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[qemu.git] / crypto / block-luks.c
1 /*
2 * QEMU Crypto block device encryption LUKS format
3 *
4 * Copyright (c) 2015-2016 Red Hat, Inc.
5 *
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2 of the License, or (at your option) any later version.
10 *
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
18 *
19 */
20
21 #include "qemu/osdep.h"
22 #include "qapi/error.h"
23 #include "qemu/bswap.h"
24
25 #include "block-luks.h"
26
27 #include "crypto/hash.h"
28 #include "crypto/afsplit.h"
29 #include "crypto/pbkdf.h"
30 #include "crypto/secret.h"
31 #include "crypto/random.h"
32 #include "qemu/uuid.h"
33
34 #include "qemu/coroutine.h"
35
36 /*
37 * Reference for the LUKS format implemented here is
38 *
39 * docs/on-disk-format.pdf
40 *
41 * in 'cryptsetup' package source code
42 *
43 * This file implements the 1.2.1 specification, dated
44 * Oct 16, 2011.
45 */
46
47 typedef struct QCryptoBlockLUKS QCryptoBlockLUKS;
48 typedef struct QCryptoBlockLUKSHeader QCryptoBlockLUKSHeader;
49 typedef struct QCryptoBlockLUKSKeySlot QCryptoBlockLUKSKeySlot;
50
51
52 /* The following constants are all defined by the LUKS spec */
53 #define QCRYPTO_BLOCK_LUKS_VERSION 1
54
55 #define QCRYPTO_BLOCK_LUKS_MAGIC_LEN 6
56 #define QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN 32
57 #define QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN 32
58 #define QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN 32
59 #define QCRYPTO_BLOCK_LUKS_DIGEST_LEN 20
60 #define QCRYPTO_BLOCK_LUKS_SALT_LEN 32
61 #define QCRYPTO_BLOCK_LUKS_UUID_LEN 40
62 #define QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS 8
63 #define QCRYPTO_BLOCK_LUKS_STRIPES 4000
64 #define QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS 1000
65 #define QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS 1000
66 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET 4096
67
68 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED 0x0000DEAD
69 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED 0x00AC71F3
70
71 #define QCRYPTO_BLOCK_LUKS_SECTOR_SIZE 512LL
72
73 static const char qcrypto_block_luks_magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN] = {
74 'L', 'U', 'K', 'S', 0xBA, 0xBE
75 };
76
77 typedef struct QCryptoBlockLUKSNameMap QCryptoBlockLUKSNameMap;
78 struct QCryptoBlockLUKSNameMap {
79 const char *name;
80 int id;
81 };
82
83 typedef struct QCryptoBlockLUKSCipherSizeMap QCryptoBlockLUKSCipherSizeMap;
84 struct QCryptoBlockLUKSCipherSizeMap {
85 uint32_t key_bytes;
86 int id;
87 };
88 typedef struct QCryptoBlockLUKSCipherNameMap QCryptoBlockLUKSCipherNameMap;
89 struct QCryptoBlockLUKSCipherNameMap {
90 const char *name;
91 const QCryptoBlockLUKSCipherSizeMap *sizes;
92 };
93
94
95 static const QCryptoBlockLUKSCipherSizeMap
96 qcrypto_block_luks_cipher_size_map_aes[] = {
97 { 16, QCRYPTO_CIPHER_ALG_AES_128 },
98 { 24, QCRYPTO_CIPHER_ALG_AES_192 },
99 { 32, QCRYPTO_CIPHER_ALG_AES_256 },
100 { 0, 0 },
101 };
102
103 static const QCryptoBlockLUKSCipherSizeMap
104 qcrypto_block_luks_cipher_size_map_cast5[] = {
105 { 16, QCRYPTO_CIPHER_ALG_CAST5_128 },
106 { 0, 0 },
107 };
108
109 static const QCryptoBlockLUKSCipherSizeMap
110 qcrypto_block_luks_cipher_size_map_serpent[] = {
111 { 16, QCRYPTO_CIPHER_ALG_SERPENT_128 },
112 { 24, QCRYPTO_CIPHER_ALG_SERPENT_192 },
113 { 32, QCRYPTO_CIPHER_ALG_SERPENT_256 },
114 { 0, 0 },
115 };
116
117 static const QCryptoBlockLUKSCipherSizeMap
118 qcrypto_block_luks_cipher_size_map_twofish[] = {
119 { 16, QCRYPTO_CIPHER_ALG_TWOFISH_128 },
120 { 24, QCRYPTO_CIPHER_ALG_TWOFISH_192 },
121 { 32, QCRYPTO_CIPHER_ALG_TWOFISH_256 },
122 { 0, 0 },
123 };
124
125 static const QCryptoBlockLUKSCipherNameMap
126 qcrypto_block_luks_cipher_name_map[] = {
127 { "aes", qcrypto_block_luks_cipher_size_map_aes },
128 { "cast5", qcrypto_block_luks_cipher_size_map_cast5 },
129 { "serpent", qcrypto_block_luks_cipher_size_map_serpent },
130 { "twofish", qcrypto_block_luks_cipher_size_map_twofish },
131 };
132
133
134 /*
135 * This struct is written to disk in big-endian format,
136 * but operated upon in native-endian format.
137 */
138 struct QCryptoBlockLUKSKeySlot {
139 /* state of keyslot, enabled/disable */
140 uint32_t active;
141 /* iterations for PBKDF2 */
142 uint32_t iterations;
143 /* salt for PBKDF2 */
144 uint8_t salt[QCRYPTO_BLOCK_LUKS_SALT_LEN];
145 /* start sector of key material */
146 uint32_t key_offset;
147 /* number of anti-forensic stripes */
148 uint32_t stripes;
149 };
150
151 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48);
152
153
154 /*
155 * This struct is written to disk in big-endian format,
156 * but operated upon in native-endian format.
