Merge tag 'configfs-for-4.7' of git://git.infradead.org/users/hch/configfs
[linux-2.6-block.git] / crypto / crypto_user.c
CommitLineData
a38f7907
SK
1/*
2 * Crypto user configuration API.
3 *
4 * Copyright (C) 2011 secunet Security Networks AG
5 * Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>
6 *
7 * This program is free software; you can redistribute it and/or modify it
8 * under the terms and conditions of the GNU General Public License,
9 * version 2, as published by the Free Software Foundation.
10 *
11 * This program is distributed in the hope it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
14 * more details.
15 *
16 * You should have received a copy of the GNU General Public License along with
17 * this program; if not, write to the Free Software Foundation, Inc.,
18 * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
19 */
20
21#include <linux/module.h>
22#include <linux/crypto.h>
23#include <linux/cryptouser.h>
1e122994 24#include <linux/sched.h>
a38f7907
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25#include <net/netlink.h>
26#include <linux/security.h>
27#include <net/net_namespace.h>
1e122994 28#include <crypto/internal/skcipher.h>
9aa867e4 29#include <crypto/internal/rng.h>
3c339ab8 30#include <crypto/akcipher.h>
1e122994 31
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32#include "internal.h"
33
8fd61d34
MK
34#define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
35
66ce0b0f 36static DEFINE_MUTEX(crypto_cfg_mutex);
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37
38/* The crypto netlink socket */
39static struct sock *crypto_nlsk;
40
41struct crypto_dump_info {
42 struct sk_buff *in_skb;
43 struct sk_buff *out_skb;
44 u32 nlmsg_seq;
45 u16 nlmsg_flags;
46};
47
48static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
49{
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50 struct crypto_alg *q, *alg = NULL;
51
52 down_read(&crypto_alg_sem);
53
a38f7907 54 list_for_each_entry(q, &crypto_alg_list, cra_list) {
e6ea64ec 55 int match = 0;
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56
57 if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
58 continue;
59
60 if (strlen(p->cru_driver_name))
61 match = !strcmp(q->cra_driver_name,
62 p->cru_driver_name);
63 else if (!exact)
64 match = !strcmp(q->cra_name, p->cru_name);
65
016baaa1
HX
66 if (!match)
67 continue;
68
69 if (unlikely(!crypto_mod_get(q)))
70 continue;
71
72 alg = q;
73 break;
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74 }
75
76 up_read(&crypto_alg_sem);
77
78 return alg;
79}
80
07a5fa4a
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81static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
82{
83 struct crypto_report_cipher rcipher;
84
9a5467bf 85 strncpy(rcipher.type, "cipher", sizeof(rcipher.type));
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86
87 rcipher.blocksize = alg->cra_blocksize;
88 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
89 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
90
6662df33
DM
91 if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
92 sizeof(struct crypto_report_cipher), &rcipher))
93 goto nla_put_failure;
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94 return 0;
95
96nla_put_failure:
97 return -EMSGSIZE;
98}
99
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100static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
101{
102 struct crypto_report_comp rcomp;
103
9a5467bf 104 strncpy(rcomp.type, "compression", sizeof(rcomp.type));
6662df33
DM
105 if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
106 sizeof(struct crypto_report_comp), &rcomp))
107 goto nla_put_failure;
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108 return 0;
109
110nla_put_failure:
111 return -EMSGSIZE;
112}
113
3c339ab8
TS
114static int crypto_report_akcipher(struct sk_buff *skb, struct crypto_alg *alg)
115{
116 struct crypto_report_akcipher rakcipher;
117
118 strncpy(rakcipher.type, "akcipher", sizeof(rakcipher.type));
119
120 if (nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER,
121 sizeof(struct crypto_report_akcipher), &rakcipher))
122 goto nla_put_failure;
123 return 0;
124
125nla_put_failure:
126 return -EMSGSIZE;
127}
128
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129static int crypto_report_one(struct crypto_alg *alg,
