sctp_auth.c

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    1 /*-
    2  * Copyright (c) 2001-2008, by Cisco Systems, Inc. All rights reserved.
    3  * Copyright (c) 2008-2012, by Randall Stewart. All rights reserved.
    4  * Copyright (c) 2008-2012, by Michael Tuexen. All rights reserved.
    5  *
    6  * Redistribution and use in source and binary forms, with or without
    7  * modification, are permitted provided that the following conditions are met:
    8  *
    9  * a) Redistributions of source code must retain the above copyright notice,
   10  *    this list of conditions and the following disclaimer.
   11  *
   12  * b) Redistributions in binary form must reproduce the above copyright
   13  *    notice, this list of conditions and the following disclaimer in
   14  *    the documentation and/or other materials provided with the distribution.
   15  *
   16  * c) Neither the name of Cisco Systems, Inc. nor the names of its
   17  *    contributors may be used to endorse or promote products derived
   18  *    from this software without specific prior written permission.
   19  *
   20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   21  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
   22  * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
   23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
   24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
   27  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
   28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
   29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
   30  * THE POSSIBILITY OF SUCH DAMAGE.
   31  */
   32 
   33 #include <sys/cdefs.h>
   34 __FBSDID("$FreeBSD: releng/9.2/sys/netinet/sctp_auth.c 268434 2014-07-08 21:55:27Z delphij $");
   35 
   36 #include <netinet/sctp_os.h>
   37 #include <netinet/sctp.h>
   38 #include <netinet/sctp_header.h>
   39 #include <netinet/sctp_pcb.h>
   40 #include <netinet/sctp_var.h>
   41 #include <netinet/sctp_sysctl.h>
   42 #include <netinet/sctputil.h>
   43 #include <netinet/sctp_indata.h>
   44 #include <netinet/sctp_output.h>
   45 #include <netinet/sctp_auth.h>
   46 
   47 #ifdef SCTP_DEBUG
   48 #define SCTP_AUTH_DEBUG         (SCTP_BASE_SYSCTL(sctp_debug_on) & SCTP_DEBUG_AUTH1)
   49 #define SCTP_AUTH_DEBUG2        (SCTP_BASE_SYSCTL(sctp_debug_on) & SCTP_DEBUG_AUTH2)
   50 #endif                          /* SCTP_DEBUG */
   51 
   52 
   53 void
   54 sctp_clear_chunklist(sctp_auth_chklist_t * chklist)
   55 {
   56         bzero(chklist, sizeof(*chklist));
   57         /* chklist->num_chunks = 0; */
   58 }
   59 
   60 sctp_auth_chklist_t *
   61 sctp_alloc_chunklist(void)
   62 {
   63         sctp_auth_chklist_t *chklist;
   64 
   65         SCTP_MALLOC(chklist, sctp_auth_chklist_t *, sizeof(*chklist),
   66             SCTP_M_AUTH_CL);
   67         if (chklist == NULL) {
   68                 SCTPDBG(SCTP_DEBUG_AUTH1, "sctp_alloc_chunklist: failed to get memory!\n");
   69         } else {
   70                 sctp_clear_chunklist(chklist);
   71         }
   72         return (chklist);
   73 }
   74 
   75 void
   76 sctp_free_chunklist(sctp_auth_chklist_t * list)
   77 {
   78         if (list != NULL)
   79                 SCTP_FREE(list, SCTP_M_AUTH_CL);
   80 }
   81 
   82 sctp_auth_chklist_t *
   83 sctp_copy_chunklist(sctp_auth_chklist_t * list)
   84 {
   85         sctp_auth_chklist_t *new_list;
   86 
   87         if (list == NULL)
   88                 return (NULL);
   89 
   90         /* get a new list */
   91         new_list = sctp_alloc_chunklist();
   92         if (new_list == NULL)
   93                 return (NULL);
   94         /* copy it */
   95         bcopy(list, new_list, sizeof(*new_list));
   96 
   97         return (new_list);
   98 }
   99 
  100 
  101 /*
  102  * add a chunk to the required chunks list
  103  */
  104 int
  105 sctp_auth_add_chunk(uint8_t chunk, sctp_auth_chklist_t * list)
  106 {
  107         if (list == NULL)
  108                 return (-1);
