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#include <crypto/internal/cryptouser.h>
33
34#include "internal.h"
35
36#define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
37
38static DEFINE_MUTEX(crypto_cfg_mutex);
39
40/* The crypto netlink socket */
41struct sock *crypto_nlsk;
42
43struct crypto_dump_info {
44 struct sk_buff *in_skb;
45 struct sk_buff *out_skb;
46 u32 nlmsg_seq;
47 u16 nlmsg_flags;
48};
49
50struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
51{
52 struct crypto_alg *q, *alg = NULL;
53
54 down_read(&crypto_alg_sem);
55
56 list_for_each_entry(q, &crypto_alg_list, cra_list) {
57 int match = 0;
58
59 if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
60 continue;
61
62 if (strlen(p->cru_driver_name))
63 match = !strcmp(q->cra_driver_name,
64 p->cru_driver_name);
65 else if (!exact)
66 match = !strcmp(q->cra_name, p->cru_name);
67
68 if (!match)
69 continue;
70
71 if (unlikely(!crypto_mod_get(q)))
72 continue;
73
74 alg = q;
75 break;
76 }
77
78 up_read(&crypto_alg_sem);
79
80 return alg;
81}
82
83static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
84{
85 struct crypto_report_cipher rcipher;
86
87 memset(&rcipher, 0, sizeof(rcipher));
88
89 strscpy(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 return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
96 sizeof(rcipher), &rcipher);
97}
98
99static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
100{
101 struct crypto_report_comp rcomp;
102
103 memset(&rcomp, 0, sizeof(rcomp));
104
105 strscpy(rcomp.type, "compression", sizeof(rcomp.type));
106
107 return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(rcomp), &rcomp);
108}
109
110static int crypto_report_one(struct crypto_alg *alg,
111 struct crypto_user_alg *ualg, struct sk_buff *skb)
112{
113 memset(ualg, 0, sizeof(*ualg));
114
115 strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
116 strscpy(ualg->cru_driver_name, alg->cra_driver_name,
117 sizeof(ualg->cru_driver_name));
118 strscpy(ualg->cru_module_name, module_name(alg->cra_module),
119 sizeof(ualg->cru_module_name));
120
121 ualg->cru_type = 0;
122 ualg->cru_mask = 0;
123 ualg->cru_flags = alg->cra_flags;
124 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
125
126 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
127 goto nla_put_failure;
128 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
129 struct crypto_report_larval rl;
130
131 memset(&rl, 0, sizeof(rl));
132 strscpy(rl.type, "larval", sizeof(rl.type));
133 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))
134 goto nla_put_failure;
135 goto out;
136 }
137
138 if (alg->cra_type && alg->cra_type->report) {
139 if (alg->cra_type->report(skb, alg))
140 goto nla_put_failure;
141
142 goto out;
143 }
144
145 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
146 case CRYPTO_ALG_TYPE_CIPHER:
147 if (crypto_report_cipher(skb, alg))
148 goto nla_put_failure;
149
150 break;
151 case CRYPTO_ALG_TYPE_COMPRESS:
152 if (crypto_report_comp(skb, alg))
153 goto nla_put_failure;
154
155 break;
156 }
157
158out:
159 return 0;
160
161nla_put_failure:
162 return -EMSGSIZE;
163}
164
165static int crypto_report_alg(struct crypto_alg *alg,
166 struct crypto_dump_info *info)
167{
168 struct sk_buff *in_skb = info->in_skb;
169 struct sk_buff *skb = info->out_skb;
170 struct nlmsghdr *nlh;
171 struct crypto_user_alg *ualg;