130 struct crypto_user_alg *ualg, struct sk_buff *skb)
131{
9a5467bf
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132 strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
133 strncpy(ualg->cru_driver_name, alg->cra_driver_name,
134 sizeof(ualg->cru_driver_name));
135 strncpy(ualg->cru_module_name, module_name(alg->cra_module),
136 sizeof(ualg->cru_module_name));
137
138 ualg->cru_type = 0;
139 ualg->cru_mask = 0;
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140 ualg->cru_flags = alg->cra_flags;
141 ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);
142
6662df33
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143 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
144 goto nla_put_failure;
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145 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
146 struct crypto_report_larval rl;
147
9a5467bf 148 strncpy(rl.type, "larval", sizeof(rl.type));
6662df33
DM
149 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL,
150 sizeof(struct crypto_report_larval), &rl))
151 goto nla_put_failure;
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152 goto out;
153 }
154
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155 if (alg->cra_type && alg->cra_type->report) {
156 if (alg->cra_type->report(skb, alg))
157 goto nla_put_failure;
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158
159 goto out;
160 }
161
162 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
163 case CRYPTO_ALG_TYPE_CIPHER:
164 if (crypto_report_cipher(skb, alg))
165 goto nla_put_failure;
166
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167 break;
168 case CRYPTO_ALG_TYPE_COMPRESS:
169 if (crypto_report_comp(skb, alg))
170 goto nla_put_failure;
171
07a5fa4a 172 break;
3c339ab8
TS
173
174 case CRYPTO_ALG_TYPE_AKCIPHER:
175 if (crypto_report_akcipher(skb, alg))
176 goto nla_put_failure;
177
178 break;
b6aa63c0
SK
179 }
180
6c5a86f5 181out:
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182 return 0;
183
184nla_put_failure:
185 return -EMSGSIZE;
186}
187
188static int crypto_report_alg(struct crypto_alg *alg,
189 struct crypto_dump_info *info)
190{
191 struct sk_buff *in_skb = info->in_skb;
192 struct sk_buff *skb = info->out_skb;
193 struct nlmsghdr *nlh;
194 struct crypto_user_alg *ualg;
195 int err = 0;
196
15e47304 197 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
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198 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
199 if (!nlh) {
200 err = -EMSGSIZE;
201 goto out;
202 }
203
204 ualg = nlmsg_data(nlh);
205
206 err = crypto_report_one(alg, ualg, skb);
207 if (err) {
208 nlmsg_cancel(skb, nlh);
209 goto out;
210 }
211
212 nlmsg_end(skb, nlh);
213
214out:
215 return err;
216}
217
218static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
219 struct nlattr **attrs)
220{
221 struct crypto_user_alg *p = nlmsg_data(in_nlh);
222 struct crypto_alg *alg;
223 struct sk_buff *skb;
224 struct crypto_dump_info info;
225 int err;
226
8fd61d34
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227 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
228 return -EINVAL;
229
5d4a5e77 230 alg = crypto_alg_match(p, 0);
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231 if (!alg)
232 return -ENOENT;
233
016baaa1 234 err = -ENOMEM;
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235 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
236 if (!skb)
016baaa1 237 goto drop_alg;
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238
239 info.in_skb = in_skb;
240 info.out_skb = skb;
241 info.nlmsg_seq = in_nlh->nlmsg_seq;
242 info.nlmsg_flags = 0;
243
244 err = crypto_report_alg(alg, &info);
016baaa1
HX
245
246drop_alg:
247 crypto_mod_put(alg);
248
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249 if (err)
250 return err;
251
15e47304 252 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
a38f7907
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253}
254
255static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
256{
257 struct crypto_alg *alg;
258 struct crypto_dump_info info;
259 int err;
260
261 if (cb->args[0])
262 goto out;
263
264 cb->args[0] = 1;
265
266 info.in_skb = cb->skb;
267 info.out_skb = skb;
268 info.nlmsg_seq = cb->nlh->nlmsg_seq;
269 info.nlmsg_flags = NLM_F_MULTI;