  109 
  110         /* is chunk restricted? */
  111         if ((chunk == SCTP_INITIATION) ||
  112             (chunk == SCTP_INITIATION_ACK) ||
  113             (chunk == SCTP_SHUTDOWN_COMPLETE) ||
  114             (chunk == SCTP_AUTHENTICATION)) {
  115                 return (-1);
  116         }
  117         if (list->chunks[chunk] == 0) {
  118                 list->chunks[chunk] = 1;
  119                 list->num_chunks++;
  120                 SCTPDBG(SCTP_DEBUG_AUTH1,
  121                     "SCTP: added chunk %u (0x%02x) to Auth list\n",
  122                     chunk, chunk);
  123         }
  124         return (0);
  125 }
  126 
  127 /*
  128  * delete a chunk from the required chunks list
  129  */
  130 int
  131 sctp_auth_delete_chunk(uint8_t chunk, sctp_auth_chklist_t * list)
  132 {
  133         if (list == NULL)
  134                 return (-1);
  135 
  136         /* is chunk restricted? */
  137         if ((chunk == SCTP_ASCONF) ||
  138             (chunk == SCTP_ASCONF_ACK)) {
  139                 return (-1);
  140         }
  141         if (list->chunks[chunk] == 1) {
  142                 list->chunks[chunk] = 0;
  143                 list->num_chunks--;
  144                 SCTPDBG(SCTP_DEBUG_AUTH1,
  145                     "SCTP: deleted chunk %u (0x%02x) from Auth list\n",
  146                     chunk, chunk);
  147         }
  148         return (0);
  149 }
  150 
  151 size_t
  152 sctp_auth_get_chklist_size(const sctp_auth_chklist_t * list)
  153 {
  154         if (list == NULL)
  155                 return (0);
  156         else
  157                 return (list->num_chunks);
  158 }
  159 
  160 /*
  161  * set the default list of chunks requiring AUTH
  162  */
  163 void
  164 sctp_auth_set_default_chunks(sctp_auth_chklist_t * list)
  165 {
  166         (void)sctp_auth_add_chunk(SCTP_ASCONF, list);
  167         (void)sctp_auth_add_chunk(SCTP_ASCONF_ACK, list);
  168 }
  169 
  170 /*
  171  * return the current number and list of required chunks caller must
  172  * guarantee ptr has space for up to 256 bytes
  173  */
  174 int
  175 sctp_serialize_auth_chunks(const sctp_auth_chklist_t * list, uint8_t * ptr)
  176 {
  177         int i, count = 0;
  178 
  179         if (list == NULL)
  180                 return (0);
  181 
  182         for (i = 0; i < 256; i++) {
  183                 if (list->chunks[i] != 0) {
  184                         *ptr++ = i;
  185                         count++;
  186                 }
  187         }
  188         return (count);
  189 }
  190 
  191 int
  192 sctp_pack_auth_chunks(const sctp_auth_chklist_t * list, uint8_t * ptr)
  193 {
  194         int i, size = 0;
  195 
  196         if (list == NULL)
  197                 return (0);
  198 
  199         if (list->num_chunks <= 32) {
  200                 /* just list them, one byte each */
  201                 for (i = 0; i < 256; i++) {
  202                         if (list->chunks[i] != 0) {
  203                                 *ptr++ = i;
  204                                 size++;
  205                         }
  206                 }
  207         } else {
  208                 int index, offset;
  209 
  210                 /* pack into a 32 byte bitfield */
  211                 for (i = 0; i < 256; i++) {
  212                         if (list->chunks[i] != 0) {
  213                                 index = i / 8;
  214                                 offset = i % 8;
  215                                 ptr[index] |= (1 << offset);
  216                         }
  217                 }
  218                 size = 32;
  219         }
  220         return (size);
  221 }
  222 
  223 int
  224 sctp_unpack_auth_chunks(const uint8_t * ptr, uint8_t num_chunks,
  225     sctp_auth_chklist_t * list)
  226 {
  227         int i;
  228         int size;
  229 
  230         if (list == NULL)
  231                 return (0);
  232 
  233         if (num_chunks <= 32) {
