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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
32#include "internal.h"
33
34#define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
35
36static DEFINE_MUTEX(crypto_cfg_mutex);
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{
50 struct crypto_alg *q, *alg = NULL;
51
52 down_read(&crypto_alg_sem);
53
54 list_for_each_entry(q, &crypto_alg_list, cra_list) {
55 int match = 0;
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
66 if (!match)
67 continue;
68
69 if (unlikely(!crypto_mod_get(q)))
70 continue;
71
72 alg = q;
73 break;
74 }
75
76 up_read(&crypto_alg_sem);
77
78 return alg;
79}
80
81static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
82{
83 struct crypto_report_cipher rcipher;
84
85 strncpy(rcipher.type, "cipher", sizeof(rcipher.type));
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
91 if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
92 sizeof(struct crypto_report_cipher), &rcipher))
93 goto nla_put_failure;
94 return 0;
95
96nla_put_failure:
97 return -EMSGSIZE;
98}
99
100static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
101{
102 struct crypto_report_comp rcomp;
103
104 strncpy(rcomp.type, "compression", sizeof(rcomp.type));
105 if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
106 sizeof(struct crypto_report_comp), &rcomp))
107 goto nla_put_failure;
108 return 0;
109
110nla_put_failure:
111 return -EMSGSIZE;
112}
113
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
129static int crypto_report_one(struct crypto_alg *alg,
130 struct crypto_user_alg *ualg, struct sk_buff *skb)
131{
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;
140 ualg->cru_flags = alg->cra_flags;
141 ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);
142
143 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
144 goto nla_put_failure;
145 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
146 struct crypto_report_larval rl;
147
148 strncpy(rl.type, "larval", sizeof(rl.type));
149 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL,
150 sizeof(struct crypto_report_larval), &rl))
151 goto nla_put_failure;
152 goto out;
153 }
154
155 if (alg->cra_type && alg->cra_type->report) {
156 if (alg->cra_type->report(skb, alg))
157 goto nla_put_failure;
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
167 break;
168 case CRYPTO_ALG_TYPE_COMPRESS:
169 if (crypto_report_comp(skb, alg))
170 goto nla_put_failure;
171
172 break;
173
174 case CRYPTO_ALG_TYPE_AKCIPHER:
175 if (crypto_report_akcipher(skb, alg))
176 goto nla_put_failure;
177
178 break;
179 }
180
181out:
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
197 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
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
227 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
228 return -EINVAL;
229
230 alg = crypto_alg_match(p, 0);
231 if (!alg)
232 return -ENOENT;
233
234 err = -ENOMEM;
235 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
236 if (!skb)
237 goto drop_alg;
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);
245
246drop_alg:
247 crypto_mod_put(alg);
248
249 if (err)
250 return err;
251
252 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
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
296 if (!netlink_capable(skb, CAP_NET_ADMIN))
297 return -EPERM;
298
299 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
300 return -EINVAL;
301
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
318 crypto_mod_put(alg);
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);
329 int err;
330
331 if (!netlink_capable(skb, CAP_NET_ADMIN))
332 return -EPERM;
333
334 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
335 return -EINVAL;
336
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. */
346 err = -EINVAL;
347 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
348 goto drop_alg;
349
350 err = -EBUSY;
351 if (atomic_read(&alg->cra_refcnt) > 2)
352 goto drop_alg;
353
354 err = crypto_unregister_instance((struct crypto_instance *)alg);
355
356drop_alg:
357 crypto_mod_put(alg);
358 return err;
359}
360
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;
378 if (fatal_signal_pending(current)) {
379 err = -EINTR;
380 break;
381 }
382 }
383
384 return ERR_PTR(err);
385}
386
387static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
388 struct nlattr **attrs)
389{
390 int exact = 0;
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
396 if (!netlink_capable(skb, CAP_NET_ADMIN))
397 return -EPERM;
398
399 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
400 return -EINVAL;
401
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);
409 if (alg) {
410 crypto_mod_put(alg);
411 return -EEXIST;
412 }
413
414 if (strlen(p->cru_driver_name))
415 name = p->cru_driver_name;
416 else
417 name = p->cru_name;
418
419 switch (p->cru_type & p->cru_mask & CRYPTO_ALG_TYPE_MASK) {
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
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
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
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),
458 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
459};
460
461static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
462 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
463};
464
465#undef MSGSIZE
466
467static const struct crypto_link {
468 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
469 int (*dump)(struct sk_buff *, struct netlink_callback *);
470 int (*done)(struct netlink_callback *);
471} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
472 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
473 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
474 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
475 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
476 .dump = crypto_dump_report,
477 .done = crypto_dump_report_done},
478 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
479};
480
481static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
482{
483 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
484 const struct crypto_link *link;
485 int type, err;
486
487 type = nlh->nlmsg_type;
488 if (type > CRYPTO_MSG_MAX)
489 return -EINVAL;
490
491 type -= CRYPTO_MSG_BASE;
492 link = &crypto_dispatch[type];
493
494 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
495 (nlh->nlmsg_flags & NLM_F_DUMP))) {
496 struct crypto_alg *alg;
497 u16 dump_alloc = 0;
498
499 if (link->dump == NULL)
500 return -EINVAL;
501
502 down_read(&crypto_alg_sem);
503 list_for_each_entry(alg, &crypto_alg_list, cra_list)
504 dump_alloc += CRYPTO_REPORT_MAXSIZE;
505
506 {
507 struct netlink_dump_control c = {
508 .dump = link->dump,
509 .done = link->done,
510 .min_dump_alloc = dump_alloc,
511 };
512 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c);
513 }
514 up_read(&crypto_alg_sem);
515
516 return err;
517 }
518
519 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
520 crypto_policy);
521 if (err < 0)
522 return err;
523
524 if (link->doit == NULL)
525 return -EINVAL;
526
527 return link->doit(skb, nlh, attrs);
528}
529
530static void crypto_netlink_rcv(struct sk_buff *skb)
531{
532 mutex_lock(&crypto_cfg_mutex);
533 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
534 mutex_unlock(&crypto_cfg_mutex);
535}
536
537static int __init crypto_user_init(void)
538{
539 struct netlink_kernel_cfg cfg = {
540 .input = crypto_netlink_rcv,
541 };
542
543 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg);
544 if (!crypto_nlsk)
545 return -ENOMEM;
546
547 return 0;
548}
549
550static void __exit crypto_user_exit(void)
551{
552 netlink_kernel_release(crypto_nlsk);
553}
554
555module_init(crypto_user_init);
556module_exit(crypto_user_exit);
557MODULE_LICENSE("GPL");
558MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
559MODULE_DESCRIPTION("Crypto userspace configuration API");
560MODULE_ALIAS("net-pf-16-proto-21");