270
271 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
272 err = crypto_report_alg(alg, &info);
273 if (err)
274 goto out_err;
275 }
276
277out:
278 return skb->len;
279out_err:
280 return err;
281}
282
283static int crypto_dump_report_done(struct netlink_callback *cb)
284{
285 return 0;
286}
287
288static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
289 struct nlattr **attrs)
290{
291 struct crypto_alg *alg;
292 struct crypto_user_alg *p = nlmsg_data(nlh);
293 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
294 LIST_HEAD(list);
295
639b4ac6 296 if (!netlink_capable(skb, CAP_NET_ADMIN))
c568398a
MCO
297 return -EPERM;
298
8fd61d34
MK
299 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
300 return -EINVAL;
301
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302 if (priority && !strlen(p->cru_driver_name))
303 return -EINVAL;
304
305 alg = crypto_alg_match(p, 1);
306 if (!alg)
307 return -ENOENT;
308
309 down_write(&crypto_alg_sem);
310
311 crypto_remove_spawns(alg, &list, NULL);
312
313 if (priority)
314 alg->cra_priority = nla_get_u32(priority);
315
316 up_write(&crypto_alg_sem);
317
016baaa1 318 crypto_mod_put(alg);
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319 crypto_remove_final(&list);
320
321 return 0;
322}
323
324static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
325 struct nlattr **attrs)
326{
327 struct crypto_alg *alg;
328 struct crypto_user_alg *p = nlmsg_data(nlh);
016baaa1 329 int err;
a38f7907 330
639b4ac6 331 if (!netlink_capable(skb, CAP_NET_ADMIN))
c568398a
MCO
332 return -EPERM;
333
8fd61d34
MK
334 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
335 return -EINVAL;
336
a38f7907
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337 alg = crypto_alg_match(p, 1);
338 if (!alg)
339 return -ENOENT;
340
341 /* We can not unregister core algorithms such as aes-generic.
342 * We would loose the reference in the crypto_alg_list to this algorithm
343 * if we try to unregister. Unregistering such an algorithm without
344 * removing the module is not possible, so we restrict to crypto
345 * instances that are build from templates. */
016baaa1 346 err = -EINVAL;
a38f7907 347 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
016baaa1 348 goto drop_alg;
a38f7907 349
016baaa1
HX
350 err = -EBUSY;
351 if (atomic_read(&alg->cra_refcnt) > 2)
352 goto drop_alg;
a38f7907 353
016baaa1
HX
354 err = crypto_unregister_instance((struct crypto_instance *)alg);
355
356drop_alg:
357 crypto_mod_put(alg);
358 return err;
a38f7907
SK
359}
360
1e122994
SK
361static struct crypto_alg *crypto_user_skcipher_alg(const char *name, u32 type,
362 u32 mask)
363{
364 int err;
365 struct crypto_alg *alg;
366
367 type = crypto_skcipher_type(type);
368 mask = crypto_skcipher_mask(mask);
369
370 for (;;) {
371 alg = crypto_lookup_skcipher(name, type, mask);
372 if (!IS_ERR(alg))
373 return alg;
374
375 err = PTR_ERR(alg);
376 if (err != -EAGAIN)
377 break;
3fc89adb 378 if (fatal_signal_pending(current)) {
1e122994
SK
379 err = -EINTR;
380 break;
381 }
382 }
383
384 return ERR_PTR(err);
385}
386
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387static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
388 struct nlattr **attrs)
389{
0cfdec7a 390 int exact = 0;
a38f7907
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391 const char *name;
392 struct crypto_alg *alg;
393 struct crypto_user_alg *p = nlmsg_data(nlh);
394 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
395
639b4ac6 396 if (!netlink_capable(skb, CAP_NET_ADMIN))
c568398a
MCO
397 return -EPERM;
398
8fd61d34
MK
399 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
400 return -EINVAL;
401
a38f7907
SK
402 if (strlen(p->cru_driver_name))
403 exact = 1;
404
405 if (priority && !exact)
406 return -EINVAL;
407
408 alg = crypto_alg_match(p, exact);
016baaa1
HX
409 if (alg) {
410 crypto_mod_put(alg);
a38f7907 411 return -EEXIST;
016baaa1 412 }
a38f7907
SK
413
414 if (strlen(p->cru_driver_name))
415 name = p->cru_driver_name;
416 else
417 name = p->cru_name;
418
1e122994 419 switch (p->cru_type & p->cru_mask & CRYPTO_ALG_TYPE_MASK) {
1e122994
SK
420 case CRYPTO_ALG_TYPE_GIVCIPHER:
421 case CRYPTO_ALG_TYPE_BLKCIPHER:
422 case CRYPTO_ALG_TYPE_ABLKCIPHER:
423 alg = crypto_user_skcipher_alg(name, p->cru_type, p->cru_mask);