  234                 /* just pull them, one byte each */
  235                 for (i = 0; i < num_chunks; i++) {
  236                         (void)sctp_auth_add_chunk(*ptr++, list);
  237                 }
  238                 size = num_chunks;
  239         } else {
  240                 int index, offset;
  241 
  242                 /* unpack from a 32 byte bitfield */
  243                 for (index = 0; index < 32; index++) {
  244                         for (offset = 0; offset < 8; offset++) {
  245                                 if (ptr[index] & (1 << offset)) {
  246                                         (void)sctp_auth_add_chunk((index * 8) + offset, list);
  247                                 }
  248                         }
  249                 }
  250                 size = 32;
  251         }
  252         return (size);
  253 }
  254 
  255 
  256 /*
  257  * allocate structure space for a key of length keylen
  258  */
  259 sctp_key_t *
  260 sctp_alloc_key(uint32_t keylen)
  261 {
  262         sctp_key_t *new_key;
  263 
  264         SCTP_MALLOC(new_key, sctp_key_t *, sizeof(*new_key) + keylen,
  265             SCTP_M_AUTH_KY);
  266         if (new_key == NULL) {
  267                 /* out of memory */
  268                 return (NULL);
  269         }
  270         new_key->keylen = keylen;
  271         return (new_key);
  272 }
  273 
  274 void
  275 sctp_free_key(sctp_key_t * key)
  276 {
  277         if (key != NULL)
  278                 SCTP_FREE(key, SCTP_M_AUTH_KY);
  279 }
  280 
  281 void
  282 sctp_print_key(sctp_key_t * key, const char *str)
  283 {
  284         uint32_t i;
  285 
  286         if (key == NULL) {
  287                 SCTP_PRINTF("%s: [Null key]\n", str);
  288                 return;
  289         }
  290         SCTP_PRINTF("%s: len %u, ", str, key->keylen);
  291         if (key->keylen) {
  292                 for (i = 0; i < key->keylen; i++)
  293                         SCTP_PRINTF("%02x", key->key[i]);
  294                 SCTP_PRINTF("\n");
  295         } else {
  296                 SCTP_PRINTF("[Null key]\n");
  297         }
  298 }
  299 
  300 void
  301 sctp_show_key(sctp_key_t * key, const char *str)
  302 {
  303         uint32_t i;
  304 
  305         if (key == NULL) {
  306                 SCTP_PRINTF("%s: [Null key]\n", str);
  307                 return;
  308         }
  309         SCTP_PRINTF("%s: len %u, ", str, key->keylen);
  310         if (key->keylen) {
  311                 for (i = 0; i < key->keylen; i++)
  312                         SCTP_PRINTF("%02x", key->key[i]);
  313                 SCTP_PRINTF("\n");
  314         } else {
  315                 SCTP_PRINTF("[Null key]\n");
  316         }
  317 }
  318 
  319 static uint32_t
  320 sctp_get_keylen(sctp_key_t * key)
  321 {
  322         if (key != NULL)
  323                 return (key->keylen);
  324         else
  325                 return (0);
  326 }
  327 
  328 /*
  329  * generate a new random key of length 'keylen'
  330  */
  331 sctp_key_t *
  332 sctp_generate_random_key(uint32_t keylen)
  333 {
  334         sctp_key_t *new_key;
  335 
  336         /* validate keylen */
  337         if (keylen > SCTP_AUTH_RANDOM_SIZE_MAX)
  338                 keylen = SCTP_AUTH_RANDOM_SIZE_MAX;
  339 
  340         new_key = sctp_alloc_key(keylen);
  341         if (new_key == NULL) {
  342                 /* out of memory */
  343                 return (NULL);
  344         }
  345         SCTP_READ_RANDOM(new_key->key, keylen);
  346         new_key->keylen = keylen;
  347         return (new_key);
  348 }
  349 
  350 sctp_key_t *
  351 sctp_set_key(uint8_t * key, uint32_t keylen)
  352 {
  353         sctp_key_t *new_key;
  354 
  355         new_key = sctp_alloc_key(keylen);
  356         if (new_key == NULL) {
  357                 /* out of memory */
  358                 return (NULL);
  359         }
  360         bcopy(key, new_key->key, keylen);
  361         return (new_key);
  362 }
  363 
  364 /*-
