1 /* SCTP kernel implementation
2 * (C) Copyright 2007 Hewlett-Packard Development Company, L.P.
4 * This file is part of the SCTP kernel implementation
6 * This SCTP implementation is free software;
7 * you can redistribute it and/or modify it under the terms of
8 * the GNU General Public License as published by
9 * the Free Software Foundation; either version 2, or (at your option)
12 * This SCTP implementation is distributed in the hope that it
13 * will be useful, but WITHOUT ANY WARRANTY; without even the implied
14 * ************************
15 * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
16 * See the GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with GNU CC; see the file COPYING. If not, see
20 * <http://www.gnu.org/licenses/>.
22 * Please send any bug reports or fixes you make to the
24 * lksctp developers <linux-sctp@vger.kernel.org>
26 * Written or modified by:
27 * Vlad Yasevich <vladislav.yasevich@hp.com>
30 #include <linux/slab.h>
31 #include <linux/types.h>
32 #include <linux/crypto.h>
33 #include <linux/scatterlist.h>
34 #include <net/sctp/sctp.h>
35 #include <net/sctp/auth.h>
37 static struct sctp_hmac sctp_hmac_list[SCTP_AUTH_NUM_HMACS] = {
39 /* id 0 is reserved. as all 0 */
40 .hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_0,
43 .hmac_id = SCTP_AUTH_HMAC_ID_SHA1,
44 .hmac_name="hmac(sha1)",
45 .hmac_len = SCTP_SHA1_SIG_SIZE,
48 /* id 2 is reserved as well */
49 .hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_2,
51 #if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
53 .hmac_id = SCTP_AUTH_HMAC_ID_SHA256,
54 .hmac_name="hmac(sha256)",
55 .hmac_len = SCTP_SHA256_SIG_SIZE,
61 void sctp_auth_key_put(struct sctp_auth_bytes *key)
66 if (atomic_dec_and_test(&key->refcnt)) {
68 SCTP_DBG_OBJCNT_DEC(keys);
72 /* Create a new key structure of a given length */
73 static struct sctp_auth_bytes *sctp_auth_create_key(__u32 key_len, gfp_t gfp)
75 struct sctp_auth_bytes *key;
77 /* Verify that we are not going to overflow INT_MAX */
78 if (key_len > (INT_MAX - sizeof(struct sctp_auth_bytes)))
81 /* Allocate the shared key */
82 key = kmalloc(sizeof(struct sctp_auth_bytes) + key_len, gfp);
87 atomic_set(&key->refcnt, 1);
88 SCTP_DBG_OBJCNT_INC(keys);
93 /* Create a new shared key container with a give key id */
94 struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp)
96 struct sctp_shared_key *new;
98 /* Allocate the shared key container */
99 new = kzalloc(sizeof(struct sctp_shared_key), gfp);
103 INIT_LIST_HEAD(&new->key_list);
104 new->key_id = key_id;
109 /* Free the shared key structure */
110 static void sctp_auth_shkey_free(struct sctp_shared_key *sh_key)
112 BUG_ON(!list_empty(&sh_key->key_list));
113 sctp_auth_key_put(sh_key->key);
118 /* Destroy the entire key list. This is done during the
119 * associon and endpoint free process.
121 void sctp_auth_destroy_keys(struct list_head *keys)
123 struct sctp_shared_key *ep_key;
124 struct sctp_shared_key *tmp;
126 if (list_empty(keys))
129 key_for_each_safe(ep_key, tmp, keys) {
130 list_del_init(&ep_key->key_list);
131 sctp_auth_shkey_free(ep_key);
135 /* Compare two byte vectors as numbers. Return values
137 * 0 - vectors are equal
138 * < 0 - vector 1 is smaller than vector2
139 * > 0 - vector 1 is greater than vector2
142 * This is performed by selecting the numerically smaller key vector...
143 * If the key vectors are equal as numbers but differ in length ...
144 * the shorter vector is considered smaller
146 * Examples (with small values):
147 * 000123456789 > 123456789 (first number is longer)
148 * 000123456789 < 234567891 (second number is larger numerically)
149 * 123456789 > 2345678 (first number is both larger & longer)
151 static int sctp_auth_compare_vectors(struct sctp_auth_bytes *vector1,
152 struct sctp_auth_bytes *vector2)
158 diff = vector1->len - vector2->len;
160 longer = (diff > 0) ? vector1->data : vector2->data;
162 /* Check to see if the longer number is
163 * lead-zero padded. If it is not, it
164 * is automatically larger numerically.
