| /* SCTP kernel reference Implementation |
| * (C) Copyright 2007 Hewlett-Packard Development Company, L.P. |
| * |
| * This file is part of the SCTP kernel reference Implementation |
| * |
| * The SCTP reference implementation is free software; |
| * you can redistribute it and/or modify it under the terms of |
| * the GNU General Public License as published by |
| * the Free Software Foundation; either version 2, or (at your option) |
| * any later version. |
| * |
| * The SCTP reference implementation is distributed in the hope that it |
| * will be useful, but WITHOUT ANY WARRANTY; without even the implied |
| * ************************ |
| * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. |
| * See the GNU General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public License |
| * along with GNU CC; see the file COPYING. If not, write to |
| * the Free Software Foundation, 59 Temple Place - Suite 330, |
| * Boston, MA 02111-1307, USA. |
| * |
| * Please send any bug reports or fixes you make to the |
| * email address(es): |
| * lksctp developers <lksctp-developers@lists.sourceforge.net> |
| * |
| * Or submit a bug report through the following website: |
| * http://www.sf.net/projects/lksctp |
| * |
| * Written or modified by: |
| * Vlad Yasevich <vladislav.yasevich@hp.com> |
| * |
| * Any bugs reported given to us we will try to fix... any fixes shared will |
| * be incorporated into the next SCTP release. |
| */ |
| |
| #include <linux/types.h> |
| #include <linux/crypto.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, |
| }, |
| { |
| .hmac_id = SCTP_AUTH_HMAC_ID_SHA256, |
| .hmac_name="hmac(sha256)", |
| .hmac_len = SCTP_SHA256_SIG_SIZE, |
| } |
| }; |
| |
| |
| void sctp_auth_key_put(struct sctp_auth_bytes *key) |
| { |
| if (!key) |
| return; |
| |
| if (atomic_dec_and_test(&key->refcnt)) { |
| kfree(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; |
| |
| /* Allocate the shared key */ |
| key = kmalloc(sizeof(struct sctp_auth_bytes) + key_len, gfp); |
| if (!key) |
| return NULL; |
| |
| key->len = key_len; |
| atomic_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); |
| new->key_id = key_id; |
| |
| return new; |
| } |
| |
| /* Free the shared key stucture */ |
| void sctp_auth_shkey_free(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); |
| } |
| |
| /* Destory 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_free(ep_key); |
| } |
| } |
| |
| /* Compare two byte vectors as numbers. Return values |
| * are: |
| * 0 - vectors are equal |
| * < 0 - vector 1 is smaller then vector2 |
| * > 0 - vector 1 is greater then 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( |
| sctp_random_param_t *random, |
| sctp_chunks_param_t *chunks, |
| sctp_hmac_algo_param_t *hmacs, |
| gfp_t gfp) |
| { |
| struct sctp_auth_bytes *new; |
| __u32 len; |
| __u32 offset = 0; |
| |
| len = ntohs(random->param_hdr.length) + ntohs(hmacs->param_hdr.length); |
| if (chunks) |
| len += ntohs(chunks->param_hdr.length); |
| |
| new = kmalloc(sizeof(struct sctp_auth_bytes) + len, gfp); |
| if (!new) |
| return NULL; |
| |
| new->len = len; |
| |
| memcpy(new->data, random, ntohs(random->param_hdr.length)); |
| offset += ntohs(random->param_hdr.length); |
| |
| if (chunks) { |
| memcpy(new->data + offset, chunks, |
| ntohs(chunks->param_hdr.length)); |
| offset += ntohs(chunks->param_hdr.length); |
| } |
| |
| memcpy(new->data + offset, hmacs, ntohs(hmacs->param_hdr.length)); |
| |
| return new; |
| } |
| |
| |
| /* Make a key vector based on our local parameters */ |
| struct sctp_auth_bytes *sctp_auth_make_local_vector( |
| const struct sctp_association *asoc, |
| gfp_t gfp) |
| { |
| return sctp_auth_make_key_vector( |
| (sctp_random_param_t*)asoc->c.auth_random, |
| (sctp_chunks_param_t*)asoc->c.auth_chunks, |
| (sctp_hmac_algo_param_t*)asoc->c.auth_hmacs, |
| gfp); |
| } |
| |
| /* Make a key vector based on peer's parameters */ |
| 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 wich 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: |
| kfree(local_key_vector); |
| kfree(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 creat 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; |
| |
| /* If we don't support AUTH, or peer is not capable |
| * we don't need to do anything. |
| */ |
| if (!sctp_auth_enable || !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; |
| |
| 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 = NULL; |
| |
| /* First search associations set of endpoint pair shared keys */ |
| key_for_each(key, &asoc->endpoint_shared_keys) { |
| if (key->key_id == key_id) |
| break; |
| } |
| |
| return key; |
| } |
| |
| /* |
| * Initialize all the possible digest transforms that we can use. Right now |
| * 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_hash *tfm = NULL; |
| __u16 id; |
| |
| /* if the transforms are already allocted, we are done */ |
| if (!sctp_auth_enable) { |
| ep->auth_hmacs = NULL; |
| return 0; |
| } |
| |
| if (ep->auth_hmacs) |
| return 0; |