  365  * given two keys of variable size, compute which key is "larger/smaller"
  366  * returns:  1 if key1 > key2
  367  *          -1 if key1 < key2
  368  *           0 if key1 = key2
  369  */
  370 static int
  371 sctp_compare_key(sctp_key_t * key1, sctp_key_t * key2)
  372 {
  373         uint32_t maxlen;
  374         uint32_t i;
  375         uint32_t key1len, key2len;
  376         uint8_t *key_1, *key_2;
  377         uint8_t temp[SCTP_AUTH_RANDOM_SIZE_MAX];
  378 
  379         /* sanity/length check */
  380         key1len = sctp_get_keylen(key1);
  381         key2len = sctp_get_keylen(key2);
  382         if ((key1len == 0) && (key2len == 0))
  383                 return (0);
  384         else if (key1len == 0)
  385                 return (-1);
  386         else if (key2len == 0)
  387                 return (1);
  388 
  389         if (key1len != key2len) {
  390                 if (key1len >= key2len)
  391                         maxlen = key1len;
  392                 else
  393                         maxlen = key2len;
  394                 bzero(temp, maxlen);
  395                 if (key1len < maxlen) {
  396                         /* prepend zeroes to key1 */
  397                         bcopy(key1->key, temp + (maxlen - key1len), key1len);
  398                         key_1 = temp;
  399                         key_2 = key2->key;
  400                 } else {
  401                         /* prepend zeroes to key2 */
  402                         bcopy(key2->key, temp + (maxlen - key2len), key2len);
  403                         key_1 = key1->key;
  404                         key_2 = temp;
  405                 }
  406         } else {
  407                 maxlen = key1len;
  408                 key_1 = key1->key;
  409                 key_2 = key2->key;
  410         }
  411 
  412         for (i = 0; i < maxlen; i++) {
  413                 if (*key_1 > *key_2)
  414                         return (1);
  415                 else if (*key_1 < *key_2)
  416                         return (-1);
  417                 key_1++;
  418                 key_2++;
  419         }
  420 
  421         /* keys are equal value, so check lengths */
  422         if (key1len == key2len)
  423                 return (0);
  424         else if (key1len < key2len)
  425                 return (-1);
  426         else
  427                 return (1);
  428 }
  429 
  430 /*
  431  * generate the concatenated keying material based on the two keys and the
  432  * shared key (if available). draft-ietf-tsvwg-auth specifies the specific
  433  * order for concatenation
  434  */
  435 sctp_key_t *
  436 sctp_compute_hashkey(sctp_key_t * key1, sctp_key_t * key2, sctp_key_t * shared)
  437 {
  438         uint32_t keylen;
  439         sctp_key_t *new_key;
  440         uint8_t *key_ptr;
  441 
  442         keylen = sctp_get_keylen(key1) + sctp_get_keylen(key2) +
  443             sctp_get_keylen(shared);
  444 
  445         if (keylen > 0) {
  446                 /* get space for the new key */
  447                 new_key = sctp_alloc_key(keylen);
  448                 if (new_key == NULL) {
  449                         /* out of memory */
  450                         return (NULL);
  451                 }
  452                 new_key->keylen = keylen;
  453                 key_ptr = new_key->key;
  454         } else {
  455                 /* all keys empty/null?! */
  456                 return (NULL);
  457         }
  458 
  459         /* concatenate the keys */
  460         if (sctp_compare_key(key1, key2) <= 0) {
  461                 /* key is shared + key1 + key2 */
  462                 if (sctp_get_keylen(shared)) {
  463                         bcopy(shared->key, key_ptr, shared->keylen);
  464                         key_ptr += shared->keylen;
  465                 }
  466                 if (sctp_get_keylen(key1)) {
  467                         bcopy(key1->key, key_ptr, key1->keylen);
  468                         key_ptr += key1->keylen;
