cipher_alg; 1310 luks->cipher_mode = luks_opts.cipher_mode; 1311 luks->ivgen_alg = luks_opts.ivgen_alg; 1312 luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg; 1313 luks->hash_alg = luks_opts.hash_alg; 1314 1315 memset(masterkey, 0, luks->header.key_bytes); 1316 g_free(masterkey); 1317 memset(slotkey, 0, luks->header.key_bytes); 1318 g_free(slotkey); 1319 g_free(splitkey); 1320 g_free(password); 1321 g_free(cipher_mode_spec); 1322 1323 qcrypto_ivgen_free(ivgen); 1324 qcrypto_cipher_free(cipher); 1325 1326 return 0; 1327 1328 error: 1329 if (masterkey) { 1330 memset(masterkey, 0, luks->header.key_bytes); 1331 } 1332 g_free(masterkey); 1333 if (slotkey) { 1334 memset(slotkey, 0, luks->header.key_bytes); 1335 } 1336 g_free(slotkey); 1337 g_free(splitkey); 1338 g_free(password); 1339 g_free(cipher_mode_spec); 1340 1341 qcrypto_ivgen_free(ivgen); 1342 qcrypto_cipher_free(cipher); 1343 1344 g_free(luks); 1345 return -1; 1346 } 1347 1348 1349 static int qcrypto_block_luks_get_info(QCryptoBlock *block, 1350 QCryptoBlockInfo *info, 1351 Error **errp) 1352 { 1353 QCryptoBlockLUKS *luks = block->opaque; 1354 QCryptoBlockInfoLUKSSlot *slot; 1355 QCryptoBlockInfoLUKSSlotList *slots = NULL, **prev = &info->u.luks.slots; 1356 size_t i; 1357 1358 info->u.luks.cipher_alg = luks->cipher_alg; 1359 info->u.luks.cipher_mode = luks->cipher_mode; 1360 info->u.luks.ivgen_alg = luks->ivgen_alg; 1361 if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 1362 info->u.luks.has_ivgen_hash_alg = true; 1363 info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg; 1364 } 1365 info->u.luks.hash_alg = luks->hash_alg; 1366 info->u.luks.payload_offset = block->payload_offset; 1367 info->u.luks.master_key_iters = luks->header.master_key_iterations; 1368 info->u.luks.uuid = g_strndup((const char *)luks->header.uuid, 1369 sizeof(luks->header.uuid)); 1370 1371 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1372 slots = g_new0(QCryptoBlockInfoLUKSSlotList, 1); 1373 *prev = slots; 1374 1375 slots->value = slot = g_new0(QCryptoBlockInfoLUKSSlot, 1); 1376 slot->active = luks->header.key_slots[i].active == 1377 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; 1378 slot->key_offset = luks->header.key_slots[i].key_offset 1379 * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1380 if (slot->active) { 1381 slot->has_iters = true; 1382 slot->iters = luks->header.key_slots[i].iterations; 1383 slot->has_stripes = true; 1384 slot->stripes = luks->header.key_slots[i].stripes; 1385 } 1386 1387 prev = &slots->next; 1388 } 1389 1390 return 0; 1391 } 1392 1393 1394 static void qcrypto_block_luks_cleanup(QCryptoBlock *block) 1395 { 1396 g_free(block->opaque); 1397 } 1398 1399 1400 static int 1401 qcrypto_block_luks_decrypt(QCryptoBlock *block, 1402 uint64_t startsector, 1403 uint8_t *buf, 1404 size_t len, 1405 Error **errp) 1406 { 1407 return qcrypto_block_decrypt_helper(block->cipher, 1408 block->niv, block->ivgen, 1409 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1410 startsector, buf, len, errp); 1411 } 1412 1413 1414 static int 1415 qcrypto_block_luks_encrypt(QCryptoBlock *block, 1416 uint64_t startsector, 1417 uint8_t *buf, 1418 size_t len, 1419 Error **errp) 1420 { 1421 return qcrypto_block_encrypt_helper(block->cipher, 1422 block->niv, block->ivgen, 1423 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1424 startsector, buf, len, errp); 1425 } 1426 1427 1428 const QCryptoBlockDriver qcrypto_block_driver_luks = { 1429 .open = qcrypto_block_luks_open, 1430 .create = qcrypto_block_luks_create, 1431 .get_info = qcrypto_block_luks_get_info, 1432 .cleanup = qcrypto_block_luks_cleanup, 1433 .decrypt = qcrypto_block_luks_decrypt, 1434 .encrypt = qcrypto_block_luks_encrypt, 1435 .has_format = qcrypto_block_luks_has_format, 1436 }; 1437