[CRYPTO] api: Add crypto_attr_alg_name
[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_blocksize > PAGE_SIZE / 8)
67                 return -EINVAL;
68
69         if (alg->cra_priority < 0)
70                 return -EINVAL;
71
72         return crypto_set_driver_name(alg);
73 }
74
75 static void crypto_destroy_instance(struct crypto_alg *alg)
76 {
77         struct crypto_instance *inst = (void *)alg;
78         struct crypto_template *tmpl = inst->tmpl;
79
80         tmpl->free(inst);
81         crypto_tmpl_put(tmpl);
82 }
83
84 static void crypto_remove_spawn(struct crypto_spawn *spawn,
85                                 struct list_head *list,
86                                 struct list_head *secondary_spawns)
87 {
88         struct crypto_instance *inst = spawn->inst;
89         struct crypto_template *tmpl = inst->tmpl;
90
91         list_del_init(&spawn->list);
92         spawn->alg = NULL;
93
94         if (crypto_is_dead(&inst->alg))
95                 return;
96
97         inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
98         if (hlist_unhashed(&inst->list))
99                 return;
100
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                         /*
156                          * Check to see if either our generic name or
157                          * specific name can satisfy the name requested
158                          * by the larval entry q.
159                          */
160                         if (strcmp(alg->cra_name, q->cra_name) &&
161                             strcmp(alg->cra_driver_name, q->cra_name))
162                                 continue;
163
164                         if (larval->adult)
165                                 continue;
166                         if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
167                                 continue;
168                         if (!crypto_mod_get(alg))
169                                 continue;
170
171                         larval->adult = alg;
172                         complete_all(&larval->completion);
173                         continue;
174                 }
175
176                 if (strcmp(alg->cra_name, q->cra_name))
177                         continue;
178
179                 if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
180                     q->cra_priority > alg->cra_priority)
181                         continue;
182
183                 crypto_remove_spawns(&q->cra_users, list, alg->cra_flags);
184         }
185         
186         list_add(&alg->cra_list, &crypto_alg_list);
187
188         crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg);
189         ret = 0;
190
191 out:    
192         return ret;
193 }
194
195 static void crypto_remove_final(struct list_head *list)
196 {
197         struct crypto_alg *alg;
198         struct crypto_alg *n;
199
200         list_for_each_entry_safe(alg, n, list, cra_list) {
201                 list_del_init(&alg->cra_list);
202                 crypto_alg_put(alg);
203         }
204 }
205
206 int crypto_register_alg(struct crypto_alg *alg)
207 {
208         LIST_HEAD(list);
209         int err;
210
211         err = crypto_check_alg(alg);
212         if (err)
213                 return err;
214
215         down_write(&crypto_alg_sem);
216         err = __crypto_register_alg(alg, &list);
217         up_write(&crypto_alg_sem);
218
219         crypto_remove_final(&list);
220         return err;
221 }
222 EXPORT_SYMBOL_GPL(crypto_register_alg);
223
224 static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
225 {
226         if (unlikely(list_empty(&alg->cra_list)))
227                 return -ENOENT;
228
229         alg->cra_flags |= CRYPTO_ALG_DEAD;
230
231         crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
232         list_del_init(&alg->cra_list);
233         crypto_remove_spawns(&alg->cra_users, list, alg->cra_flags);
234
235         return 0;
236 }
237
238 int crypto_unregister_alg(struct crypto_alg *alg)
239 {
240         int ret;
241         LIST_HEAD(list);
242         
243         down_write(&crypto_alg_sem);
244         ret = crypto_remove_alg(alg, &list);
245         up_write(&crypto_alg_sem);
246
247         if (ret)
248                 return ret;
