1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16#include <crypto/internal/skcipher.h>
17#include <linux/cpumask.h>
18#include <linux/err.h>
19#include <linux/kernel.h>
20#include <linux/rtnetlink.h>
21#include <linux/sched.h>
22#include <linux/slab.h>
23#include <linux/seq_file.h>
24#include <linux/cryptouser.h>
25#include <net/netlink.h>
26
27#include <crypto/scatterwalk.h>
28
29#include "internal.h"
30
31struct ablkcipher_buffer {
32 struct list_head entry;
33 struct scatter_walk dst;
34 unsigned int len;
35 void *data;
36};
37
38enum {
39 ABLKCIPHER_WALK_SLOW = 1 << 0,
40};
41
42static inline void ablkcipher_buffer_write(struct ablkcipher_buffer *p)
43{
44 scatterwalk_copychunks(p->data, &p->dst, p->len, 1);
45}
46
47void __ablkcipher_walk_complete(struct ablkcipher_walk *walk)
48{
49 struct ablkcipher_buffer *p, *tmp;
50
51 list_for_each_entry_safe(p, tmp, &walk->buffers, entry) {
52 ablkcipher_buffer_write(p);
53 list_del(&p->entry);
54 kfree(p);
55 }
56}
57EXPORT_SYMBOL_GPL(__ablkcipher_walk_complete);
58
59static inline void ablkcipher_queue_write(struct ablkcipher_walk *walk,
60 struct ablkcipher_buffer *p)
61{
62 p->dst = walk->out;
63 list_add_tail(&p->entry, &walk->buffers);
64}
65
66
67
68
69static inline u8 *ablkcipher_get_spot(u8 *start, unsigned int len)
70{
71 u8 *end_page = (u8 *)(((unsigned long)(start + len - 1)) & PAGE_MASK);
72 return max(start, end_page);
73}
74
75static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
76 unsigned int bsize)
77{
78 unsigned int n = bsize;
79
80 for (;;) {
81 unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
82
83 if (len_this_page > n)
84 len_this_page = n;
85 scatterwalk_advance(&walk->out, n);
86 if (n == len_this_page)
87 break;
88 n -= len_this_page;
89 scatterwalk_start(&walk->out, scatterwalk_sg_next(walk->out.sg));
90 }
91
92 return bsize;
93}
94
95static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
96 unsigned int n)
97{
98 scatterwalk_advance(&walk->in, n);
99 scatterwalk_advance(&walk->out, n);
100
101 return n;
102}
103
104static int ablkcipher_walk_next(struct ablkcipher_request *req,
105 struct ablkcipher_walk *walk);
106
107int ablkcipher_walk_done(struct ablkcipher_request *req,
108 struct ablkcipher_walk *walk, int err)
109{
110 struct crypto_tfm *tfm = req->base.tfm;
111 unsigned int nbytes = 0;
112
113 if (likely(err >= 0)) {
114 unsigned int n = walk->nbytes - err;
115
116 if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
117 n = ablkcipher_done_fast(walk, n);
118 else if (WARN_ON(err)) {
119 err = -EINVAL;
120 goto err;
121 } else
122 n = ablkcipher_done_slow(walk, n);
123
124 nbytes = walk->total - n;
125 err = 0;
126 }
127
128 scatterwalk_done(&walk->in, 0, nbytes);
129 scatterwalk_done(&walk->out, 1, nbytes);
130
131err:
132 walk->total = nbytes;
133 walk->nbytes = nbytes;
134
135 if (nbytes) {
136 crypto_yield(req->base.flags);
137 return ablkcipher_walk_next(req, walk);
138 }
139
140 if (walk->iv != req->info)
141 memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
142 kfree(walk->iv_buffer);
143
144 return err;
145}
146EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
147
148static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
149 struct ablkcipher_walk *walk,
150 unsigned int bsize,
151 unsigned int alignmask,
152 void **src_p, void **dst_p)
153{
154 unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
155 struct ablkcipher_buffer *p;
156 void *src, *dst, *base;
157 unsigned int n;
158
159 n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
160 n += (aligned_bsize * 3 - (alignmask + 1) +
161 (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
162
163 p = kmalloc(n, GFP_ATOMIC);
164 if (!p)
165 return ablkcipher_walk_done(req, walk, -ENOMEM);
166
167 base = p + 1;
168
169 dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
170 src = dst = ablkcipher_get_spot(dst, bsize);
171
172 p->len = bsize;
173 p->data = dst;
174
175 scatterwalk_copychunks(src, &walk->in, bsize, 0);
176
177 ablkcipher_queue_write(walk, p);
178
179 walk->nbytes = bsize;
180 walk->flags |= ABLKCIPHER_WALK_SLOW;
181
182 *src_p = src;
183 *dst_p = dst;
184
185 return 0;
186}
187
188static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
189 struct crypto_tfm *tfm,
190 unsigned int alignmask)
191{
192 unsigned bs = walk->blocksize;
193 unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
194 unsigned aligned_bs = ALIGN(bs, alignmask + 1);
195 unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
196 (alignmask + 1);
197 u8 *iv;
198
199 size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
200 walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
