timer: Fix MODS kernel compile error
[linux-3.10.git] / crypto / shash.c
1 /*
2  * Synchronous Cryptographic Hash operations.
3  *
4  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  *
11  */
12
13 #include <crypto/scatterwalk.h>
14 #include <crypto/internal/hash.h>
15 #include <linux/err.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/seq_file.h>
20 #include <linux/cryptouser.h>
21 #include <net/netlink.h>
22
23 #include "internal.h"
24
25 static const struct crypto_type crypto_shash_type;
26
27 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
28                            unsigned int keylen)
29 {
30         return -ENOSYS;
31 }
32
33 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
34                                   unsigned int keylen)
35 {
36         struct shash_alg *shash = crypto_shash_alg(tfm);
37         unsigned long alignmask = crypto_shash_alignmask(tfm);
38         unsigned long absize;
39         u8 *buffer, *alignbuffer;
40         int err;
41
42         absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
43         buffer = kmalloc(absize, GFP_KERNEL);
44         if (!buffer)
45                 return -ENOMEM;
46
47         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
48         memcpy(alignbuffer, key, keylen);
49         err = shash->setkey(tfm, alignbuffer, keylen);
50         kzfree(buffer);
51         return err;
52 }
53
54 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
55                         unsigned int keylen)
56 {
57         struct shash_alg *shash = crypto_shash_alg(tfm);
58         unsigned long alignmask = crypto_shash_alignmask(tfm);
59
60         if ((unsigned long)key & alignmask)
61                 return shash_setkey_unaligned(tfm, key, keylen);
62
63         return shash->setkey(tfm, key, keylen);
64 }
65 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
66
67 static inline unsigned int shash_align_buffer_size(unsigned len,
68                                                    unsigned long mask)
69 {
70         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
71 }
72
73 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
74                                   unsigned int len)
75 {
76         struct crypto_shash *tfm = desc->tfm;
77         struct shash_alg *shash = crypto_shash_alg(tfm);
78         unsigned long alignmask = crypto_shash_alignmask(tfm);
79         unsigned int unaligned_len = alignmask + 1 -
80                                      ((unsigned long)data & alignmask);
81         u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
82                 __attribute__ ((aligned));
83         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
84         int err;
85
86         if (unaligned_len > len)
87                 unaligned_len = len;
88
89         memcpy(buf, data, unaligned_len);
90         err = shash->update(desc, buf, unaligned_len);
91         memset(buf, 0, unaligned_len);
92
93         return err ?:
94                shash->update(desc, data + unaligned_len, len - unaligned_len);
95 }
96
97 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
98                         unsigned int len)
99 {
100         struct crypto_shash *tfm = desc->tfm;
101         struct shash_alg *shash = crypto_shash_alg(tfm);
102         unsigned long alignmask = crypto_shash_alignmask(tfm);
103
104         if ((unsigned long)data & alignmask)
105                 return shash_update_unaligned(desc, data, len);
106
107         return shash->update(desc, data, len);
108 }
109 EXPORT_SYMBOL_GPL(crypto_shash_update);
110
111 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
112 {
113         struct crypto_shash *tfm = desc->tfm;
114         unsigned long alignmask = crypto_shash_alignmask(tfm);
115         struct shash_alg *shash = crypto_shash_alg(tfm);
116         unsigned int ds = crypto_shash_digestsize(tfm);
117         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
118                 __attribute__ ((aligned));
119         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
120         int err;
121
122         err = shash->final(desc, buf);
123         if (err)
124                 goto out;
125
