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
37 static DEFINE_MUTEX(crypto_cfg_mutex);
38
39 /* The crypto netlink socket */
40 static struct sock *crypto_nlsk;
41
42 struct 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
crypto_alg_match(struct crypto_user_alg * p,int exact)49 static 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 (crypto_is_larval(q))
59 continue;
60
61 if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
62 continue;
63
64 if (strlen(p->cru_driver_name))
65 match = !strcmp(q->cra_driver_name,
66 p->cru_driver_name);
67 else if (!exact)
68 match = !strcmp(q->cra_name, p->cru_name);
69
70 if (!match)
71 continue;
72
73 if (unlikely(!crypto_mod_get(q)))
74 continue;
75
76 alg = q;
77 break;
78 }
79
80 up_read(&crypto_alg_sem);
81
82 return alg;
83 }
84
crypto_report_cipher(struct sk_buff * skb,struct crypto_alg * alg)85 static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
86 {
87 struct crypto_report_cipher rcipher;
88
89 strncpy(rcipher.type, "cipher", sizeof(rcipher.type));
90
91 rcipher.blocksize = alg->cra_blocksize;
92 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
93 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
94
95 if (nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
96 sizeof(struct crypto_report_cipher), &rcipher))
97 goto nla_put_failure;
98 return 0;
99
100 nla_put_failure:
101 return -EMSGSIZE;
102 }
103
crypto_report_comp(struct sk_buff * skb,struct crypto_alg * alg)104 static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
105 {
106 struct crypto_report_comp rcomp;
107
108 strncpy(rcomp.type, "compression", sizeof(rcomp.type));
109 if (nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS,
110 sizeof(struct crypto_report_comp), &rcomp))
111 goto nla_put_failure;
112 return 0;
113
114 nla_put_failure:
115 return -EMSGSIZE;
116 }
117
crypto_report_acomp(struct sk_buff * skb,struct crypto_alg * alg)118 static int crypto_report_acomp(struct sk_buff *skb, struct crypto_alg *alg)
119 {
120 struct crypto_report_acomp racomp;
121
122 strncpy(racomp.type, "acomp", sizeof(racomp.type));
123
124 if (nla_put(skb, CRYPTOCFGA_REPORT_ACOMP,
125 sizeof(struct crypto_report_acomp), &racomp))
126 goto nla_put_failure;
127 return 0;
128
129 nla_put_failure:
130 return -EMSGSIZE;
131 }
132
crypto_report_akcipher(struct sk_buff * skb,struct crypto_alg * alg)133 static int crypto_report_akcipher(struct sk_buff *skb, struct crypto_alg *alg)
134 {
135 struct crypto_report_akcipher rakcipher;
136
137 strncpy(rakcipher.type, "akcipher", sizeof(rakcipher.type));
138
139 if (nla_put(skb, CRYPTOCFGA_REPORT_AKCIPHER,
140 sizeof(struct crypto_report_akcipher), &rakcipher))
141 goto nla_put_failure;
142 return 0;
143
144 nla_put_failure:
145 return -EMSGSIZE;
146 }
147
crypto_report_kpp(struct sk_buff * skb,struct crypto_alg * alg)148 static int crypto_report_kpp(struct sk_buff *skb, struct crypto_alg *alg)
149 {
150 struct crypto_report_kpp rkpp;
151
152 strncpy(rkpp.type, "kpp", sizeof(rkpp.type));
153
154 if (nla_put(skb, CRYPTOCFGA_REPORT_KPP,
155 sizeof(struct crypto_report_kpp), &rkpp))
156 goto nla_put_failure;
157 return 0;
158
159 nla_put_failure:
160 return -EMSGSIZE;
161 }
162
crypto_report_one(struct crypto_alg * alg,struct crypto_user_alg * ualg,struct sk_buff * skb)163 static int crypto_report_one(struct crypto_alg *alg,
164 struct crypto_user_alg *ualg, struct sk_buff *skb)
165 {
166 strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
167 strncpy(ualg->cru_driver_name, alg->cra_driver_name,
168 sizeof(ualg->cru_driver_name));
169 strncpy(ualg->cru_module_name, module_name(alg->cra_module),
170 sizeof(ualg->cru_module_name));
171
172 ualg->cru_type = 0;
173 ualg->cru_mask = 0;
174 ualg->cru_flags = alg->cra_flags;
175 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
176
177 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
178 goto nla_put_failure;
179 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
180 struct crypto_report_larval rl;
181
182 strncpy(rl.type, "larval", sizeof(rl.type));
183 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL,
184 sizeof(struct crypto_report_larval), &rl))
185 goto nla_put_failure;
186 goto out;
187 }
188
189 if (alg->cra_type && alg->cra_type->report) {
190 if (alg->cra_type->report(skb, alg))
191 goto nla_put_failure;
192
193 goto out;
194 }
195
196 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
197 case CRYPTO_ALG_TYPE_CIPHER:
198 if (crypto_report_cipher(skb, alg))
199 goto nla_put_failure;
200
201 break;
