summaryrefslogtreecommitdiffstats
path: root/crypto/blkcipher.c
blob: 4dd80c725498a3bb48cd9f4c961baced47f9cc6c (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
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
/*
 * Block chaining cipher operations.
 * 
 * Generic encrypt/decrypt wrapper for ciphers, handles operations across
 * multiple page boundaries by using temporary blocks.  In user context,
 * the kernel is given a chance to schedule us once per page.
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option) 
 * any later version.
 *
 */

#include <crypto/internal/skcipher.h>
#include <crypto/scatterwalk.h>
#include <linux/errno.h>
#include <linux/hardirq.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/scatterlist.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/cryptouser.h>
#include <net/netlink.h>

#include "internal.h"

enum {
	BLKCIPHER_WALK_PHYS = 1 << 0,
	BLKCIPHER_WALK_SLOW = 1 << 1,
	BLKCIPHER_WALK_COPY = 1 << 2,
	BLKCIPHER_WALK_DIFF = 1 << 3,
};

static int blkcipher_walk_next(struct blkcipher_desc *desc,
			       struct blkcipher_walk *walk);
static int blkcipher_walk_first(struct blkcipher_desc *desc,
				struct blkcipher_walk *walk);

static inline void blkcipher_map_src(struct blkcipher_walk *walk)
{
	walk->src.virt.addr = scatterwalk_map(&walk->in);
}

static inline void blkcipher_map_dst(struct blkcipher_walk *walk)
{
	walk->dst.virt.addr = scatterwalk_map(&walk->out);
}

static inline void blkcipher_unmap_src(struct blkcipher_walk *walk)
{
	scatterwalk_unmap(walk->src.virt.addr);
}

static inline void blkcipher_unmap_dst(struct blkcipher_walk *walk)
{
	scatterwalk_unmap(walk->dst.virt.addr);
}

/* Get a spot of the specified length that does not straddle a page.
 * The caller needs to ensure that there is enough space for this operation.
 */
static inline u8 *blkcipher_get_spot(u8 *start, unsigned int len)
{
	u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
	return max(start, end_page);
}

static inline unsigned int blkcipher_done_slow(struct crypto_blkcipher *tfm,
					       struct blkcipher_walk *walk,
					       unsigned int bsize)
{
	u8 *addr;
	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);

	addr = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
	addr = blkcipher_get_spot(addr, bsize);
	scatterwalk_copychunks(addr, &walk->out, bsize, 1);
	return bsize;
}

static inline unsigned int blkcipher_done_fast(struct blkcipher_walk *walk,
					       unsigned int n)
{
	if (walk->flags & BLKCIPHER_WALK_COPY) {
		blkcipher_map_dst(walk);
		memcpy(walk->dst.virt.addr, walk->page, n);
		blkcipher_unmap_dst(walk);
	} else if (!(walk->flags & BLKCIPHER_WALK_PHYS)) {
		if (walk->flags & BLKCIPHER_WALK_DIFF)
			blkcipher_unmap_dst(walk);
		blkcipher_unmap_src(walk);
	}

	scatterwalk_advance(&walk->in, n);
	scatterwalk_advance(&walk->out, n);

	return n;
}

int blkcipher_walk_done(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk, int err)
{
	struct crypto_blkcipher *tfm = desc->tfm;
	unsigned int nbytes = 0;

	if (likely(err >= 0)) {
		unsigned int n = walk->nbytes - err;

		if (likely(!(walk->flags & BLKCIPHER_WALK_SLOW)))
			n = blkcipher_done_fast(walk, n);
		else if (WARN_ON(err)) {
			err = -EINVAL;
			goto err;
		} else
			n = blkcipher_done_slow(tfm, walk, n);

		nbytes = walk->total - n;
		err = 0;
	}

	scatterwalk_done(&walk->in, 0, nbytes);
	scatterwalk_done(&walk->out, 1, nbytes);

err:
	walk->total = nbytes;
	walk->nbytes = nbytes;

	if (nbytes) {
		crypto_yield(desc->flags);
		return blkcipher_walk_next(desc, walk);
	}

