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_MUTEX(crypto_cfg_mutex);
34
35 /* The crypto netlink socket */
36 static struct sock *crypto_nlsk;
37
38 struct crypto_dump_info {
39 struct sk_buff *in_skb;
40 struct sk_buff *out_skb;
41 u32 nlmsg_seq;
42 u16 nlmsg_flags;
43 };
44
crypto_alg_match(struct crypto_user_alg * p,int exact)45 static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
46 {
47 struct crypto_alg *q, *alg = NULL;
48
49 down_read(&crypto_alg_sem);
50
51 list_for_each_entry(q, &crypto_alg_list, cra_list) {
52 int match = 0;
53
54 if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
55 continue;
56
57 if (strlen(p->cru_driver_name))
58 match = !strcmp(q->cra_driver_name,
59 p->cru_driver_name);
60 else if (!exact)
61 match = !strcmp(q->cra_name, p->cru_name);
62
63 if (match) {
64 alg = q;
65 break;
66 }
67 }
68
69 up_read(&crypto_alg_sem);
70
71 return alg;
72 }
73
crypto_report_cipher(struct sk_buff * skb,struct crypto_alg * alg)74 static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
75 {
76 struct crypto_report_cipher rcipher;
77
78 strncpy(rcipher.type, "cipher", sizeof(rcipher.type));
79
80 rcipher.blocksize = alg->cra_blocksize;
81 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
82 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
83
84 NLA_PUT(skb, CRYPTOCFGA_REPORT_CIPHER,
85 sizeof(struct crypto_report_cipher), &rcipher);
86
87 return 0;
88
89 nla_put_failure:
90 return -EMSGSIZE;
91 }
92
crypto_report_comp(struct sk_buff * skb,struct crypto_alg * alg)93 static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
94 {
95 struct crypto_report_comp rcomp;
96
97 strncpy(rcomp.type, "compression", sizeof(rcomp.type));
98 NLA_PUT(skb, CRYPTOCFGA_REPORT_COMPRESS,
99 sizeof(struct crypto_report_comp), &rcomp);
100
101 return 0;
102
103 nla_put_failure:
104 return -EMSGSIZE;
105 }
106
crypto_report_one(struct crypto_alg * alg,struct crypto_user_alg * ualg,struct sk_buff * skb)107 static int crypto_report_one(struct crypto_alg *alg,
108 struct crypto_user_alg *ualg, struct sk_buff *skb)
109 {
110 strncpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
111 strncpy(ualg->cru_driver_name, alg->cra_driver_name,
112 sizeof(ualg->cru_driver_name));
113 strncpy(ualg->cru_module_name, module_name(alg->cra_module),
114 sizeof(ualg->cru_module_name));
115
116 ualg->cru_type = 0;
117 ualg->cru_mask = 0;
118 ualg->cru_flags = alg->cra_flags;
119 ualg->cru_refcnt = atomic_read(&alg->cra_refcnt);
120
121 NLA_PUT_U32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority);
122
123 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
124 struct crypto_report_larval rl;
125
126 strncpy(rl.type, "larval", sizeof(rl.type));
127 NLA_PUT(skb, CRYPTOCFGA_REPORT_LARVAL,
128 sizeof(struct crypto_report_larval), &rl);
129
130 goto out;
131 }
132
133 if (alg->cra_type && alg->cra_type->report) {
134 if (alg->cra_type->report(skb, alg))
135 goto nla_put_failure;
136
137 goto out;
138 }
139
140 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
141 case CRYPTO_ALG_TYPE_CIPHER:
142 if (crypto_report_cipher(skb, alg))
143 goto nla_put_failure;
144
145 break;
146 case CRYPTO_ALG_TYPE_COMPRESS:
147 if (crypto_report_comp(skb, alg))
148 goto nla_put_failure;
149
150 break;
151 }
152
153 out:
154 return 0;
155
156 nla_put_failure:
157 return -EMSGSIZE;
158 }
159
crypto_report_alg(struct crypto_alg * alg,struct crypto_dump_info * info)160 static int crypto_report_alg(struct crypto_alg *alg,
161 struct crypto_dump_info *info)
162 {
163 struct sk_buff *in_skb = info->in_skb;
164 struct sk_buff *skb = info->out_skb;
165 struct nlmsghdr *nlh;
166 struct crypto_user_alg *ualg;
167 int err = 0;
168
169 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, info->nlmsg_seq,
170 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
171 if (!nlh) {
172 err = -EMSGSIZE;
173 goto out;
174 }
175
176 ualg = nlmsg_data(nlh);
177
178 err = crypto_report_one(alg, ualg, skb);
179 if (err) {
180 nlmsg_cancel(skb, nlh);
181 goto out;
182 }
183
184 nlmsg_end(skb, nlh);
185
186 out:
187 return err;
188 }
189
crypto_report(struct sk_buff * in_skb,struct nlmsghdr * in_nlh,struct nlattr ** attrs)190 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
191 struct nlattr **attrs)
192 {
193 struct crypto_user_alg *p = nlmsg_data(in_nlh);
