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
crypto_alg_match(struct crypto_user_alg * p,int exact)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
crypto_report_cipher(struct sk_buff * skb,struct crypto_alg * alg)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
crypto_report_one(struct crypto_alg * alg,struct crypto_user_alg * ualg,struct sk_buff * skb)87 static int crypto_report_one(struct crypto_alg *alg,
88 struct crypto_user_alg *ualg, struct sk_buff *skb)
89 {
90 memset(ualg, 0, sizeof(*ualg));
91
92 strscpy(ualg->cru_name, alg->cra_name, sizeof(ualg->cru_name));
93 strscpy(ualg->cru_driver_name, alg->cra_driver_name,
94 sizeof(ualg->cru_driver_name));
95 strscpy(ualg->cru_module_name, module_name(alg->cra_module),
96 sizeof(ualg->cru_module_name));
97
98 ualg->cru_type = 0;
99 ualg->cru_mask = 0;
100 ualg->cru_flags = alg->cra_flags;
101 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
102
103 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
104 goto nla_put_failure;
105 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
106 struct crypto_report_larval rl;
107
108 memset(&rl, 0, sizeof(rl));
109 strscpy(rl.type, "larval", sizeof(rl.type));
110 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))
111 goto nla_put_failure;
112 goto out;
113 }
114
115 if (alg->cra_type && alg->cra_type->report) {
116 if (alg->cra_type->report(skb, alg))
117 goto nla_put_failure;
118
119 goto out;
120 }
121
122 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
123 case CRYPTO_ALG_TYPE_CIPHER:
124 if (crypto_report_cipher(skb, alg))
125 goto nla_put_failure;
126
127 break;
128 }
129
130 out:
131 return 0;
132
133 nla_put_failure:
134 return -EMSGSIZE;
135 }
136
crypto_report_alg(struct crypto_alg * alg,struct crypto_dump_info * info)137 static int crypto_report_alg(struct crypto_alg *alg,
138 struct crypto_dump_info *info)
139 {
140 struct sk_buff *in_skb = info->in_skb;
141 struct sk_buff *skb = info->out_skb;
142 struct nlmsghdr *nlh;
143 struct crypto_user_alg *ualg;
144 int err = 0;
145
146 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
147 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
148 if (!nlh) {
149 err = -EMSGSIZE;
150 goto out;
151 }
152
153 ualg = nlmsg_data(nlh);
154
155 err = crypto_report_one(alg, ualg, skb);
156 if (err) {
157 nlmsg_cancel(skb, nlh);
158 goto out;
159 }
160
161 nlmsg_end(skb, nlh);
162
163 out:
164 return err;
165 }
166
crypto_report(struct sk_buff * in_skb,struct nlmsghdr * in_nlh,struct nlattr ** attrs)167 static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
168 struct nlattr **attrs)
169 {
170 struct net *net = sock_net(in_skb->sk);
171 struct crypto_user_alg *p = nlmsg_data(in_nlh);
172 struct crypto_alg *alg;
173 struct sk_buff *skb;
174 struct crypto_dump_info info;
175 int err;
176
177 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
178 return -EINVAL;
179
180 alg = crypto_alg_match(p, 0);
181 if (!alg)
182 return -ENOENT;
183
184 err = -ENOMEM;
185 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
186 if (!skb)
187 goto drop_alg;
188
189 info.in_skb = in_skb;
190 info.out_skb = skb;
191 info.nlmsg_seq = in_nlh->nlmsg_seq;
192 info.nlmsg_flags = 0;
193
194 err = crypto_report_alg(alg, &info);
195
196 drop_alg:
197 crypto_mod_put(alg);
198
199 if (err) {
200 kfree_skb(skb);
201 return err;
202 }
203
204 return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
205 }
206
crypto_dump_report(struct sk_buff * skb,struct netlink_callback * cb)207 static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
208 {
209 const size_t start_pos = cb->args[0];
210 size_t pos = 0;
211 struct crypto_dump_info info;
212 struct crypto_alg *alg;
213 int res;
214
215 info.in_skb = cb->skb;
216 info.out_skb = skb;
217 info.nlmsg_seq = cb->nlh->nlmsg_seq;
218 info.nlmsg_flags = NLM_F_MULTI;
219
220 down_read(&crypto_alg_sem);
221 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
222 if (pos >= start_pos) {
223 res = crypto_report_alg(alg, &info);
224 if (res == -EMSGSIZE)
225 break;
226 if (res)
227 goto out;
228 }
