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 // SPDX-License-Identifier: GPL-2.0-or-later
 /* SCTP kernel implementation
  * (C) Copyright 2007 Hewlett-Packard Development Company, L.P.
  *
  * This file is part of the SCTP kernel implementation
  *
  * Please send any bug reports or fixes you make to the
  * email address(es):
  *    lksctp developers <linux-sctp@vger.kernel.org>
  *
  * Written or modified by:
  *   Vlad Yasevich     <vladislav.yasevich@hp.com>
  */
 
 #include <crypto/hash.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/scatterlist.h>
 #include <net/sctp/sctp.h>
 #include <net/sctp/auth.h>
 
 static struct sctp_hmac sctp_hmac_list[SCTP_AUTH_NUM_HMACS] = {
     {
         /* id 0 is reserved.  as all 0 */
         .hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_0,
     },
     {
         .hmac_id = SCTP_AUTH_HMAC_ID_SHA1,
         .hmac_name = "hmac(sha1)",
         .hmac_len = SCTP_SHA1_SIG_SIZE,
     },
     {
         /* id 2 is reserved as well */
         .hmac_id = SCTP_AUTH_HMAC_ID_RESERVED_2,
     },
 #if IS_ENABLED(CONFIG_CRYPTO_SHA256)
     {
         .hmac_id = SCTP_AUTH_HMAC_ID_SHA256,
         .hmac_name = "hmac(sha256)",
         .hmac_len = SCTP_SHA256_SIG_SIZE,
     }
 #endif
 };
 
 
 void sctp_auth_key_put(struct sctp_auth_bytes *key)
 {
     if (!key)
         return;
 
     if (refcount_dec_and_test(&key->refcnt)) {
         kfree_sensitive(key);
         SCTP_DBG_OBJCNT_DEC(keys);
     }
 }
 
 /* Create a new key structure of a given length */
 static struct sctp_auth_bytes *sctp_auth_create_key(__u32 key_len, gfp_t gfp)
 {
     struct sctp_auth_bytes *key;
 
     /* Verify that we are not going to overflow INT_MAX */
     if (key_len > (INT_MAX - sizeof(struct sctp_auth_bytes)))
         return NULL;
 
     /* Allocate the shared key */
     key = kmalloc(sizeof(struct sctp_auth_bytes) + key_len, gfp);
     if (!key)
         return NULL;
 
     key->len = key_len;
     refcount_set(&key->refcnt, 1);
     SCTP_DBG_OBJCNT_INC(keys);
 
     return key;
 }
 
 /* Create a new shared key container with a give key id */
 struct sctp_shared_key *sctp_auth_shkey_create(__u16 key_id, gfp_t gfp)
 {
     struct sctp_shared_key *new;
 
     /* Allocate the shared key container */
     new = kzalloc(sizeof(struct sctp_shared_key), gfp);
     if (!new)
         return NULL;
 
     INIT_LIST_HEAD(&new->key_list);
     refcount_set(&new->refcnt, 1);
     new->key_id = key_id;
 
     return new;
 }
 
 /* Free the shared key structure */
 static void sctp_auth_shkey_destroy(struct sctp_shared_key *sh_key)
 {
     BUG_ON(!list_empty(&sh_key->key_list));
     sctp_auth_key_put(sh_key->key);
     sh_key->key = NULL;
     kfree(sh_key);
 }
 
 void sctp_auth_shkey_release(struct sctp_shared_key *sh_key)
 {
     if (refcount_dec_and_test(&sh_key->refcnt))
         sctp_auth_shkey_destroy(sh_key);
 }
 
 void sctp_auth_shkey_hold(struct sctp_shared_key *sh_key)
 {
     refcount_inc(&sh_key->refcnt);
 }
 
 /* Destroy the entire key list.  This is done during the
  * associon and endpoint free process.
  */
 void sctp_auth_destroy_keys(struct list_head *keys)
 {
     struct sctp_shared_key *ep_key;
     struct sctp_shared_key *tmp;
 
     if (list_empty(keys))
         return;
 
     key_for_each_safe(ep_key, tmp, keys) {
         list_del_init(&ep_key->key_list);
         sctp_auth_shkey_release(ep_key);
     }
 }
 
