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 kfree_skb(skb);
218 return err;
219 }
220
221 return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
222 }
223
crypto_dump_report(struct sk_buff * skb,struct netlink_callback * cb)224 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
225 {
226 const size_t start_pos = cb->args[0];
227 size_t pos = 0;
228 struct crypto_dump_info info;
229 struct crypto_alg *alg;
230 int res;
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 down_read(&crypto_alg_sem);
238 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
239 if (pos >= start_pos) {
240 res = crypto_report_alg(alg, &info);
241 if (res == -EMSGSIZE)
242 break;
243 if (res)
244 goto out;
245 }
246 pos++;
247 }
248 cb->args[0] = pos;
249 res = skb->len;
250 out:
251 up_read(&crypto_alg_sem);
252 return res;
253 }
254
crypto_dump_report_done(struct netlink_callback * cb)255 static int crypto_dump_report_done(struct netlink_callback *cb)
256 {
257 return 0;
258 }
259
crypto_update_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)260 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
261 struct nlattr **attrs)
262 {
263 struct crypto_alg *alg;
264 struct crypto_user_alg *p = nlmsg_data(nlh);
265 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
266 LIST_HEAD(list);
267
268 if (!netlink_capable(skb, CAP_NET_ADMIN))
269 return -EPERM;
270
271 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
272 return -EINVAL;
273
274 if (priority && !strlen(p->cru_driver_name))
275 return -EINVAL;
276
277 alg = crypto_alg_match(p, 1);
278 if (!alg)
279 return -ENOENT;
280
281 down_write(&crypto_alg_sem);
282
283 crypto_remove_spawns(alg, &list, NULL);
284
285 if (priority)
286 alg->cra_priority = nla_get_u32(priority);
287
288 up_write(&crypto_alg_sem);
289
290 crypto_mod_put(alg);
291 crypto_remove_final(&list);
292
293 return 0;
294 }
295
crypto_del_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)296 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
297 struct nlattr **attrs)
298 {
299 struct crypto_alg *alg;
300 struct crypto_user_alg *p = nlmsg_data(nlh);
301 int err;
302
303 if (!netlink_capable(skb, CAP_NET_ADMIN))
304 return -EPERM;
305
306 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
307 return -EINVAL;
308
309 alg = crypto_alg_match(p, 1);
310 if (!alg)
311 return -ENOENT;
312
313 /* We can not unregister core algorithms such as aes-generic.
314 * We would loose the reference in the crypto_alg_list to this algorithm
315 * if we try to unregister. Unregistering such an algorithm without
316 * removing the module is not possible, so we restrict to crypto
317 * instances that are build from templates. */
318 err = -EINVAL;
319 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
320 goto drop_alg;
321
322 err = -EBUSY;
323 if (refcount_read(&alg->cra_refcnt) > 2)
324 goto drop_alg;
325
326 crypto_unregister_instance((struct crypto_instance *)alg);
327 err = 0;
328
329 drop_alg:
330 crypto_mod_put(alg);
331 return err;
332 }
333
crypto_add_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)334 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
335 struct nlattr **attrs)
336 {
337 int exact = 0;
338 const char *name;
339 struct crypto_alg *alg;
340 struct crypto_user_alg *p = nlmsg_data(nlh);
341 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
342
343 if (!netlink_capable(skb, CAP_NET_ADMIN))
344 return -EPERM;
345
346 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
347 return -EINVAL;
348
349 if (strlen(p->cru_driver_name))
350 exact = 1;
351
352 if (priority && !exact)
353 return -EINVAL;
354
355 alg = crypto_alg_match(p, exact);
356 if (alg) {
357 crypto_mod_put(alg);
358 return -EEXIST;
359 }
360
361 if (strlen(p->cru_driver_name))
362 name = p->cru_driver_name;
363 else
364 name = p->cru_name;
365
366 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
367 if (IS_ERR(alg))
368 return PTR_ERR(alg);
369
370 down_write(&crypto_alg_sem);
371
372 if (priority)
373 alg->cra_priority = nla_get_u32(priority);
374
375 up_write(&crypto_alg_sem);
376
377 crypto_mod_put(alg);
378
379 return 0;
380 }
381
crypto_del_rng(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)382 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