  469                 }
  470                 if (sctp_get_keylen(key2)) {
  471                         bcopy(key2->key, key_ptr, key2->keylen);
  472                 }
  473         } else {
  474                 /* key is shared + key2 + key1 */
  475                 if (sctp_get_keylen(shared)) {
  476                         bcopy(shared->key, key_ptr, shared->keylen);
  477                         key_ptr += shared->keylen;
  478                 }
  479                 if (sctp_get_keylen(key2)) {
  480                         bcopy(key2->key, key_ptr, key2->keylen);
  481                         key_ptr += key2->keylen;
  482                 }
  483                 if (sctp_get_keylen(key1)) {
  484                         bcopy(key1->key, key_ptr, key1->keylen);
  485                 }
  486         }
  487         return (new_key);
  488 }
  489 
  490 
  491 sctp_sharedkey_t *
  492 sctp_alloc_sharedkey(void)
  493 {
  494         sctp_sharedkey_t *new_key;
  495 
  496         SCTP_MALLOC(new_key, sctp_sharedkey_t *, sizeof(*new_key),
  497             SCTP_M_AUTH_KY);
  498         if (new_key == NULL) {
  499                 /* out of memory */
  500                 return (NULL);
  501         }
  502         new_key->keyid = 0;
  503         new_key->key = NULL;
  504         new_key->refcount = 1;
  505         new_key->deactivated = 0;
  506         return (new_key);
  507 }
  508 
  509 void
  510 sctp_free_sharedkey(sctp_sharedkey_t * skey)
  511 {
  512         if (skey == NULL)
  513                 return;
  514 
  515         if (SCTP_DECREMENT_AND_CHECK_REFCOUNT(&skey->refcount)) {
  516                 if (skey->key != NULL)
  517                         sctp_free_key(skey->key);
  518                 SCTP_FREE(skey, SCTP_M_AUTH_KY);
  519         }
  520 }
  521 
  522 sctp_sharedkey_t *
  523 sctp_find_sharedkey(struct sctp_keyhead *shared_keys, uint16_t key_id)
  524 {
  525         sctp_sharedkey_t *skey;
  526 
  527         LIST_FOREACH(skey, shared_keys, next) {
  528                 if (skey->keyid == key_id)
  529                         return (skey);
  530         }
  531         return (NULL);
  532 }
  533 
  534 int
  535 sctp_insert_sharedkey(struct sctp_keyhead *shared_keys,
  536     sctp_sharedkey_t * new_skey)
  537 {
  538         sctp_sharedkey_t *skey;
  539 
  540         if ((shared_keys == NULL) || (new_skey == NULL))
  541                 return (EINVAL);
  542 
  543         /* insert into an empty list? */
  544         if (LIST_EMPTY(shared_keys)) {
  545                 LIST_INSERT_HEAD(shared_keys, new_skey, next);
  546                 return (0);
  547         }
  548         /* insert into the existing list, ordered by key id */
  549         LIST_FOREACH(skey, shared_keys, next) {
  550                 if (new_skey->keyid < skey->keyid) {
  551                         /* insert it before here */
  552                         LIST_INSERT_BEFORE(skey, new_skey, next);
  553                         return (0);
  554                 } else if (new_skey->keyid == skey->keyid) {
  555                         /* replace the existing key */
  556                         /* verify this key *can* be replaced */
  557                         if ((skey->deactivated) && (skey->refcount > 1)) {
  558                                 SCTPDBG(SCTP_DEBUG_AUTH1,
  559                                     "can't replace shared key id %u\n",
  560                                     new_skey->keyid);
  561                                 return (EBUSY);
  562                         }
  563                         SCTPDBG(SCTP_DEBUG_AUTH1,
  564                             "replacing shared key id %u\n",
  565                             new_skey->keyid);
  566                         LIST_INSERT_BEFORE(skey, new_skey, next);
  567                         LIST_REMOVE(skey, next);
  568                         sctp_free_sharedkey(skey);
  569                         return (0);
  570                 }