249
250         BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
251         if (alg->cra_destroy)
252                 alg->cra_destroy(alg);
253
254         crypto_remove_final(&list);
255         return 0;
256 }
257 EXPORT_SYMBOL_GPL(crypto_unregister_alg);
258
259 int crypto_register_template(struct crypto_template *tmpl)
260 {
261         struct crypto_template *q;
262         int err = -EEXIST;
263
264         down_write(&crypto_alg_sem);
265
266         list_for_each_entry(q, &crypto_template_list, list) {
267                 if (q == tmpl)
268                         goto out;
269         }
270
271         list_add(&tmpl->list, &crypto_template_list);
272         crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
273         err = 0;
274 out:
275         up_write(&crypto_alg_sem);
276         return err;
277 }
278 EXPORT_SYMBOL_GPL(crypto_register_template);
279
280 void crypto_unregister_template(struct crypto_template *tmpl)
281 {
282         struct crypto_instance *inst;
283         struct hlist_node *p, *n;
284         struct hlist_head *list;
285         LIST_HEAD(users);
286
287         down_write(&crypto_alg_sem);
288
289         BUG_ON(list_empty(&tmpl->list));
290         list_del_init(&tmpl->list);
291
292         list = &tmpl->instances;
293         hlist_for_each_entry(inst, p, list, list) {
294                 int err = crypto_remove_alg(&inst->alg, &users);
295                 BUG_ON(err);
296         }
297
298         crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);
299
300         up_write(&crypto_alg_sem);
301
302         hlist_for_each_entry_safe(inst, p, n, list, list) {
303                 BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
304                 tmpl->free(inst);
305         }
306         crypto_remove_final(&users);
307 }
308 EXPORT_SYMBOL_GPL(crypto_unregister_template);
309
310 static struct crypto_template *__crypto_lookup_template(const char *name)
311 {
312         struct crypto_template *q, *tmpl = NULL;
313
314         down_read(&crypto_alg_sem);
315         list_for_each_entry(q, &crypto_template_list, list) {
316                 if (strcmp(q->name, name))
317                         continue;
318                 if (unlikely(!crypto_tmpl_get(q)))
319                         continue;
320
321                 tmpl = q;
322                 break;
323         }
324         up_read(&crypto_alg_sem);
325
326         return tmpl;
327 }
328
329 struct crypto_template *crypto_lookup_template(const char *name)
330 {
331         return try_then_request_module(__crypto_lookup_template(name), name);
332 }
333 EXPORT_SYMBOL_GPL(crypto_lookup_template);
334
335 int crypto_register_instance(struct crypto_template *tmpl,
336                              struct crypto_instance *inst)
337 {
338         LIST_HEAD(list);
339         int err = -EINVAL;
340
341         err = crypto_check_alg(&inst->alg);
342         if (err)
343                 goto err;
344
345         inst->alg.cra_module = tmpl->module;
346
347         down_write(&crypto_alg_sem);
348
349         err = __crypto_register_alg(&inst->alg, &list);
350         if (err)
351                 goto unlock;
352
353         hlist_add_head(&inst->list, &tmpl->instances);
354         inst->tmpl = tmpl;
355
356 unlock:
357         up_write(&crypto_alg_sem);
358
359         crypto_remove_final(&list);
360
361 err:
362         return err;
363 }
364 EXPORT_SYMBOL_GPL(crypto_register_instance);
365
366 int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
367                       struct crypto_instance *inst, u32 mask)
368 {
369         int err = -EAGAIN;
370
371         spawn->inst = inst;
372         spawn->mask = mask;
373
374         down_write(&crypto_alg_sem);
375         if (!crypto_is_moribund(alg)) {
376                 list_add(&spawn->list, &alg->cra_users);
377                 spawn->alg = alg;
378                 err = 0;
379         }
380         up_write(&crypto_alg_sem);
381
382         return err;
383 }
384 EXPORT_SYMBOL_GPL(crypto_init_spawn);
385
386 void crypto_drop_spawn(struct crypto_spawn *spawn)
387 {
388         down_write(&crypto_alg_sem);
389         list_del(&spawn->list);
390         up_write(&crypto_alg_sem);
391 }
