1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Crypto user configuration API.
4 *
5 * Copyright (C) 2011 secunet Security Networks AG
6 * Copyright (C) 2011 Steffen Klassert <steffen.klassert@secunet.com>
7 */
8
9 #include <linux/module.h>
10 #include <linux/crypto.h>
11 #include <linux/cryptouser.h>
12 #include <linux/sched.h>
13 #include <linux/security.h>
14 #include <net/netlink.h>
15 #include <net/net_namespace.h>
16 #include <net/sock.h>
17 #include <crypto/internal/skcipher.h>
18 #include <crypto/internal/rng.h>
19 #include <crypto/akcipher.h>
20 #include <crypto/kpp.h>
21 #include <crypto/internal/cryptouser.h>
22
23 #include "internal.h"
24
25 #define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
26
27 static DEFINE_MUTEX(crypto_cfg_mutex);
28
29 struct crypto_dump_info {
30 struct sk_buff *in_skb;
31 struct sk_buff *out_skb;
32 u32 nlmsg_seq;
33 u16 nlmsg_flags;
34 };
35
crypto_alg_match(struct crypto_user_alg * p,int exact)36 struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
37 {
38 struct crypto_alg *q, *alg = NULL;
39
40 down_read(&crypto_alg_sem);
41
42 list_for_each_entry(q, &crypto_alg_list, cra_list) {
43 int match = 0;
44
45 if (crypto_is_larval(q))
46 continue;
47
48 if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
49 continue;
50
51 if (strlen(p->cru_driver_name))
52 match = !strcmp(q->cra_driver_name,
53 p->cru_driver_name);
54 else if (!exact)
55 match = !strcmp(q->cra_name, p->cru_name);
56
57 if (!match)
58 continue;
59
60 if (unlikely(!crypto_mod_get(q)))
61 continue;
62
63 alg = q;
64 break;
65 }
66
67 up_read(&crypto_alg_sem);
68
69 return alg;
70 }
71
crypto_report_cipher(struct sk_buff * skb,struct crypto_alg * alg)72 static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
73 {
74 struct crypto_report_cipher rcipher;
75
76 memset(&rcipher, 0, sizeof(rcipher));
77
78 strscpy(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 return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
85 sizeof(rcipher), &rcipher);
86 }
87
crypto_report_comp(struct sk_buff * skb,struct crypto_alg * alg)88 static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
89 {
90 struct crypto_report_comp rcomp;
91
92 memset(&rcomp, 0, sizeof(rcomp));
93
94 strscpy(rcomp.type, "compression", sizeof(rcomp.type));
95
96 return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(rcomp), &rcomp);
97 }
98
crypto_report_one(struct crypto_alg * alg,struct crypto_user_alg * ualg,struct sk_buff * skb)99 static int crypto_report_one(struct crypto_alg *alg,
100 struct crypto_user_alg *ualg, struct sk_buff *skb)
101 {
102 memset(ualg, 0, sizeof(*ualg));
103
104 strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
105 strscpy(ualg->cru_driver_name, alg->cra_driver_name,
106 sizeof(ualg->cru_driver_name));
107 strscpy(ualg->cru_module_name, module_name(alg->cra_module),
108 sizeof(ualg->cru_module_name));
109
110 ualg->cru_type = 0;
111 ualg->cru_mask = 0;
112 ualg->cru_flags = alg->cra_flags;
113 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
114
115 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
116 goto nla_put_failure;
117 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
118 struct crypto_report_larval rl;
119
120 memset(&rl, 0, sizeof(rl));
121 strscpy(rl.type, "larval", sizeof(rl.type));
122 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))
123 goto nla_put_failure;
124 goto out;
125 }
126
127 if (alg->cra_type && alg->cra_type->report) {
128 if (alg->cra_type->report(skb, alg))
129 goto nla_put_failure;
130
131 goto out;
132 }
133
134 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
135 case CRYPTO_ALG_TYPE_CIPHER:
136 if (crypto_report_cipher(skb, alg))
137 goto nla_put_failure;
138
139 break;
140 case CRYPTO_ALG_TYPE_COMPRESS:
141 if (crypto_report_comp(skb, alg))
142 goto nla_put_failure;
143
144 break;
145 }
146
147 out:
148 return 0;
149
150 nla_put_failure:
151 return -EMSGSIZE;
152 }
153
crypto_report_alg(struct crypto_alg * alg,struct crypto_dump_info * info)154 static int crypto_report_alg(struct crypto_alg *alg,
155 struct crypto_dump_info *info)
156 {
157 struct sk_buff *in_skb = info->in_skb;
158 struct sk_buff *skb = info->out_skb;
159 struct nlmsghdr *nlh;
160 struct crypto_user_alg *ualg;
161 int err = 0;
162
163 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
164 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
165 if (!nlh) {
166 err = -EMSGSIZE;
167 goto out;
168 }
169
170 ualg = nlmsg_data(nlh);