202 case CRYPTO_ALG_TYPE_COMPRESS:
203 if (crypto_report_comp(skb, alg))
204 goto nla_put_failure;
205
206 break;
207 case CRYPTO_ALG_TYPE_ACOMPRESS:
208 if (crypto_report_acomp(skb, alg))
209 goto nla_put_failure;
210
211 break;
212 case CRYPTO_ALG_TYPE_AKCIPHER:
213 if (crypto_report_akcipher(skb, alg))
214 goto nla_put_failure;
215
216 break;
217 case CRYPTO_ALG_TYPE_KPP:
218 if (crypto_report_kpp(skb, alg))
219 goto nla_put_failure;
220 break;
221 }
222
223 out:
224 return 0;
225
226 nla_put_failure:
227 return -EMSGSIZE;
228 }
229
crypto_report_alg(struct crypto_alg * alg,struct crypto_dump_info * info)230 static int crypto_report_alg(struct crypto_alg *alg,
231 struct crypto_dump_info *info)
232 {
233 struct sk_buff *in_skb = info->in_skb;
234 struct sk_buff *skb = info->out_skb;
235 struct nlmsghdr *nlh;
236 struct crypto_user_alg *ualg;
237 int err = 0;
238
239 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
240 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
241 if (!nlh) {
242 err = -EMSGSIZE;
243 goto out;
244 }
245
246 ualg = nlmsg_data(nlh);
247
248 err = crypto_report_one(alg, ualg, skb);
249 if (err) {
250 nlmsg_cancel(skb, nlh);
251 goto out;
252 }
253
254 nlmsg_end(skb, nlh);
255
256 out:
257 return err;
258 }
259
crypto_report(struct sk_buff * in_skb,struct nlmsghdr * in_nlh,struct nlattr ** attrs)260 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
261 struct nlattr **attrs)
262 {
263 struct crypto_user_alg *p = nlmsg_data(in_nlh);
264 struct crypto_alg *alg;
265 struct sk_buff *skb;
266 struct crypto_dump_info info;
267 int err;
268
269 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
270 return -EINVAL;
271
272 alg = crypto_alg_match(p, 0);
273 if (!alg)
274 return -ENOENT;
275
276 err = -ENOMEM;
277 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
278 if (!skb)
279 goto drop_alg;
280
281 info.in_skb = in_skb;
282 info.out_skb = skb;
283 info.nlmsg_seq = in_nlh->nlmsg_seq;
284 info.nlmsg_flags = 0;
285
286 err = crypto_report_alg(alg, &info);
287
288 drop_alg:
289 crypto_mod_put(alg);
290
291 if (err) {
292 kfree_skb(skb);
293 return err;
294 }
295
296 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
297 }
298
crypto_dump_report(struct sk_buff * skb,struct netlink_callback * cb)299 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
300 {
301 const size_t start_pos = cb->args[0];
302 size_t pos = 0;
303 struct crypto_dump_info info;
304 struct crypto_alg *alg;
305 int res;
306
307 info.in_skb = cb->skb;
308 info.out_skb = skb;
309 info.nlmsg_seq = cb->nlh->nlmsg_seq;
310 info.nlmsg_flags = NLM_F_MULTI;
311
312 down_read(&crypto_alg_sem);
313 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
314 if (pos >= start_pos) {
315 res = crypto_report_alg(alg, &info);
316 if (res == -EMSGSIZE)
317 break;
318 if (res)
319 goto out;
320 }
321 pos++;
322 }
323 cb->args[0] = pos;
324 res = skb->len;
325 out:
326 up_read(&crypto_alg_sem);
327 return res;
328 }
329
crypto_dump_report_done(struct netlink_callback * cb)330 static int crypto_dump_report_done(struct netlink_callback *cb)
331 {
332 return 0;
333 }
334
crypto_update_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)335 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
336 struct nlattr **attrs)
337 {
338 struct crypto_alg *alg;
339 struct crypto_user_alg *p = nlmsg_data(nlh);
340 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
341 LIST_HEAD(list);
342
343 if (!netlink_capable(skb, CAP_NET_ADMIN))
344 return -EPERM;
345
346 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
347 return -EINVAL;
348
349 if (priority && !strlen(p->cru_driver_name))
350 return -EINVAL;
351
352 alg = crypto_alg_match(p, 1);
353 if (!alg)
354 return -ENOENT;
355
356 down_write(&crypto_alg_sem);
357
358 crypto_remove_spawns(alg, &list, NULL);
359
360 if (priority)
361 alg->cra_priority = nla_get_u32(priority);
362
363 up_write(&crypto_alg_sem);
364
365 crypto_mod_put(alg);
366 crypto_remove_final(&list);
367
368 return 0;
369 }
370
crypto_del_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)371 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
372 struct nlattr **attrs)
373 {
374 struct crypto_alg *alg;
375 struct crypto_user_alg *p = nlmsg_data(nlh);
376 int err;
377
378 if (!netlink_capable(skb, CAP_NET_ADMIN))
379 return -EPERM;
380
381 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
382 return -EINVAL;
383
384 alg = crypto_alg_match(p, 1);
385 if (!alg)
386 return -ENOENT;
387
388 /* We can not unregister core algorithms such as aes-generic.