126         memcpy(out, buf, ds);
127
128 out:
129         memset(buf, 0, ds);
130         return err;
131 }
132
133 int crypto_shash_final(struct shash_desc *desc, u8 *out)
134 {
135         struct crypto_shash *tfm = desc->tfm;
136         struct shash_alg *shash = crypto_shash_alg(tfm);
137         unsigned long alignmask = crypto_shash_alignmask(tfm);
138
139         if ((unsigned long)out & alignmask)
140                 return shash_final_unaligned(desc, out);
141
142         return shash->final(desc, out);
143 }
144 EXPORT_SYMBOL_GPL(crypto_shash_final);
145
146 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
147                                  unsigned int len, u8 *out)
148 {
149         return crypto_shash_update(desc, data, len) ?:
150                crypto_shash_final(desc, out);
151 }
152
153 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
154                        unsigned int len, u8 *out)
155 {
156         struct crypto_shash *tfm = desc->tfm;
157         struct shash_alg *shash = crypto_shash_alg(tfm);
158         unsigned long alignmask = crypto_shash_alignmask(tfm);
159
160         if (((unsigned long)data | (unsigned long)out) & alignmask)
161                 return shash_finup_unaligned(desc, data, len, out);
162
163         return shash->finup(desc, data, len, out);
164 }
165 EXPORT_SYMBOL_GPL(crypto_shash_finup);
166
167 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
168                                   unsigned int len, u8 *out)
169 {
170         return crypto_shash_init(desc) ?:
171                crypto_shash_finup(desc, data, len, out);
172 }
173
174 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
175                         unsigned int len, u8 *out)
176 {
177         struct crypto_shash *tfm = desc->tfm;
178         struct shash_alg *shash = crypto_shash_alg(tfm);
179         unsigned long alignmask = crypto_shash_alignmask(tfm);
180
181         if (((unsigned long)data | (unsigned long)out) & alignmask)
182                 return shash_digest_unaligned(desc, data, len, out);
183
184         return shash->digest(desc, data, len, out);
185 }
186 EXPORT_SYMBOL_GPL(crypto_shash_digest);
187
188 static int shash_default_export(struct shash_desc *desc, void *out)
189 {
190         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
191         return 0;
192 }
193
194 static int shash_default_import(struct shash_desc *desc, const void *in)
195 {
196         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
197         return 0;
198 }
199
200 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
201                               unsigned int keylen)
202 {
203         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
204
205         return crypto_shash_setkey(*ctx, key, keylen);
206 }
207
208 static int shash_async_init(struct ahash_request *req)
209 {
210         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
211         struct shash_desc *desc = ahash_request_ctx(req);
212
213         desc->tfm = *ctx;
214         desc->flags = req->base.flags;
215
216         return crypto_shash_init(desc);
217 }
218
219 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
220 {
221         struct crypto_hash_walk walk;
222         int nbytes;
223
224         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
225              nbytes = crypto_hash_walk_done(&walk, nbytes))
226                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
227
228         return nbytes;
229 }
230 EXPORT_SYMBOL_GPL(shash_ahash_update);
231
232 static int shash_async_update(struct ahash_request *req)
233 {
234         return shash_ahash_update(req, ahash_request_ctx(req));
235 }
236
237 static int shash_async_final(struct ahash_request *req)
238 {
239         return crypto_shash_final(ahash_request_ctx(req), req->result);
240 }
241
242 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
243 {
244         struct crypto_hash_walk walk;
245         int nbytes;
246
247         nbytes = crypto_hash_walk_first(req, &walk);
248         if (!nbytes)
249                 return crypto_shash_final(desc, req->result);
250
251         do {
252                 nbytes = crypto_hash_walk_last(&walk) ?