157 */
158 struct QCryptoBlockLUKSHeader {
159 /* 'L', 'U', 'K', 'S', '0xBA', '0xBE' */
160 char magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN];
161
162 /* LUKS version, currently 1 */
163 uint16_t version;
164
165 /* cipher name specification (aes, etc) */
166 char cipher_name[QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN];
167
168 /* cipher mode specification (cbc-plain, xts-essiv:sha256, etc) */
169 char cipher_mode[QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN];
170
171 /* hash specification (sha256, etc) */
172 char hash_spec[QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN];
173
174 /* start offset of the volume data (in 512 byte sectors) */
175 uint32_t payload_offset;
176
177 /* Number of key bytes */
178 uint32_t key_bytes;
179
180 /* master key checksum after PBKDF2 */
181 uint8_t master_key_digest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN];
182
183 /* salt for master key PBKDF2 */
184 uint8_t master_key_salt[QCRYPTO_BLOCK_LUKS_SALT_LEN];
185
186 /* iterations for master key PBKDF2 */
187 uint32_t master_key_iterations;
188
189 /* UUID of the partition in standard ASCII representation */
190 uint8_t uuid[QCRYPTO_BLOCK_LUKS_UUID_LEN];
191
192 /* key slots */
193 QCryptoBlockLUKSKeySlot key_slots[QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS];
194 };
195
196 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592);
197
198
199 struct QCryptoBlockLUKS {
200 QCryptoBlockLUKSHeader header;
201
202 /* Cache parsed versions of what's in header fields,
203 * as we can't rely on QCryptoBlock.cipher being
204 * non-NULL */
205 QCryptoCipherAlgorithm cipher_alg;
206 QCryptoCipherMode cipher_mode;
207 QCryptoIVGenAlgorithm ivgen_alg;
208 QCryptoHashAlgorithm ivgen_hash_alg;
209 QCryptoHashAlgorithm hash_alg;
210 };
211
212
213 static int qcrypto_block_luks_cipher_name_lookup(const char *name,
214 QCryptoCipherMode mode,
215 uint32_t key_bytes,
216 Error **errp)
217 {
218 const QCryptoBlockLUKSCipherNameMap *map =
219 qcrypto_block_luks_cipher_name_map;
220 size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
221 size_t i, j;
222
223 if (mode == QCRYPTO_CIPHER_MODE_XTS) {
224 key_bytes /= 2;
225 }
226
227 for (i = 0; i < maplen; i++) {
228 if (!g_str_equal(map[i].name, name)) {
229 continue;
230 }
231 for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
232 if (map[i].sizes[j].key_bytes == key_bytes) {
233 return map[i].sizes[j].id;
234 }
235 }
236 }
237
238 error_setg(errp, "Algorithm %s with key size %d bytes not supported",
239 name, key_bytes);
240 return 0;
241 }
242
243 static const char *
244 qcrypto_block_luks_cipher_alg_lookup(QCryptoCipherAlgorithm alg,
245 Error **errp)
246 {
247 const QCryptoBlockLUKSCipherNameMap *map =
248 qcrypto_block_luks_cipher_name_map;
249 size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
250 size_t i, j;
251 for (i = 0; i < maplen; i++) {
252 for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
253 if (map[i].sizes[j].id == alg) {
254 return map[i].name;
255 }
256 }
257 }
258
259 error_setg(errp, "Algorithm '%s' not supported",
260 QCryptoCipherAlgorithm_str(alg));
261 return NULL;
262 }
263
264 /* XXX replace with qapi_enum_parse() in future, when we can
265 * make that function emit a more friendly error message */
266 static int qcrypto_block_luks_name_lookup(const char *name,
267 const QEnumLookup *map,
268 const char *type,
269 Error **errp)
270 {
271 int ret = qapi_enum_parse(map, name, -1, NULL);
272
273 if (ret < 0) {
274 error_setg(errp, "%s %s not supported", type, name);
275 return 0;
276 }
277 return ret;
278 }
279
280 #define qcrypto_block_luks_cipher_mode_lookup(name, errp) \
281 qcrypto_block_luks_name_lookup(name, \
282 &QCryptoCipherMode_lookup, \
283 "Cipher mode", \
284 errp)
285
286 #define qcrypto_block_luks_hash_name_lookup(name, errp) \
287 qcrypto_block_luks_name_lookup(name, \
288 &QCryptoHashAlgorithm_lookup, \
289 "Hash algorithm", \
290 errp)
291
292 #define qcrypto_block_luks_ivgen_name_lookup(name, errp) \
293 qcrypto_block_luks_name_lookup(name, \
294 &QCryptoIVGenAlgorithm_lookup, \
295 "IV generator", \
296 errp)
297
298
299 static bool
300 qcrypto_block_luks_has_format(const uint8_t *buf,
301 size_t buf_size)
302 {
303 const QCryptoBlockLUKSHeader *luks_header = (const void *)buf;
304
305 if (buf_size >= offsetof(QCryptoBlockLUKSHeader, cipher_name) &&
306 memcmp(luks_header->magic, qcrypto_block_luks_magic,
307 QCRYPTO_BLOCK_LUKS_MAGIC_LEN) == 0 &&
308 be16_to_cpu(luks_header->version) == QCRYPTO_BLOCK_LUKS_VERSION) {
309 return true;
310 } else {
311 return false;
312 }
313 }
314
315
316 /**
317 * Deal with a quirk of dm-crypt usage of ESSIV.
