xref: /openbmc/qemu/crypto/block-luks.c (revision 35658f6e)
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 
33 #ifdef CONFIG_UUID
34 #include <uuid/uuid.h>
35 #endif
36 
37 #include "qemu/coroutine.h"
38 
39 /*
40  * Reference for the LUKS format implemented here is
41  *
42  *   docs/on-disk-format.pdf
43  *
44  * in 'cryptsetup' package source code
45  *
46  * This file implements the 1.2.1 specification, dated
47  * Oct 16, 2011.
48  */
49 
50 typedef struct QCryptoBlockLUKS QCryptoBlockLUKS;
51 typedef struct QCryptoBlockLUKSHeader QCryptoBlockLUKSHeader;
52 typedef struct QCryptoBlockLUKSKeySlot QCryptoBlockLUKSKeySlot;
53 
54 
55 /* The following constants are all defined by the LUKS spec */
56 #define QCRYPTO_BLOCK_LUKS_VERSION 1
57 
58 #define QCRYPTO_BLOCK_LUKS_MAGIC_LEN 6
59 #define QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN 32
60 #define QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN 32
61 #define QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN 32
62 #define QCRYPTO_BLOCK_LUKS_DIGEST_LEN 20
63 #define QCRYPTO_BLOCK_LUKS_SALT_LEN 32
64 #define QCRYPTO_BLOCK_LUKS_UUID_LEN 40
65 #define QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS 8
66 #define QCRYPTO_BLOCK_LUKS_STRIPES 4000
67 #define QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS 1000
68 #define QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS 1000
69 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET 4096
70 
71 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED 0x0000DEAD
72 #define QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED 0x00AC71F3
73 
74 #define QCRYPTO_BLOCK_LUKS_SECTOR_SIZE 512LL
75 
76 static const char qcrypto_block_luks_magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN] = {
77     'L', 'U', 'K', 'S', 0xBA, 0xBE
78 };
79 
80 typedef struct QCryptoBlockLUKSNameMap QCryptoBlockLUKSNameMap;
81 struct QCryptoBlockLUKSNameMap {
82     const char *name;
83     int id;
84 };
85 
86 typedef struct QCryptoBlockLUKSCipherSizeMap QCryptoBlockLUKSCipherSizeMap;
87 struct QCryptoBlockLUKSCipherSizeMap {
88     uint32_t key_bytes;
89     int id;
90 };
91 typedef struct QCryptoBlockLUKSCipherNameMap QCryptoBlockLUKSCipherNameMap;
92 struct QCryptoBlockLUKSCipherNameMap {
93     const char *name;
94     const QCryptoBlockLUKSCipherSizeMap *sizes;
95 };
96 
97 
98 static const QCryptoBlockLUKSCipherSizeMap
99 qcrypto_block_luks_cipher_size_map_aes[] = {
100     { 16, QCRYPTO_CIPHER_ALG_AES_128 },
101     { 24, QCRYPTO_CIPHER_ALG_AES_192 },
102     { 32, QCRYPTO_CIPHER_ALG_AES_256 },
103     { 0, 0 },
104 };
105 
106 static const QCryptoBlockLUKSCipherSizeMap
107 qcrypto_block_luks_cipher_size_map_cast5[] = {
108     { 16, QCRYPTO_CIPHER_ALG_CAST5_128 },
109     { 0, 0 },
110 };
111 
112 static const QCryptoBlockLUKSCipherSizeMap
113 qcrypto_block_luks_cipher_size_map_serpent[] = {
114     { 16, QCRYPTO_CIPHER_ALG_SERPENT_128 },
115     { 24, QCRYPTO_CIPHER_ALG_SERPENT_192 },
116     { 32, QCRYPTO_CIPHER_ALG_SERPENT_256 },
117     { 0, 0 },
118 };
119 
120 static const QCryptoBlockLUKSCipherSizeMap
121 qcrypto_block_luks_cipher_size_map_twofish[] = {
122     { 16, QCRYPTO_CIPHER_ALG_TWOFISH_128 },
123     { 24, QCRYPTO_CIPHER_ALG_TWOFISH_192 },
124     { 32, QCRYPTO_CIPHER_ALG_TWOFISH_256 },
125     { 0, 0 },
126 };
127 
128 static const QCryptoBlockLUKSCipherNameMap
129 qcrypto_block_luks_cipher_name_map[] = {
130     { "aes", qcrypto_block_luks_cipher_size_map_aes },
131     { "cast5", qcrypto_block_luks_cipher_size_map_cast5 },
132     { "serpent", qcrypto_block_luks_cipher_size_map_serpent },
133     { "twofish", qcrypto_block_luks_cipher_size_map_twofish },
134 };
135 
136 
137 /*
138  * This struct is written to disk in big-endian format,
139  * but operated upon in native-endian format.