253                          crypto_shash_finup(desc, walk.data, nbytes,
254                                             req->result) :
255                          crypto_shash_update(desc, walk.data, nbytes);
256                 nbytes = crypto_hash_walk_done(&walk, nbytes);
257         } while (nbytes > 0);
258
259         return nbytes;
260 }
261 EXPORT_SYMBOL_GPL(shash_ahash_finup);
262
263 static int shash_async_finup(struct ahash_request *req)
264 {
265         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
266         struct shash_desc *desc = ahash_request_ctx(req);
267
268         desc->tfm = *ctx;
269         desc->flags = req->base.flags;
270
271         return shash_ahash_finup(req, desc);
272 }
273
274 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
275 {
276         struct scatterlist *sg = req->src;
277         unsigned int offset = sg->offset;
278         unsigned int nbytes = req->nbytes;
279         int err;
280
281         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
282                 void *data;
283
284                 data = kmap_atomic(sg_page(sg));
285                 err = crypto_shash_digest(desc, data + offset, nbytes,
286                                           req->result);
287                 kunmap_atomic(data);
288                 crypto_yield(desc->flags);
289         } else
290                 err = crypto_shash_init(desc) ?:
291                       shash_ahash_finup(req, desc);
292
293         return err;
294 }
295 EXPORT_SYMBOL_GPL(shash_ahash_digest);
296
297 static int shash_async_digest(struct ahash_request *req)
298 {
299         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
300         struct shash_desc *desc = ahash_request_ctx(req);
301
302         desc->tfm = *ctx;
303         desc->flags = req->base.flags;
304
305         return shash_ahash_digest(req, desc);
306 }
307
308 static int shash_async_export(struct ahash_request *req, void *out)
309 {
310         return crypto_shash_export(ahash_request_ctx(req), out);
311 }
312
313 static int shash_async_import(struct ahash_request *req, const void *in)
314 {
315         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
316         struct shash_desc *desc = ahash_request_ctx(req);
317
318         desc->tfm = *ctx;
319         desc->flags = req->base.flags;
320
321         return crypto_shash_import(desc, in);
322 }
323
324 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
325 {
326         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
327
328         crypto_free_shash(*ctx);
329 }
330
331 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
332 {
333         struct crypto_alg *calg = tfm->__crt_alg;
334         struct shash_alg *alg = __crypto_shash_alg(calg);
335         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
336         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
337         struct crypto_shash *shash;
338
339         if (!crypto_mod_get(calg))
340                 return -EAGAIN;
341
342         shash = crypto_create_tfm(calg, &crypto_shash_type);
343         if (IS_ERR(shash)) {
344                 crypto_mod_put(calg);
345                 return PTR_ERR(shash);
346         }
347
348         *ctx = shash;
349         tfm->exit = crypto_exit_shash_ops_async;
350
351         crt->init = shash_async_init;
352         crt->update = shash_async_update;
353         crt->final = shash_async_final;
354         crt->finup = shash_async_finup;
355         crt->digest = shash_async_digest;
356
357         if (alg->setkey)
358                 crt->setkey = shash_async_setkey;
359         if (alg->export)
360                 crt->export = shash_async_export;
361         if (alg->import)
362                 crt->import = shash_async_import;
363
364         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
365
366         return 0;
367 }
368
369 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
370                                unsigned int keylen)
371 {
372         struct shash_desc **descp = crypto_hash_ctx(tfm);
373         struct shash_desc *desc = *descp;
374
375         return crypto_shash_setkey(desc->tfm, key, keylen);
376 }
377
378 static int shash_compat_init(struct hash_desc *hdesc)
379 {
380         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
381         struct shash_desc *desc = *descp;
382
383         desc->flags = hdesc->flags;
384
385         return crypto_shash_init(desc);
386 }
387
388 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
389                                unsigned int len)
390 {
391         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
392         struct shash_desc *desc = *descp;
393         struct crypto_hash_walk walk;
394         int nbytes;
395
396         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
397              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