201 if (!walk->iv_buffer)
202 return -ENOMEM;
203
204 iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
205 iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
206 iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
207 iv = ablkcipher_get_spot(iv, ivsize);
208
209 walk->iv = memcpy(iv, walk->iv, ivsize);
210 return 0;
211}
212
213static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
214 struct ablkcipher_walk *walk)
215{
216 walk->src.page = scatterwalk_page(&walk->in);
217 walk->src.offset = offset_in_page(walk->in.offset);
218 walk->dst.page = scatterwalk_page(&walk->out);
219 walk->dst.offset = offset_in_page(walk->out.offset);
220
221 return 0;
222}
223
224static int ablkcipher_walk_next(struct ablkcipher_request *req,
225 struct ablkcipher_walk *walk)
226{
227 struct crypto_tfm *tfm = req->base.tfm;
228 unsigned int alignmask, bsize, n;
229 void *src, *dst;
230 int err;
231
232 alignmask = crypto_tfm_alg_alignmask(tfm);
233 n = walk->total;
234 if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
235 req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
236 return ablkcipher_walk_done(req, walk, -EINVAL);
237 }
238
239 walk->flags &= ~ABLKCIPHER_WALK_SLOW;
240 src = dst = NULL;
241
242 bsize = min(walk->blocksize, n);
243 n = scatterwalk_clamp(&walk->in, n);
244 n = scatterwalk_clamp(&walk->out, n);
245
246 if (n < bsize ||
247 !scatterwalk_aligned(&walk->in, alignmask) ||
248 !scatterwalk_aligned(&walk->out, alignmask)) {
249 err = ablkcipher_next_slow(req, walk, bsize, alignmask,
250 &src, &dst);
251 goto set_phys_lowmem;
252 }
253
254 walk->nbytes = n;
255
256 return ablkcipher_next_fast(req, walk);
257
258set_phys_lowmem:
259 if (err >= 0) {
260 walk->src.page = virt_to_page(src);
261 walk->dst.page = virt_to_page(dst);
262 walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
263 walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
264 }
265
266 return err;
267}
268
269static int ablkcipher_walk_first(struct ablkcipher_request *req,
270 struct ablkcipher_walk *walk)
271{
272 struct crypto_tfm *tfm = req->base.tfm;
273 unsigned int alignmask;
274
275 alignmask = crypto_tfm_alg_alignmask(tfm);
276 if (WARN_ON_ONCE(in_irq()))
277 return -EDEADLK;
278
279 walk->nbytes = walk->total;
280 if (unlikely(!walk->total))
281 return 0;
282
283 walk->iv_buffer = NULL;
284 walk->iv = req->info;
285 if (unlikely(((unsigned long)walk->iv & alignmask))) {
286 int err = ablkcipher_copy_iv(walk, tfm, alignmask);
287 if (err)
288 return err;
289 }
290
291 scatterwalk_start(&walk->in, walk->in.sg);
292 scatterwalk_start(&walk->out, walk->out.sg);
293
294 return ablkcipher_walk_next(req, walk);
295}
296
297int ablkcipher_walk_phys(struct ablkcipher_request *req,
298 struct ablkcipher_walk *walk)
299{
300 walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
301 return ablkcipher_walk_first(req, walk);
302}
303EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
304
305static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
306 unsigned int keylen)
307{
308 struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
309 unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
310 int ret;
311 u8 *buffer, *alignbuffer;
312 unsigned long absize;
313
314 absize = keylen + alignmask;
315 buffer = kmalloc(absize, GFP_ATOMIC);
316 if (!buffer)
317 return -ENOMEM;
318
319 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
320 memcpy(alignbuffer, key, keylen);
321 ret = cipher->setkey(tfm, alignbuffer, keylen);
322 memset(alignbuffer, 0, keylen);
323 kfree(buffer);
324 return ret;
325}
326
327static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
328 unsigned int keylen)
329{
330 struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
331 unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
332
333 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
334 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
335 return -EINVAL;
336 }
337
338 if ((unsigned long)key & alignmask)
339 return setkey_unaligned(tfm, key, keylen);
340
341 return cipher->setkey(tfm, key, keylen);
342}
343
344static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
345 u32 mask)
346{
347 return alg->cra_ctxsize;
348}
349
350int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
351{
352 return crypto_ablkcipher_encrypt(&req->creq);
353}
354
355int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
356{
357 return crypto_ablkcipher_decrypt(&req->creq);
358}
359
360static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
361 u32 mask)
362{
363 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
364 struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
365