  571                 if (LIST_NEXT(skey, next) == NULL) {
  572                         /* belongs at the end of the list */
  573                         LIST_INSERT_AFTER(skey, new_skey, next);
  574                         return (0);
  575                 }
  576         }
  577         /* shouldn't reach here */
  578         return (0);
  579 }
  580 
  581 void
  582 sctp_auth_key_acquire(struct sctp_tcb *stcb, uint16_t key_id)
  583 {
  584         sctp_sharedkey_t *skey;
  585 
  586         /* find the shared key */
  587         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, key_id);
  588 
  589         /* bump the ref count */
  590         if (skey) {
  591                 atomic_add_int(&skey->refcount, 1);
  592                 SCTPDBG(SCTP_DEBUG_AUTH2,
  593                     "%s: stcb %p key %u refcount acquire to %d\n",
  594                     __FUNCTION__, (void *)stcb, key_id, skey->refcount);
  595         }
  596 }
  597 
  598 void
  599 sctp_auth_key_release(struct sctp_tcb *stcb, uint16_t key_id, int so_locked
  600 #if !defined(__APPLE__) && !defined(SCTP_SO_LOCK_TESTING)
  601     SCTP_UNUSED
  602 #endif
  603 )
  604 {
  605         sctp_sharedkey_t *skey;
  606 
  607         /* find the shared key */
  608         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, key_id);
  609 
  610         /* decrement the ref count */
  611         if (skey) {
  612                 sctp_free_sharedkey(skey);
  613                 SCTPDBG(SCTP_DEBUG_AUTH2,
  614                     "%s: stcb %p key %u refcount release to %d\n",
  615                     __FUNCTION__, (void *)stcb, key_id, skey->refcount);
  616 
  617                 /* see if a notification should be generated */
  618                 if ((skey->refcount <= 1) && (skey->deactivated)) {
  619                         /* notify ULP that key is no longer used */
  620                         sctp_ulp_notify(SCTP_NOTIFY_AUTH_FREE_KEY, stcb,
  621                             key_id, 0, so_locked);
  622                         SCTPDBG(SCTP_DEBUG_AUTH2,
  623                             "%s: stcb %p key %u no longer used, %d\n",
  624                             __FUNCTION__, (void *)stcb, key_id, skey->refcount);
  625                 }
  626         }
  627 }
  628 
  629 static sctp_sharedkey_t *
  630 sctp_copy_sharedkey(const sctp_sharedkey_t * skey)
  631 {
  632         sctp_sharedkey_t *new_skey;
  633 
  634         if (skey == NULL)
  635                 return (NULL);
  636         new_skey = sctp_alloc_sharedkey();
  637         if (new_skey == NULL)
  638                 return (NULL);
  639         if (skey->key != NULL)
  640                 new_skey->key = sctp_set_key(skey->key->key, skey->key->keylen);
  641         else
  642                 new_skey->key = NULL;
  643         new_skey->keyid = skey->keyid;
  644         return (new_skey);
  645 }
  646 
  647 int
  648 sctp_copy_skeylist(const struct sctp_keyhead *src, struct sctp_keyhead *dest)
  649 {
  650         sctp_sharedkey_t *skey, *new_skey;
  651         int count = 0;
  652 
  653         if ((src == NULL) || (dest == NULL))
  654                 return (0);
  655         LIST_FOREACH(skey, src, next) {
  656                 new_skey = sctp_copy_sharedkey(skey);
  657                 if (new_skey != NULL) {
  658                         (void)sctp_insert_sharedkey(dest, new_skey);
  659                         count++;
  660                 }
  661         }
  662         return (count);
  663 }
  664 
  665 
  666 sctp_hmaclist_t *
  667 sctp_alloc_hmaclist(uint8_t num_hmacs)
  668 {
  669         sctp_hmaclist_t *new_list;
  670         int alloc_size;
  671 
  672         alloc_size = sizeof(*new_list) + num_hmacs * sizeof(new_list->hmac[0]);
  673         SCTP_MALLOC(new_list, sctp_hmaclist_t *, alloc_size,
  674             SCTP_M_AUTH_HL);
  675         if (new_list == NULL) {
  676                 /* out of memory */
  677                 return (NULL);
  678         }