318 *
319 * When calculating ESSIV IVs, the cipher length used by ESSIV
320 * may be different from the cipher length used for the block
321 * encryption, becauses dm-crypt uses the hash digest length
322 * as the key size. ie, if you have AES 128 as the block cipher
323 * and SHA 256 as ESSIV hash, then ESSIV will use AES 256 as
324 * the cipher since that gets a key length matching the digest
325 * size, not AES 128 with truncated digest as might be imagined
326 */
327 static QCryptoCipherAlgorithm
328 qcrypto_block_luks_essiv_cipher(QCryptoCipherAlgorithm cipher,
329 QCryptoHashAlgorithm hash,
330 Error **errp)
331 {
332 size_t digestlen = qcrypto_hash_digest_len(hash);
333 size_t keylen = qcrypto_cipher_get_key_len(cipher);
334 if (digestlen == keylen) {
335 return cipher;
336 }
337
338 switch (cipher) {
339 case QCRYPTO_CIPHER_ALG_AES_128:
340 case QCRYPTO_CIPHER_ALG_AES_192:
341 case QCRYPTO_CIPHER_ALG_AES_256:
342 if (digestlen == qcrypto_cipher_get_key_len(
343 QCRYPTO_CIPHER_ALG_AES_128)) {
344 return QCRYPTO_CIPHER_ALG_AES_128;
345 } else if (digestlen == qcrypto_cipher_get_key_len(
346 QCRYPTO_CIPHER_ALG_AES_192)) {
347 return QCRYPTO_CIPHER_ALG_AES_192;
348 } else if (digestlen == qcrypto_cipher_get_key_len(
349 QCRYPTO_CIPHER_ALG_AES_256)) {
350 return QCRYPTO_CIPHER_ALG_AES_256;
351 } else {
352 error_setg(errp, "No AES cipher with key size %zu available",
353 digestlen);
354 return 0;
355 }
356 break;
357 case QCRYPTO_CIPHER_ALG_SERPENT_128:
358 case QCRYPTO_CIPHER_ALG_SERPENT_192:
359 case QCRYPTO_CIPHER_ALG_SERPENT_256:
360 if (digestlen == qcrypto_cipher_get_key_len(
361 QCRYPTO_CIPHER_ALG_SERPENT_128)) {
362 return QCRYPTO_CIPHER_ALG_SERPENT_128;
363 } else if (digestlen == qcrypto_cipher_get_key_len(
364 QCRYPTO_CIPHER_ALG_SERPENT_192)) {
365 return QCRYPTO_CIPHER_ALG_SERPENT_192;
366 } else if (digestlen == qcrypto_cipher_get_key_len(
367 QCRYPTO_CIPHER_ALG_SERPENT_256)) {
368 return QCRYPTO_CIPHER_ALG_SERPENT_256;
369 } else {
370 error_setg(errp, "No Serpent cipher with key size %zu available",
371 digestlen);
372 return 0;
373 }
374 break;
375 case QCRYPTO_CIPHER_ALG_TWOFISH_128:
376 case QCRYPTO_CIPHER_ALG_TWOFISH_192:
377 case QCRYPTO_CIPHER_ALG_TWOFISH_256:
378 if (digestlen == qcrypto_cipher_get_key_len(
379 QCRYPTO_CIPHER_ALG_TWOFISH_128)) {
380 return QCRYPTO_CIPHER_ALG_TWOFISH_128;
381 } else if (digestlen == qcrypto_cipher_get_key_len(
382 QCRYPTO_CIPHER_ALG_TWOFISH_192)) {
383 return QCRYPTO_CIPHER_ALG_TWOFISH_192;
384 } else if (digestlen == qcrypto_cipher_get_key_len(
385 QCRYPTO_CIPHER_ALG_TWOFISH_256)) {
386 return QCRYPTO_CIPHER_ALG_TWOFISH_256;
387 } else {
388 error_setg(errp, "No Twofish cipher with key size %zu available",
389 digestlen);
390 return 0;
391 }
392 break;
393 default:
394 error_setg(errp, "Cipher %s not supported with essiv",
395 QCryptoCipherAlgorithm_str(cipher));
396 return 0;
397 }
398 }
399
400 /*
401 * Given a key slot, and user password, this will attempt to unlock
402 * the master encryption key from the key slot.
403 *
404 * Returns:
405 * 0 if the key slot is disabled, or key could not be decrypted
406 * with the provided password
407 * 1 if the key slot is enabled, and key decrypted successfully
408 * with the provided password
409 * -1 if a fatal error occurred loading the key
410 */
411 static int
412 qcrypto_block_luks_load_key(QCryptoBlock *block,
413 QCryptoBlockLUKSKeySlot *slot,
414 const char *password,
415 QCryptoCipherAlgorithm cipheralg,
416 QCryptoCipherMode ciphermode,
417 QCryptoHashAlgorithm hash,
418 QCryptoIVGenAlgorithm ivalg,
419 QCryptoCipherAlgorithm ivcipheralg,
420 QCryptoHashAlgorithm ivhash,
421 uint8_t *masterkey,
422 size_t masterkeylen,
423 QCryptoBlockReadFunc readfunc,
424 void *opaque,
425 Error **errp)
426 {
427 QCryptoBlockLUKS *luks = block->opaque;
428 uint8_t *splitkey;
429 size_t splitkeylen;
430 uint8_t *possiblekey;
431 int ret = -1;
432 ssize_t rv;
433 QCryptoCipher *cipher = NULL;
434 uint8_t keydigest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN];
435 QCryptoIVGen *ivgen = NULL;
436 size_t niv;
437
438 if (slot->active != QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED) {
439 return 0;
440 }
441
442 splitkeylen = masterkeylen * slot->stripes;
443 splitkey = g_new0(uint8_t, splitkeylen);
444 possiblekey = g_new0(uint8_t, masterkeylen);
445
446 /*
447 * The user password is used to generate a (possible)
448 * decryption key. This may or may not successfully
449 * decrypt the master key - we just blindly assume
450 * the key is correct and validate the results of
451 * decryption later.
452 */
453 if (qcrypto_pbkdf2(hash,
454 (const uint8_t *)password, strlen(password),
455 slot->salt, QCRYPTO_BLOCK_LUKS_SALT_LEN,
456 slot->iterations,
457 possiblekey, masterkeylen,
458 errp) < 0) {
459 goto cleanup;
460 }
461
462 /*
463 * We need to read the master key material from the
464 * LUKS key material header. What we're reading is
465 * not the raw master key, but rather the data after
466 * it has been passed through AFSplit and the result
467 * then encrypted.
468 */
469 rv = readfunc(block,
470 slot->key_offset * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
471 splitkey, splitkeylen,
472 opaque,
473 errp);
474 if (rv < 0) {
475 goto cleanup;
476 }
477
478
479 /* Setup the cipher/ivgen that we'll use to try to decrypt
480 * the split master key material */
481 cipher = qcrypto_cipher_new(cipheralg, ciphermode,
482 possiblekey, masterkeylen,
483 errp);
484 if (!cipher) {
485 goto cleanup;
486 }
487
488 niv = qcrypto_cipher_get_iv_len(cipheralg,
489 ciphermode);
490 ivgen = qcrypto_ivgen_new(ivalg,
491 ivcipheralg,
492 ivhash,
493 possiblekey, masterkeylen,
494 errp);
495 if (!ivgen) {
496 goto cleanup;
497 }
498
499
500 /*
501 * The master key needs to be decrypted in the same
502 * way that the block device payload will be decrypted
503 * later. In particular we'll be using the IV generator
504 * to reset the encryption cipher every time the master
505 * key crosses a sector boundary.
