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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
73 return max(start, end_page);
74}
75
76static inline unsigned int ablkcipher_done_slow(struct ablkcipher_walk *walk,
77 unsigned int bsize)
78{
79 unsigned int n = bsize;
80
81 for (;;) {
82 unsigned int len_this_page = scatterwalk_pagelen(&walk->out);
83
84 if (len_this_page > n)
85 len_this_page = n;
86 scatterwalk_advance(&walk->out, n);
87 if (n == len_this_page)
88 break;
89 n -= len_this_page;
90 scatterwalk_start(&walk->out, sg_next(walk->out.sg));
91 }
92
93 return bsize;
94}
95
96static inline unsigned int ablkcipher_done_fast(struct ablkcipher_walk *walk,
97 unsigned int n)
98{
99 scatterwalk_advance(&walk->in, n);
100 scatterwalk_advance(&walk->out, n);
101
102 return n;
103}
104
105static int ablkcipher_walk_next(struct ablkcipher_request *req,
106 struct ablkcipher_walk *walk);
107
108int ablkcipher_walk_done(struct ablkcipher_request *req,
109 struct ablkcipher_walk *walk, int err)
110{
111 struct crypto_tfm *tfm = req->base.tfm;
112 unsigned int nbytes = 0;
113
114 if (likely(err >= 0)) {
115 unsigned int n = walk->nbytes - err;
116
117 if (likely(!(walk->flags & ABLKCIPHER_WALK_SLOW)))
118 n = ablkcipher_done_fast(walk, n);
119 else if (WARN_ON(err)) {
120 err = -EINVAL;
121 goto err;
122 } else
123 n = ablkcipher_done_slow(walk, n);
124
125 nbytes = walk->total - n;
126 err = 0;
127 }
128
129 scatterwalk_done(&walk->in, 0, nbytes);
130 scatterwalk_done(&walk->out, 1, nbytes);
131
132err:
133 walk->total = nbytes;
134 walk->nbytes = nbytes;
135
136 if (nbytes) {
137 crypto_yield(req->base.flags);
138 return ablkcipher_walk_next(req, walk);
139 }
140
141 if (walk->iv != req->info)
142 memcpy(req->info, walk->iv, tfm->crt_ablkcipher.ivsize);
143 kfree(walk->iv_buffer);
144
145 return err;
146}
147EXPORT_SYMBOL_GPL(ablkcipher_walk_done);
148
149static inline int ablkcipher_next_slow(struct ablkcipher_request *req,
150 struct ablkcipher_walk *walk,
151 unsigned int bsize,
152 unsigned int alignmask,
153 void **src_p, void **dst_p)
154{
155 unsigned aligned_bsize = ALIGN(bsize, alignmask + 1);
156 struct ablkcipher_buffer *p;
157 void *src, *dst, *base;
158 unsigned int n;
159
160 n = ALIGN(sizeof(struct ablkcipher_buffer), alignmask + 1);
161 n += (aligned_bsize * 3 - (alignmask + 1) +
162 (alignmask & ~(crypto_tfm_ctx_alignment() - 1)));
163
164 p = kmalloc(n, GFP_ATOMIC);
165 if (!p)
166 return ablkcipher_walk_done(req, walk, -ENOMEM);
167
168 base = p + 1;
169
170 dst = (u8 *)ALIGN((unsigned long)base, alignmask + 1);
171 src = dst = ablkcipher_get_spot(dst, bsize);
172
173 p->len = bsize;
174 p->data = dst;
175
176 scatterwalk_copychunks(src, &walk->in, bsize, 0);
177
178 ablkcipher_queue_write(walk, p);
179
180 walk->nbytes = bsize;
181 walk->flags |= ABLKCIPHER_WALK_SLOW;
182
183 *src_p = src;
184 *dst_p = dst;
185
186 return 0;
187}
188
189static inline int ablkcipher_copy_iv(struct ablkcipher_walk *walk,
190 struct crypto_tfm *tfm,
191 unsigned int alignmask)
192{
193 unsigned bs = walk->blocksize;
194 unsigned int ivsize = tfm->crt_ablkcipher.ivsize;
195 unsigned aligned_bs = ALIGN(bs, alignmask + 1);
196 unsigned int size = aligned_bs * 2 + ivsize + max(aligned_bs, ivsize) -
197 (alignmask + 1);
198 u8 *iv;
199
200 size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
201 walk->iv_buffer = kmalloc(size, GFP_ATOMIC);
202 if (!walk->iv_buffer)
203 return -ENOMEM;
204
205 iv = (u8 *)ALIGN((unsigned long)walk->iv_buffer, alignmask + 1);
206 iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
207 iv = ablkcipher_get_spot(iv, bs) + aligned_bs;