392 EXPORT_SYMBOL_GPL(crypto_drop_spawn);
393
394 struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
395                                     u32 mask)
396 {
397         struct crypto_alg *alg;
398         struct crypto_alg *alg2;
399         struct crypto_tfm *tfm;
400
401         down_read(&crypto_alg_sem);
402         alg = spawn->alg;
403         alg2 = alg;
404         if (alg2)
405                 alg2 = crypto_mod_get(alg2);
406         up_read(&crypto_alg_sem);
407
408         if (!alg2) {
409                 if (alg)
410                         crypto_shoot_alg(alg);
411                 return ERR_PTR(-EAGAIN);
412         }
413
414         tfm = ERR_PTR(-EINVAL);
415         if (unlikely((alg->cra_flags ^ type) & mask))
416                 goto out_put_alg;
417
418         tfm = __crypto_alloc_tfm(alg, type, mask);
419         if (IS_ERR(tfm))
420                 goto out_put_alg;
421
422         return tfm;
423
424 out_put_alg:
425         crypto_mod_put(alg);
426         return tfm;
427 }
428 EXPORT_SYMBOL_GPL(crypto_spawn_tfm);
429
430 int crypto_register_notifier(struct notifier_block *nb)
431 {
432         return blocking_notifier_chain_register(&crypto_chain, nb);
433 }
434 EXPORT_SYMBOL_GPL(crypto_register_notifier);
435
436 int crypto_unregister_notifier(struct notifier_block *nb)
437 {
438         return blocking_notifier_chain_unregister(&crypto_chain, nb);
439 }
440 EXPORT_SYMBOL_GPL(crypto_unregister_notifier);
441
442 struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
443 {
444         struct rtattr *rta = tb[0];
445         struct crypto_attr_type *algt;
446
447         if (!rta)
448                 return ERR_PTR(-ENOENT);
449         if (RTA_PAYLOAD(rta) < sizeof(*algt))
450                 return ERR_PTR(-EINVAL);
451         if (rta->rta_type != CRYPTOA_TYPE)
452                 return ERR_PTR(-EINVAL);
453
454         algt = RTA_DATA(rta);
455
456         return algt;
457 }
458 EXPORT_SYMBOL_GPL(crypto_get_attr_type);
459
460 int crypto_check_attr_type(struct rtattr **tb, u32 type)
461 {
462         struct crypto_attr_type *algt;
463
464         algt = crypto_get_attr_type(tb);
465         if (IS_ERR(algt))
466                 return PTR_ERR(algt);
467
468         if ((algt->type ^ type) & algt->mask)
469                 return -EINVAL;
470
471         return 0;
472 }
473 EXPORT_SYMBOL_GPL(crypto_check_attr_type);
474
475 const char *crypto_attr_alg_name(struct rtattr *rta)
476 {
477         struct crypto_attr_alg *alga;
478
479         if (!rta)
480                 return ERR_PTR(-ENOENT);
481         if (RTA_PAYLOAD(rta) < sizeof(*alga))
482                 return ERR_PTR(-EINVAL);
483         if (rta->rta_type != CRYPTOA_ALG)
484                 return ERR_PTR(-EINVAL);
485
486         alga = RTA_DATA(rta);
487         alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;
488
489         return alga->name;
490 }
491 EXPORT_SYMBOL_GPL(crypto_attr_alg_name);
492
493 struct crypto_alg *crypto_attr_alg(struct rtattr *rta, u32 type, u32 mask)
494 {
495         const char *name;
496         int err;
497
498         name = crypto_attr_alg_name(rta);
499         err = PTR_ERR(name);
500         if (IS_ERR(name))
501                 return ERR_PTR(err);
502
503         return crypto_alg_mod_lookup(name, type, mask);
504 }
505 EXPORT_SYMBOL_GPL(crypto_attr_alg);
506
507 int crypto_attr_u32(struct rtattr *rta, u32 *num)
508 {
509         struct crypto_attr_u32 *nu32;
510
511         if (!rta)
512                 return -ENOENT;
513         if (RTA_PAYLOAD(rta) < sizeof(*nu32))
514                 return -EINVAL;
515         if (rta->rta_type != CRYPTOA_U32)
516                 return -EINVAL;
517
518         nu32 = RTA_DATA(rta);
519         *num = nu32->num;
520
521         return 0;
522 }
523 EXPORT_SYMBOL_GPL(crypto_attr_u32);
524
525 struct crypto_instance *crypto_alloc_instance(const char *name,
526                                               struct crypto_alg *alg)
527 {
528         struct crypto_instance *inst;
529         struct crypto_spawn *spawn;
530         int err;
531
532         inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
533         if (!inst)
534                 return ERR_PTR(-ENOMEM);
535
536         err = -ENAMETOOLONG;