506 */
507 if (qcrypto_block_cipher_decrypt_helper(cipher,
508 niv,
509 ivgen,
510 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
511 0,
512 splitkey,
513 splitkeylen,
514 errp) < 0) {
515 goto cleanup;
516 }
517
518 /*
519 * Now we've decrypted the split master key, join
520 * it back together to get the actual master key.
521 */
522 if (qcrypto_afsplit_decode(hash,
523 masterkeylen,
524 slot->stripes,
525 splitkey,
526 masterkey,
527 errp) < 0) {
528 goto cleanup;
529 }
530
531
532 /*
533 * We still don't know that the masterkey we got is valid,
534 * because we just blindly assumed the user's password
535 * was correct. This is where we now verify it. We are
536 * creating a hash of the master key using PBKDF and
537 * then comparing that to the hash stored in the key slot
538 * header
539 */
540 if (qcrypto_pbkdf2(hash,
541 masterkey, masterkeylen,
542 luks->header.master_key_salt,
543 QCRYPTO_BLOCK_LUKS_SALT_LEN,
544 luks->header.master_key_iterations,
545 keydigest, G_N_ELEMENTS(keydigest),
546 errp) < 0) {
547 goto cleanup;
548 }
549
550 if (memcmp(keydigest, luks->header.master_key_digest,
551 QCRYPTO_BLOCK_LUKS_DIGEST_LEN) == 0) {
552 /* Success, we got the right master key */
553 ret = 1;
554 goto cleanup;
555 }
556
557 /* Fail, user's password was not valid for this key slot,
558 * tell caller to try another slot */
559 ret = 0;
560
561 cleanup:
562 qcrypto_ivgen_free(ivgen);
563 qcrypto_cipher_free(cipher);
564 g_free(splitkey);
565 g_free(possiblekey);
566 return ret;
567 }
568
569
570 /*
571 * Given a user password, this will iterate over all key
572 * slots and try to unlock each active key slot using the
573 * password until it successfully obtains a master key.
574 *
575 * Returns 0 if a key was loaded, -1 if no keys could be loaded
576 */
577 static int
578 qcrypto_block_luks_find_key(QCryptoBlock *block,
579 const char *password,
580 QCryptoCipherAlgorithm cipheralg,
581 QCryptoCipherMode ciphermode,
582 QCryptoHashAlgorithm hash,
583 QCryptoIVGenAlgorithm ivalg,
584 QCryptoCipherAlgorithm ivcipheralg,
585 QCryptoHashAlgorithm ivhash,
586 uint8_t **masterkey,
587 size_t *masterkeylen,
588 QCryptoBlockReadFunc readfunc,
589 void *opaque,
590 Error **errp)
591 {
592 QCryptoBlockLUKS *luks = block->opaque;
593 size_t i;
594 int rv;
595
596 *masterkey = g_new0(uint8_t, luks->header.key_bytes);
597 *masterkeylen = luks->header.key_bytes;
598
599 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
600 rv = qcrypto_block_luks_load_key(block,
601 &luks->header.key_slots[i],
602 password,
603 cipheralg,
604 ciphermode,
605 hash,
606 ivalg,
607 ivcipheralg,
608 ivhash,
609 *masterkey,
610 *masterkeylen,
611 readfunc,
612 opaque,
613 errp);
614 if (rv < 0) {
615 goto error;
616 }
617 if (rv == 1) {
618 return 0;
619 }
620 }
621
622 error_setg(errp, "Invalid password, cannot unlock any keyslot");
623
624 error:
625 g_free(*masterkey);
626 *masterkey = NULL;
627 *masterkeylen = 0;
628 return -1;
629 }
630
631
632 static int
633 qcrypto_block_luks_open(QCryptoBlock *block,
634 QCryptoBlockOpenOptions *options,
635 const char *optprefix,
636 QCryptoBlockReadFunc readfunc,
637 void *opaque,
638 unsigned int flags,
639 size_t n_threads,
640 Error **errp)
641 {
642 QCryptoBlockLUKS *luks;
643 Error *local_err = NULL;
644 int ret = 0;
645 size_t i;
646 ssize_t rv;
647 uint8_t *masterkey = NULL;
648 size_t masterkeylen;
649 char *ivgen_name, *ivhash_name;
650 QCryptoCipherMode ciphermode;
651 QCryptoCipherAlgorithm cipheralg;
652 QCryptoIVGenAlgorithm ivalg;
653 QCryptoCipherAlgorithm ivcipheralg;
654 QCryptoHashAlgorithm hash;
655 QCryptoHashAlgorithm ivhash;
656 char *password = NULL;
657
658 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
659 if (!options->u.luks.key_secret) {
660 error_setg(errp, "Parameter '%skey-secret' is required for cipher",
661 optprefix ? optprefix : "");
662 return -1;
663 }
664 password = qcrypto_secret_lookup_as_utf8(
665 options->u.luks.key_secret, errp);
666 if (!password) {
667 return -1;
668 }
669 }
670
671 luks = g_new0(QCryptoBlockLUKS, 1);
672 block->opaque = luks;
673
674 /* Read the entire LUKS header, minus the key material from
675 * the underlying device */
676 rv = readfunc(block, 0,
677 (uint8_t *)&luks->header,
678 sizeof(luks->header),
679 opaque,
680 errp);
681 if (rv < 0) {
682 ret = rv;
683 goto fail;
684 }
685
686 /* The header is always stored in big-endian format, so
687 * convert everything to native */
688 be16_to_cpus(&luks->header.version);
689 be32_to_cpus(&luks->header.payload_offset);
690 be32_to_cpus(&luks->header.key_bytes);
691 be32_to_cpus(&luks->header.master_key_iterations);
692
693 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
694 be32_to_cpus(&luks->header.key_slots[i].active);
695 be32_to_cpus(&luks->header.key_slots[i].iterations);
696 be32_to_cpus(&luks->header.key_slots[i].key_offset);
697 be32_to_cpus(&luks->header.key_slots[i].stripes);
698 }
699
700 if (memcmp(luks->header.magic, qcrypto_block_luks_magic,
701 QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) {
702 error_setg(errp, "Volume is not in LUKS format");
703 ret = -EINVAL;
704 goto fail;
705 }
706 if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) {
707 error_setg(errp, "LUKS version %" PRIu32 " is not supported",
708 luks->header.version);
709 ret = -ENOTSUP;
710 goto fail;
711 }
712
713 /*
714 * The cipher_mode header contains a string that we have
715 * to further parse, of the format
716 *
717 * <cipher-mode>-<iv-generator>[:<iv-hash>]
718 *
719 * eg cbc-essiv:sha256, cbc-plain64
720 */
721 ivgen_name = strchr(luks->header.cipher_mode, '-');
722 if (!ivgen_name) {
723 ret = -EINVAL;