229 pos++;
230 }
231 cb->args[0] = pos;
232 res = skb->len;
233 out:
234 up_read(&crypto_alg_sem);
235 return res;
236 }
237
crypto_dump_report_done(struct netlink_callback * cb)238 static int crypto_dump_report_done(struct netlink_callback *cb)
239 {
240 return 0;
241 }
242
crypto_update_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)243 static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
244 struct nlattr **attrs)
245 {
246 struct crypto_alg *alg;
247 struct crypto_user_alg *p = nlmsg_data(nlh);
248 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
249 LIST_HEAD(list);
250
251 if (!netlink_capable(skb, CAP_NET_ADMIN))
252 return -EPERM;
253
254 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
255 return -EINVAL;
256
257 if (priority && !strlen(p->cru_driver_name))
258 return -EINVAL;
259
260 alg = crypto_alg_match(p, 1);
261 if (!alg)
262 return -ENOENT;
263
264 down_write(&crypto_alg_sem);
265
266 crypto_remove_spawns(alg, &list, NULL);
267
268 if (priority)
269 alg->cra_priority = nla_get_u32(priority);
270
271 up_write(&crypto_alg_sem);
272
273 crypto_mod_put(alg);
274 crypto_remove_final(&list);
275
276 return 0;
277 }
278
crypto_del_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)279 static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
280 struct nlattr **attrs)
281 {
282 struct crypto_alg *alg;
283 struct crypto_user_alg *p = nlmsg_data(nlh);
284 int err;
285
286 if (!netlink_capable(skb, CAP_NET_ADMIN))
287 return -EPERM;
288
289 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
290 return -EINVAL;
291
292 alg = crypto_alg_match(p, 1);
293 if (!alg)
294 return -ENOENT;
295
296 /* We can not unregister core algorithms such as aes-generic.
297 * We would loose the reference in the crypto_alg_list to this algorithm
298 * if we try to unregister. Unregistering such an algorithm without
299 * removing the module is not possible, so we restrict to crypto
300 * instances that are build from templates. */
301 err = -EINVAL;
302 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
303 goto drop_alg;
304
305 err = -EBUSY;
306 if (refcount_read(&alg->cra_refcnt) > 2)
307 goto drop_alg;
308
309 crypto_unregister_instance((struct crypto_instance *)alg);
310 err = 0;
311
312 drop_alg:
313 crypto_mod_put(alg);
314 return err;
315 }
316
crypto_add_alg(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)317 static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
318 struct nlattr **attrs)
319 {
320 int exact = 0;
321 const char *name;
322 struct crypto_alg *alg;
323 struct crypto_user_alg *p = nlmsg_data(nlh);
324 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
325
326 if (!netlink_capable(skb, CAP_NET_ADMIN))
327 return -EPERM;
328
329 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
330 return -EINVAL;
331
332 if (strlen(p->cru_driver_name))
333 exact = 1;
334
335 if (priority && !exact)
336 return -EINVAL;
337
338 alg = crypto_alg_match(p, exact);
339 if (alg) {
340 crypto_mod_put(alg);
341 return -EEXIST;
342 }
343
344 if (strlen(p->cru_driver_name))
345 name = p->cru_driver_name;
346 else
347 name = p->cru_name;
348
349 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
350 if (IS_ERR(alg))
351 return PTR_ERR(alg);
352
353 down_write(&crypto_alg_sem);
354
355 if (priority)
356 alg->cra_priority = nla_get_u32(priority);
357
358 up_write(&crypto_alg_sem);
359
360 crypto_mod_put(alg);
361
362 return 0;
363 }
364
crypto_del_rng(struct sk_buff * skb,struct nlmsghdr * nlh,struct nlattr ** attrs)365 static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
366 struct nlattr **attrs)
367 {
368 if (!netlink_capable(skb, CAP_NET_ADMIN))
369 return -EPERM;
370 return crypto_del_default_rng();
371 }
372
crypto_reportstat(struct sk_buff * in_skb,struct nlmsghdr * in_nlh,struct nlattr ** attrs)373 static int crypto_reportstat(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
374 struct nlattr **attrs)
375 {
376 /* No longer supported */
377 return -ENOTSUPP;
378 }
379
380 #define MSGSIZE(type) sizeof(struct type)
381