140  */
141 struct QCryptoBlockLUKSKeySlot {
142     /* state of keyslot, enabled/disable */
143     uint32_t active;
144     /* iterations for PBKDF2 */
145     uint32_t iterations;
146     /* salt for PBKDF2 */
147     uint8_t salt[QCRYPTO_BLOCK_LUKS_SALT_LEN];
148     /* start sector of key material */
149     uint32_t key_offset;
150     /* number of anti-forensic stripes */
151     uint32_t stripes;
152 } QEMU_PACKED;
153 
154 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSKeySlot) != 48);
155 
156 
157 /*
158  * This struct is written to disk in big-endian format,
159  * but operated upon in native-endian format.
160  */
161 struct QCryptoBlockLUKSHeader {
162     /* 'L', 'U', 'K', 'S', '0xBA', '0xBE' */
163     char magic[QCRYPTO_BLOCK_LUKS_MAGIC_LEN];
164 
165     /* LUKS version, currently 1 */
166     uint16_t version;
167 
168     /* cipher name specification (aes, etc) */
169     char cipher_name[QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN];
170 
171     /* cipher mode specification (cbc-plain, xts-essiv:sha256, etc) */
172     char cipher_mode[QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN];
173 
174     /* hash specification (sha256, etc) */
175     char hash_spec[QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN];
176 
177     /* start offset of the volume data (in 512 byte sectors) */
178     uint32_t payload_offset;
179 
180     /* Number of key bytes */
181     uint32_t key_bytes;
182 
183     /* master key checksum after PBKDF2 */
184     uint8_t master_key_digest[QCRYPTO_BLOCK_LUKS_DIGEST_LEN];
185 
186     /* salt for master key PBKDF2 */
187     uint8_t master_key_salt[QCRYPTO_BLOCK_LUKS_SALT_LEN];
188 
189     /* iterations for master key PBKDF2 */
190     uint32_t master_key_iterations;
191 
192     /* UUID of the partition in standard ASCII representation */
193     uint8_t uuid[QCRYPTO_BLOCK_LUKS_UUID_LEN];
194 
195     /* key slots */
196     QCryptoBlockLUKSKeySlot key_slots[QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS];
197 } QEMU_PACKED;
198 
199 QEMU_BUILD_BUG_ON(sizeof(struct QCryptoBlockLUKSHeader) != 592);
200 
201 
202 struct QCryptoBlockLUKS {
203     QCryptoBlockLUKSHeader header;
204 };
205 
206 
207 static int qcrypto_block_luks_cipher_name_lookup(const char *name,
208                                                  QCryptoCipherMode mode,
209                                                  uint32_t key_bytes,
210                                                  Error **errp)
211 {
212     const QCryptoBlockLUKSCipherNameMap *map =
213         qcrypto_block_luks_cipher_name_map;
214     size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
215     size_t i, j;
216 
217     if (mode == QCRYPTO_CIPHER_MODE_XTS) {
218         key_bytes /= 2;
219     }
220 
221     for (i = 0; i < maplen; i++) {
222         if (!g_str_equal(map[i].name, name)) {
223             continue;
224         }
225         for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
226             if (map[i].sizes[j].key_bytes == key_bytes) {
227                 return map[i].sizes[j].id;
228             }
229         }
230     }
231 
232     error_setg(errp, "Algorithm %s with key size %d bytes not supported",
233                name, key_bytes);
234     return 0;
235 }
236 
237 static const char *
238 qcrypto_block_luks_cipher_alg_lookup(QCryptoCipherAlgorithm alg,
239                                      Error **errp)
240 {
241     const QCryptoBlockLUKSCipherNameMap *map =
242         qcrypto_block_luks_cipher_name_map;
243     size_t maplen = G_N_ELEMENTS(qcrypto_block_luks_cipher_name_map);
244     size_t i, j;
245     for (i = 0; i < maplen; i++) {
246         for (j = 0; j < map[i].sizes[j].key_bytes; j++) {
247             if (map[i].sizes[j].id == alg) {
248                 return map[i].name;
249             }
250         }
251     }
252 
253     error_setg(errp, "Algorithm '%s' not supported",
254                QCryptoCipherAlgorithm_lookup[alg]);
255     return NULL;
256 }
257 
258 /* XXX replace with qapi_enum_parse() in future, when we can
259  * make that function emit a more friendly error message */
260 static int qcrypto_block_luks_name_lookup(const char *name,
261                                           const char *const *map,
262                                           size_t maplen,
263                                           const char *type,
264                                           Error **errp)
265 {
266     size_t i;
267     for (i = 0; i < maplen; i++) {
268         if (g_str_equal(map[i], name)) {
269             return i;
270         }
271     }
