aboutsummaryrefslogtreecommitdiffstats
path: root/crypto/algapi.c
blob: 1c2185b5b005ef4d82a22a2130c953f86f735bc8 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
/*
 * Cryptographic API for algorithms (i.e., low-level API).
 *
 * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
 *
 * This program is free software; you can redistribute it and/or modify it
 * under the terms of the GNU General Public License as published by the Free
 * Software Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 */

#include <linux/err.h>
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/list.h>
#include <linux/module.h>
#include <linux/rtnetlink.h>
#include <linux/string.h>

#include "internal.h"

static LIST_HEAD(crypto_template_list);

void crypto_larval_error(const char *name, u32 type, u32 mask)
{
	struct crypto_alg *alg;

	down_read(&crypto_alg_sem);
	alg = __crypto_alg_lookup(name, type, mask);
	up_read(&crypto_alg_sem);

	if (alg) {
		if (crypto_is_larval(alg)) {
			struct crypto_larval *larval = (void *)alg;
			complete(&larval->completion);
		}
		crypto_mod_put(alg);
	}
}
EXPORT_SYMBOL_GPL(crypto_larval_error);

static inline int crypto_set_driver_name(struct crypto_alg *alg)
{
	static const char suffix[] = "-generic";
	char *driver_name = alg->cra_driver_name;
	int len;

	if (*driver_name)
		return 0;

	len = strlcpy(driver_name, alg->cra_name, CRYPTO_MAX_ALG_NAME);
	if (len + sizeof(suffix) > CRYPTO_MAX_ALG_NAME)
		return -ENAMETOOLONG;

	memcpy(driver_name + len, suffix, sizeof(suffix));
	return 0;
}

static int crypto_check_alg(struct crypto_alg *alg)
{
	if (alg->cra_alignmask & (alg->cra_alignmask + 1))
		return -EINVAL;

	if (alg->cra_alignmask & alg->cra_blocksize)
		return -EINVAL;

	if (alg->cra_blocksize > PAGE_SIZE / 8)
		return -EINVAL;

	if (alg->cra_priority < 0)
		return -EINVAL;

	return crypto_set_driver_name(alg);
}

static void crypto_destroy_instance(struct crypto_alg *alg)
{
	struct crypto_instance *inst = (void *)alg;
	struct crypto_template *tmpl = inst->tmpl;

	tmpl->free(inst);
	crypto_tmpl_put(tmpl);
}

static void crypto_remove_spawns(struct list_head *spawns,
				 struct list_head *list)
{
	struct crypto_spawn *spawn, *n;

	list_for_each_entry_safe(spawn, n, spawns, list) {
		struct crypto_instance *inst = spawn->inst;
		struct crypto_template *tmpl = inst->tmpl;

		list_del_init(&spawn->list);
		spawn->alg = NULL;

		if (crypto_is_dead(&inst->alg))
			continue;

		inst->alg.cra_flags |= CRYPTO_ALG_DEAD;
		if (!tmpl || !crypto_tmpl_get(tmpl))
			continue;

		crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, &inst->alg);
		list_move(&inst->alg.cra_list, list);
		hlist_del(&inst->list);
		inst->alg.cra_destroy = crypto_destroy_instance;

		if (!list_empty(&inst->alg.cra_users)) {
			if (&n->list == spawns)
				n = list_entry(inst->alg.cra_users.next,
					       typeof(*n), list);
			__list_splice(&inst->alg.cra_users, spawns->prev);
		}
	}
}

static int __crypto_register_alg(struct crypto_alg *alg,
				 struct list_head *list)
{
	struct crypto_alg *q;
	int ret = -EAGAIN;

	if (crypto_is_dead(alg))
		goto out;

