summaryrefslogtreecommitdiffstats
path: root/crypto/cipher-nettle.c.inc
blob: 24cc61f87bfc4ae7ab8ff523a4105a67bace67a1 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
/*
 * QEMU Crypto cipher nettle algorithms
 *
 * Copyright (c) 2015 Red Hat, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifdef CONFIG_QEMU_PRIVATE_XTS
#include "crypto/xts.h"
#endif

#include <nettle/nettle-types.h>
#include <nettle/aes.h>
#include <nettle/des.h>
#include <nettle/cbc.h>
#include <nettle/cast128.h>
#include <nettle/serpent.h>
#include <nettle/twofish.h>
#include <nettle/ctr.h>
#ifndef CONFIG_QEMU_PRIVATE_XTS
#include <nettle/xts.h>
#endif

static inline bool qcrypto_length_check(size_t len, size_t blocksize,
                                        Error **errp)
{
    if (unlikely(len & (blocksize - 1))) {
        error_setg(errp, "Length %zu must be a multiple of block size %zu",
                   len, blocksize);
        return false;
    }
    return true;
}


static void qcrypto_cipher_ctx_free(QCryptoCipher *ctx)
{
    g_free(ctx);
}

static int qcrypto_cipher_no_setiv(QCryptoCipher *cipher,
                                   const uint8_t *iv, size_t niv,
                                   Error **errp)
{
    error_setg(errp, "Setting IV is not supported");
    return -1;
}


#define DEFINE_SETIV(NAME, TYPE, BLEN)                                  \
static int NAME##_setiv(QCryptoCipher *cipher, const uint8_t *iv,       \
                        size_t niv, Error **errp)                       \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (niv != BLEN) {                                                  \
        error_setg(errp, "Expected IV size %d not %zu", BLEN, niv);     \
        return -1;                                                      \
    }                                                                   \
    memcpy(ctx->iv, iv, niv);                                           \
    return 0;                                                           \
}


#define DEFINE_ECB(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)                  \
static int NAME##_encrypt_ecb(QCryptoCipher *cipher, const void *in,    \
                              void *out, size_t len, Error **errp)      \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (!qcrypto_length_check(len, BLEN, errp)) {                       \
        return -1;                                                      \
    }                                                                   \
    ENCRYPT(&ctx->key, len, out, in);                                   \
    return 0;                                                           \
}                                                                       \
static int NAME##_decrypt_ecb(QCryptoCipher *cipher, const void *in,    \
                              void *out, size_t len, Error **errp)      \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (!qcrypto_length_check(len, BLEN, errp)) {                       \
        return -1;                                                      \
    }                                                                   \
    DECRYPT(&ctx->key, len, out, in);                                   \
    return 0;                                                           \
}                                                                       \
static const struct QCryptoCipherDriver NAME##_driver_ecb = {           \
    .cipher_encrypt = NAME##_encrypt_ecb,                               \
    .cipher_decrypt = NAME##_decrypt_ecb,                               \
    .cipher_setiv = qcrypto_cipher_no_setiv,                            \
    .cipher_free = qcrypto_cipher_ctx_free,                             \
};


#define DEFINE_CBC(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)                  \
static int NAME##_encrypt_cbc(QCryptoCipher *cipher, const void *in,    \
                              void *out, size_t len, Error **errp)      \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (!qcrypto_length_check(len, BLEN, errp)) {                       \
        return -1;                                                      \
    }                                                                   \
    cbc_encrypt(&ctx->key, ENCRYPT, BLEN, ctx->iv, len, out, in);       \
    return 0;                                                           \
}                                                                       \
static int NAME##_decrypt_cbc(QCryptoCipher *cipher, const void *in,    \
                              void *out, size_t len, Error **errp)      \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (!qcrypto_length_check(len, BLEN, errp)) {                       \
        return -1;                                                      \
    }                                                                   \
    cbc_decrypt(&ctx->key, DECRYPT, BLEN, ctx->iv, len, out, in);       \
    return 0;                                                           \
}                                                                       \
static const struct QCryptoCipherDriver NAME##_driver_cbc = {           \
    .cipher_encrypt = NAME##_encrypt_cbc,                               \
    .cipher_decrypt = NAME##_decrypt_cbc,                               \
    .cipher_setiv = NAME##_setiv,                                       \
    .cipher_free = qcrypto_cipher_ctx_free,                             \
};