272 
273     error_setg(errp, "%s %s not supported", type, name);
274     return 0;
275 }
276 
277 #define qcrypto_block_luks_cipher_mode_lookup(name, errp)               \
278     qcrypto_block_luks_name_lookup(name,                                \
279                                    QCryptoCipherMode_lookup,            \
280                                    QCRYPTO_CIPHER_MODE__MAX,            \
281                                    "Cipher mode",                       \
282                                    errp)
283 
284 #define qcrypto_block_luks_hash_name_lookup(name, errp)                 \
285     qcrypto_block_luks_name_lookup(name,                                \
286                                    QCryptoHashAlgorithm_lookup,         \
287                                    QCRYPTO_HASH_ALG__MAX,               \
288                                    "Hash algorithm",                    \
289                                    errp)
290 
291 #define qcrypto_block_luks_ivgen_name_lookup(name, errp)                \
292     qcrypto_block_luks_name_lookup(name,                                \
293                                    QCryptoIVGenAlgorithm_lookup,        \
294                                    QCRYPTO_IVGEN_ALG__MAX,              \
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_lookup[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                   errp,
473                   opaque);
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_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                         QCryptoBlockReadFunc readfunc,
636                         void *opaque,
637                         unsigned int flags,
638                         Error **errp)
639 {
640     QCryptoBlockLUKS *luks;
641     Error *local_err = NULL;
642     int ret = 0;
643     size_t i;
644     ssize_t rv;
645     uint8_t *masterkey = NULL;
646     size_t masterkeylen;
647     char *ivgen_name, *ivhash_name;
648     QCryptoCipherMode ciphermode;
649     QCryptoCipherAlgorithm cipheralg;
650     QCryptoIVGenAlgorithm ivalg;
651     QCryptoCipherAlgorithm ivcipheralg;
652     QCryptoHashAlgorithm hash;
653     QCryptoHashAlgorithm ivhash;
654     char *password = NULL;
655 
656     if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
657         if (!options->u.luks.key_secret) {
658             error_setg(errp, "Parameter 'key-secret' is required for cipher");
659             return -1;
660         }
661         password = qcrypto_secret_lookup_as_utf8(
662             options->u.luks.key_secret, errp);
663         if (!password) {
664             return -1;
665         }
666     }
667 
668     luks = g_new0(QCryptoBlockLUKS, 1);
669     block->opaque = luks;
670 
671     /* Read the entire LUKS header, minus the key material from
672      * the underlying device */
673     rv = readfunc(block, 0,
674                   (uint8_t *)&luks->header,
675                   sizeof(luks->header),
676                   errp,
677                   opaque);
678     if (rv < 0) {
679         ret = rv;
680         goto fail;
681     }
682 
683     /* The header is always stored in big-endian format, so
684      * convert everything to native */
685     be16_to_cpus(&luks->header.version);
686     be32_to_cpus(&luks->header.payload_offset);
687     be32_to_cpus(&luks->header.key_bytes);
688     be32_to_cpus(&luks->header.master_key_iterations);
689 
690     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
691         be32_to_cpus(&luks->header.key_slots[i].active);
692         be32_to_cpus(&luks->header.key_slots[i].iterations);
693         be32_to_cpus(&luks->header.key_slots[i].key_offset);
694         be32_to_cpus(&luks->header.key_slots[i].stripes);
695     }
696 
697     if (memcmp(luks->header.magic, qcrypto_block_luks_magic,
698                QCRYPTO_BLOCK_LUKS_MAGIC_LEN) != 0) {
699         error_setg(errp, "Volume is not in LUKS format");
700         ret = -EINVAL;
701         goto fail;
702     }
703     if (luks->header.version != QCRYPTO_BLOCK_LUKS_VERSION) {
704         error_setg(errp, "LUKS version %" PRIu32 " is not supported",
705                    luks->header.version);
706         ret = -ENOTSUP;
707         goto fail;
708     }
709 
710     /*
711      * The cipher_mode header contains a string that we have
712      * to further parse, of the format
713      *
714      *    <cipher-mode>-<iv-generator>[:<iv-hash>]
715      *
716      * eg  cbc-essiv:sha256, cbc-plain64
717      */
718     ivgen_name = strchr(luks->header.cipher_mode, '-');
719     if (!ivgen_name) {
720         ret = -EINVAL;
