sctp_auth.c

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    1 /*-
    2  * SPDX-License-Identifier: BSD-3-Clause
    3  *
    4  * Copyright (c) 2001-2008, by Cisco Systems, Inc. All rights reserved.
    5  * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
    6  * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
    7  *
    8  * Redistribution and use in source and binary forms, with or without
    9  * modification, are permitted provided that the following conditions are met:
   10  *
   11  * a) Redistributions of source code must retain the above copyright notice,
   12  *    this list of conditions and the following disclaimer.
   13  *
   14  * b) Redistributions in binary form must reproduce the above copyright
   15  *    notice, this list of conditions and the following disclaimer in
   16  *    the documentation and/or other materials provided with the distribution.
   17  *
   18  * c) Neither the name of Cisco Systems, Inc. nor the names of its
   19  *    contributors may be used to endorse or promote products derived
   20  *    from this software without specific prior written permission.
   21  *
   22  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   23  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
   24  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   25  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   26  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   27  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   28  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   29  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   30  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   31  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
   32  * THE POSSIBILITY OF SUCH DAMAGE.
   33  */
   34 
   35 #include <sys/cdefs.h>
   36 __FBSDID("$FreeBSD: releng/12.0/sys/netinet/sctp_auth.c 339042 2018-10-01 14:05:31Z tuexen $");
   37 
   38 #include <netinet/sctp_os.h>
   39 #include <netinet/sctp.h>
   40 #include <netinet/sctp_header.h>
   41 #include <netinet/sctp_pcb.h>
   42 #include <netinet/sctp_var.h>
   43 #include <netinet/sctp_sysctl.h>
   44 #include <netinet/sctputil.h>
   45 #include <netinet/sctp_indata.h>
   46 #include <netinet/sctp_output.h>
   47 #include <netinet/sctp_auth.h>
   48 
   49 #ifdef SCTP_DEBUG
   50 #define SCTP_AUTH_DEBUG         (SCTP_BASE_SYSCTL(sctp_debug_on) & SCTP_DEBUG_AUTH1)
   51 #define SCTP_AUTH_DEBUG2        (SCTP_BASE_SYSCTL(sctp_debug_on) & SCTP_DEBUG_AUTH2)
   52 #endif                          /* SCTP_DEBUG */
   53 
   54 
   55 void
   56 sctp_clear_chunklist(sctp_auth_chklist_t *chklist)
   57 {
   58         memset(chklist, 0, sizeof(*chklist));
   59         /* chklist->num_chunks = 0; */
   60 }
   61 
   62 sctp_auth_chklist_t *
   63 sctp_alloc_chunklist(void)
   64 {
   65         sctp_auth_chklist_t *chklist;
   66 
   67         SCTP_MALLOC(chklist, sctp_auth_chklist_t *, sizeof(*chklist),
   68             SCTP_M_AUTH_CL);
   69         if (chklist == NULL) {
   70                 SCTPDBG(SCTP_DEBUG_AUTH1, "sctp_alloc_chunklist: failed to get memory!\n");
   71         } else {
   72                 sctp_clear_chunklist(chklist);
   73         }
   74         return (chklist);
   75 }
   76 
   77 void
   78 sctp_free_chunklist(sctp_auth_chklist_t *list)
   79 {
   80         if (list != NULL)
   81                 SCTP_FREE(list, SCTP_M_AUTH_CL);
   82 }
   83 
   84 sctp_auth_chklist_t *
   85 sctp_copy_chunklist(sctp_auth_chklist_t *list)
   86 {
   87         sctp_auth_chklist_t *new_list;
   88 
   89         if (list == NULL)
   90                 return (NULL);
   91 
   92         /* get a new list */
   93         new_list = sctp_alloc_chunklist();
   94         if (new_list == NULL)
   95                 return (NULL);
   96         /* copy it */
   97         memcpy(new_list, list, sizeof(*new_list));
   98 
   99         return (new_list);
  100 }
  101 
  102 
  103 /*
  104  * add a chunk to the required chunks list
  105  */
  106 int
  107 sctp_auth_add_chunk(uint8_t chunk, sctp_auth_chklist_t *list)
  108 {
  109         if (list == NULL)
  110                 return (-1);
  111 
  112         /* is chunk restricted? */
  113         if ((chunk == SCTP_INITIATION) ||
  114             (chunk == SCTP_INITIATION_ACK) ||
  115             (chunk == SCTP_SHUTDOWN_COMPLETE) ||
  116             (chunk == SCTP_AUTHENTICATION)) {
  117                 return (-1);
  118         }
  119         if (list->chunks[chunk] == 0) {
  120                 list->chunks[chunk] = 1;
  121                 list->num_chunks++;
  122                 SCTPDBG(SCTP_DEBUG_AUTH1,
  123                     "SCTP: added chunk %u (0x%02x) to Auth list\n",
  124                     chunk, chunk);
  125         }
  126         return (0);
  127 }
  128 
  129 /*
  130  * delete a chunk from the required chunks list
  131  */
  132 int
  133 sctp_auth_delete_chunk(uint8_t chunk, sctp_auth_chklist_t *list)
  134 {
  135         if (list == NULL)
  136                 return (-1);
  137 
  138         if (list->chunks[chunk] == 1) {
  139                 list->chunks[chunk] = 0;
  140                 list->num_chunks--;
  141                 SCTPDBG(SCTP_DEBUG_AUTH1,
  142                     "SCTP: deleted chunk %u (0x%02x) from Auth list\n",
  143                     chunk, chunk);
  144         }
  145         return (0);
  146 }
  147 
  148 size_t
  149 sctp_auth_get_chklist_size(const sctp_auth_chklist_t *list)
  150 {
  151         if (list == NULL)
  152                 return (0);
  153         else
  154                 return (list->num_chunks);
  155 }
  156 
  157 /*
  158  * return the current number and list of required chunks caller must
  159  * guarantee ptr has space for up to 256 bytes
  160  */
  161 int
  162 sctp_serialize_auth_chunks(const sctp_auth_chklist_t *list, uint8_t *ptr)
  163 {
  164         int i, count = 0;
  165 
  166         if (list == NULL)
  167                 return (0);
  168 
  169         for (i = 0; i < 256; i++) {
  170                 if (list->chunks[i] != 0) {
  171                         *ptr++ = i;
  172                         count++;
  173                 }
  174         }
  175         return (count);
  176 }
  177 
  178 int
  179 sctp_pack_auth_chunks(const sctp_auth_chklist_t *list, uint8_t *ptr)
  180 {
  181         int i, size = 0;
  182 
  183         if (list == NULL)
  184                 return (0);
  185 
  186         if (list->num_chunks <= 32) {
  187                 /* just list them, one byte each */
  188                 for (i = 0; i < 256; i++) {
  189                         if (list->chunks[i] != 0) {
  190                                 *ptr++ = i;
  191                                 size++;
  192                         }
  193                 }
  194         } else {
  195                 int index, offset;
  196 
  197                 /* pack into a 32 byte bitfield */
  198                 for (i = 0; i < 256; i++) {
  199                         if (list->chunks[i] != 0) {
  200                                 index = i / 8;
  201                                 offset = i % 8;
  202                                 ptr[index] |= (1 << offset);
  203                         }
  204                 }
  205                 size = 32;
  206         }
  207         return (size);
  208 }
  209 
  210 int
  211 sctp_unpack_auth_chunks(const uint8_t *ptr, uint8_t num_chunks,
  212     sctp_auth_chklist_t *list)
  213 {
  214         int i;
  215         int size;
  216 
  217         if (list == NULL)
  218                 return (0);
  219 
  220         if (num_chunks <= 32) {
  221                 /* just pull them, one byte each */
  222                 for (i = 0; i < num_chunks; i++) {
  223                         (void)sctp_auth_add_chunk(*ptr++, list);
  224                 }
  225                 size = num_chunks;
  226         } else {
  227                 int index, offset;
  228 
  229                 /* unpack from a 32 byte bitfield */
  230                 for (index = 0; index < 32; index++) {
  231                         for (offset = 0; offset < 8; offset++) {
  232                                 if (ptr[index] & (1 << offset)) {
  233                                         (void)sctp_auth_add_chunk((index * 8) + offset, list);
  234                                 }
  235                         }
  236                 }
  237                 size = 32;
  238         }
  239         return (size);
  240 }
  241 
  242 
  243 /*
  244  * allocate structure space for a key of length keylen
  245  */
  246 sctp_key_t *
  247 sctp_alloc_key(uint32_t keylen)
  248 {
  249         sctp_key_t *new_key;
  250 
  251         SCTP_MALLOC(new_key, sctp_key_t *, sizeof(*new_key) + keylen,
  252             SCTP_M_AUTH_KY);
  253         if (new_key == NULL) {
  254                 /* out of memory */
  255                 return (NULL);
  256         }
  257         new_key->keylen = keylen;
  258         return (new_key);
  259 }
  260 
  261 void
  262 sctp_free_key(sctp_key_t *key)
  263 {
  264         if (key != NULL)
  265                 SCTP_FREE(key, SCTP_M_AUTH_KY);
  266 }
  267 
  268 void
  269 sctp_print_key(sctp_key_t *key, const char *str)
  270 {
  271         uint32_t i;
  272 
  273         if (key == NULL) {
  274                 SCTP_PRINTF("%s: [Null key]\n", str);
  275                 return;
  276         }
  277         SCTP_PRINTF("%s: len %u, ", str, key->keylen);
  278         if (key->keylen) {
  279                 for (i = 0; i < key->keylen; i++)
  280                         SCTP_PRINTF("%02x", key->key[i]);
  281                 SCTP_PRINTF("\n");
  282         } else {
  283                 SCTP_PRINTF("[Null key]\n");
  284         }
  285 }
  286 
  287 void
  288 sctp_show_key(sctp_key_t *key, const char *str)
  289 {
  290         uint32_t i;
  291 
  292         if (key == NULL) {
  293                 SCTP_PRINTF("%s: [Null key]\n", str);
  294                 return;
  295         }
  296         SCTP_PRINTF("%s: len %u, ", str, key->keylen);
  297         if (key->keylen) {
  298                 for (i = 0; i < key->keylen; i++)
  299                         SCTP_PRINTF("%02x", key->key[i]);
  300                 SCTP_PRINTF("\n");
  301         } else {
  302                 SCTP_PRINTF("[Null key]\n");
  303         }
  304 }
  305 
  306 static uint32_t
  307 sctp_get_keylen(sctp_key_t *key)
  308 {
  309         if (key != NULL)
  310                 return (key->keylen);
  311         else
  312                 return (0);
  313 }
  314 
  315 /*
  316  * generate a new random key of length 'keylen'
  317  */
  318 sctp_key_t *
  319 sctp_generate_random_key(uint32_t keylen)
  320 {
  321         sctp_key_t *new_key;
  322 