166 for (i = 0; i < abs(diff); i++ ) {
172 /* lengths are the same, compare numbers */
173 return memcmp(vector1->data, vector2->data, vector1->len);
177 * Create a key vector as described in SCTP-AUTH, Section 6.1
178 * The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO
179 * parameter sent by each endpoint are concatenated as byte vectors.
180 * These parameters include the parameter type, parameter length, and
181 * the parameter value, but padding is omitted; all padding MUST be
182 * removed from this concatenation before proceeding with further
183 * computation of keys. Parameters which were not sent are simply
184 * omitted from the concatenation process. The resulting two vectors
185 * are called the two key vectors.
187 static 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,
193 struct sctp_auth_bytes *new;
196 __u16 random_len, hmacs_len, chunks_len = 0;
198 random_len = ntohs(random->param_hdr.length);
199 hmacs_len = ntohs(hmacs->param_hdr.length);
201 chunks_len = ntohs(chunks->param_hdr.length);
203 len = random_len + hmacs_len + chunks_len;
205 new = sctp_auth_create_key(len, gfp);
209 memcpy(new->data, random, random_len);
210 offset += random_len;
213 memcpy(new->data + offset, chunks, chunks_len);
214 offset += chunks_len;
217 memcpy(new->data + offset, hmacs, hmacs_len);
223 /* Make a key vector based on our local parameters */
224 static struct sctp_auth_bytes *sctp_auth_make_local_vector(
225 const struct sctp_association *asoc,
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,
235 /* Make a key vector based on peer's parameters */
236 static struct sctp_auth_bytes *sctp_auth_make_peer_vector(
237 const struct sctp_association *asoc,
240 return sctp_auth_make_key_vector(asoc->peer.peer_random,
241 asoc->peer.peer_chunks,
242 asoc->peer.peer_hmacs,
247 /* Set the value of the association shared key base on the parameters
248 * given. The algorithm is:
249 * From the endpoint pair shared keys and the key vectors the
250 * association shared keys are computed. This is performed by selecting
251 * the numerically smaller key vector and concatenating it to the
252 * endpoint pair shared key, and then concatenating the numerically
253 * larger key vector to that. The result of the concatenation is the
254 * association shared key.
256 static 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,
262 struct sctp_auth_bytes *secret;
266 auth_len = first_vector->len + last_vector->len;
268 auth_len += ep_key->key->len;
270 secret = sctp_auth_create_key(auth_len, gfp);
275 memcpy(secret->data, ep_key->key->data, ep_key->key->len);
276 offset += ep_key->key->len;
279 memcpy(secret->data + offset, first_vector->data, first_vector->len);
280 offset += first_vector->len;
282 memcpy(secret->data + offset, last_vector->data, last_vector->len);
287 /* Create an association shared key. Follow the algorithm
288 * described in SCTP-AUTH, Section 6.1
290 static struct sctp_auth_bytes *sctp_auth_asoc_create_secret(
291 const struct sctp_association *asoc,
292 struct sctp_shared_key *ep_key,
295 struct sctp_auth_bytes *local_key_vector;
296 struct sctp_auth_bytes *peer_key_vector;
297 struct sctp_auth_bytes *first_vector,
299 struct sctp_auth_bytes *secret = NULL;
303 /* Now we need to build the key vectors
304 * SCTP-AUTH , Section 6.1
305 * The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO
306 * parameter sent by each endpoint are concatenated as byte vectors.
307 * These parameters include the parameter type, parameter length, and
308 * the parameter value, but padding is omitted; all padding MUST be
309 * removed from this concatenation before proceeding with further
310 * computation of keys. Parameters which were not sent are simply
311 * omitted from the concatenation process. The resulting two vectors
312 * are called the two key vectors.
315 local_key_vector = sctp_auth_make_local_vector(asoc, gfp);
316 peer_key_vector = sctp_auth_make_peer_vector(asoc, gfp);
318 if (!peer_key_vector || !local_key_vector)
321 /* Figure out the order in which the key_vectors will be
322 * added to the endpoint shared key.
323 * SCTP-AUTH, Section 6.1:
324 * This is performed by selecting the numerically smaller key
325 * vector and concatenating it to the endpoint pair shared
326 * key, and then concatenating the numerically larger key
327 * vector to that. If the key vectors are equal as numbers
328 * but differ in length, then the concatenation order is the
329 * endpoint shared key, followed by the shorter key vector,
330 * followed by the longer key vector. Otherwise, the key
331 * vectors are identical, and may be concatenated to the
332 * endpoint pair key in any order.