398                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
399
400         return nbytes;
401 }
402
403 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
404 {
405         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
406
407         return crypto_shash_final(*descp, out);
408 }
409
410 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
411                                unsigned int nbytes, u8 *out)
412 {
413         unsigned int offset = sg->offset;
414         int err;
415
416         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
417                 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
418                 struct shash_desc *desc = *descp;
419                 void *data;
420
421                 desc->flags = hdesc->flags;
422
423                 data = kmap_atomic(sg_page(sg));
424                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
425                 kunmap_atomic(data);
426                 crypto_yield(desc->flags);
427                 goto out;
428         }
429
430         err = shash_compat_init(hdesc);
431         if (err)
432                 goto out;
433
434         err = shash_compat_update(hdesc, sg, nbytes);
435         if (err)
436                 goto out;
437
438         err = shash_compat_final(hdesc, out);
439
440 out:
441         return err;
442 }
443
444 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
445 {
446         struct shash_desc **descp = crypto_tfm_ctx(tfm);
447         struct shash_desc *desc = *descp;
448
449         crypto_free_shash(desc->tfm);
450         kzfree(desc);
451 }
452
453 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
454 {
455         struct hash_tfm *crt = &tfm->crt_hash;
456         struct crypto_alg *calg = tfm->__crt_alg;
457         struct shash_alg *alg = __crypto_shash_alg(calg);
458         struct shash_desc **descp = crypto_tfm_ctx(tfm);
459         struct crypto_shash *shash;
460         struct shash_desc *desc;
461
462         if (!crypto_mod_get(calg))
463                 return -EAGAIN;
464
465         shash = crypto_create_tfm(calg, &crypto_shash_type);
466         if (IS_ERR(shash)) {
467                 crypto_mod_put(calg);
468                 return PTR_ERR(shash);
469         }
470
471         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
472                        GFP_KERNEL);
473         if (!desc) {
474                 crypto_free_shash(shash);
475                 return -ENOMEM;
476         }
477
478         *descp = desc;
479         desc->tfm = shash;
480         tfm->exit = crypto_exit_shash_ops_compat;
481
482         crt->init = shash_compat_init;
483         crt->update = shash_compat_update;
484         crt->final  = shash_compat_final;
485         crt->digest = shash_compat_digest;
486         crt->setkey = shash_compat_setkey;
487
488         crt->digestsize = alg->digestsize;
489
490         return 0;
491 }
492
493 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
494 {
495         switch (mask & CRYPTO_ALG_TYPE_MASK) {
496         case CRYPTO_ALG_TYPE_HASH_MASK:
497                 return crypto_init_shash_ops_compat(tfm);
498         }
499
500         return -EINVAL;
501 }
502
503 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
504                                          u32 mask)
505 {
506         switch (mask & CRYPTO_ALG_TYPE_MASK) {
507         case CRYPTO_ALG_TYPE_HASH_MASK:
508                 return sizeof(struct shash_desc *);
509         }
510
511         return 0;
512 }
513
514 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
515 {
516         struct crypto_shash *hash = __crypto_shash_cast(tfm);
517
518         hash->descsize = crypto_shash_alg(hash)->descsize;
519         return 0;
520 }
521
522 static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
523 {
524         return alg->cra_ctxsize;
525 }
526
527 #ifdef CONFIG_NET
528 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
529 {
530         struct crypto_report_hash rhash;
531         struct shash_alg *salg = __crypto_shash_alg(alg);
532
533         strncpy(rhash.type, "shash", sizeof(rhash.type));
534
535         rhash.blocksize = alg->cra_blocksize;
536         rhash.digestsize = salg->digestsize;
537
538         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
539                     sizeof(struct crypto_report_hash), &rhash))
540                 goto nla_put_failure;
541         return 0;
542
543 nla_put_failure:
544         return -EMSGSIZE;
545 }
546 #else
547 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
548 {
549         return -ENOSYS;
550 }
551 #endif
552
553 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
554         __attribute__ ((unused));
555 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
556 {
557         struct shash_alg *salg = __crypto_shash_alg(alg);
558
559         seq_printf(m, "type         : shash\n");