  323         new_key = sctp_alloc_key(keylen);
  324         if (new_key == NULL) {
  325                 /* out of memory */
  326                 return (NULL);
  327         }
  328         SCTP_READ_RANDOM(new_key->key, keylen);
  329         new_key->keylen = keylen;
  330         return (new_key);
  331 }
  332 
  333 sctp_key_t *
  334 sctp_set_key(uint8_t *key, uint32_t keylen)
  335 {
  336         sctp_key_t *new_key;
  337 
  338         new_key = sctp_alloc_key(keylen);
  339         if (new_key == NULL) {
  340                 /* out of memory */
  341                 return (NULL);
  342         }
  343         memcpy(new_key->key, key, keylen);
  344         return (new_key);
  345 }
  346 
  347 /*-
  348  * given two keys of variable size, compute which key is "larger/smaller"
  349  * returns:  1 if key1 > key2
  350  *          -1 if key1 < key2
  351  *           0 if key1 = key2
  352  */
  353 static int
  354 sctp_compare_key(sctp_key_t *key1, sctp_key_t *key2)
  355 {
  356         uint32_t maxlen;
  357         uint32_t i;
  358         uint32_t key1len, key2len;
  359         uint8_t *key_1, *key_2;
  360         uint8_t val1, val2;
  361 
  362         /* sanity/length check */
  363         key1len = sctp_get_keylen(key1);
  364         key2len = sctp_get_keylen(key2);
  365         if ((key1len == 0) && (key2len == 0))
  366                 return (0);
  367         else if (key1len == 0)
  368                 return (-1);
  369         else if (key2len == 0)
  370                 return (1);
  371 
  372         if (key1len < key2len) {
  373                 maxlen = key2len;
  374         } else {
  375                 maxlen = key1len;
  376         }
  377         key_1 = key1->key;
  378         key_2 = key2->key;
  379         /* check for numeric equality */
  380         for (i = 0; i < maxlen; i++) {
  381                 /* left-pad with zeros */
  382                 val1 = (i < (maxlen - key1len)) ? 0 : *(key_1++);
  383                 val2 = (i < (maxlen - key2len)) ? 0 : *(key_2++);
  384                 if (val1 > val2) {
  385                         return (1);
  386                 } else if (val1 < val2) {
  387                         return (-1);
  388                 }
  389         }
  390         /* keys are equal value, so check lengths */
  391         if (key1len == key2len)
  392                 return (0);
  393         else if (key1len < key2len)
  394                 return (-1);
  395         else
  396                 return (1);
  397 }
  398 
  399 /*
  400  * generate the concatenated keying material based on the two keys and the
  401  * shared key (if available). draft-ietf-tsvwg-auth specifies the specific
  402  * order for concatenation
  403  */
  404 sctp_key_t *
  405 sctp_compute_hashkey(sctp_key_t *key1, sctp_key_t *key2, sctp_key_t *shared)
  406 {
  407         uint32_t keylen;
  408         sctp_key_t *new_key;
  409         uint8_t *key_ptr;
  410 
  411         keylen = sctp_get_keylen(key1) + sctp_get_keylen(key2) +
  412             sctp_get_keylen(shared);
  413 
  414         if (keylen > 0) {
  415                 /* get space for the new key */
  416                 new_key = sctp_alloc_key(keylen);
  417                 if (new_key == NULL) {
  418                         /* out of memory */
  419                         return (NULL);
  420                 }
  421                 new_key->keylen = keylen;
  422                 key_ptr = new_key->key;
  423         } else {
  424                 /* all keys empty/null?! */
  425                 return (NULL);
  426         }
  427 
  428         /* concatenate the keys */
  429         if (sctp_compare_key(key1, key2) <= 0) {
  430                 /* key is shared + key1 + key2 */
  431                 if (sctp_get_keylen(shared)) {
  432                         memcpy(key_ptr, shared->key, shared->keylen);
  433                         key_ptr += shared->keylen;
  434                 }
  435                 if (sctp_get_keylen(key1)) {
  436                         memcpy(key_ptr, key1->key, key1->keylen);
  437                         key_ptr += key1->keylen;
  438                 }
  439                 if (sctp_get_keylen(key2)) {
  440                         memcpy(key_ptr, key2->key, key2->keylen);
  441                 }
  442         } else {
  443                 /* key is shared + key2 + key1 */
  444                 if (sctp_get_keylen(shared)) {
  445                         memcpy(key_ptr, shared->key, shared->keylen);
  446                         key_ptr += shared->keylen;
  447                 }
  448                 if (sctp_get_keylen(key2)) {
  449                         memcpy(key_ptr, key2->key, key2->keylen);
  450                         key_ptr += key2->keylen;
  451                 }
  452                 if (sctp_get_keylen(key1)) {
  453                         memcpy(key_ptr, key1->key, key1->keylen);
  454                 }
  455         }
  456         return (new_key);
  457 }
  458 
  459 
  460 sctp_sharedkey_t *
  461 sctp_alloc_sharedkey(void)
  462 {
  463         sctp_sharedkey_t *new_key;
  464 
  465         SCTP_MALLOC(new_key, sctp_sharedkey_t *, sizeof(*new_key),
  466             SCTP_M_AUTH_KY);
  467         if (new_key == NULL) {
  468                 /* out of memory */
  469                 return (NULL);
  470         }
  471         new_key->keyid = 0;
  472         new_key->key = NULL;
  473         new_key->refcount = 1;
  474         new_key->deactivated = 0;
  475         return (new_key);
  476 }
  477 
  478 void
  479 sctp_free_sharedkey(sctp_sharedkey_t *skey)
  480 {
  481         if (skey == NULL)
  482                 return;
  483 
  484         if (SCTP_DECREMENT_AND_CHECK_REFCOUNT(&skey->refcount)) {
  485                 if (skey->key != NULL)
  486                         sctp_free_key(skey->key);
  487                 SCTP_FREE(skey, SCTP_M_AUTH_KY);
  488         }
  489 }
  490 
  491 sctp_sharedkey_t *
  492 sctp_find_sharedkey(struct sctp_keyhead *shared_keys, uint16_t key_id)
  493 {
  494         sctp_sharedkey_t *skey;
  495 
  496         LIST_FOREACH(skey, shared_keys, next) {
  497                 if (skey->keyid == key_id)
  498                         return (skey);
  499         }
  500         return (NULL);
  501 }
  502 
  503 int
  504 sctp_insert_sharedkey(struct sctp_keyhead *shared_keys,
  505     sctp_sharedkey_t *new_skey)
  506 {
  507         sctp_sharedkey_t *skey;
  508 
  509         if ((shared_keys == NULL) || (new_skey == NULL))
  510                 return (EINVAL);
  511 
  512         /* insert into an empty list? */
  513         if (LIST_EMPTY(shared_keys)) {
  514                 LIST_INSERT_HEAD(shared_keys, new_skey, next);
  515                 return (0);
  516         }
  517         /* insert into the existing list, ordered by key id */
  518         LIST_FOREACH(skey, shared_keys, next) {
  519                 if (new_skey->keyid < skey->keyid) {
  520                         /* insert it before here */
  521                         LIST_INSERT_BEFORE(skey, new_skey, next);
  522                         return (0);
  523                 } else if (new_skey->keyid == skey->keyid) {
  524                         /* replace the existing key */
  525                         /* verify this key *can* be replaced */
  526                         if ((skey->deactivated) && (skey->refcount > 1)) {
  527                                 SCTPDBG(SCTP_DEBUG_AUTH1,
  528                                     "can't replace shared key id %u\n",
  529                                     new_skey->keyid);
  530                                 return (EBUSY);
  531                         }
  532                         SCTPDBG(SCTP_DEBUG_AUTH1,
  533                             "replacing shared key id %u\n",
  534                             new_skey->keyid);
  535                         LIST_INSERT_BEFORE(skey, new_skey, next);
  536                         LIST_REMOVE(skey, next);
  537                         sctp_free_sharedkey(skey);
  538                         return (0);
  539                 }
  540                 if (LIST_NEXT(skey, next) == NULL) {
  541                         /* belongs at the end of the list */
  542                         LIST_INSERT_AFTER(skey, new_skey, next);
  543                         return (0);
  544                 }
  545         }
  546         /* shouldn't reach here */
  547         return (EINVAL);
  548 }
  549 
  550 void
  551 sctp_auth_key_acquire(struct sctp_tcb *stcb, uint16_t key_id)
  552 {
  553         sctp_sharedkey_t *skey;
  554 
  555         /* find the shared key */
  556         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, key_id);
  557 
  558         /* bump the ref count */
  559         if (skey) {
  560                 atomic_add_int(&skey->refcount, 1);
  561                 SCTPDBG(SCTP_DEBUG_AUTH2,
  562                     "%s: stcb %p key %u refcount acquire to %d\n",
  563                     __func__, (void *)stcb, key_id, skey->refcount);
  564         }
  565 }
  566 
  567 void
  568 sctp_auth_key_release(struct sctp_tcb *stcb, uint16_t key_id, int so_locked
  569 #if !defined(__APPLE__) && !defined(SCTP_SO_LOCK_TESTING)
  570     SCTP_UNUSED
  571 #endif
  572 )
  573 {
  574         sctp_sharedkey_t *skey;
  575 
  576         /* find the shared key */
  577         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, key_id);
  578 
  579         /* decrement the ref count */
  580         if (skey) {
  581                 SCTPDBG(SCTP_DEBUG_AUTH2,
  582                     "%s: stcb %p key %u refcount release to %d\n",
  583                     __func__, (void *)stcb, key_id, skey->refcount);
  584 
  585                 /* see if a notification should be generated */
  586                 if ((skey->refcount <= 2) && (skey->deactivated)) {
  587                         /* notify ULP that key is no longer used */
  588                         sctp_ulp_notify(SCTP_NOTIFY_AUTH_FREE_KEY, stcb,
  589                             key_id, 0, so_locked);
  590                         SCTPDBG(SCTP_DEBUG_AUTH2,
  591                             "%s: stcb %p key %u no longer used, %d\n",
  592                             __func__, (void *)stcb, key_id, skey->refcount);
  593                 }
  594                 sctp_free_sharedkey(skey);
  595         }
  596 }
  597 
  598 static sctp_sharedkey_t *
  599 sctp_copy_sharedkey(const sctp_sharedkey_t *skey)
  600 {
  601         sctp_sharedkey_t *new_skey;
  602 
  603         if (skey == NULL)
  604                 return (NULL);
  605         new_skey = sctp_alloc_sharedkey();
  606         if (new_skey == NULL)
  607                 return (NULL);
  608         if (skey->key != NULL)
  609                 new_skey->key = sctp_set_key(skey->key->key, skey->key->keylen);