172 int err = 0;
173
174 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
175 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
176 if (!nlh) {
177 err = -EMSGSIZE;
178 goto out;
179 }
180
181 ualg = nlmsg_data(nlh);
182
183 err = crypto_report_one(alg, ualg, skb);
184 if (err) {
185 nlmsg_cancel(skb, nlh);
186 goto out;
187 }
188
189 nlmsg_end(skb, nlh);
190
191out:
192 return err;
193}
194
195static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
196 struct nlattr **attrs)
197{
198 struct crypto_user_alg *p = nlmsg_data(in_nlh);
199 struct crypto_alg *alg;
200 struct sk_buff *skb;
201 struct crypto_dump_info info;
202 int err;
203
204 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
205 return -EINVAL;
206
207 alg = crypto_alg_match(p, 0);
208 if (!alg)
209 return -ENOENT;
210
211 err = -ENOMEM;
212 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
213 if (!skb)
214 goto drop_alg;
215
216 info.in_skb = in_skb;
217 info.out_skb = skb;
218 info.nlmsg_seq = in_nlh->nlmsg_seq;
219 info.nlmsg_flags = 0;
220
221 err = crypto_report_alg(alg, &info);
222
223drop_alg:
224 crypto_mod_put(alg);
225
226 if (err)
227 return err;
228
229 return nlmsg_unicast(crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
230}
231
232static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
233{
234 const size_t start_pos = cb->args[0];
235 size_t pos = 0;
236 struct crypto_dump_info info;
237 struct crypto_alg *alg;
238 int res;
239
240 info.in_skb = cb->skb;
241 info.out_skb = skb;
242 info.nlmsg_seq = cb->nlh->nlmsg_seq;
243 info.nlmsg_flags = NLM_F_MULTI;
244
245 down_read(&crypto_alg_sem);
246 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
247 if (pos >= start_pos) {
248 res = crypto_report_alg(alg, &info);
249 if (res == -EMSGSIZE)
250 break;
251 if (res)
252 goto out;
253 }
254 pos++;
255 }
256 cb->args[0] = pos;
257 res = skb->len;
258out:
259 up_read(&crypto_alg_sem);
260 return res;
261}
262
263static int crypto_dump_report_done(struct netlink_callback *cb)
264{
265 return 0;
266}
267
268static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
269 struct nlattr **attrs)
270{
271 struct crypto_alg *alg;
272 struct crypto_user_alg *p = nlmsg_data(nlh);
273 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
274 LIST_HEAD(list);
275
276 if (!netlink_capable(skb, CAP_NET_ADMIN))
277 return -EPERM;
278
279 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
280 return -EINVAL;
281
282 if (priority && !strlen(p->cru_driver_name))
283 return -EINVAL;
284
285 alg = crypto_alg_match(p, 1);
286 if (!alg)
287 return -ENOENT;
288
289 down_write(&crypto_alg_sem);
290
291 crypto_remove_spawns(alg, &list, NULL);
292
293 if (priority)
294 alg->cra_priority = nla_get_u32(priority);
295
296 up_write(&crypto_alg_sem);
297
298 crypto_mod_put(alg);
299 crypto_remove_final(&list);
300
301 return 0;
302}
303
304static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
305 struct nlattr **attrs)
306{
307 struct crypto_alg *alg;
308 struct crypto_user_alg *p = nlmsg_data(nlh);
309 int err;
310
311 if (!netlink_capable(skb, CAP_NET_ADMIN))
312 return -EPERM;
313
314 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
315 return -EINVAL;
316
317 alg = crypto_alg_match(p, 1);
318 if (!alg)
319 return -ENOENT;
320
321 /* We can not unregister core algorithms such as aes-generic.