	if (walk->iv != desc->info)
		memcpy(desc->info, walk->iv, crypto_blkcipher_ivsize(tfm));
	if (walk->buffer != walk->page)
		kfree(walk->buffer);
	if (walk->page)
		free_page((unsigned long)walk->page);

	return err;
}
EXPORT_SYMBOL_GPL(blkcipher_walk_done);

static inline int blkcipher_next_slow(struct blkcipher_desc *desc,
				      struct blkcipher_walk *walk,
				      unsigned int bsize,
				      unsigned int alignmask)
{
	unsigned int n;
	unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);

	if (walk->buffer)
		goto ok;

	walk->buffer = walk->page;
	if (walk->buffer)
		goto ok;

	n = aligned_bsize * 3 - (alignmask + 1) +
	    (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
	walk->buffer = kmalloc(n, GFP_ATOMIC);
	if (!walk->buffer)
		return blkcipher_walk_done(desc, walk, -ENOMEM);

ok:
	walk->dst.virt.addr = (u8 *)ALIGN((unsigned long)walk->buffer,
					  alignmask + 1);
	walk->dst.virt.addr = blkcipher_get_spot(walk->dst.virt.addr, bsize);
	walk->src.virt.addr = blkcipher_get_spot(walk->dst.virt.addr +
						 aligned_bsize, bsize);

	scatterwalk_copychunks(walk->src.virt.addr, &walk->in, bsize, 0);

	walk->nbytes = bsize;
	walk->flags |= BLKCIPHER_WALK_SLOW;

	return 0;
}

static inline int blkcipher_next_copy(struct blkcipher_walk *walk)
{
	u8 *tmp = walk->page;

	blkcipher_map_src(walk);
	memcpy(tmp, walk->src.virt.addr, walk->nbytes);
	blkcipher_unmap_src(walk);

	walk->src.virt.addr = tmp;
	walk->dst.virt.addr = tmp;

	return 0;
}

static inline int blkcipher_next_fast(struct blkcipher_desc *desc,
				      struct blkcipher_walk *walk)
{
	unsigned long diff;

	walk->src.phys.page = scatterwalk_page(&walk->in);
	walk->src.phys.offset = offset_in_page(walk->in.offset);
	walk->dst.phys.page = scatterwalk_page(&walk->out);
	walk->dst.phys.offset = offset_in_page(walk->out.offset);

	if (walk->flags & BLKCIPHER_WALK_PHYS)
		return 0;

	diff = walk->src.phys.offset - walk->dst.phys.offset;
	diff |= walk->src.virt.page - walk->dst.virt.page;

	blkcipher_map_src(walk);
	walk->dst.virt.addr = walk->src.virt.addr;

	if (diff) {
		walk->flags |= BLKCIPHER_WALK_DIFF;
		blkcipher_map_dst(walk);
	}

	return 0;
}

static int blkcipher_walk_next(struct blkcipher_desc *desc,
			       struct blkcipher_walk *walk)
{
	struct crypto_blkcipher *tfm = desc->tfm;
	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);
	unsigned int bsize;
	unsigned int n;
	int err;

	n = walk->total;
	if (unlikely(n < crypto_blkcipher_blocksize(tfm))) {
		desc->flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
		return blkcipher_walk_done(desc, walk, -EINVAL);
	}

	walk->flags &= ~(BLKCIPHER_WALK_SLOW | BLKCIPHER_WALK_COPY |
			 BLKCIPHER_WALK_DIFF);
	if (!scatterwalk_aligned(&walk->in, alignmask) ||
	    !scatterwalk_aligned(&walk->out, alignmask)) {
		walk->flags |= BLKCIPHER_WALK_COPY;
		if (!walk->page) {
			walk->page = (void *)__get_free_page(GFP_ATOMIC);
			if (!walk->page)
				n = 0;
		}
	}

	bsize = min(walk->blocksize, n);
	n = scatterwalk_clamp(&walk->in, n);
	n = scatterwalk_clamp(&walk->out, n);

	if (unlikely(n < bsize)) {
		err = blkcipher_next_slow(desc, walk, bsize, alignmask);
		goto set_phys_lowmem;
	}