208 iv = ablkcipher_get_spot(iv, ivsize);
209
210 walk->iv = memcpy(iv, walk->iv, ivsize);
211 return 0;
212}
213
214static inline int ablkcipher_next_fast(struct ablkcipher_request *req,
215 struct ablkcipher_walk *walk)
216{
217 walk->src.page = scatterwalk_page(&walk->in);
218 walk->src.offset = offset_in_page(walk->in.offset);
219 walk->dst.page = scatterwalk_page(&walk->out);
220 walk->dst.offset = offset_in_page(walk->out.offset);
221
222 return 0;
223}
224
225static int ablkcipher_walk_next(struct ablkcipher_request *req,
226 struct ablkcipher_walk *walk)
227{
228 struct crypto_tfm *tfm = req->base.tfm;
229 unsigned int alignmask, bsize, n;
230 void *src, *dst;
231 int err;
232
233 alignmask = crypto_tfm_alg_alignmask(tfm);
234 n = walk->total;
235 if (unlikely(n < crypto_tfm_alg_blocksize(tfm))) {
236 req->base.flags |= CRYPTO_TFM_RES_BAD_BLOCK_LEN;
237 return ablkcipher_walk_done(req, walk, -EINVAL);
238 }
239
240 walk->flags &= ~ABLKCIPHER_WALK_SLOW;
241 src = dst = NULL;
242
243 bsize = min(walk->blocksize, n);
244 n = scatterwalk_clamp(&walk->in, n);
245 n = scatterwalk_clamp(&walk->out, n);
246
247 if (n < bsize ||
248 !scatterwalk_aligned(&walk->in, alignmask) ||
249 !scatterwalk_aligned(&walk->out, alignmask)) {
250 err = ablkcipher_next_slow(req, walk, bsize, alignmask,
251 &src, &dst);
252 goto set_phys_lowmem;
253 }
254
255 walk->nbytes = n;
256
257 return ablkcipher_next_fast(req, walk);
258
259set_phys_lowmem:
260 if (err >= 0) {
261 walk->src.page = virt_to_page(src);
262 walk->dst.page = virt_to_page(dst);
263 walk->src.offset = ((unsigned long)src & (PAGE_SIZE - 1));
264 walk->dst.offset = ((unsigned long)dst & (PAGE_SIZE - 1));
265 }
266
267 return err;
268}
269
270static int ablkcipher_walk_first(struct ablkcipher_request *req,
271 struct ablkcipher_walk *walk)
272{
273 struct crypto_tfm *tfm = req->base.tfm;
274 unsigned int alignmask;
275
276 alignmask = crypto_tfm_alg_alignmask(tfm);
277 if (WARN_ON_ONCE(in_irq()))
278 return -EDEADLK;
279
280 walk->nbytes = walk->total;
281 if (unlikely(!walk->total))
282 return 0;
283
284 walk->iv_buffer = NULL;
285 walk->iv = req->info;
286 if (unlikely(((unsigned long)walk->iv & alignmask))) {
287 int err = ablkcipher_copy_iv(walk, tfm, alignmask);
288
289 if (err)
290 return err;
291 }
292
293 scatterwalk_start(&walk->in, walk->in.sg);
294 scatterwalk_start(&walk->out, walk->out.sg);
295
296 return ablkcipher_walk_next(req, walk);
297}
298
299int ablkcipher_walk_phys(struct ablkcipher_request *req,
300 struct ablkcipher_walk *walk)
301{
302 walk->blocksize = crypto_tfm_alg_blocksize(req->base.tfm);
303 return ablkcipher_walk_first(req, walk);
304}
305EXPORT_SYMBOL_GPL(ablkcipher_walk_phys);
306
307static int setkey_unaligned(struct crypto_ablkcipher *tfm, const u8 *key,
308 unsigned int keylen)
309{
310 struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
311 unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
312 int ret;
313 u8 *buffer, *alignbuffer;
314 unsigned long absize;
315
316 absize = keylen + alignmask;
317 buffer = kmalloc(absize, GFP_ATOMIC);
318 if (!buffer)
319 return -ENOMEM;
320
321 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
322 memcpy(alignbuffer, key, keylen);
323 ret = cipher->setkey(tfm, alignbuffer, keylen);
324 memset(alignbuffer, 0, keylen);
325 kfree(buffer);
326 return ret;
327}
328
329static int setkey(struct crypto_ablkcipher *tfm, const u8 *key,
330 unsigned int keylen)
331{
332 struct ablkcipher_alg *cipher = crypto_ablkcipher_alg(tfm);
333 unsigned long alignmask = crypto_ablkcipher_alignmask(tfm);
334
