Merge remote-tracking branch 'remotes/kraxel/tags/pull-vga-20170103-1' into staging
[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 "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 };