	walk->nbytes = n;
	if (walk->flags & BLKCIPHER_WALK_COPY) {
		err = blkcipher_next_copy(walk);
		goto set_phys_lowmem;
	}

	return blkcipher_next_fast(desc, walk);

set_phys_lowmem:
	if (walk->flags & BLKCIPHER_WALK_PHYS) {
		walk->src.phys.page = virt_to_page(walk->src.virt.addr);
		walk->dst.phys.page = virt_to_page(walk->dst.virt.addr);
		walk->src.phys.offset &= PAGE_SIZE - 1;
		walk->dst.phys.offset &= PAGE_SIZE - 1;
	}
	return err;
}

static inline int blkcipher_copy_iv(struct blkcipher_walk *walk,
				    struct crypto_blkcipher *tfm,
				    unsigned int alignmask)
{
	unsigned bs = walk->blocksize;
	unsigned int ivsize = crypto_blkcipher_ivsize(tfm);
	unsigned aligned_bs = ALIGN(bs, alignmask + 1);
	unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
			    (alignmask + 1);
	u8 *iv;

	size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
	walk->buffer = kmalloc(size, GFP_ATOMIC);
	if (!walk->buffer)
		return -ENOMEM;

	iv = (u8 *)ALIGN((unsigned long)walk->buffer, alignmask + 1);
	iv = blkcipher_get_spot(iv, bs) + aligned_bs;
	iv = blkcipher_get_spot(iv, bs) + aligned_bs;
	iv = blkcipher_get_spot(iv, ivsize);

	walk->iv = memcpy(iv, walk->iv, ivsize);
	return 0;
}

int blkcipher_walk_virt(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk)
{
	walk->flags &= ~BLKCIPHER_WALK_PHYS;
	walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
	return blkcipher_walk_first(desc, walk);
}
EXPORT_SYMBOL_GPL(blkcipher_walk_virt);

int blkcipher_walk_phys(struct blkcipher_desc *desc,
			struct blkcipher_walk *walk)
{
	walk->flags |= BLKCIPHER_WALK_PHYS;
	walk->blocksize = crypto_blkcipher_blocksize(desc->tfm);
	return blkcipher_walk_first(desc, walk);
}
EXPORT_SYMBOL_GPL(blkcipher_walk_phys);

static int blkcipher_walk_first(struct blkcipher_desc *desc,
				struct blkcipher_walk *walk)
{
	struct crypto_blkcipher *tfm = desc->tfm;
	unsigned int alignmask = crypto_blkcipher_alignmask(tfm);

	if (WARN_ON_ONCE(in_irq()))
		return -EDEADLK;

	walk->nbytes = walk->total;
	if (unlikely(!walk->total))
		return 0;

	walk->buffer = NULL;
	walk->iv = desc->info;
	if (unlikely(((unsigned long)walk->iv & alignmask))) {
		int err = blkcipher_copy_iv(walk, tfm, alignmask);
		if (err)
			return err;
	}

	scatterwalk_start(&walk->in, walk->in.sg);
	scatterwalk_start(&walk->out, walk->out.sg);
	walk->page = NULL;

	return blkcipher_walk_next(desc, walk);
}

int blkcipher_walk_virt_block(struct blkcipher_desc *desc,
			      struct blkcipher_walk *walk,
			      unsigned int blocksize)
{
	walk->flags &= ~BLKCIPHER_WALK_PHYS;
	walk->blocksize = blocksize;
	return blkcipher_walk_first(desc, walk);
}
EXPORT_SYMBOL_GPL(blkcipher_walk_virt_block);

static int setkey_unaligned(struct crypto_tfm *tfm, const u8 *key,
			    unsigned int keylen)
{
	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);
	int ret;
	u8 *buffer, *alignbuffer;
	unsigned long absize;

	absize = keylen + alignmask;
	buffer = kmalloc(absize, GFP_ATOMIC);
	if (!buffer)
		return -ENOMEM;

