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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 <[email protected]>
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 <linux/string.h>
15#include <net/netlink.h>
16#include <net/net_namespace.h>
17#include <net/sock.h>
18#include <crypto/internal/skcipher.h>
19#include <crypto/internal/rng.h>
20#include <crypto/akcipher.h>
21#include <crypto/kpp.h>
22
23#include "internal.h"
24
25#define null_terminated(x) (strnlen(x, sizeof(x)) < sizeof(x))
26
27static DEFINE_MUTEX(crypto_cfg_mutex);
28
29struct 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
36static 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
72static int crypto_report_cipher(struct sk_buff *skb, struct crypto_alg *alg)
73{
74 struct crypto_report_cipher rcipher = {
75 .type = "cipher",
76 };
77
78 rcipher.blocksize = alg->cra_blocksize;
79 rcipher.min_keysize = alg->cra_cipher.cia_min_keysize;
80 rcipher.max_keysize = alg->cra_cipher.cia_max_keysize;
81
82 return nla_put(skb, CRYPTOCFGA_REPORT_CIPHER,
83 sizeof(rcipher), &rcipher);
84}
85
86static int crypto_report_one(struct crypto_alg *alg,
87 struct crypto_user_alg *ualg, struct sk_buff *skb)
88{
89 memset(ualg, 0, sizeof(*ualg));
90
91 strscpy(ualg->cru_name, alg->cra_name);
92 strscpy(ualg->cru_driver_name, alg->cra_driver_name);
93 strscpy(ualg->cru_module_name, module_name(alg->cra_module));
94
95 ualg->cru_type = 0;
96 ualg->cru_mask = 0;
97 ualg->cru_flags = alg->cra_flags;
98 ualg->cru_refcnt = refcount_read(&alg->cra_refcnt);
99
100 if (nla_put_u32(skb, CRYPTOCFGA_PRIORITY_VAL, alg->cra_priority))
101 goto nla_put_failure;
102 if (alg->cra_flags & CRYPTO_ALG_LARVAL) {
103 struct crypto_report_larval rl = {
104 .type = "larval",
105 };
106
107 if (nla_put(skb, CRYPTOCFGA_REPORT_LARVAL, sizeof(rl), &rl))
108 goto nla_put_failure;
109 goto out;
110 }
111
112 if (alg->cra_type && alg->cra_type->report) {
113 if (alg->cra_type->report(skb, alg))
114 goto nla_put_failure;
115
116 goto out;
117 }
118
119 switch (alg->cra_flags & (CRYPTO_ALG_TYPE_MASK | CRYPTO_ALG_LARVAL)) {
120 case CRYPTO_ALG_TYPE_CIPHER:
121 if (crypto_report_cipher(skb, alg))
122 goto nla_put_failure;
123
124 break;
125 }
126
127out:
128 return 0;
129
130nla_put_failure:
131 return -EMSGSIZE;
132}
133
134static int crypto_report_alg(struct crypto_alg *alg,
135 struct crypto_dump_info *info)
136{
137 struct sk_buff *in_skb = info->in_skb;
138 struct sk_buff *skb = info->out_skb;
139 struct nlmsghdr *nlh;
140 struct crypto_user_alg *ualg;
141 int err = 0;
142
143 nlh = nlmsg_put(skb, NETLINK_CB(in_skb).portid, info->nlmsg_seq,
144 CRYPTO_MSG_GETALG, sizeof(*ualg), info->nlmsg_flags);
145 if (!nlh) {
146 err = -EMSGSIZE;
147 goto out;
148 }
149
150 ualg = nlmsg_data(nlh);
151
152 err = crypto_report_one(alg, ualg, skb);
153 if (err) {
154 nlmsg_cancel(skb, nlh);
155 goto out;
156 }
157
158 nlmsg_end(skb, nlh);
159
160out:
161 return err;
162}
163
164static int crypto_report(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
165 struct nlattr **attrs)
166{
167 struct net *net = sock_net(in_skb->sk);
168 struct crypto_user_alg *p = nlmsg_data(in_nlh);
169 struct crypto_alg *alg;
170 struct sk_buff *skb;
171 struct crypto_dump_info info;
172 int err;
173
174 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
175 return -EINVAL;
176
177 alg = crypto_alg_match(p, 0);
178 if (!alg)
179 return -ENOENT;
180
181 err = -ENOMEM;
182 skb = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
183 if (!skb)
184 goto drop_alg;
185
186 info.in_skb = in_skb;
187 info.out_skb = skb;
188 info.nlmsg_seq = in_nlh->nlmsg_seq;
189 info.nlmsg_flags = 0;
190
191 err = crypto_report_alg(alg, &info);
192
193drop_alg:
194 crypto_mod_put(alg);
195
196 if (err) {
197 kfree_skb(skb);
198 return err;
199 }
200
201 return nlmsg_unicast(net->crypto_nlsk, skb, NETLINK_CB(in_skb).portid);
202}
203
204static int crypto_dump_report(struct sk_buff *skb, struct netlink_callback *cb)
205{
206 const size_t start_pos = cb->args[0];