721         error_setg(errp, "Unexpected cipher mode string format %s",
722                    luks->header.cipher_mode);
723         goto fail;
724     }
725     *ivgen_name = '\0';
726     ivgen_name++;
727 
728     ivhash_name = strchr(ivgen_name, ':');
729     if (!ivhash_name) {
730         ivhash = 0;
731     } else {
732         *ivhash_name = '\0';
733         ivhash_name++;
734 
735         ivhash = qcrypto_block_luks_hash_name_lookup(ivhash_name,
736                                                      &local_err);
737         if (local_err) {
738             ret = -ENOTSUP;
739             error_propagate(errp, local_err);
740             goto fail;
741         }
742     }
743 
744     ciphermode = qcrypto_block_luks_cipher_mode_lookup(luks->header.cipher_mode,
745                                                        &local_err);
746     if (local_err) {
747         ret = -ENOTSUP;
748         error_propagate(errp, local_err);
749         goto fail;
750     }
751 
752     cipheralg = qcrypto_block_luks_cipher_name_lookup(luks->header.cipher_name,
753                                                       ciphermode,
754                                                       luks->header.key_bytes,
755                                                       &local_err);
756     if (local_err) {
757         ret = -ENOTSUP;
758         error_propagate(errp, local_err);
759         goto fail;
760     }
761 
762     hash = qcrypto_block_luks_hash_name_lookup(luks->header.hash_spec,
763                                                &local_err);
764     if (local_err) {
765         ret = -ENOTSUP;
766         error_propagate(errp, local_err);
767         goto fail;
768     }
769 
770     ivalg = qcrypto_block_luks_ivgen_name_lookup(ivgen_name,
771                                                  &local_err);
772     if (local_err) {
773         ret = -ENOTSUP;
774         error_propagate(errp, local_err);
775         goto fail;
776     }
777 
778     if (ivalg == QCRYPTO_IVGEN_ALG_ESSIV) {
779         ivcipheralg = qcrypto_block_luks_essiv_cipher(cipheralg,
780                                                       ivhash,
781                                                       &local_err);
782         if (local_err) {
783             ret = -ENOTSUP;
784             error_propagate(errp, local_err);
785             goto fail;
786         }
787     } else {
788         ivcipheralg = cipheralg;
789     }
790 
791     if (!(flags & QCRYPTO_BLOCK_OPEN_NO_IO)) {
792         /* Try to find which key slot our password is valid for
793          * and unlock the master key from that slot.
794          */
795         if (qcrypto_block_luks_find_key(block,
796                                         password,
797                                         cipheralg, ciphermode,
798                                         hash,
799                                         ivalg,
800                                         ivcipheralg,
801                                         ivhash,
802                                         &masterkey, &masterkeylen,
803                                         readfunc, opaque,
804                                         errp) < 0) {
805             ret = -EACCES;
806             goto fail;
807         }
808 
809         /* We have a valid master key now, so can setup the
810          * block device payload decryption objects
811          */
812         block->kdfhash = hash;
813         block->niv = qcrypto_cipher_get_iv_len(cipheralg,
814                                                ciphermode);
815         block->ivgen = qcrypto_ivgen_new(ivalg,
816                                          ivcipheralg,
817                                          ivhash,
818                                          masterkey, masterkeylen,
819                                          errp);
820         if (!block->ivgen) {
821             ret = -ENOTSUP;
822             goto fail;
823         }
824 
825         block->cipher = qcrypto_cipher_new(cipheralg,
826                                            ciphermode,
827                                            masterkey, masterkeylen,
828                                            errp);
829         if (!block->cipher) {
830             ret = -ENOTSUP;
831             goto fail;
832         }
833     }
834 
835     block->payload_offset = luks->header.payload_offset *
836         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
837 
838     g_free(masterkey);
839     g_free(password);
840 
841     return 0;
842 
843  fail:
844     g_free(masterkey);