	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
	memcpy(alignbuffer, key, keylen);
	ret = cipher->setkey(tfm, alignbuffer, keylen);
	memset(alignbuffer, 0, keylen);
	kfree(buffer);
	return ret;
}

static int setkey(struct crypto_tfm *tfm, const u8 *key, unsigned int keylen)
{
	struct blkcipher_alg *cipher = &tfm->__crt_alg->cra_blkcipher;
	unsigned long alignmask = crypto_tfm_alg_alignmask(tfm);

	if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
		tfm->crt_flags |= CRYPTO_TFM_RES_BAD_KEY_LEN;
		return -EINVAL;
	}

	if ((unsigned long)key & alignmask)
		return setkey_unaligned(tfm, key, keylen);

	return cipher->setkey(tfm, key, keylen);
}

static int async_setkey(struct crypto_ablkcipher *tfm, const u8 *key,
			unsigned int keylen)
{
	return setkey(crypto_ablkcipher_tfm(tfm), key, keylen);
}

static int async_encrypt(struct ablkcipher_request *req)
{
	struct crypto_tfm *tfm = req->base.tfm;
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	struct blkcipher_desc desc = {
		.tfm = __crypto_blkcipher_cast(tfm),
		.info = req->info,
		.flags = req->base.flags,
	};


	return alg->encrypt(&desc, req->dst, req->src, req->nbytes);
}

static int async_decrypt(struct ablkcipher_request *req)
{
	struct crypto_tfm *tfm = req->base.tfm;
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	struct blkcipher_desc desc = {
		.tfm = __crypto_blkcipher_cast(tfm),
		.info = req->info,
		.flags = req->base.flags,
	};

	return alg->decrypt(&desc, req->dst, req->src, req->nbytes);
}

static unsigned int crypto_blkcipher_ctxsize(struct crypto_alg *alg, u32 type,
					     u32 mask)
{
	struct blkcipher_alg *cipher = &alg->cra_blkcipher;
	unsigned int len = alg->cra_ctxsize;

	if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK &&
	    cipher->ivsize) {
		len = ALIGN(len, (unsigned long)alg->cra_alignmask + 1);
		len += cipher->ivsize;
	}

	return len;
}

static int crypto_init_blkcipher_ops_async(struct crypto_tfm *tfm)
{
	struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;

	crt->setkey = async_setkey;
	crt->encrypt = async_encrypt;
	crt->decrypt = async_decrypt;
	if (!alg->ivsize) {
		crt->givencrypt = skcipher_null_givencrypt;
		crt->givdecrypt = skcipher_null_givdecrypt;
	}
	crt->base = __crypto_ablkcipher_cast(tfm);
	crt->ivsize = alg->ivsize;

	return 0;
}

static int crypto_init_blkcipher_ops_sync(struct crypto_tfm *tfm)
{
	struct blkcipher_tfm *crt = &tfm->crt_blkcipher;
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;
	unsigned long align = crypto_tfm_alg_alignmask(tfm) + 1;
	unsigned long addr;

	crt->setkey = setkey;
	crt->encrypt = alg->encrypt;
	crt->decrypt = alg->decrypt;

	addr = (unsigned long)crypto_tfm_ctx(tfm);
	addr = ALIGN(addr, align);
	addr += ALIGN(tfm->__crt_alg->cra_ctxsize, align);
	crt->iv = (void *)addr;

	return 0;
}

static int crypto_init_blkcipher_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
{
	struct blkcipher_alg *alg = &tfm->__crt_alg->cra_blkcipher;

	if (alg->ivsize > PAGE_SIZE / 8)
		return -EINVAL;

	if ((mask & CRYPTO_ALG_TYPE_MASK) == CRYPTO_ALG_TYPE_MASK)
		return crypto_init_blkcipher_ops_sync(tfm);
	else
		return crypto_init_blkcipher_ops_async(tfm);
}

#ifdef CONFIG_NET
static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	struct crypto_report_blkcipher rblkcipher;

	snprintf(rblkcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "blkcipher");
	snprintf(rblkcipher.geniv, CRYPTO_MAX_ALG_NAME, "%s",
		 alg->cra_blkcipher.geniv ?: "<default>");

	rblkcipher.blocksize = alg->cra_blocksize;
	rblkcipher.min_keysize = alg->cra_blkcipher.min_keysize;
	rblkcipher.max_keysize = alg->cra_blkcipher.max_keysize;
	rblkcipher.ivsize = alg->cra_blkcipher.ivsize;