| |
| /* Allocated the array of pointers to transorms */ |
| ep->auth_hmacs = kzalloc( |
| sizeof(struct crypto_hash *) * SCTP_AUTH_NUM_HMACS, |
| 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_hash(sctp_hmac_list[id].hmac_name, 0, |
| CRYPTO_ALG_ASYNC); |
| if (IS_ERR(tfm)) |
| goto out_err; |
| |
| ep->auth_hmacs[id] = tfm; |
| } |
| |
| return 0; |
| |
| out_err: |
| /* Clean up any successfull allocations */ |
| sctp_auth_destroy_hmacs(ep->auth_hmacs); |
| return -ENOMEM; |
| } |
| |
| /* Destroy the hmac tfm array */ |
| void sctp_auth_destroy_hmacs(struct crypto_hash *auth_hmacs[]) |
| { |
| int i; |
| |
| if (!auth_hmacs) |
| return; |
| |
| for (i = 0; i < SCTP_AUTH_NUM_HMACS; i++) |
| { |
| if (auth_hmacs[i]) |
| crypto_free_hash(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(sctp_paramhdr_t)) >> 1; |
| for (i = 0; i < n_elt; i++) { |
| id = ntohs(hmacs->hmac_ids[i]); |
| |
| /* Check the id is in the supported range */ |
| if (id > SCTP_AUTH_HMAC_ID_MAX) |
| continue; |
| |
| /* 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; |
| |
| break; |
| } |
| |
| if (id == 0) |
| return NULL; |
| |
| return &sctp_hmac_list[id]; |
| } |
| |
| static int __sctp_auth_find_hmacid(__u16 *hmacs, int n_elts, __u16 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, |
| __u16 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(sctp_paramhdr_t)) >> 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(sctp_paramhdr_t)) >> 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(sctp_cid_t chunk, struct sctp_chunks_param *param) |
| { |
| unsigned short len; |
| int found = 0; |
| int i; |
| |
| if (!param) |
| return 0; |
| |
| len = ntohs(param->param_hdr.length) - sizeof(sctp_paramhdr_t); |
| |
| /* 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(sctp_cid_t chunk, const struct sctp_association *asoc) |
| { |
| if (!sctp_auth_enable || !asoc || !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(sctp_cid_t chunk, const struct sctp_association *asoc) |
| { |
| if (!sctp_auth_enable || !asoc) |
| 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, |
| gfp_t gfp) |
| { |
| struct scatterlist sg; |
| struct hash_desc desc; |
| struct sctp_auth_bytes *asoc_key; |
| __u16 key_id, hmac_id; |
| __u8 *digest; |
| unsigned char *end; |
| int free_key = 0; |
| |
| /* 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 { |
| struct sctp_shared_key *ep_key; |
| |
| ep_key = sctp_auth_get_shkey(asoc, key_id); |
| if (!ep_key) |
| return; |
| |
| 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); |
| sg_init_table(&sg, 1); |
| sg_set_buf(&sg, auth, end - (unsigned char *)auth); |
| |
| desc.tfm = asoc->ep->auth_hmacs[hmac_id]; |
| desc.flags = 0; |
| |
| digest = auth->auth_hdr.hmac; |
| if (crypto_hash_setkey(desc.tfm, &asoc_key->data[0], asoc_key->len)) |
| goto free; |
| |
| crypto_hash_digest(&desc, &sg, sg.length, 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(sctp_paramhdr_t); |
| 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 (SCTP_AUTH_HMAC_ID_SHA1 == id) |
| has_sha1 = 1; |
| |
| if (!sctp_hmac_list[id].hmac_name) |
| return -EOPNOTSUPP; |
| } |
| |
| if (!has_sha1) |
| return -EINVAL; |
| |
| memcpy(ep->auth_hmacs_list->hmac_ids, &hmacs->shmac_idents[0], |
| hmacs->shmac_num_idents * sizeof(__u16)); |
| ep->auth_hmacs_list->param_hdr.length = htons(sizeof(sctp_paramhdr_t) + |
| hmacs->shmac_num_idents * sizeof(__u16)); |
| return 0; |
| } |
| |
| /* Set a new shared key on either endpoint or association. If the |
| * 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 = NULL; |
| 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) |
| sh_keys = &asoc->endpoint_shared_keys; |
| else |
| sh_keys = &ep->endpoint_shared_keys; |
| |
| key_for_each(cur_key, sh_keys) { |
| if (cur_key->key_id == auth_key->sca_keynumber) { |
| replace = 1; |
| break; |
| } |
| } |
| |
| /* If we are not replacing a key id, we need to allocate |
| * a shared key. |
| */ |
| if (!replace) { |
| 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_keylen, GFP_KERNEL); |
| if (!key) |
| goto nomem; |
| |
| memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylen); |
| |
| /* If we are replacing, remove the old keys data from the |
| * key id. If we are adding new key id, add it to the |
| * list. |
| */ |
| if (replace) |
| sctp_auth_key_put(cur_key->key); |
| else |
| list_add(&cur_key->key_list, sh_keys); |
| |
| cur_key->key = key; |
| sctp_auth_key_hold(key); |
| |
| return 0; |
| nomem: |
| if (!replace) |
| sctp_auth_shkey_free(cur_key); |
| |
| return -ENOMEM; |
| } |
| |
| 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) |
| sh_keys = &asoc->endpoint_shared_keys; |
| else |
| 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; |
| |
| 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->active_key_id == key_id) |
| return -EINVAL; |
| |
| sh_keys = &asoc->endpoint_shared_keys; |
| } else { |
| 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_free(key); |
| |
| return 0; |
| } |