424 break;
425 default:
426 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
427 }
428
a38f7907
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429 if (IS_ERR(alg))
430 return PTR_ERR(alg);
431
432 down_write(&crypto_alg_sem);
433
434 if (priority)
435 alg->cra_priority = nla_get_u32(priority);
436
437 up_write(&crypto_alg_sem);
438
439 crypto_mod_put(alg);
440
441 return 0;
442}
443
9aa867e4
HX
444static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
445 struct nlattr **attrs)
446{
447 if (!netlink_capable(skb, CAP_NET_ADMIN))
448 return -EPERM;
449 return crypto_del_default_rng();
450}
451
a38f7907
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452#define MSGSIZE(type) sizeof(struct type)
453
454static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
455 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
456 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
457 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
055ddaac 458 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
9aa867e4 459 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
a38f7907
SK
460};
461
462static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
463 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
464};
465
466#undef MSGSIZE
467
a84fb791 468static const struct crypto_link {
a38f7907
SK
469 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
470 int (*dump)(struct sk_buff *, struct netlink_callback *);
471 int (*done)(struct netlink_callback *);
472} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
473 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
474 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
475 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
476 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
477 .dump = crypto_dump_report,
478 .done = crypto_dump_report_done},
9aa867e4 479 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
a38f7907
SK
480};
481
482static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
483{
484 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
a84fb791 485 const struct crypto_link *link;
a38f7907
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486 int type, err;
487
488 type = nlh->nlmsg_type;
489 if (type > CRYPTO_MSG_MAX)
490 return -EINVAL;
491
492 type -= CRYPTO_MSG_BASE;
493 link = &crypto_dispatch[type];
494
a38f7907
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495 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
496 (nlh->nlmsg_flags & NLM_F_DUMP))) {
5219a534
SK
497 struct crypto_alg *alg;
498 u16 dump_alloc = 0;
499
a38f7907
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500 if (link->dump == NULL)
501 return -EINVAL;
5219a534 502
63e41ebc 503 down_read(&crypto_alg_sem);
5219a534
SK
504 list_for_each_entry(alg, &crypto_alg_list, cra_list)
505 dump_alloc += CRYPTO_REPORT_MAXSIZE;
506
80d326fa
PNA
507 {
508 struct netlink_dump_control c = {
509 .dump = link->dump,
510 .done = link->done,
5219a534 511 .min_dump_alloc = dump_alloc,
80d326fa 512 };
63e41ebc 513 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c);
80d326fa 514 }
63e41ebc
MK
515 up_read(&crypto_alg_sem);
516
517 return err;
a38f7907
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518 }
519
520 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
521 crypto_policy);
522 if (err < 0)
523 return err;
524
525 if (link->doit == NULL)
526 return -EINVAL;
527
528 return link->doit(skb, nlh, attrs);
529}
530
531static void crypto_netlink_rcv(struct sk_buff *skb)
532{
533 mutex_lock(&crypto_cfg_mutex);
534 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
535 mutex_unlock(&crypto_cfg_mutex);
536}
537
538static int __init crypto_user_init(void)
539{
a31f2d17
PNA
540 struct netlink_kernel_cfg cfg = {
541 .input = crypto_netlink_rcv,
542 };
543
9f00d977 544 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg);
a38f7907
SK
545 if (!crypto_nlsk)
546 return -ENOMEM;
547
548 return 0;
549}
550
551static void __exit crypto_user_exit(void)
552{
553 netlink_kernel_release(crypto_nlsk);
554}
555
556module_init(crypto_user_init);
557module_exit(crypto_user_exit);
558MODULE_LICENSE("GPL");
559MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
560MODULE_DESCRIPTION("Crypto userspace configuration API");
476c7fe2 561MODULE_ALIAS("net-pf-16-proto-21");