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 opaque, 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 const char *optprefix, 642 QCryptoBlockReadFunc readfunc, 643 void *opaque, 644 unsigned int flags, 645 Error **errp) 646 { 647 QCryptoBlockLUKS *luks; 648 Error *local_err = NULL; 649 int ret = 0; 650 size_t i; 651 ssize_t rv; 652 uint8_t *masterkey = NULL; 653 size_t masterkeylen; 654 char *ivgen_name, *ivhash_name; 655 QCryptoCipherMode ciphermode; 656 QCryptoCipherAlgorithm cipheralg; 657 QCryptoIVGenAlgorithm ivalg; 658 QCryptoCipherAlgorithm ivcipheralg; 659 QCryptoHashAlgorithm hash; 660 QCryptoHashAlgorithm ivhash; 661 char *password = NULL; 662 663 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { 664 if (!options->u.luks.key_secret) { 665 error_setg(errp, "Parameter '%skey-secret' is required for cipher", 666 optprefix ? optprefix : ""); 667 return -1; 668 } 669 password = qcrypto_secret_lookup_as_utf8( 670 options->u.luks.key_secret, errp); 671 if (!password) { 672 return -1; 673 } 674 } 675 676 luks = g_new0(QCryptoBlockLUKS, 1); 677 block->opaque = luks; 678 679 /* Read the entire LUKS header, minus the key material from 680 * the underlying device */ 681 rv = readfunc(block, 0, 682 (uint8_t *)&luks->header, 683 sizeof(luks->header), 684 opaque, 685 errp); 686 if (rv < 0) { 687 ret = rv; 688 goto fail; 689 } 690 691 /* The header is always stored in big-endian format, so 692 * convert everything to native */ 693 be16_to_cpus(&luks->header.version); 694 be32_to_cpus(&luks->header.payload_offset); 695 be32_to_cpus(&luks->header.key_bytes); 696 be32_to_cpus(&luks->header.master_key_iterations); 697 698 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 699 be32_to_cpus(&luks->header.key_slots[i].active); 700 be32_to_cpus(&luks->header.key_slots[i].iterations); 701 be32_to_cpus(&luks->header.key_slots[i].key_offset); 702 be32_to_cpus(&luks->header.key_slots[i].stripes); 703 } 704 705 if (memcmp(luks->header.magic, qcrypto_block_luks_magic, 706 QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) { 707 error_setg(errp, "Volume is not in LUKS format"); 708 ret = -EINVAL; 709 goto fail; 710 } 711 if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) { 712 error_setg(errp, "LUKS version %" PRIu32 " is not supported", 713 luks->header.version); 714 ret = -ENOTSUP; 715 goto fail; 716 } 717 718 /* 719 * The cipher_mode header contains a string that we have 720 * to further parse, of the format 721 * 722 * <cipher-mode>-<iv-generator>[:<iv-hash>] 723 * 724 * eg cbc-essiv:sha256, cbc-plain64 725 */ 726 ivgen_name = strchr(luks->header.cipher_mode, '-'); 727 if (!ivgen_name) { 728 ret = -EINVAL; 729 error_setg(errp, "Unexpected cipher mode string format %s", 730 luks->header.cipher_mode); 731 goto fail; 732 } 733 *ivgen_name = '\0'; 734 ivgen_name++; 735 736 ivhash_name = strchr(ivgen_name, ':'); 737 if (!ivhash_name) { 738 ivhash = 0; 739 } else { 740 *ivhash_name = '\0'; 741 ivhash_name++; 742 743 ivhash = qcrypto_block_luks_hash_name_lookup(ivhash_name, 744 &local_err); 745 if (local_err) { 746 ret = -ENOTSUP; 747 error_propagate(errp, local_err); 748 goto fail; 749 } 750 } 751 752 ciphermode = qcrypto_block_luks_cipher_mode_lookup(luks->header.cipher_mode, 753 &local_err); 754 if (local_err) { 755 ret = -ENOTSUP; 756 error_propagate(errp, local_err); 757 goto fail; 758 } 759 760 cipheralg = qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name, 761 ciphermode, 762 luks->header.key_bytes, 763 &local_err); 764 if (local_err) { 765 ret = -ENOTSUP; 766 error_propagate(errp, local_err); 767 goto fail; 768 } 769 770 hash = qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec, 771 &local_err); 772 if (local_err) { 773 ret = -ENOTSUP; 774 error_propagate(errp, local_err); 775 goto fail; 776 } 777 778 ivalg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name, 779 &local_err); 780 if (local_err) { 781 ret = -ENOTSUP; 782 error_propagate(errp, local_err); 783 goto fail; 784 } 785 786 if (ivalg == QCRYPTO_IVGEN_ALG_ESSIV) { 787 if (!ivhash_name) { 788 ret = -EINVAL; 789 error_setg(errp, "Missing IV generator hash specification"); 790 goto fail; 791 } 792 ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg, 793 ivhash, 794 &local_err); 795 if (local_err) { 796 ret = -ENOTSUP; 797 error_propagate(errp, local_err); 798 goto fail; 799 } 800 } else { 801 /* Note we parsed the ivhash_name earlier in the cipher_mode 802 * spec string even with plain/plain64 ivgens, but we 803 * will ignore it, since it is irrelevant for these ivgens. 