 /* Compare two byte vectors as numbers.  Return values
  * are:
  *    0 - vectors are equal
  *  < 0 - vector 1 is smaller than vector2
  *  > 0 - vector 1 is greater than vector2
  *
  * Algorithm is:
  *  This is performed by selecting the numerically smaller key vector...
  *  If the key vectors are equal as numbers but differ in length ...
  *  the shorter vector is considered smaller
  *
  * Examples (with small values):
  *  000123456789 > 123456789 (first number is longer)
  *  000123456789 < 234567891 (second number is larger numerically)
  *  123456789 > 2345678      (first number is both larger & longer)
  */
 static int sctp_auth_compare_vectors(struct sctp_auth_bytes *vector1,
                   struct sctp_auth_bytes *vector2)
 {
     int diff;
     int i;
     const __u8 *longer;
 
     diff = vector1->len - vector2->len;
     if (diff) {
         longer = (diff > 0) ? vector1->data : vector2->data;
 
         /* Check to see if the longer number is
          * lead-zero padded.  If it is not, it
          * is automatically larger numerically.
          */
         for (i = 0; i < abs(diff); i++) {
             if (longer[i] != 0)
                 return diff;
         }
     }
 
     /* lengths are the same, compare numbers */
     return memcmp(vector1->data, vector2->data, vector1->len);
 }
 
 /*
  * Create a key vector as described in SCTP-AUTH, Section 6.1
  *    The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO
  *    parameter sent by each endpoint are concatenated as byte vectors.
  *    These parameters include the parameter type, parameter length, and
  *    the parameter value, but padding is omitted; all padding MUST be
  *    removed from this concatenation before proceeding with further
  *    computation of keys.  Parameters which were not sent are simply
  *    omitted from the concatenation process.  The resulting two vectors
  *    are called the two key vectors.
  */
 static struct sctp_auth_bytes *sctp_auth_make_key_vector(
             struct sctp_random_param *random,
             struct sctp_chunks_param *chunks,
             struct sctp_hmac_algo_param *hmacs,
             gfp_t gfp)
 {
     struct sctp_auth_bytes *new;
     __u32   len;
     __u32   offset = 0;
     __u16   random_len, hmacs_len, chunks_len = 0;
 
     random_len = ntohs(random->param_hdr.length);
     hmacs_len = ntohs(hmacs->param_hdr.length);
     if (chunks)
         chunks_len = ntohs(chunks->param_hdr.length);
 
     len = random_len + hmacs_len + chunks_len;
 
     new = sctp_auth_create_key(len, gfp);
     if (!new)
         return NULL;
 
     memcpy(new->data, random, random_len);
     offset += random_len;
 
     if (chunks) {
         memcpy(new->data + offset, chunks, chunks_len);
         offset += chunks_len;
     }
 
     memcpy(new->data + offset, hmacs, hmacs_len);
 
     return new;
 }
 
 
 /* Make a key vector based on our local parameters */
 static struct sctp_auth_bytes *sctp_auth_make_local_vector(
                     const struct sctp_association *asoc,
                     gfp_t gfp)
 {
     return sctp_auth_make_key_vector(
             (struct sctp_random_param *)asoc->c.auth_random,
             (struct sctp_chunks_param *)asoc->c.auth_chunks,
             (struct sctp_hmac_algo_param *)asoc->c.auth_hmacs, gfp);
 }
 
 /* Make a key vector based on peer's parameters */
 static struct sctp_auth_bytes *sctp_auth_make_peer_vector(
                     const struct sctp_association *asoc,
                     gfp_t gfp)
 {
     return sctp_auth_make_key_vector(asoc->peer.peer_random,
                      asoc->peer.peer_chunks,
                      asoc->peer.peer_hmacs,
                      gfp);
 }
 
 
 /* Set the value of the association shared key base on the parameters
  * given.  The algorithm is:
  *    From the endpoint pair shared keys and the key vectors the
  *    association shared keys are computed.  This is performed by selecting
  *    the numerically smaller key vector and concatenating it to the
  *    endpoint pair shared key, and then concatenating the numerically
  *    larger key vector to that.  The result of the concatenation is the
  *    association shared key.
  */
 static struct sctp_auth_bytes *sctp_auth_asoc_set_secret(
             struct sctp_shared_key *ep_key,
             struct sctp_auth_bytes *first_vector,
             struct sctp_auth_bytes *last_vector,
             gfp_t gfp)
 {
     struct sctp_auth_bytes *secret;
     __u32 offset = 0;
     __u32 auth_len;
 
     auth_len = first_vector->len + last_vector->len;
     if (ep_key->key)
         auth_len += ep_key->key->len;
 
