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