845     qcrypto_cipher_free(block->cipher);
846     qcrypto_ivgen_free(block->ivgen);
847     g_free(luks);
848     g_free(password);
849     return ret;
850 }
851 
852 
853 static int
854 qcrypto_block_luks_uuid_gen(uint8_t *uuidstr, Error **errp)
855 {
856 #ifdef CONFIG_UUID
857     uuid_t uuid;
858     uuid_generate(uuid);
859     uuid_unparse(uuid, (char *)uuidstr);
860     return 0;
861 #else
862     error_setg(errp, "Unable to generate uuids on this platform");
863     return -1;
864 #endif
865 }
866 
867 static int
868 qcrypto_block_luks_create(QCryptoBlock *block,
869                           QCryptoBlockCreateOptions *options,
870                           QCryptoBlockInitFunc initfunc,
871                           QCryptoBlockWriteFunc writefunc,
872                           void *opaque,
873                           Error **errp)
874 {
875     QCryptoBlockLUKS *luks;
876     QCryptoBlockCreateOptionsLUKS luks_opts;
877     Error *local_err = NULL;
878     uint8_t *masterkey = NULL;
879     uint8_t *slotkey = NULL;
880     uint8_t *splitkey = NULL;
881     size_t splitkeylen = 0;
882     size_t i;
883     QCryptoCipher *cipher = NULL;
884     QCryptoIVGen *ivgen = NULL;
885     char *password;
886     const char *cipher_alg;
887     const char *cipher_mode;
888     const char *ivgen_alg;
889     const char *ivgen_hash_alg = NULL;
890     const char *hash_alg;
891     char *cipher_mode_spec = NULL;
892     QCryptoCipherAlgorithm ivcipheralg = 0;
893 
894     memcpy(&luks_opts, &options->u.luks, sizeof(luks_opts));
895     if (!luks_opts.has_cipher_alg) {
896         luks_opts.cipher_alg = QCRYPTO_CIPHER_ALG_AES_256;
897     }
898     if (!luks_opts.has_cipher_mode) {
899         luks_opts.cipher_mode = QCRYPTO_CIPHER_MODE_XTS;
900     }
901     if (!luks_opts.has_ivgen_alg) {
902         luks_opts.ivgen_alg = QCRYPTO_IVGEN_ALG_PLAIN64;
903     }
904     if (!luks_opts.has_hash_alg) {
905         luks_opts.hash_alg = QCRYPTO_HASH_ALG_SHA256;
906     }
907 
908     if (!options->u.luks.key_secret) {
909         error_setg(errp, "Parameter 'key-secret' is required for cipher");
910         return -1;
911     }
912     password = qcrypto_secret_lookup_as_utf8(luks_opts.key_secret, errp);
913     if (!password) {
914         return -1;
915     }
916 
917     luks = g_new0(QCryptoBlockLUKS, 1);
918     block->opaque = luks;
919 
920     memcpy(luks->header.magic, qcrypto_block_luks_magic,
921            QCRYPTO_BLOCK_LUKS_MAGIC_LEN);
922 
923     /* We populate the header in native endianness initially and
924      * then convert everything to big endian just before writing
925      * it out to disk
926      */
927     luks->header.version = QCRYPTO_BLOCK_LUKS_VERSION;
928     if (qcrypto_block_luks_uuid_gen(luks->header.uuid,
929                                     errp) < 0) {
930         goto error;
931     }
932 
933     cipher_alg = qcrypto_block_luks_cipher_alg_lookup(luks_opts.cipher_alg,
934                                                       errp);
935     if (!cipher_alg) {
936         goto error;
937     }
938 
939     cipher_mode = QCryptoCipherMode_lookup[luks_opts.cipher_mode];
940     ivgen_alg = QCryptoIVGenAlgorithm_lookup[luks_opts.ivgen_alg];
941     if (luks_opts.has_ivgen_hash_alg) {
942         ivgen_hash_alg = QCryptoHashAlgorithm_lookup[luks_opts.ivgen_hash_alg];
943         cipher_mode_spec = g_strdup_printf("%s-%s:%s", cipher_mode, ivgen_alg,
944                                            ivgen_hash_alg);
945     } else {
946         cipher_mode_spec = g_strdup_printf("%s-%s", cipher_mode, ivgen_alg);
947     }
948     hash_alg = QCryptoHashAlgorithm_lookup[luks_opts.hash_alg];
949 
950 
951     if (strlen(cipher_alg) >= QCRYPTO_BLOCK_LUKS_CIPHER_NAME_LEN) {
952         error_setg(errp, "Cipher name '%s' is too long for LUKS header",
953                    cipher_alg);
954         goto error;
955     }
956     if (strlen(cipher_mode_spec) >= QCRYPTO_BLOCK_LUKS_CIPHER_MODE_LEN) {
957         error_setg(errp, "Cipher mode '%s' is too long for LUKS header",
958                    cipher_mode_spec);
959         goto error;
960     }
961     if (strlen(hash_alg) >= QCRYPTO_BLOCK_LUKS_HASH_SPEC_LEN) {
962         error_setg(errp, "Hash name '%s' is too long for LUKS header",
963                    hash_alg);
964         goto error;
965     }
966 
967     if (luks_opts.ivgen_alg == QCRYPTO_IVGEN_ALG_ESSIV) {
968         ivcipheralg = qcrypto_block_luks_essiv_cipher(luks_opts.cipher_alg,
969                                                       luks_opts.ivgen_hash_alg,
970                                                       &local_err);