724 error_setg(errp, "Unexpected cipher mode string format %s",
725 luks->header.cipher_mode);
726 goto fail;
727 }
728 *ivgen_name = '\0';
729 ivgen_name++;
730
731 ivhash_name = strchr(ivgen_name, ':');
732 if (!ivhash_name) {
733 ivhash = 0;
734 } else {
735 *ivhash_name = '\0';
736 ivhash_name++;
737
738 ivhash = qcrypto_block_luks_hash_name_lookup(ivhash_name,
739 &local_err);
740 if (local_err) {
741 ret = -ENOTSUP;
742 error_propagate(errp, local_err);
743 goto fail;
744 }
745 }
746
747 ciphermode = qcrypto_block_luks_cipher_mode_lookup(luks->header.cipher_mode,
748 &local_err);
749 if (local_err) {
750 ret = -ENOTSUP;
751 error_propagate(errp, local_err);
752 goto fail;
753 }
754
755 cipheralg = qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name,
756 ciphermode,
757 luks->header.key_bytes,
758 &local_err);
759 if (local_err) {
760 ret = -ENOTSUP;
761 error_propagate(errp, local_err);
762 goto fail;
763 }
764
765 hash = qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec,
766 &local_err);
767 if (local_err) {
768 ret = -ENOTSUP;
769 error_propagate(errp, local_err);
770 goto fail;
771 }
772
773 ivalg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name,
774 &local_err);
775 if (local_err) {
776 ret = -ENOTSUP;
777 error_propagate(errp, local_err);
778 goto fail;
779 }
780
781 if (ivalg == QCRYPTO_IVGEN_ALG_ESSIV) {
782 if (!ivhash_name) {
783 ret = -EINVAL;
784 error_setg(errp, "Missing IV generator hash specification");
785 goto fail;
786 }
787 ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg,
788 ivhash,
789 &local_err);
790 if (local_err) {
791 ret = -ENOTSUP;
792 error_propagate(errp, local_err);
793 goto fail;
794 }
795 } else {
796 /* Note we parsed the ivhash_name earlier in the cipher_mode
797 * spec string even with plain/plain64 ivgens, but we
798 * will ignore it, since it is irrelevant for these ivgens.
799 * This is for compat with dm-crypt which will silently
800 * ignore hash names with these ivgens rather than report
801 * an error about the invalid usage
802 */
803 ivcipheralg = cipheralg;
804 }
805
806 if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
807 /* Try to find which key slot our password is valid for
808 * and unlock the master key from that slot.
809 */
810 if (qcrypto_block_luks_find_key(block,
811 password,
812 cipheralg, ciphermode,
813 hash,
814 ivalg,
815 ivcipheralg,
816 ivhash,
817 &masterkey, &masterkeylen,
818 readfunc, opaque,
819 errp) < 0) {
820 ret = -EACCES;
821 goto fail;
822 }
823
824 /* We have a valid master key now, so can setup the
825 * block device payload decryption objects
826 */
827 block->kdfhash = hash;
828 block->niv = qcrypto_cipher_get_iv_len(cipheralg,
829 ciphermode);
830 block->ivgen = qcrypto_ivgen_new(ivalg,
831 ivcipheralg,
832 ivhash,
833 masterkey, masterkeylen,
834 errp);
835 if (!block->ivgen) {
836 ret = -ENOTSUP;
837 goto fail;
838 }
839
840 ret = qcrypto_block_init_cipher(block, cipheralg, ciphermode,
841 masterkey, masterkeylen, n_threads,
842 errp);
843 if (ret < 0) {
844 ret = -ENOTSUP;
845 goto fail;
846 }
847 }
848
849 block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
850 block->payload_offset = luks->header.payload_offset *
851 block->sector_size;
852
853 luks->cipher_alg = cipheralg;
854 luks->cipher_mode = ciphermode;
855 luks->ivgen_alg = ivalg;
856 luks->ivgen_hash_alg = ivhash;
857 luks->hash_alg = hash;
858
859 g_free(masterkey);
860 g_free(password);
861
862 return 0;
863
864 fail:
865 g_free(masterkey);
866 qcrypto_block_free_cipher(block);
867 qcrypto_ivgen_free(block->ivgen);
868 g_free(luks);
869 g_free(password);
870 return ret;
871 }
872
873
874 static void
875 qcrypto_block_luks_uuid_gen(uint8_t *uuidstr)
876 {
877 QemuUUID uuid;
878 qemu_uuid_generate(&uuid);
879 qemu_uuid_unparse(&uuid, (char *)uuidstr);
880 }
881
882 static int
883 qcrypto_block_luks_create(QCryptoBlock *block,
884 QCryptoBlockCreateOptions *options,
885 const char *optprefix,
886 QCryptoBlockInitFunc initfunc,
887 QCryptoBlockWriteFunc writefunc,
888 void *opaque,
889 Error **errp)
890 {
891 QCryptoBlockLUKS *luks;
892 QCryptoBlockCreateOptionsLUKS luks_opts;
893 Error *local_err = NULL;
894 uint8_t *masterkey = NULL;
895 uint8_t *slotkey = NULL;
896 uint8_t *splitkey = NULL;
897 size_t splitkeylen = 0;
898 size_t i;
899 QCryptoCipher *cipher = NULL;
900 QCryptoIVGen *ivgen = NULL;
901 char *password;
902 const char *cipher_alg;
903 const char *cipher_mode;
904 const char *ivgen_alg;
905 const char *ivgen_hash_alg = NULL;
906 const char *hash_alg;
907 char *cipher_mode_spec = NULL;
908 QCryptoCipherAlgorithm ivcipheralg = 0;
909 uint64_t iters;
910
911 memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts));
912 if (!luks_opts.has_iter_time) {
913 luks_opts.iter_time = 2000;
914 }
915 if (!luks_opts.has_cipher_alg) {
916 luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256;
917 }
918 if (!luks_opts.has_cipher_mode) {
919 luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS;
920 }
921 if (!luks_opts.has_ivgen_alg) {
922 luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64;
923 }
924 if (!luks_opts.has_hash_alg) {
925 luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256;
926 }
927 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
928 if (!luks_opts.has_ivgen_hash_alg) {
929 luks_opts.ivgen_hash_alg = QCRYPTO_HASH_ALG_SHA256;
930 luks_opts.has_ivgen_hash_alg = true;
931 }
932 }
933 /* Note we're allowing ivgen_hash_alg to be set even for
934 * non-essiv iv generators that don't need a hash. It will
935 * be silently ignored, for compatibility with dm-crypt */
936
937 if (!options->u.luks.key_secret) {
