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("$FreeBSD$");
   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 {
  570         sctp_sharedkey_t *skey;
  571 
  572         /* find the shared key */
  573         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, key_id);
  574 
  575         /* decrement the ref count */
  576         if (skey) {
  577                 SCTPDBG(SCTP_DEBUG_AUTH2,
  578                     "%s: stcb %p key %u refcount release to %d\n",
  579                     __func__, (void *)stcb, key_id, skey->refcount);
  580 
  581                 /* see if a notification should be generated */
  582                 if ((skey->refcount <= 2) && (skey->deactivated)) {
  583                         /* notify ULP that key is no longer used */
  584                         sctp_ulp_notify(SCTP_NOTIFY_AUTH_FREE_KEY, stcb,
  585                             key_id, 0, so_locked);
  586                         SCTPDBG(SCTP_DEBUG_AUTH2,
  587                             "%s: stcb %p key %u no longer used, %d\n",
  588                             __func__, (void *)stcb, key_id, skey->refcount);
  589                 }
  590                 sctp_free_sharedkey(skey);
  591         }
  592 }
  593 
  594 static sctp_sharedkey_t *
  595 sctp_copy_sharedkey(const sctp_sharedkey_t *skey)
  596 {
  597         sctp_sharedkey_t *new_skey;
  598 
  599         if (skey == NULL)
  600                 return (NULL);
  601         new_skey = sctp_alloc_sharedkey();
  602         if (new_skey == NULL)
  603                 return (NULL);
  604         if (skey->key != NULL)
  605                 new_skey->key = sctp_set_key(skey->key->key, skey->key->keylen);
  606         else
  607                 new_skey->key = NULL;
  608         new_skey->keyid = skey->keyid;
  609         return (new_skey);
  610 }
  611 
  612 int
  613 sctp_copy_skeylist(const struct sctp_keyhead *src, struct sctp_keyhead *dest)
  614 {
  615         sctp_sharedkey_t *skey, *new_skey;
  616         int count = 0;
  617 
  618         if ((src == NULL) || (dest == NULL))
  619                 return (0);
  620         LIST_FOREACH(skey, src, next) {
  621                 new_skey = sctp_copy_sharedkey(skey);
  622                 if (new_skey != NULL) {
  623                         if (sctp_insert_sharedkey(dest, new_skey)) {
  624                                 sctp_free_sharedkey(new_skey);
  625                         } else {
  626                                 count++;
  627                         }
  628                 }
  629         }
  630         return (count);
  631 }
  632 
  633 
  634 sctp_hmaclist_t *
  635 sctp_alloc_hmaclist(uint16_t num_hmacs)
  636 {
  637         sctp_hmaclist_t *new_list;
  638         int alloc_size;
  639 
  640         alloc_size = sizeof(*new_list) + num_hmacs * sizeof(new_list->hmac[0]);
  641         SCTP_MALLOC(new_list, sctp_hmaclist_t *, alloc_size,
  642             SCTP_M_AUTH_HL);
  643         if (new_list == NULL) {
  644                 /* out of memory */
  645                 return (NULL);
  646         }
  647         new_list->max_algo = num_hmacs;
  648         new_list->num_algo = 0;
  649         return (new_list);
  650 }
  651 
  652 void
  653 sctp_free_hmaclist(sctp_hmaclist_t *list)
  654 {
  655         if (list != NULL) {
  656                 SCTP_FREE(list, SCTP_M_AUTH_HL);
  657         }
  658 }
  659 
  660 int
  661 sctp_auth_add_hmacid(sctp_hmaclist_t *list, uint16_t hmac_id)
  662 {
  663         int i;
  664 
  665         if (list == NULL)
  666                 return (-1);
  667         if (list->num_algo == list->max_algo) {
  668                 SCTPDBG(SCTP_DEBUG_AUTH1,
  669                     "SCTP: HMAC id list full, ignoring add %u\n", hmac_id);
  670                 return (-1);
  671         }
  672         if ((hmac_id != SCTP_AUTH_HMAC_ID_SHA1) &&
  673             (hmac_id != SCTP_AUTH_HMAC_ID_SHA256)) {
  674                 return (-1);
  675         }
  676         /* Now is it already in the list */
  677         for (i = 0; i < list->num_algo; i++) {
  678                 if (list->hmac[i] == hmac_id) {
  679                         /* already in list */
  680                         return (-1);
  681                 }
  682         }
  683         SCTPDBG(SCTP_DEBUG_AUTH1, "SCTP: add HMAC id %u to list\n", hmac_id);
  684         list->hmac[list->num_algo++] = hmac_id;
  685         return (0);
  686 }
  687 
  688 sctp_hmaclist_t *
  689 sctp_copy_hmaclist(sctp_hmaclist_t *list)
  690 {
  691         sctp_hmaclist_t *new_list;
  692         int i;
  693 
  694         if (list == NULL)
  695                 return (NULL);
  696         /* get a new list */
  697         new_list = sctp_alloc_hmaclist(list->max_algo);
  698         if (new_list == NULL)
  699                 return (NULL);
  700         /* copy it */
  701         new_list->max_algo = list->max_algo;
  702         new_list->num_algo = list->num_algo;
  703         for (i = 0; i < list->num_algo; i++)
  704                 new_list->hmac[i] = list->hmac[i];
  705         return (new_list);
  706 }
  707 
  708 sctp_hmaclist_t *
  709 sctp_default_supported_hmaclist(void)
  710 {
  711         sctp_hmaclist_t *new_list;
  712 
  713         new_list = sctp_alloc_hmaclist(2);
  714         if (new_list == NULL)
  715                 return (NULL);
  716         /* We prefer SHA256, so list it first */
  717         (void)sctp_auth_add_hmacid(new_list, SCTP_AUTH_HMAC_ID_SHA256);
  718         (void)sctp_auth_add_hmacid(new_list, SCTP_AUTH_HMAC_ID_SHA1);
  719         return (new_list);
  720 }
  721 
  722 /*-
  723  * HMAC algos are listed in priority/preference order
  724  * find the best HMAC id to use for the peer based on local support
  725  */
  726 uint16_t
  727 sctp_negotiate_hmacid(sctp_hmaclist_t *peer, sctp_hmaclist_t *local)
  728 {
  729         int i, j;
  730 
  731         if ((local == NULL) || (peer == NULL))
  732                 return (SCTP_AUTH_HMAC_ID_RSVD);
  733 
  734         for (i = 0; i < peer->num_algo; i++) {
  735                 for (j = 0; j < local->num_algo; j++) {
  736                         if (peer->hmac[i] == local->hmac[j]) {
  737                                 /* found the "best" one */