  679         new_list->max_algo = num_hmacs;
  680         new_list->num_algo = 0;
  681         return (new_list);
  682 }
  683 
  684 void
  685 sctp_free_hmaclist(sctp_hmaclist_t * list)
  686 {
  687         if (list != NULL) {
  688                 SCTP_FREE(list, SCTP_M_AUTH_HL);
  689                 list = NULL;
  690         }
  691 }
  692 
  693 int
  694 sctp_auth_add_hmacid(sctp_hmaclist_t * list, uint16_t hmac_id)
  695 {
  696         int i;
  697 
  698         if (list == NULL)
  699                 return (-1);
  700         if (list->num_algo == list->max_algo) {
  701                 SCTPDBG(SCTP_DEBUG_AUTH1,
  702                     "SCTP: HMAC id list full, ignoring add %u\n", hmac_id);
  703                 return (-1);
  704         }
  705         if ((hmac_id != SCTP_AUTH_HMAC_ID_SHA1) &&
  706 #ifdef HAVE_SHA224
  707             (hmac_id != SCTP_AUTH_HMAC_ID_SHA224) &&
  708 #endif
  709 #ifdef HAVE_SHA2
  710             (hmac_id != SCTP_AUTH_HMAC_ID_SHA256) &&
  711             (hmac_id != SCTP_AUTH_HMAC_ID_SHA384) &&
  712             (hmac_id != SCTP_AUTH_HMAC_ID_SHA512) &&
  713 #endif
  714             1) {
  715                 return (-1);
  716         }
  717         /* Now is it already in the list */
  718         for (i = 0; i < list->num_algo; i++) {
  719                 if (list->hmac[i] == hmac_id) {
  720                         /* already in list */
  721                         return (-1);
  722                 }
  723         }
  724         SCTPDBG(SCTP_DEBUG_AUTH1, "SCTP: add HMAC id %u to list\n", hmac_id);
  725         list->hmac[list->num_algo++] = hmac_id;
  726         return (0);
  727 }
  728 
  729 sctp_hmaclist_t *
  730 sctp_copy_hmaclist(sctp_hmaclist_t * list)
  731 {
  732         sctp_hmaclist_t *new_list;
  733         int i;
  734 
  735         if (list == NULL)
  736                 return (NULL);
  737         /* get a new list */
  738         new_list = sctp_alloc_hmaclist(list->max_algo);
  739         if (new_list == NULL)
  740                 return (NULL);
  741         /* copy it */
  742         new_list->max_algo = list->max_algo;
  743         new_list->num_algo = list->num_algo;
  744         for (i = 0; i < list->num_algo; i++)
  745                 new_list->hmac[i] = list->hmac[i];
  746         return (new_list);
  747 }
  748 
  749 sctp_hmaclist_t *
  750 sctp_default_supported_hmaclist(void)
  751 {
  752         sctp_hmaclist_t *new_list;
  753 
  754         new_list = sctp_alloc_hmaclist(2);
  755         if (new_list == NULL)
  756                 return (NULL);
  757         (void)sctp_auth_add_hmacid(new_list, SCTP_AUTH_HMAC_ID_SHA1);
  758         (void)sctp_auth_add_hmacid(new_list, SCTP_AUTH_HMAC_ID_SHA256);
  759         return (new_list);
  760 }
  761 
  762 /*-
  763  * HMAC algos are listed in priority/preference order
  764  * find the best HMAC id to use for the peer based on local support
  765  */
  766 uint16_t
  767 sctp_negotiate_hmacid(sctp_hmaclist_t * peer, sctp_hmaclist_t * local)
  768 {
  769         int i, j;
  770 
  771         if ((local == NULL) || (peer == NULL))
  772                 return (SCTP_AUTH_HMAC_ID_RSVD);
  773 
  774         for (i = 0; i < peer->num_algo; i++) {
  775                 for (j = 0; j < local->num_algo; j++) {
  776                         if (peer->hmac[i] == local->hmac[j]) {
  777                                 /* found the "best" one */
  778                                 SCTPDBG(SCTP_DEBUG_AUTH1,
  779                                     "SCTP: negotiated peer HMAC id %u\n",
  780                                     peer->hmac[i]);
  781                                 return (peer->hmac[i]);
  782                         }
  783                 }
  784         }
  785         /* didn't find one! */
  786         return (SCTP_AUTH_HMAC_ID_RSVD);
  787 }
  788 
  789 /*-
  790  * serialize the HMAC algo list and return space used
  791  * caller must guarantee ptr has appropriate space
  792  */
  793 int