334 cmp = sctp_auth_compare_vectors(local_key_vector,
337 first_vector = local_key_vector;
338 last_vector = peer_key_vector;
340 first_vector = peer_key_vector;
341 last_vector = local_key_vector;
344 secret = sctp_auth_asoc_set_secret(ep_key, first_vector, last_vector,
347 sctp_auth_key_put(local_key_vector);
348 sctp_auth_key_put(peer_key_vector);
354 * Populate the association overlay list with the list
357 int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
358 struct sctp_association *asoc,
361 struct sctp_shared_key *sh_key;
362 struct sctp_shared_key *new;
364 BUG_ON(!list_empty(&asoc->endpoint_shared_keys));
366 key_for_each(sh_key, &ep->endpoint_shared_keys) {
367 new = sctp_auth_shkey_create(sh_key->key_id, gfp);
371 new->key = sh_key->key;
372 sctp_auth_key_hold(new->key);
373 list_add(&new->key_list, &asoc->endpoint_shared_keys);
379 sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
384 /* Public interface to creat the association shared key.
385 * See code above for the algorithm.
387 int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp)
389 struct net *net = sock_net(asoc->base.sk);
390 struct sctp_auth_bytes *secret;
391 struct sctp_shared_key *ep_key;
393 /* If we don't support AUTH, or peer is not capable
394 * we don't need to do anything.
396 if (!net->sctp.auth_enable || !asoc->peer.auth_capable)
399 /* If the key_id is non-zero and we couldn't find an
400 * endpoint pair shared key, we can't compute the
402 * For key_id 0, endpoint pair shared key is a NULL key.
404 ep_key = sctp_auth_get_shkey(asoc, asoc->active_key_id);
407 secret = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
411 sctp_auth_key_put(asoc->asoc_shared_key);
412 asoc->asoc_shared_key = secret;
418 /* Find the endpoint pair shared key based on the key_id */
419 struct sctp_shared_key *sctp_auth_get_shkey(
420 const struct sctp_association *asoc,
423 struct sctp_shared_key *key;
425 /* First search associations set of endpoint pair shared keys */
426 key_for_each(key, &asoc->endpoint_shared_keys) {
427 if (key->key_id == key_id)
435 * Initialize all the possible digest transforms that we can use. Right now
436 * now, the supported digests are SHA1 and SHA256. We do this here once
437 * because of the restrictiong that transforms may only be allocated in
438 * user context. This forces us to pre-allocated all possible transforms
439 * at the endpoint init time.
441 int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp)
443 struct net *net = sock_net(ep->base.sk);
444 struct crypto_hash *tfm = NULL;
447 /* if the transforms are already allocted, we are done */
448 if (!net->sctp.auth_enable) {
449 ep->auth_hmacs = NULL;
456 /* Allocated the array of pointers to transorms */
457 ep->auth_hmacs = kzalloc(
458 sizeof(struct crypto_hash *) * SCTP_AUTH_NUM_HMACS,
463 for (id = 0; id < SCTP_AUTH_NUM_HMACS; id++) {
465 /* See is we support the id. Supported IDs have name and
466 * length fields set, so that we can allocated and use
467 * them. We can safely just check for name, for without the
468 * name, we can't allocate the TFM.
470 if (!sctp_hmac_list[id].hmac_name)
473 /* If this TFM has been allocated, we are all set */
474 if (ep->auth_hmacs[id])
477 /* Allocate the ID */
478 tfm = crypto_alloc_hash(sctp_hmac_list[id].hmac_name, 0,
483 ep->auth_hmacs[id] = tfm;
489 /* Clean up any successful allocations */
490 sctp_auth_destroy_hmacs(ep->auth_hmacs);
494 /* Destroy the hmac tfm array */
495 void sctp_auth_destroy_hmacs(struct crypto_hash *auth_hmacs[])
502 for (i = 0; i < SCTP_AUTH_NUM_HMACS; i++)
505 crypto_free_hash(auth_hmacs[i]);
511 struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id)
513 return &sctp_hmac_list[hmac_id];
516 /* Get an hmac description information that we can use to build
519 struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc)
521 struct sctp_hmac_algo_param *hmacs;
526 /* If we have a default entry, use it */
527 if (asoc->default_hmac_id)
528 return &sctp_hmac_list[asoc->default_hmac_id];
530 /* Since we do not have a default entry, find the first entry
531 * we support and return that. Do not cache that id.
533 hmacs = asoc->peer.peer_hmacs;
537 n_elt = (ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t)) >> 1;
538 for (i = 0; i < n_elt; i++) {
539 id = ntohs(hmacs->hmac_ids[i]);
541 /* Check the id is in the supported range. And
542 * see if we support the id. Supported IDs have name and
543 * length fields set, so that we can allocate and use
544 * them. We can safely just check for name, for without the
545 * name, we can't allocate the TFM.