  610         else
  611                 new_skey->key = NULL;
  612         new_skey->keyid = skey->keyid;
  613         return (new_skey);
  614 }
  615 
  616 int
  617 sctp_copy_skeylist(const struct sctp_keyhead *src, struct sctp_keyhead *dest)
  618 {
  619         sctp_sharedkey_t *skey, *new_skey;
  620         int count = 0;
  621 
  622         if ((src == NULL) || (dest == NULL))
  623                 return (0);
  624         LIST_FOREACH(skey, src, next) {
  625                 new_skey = sctp_copy_sharedkey(skey);
  626                 if (new_skey != NULL) {
  627                         if (sctp_insert_sharedkey(dest, new_skey)) {
  628                                 sctp_free_sharedkey(new_skey);
  629                         } else {
  630                                 count++;
  631                         }
  632                 }
  633         }
  634         return (count);
  635 }
  636 
  637 
  638 sctp_hmaclist_t *
  639 sctp_alloc_hmaclist(uint16_t num_hmacs)
  640 {
  641         sctp_hmaclist_t *new_list;
  642         int alloc_size;
  643 
  644         alloc_size = sizeof(*new_list) + num_hmacs * sizeof(new_list->hmac[0]);
  645         SCTP_MALLOC(new_list, sctp_hmaclist_t *, alloc_size,
  646             SCTP_M_AUTH_HL);
  647         if (new_list == NULL) {
  648                 /* out of memory */
  649                 return (NULL);
  650         }
  651         new_list->max_algo = num_hmacs;
  652         new_list->num_algo = 0;
  653         return (new_list);
  654 }
  655 
  656 void
  657 sctp_free_hmaclist(sctp_hmaclist_t *list)
  658 {
  659         if (list != NULL) {
  660                 SCTP_FREE(list, SCTP_M_AUTH_HL);
  661                 list = NULL;
  662         }
  663 }
  664 
  665 int
  666 sctp_auth_add_hmacid(sctp_hmaclist_t *list, uint16_t hmac_id)
  667 {
  668         int i;
  669 
  670         if (list == NULL)
  671                 return (-1);
  672         if (list->num_algo == list->max_algo) {
  673                 SCTPDBG(SCTP_DEBUG_AUTH1,
  674                     "SCTP: HMAC id list full, ignoring add %u\n", hmac_id);
  675                 return (-1);
  676         }
  677         if ((hmac_id != SCTP_AUTH_HMAC_ID_SHA1) &&
  678             (hmac_id != SCTP_AUTH_HMAC_ID_SHA256)) {
  679                 return (-1);
  680         }
  681         /* Now is it already in the list */
  682         for (i = 0; i < list->num_algo; i++) {
  683                 if (list->hmac[i] == hmac_id) {
  684                         /* already in list */
  685                         return (-1);
  686                 }
  687         }
  688         SCTPDBG(SCTP_DEBUG_AUTH1, "SCTP: add HMAC id %u to list\n", hmac_id);
  689         list->hmac[list->num_algo++] = hmac_id;
  690         return (0);
  691 }
  692 
  693 sctp_hmaclist_t *
  694 sctp_copy_hmaclist(sctp_hmaclist_t *list)
  695 {
  696         sctp_hmaclist_t *new_list;
  697         int i;
  698 
  699         if (list == NULL)
  700                 return (NULL);
  701         /* get a new list */
  702         new_list = sctp_alloc_hmaclist(list->max_algo);
  703         if (new_list == NULL)
  704                 return (NULL);
  705         /* copy it */
  706         new_list->max_algo = list->max_algo;
  707         new_list->num_algo = list->num_algo;
  708         for (i = 0; i < list->num_algo; i++)
  709                 new_list->hmac[i] = list->hmac[i];
  710         return (new_list);
  711 }
  712 
  713 sctp_hmaclist_t *
  714 sctp_default_supported_hmaclist(void)
  715 {
  716         sctp_hmaclist_t *new_list;
  717 
  718         new_list = sctp_alloc_hmaclist(2);
  719         if (new_list == NULL)
  720                 return (NULL);
  721         /* We prefer SHA256, so list it first */
  722         (void)sctp_auth_add_hmacid(new_list, SCTP_AUTH_HMAC_ID_SHA256);
  723         (void)sctp_auth_add_hmacid(new_list, SCTP_AUTH_HMAC_ID_SHA1);
  724         return (new_list);
  725 }
  726 
  727 /*-
  728  * HMAC algos are listed in priority/preference order
  729  * find the best HMAC id to use for the peer based on local support
  730  */
  731 uint16_t
  732 sctp_negotiate_hmacid(sctp_hmaclist_t *peer, sctp_hmaclist_t *local)
  733 {
  734         int i, j;
  735 
  736         if ((local == NULL) || (peer == NULL))
  737                 return (SCTP_AUTH_HMAC_ID_RSVD);
  738 
  739         for (i = 0; i < peer->num_algo; i++) {
  740                 for (j = 0; j < local->num_algo; j++) {
  741                         if (peer->hmac[i] == local->hmac[j]) {
  742                                 /* found the "best" one */
  743                                 SCTPDBG(SCTP_DEBUG_AUTH1,
  744                                     "SCTP: negotiated peer HMAC id %u\n",
  745                                     peer->hmac[i]);
  746                                 return (peer->hmac[i]);
  747                         }
  748                 }
  749         }
  750         /* didn't find one! */
  751         return (SCTP_AUTH_HMAC_ID_RSVD);
  752 }
  753 
  754 /*-
  755  * serialize the HMAC algo list and return space used
  756  * caller must guarantee ptr has appropriate space
  757  */
  758 int
  759 sctp_serialize_hmaclist(sctp_hmaclist_t *list, uint8_t *ptr)
  760 {
  761         int i;
  762         uint16_t hmac_id;
  763 
  764         if (list == NULL)
  765                 return (0);
  766 
  767         for (i = 0; i < list->num_algo; i++) {
  768                 hmac_id = htons(list->hmac[i]);
  769                 memcpy(ptr, &hmac_id, sizeof(hmac_id));
  770                 ptr += sizeof(hmac_id);
  771         }
  772         return (list->num_algo * sizeof(hmac_id));
  773 }
  774 
  775 int
  776 sctp_verify_hmac_param(struct sctp_auth_hmac_algo *hmacs, uint32_t num_hmacs)
  777 {
  778         uint32_t i;
  779 
  780         for (i = 0; i < num_hmacs; i++) {
  781                 if (ntohs(hmacs->hmac_ids[i]) == SCTP_AUTH_HMAC_ID_SHA1) {
  782                         return (0);
  783                 }
  784         }
  785         return (-1);
  786 }
  787 
  788 sctp_authinfo_t *
  789 sctp_alloc_authinfo(void)
  790 {
  791         sctp_authinfo_t *new_authinfo;
  792 
  793         SCTP_MALLOC(new_authinfo, sctp_authinfo_t *, sizeof(*new_authinfo),
  794             SCTP_M_AUTH_IF);
  795 
  796         if (new_authinfo == NULL) {
  797                 /* out of memory */
  798                 return (NULL);
  799         }
  800         memset(new_authinfo, 0, sizeof(*new_authinfo));
  801         return (new_authinfo);
  802 }
  803 
  804 void
  805 sctp_free_authinfo(sctp_authinfo_t *authinfo)
  806 {
  807         if (authinfo == NULL)
  808                 return;
  809 
  810         if (authinfo->random != NULL)
  811                 sctp_free_key(authinfo->random);
  812         if (authinfo->peer_random != NULL)
  813                 sctp_free_key(authinfo->peer_random);
  814         if (authinfo->assoc_key != NULL)
  815                 sctp_free_key(authinfo->assoc_key);
  816         if (authinfo->recv_key != NULL)
  817                 sctp_free_key(authinfo->recv_key);
  818 
  819         /* We are NOT dynamically allocating authinfo's right now... */
  820         /* SCTP_FREE(authinfo, SCTP_M_AUTH_??); */
  821 }
  822 
  823 
  824 uint32_t
  825 sctp_get_auth_chunk_len(uint16_t hmac_algo)
  826 {
  827         int size;
  828 
  829         size = sizeof(struct sctp_auth_chunk) + sctp_get_hmac_digest_len(hmac_algo);
  830         return (SCTP_SIZE32(size));
  831 }
  832 
  833 uint32_t
  834 sctp_get_hmac_digest_len(uint16_t hmac_algo)
  835 {
  836         switch (hmac_algo) {
  837         case SCTP_AUTH_HMAC_ID_SHA1:
  838                 return (SCTP_AUTH_DIGEST_LEN_SHA1);
  839         case SCTP_AUTH_HMAC_ID_SHA256:
  840                 return (SCTP_AUTH_DIGEST_LEN_SHA256);
  841         default:
  842                 /* unknown HMAC algorithm: can't do anything */
  843                 return (0);
  844         }                       /* end switch */
  845 }
  846 
  847 static inline int
  848 sctp_get_hmac_block_len(uint16_t hmac_algo)
  849 {
  850         switch (hmac_algo) {
  851         case SCTP_AUTH_HMAC_ID_SHA1:
  852                 return (64);
  853         case SCTP_AUTH_HMAC_ID_SHA256:
  854                 return (64);
  855         case SCTP_AUTH_HMAC_ID_RSVD:
  856         default:
  857                 /* unknown HMAC algorithm: can't do anything */
  858                 return (0);
  859         }                       /* end switch */
  860 }
  861 
  862 static void
  863 sctp_hmac_init(uint16_t hmac_algo, sctp_hash_context_t *ctx)
  864 {
  865         switch (hmac_algo) {
  866         case SCTP_AUTH_HMAC_ID_SHA1:
  867                 SCTP_SHA1_INIT(&ctx->sha1);
  868                 break;
  869         case SCTP_AUTH_HMAC_ID_SHA256:
  870                 SCTP_SHA256_INIT(&ctx->sha256);
  871                 break;
  872         case SCTP_AUTH_HMAC_ID_RSVD:
  873         default:
  874                 /* unknown HMAC algorithm: can't do anything */
  875                 return;
  876         }                       /* end switch */
  877 }
  878 
  879 static void
  880 sctp_hmac_update(uint16_t hmac_algo, sctp_hash_context_t *ctx,
  881     uint8_t *text, uint32_t textlen)
  882 {
  883         switch (hmac_algo) {
  884         case SCTP_AUTH_HMAC_ID_SHA1:
  885                 SCTP_SHA1_UPDATE(&ctx->sha1, text, textlen);
  886                 break;
  887         case SCTP_AUTH_HMAC_ID_SHA256:
  888                 SCTP_SHA256_UPDATE(&ctx->sha256, text, textlen);
  889                 break;
  890         case SCTP_AUTH_HMAC_ID_RSVD:
  891         default:
  892                 /* unknown HMAC algorithm: can't do anything */
  893                 return;
  894         }                       /* end switch */
  895 }
  896 
  897 static void
  898 sctp_hmac_final(uint16_t hmac_algo, sctp_hash_context_t *ctx,
  899     uint8_t *digest)
  900 {
  901         switch (hmac_algo) {
  902         case SCTP_AUTH_HMAC_ID_SHA1:
  903                 SCTP_SHA1_FINAL(digest, &ctx->sha1);
  904                 break;
  905         case SCTP_AUTH_HMAC_ID_SHA256:
  906                 SCTP_SHA256_FINAL(digest, &ctx->sha256);
  907                 break;
  908         case SCTP_AUTH_HMAC_ID_RSVD:
  909         default:
  910                 /* unknown HMAC algorithm: can't do anything */
  911                 return;
  912         }                       /* end switch */
  913 }
  914 
  915 /*-
  916  * Keyed-Hashing for Message Authentication: FIPS 198 (RFC 2104)
  917  *
  918  * Compute the HMAC digest using the desired hash key, text, and HMAC
  919  * algorithm.  Resulting digest is placed in 'digest' and digest length
  920  * is returned, if the HMAC was performed.