  738                                 SCTPDBG(SCTP_DEBUG_AUTH1,
  739                                     "SCTP: negotiated peer HMAC id %u\n",
  740                                     peer->hmac[i]);
  741                                 return (peer->hmac[i]);
  742                         }
  743                 }
  744         }
  745         /* didn't find one! */
  746         return (SCTP_AUTH_HMAC_ID_RSVD);
  747 }
  748 
  749 /*-
  750  * serialize the HMAC algo list and return space used
  751  * caller must guarantee ptr has appropriate space
  752  */
  753 int
  754 sctp_serialize_hmaclist(sctp_hmaclist_t *list, uint8_t *ptr)
  755 {
  756         int i;
  757         uint16_t hmac_id;
  758 
  759         if (list == NULL)
  760                 return (0);
  761 
  762         for (i = 0; i < list->num_algo; i++) {
  763                 hmac_id = htons(list->hmac[i]);
  764                 memcpy(ptr, &hmac_id, sizeof(hmac_id));
  765                 ptr += sizeof(hmac_id);
  766         }
  767         return (list->num_algo * sizeof(hmac_id));
  768 }
  769 
  770 int
  771 sctp_verify_hmac_param(struct sctp_auth_hmac_algo *hmacs, uint32_t num_hmacs)
  772 {
  773         uint32_t i;
  774 
  775         for (i = 0; i < num_hmacs; i++) {
  776                 if (ntohs(hmacs->hmac_ids[i]) == SCTP_AUTH_HMAC_ID_SHA1) {
  777                         return (0);
  778                 }
  779         }
  780         return (-1);
  781 }
  782 
  783 sctp_authinfo_t *
  784 sctp_alloc_authinfo(void)
  785 {
  786         sctp_authinfo_t *new_authinfo;
  787 
  788         SCTP_MALLOC(new_authinfo, sctp_authinfo_t *, sizeof(*new_authinfo),
  789             SCTP_M_AUTH_IF);
  790 
  791         if (new_authinfo == NULL) {
  792                 /* out of memory */
  793                 return (NULL);
  794         }
  795         memset(new_authinfo, 0, sizeof(*new_authinfo));
  796         return (new_authinfo);
  797 }
  798 
  799 void
  800 sctp_free_authinfo(sctp_authinfo_t *authinfo)
  801 {
  802         if (authinfo == NULL)
  803                 return;
  804 
  805         if (authinfo->random != NULL)
  806                 sctp_free_key(authinfo->random);
  807         if (authinfo->peer_random != NULL)
  808                 sctp_free_key(authinfo->peer_random);
  809         if (authinfo->assoc_key != NULL)
  810                 sctp_free_key(authinfo->assoc_key);
  811         if (authinfo->recv_key != NULL)
  812                 sctp_free_key(authinfo->recv_key);
  813 
  814         /* We are NOT dynamically allocating authinfo's right now... */
  815         /* SCTP_FREE(authinfo, SCTP_M_AUTH_??); */
  816 }
  817 
  818 
  819 uint32_t
  820 sctp_get_auth_chunk_len(uint16_t hmac_algo)
  821 {
  822         int size;
  823 
  824         size = sizeof(struct sctp_auth_chunk) + sctp_get_hmac_digest_len(hmac_algo);
  825         return (SCTP_SIZE32(size));
  826 }
  827 
  828 uint32_t
  829 sctp_get_hmac_digest_len(uint16_t hmac_algo)
  830 {
  831         switch (hmac_algo) {
  832         case SCTP_AUTH_HMAC_ID_SHA1:
  833                 return (SCTP_AUTH_DIGEST_LEN_SHA1);
  834         case SCTP_AUTH_HMAC_ID_SHA256:
  835                 return (SCTP_AUTH_DIGEST_LEN_SHA256);
  836         default:
  837                 /* unknown HMAC algorithm: can't do anything */
  838                 return (0);
  839         }                       /* end switch */
  840 }
  841 
  842 static inline int
  843 sctp_get_hmac_block_len(uint16_t hmac_algo)
  844 {
  845         switch (hmac_algo) {
  846         case SCTP_AUTH_HMAC_ID_SHA1:
  847                 return (64);
  848         case SCTP_AUTH_HMAC_ID_SHA256:
  849                 return (64);
  850         case SCTP_AUTH_HMAC_ID_RSVD:
  851         default:
  852                 /* unknown HMAC algorithm: can't do anything */
  853                 return (0);
  854         }                       /* end switch */
  855 }
  856 
  857 static void
  858 sctp_hmac_init(uint16_t hmac_algo, sctp_hash_context_t *ctx)
  859 {
  860         switch (hmac_algo) {
  861         case SCTP_AUTH_HMAC_ID_SHA1:
  862                 SCTP_SHA1_INIT(&ctx->sha1);
  863                 break;
  864         case SCTP_AUTH_HMAC_ID_SHA256:
  865                 SCTP_SHA256_INIT(&ctx->sha256);
  866                 break;
  867         case SCTP_AUTH_HMAC_ID_RSVD:
  868         default:
  869                 /* unknown HMAC algorithm: can't do anything */
  870                 return;
  871         }                       /* end switch */
  872 }
  873 
  874 static void
  875 sctp_hmac_update(uint16_t hmac_algo, sctp_hash_context_t *ctx,
  876     uint8_t *text, uint32_t textlen)
  877 {
  878         switch (hmac_algo) {
  879         case SCTP_AUTH_HMAC_ID_SHA1:
  880                 SCTP_SHA1_UPDATE(&ctx->sha1, text, textlen);
  881                 break;
  882         case SCTP_AUTH_HMAC_ID_SHA256:
  883                 SCTP_SHA256_UPDATE(&ctx->sha256, text, textlen);
  884                 break;
  885         case SCTP_AUTH_HMAC_ID_RSVD:
  886         default:
  887                 /* unknown HMAC algorithm: can't do anything */
  888                 return;
  889         }                       /* end switch */
  890 }
  891 
  892 static void
  893 sctp_hmac_final(uint16_t hmac_algo, sctp_hash_context_t *ctx,
  894     uint8_t *digest)
  895 {
  896         switch (hmac_algo) {
  897         case SCTP_AUTH_HMAC_ID_SHA1:
  898                 SCTP_SHA1_FINAL(digest, &ctx->sha1);
  899                 break;
  900         case SCTP_AUTH_HMAC_ID_SHA256:
  901                 SCTP_SHA256_FINAL(digest, &ctx->sha256);
  902                 break;
  903         case SCTP_AUTH_HMAC_ID_RSVD:
  904         default:
  905                 /* unknown HMAC algorithm: can't do anything */
  906                 return;
  907         }                       /* end switch */
  908 }
  909 
  910 /*-
  911  * Keyed-Hashing for Message Authentication: FIPS 198 (RFC 2104)
  912  *
  913  * Compute the HMAC digest using the desired hash key, text, and HMAC
  914  * algorithm.  Resulting digest is placed in 'digest' and digest length
  915  * is returned, if the HMAC was performed.
  916  *
  917  * WARNING: it is up to the caller to supply sufficient space to hold the
  918  * resultant digest.