938 error_setg(errp, "Parameter '%skey-secret' is required for cipher",
939 optprefix ? optprefix : "");
940 return -1;
941 }
942 password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp);
943 if (!password) {
944 return -1;
945 }
946
947 luks = g_new0(QCryptoBlockLUKS, 1);
948 block->opaque = luks;
949
950 memcpy(luks->header.magic, qcrypto_block_luks_magic,
951 QCRYPTO_BLOCK_LUKS_MAGIC_LEN);
952
953 /* We populate the header in native endianness initially and
954 * then convert everything to big endian just before writing
955 * it out to disk
956 */
957 luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION;
958 qcrypto_block_luks_uuid_gen(luks->header.uuid);
959
960 cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg,
961 errp);
962 if (!cipher_alg) {
963 goto error;
964 }
965
966 cipher_mode = QCryptoCipherMode_str(luks_opts.cipher_mode);
967 ivgen_alg = QCryptoIVGenAlgorithm_str(luks_opts.ivgen_alg);
968 if (luks_opts.has_ivgen_hash_alg) {
969 ivgen_hash_alg = QCryptoHashAlgorithm_str(luks_opts.ivgen_hash_alg);
970 cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg,
971 ivgen_hash_alg);
972 } else {
973 cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg);
974 }
975 hash_alg = QCryptoHashAlgorithm_str(luks_opts.hash_alg);
976
977
978 if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) {
979 error_setg(errp, "Cipher name '%s' is too long for LUKS header",
980 cipher_alg);
981 goto error;
982 }
983 if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) {
984 error_setg(errp, "Cipher mode '%s' is too long for LUKS header",
985 cipher_mode_spec);
986 goto error;
987 }
988 if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) {
989 error_setg(errp, "Hash name '%s' is too long for LUKS header",
990 hash_alg);
991 goto error;
992 }
993
994 if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
995 ivcipheralg = qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg,
996 luks_opts.ivgen_hash_alg,
997 &local_err);
998 if (local_err) {
999 error_propagate(errp, local_err);
1000 goto error;
1001 }
1002 } else {
1003 ivcipheralg = luks_opts.cipher_alg;
1004 }
1005
1006 strcpy(luks->header.cipher_name, cipher_alg);
1007 strcpy(luks->header.cipher_mode, cipher_mode_spec);
1008 strcpy(luks->header.hash_spec, hash_alg);
1009
1010 luks->header.key_bytes = qcrypto_cipher_get_key_len(luks_opts.cipher_alg);
1011 if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) {
1012 luks->header.key_bytes *= 2;
1013 }
1014
1015 /* Generate the salt used for hashing the master key
1016 * with PBKDF later
1017 */
1018 if (qcrypto_random_bytes(luks->header.master_key_salt,
1019 QCRYPTO_BLOCK_LUKS_SALT_LEN,
1020 errp) < 0) {
1021 goto error;
1022 }
1023
1024 /* Generate random master key */
1025 masterkey = g_new0(uint8_t, luks->header.key_bytes);
1026 if (qcrypto_random_bytes(masterkey,
1027 luks->header.key_bytes, errp) < 0) {
1028 goto error;
1029 }
1030
1031
1032 /* Setup the block device payload encryption objects */
1033 if (qcrypto_block_init_cipher(block, luks_opts.cipher_alg,
1034 luks_opts.cipher_mode, masterkey,
1035 luks->header.key_bytes, 1, errp) < 0) {
1036 goto error;
1037 }
1038
1039 block->kdfhash = luks_opts.hash_alg;
1040 block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg,
1041 luks_opts.cipher_mode);
1042 block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg,
1043 ivcipheralg,
1044 luks_opts.ivgen_hash_alg,
1045 masterkey, luks->header.key_bytes,
1046 errp);
1047
1048 if (!block->ivgen) {
1049 goto error;
1050 }
1051
1052
1053 /* Determine how many iterations we need to hash the master
1054 * key, in order to have 1 second of compute time used
1055 */
1056 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg,
1057 masterkey, luks->header.key_bytes,
1058 luks->header.master_key_salt,
1059 QCRYPTO_BLOCK_LUKS_SALT_LEN,
1060 QCRYPTO_BLOCK_LUKS_DIGEST_LEN,
1061 &local_err);
1062 if (local_err) {
1063 error_propagate(errp, local_err);
1064 goto error;
1065 }
1066
1067 if (iters > (ULLONG_MAX / luks_opts.iter_time)) {
1068 error_setg_errno(errp, ERANGE,
1069 "PBKDF iterations %llu too large to scale",
1070 (unsigned long long)iters);
1071 goto error;
1072 }
1073
1074 /* iter_time was in millis, but count_iters reported for secs */
1075 iters = iters * luks_opts.iter_time / 1000;
1076
1077 /* Why /= 8 ? That matches cryptsetup, but there's no
1078 * explanation why they chose /= 8... Probably so that
1079 * if all 8 keyslots are active we only spend 1 second
1080 * in total time to check all keys */
1081 iters /= 8;
1082 if (iters > UINT32_MAX) {
1083 error_setg_errno(errp, ERANGE,
1084 "PBKDF iterations %llu larger than %u",
1085 (unsigned long long)iters, UINT32_MAX);
1086 goto error;
1087 }
1088 iters = MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS);
1089 luks->header.master_key_iterations = iters;
1090
1091 /* Hash the master key, saving the result in the LUKS
1092 * header. This hash is used when opening the encrypted
1093 * device to verify that the user password unlocked a
1094 * valid master key
1095 */
1096 if (qcrypto_pbkdf2(luks_opts.hash_alg,
1097 masterkey, luks->header.key_bytes,
1098 luks->header.master_key_salt,
1099 QCRYPTO_BLOCK_LUKS_SALT_LEN,
1100 luks->header.master_key_iterations,
1101 luks->header.master_key_digest,
1102 QCRYPTO_BLOCK_LUKS_DIGEST_LEN,
1103 errp) < 0) {
1104 goto error;
1105 }
1106
1107
1108 /* Although LUKS has multiple key slots, we're just going
1109 * to use the first key slot */
1110 splitkeylen = luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRIPES;
1111 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1112 luks->header.key_slots[i].active = i == 0 ?
