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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>
24#include <linux/sched.h>
25#include <net/netlink.h>
26#include <linux/security.h>
27#include <net/net_namespace.h>
28#include <crypto/internal/skcipher.h>
29#include <crypto/internal/rng.h>
30#include <crypto/akcipher.h>
31#include <crypto/kpp.h>
32
33#include "internal.h"
34
35#define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
36
37static DEFINE_MUTEX(crypto_cfg_mutex);
38
39/* The crypto netlink socket */
40static struct sock *crypto_nlsk;
41
42struct crypto_dump_info {
43 struct sk_buff *in_skb;
44 struct sk_buff *out_skb;
45 u32 nlmsg_seq;
46 u16 nlmsg_flags;
47};
48
49static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
50{
51 struct crypto_alg *q, *alg = NULL;
52
53 down_read(&crypto_alg_sem);
54
55 list_for_each_entry(q, &crypto_alg_list, cra_list) {
56 int match = 0;
57
58 if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
59 continue;
60
61 if (strlen(p->cru_driver_name))
62 match = !strcmp(q->cra_driver_name,
63 p->cru_driver_name);
64 else if (!exact)
65 match = !strcmp(q->cra_name, p->cru_name);
66
67 if (!match)
68 continue;
69
70 if (unlikely(!crypto_mod_get(q)))
71 continue;
72
73 alg = q;
74 break;
75 }
76
77 up_read(&crypto_alg_sem);
78
79 return alg;
80}
81
82static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
83{
84 struct crypto_report_cipher rcipher;
85
86 strlcpy(rcipher.type, "cipher", sizeof(rcipher.type));
87
88 rcipher.blocksize = alg->cra_blocksize;
89 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
90 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
91
92 if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
93 sizeof(struct crypto_report_cipher), &rcipher))
94 goto nla_put_failure;
95 return 0;
96
97nla_put_failure:
98 return -EMSGSIZE;
99}
100
101static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
102{
103 struct crypto_report_comp rcomp;
104
105 strlcpy(rcomp.type, "compression", sizeof(rcomp.type));
106 if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
107 sizeof(struct crypto_report_comp), &rcomp))
108 goto nla_put_failure;
109 return 0;
110
111nla_put_failure:
112 return -EMSGSIZE;
113}
114
115static int crypto_report_acomp(struct sk_buff *skb, struct crypto_alg *alg)
116{
117 struct crypto_report_acomp racomp;
118
119 strlcpy(racomp.type, "acomp", sizeof(racomp.type));
120
121 if (nla_put(skb, CRYPTOCFGA_REPORT_ACOMP,
122 sizeof(struct crypto_report_acomp), &racomp))
123 goto nla_put_failure;
124 return 0;
125
126nla_put_failure:
127 return -EMSGSIZE;
128}
129
130static int crypto_report_akcipher(struct sk_buff *skb, struct crypto_alg *alg)
131{
132 struct crypto_report_akcipher rakcipher;
133
134 strlcpy(rakcipher.type, "akcipher", sizeof(rakcipher.type));
135
136 if (nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER,
137 sizeof(struct crypto_report_akcipher), &rakcipher))
138 goto nla_put_failure;
139 return 0;
140
141nla_put_failure:
142 return -EMSGSIZE;
143}
144
145static int crypto_report_kpp(struct sk_buff *skb, struct crypto_alg *alg)
146{
147 struct crypto_report_kpp rkpp;
148
149 strlcpy(rkpp.type, "kpp", sizeof(rkpp.type));
150
151 if (nla_put(skb, CRYPTOCFGA_REPORT_KPP,
152 sizeof(struct crypto_report_kpp), &rkpp))
153 goto nla_put_failure;
154 return 0;
155
156nla_put_failure:
157 return -EMSGSIZE;
158}
159
160static int crypto_report_one(struct crypto_alg *alg,
161 struct crypto_user_alg *ualg, struct sk_buff *skb)
162{
163 strlcpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
164 strlcpy(ualg->cru_driver_name, alg->cra_driver_name,
165 sizeof(ualg->cru_driver_name));
166 strlcpy(ualg->cru_module_name, module_name(alg->cra_module),
167 sizeof(ualg->cru_module_name));
168
169 ualg->cru_type = 0;
170 ualg->cru_mask = 0;
171 ualg->cru_flags = alg->cra_flags;
172 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
173
174 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
175 goto nla_put_failure;
176 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
177 struct crypto_report_larval rl;
178
179 strlcpy(rl.type, "larval", sizeof(rl.type));
180 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL,
181 sizeof(struct crypto_report_larval), &rl))
182 goto nla_put_failure;
183 goto out;