194 struct crypto_alg *alg;
195 struct sk_buff *skb;
196 struct crypto_dump_info info;
197 int err;
198
199 if (!p->cru_driver_name)
200 return -EINVAL;
201
202 alg = crypto_alg_match(p, 1);
203 if (!alg)
204 return -ENOENT;
205
206 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC);
207 if (!skb)
208 return -ENOMEM;
209
210 info.in_skb = in_skb;
211 info.out_skb = skb;
212 info.nlmsg_seq = in_nlh->nlmsg_seq;
213 info.nlmsg_flags = 0;
214
215 err = crypto_report_alg(alg, &info);
216 if (err)
217 return err;
218
219 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).pid);
220 }
221
crypto_dump_report(struct sk_buff * skb,struct netlink_callback * cb)222 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
223 {
224 struct crypto_alg *alg;
225 struct crypto_dump_info info;
226 int err;
227
228 if (cb->args[0])
229 goto out;
230
231 cb->args[0] = 1;
232
233 info.in_skb = cb->skb;
234 info.out_skb = skb;
235 info.nlmsg_seq = cb->nlh->nlmsg_seq;
236 info.nlmsg_flags = NLM_F_MULTI;
237
238 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
239 err = crypto_report_alg(alg, &info);
240 if (err)
241 goto out_err;
242 }
243
244 out:
245 return skb->len;
246 out_err:
247 return err;
248 }
249
crypto_dump_report_done(struct netlink_callback * cb)250 static int crypto_dump_report_done(struct netlink_callback *cb)
251 {
252 return 0;
253 }
254
crypto_update_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)255 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
256 struct nlattr **attrs)
257 {
258 struct crypto_alg *alg;
259 struct crypto_user_alg *p = nlmsg_data(nlh);
260 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
261 LIST_HEAD(list);
262
263 if (priority && !strlen(p->cru_driver_name))
264 return -EINVAL;
265
266 alg = crypto_alg_match(p, 1);
267 if (!alg)
268 return -ENOENT;
269
270 down_write(&crypto_alg_sem);
271
272 crypto_remove_spawns(alg, &list, NULL);
273
274 if (priority)
275 alg->cra_priority = nla_get_u32(priority);
276
277 up_write(&crypto_alg_sem);
278
279 crypto_remove_final(&list);
280
281 return 0;
282 }
283
crypto_del_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)284 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
285 struct nlattr **attrs)
286 {
287 struct crypto_alg *alg;
288 struct crypto_user_alg *p = nlmsg_data(nlh);
289
290 alg = crypto_alg_match(p, 1);
291 if (!alg)
292 return -ENOENT;
293
294 /* We can not unregister core algorithms such as aes-generic.
295 * We would loose the reference in the crypto_alg_list to this algorithm
296 * if we try to unregister. Unregistering such an algorithm without
297 * removing the module is not possible, so we restrict to crypto
298 * instances that are build from templates. */
299 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
300 return -EINVAL;
301
302 if (atomic_read(&alg->cra_refcnt) != 1)
303 return -EBUSY;
304
305 return crypto_unregister_instance(alg);
306 }
307
crypto_user_skcipher_alg(const char * name,u32 type,u32 mask)308 static struct crypto_alg *crypto_user_skcipher_alg(const char *name, u32 type,
309 u32 mask)
310 {
311 int err;
312 struct crypto_alg *alg;
313
314 type = crypto_skcipher_type(type);
315 mask = crypto_skcipher_mask(mask);
316
317 for (;;) {
318 alg = crypto_lookup_skcipher(name, type, mask);
319 if (!IS_ERR(alg))
320 return alg;
321
322 err = PTR_ERR(alg);
323 if (err != -EAGAIN)
324 break;
325 if (signal_pending(current)) {
326 err = -EINTR;
327 break;
328 }
329 }
330
331 return ERR_PTR(err);
332 }
333
crypto_user_aead_alg(const char * name,u32 type,u32 mask)334 static struct crypto_alg *crypto_user_aead_alg(const char *name, u32 type,
335 u32 mask)
336 {
337 int err;
338 struct crypto_alg *alg;
339
340 type &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
341 type |= CRYPTO_ALG_TYPE_AEAD;
342 mask &= ~(CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_GENIV);
343 mask |= CRYPTO_ALG_TYPE_MASK;
344
345 for (;;) {
346 alg = crypto_lookup_aead(name, type, mask);
347 if (!IS_ERR(alg))
348 return alg;
349
350 err = PTR_ERR(alg);
351 if (err != -EAGAIN)
352 break;
353 if (signal_pending(current)) {
354 err = -EINTR;
355 break;
356 }
357 }
358
359 return ERR_PTR(err);
360 }
361
crypto_add_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)362 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