  921  *
  922  * WARNING: it is up to the caller to supply sufficient space to hold the
  923  * resultant digest.
  924  */
  925 uint32_t
  926 sctp_hmac(uint16_t hmac_algo, uint8_t *key, uint32_t keylen,
  927     uint8_t *text, uint32_t textlen, uint8_t *digest)
  928 {
  929         uint32_t digestlen;
  930         uint32_t blocklen;
  931         sctp_hash_context_t ctx;
  932         uint8_t ipad[128], opad[128];   /* keyed hash inner/outer pads */
  933         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
  934         uint32_t i;
  935 
  936         /* sanity check the material and length */
  937         if ((key == NULL) || (keylen == 0) || (text == NULL) ||
  938             (textlen == 0) || (digest == NULL)) {
  939                 /* can't do HMAC with empty key or text or digest store */
  940                 return (0);
  941         }
  942         /* validate the hmac algo and get the digest length */
  943         digestlen = sctp_get_hmac_digest_len(hmac_algo);
  944         if (digestlen == 0)
  945                 return (0);
  946 
  947         /* hash the key if it is longer than the hash block size */
  948         blocklen = sctp_get_hmac_block_len(hmac_algo);
  949         if (keylen > blocklen) {
  950                 sctp_hmac_init(hmac_algo, &ctx);
  951                 sctp_hmac_update(hmac_algo, &ctx, key, keylen);
  952                 sctp_hmac_final(hmac_algo, &ctx, temp);
  953                 /* set the hashed key as the key */
  954                 keylen = digestlen;
  955                 key = temp;
  956         }
  957         /* initialize the inner/outer pads with the key and "append" zeroes */
  958         memset(ipad, 0, blocklen);
  959         memset(opad, 0, blocklen);
  960         memcpy(ipad, key, keylen);
  961         memcpy(opad, key, keylen);
  962 
  963         /* XOR the key with ipad and opad values */
  964         for (i = 0; i < blocklen; i++) {
  965                 ipad[i] ^= 0x36;
  966                 opad[i] ^= 0x5c;
  967         }
  968 
  969         /* perform inner hash */
  970         sctp_hmac_init(hmac_algo, &ctx);
  971         sctp_hmac_update(hmac_algo, &ctx, ipad, blocklen);
  972         sctp_hmac_update(hmac_algo, &ctx, text, textlen);
  973         sctp_hmac_final(hmac_algo, &ctx, temp);
  974 
  975         /* perform outer hash */
  976         sctp_hmac_init(hmac_algo, &ctx);
  977         sctp_hmac_update(hmac_algo, &ctx, opad, blocklen);
  978         sctp_hmac_update(hmac_algo, &ctx, temp, digestlen);
  979         sctp_hmac_final(hmac_algo, &ctx, digest);
  980 
  981         return (digestlen);
  982 }
  983 
  984 /* mbuf version */
  985 uint32_t
  986 sctp_hmac_m(uint16_t hmac_algo, uint8_t *key, uint32_t keylen,
  987     struct mbuf *m, uint32_t m_offset, uint8_t *digest, uint32_t trailer)
  988 {
  989         uint32_t digestlen;
  990         uint32_t blocklen;
  991         sctp_hash_context_t ctx;
  992         uint8_t ipad[128], opad[128];   /* keyed hash inner/outer pads */
  993         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
  994         uint32_t i;
  995         struct mbuf *m_tmp;
  996 
  997         /* sanity check the material and length */
  998         if ((key == NULL) || (keylen == 0) || (m == NULL) || (digest == NULL)) {
  999                 /* can't do HMAC with empty key or text or digest store */
 1000                 return (0);
 1001         }
 1002         /* validate the hmac algo and get the digest length */
 1003         digestlen = sctp_get_hmac_digest_len(hmac_algo);
 1004         if (digestlen == 0)
 1005                 return (0);
 1006 
 1007         /* hash the key if it is longer than the hash block size */
 1008         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1009         if (keylen > blocklen) {
 1010                 sctp_hmac_init(hmac_algo, &ctx);
 1011                 sctp_hmac_update(hmac_algo, &ctx, key, keylen);
 1012                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1013                 /* set the hashed key as the key */
 1014                 keylen = digestlen;
 1015                 key = temp;
 1016         }
 1017         /* initialize the inner/outer pads with the key and "append" zeroes */
 1018         memset(ipad, 0, blocklen);
 1019         memset(opad, 0, blocklen);
 1020         memcpy(ipad, key, keylen);
 1021         memcpy(opad, key, keylen);
 1022 
 1023         /* XOR the key with ipad and opad values */
 1024         for (i = 0; i < blocklen; i++) {
 1025                 ipad[i] ^= 0x36;
 1026                 opad[i] ^= 0x5c;
 1027         }
 1028 
 1029         /* perform inner hash */
 1030         sctp_hmac_init(hmac_algo, &ctx);
 1031         sctp_hmac_update(hmac_algo, &ctx, ipad, blocklen);
 1032         /* find the correct starting mbuf and offset (get start of text) */
 1033         m_tmp = m;
 1034         while ((m_tmp != NULL) && (m_offset >= (uint32_t)SCTP_BUF_LEN(m_tmp))) {
 1035                 m_offset -= SCTP_BUF_LEN(m_tmp);
 1036                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1037         }
 1038         /* now use the rest of the mbuf chain for the text */
 1039         while (m_tmp != NULL) {
 1040                 if ((SCTP_BUF_NEXT(m_tmp) == NULL) && trailer) {
 1041                         sctp_hmac_update(hmac_algo, &ctx, mtod(m_tmp, uint8_t *)+m_offset,
 1042                             SCTP_BUF_LEN(m_tmp) - (trailer + m_offset));
 1043                 } else {
 1044                         sctp_hmac_update(hmac_algo, &ctx, mtod(m_tmp, uint8_t *)+m_offset,
 1045                             SCTP_BUF_LEN(m_tmp) - m_offset);
 1046                 }
 1047 
 1048                 /* clear the offset since it's only for the first mbuf */
 1049                 m_offset = 0;
 1050                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1051         }
 1052         sctp_hmac_final(hmac_algo, &ctx, temp);
 1053 
 1054         /* perform outer hash */
 1055         sctp_hmac_init(hmac_algo, &ctx);
 1056         sctp_hmac_update(hmac_algo, &ctx, opad, blocklen);
 1057         sctp_hmac_update(hmac_algo, &ctx, temp, digestlen);
 1058         sctp_hmac_final(hmac_algo, &ctx, digest);
 1059 
 1060         return (digestlen);
 1061 }
 1062 
 1063 /*
 1064  * computes the requested HMAC using a key struct (which may be modified if
 1065  * the keylen exceeds the HMAC block len).