  919  */
  920 uint32_t
  921 sctp_hmac(uint16_t hmac_algo, uint8_t *key, uint32_t keylen,
  922     uint8_t *text, uint32_t textlen, uint8_t *digest)
  923 {
  924         uint32_t digestlen;
  925         uint32_t blocklen;
  926         sctp_hash_context_t ctx;
  927         uint8_t ipad[128], opad[128];   /* keyed hash inner/outer pads */
  928         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
  929         uint32_t i;
  930 
  931         /* sanity check the material and length */
  932         if ((key == NULL) || (keylen == 0) || (text == NULL) ||
  933             (textlen == 0) || (digest == NULL)) {
  934                 /* can't do HMAC with empty key or text or digest store */
  935                 return (0);
  936         }
  937         /* validate the hmac algo and get the digest length */
  938         digestlen = sctp_get_hmac_digest_len(hmac_algo);
  939         if (digestlen == 0)
  940                 return (0);
  941 
  942         /* hash the key if it is longer than the hash block size */
  943         blocklen = sctp_get_hmac_block_len(hmac_algo);
  944         if (keylen > blocklen) {
  945                 sctp_hmac_init(hmac_algo, &ctx);
  946                 sctp_hmac_update(hmac_algo, &ctx, key, keylen);
  947                 sctp_hmac_final(hmac_algo, &ctx, temp);
  948                 /* set the hashed key as the key */
  949                 keylen = digestlen;
  950                 key = temp;
  951         }
  952         /* initialize the inner/outer pads with the key and "append" zeroes */
  953         memset(ipad, 0, blocklen);
  954         memset(opad, 0, blocklen);
  955         memcpy(ipad, key, keylen);
  956         memcpy(opad, key, keylen);
  957 
  958         /* XOR the key with ipad and opad values */
  959         for (i = 0; i < blocklen; i++) {
  960                 ipad[i] ^= 0x36;
  961                 opad[i] ^= 0x5c;
  962         }
  963 
  964         /* perform inner hash */
  965         sctp_hmac_init(hmac_algo, &ctx);
  966         sctp_hmac_update(hmac_algo, &ctx, ipad, blocklen);
  967         sctp_hmac_update(hmac_algo, &ctx, text, textlen);
  968         sctp_hmac_final(hmac_algo, &ctx, temp);
  969 
  970         /* perform outer hash */
  971         sctp_hmac_init(hmac_algo, &ctx);
  972         sctp_hmac_update(hmac_algo, &ctx, opad, blocklen);
  973         sctp_hmac_update(hmac_algo, &ctx, temp, digestlen);
  974         sctp_hmac_final(hmac_algo, &ctx, digest);
  975 
  976         return (digestlen);
  977 }
  978 
  979 /* mbuf version */
  980 uint32_t
  981 sctp_hmac_m(uint16_t hmac_algo, uint8_t *key, uint32_t keylen,
  982     struct mbuf *m, uint32_t m_offset, uint8_t *digest, uint32_t trailer)
  983 {
  984         uint32_t digestlen;
  985         uint32_t blocklen;
  986         sctp_hash_context_t ctx;
  987         uint8_t ipad[128], opad[128];   /* keyed hash inner/outer pads */
  988         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
  989         uint32_t i;
  990         struct mbuf *m_tmp;
  991 
  992         /* sanity check the material and length */
  993         if ((key == NULL) || (keylen == 0) || (m == NULL) || (digest == NULL)) {
  994                 /* can't do HMAC with empty key or text or digest store */
  995                 return (0);
  996         }
  997         /* validate the hmac algo and get the digest length */
  998         digestlen = sctp_get_hmac_digest_len(hmac_algo);
  999         if (digestlen == 0)
 1000                 return (0);
 1001 
 1002         /* hash the key if it is longer than the hash block size */
 1003         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1004         if (keylen > blocklen) {
 1005                 sctp_hmac_init(hmac_algo, &ctx);
 1006                 sctp_hmac_update(hmac_algo, &ctx, key, keylen);
 1007                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1008                 /* set the hashed key as the key */
 1009                 keylen = digestlen;
 1010                 key = temp;
 1011         }
 1012         /* initialize the inner/outer pads with the key and "append" zeroes */
 1013         memset(ipad, 0, blocklen);
 1014         memset(opad, 0, blocklen);
 1015         memcpy(ipad, key, keylen);
 1016         memcpy(opad, key, keylen);
 1017 
 1018         /* XOR the key with ipad and opad values */
 1019         for (i = 0; i < blocklen; i++) {
 1020                 ipad[i] ^= 0x36;
 1021                 opad[i] ^= 0x5c;
 1022         }
 1023 
 1024         /* perform inner hash */
 1025         sctp_hmac_init(hmac_algo, &ctx);
 1026         sctp_hmac_update(hmac_algo, &ctx, ipad, blocklen);
 1027         /* find the correct starting mbuf and offset (get start of text) */
 1028         m_tmp = m;
 1029         while ((m_tmp != NULL) && (m_offset >= (uint32_t)SCTP_BUF_LEN(m_tmp))) {
 1030                 m_offset -= SCTP_BUF_LEN(m_tmp);
 1031                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1032         }
 1033         /* now use the rest of the mbuf chain for the text */
 1034         while (m_tmp != NULL) {
 1035                 if ((SCTP_BUF_NEXT(m_tmp) == NULL) && trailer) {
 1036                         sctp_hmac_update(hmac_algo, &ctx, mtod(m_tmp, uint8_t *)+m_offset,
 1037                             SCTP_BUF_LEN(m_tmp) - (trailer + m_offset));
 1038                 } else {
 1039                         sctp_hmac_update(hmac_algo, &ctx, mtod(m_tmp, uint8_t *)+m_offset,
 1040                             SCTP_BUF_LEN(m_tmp) - m_offset);
 1041                 }
 1042 
 1043                 /* clear the offset since it's only for the first mbuf */
 1044                 m_offset = 0;
 1045                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1046         }
 1047         sctp_hmac_final(hmac_algo, &ctx, temp);
 1048 
 1049         /* perform outer hash */
 1050         sctp_hmac_init(hmac_algo, &ctx);
 1051         sctp_hmac_update(hmac_algo, &ctx, opad, blocklen);
 1052         sctp_hmac_update(hmac_algo, &ctx, temp, digestlen);
 1053         sctp_hmac_final(hmac_algo, &ctx, digest);
 1054 
 1055         return (digestlen);
 1056 }
 1057 
 1058 /*
 1059  * computes the requested HMAC using a key struct (which may be modified if
 1060  * the keylen exceeds the HMAC block len).
 1061  */
 1062 uint32_t
 1063 sctp_compute_hmac(uint16_t hmac_algo, sctp_key_t *key, uint8_t *text,
 1064     uint32_t textlen, uint8_t *digest)
 1065 {
 1066         uint32_t digestlen;
 1067         uint32_t blocklen;
 1068         sctp_hash_context_t ctx;
 1069         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
 1070 
 1071         /* sanity check */
 1072         if ((key == NULL) || (text == NULL) || (textlen == 0) ||
 1073             (digest == NULL)) {
 1074                 /* can't do HMAC with empty key or text or digest store */
 1075                 return (0);
 1076         }
 1077         /* validate the hmac algo and get the digest length */
 1078         digestlen = sctp_get_hmac_digest_len(hmac_algo);
 1079         if (digestlen == 0)
 1080                 return (0);
 1081 
 1082         /* hash the key if it is longer than the hash block size */
 1083         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1084         if (key->keylen > blocklen) {
 1085                 sctp_hmac_init(hmac_algo, &ctx);
 1086                 sctp_hmac_update(hmac_algo, &ctx, key->key, key->keylen);
 1087                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1088                 /* save the hashed key as the new key */
 1089                 key->keylen = digestlen;
 1090                 memcpy(key->key, temp, key->keylen);
 1091         }
 1092         return (sctp_hmac(hmac_algo, key->key, key->keylen, text, textlen,
 1093             digest));
 1094 }
 1095 
 1096 /* mbuf version */
 1097 uint32_t
 1098 sctp_compute_hmac_m(uint16_t hmac_algo, sctp_key_t *key, struct mbuf *m,
 1099     uint32_t m_offset, uint8_t *digest)
 1100 {
 1101         uint32_t digestlen;
 1102         uint32_t blocklen;
 1103         sctp_hash_context_t ctx;
 1104         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
 1105 
 1106         /* sanity check */
 1107         if ((key == NULL) || (m == NULL) || (digest == NULL)) {
 1108                 /* can't do HMAC with empty key or text or digest store */
 1109                 return (0);
 1110         }
 1111         /* validate the hmac algo and get the digest length */
 1112         digestlen = sctp_get_hmac_digest_len(hmac_algo);
 1113         if (digestlen == 0)
 1114                 return (0);
 1115 
 1116         /* hash the key if it is longer than the hash block size */
 1117         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1118         if (key->keylen > blocklen) {
 1119                 sctp_hmac_init(hmac_algo, &ctx);
 1120                 sctp_hmac_update(hmac_algo, &ctx, key->key, key->keylen);
 1121                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1122                 /* save the hashed key as the new key */
 1123                 key->keylen = digestlen;
 1124                 memcpy(key->key, temp, key->keylen);
 1125         }
 1126         return (sctp_hmac_m(hmac_algo, key->key, key->keylen, m, m_offset, digest, 0));
 1127 }
 1128 
 1129 int
 1130 sctp_auth_is_supported_hmac(sctp_hmaclist_t *list, uint16_t id)
 1131 {
 1132         int i;
 1133 
 1134         if ((list == NULL) || (id == SCTP_AUTH_HMAC_ID_RSVD))
 1135                 return (0);
 1136 
 1137         for (i = 0; i < list->num_algo; i++)
 1138                 if (list->hmac[i] == id)
 1139                         return (1);
 1140 
 1141         /* not in the list */
 1142         return (0);
 1143 }
 1144 
 1145 
 1146 /*-
 1147  * clear any cached key(s) if they match the given key id on an association.