     secret = sctp_auth_create_key(auth_len, gfp);
     if (!secret)
         return NULL;
 
     if (ep_key->key) {
         memcpy(secret->data, ep_key->key->data, ep_key->key->len);
         offset += ep_key->key->len;
     }
 
     memcpy(secret->data + offset, first_vector->data, first_vector->len);
     offset += first_vector->len;
 
     memcpy(secret->data + offset, last_vector->data, last_vector->len);
 
     return secret;
 }
 
 /* Create an association shared key.  Follow the algorithm
  * described in SCTP-AUTH, Section 6.1
  */
 static struct sctp_auth_bytes *sctp_auth_asoc_create_secret(
                  const struct sctp_association *asoc,
                  struct sctp_shared_key *ep_key,
                  gfp_t gfp)
 {
     struct sctp_auth_bytes *local_key_vector;
     struct sctp_auth_bytes *peer_key_vector;
     struct sctp_auth_bytes  *first_vector,
                 *last_vector;
     struct sctp_auth_bytes  *secret = NULL;
     int cmp;
 
 
     /* Now we need to build the key vectors
      * SCTP-AUTH , Section 6.1
      *    The RANDOM parameter, the CHUNKS parameter and the HMAC-ALGO
      *    parameter sent by each endpoint are concatenated as byte vectors.
      *    These parameters include the parameter type, parameter length, and
      *    the parameter value, but padding is omitted; all padding MUST be
      *    removed from this concatenation before proceeding with further
      *    computation of keys.  Parameters which were not sent are simply
      *    omitted from the concatenation process.  The resulting two vectors
      *    are called the two key vectors.
      */
 
     local_key_vector = sctp_auth_make_local_vector(asoc, gfp);
     peer_key_vector = sctp_auth_make_peer_vector(asoc, gfp);
 
     if (!peer_key_vector || !local_key_vector)
         goto out;
 
     /* Figure out the order in which the key_vectors will be
      * added to the endpoint shared key.
      * SCTP-AUTH, Section 6.1:
      *   This is performed by selecting the numerically smaller key
      *   vector and concatenating it to the endpoint pair shared
      *   key, and then concatenating the numerically larger key
      *   vector to that.  If the key vectors are equal as numbers
      *   but differ in length, then the concatenation order is the
      *   endpoint shared key, followed by the shorter key vector,
      *   followed by the longer key vector.  Otherwise, the key
      *   vectors are identical, and may be concatenated to the
      *   endpoint pair key in any order.
      */
     cmp = sctp_auth_compare_vectors(local_key_vector,
                     peer_key_vector);
     if (cmp < 0) {
         first_vector = local_key_vector;
         last_vector = peer_key_vector;
     } else {
         first_vector = peer_key_vector;
         last_vector = local_key_vector;
     }
 
     secret = sctp_auth_asoc_set_secret(ep_key, first_vector, last_vector,
                         gfp);
 out:
     sctp_auth_key_put(local_key_vector);
     sctp_auth_key_put(peer_key_vector);
 
     return secret;
 }
 
 /*
  * Populate the association overlay list with the list
  * from the endpoint.
  */
 int sctp_auth_asoc_copy_shkeys(const struct sctp_endpoint *ep,
                 struct sctp_association *asoc,
                 gfp_t gfp)
 {
     struct sctp_shared_key *sh_key;
     struct sctp_shared_key *new;
 
     BUG_ON(!list_empty(&asoc->endpoint_shared_keys));
 
     key_for_each(sh_key, &ep->endpoint_shared_keys) {
         new = sctp_auth_shkey_create(sh_key->key_id, gfp);
         if (!new)
             goto nomem;
 
         new->key = sh_key->key;
         sctp_auth_key_hold(new->key);
         list_add(&new->key_list, &asoc->endpoint_shared_keys);
     }
 
     return 0;
 
 nomem:
     sctp_auth_destroy_keys(&asoc->endpoint_shared_keys);
     return -ENOMEM;
 }
 
 
 /* Public interface to create the association shared key.
  * See code above for the algorithm.
  */
 int sctp_auth_asoc_init_active_key(struct sctp_association *asoc, gfp_t gfp)
 {
     struct sctp_auth_bytes  *secret;
     struct sctp_shared_key *ep_key;
     struct sctp_chunk *chunk;
 