#define DEFINE_CTR(NAME, TYPE, BLEN, ENCRYPT)                           \
static int NAME##_encrypt_ctr(QCryptoCipher *cipher, const void *in,    \
                              void *out, size_t len, Error **errp)      \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (!qcrypto_length_check(len, BLEN, errp)) {                       \
        return -1;                                                      \
    }                                                                   \
    ctr_crypt(&ctx->key, ENCRYPT, BLEN, ctx->iv, len, out, in);         \
    return 0;                                                           \
}                                                                       \
static const struct QCryptoCipherDriver NAME##_driver_ctr = {           \
    .cipher_encrypt = NAME##_encrypt_ctr,                               \
    .cipher_decrypt = NAME##_encrypt_ctr,                               \
    .cipher_setiv = NAME##_setiv,                                       \
    .cipher_free = qcrypto_cipher_ctx_free,                             \
};


#ifdef CONFIG_QEMU_PRIVATE_XTS
#define DEFINE__XTS(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)                 \
static void NAME##_xts_wrape(const void *ctx, size_t length,            \
                             uint8_t *dst, const uint8_t *src)          \
{                                                                       \
    ENCRYPT((const void *)ctx, length, dst, src);                       \
}                                                                       \
static void NAME##_xts_wrapd(const void *ctx, size_t length,            \
                             uint8_t *dst, const uint8_t *src)          \
{                                                                       \
    DECRYPT((const void *)ctx, length, dst, src);                       \
}                                                                       \
static int NAME##_encrypt_xts(QCryptoCipher *cipher, const void *in,    \
                              void *out, size_t len, Error **errp)      \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (!qcrypto_length_check(len, BLEN, errp)) {                       \
        return -1;                                                      \
    }                                                                   \
    xts_encrypt(&ctx->key, &ctx->key_xts,                               \
                NAME##_xts_wrape, NAME##_xts_wrapd,                     \
                ctx->iv, len, out, in);                                 \
    return 0;                                                           \
}                                                                       \
static int NAME##_decrypt_xts(QCryptoCipher *cipher, const void *in,    \
                              void *out, size_t len, Error **errp)      \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (!qcrypto_length_check(len, BLEN, errp)) {                       \
        return -1;                                                      \
    }                                                                   \
    xts_decrypt(&ctx->key, &ctx->key_xts,                               \
                NAME##_xts_wrape, NAME##_xts_wrapd,                     \
                ctx->iv, len, out, in);                                 \
    return 0;                                                           \
}
#else
#define DEFINE__XTS(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)                 \
static int NAME##_encrypt_xts(QCryptoCipher *cipher, const void *in,    \
                              void *out, size_t len, Error **errp)      \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (!qcrypto_length_check(len, BLEN, errp)) {                       \
        return -1;                                                      \
    }                                                                   \
    xts_encrypt_message(&ctx->key, &ctx->key_xts, ENCRYPT,              \
                        ctx->iv, len, out, in);                         \
    return 0;                                                           \
}                                                                       \
static int NAME##_decrypt_xts(QCryptoCipher *cipher, const void *in,    \
                              void *out, size_t len, Error **errp)      \
{                                                                       \
    TYPE *ctx = container_of(cipher, TYPE, base);                       \
    if (!qcrypto_length_check(len, BLEN, errp)) {                       \
        return -1;                                                      \
    }                                                                   \
    xts_decrypt_message(&ctx->key, &ctx->key_xts, DECRYPT, ENCRYPT,     \
                        ctx->iv, len, out, in);                         \
    return 0;                                                           \
}
#endif

#define DEFINE_XTS(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)          \
    QEMU_BUILD_BUG_ON(BLEN != XTS_BLOCK_SIZE);                  \
    DEFINE__XTS(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)             \
static const struct QCryptoCipherDriver NAME##_driver_xts = {   \
    .cipher_encrypt = NAME##_encrypt_xts,                       \
    .cipher_decrypt = NAME##_decrypt_xts,                       \
    .cipher_setiv = NAME##_setiv,                               \
    .cipher_free = qcrypto_cipher_ctx_free,                     \
};


#define DEFINE_ECB_CBC_CTR(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)  \
    DEFINE_SETIV(NAME, TYPE, BLEN)                              \
    DEFINE_ECB(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)              \
    DEFINE_CBC(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)              \
    DEFINE_CTR(NAME, TYPE, BLEN, ENCRYPT)