 1066  */
 1067 uint32_t
 1068 sctp_compute_hmac(uint16_t hmac_algo, sctp_key_t *key, uint8_t *text,
 1069     uint32_t textlen, uint8_t *digest)
 1070 {
 1071         uint32_t digestlen;
 1072         uint32_t blocklen;
 1073         sctp_hash_context_t ctx;
 1074         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
 1075 
 1076         /* sanity check */
 1077         if ((key == NULL) || (text == NULL) || (textlen == 0) ||
 1078             (digest == NULL)) {
 1079                 /* can't do HMAC with empty key or text or digest store */
 1080                 return (0);
 1081         }
 1082         /* validate the hmac algo and get the digest length */
 1083         digestlen = sctp_get_hmac_digest_len(hmac_algo);
 1084         if (digestlen == 0)
 1085                 return (0);
 1086 
 1087         /* hash the key if it is longer than the hash block size */
 1088         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1089         if (key->keylen > blocklen) {
 1090                 sctp_hmac_init(hmac_algo, &ctx);
 1091                 sctp_hmac_update(hmac_algo, &ctx, key->key, key->keylen);
 1092                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1093                 /* save the hashed key as the new key */
 1094                 key->keylen = digestlen;
 1095                 memcpy(key->key, temp, key->keylen);
 1096         }
 1097         return (sctp_hmac(hmac_algo, key->key, key->keylen, text, textlen,
 1098             digest));
 1099 }
 1100 
 1101 /* mbuf version */
 1102 uint32_t
 1103 sctp_compute_hmac_m(uint16_t hmac_algo, sctp_key_t *key, struct mbuf *m,
 1104     uint32_t m_offset, uint8_t *digest)
 1105 {
 1106         uint32_t digestlen;
 1107         uint32_t blocklen;
 1108         sctp_hash_context_t ctx;
 1109         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
 1110 
 1111         /* sanity check */
 1112         if ((key == NULL) || (m == NULL) || (digest == NULL)) {
 1113                 /* can't do HMAC with empty key or text or digest store */
 1114                 return (0);
 1115         }
 1116         /* validate the hmac algo and get the digest length */
 1117         digestlen = sctp_get_hmac_digest_len(hmac_algo);
 1118         if (digestlen == 0)
 1119                 return (0);
 1120 
 1121         /* hash the key if it is longer than the hash block size */
 1122         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1123         if (key->keylen > blocklen) {
 1124                 sctp_hmac_init(hmac_algo, &ctx);
 1125                 sctp_hmac_update(hmac_algo, &ctx, key->key, key->keylen);
 1126                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1127                 /* save the hashed key as the new key */
 1128                 key->keylen = digestlen;
 1129                 memcpy(key->key, temp, key->keylen);
 1130         }
 1131         return (sctp_hmac_m(hmac_algo, key->key, key->keylen, m, m_offset, digest, 0));
 1132 }
 1133 
 1134 int
 1135 sctp_auth_is_supported_hmac(sctp_hmaclist_t *list, uint16_t id)
 1136 {
 1137         int i;
 1138 
 1139         if ((list == NULL) || (id == SCTP_AUTH_HMAC_ID_RSVD))
 1140                 return (0);
 1141 
 1142         for (i = 0; i < list->num_algo; i++)
 1143                 if (list->hmac[i] == id)
 1144                         return (1);
 1145 
 1146         /* not in the list */
 1147         return (0);
 1148 }
 1149 
 1150 
 1151 /*-
 1152  * clear any cached key(s) if they match the given key id on an association.
 1153  * the cached key(s) will be recomputed and re-cached at next use.
 1154  * ASSUMES TCB_LOCK is already held
 1155  */
 1156 void
 1157 sctp_clear_cachedkeys(struct sctp_tcb *stcb, uint16_t keyid)
 1158 {
 1159         if (stcb == NULL)
 1160                 return;
 1161 
 1162         if (keyid == stcb->asoc.authinfo.assoc_keyid) {
 1163                 sctp_free_key(stcb->asoc.authinfo.assoc_key);
 1164                 stcb->asoc.authinfo.assoc_key = NULL;
 1165         }
 1166         if (keyid == stcb->asoc.authinfo.recv_keyid) {
 1167                 sctp_free_key(stcb->asoc.authinfo.recv_key);
 1168                 stcb->asoc.authinfo.recv_key = NULL;
 1169         }
 1170 }
 1171 
 1172 /*-
 1173  * clear any cached key(s) if they match the given key id for all assocs on
 1174  * an endpoint.
 1175  * ASSUMES INP_WLOCK is already held
 1176  */
 1177 void
 1178 sctp_clear_cachedkeys_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1179 {
 1180         struct sctp_tcb *stcb;
 1181 
 1182         if (inp == NULL)
 1183                 return;
 1184 
 1185         /* clear the cached keys on all assocs on this instance */
 1186         LIST_FOREACH(stcb, &inp->sctp_asoc_list, sctp_tcblist) {
 1187                 SCTP_TCB_LOCK(stcb);
 1188                 sctp_clear_cachedkeys(stcb, keyid);
 1189                 SCTP_TCB_UNLOCK(stcb);
 1190         }
 1191 }
 1192 
 1193 /*-
 1194  * delete a shared key from an association
 1195  * ASSUMES TCB_LOCK is already held
 1196  */
 1197 int
 1198 sctp_delete_sharedkey(struct sctp_tcb *stcb, uint16_t keyid)
 1199 {
 1200         sctp_sharedkey_t *skey;
 1201 
 1202         if (stcb == NULL)
 1203                 return (-1);
 1204 
 1205         /* is the keyid the assoc active sending key */
 1206         if (keyid == stcb->asoc.authinfo.active_keyid)
 1207                 return (-1);
 1208 
 1209         /* does the key exist? */
 1210         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1211         if (skey == NULL)
 1212                 return (-1);
 1213 
 1214         /* are there other refcount holders on the key? */
 1215         if (skey->refcount > 1)
 1216                 return (-1);
 1217 
 1218         /* remove it */
 1219         LIST_REMOVE(skey, next);
 1220         sctp_free_sharedkey(skey);      /* frees skey->key as well */
 1221 
 1222         /* clear any cached keys */
 1223         sctp_clear_cachedkeys(stcb, keyid);
 1224         return (0);
 1225 }
 1226 
 1227 /*-
 1228  * deletes a shared key from the endpoint
 1229  * ASSUMES INP_WLOCK is already held
 1230  */
 1231 int
 1232 sctp_delete_sharedkey_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1233 {
 1234         sctp_sharedkey_t *skey;
 1235 
 1236         if (inp == NULL)
 1237                 return (-1);
 1238 
 1239         /* is the keyid the active sending key on the endpoint */
 1240         if (keyid == inp->sctp_ep.default_keyid)
 1241                 return (-1);
 1242 
 1243         /* does the key exist? */
 1244         skey = sctp_find_sharedkey(&inp->sctp_ep.shared_keys, keyid);
 1245         if (skey == NULL)
 1246                 return (-1);
 1247 
 1248         /* endpoint keys are not refcounted */
 1249 
 1250         /* remove it */
 1251         LIST_REMOVE(skey, next);
 1252         sctp_free_sharedkey(skey);      /* frees skey->key as well */
 1253 
 1254         /* clear any cached keys */
 1255         sctp_clear_cachedkeys_ep(inp, keyid);
 1256         return (0);
 1257 }
 1258 
 1259 /*-
 1260  * set the active key on an association
 1261  * ASSUMES TCB_LOCK is already held
 1262  */
 1263 int
 1264 sctp_auth_setactivekey(struct sctp_tcb *stcb, uint16_t keyid)
 1265 {
 1266         sctp_sharedkey_t *skey = NULL;
 1267 
 1268         /* find the key on the assoc */
 1269         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1270         if (skey == NULL) {
 1271                 /* that key doesn't exist */
 1272                 return (-1);
 1273         }
 1274         if ((skey->deactivated) && (skey->refcount > 1)) {
 1275                 /* can't reactivate a deactivated key with other refcounts */
 1276                 return (-1);
 1277         }
 1278 
 1279         /* set the (new) active key */
 1280         stcb->asoc.authinfo.active_keyid = keyid;
 1281         /* reset the deactivated flag */
 1282         skey->deactivated = 0;
 1283 
 1284         return (0);
 1285 }
 1286 
 1287 /*-
 1288  * set the active key on an endpoint
 1289  * ASSUMES INP_WLOCK is already held
 1290  */
 1291 int
 1292 sctp_auth_setactivekey_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1293 {
 1294         sctp_sharedkey_t *skey;
 1295 
 1296         /* find the key */
 1297         skey = sctp_find_sharedkey(&inp->sctp_ep.shared_keys, keyid);
 1298         if (skey == NULL) {
 1299                 /* that key doesn't exist */
 1300                 return (-1);
 1301         }
 1302         inp->sctp_ep.default_keyid = keyid;
 1303         return (0);
 1304 }
 1305 
 1306 /*-
 1307  * deactivates a shared key from the association
 1308  * ASSUMES INP_WLOCK is already held
 1309  */
 1310 int
 1311 sctp_deact_sharedkey(struct sctp_tcb *stcb, uint16_t keyid)
 1312 {
 1313         sctp_sharedkey_t *skey;
 1314 
 1315         if (stcb == NULL)
 1316                 return (-1);
 1317 
 1318         /* is the keyid the assoc active sending key */
 1319         if (keyid == stcb->asoc.authinfo.active_keyid)
 1320                 return (-1);
 1321 
 1322         /* does the key exist? */
 1323         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1324         if (skey == NULL)
 1325                 return (-1);
 1326 
 1327         /* are there other refcount holders on the key? */
 1328         if (skey->refcount == 1) {
 1329                 /* no other users, send a notification for this key */
 1330                 sctp_ulp_notify(SCTP_NOTIFY_AUTH_FREE_KEY, stcb, keyid, 0,
 1331                     SCTP_SO_LOCKED);
 1332         }
 1333 
 1334         /* mark the key as deactivated */
 1335         skey->deactivated = 1;
 1336 
 1337         return (0);
 1338 }
 1339 
 1340 /*-
 1341  * deactivates a shared key from the endpoint
 1342  * ASSUMES INP_WLOCK is already held
 1343  */
 1344 int
 1345 sctp_deact_sharedkey_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1346 {
 1347         sctp_sharedkey_t *skey;
 1348 
 1349         if (inp == NULL)
 1350                 return (-1);
 1351 
 1352         /* is the keyid the active sending key on the endpoint */
 1353         if (keyid == inp->sctp_ep.default_keyid)
 1354                 return (-1);
 1355 
 1356         /* does the key exist? */
 1357         skey = sctp_find_sharedkey(&inp->sctp_ep.shared_keys, keyid);
 1358         if (skey == NULL)
 1359                 return (-1);
 1360 
 1361         /* endpoint keys are not refcounted */
 1362 
 1363         /* remove it */
 1364         LIST_REMOVE(skey, next);
