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
22 #include "internal.h"
23
24 #define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
25
26 static DEFINE_MUTEX(crypto_cfg_mutex);
27
28 struct crypto_dump_info {
29 struct sk_buff *in_skb;
30 struct sk_buff *out_skb;
31 u32 nlmsg_seq;
32 u16 nlmsg_flags;
33 };
34
35 static struct crypto_alg *crypto_alg_match(struct crypto_user_alg *p, int exact)
36 {
37 struct crypto_alg *q, *alg = NULL;
38
39 down_read(&crypto_alg_sem);
40
41 list_for_each_entry(q, &crypto_alg_list, cra_list) {
42 int match = 0;
43
44 if (crypto_is_larval(q))
45 continue;
46
47 if ((q->cra_flags ^ p->cru_type) & p->cru_mask)
48 continue;
49
50 if (strlen(p->cru_driver_name))
51 match = !strcmp(q->cra_driver_name,
52 p->cru_driver_name);
53 else if (!exact)
54 match = !strcmp(q->cra_name, p->cru_name);
55
56 if (!match)
57 continue;
58
59 if (unlikely(!crypto_mod_get(q)))
60 continue;
61
62 alg = q;
63 break;
64 }
65
66 up_read(&crypto_alg_sem);
67
68 return alg;
69 }
70
71 static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
72 {
73 struct crypto_report_cipher rcipher;
74
75 memset(&rcipher, 0, sizeof(rcipher));
76
77 strscpy(rcipher.type, "cipher", sizeof(rcipher.type));
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 return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
84 sizeof(rcipher), &rcipher);
85 }
86
87 static int crypto_report_comp(struct sk_buff *skb, struct crypto_alg *alg)
88 {
89 struct crypto_report_comp rcomp;
90
91 memset(&rcomp, 0, sizeof(rcomp));
92
93 strscpy(rcomp.type, "compression", sizeof(rcomp.type));
94
95 return nla_put(skb, CRYPTOCFGA_REPORT_COMPRESS, sizeof(rcomp), &rcomp);
96 }
97
98 static int crypto_report_one(struct crypto_alg *alg,
99 struct crypto_user_alg *ualg, struct sk_buff *skb)
100 {
101 memset(ualg, 0, sizeof(*ualg));
102
103 strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
104 strscpy(ualg->cru_driver_name, alg->cra_driver_name,
105 sizeof(ualg->cru_driver_name));
106 strscpy(ualg->cru_module_name, module_name(alg->cra_module),
107 sizeof(ualg->cru_module_name));
108
109 ualg->cru_type = 0;
110 ualg->cru_mask = 0;
111 ualg->cru_flags = alg->cra_flags;
112 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
113
114 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
115 goto nla_put_failure;
116 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
117 struct crypto_report_larval rl;
118
119 memset(&rl, 0, sizeof(rl));
120 strscpy(rl.type, "larval", sizeof(rl.type));
121 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))
122 goto nla_put_failure;
123 goto out;
124 }
125
126 if (alg->cra_type && alg->cra_type->report) {
127 if (alg->cra_type->report(skb, alg))
128 goto nla_put_failure;
129
130 goto out;
131 }
132
133 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
134 case CRYPTO_ALG_TYPE_CIPHER:
135 if (crypto_report_cipher(skb, alg))
136 goto nla_put_failure;
137
138 break;
139 case CRYPTO_ALG_TYPE_COMPRESS:
140 if (crypto_report_comp(skb, alg))
141 goto nla_put_failure;
142
143 break;
144 }
145
146 out:
147 return 0;
148
149 nla_put_failure:
150 return -EMSGSIZE;
151 }
152
153 static int crypto_report_alg(struct crypto_alg *alg,
154 struct crypto_dump_info *info)
155 {
156 struct sk_buff *in_skb = info->in_skb;
157 struct sk_buff *skb = info->out_skb;