335 if (keylen < cipher->min_keysize || keylen > cipher->max_keysize) {
336 crypto_ablkcipher_set_flags(tfm, CRYPTO_TFM_RES_BAD_KEY_LEN);
337 return -EINVAL;
338 }
339
340 if ((unsigned long)key & alignmask)
341 return setkey_unaligned(tfm, key, keylen);
342
343 return cipher->setkey(tfm, key, keylen);
344}
345
346static unsigned int crypto_ablkcipher_ctxsize(struct crypto_alg *alg, u32 type,
347 u32 mask)
348{
349 return alg->cra_ctxsize;
350}
351
352int skcipher_null_givencrypt(struct skcipher_givcrypt_request *req)
353{
354 return crypto_ablkcipher_encrypt(&req->creq);
355}
356
357int skcipher_null_givdecrypt(struct skcipher_givcrypt_request *req)
358{
359 return crypto_ablkcipher_decrypt(&req->creq);
360}
361
362static int crypto_init_ablkcipher_ops(struct crypto_tfm *tfm, u32 type,
363 u32 mask)
364{
365 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
366 struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
367
368 if (alg->ivsize > PAGE_SIZE / 8)
369 return -EINVAL;
370
371 crt->setkey = setkey;
372 crt->encrypt = alg->encrypt;
373 crt->decrypt = alg->decrypt;
374 if (!alg->ivsize) {
375 crt->givencrypt = skcipher_null_givencrypt;
376 crt->givdecrypt = skcipher_null_givdecrypt;
377 }
378 crt->base = __crypto_ablkcipher_cast(tfm);
379 crt->ivsize = alg->ivsize;
380
381 return 0;
382}
383
384#ifdef CONFIG_NET
385static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
386{
387 struct crypto_report_blkcipher rblkcipher;
388
389 strncpy(rblkcipher.type, "ablkcipher", sizeof(rblkcipher.type));
390 strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<default>",
391 sizeof(rblkcipher.geniv));
392
393 rblkcipher.blocksize = alg->cra_blocksize;
394 rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
395 rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
396 rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
397
398 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
399 sizeof(struct crypto_report_blkcipher), &rblkcipher))
400 goto nla_put_failure;
401 return 0;
402
403nla_put_failure:
404 return -EMSGSIZE;
405}
406#else
407static int crypto_ablkcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
408{
409 return -ENOSYS;
410}
411#endif
412
413static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
414 __attribute__ ((unused));
415static void crypto_ablkcipher_show(struct seq_file *m, struct crypto_alg *alg)
416{
417 struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
418
419 seq_printf(m, "type : ablkcipher\n");
420 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
421 "yes" : "no");
422 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
423 seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
424 seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
425 seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
426 seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<default>");
427}
428
429const struct crypto_type crypto_ablkcipher_type = {
430 .ctxsize = crypto_ablkcipher_ctxsize,
431 .init = crypto_init_ablkcipher_ops,
432#ifdef CONFIG_PROC_FS
433 .show = crypto_ablkcipher_show,
434#endif
435 .report = crypto_ablkcipher_report,
436};
437EXPORT_SYMBOL_GPL(crypto_ablkcipher_type);
438
439static int no_givdecrypt(struct skcipher_givcrypt_request *req)
440{
441 return -ENOSYS;
442}
443
444static int crypto_init_givcipher_ops(struct crypto_tfm *tfm, u32 type,
445 u32 mask)
446{
447 struct ablkcipher_alg *alg = &tfm->__crt_alg->cra_ablkcipher;
448 struct ablkcipher_tfm *crt = &tfm->crt_ablkcipher;
449
450 if (alg->ivsize > PAGE_SIZE / 8)
451 return -EINVAL;
452
453 crt->setkey = tfm->__crt_alg->cra_flags & CRYPTO_ALG_GENIV ?
