1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30#include <crypto/hash.h>
31#include <linux/slab.h>
32#include <linux/types.h>
33#include <linux/scatterlist.h>
34#include <net/sctp/sctp.h>
35#include <net/sctp/auth.h>
36
37static struct sctp_hmac sctp_hmac_list[SCTP_AUTH_NUM_HMACS] = {
38 {
39
40 .hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_0,
41 },
42 {
43 .hmac_id = SCTP_AUTH_HMAC_ID_SHA1,
44 .hmac_name = "hmac(sha1)",
45 .hmac_len = SCTP_SHA1_SIG_SIZE,
46 },
47 {
48
49 .hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_2,
50 },
51#if IS_ENABLED(CONFIG_CRYPTO_SHA256)
52 {
53 .hmac_id = SCTP_AUTH_HMAC_ID_SHA256,
54 .hmac_name = "hmac(sha256)",
55 .hmac_len = SCTP_SHA256_SIG_SIZE,
56 }
57#endif
58};
59
60
61void sctp_auth_key_put(struct sctp_auth_bytes *key)
62{
63 if (!key)
64 return;
65
66 if (atomic_dec_and_test(&key->refcnt)) {
67 kzfree(key);
68 SCTP_DBG_OBJCNT_DEC(keys);
69 }
70}
71
72
73static struct sctp_auth_bytes *sctp_auth_create_key(__u32 key_len, gfp_t gfp)
74{
75 struct sctp_auth_bytes *key;
76
77
78 if (key_len > (INT_MAX - sizeof(struct sctp_auth_bytes)))
79 return NULL;
80
81
82 key = kmalloc(sizeof(struct sctp_auth_bytes) + key_len, gfp);
83 if (!key)
84 return NULL;
85
86 key->len = key_len;
87 atomic_set(&key->refcnt, 1);
88 SCTP_DBG_OBJCNT_INC(keys);
89
90 return key;
91}
92
93
94struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp)
95{
96 struct sctp_shared_key *new;
97
98
99 new = kzalloc(sizeof(struct sctp_shared_key), gfp);
100 if (!new)
101 return NULL;
102
103 INIT_LIST_HEAD(&new->key_list);
104 new->key_id = key_id;
105
106 return new;
107}
108
109
110static void sctp_auth_shkey_free(struct sctp_shared_key *sh_key)
111{
112 BUG_ON(!list_empty(&sh_key->key_list));
113 sctp_auth_key_put(sh_key->key);
114 sh_key->key = NULL;
115 kfree(sh_key);
116}
117
118
119
120
121void sctp_auth_destroy_keys(struct list_head *keys)
122{
123 struct sctp_shared_key *ep_key;
124 struct sctp_shared_key *tmp;
125
126 if (list_empty(keys))
127 return;
128
129 key_for_each_safe(ep_key, tmp, keys) {
130 list_del_init(&ep_key->key_list);
131 sctp_auth_shkey_free(ep_key);
132 }
133}
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151static int sctp_auth_compare_vectors(struct sctp_auth_bytes *vector1,
152 struct sctp_auth_bytes *vector2)
153{
154 int diff;
155 int i;
156 const __u8 *longer;
157
158 diff = vector1->len - vector2->len;
159 if (diff) {
160 longer = (diff > 0) ? vector1->data : vector2->data;
161
162
163
164
165
166 for (i = 0; i < abs(diff); i++) {
167 if (longer[i] != 0)
168 return diff;
169 }
170 }
171
172
173 return memcmp(vector1->data, vector2->data, vector1->len);
174}
175
176
177
178
179
180
181
182
183
184
185
186
187static struct sctp_auth_bytes *sctp_auth_make_key_vector(
188 sctp_random_param_t *random,
189 sctp_chunks_param_t *chunks,
190 sctp_hmac_algo_param_t *hmacs,
191 gfp_t gfp)
192{
193 struct sctp_auth_bytes *new;
194 __u32 len;
195 __u32 offset = 0;
196 __u16 random_len, hmacs_len, chunks_len = 0;
197
198 random_len = ntohs(random->param_hdr.length);
199 hmacs_len = ntohs(hmacs->param_hdr.length);
200 if (chunks)
201 chunks_len = ntohs(chunks->param_hdr.length);
202
203 len = random_len + hmacs_len + chunks_len;
204
205 new = sctp_auth_create_key(len, gfp);
206 if (!new)
207 return NULL;
208
209 memcpy(new->data, random, random_len);
210 offset += random_len;
211
212 if (chunks) {
213 memcpy(new->data + offset, chunks, chunks_len);