 1365         sctp_free_sharedkey(skey);      /* frees skey->key as well */
 1366 
 1367         return (0);
 1368 }
 1369 
 1370 /*
 1371  * get local authentication parameters from cookie (from INIT-ACK)
 1372  */
 1373 void
 1374 sctp_auth_get_cookie_params(struct sctp_tcb *stcb, struct mbuf *m,
 1375     uint32_t offset, uint32_t length)
 1376 {
 1377         struct sctp_paramhdr *phdr, tmp_param;
 1378         uint16_t plen, ptype;
 1379         uint8_t random_store[SCTP_PARAM_BUFFER_SIZE];
 1380         struct sctp_auth_random *p_random = NULL;
 1381         uint16_t random_len = 0;
 1382         uint8_t hmacs_store[SCTP_PARAM_BUFFER_SIZE];
 1383         struct sctp_auth_hmac_algo *hmacs = NULL;
 1384         uint16_t hmacs_len = 0;
 1385         uint8_t chunks_store[SCTP_PARAM_BUFFER_SIZE];
 1386         struct sctp_auth_chunk_list *chunks = NULL;
 1387         uint16_t num_chunks = 0;
 1388         sctp_key_t *new_key;
 1389         uint32_t keylen;
 1390 
 1391         /* convert to upper bound */
 1392         length += offset;
 1393 
 1394         phdr = (struct sctp_paramhdr *)sctp_m_getptr(m, offset,
 1395             sizeof(struct sctp_paramhdr), (uint8_t *)&tmp_param);
 1396         while (phdr != NULL) {
 1397                 ptype = ntohs(phdr->param_type);
 1398                 plen = ntohs(phdr->param_length);
 1399 
 1400                 if ((plen == 0) || (offset + plen > length))
 1401                         break;
 1402 
 1403                 if (ptype == SCTP_RANDOM) {
 1404                         if (plen > sizeof(random_store))
 1405                                 break;
 1406                         phdr = sctp_get_next_param(m, offset,
 1407                             (struct sctp_paramhdr *)random_store, plen);
 1408                         if (phdr == NULL)
 1409                                 return;
 1410                         /* save the random and length for the key */
 1411                         p_random = (struct sctp_auth_random *)phdr;
 1412                         random_len = plen - sizeof(*p_random);
 1413                 } else if (ptype == SCTP_HMAC_LIST) {
 1414                         uint16_t num_hmacs;
 1415                         uint16_t i;
 1416 
 1417                         if (plen > sizeof(hmacs_store))
 1418                                 break;
 1419                         phdr = sctp_get_next_param(m, offset,
 1420                             (struct sctp_paramhdr *)hmacs_store, plen);
 1421                         if (phdr == NULL)
 1422                                 return;
 1423                         /* save the hmacs list and num for the key */
 1424                         hmacs = (struct sctp_auth_hmac_algo *)phdr;
 1425                         hmacs_len = plen - sizeof(*hmacs);
 1426                         num_hmacs = hmacs_len / sizeof(hmacs->hmac_ids[0]);
 1427                         if (stcb->asoc.local_hmacs != NULL)
 1428                                 sctp_free_hmaclist(stcb->asoc.local_hmacs);
 1429                         stcb->asoc.local_hmacs = sctp_alloc_hmaclist(num_hmacs);
 1430                         if (stcb->asoc.local_hmacs != NULL) {
 1431                                 for (i = 0; i < num_hmacs; i++) {
 1432                                         (void)sctp_auth_add_hmacid(stcb->asoc.local_hmacs,
 1433                                             ntohs(hmacs->hmac_ids[i]));
 1434                                 }
 1435                         }
 1436                 } else if (ptype == SCTP_CHUNK_LIST) {
 1437                         int i;
 1438 
 1439                         if (plen > sizeof(chunks_store))
 1440                                 break;
 1441                         phdr = sctp_get_next_param(m, offset,
 1442                             (struct sctp_paramhdr *)chunks_store, plen);
 1443                         if (phdr == NULL)
 1444                                 return;
 1445                         chunks = (struct sctp_auth_chunk_list *)phdr;
 1446                         num_chunks = plen - sizeof(*chunks);
 1447                         /* save chunks list and num for the key */
 1448                         if (stcb->asoc.local_auth_chunks != NULL)
 1449                                 sctp_clear_chunklist(stcb->asoc.local_auth_chunks);
 1450                         else
 1451                                 stcb->asoc.local_auth_chunks = sctp_alloc_chunklist();
 1452                         for (i = 0; i < num_chunks; i++) {
 1453                                 (void)sctp_auth_add_chunk(chunks->chunk_types[i],
 1454                                     stcb->asoc.local_auth_chunks);
 1455                         }
 1456                 }
 1457                 /* get next parameter */
 1458                 offset += SCTP_SIZE32(plen);
 1459                 if (offset + sizeof(struct sctp_paramhdr) > length)
 1460                         break;
 1461                 phdr = (struct sctp_paramhdr *)sctp_m_getptr(m, offset, sizeof(struct sctp_paramhdr),
 1462                     (uint8_t *)&tmp_param);
 1463         }
 1464         /* concatenate the full random key */
 1465         keylen = sizeof(*p_random) + random_len + sizeof(*hmacs) + hmacs_len;
 1466         if (chunks != NULL) {
 1467                 keylen += sizeof(*chunks) + num_chunks;
 1468         }
 1469         new_key = sctp_alloc_key(keylen);
 1470         if (new_key != NULL) {
 1471                 /* copy in the RANDOM */
 1472                 if (p_random != NULL) {
 1473                         keylen = sizeof(*p_random) + random_len;
 1474                         memcpy(new_key->key, p_random, keylen);
 1475                 } else {
 1476                         keylen = 0;
 1477                 }
 1478                 /* append in the AUTH chunks */
 1479                 if (chunks != NULL) {
 1480                         memcpy(new_key->key + keylen, chunks,
 1481                             sizeof(*chunks) + num_chunks);
 1482                         keylen += sizeof(*chunks) + num_chunks;
 1483                 }
 1484                 /* append in the HMACs */
 1485                 if (hmacs != NULL) {
 1486                         memcpy(new_key->key + keylen, hmacs,
 1487                             sizeof(*hmacs) + hmacs_len);
 1488                 }
 1489         }
 1490         if (stcb->asoc.authinfo.random != NULL)
 1491                 sctp_free_key(stcb->asoc.authinfo.random);
 1492         stcb->asoc.authinfo.random = new_key;
 1493         stcb->asoc.authinfo.random_len = random_len;
 1494         sctp_clear_cachedkeys(stcb, stcb->asoc.authinfo.assoc_keyid);
 1495         sctp_clear_cachedkeys(stcb, stcb->asoc.authinfo.recv_keyid);
 1496 
 1497         /* negotiate what HMAC to use for the peer */
 1498         stcb->asoc.peer_hmac_id = sctp_negotiate_hmacid(stcb->asoc.peer_hmacs,
 1499             stcb->asoc.local_hmacs);
 1500 
 1501         /* copy defaults from the endpoint */
 1502         /* FIX ME: put in cookie? */
 1503         stcb->asoc.authinfo.active_keyid = stcb->sctp_ep->sctp_ep.default_keyid;
 1504         /* copy out the shared key list (by reference) from the endpoint */
 1505         (void)sctp_copy_skeylist(&stcb->sctp_ep->sctp_ep.shared_keys,
 1506             &stcb->asoc.shared_keys);
 1507 }
 1508 
 1509 /*
 1510  * compute and fill in the HMAC digest for a packet
 1511  */
 1512 void
 1513 sctp_fill_hmac_digest_m(struct mbuf *m, uint32_t auth_offset,
 1514     struct sctp_auth_chunk *auth, struct sctp_tcb *stcb, uint16_t keyid)
 1515 {
 1516         uint32_t digestlen;
 1517         sctp_sharedkey_t *skey;
 1518         sctp_key_t *key;
 1519 
 1520         if ((stcb == NULL) || (auth == NULL))
 1521                 return;
 1522 
 1523         /* zero the digest + chunk padding */
 1524         digestlen = sctp_get_hmac_digest_len(stcb->asoc.peer_hmac_id);
 1525         memset(auth->hmac, 0, SCTP_SIZE32(digestlen));
 1526 
 1527         /* is the desired key cached? */
 1528         if ((keyid != stcb->asoc.authinfo.assoc_keyid) ||
 1529             (stcb->asoc.authinfo.assoc_key == NULL)) {
 1530                 if (stcb->asoc.authinfo.assoc_key != NULL) {
 1531                         /* free the old cached key */
 1532                         sctp_free_key(stcb->asoc.authinfo.assoc_key);
 1533                 }
 1534                 skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1535                 /* the only way skey is NULL is if null key id 0 is used */
 1536                 if (skey != NULL)
 1537                         key = skey->key;
 1538                 else
 1539                         key = NULL;
 1540                 /* compute a new assoc key and cache it */
 1541                 stcb->asoc.authinfo.assoc_key =
 1542                     sctp_compute_hashkey(stcb->asoc.authinfo.random,
 1543                     stcb->asoc.authinfo.peer_random, key);
 1544                 stcb->asoc.authinfo.assoc_keyid = keyid;
 1545                 SCTPDBG(SCTP_DEBUG_AUTH1, "caching key id %u\n",
 1546                     stcb->asoc.authinfo.assoc_keyid);
 1547 #ifdef SCTP_DEBUG
 1548                 if (SCTP_AUTH_DEBUG)
 1549                         sctp_print_key(stcb->asoc.authinfo.assoc_key,
 1550                             "Assoc Key");
 1551 #endif
 1552         }
 1553 
 1554         /* set in the active key id */
 1555         auth->shared_key_id = htons(keyid);
 1556 
 1557         /* compute and fill in the digest */
 1558         (void)sctp_compute_hmac_m(stcb->asoc.peer_hmac_id, stcb->asoc.authinfo.assoc_key,
 1559             m, auth_offset, auth->hmac);
 1560 }
 1561 
 1562 
 1563 static void
 1564 sctp_zero_m(struct mbuf *m, uint32_t m_offset, uint32_t size)
 1565 {
 1566         struct mbuf *m_tmp;
 1567         uint8_t *data;
 1568 
 1569         /* sanity check */
 1570         if (m == NULL)
 1571                 return;
 1572 
 1573         /* find the correct starting mbuf and offset (get start position) */
 1574         m_tmp = m;
 1575         while ((m_tmp != NULL) && (m_offset >= (uint32_t)SCTP_BUF_LEN(m_tmp))) {
 1576                 m_offset -= SCTP_BUF_LEN(m_tmp);
 1577                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1578         }
 1579         /* now use the rest of the mbuf chain */
 1580         while ((m_tmp != NULL) && (size > 0)) {
 1581                 data = mtod(m_tmp, uint8_t *)+m_offset;