207 size_t pos = 0;
208 struct crypto_dump_info info;
209 struct crypto_alg *alg;
210 int res;
211
212 info.in_skb = cb->skb;
213 info.out_skb = skb;
214 info.nlmsg_seq = cb->nlh->nlmsg_seq;
215 info.nlmsg_flags = NLM_F_MULTI;
216
217 down_read(&crypto_alg_sem);
218 list_for_each_entry(alg, &crypto_alg_list, cra_list) {
219 if (pos >= start_pos) {
220 res = crypto_report_alg(alg, &info);
221 if (res == -EMSGSIZE)
222 break;
223 if (res)
224 goto out;
225 }
226 pos++;
227 }
228 cb->args[0] = pos;
229 res = skb->len;
230out:
231 up_read(&crypto_alg_sem);
232 return res;
233}
234
235static int crypto_dump_report_done(struct netlink_callback *cb)
236{
237 return 0;
238}
239
240static int crypto_update_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
241 struct nlattr **attrs)
242{
243 struct crypto_alg *alg;
244 struct crypto_user_alg *p = nlmsg_data(nlh);
245 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
246 LIST_HEAD(list);
247
248 if (!netlink_capable(skb, CAP_NET_ADMIN))
249 return -EPERM;
250
251 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
252 return -EINVAL;
253
254 if (priority && !strlen(p->cru_driver_name))
255 return -EINVAL;
256
257 alg = crypto_alg_match(p, 1);
258 if (!alg)
259 return -ENOENT;
260
261 down_write(&crypto_alg_sem);
262
263 crypto_remove_spawns(alg, &list, NULL);
264
265 if (priority)
266 alg->cra_priority = nla_get_u32(priority);
267
268 up_write(&crypto_alg_sem);
269
270 crypto_mod_put(alg);
271 crypto_remove_final(&list);
272
273 return 0;
274}
275
276static int crypto_del_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
277 struct nlattr **attrs)
278{
279 struct crypto_alg *alg;
280 struct crypto_user_alg *p = nlmsg_data(nlh);
281 int err;
282
283 if (!netlink_capable(skb, CAP_NET_ADMIN))
284 return -EPERM;
285
286 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
287 return -EINVAL;
288
289 alg = crypto_alg_match(p, 1);
290 if (!alg)
291 return -ENOENT;
292
293 /* We can not unregister core algorithms such as aes.
294 * We would loose the reference in the crypto_alg_list to this algorithm
295 * if we try to unregister. Unregistering such an algorithm without
296 * removing the module is not possible, so we restrict to crypto
297 * instances that are build from templates. */
298 err = -EINVAL;
299 if (!(alg->cra_flags & CRYPTO_ALG_INSTANCE))
300 goto drop_alg;
301
302 err = -EBUSY;
303 if (refcount_read(&alg->cra_refcnt) > 2)
304 goto drop_alg;
305
306 crypto_unregister_instance((struct crypto_instance *)alg);
307 err = 0;
308
309drop_alg:
310 crypto_mod_put(alg);
311 return err;
312}
313
314static int crypto_add_alg(struct sk_buff *skb, struct nlmsghdr *nlh,
315 struct nlattr **attrs)
316{
317 int exact = 0;
318 const char *name;
319 struct crypto_alg *alg;
320 struct crypto_user_alg *p = nlmsg_data(nlh);
321 struct nlattr *priority = attrs[CRYPTOCFGA_PRIORITY_VAL];
322
323 if (!netlink_capable(skb, CAP_NET_ADMIN))
324 return -EPERM;
325
326 if (!null_terminated(p->cru_name) || !null_terminated(p->cru_driver_name))
327 return -EINVAL;
328
329 if (strlen(p->cru_driver_name))
330 exact = 1;
331
332 if (priority && !exact)
333 return -EINVAL;
334
335 alg = crypto_alg_match(p, exact);
336 if (alg) {
337 crypto_mod_put(alg);
338 return -EEXIST;
339 }
340
341 if (strlen(p->cru_driver_name))
342 name = p->cru_driver_name;
343 else
344 name = p->cru_name;
345
346 alg = crypto_alg_mod_lookup(name, p->cru_type, p->cru_mask);
347 if (IS_ERR(alg))
348 return PTR_ERR(alg);
349
350 down_write(&crypto_alg_sem);
351
352 if (priority)
353 alg->cra_priority = nla_get_u32(priority);
354
355 up_write(&crypto_alg_sem);
356
357 crypto_mod_put(alg);
358
359 return 0;
360}
361
362static int crypto_del_rng(struct sk_buff *skb, struct nlmsghdr *nlh,
363 struct nlattr **attrs)
364{
365 if (!netlink_capable(skb, CAP_NET_ADMIN))
366 return -EPERM;
367 return crypto_del_default_rng();
368}
369
370static int crypto_reportstat(struct sk_buff *in_skb, struct nlmsghdr *in_nlh,
371 struct nlattr **attrs)
372{
373 /* No longer supported */