366 if (alg->ivsize > PAGE_SIZE / 8)
367 return -EINVAL;
368
369 crt->setkey = setkey;
370 crt->encrypt = alg->encrypt;
371 crt->decrypt = alg->decrypt;
372 if (!alg->ivsize) {
373 crt->givencrypt = skcipher_null_givencrypt;
374 crt->givdecrypt = skcipher_null_givdecrypt;
375 }
376 crt->base = __crypto_ablkcipher_cast(tfm);
377 crt->ivsize = alg->ivsize;
378
379 return 0;
380}
381
382#ifdef CONFIG_NET
383static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
384{
385 struct crypto_report_blkcipher rblkcipher;
386
387 strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
388 strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
389 sizeof(rblkcipher.geniv));
390
391 rblkcipher.blocksize = alg->cra_blocksize;
392 rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
393 rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
394 rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
395
396 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
397 sizeof(struct crypto_report_blkcipher), &rblkcipher))
398 goto nla_put_failure;
399 return 0;
400
401nla_put_failure:
402 return -EMSGSIZE;
403}
404#else
405static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
406{
407 return -ENOSYS;
408}
409#endif
410
411static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
412 __attribute__ ((unused));
413static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
414{
415 struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
416
417 seq_printf(m, "type : ablkcipher\n");
418 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
419 "yes" : "no");
420 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
421 seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
422 seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
423 seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
424 seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<default>");
425}
426
427const struct crypto_type crypto_ablkcipher_type = {
428 .ctxsize = crypto_ablkcipher_ctxsize,
429 .init = crypto_init_ablkcipher_ops,
430#ifdef CONFIG_PROC_FS
431 .show = crypto_ablkcipher_show,
432#endif
433 .report = crypto_ablkcipher_report,
434};
435EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
436
437static int no_givdecrypt(struct skcipher_givcrypt_request *req)
438{
439 return -ENOSYS;
440}
441
442static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
443 u32 mask)
444{
445 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
446 struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
447
448 if (alg->ivsize > PAGE_SIZE / 8)
449 return -EINVAL;
450
451 crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
452 alg->setkey : setkey;
453 crt->encrypt = alg->encrypt;
454 crt->decrypt = alg->decrypt;
455 crt->givencrypt = alg->givencrypt;
456 crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
457 crt->base = __crypto_ablkcipher_cast(tfm);
458 crt->ivsize = alg->ivsize;
459
460 return 0;
461}
462
463#ifdef CONFIG_NET
464static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
465{
466 struct crypto_report_blkcipher rblkcipher;
467
468 strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
469 strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
470 sizeof(rblkcipher.geniv));
471
472 rblkcipher.blocksize = alg->cra_blocksize;
473 rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
474 rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
475 rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
476
477 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
478 sizeof(struct crypto_report_blkcipher), &rblkcipher))
479 goto nla_put_failure;
480 return 0;
481
482nla_put_failure:
483 return -EMSGSIZE;
484}
485#else
486static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
487{
488 return -ENOSYS;
489}
490#endif
491
492static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
493 __attribute__ ((unused));
494static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
495{
496 struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
497
498 seq_printf(m, "type : givcipher\n");
499 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
500 "yes" : "no");
501 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
502 seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
503 seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
504 seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
505 seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<built-in>");
506}
507
508const struct crypto_type crypto_givcipher_type = {
509 .ctxsize = crypto_ablkcipher_ctxsize,
510 .init = crypto_init_givcipher_ops,
511#ifdef CONFIG_PROC_FS
512 .show = crypto_givcipher_show,
513#endif