     /* If we don't support AUTH, or peer is not capable
      * we don't need to do anything.
      */
     if (!asoc->peer.auth_capable)
         return 0;
 
     /* If the key_id is non-zero and we couldn't find an
      * endpoint pair shared key, we can't compute the
      * secret.
      * For key_id 0, endpoint pair shared key is a NULL key.
      */
     ep_key = sctp_auth_get_shkey(asoc, asoc->active_key_id);
     BUG_ON(!ep_key);
 
     secret = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
     if (!secret)
         return -ENOMEM;
 
     sctp_auth_key_put(asoc->asoc_shared_key);
     asoc->asoc_shared_key = secret;
     asoc->shkey = ep_key;
 
     /* Update send queue in case any chunk already in there now
      * needs authenticating
      */
     list_for_each_entry(chunk, &asoc->outqueue.out_chunk_list, list) {
         if (sctp_auth_send_cid(chunk->chunk_hdr->type, asoc)) {
             chunk->auth = 1;
             if (!chunk->shkey) {
                 chunk->shkey = asoc->shkey;
                 sctp_auth_shkey_hold(chunk->shkey);
             }
         }
     }
 
     return 0;
 }
 
 
 /* Find the endpoint pair shared key based on the key_id */
 struct sctp_shared_key *sctp_auth_get_shkey(
                 const struct sctp_association *asoc,
                 __u16 key_id)
 {
     struct sctp_shared_key *key;
 
     /* First search associations set of endpoint pair shared keys */
     key_for_each(key, &asoc->endpoint_shared_keys) {
         if (key->key_id == key_id) {
             if (!key->deactivated)
                 return key;
             break;
         }
     }
 
     return NULL;
 }
 
 /*
  * Initialize all the possible digest transforms that we can use.  Right
  * now, the supported digests are SHA1 and SHA256.  We do this here once
  * because of the restrictiong that transforms may only be allocated in
  * user context.  This forces us to pre-allocated all possible transforms
  * at the endpoint init time.
  */
 int sctp_auth_init_hmacs(struct sctp_endpoint *ep, gfp_t gfp)
 {
     struct crypto_shash *tfm = NULL;
     __u16   id;
 
     /* If the transforms are already allocated, we are done */
     if (ep->auth_hmacs)
         return 0;
 
     /* Allocated the array of pointers to transorms */
     ep->auth_hmacs = kcalloc(SCTP_AUTH_NUM_HMACS,
                  sizeof(struct crypto_shash *),
                  gfp);
     if (!ep->auth_hmacs)
         return -ENOMEM;
 
     for (id = 0; id < SCTP_AUTH_NUM_HMACS; id++) {
 
         /* See is we support the id.  Supported IDs have name and
          * length fields set, so that we can allocated and use
          * them.  We can safely just check for name, for without the
          * name, we can't allocate the TFM.
          */
         if (!sctp_hmac_list[id].hmac_name)
             continue;
 
         /* If this TFM has been allocated, we are all set */
         if (ep->auth_hmacs[id])
             continue;
 
         /* Allocate the ID */
         tfm = crypto_alloc_shash(sctp_hmac_list[id].hmac_name, 0, 0);
         if (IS_ERR(tfm))
             goto out_err;
 
         ep->auth_hmacs[id] = tfm;
     }
 
     return 0;
 
 out_err:
     /* Clean up any successful allocations */
     sctp_auth_destroy_hmacs(ep->auth_hmacs);
     ep->auth_hmacs = NULL;
     return -ENOMEM;
 }
 
 /* Destroy the hmac tfm array */
 void sctp_auth_destroy_hmacs(struct crypto_shash *auth_hmacs[])
 {
     int i;
 
     if (!auth_hmacs)
         return;
 
     for (i = 0; i < SCTP_AUTH_NUM_HMACS; i++) {
         crypto_free_shash(auth_hmacs[i]);
     }
     kfree(auth_hmacs);
 }
 
 
 struct sctp_hmac *sctp_auth_get_hmac(__u16 hmac_id)
 {
     return &sctp_hmac_list[hmac_id];
 }
 
 /* Get an hmac description information that we can use to build
  * the AUTH chunk
  */
 struct sctp_hmac *sctp_auth_asoc_get_hmac(const struct sctp_association *asoc)
 {
     struct sctp_hmac_algo_param *hmacs;
     __u16 n_elt;
     __u16 id = 0;
     int i;
 