971         if (local_err) {
972             error_propagate(errp, local_err);
973             goto error;
974         }
975     } else {
976         ivcipheralg = luks_opts.cipher_alg;
977     }
978 
979     strcpy(luks->header.cipher_name, cipher_alg);
980     strcpy(luks->header.cipher_mode, cipher_mode_spec);
981     strcpy(luks->header.hash_spec, hash_alg);
982 
983     luks->header.key_bytes = qcrypto_cipher_get_key_len(luks_opts.cipher_alg);
984     if (luks_opts.cipher_mode == QCRYPTO_CIPHER_MODE_XTS) {
985         luks->header.key_bytes *= 2;
986     }
987 
988     /* Generate the salt used for hashing the master key
989      * with PBKDF later
990      */
991     if (qcrypto_random_bytes(luks->header.master_key_salt,
992                              QCRYPTO_BLOCK_LUKS_SALT_LEN,
993                              errp) < 0) {
994         goto error;
995     }
996 
997     /* Generate random master key */
998     masterkey = g_new0(uint8_t, luks->header.key_bytes);
999     if (qcrypto_random_bytes(masterkey,
1000                              luks->header.key_bytes, errp) < 0) {
1001         goto error;
1002     }
1003 
1004 
1005     /* Setup the block device payload encryption objects */
1006     block->cipher = qcrypto_cipher_new(luks_opts.cipher_alg,
1007                                        luks_opts.cipher_mode,
1008                                        masterkey, luks->header.key_bytes,
1009                                        errp);
1010     if (!block->cipher) {
1011         goto error;
1012     }
1013 
1014     block->kdfhash = luks_opts.hash_alg;
1015     block->niv = qcrypto_cipher_get_iv_len(luks_opts.cipher_alg,
1016                                            luks_opts.cipher_mode);
1017     block->ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg,
1018                                      ivcipheralg,
1019                                      luks_opts.ivgen_hash_alg,
1020                                      masterkey, luks->header.key_bytes,
1021                                      errp);
1022 
1023     if (!block->ivgen) {
1024         goto error;
1025     }
1026 
1027 
1028     /* Determine how many iterations we need to hash the master
1029      * key, in order to have 1 second of compute time used
1030      */
1031     luks->header.master_key_iterations =
1032         qcrypto_pbkdf2_count_iters(luks_opts.hash_alg,
1033                                    masterkey, luks->header.key_bytes,
1034                                    luks->header.master_key_salt,
1035                                    QCRYPTO_BLOCK_LUKS_SALT_LEN,
1036                                    &local_err);
1037     if (local_err) {
1038         error_propagate(errp, local_err);
1039         goto error;
1040     }
1041 
1042     /* Why /= 8 ?  That matches cryptsetup, but there's no
1043      * explanation why they chose /= 8... Probably so that
1044      * if all 8 keyslots are active we only spend 1 second
1045      * in total time to check all keys */
1046     luks->header.master_key_iterations /= 8;
1047     luks->header.master_key_iterations = MAX(
1048         luks->header.master_key_iterations,
1049         QCRYPTO_BLOCK_LUKS_MIN_MASTER_KEY_ITERS);
1050 
1051 
1052     /* Hash the master key, saving the result in the LUKS
1053      * header. This hash is used when opening the encrypted
1054      * device to verify that the user password unlocked a
1055      * valid master key
1056      */
1057     if (qcrypto_pbkdf2(luks_opts.hash_alg,
1058                        masterkey, luks->header.key_bytes,
1059                        luks->header.master_key_salt,
1060                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
1061                        luks->header.master_key_iterations,
1062                        luks->header.master_key_digest,
1063                        QCRYPTO_BLOCK_LUKS_DIGEST_LEN,
1064                        errp) < 0) {
1065         goto error;
1066     }
1067 
1068 
1069     /* Although LUKS has multiple key slots, we're just going
1070      * to use the first key slot */
1071     splitkeylen = luks->header.key_bytes * QCRYPTO_BLOCK_LUKS_STRIPES;
1072     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1073         luks->header.key_slots[i].active = i == 0 ?
1074             QCRYPTO_BLOCK_LUKS_KEY_SLOT_ENABLED :
1075             QCRYPTO_BLOCK_LUKS_KEY_SLOT_DISABLED;
1076         luks->header.key_slots[i].stripes = QCRYPTO_BLOCK_LUKS_STRIPES;
1077 
1078         /* This calculation doesn't match that shown in the spec,
1079          * but instead follows the cryptsetup implementation.