804 * This is for compat with dm-crypt which will silently 805 * ignore hash names with these ivgens rather than report 806 * an error about the invalid usage 807 */ 808 ivcipheralg = cipheralg; 809 } 810 811 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) { 812 /* Try to find which key slot our password is valid for 813 * and unlock the master key from that slot. 814 */ 815 if (qcrypto_block_luks_find_key(block, 816 password, 817 cipheralg, ciphermode, 818 hash, 819 ivalg, 820 ivcipheralg, 821 ivhash, 822 &masterkey, &masterkeylen, 823 readfunc, opaque, 824 errp) < 0) { 825 ret = -EACCES; 826 goto fail; 827 } 828 829 /* We have a valid master key now, so can setup the 830 * block device payload decryption objects 831 */ 832 block->kdfhash = hash; 833 block->niv = qcrypto_cipher_get_iv_len(cipheralg, 834 ciphermode); 835 block->ivgen = qcrypto_ivgen_new(ivalg, 836 ivcipheralg, 837 ivhash, 838 masterkey, masterkeylen, 839 errp); 840 if (!block->ivgen) { 841 ret = -ENOTSUP; 842 goto fail; 843 } 844 845 block->cipher = qcrypto_cipher_new(cipheralg, 846 ciphermode, 847 masterkey, masterkeylen, 848 errp); 849 if (!block->cipher) { 850 ret = -ENOTSUP; 851 goto fail; 852 } 853 } 854 855 block->payload_offset = luks->header.payload_offset * 856 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 857 858 luks->cipher_alg = cipheralg; 859 luks->cipher_mode = ciphermode; 860 luks->ivgen_alg = ivalg; 861 luks->ivgen_hash_alg = ivhash; 862 luks->hash_alg = hash; 863 864 g_free(masterkey); 865 g_free(password); 866 867 return 0; 868 869 fail: 870 g_free(masterkey); 871 qcrypto_cipher_free(block->cipher); 872 qcrypto_ivgen_free(block->ivgen); 873 g_free(luks); 874 g_free(password); 875 return ret; 876 } 877 878 879 static void 880 qcrypto_block_luks_uuid_gen(uint8_t *uuidstr) 881 { 882 QemuUUID uuid; 883 qemu_uuid_generate(&uuid); 884 qemu_uuid_unparse(&uuid, (char *)uuidstr); 885 } 886 887 static int 888 qcrypto_block_luks_create(QCryptoBlock *block, 889 QCryptoBlockCreateOptions *options, 890 const char *optprefix, 891 QCryptoBlockInitFunc initfunc, 892 QCryptoBlockWriteFunc writefunc, 893 void *opaque, 894 Error **errp) 895 { 896 QCryptoBlockLUKS *luks; 897 QCryptoBlockCreateOptionsLUKS luks_opts; 898 Error *local_err = NULL; 899 uint8_t *masterkey = NULL; 900 uint8_t *slotkey = NULL; 901 uint8_t *splitkey = NULL; 902 size_t splitkeylen = 0; 903 size_t i; 904 QCryptoCipher *cipher = NULL; 905 QCryptoIVGen *ivgen = NULL; 906 char *password; 907 const char *cipher_alg; 908 const char *cipher_mode; 909 const char *ivgen_alg; 910 const char *ivgen_hash_alg = NULL; 911 const char *hash_alg; 912 char *cipher_mode_spec = NULL; 913 QCryptoCipherAlgorithm ivcipheralg = 0; 914 uint64_t iters; 915 916 memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts)); 917 if (!luks_opts.has_iter_time) { 918 luks_opts.iter_time = 2000; 919 } 920 if (!luks_opts.has_cipher_alg) { 921 luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256; 922 } 923 if (!luks_opts.has_cipher_mode) { 924 luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS; 925 } 926 if (!luks_opts.has_ivgen_alg) { 927 luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64; 928 } 929 if (!luks_opts.has_hash_alg) { 930 luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256; 931 } 932 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 933 if (!luks_opts.has_ivgen_hash_alg) { 934 luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256; 935 luks_opts.has_ivgen_hash_alg = true; 936 } 937 } 938 /* Note we're allowing ivgen_hash_alg to be set even for 939 * non-essiv iv generators that don't need a hash. It will 940 * be silently ignored, for compatibility with dm-crypt */ 941 942 if (!options->u.luks.key_secret) { 943 error_setg(errp, "Parameter '%skey-secret' is required for cipher", 944 optprefix ? optprefix : ""); 945 return -1; 946 } 947 password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp); 948 if (!password) { 949 return -1; 950 } 951 952 luks = g_new0(QCryptoBlockLUKS, 1); 953 block->opaque = luks; 954 955 memcpy(luks->header.magic, qcrypto_block_luks_magic, 956 QCRYPTO_BLOCK_LUKS_MAGIC_LEN); 957 958 /* We populate the header in native endianness initially and 959 * then convert everything to big endian just before writing 960 * it out to disk 961 */ 962 luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION; 963 qcrypto_block_luks_uuid_gen(luks->header.uuid); 964 965 cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg, 966 errp); 967 if (!cipher_alg) { 968 goto error; 969 } 970 971 cipher_mode = QCryptoCipherMode_lookup[luks_opts.cipher_mode]; 972 ivgen_alg = QCryptoIVGenAlgorithm_lookup[luks_opts.ivgen_alg]; 973 if (luks_opts.has_ivgen_hash_alg) { 974 ivgen_hash_alg = QCryptoHashAlgorithm_lookup[luks_opts.ivgen_hash_alg]; 975 cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg, 976 ivgen_hash_alg); 977 } else { 978 cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg); 979 } 980 hash_alg = QCryptoHashAlgorithm_lookup[luks_opts.hash_alg]; 981 982 983 if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) { 984 error_setg(errp, "Cipher name '%s' is too long for LUKS header", 985 cipher_alg); 986 goto error; 987 } 988 if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) { 989 error_setg(errp, "Cipher mode '%s' is too long for LUKS header", 990 cipher_mode_spec); 991 goto error; 992 } 993 if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) { 994 error_setg(errp, "Hash name '%s' is too long for LUKS header", 995 hash_alg); 996 goto error; 997 } 998 999 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 1000 ivcipheralg = qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg, 1001 luks_opts.ivgen_hash_alg, 1002 &local_err); 1003 if (local_err) { 1004 error_propagate(errp, local_err); 1005 goto error; 1006 } 1007 } else { 1008 ivcipheralg = luks_opts.cipher_alg; 1009 } 1010 1011 strcpy(luks->header.cipher_name, cipher_alg); 1012 strcpy(luks->header.cipher_mode, cipher_mode_spec); 1013 strcpy(luks->header.hash_spec, hash_alg); 1014 1015 luks->header.key_bytes = qcrypto_cipher_get_key_len(luks_opts.cipher_alg); 1016 if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) { 1017 luks->header.key_bytes *= 2; 1018 } 1019 1020 /* Generate the salt used for hashing the master key 1021 * with PBKDF later 1022 */ 1023 if (qcrypto_random_bytes(luks->header.master_key_salt, 1024 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1025 errp) < 0) { 1026 goto error; 1027 } 1028 1029 /* Generate random master key */ 1030 masterkey = g_new0(uint8_t, luks->header.key_bytes); 1031 if (qcrypto_random_bytes(masterkey, 1032 luks->header.key_bytes, errp) < 0) { 1033 goto error; 1034 } 1035 1036 1037 /* Setup the block device payload encryption objects */ 1038 block->cipher = qcrypto_cipher_new(luks_opts.cipher_alg, 1039 luks_opts.cipher_mode, 1040 masterkey, luks->header.key_bytes, 1041 errp); 1042 if (!block->cipher) { 1043 goto error; 1044 } 1045 1046 block->kdfhash = luks_opts.hash_alg; 1047 block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg, 1048 luks_opts.cipher_mode); 1049 block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1050 ivcipheralg, 1051 luks_opts.ivgen_hash_alg, 1052 masterkey, luks->header.key_bytes, 1053 errp); 1054 1055 if (!block->ivgen) { 1056 goto error; 1057 } 1058 1059 1060 /* Determine how many iterations we need to hash the master 1061 * key, in order to have 1 second of compute time used 1062 */ 1063 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1064 masterkey, luks->header.key_bytes, 1065 luks->header.master_key_salt, 1066 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1067 