     /* If we have a default entry, use it */
     if (asoc->default_hmac_id)
         return &sctp_hmac_list[asoc->default_hmac_id];
 
     /* Since we do not have a default entry, find the first entry
      * we support and return that.  Do not cache that id.
      */
     hmacs = asoc->peer.peer_hmacs;
     if (!hmacs)
         return NULL;
 
     n_elt = (ntohs(hmacs->param_hdr.length) -
          sizeof(struct sctp_paramhdr)) >> 1;
     for (i = 0; i < n_elt; i++) {
         id = ntohs(hmacs->hmac_ids[i]);
 
         /* Check the id is in the supported range. And
          * see if we support the id.  Supported IDs have name and
          * length fields set, so that we can allocate and use
          * them.  We can safely just check for name, for without the
          * name, we can't allocate the TFM.
          */
         if (id > SCTP_AUTH_HMAC_ID_MAX ||
             !sctp_hmac_list[id].hmac_name) {
             id = 0;
             continue;
         }
 
         break;
     }
 
     if (id == 0)
         return NULL;
 
     return &sctp_hmac_list[id];
 }
 
 static int __sctp_auth_find_hmacid(__be16 *hmacs, int n_elts, __be16 hmac_id)
 {
     int  found = 0;
     int  i;
 
     for (i = 0; i < n_elts; i++) {
         if (hmac_id == hmacs[i]) {
             found = 1;
             break;
         }
     }
 
     return found;
 }
 
 /* See if the HMAC_ID is one that we claim as supported */
 int sctp_auth_asoc_verify_hmac_id(const struct sctp_association *asoc,
                     __be16 hmac_id)
 {
     struct sctp_hmac_algo_param *hmacs;
     __u16 n_elt;
 
     if (!asoc)
         return 0;
 
     hmacs = (struct sctp_hmac_algo_param *)asoc->c.auth_hmacs;
     n_elt = (ntohs(hmacs->param_hdr.length) -
          sizeof(struct sctp_paramhdr)) >> 1;
 
     return __sctp_auth_find_hmacid(hmacs->hmac_ids, n_elt, hmac_id);
 }
 
 
 /* Cache the default HMAC id.  This to follow this text from SCTP-AUTH:
  * Section 6.1:
  *   The receiver of a HMAC-ALGO parameter SHOULD use the first listed
  *   algorithm it supports.
  */
 void sctp_auth_asoc_set_default_hmac(struct sctp_association *asoc,
                      struct sctp_hmac_algo_param *hmacs)
 {
     struct sctp_endpoint *ep;
     __u16   id;
     int i;
     int n_params;
 
     /* if the default id is already set, use it */
     if (asoc->default_hmac_id)
         return;
 
     n_params = (ntohs(hmacs->param_hdr.length) -
             sizeof(struct sctp_paramhdr)) >> 1;
     ep = asoc->ep;
     for (i = 0; i < n_params; i++) {
         id = ntohs(hmacs->hmac_ids[i]);
 
         /* Check the id is in the supported range */
         if (id > SCTP_AUTH_HMAC_ID_MAX)
             continue;
 
         /* If this TFM has been allocated, use this id */
         if (ep->auth_hmacs[id]) {
             asoc->default_hmac_id = id;
             break;
         }
     }
 }
 
 
 /* Check to see if the given chunk is supposed to be authenticated */
 static int __sctp_auth_cid(enum sctp_cid chunk, struct sctp_chunks_param *param)
 {
     unsigned short len;
     int found = 0;
     int i;
 
     if (!param || param->param_hdr.length == 0)
         return 0;
 
     len = ntohs(param->param_hdr.length) - sizeof(struct sctp_paramhdr);
 
     /* SCTP-AUTH, Section 3.2
      *    The chunk types for INIT, INIT-ACK, SHUTDOWN-COMPLETE and AUTH
      *    chunks MUST NOT be listed in the CHUNKS parameter.  However, if
      *    a CHUNKS parameter is received then the types for INIT, INIT-ACK,
      *    SHUTDOWN-COMPLETE and AUTH chunks MUST be ignored.
      */
     for (i = 0; !found && i < len; i++) {
         switch (param->chunks[i]) {
         case SCTP_CID_INIT:
         case SCTP_CID_INIT_ACK:
         case SCTP_CID_SHUTDOWN_COMPLETE:
         case SCTP_CID_AUTH:
             break;
 
         default:
             if (param->chunks[i] == chunk)
                 found = 1;
             break;
         }
     }
 
