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a38f7907 SK |
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 <net/netlink.h> | |
25 | #include <linux/security.h> | |
26 | #include <net/net_namespace.h> | |
27 | #include "internal.h" | |
28 | ||
29 | DEFINE_MUTEX(crypto_cfg_mutex); | |
30 | ||
31 | /* The crypto netlink socket */ | |
32 | static struct sock *crypto_nlsk; | |
33 | ||
34 | struct crypto_dump_info { | |
35 | struct sk_buff *in_skb; | |
36 | struct sk_buff *out_skb; | |
37 | u32 nlmsg_seq; | |
38 | u16 nlmsg_flags; | |
39 | }; | |
40 | ||
41 | static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact) | |
42 | { | |
a38f7907 SK |
43 | struct crypto_alg *q, *alg = NULL; |
44 | ||
45 | down_read(&crypto_alg_sem); | |
46 | ||
47 | if (list_empty(&crypto_alg_list)) | |
48 | return NULL; | |
49 | ||
50 | list_for_each_entry(q, &crypto_alg_list, cra_list) { | |
e6ea64ec | 51 | int match = 0; |
a38f7907 SK |
52 | |
53 | if ((q->cra_flags ^ p->cru_type) & p->cru_mask) | |
54 | continue; | |
55 | ||
56 | if (strlen(p->cru_driver_name)) | |
57 | match = !strcmp(q->cra_driver_name, | |
58 | p->cru_driver_name); | |
59 | else if (!exact) | |
60 | match = !strcmp(q->cra_name, p->cru_name); | |
61 | ||
62 | if (match) { | |
63 | alg = q; | |
64 | break; | |
65 | } | |
66 | } | |
67 | ||
68 | up_read(&crypto_alg_sem); | |
69 | ||
70 | return alg; | |
71 | } | |
72 | ||
07a5fa4a SK |
73 | static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg) |
74 | { | |
75 | struct crypto_report_cipher rcipher; | |
76 | ||
77 | snprintf(rcipher.type, CRYPTO_MAX_ALG_NAME, "%s", "cipher"); | |
78 | ||
79 | rcipher.blocksize = alg->cra_blocksize; | |
80 | rcipher.min_keysize = alg->cra_cipher.cia_min_keysize; | |
81 | rcipher.max_keysize = alg->cra_cipher.cia_max_keysize; | |
82 | ||
83 | NLA_PUT(skb, CRYPTOCFGA_REPORT_CIPHER, | |
84 | sizeof(struct crypto_report_cipher), &rcipher); | |
85 | ||
86 | return 0; | |
87 | ||
88 | nla_put_failure: | |
89 | return -EMSGSIZE; | |
90 | } | |
91 | ||
540b97c1 SK |
92 | static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg) |
93 | { | |
94 | struct crypto_report_comp rcomp; | |
95 | ||
96 | snprintf(rcomp.type, CRYPTO_MAX_ALG_NAME, "%s", "compression"); | |
97 | ||
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 | ||
a38f7907 SK |
107 | static int crypto_report_one(struct crypto_alg *alg, |
108 | struct crypto_user_alg *ualg, struct sk_buff *skb) | |
109 | { | |
110 | memcpy(&ualg->cru_name, &alg->cra_name, sizeof(ualg->cru_name)); | |
111 | memcpy(&ualg->cru_driver_name, &alg->cra_driver_name, | |
112 | sizeof(ualg->cru_driver_name)); | |
113 | memcpy(&ualg->cru_module_name, module_name(alg->cra_module), | |
114 | CRYPTO_MAX_ALG_NAME); | |
115 | ||
116 | ualg->cru_flags = alg->cra_flags; | |
117 | ualg->cru_refcnt = atomic_read(&alg->cra_refcnt); | |
118 | ||
119 | NLA_PUT_U32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority); | |
120 | ||
6c5a86f5 SK |
121 | if (alg->cra_flags & CRYPTO_ALG_LARVAL) { |
122 | struct crypto_report_larval rl; | |
123 | ||
124 | snprintf(rl.type, CRYPTO_MAX_ALG_NAME, "%s", "larval"); | |
125 | ||
126 | NLA_PUT(skb, CRYPTOCFGA_REPORT_LARVAL, | |
127 | sizeof(struct crypto_report_larval), &rl); | |
128 | ||
129 | goto out; | |
130 | } | |
131 | ||
b6aa63c0 SK |
132 | if (alg->cra_type && alg->cra_type->report) { |
133 | if (alg->cra_type->report(skb, alg)) | |
134 | goto nla_put_failure; | |
07a5fa4a SK |
135 | |
136 | goto out; | |
137 | } | |
138 | ||
139 | switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) { | |
140 | case CRYPTO_ALG_TYPE_CIPHER: | |
141 | if (crypto_report_cipher(skb, alg)) | |
142 | goto nla_put_failure; | |
143 | ||
540b97c1 SK |
144 | break; |
145 | case CRYPTO_ALG_TYPE_COMPRESS: | |
146 | if (crypto_report_comp(skb, alg)) | |
147 | goto nla_put_failure; | |
148 | ||
07a5fa4a | 149 | break; |
b6aa63c0 SK |
150 | } |
151 | ||
6c5a86f5 | 152 | out: |
a38f7907 SK |
153 | return 0; |
154 | ||
155 | nla_put_failure: | |
156 | return -EMSGSIZE; | |
157 | } | |
158 | ||
159 | static int crypto_report_alg(struct crypto_alg *alg, | |
160 | struct crypto_dump_info *info) | |
161 | { | |
162 | struct sk_buff *in_skb = info->in_skb; | |
163 | struct sk_buff *skb = info->out_skb; | |