1113 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED :
1114 QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
1115 luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES;
1116
1117 /* This calculation doesn't match that shown in the spec,
1118 * but instead follows the cryptsetup implementation.
1119 */
1120 luks->header.key_slots[i].key_offset =
1121 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1122 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
1123 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
1124 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1125 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i);
1126 }
1127
1128 if (qcrypto_random_bytes(luks->header.key_slots[0].salt,
1129 QCRYPTO_BLOCK_LUKS_SALT_LEN,
1130 errp) < 0) {
1131 goto error;
1132 }
1133
1134 /* Again we determine how many iterations are required to
1135 * hash the user password while consuming 1 second of compute
1136 * time */
1137 iters = qcrypto_pbkdf2_count_iters(luks_opts.hash_alg,
1138 (uint8_t *)password, strlen(password),
1139 luks->header.key_slots[0].salt,
1140 QCRYPTO_BLOCK_LUKS_SALT_LEN,
1141 luks->header.key_bytes,
1142 &local_err);
1143 if (local_err) {
1144 error_propagate(errp, local_err);
1145 goto error;
1146 }
1147
1148 if (iters > (ULLONG_MAX / luks_opts.iter_time)) {
1149 error_setg_errno(errp, ERANGE,
1150 "PBKDF iterations %llu too large to scale",
1151 (unsigned long long)iters);
1152 goto error;
1153 }
1154
1155 /* iter_time was in millis, but count_iters reported for secs */
1156 iters = iters * luks_opts.iter_time / 1000;
1157
1158 if (iters > UINT32_MAX) {
1159 error_setg_errno(errp, ERANGE,
1160 "PBKDF iterations %llu larger than %u",
1161 (unsigned long long)iters, UINT32_MAX);
1162 goto error;
1163 }
1164
1165 luks->header.key_slots[0].iterations =
1166 MAX(iters, QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS);
1167
1168
1169 /* Generate a key that we'll use to encrypt the master
1170 * key, from the user's password
1171 */
1172 slotkey = g_new0(uint8_t, luks->header.key_bytes);
1173 if (qcrypto_pbkdf2(luks_opts.hash_alg,
1174 (uint8_t *)password, strlen(password),
1175 luks->header.key_slots[0].salt,
1176 QCRYPTO_BLOCK_LUKS_SALT_LEN,
1177 luks->header.key_slots[0].iterations,
1178 slotkey, luks->header.key_bytes,
1179 errp) < 0) {
1180 goto error;
1181 }
1182
1183
1184 /* Setup the encryption objects needed to encrypt the
1185 * master key material
1186 */
1187 cipher = qcrypto_cipher_new(luks_opts.cipher_alg,
1188 luks_opts.cipher_mode,
1189 slotkey, luks->header.key_bytes,
1190 errp);
1191 if (!cipher) {
1192 goto error;
1193 }
1194
1195 ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg,
1196 ivcipheralg,
1197 luks_opts.ivgen_hash_alg,
1198 slotkey, luks->header.key_bytes,
1199 errp);
1200 if (!ivgen) {
1201 goto error;
1202 }
1203
1204 /* Before storing the master key, we need to vastly
1205 * increase its size, as protection against forensic
1206 * disk data recovery */
1207 splitkey = g_new0(uint8_t, splitkeylen);
1208
1209 if (qcrypto_afsplit_encode(luks_opts.hash_alg,
1210 luks->header.key_bytes,
1211 luks->header.key_slots[0].stripes,
1212 masterkey,
1213 splitkey,
1214 errp) < 0) {
1215 goto error;
1216 }
1217
1218 /* Now we encrypt the split master key with the key generated
1219 * from the user's password, before storing it */
1220 if (qcrypto_block_cipher_encrypt_helper(cipher, block->niv, ivgen,
1221 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1222 0,
1223 splitkey,
1224 splitkeylen,
1225 errp) < 0) {
1226 goto error;
1227 }
1228
1229
1230 /* The total size of the LUKS headers is the partition header + key
1231 * slot headers, rounded up to the nearest sector, combined with
1232 * the size of each master key material region, also rounded up
1233 * to the nearest sector */
1234 luks->header.payload_offset =
1235 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1236 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
1237 (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
1238 (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1239 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) *
1240 QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
1241
1242 block->sector_size = QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1243 block->payload_offset = luks->header.payload_offset *
1244 block->sector_size;
1245
1246 /* Reserve header space to match payload offset */
1247 initfunc(block, block->payload_offset, opaque, &local_err);
1248 if (local_err) {
1249 error_propagate(errp, local_err);
1250 goto error;
1251 }
1252
1253 /* Everything on disk uses Big Endian, so flip header fields
1254 * before writing them */
1255 cpu_to_be16s(&luks->header.version);
1256 cpu_to_be32s(&luks->header.payload_offset);
1257 cpu_to_be32s(&luks->header.key_bytes);
1258 cpu_to_be32s(&luks->header.master_key_iterations);
1259
1260 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1261 cpu_to_be32s(&luks->header.key_slots[i].active);
1262 cpu_to_be32s(&luks->header.key_slots[i].iterations);
1263 cpu_to_be32s(&luks->header.key_slots[i].key_offset);
1264 cpu_to_be32s(&luks->header.key_slots[i].stripes);
1265 }
1266
1267
1268 /* Write out the partition header and key slot headers */
1269 writefunc(block, 0,