	NLA_PUT(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
		sizeof(struct crypto_report_blkcipher), &rblkcipher);

	return 0;

nla_put_failure:
	return -EMSGSIZE;
}
#else
static int crypto_blkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
{
	return -ENOSYS;
}
#endif

static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
	__attribute__ ((unused));
static void crypto_blkcipher_show(struct seq_file *m, struct crypto_alg *alg)
{
	seq_printf(m, "type         : blkcipher\n");
	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
	seq_printf(m, "min keysize  : %u\n", alg->cra_blkcipher.min_keysize);
	seq_printf(m, "max keysize  : %u\n", alg->cra_blkcipher.max_keysize);
	seq_printf(m, "ivsize       : %u\n", alg->cra_blkcipher.ivsize);
	seq_printf(m, "geniv        : %s\n", alg->cra_blkcipher.geniv ?:
					     "<default>");
}

const struct crypto_type crypto_blkcipher_type = {
	.ctxsize = crypto_blkcipher_ctxsize,
	.init = crypto_init_blkcipher_ops,
#ifdef CONFIG_PROC_FS
	.show = crypto_blkcipher_show,
#endif
	.report = crypto_blkcipher_report,
};
EXPORT_SYMBOL_GPL(crypto_blkcipher_type);

static int crypto_grab_nivcipher(struct crypto_skcipher_spawn *spawn,
				const char *name, u32 type, u32 mask)
{
	struct crypto_alg *alg;
	int err;

	type = crypto_skcipher_type(type);
	mask = crypto_skcipher_mask(mask)| CRYPTO_ALG_GENIV;

	alg = crypto_alg_mod_lookup(name, type, mask);
	if (IS_ERR(alg))
		return PTR_ERR(alg);

	err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
	crypto_mod_put(alg);
	return err;
}

struct crypto_instance *skcipher_geniv_alloc(struct crypto_template *tmpl,
					     struct rtattr **tb, u32 type,
					     u32 mask)
{
	struct {
		int (*setkey)(struct crypto_ablkcipher *tfm, const u8 *key,
			      unsigned int keylen);
		int (*encrypt)(struct ablkcipher_request *req);
		int (*decrypt)(struct ablkcipher_request *req);

		unsigned int min_keysize;
		unsigned int max_keysize;
		unsigned int ivsize;

		const char *geniv;
	} balg;
	const char *name;
	struct crypto_skcipher_spawn *spawn;
	struct crypto_attr_type *algt;
	struct crypto_instance *inst;
	struct crypto_alg *alg;
	int err;

	algt = crypto_get_attr_type(tb);
	err = PTR_ERR(algt);
	if (IS_ERR(algt))
		return ERR_PTR(err);

	if ((algt->type ^ (CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV)) &
	    algt->mask)
		return ERR_PTR(-EINVAL);

	name = crypto_attr_alg_name(tb[1]);
	err = PTR_ERR(name);
	if (IS_ERR(name))
		return ERR_PTR(err);

	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
	if (!inst)
		return ERR_PTR(-ENOMEM);

	spawn = crypto_instance_ctx(inst);

	/* Ignore async algorithms if necessary. */
	mask |= crypto_requires_sync(algt->type, algt->mask);

	crypto_set_skcipher_spawn(spawn, inst);
	err = crypto_grab_nivcipher(spawn, name, type, mask);
	if (err)
		goto err_free_inst;

	alg = crypto_skcipher_spawn_alg(spawn);

	if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
	    CRYPTO_ALG_TYPE_BLKCIPHER) {
		balg.ivsize = alg->cra_blkcipher.ivsize;
		balg.min_keysize = alg->cra_blkcipher.min_keysize;
		balg.max_keysize = alg->cra_blkcipher.max_keysize;

		balg.setkey = async_setkey;
		balg.encrypt = async_encrypt;
		balg.decrypt = async_decrypt;