#define DEFINE_ECB_CBC_CTR_XTS(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)      \
    DEFINE_ECB_CBC_CTR(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)              \
    DEFINE_XTS(NAME, TYPE, BLEN, ENCRYPT, DECRYPT)


typedef struct QCryptoNettleDES {
    QCryptoCipher base;
    struct des_ctx key;
    uint8_t iv[DES_BLOCK_SIZE];
} QCryptoNettleDES;

static void des_encrypt_native(const void *ctx, size_t length,
                               uint8_t *dst, const uint8_t *src)
{
    des_encrypt(ctx, length, dst, src);
}

static void des_decrypt_native(const void *ctx, size_t length,
                               uint8_t *dst, const uint8_t *src)
{
    des_decrypt(ctx, length, dst, src);
}

DEFINE_ECB_CBC_CTR(qcrypto_nettle_des, QCryptoNettleDES,
                   DES_BLOCK_SIZE, des_encrypt_native, des_decrypt_native)


typedef struct QCryptoNettleDES3 {
    QCryptoCipher base;
    struct des3_ctx key;
    uint8_t iv[DES3_BLOCK_SIZE];
} QCryptoNettleDES3;

static void des3_encrypt_native(const void *ctx, size_t length,
                                uint8_t *dst, const uint8_t *src)
{
    des3_encrypt(ctx, length, dst, src);
}

static void des3_decrypt_native(const void *ctx, size_t length,
                                uint8_t *dst, const uint8_t *src)
{
    des3_decrypt(ctx, length, dst, src);
}

DEFINE_ECB_CBC_CTR(qcrypto_nettle_des3, QCryptoNettleDES3, DES3_BLOCK_SIZE,
                   des3_encrypt_native, des3_decrypt_native)


typedef struct QCryptoNettleAES128 {
    QCryptoCipher base;
    uint8_t iv[AES_BLOCK_SIZE];
    /* First key from pair is encode, second key is decode. */
    struct aes128_ctx key[2], key_xts[2];
} QCryptoNettleAES128;

static void aes128_encrypt_native(const void *ctx, size_t length,
                                  uint8_t *dst, const uint8_t *src)
{
    const struct aes128_ctx *keys = ctx;
    aes128_encrypt(&keys[0], length, dst, src);
}

static void aes128_decrypt_native(const void *ctx, size_t length,
                                  uint8_t *dst, const uint8_t *src)
{
    const struct aes128_ctx *keys = ctx;
    aes128_decrypt(&keys[1], length, dst, src);
}

DEFINE_ECB_CBC_CTR_XTS(qcrypto_nettle_aes128,
                       QCryptoNettleAES128, AES_BLOCK_SIZE,
                       aes128_encrypt_native, aes128_decrypt_native)


typedef struct QCryptoNettleAES192 {
    QCryptoCipher base;
    uint8_t iv[AES_BLOCK_SIZE];
    /* First key from pair is encode, second key is decode. */
    struct aes192_ctx key[2], key_xts[2];
} QCryptoNettleAES192;

static void aes192_encrypt_native(const void *ctx, size_t length,
                                  uint8_t *dst, const uint8_t *src)
{
    const struct aes192_ctx *keys = ctx;
    aes192_encrypt(&keys[0], length, dst, src);
}

static void aes192_decrypt_native(const void *ctx, size_t length,
                                  uint8_t *dst, const uint8_t *src)
{
    const struct aes192_ctx *keys = ctx;
    aes192_decrypt(&keys[1], length, dst, src);
}

DEFINE_ECB_CBC_CTR_XTS(qcrypto_nettle_aes192,
                       QCryptoNettleAES192, AES_BLOCK_SIZE,
                       aes192_encrypt_native, aes192_decrypt_native)


typedef struct QCryptoNettleAES256 {
    QCryptoCipher base;
    uint8_t iv[AES_BLOCK_SIZE];
    /* First key from pair is encode, second key is decode. */
    struct aes256_ctx key[2], key_xts[2];
} QCryptoNettleAES256;

static void aes256_encrypt_native(const void *ctx, size_t length,
                                  uint8_t *dst, const uint8_t *src)
{
    const struct aes256_ctx *keys = ctx;
    aes256_encrypt(&keys[0], length, dst, src);
}

static void aes256_decrypt_native(const void *ctx, size_t length,
                                  uint8_t *dst, const uint8_t *src)
{
    const struct aes256_ctx *keys = ctx;
    aes256_decrypt(&keys[1], length, dst, src);
}