382 static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
383 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
384 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
385 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
386 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
387 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
388 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
389 };
390
391 static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
392 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
393 };
394
395 #undef MSGSIZE
396
397 static const struct crypto_link {
398 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
399 int (*dump)(struct sk_buff *, struct netlink_callback *);
400 int (*done)(struct netlink_callback *);
401 } crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
402 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
403 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
404 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
405 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
406 .dump = crypto_dump_report,
407 .done = crypto_dump_report_done},
408 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
409 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
410 };
411
crypto_user_rcv_msg(struct sk_buff * skb,struct nlmsghdr * nlh,struct netlink_ext_ack * extack)412 static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
413 struct netlink_ext_ack *extack)
414 {
415 struct net *net = sock_net(skb->sk);
416 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
417 const struct crypto_link *link;
418 int type, err;
419
420 type = nlh->nlmsg_type;
421 if (type > CRYPTO_MSG_MAX)
422 return -EINVAL;
423
424 type -= CRYPTO_MSG_BASE;
425 link = &crypto_dispatch[type];
426
427 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
428 (nlh->nlmsg_flags & NLM_F_DUMP))) {
429 struct crypto_alg *alg;
430 unsigned long dump_alloc = 0;
431
432 if (link->dump == NULL)
433 return -EINVAL;
434
435 down_read(&crypto_alg_sem);
436 list_for_each_entry(alg, &crypto_alg_list, cra_list)
437 dump_alloc += CRYPTO_REPORT_MAXSIZE;
438 up_read(&crypto_alg_sem);
439
440 {
441 struct netlink_dump_control c = {
442 .dump = link->dump,
443 .done = link->done,
444 .min_dump_alloc = min(dump_alloc, 65535UL),
445 };
446 err = netlink_dump_start(net->crypto_nlsk, skb, nlh, &c);
447 }
448
449 return err;
450 }
451
452 err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,
453 CRYPTOCFGA_MAX, crypto_policy, extack);
454 if (err < 0)
455 return err;
456
457 if (link->doit == NULL)
458 return -EINVAL;
459
460 return link->doit(skb, nlh, attrs);
461 }
462
crypto_netlink_rcv(struct sk_buff * skb)463 static void crypto_netlink_rcv(struct sk_buff *skb)
464 {
465 mutex_lock(&crypto_cfg_mutex);
466 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
467 mutex_unlock(&crypto_cfg_mutex);
468 }
469
crypto_netlink_init(struct net * net)470 static int __net_init crypto_netlink_init(struct net *net)
471 {
472 struct netlink_kernel_cfg cfg = {
473 .input = crypto_netlink_rcv,
474 };
475
476 net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);
477 return net->crypto_nlsk == NULL ? -ENOMEM : 0;
478 }
479
crypto_netlink_exit(struct net * net)480 static void __net_exit crypto_netlink_exit(struct net *net)
481 {
482 netlink_kernel_release(net->crypto_nlsk);
483 net->crypto_nlsk = NULL;
484 }
485
486 static struct pernet_operations crypto_netlink_net_ops = {
487 .init = crypto_netlink_init,
488 .exit = crypto_netlink_exit,
489 };
490
crypto_user_init(void)491 static int __init crypto_user_init(void)
492 {
493 return register_pernet_subsys(&crypto_netlink_net_ops);
494 }
495
crypto_user_exit(void)496 static void __exit crypto_user_exit(void)
497 {
498 unregister_pernet_subsys(&crypto_netlink_net_ops);
499 }
500
501 module_init(crypto_user_init);
502 module_exit(crypto_user_exit);
503 MODULE_LICENSE("GPL");
504 MODULE_AUTHOR("Steffen Klassert <steffen.klassert@secunet.com>");
505 MODULE_DESCRIPTION("Crypto userspace configuration API");
506 MODULE_ALIAS("net-pf-16-proto-21");
507