184 }
185
186 if (alg->cra_type && alg->cra_type->report) {
187 if (alg->cra_type->report(skb, alg))
188 goto nla_put_failure;
189
190 goto out;
191 }
192
193 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
194 case CRYPTO_ALG_TYPE_CIPHER:
195 if (crypto_report_cipher(skb, alg))
196 goto nla_put_failure;
197
198 break;
199 case CRYPTO_ALG_TYPE_COMPRESS:
200 if (crypto_report_comp(skb, alg))
201 goto nla_put_failure;
202
203 break;
204 case CRYPTO_ALG_TYPE_ACOMPRESS:
205 if (crypto_report_acomp(skb, alg))
206 goto nla_put_failure;
207
208 break;
209 case CRYPTO_ALG_TYPE_AKCIPHER:
210 if (crypto_report_akcipher(skb, alg))
211 goto nla_put_failure;
212
213 break;
214 case CRYPTO_ALG_TYPE_KPP:
215 if (crypto_report_kpp(skb, alg))
216 goto nla_put_failure;
217 break;
218 }
219
220out:
221 return 0;
222
223nla_put_failure:
224 return -EMSGSIZE;
225}
226
227static int crypto_report_alg(struct crypto_alg *alg,
228 struct crypto_dump_info *info)
229{
230 struct sk_buff *in_skb = info->in_skb;
231 struct sk_buff *skb = info->out_skb;
232 struct nlmsghdr *nlh;
233 struct crypto_user_alg *ualg;
234 int err = 0;
235
236 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
237 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
238 if (!nlh) {
239 err = -EMSGSIZE;
240 goto out;
241 }
242
243 ualg = nlmsg_data(nlh);
244
245 err = crypto_report_one(alg, ualg, skb);
246 if (err) {
247 nlmsg_cancel(skb, nlh);
248 goto out;
249 }
250
251 nlmsg_end(skb, nlh);
252
253out:
254 return err;
255}
256
257static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
258 struct nlattr **attrs)
259{
260 struct crypto_user_alg *p = nlmsg_data(in_nlh);
261 struct crypto_alg *alg;
262 struct sk_buff *skb;
263 struct crypto_dump_info info;
264 int err;
265
266 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
267 return -EINVAL;
268
269 alg = crypto_alg_match(p, 0);
270 if (!alg)
271 return -ENOENT;
272
273 err = -ENOMEM;
274 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
275 if (!skb)
276 goto drop_alg;
277
278 info.in_skb = in_skb;
279 info.out_skb = skb;
280 info.nlmsg_seq = in_nlh->nlmsg_seq;
281 info.nlmsg_flags = 0;
282
283 err = crypto_report_alg(alg, &info);
284
285drop_alg:
286 crypto_mod_put(alg);
287
288 if (err)
289 return err;
290
291 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
292}
293
294static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
295{
296 struct crypto_alg *alg;
297 struct crypto_dump_info info;
298 int err;
299
300 if (cb->args[0])
301 goto out;
302
303 cb->args[0] = 1;
304
305 info.in_skb = cb->skb;
306 info.out_skb = skb;
307 info.nlmsg_seq = cb->nlh->nlmsg_seq;
308 info.nlmsg_flags = NLM_F_MULTI;
309
310 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
311 err = crypto_report_alg(alg, &info);
312 if (err)
313 goto out_err;
314 }
315
316out:
317 return skb->len;
318out_err:
319 return err;
320}
321
322static int crypto_dump_report_done(struct netlink_callback *cb)
323{
324 return 0;
325}
326
327static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
328 struct nlattr **attrs)
329{
330 struct crypto_alg *alg;
331 struct crypto_user_alg *p = nlmsg_data(nlh);
332 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
333 LIST_HEAD(list);
334
335 if (!netlink_capable(skb, CAP_NET_ADMIN))
336 return -EPERM;
337
338 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
339 return -EINVAL;
340
341 if (priority && !strlen(p->cru_driver_name))
342 return -EINVAL;
343
344 alg = crypto_alg_match(p, 1);
345 if (!alg)
346 return -ENOENT;
347
348 down_write(&crypto_alg_sem);
349
350 crypto_remove_spawns(alg, &list, NULL);
351
352 if (priority)
353 alg->cra_priority = nla_get_u32(priority);
354
355 up_write(&crypto_alg_sem);
356
357 crypto_mod_put(alg);
358 crypto_remove_final(&list);
359
360 return 0;
361}
362
363static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
364 struct nlattr **attrs)
365{
366 struct crypto_alg *alg;
367 struct crypto_user_alg *p = nlmsg_data(nlh);
368 int err;
369
370 if (!netlink_capable(skb, CAP_NET_ADMIN))
371 return -EPERM;
372
373 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
374 return -EINVAL;
375
376 alg = crypto_alg_match(p, 1);
377 if (!alg)
378 return -ENOENT;
379
380 /* We can not unregister core algorithms such as aes-generic.