DEFINE_ECB_CBC_CTR_XTS(qcrypto_nettle_aes256,
                       QCryptoNettleAES256, AES_BLOCK_SIZE,
                       aes256_encrypt_native, aes256_decrypt_native)


typedef struct QCryptoNettleCAST128 {
    QCryptoCipher base;
    uint8_t iv[CAST128_BLOCK_SIZE];
    struct cast128_ctx key, key_xts;
} QCryptoNettleCAST128;

static void cast128_encrypt_native(const void *ctx, size_t length,
                                   uint8_t *dst, const uint8_t *src)
{
    cast128_encrypt(ctx, length, dst, src);
}

static void cast128_decrypt_native(const void *ctx, size_t length,
                                   uint8_t *dst, const uint8_t *src)
{
    cast128_decrypt(ctx, length, dst, src);
}

DEFINE_ECB_CBC_CTR(qcrypto_nettle_cast128,
                   QCryptoNettleCAST128, CAST128_BLOCK_SIZE,
                   cast128_encrypt_native, cast128_decrypt_native)


typedef struct QCryptoNettleSerpent {
    QCryptoCipher base;
    uint8_t iv[SERPENT_BLOCK_SIZE];
    struct serpent_ctx key, key_xts;
} QCryptoNettleSerpent;


static void serpent_encrypt_native(const void *ctx, size_t length,
                                   uint8_t *dst, const uint8_t *src)
{
    serpent_encrypt(ctx, length, dst, src);
}

static void serpent_decrypt_native(const void *ctx, size_t length,
                                   uint8_t *dst, const uint8_t *src)
{
    serpent_decrypt(ctx, length, dst, src);
}

DEFINE_ECB_CBC_CTR_XTS(qcrypto_nettle_serpent,
                       QCryptoNettleSerpent, SERPENT_BLOCK_SIZE,
                       serpent_encrypt_native, serpent_decrypt_native)


typedef struct QCryptoNettleTwofish {
    QCryptoCipher base;
    uint8_t iv[TWOFISH_BLOCK_SIZE];
    struct twofish_ctx key, key_xts;
} QCryptoNettleTwofish;

static void twofish_encrypt_native(const void *ctx, size_t length,
                                   uint8_t *dst, const uint8_t *src)
{
    twofish_encrypt(ctx, length, dst, src);
}

static void twofish_decrypt_native(const void *ctx, size_t length,
                                   uint8_t *dst, const uint8_t *src)
{
    twofish_decrypt(ctx, length, dst, src);
}

DEFINE_ECB_CBC_CTR_XTS(qcrypto_nettle_twofish,
                       QCryptoNettleTwofish, TWOFISH_BLOCK_SIZE,
                       twofish_encrypt_native, twofish_decrypt_native)


bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg,
                             QCryptoCipherMode mode)
{
    switch (alg) {
    case QCRYPTO_CIPHER_ALG_DES:
    case QCRYPTO_CIPHER_ALG_3DES:
    case QCRYPTO_CIPHER_ALG_AES_128:
    case QCRYPTO_CIPHER_ALG_AES_192:
    case QCRYPTO_CIPHER_ALG_AES_256:
    case QCRYPTO_CIPHER_ALG_CAST5_128:
    case QCRYPTO_CIPHER_ALG_SERPENT_128:
    case QCRYPTO_CIPHER_ALG_SERPENT_192:
    case QCRYPTO_CIPHER_ALG_SERPENT_256:
    case QCRYPTO_CIPHER_ALG_TWOFISH_128:
    case QCRYPTO_CIPHER_ALG_TWOFISH_192:
    case QCRYPTO_CIPHER_ALG_TWOFISH_256:
        break;
    default:
        return false;
    }

    switch (mode) {
    case QCRYPTO_CIPHER_MODE_ECB:
    case QCRYPTO_CIPHER_MODE_CBC:
    case QCRYPTO_CIPHER_MODE_XTS:
    case QCRYPTO_CIPHER_MODE_CTR:
        return true;
    default:
        return false;
    }
}

static QCryptoCipher *qcrypto_cipher_ctx_new(QCryptoCipherAlgorithm alg,
                                             QCryptoCipherMode mode,
                                             const uint8_t *key,
                                             size_t nkey,
                                             Error **errp)
{
    switch (mode) {
    case QCRYPTO_CIPHER_MODE_ECB:
    case QCRYPTO_CIPHER_MODE_CBC:
    case QCRYPTO_CIPHER_MODE_XTS:
    case QCRYPTO_CIPHER_MODE_CTR:
        break;
    default:
        goto bad_cipher_mode;
    }

    if (!qcrypto_cipher_validate_key_length(alg, mode, nkey, errp)) {
        return NULL;
    }