 1582                 if (size > (uint32_t)(SCTP_BUF_LEN(m_tmp) - m_offset)) {
 1583                         memset(data, 0, SCTP_BUF_LEN(m_tmp) - m_offset);
 1584                         size -= SCTP_BUF_LEN(m_tmp) - m_offset;
 1585                 } else {
 1586                         memset(data, 0, size);
 1587                         size = 0;
 1588                 }
 1589                 /* clear the offset since it's only for the first mbuf */
 1590                 m_offset = 0;
 1591                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1592         }
 1593 }
 1594 
 1595 /*-
 1596  * process the incoming Authentication chunk
 1597  * return codes:
 1598  *   -1 on any authentication error
 1599  *    0 on authentication verification
 1600  */
 1601 int
 1602 sctp_handle_auth(struct sctp_tcb *stcb, struct sctp_auth_chunk *auth,
 1603     struct mbuf *m, uint32_t offset)
 1604 {
 1605         uint16_t chunklen;
 1606         uint16_t shared_key_id;
 1607         uint16_t hmac_id;
 1608         sctp_sharedkey_t *skey;
 1609         uint32_t digestlen;
 1610         uint8_t digest[SCTP_AUTH_DIGEST_LEN_MAX];
 1611         uint8_t computed_digest[SCTP_AUTH_DIGEST_LEN_MAX];
 1612 
 1613         /* auth is checked for NULL by caller */
 1614         chunklen = ntohs(auth->ch.chunk_length);
 1615         if (chunklen < sizeof(*auth)) {
 1616                 SCTP_STAT_INCR(sctps_recvauthfailed);
 1617                 return (-1);
 1618         }
 1619         SCTP_STAT_INCR(sctps_recvauth);
 1620 
 1621         /* get the auth params */
 1622         shared_key_id = ntohs(auth->shared_key_id);
 1623         hmac_id = ntohs(auth->hmac_id);
 1624         SCTPDBG(SCTP_DEBUG_AUTH1,
 1625             "SCTP AUTH Chunk: shared key %u, HMAC id %u\n",
 1626             shared_key_id, hmac_id);
 1627 
 1628         /* is the indicated HMAC supported? */
 1629         if (!sctp_auth_is_supported_hmac(stcb->asoc.local_hmacs, hmac_id)) {
 1630                 struct mbuf *op_err;
 1631                 struct sctp_error_auth_invalid_hmac *cause;
 1632 
 1633                 SCTP_STAT_INCR(sctps_recvivalhmacid);
 1634                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1635                     "SCTP Auth: unsupported HMAC id %u\n",
 1636                     hmac_id);
 1637                 /*
 1638                  * report this in an Error Chunk: Unsupported HMAC
 1639                  * Identifier
 1640                  */
 1641                 op_err = sctp_get_mbuf_for_msg(sizeof(struct sctp_error_auth_invalid_hmac),
 1642                     0, M_NOWAIT, 1, MT_HEADER);
 1643                 if (op_err != NULL) {
 1644                         /* pre-reserve some space */
 1645                         SCTP_BUF_RESV_UF(op_err, sizeof(struct sctp_chunkhdr));
 1646                         /* fill in the error */
 1647                         cause = mtod(op_err, struct sctp_error_auth_invalid_hmac *);
 1648                         cause->cause.code = htons(SCTP_CAUSE_UNSUPPORTED_HMACID);
 1649                         cause->cause.length = htons(sizeof(struct sctp_error_auth_invalid_hmac));
 1650                         cause->hmac_id = ntohs(hmac_id);
 1651                         SCTP_BUF_LEN(op_err) = sizeof(struct sctp_error_auth_invalid_hmac);
 1652                         /* queue it */
 1653                         sctp_queue_op_err(stcb, op_err);
 1654                 }
 1655                 return (-1);
 1656         }
 1657         /* get the indicated shared key, if available */
 1658         if ((stcb->asoc.authinfo.recv_key == NULL) ||
 1659             (stcb->asoc.authinfo.recv_keyid != shared_key_id)) {
 1660                 /* find the shared key on the assoc first */
 1661                 skey = sctp_find_sharedkey(&stcb->asoc.shared_keys,
 1662                     shared_key_id);
 1663                 /* if the shared key isn't found, discard the chunk */
 1664                 if (skey == NULL) {
 1665                         SCTP_STAT_INCR(sctps_recvivalkeyid);
 1666                         SCTPDBG(SCTP_DEBUG_AUTH1,
 1667                             "SCTP Auth: unknown key id %u\n",
 1668                             shared_key_id);
 1669                         return (-1);
 1670                 }
 1671                 /* generate a notification if this is a new key id */
 1672                 if (stcb->asoc.authinfo.recv_keyid != shared_key_id)
 1673                         /*
 1674                          * sctp_ulp_notify(SCTP_NOTIFY_AUTH_NEW_KEY, stcb,
 1675                          * shared_key_id, (void
 1676                          * *)stcb->asoc.authinfo.recv_keyid);
 1677                          */
 1678                         sctp_notify_authentication(stcb, SCTP_AUTH_NEW_KEY,
 1679                             shared_key_id, stcb->asoc.authinfo.recv_keyid,
 1680                             SCTP_SO_NOT_LOCKED);
 1681                 /* compute a new recv assoc key and cache it */
 1682                 if (stcb->asoc.authinfo.recv_key != NULL)
 1683                         sctp_free_key(stcb->asoc.authinfo.recv_key);
 1684                 stcb->asoc.authinfo.recv_key =
 1685                     sctp_compute_hashkey(stcb->asoc.authinfo.random,
 1686                     stcb->asoc.authinfo.peer_random, skey->key);
 1687                 stcb->asoc.authinfo.recv_keyid = shared_key_id;
 1688 #ifdef SCTP_DEBUG
 1689                 if (SCTP_AUTH_DEBUG)
 1690                         sctp_print_key(stcb->asoc.authinfo.recv_key, "Recv Key");
 1691 #endif
 1692         }
 1693         /* validate the digest length */
 1694         digestlen = sctp_get_hmac_digest_len(hmac_id);
 1695         if (chunklen < (sizeof(*auth) + digestlen)) {
 1696                 /* invalid digest length */
 1697                 SCTP_STAT_INCR(sctps_recvauthfailed);
 1698                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1699                     "SCTP Auth: chunk too short for HMAC\n");
 1700                 return (-1);
 1701         }
 1702         /* save a copy of the digest, zero the pseudo header, and validate */
 1703         memcpy(digest, auth->hmac, digestlen);
 1704         sctp_zero_m(m, offset + sizeof(*auth), SCTP_SIZE32(digestlen));
 1705         (void)sctp_compute_hmac_m(hmac_id, stcb->asoc.authinfo.recv_key,
 1706             m, offset, computed_digest);
 1707 
 1708         /* compare the computed digest with the one in the AUTH chunk */
 1709         if (timingsafe_bcmp(digest, computed_digest, digestlen) != 0) {
 1710                 SCTP_STAT_INCR(sctps_recvauthfailed);
 1711                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1712                     "SCTP Auth: HMAC digest check failed\n");
 1713                 return (-1);
 1714         }
 1715         return (0);
 1716 }
 1717 
 1718 /*
 1719  * Generate NOTIFICATION
 1720  */
 1721 void
 1722 sctp_notify_authentication(struct sctp_tcb *stcb, uint32_t indication,
 1723     uint16_t keyid, uint16_t alt_keyid, int so_locked
 1724 #if !defined(__APPLE__) && !defined(SCTP_SO_LOCK_TESTING)
 1725     SCTP_UNUSED
 1726 #endif
 1727 )
 1728 {
 1729         struct mbuf *m_notify;
 1730         struct sctp_authkey_event *auth;
 1731         struct sctp_queued_to_read *control;
 1732 
 1733         if ((stcb == NULL) ||
 1734             (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) ||
 1735             (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_ALLGONE) ||
 1736             (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET)
 1737             ) {
 1738                 /* If the socket is gone we are out of here */
 1739                 return;
 1740         }
 1741 
 1742         if (sctp_stcb_is_feature_off(stcb->sctp_ep, stcb, SCTP_PCB_FLAGS_AUTHEVNT))
 1743                 /* event not enabled */
 1744                 return;
 1745 
 1746         m_notify = sctp_get_mbuf_for_msg(sizeof(struct sctp_authkey_event),
 1747             0, M_NOWAIT, 1, MT_HEADER);
 1748         if (m_notify == NULL)
 1749                 /* no space left */
 1750                 return;
 1751 
 1752         SCTP_BUF_LEN(m_notify) = 0;
 1753         auth = mtod(m_notify, struct sctp_authkey_event *);
 1754         memset(auth, 0, sizeof(struct sctp_authkey_event));
 1755         auth->auth_type = SCTP_AUTHENTICATION_EVENT;
 1756         auth->auth_flags = 0;
 1757         auth->auth_length = sizeof(*auth);
 1758         auth->auth_keynumber = keyid;
 1759         auth->auth_altkeynumber = alt_keyid;
 1760         auth->auth_indication = indication;
 1761         auth->auth_assoc_id = sctp_get_associd(stcb);
 1762 
 1763         SCTP_BUF_LEN(m_notify) = sizeof(*auth);
 1764         SCTP_BUF_NEXT(m_notify) = NULL;
 1765 
 1766         /* append to socket */
 1767         control = sctp_build_readq_entry(stcb, stcb->asoc.primary_destination,
 1768             0, 0, stcb->asoc.context, 0, 0, 0, m_notify);
 1769         if (control == NULL) {
 1770                 /* no memory */
 1771                 sctp_m_freem(m_notify);
 1772                 return;
 1773         }
 1774         control->length = SCTP_BUF_LEN(m_notify);
 1775         control->spec_flags = M_NOTIFICATION;
 1776         /* not that we need this */
 1777         control->tail_mbuf = m_notify;
 1778         sctp_add_to_readq(stcb->sctp_ep, stcb, control,
 1779             &stcb->sctp_socket->so_rcv, 1, SCTP_READ_LOCK_NOT_HELD, so_locked);
 1780 }
 1781 
 1782 
 1783 /*-
 1784  * validates the AUTHentication related parameters in an INIT/INIT-ACK
 1785  * Note: currently only used for INIT as INIT-ACK is handled inline
 1786  * with sctp_load_addresses_from_init()
 1787  */
 1788 int
 1789 sctp_validate_init_auth_params(struct mbuf *m, int offset, int limit)
 1790 {
 1791         struct sctp_paramhdr *phdr, param_buf;
 1792         uint16_t ptype, plen;
 1793         int peer_supports_asconf = 0;
 1794         int peer_supports_auth = 0;
 1795         int got_random = 0, got_hmacs = 0, got_chklist = 0;
 1796         uint8_t saw_asconf = 0;
 1797         uint8_t saw_asconf_ack = 0;
 1798 
 1799         /* go through each of the params. */
 1800         phdr = sctp_get_next_param(m, offset, &param_buf, sizeof(param_buf));
 1801         while (phdr) {
 1802                 ptype = ntohs(phdr->param_type);
 1803                 plen = ntohs(phdr->param_length);
 1804 
 1805                 if (offset + plen > limit) {
 1806                         break;