381 * We would loose the reference in the crypto_alg_list to this algorithm
382 * if we try to unregister. Unregistering such an algorithm without
383 * removing the module is not possible, so we restrict to crypto
384 * instances that are build from templates. */
385 err = -EINVAL;
386 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
387 goto drop_alg;
388
389 err = -EBUSY;
390 if (refcount_read(&alg->cra_refcnt) > 2)
391 goto drop_alg;
392
393 err = crypto_unregister_instance((struct crypto_instance *)alg);
394
395drop_alg:
396 crypto_mod_put(alg);
397 return err;
398}
399
400static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
401 struct nlattr **attrs)
402{
403 int exact = 0;
404 const char *name;
405 struct crypto_alg *alg;
406 struct crypto_user_alg *p = nlmsg_data(nlh);
407 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
408
409 if (!netlink_capable(skb, CAP_NET_ADMIN))
410 return -EPERM;
411
412 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
413 return -EINVAL;
414
415 if (strlen(p->cru_driver_name))
416 exact = 1;
417
418 if (priority && !exact)
419 return -EINVAL;
420
421 alg = crypto_alg_match(p, exact);
422 if (alg) {
423 crypto_mod_put(alg);
424 return -EEXIST;
425 }
426
427 if (strlen(p->cru_driver_name))
428 name = p->cru_driver_name;
429 else
430 name = p->cru_name;
431
432 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
433 if (IS_ERR(alg))
434 return PTR_ERR(alg);
435
436 down_write(&crypto_alg_sem);
437
438 if (priority)
439 alg->cra_priority = nla_get_u32(priority);
440
441 up_write(&crypto_alg_sem);
442
443 crypto_mod_put(alg);
444
445 return 0;
446}
447
448static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
449 struct nlattr **attrs)
450{
451 if (!netlink_capable(skb, CAP_NET_ADMIN))
452 return -EPERM;
453 return crypto_del_default_rng();
454}
455
456#define MSGSIZE(type) sizeof(struct type)
457
458static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
459 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
460 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
461 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
462 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
463 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
464};
465
466static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
467 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
468};
469
470#undef MSGSIZE
471
472static const struct crypto_link {
473 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
474 int (*dump)(struct sk_buff *, struct netlink_callback *);
475 int (*done)(struct netlink_callback *);
476} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
477 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
478 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
479 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
480 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
481 .dump = crypto_dump_report,
482 .done = crypto_dump_report_done},
483 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
484};
485
486static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
487 struct netlink_ext_ack *extack)
488{
489 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
490 const struct crypto_link *link;
491 int type, err;
492
493 type = nlh->nlmsg_type;
494 if (type > CRYPTO_MSG_MAX)
495 return -EINVAL;
496
497 type -= CRYPTO_MSG_BASE;
498 link = &crypto_dispatch[type];
499
500 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
501 (nlh->nlmsg_flags & NLM_F_DUMP))) {
502 struct crypto_alg *alg;
503 u16 dump_alloc = 0;
504
505 if (link->dump == NULL)
506 return -EINVAL;
507
508 down_read(&crypto_alg_sem);
509 list_for_each_entry(alg, &crypto_alg_list, cra_list)
510 dump_alloc += CRYPTO_REPORT_MAXSIZE;
511
512 {
513 struct netlink_dump_control c = {
514 .dump = link->dump,
515 .done = link->done,
516 .min_dump_alloc = dump_alloc,
517 };
518 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c);
519 }
520 up_read(&crypto_alg_sem);
521
522 return err;
523 }
524
525 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
526 crypto_policy, extack);
527 if (err < 0)
528 return err;
529
530 if (link->doit == NULL)
531 return -EINVAL;
532
533 return link->doit(skb, nlh, attrs);
534}
535
536static void crypto_netlink_rcv(struct sk_buff *skb)
537{
538 mutex_lock(&crypto_cfg_mutex);
539 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
540 mutex_unlock(&crypto_cfg_mutex);
541}
542
543static int __init crypto_user_init(void)
544{
545 struct netlink_kernel_cfg cfg = {
546 .input = crypto_netlink_rcv,
547 };
548
549 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg);
550 if (!crypto_nlsk)
551 return -ENOMEM;
552
553 return 0;
554}
555
556static void __exit crypto_user_exit(void)
557{
558 netlink_kernel_release(crypto_nlsk);
559}
560
561module_init(crypto_user_init);
562module_exit(crypto_user_exit);
563MODULE_LICENSE("GPL");
564MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
565MODULE_DESCRIPTION("Crypto userspace configuration API");
566MODULE_ALIAS("net-pf-16-proto-21");