171
172 err = crypto_report_one(alg, ualg, skb);
173 if (err) {
174 nlmsg_cancel(skb, nlh);
175 goto out;
176 }
177
178 nlmsg_end(skb, nlh);
179
180 out:
181 return err;
182 }
183
crypto_report(struct sk_buff * in_skb,struct nlmsghdr * in_nlh,struct nlattr ** attrs)184 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
185 struct nlattr **attrs)
186 {
187 struct net *net = sock_net(in_skb->sk);
188 struct crypto_user_alg *p = nlmsg_data(in_nlh);
189 struct crypto_alg *alg;
190 struct sk_buff *skb;
191 struct crypto_dump_info info;
192 int err;
193
194 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
195 return -EINVAL;
196
197 alg = crypto_alg_match(p, 0);
198 if (!alg)
199 return -ENOENT;
200
201 err = -ENOMEM;
202 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
203 if (!skb)
204 goto drop_alg;
205
206 info.in_skb = in_skb;
207 info.out_skb = skb;
208 info.nlmsg_seq = in_nlh->nlmsg_seq;
209 info.nlmsg_flags = 0;
210
211 err = crypto_report_alg(alg, &info);
212
213 drop_alg:
214 crypto_mod_put(alg);
215
216 if (err)
217 return err;
218
219 return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
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 const size_t start_pos = cb->args[0];
225 size_t pos = 0;
226 struct crypto_dump_info info;
227 struct crypto_alg *alg;
228 int res;
229
230 info.in_skb = cb->skb;
231 info.out_skb = skb;
232 info.nlmsg_seq = cb->nlh->nlmsg_seq;
233 info.nlmsg_flags = NLM_F_MULTI;
234
235 down_read(&crypto_alg_sem);
236 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
237 if (pos >= start_pos) {
238 res = crypto_report_alg(alg, &info);
239 if (res == -EMSGSIZE)
240 break;
241 if (res)
242 goto out;
243 }
244 pos++;
245 }
246 cb->args[0] = pos;
247 res = skb->len;
248 out:
249 up_read(&crypto_alg_sem);
250 return res;
251 }
252
crypto_dump_report_done(struct netlink_callback * cb)253 static int crypto_dump_report_done(struct netlink_callback *cb)
254 {
255 return 0;
256 }
257
crypto_update_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)258 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
259 struct nlattr **attrs)
260 {
261 struct crypto_alg *alg;
262 struct crypto_user_alg *p = nlmsg_data(nlh);
263 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
264 LIST_HEAD(list);
265
266 if (!netlink_capable(skb, CAP_NET_ADMIN))
267 return -EPERM;
268
269 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
270 return -EINVAL;
271
272 if (priority && !strlen(p->cru_driver_name))
273 return -EINVAL;
274
275 alg = crypto_alg_match(p, 1);
276 if (!alg)
277 return -ENOENT;
278
279 down_write(&crypto_alg_sem);
280
281 crypto_remove_spawns(alg, &list, NULL);
282
283 if (priority)
284 alg->cra_priority = nla_get_u32(priority);
285
286 up_write(&crypto_alg_sem);
287
288 crypto_mod_put(alg);
289 crypto_remove_final(&list);
290
291 return 0;
292 }
293
crypto_del_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)294 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
295 struct nlattr **attrs)
296 {
297 struct crypto_alg *alg;
298 struct crypto_user_alg *p = nlmsg_data(nlh);
299 int err;
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 err = -EINVAL;
317 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
318 goto drop_alg;
319
320 err = -EBUSY;
321 if (refcount_read(&alg->cra_refcnt) > 2)
322 goto drop_alg;
323
324 err = crypto_unregister_instance((struct crypto_instance *)alg);
325
326 drop_alg:
327 crypto_mod_put(alg);
328 return err;
329 }
330
crypto_add_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)331 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
332 struct nlattr **attrs)
333 {
334 int exact = 0;
335 const char *name;
336 struct crypto_alg *alg;
337 struct crypto_user_alg *p = nlmsg_data(nlh);
338 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
339
340 if (!netlink_capable(skb, CAP_NET_ADMIN))
341 return -EPERM;
342
343 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
344 return -EINVAL;
345
346 if (strlen(p->cru_driver_name))
347 exact = 1;
348
349 if (priority && !exact)
350 return -EINVAL;
351
352 alg = crypto_alg_match(p, exact);
353 if (alg) {
354 crypto_mod_put(alg);
355 return -EEXIST;
356 }
357
358 if (strlen(p->cru_driver_name))
359 name = p->cru_driver_name;
360 else
361 name = p->cru_name;
362
363 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
364 if (IS_ERR(alg))
365 return PTR_ERR(alg);
366
367 down_write(&crypto_alg_sem);
368
369 if (priority)
370 alg->cra_priority = nla_get_u32(priority);