383 struct nlattr **attrs)
384 {
385 if (!netlink_capable(skb, CAP_NET_ADMIN))
386 return -EPERM;
387 return crypto_del_default_rng();
388 }
389
390 #define MSGSIZE(type) sizeof(struct type)
391
392 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
393 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
394 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
395 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
396 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
397 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
398 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
399 };
400
401 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
402 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
403 };
404
405 #undef MSGSIZE
406
407 static const struct crypto_link {
408 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
409 int (*dump)(struct sk_buff *, struct netlink_callback *);
410 int (*done)(struct netlink_callback *);
411 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
412 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
413 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
414 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
415 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
416 .dump = crypto_dump_report,
417 .done = crypto_dump_report_done},
418 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
419 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
420 };
421
crypto_user_rcv_msg(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)422 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
423 struct netlink_ext_ack *extack)
424 {
425 struct net *net = sock_net(skb->sk);
426 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
427 const struct crypto_link *link;
428 int type, err;
429
430 type = nlh->nlmsg_type;
431 if (type > CRYPTO_MSG_MAX)
432 return -EINVAL;
433
434 type -= CRYPTO_MSG_BASE;
435 link = &crypto_dispatch[type];
436
437 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
438 (nlh->nlmsg_flags & NLM_F_DUMP))) {
439 struct crypto_alg *alg;
440 unsigned long dump_alloc = 0;
441
442 if (link->dump == NULL)
443 return -EINVAL;
444
445 down_read(&crypto_alg_sem);
446 list_for_each_entry(alg, &crypto_alg_list, cra_list)
447 dump_alloc += CRYPTO_REPORT_MAXSIZE;
448 up_read(&crypto_alg_sem);
449
450 {
451 struct netlink_dump_control c = {
452 .dump = link->dump,
453 .done = link->done,
454 .min_dump_alloc = min(dump_alloc, 65535UL),
455 };
456 err = netlink_dump_start(net->crypto_nlsk, skb, nlh, &c);
457 }
458
459 return err;
460 }
461
462 err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,
463 CRYPTOCFGA_MAX, crypto_policy, extack);
464 if (err < 0)
465 return err;
466
467 if (link->doit == NULL)
468 return -EINVAL;
469
470 return link->doit(skb, nlh, attrs);
471 }
472
crypto_netlink_rcv(struct sk_buff * skb)473 static void crypto_netlink_rcv(struct sk_buff *skb)
474 {
475 mutex_lock(&crypto_cfg_mutex);
476 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
477 mutex_unlock(&crypto_cfg_mutex);
478 }
479
crypto_netlink_init(struct net * net)480 static int __net_init crypto_netlink_init(struct net *net)
481 {
482 struct netlink_kernel_cfg cfg = {
483 .input = crypto_netlink_rcv,
484 };
485
486 net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);
487 return net->crypto_nlsk == NULL ? -ENOMEM : 0;
488 }
489
crypto_netlink_exit(struct net * net)490 static void __net_exit crypto_netlink_exit(struct net *net)
491 {
492 netlink_kernel_release(net->crypto_nlsk);
493 net->crypto_nlsk = NULL;
494 }
495
496 static struct pernet_operations crypto_netlink_net_ops = {
497 .init = crypto_netlink_init,
498 .exit = crypto_netlink_exit,
499 };
500
crypto_user_init(void)501 static int __init crypto_user_init(void)
502 {
503 return register_pernet_subsys(&crypto_netlink_net_ops);
504 }
505
crypto_user_exit(void)506 static void __exit crypto_user_exit(void)
507 {
508 unregister_pernet_subsys(&crypto_netlink_net_ops);
509 }
510
511 module_init(crypto_user_init);
512 module_exit(crypto_user_exit);
513 MODULE_LICENSE("GPL");
514 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
515 MODULE_DESCRIPTION("Crypto userspace configuration API");
516 MODULE_ALIAS("net-pf-16-proto-21");
517