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1068 &local_err); 1069 if (local_err) { 1070 error_propagate(errp, local_err); 1071 goto error; 1072 } 1073 1074 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1075 error_setg_errno(errp, ERANGE, 1076 "PBKDF iterations %llu too large to scale", 1077 (unsigned long long)iters); 1078 goto error; 1079 } 1080 1081 /* iter_time was in millis, but count_iters reported for secs */ 1082 iters = iters * luks_opts.iter_time / 1000; 1083 1084 /* Why /= 8 ? That matches cryptsetup, but there's no 1085 * explanation why they chose /= 8... Probably so that 1086 * if all 8 keyslots are active we only spend 1 second 1087 * in total time to check all keys */ 1088 iters /= 8; 1089 if (iters > UINT32_MAX) { 1090 error_setg_errno(errp, ERANGE, 1091 "PBKDF iterations %llu larger than %u", 1092 (unsigned long long)iters, UINT32_MAX); 1093 goto error; 1094 } 1095 iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS); 1096 luks->header.master_key_iterations = iters; 1097 1098 /* Hash the master key, saving the result in the LUKS 1099 * header. This hash is used when opening the encrypted 1100 * device to verify that the user password unlocked a 1101 * valid master key 1102 */ 1103 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1104 masterkey, luks->header.key_bytes, 1105 luks->header.master_key_salt, 1106 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1107 luks->header.master_key_iterations, 1108 luks->header.master_key_digest, 1109 QCRYPTO_BLOCK_LUKS_DIGEST_LEN, 1110 errp) < 0) { 1111 goto error; 1112 } 1113 1114 1115 /* Although LUKS has multiple key slots, we're just going 1116 * to use the first key slot */ 1117 splitkeylen = luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRIPES; 1118 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1119 luks->header.key_slots[i].active = i == 0 ? 1120 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED : 1121 QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED; 1122 luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES; 1123 1124 /* This calculation doesn't match that shown in the spec, 1125 * but instead follows the cryptsetup implementation. 1126 */ 1127 luks->header.key_slots[i].key_offset = 1128 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1129 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1130 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1131 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1132 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i); 1133 } 1134 1135 if (qcrypto_random_bytes(luks->header.key_slots[0].salt, 1136 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1137 errp) < 0) { 1138 goto error; 1139 } 1140 1141 /* Again we determine how many iterations are required to 1142 * hash the user password while consuming 1 second of compute 1143 * time */ 1144 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg, 1145 (uint8_t *)password, strlen(password), 1146 luks->header.key_slots[0].salt, 1147 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1148 luks->header.key_bytes, 1149 &local_err); 1150 if (local_err) { 1151 error_propagate(errp, local_err); 1152 goto error; 1153 } 1154 1155 if (iters > (ULLONG_MAX / luks_opts.iter_time)) { 1156 error_setg_errno(errp, ERANGE, 1157 "PBKDF iterations %llu too large to scale", 1158 (unsigned long long)iters); 1159 goto error; 1160 } 1161 1162 /* iter_time was in millis, but count_iters reported for secs */ 1163 iters = iters * luks_opts.iter_time / 1000; 1164 1165 if (iters > UINT32_MAX) { 1166 error_setg_errno(errp, ERANGE, 1167 "PBKDF iterations %llu larger than %u", 1168 (unsigned long long)iters, UINT32_MAX); 1169 goto error; 1170 } 1171 1172 luks->header.key_slots[0].iterations = 1173 MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS); 1174 1175 1176 /* Generate a key that we'll use to encrypt the master 1177 * key, from the user's password 1178 */ 1179 slotkey = g_new0(uint8_t, luks->header.key_bytes); 1180 if (qcrypto_pbkdf2(luks_opts.hash_alg, 1181 (uint8_t *)password, strlen(password), 1182 luks->header.key_slots[0].salt, 1183 QCRYPTO_BLOCK_LUKS_SALT_LEN, 1184 luks->header.key_slots[0].iterations, 1185 slotkey, luks->header.key_bytes, 1186 errp) < 0) { 1187 goto error; 1188 } 1189 1190 1191 /* Setup the encryption objects needed to encrypt the 1192 * master key material 1193 */ 1194 cipher = qcrypto_cipher_new(luks_opts.cipher_alg, 1195 luks_opts.cipher_mode, 1196 slotkey, luks->header.key_bytes, 1197 errp); 1198 if (!cipher) { 1199 goto error; 1200 } 1201 1202 ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg, 1203 ivcipheralg, 1204 luks_opts.ivgen_hash_alg, 1205 slotkey, luks->header.key_bytes, 1206 errp); 1207 if (!ivgen) { 1208 goto error; 1209 } 1210 1211 /* Before storing the master key, we need to vastly 1212 * increase its size, as protection against forensic 1213 * disk data recovery */ 1214 splitkey = g_new0(uint8_t, splitkeylen); 1215 1216 if (qcrypto_afsplit_encode(luks_opts.hash_alg, 1217 luks->header.key_bytes, 1218 luks->header.key_slots[0].stripes, 1219 masterkey, 1220 splitkey, 1221 errp) < 0) { 1222 goto error; 1223 } 1224 1225 /* Now we encrypt the split master key with the key generated 1226 * from the user's password, before storing it */ 1227 if (qcrypto_block_encrypt_helper(cipher, block->niv, ivgen, 1228 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1229 0, 1230 splitkey, 1231 splitkeylen, 1232 errp) < 0) { 1233 goto error; 1234 } 1235 1236 1237 /* The total size of the LUKS headers is the partition header + key 1238 * slot headers, rounded up to the nearest sector, combined with 1239 * the size of each master key material region, also rounded up 1240 * to the nearest sector */ 1241 luks->header.payload_offset = 1242 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1243 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) + 1244 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE), 1245 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET / 1246 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * 1247 QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS); 1248 1249 block->payload_offset = luks->header.payload_offset * 1250 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1251 1252 /* Reserve header space to match payload offset */ 1253 initfunc(block, block->payload_offset, opaque, &local_err); 1254 if (local_err) { 1255 error_propagate(errp, local_err); 1256 goto error; 1257 } 1258 1259 /* Everything on disk uses Big Endian, so flip header fields 1260 * before writing them */ 1261 cpu_to_be16s(&luks->header.version); 1262 cpu_to_be32s(&luks->header.payload_offset); 1263 cpu_to_be32s(&luks->header.key_bytes); 1264 cpu_to_be32s(&luks->header.master_key_iterations); 1265 1266 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1267 cpu_to_be32s(&luks->header.key_slots[i].active); 1268 cpu_to_be32s(&luks->header.key_slots[i].iterations); 1269 cpu_to_be32s(&luks->header.key_slots[i].key_offset); 1270 cpu_to_be32s(&luks->header.key_slots[i].stripes); 1271 } 1272 1273 1274 /* Write out the partition header and key slot headers */ 1275 writefunc(block, 0, 1276 (const uint8_t *)&luks->header, 1277 sizeof(luks->header), 1278 opaque, 1279 &local_err); 1280 1281 /* Delay checking local_err until we've byte-swapped */ 1282 1283 /* Byte swap the header back to native, in case we need 1284 * to read it again later */ 1285 be16_to_cpus(&luks->header.version); 1286 be32_to_cpus(&luks->header.payload_offset); 1287 be32_to_cpus(&luks->header.key_bytes); 1288 be32_to_cpus(&luks->header.master_key_iterations); 1289 1290 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1291 be32_to_cpus(&luks->header.key_slots[i].active); 1292 be32_to_cpus(&luks->header.key_slots[i].iterations); 1293 be32_to_cpus(&luks->header.key_slots[i].key_offset); 1294 be32_to_cpus(&luks->header.key_slots[i].stripes); 1295 } 1296 1297 if (local_err) { 1298 error_propagate(errp, local_err); 1299 goto error; 1300 } 1301 1302 /* Write out the master key material, starting at the 1303 * sector immediately following the partition header. */ 