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-rw-r--r--net/sctp/auth.c953
1 files changed, 953 insertions, 0 deletions
diff --git a/net/sctp/auth.c b/net/sctp/auth.c
new file mode 100644
index 000000000..4f15b7d73
--- /dev/null
+++ b/net/sctp/auth.c
@@ -0,0 +1,953 @@
+/* SCTP kernel implementation
+ * (C) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ *
+ * This file is part of the SCTP kernel implementation
+ *
+ * This SCTP 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.
+ *
+ * This SCTP 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, see
+ * <http://www.gnu.org/licenses/>.
+ *
+ * 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 <linux/slab.h>
+#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,
+ },
+#if defined (CONFIG_CRYPTO_SHA256) || defined (CONFIG_CRYPTO_SHA256_MODULE)
+ {
+ .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 (atomic_dec_and_test(&key->refcnt)) {
+ kzfree(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;
+ 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 structure */
+static 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);
+}
+
+/* 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_free(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(
+ 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;
+ __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(
+ (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 */
+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->ep->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;
+
+ /* 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;
+ }
+
+ 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)
+ return key;
+ }
+
+ return NULL;
+}
+
+/*
+ * 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 AUTH extension is disabled, we are done */
+ if (!ep->auth_enable) {
+ ep->auth_hmacs = NULL;
+ return 0;
+ }
+
+ /* 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 = 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 successful 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. 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(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 || param->param_hdr.length == 0)
+ 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 (!asoc)
+ return 0;
+
+ if (!asoc->ep->auth_enable || !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 (!asoc)
+ return 0;
+
+ if (!asoc->ep->auth_enable)
+ 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_one(&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 (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;
+
+ 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_keylength, GFP_KERNEL);
+ if (!key)
+ goto nomem;
+
+ memcpy(key->data, &auth_key->sca_key[0], auth_key->sca_keylength);
+
+ /* 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;
+ 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;
+}
generated by cgit v1.2.3-54-g00ecf (git 2.45.2) at 2024-11-19 03:52:45 +0000