454 alg->setkey : setkey;
455 crt->encrypt = alg->encrypt;
456 crt->decrypt = alg->decrypt;
457 crt->givencrypt = alg->givencrypt;
458 crt->givdecrypt = alg->givdecrypt ?: no_givdecrypt;
459 crt->base = __crypto_ablkcipher_cast(tfm);
460 crt->ivsize = alg->ivsize;
461
462 return 0;
463}
464
465#ifdef CONFIG_NET
466static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
467{
468 struct crypto_report_blkcipher rblkcipher;
469
470 strncpy(rblkcipher.type, "givcipher", sizeof(rblkcipher.type));
471 strncpy(rblkcipher.geniv, alg->cra_ablkcipher.geniv ?: "<built-in>",
472 sizeof(rblkcipher.geniv));
473
474 rblkcipher.blocksize = alg->cra_blocksize;
475 rblkcipher.min_keysize = alg->cra_ablkcipher.min_keysize;
476 rblkcipher.max_keysize = alg->cra_ablkcipher.max_keysize;
477 rblkcipher.ivsize = alg->cra_ablkcipher.ivsize;
478
479 if (nla_put(skb, CRYPTOCFGA_REPORT_BLKCIPHER,
480 sizeof(struct crypto_report_blkcipher), &rblkcipher))
481 goto nla_put_failure;
482 return 0;
483
484nla_put_failure:
485 return -EMSGSIZE;
486}
487#else
488static int crypto_givcipher_report(struct sk_buff *skb, struct crypto_alg *alg)
489{
490 return -ENOSYS;
491}
492#endif
493
494static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
495 __attribute__ ((unused));
496static void crypto_givcipher_show(struct seq_file *m, struct crypto_alg *alg)
497{
498 struct ablkcipher_alg *ablkcipher = &alg->cra_ablkcipher;
499
500 seq_printf(m, "type : givcipher\n");
501 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
502 "yes" : "no");
503 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
504 seq_printf(m, "min keysize : %u\n", ablkcipher->min_keysize);
505 seq_printf(m, "max keysize : %u\n", ablkcipher->max_keysize);
506 seq_printf(m, "ivsize : %u\n", ablkcipher->ivsize);
507 seq_printf(m, "geniv : %s\n", ablkcipher->geniv ?: "<built-in>");
508}
509
510const struct crypto_type crypto_givcipher_type = {
511 .ctxsize = crypto_ablkcipher_ctxsize,
512 .init = crypto_init_givcipher_ops,
513#ifdef CONFIG_PROC_FS
514 .show = crypto_givcipher_show,
515#endif
516 .report = crypto_givcipher_report,
517};
518EXPORT_SYMBOL_GPL(crypto_givcipher_type);
519
520const char *crypto_default_geniv(const struct crypto_alg *alg)
521{
522 if (((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
523 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
524 alg->cra_ablkcipher.ivsize) !=
525 alg->cra_blocksize)
526 return "chainiv";
527
528 return "eseqiv";
529}
530
531static int crypto_givcipher_default(struct crypto_alg *alg, u32 type, u32 mask)
532{
533 struct rtattr *tb[3];
534 struct {
535 struct rtattr attr;
536 struct crypto_attr_type data;
537 } ptype;
538 struct {
539 struct rtattr attr;
540 struct crypto_attr_alg data;
541 } palg;
542 struct crypto_template *tmpl;
543 struct crypto_instance *inst;
544 struct crypto_alg *larval;
545 const char *geniv;
546 int err;
547
548 larval = crypto_larval_lookup(alg->cra_driver_name,
549 (type & ~CRYPTO_ALG_TYPE_MASK) |
550 CRYPTO_ALG_TYPE_GIVCIPHER,
551 mask | CRYPTO_ALG_TYPE_MASK);
552 err = PTR_ERR(larval);
553 if (IS_ERR(larval))
554 goto out;
555
556 err = -EAGAIN;
557 if (!crypto_is_larval(larval))
558 goto drop_larval;
559
560 ptype.attr.rta_len = sizeof(ptype);
561 ptype.attr.rta_type = CRYPTOA_TYPE;
562 ptype.data.type = type | CRYPTO_ALG_GENIV;
563
564 ptype.data.mask = mask | CRYPTO_ALG_GENIV;
565 tb[0] = &ptype.attr;
566
567 palg.attr.rta_len = sizeof(palg);
