Merge tag 'for-5.6/dm-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/device...
[platform/kernel/linux-rpi.git] / crypto / crypto_user_base.c
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
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
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
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
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
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
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
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
255 static int crypto_dump_report_done(struct netlink_callback *cb)
256 {
257         return 0;
258 }
259
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
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
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
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
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
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
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
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
501 static int __init crypto_user_init(void)
502 {
503         return register_pernet_subsys(&crypto_netlink_net_ops);
504 }
505
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");