     return found;
 }
 
 /* Check if peer requested that this chunk is authenticated */
 int sctp_auth_send_cid(enum sctp_cid chunk, const struct sctp_association *asoc)
 {
     if (!asoc)
         return 0;
 
     if (!asoc->peer.auth_capable)
         return 0;
 
     return __sctp_auth_cid(chunk, asoc->peer.peer_chunks);
 }
 
 /* Check if we requested that peer authenticate this chunk. */
 int sctp_auth_recv_cid(enum sctp_cid chunk, const struct sctp_association *asoc)
 {
     if (!asoc)
         return 0;
 
     if (!asoc->peer.auth_capable)
         return 0;
 
     return __sctp_auth_cid(chunk,
                   (struct sctp_chunks_param *)asoc->c.auth_chunks);
 }
 
 /* SCTP-AUTH: Section 6.2:
  *    The sender MUST calculate the MAC as described in RFC2104 [2] using
  *    the hash function H as described by the MAC Identifier and the shared
  *    association key K based on the endpoint pair shared key described by
  *    the shared key identifier.  The 'data' used for the computation of
  *    the AUTH-chunk is given by the AUTH chunk with its HMAC field set to
  *    zero (as shown in Figure 6) followed by all chunks that are placed
  *    after the AUTH chunk in the SCTP packet.
  */
 void sctp_auth_calculate_hmac(const struct sctp_association *asoc,
                   struct sk_buff *skb, struct sctp_auth_chunk *auth,
                   struct sctp_shared_key *ep_key, gfp_t gfp)
 {
     struct sctp_auth_bytes *asoc_key;
     struct crypto_shash *tfm;
     __u16 key_id, hmac_id;
     unsigned char *end;
     int free_key = 0;
     __u8 *digest;
 
     /* Extract the info we need:
      * - hmac id
      * - key id
      */
     key_id = ntohs(auth->auth_hdr.shkey_id);
     hmac_id = ntohs(auth->auth_hdr.hmac_id);
 
     if (key_id == asoc->active_key_id)
         asoc_key = asoc->asoc_shared_key;
     else {
         /* ep_key can't be NULL here */
         asoc_key = sctp_auth_asoc_create_secret(asoc, ep_key, gfp);
         if (!asoc_key)
             return;
 
         free_key = 1;
     }
 
     /* set up scatter list */
     end = skb_tail_pointer(skb);
 
     tfm = asoc->ep->auth_hmacs[hmac_id];
 
     digest = auth->auth_hdr.hmac;
     if (crypto_shash_setkey(tfm, &asoc_key->data[0], asoc_key->len))
         goto free;
 
     crypto_shash_tfm_digest(tfm, (u8 *)auth, end - (unsigned char *)auth,
                 digest);
 
 free:
     if (free_key)
         sctp_auth_key_put(asoc_key);
 }
 
 /* API Helpers */
 
 /* Add a chunk to the endpoint authenticated chunk list */
 int sctp_auth_ep_add_chunkid(struct sctp_endpoint *ep, __u8 chunk_id)
 {
     struct sctp_chunks_param *p = ep->auth_chunk_list;
     __u16 nchunks;
     __u16 param_len;
 
     /* If this chunk is already specified, we are done */
     if (__sctp_auth_cid(chunk_id, p))
         return 0;
 
     /* Check if we can add this chunk to the array */
     param_len = ntohs(p->param_hdr.length);
     nchunks = param_len - sizeof(struct sctp_paramhdr);
     if (nchunks == SCTP_NUM_CHUNK_TYPES)
         return -EINVAL;
 
     p->chunks[nchunks] = chunk_id;
     p->param_hdr.length = htons(param_len + 1);
     return 0;
 }
 
 /* Add hmac identifires to the endpoint list of supported hmac ids */
 int sctp_auth_ep_set_hmacs(struct sctp_endpoint *ep,
                struct sctp_hmacalgo *hmacs)
 {
     int has_sha1 = 0;
     __u16 id;
     int i;
 