 1148  * the cached key(s) will be recomputed and re-cached at next use.
 1149  * ASSUMES TCB_LOCK is already held
 1150  */
 1151 void
 1152 sctp_clear_cachedkeys(struct sctp_tcb *stcb, uint16_t keyid)
 1153 {
 1154         if (stcb == NULL)
 1155                 return;
 1156 
 1157         if (keyid == stcb->asoc.authinfo.assoc_keyid) {
 1158                 sctp_free_key(stcb->asoc.authinfo.assoc_key);
 1159                 stcb->asoc.authinfo.assoc_key = NULL;
 1160         }
 1161         if (keyid == stcb->asoc.authinfo.recv_keyid) {
 1162                 sctp_free_key(stcb->asoc.authinfo.recv_key);
 1163                 stcb->asoc.authinfo.recv_key = NULL;
 1164         }
 1165 }
 1166 
 1167 /*-
 1168  * clear any cached key(s) if they match the given key id for all assocs on
 1169  * an endpoint.
 1170  * ASSUMES INP_WLOCK is already held
 1171  */
 1172 void
 1173 sctp_clear_cachedkeys_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1174 {
 1175         struct sctp_tcb *stcb;
 1176 
 1177         if (inp == NULL)
 1178                 return;
 1179 
 1180         /* clear the cached keys on all assocs on this instance */
 1181         LIST_FOREACH(stcb, &inp->sctp_asoc_list, sctp_tcblist) {
 1182                 SCTP_TCB_LOCK(stcb);
 1183                 sctp_clear_cachedkeys(stcb, keyid);
 1184                 SCTP_TCB_UNLOCK(stcb);
 1185         }
 1186 }
 1187 
 1188 /*-
 1189  * delete a shared key from an association
 1190  * ASSUMES TCB_LOCK is already held
 1191  */
 1192 int
 1193 sctp_delete_sharedkey(struct sctp_tcb *stcb, uint16_t keyid)
 1194 {
 1195         sctp_sharedkey_t *skey;
 1196 
 1197         if (stcb == NULL)
 1198                 return (-1);
 1199 
 1200         /* is the keyid the assoc active sending key */
 1201         if (keyid == stcb->asoc.authinfo.active_keyid)
 1202                 return (-1);
 1203 
 1204         /* does the key exist? */
 1205         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1206         if (skey == NULL)
 1207                 return (-1);
 1208 
 1209         /* are there other refcount holders on the key? */
 1210         if (skey->refcount > 1)
 1211                 return (-1);
 1212 
 1213         /* remove it */
 1214         LIST_REMOVE(skey, next);
 1215         sctp_free_sharedkey(skey);      /* frees skey->key as well */
 1216 
 1217         /* clear any cached keys */
 1218         sctp_clear_cachedkeys(stcb, keyid);
 1219         return (0);
 1220 }
 1221 
 1222 /*-
 1223  * deletes a shared key from the endpoint
 1224  * ASSUMES INP_WLOCK is already held
 1225  */
 1226 int
 1227 sctp_delete_sharedkey_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1228 {
 1229         sctp_sharedkey_t *skey;
 1230 
 1231         if (inp == NULL)
 1232                 return (-1);
 1233 
 1234         /* is the keyid the active sending key on the endpoint */
 1235         if (keyid == inp->sctp_ep.default_keyid)
 1236                 return (-1);
 1237 
 1238         /* does the key exist? */
 1239         skey = sctp_find_sharedkey(&inp->sctp_ep.shared_keys, keyid);
 1240         if (skey == NULL)
 1241                 return (-1);
 1242 
 1243         /* endpoint keys are not refcounted */
 1244 
 1245         /* remove it */
 1246         LIST_REMOVE(skey, next);
 1247         sctp_free_sharedkey(skey);      /* frees skey->key as well */
 1248 
 1249         /* clear any cached keys */
 1250         sctp_clear_cachedkeys_ep(inp, keyid);
 1251         return (0);
 1252 }
 1253 
 1254 /*-
 1255  * set the active key on an association
 1256  * ASSUMES TCB_LOCK is already held
 1257  */
 1258 int
 1259 sctp_auth_setactivekey(struct sctp_tcb *stcb, uint16_t keyid)
 1260 {
 1261         sctp_sharedkey_t *skey = NULL;
 1262 
 1263         /* find the key on the assoc */
 1264         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1265         if (skey == NULL) {
 1266                 /* that key doesn't exist */
 1267                 return (-1);
 1268         }
 1269         if ((skey->deactivated) && (skey->refcount > 1)) {
 1270                 /* can't reactivate a deactivated key with other refcounts */
 1271                 return (-1);
 1272         }
 1273 
 1274         /* set the (new) active key */
 1275         stcb->asoc.authinfo.active_keyid = keyid;
 1276         /* reset the deactivated flag */
 1277         skey->deactivated = 0;
 1278 
 1279         return (0);
 1280 }
 1281 
 1282 /*-
 1283  * set the active key on an endpoint
 1284  * ASSUMES INP_WLOCK is already held
 1285  */
 1286 int
 1287 sctp_auth_setactivekey_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1288 {
 1289         sctp_sharedkey_t *skey;
 1290 
 1291         /* find the key */
 1292         skey = sctp_find_sharedkey(&inp->sctp_ep.shared_keys, keyid);
 1293         if (skey == NULL) {
 1294                 /* that key doesn't exist */
 1295                 return (-1);
 1296         }
 1297         inp->sctp_ep.default_keyid = keyid;
 1298         return (0);
 1299 }
 1300 
 1301 /*-
 1302  * deactivates a shared key from the association
 1303  * ASSUMES INP_WLOCK is already held
 1304  */
 1305 int
 1306 sctp_deact_sharedkey(struct sctp_tcb *stcb, uint16_t keyid)
 1307 {
 1308         sctp_sharedkey_t *skey;
 1309 
 1310         if (stcb == NULL)
 1311                 return (-1);
 1312 
 1313         /* is the keyid the assoc active sending key */
 1314         if (keyid == stcb->asoc.authinfo.active_keyid)
 1315                 return (-1);
 1316 
 1317         /* does the key exist? */
 1318         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1319         if (skey == NULL)
 1320                 return (-1);
 1321 
 1322         /* are there other refcount holders on the key? */
 1323         if (skey->refcount == 1) {
 1324                 /* no other users, send a notification for this key */
 1325                 sctp_ulp_notify(SCTP_NOTIFY_AUTH_FREE_KEY, stcb, keyid, 0,
 1326                     SCTP_SO_LOCKED);
 1327         }
 1328 
 1329         /* mark the key as deactivated */
 1330         skey->deactivated = 1;
 1331 
 1332         return (0);
 1333 }
 1334 
 1335 /*-
 1336  * deactivates a shared key from the endpoint
 1337  * ASSUMES INP_WLOCK is already held
 1338  */
 1339 int
 1340 sctp_deact_sharedkey_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1341 {
 1342         sctp_sharedkey_t *skey;
 1343 
 1344         if (inp == NULL)
 1345                 return (-1);
 1346 
 1347         /* is the keyid the active sending key on the endpoint */
 1348         if (keyid == inp->sctp_ep.default_keyid)
 1349                 return (-1);
 1350 
 1351         /* does the key exist? */
 1352         skey = sctp_find_sharedkey(&inp->sctp_ep.shared_keys, keyid);
 1353         if (skey == NULL)
 1354                 return (-1);
 1355 
 1356         /* endpoint keys are not refcounted */
 1357 
 1358         /* remove it */
 1359         LIST_REMOVE(skey, next);
 1360         sctp_free_sharedkey(skey);      /* frees skey->key as well */
 1361 
 1362         return (0);
 1363 }
 1364 
 1365 /*
 1366  * get local authentication parameters from cookie (from INIT-ACK)
 1367  */
 1368 void
 1369 sctp_auth_get_cookie_params(struct sctp_tcb *stcb, struct mbuf *m,
 1370     uint32_t offset, uint32_t length)
 1371 {
 1372         struct sctp_paramhdr *phdr, tmp_param;
 1373         uint16_t plen, ptype;
 1374         uint8_t random_store[SCTP_PARAM_BUFFER_SIZE];
 1375         struct sctp_auth_random *p_random = NULL;
 1376         uint16_t random_len = 0;
 1377         uint8_t hmacs_store[SCTP_PARAM_BUFFER_SIZE];
 1378         struct sctp_auth_hmac_algo *hmacs = NULL;
 1379         uint16_t hmacs_len = 0;
 1380         uint8_t chunks_store[SCTP_PARAM_BUFFER_SIZE];
 1381         struct sctp_auth_chunk_list *chunks = NULL;
 1382         uint16_t num_chunks = 0;
 1383         sctp_key_t *new_key;
 1384         uint32_t keylen;
 1385 
 1386         /* convert to upper bound */
 1387         length += offset;
 1388 
 1389         phdr = (struct sctp_paramhdr *)sctp_m_getptr(m, offset,
