| // 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_del_init(&shkey->key_list); |
| sctp_auth_shkey_release(shkey); |
| if (asoc && asoc->active_key_id == auth_key->sca_keynumber) |
| sctp_auth_asoc_init_active_key(asoc, GFP_KERNEL); |
| } |
| list_add(&cur_key->key_list, sh_keys); |
| |
| 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; |
| } |