    switch (alg) {
    case QCRYPTO_CIPHER_ALG_DES:
        {
            QCryptoNettleDES *ctx;
            const QCryptoCipherDriver *drv;

            switch (mode) {
            case QCRYPTO_CIPHER_MODE_ECB:
                drv = &qcrypto_nettle_des_driver_ecb;
                break;
            case QCRYPTO_CIPHER_MODE_CBC:
                drv = &qcrypto_nettle_des_driver_cbc;
                break;
            case QCRYPTO_CIPHER_MODE_CTR:
                drv = &qcrypto_nettle_des_driver_ctr;
                break;
            default:
                goto bad_cipher_mode;
            }

            ctx = g_new0(QCryptoNettleDES, 1);
            ctx->base.driver = drv;
            des_set_key(&ctx->key, key);

            return &ctx->base;
        }

    case QCRYPTO_CIPHER_ALG_3DES:
        {
            QCryptoNettleDES3 *ctx;
            const QCryptoCipherDriver *drv;

            switch (mode) {
            case QCRYPTO_CIPHER_MODE_ECB:
                drv = &qcrypto_nettle_des3_driver_ecb;
                break;
            case QCRYPTO_CIPHER_MODE_CBC:
                drv = &qcrypto_nettle_des3_driver_cbc;
                break;
            case QCRYPTO_CIPHER_MODE_CTR:
                drv = &qcrypto_nettle_des3_driver_ctr;
                break;
            default:
                goto bad_cipher_mode;
            }

            ctx = g_new0(QCryptoNettleDES3, 1);
            ctx->base.driver = drv;
            des3_set_key(&ctx->key, key);
            return &ctx->base;
        }

    case QCRYPTO_CIPHER_ALG_AES_128:
        {
            QCryptoNettleAES128 *ctx = g_new0(QCryptoNettleAES128, 1);

            switch (mode) {
            case QCRYPTO_CIPHER_MODE_ECB:
                ctx->base.driver = &qcrypto_nettle_aes128_driver_ecb;
                break;
            case QCRYPTO_CIPHER_MODE_CBC:
                ctx->base.driver = &qcrypto_nettle_aes128_driver_cbc;
                break;
            case QCRYPTO_CIPHER_MODE_CTR:
                ctx->base.driver = &qcrypto_nettle_aes128_driver_ctr;
                break;
            case QCRYPTO_CIPHER_MODE_XTS:
                ctx->base.driver = &qcrypto_nettle_aes128_driver_xts;
                nkey /= 2;
                aes128_set_encrypt_key(&ctx->key_xts[0], key + nkey);
                aes128_set_decrypt_key(&ctx->key_xts[1], key + nkey);
                break;
            default:
                g_assert_not_reached();
            }
            aes128_set_encrypt_key(&ctx->key[0], key);
            aes128_set_decrypt_key(&ctx->key[1], key);

            return &ctx->base;
        }

    case QCRYPTO_CIPHER_ALG_AES_192:
        {
            QCryptoNettleAES192 *ctx = g_new0(QCryptoNettleAES192, 1);

            switch (mode) {
            case QCRYPTO_CIPHER_MODE_ECB:
                ctx->base.driver = &qcrypto_nettle_aes192_driver_ecb;
                break;
            case QCRYPTO_CIPHER_MODE_CBC:
                ctx->base.driver = &qcrypto_nettle_aes192_driver_cbc;
                break;
            case QCRYPTO_CIPHER_MODE_CTR:
                ctx->base.driver = &qcrypto_nettle_aes192_driver_ctr;
                break;
            case QCRYPTO_CIPHER_MODE_XTS:
                ctx->base.driver = &qcrypto_nettle_aes192_driver_xts;
                nkey /= 2;
                aes192_set_encrypt_key(&ctx->key_xts[0], key + nkey);
                aes192_set_decrypt_key(&ctx->key_xts[1], key + nkey);
                break;
            default:
                g_assert_not_reached();
            }
            aes192_set_encrypt_key(&ctx->key[0], key);
            aes192_set_decrypt_key(&ctx->key[1], key);

            return &ctx->base;
        }

    case QCRYPTO_CIPHER_ALG_AES_256:
        {
            QCryptoNettleAES256 *ctx = g_new0(QCryptoNettleAES256, 1);