389 * We would loose the reference in the crypto_alg_list to this algorithm
390 * if we try to unregister. Unregistering such an algorithm without
391 * removing the module is not possible, so we restrict to crypto
392 * instances that are build from templates. */
393 err = -EINVAL;
394 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
395 goto drop_alg;
396
397 err = -EBUSY;
398 if (refcount_read(&alg->cra_refcnt) > 2)
399 goto drop_alg;
400
401 err = crypto_unregister_instance((struct crypto_instance *)alg);
402
403 drop_alg:
404 crypto_mod_put(alg);
405 return err;
406 }
407
crypto_add_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)408 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
409 struct nlattr **attrs)
410 {
411 int exact = 0;
412 const char *name;
413 struct crypto_alg *alg;
414 struct crypto_user_alg *p = nlmsg_data(nlh);
415 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
416
417 if (!netlink_capable(skb, CAP_NET_ADMIN))
418 return -EPERM;
419
420 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
421 return -EINVAL;
422
423 if (strlen(p->cru_driver_name))
424 exact = 1;
425
426 if (priority && !exact)
427 return -EINVAL;
428
429 alg = crypto_alg_match(p, exact);
430 if (alg) {
431 crypto_mod_put(alg);
432 return -EEXIST;
433 }
434
435 if (strlen(p->cru_driver_name))
436 name = p->cru_driver_name;
437 else
438 name = p->cru_name;
439
440 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
441 if (IS_ERR(alg))
442 return PTR_ERR(alg);
443
444 down_write(&crypto_alg_sem);
445
446 if (priority)
447 alg->cra_priority = nla_get_u32(priority);
448
449 up_write(&crypto_alg_sem);
450
451 crypto_mod_put(alg);
452
453 return 0;
454 }
455
crypto_del_rng(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)456 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
457 struct nlattr **attrs)
458 {
459 if (!netlink_capable(skb, CAP_NET_ADMIN))
460 return -EPERM;
461 return crypto_del_default_rng();
462 }
463
464 #define MSGSIZE(type) sizeof(struct type)
465
466 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
467 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
468 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
469 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
470 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
471 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
472 };
473
474 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
475 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
476 };
477
478 #undef MSGSIZE
479
480 static const struct crypto_link {
481 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
482 int (*dump)(struct sk_buff *, struct netlink_callback *);
483 int (*done)(struct netlink_callback *);
484 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
485 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
486 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
487 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
488 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
489 .dump = crypto_dump_report,
490 .done = crypto_dump_report_done},
491 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
492 };
493
crypto_user_rcv_msg(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)494 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
495 struct netlink_ext_ack *extack)
496 {
497 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
498 const struct crypto_link *link;
499 int type, err;
500
501 type = nlh->nlmsg_type;
502 if (type > CRYPTO_MSG_MAX)
503 return -EINVAL;
504
505 type -= CRYPTO_MSG_BASE;
506 link = &crypto_dispatch[type];
507
508 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
509 (nlh->nlmsg_flags & NLM_F_DUMP))) {
510 struct crypto_alg *alg;
511 unsigned long dump_alloc = 0;
512
513 if (link->dump == NULL)
514 return -EINVAL;
515
516 down_read(&crypto_alg_sem);
517 list_for_each_entry(alg, &crypto_alg_list, cra_list)
518 dump_alloc += CRYPTO_REPORT_MAXSIZE;
519 up_read(&crypto_alg_sem);
520
521 {
522 struct netlink_dump_control c = {
523 .dump = link->dump,
524 .done = link->done,
525 .min_dump_alloc = min(dump_alloc, 65535UL),
526 };
527 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c);
528 }
529
530 return err;
531 }
532
533 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
534 crypto_policy, extack);
535 if (err < 0)
536 return err;
537
538 if (link->doit == NULL)
539 return -EINVAL;
540
541 return link->doit(skb, nlh, attrs);
542 }
543
crypto_netlink_rcv(struct sk_buff * skb)544 static void crypto_netlink_rcv(struct sk_buff *skb)
545 {
546 mutex_lock(&crypto_cfg_mutex);
547 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
548 mutex_unlock(&crypto_cfg_mutex);
549 }
550
crypto_user_init(void)551 static int __init crypto_user_init(void)
552 {
553 struct netlink_kernel_cfg cfg = {
554 .input = crypto_netlink_rcv,
555 };
556
557 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg);
558 if (!crypto_nlsk)
559 return -ENOMEM;
560
561 return 0;
562 }
563
crypto_user_exit(void)564 static void __exit crypto_user_exit(void)
565 {
566 netlink_kernel_release(crypto_nlsk);
567 }
568
569 module_init(crypto_user_init);
570 module_exit(crypto_user_exit);
571 MODULE_LICENSE("GPL");
572 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
573 MODULE_DESCRIPTION("Crypto userspace configuration API");
574 MODULE_ALIAS("net-pf-16-proto-21");
575