514 .report = crypto_givcipher_report,
515};
516EXPORT_SYMBOL_GPL(crypto_givcipher_type);
517
518const char *crypto_default_geniv(const struct crypto_alg *alg)
519{
520 if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
521 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
522 alg->cra_ablkcipher.ivsize) !=
523 alg->cra_blocksize)
524 return "chainiv";
525
526 return "eseqiv";
527}
528
529static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
530{
531 struct rtattr *tb[3];
532 struct {
533 struct rtattr attr;
534 struct crypto_attr_type data;
535 } ptype;
536 struct {
537 struct rtattr attr;
538 struct crypto_attr_alg data;
539 } palg;
540 struct crypto_template *tmpl;
541 struct crypto_instance *inst;
542 struct crypto_alg *larval;
543 const char *geniv;
544 int err;
545
546 larval = crypto_larval_lookup(alg->cra_driver_name,
547 (type & ~CRYPTO_ALG_TYPE_MASK) |
548 CRYPTO_ALG_TYPE_GIVCIPHER,
549 mask | CRYPTO_ALG_TYPE_MASK);
550 err = PTR_ERR(larval);
551 if (IS_ERR(larval))
552 goto out;
553
554 err = -EAGAIN;
555 if (!crypto_is_larval(larval))
556 goto drop_larval;
557
558 ptype.attr.rta_len = sizeof(ptype);
559 ptype.attr.rta_type = CRYPTOA_TYPE;
560 ptype.data.type = type | CRYPTO_ALG_GENIV;
561
562 ptype.data.mask = mask | CRYPTO_ALG_GENIV;
563 tb[0] = &ptype.attr;
564
565 palg.attr.rta_len = sizeof(palg);
566 palg.attr.rta_type = CRYPTOA_ALG;
567
568 memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
569 tb[1] = &palg.attr;
570
571 tb[2] = NULL;
572
573 if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
574 CRYPTO_ALG_TYPE_BLKCIPHER)
575 geniv = alg->cra_blkcipher.geniv;
576 else
577 geniv = alg->cra_ablkcipher.geniv;
578
579 if (!geniv)
580 geniv = crypto_default_geniv(alg);
581
582 tmpl = crypto_lookup_template(geniv);
583 err = -ENOENT;
584 if (!tmpl)
585 goto kill_larval;
586
587 inst = tmpl->alloc(tb);
588 err = PTR_ERR(inst);
589 if (IS_ERR(inst))
590 goto put_tmpl;
591
592 if ((err = crypto_register_instance(tmpl, inst))) {
593 tmpl->free(inst);
594 goto put_tmpl;
595 }
596
597
598 err = -EAGAIN;
599
600put_tmpl:
601 crypto_tmpl_put(tmpl);
602kill_larval:
603 crypto_larval_kill(larval);
604drop_larval:
605 crypto_mod_put(larval);
606out:
607 crypto_mod_put(alg);
608 return err;
609}
610
611struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask)
612{
613 struct crypto_alg *alg;
614
615 alg = crypto_alg_mod_lookup(name, type, mask);
616 if (IS_ERR(alg))
617 return alg;
618
619 if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
620 CRYPTO_ALG_TYPE_GIVCIPHER)
621 return alg;
622
623 if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
624 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
625 alg->cra_ablkcipher.ivsize))
626 return alg;
627
628 crypto_mod_put(alg);
629 alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
630 mask & ~CRYPTO_ALG_TESTED);
631 if (IS_ERR(alg))
632 return alg;
633
634 if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
635 CRYPTO_ALG_TYPE_GIVCIPHER) {
636 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
637 crypto_mod_put(alg);
638 alg = ERR_PTR(-ENOENT);
639 }
640 return alg;
641 }
642
643 BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
644 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
645 alg->cra_ablkcipher.ivsize));
646
647 return ERR_PTR(crypto_givcipher_default(alg, type, mask));
648}
649EXPORT_SYMBOL_GPL(crypto_lookup_skcipher);
650
651int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
652 u32 type, u32 mask)
653{
654 struct crypto_alg *alg;
655 int err;
656
657 type = crypto_skcipher_type(type);
658 mask = crypto_skcipher_mask(mask);
659
660 alg = crypto_lookup_skcipher(name, type, mask);
661 if (IS_ERR(alg))
662 return PTR_ERR(alg);
663
664 err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
665 crypto_mod_put(alg);
666 return err;
667}
668EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
669
670struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
671 u32 type, u32 mask)
672{
673 struct crypto_tfm *tfm;
674 int err;
675
676 type = crypto_skcipher_type(type);
677 mask = crypto_skcipher_mask(mask);
678
679 for (;;) {
680 struct crypto_alg *alg;
681
682 alg = crypto_lookup_skcipher(alg_name, type, mask);
683 if (IS_ERR(alg)) {
684 err = PTR_ERR(alg);
685 goto err;
686 }
687
688 tfm = __crypto_alloc_tfm(alg, type, mask);
689 if (!IS_ERR(tfm))
690 return __crypto_ablkcipher_cast(tfm);
691
692 crypto_mod_put(alg);
693 err = PTR_ERR(tfm);
694
695err:
696 if (err != -EAGAIN)
697 break;
698 if (signal_pending(current)) {
699 err = -EINTR;
700 break;
701 }
702 }
703
704 return ERR_PTR(err);
705}
706EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
707