            switch (mode) {
            case QCRYPTO_CIPHER_MODE_ECB:
                ctx->base.driver = &qcrypto_nettle_aes256_driver_ecb;
                break;
            case QCRYPTO_CIPHER_MODE_CBC:
                ctx->base.driver = &qcrypto_nettle_aes256_driver_cbc;
                break;
            case QCRYPTO_CIPHER_MODE_CTR:
                ctx->base.driver = &qcrypto_nettle_aes256_driver_ctr;
                break;
            case QCRYPTO_CIPHER_MODE_XTS:
                ctx->base.driver = &qcrypto_nettle_aes256_driver_xts;
                nkey /= 2;
                aes256_set_encrypt_key(&ctx->key_xts[0], key + nkey);
                aes256_set_decrypt_key(&ctx->key_xts[1], key + nkey);
                break;
            default:
                g_assert_not_reached();
            }
            aes256_set_encrypt_key(&ctx->key[0], key);
            aes256_set_decrypt_key(&ctx->key[1], key);

            return &ctx->base;
        }

    case QCRYPTO_CIPHER_ALG_CAST5_128:
        {
            QCryptoNettleCAST128 *ctx;
            const QCryptoCipherDriver *drv;

            switch (mode) {
            case QCRYPTO_CIPHER_MODE_ECB:
                drv = &qcrypto_nettle_cast128_driver_ecb;
                break;
            case QCRYPTO_CIPHER_MODE_CBC:
                drv = &qcrypto_nettle_cast128_driver_cbc;
                break;
            case QCRYPTO_CIPHER_MODE_CTR:
                drv = &qcrypto_nettle_cast128_driver_ctr;
                break;
            default:
                goto bad_cipher_mode;
            }

            ctx = g_new0(QCryptoNettleCAST128, 1);
            ctx->base.driver = drv;
            cast5_set_key(&ctx->key, nkey, key);

            return &ctx->base;
        }

    case QCRYPTO_CIPHER_ALG_SERPENT_128:
    case QCRYPTO_CIPHER_ALG_SERPENT_192:
    case QCRYPTO_CIPHER_ALG_SERPENT_256:
        {
            QCryptoNettleSerpent *ctx = g_new0(QCryptoNettleSerpent, 1);

            switch (mode) {
            case QCRYPTO_CIPHER_MODE_ECB:
                ctx->base.driver = &qcrypto_nettle_serpent_driver_ecb;
                break;
            case QCRYPTO_CIPHER_MODE_CBC:
                ctx->base.driver = &qcrypto_nettle_serpent_driver_cbc;
                break;
            case QCRYPTO_CIPHER_MODE_CTR:
                ctx->base.driver = &qcrypto_nettle_serpent_driver_ctr;
                break;
            case QCRYPTO_CIPHER_MODE_XTS:
                ctx->base.driver = &qcrypto_nettle_serpent_driver_xts;
                nkey /= 2;
                serpent_set_key(&ctx->key_xts, nkey, key + nkey);
                break;
            default:
                g_assert_not_reached();
            }
            serpent_set_key(&ctx->key, nkey, key);

            return &ctx->base;
        }

    case QCRYPTO_CIPHER_ALG_TWOFISH_128:
    case QCRYPTO_CIPHER_ALG_TWOFISH_192:
    case QCRYPTO_CIPHER_ALG_TWOFISH_256:
        {
            QCryptoNettleTwofish *ctx = g_new0(QCryptoNettleTwofish, 1);

            switch (mode) {
            case QCRYPTO_CIPHER_MODE_ECB:
                ctx->base.driver = &qcrypto_nettle_twofish_driver_ecb;
                break;
            case QCRYPTO_CIPHER_MODE_CBC:
                ctx->base.driver = &qcrypto_nettle_twofish_driver_cbc;
                break;
            case QCRYPTO_CIPHER_MODE_CTR:
                ctx->base.driver = &qcrypto_nettle_twofish_driver_ctr;
                break;
            case QCRYPTO_CIPHER_MODE_XTS:
                ctx->base.driver = &qcrypto_nettle_twofish_driver_xts;
                nkey /= 2;
                twofish_set_key(&ctx->key_xts, nkey, key + nkey);
                break;
            default:
                g_assert_not_reached();
            }
            twofish_set_key(&ctx->key, nkey, key);

            return &ctx->base;
        }

    default:
        error_setg(errp, "Unsupported cipher algorithm %s",
                   QCryptoCipherAlgorithm_str(alg));
        return NULL;
    }

 bad_cipher_mode:
    error_setg(errp, "Unsupported cipher mode %s",
               QCryptoCipherMode_str(mode));
    return NULL;
}