 1390             sizeof(struct sctp_paramhdr), (uint8_t *)&tmp_param);
 1391         while (phdr != NULL) {
 1392                 ptype = ntohs(phdr->param_type);
 1393                 plen = ntohs(phdr->param_length);
 1394 
 1395                 if ((plen < sizeof(struct sctp_paramhdr)) ||
 1396                     (offset + plen > length))
 1397                         break;
 1398 
 1399                 if (ptype == SCTP_RANDOM) {
 1400                         if (plen > sizeof(random_store))
 1401                                 break;
 1402                         phdr = sctp_get_next_param(m, offset,
 1403                             (struct sctp_paramhdr *)random_store, plen);
 1404                         if (phdr == NULL)
 1405                                 return;
 1406                         /* save the random and length for the key */
 1407                         p_random = (struct sctp_auth_random *)phdr;
 1408                         random_len = plen - sizeof(*p_random);
 1409                 } else if (ptype == SCTP_HMAC_LIST) {
 1410                         uint16_t num_hmacs;
 1411                         uint16_t i;
 1412 
 1413                         if (plen > sizeof(hmacs_store))
 1414                                 break;
 1415                         phdr = sctp_get_next_param(m, offset,
 1416                             (struct sctp_paramhdr *)hmacs_store, plen);
 1417                         if (phdr == NULL)
 1418                                 return;
 1419                         /* save the hmacs list and num for the key */
 1420                         hmacs = (struct sctp_auth_hmac_algo *)phdr;
 1421                         hmacs_len = plen - sizeof(*hmacs);
 1422                         num_hmacs = hmacs_len / sizeof(hmacs->hmac_ids[0]);
 1423                         if (stcb->asoc.local_hmacs != NULL)
 1424                                 sctp_free_hmaclist(stcb->asoc.local_hmacs);
 1425                         stcb->asoc.local_hmacs = sctp_alloc_hmaclist(num_hmacs);
 1426                         if (stcb->asoc.local_hmacs != NULL) {
 1427                                 for (i = 0; i < num_hmacs; i++) {
 1428                                         (void)sctp_auth_add_hmacid(stcb->asoc.local_hmacs,
 1429                                             ntohs(hmacs->hmac_ids[i]));
 1430                                 }
 1431                         }
 1432                 } else if (ptype == SCTP_CHUNK_LIST) {
 1433                         int i;
 1434 
 1435                         if (plen > sizeof(chunks_store))
 1436                                 break;
 1437                         phdr = sctp_get_next_param(m, offset,
 1438                             (struct sctp_paramhdr *)chunks_store, plen);
 1439                         if (phdr == NULL)
 1440                                 return;
 1441                         chunks = (struct sctp_auth_chunk_list *)phdr;
 1442                         num_chunks = plen - sizeof(*chunks);
 1443                         /* save chunks list and num for the key */
 1444                         if (stcb->asoc.local_auth_chunks != NULL)
 1445                                 sctp_clear_chunklist(stcb->asoc.local_auth_chunks);
 1446                         else
 1447                                 stcb->asoc.local_auth_chunks = sctp_alloc_chunklist();
 1448                         for (i = 0; i < num_chunks; i++) {
 1449                                 (void)sctp_auth_add_chunk(chunks->chunk_types[i],
 1450                                     stcb->asoc.local_auth_chunks);
 1451                         }
 1452                 }
 1453                 /* get next parameter */
 1454                 offset += SCTP_SIZE32(plen);
 1455                 if (offset + sizeof(struct sctp_paramhdr) > length)
 1456                         break;
 1457                 phdr = (struct sctp_paramhdr *)sctp_m_getptr(m, offset, sizeof(struct sctp_paramhdr),
 1458                     (uint8_t *)&tmp_param);
 1459         }
 1460         /* concatenate the full random key */
 1461         keylen = sizeof(*p_random) + random_len + sizeof(*hmacs) + hmacs_len;
 1462         if (chunks != NULL) {
 1463                 keylen += sizeof(*chunks) + num_chunks;
 1464         }
 1465         new_key = sctp_alloc_key(keylen);
 1466         if (new_key != NULL) {
 1467                 /* copy in the RANDOM */
 1468                 if (p_random != NULL) {
 1469                         keylen = sizeof(*p_random) + random_len;
 1470                         memcpy(new_key->key, p_random, keylen);
 1471                 } else {
 1472                         keylen = 0;
 1473                 }
 1474                 /* append in the AUTH chunks */
 1475                 if (chunks != NULL) {
 1476                         memcpy(new_key->key + keylen, chunks,
 1477                             sizeof(*chunks) + num_chunks);
 1478                         keylen += sizeof(*chunks) + num_chunks;
 1479                 }
 1480                 /* append in the HMACs */
 1481                 if (hmacs != NULL) {
 1482                         memcpy(new_key->key + keylen, hmacs,
 1483                             sizeof(*hmacs) + hmacs_len);
 1484                 }
 1485         }
 1486         if (stcb->asoc.authinfo.random != NULL)
 1487                 sctp_free_key(stcb->asoc.authinfo.random);
 1488         stcb->asoc.authinfo.random = new_key;
 1489         stcb->asoc.authinfo.random_len = random_len;
 1490         sctp_clear_cachedkeys(stcb, stcb->asoc.authinfo.assoc_keyid);
 1491         sctp_clear_cachedkeys(stcb, stcb->asoc.authinfo.recv_keyid);
 1492 
 1493         /* negotiate what HMAC to use for the peer */
 1494         stcb->asoc.peer_hmac_id = sctp_negotiate_hmacid(stcb->asoc.peer_hmacs,
 1495             stcb->asoc.local_hmacs);
 1496 
 1497         /* copy defaults from the endpoint */
 1498         /* FIX ME: put in cookie? */
 1499         stcb->asoc.authinfo.active_keyid = stcb->sctp_ep->sctp_ep.default_keyid;
 1500         /* copy out the shared key list (by reference) from the endpoint */
 1501         (void)sctp_copy_skeylist(&stcb->sctp_ep->sctp_ep.shared_keys,
 1502             &stcb->asoc.shared_keys);
 1503 }
 1504 
 1505 /*
 1506  * compute and fill in the HMAC digest for a packet
 1507  */
 1508 void
 1509 sctp_fill_hmac_digest_m(struct mbuf *m, uint32_t auth_offset,
 1510     struct sctp_auth_chunk *auth, struct sctp_tcb *stcb, uint16_t keyid)
 1511 {
 1512         uint32_t digestlen;
 1513         sctp_sharedkey_t *skey;
 1514         sctp_key_t *key;
 1515 
 1516         if ((stcb == NULL) || (auth == NULL))
 1517                 return;
 1518 
 1519         /* zero the digest + chunk padding */
 1520         digestlen = sctp_get_hmac_digest_len(stcb->asoc.peer_hmac_id);
 1521         memset(auth->hmac, 0, SCTP_SIZE32(digestlen));
 1522 
 1523         /* is the desired key cached? */
 1524         if ((keyid != stcb->asoc.authinfo.assoc_keyid) ||
 1525             (stcb->asoc.authinfo.assoc_key == NULL)) {
 1526                 if (stcb->asoc.authinfo.assoc_key != NULL) {
 1527                         /* free the old cached key */
 1528                         sctp_free_key(stcb->asoc.authinfo.assoc_key);
 1529                 }
 1530                 skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1531                 /* the only way skey is NULL is if null key id 0 is used */
 1532                 if (skey != NULL)
 1533                         key = skey->key;
 1534                 else
 1535                         key = NULL;
 1536                 /* compute a new assoc key and cache it */
 1537                 stcb->asoc.authinfo.assoc_key =
 1538                     sctp_compute_hashkey(stcb->asoc.authinfo.random,
 1539                     stcb->asoc.authinfo.peer_random, key);
 1540                 stcb->asoc.authinfo.assoc_keyid = keyid;
 1541                 SCTPDBG(SCTP_DEBUG_AUTH1, "caching key id %u\n",
 1542                     stcb->asoc.authinfo.assoc_keyid);
