[CRYPTO] aead: Add authenc
[linux-2.6.git] / crypto / algapi.c
1 /*
2  * Cryptographic API for algorithms (i.e., low-level API).
3  *
4  * Copyright (c) 2006 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 <linux/err.h>
14 #include <linux/errno.h>
15 #include <linux/init.h>
16 #include <linux/kernel.h>
17 #include <linux/list.h>
18 #include <linux/module.h>
19 #include <linux/rtnetlink.h>
20 #include <linux/string.h>
21
22 #include "internal.h"
23
24 static LIST_HEAD(crypto_template_list);
25
26 void crypto_larval_error(const char *name, u32 type, u32 mask)
27 {
28         struct crypto_alg *alg;
29
30         down_read(&crypto_alg_sem);
31         alg = __crypto_alg_lookup(name, type, mask);
32         up_read(&crypto_alg_sem);
33
34         if (alg) {
35                 if (crypto_is_larval(alg)) {
36                         struct crypto_larval *larval = (void *)alg;
37                         complete_all(&larval->completion);
38                 }
39                 crypto_mod_put(alg);
40         }
41 }
42 EXPORT_SYMBOL_GPL(crypto_larval_error);
43
44 static inline int crypto_set_driver_name(struct crypto_alg *alg)
45 {
46         static const char suffix[] = "-generic";
47         char *driver_name = alg->cra_driver_name;
48         int len;
49
50         if (*driver_name)
51                 return 0;
52
53         len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
54         if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
55                 return -ENAMETOOLONG;
56
57         memcpy(driver_name + len, suffix, sizeof(suffix));
58         return 0;
59 }
60
61 static int crypto_check_alg(struct crypto_alg *alg)
62 {
63         if (alg->cra_alignmask & (alg->cra_alignmask + 1))
64                 return -EINVAL;
65
66         if (alg->cra_alignmask & alg->cra_blocksize)
67                 return -EINVAL;
68
69         if (alg->cra_blocksize > PAGE_SIZE / 8)
70                 return -EINVAL;
71
72         if (alg->cra_priority < 0)
73                 return -EINVAL;
74
75         return crypto_set_driver_name(alg);
76 }
77
78 static void crypto_destroy_instance(struct crypto_alg *alg)
79 {
80         struct crypto_instance *inst = (void *)alg;
81         struct crypto_template *tmpl = inst->tmpl;
82
83         tmpl->free(inst);
84         crypto_tmpl_put(tmpl);
85 }
86
87 static void crypto_remove_spawn(struct crypto_spawn *spawn,
88                                 struct list_head *list,
89                                 struct list_head *secondary_spawns)
90 {
91         struct crypto_instance *inst = spawn->inst;
92         struct crypto_template *tmpl = inst->tmpl;
93
94         list_del_init(&spawn->list);
95         spawn->alg = NULL;
96
97         if (crypto_is_dead(&inst->alg))
98                 return;
99
100         inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
101         if (!tmpl || !crypto_tmpl_get(tmpl))
102                 return;
103
104         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
105         list_move(&inst->alg.cra_list, list);
106         hlist_del(&inst->list);
107         inst->alg.cra_destroy = crypto_destroy_instance;
108
109         list_splice(&inst->alg.cra_users, secondary_spawns);
110 }
111
112 static void crypto_remove_spawns(struct list_head *spawns,
113                                  struct list_head *list, u32 new_type)
114 {
115         struct crypto_spawn *spawn, *n;
116         LIST_HEAD(secondary_spawns);
117
118         list_for_each_entry_safe(spawn, n, spawns, list) {
119                 if ((spawn->alg->cra_flags ^ new_type) & spawn->mask)
120                         continue;
121
122                 crypto_remove_spawn(spawn, list, &secondary_spawns);
123         }
124
125         while (!list_empty(&secondary_spawns)) {
126                 list_for_each_entry_safe(spawn, n, &secondary_spawns, list)
127                         crypto_remove_spawn(spawn, list, &secondary_spawns);
128         }
129 }
130
131 static int __crypto_register_alg(struct crypto_alg *alg,
132                                  struct list_head *list)
133 {
134         struct crypto_alg *q;
135         int ret = -EAGAIN;
136
137         if (crypto_is_dead(alg))
138                 goto out;
139
140         INIT_LIST_HEAD(&alg->cra_users);
141
142         ret = -EEXIST;
143
144         atomic_set(&alg->cra_refcnt, 1);
145         list_for_each_entry(q, &crypto_alg_list, cra_list) {
146                 if (q == alg)
147                         goto out;
148
149                 if (crypto_is_moribund(q))
150                         continue;
151
152                 if (crypto_is_larval(q)) {
153                         struct crypto_larval *larval = (void *)q;
154