1080          */
1081         luks->header.key_slots[i].key_offset =
1082             (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1083              QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
1084             (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
1085                       (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1086                        QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) * i);
1087     }
1088 
1089     if (qcrypto_random_bytes(luks->header.key_slots[0].salt,
1090                              QCRYPTO_BLOCK_LUKS_SALT_LEN,
1091                              errp) < 0) {
1092         goto error;
1093     }
1094 
1095     /* Again we determine how many iterations are required to
1096      * hash the user password while consuming 1 second of compute
1097      * time */
1098     luks->header.key_slots[0].iterations =
1099         qcrypto_pbkdf2_count_iters(luks_opts.hash_alg,
1100                                    (uint8_t *)password, strlen(password),
1101                                    luks->header.key_slots[0].salt,
1102                                    QCRYPTO_BLOCK_LUKS_SALT_LEN,
1103                                    &local_err);
1104     if (local_err) {
1105         error_propagate(errp, local_err);
1106         goto error;
1107     }
1108     /* Why /= 2 ?  That matches cryptsetup, but there's no
1109      * explanation why they chose /= 2... */
1110     luks->header.key_slots[0].iterations /= 2;
1111     luks->header.key_slots[0].iterations = MAX(
1112         luks->header.key_slots[0].iterations,
1113         QCRYPTO_BLOCK_LUKS_MIN_SLOT_KEY_ITERS);
1114 
1115 
1116     /* Generate a key that we'll use to encrypt the master
1117      * key, from the user's password
1118      */
1119     slotkey = g_new0(uint8_t, luks->header.key_bytes);
1120     if (qcrypto_pbkdf2(luks_opts.hash_alg,
1121                        (uint8_t *)password, strlen(password),
1122                        luks->header.key_slots[0].salt,
1123                        QCRYPTO_BLOCK_LUKS_SALT_LEN,
1124                        luks->header.key_slots[0].iterations,
1125                        slotkey, luks->header.key_bytes,
1126                        errp) < 0) {
1127         goto error;
1128     }
1129 
1130 
1131     /* Setup the encryption objects needed to encrypt the
1132      * master key material
1133      */
1134     cipher = qcrypto_cipher_new(luks_opts.cipher_alg,
1135                                 luks_opts.cipher_mode,
1136                                 slotkey, luks->header.key_bytes,
1137                                 errp);
1138     if (!cipher) {
1139         goto error;
1140     }
1141 
1142     ivgen = qcrypto_ivgen_new(luks_opts.ivgen_alg,
1143                               ivcipheralg,
1144                               luks_opts.ivgen_hash_alg,
1145                               slotkey, luks->header.key_bytes,
1146                               errp);
1147     if (!ivgen) {
1148         goto error;
1149     }
1150 
1151     /* Before storing the master key, we need to vastly
1152      * increase its size, as protection against forensic
1153      * disk data recovery */
1154     splitkey = g_new0(uint8_t, splitkeylen);
1155 
1156     if (qcrypto_afsplit_encode(luks_opts.hash_alg,
1157                                luks->header.key_bytes,
1158                                luks->header.key_slots[0].stripes,
1159                                masterkey,
1160                                splitkey,
1161                                errp) < 0) {
1162         goto error;
1163     }
1164 
1165     /* Now we encrypt the split master key with the key generated
1166      * from the user's password, before storing it */
1167     if (qcrypto_block_encrypt_helper(cipher, block->niv, ivgen,
1168                                      QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1169                                      0,
1170                                      splitkey,
1171                                      splitkeylen,
1172                                      errp) < 0) {
1173         goto error;
1174     }
1175 
1176 
1177     /* The total size of the LUKS headers is the partition header + key
1178      * slot headers, rounded up to the nearest sector, combined with
1179      * the size of each master key material region, also rounded up
1180      * to the nearest sector */
1181     luks->header.payload_offset =
1182         (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1183          QCRYPTO_BLOCK_LUKS_SECTOR_SIZE) +
1184         (ROUND_UP(DIV_ROUND_UP(splitkeylen, QCRYPTO_BLOCK_LUKS_SECTOR_SIZE),
1185                   (QCRYPTO_BLOCK_LUKS_KEY_SLOT_OFFSET /
1186                    QCRYPTO_BLOCK_LUKS_SECTOR_SIZE)) *
1187          QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS);
1188 
1189     block->payload_offset = luks->header.payload_offset *
1190         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE;