 1543 #ifdef SCTP_DEBUG
 1544                 if (SCTP_AUTH_DEBUG)
 1545                         sctp_print_key(stcb->asoc.authinfo.assoc_key,
 1546                             "Assoc Key");
 1547 #endif
 1548         }
 1549 
 1550         /* set in the active key id */
 1551         auth->shared_key_id = htons(keyid);
 1552 
 1553         /* compute and fill in the digest */
 1554         (void)sctp_compute_hmac_m(stcb->asoc.peer_hmac_id, stcb->asoc.authinfo.assoc_key,
 1555             m, auth_offset, auth->hmac);
 1556 }
 1557 
 1558 
 1559 static void
 1560 sctp_zero_m(struct mbuf *m, uint32_t m_offset, uint32_t size)
 1561 {
 1562         struct mbuf *m_tmp;
 1563         uint8_t *data;
 1564 
 1565         /* sanity check */
 1566         if (m == NULL)
 1567                 return;
 1568 
 1569         /* find the correct starting mbuf and offset (get start position) */
 1570         m_tmp = m;
 1571         while ((m_tmp != NULL) && (m_offset >= (uint32_t)SCTP_BUF_LEN(m_tmp))) {
 1572                 m_offset -= SCTP_BUF_LEN(m_tmp);
 1573                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1574         }
 1575         /* now use the rest of the mbuf chain */
 1576         while ((m_tmp != NULL) && (size > 0)) {
 1577                 data = mtod(m_tmp, uint8_t *)+m_offset;
 1578                 if (size > (uint32_t)(SCTP_BUF_LEN(m_tmp) - m_offset)) {
 1579                         memset(data, 0, SCTP_BUF_LEN(m_tmp) - m_offset);
 1580                         size -= SCTP_BUF_LEN(m_tmp) - m_offset;
 1581                 } else {
 1582                         memset(data, 0, size);
 1583                         size = 0;
 1584                 }
 1585                 /* clear the offset since it's only for the first mbuf */
 1586                 m_offset = 0;
 1587                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1588         }
 1589 }
 1590 
 1591 /*-
 1592  * process the incoming Authentication chunk
 1593  * return codes:
 1594  *   -1 on any authentication error
 1595  *    0 on authentication verification
 1596  */
 1597 int
 1598 sctp_handle_auth(struct sctp_tcb *stcb, struct sctp_auth_chunk *auth,
 1599     struct mbuf *m, uint32_t offset)
 1600 {
 1601         uint16_t chunklen;
 1602         uint16_t shared_key_id;
 1603         uint16_t hmac_id;
 1604         sctp_sharedkey_t *skey;
 1605         uint32_t digestlen;
 1606         uint8_t digest[SCTP_AUTH_DIGEST_LEN_MAX];
 1607         uint8_t computed_digest[SCTP_AUTH_DIGEST_LEN_MAX];
 1608 
 1609         /* auth is checked for NULL by caller */
 1610         chunklen = ntohs(auth->ch.chunk_length);
 1611         if (chunklen < sizeof(*auth)) {
 1612                 SCTP_STAT_INCR(sctps_recvauthfailed);
 1613                 return (-1);
 1614         }
 1615         SCTP_STAT_INCR(sctps_recvauth);
 1616 
 1617         /* get the auth params */
 1618         shared_key_id = ntohs(auth->shared_key_id);
 1619         hmac_id = ntohs(auth->hmac_id);
 1620         SCTPDBG(SCTP_DEBUG_AUTH1,
 1621             "SCTP AUTH Chunk: shared key %u, HMAC id %u\n",
 1622             shared_key_id, hmac_id);
 1623 
 1624         /* is the indicated HMAC supported? */
 1625         if (!sctp_auth_is_supported_hmac(stcb->asoc.local_hmacs, hmac_id)) {
 1626                 struct mbuf *op_err;
 1627                 struct sctp_error_auth_invalid_hmac *cause;
 1628 
 1629                 SCTP_STAT_INCR(sctps_recvivalhmacid);
 1630                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1631                     "SCTP Auth: unsupported HMAC id %u\n",
 1632                     hmac_id);
 1633                 /*
 1634                  * report this in an Error Chunk: Unsupported HMAC
 1635                  * Identifier
 1636                  */
 1637                 op_err = sctp_get_mbuf_for_msg(sizeof(struct sctp_error_auth_invalid_hmac),
 1638                     0, M_NOWAIT, 1, MT_HEADER);
 1639                 if (op_err != NULL) {
 1640                         /* pre-reserve some space */
 1641                         SCTP_BUF_RESV_UF(op_err, sizeof(struct sctp_chunkhdr));
 1642                         /* fill in the error */
 1643                         cause = mtod(op_err, struct sctp_error_auth_invalid_hmac *);
 1644                         cause->cause.code = htons(SCTP_CAUSE_UNSUPPORTED_HMACID);
 1645                         cause->cause.length = htons(sizeof(struct sctp_error_auth_invalid_hmac));
 1646                         cause->hmac_id = ntohs(hmac_id);
 1647                         SCTP_BUF_LEN(op_err) = sizeof(struct sctp_error_auth_invalid_hmac);
 1648                         /* queue it */
 1649                         sctp_queue_op_err(stcb, op_err);
 1650                 }
 1651                 return (-1);
 1652         }
 1653         /* get the indicated shared key, if available */
 1654         if ((stcb->asoc.authinfo.recv_key == NULL) ||
 1655             (stcb->asoc.authinfo.recv_keyid != shared_key_id)) {
 1656                 /* find the shared key on the assoc first */
 1657                 skey = sctp_find_sharedkey(&stcb->asoc.shared_keys,
 1658                     shared_key_id);
 1659                 /* if the shared key isn't found, discard the chunk */
 1660                 if (skey == NULL) {
 1661                         SCTP_STAT_INCR(sctps_recvivalkeyid);
 1662                         SCTPDBG(SCTP_DEBUG_AUTH1,
 1663                             "SCTP Auth: unknown key id %u\n",
 1664                             shared_key_id);
 1665                         return (-1);
 1666                 }
 1667                 /* generate a notification if this is a new key id */
 1668                 if (stcb->asoc.authinfo.recv_keyid != shared_key_id)
 1669                         /*
 1670                          * sctp_ulp_notify(SCTP_NOTIFY_AUTH_NEW_KEY, stcb,
 1671                          * shared_key_id, (void
 1672                          * *)stcb->asoc.authinfo.recv_keyid);
 1673                          */
 1674                         sctp_notify_authentication(stcb, SCTP_AUTH_NEW_KEY,
 1675                             shared_key_id, stcb->asoc.authinfo.recv_keyid,
 1676                             SCTP_SO_NOT_LOCKED);
 1677                 /* compute a new recv assoc key and cache it */
 1678                 if (stcb->asoc.authinfo.recv_key != NULL)
 1679                         sctp_free_key(stcb->asoc.authinfo.recv_key);
 1680                 stcb->asoc.authinfo.recv_key =
 1681                     sctp_compute_hashkey(stcb->asoc.authinfo.random,
 1682                     stcb->asoc.authinfo.peer_random, skey->key);
 1683                 stcb->asoc.authinfo.recv_keyid = shared_key_id;
 1684 #ifdef SCTP_DEBUG
 1685                 if (SCTP_AUTH_DEBUG)
 1686                         sctp_print_key(stcb->asoc.authinfo.recv_key, "Recv Key");
 1687 #endif
 1688         }
 1689         /* validate the digest length */
 1690         digestlen = sctp_get_hmac_digest_len(hmac_id);
 1691         if (chunklen < (sizeof(*auth) + digestlen)) {
 1692                 /* invalid digest length */
 1693                 SCTP_STAT_INCR(sctps_recvauthfailed);
 1694                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1695                     "SCTP Auth: chunk too short for HMAC\n");
 1696                 return (-1);
 1697         }
 1698         /* save a copy of the digest, zero the pseudo header, and validate */
 1699         memcpy(digest, auth->hmac, digestlen);
 1700         sctp_zero_m(m, offset + sizeof(*auth), SCTP_SIZE32(digestlen));
 1701         (void)sctp_compute_hmac_m(hmac_id, stcb->asoc.authinfo.recv_key,
 1702             m, offset, computed_digest);
 1703 
 1704         /* compare the computed digest with the one in the AUTH chunk */
 1705         if (timingsafe_bcmp(digest, computed_digest, digestlen) != 0) {
 1706                 SCTP_STAT_INCR(sctps_recvauthfailed);
 1707                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1708                     "SCTP Auth: HMAC digest check failed\n");