214 offset += chunks_len;
215 }
216
217 memcpy(new->data + offset, hmacs, hmacs_len);
218
219 return new;
220}
221
222
223
224static struct sctp_auth_bytes *sctp_auth_make_local_vector(
225 const struct sctp_association *asoc,
226 gfp_t gfp)
227{
228 return sctp_auth_make_key_vector(
229 (sctp_random_param_t *)asoc->c.auth_random,
230 (sctp_chunks_param_t *)asoc->c.auth_chunks,
231 (sctp_hmac_algo_param_t *)asoc->c.auth_hmacs,
232 gfp);
233}
234
235
236static struct sctp_auth_bytes *sctp_auth_make_peer_vector(
237 const struct sctp_association *asoc,
238 gfp_t gfp)
239{
240 return sctp_auth_make_key_vector(asoc->peer.peer_random,
241 asoc->peer.peer_chunks,
242 asoc->peer.peer_hmacs,
243 gfp);
244}
245
246
247
248
249
250
251
252
253
254
255
256static struct sctp_auth_bytes *sctp_auth_asoc_set_secret(
257 struct sctp_shared_key *ep_key,
258 struct sctp_auth_bytes *first_vector,
259 struct sctp_auth_bytes *last_vector,
260 gfp_t gfp)
261{
262 struct sctp_auth_bytes *secret;
263 __u32 offset = 0;
264 __u32 auth_len;
265
266 auth_len = first_vector->len + last_vector->len;
267 if (ep_key->key)
268 auth_len += ep_key->key->len;
269
270 secret = sctp_auth_create_key(auth_len, gfp);
271 if (!secret)
272 return NULL;
273
274 if (ep_key->key) {
275 memcpy(secret->data, ep_key->key->data, ep_key->key->len);
276 offset += ep_key->key->len;
277 }
278
279 memcpy(secret->data + offset, first_vector->data, first_vector->len);
280 offset += first_vector->len;
281
282 memcpy(secret->data + offset, last_vector->data, last_vector->len);
283
284 return secret;
285}
286
287
288
289
290static struct sctp_auth_bytes *sctp_auth_asoc_create_secret(
291 const struct sctp_association *asoc,
292 struct sctp_shared_key *ep_key,
293 gfp_t gfp)
294{
295 struct sctp_auth_bytes *local_key_vector;
296 struct sctp_auth_bytes *peer_key_vector;
297 struct sctp_auth_bytes *first_vector,
298 *last_vector;
299 struct sctp_auth_bytes *secret = NULL;
300 int cmp;
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315 local_key_vector = sctp_auth_make_local_vector(asoc, gfp);
316 peer_key_vector = sctp_auth_make_peer_vector(asoc, gfp);
317
318 if (!peer_key_vector || !local_key_vector)
319 goto out;
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334 cmp = sctp_auth_compare_vectors(local_key_vector,
335 peer_key_vector);
336 if (cmp < 0) {
337 first_vector = local_key_vector;
338 last_vector = peer_key_vector;
339 } else {
340 first_vector = peer_key_vector;
341 last_vector = local_key_vector;
342 }
343
344 secret = sctp_auth_asoc_set_secret(ep_key, first_vector, last_vector,
345 gfp);
346out:
347 sctp_auth_key_put(local_key_vector);
348 sctp_auth_key_put(peer_key_vector);
349
350 return secret;
351}
352
353
354
355
356
357int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
358 struct sctp_association *asoc,
359 gfp_t gfp)
360{
361 struct sctp_shared_key *sh_key;
362 struct sctp_shared_key *new;
363
364 BUG_ON(!list_empty(&asoc->endpoint_shared_keys));
365
366 key_for_each(sh_key, &ep->endpoint_shared_keys) {
367 new = sctp_auth_shkey_create(sh_key->key_id, gfp);
368 if (!new)
369 goto nomem;
370
371 new->key = sh_key->key;
372 sctp_auth_key_hold(new->key);
373 list_add(&new->key_list, &asoc->endpoint_shared_keys);
374 }
375
376 return 0;
377
378nomem:
379 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
380 return -ENOMEM;
381}
382
383
384
385
386
387int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp)
388{