 1807                 }
 1808                 if (plen < sizeof(struct sctp_paramhdr)) {
 1809                         break;
 1810                 }
 1811                 if (ptype == SCTP_SUPPORTED_CHUNK_EXT) {
 1812                         /* A supported extension chunk */
 1813                         struct sctp_supported_chunk_types_param *pr_supported;
 1814                         uint8_t local_store[SCTP_SMALL_CHUNK_STORE];
 1815                         int num_ent, i;
 1816 
 1817                         if (plen > sizeof(local_store)) {
 1818                                 break;
 1819                         }
 1820                         phdr = sctp_get_next_param(m, offset,
 1821                             (struct sctp_paramhdr *)&local_store,
 1822                             plen);
 1823                         if (phdr == NULL) {
 1824                                 return (-1);
 1825                         }
 1826                         pr_supported = (struct sctp_supported_chunk_types_param *)phdr;
 1827                         num_ent = plen - sizeof(struct sctp_paramhdr);
 1828                         for (i = 0; i < num_ent; i++) {
 1829                                 switch (pr_supported->chunk_types[i]) {
 1830                                 case SCTP_ASCONF:
 1831                                 case SCTP_ASCONF_ACK:
 1832                                         peer_supports_asconf = 1;
 1833                                         break;
 1834                                 default:
 1835                                         /* one we don't care about */
 1836                                         break;
 1837                                 }
 1838                         }
 1839                 } else if (ptype == SCTP_RANDOM) {
 1840                         /* enforce the random length */
 1841                         if (plen != (sizeof(struct sctp_auth_random) +
 1842                             SCTP_AUTH_RANDOM_SIZE_REQUIRED)) {
 1843                                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1844                                     "SCTP: invalid RANDOM len\n");
 1845                                 return (-1);
 1846                         }
 1847                         got_random = 1;
 1848                 } else if (ptype == SCTP_HMAC_LIST) {
 1849                         struct sctp_auth_hmac_algo *hmacs;
 1850                         uint8_t store[SCTP_PARAM_BUFFER_SIZE];
 1851                         int num_hmacs;
 1852 
 1853                         if (plen > sizeof(store)) {
 1854                                 break;
 1855                         }
 1856                         phdr = sctp_get_next_param(m, offset,
 1857                             (struct sctp_paramhdr *)store,
 1858                             plen);
 1859                         if (phdr == NULL) {
 1860                                 return (-1);
 1861                         }
 1862                         hmacs = (struct sctp_auth_hmac_algo *)phdr;
 1863                         num_hmacs = (plen - sizeof(*hmacs)) / sizeof(hmacs->hmac_ids[0]);
 1864                         /* validate the hmac list */
 1865                         if (sctp_verify_hmac_param(hmacs, num_hmacs)) {
 1866                                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1867                                     "SCTP: invalid HMAC param\n");
 1868                                 return (-1);
 1869                         }
 1870                         got_hmacs = 1;
 1871                 } else if (ptype == SCTP_CHUNK_LIST) {
 1872                         struct sctp_auth_chunk_list *chunks;
 1873                         uint8_t chunks_store[SCTP_SMALL_CHUNK_STORE];
 1874                         int i, num_chunks;
 1875 
 1876                         if (plen > sizeof(chunks_store)) {
 1877                                 break;
 1878                         }
 1879                         phdr = sctp_get_next_param(m, offset,
 1880                             (struct sctp_paramhdr *)chunks_store,
 1881                             plen);
 1882                         if (phdr == NULL) {
 1883                                 return (-1);
 1884                         }
 1885                         /*-
 1886                          * Flip through the list and mark that the
 1887                          * peer supports asconf/asconf_ack.
 1888                          */
 1889                         chunks = (struct sctp_auth_chunk_list *)phdr;
 1890                         num_chunks = plen - sizeof(*chunks);
 1891                         for (i = 0; i < num_chunks; i++) {
 1892                                 /* record asconf/asconf-ack if listed */
 1893                                 if (chunks->chunk_types[i] == SCTP_ASCONF)
 1894                                         saw_asconf = 1;
 1895                                 if (chunks->chunk_types[i] == SCTP_ASCONF_ACK)
 1896                                         saw_asconf_ack = 1;
 1897 
 1898                         }
 1899                         if (num_chunks)
 1900                                 got_chklist = 1;
 1901                 }
 1902 
 1903                 offset += SCTP_SIZE32(plen);
 1904                 if (offset >= limit) {
 1905                         break;
 1906                 }
 1907                 phdr = sctp_get_next_param(m, offset, &param_buf,
 1908                     sizeof(param_buf));
 1909         }
 1910         /* validate authentication required parameters */
 1911         if (got_random && got_hmacs) {
 1912                 peer_supports_auth = 1;
 1913         } else {
 1914                 peer_supports_auth = 0;
 1915         }
 1916         if (!peer_supports_auth && got_chklist) {
 1917                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1918                     "SCTP: peer sent chunk list w/o AUTH\n");
 1919                 return (-1);
 1920         }
 1921         if (peer_supports_asconf && !peer_supports_auth) {
 1922                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1923                     "SCTP: peer supports ASCONF but not AUTH\n");
 1924                 return (-1);
 1925         } else if ((peer_supports_asconf) && (peer_supports_auth) &&
 1926             ((saw_asconf == 0) || (saw_asconf_ack == 0))) {
 1927                 return (-2);
 1928         }
 1929         return (0);
 1930 }
 1931 
 1932 void
 1933 sctp_initialize_auth_params(struct sctp_inpcb *inp, struct sctp_tcb *stcb)
 1934 {
 1935         uint16_t chunks_len = 0;
 1936         uint16_t hmacs_len = 0;
 1937         uint16_t random_len = SCTP_AUTH_RANDOM_SIZE_DEFAULT;
 1938         sctp_key_t *new_key;
 1939         uint16_t keylen;
 1940 
 1941         /* initialize hmac list from endpoint */
 1942         stcb->asoc.local_hmacs = sctp_copy_hmaclist(inp->sctp_ep.local_hmacs);
 1943         if (stcb->asoc.local_hmacs != NULL) {
 1944                 hmacs_len = stcb->asoc.local_hmacs->num_algo *
 1945                     sizeof(stcb->asoc.local_hmacs->hmac[0]);
 1946         }
 1947         /* initialize auth chunks list from endpoint */
 1948         stcb->asoc.local_auth_chunks =
 1949             sctp_copy_chunklist(inp->sctp_ep.local_auth_chunks);
 1950         if (stcb->asoc.local_auth_chunks != NULL) {
 1951                 int i;
 1952 
 1953                 for (i = 0; i < 256; i++) {
 1954                         if (stcb->asoc.local_auth_chunks->chunks[i])
 1955                                 chunks_len++;
 1956                 }
 1957         }
 1958         /* copy defaults from the endpoint */
 1959         stcb->asoc.authinfo.active_keyid = inp->sctp_ep.default_keyid;
 1960 
 1961         /* copy out the shared key list (by reference) from the endpoint */
 1962         (void)sctp_copy_skeylist(&inp->sctp_ep.shared_keys,
 1963             &stcb->asoc.shared_keys);
 1964 
 1965         /* now set the concatenated key (random + chunks + hmacs) */
 1966         /* key includes parameter headers */
 1967         keylen = (3 * sizeof(struct sctp_paramhdr)) + random_len + chunks_len +
 1968             hmacs_len;
 1969         new_key = sctp_alloc_key(keylen);
 1970         if (new_key != NULL) {
 1971                 struct sctp_paramhdr *ph;
 1972                 int plen;
 1973 
 1974                 /* generate and copy in the RANDOM */
 1975                 ph = (struct sctp_paramhdr *)new_key->key;
 1976                 ph->param_type = htons(SCTP_RANDOM);
 1977                 plen = sizeof(*ph) + random_len;
 1978                 ph->param_length = htons(plen);
 1979                 SCTP_READ_RANDOM(new_key->key + sizeof(*ph), random_len);
 1980                 keylen = plen;
 1981 
 1982                 /* append in the AUTH chunks */
 1983                 /* NOTE: currently we always have chunks to list */
 1984                 ph = (struct sctp_paramhdr *)(new_key->key + keylen);
 1985                 ph->param_type = htons(SCTP_CHUNK_LIST);
 1986                 plen = sizeof(*ph) + chunks_len;
 1987                 ph->param_length = htons(plen);
 1988                 keylen += sizeof(*ph);
 1989                 if (stcb->asoc.local_auth_chunks) {
 1990                         int i;
 1991 
 1992                         for (i = 0; i < 256; i++) {
 1993                                 if (stcb->asoc.local_auth_chunks->chunks[i])
 1994                                         new_key->key[keylen++] = i;
 1995                         }
 1996                 }
 1997 
 1998                 /* append in the HMACs */
 1999                 ph = (struct sctp_paramhdr *)(new_key->key + keylen);
 2000                 ph->param_type = htons(SCTP_HMAC_LIST);
 2001                 plen = sizeof(*ph) + hmacs_len;
 2002                 ph->param_length = htons(plen);
 2003                 keylen += sizeof(*ph);
 2004                 (void)sctp_serialize_hmaclist(stcb->asoc.local_hmacs,
 2005                     new_key->key + keylen);
 2006         }
 2007         if (stcb->asoc.authinfo.random != NULL)
 2008                 sctp_free_key(stcb->asoc.authinfo.random);
 2009         stcb->asoc.authinfo.random = new_key;
 2010         stcb->asoc.authinfo.random_len = random_len;
 2011 }
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FreeBSD/Linux Kernel Cross Reference sys/netinet/sctp_auth.c

FreeBSD/Linux Kernel Cross Reference
sys/netinet/sctp_auth.c