		balg.geniv = alg->cra_blkcipher.geniv;
	} else {
		balg.ivsize = alg->cra_ablkcipher.ivsize;
		balg.min_keysize = alg->cra_ablkcipher.min_keysize;
		balg.max_keysize = alg->cra_ablkcipher.max_keysize;

		balg.setkey = alg->cra_ablkcipher.setkey;
		balg.encrypt = alg->cra_ablkcipher.encrypt;
		balg.decrypt = alg->cra_ablkcipher.decrypt;

		balg.geniv = alg->cra_ablkcipher.geniv;
	}

	err = -EINVAL;
	if (!balg.ivsize)
		goto err_drop_alg;

	/*
	 * This is only true if we're constructing an algorithm with its
	 * default IV generator.  For the default generator we elide the
	 * template name and double-check the IV generator.
	 */
	if (algt->mask & CRYPTO_ALG_GENIV) {
		if (!balg.geniv)
			balg.geniv = crypto_default_geniv(alg);
		err = -EAGAIN;
		if (strcmp(tmpl->name, balg.geniv))
			goto err_drop_alg;

		memcpy(inst->alg.cra_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
		memcpy(inst->alg.cra_driver_name, alg->cra_driver_name,
		       CRYPTO_MAX_ALG_NAME);
	} else {
		err = -ENAMETOOLONG;
		if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME,
			     "%s(%s)", tmpl->name, alg->cra_name) >=
		    CRYPTO_MAX_ALG_NAME)
			goto err_drop_alg;
		if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME,
			     "%s(%s)", tmpl->name, alg->cra_driver_name) >=
		    CRYPTO_MAX_ALG_NAME)
			goto err_drop_alg;
	}

	inst->alg.cra_flags = CRYPTO_ALG_TYPE_GIVCIPHER | CRYPTO_ALG_GENIV;
	inst->alg.cra_flags |= alg->cra_flags & CRYPTO_ALG_ASYNC;
	inst->alg.cra_priority = alg->cra_priority;
	inst->alg.cra_blocksize = alg->cra_blocksize;
	inst->alg.cra_alignmask = alg->cra_alignmask;
	inst->alg.cra_type = &crypto_givcipher_type;

	inst->alg.cra_ablkcipher.ivsize = balg.ivsize;
	inst->alg.cra_ablkcipher.min_keysize = balg.min_keysize;
	inst->alg.cra_ablkcipher.max_keysize = balg.max_keysize;
	inst->alg.cra_ablkcipher.geniv = balg.geniv;

	inst->alg.cra_ablkcipher.setkey = balg.setkey;
	inst->alg.cra_ablkcipher.encrypt = balg.encrypt;
	inst->alg.cra_ablkcipher.decrypt = balg.decrypt;

out:
	return inst;

err_drop_alg:
	crypto_drop_skcipher(spawn);
err_free_inst:
	kfree(inst);
	inst = ERR_PTR(err);
	goto out;
}
EXPORT_SYMBOL_GPL(skcipher_geniv_alloc);

void skcipher_geniv_free(struct crypto_instance *inst)
{
	crypto_drop_skcipher(crypto_instance_ctx(inst));
	kfree(inst);
}
EXPORT_SYMBOL_GPL(skcipher_geniv_free);

int skcipher_geniv_init(struct crypto_tfm *tfm)
{
	struct crypto_instance *inst = (void *)tfm->__crt_alg;
	struct crypto_ablkcipher *cipher;

	cipher = crypto_spawn_skcipher(crypto_instance_ctx(inst));
	if (IS_ERR(cipher))
		return PTR_ERR(cipher);

	tfm->crt_ablkcipher.base = cipher;
	tfm->crt_ablkcipher.reqsize += crypto_ablkcipher_reqsize(cipher);

	return 0;
}
EXPORT_SYMBOL_GPL(skcipher_geniv_init);

void skcipher_geniv_exit(struct crypto_tfm *tfm)
{
	crypto_free_ablkcipher(tfm->crt_ablkcipher.base);
}
EXPORT_SYMBOL_GPL(skcipher_geniv_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Generic block chaining cipher type");