389 struct sctp_auth_bytes *secret;
390 struct sctp_shared_key *ep_key;
391 struct sctp_chunk *chunk;
392
393
394
395
396 if (!asoc->ep->auth_enable || !asoc->peer.auth_capable)
397 return 0;
398
399
400
401
402
403
404 ep_key = sctp_auth_get_shkey(asoc, asoc->active_key_id);
405 BUG_ON(!ep_key);
406
407 secret = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
408 if (!secret)
409 return -ENOMEM;
410
411 sctp_auth_key_put(asoc->asoc_shared_key);
412 asoc->asoc_shared_key = secret;
413
414
415
416
417 list_for_each_entry(chunk, &asoc->outqueue.out_chunk_list, list) {
418 if (sctp_auth_send_cid(chunk->chunk_hdr->type, asoc))
419 chunk->auth = 1;
420 }
421
422 return 0;
423}
424
425
426
427struct sctp_shared_key *sctp_auth_get_shkey(
428 const struct sctp_association *asoc,
429 __u16 key_id)
430{
431 struct sctp_shared_key *key;
432
433
434 key_for_each(key, &asoc->endpoint_shared_keys) {
435 if (key->key_id == key_id)
436 return key;
437 }
438
439 return NULL;
440}
441
442
443
444
445
446
447
448
449int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp)
450{
451 struct crypto_shash *tfm = NULL;
452 __u16 id;
453
454
455 if (!ep->auth_enable) {
456 ep->auth_hmacs = NULL;
457 return 0;
458 }
459
460
461 if (ep->auth_hmacs)
462 return 0;
463
464
465 ep->auth_hmacs = kzalloc(sizeof(struct crypto_shash *) *
466 SCTP_AUTH_NUM_HMACS, gfp);
467 if (!ep->auth_hmacs)
468 return -ENOMEM;
469
470 for (id = 0; id < SCTP_AUTH_NUM_HMACS; id++) {
471
472
473
474
475
476
477 if (!sctp_hmac_list[id].hmac_name)
478 continue;
479
480
481 if (ep->auth_hmacs[id])
482 continue;
483
484
485 tfm = crypto_alloc_shash(sctp_hmac_list[id].hmac_name, 0, 0);
486 if (IS_ERR(tfm))
487 goto out_err;
488
489 ep->auth_hmacs[id] = tfm;
490 }
491
492 return 0;
493
494out_err:
495
496 sctp_auth_destroy_hmacs(ep->auth_hmacs);
497 return -ENOMEM;
498}
499
500
501void sctp_auth_destroy_hmacs(struct crypto_shash *auth_hmacs[])
502{
503 int i;
504
505 if (!auth_hmacs)
506 return;
507
508 for (i = 0; i < SCTP_AUTH_NUM_HMACS; i++) {
509 crypto_free_shash(auth_hmacs[i]);
510 }
511 kfree(auth_hmacs);
512}
513
514
515struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id)
516{
517 return &sctp_hmac_list[hmac_id];
518}
519
520
521
522
523struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc)
524{
525 struct sctp_hmac_algo_param *hmacs;
526 __u16 n_elt;
527 __u16 id = 0;
528 int i;
529
530
531 if (asoc->default_hmac_id)
532 return &sctp_hmac_list[asoc->default_hmac_id];
533
534
535
536
537 hmacs = asoc->peer.peer_hmacs;
538 if (!hmacs)
539 return NULL;
540
541 n_elt = (ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t)) >> 1;
542 for (i = 0; i < n_elt; i++) {
543 id = ntohs(hmacs->hmac_ids[i]);
544
545
546
547
548
549
550
551 if (id > SCTP_AUTH_HMAC_ID_MAX ||
552 !sctp_hmac_list[id].hmac_name) {
553 id = 0;
554 continue;
555 }
556
557 break;
558 }
559
560 if (id == 0)
561 return NULL;
562
563 return &sctp_hmac_list[id];
564}
565
566static int __sctp_auth_find_hmacid(__be16 *hmacs, int n_elts, __be16 hmac_id)
567{
568 int found = 0;
569 int i;
570
571 for (i = 0; i < n_elts; i++) {
572 if (hmac_id == hmacs[i]) {
573 found = 1;
574 break;
575 }
576 }
577
578 return found;
579}
580
581
582int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
583 __be16 hmac_id)
584{
585 struct sctp_hmac_algo_param *hmacs;
586 __u16 n_elt;
587
588 if (!asoc)
589 return 0;
590
591 hmacs = (struct sctp_hmac_algo_param *)asoc->c.auth_hmacs;