363 struct nlattr **attrs)
364 {
365 int exact = 0;
366 const char *name;
367 struct crypto_alg *alg;
368 struct crypto_user_alg *p = nlmsg_data(nlh);
369 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
370
371 if (strlen(p->cru_driver_name))
372 exact = 1;
373
374 if (priority && !exact)
375 return -EINVAL;
376
377 alg = crypto_alg_match(p, exact);
378 if (alg)
379 return -EEXIST;
380
381 if (strlen(p->cru_driver_name))
382 name = p->cru_driver_name;
383 else
384 name = p->cru_name;
385
386 switch (p->cru_type & p->cru_mask & CRYPTO_ALG_TYPE_MASK) {
387 case CRYPTO_ALG_TYPE_AEAD:
388 alg = crypto_user_aead_alg(name, p->cru_type, p->cru_mask);
389 break;
390 case CRYPTO_ALG_TYPE_GIVCIPHER:
391 case CRYPTO_ALG_TYPE_BLKCIPHER:
392 case CRYPTO_ALG_TYPE_ABLKCIPHER:
393 alg = crypto_user_skcipher_alg(name, p->cru_type, p->cru_mask);
394 break;
395 default:
396 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
397 }
398
399 if (IS_ERR(alg))
400 return PTR_ERR(alg);
401
402 down_write(&crypto_alg_sem);
403
404 if (priority)
405 alg->cra_priority = nla_get_u32(priority);
406
407 up_write(&crypto_alg_sem);
408
409 crypto_mod_put(alg);
410
411 return 0;
412 }
413
414 #define MSGSIZE(type) sizeof(struct type)
415
416 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
417 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
418 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
419 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
420 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
421 };
422
423 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
424 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
425 };
426
427 #undef MSGSIZE
428
429 static struct crypto_link {
430 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
431 int (*dump)(struct sk_buff *, struct netlink_callback *);
432 int (*done)(struct netlink_callback *);
433 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
434 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
435 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
436 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
437 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
438 .dump = crypto_dump_report,
439 .done = crypto_dump_report_done},
440 };
441
crypto_user_rcv_msg(struct sk_buff * skb,struct nlmsghdr * nlh)442 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
443 {
444 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
445 struct crypto_link *link;
446 int type, err;
447
448 type = nlh->nlmsg_type;
449 if (type > CRYPTO_MSG_MAX)
450 return -EINVAL;
451
452 type -= CRYPTO_MSG_BASE;
453 link = &crypto_dispatch[type];
454
455 if (!capable(CAP_NET_ADMIN))
456 return -EPERM;
457
458 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
459 (nlh->nlmsg_flags & NLM_F_DUMP))) {
460 struct crypto_alg *alg;
461 u16 dump_alloc = 0;
462
463 if (link->dump == NULL)
464 return -EINVAL;
465
466 list_for_each_entry(alg, &crypto_alg_list, cra_list)
467 dump_alloc += CRYPTO_REPORT_MAXSIZE;
468
469 {
470 struct netlink_dump_control c = {
471 .dump = link->dump,
472 .done = link->done,
473 .min_dump_alloc = dump_alloc,
474 };
475 return netlink_dump_start(crypto_nlsk, skb, nlh, &c);
476 }
477 }
478
479 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
480 crypto_policy);
481 if (err < 0)
482 return err;
483
484 if (link->doit == NULL)
485 return -EINVAL;
486
487 return link->doit(skb, nlh, attrs);
488 }
489
crypto_netlink_rcv(struct sk_buff * skb)490 static void crypto_netlink_rcv(struct sk_buff *skb)
491 {
492 mutex_lock(&crypto_cfg_mutex);
493 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
494 mutex_unlock(&crypto_cfg_mutex);
495 }
496
crypto_user_init(void)497 static int __init crypto_user_init(void)
498 {
499 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO,
500 0, crypto_netlink_rcv,
501 NULL, THIS_MODULE);
502 if (!crypto_nlsk)
503 return -ENOMEM;
504
505 return 0;
506 }
507
crypto_user_exit(void)508 static void __exit crypto_user_exit(void)
509 {
510 netlink_kernel_release(crypto_nlsk);
511 }
512
513 module_init(crypto_user_init);
514 module_exit(crypto_user_exit);
515 MODULE_LICENSE("GPL");
516 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
517 MODULE_DESCRIPTION("Crypto userspace configuration API");
518