547 if (id > SCTP_AUTH_HMAC_ID_MAX ||
548 !sctp_hmac_list[id].hmac_name) {
559 return &sctp_hmac_list[id];
562 static int __sctp_auth_find_hmacid(__be16 *hmacs, int n_elts, __be16 hmac_id)
567 for (i = 0; i < n_elts; i++) {
568 if (hmac_id == hmacs[i]) {
577 /* See if the HMAC_ID is one that we claim as supported */
578 int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
581 struct sctp_hmac_algo_param *hmacs;
587 hmacs = (struct sctp_hmac_algo_param *)asoc->c.auth_hmacs;
588 n_elt = (ntohs(hmacs->param_hdr.length) - sizeof(sctp_paramhdr_t)) >> 1;
590 return __sctp_auth_find_hmacid(hmacs->hmac_ids, n_elt, hmac_id);
594 /* Cache the default HMAC id. This to follow this text from SCTP-AUTH:
596 * The receiver of a HMAC-ALGO parameter SHOULD use the first listed
597 * algorithm it supports.
599 void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
600 struct sctp_hmac_algo_param *hmacs)
602 struct sctp_endpoint *ep;
607 /* if the default id is already set, use it */
608 if (asoc->default_hmac_id)
611 n_params = (ntohs(hmacs->param_hdr.length)
612 - sizeof(sctp_paramhdr_t)) >> 1;
614 for (i = 0; i < n_params; i++) {
615 id = ntohs(hmacs->hmac_ids[i]);
617 /* Check the id is in the supported range */
618 if (id > SCTP_AUTH_HMAC_ID_MAX)
621 /* If this TFM has been allocated, use this id */
622 if (ep->auth_hmacs[id]) {
623 asoc->default_hmac_id = id;
630 /* Check to see if the given chunk is supposed to be authenticated */
631 static int __sctp_auth_cid(sctp_cid_t chunk, struct sctp_chunks_param *param)
637 if (!param || param->param_hdr.length == 0)
640 len = ntohs(param->param_hdr.length) - sizeof(sctp_paramhdr_t);
642 /* SCTP-AUTH, Section 3.2
643 * The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH
644 * chunks MUST NOT be listed in the CHUNKS parameter. However, if
645 * a CHUNKS parameter is received then the types for INIT, INIT-ACK,
646 * SHUTDOWN-COMPLETE and AUTH chunks MUST be ignored.
648 for (i = 0; !found && i < len; i++) {
649 switch (param->chunks[i]) {
651 case SCTP_CID_INIT_ACK:
652 case SCTP_CID_SHUTDOWN_COMPLETE:
657 if (param->chunks[i] == chunk)
666 /* Check if peer requested that this chunk is authenticated */
667 int sctp_auth_send_cid(sctp_cid_t chunk, const struct sctp_association *asoc)
673 net = sock_net(asoc->base.sk);
674 if (!net->sctp.auth_enable || !asoc->peer.auth_capable)
677 return __sctp_auth_cid(chunk, asoc->peer.peer_chunks);
680 /* Check if we requested that peer authenticate this chunk. */
681 int sctp_auth_recv_cid(sctp_cid_t chunk, const struct sctp_association *asoc)
687 net = sock_net(asoc->base.sk);
688 if (!net->sctp.auth_enable)
691 return __sctp_auth_cid(chunk,
692 (struct sctp_chunks_param *)asoc->c.auth_chunks);
695 /* SCTP-AUTH: Section 6.2:
696 * The sender MUST calculate the MAC as described in RFC2104 [2] using
697 * the hash function H as described by the MAC Identifier and the shared
698 * association key K based on the endpoint pair shared key described by
699 * the shared key identifier. The 'data' used for the computation of
700 * the AUTH-chunk is given by the AUTH chunk with its HMAC field set to
701 * zero (as shown in Figure 6) followed by all chunks that are placed
702 * after the AUTH chunk in the SCTP packet.