1304 if (writefunc(block, 1305 luks->header.key_slots[0].key_offset * 1306 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1307 splitkey, splitkeylen, 1308 opaque, 1309 errp) != splitkeylen) { 1310 goto error; 1311 } 1312 1313 luks->cipher_alg = luks_opts.cipher_alg; 1314 luks->cipher_mode = luks_opts.cipher_mode; 1315 luks->ivgen_alg = luks_opts.ivgen_alg; 1316 luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg; 1317 luks->hash_alg = luks_opts.hash_alg; 1318 1319 memset(masterkey, 0, luks->header.key_bytes); 1320 g_free(masterkey); 1321 memset(slotkey, 0, luks->header.key_bytes); 1322 g_free(slotkey); 1323 g_free(splitkey); 1324 g_free(password); 1325 g_free(cipher_mode_spec); 1326 1327 qcrypto_ivgen_free(ivgen); 1328 qcrypto_cipher_free(cipher); 1329 1330 return 0; 1331 1332 error: 1333 if (masterkey) { 1334 memset(masterkey, 0, luks->header.key_bytes); 1335 } 1336 g_free(masterkey); 1337 if (slotkey) { 1338 memset(slotkey, 0, luks->header.key_bytes); 1339 } 1340 g_free(slotkey); 1341 g_free(splitkey); 1342 g_free(password); 1343 g_free(cipher_mode_spec); 1344 1345 qcrypto_ivgen_free(ivgen); 1346 qcrypto_cipher_free(cipher); 1347 1348 g_free(luks); 1349 return -1; 1350 } 1351 1352 1353 static int qcrypto_block_luks_get_info(QCryptoBlock *block, 1354 QCryptoBlockInfo *info, 1355 Error **errp) 1356 { 1357 QCryptoBlockLUKS *luks = block->opaque; 1358 QCryptoBlockInfoLUKSSlot *slot; 1359 QCryptoBlockInfoLUKSSlotList *slots = NULL, **prev = &info->u.luks.slots; 1360 size_t i; 1361 1362 info->u.luks.cipher_alg = luks->cipher_alg; 1363 info->u.luks.cipher_mode = luks->cipher_mode; 1364 info->u.luks.ivgen_alg = luks->ivgen_alg; 1365 if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) { 1366 info->u.luks.has_ivgen_hash_alg = true; 1367 info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg; 1368 } 1369 info->u.luks.hash_alg = luks->hash_alg; 1370 info->u.luks.payload_offset = block->payload_offset; 1371 info->u.luks.master_key_iters = luks->header.master_key_iterations; 1372 info->u.luks.uuid = g_strndup((const char *)luks->header.uuid, 1373 sizeof(luks->header.uuid)); 1374 1375 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) { 1376 slots = g_new0(QCryptoBlockInfoLUKSSlotList, 1); 1377 *prev = slots; 1378 1379 slots->value = slot = g_new0(QCryptoBlockInfoLUKSSlot, 1); 1380 slot->active = luks->header.key_slots[i].active == 1381 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED; 1382 slot->key_offset = luks->header.key_slots[i].key_offset 1383 * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE; 1384 if (slot->active) { 1385 slot->has_iters = true; 1386 slot->iters = luks->header.key_slots[i].iterations; 1387 slot->has_stripes = true; 1388 slot->stripes = luks->header.key_slots[i].stripes; 1389 } 1390 1391 prev = &slots->next; 1392 } 1393 1394 return 0; 1395 } 1396 1397 1398 static void qcrypto_block_luks_cleanup(QCryptoBlock *block) 1399 { 1400 g_free(block->opaque); 1401 } 1402 1403 1404 static int 1405 qcrypto_block_luks_decrypt(QCryptoBlock *block, 1406 uint64_t startsector, 1407 uint8_t *buf, 1408 size_t len, 1409 Error **errp) 1410 { 1411 return qcrypto_block_decrypt_helper(block->cipher, 1412 block->niv, block->ivgen, 1413 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1414 startsector, buf, len, errp); 1415 } 1416 1417 1418 static int 1419 qcrypto_block_luks_encrypt(QCryptoBlock *block, 1420 uint64_t startsector, 1421 uint8_t *buf, 1422 size_t len, 1423 Error **errp) 1424 { 1425 return qcrypto_block_encrypt_helper(block->cipher, 1426 block->niv, block->ivgen, 1427 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE, 1428 startsector, buf, len, errp); 1429 } 1430 1431 1432 const QCryptoBlockDriver qcrypto_block_driver_luks = { 1433 .open = qcrypto_block_luks_open, 1434 .create = qcrypto_block_luks_create, 1435 .get_info = qcrypto_block_luks_get_info, 1436 .cleanup = qcrypto_block_luks_cleanup, 1437 .decrypt = qcrypto_block_luks_decrypt, 1438 .encrypt = qcrypto_block_luks_encrypt, 1439 .has_format = qcrypto_block_luks_has_format, 1440 }; 1441