371
372 up_write(&crypto_alg_sem);
373
374 crypto_mod_put(alg);
375
376 return 0;
377 }
378
crypto_del_rng(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)379 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
380 struct nlattr **attrs)
381 {
382 if (!netlink_capable(skb, CAP_NET_ADMIN))
383 return -EPERM;
384 return crypto_del_default_rng();
385 }
386
387 #define MSGSIZE(type) sizeof(struct type)
388
389 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
390 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
391 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
392 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
393 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
394 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
395 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
396 };
397
398 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
399 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
400 };
401
402 #undef MSGSIZE
403
404 static const struct crypto_link {
405 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
406 int (*dump)(struct sk_buff *, struct netlink_callback *);
407 int (*done)(struct netlink_callback *);
408 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
409 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
410 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
411 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
412 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
413 .dump = crypto_dump_report,
414 .done = crypto_dump_report_done},
415 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
416 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
417 };
418
crypto_user_rcv_msg(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)419 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
420 struct netlink_ext_ack *extack)
421 {
422 struct net *net = sock_net(skb->sk);
423 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
424 const struct crypto_link *link;
425 int type, err;
426
427 type = nlh->nlmsg_type;
428 if (type > CRYPTO_MSG_MAX)
429 return -EINVAL;
430
431 type -= CRYPTO_MSG_BASE;
432 link = &crypto_dispatch[type];
433
434 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
435 (nlh->nlmsg_flags & NLM_F_DUMP))) {
436 struct crypto_alg *alg;
437 unsigned long dump_alloc = 0;
438
439 if (link->dump == NULL)
440 return -EINVAL;
441
442 down_read(&crypto_alg_sem);
443 list_for_each_entry(alg, &crypto_alg_list, cra_list)
444 dump_alloc += CRYPTO_REPORT_MAXSIZE;
445 up_read(&crypto_alg_sem);
446
447 {
448 struct netlink_dump_control c = {
449 .dump = link->dump,
450 .done = link->done,
451 .min_dump_alloc = min(dump_alloc, 65535UL),
452 };
453 err = netlink_dump_start(net->crypto_nlsk, skb, nlh, &c);
454 }
455
456 return err;
457 }
458
459 err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,
460 CRYPTOCFGA_MAX, crypto_policy, extack);
461 if (err < 0)
462 return err;
463
464 if (link->doit == NULL)
465 return -EINVAL;
466
467 return link->doit(skb, nlh, attrs);
468 }
469
crypto_netlink_rcv(struct sk_buff * skb)470 static void crypto_netlink_rcv(struct sk_buff *skb)
471 {
472 mutex_lock(&crypto_cfg_mutex);
473 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
474 mutex_unlock(&crypto_cfg_mutex);
475 }
476
crypto_netlink_init(struct net * net)477 static int __net_init crypto_netlink_init(struct net *net)
478 {
479 struct netlink_kernel_cfg cfg = {
480 .input = crypto_netlink_rcv,
481 };
482
483 net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);
484 return net->crypto_nlsk == NULL ? -ENOMEM : 0;
485 }
486
crypto_netlink_exit(struct net * net)487 static void __net_exit crypto_netlink_exit(struct net *net)
488 {
489 netlink_kernel_release(net->crypto_nlsk);
490 net->crypto_nlsk = NULL;
491 }
492
493 static struct pernet_operations crypto_netlink_net_ops = {
494 .init = crypto_netlink_init,
495 .exit = crypto_netlink_exit,
496 };
497
crypto_user_init(void)498 static int __init crypto_user_init(void)
499 {
500 return register_pernet_subsys(&crypto_netlink_net_ops);
501 }
502
crypto_user_exit(void)503 static void __exit crypto_user_exit(void)
504 {
505 unregister_pernet_subsys(&crypto_netlink_net_ops);
506 }
507
508 module_init(crypto_user_init);
509 module_exit(crypto_user_exit);
510 MODULE_LICENSE("GPL");
511 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
512 MODULE_DESCRIPTION("Crypto userspace configuration API");
513 MODULE_ALIAS("net-pf-16-proto-21");
514