1270 (const uint8_t *)&luks->header,
1271 sizeof(luks->header),
1272 opaque,
1273 &local_err);
1274
1275 /* Delay checking local_err until we've byte-swapped */
1276
1277 /* Byte swap the header back to native, in case we need
1278 * to read it again later */
1279 be16_to_cpus(&luks->header.version);
1280 be32_to_cpus(&luks->header.payload_offset);
1281 be32_to_cpus(&luks->header.key_bytes);
1282 be32_to_cpus(&luks->header.master_key_iterations);
1283
1284 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1285 be32_to_cpus(&luks->header.key_slots[i].active);
1286 be32_to_cpus(&luks->header.key_slots[i].iterations);
1287 be32_to_cpus(&luks->header.key_slots[i].key_offset);
1288 be32_to_cpus(&luks->header.key_slots[i].stripes);
1289 }
1290
1291 if (local_err) {
1292 error_propagate(errp, local_err);
1293 goto error;
1294 }
1295
1296 /* Write out the master key material, starting at the
1297 * sector immediately following the partition header. */
1298 if (writefunc(block,
1299 luks->header.key_slots[0].key_offset *
1300 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1301 splitkey, splitkeylen,
1302 opaque,
1303 errp) != splitkeylen) {
1304 goto error;
1305 }
1306
1307 luks->cipher_alg = luks_opts.cipher_alg;
1308 luks->cipher_mode = luks_opts.cipher_mode;
1309 luks->ivgen_alg = luks_opts.ivgen_alg;
1310 luks->ivgen_hash_alg = luks_opts.ivgen_hash_alg;
1311 luks->hash_alg = luks_opts.hash_alg;
1312
1313 memset(masterkey, 0, luks->header.key_bytes);
1314 g_free(masterkey);
1315 memset(slotkey, 0, luks->header.key_bytes);
1316 g_free(slotkey);
1317 g_free(splitkey);
1318 g_free(password);
1319 g_free(cipher_mode_spec);
1320
1321 qcrypto_ivgen_free(ivgen);
1322 qcrypto_cipher_free(cipher);
1323
1324 return 0;
1325
1326 error:
1327 if (masterkey) {
1328 memset(masterkey, 0, luks->header.key_bytes);
1329 }
1330 g_free(masterkey);
1331 if (slotkey) {
1332 memset(slotkey, 0, luks->header.key_bytes);
1333 }
1334 g_free(slotkey);
1335 g_free(splitkey);
1336 g_free(password);
1337 g_free(cipher_mode_spec);
1338
1339 qcrypto_ivgen_free(ivgen);
1340 qcrypto_cipher_free(cipher);
1341
1342 qcrypto_block_free_cipher(block);
1343 qcrypto_ivgen_free(block->ivgen);
1344
1345 g_free(luks);
1346 return -1;
1347 }
1348
1349
1350 static int qcrypto_block_luks_get_info(QCryptoBlock *block,
1351 QCryptoBlockInfo *info,
1352 Error **errp)
1353 {
1354 QCryptoBlockLUKS *luks = block->opaque;
1355 QCryptoBlockInfoLUKSSlot *slot;
1356 QCryptoBlockInfoLUKSSlotList *slots = NULL, **prev = &info->u.luks.slots;
1357 size_t i;
1358
1359 info->u.luks.cipher_alg = luks->cipher_alg;
1360 info->u.luks.cipher_mode = luks->cipher_mode;
1361 info->u.luks.ivgen_alg = luks->ivgen_alg;
1362 if (info->u.luks.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
1363 info->u.luks.has_ivgen_hash_alg = true;
1364 info->u.luks.ivgen_hash_alg = luks->ivgen_hash_alg;
1365 }
1366 info->u.luks.hash_alg = luks->hash_alg;
1367 info->u.luks.payload_offset = block->payload_offset;
1368 info->u.luks.master_key_iters = luks->header.master_key_iterations;
1369 info->u.luks.uuid = g_strndup((const char *)luks->header.uuid,
1370 sizeof(luks->header.uuid));
1371
1372 for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1373 slots = g_new0(QCryptoBlockInfoLUKSSlotList, 1);
1374 *prev = slots;
1375
1376 slots->value = slot = g_new0(QCryptoBlockInfoLUKSSlot, 1);
1377 slot->active = luks->header.key_slots[i].active ==
1378 QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED;
1379 slot->key_offset = luks->header.key_slots[i].key_offset
1380 * QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1381 if (slot->active) {
1382 slot->has_iters = true;
1383 slot->iters = luks->header.key_slots[i].iterations;
1384 slot->has_stripes = true;
1385 slot->stripes = luks->header.key_slots[i].stripes;
1386 }
1387
1388 prev = &slots->next;
1389 }
1390
1391 return 0;
1392 }
1393
1394
1395 static void qcrypto_block_luks_cleanup(QCryptoBlock *block)
1396 {
1397 g_free(block->opaque);
1398 }
1399
1400
1401 static int
1402 qcrypto_block_luks_decrypt(QCryptoBlock *block,
1403 uint64_t offset,
1404 uint8_t *buf,
1405 size_t len,
1406 Error **errp)
1407 {
1408 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1409 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1410 return qcrypto_block_decrypt_helper(block,
1411 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1412 offset, buf, len, errp);
1413 }
1414
1415
1416 static int
1417 qcrypto_block_luks_encrypt(QCryptoBlock *block,
1418 uint64_t offset,
1419 uint8_t *buf,
1420 size_t len,
1421 Error **errp)
1422 {
1423 assert(QEMU_IS_ALIGNED(offset, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1424 assert(QEMU_IS_ALIGNED(len, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE));
1425 return qcrypto_block_encrypt_helper(block,
1426 QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1427 offset, buf, len, errp);
1428 }
1429
1430
1431 const QCryptoBlockDriver qcrypto_block_driver_luks = {
1432 .open = qcrypto_block_luks_open,
1433 .create = qcrypto_block_luks_create,
1434 .get_info = qcrypto_block_luks_get_info,
1435 .cleanup = qcrypto_block_luks_cleanup,
1436 .decrypt = qcrypto_block_luks_decrypt,
1437 .encrypt = qcrypto_block_luks_encrypt,
1438 .has_format = qcrypto_block_luks_has_format,
1439 };