560         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
561         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
562 }
563
564 static const struct crypto_type crypto_shash_type = {
565         .ctxsize = crypto_shash_ctxsize,
566         .extsize = crypto_shash_extsize,
567         .init = crypto_init_shash_ops,
568         .init_tfm = crypto_shash_init_tfm,
569 #ifdef CONFIG_PROC_FS
570         .show = crypto_shash_show,
571 #endif
572         .report = crypto_shash_report,
573         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
574         .maskset = CRYPTO_ALG_TYPE_MASK,
575         .type = CRYPTO_ALG_TYPE_SHASH,
576         .tfmsize = offsetof(struct crypto_shash, base),
577 };
578
579 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
580                                         u32 mask)
581 {
582         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
583 }
584 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
585
586 static int shash_prepare_alg(struct shash_alg *alg)
587 {
588         struct crypto_alg *base = &alg->base;
589
590         if (alg->digestsize > PAGE_SIZE / 8 ||
591             alg->descsize > PAGE_SIZE / 8 ||
592             alg->statesize > PAGE_SIZE / 8)
593                 return -EINVAL;
594
595         base->cra_type = &crypto_shash_type;
596         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
597         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
598
599         if (!alg->finup)
600                 alg->finup = shash_finup_unaligned;
601         if (!alg->digest)
602                 alg->digest = shash_digest_unaligned;
603         if (!alg->export) {
604                 alg->export = shash_default_export;
605                 alg->import = shash_default_import;
606                 alg->statesize = alg->descsize;
607         }
608         if (!alg->setkey)
609                 alg->setkey = shash_no_setkey;
610
611         return 0;
612 }
613
614 int crypto_register_shash(struct shash_alg *alg)
615 {
616         struct crypto_alg *base = &alg->base;
617         int err;
618
619         err = shash_prepare_alg(alg);
620         if (err)
621                 return err;
622
623         return crypto_register_alg(base);
624 }
625 EXPORT_SYMBOL_GPL(crypto_register_shash);
626
627 int crypto_unregister_shash(struct shash_alg *alg)
628 {
629         return crypto_unregister_alg(&alg->base);
630 }
631 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
632
633 int crypto_register_shashes(struct shash_alg *algs, int count)
634 {
635         int i, ret;
636
637         for (i = 0; i < count; i++) {
638                 ret = crypto_register_shash(&algs[i]);
639                 if (ret)
640                         goto err;
641         }
642
643         return 0;
644
645 err:
646         for (--i; i >= 0; --i)
647                 crypto_unregister_shash(&algs[i]);
648
649         return ret;
650 }
651 EXPORT_SYMBOL_GPL(crypto_register_shashes);
652
653 int crypto_unregister_shashes(struct shash_alg *algs, int count)
654 {
655         int i, ret;
656
657         for (i = count - 1; i >= 0; --i) {
658                 ret = crypto_unregister_shash(&algs[i]);
659                 if (ret)
660                         pr_err("Failed to unregister %s %s: %d\n",
661                                algs[i].base.cra_driver_name,
662                                algs[i].base.cra_name, ret);
663         }
664
665         return 0;
666 }
667 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
668
669 int shash_register_instance(struct crypto_template *tmpl,
670                             struct shash_instance *inst)
671 {
672         int err;
673
674         err = shash_prepare_alg(&inst->alg);
675         if (err)
676                 return err;
677
678         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
679 }
680 EXPORT_SYMBOL_GPL(shash_register_instance);
681
682 void shash_free_instance(struct crypto_instance *inst)
683 {
684         crypto_drop_spawn(crypto_instance_ctx(inst));
685         kfree(shash_instance(inst));
686 }
687 EXPORT_SYMBOL_GPL(shash_free_instance);
688
689 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
690                             struct shash_alg *alg,
691                             struct crypto_instance *inst)
692 {
693         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
694                                   &crypto_shash_type);
695 }
696 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
697
698 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
699 {
700         struct crypto_alg *alg;
701
702         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
703         return IS_ERR(alg) ? ERR_CAST(alg) :
704                container_of(alg, struct shash_alg, base);
705 }
706 EXPORT_SYMBOL_GPL(shash_attr_alg);
707
708 MODULE_LICENSE("GPL");
709 MODULE_DESCRIPTION("Synchronous cryptographic hash type");