1191 
1192     /* Reserve header space to match payload offset */
1193     initfunc(block, block->payload_offset, &local_err, opaque);
1194     if (local_err) {
1195         error_propagate(errp, local_err);
1196         goto error;
1197     }
1198 
1199     /* Everything on disk uses Big Endian, so flip header fields
1200      * before writing them */
1201     cpu_to_be16s(&luks->header.version);
1202     cpu_to_be32s(&luks->header.payload_offset);
1203     cpu_to_be32s(&luks->header.key_bytes);
1204     cpu_to_be32s(&luks->header.master_key_iterations);
1205 
1206     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1207         cpu_to_be32s(&luks->header.key_slots[i].active);
1208         cpu_to_be32s(&luks->header.key_slots[i].iterations);
1209         cpu_to_be32s(&luks->header.key_slots[i].key_offset);
1210         cpu_to_be32s(&luks->header.key_slots[i].stripes);
1211     }
1212 
1213 
1214     /* Write out the partition header and key slot headers */
1215     writefunc(block, 0,
1216               (const uint8_t *)&luks->header,
1217               sizeof(luks->header),
1218               &local_err,
1219               opaque);
1220 
1221     /* Delay checking local_err until we've byte-swapped */
1222 
1223     /* Byte swap the header back to native, in case we need
1224      * to read it again later */
1225     be16_to_cpus(&luks->header.version);
1226     be32_to_cpus(&luks->header.payload_offset);
1227     be32_to_cpus(&luks->header.key_bytes);
1228     be32_to_cpus(&luks->header.master_key_iterations);
1229 
1230     for (i = 0; i < QCRYPTO_BLOCK_LUKS_NUM_KEY_SLOTS; i++) {
1231         be32_to_cpus(&luks->header.key_slots[i].active);
1232         be32_to_cpus(&luks->header.key_slots[i].iterations);
1233         be32_to_cpus(&luks->header.key_slots[i].key_offset);
1234         be32_to_cpus(&luks->header.key_slots[i].stripes);
1235     }
1236 
1237     if (local_err) {
1238         error_propagate(errp, local_err);
1239         goto error;
1240     }
1241 
1242     /* Write out the master key material, starting at the
1243      * sector immediately following the partition header. */
1244     if (writefunc(block,
1245                   luks->header.key_slots[0].key_offset *
1246                   QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1247                   splitkey, splitkeylen,
1248                   errp,
1249                   opaque) != splitkeylen) {
1250         goto error;
1251     }
1252 
1253     memset(masterkey, 0, luks->header.key_bytes);
1254     g_free(masterkey);
1255     memset(slotkey, 0, luks->header.key_bytes);
1256     g_free(slotkey);
1257     g_free(splitkey);
1258     g_free(password);
1259     g_free(cipher_mode_spec);
1260 
1261     qcrypto_ivgen_free(ivgen);
1262     qcrypto_cipher_free(cipher);
1263 
1264     return 0;
1265 
1266  error:
1267     if (masterkey) {
1268         memset(masterkey, 0, luks->header.key_bytes);
1269     }
1270     g_free(masterkey);
1271     if (slotkey) {
1272         memset(slotkey, 0, luks->header.key_bytes);
1273     }
1274     g_free(slotkey);
1275     g_free(splitkey);
1276     g_free(password);
1277     g_free(cipher_mode_spec);
1278 
1279     qcrypto_ivgen_free(ivgen);
1280     qcrypto_cipher_free(cipher);
1281 
1282     g_free(luks);
1283     return -1;
1284 }
1285 
1286 
1287 static void qcrypto_block_luks_cleanup(QCryptoBlock *block)
1288 {
1289     g_free(block->opaque);
1290 }
1291 
1292 
1293 static int
1294 qcrypto_block_luks_decrypt(QCryptoBlock *block,
1295                            uint64_t startsector,
1296                            uint8_t *buf,
1297                            size_t len,
1298                            Error **errp)
1299 {
1300     return qcrypto_block_decrypt_helper(block->cipher,
1301                                         block->niv, block->ivgen,
1302                                         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1303                                         startsector, buf, len, errp);
1304 }
1305 
1306 
1307 static int
1308 qcrypto_block_luks_encrypt(QCryptoBlock *block,
1309                            uint64_t startsector,
1310                            uint8_t *buf,
1311                            size_t len,
1312                            Error **errp)
1313 {
1314     return qcrypto_block_encrypt_helper(block->cipher,
1315                                         block->niv, block->ivgen,
1316                                         QCRYPTO_BLOCK_LUKS_SECTOR_SIZE,
1317                                         startsector, buf, len, errp);
1318 }
1319 
1320 
1321 const QCryptoBlockDriver qcrypto_block_driver_luks = {
1322     .open = qcrypto_block_luks_open,
1323     .create = qcrypto_block_luks_create,
1324     .cleanup = qcrypto_block_luks_cleanup,
1325     .decrypt = qcrypto_block_luks_decrypt,
1326     .encrypt = qcrypto_block_luks_encrypt,
1327     .has_format = qcrypto_block_luks_has_format,
1328 };
1329