164 | struct nlmsghdr *nlh; | |
165 | struct crypto_user_alg *ualg; | |
166 | int err = 0; | |
167 | ||
168 | nlh = nlmsg_put(skb, NETLINK_CB(in_skb).pid, info->nlmsg_seq, | |
169 | CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags); | |
170 | if (!nlh) { | |
171 | err = -EMSGSIZE; | |
172 | goto out; | |
173 | } | |
174 | ||
175 | ualg = nlmsg_data(nlh); | |
176 | ||
177 | err = crypto_report_one(alg, ualg, skb); | |
178 | if (err) { | |
179 | nlmsg_cancel(skb, nlh); | |
180 | goto out; | |
181 | } | |
182 | ||
183 | nlmsg_end(skb, nlh); | |
184 | ||
185 | out: | |
186 | return err; | |
187 | } | |
188 | ||
189 | static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh, | |
190 | struct nlattr **attrs) | |
191 | { | |
192 | struct crypto_user_alg *p = nlmsg_data(in_nlh); | |
193 | struct crypto_alg *alg; | |
194 | struct sk_buff *skb; | |
195 | struct crypto_dump_info info; | |
196 | int err; | |
197 | ||
198 | if (!p->cru_driver_name) | |
199 | return -EINVAL; | |
200 | ||
201 | alg = crypto_alg_match(p, 1); | |
202 | if (!alg) | |
203 | return -ENOENT; | |
204 | ||
205 | skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_ATOMIC); | |
206 | if (!skb) | |
207 | return -ENOMEM; | |
208 | ||
209 | info.in_skb = in_skb; | |
210 | info.out_skb = skb; | |
211 | info.nlmsg_seq = in_nlh->nlmsg_seq; | |
212 | info.nlmsg_flags = 0; | |
213 | ||
214 | err = crypto_report_alg(alg, &info); | |
215 | if (err) | |
216 | return err; | |
217 | ||
218 | return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).pid); | |
219 | } | |
220 | ||
221 | static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb) | |
222 | { | |
223 | struct crypto_alg *alg; | |
224 | struct crypto_dump_info info; | |
225 | int err; | |
226 | ||
227 | if (cb->args[0]) | |
228 | goto out; | |
229 | ||
230 | cb->args[0] = 1; | |
231 | ||
232 | info.in_skb = cb->skb; | |
233 | info.out_skb = skb; | |
234 | info.nlmsg_seq = cb->nlh->nlmsg_seq; | |
235 | info.nlmsg_flags = NLM_F_MULTI; | |
236 | ||
237 | list_for_each_entry(alg, &crypto_alg_list, cra_list) { | |
238 | err = crypto_report_alg(alg, &info); | |
239 | if (err) | |
240 | goto out_err; | |
241 | } | |
242 | ||
243 | out: | |
244 | return skb->len; | |
245 | out_err: | |
246 | return err; | |
247 | } | |
248 | ||
249 | static int crypto_dump_report_done(struct netlink_callback *cb) | |
250 | { | |
251 | return 0; | |
252 | } | |
253 | ||
254 | static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh, | |
255 | struct nlattr **attrs) | |
256 | { | |
257 | struct crypto_alg *alg; | |
258 | struct crypto_user_alg *p = nlmsg_data(nlh); | |
259 | struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; | |
260 | LIST_HEAD(list); | |
261 | ||
262 | if (priority && !strlen(p->cru_driver_name)) | |
263 | return -EINVAL; | |
264 | ||
265 | alg = crypto_alg_match(p, 1); | |
266 | if (!alg) | |
267 | return -ENOENT; | |
268 | ||
269 | down_write(&crypto_alg_sem); | |
270 | ||
271 | crypto_remove_spawns(alg, &list, NULL); | |
272 | ||
273 | if (priority) | |
274 | alg->cra_priority = nla_get_u32(priority); | |
275 | ||
276 | up_write(&crypto_alg_sem); | |
277 | ||
278 | crypto_remove_final(&list); | |
279 | ||
280 | return 0; | |
281 | } | |
282 | ||
283 | static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh, | |
284 | struct nlattr **attrs) | |
285 | { | |
286 | struct crypto_alg *alg; | |
287 | struct crypto_user_alg *p = nlmsg_data(nlh); | |
288 | ||
289 | alg = crypto_alg_match(p, 1); | |
290 | if (!alg) | |
291 | return -ENOENT; | |
292 | ||
293 | /* We can not unregister core algorithms such as aes-generic. | |
294 | * We would loose the reference in the crypto_alg_list to this algorithm | |
295 | * if we try to unregister. Unregistering such an algorithm without | |
296 | * removing the module is not possible, so we restrict to crypto | |
297 | * instances that are build from templates. */ | |
298 | if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE)) | |
299 | return -EINVAL; | |
300 | ||
301 | if (atomic_read(&alg->cra_refcnt) != 1) | |
302 | return -EBUSY; | |
303 | ||
304 | return crypto_unregister_alg(alg); | |
305 | } | |
306 | ||
307 | static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh, | |
308 | struct nlattr **attrs) | |