	INIT_LIST_HEAD(&alg->cra_users);

	ret = -EEXIST;

	atomic_set(&alg->cra_refcnt, 1);
	list_for_each_entry(q, &crypto_alg_list, cra_list) {
		if (q == alg)
			goto out;

		if (crypto_is_moribund(q))
			continue;

		if (crypto_is_larval(q)) {
			struct crypto_larval *larval = (void *)q;

			if (strcmp(alg->cra_name, q->cra_name) &&
			    strcmp(alg->cra_driver_name, q->cra_name))
				continue;

			if (larval->adult)
				continue;
			if ((q->cra_flags ^ alg->cra_flags) & larval->mask)
				continue;
			if (!crypto_mod_get(alg))
				continue;

			larval->adult = alg;
			complete(&larval->completion);
			continue;
		}

		if (strcmp(alg->cra_name, q->cra_name))
			continue;

		if (strcmp(alg->cra_driver_name, q->cra_driver_name) &&
		    q->cra_priority > alg->cra_priority)
			continue;

		crypto_remove_spawns(&q->cra_users, list);
	}
	
	list_add(&alg->cra_list, &crypto_alg_list);

	crypto_notify(CRYPTO_MSG_ALG_REGISTER, alg);
	ret = 0;

out:	
	return ret;
}

static void crypto_remove_final(struct list_head *list)
{
	struct crypto_alg *alg;
	struct crypto_alg *n;

	list_for_each_entry_safe(alg, n, list, cra_list) {
		list_del_init(&alg->cra_list);
		crypto_alg_put(alg);
	}
}

int crypto_register_alg(struct crypto_alg *alg)
{
	LIST_HEAD(list);
	int err;

	err = crypto_check_alg(alg);
	if (err)
		return err;

	down_write(&crypto_alg_sem);
	err = __crypto_register_alg(alg, &list);
	up_write(&crypto_alg_sem);

	crypto_remove_final(&list);
	return err;
}
EXPORT_SYMBOL_GPL(crypto_register_alg);

static int crypto_remove_alg(struct crypto_alg *alg, struct list_head *list)
{
	if (unlikely(list_empty(&alg->cra_list)))
		return -ENOENT;

	alg->cra_flags |= CRYPTO_ALG_DEAD;

	crypto_notify(CRYPTO_MSG_ALG_UNREGISTER, alg);
	list_del_init(&alg->cra_list);
	crypto_remove_spawns(&alg->cra_users, list);

	return 0;
}

int crypto_unregister_alg(struct crypto_alg *alg)
{
	int ret;
	LIST_HEAD(list);
	
	down_write(&crypto_alg_sem);
	ret = crypto_remove_alg(alg, &list);
	up_write(&crypto_alg_sem);

	if (ret)
		return ret;

	BUG_ON(atomic_read(&alg->cra_refcnt) != 1);
	if (alg->cra_destroy)
		alg->cra_destroy(alg);

	crypto_remove_final(&list);
	return 0;
}
EXPORT_SYMBOL_GPL(crypto_unregister_alg);

int crypto_register_template(struct crypto_template *tmpl)
{
	struct crypto_template *q;
	int err = -EEXIST;

	down_write(&crypto_alg_sem);

	list_for_each_entry(q, &crypto_template_list, list) {
		if (q == tmpl)
			goto out;
	}

	list_add(&tmpl->list, &crypto_template_list);
	crypto_notify(CRYPTO_MSG_TMPL_REGISTER, tmpl);
	err = 0;
out:
	up_write(&crypto_alg_sem);
	return err;
}
EXPORT_SYMBOL_GPL(crypto_register_template);

void crypto_unregister_template(struct crypto_template *tmpl)
{
	struct crypto_instance *inst;
	struct hlist_node *p, *n;
	struct hlist_head *list;
	LIST_HEAD(users);

	down_write(&crypto_alg_sem);

	BUG_ON(list_empty(&tmpl->list));
	list_del_init(&tmpl->list);

	list = &tmpl->instances;
	hlist_for_each_entry(inst, p, list, list) {
		int err = crypto_remove_alg(&inst->alg, &users);
		BUG_ON(err);
	}

	crypto_notify(CRYPTO_MSG_TMPL_UNREGISTER, tmpl);

	up_write(&crypto_alg_sem);

	hlist_for_each_entry_safe(inst, p, n, list, list) {
		BUG_ON(atomic_read(&inst->alg.cra_refcnt) != 1);
		tmpl->free(inst);
	}
	crypto_remove_final(&users);
}
EXPORT_SYMBOL_GPL(crypto_unregister_template);