 1709                 return (-1);
 1710         }
 1711         return (0);
 1712 }
 1713 
 1714 /*
 1715  * Generate NOTIFICATION
 1716  */
 1717 void
 1718 sctp_notify_authentication(struct sctp_tcb *stcb, uint32_t indication,
 1719     uint16_t keyid, uint16_t alt_keyid, int so_locked)
 1720 {
 1721         struct mbuf *m_notify;
 1722         struct sctp_authkey_event *auth;
 1723         struct sctp_queued_to_read *control;
 1724 
 1725         if ((stcb == NULL) ||
 1726             (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) ||
 1727             (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_ALLGONE) ||
 1728             (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET)
 1729             ) {
 1730                 /* If the socket is gone we are out of here */
 1731                 return;
 1732         }
 1733 
 1734         if (sctp_stcb_is_feature_off(stcb->sctp_ep, stcb, SCTP_PCB_FLAGS_AUTHEVNT))
 1735                 /* event not enabled */
 1736                 return;
 1737 
 1738         m_notify = sctp_get_mbuf_for_msg(sizeof(struct sctp_authkey_event),
 1739             0, M_NOWAIT, 1, MT_HEADER);
 1740         if (m_notify == NULL)
 1741                 /* no space left */
 1742                 return;
 1743 
 1744         SCTP_BUF_LEN(m_notify) = 0;
 1745         auth = mtod(m_notify, struct sctp_authkey_event *);
 1746         memset(auth, 0, sizeof(struct sctp_authkey_event));
 1747         auth->auth_type = SCTP_AUTHENTICATION_EVENT;
 1748         auth->auth_flags = 0;
 1749         auth->auth_length = sizeof(*auth);
 1750         auth->auth_keynumber = keyid;
 1751         auth->auth_altkeynumber = alt_keyid;
 1752         auth->auth_indication = indication;
 1753         auth->auth_assoc_id = sctp_get_associd(stcb);
 1754 
 1755         SCTP_BUF_LEN(m_notify) = sizeof(*auth);
 1756         SCTP_BUF_NEXT(m_notify) = NULL;
 1757 
 1758         /* append to socket */
 1759         control = sctp_build_readq_entry(stcb, stcb->asoc.primary_destination,
 1760             0, 0, stcb->asoc.context, 0, 0, 0, m_notify);
 1761         if (control == NULL) {
 1762                 /* no memory */
 1763                 sctp_m_freem(m_notify);
 1764                 return;
 1765         }
 1766         control->length = SCTP_BUF_LEN(m_notify);
 1767         control->spec_flags = M_NOTIFICATION;
 1768         /* not that we need this */
 1769         control->tail_mbuf = m_notify;
 1770         sctp_add_to_readq(stcb->sctp_ep, stcb, control,
 1771             &stcb->sctp_socket->so_rcv, 1, SCTP_READ_LOCK_NOT_HELD, so_locked);
 1772 }
 1773 
 1774 
 1775 /*-
 1776  * validates the AUTHentication related parameters in an INIT/INIT-ACK
 1777  * Note: currently only used for INIT as INIT-ACK is handled inline
 1778  * with sctp_load_addresses_from_init()
 1779  */
 1780 int
 1781 sctp_validate_init_auth_params(struct mbuf *m, int offset, int limit)
 1782 {
 1783         struct sctp_paramhdr *phdr, param_buf;
 1784         uint16_t ptype, plen;
 1785         int peer_supports_asconf = 0;
 1786         int peer_supports_auth = 0;
 1787         int got_random = 0, got_hmacs = 0, got_chklist = 0;
 1788         uint8_t saw_asconf = 0;
 1789         uint8_t saw_asconf_ack = 0;
 1790 
 1791         /* go through each of the params. */
 1792         phdr = sctp_get_next_param(m, offset, &param_buf, sizeof(param_buf));
 1793         while (phdr) {
 1794                 ptype = ntohs(phdr->param_type);
 1795                 plen = ntohs(phdr->param_length);
 1796 
 1797                 if (offset + plen > limit) {
 1798                         break;
 1799                 }
 1800                 if (plen < sizeof(struct sctp_paramhdr)) {
 1801                         break;
 1802                 }
 1803                 if (ptype == SCTP_SUPPORTED_CHUNK_EXT) {
 1804                         /* A supported extension chunk */
 1805                         struct sctp_supported_chunk_types_param *pr_supported;
 1806                         uint8_t local_store[SCTP_SMALL_CHUNK_STORE];
 1807                         int num_ent, i;
 1808 
 1809                         if (plen > sizeof(local_store)) {
 1810                                 break;
 1811                         }
 1812                         phdr = sctp_get_next_param(m, offset,
 1813                             (struct sctp_paramhdr *)&local_store,
 1814                             plen);
 1815                         if (phdr == NULL) {
 1816                                 return (-1);
 1817                         }
 1818                         pr_supported = (struct sctp_supported_chunk_types_param *)phdr;
 1819                         num_ent = plen - sizeof(struct sctp_paramhdr);
 1820                         for (i = 0; i < num_ent; i++) {
 1821                                 switch (pr_supported->chunk_types[i]) {
 1822                                 case SCTP_ASCONF:
 1823                                 case SCTP_ASCONF_ACK:
 1824                                         peer_supports_asconf = 1;
 1825                                         break;
 1826                                 default:
 1827                                         /* one we don't care about */
 1828                                         break;
 1829                                 }
 1830                         }
 1831                 } else if (ptype == SCTP_RANDOM) {
 1832                         /* enforce the random length */
 1833                         if (plen != (sizeof(struct sctp_auth_random) +
 1834                             SCTP_AUTH_RANDOM_SIZE_REQUIRED)) {
 1835                                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1836                                     "SCTP: invalid RANDOM len\n");
 1837                                 return (-1);
 1838                         }
 1839                         got_random = 1;
 1840                 } else if (ptype == SCTP_HMAC_LIST) {
 1841                         struct sctp_auth_hmac_algo *hmacs;
 1842                         uint8_t store[SCTP_PARAM_BUFFER_SIZE];
 1843                         int num_hmacs;
 1844 
 1845                         if (plen > sizeof(store)) {
 1846                                 break;
 1847                         }
 1848                         phdr = sctp_get_next_param(m, offset,
 1849                             (struct sctp_paramhdr *)store,
 1850                             plen);
 1851                         if (phdr == NULL) {
 1852                                 return (-1);
 1853                         }
 1854                         hmacs = (struct sctp_auth_hmac_algo *)phdr;
 1855                         num_hmacs = (plen - sizeof(*hmacs)) / sizeof(hmacs->hmac_ids[0]);
 1856                         /* validate the hmac list */
 1857                         if (sctp_verify_hmac_param(hmacs, num_hmacs)) {
 1858                                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1859                                     "SCTP: invalid HMAC param\n");
 1860                                 return (-1);
 1861                         }
 1862                         got_hmacs = 1;
 1863                 } else if (ptype == SCTP_CHUNK_LIST) {
 1864                         struct sctp_auth_chunk_list *chunks;
 1865                         uint8_t chunks_store[SCTP_SMALL_CHUNK_STORE];
 1866                         int i, num_chunks;
 1867 
 1868                         if (plen > sizeof(chunks_store)) {
 1869                                 break;
 1870                         }
 1871                         phdr = sctp_get_next_param(m, offset,
 1872                             (struct sctp_paramhdr *)chunks_store,
 1873                             plen);
 1874                         if (phdr == NULL) {
 1875                                 return (-1);
 1876                         }
 1877                         /*-
 1878                          * Flip through the list and mark that the
 1879                          * peer supports asconf/asconf_ack.