537         if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
538                      alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
539                 goto err_free_inst;
540
541         if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
542                      name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
543                 goto err_free_inst;
544
545         spawn = crypto_instance_ctx(inst);
546         err = crypto_init_spawn(spawn, alg, inst,
547                                 CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_ASYNC);
548
549         if (err)
550                 goto err_free_inst;
551
552         return inst;
553
554 err_free_inst:
555         kfree(inst);
556         return ERR_PTR(err);
557 }
558 EXPORT_SYMBOL_GPL(crypto_alloc_instance);
559
560 void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
561 {
562         INIT_LIST_HEAD(&queue->list);
563         queue->backlog = &queue->list;
564         queue->qlen = 0;
565         queue->max_qlen = max_qlen;
566 }
567 EXPORT_SYMBOL_GPL(crypto_init_queue);
568
569 int crypto_enqueue_request(struct crypto_queue *queue,
570                            struct crypto_async_request *request)
571 {
572         int err = -EINPROGRESS;
573
574         if (unlikely(queue->qlen >= queue->max_qlen)) {
575                 err = -EBUSY;
576                 if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
577                         goto out;
578                 if (queue->backlog == &queue->list)
579                         queue->backlog = &request->list;
580         }
581
582         queue->qlen++;
583         list_add_tail(&request->list, &queue->list);
584
585 out:
586         return err;
587 }
588 EXPORT_SYMBOL_GPL(crypto_enqueue_request);
589
590 struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
591 {
592         struct list_head *request;
593
594         if (unlikely(!queue->qlen))
595                 return NULL;
596
597         queue->qlen--;
598
599         if (queue->backlog != &queue->list)
600                 queue->backlog = queue->backlog->next;
601
602         request = queue->list.next;
603         list_del(request);
604
605         return list_entry(request, struct crypto_async_request, list);
606 }
607 EXPORT_SYMBOL_GPL(crypto_dequeue_request);
608
609 int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
610 {
611         struct crypto_async_request *req;
612
613         list_for_each_entry(req, &queue->list, list) {
614                 if (req->tfm == tfm)
615                         return 1;
616         }
617
618         return 0;
619 }
620 EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);
621
622 static inline void crypto_inc_byte(u8 *a, unsigned int size)
623 {
624         u8 *b = (a + size);
625         u8 c;
626
627         for (; size; size--) {
628                 c = *--b + 1;
629                 *b = c;
630                 if (c)
631                         break;
632         }
633 }
634
635 void crypto_inc(u8 *a, unsigned int size)
636 {
637         __be32 *b = (__be32 *)(a + size);
638         u32 c;
639
640         for (; size >= 4; size -= 4) {
641                 c = be32_to_cpu(*--b) + 1;
642                 *b = cpu_to_be32(c);
643                 if (c)
644                         return;
645         }
646
647         crypto_inc_byte(a, size);
648 }
649 EXPORT_SYMBOL_GPL(crypto_inc);
650
651 static inline void crypto_xor_byte(u8 *a, const u8 *b, unsigned int size)
652 {
653         for (; size; size--)
654                 *a++ ^= *b++;
655 }
656
657 void crypto_xor(u8 *dst, const u8 *src, unsigned int size)
658 {
659         u32 *a = (u32 *)dst;
660         u32 *b = (u32 *)src;
661
662         for (; size >= 4; size -= 4)
663                 *a++ ^= *b++;
664
665         crypto_xor_byte((u8 *)a, (u8 *)b, size);
666 }
667 EXPORT_SYMBOL_GPL(crypto_xor);
668
669 static int __init crypto_algapi_init(void)
670 {
671         crypto_init_proc();
672         return 0;
673 }
674
675 static void __exit crypto_algapi_exit(void)
676 {
677         crypto_exit_proc();
678 }
679
680 module_init(crypto_algapi_init);
681 module_exit(crypto_algapi_exit);
682
683 MODULE_LICENSE("GPL");
684 MODULE_DESCRIPTION("Cryptographic algorithms API");