158 struct nlmsghdr *nlh;
159 struct crypto_user_alg *ualg;
160 int err = 0;
161
162 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
163 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
164 if (!nlh) {
165 err = -EMSGSIZE;
166 goto out;
167 }
168
169 ualg = nlmsg_data(nlh);
170
171 err = crypto_report_one(alg, ualg, skb);
172 if (err) {
173 nlmsg_cancel(skb, nlh);
174 goto out;
175 }
176
177 nlmsg_end(skb, nlh);
178
179 out:
180 return err;
181 }
182
183 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
184 struct nlattr **attrs)
185 {
186 struct net *net = sock_net(in_skb->sk);
187 struct crypto_user_alg *p = nlmsg_data(in_nlh);
188 struct crypto_alg *alg;
189 struct sk_buff *skb;
190 struct crypto_dump_info info;
191 int err;
192
193 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
194 return -EINVAL;
195
196 alg = crypto_alg_match(p, 0);
197 if (!alg)
198 return -ENOENT;
199
200 err = -ENOMEM;
201 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
202 if (!skb)
203 goto drop_alg;
204
205 info.in_skb = in_skb;
206 info.out_skb = skb;
207 info.nlmsg_seq = in_nlh->nlmsg_seq;
208 info.nlmsg_flags = 0;
209
210 err = crypto_report_alg(alg, &info);
211
212 drop_alg:
213 crypto_mod_put(alg);
214
215 if (err) {
216 kfree_skb(skb);
217 return err;
218 }
219
220 return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
221 }
222
223 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
224 {
225 const size_t start_pos = cb->args[0];
226 size_t pos = 0;
227 struct crypto_dump_info info;
228 struct crypto_alg *alg;
229 int res;
230
231 info.in_skb = cb->skb;
232 info.out_skb = skb;
233 info.nlmsg_seq = cb->nlh->nlmsg_seq;
234 info.nlmsg_flags = NLM_F_MULTI;
235
236 down_read(&crypto_alg_sem);
237 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
238 if (pos >= start_pos) {
239 res = crypto_report_alg(alg, &info);
240 if (res == -EMSGSIZE)
241 break;
242 if (res)
243 goto out;
244 }
245 pos++;
246 }
247 cb->args[0] = pos;
248 res = skb->len;
249 out:
250 up_read(&crypto_alg_sem);
251 return res;
252 }
253
254 static int crypto_dump_report_done(struct netlink_callback *cb)
255 {
256 return 0;
257 }
258
259 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
260 struct nlattr **attrs)
261 {
262 struct crypto_alg *alg;
263 struct crypto_user_alg *p = nlmsg_data(nlh);
264 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
265 LIST_HEAD(list);
266
267 if (!netlink_capable(skb, CAP_NET_ADMIN))
268 return -EPERM;
269
270 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
271 return -EINVAL;
272
273 if (priority && !strlen(p->cru_driver_name))
274 return -EINVAL;
275
276 alg = crypto_alg_match(p, 1);
277 if (!alg)
278 return -ENOENT;
279
280 down_write(&crypto_alg_sem);
281
282 crypto_remove_spawns(alg, &list, NULL);
283
284 if (priority)
285 alg->cra_priority = nla_get_u32(priority);
286
287 up_write(&crypto_alg_sem);
288
289 crypto_mod_put(alg);
290 crypto_remove_final(&list);
291
292 return 0;
293 }
294
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 int err;
301
302 if (!netlink_capable(skb, CAP_NET_ADMIN))
303 return -EPERM;
304
305 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
306 return -EINVAL;
307
308 alg = crypto_alg_match(p, 1);
309 if (!alg)
310 return -ENOENT;
311
312 /* We can not unregister core algorithms such as aes-generic.