568 palg.attr.rta_type = CRYPTOA_ALG;
569
570 memcpy(palg.data.name, alg->cra_driver_name, CRYPTO_MAX_ALG_NAME);
571 tb[1] = &palg.attr;
572
573 tb[2] = NULL;
574
575 if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
576 CRYPTO_ALG_TYPE_BLKCIPHER)
577 geniv = alg->cra_blkcipher.geniv;
578 else
579 geniv = alg->cra_ablkcipher.geniv;
580
581 if (!geniv)
582 geniv = crypto_default_geniv(alg);
583
584 tmpl = crypto_lookup_template(geniv);
585 err = -ENOENT;
586 if (!tmpl)
587 goto kill_larval;
588
589 inst = tmpl->alloc(tb);
590 err = PTR_ERR(inst);
591 if (IS_ERR(inst))
592 goto put_tmpl;
593
594 err = crypto_register_instance(tmpl, inst);
595 if (err) {
596 tmpl->free(inst);
597 goto put_tmpl;
598 }
599
600
601 err = -EAGAIN;
602
603put_tmpl:
604 crypto_tmpl_put(tmpl);
605kill_larval:
606 crypto_larval_kill(larval);
607drop_larval:
608 crypto_mod_put(larval);
609out:
610 crypto_mod_put(alg);
611 return err;
612}
613
614struct crypto_alg *crypto_lookup_skcipher(const char *name, u32 type, u32 mask)
615{
616 struct crypto_alg *alg;
617
618 alg = crypto_alg_mod_lookup(name, type, mask);
619 if (IS_ERR(alg))
620 return alg;
621
622 if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
623 CRYPTO_ALG_TYPE_GIVCIPHER)
624 return alg;
625
626 if (!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
627 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
628 alg->cra_ablkcipher.ivsize))
629 return alg;
630
631 crypto_mod_put(alg);
632 alg = crypto_alg_mod_lookup(name, type | CRYPTO_ALG_TESTED,
633 mask & ~CRYPTO_ALG_TESTED);
634 if (IS_ERR(alg))
635 return alg;
636
637 if ((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
638 CRYPTO_ALG_TYPE_GIVCIPHER) {
639 if ((alg->cra_flags ^ type ^ ~mask) & CRYPTO_ALG_TESTED) {
640 crypto_mod_put(alg);
641 alg = ERR_PTR(-ENOENT);
642 }
643 return alg;
644 }
645
646 BUG_ON(!((alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
647 CRYPTO_ALG_TYPE_BLKCIPHER ? alg->cra_blkcipher.ivsize :
648 alg->cra_ablkcipher.ivsize));
649
650 return ERR_PTR(crypto_givcipher_default(alg, type, mask));
651}
652EXPORT_SYMBOL_GPL(crypto_lookup_skcipher);
653
654int crypto_grab_skcipher(struct crypto_skcipher_spawn *spawn, const char *name,
655 u32 type, u32 mask)
656{
657 struct crypto_alg *alg;
658 int err;
659
660 type = crypto_skcipher_type(type);
661 mask = crypto_skcipher_mask(mask);
662
663 alg = crypto_lookup_skcipher(name, type, mask);
664 if (IS_ERR(alg))
665 return PTR_ERR(alg);
666
667 err = crypto_init_spawn(&spawn->base, alg, spawn->base.inst, mask);
668 crypto_mod_put(alg);
669 return err;
670}
671EXPORT_SYMBOL_GPL(crypto_grab_skcipher);
672
673struct crypto_ablkcipher *crypto_alloc_ablkcipher(const char *alg_name,
674 u32 type, u32 mask)
675{
676 struct crypto_tfm *tfm;
677 int err;
678
679 type = crypto_skcipher_type(type);
680 mask = crypto_skcipher_mask(mask);
681
682 for (;;) {
683 struct crypto_alg *alg;
684
685 alg = crypto_lookup_skcipher(alg_name, type, mask);
686 if (IS_ERR(alg)) {
687 err = PTR_ERR(alg);
688 goto err;
689 }
690
691 tfm = __crypto_alloc_tfm(alg, type, mask);
692 if (!IS_ERR(tfm))
693 return __crypto_ablkcipher_cast(tfm);
694
695 crypto_mod_put(alg);
696 err = PTR_ERR(tfm);
697
698err:
699 if (err != -EAGAIN)
700 break;
701 if (signal_pending(current)) {
702 err = -EINTR;
703 break;
704 }
705 }
706
707 return ERR_PTR(err);
708}
709EXPORT_SYMBOL_GPL(crypto_alloc_ablkcipher);
710