155                         if (strcmp(alg->cra_name, q->cra_name) &&
156                             strcmp(alg->cra_driver_name, q->cra_name))
157                                 continue;
158
159                         if (larval->adult)
160                                 continue;
161                         if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
162                                 continue;
163                         if (!crypto_mod_get(alg))
164                                 continue;
165
166                         larval->adult = alg;
167                         complete_all(&larval->completion);
168                         continue;
169                 }
170
171                 if (strcmp(alg->cra_name, q->cra_name))
172                         continue;
173
174                 if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
175                     q->cra_priority > alg->cra_priority)
176                         continue;
177
178                 crypto_remove_spawns(&q->cra_users, list, alg->cra_flags);
179         }
180         
181         list_add(&alg->cra_list, &crypto_alg_list);
182
183         crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg);
184         ret = 0;
185
186 out:    
187         return ret;
188 }
189
190 static void crypto_remove_final(struct list_head *list)
191 {
192         struct crypto_alg *alg;
193         struct crypto_alg *n;
194
195         list_for_each_entry_safe(alg, n, list, cra_list) {
196                 list_del_init(&alg->cra_list);
197                 crypto_alg_put(alg);
198         }
199 }
200
201 int crypto_register_alg(struct crypto_alg *alg)
202 {
203         LIST_HEAD(list);
204         int err;
205
206         err = crypto_check_alg(alg);
207         if (err)
208                 return err;
209
210         down_write(&crypto_alg_sem);
211         err = __crypto_register_alg(alg, &list);
212         up_write(&crypto_alg_sem);
213
214         crypto_remove_final(&list);
215         return err;
216 }
217 EXPORT_SYMBOL_GPL(crypto_register_alg);
218
219 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
220 {
221         if (unlikely(list_empty(&alg->cra_list)))
222                 return -ENOENT;
223
224         alg->cra_flags |= CRYPTO_ALG_DEAD;
225
226         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
227         list_del_init(&alg->cra_list);
228         crypto_remove_spawns(&alg->cra_users, list, alg->cra_flags);
229
230         return 0;
231 }
232
233 int crypto_unregister_alg(struct crypto_alg *alg)
234 {
235         int ret;
236         LIST_HEAD(list);
237         
238         down_write(&crypto_alg_sem);
239         ret = crypto_remove_alg(alg, &list);
240         up_write(&crypto_alg_sem);
241
242         if (ret)
243                 return ret;
244
245         BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
246         if (alg->cra_destroy)
247                 alg->cra_destroy(alg);
248
249         crypto_remove_final(&list);
250         return 0;
251 }
252 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
253
254 int crypto_register_template(struct crypto_template *tmpl)
255 {
256         struct crypto_template *q;
257         int err = -EEXIST;
258
259         down_write(&crypto_alg_sem);
260
261         list_for_each_entry(q, &crypto_template_list, list) {
262                 if (q == tmpl)
263                         goto out;
264         }
265
266         list_add(&tmpl->list, &crypto_template_list);
267         crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
268         err = 0;
269 out:
270         up_write(&crypto_alg_sem);
271         return err;
272 }
273 EXPORT_SYMBOL_GPL(crypto_register_template);
274
275 void crypto_unregister_template(struct crypto_template *tmpl)
276 {
277         struct crypto_instance *inst;
278         struct hlist_node *p, *n;
279         struct hlist_head *list;
280         LIST_HEAD(users);
281
282         down_write(&crypto_alg_sem);
283
284         BUG_ON(list_empty(&tmpl->list));
285         list_del_init(&tmpl->list);
286
287         list = &tmpl->instances;
288         hlist_for_each_entry(inst, p, list, list) {
289                 int err = crypto_remove_alg(&inst->alg, &users);
290                 BUG_ON(err);
291         }
292
293         crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
294
295         up_write(&crypto_alg_sem);
296
297         hlist_for_each_entry_safe(inst, p, n, list, list) {
298                 BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
299                 tmpl->free(inst);
300         }
301         crypto_remove_final(&users);
302 }
303 EXPORT_SYMBOL_GPL(crypto_unregister_template);
304