313 * We would loose the reference in the crypto_alg_list to this algorithm
314 * if we try to unregister. Unregistering such an algorithm without
315 * removing the module is not possible, so we restrict to crypto
316 * instances that are build from templates. */
317 err = -EINVAL;
318 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
319 goto drop_alg;
320
321 err = -EBUSY;
322 if (refcount_read(&alg->cra_refcnt) > 2)
323 goto drop_alg;
324
325 crypto_unregister_instance((struct crypto_instance *)alg);
326 err = 0;
327
328 drop_alg:
329 crypto_mod_put(alg);
330 return err;
331 }
332
333 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
334 struct nlattr **attrs)
335 {
336 int exact = 0;
337 const char *name;
338 struct crypto_alg *alg;
339 struct crypto_user_alg *p = nlmsg_data(nlh);
340 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
341
342 if (!netlink_capable(skb, CAP_NET_ADMIN))
343 return -EPERM;
344
345 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
346 return -EINVAL;
347
348 if (strlen(p->cru_driver_name))
349 exact = 1;
350
351 if (priority && !exact)
352 return -EINVAL;
353
354 alg = crypto_alg_match(p, exact);
355 if (alg) {
356 crypto_mod_put(alg);
357 return -EEXIST;
358 }
359
360 if (strlen(p->cru_driver_name))
361 name = p->cru_driver_name;
362 else
363 name = p->cru_name;
364
365 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
366 if (IS_ERR(alg))
367 return PTR_ERR(alg);
368
369 down_write(&crypto_alg_sem);
370
371 if (priority)
372 alg->cra_priority = nla_get_u32(priority);
373
374 up_write(&crypto_alg_sem);
375
376 crypto_mod_put(alg);
377
378 return 0;
379 }
380
381 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
382 struct nlattr **attrs)
383 {
384 if (!netlink_capable(skb, CAP_NET_ADMIN))
385 return -EPERM;
386 return crypto_del_default_rng();
387 }
388
389 static int crypto_reportstat(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
390 struct nlattr **attrs)
391 {
392 /* No longer supported */
393 return -ENOTSUPP;
394 }
395
396 #define MSGSIZE(type) sizeof(struct type)
397
398 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
399 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
400 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
401 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
402 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
403 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
404 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
405 };
406
407 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
408 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
409 };
410
411 #undef MSGSIZE
412
413 static const struct crypto_link {
414 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
415 int (*dump)(struct sk_buff *, struct netlink_callback *);
416 int (*done)(struct netlink_callback *);
417 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
418 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
419 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
420 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
421 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
422 .dump = crypto_dump_report,
423 .done = crypto_dump_report_done},
424 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
425 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
426 };
427
428 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
429 struct netlink_ext_ack *extack)
430 {
431 struct net *net = sock_net(skb->sk);
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(net->crypto_nlsk, skb, nlh, &c);
463 }
464
465 return err;
466 }
467
468 err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,
469 CRYPTOCFGA_MAX, 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
479 static 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
486 static int __net_init crypto_netlink_init(struct net *net)
487 {
488 struct netlink_kernel_cfg cfg = {
489 .input = crypto_netlink_rcv,
490 };
491
492 net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);
493 return net->crypto_nlsk == NULL ? -ENOMEM : 0;
494 }
495
496 static void __net_exit crypto_netlink_exit(struct net *net)
497 {
498 netlink_kernel_release(net->crypto_nlsk);
499 net->crypto_nlsk = NULL;
500 }
501
502 static struct pernet_operations crypto_netlink_net_ops = {
503 .init = crypto_netlink_init,
504 .exit = crypto_netlink_exit,
505 };
506
507 static int __init crypto_user_init(void)
508 {
509 return register_pernet_subsys(&crypto_netlink_net_ops);
510 }
511
512 static void __exit crypto_user_exit(void)
513 {
514 unregister_pernet_subsys(&crypto_netlink_net_ops);
515 }
516
517 module_init(crypto_user_init);
518 module_exit(crypto_user_exit);
519 MODULE_LICENSE("GPL");
520 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
521 MODULE_DESCRIPTION("Crypto userspace configuration API");
522 MODULE_ALIAS("net-pf-16-proto-21");
523
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