 1880                          */
 1881                         chunks = (struct sctp_auth_chunk_list *)phdr;
 1882                         num_chunks = plen - sizeof(*chunks);
 1883                         for (i = 0; i < num_chunks; i++) {
 1884                                 /* record asconf/asconf-ack if listed */
 1885                                 if (chunks->chunk_types[i] == SCTP_ASCONF)
 1886                                         saw_asconf = 1;
 1887                                 if (chunks->chunk_types[i] == SCTP_ASCONF_ACK)
 1888                                         saw_asconf_ack = 1;
 1889 
 1890                         }
 1891                         if (num_chunks)
 1892                                 got_chklist = 1;
 1893                 }
 1894 
 1895                 offset += SCTP_SIZE32(plen);
 1896                 if (offset >= limit) {
 1897                         break;
 1898                 }
 1899                 phdr = sctp_get_next_param(m, offset, &param_buf,
 1900                     sizeof(param_buf));
 1901         }
 1902         /* validate authentication required parameters */
 1903         if (got_random && got_hmacs) {
 1904                 peer_supports_auth = 1;
 1905         } else {
 1906                 peer_supports_auth = 0;
 1907         }
 1908         if (!peer_supports_auth && got_chklist) {
 1909                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1910                     "SCTP: peer sent chunk list w/o AUTH\n");
 1911                 return (-1);
 1912         }
 1913         if (peer_supports_asconf && !peer_supports_auth) {
 1914                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1915                     "SCTP: peer supports ASCONF but not AUTH\n");
 1916                 return (-1);
 1917         } else if ((peer_supports_asconf) && (peer_supports_auth) &&
 1918             ((saw_asconf == 0) || (saw_asconf_ack == 0))) {
 1919                 return (-2);
 1920         }
 1921         return (0);
 1922 }
 1923 
 1924 void
 1925 sctp_initialize_auth_params(struct sctp_inpcb *inp, struct sctp_tcb *stcb)
 1926 {
 1927         uint16_t chunks_len = 0;
 1928         uint16_t hmacs_len = 0;
 1929         uint16_t random_len = SCTP_AUTH_RANDOM_SIZE_DEFAULT;
 1930         sctp_key_t *new_key;
 1931         uint16_t keylen;
 1932 
 1933         /* initialize hmac list from endpoint */
 1934         stcb->asoc.local_hmacs = sctp_copy_hmaclist(inp->sctp_ep.local_hmacs);
 1935         if (stcb->asoc.local_hmacs != NULL) {
 1936                 hmacs_len = stcb->asoc.local_hmacs->num_algo *
 1937                     sizeof(stcb->asoc.local_hmacs->hmac[0]);
 1938         }
 1939         /* initialize auth chunks list from endpoint */
 1940         stcb->asoc.local_auth_chunks =
 1941             sctp_copy_chunklist(inp->sctp_ep.local_auth_chunks);
 1942         if (stcb->asoc.local_auth_chunks != NULL) {
 1943                 int i;
 1944 
 1945                 for (i = 0; i < 256; i++) {
 1946                         if (stcb->asoc.local_auth_chunks->chunks[i])
 1947                                 chunks_len++;
 1948                 }
 1949         }
 1950         /* copy defaults from the endpoint */
 1951         stcb->asoc.authinfo.active_keyid = inp->sctp_ep.default_keyid;
 1952 
 1953         /* copy out the shared key list (by reference) from the endpoint */
 1954         (void)sctp_copy_skeylist(&inp->sctp_ep.shared_keys,
 1955             &stcb->asoc.shared_keys);
 1956 
 1957         /* now set the concatenated key (random + chunks + hmacs) */
 1958         /* key includes parameter headers */
 1959         keylen = (3 * sizeof(struct sctp_paramhdr)) + random_len + chunks_len +
 1960             hmacs_len;
 1961         new_key = sctp_alloc_key(keylen);
 1962         if (new_key != NULL) {
 1963                 struct sctp_paramhdr *ph;
 1964                 int plen;
 1965 
 1966                 /* generate and copy in the RANDOM */
 1967                 ph = (struct sctp_paramhdr *)new_key->key;
 1968                 ph->param_type = htons(SCTP_RANDOM);
 1969                 plen = sizeof(*ph) + random_len;
 1970                 ph->param_length = htons(plen);
 1971                 SCTP_READ_RANDOM(new_key->key + sizeof(*ph), random_len);
 1972                 keylen = plen;
 1973 
 1974                 /* append in the AUTH chunks */
 1975                 /* NOTE: currently we always have chunks to list */
 1976                 ph = (struct sctp_paramhdr *)(new_key->key + keylen);
 1977                 ph->param_type = htons(SCTP_CHUNK_LIST);
 1978                 plen = sizeof(*ph) + chunks_len;
 1979                 ph->param_length = htons(plen);
 1980                 keylen += sizeof(*ph);
 1981                 if (stcb->asoc.local_auth_chunks) {
 1982                         int i;
 1983 
 1984                         for (i = 0; i < 256; i++) {
 1985                                 if (stcb->asoc.local_auth_chunks->chunks[i])
 1986                                         new_key->key[keylen++] = i;
 1987                         }
 1988                 }
 1989 
 1990                 /* append in the HMACs */
 1991                 ph = (struct sctp_paramhdr *)(new_key->key + keylen);
 1992                 ph->param_type = htons(SCTP_HMAC_LIST);
 1993                 plen = sizeof(*ph) + hmacs_len;
 1994                 ph->param_length = htons(plen);
 1995                 keylen += sizeof(*ph);
 1996                 (void)sctp_serialize_hmaclist(stcb->asoc.local_hmacs,
 1997                     new_key->key + keylen);
 1998         }
 1999         if (stcb->asoc.authinfo.random != NULL)
 2000                 sctp_free_key(stcb->asoc.authinfo.random);
 2001         stcb->asoc.authinfo.random = new_key;
 2002         stcb->asoc.authinfo.random_len = random_len;
 2003 }
Cache object: 3efbc4825c23b0cc888d08a6330ea857
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FreeBSD/Linux Kernel Cross Reference sys/netinet/sctp_auth.c

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