592 n_elt = (ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t)) >> 1;
593
594 return __sctp_auth_find_hmacid(hmacs->hmac_ids, n_elt, hmac_id);
595}
596
597
598
599
600
601
602
603void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
604 struct sctp_hmac_algo_param *hmacs)
605{
606 struct sctp_endpoint *ep;
607 __u16 id;
608 int i;
609 int n_params;
610
611
612 if (asoc->default_hmac_id)
613 return;
614
615 n_params = (ntohs(hmacs->param_hdr.length)
616 - sizeof(sctp_paramhdr_t)) >> 1;
617 ep = asoc->ep;
618 for (i = 0; i < n_params; i++) {
619 id = ntohs(hmacs->hmac_ids[i]);
620
621
622 if (id > SCTP_AUTH_HMAC_ID_MAX)
623 continue;
624
625
626 if (ep->auth_hmacs[id]) {
627 asoc->default_hmac_id = id;
628 break;
629 }
630 }
631}
632
633
634
635static int __sctp_auth_cid(sctp_cid_t chunk, struct sctp_chunks_param *param)
636{
637 unsigned short len;
638 int found = 0;
639 int i;
640
641 if (!param || param->param_hdr.length == 0)
642 return 0;
643
644 len = ntohs(param->param_hdr.length) - sizeof(sctp_paramhdr_t);
645
646
647
648
649
650
651
652 for (i = 0; !found && i < len; i++) {
653 switch (param->chunks[i]) {
654 case SCTP_CID_INIT:
655 case SCTP_CID_INIT_ACK:
656 case SCTP_CID_SHUTDOWN_COMPLETE:
657 case SCTP_CID_AUTH:
658 break;
659
660 default:
661 if (param->chunks[i] == chunk)
662 found = 1;
663 break;
664 }
665 }
666
667 return found;
668}
669
670
671int sctp_auth_send_cid(sctp_cid_t chunk, const struct sctp_association *asoc)
672{
673 if (!asoc)
674 return 0;
675
676 if (!asoc->ep->auth_enable || !asoc->peer.auth_capable)
677 return 0;
678
679 return __sctp_auth_cid(chunk, asoc->peer.peer_chunks);
680}
681
682
683int sctp_auth_recv_cid(sctp_cid_t chunk, const struct sctp_association *asoc)
684{
685 if (!asoc)
686 return 0;
687
688 if (!asoc->ep->auth_enable)
689 return 0;
690
691 return __sctp_auth_cid(chunk,
692 (struct sctp_chunks_param *)asoc->c.auth_chunks);
693}
694
695
696
697
698
699
700
701
702
703
704void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
705 struct sk_buff *skb,
706 struct sctp_auth_chunk *auth,
707 gfp_t gfp)
708{
709 struct crypto_shash *tfm;
710 struct sctp_auth_bytes *asoc_key;
711 __u16 key_id, hmac_id;
712 __u8 *digest;
713 unsigned char *end;
714 int free_key = 0;
715
716
717
718
719
720 key_id = ntohs(auth->auth_hdr.shkey_id);
721 hmac_id = ntohs(auth->auth_hdr.hmac_id);
722
723 if (key_id == asoc->active_key_id)
724 asoc_key = asoc->asoc_shared_key;
725 else {
726 struct sctp_shared_key *ep_key;
727
728 ep_key = sctp_auth_get_shkey(asoc, key_id);
729 if (!ep_key)
730 return;
731
732 asoc_key = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
733 if (!asoc_key)
734 return;
735
736 free_key = 1;
737 }
738
739
740 end = skb_tail_pointer(skb);
741
742 tfm = asoc->ep->auth_hmacs[hmac_id];
743
744 digest = auth->auth_hdr.hmac;
745 if (crypto_shash_setkey(tfm, &asoc_key->data[0], asoc_key->len))
746 goto free;
747
748 {
749 SHASH_DESC_ON_STACK(desc, tfm);
750
751 desc->tfm = tfm;
752 desc->flags = 0;
753 crypto_shash_digest(desc, (u8 *)auth,
754 end - (unsigned char *)auth, digest);
755 shash_desc_zero(desc);
756 }
757
758free:
759 if (free_key)
760 sctp_auth_key_put(asoc_key);
761}
762
763
764
765
766int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id)
767{
768 struct sctp_chunks_param *p = ep->auth_chunk_list;
769 __u16 nchunks;
770 __u16 param_len;
771
772
773 if (__sctp_auth_cid(chunk_id, p))
774 return 0;
775
776
777 param_len = ntohs(p->param_hdr.length);