704 void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
706 struct sctp_auth_chunk *auth,
709 struct scatterlist sg;
710 struct hash_desc desc;
711 struct sctp_auth_bytes *asoc_key;
712 __u16 key_id, hmac_id;
717 /* Extract the info we need:
721 key_id = ntohs(auth->auth_hdr.shkey_id);
722 hmac_id = ntohs(auth->auth_hdr.hmac_id);
724 if (key_id == asoc->active_key_id)
725 asoc_key = asoc->asoc_shared_key;
727 struct sctp_shared_key *ep_key;
729 ep_key = sctp_auth_get_shkey(asoc, key_id);
733 asoc_key = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
740 /* set up scatter list */
741 end = skb_tail_pointer(skb);
742 sg_init_one(&sg, auth, end - (unsigned char *)auth);
744 desc.tfm = asoc->ep->auth_hmacs[hmac_id];
747 digest = auth->auth_hdr.hmac;
748 if (crypto_hash_setkey(desc.tfm, &asoc_key->data[0], asoc_key->len))
751 crypto_hash_digest(&desc, &sg, sg.length, digest);
755 sctp_auth_key_put(asoc_key);
760 /* Add a chunk to the endpoint authenticated chunk list */
761 int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id)
763 struct sctp_chunks_param *p = ep->auth_chunk_list;
767 /* If this chunk is already specified, we are done */
768 if (__sctp_auth_cid(chunk_id, p))
771 /* Check if we can add this chunk to the array */
772 param_len = ntohs(p->param_hdr.length);
773 nchunks = param_len - sizeof(sctp_paramhdr_t);
774 if (nchunks == SCTP_NUM_CHUNK_TYPES)
777 p->chunks[nchunks] = chunk_id;
778 p->param_hdr.length = htons(param_len + 1);
782 /* Add hmac identifires to the endpoint list of supported hmac ids */
783 int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep,
784 struct sctp_hmacalgo *hmacs)
790 /* Scan the list looking for unsupported id. Also make sure that
793 for (i = 0; i < hmacs->shmac_num_idents; i++) {
794 id = hmacs->shmac_idents[i];
796 if (id > SCTP_AUTH_HMAC_ID_MAX)
799 if (SCTP_AUTH_HMAC_ID_SHA1 == id)
802 if (!sctp_hmac_list[id].hmac_name)
809 memcpy(ep->auth_hmacs_list->hmac_ids, &hmacs->shmac_idents[0],
810 hmacs->shmac_num_idents * sizeof(__u16));
811 ep->auth_hmacs_list->param_hdr.length = htons(sizeof(sctp_paramhdr_t) +
812 hmacs->shmac_num_idents * sizeof(__u16));
816 /* Set a new shared key on either endpoint or association. If the
817 * the key with a same ID already exists, replace the key (remove the
818 * old key and add a new one).
820 int sctp_auth_set_key(struct sctp_endpoint *ep,
821 struct sctp_association *asoc,
822 struct sctp_authkey *auth_key)
824 struct sctp_shared_key *cur_key = NULL;
825 struct sctp_auth_bytes *key;
826 struct list_head *sh_keys;
829 /* Try to find the given key id to see if
830 * we are doing a replace, or adding a new key
833 sh_keys = &asoc->endpoint_shared_keys;
835 sh_keys = &ep->endpoint_shared_keys;
837 key_for_each(cur_key, sh_keys) {
838 if (cur_key->key_id == auth_key->sca_keynumber) {
844 /* If we are not replacing a key id, we need to allocate
848 cur_key = sctp_auth_shkey_create(auth_key->sca_keynumber,
854 /* Create a new key data based on the info passed in */
855 key = sctp_auth_create_key(auth_key->sca_keylength, GFP_KERNEL);
859 memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylength);
861 /* If we are replacing, remove the old keys data from the
862 * key id. If we are adding new key id, add it to the
866 sctp_auth_key_put(cur_key->key);
868 list_add(&cur_key->key_list, sh_keys);
871 sctp_auth_key_hold(key);
876 sctp_auth_shkey_free(cur_key);
881 int sctp_auth_set_active_key(struct sctp_endpoint *ep,
882 struct sctp_association *asoc,
885 struct sctp_shared_key *key;
886 struct list_head *sh_keys;
889 /* The key identifier MUST correst to an existing key */
891 sh_keys = &asoc->endpoint_shared_keys;
893 sh_keys = &ep->endpoint_shared_keys;
895 key_for_each(key, sh_keys) {
896 if (key->key_id == key_id) {
906 asoc->active_key_id = key_id;
907 sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL);
909 ep->active_key_id = key_id;
914 int sctp_auth_del_key_id(struct sctp_endpoint *ep,
915 struct sctp_association *asoc,
918 struct sctp_shared_key *key;
919 struct list_head *sh_keys;
922 /* The key identifier MUST NOT be the current active key
923 * The key identifier MUST correst to an existing key
926 if (asoc->active_key_id == key_id)
929 sh_keys = &asoc->endpoint_shared_keys;
931 if (ep->active_key_id == key_id)
934 sh_keys = &ep->endpoint_shared_keys;
937 key_for_each(key, sh_keys) {
938 if (key->key_id == key_id) {
947 /* Delete the shared key */
948 list_del_init(&key->key_list);
949 sctp_auth_shkey_free(key);