309 | { | |
310 | int exact; | |
311 | const char *name; | |
312 | struct crypto_alg *alg; | |
313 | struct crypto_user_alg *p = nlmsg_data(nlh); | |
314 | struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL]; | |
315 | ||
316 | if (strlen(p->cru_driver_name)) | |
317 | exact = 1; | |
318 | ||
319 | if (priority && !exact) | |
320 | return -EINVAL; | |
321 | ||
322 | alg = crypto_alg_match(p, exact); | |
323 | if (alg) | |
324 | return -EEXIST; | |
325 | ||
326 | if (strlen(p->cru_driver_name)) | |
327 | name = p->cru_driver_name; | |
328 | else | |
329 | name = p->cru_name; | |
330 | ||
331 | alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask); | |
332 | if (IS_ERR(alg)) | |
333 | return PTR_ERR(alg); | |
334 | ||
335 | down_write(&crypto_alg_sem); | |
336 | ||
337 | if (priority) | |
338 | alg->cra_priority = nla_get_u32(priority); | |
339 | ||
340 | up_write(&crypto_alg_sem); | |
341 | ||
342 | crypto_mod_put(alg); | |
343 | ||
344 | return 0; | |
345 | } | |
346 | ||
347 | #define MSGSIZE(type) sizeof(struct type) | |
348 | ||
349 | static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = { | |
350 | [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), | |
351 | [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), | |
352 | [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), | |
353 | [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg), | |
354 | }; | |
355 | ||
356 | static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = { | |
357 | [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32}, | |
358 | }; | |
359 | ||
360 | #undef MSGSIZE | |
361 | ||
362 | static struct crypto_link { | |
363 | int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **); | |
364 | int (*dump)(struct sk_buff *, struct netlink_callback *); | |
365 | int (*done)(struct netlink_callback *); | |
366 | } crypto_dispatch[CRYPTO_NR_MSGTYPES] = { | |
367 | [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg}, | |
368 | [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg}, | |
369 | [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg}, | |
370 | [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report, | |
371 | .dump = crypto_dump_report, | |
372 | .done = crypto_dump_report_done}, | |
373 | }; | |
374 | ||
375 | static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh) | |
376 | { | |
377 | struct nlattr *attrs[CRYPTOCFGA_MAX+1]; | |
378 | struct crypto_link *link; | |
379 | int type, err; | |
380 | ||
381 | type = nlh->nlmsg_type; | |
382 | if (type > CRYPTO_MSG_MAX) | |
383 | return -EINVAL; | |
384 | ||
385 | type -= CRYPTO_MSG_BASE; | |
386 | link = &crypto_dispatch[type]; | |
387 | ||
388 | if (security_netlink_recv(skb, CAP_NET_ADMIN)) | |
389 | return -EPERM; | |
390 | ||
391 | if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) && | |
392 | (nlh->nlmsg_flags & NLM_F_DUMP))) { | |
393 | if (link->dump == NULL) | |
394 | return -EINVAL; | |
395 | ||
396 | return netlink_dump_start(crypto_nlsk, skb, nlh, | |
397 | link->dump, link->done, 0); | |
398 | } | |
399 | ||
400 | err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX, | |
401 | crypto_policy); | |
402 | if (err < 0) | |
403 | return err; | |
404 | ||
405 | if (link->doit == NULL) | |
406 | return -EINVAL; | |
407 | ||
408 | return link->doit(skb, nlh, attrs); | |
409 | } | |
410 | ||
411 | static void crypto_netlink_rcv(struct sk_buff *skb) | |
412 | { | |
413 | mutex_lock(&crypto_cfg_mutex); | |
414 | netlink_rcv_skb(skb, &crypto_user_rcv_msg); | |
415 | mutex_unlock(&crypto_cfg_mutex); | |
416 | } | |
417 | ||
418 | static int __init crypto_user_init(void) | |
419 | { | |
420 | crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, | |
421 | 0, crypto_netlink_rcv, | |
422 | NULL, THIS_MODULE); | |
423 | if (!crypto_nlsk) | |
424 | return -ENOMEM; | |
425 | ||
426 | return 0; | |
427 | } | |
428 | ||
429 | static void __exit crypto_user_exit(void) | |
430 | { | |
431 | netlink_kernel_release(crypto_nlsk); | |
432 | } | |
433 | ||
434 | module_init(crypto_user_init); | |
435 | module_exit(crypto_user_exit); | |
436 | MODULE_LICENSE("GPL"); | |
437 | MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>"); | |
438 | MODULE_DESCRIPTION("Crypto userspace configuration API"); |