322 * We would loose the reference in the crypto_alg_list to this algorithm
323 * if we try to unregister. Unregistering such an algorithm without
324 * removing the module is not possible, so we restrict to crypto
325 * instances that are build from templates. */
326 err = -EINVAL;
327 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
328 goto drop_alg;
329
330 err = -EBUSY;
331 if (refcount_read(&alg->cra_refcnt) > 2)
332 goto drop_alg;
333
334 err = crypto_unregister_instance((struct crypto_instance *)alg);
335
336drop_alg:
337 crypto_mod_put(alg);
338 return err;
339}
340
341static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
342 struct nlattr **attrs)
343{
344 int exact = 0;
345 const char *name;
346 struct crypto_alg *alg;
347 struct crypto_user_alg *p = nlmsg_data(nlh);
348 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
349
350 if (!netlink_capable(skb, CAP_NET_ADMIN))
351 return -EPERM;
352
353 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
354 return -EINVAL;
355
356 if (strlen(p->cru_driver_name))
357 exact = 1;
358
359 if (priority && !exact)
360 return -EINVAL;
361
362 alg = crypto_alg_match(p, exact);
363 if (alg) {
364 crypto_mod_put(alg);
365 return -EEXIST;
366 }
367
368 if (strlen(p->cru_driver_name))
369 name = p->cru_driver_name;
370 else
371 name = p->cru_name;
372
373 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
374 if (IS_ERR(alg))
375 return PTR_ERR(alg);
376
377 down_write(&crypto_alg_sem);
378
379 if (priority)
380 alg->cra_priority = nla_get_u32(priority);
381
382 up_write(&crypto_alg_sem);
383
384 crypto_mod_put(alg);
385
386 return 0;
387}
388
389static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
390 struct nlattr **attrs)
391{
392 if (!netlink_capable(skb, CAP_NET_ADMIN))
393 return -EPERM;
394 return crypto_del_default_rng();
395}
396
397#define MSGSIZE(type) sizeof(struct type)
398
399static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
400 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
401 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
402 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
403 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
404 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
405 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
406};
407
408static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
409 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
410};
411
412#undef MSGSIZE
413
414static const struct crypto_link {
415 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
416 int (*dump)(struct sk_buff *, struct netlink_callback *);
417 int (*done)(struct netlink_callback *);
418} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
419 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
420 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
421 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
422 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
423 .dump = crypto_dump_report,
424 .done = crypto_dump_report_done},
425 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
426 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
427};
428
429static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
430 struct netlink_ext_ack *extack)
431{
432 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
433 const struct crypto_link *link;
434 int type, err;
435
436 type = nlh->nlmsg_type;
437 if (type > CRYPTO_MSG_MAX)
438 return -EINVAL;
439
440 type -= CRYPTO_MSG_BASE;
441 link = &crypto_dispatch[type];
442
443 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
444 (nlh->nlmsg_flags & NLM_F_DUMP))) {
445 struct crypto_alg *alg;
446 unsigned long dump_alloc = 0;
447
448 if (link->dump == NULL)
449 return -EINVAL;
450
451 down_read(&crypto_alg_sem);
452 list_for_each_entry(alg, &crypto_alg_list, cra_list)
453 dump_alloc += CRYPTO_REPORT_MAXSIZE;
454 up_read(&crypto_alg_sem);
455
456 {
457 struct netlink_dump_control c = {
458 .dump = link->dump,
459 .done = link->done,
460 .min_dump_alloc = min(dump_alloc, 65535UL),
461 };
462 err = netlink_dump_start(crypto_nlsk, skb, nlh, &c);
463 }
464
465 return err;
466 }
467
468 err = nlmsg_parse(nlh, crypto_msg_min[type], attrs, CRYPTOCFGA_MAX,
469 crypto_policy, extack);
470 if (err < 0)
471 return err;
472
473 if (link->doit == NULL)
474 return -EINVAL;
475
476 return link->doit(skb, nlh, attrs);
477}
478
479static void crypto_netlink_rcv(struct sk_buff *skb)
480{
481 mutex_lock(&crypto_cfg_mutex);
482 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
483 mutex_unlock(&crypto_cfg_mutex);
484}
485
486static int __init crypto_user_init(void)
487{
488 struct netlink_kernel_cfg cfg = {
489 .input = crypto_netlink_rcv,
490 };
491
492 crypto_nlsk = netlink_kernel_create(&init_net, NETLINK_CRYPTO, &cfg);
493 if (!crypto_nlsk)
494 return -ENOMEM;
495
496 return 0;
497}
498
499static void __exit crypto_user_exit(void)
500{
501 netlink_kernel_release(crypto_nlsk);
502}
503
504module_init(crypto_user_init);
505module_exit(crypto_user_exit);
506MODULE_LICENSE("GPL");
507MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
508MODULE_DESCRIPTION("Crypto userspace configuration API");
509MODULE_ALIAS("net-pf-16-proto-21");
510