static struct crypto_template *__crypto_lookup_template(const char *name)
{
	struct crypto_template *q, *tmpl = NULL;

	down_read(&crypto_alg_sem);
	list_for_each_entry(q, &crypto_template_list, list) {
		if (strcmp(q->name, name))
			continue;
		if (unlikely(!crypto_tmpl_get(q)))
			continue;

		tmpl = q;
		break;
	}
	up_read(&crypto_alg_sem);

	return tmpl;
}

struct crypto_template *crypto_lookup_template(const char *name)
{
	return try_then_request_module(__crypto_lookup_template(name), name);
}
EXPORT_SYMBOL_GPL(crypto_lookup_template);

int crypto_register_instance(struct crypto_template *tmpl,
			     struct crypto_instance *inst)
{
	LIST_HEAD(list);
	int err = -EINVAL;

	if (inst->alg.cra_destroy)
		goto err;

	err = crypto_check_alg(&inst->alg);
	if (err)
		goto err;

	inst->alg.cra_module = tmpl->module;

	down_write(&crypto_alg_sem);

	err = __crypto_register_alg(&inst->alg, &list);
	if (err)
		goto unlock;

	hlist_add_head(&inst->list, &tmpl->instances);
	inst->tmpl = tmpl;

unlock:
	up_write(&crypto_alg_sem);

	crypto_remove_final(&list);

err:
	return err;
}
EXPORT_SYMBOL_GPL(crypto_register_instance);

int crypto_init_spawn(struct crypto_spawn *spawn, struct crypto_alg *alg,
		      struct crypto_instance *inst)
{
	int err = -EAGAIN;

	spawn->inst = inst;

	down_write(&crypto_alg_sem);
	if (!crypto_is_moribund(alg)) {
		list_add(&spawn->list, &alg->cra_users);
		spawn->alg = alg;
		err = 0;
	}
	up_write(&crypto_alg_sem);

	return err;
}
EXPORT_SYMBOL_GPL(crypto_init_spawn);

void crypto_drop_spawn(struct crypto_spawn *spawn)
{
	down_write(&crypto_alg_sem);
	list_del(&spawn->list);
	up_write(&crypto_alg_sem);
}
EXPORT_SYMBOL_GPL(crypto_drop_spawn);

struct crypto_tfm *crypto_spawn_tfm(struct crypto_spawn *spawn, u32 type,
				    u32 mask)
{
	struct crypto_alg *alg;
	struct crypto_alg *alg2;
	struct crypto_tfm *tfm;

	down_read(&crypto_alg_sem);
	alg = spawn->alg;
	alg2 = alg;
	if (alg2)
		alg2 = crypto_mod_get(alg2);
	up_read(&crypto_alg_sem);

	if (!alg2) {
		if (alg)
			crypto_shoot_alg(alg);
		return ERR_PTR(-EAGAIN);
	}

	tfm = ERR_PTR(-EINVAL);
	if (unlikely((alg->cra_flags ^ type) & mask))
		goto out_put_alg;

	tfm = __crypto_alloc_tfm(alg, type, mask);
	if (IS_ERR(tfm))
		goto out_put_alg;

	return tfm;

out_put_alg:
	crypto_mod_put(alg);
	return tfm;
}
EXPORT_SYMBOL_GPL(crypto_spawn_tfm);

int crypto_register_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_register(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_register_notifier);

int crypto_unregister_notifier(struct notifier_block *nb)
{
	return blocking_notifier_chain_unregister(&crypto_chain, nb);
}
EXPORT_SYMBOL_GPL(crypto_unregister_notifier);

struct crypto_attr_type *crypto_get_attr_type(struct rtattr **tb)
{
	struct rtattr *rta = tb[CRYPTOA_TYPE - 1];
	struct crypto_attr_type *algt;

	if (!rta)
		return ERR_PTR(-ENOENT);
	if (RTA_PAYLOAD(rta) < sizeof(*algt))
		return ERR_PTR(-EINVAL);

	algt = RTA_DATA(rta);

	return algt;
}
EXPORT_SYMBOL_GPL(crypto_get_attr_type);

int crypto_check_attr_type(struct rtattr **tb, u32 type)
{
	struct crypto_attr_type *algt;

	algt = crypto_get_attr_type(tb);
	if (IS_ERR(algt))
		return PTR_ERR(algt);

	if ((algt->type ^ type) & algt->mask)
		return -EINVAL;