374 return -ENOTSUPP;
375}
376
377#define MSGSIZE(type) sizeof(struct type)
378
379static const int crypto_msg_min[CRYPTO_NR_MSGTYPES] = {
380 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
381 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
382 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
383 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
384 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = 0,
385 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = MSGSIZE(crypto_user_alg),
386};
387
388static const struct nla_policy crypto_policy[CRYPTOCFGA_MAX+1] = {
389 [CRYPTOCFGA_PRIORITY_VAL] = { .type = NLA_U32},
390};
391
392#undef MSGSIZE
393
394static const struct crypto_link {
395 int (*doit)(struct sk_buff *, struct nlmsghdr *, struct nlattr **);
396 int (*dump)(struct sk_buff *, struct netlink_callback *);
397 int (*done)(struct netlink_callback *);
398} crypto_dispatch[CRYPTO_NR_MSGTYPES] = {
399 [CRYPTO_MSG_NEWALG - CRYPTO_MSG_BASE] = { .doit = crypto_add_alg},
400 [CRYPTO_MSG_DELALG - CRYPTO_MSG_BASE] = { .doit = crypto_del_alg},
401 [CRYPTO_MSG_UPDATEALG - CRYPTO_MSG_BASE] = { .doit = crypto_update_alg},
402 [CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE] = { .doit = crypto_report,
403 .dump = crypto_dump_report,
404 .done = crypto_dump_report_done},
405 [CRYPTO_MSG_DELRNG - CRYPTO_MSG_BASE] = { .doit = crypto_del_rng },
406 [CRYPTO_MSG_GETSTAT - CRYPTO_MSG_BASE] = { .doit = crypto_reportstat},
407};
408
409static int crypto_user_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
410 struct netlink_ext_ack *extack)
411{
412 struct net *net = sock_net(skb->sk);
413 struct nlattr *attrs[CRYPTOCFGA_MAX+1];
414 const struct crypto_link *link;
415 int type, err;
416
417 type = nlh->nlmsg_type;
418 if (type > CRYPTO_MSG_MAX)
419 return -EINVAL;
420
421 type -= CRYPTO_MSG_BASE;
422 link = &crypto_dispatch[type];
423
424 if ((type == (CRYPTO_MSG_GETALG - CRYPTO_MSG_BASE) &&
425 (nlh->nlmsg_flags & NLM_F_DUMP))) {
426 struct crypto_alg *alg;
427 unsigned long dump_alloc = 0;
428
429 if (link->dump == NULL)
430 return -EINVAL;
431
432 down_read(&crypto_alg_sem);
433 list_for_each_entry(alg, &crypto_alg_list, cra_list)
434 dump_alloc += CRYPTO_REPORT_MAXSIZE;
435 up_read(&crypto_alg_sem);
436
437 {
438 struct netlink_dump_control c = {
439 .dump = link->dump,
440 .done = link->done,
441 .min_dump_alloc = min(dump_alloc, 65535UL),
442 };
443 err = netlink_dump_start(net->crypto_nlsk, skb, nlh, &c);
444 }
445
446 return err;
447 }
448
449 err = nlmsg_parse_deprecated(nlh, crypto_msg_min[type], attrs,
450 CRYPTOCFGA_MAX, crypto_policy, extack);
451 if (err < 0)
452 return err;
453
454 if (link->doit == NULL)
455 return -EINVAL;
456
457 return link->doit(skb, nlh, attrs);
458}
459
460static void crypto_netlink_rcv(struct sk_buff *skb)
461{
462 mutex_lock(&crypto_cfg_mutex);
463 netlink_rcv_skb(skb, &crypto_user_rcv_msg);
464 mutex_unlock(&crypto_cfg_mutex);
465}
466
467static int __net_init crypto_netlink_init(struct net *net)
468{
469 struct netlink_kernel_cfg cfg = {
470 .input = crypto_netlink_rcv,
471 };
472
473 net->crypto_nlsk = netlink_kernel_create(net, NETLINK_CRYPTO, &cfg);
474 return net->crypto_nlsk == NULL ? -ENOMEM : 0;
475}
476
477static void __net_exit crypto_netlink_exit(struct net *net)
478{
479 netlink_kernel_release(net->crypto_nlsk);
480 net->crypto_nlsk = NULL;
481}
482
483static struct pernet_operations crypto_netlink_net_ops = {
484 .init = crypto_netlink_init,
485 .exit = crypto_netlink_exit,
486};
487
488static int __init crypto_user_init(void)
489{
490 return register_pernet_subsys(&crypto_netlink_net_ops);
491}
492
493static void __exit crypto_user_exit(void)
494{
495 unregister_pernet_subsys(&crypto_netlink_net_ops);
496}
497
498module_init(crypto_user_init);
499module_exit(crypto_user_exit);
500MODULE_LICENSE("GPL");
501MODULE_AUTHOR("Steffen Klassert <[email protected]>");
502MODULE_DESCRIPTION("Crypto userspace configuration API");
503MODULE_ALIAS("net-pf-16-proto-21");