305 static struct crypto_template *__crypto_lookup_template(const char *name)
306 {
307         struct crypto_template *q, *tmpl = NULL;
308
309         down_read(&crypto_alg_sem);
310         list_for_each_entry(q, &crypto_template_list, list) {
311                 if (strcmp(q->name, name))
312                         continue;
313                 if (unlikely(!crypto_tmpl_get(q)))
314                         continue;
315
316                 tmpl = q;
317                 break;
318         }
319         up_read(&crypto_alg_sem);
320
321         return tmpl;
322 }
323
324 struct crypto_template *crypto_lookup_template(const char *name)
325 {
326         return try_then_request_module(__crypto_lookup_template(name), name);
327 }
328 EXPORT_SYMBOL_GPL(crypto_lookup_template);
329
330 int crypto_register_instance(struct crypto_template *tmpl,
331                              struct crypto_instance *inst)
332 {
333         LIST_HEAD(list);
334         int err = -EINVAL;
335
336         if (inst->alg.cra_destroy)
337                 goto err;
338
339         err = crypto_check_alg(&inst->alg);
340         if (err)
341                 goto err;
342
343         inst->alg.cra_module = tmpl->module;
344
345         down_write(&crypto_alg_sem);
346
347         err = __crypto_register_alg(&inst->alg, &list);
348         if (err)
349                 goto unlock;
350
351         hlist_add_head(&inst->list, &tmpl->instances);
352         inst->tmpl = tmpl;
353
354 unlock:
355         up_write(&crypto_alg_sem);
356
357         crypto_remove_final(&list);
358
359 err:
360         return err;
361 }
362 EXPORT_SYMBOL_GPL(crypto_register_instance);
363
364 int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
365                       struct crypto_instance *inst, u32 mask)
366 {
367         int err = -EAGAIN;
368
369         spawn->inst = inst;
370         spawn->mask = mask;
371
372         down_write(&crypto_alg_sem);
373         if (!crypto_is_moribund(alg)) {
374                 list_add(&spawn->list, &alg->cra_users);
375                 spawn->alg = alg;
376                 err = 0;
377         }
378         up_write(&crypto_alg_sem);
379
380         return err;
381 }
382 EXPORT_SYMBOL_GPL(crypto_init_spawn);
383
384 void crypto_drop_spawn(struct crypto_spawn *spawn)
385 {
386         down_write(&crypto_alg_sem);
387         list_del(&spawn->list);
388         up_write(&crypto_alg_sem);
389 }
390 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
391
392 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
393                                     u32 mask)
394 {
395         struct crypto_alg *alg;
396         struct crypto_alg *alg2;
397         struct crypto_tfm *tfm;
398
399         down_read(&crypto_alg_sem);
400         alg = spawn->alg;
401         alg2 = alg;
402         if (alg2)
403                 alg2 = crypto_mod_get(alg2);
404         up_read(&crypto_alg_sem);
405
406         if (!alg2) {
407                 if (alg)
408                         crypto_shoot_alg(alg);
409                 return ERR_PTR(-EAGAIN);
410         }
411
412         tfm = ERR_PTR(-EINVAL);
413         if (unlikely((alg->cra_flags ^ type) & mask))
414                 goto out_put_alg;
415
416         tfm = __crypto_alloc_tfm(alg, type, mask);
417         if (IS_ERR(tfm))
418                 goto out_put_alg;
419
420         return tfm;
421
422 out_put_alg:
423         crypto_mod_put(alg);
424         return tfm;
425 }
426 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
427
428 int crypto_register_notifier(struct notifier_block *nb)
429 {
430         return blocking_notifier_chain_register(&crypto_chain, nb);
431 }
432 EXPORT_SYMBOL_GPL(crypto_register_notifier);
433
434 int crypto_unregister_notifier(struct notifier_block *nb)
435 {
436         return blocking_notifier_chain_unregister(&crypto_chain, nb);
437 }
438 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
439
440 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
441 {
442         struct rtattr *rta = tb[0];
443         struct crypto_attr_type *algt;
444
445         if (!rta)
446                 return ERR_PTR(-ENOENT);
447         if (RTA_PAYLOAD(rta) < sizeof(*algt))
448                 return ERR_PTR(-EINVAL);
449         if (rta->rta_type != CRYPTOA_TYPE)
450                 return ERR_PTR(-EINVAL);
451
452         algt = RTA_DATA(rta);
453
454         return algt;
455 }
456 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
457
458 int crypto_check_attr_type(struct rtattr **tb, u32 type)
459 {
460         struct crypto_attr_type *algt;
461
462         algt = crypto_get_attr_type(tb);
463         if (IS_ERR(algt))
464                 return PTR_ERR(algt);
465
466         if ((algt->type ^ type) & algt->mask)