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_check_attr_type);

struct crypto_alg *crypto_get_attr_alg(struct rtattr **tb, u32 type, u32 mask)
{
	struct rtattr *rta = tb[CRYPTOA_ALG - 1];
	struct crypto_attr_alg *alga;

	if (!rta)
		return ERR_PTR(-ENOENT);
	if (RTA_PAYLOAD(rta) < sizeof(*alga))
		return ERR_PTR(-EINVAL);

	alga = RTA_DATA(rta);
	alga->name[CRYPTO_MAX_ALG_NAME - 1] = 0;

	return crypto_alg_mod_lookup(alga->name, type, mask);
}
EXPORT_SYMBOL_GPL(crypto_get_attr_alg);

struct crypto_instance *crypto_alloc_instance(const char *name,
					      struct crypto_alg *alg)
{
	struct crypto_instance *inst;
	struct crypto_spawn *spawn;
	int err;

	inst = kzalloc(sizeof(*inst) + sizeof(*spawn), GFP_KERNEL);
	if (!inst)
		return ERR_PTR(-ENOMEM);

	err = -ENAMETOOLONG;
	if (snprintf(inst->alg.cra_name, CRYPTO_MAX_ALG_NAME, "%s(%s)", name,
		     alg->cra_name) >= CRYPTO_MAX_ALG_NAME)
		goto err_free_inst;

	if (snprintf(inst->alg.cra_driver_name, CRYPTO_MAX_ALG_NAME, "%s(%s)",
		     name, alg->cra_driver_name) >= CRYPTO_MAX_ALG_NAME)
		goto err_free_inst;

	spawn = crypto_instance_ctx(inst);
	err = crypto_init_spawn(spawn, alg, inst);

	if (err)
		goto err_free_inst;

	return inst;

err_free_inst:
	kfree(inst);
	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(crypto_alloc_instance);

void crypto_init_queue(struct crypto_queue *queue, unsigned int max_qlen)
{
	INIT_LIST_HEAD(&queue->list);
	queue->backlog = &queue->list;
	queue->qlen = 0;
	queue->max_qlen = max_qlen;
}
EXPORT_SYMBOL_GPL(crypto_init_queue);

int crypto_enqueue_request(struct crypto_queue *queue,
			   struct crypto_async_request *request)
{
	int err = -EINPROGRESS;

	if (unlikely(queue->qlen >= queue->max_qlen)) {
		err = -EBUSY;
		if (!(request->flags & CRYPTO_TFM_REQ_MAY_BACKLOG))
			goto out;
		if (queue->backlog == &queue->list)
			queue->backlog = &request->list;
	}

	queue->qlen++;
	list_add_tail(&request->list, &queue->list);

out:
	return err;
}
EXPORT_SYMBOL_GPL(crypto_enqueue_request);

struct crypto_async_request *crypto_dequeue_request(struct crypto_queue *queue)
{
	struct list_head *request;

	if (unlikely(!queue->qlen))
		return NULL;

	queue->qlen--;

	if (queue->backlog != &queue->list)
		queue->backlog = queue->backlog->next;

	request = queue->list.next;
	list_del(request);

	return list_entry(request, struct crypto_async_request, list);
}
EXPORT_SYMBOL_GPL(crypto_dequeue_request);

int crypto_tfm_in_queue(struct crypto_queue *queue, struct crypto_tfm *tfm)
{
	struct crypto_async_request *req;

	list_for_each_entry(req, &queue->list, list) {
		if (req->tfm == tfm)
			return 1;
	}

	return 0;
}
EXPORT_SYMBOL_GPL(crypto_tfm_in_queue);

static int __init crypto_algapi_init(void)
{
	crypto_init_proc();
	return 0;
}

static void __exit crypto_algapi_exit(void)
{
	crypto_exit_proc();
}

module_init(crypto_algapi_init);
module_exit(crypto_algapi_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Cryptographic algorithms API");