     /* Scan the list looking for unsupported id.  Also make sure that
      * SHA1 is specified.
      */
     for (i = 0; i < hmacs->shmac_num_idents; i++) {
         id = hmacs->shmac_idents[i];
 
         if (id > SCTP_AUTH_HMAC_ID_MAX)
             return -EOPNOTSUPP;
 
         if (SCTP_AUTH_HMAC_ID_SHA1 == id)
             has_sha1 = 1;
 
         if (!sctp_hmac_list[id].hmac_name)
             return -EOPNOTSUPP;
     }
 
     if (!has_sha1)
         return -EINVAL;
 
     for (i = 0; i < hmacs->shmac_num_idents; i++)
         ep->auth_hmacs_list->hmac_ids[i] =
                 htons(hmacs->shmac_idents[i]);
     ep->auth_hmacs_list->param_hdr.length =
             htons(sizeof(struct sctp_paramhdr) +
             hmacs->shmac_num_idents * sizeof(__u16));
     return 0;
 }
 
 /* Set a new shared key on either endpoint or association.  If the
  * key with a same ID already exists, replace the key (remove the
  * old key and add a new one).
  */
 int sctp_auth_set_key(struct sctp_endpoint *ep,
               struct sctp_association *asoc,
               struct sctp_authkey *auth_key)
 {
     struct sctp_shared_key *cur_key, *shkey;
     struct sctp_auth_bytes *key;
     struct list_head *sh_keys;
     int replace = 0;
 
     /* Try to find the given key id to see if
      * we are doing a replace, or adding a new key
      */
     if (asoc) {
         if (!asoc->peer.auth_capable)
             return -EACCES;
         sh_keys = &asoc->endpoint_shared_keys;
     } else {
         if (!ep->auth_enable)
             return -EACCES;
         sh_keys = &ep->endpoint_shared_keys;
     }
 
     key_for_each(shkey, sh_keys) {
         if (shkey->key_id == auth_key->sca_keynumber) {
             replace = 1;
             break;
         }
     }
 
     cur_key = sctp_auth_shkey_create(auth_key->sca_keynumber, GFP_KERNEL);
     if (!cur_key)
         return -ENOMEM;
 
     /* Create a new key data based on the info passed in */
     key = sctp_auth_create_key(auth_key->sca_keylength, GFP_KERNEL);
     if (!key) {
         kfree(cur_key);
         return -ENOMEM;
     }
 
     memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylength);
     cur_key->key = key;
 
     if (!replace) {
         list_add(&cur_key->key_list, sh_keys);
         return 0;
     }
 
     list_del_init(&shkey->key_list);
     sctp_auth_shkey_release(shkey);
     list_add(&cur_key->key_list, sh_keys);
 
     if (asoc && asoc->active_key_id == auth_key->sca_keynumber)
         sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL);
 
     return 0;
 }
 
 int sctp_auth_set_active_key(struct sctp_endpoint *ep,
                  struct sctp_association *asoc,
                  __u16  key_id)
 {
     struct sctp_shared_key *key;
     struct list_head *sh_keys;
     int found = 0;
 
     /* The key identifier MUST correst to an existing key */
     if (asoc) {
         if (!asoc->peer.auth_capable)
             return -EACCES;
         sh_keys = &asoc->endpoint_shared_keys;
     } else {
         if (!ep->auth_enable)
             return -EACCES;
         sh_keys = &ep->endpoint_shared_keys;
     }
 
     key_for_each(key, sh_keys) {
         if (key->key_id == key_id) {
             found = 1;
             break;
         }
     }
 
     if (!found || key->deactivated)
         return -EINVAL;
 
     if (asoc) {
         asoc->active_key_id = key_id;
         sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL);
     } else
         ep->active_key_id = key_id;
 
     return 0;
 }
 
 int sctp_auth_del_key_id(struct sctp_endpoint *ep,
              struct sctp_association *asoc,
              __u16  key_id)
 {
     struct sctp_shared_key *key;
     struct list_head *sh_keys;
     int found = 0;
 
     /* The key identifier MUST NOT be the current active key
      * The key identifier MUST correst to an existing key
      */
     if (asoc) {
         if (!asoc->peer.auth_capable)
             return -EACCES;
         if (asoc->active_key_id == key_id)
             return -EINVAL;
 
         sh_keys = &asoc->endpoint_shared_keys;
     } else {
         if (!ep->auth_enable)
             return -EACCES;
         if (ep->active_key_id == key_id)
             return -EINVAL;
 
         sh_keys = &ep->endpoint_shared_keys;
     }
 
     key_for_each(key, sh_keys) {
         if (key->key_id == key_id) {
             found = 1;
             break;
         }
     }
 
     if (!found)
         return -EINVAL;
 