467                 return -EINVAL;
468
469         return 0;
470 }
471 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
472
473 struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask)
474 {
475         struct crypto_attr_alg *alga;
476
477         if (!rta)
478                 return ERR_PTR(-ENOENT);
479         if (RTA_PAYLOAD(rta) < sizeof(*alga))
480                 return ERR_PTR(-EINVAL);
481         if (rta->rta_type != CRYPTOA_ALG)
482                 return ERR_PTR(-EINVAL);
483
484         alga = RTA_DATA(rta);
485         alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
486
487         return crypto_alg_mod_lookup(alga->name, type, mask);
488 }
489 EXPORT_SYMBOL_GPL(crypto_attr_alg);
490
491 int crypto_attr_u32(struct rtattr *rta, u32 *num)
492 {
493         struct crypto_attr_u32 *nu32;
494
495         if (!rta)
496                 return -ENOENT;
497         if (RTA_PAYLOAD(rta) < sizeof(*nu32))
498                 return -EINVAL;
499         if (rta->rta_type != CRYPTOA_U32)
500                 return -EINVAL;
501
502         nu32 = RTA_DATA(rta);
503         *num = nu32->num;
504
505         return 0;
506 }
507 EXPORT_SYMBOL_GPL(crypto_attr_u32);
508
509 struct crypto_instance *crypto_alloc_instance(const char *name,
510                                               struct crypto_alg *alg)
511 {
512         struct crypto_instance *inst;
513         struct crypto_spawn *spawn;
514         int err;
515
516         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
517         if (!inst)
518                 return ERR_PTR(-ENOMEM);
519
520         err = -ENAMETOOLONG;
521         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
522                      alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
523                 goto err_free_inst;
524
525         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
526                      name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
527                 goto err_free_inst;
528
529         spawn = crypto_instance_ctx(inst);
530         err = crypto_init_spawn(spawn, alg, inst,
531                                 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
532
533         if (err)
534                 goto err_free_inst;
535
536         return inst;
537
538 err_free_inst:
539         kfree(inst);
540         return ERR_PTR(err);
541 }
542 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
543
544 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
545 {
546         INIT_LIST_HEAD(&queue->list);
547         queue->backlog = &queue->list;
548         queue->qlen = 0;
549         queue->max_qlen = max_qlen;
550 }
551 EXPORT_SYMBOL_GPL(crypto_init_queue);
552
553 int crypto_enqueue_request(struct crypto_queue *queue,
554                            struct crypto_async_request *request)
555 {
556         int err = -EINPROGRESS;
557
558         if (unlikely(queue->qlen >= queue->max_qlen)) {
559                 err = -EBUSY;
560                 if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
561                         goto out;
562                 if (queue->backlog == &queue->list)
563                         queue->backlog = &request->list;
564         }
565
566         queue->qlen++;
567         list_add_tail(&request->list, &queue->list);
568
569 out:
570         return err;
571 }
572 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
573
574 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
575 {
576         struct list_head *request;
577
578         if (unlikely(!queue->qlen))
579                 return NULL;
580
581         queue->qlen--;
582
583         if (queue->backlog != &queue->list)
584                 queue->backlog = queue->backlog->next;
585
586         request = queue->list.next;
587         list_del(request);
588
589         return list_entry(request, struct crypto_async_request, list);
590 }
591 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
592
593 int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
594 {
595         struct crypto_async_request *req;
596
597         list_for_each_entry(req, &queue->list, list) {
598                 if (req->tfm == tfm)
599                         return 1;
600         }
601
602         return 0;
603 }
604 EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
605
606 static int __init crypto_algapi_init(void)
607 {
608         crypto_init_proc();
609         return 0;
610 }
611
612 static void __exit crypto_algapi_exit(void)
613 {
614         crypto_exit_proc();
615 }
616
617 module_init(crypto_algapi_init);
618 module_exit(crypto_algapi_exit);
619
620 MODULE_LICENSE("GPL");
621 MODULE_DESCRIPTION("Cryptographic algorithms API");