778 nchunks = param_len - sizeof(sctp_paramhdr_t);
779 if (nchunks == SCTP_NUM_CHUNK_TYPES)
780 return -EINVAL;
781
782 p->chunks[nchunks] = chunk_id;
783 p->param_hdr.length = htons(param_len + 1);
784 return 0;
785}
786
787
788int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep,
789 struct sctp_hmacalgo *hmacs)
790{
791 int has_sha1 = 0;
792 __u16 id;
793 int i;
794
795
796
797
798 for (i = 0; i < hmacs->shmac_num_idents; i++) {
799 id = hmacs->shmac_idents[i];
800
801 if (id > SCTP_AUTH_HMAC_ID_MAX)
802 return -EOPNOTSUPP;
803
804 if (SCTP_AUTH_HMAC_ID_SHA1 == id)
805 has_sha1 = 1;
806
807 if (!sctp_hmac_list[id].hmac_name)
808 return -EOPNOTSUPP;
809 }
810
811 if (!has_sha1)
812 return -EINVAL;
813
814 for (i = 0; i < hmacs->shmac_num_idents; i++)
815 ep->auth_hmacs_list->hmac_ids[i] = htons(hmacs->shmac_idents[i]);
816 ep->auth_hmacs_list->param_hdr.length = htons(sizeof(sctp_paramhdr_t) +
817 hmacs->shmac_num_idents * sizeof(__u16));
818 return 0;
819}
820
821
822
823
824
825int sctp_auth_set_key(struct sctp_endpoint *ep,
826 struct sctp_association *asoc,
827 struct sctp_authkey *auth_key)
828{
829 struct sctp_shared_key *cur_key = NULL;
830 struct sctp_auth_bytes *key;
831 struct list_head *sh_keys;
832 int replace = 0;
833
834
835
836
837 if (asoc)
838 sh_keys = &asoc->endpoint_shared_keys;
839 else
840 sh_keys = &ep->endpoint_shared_keys;
841
842 key_for_each(cur_key, sh_keys) {
843 if (cur_key->key_id == auth_key->sca_keynumber) {
844 replace = 1;
845 break;
846 }
847 }
848
849
850
851
852 if (!replace) {
853 cur_key = sctp_auth_shkey_create(auth_key->sca_keynumber,
854 GFP_KERNEL);
855 if (!cur_key)
856 return -ENOMEM;
857 }
858
859
860 key = sctp_auth_create_key(auth_key->sca_keylength, GFP_KERNEL);
861 if (!key)
862 goto nomem;
863
864 memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylength);
865
866
867
868
869
870 if (replace)
871 sctp_auth_key_put(cur_key->key);
872 else
873 list_add(&cur_key->key_list, sh_keys);
874
875 cur_key->key = key;
876 return 0;
877nomem:
878 if (!replace)
879 sctp_auth_shkey_free(cur_key);
880
881 return -ENOMEM;
882}
883
884int sctp_auth_set_active_key(struct sctp_endpoint *ep,
885 struct sctp_association *asoc,
886 __u16 key_id)
887{
888 struct sctp_shared_key *key;
889 struct list_head *sh_keys;
890 int found = 0;
891
892
893 if (asoc)
894 sh_keys = &asoc->endpoint_shared_keys;
895 else
896 sh_keys = &ep->endpoint_shared_keys;
897
898 key_for_each(key, sh_keys) {
899 if (key->key_id == key_id) {
900 found = 1;
901 break;
902 }
903 }
904
905 if (!found)
906 return -EINVAL;
907
908 if (asoc) {
909 asoc->active_key_id = key_id;
910 sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL);
911 } else
912 ep->active_key_id = key_id;
913
914 return 0;
915}
916
917int sctp_auth_del_key_id(struct sctp_endpoint *ep,
918 struct sctp_association *asoc,
919 __u16 key_id)
920{
921 struct sctp_shared_key *key;
922 struct list_head *sh_keys;
923 int found = 0;
924
925
926
927
928 if (asoc) {
929 if (asoc->active_key_id == key_id)
930 return -EINVAL;
931
932 sh_keys = &asoc->endpoint_shared_keys;
933 } else {
934 if (ep->active_key_id == key_id)
935 return -EINVAL;
936
937 sh_keys = &ep->endpoint_shared_keys;
938 }
939
940 key_for_each(key, sh_keys) {
941 if (key->key_id == key_id) {
942 found = 1;
943 break;
944 }
945 }
946
947 if (!found)
948 return -EINVAL;
949
950
951 list_del_init(&key->key_list);
952 sctp_auth_shkey_free(key);
953
954 return 0;
955}
956