     /* Delete the shared key */
     list_del_init(&key->key_list);
     sctp_auth_shkey_release(key);
 
     return 0;
 }
 
 int sctp_auth_deact_key_id(struct sctp_endpoint *ep,
                struct sctp_association *asoc, __u16  key_id)
 {
     struct sctp_shared_key *key;
     struct list_head *sh_keys;
     int found = 0;
 
     /* The key identifier MUST NOT be the current active key
      * The key identifier MUST correst to an existing key
      */
     if (asoc) {
         if (!asoc->peer.auth_capable)
             return -EACCES;
         if (asoc->active_key_id == key_id)
             return -EINVAL;
 
         sh_keys = &asoc->endpoint_shared_keys;
     } else {
         if (!ep->auth_enable)
             return -EACCES;
         if (ep->active_key_id == key_id)
             return -EINVAL;
 
         sh_keys = &ep->endpoint_shared_keys;
     }
 
     key_for_each(key, sh_keys) {
         if (key->key_id == key_id) {
             found = 1;
             break;
         }
     }
 
     if (!found)
         return -EINVAL;
 
     /* refcnt == 1 and !list_empty mean it's not being used anywhere
      * and deactivated will be set, so it's time to notify userland
      * that this shkey can be freed.
      */
     if (asoc && !list_empty(&key->key_list) &&
         refcount_read(&key->refcnt) == 1) {
         struct sctp_ulpevent *ev;
 
         ev = sctp_ulpevent_make_authkey(asoc, key->key_id,
                         SCTP_AUTH_FREE_KEY, GFP_KERNEL);
         if (ev)
             asoc->stream.si->enqueue_event(&asoc->ulpq, ev);
     }
 
     key->deactivated = 1;
 
     return 0;
 }
 
 int sctp_auth_init(struct sctp_endpoint *ep, gfp_t gfp)
 {
     int err = -ENOMEM;
 
     /* Allocate space for HMACS and CHUNKS authentication
      * variables.  There are arrays that we encode directly
      * into parameters to make the rest of the operations easier.
      */
     if (!ep->auth_hmacs_list) {
         struct sctp_hmac_algo_param *auth_hmacs;
 
         auth_hmacs = kzalloc(struct_size(auth_hmacs, hmac_ids,
                          SCTP_AUTH_NUM_HMACS), gfp);
         if (!auth_hmacs)
             goto nomem;
         /* Initialize the HMACS parameter.
          * SCTP-AUTH: Section 3.3
          *    Every endpoint supporting SCTP chunk authentication MUST
          *    support the HMAC based on the SHA-1 algorithm.
          */
         auth_hmacs->param_hdr.type = SCTP_PARAM_HMAC_ALGO;
         auth_hmacs->param_hdr.length =
                 htons(sizeof(struct sctp_paramhdr) + 2);
         auth_hmacs->hmac_ids[0] = htons(SCTP_AUTH_HMAC_ID_SHA1);
         ep->auth_hmacs_list = auth_hmacs;
     }
 
     if (!ep->auth_chunk_list) {
         struct sctp_chunks_param *auth_chunks;
 
         auth_chunks = kzalloc(sizeof(*auth_chunks) +
                       SCTP_NUM_CHUNK_TYPES, gfp);
         if (!auth_chunks)
             goto nomem;
         /* Initialize the CHUNKS parameter */
         auth_chunks->param_hdr.type = SCTP_PARAM_CHUNKS;
         auth_chunks->param_hdr.length =
                 htons(sizeof(struct sctp_paramhdr));
         ep->auth_chunk_list = auth_chunks;
     }
 
     /* Allocate and initialize transorms arrays for supported
      * HMACs.
      */
     err = sctp_auth_init_hmacs(ep, gfp);
     if (err)
         goto nomem;
 
     return 0;
 
 nomem:
     /* Free all allocations */
     kfree(ep->auth_hmacs_list);
     kfree(ep->auth_chunk_list);
     ep->auth_hmacs_list = NULL;
     ep->auth_chunk_list = NULL;
     return err;
 }
 
 void sctp_auth_free(struct sctp_endpoint *ep)
 {
     kfree(ep->auth_hmacs_list);
     kfree(ep->auth_chunk_list);
     ep->auth_hmacs_list = NULL;
     ep->auth_chunk_list = NULL;
     sctp_auth_destroy_hmacs(ep->auth_hmacs);
     ep->auth_hmacs = NULL;
 }

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