  794 sctp_serialize_hmaclist(sctp_hmaclist_t * list, uint8_t * ptr)
  795 {
  796         int i;
  797         uint16_t hmac_id;
  798 
  799         if (list == NULL)
  800                 return (0);
  801 
  802         for (i = 0; i < list->num_algo; i++) {
  803                 hmac_id = htons(list->hmac[i]);
  804                 bcopy(&hmac_id, ptr, sizeof(hmac_id));
  805                 ptr += sizeof(hmac_id);
  806         }
  807         return (list->num_algo * sizeof(hmac_id));
  808 }
  809 
  810 int
  811 sctp_verify_hmac_param(struct sctp_auth_hmac_algo *hmacs, uint32_t num_hmacs)
  812 {
  813         uint32_t i;
  814         uint16_t hmac_id;
  815         uint32_t sha1_supported = 0;
  816 
  817         for (i = 0; i < num_hmacs; i++) {
  818                 hmac_id = ntohs(hmacs->hmac_ids[i]);
  819                 if (hmac_id == SCTP_AUTH_HMAC_ID_SHA1)
  820                         sha1_supported = 1;
  821         }
  822         /* all HMAC id's are supported */
  823         if (sha1_supported == 0)
  824                 return (-1);
  825         else
  826                 return (0);
  827 }
  828 
  829 sctp_authinfo_t *
  830 sctp_alloc_authinfo(void)
  831 {
  832         sctp_authinfo_t *new_authinfo;
  833 
  834         SCTP_MALLOC(new_authinfo, sctp_authinfo_t *, sizeof(*new_authinfo),
  835             SCTP_M_AUTH_IF);
  836 
  837         if (new_authinfo == NULL) {
  838                 /* out of memory */
  839                 return (NULL);
  840         }
  841         bzero(new_authinfo, sizeof(*new_authinfo));
  842         return (new_authinfo);
  843 }
  844 
  845 void
  846 sctp_free_authinfo(sctp_authinfo_t * authinfo)
  847 {
  848         if (authinfo == NULL)
  849                 return;
  850 
  851         if (authinfo->random != NULL)
  852                 sctp_free_key(authinfo->random);
  853         if (authinfo->peer_random != NULL)
  854                 sctp_free_key(authinfo->peer_random);
  855         if (authinfo->assoc_key != NULL)
  856                 sctp_free_key(authinfo->assoc_key);
  857         if (authinfo->recv_key != NULL)
  858                 sctp_free_key(authinfo->recv_key);
  859 
  860         /* We are NOT dynamically allocating authinfo's right now... */
  861         /* SCTP_FREE(authinfo, SCTP_M_AUTH_??); */
  862 }
  863 
  864 
  865 uint32_t
  866 sctp_get_auth_chunk_len(uint16_t hmac_algo)
  867 {
  868         int size;
  869 
  870         size = sizeof(struct sctp_auth_chunk) + sctp_get_hmac_digest_len(hmac_algo);
  871         return (SCTP_SIZE32(size));
  872 }
  873 
  874 uint32_t
  875 sctp_get_hmac_digest_len(uint16_t hmac_algo)
  876 {
  877         switch (hmac_algo) {
  878         case SCTP_AUTH_HMAC_ID_SHA1:
  879                 return (SCTP_AUTH_DIGEST_LEN_SHA1);
  880 #ifdef HAVE_SHA224
  881         case SCTP_AUTH_HMAC_ID_SHA224:
  882                 return (SCTP_AUTH_DIGEST_LEN_SHA224);
  883 #endif
  884 #ifdef HAVE_SHA2
  885         case SCTP_AUTH_HMAC_ID_SHA256:
  886                 return (SCTP_AUTH_DIGEST_LEN_SHA256);
  887         case SCTP_AUTH_HMAC_ID_SHA384:
  888                 return (SCTP_AUTH_DIGEST_LEN_SHA384);
  889         case SCTP_AUTH_HMAC_ID_SHA512:
  890                 return (SCTP_AUTH_DIGEST_LEN_SHA512);
  891 #endif
  892         default:
  893                 /* unknown HMAC algorithm: can't do anything */
  894                 return (0);
  895         }                       /* end switch */
  896 }
  897 
  898 static inline int
  899 sctp_get_hmac_block_len(uint16_t hmac_algo)
  900 {
  901         switch (hmac_algo) {
  902         case SCTP_AUTH_HMAC_ID_SHA1:
  903 #ifdef HAVE_SHA224
  904         case SCTP_AUTH_HMAC_ID_SHA224:
  905 #endif
  906                 return (64);
  907 #ifdef HAVE_SHA2
  908         case SCTP_AUTH_HMAC_ID_SHA256:
  909                 return (64);
  910         case SCTP_AUTH_HMAC_ID_SHA384:
  911         case SCTP_AUTH_HMAC_ID_SHA512:
  912                 return (128);
  913 #endif
  914         case SCTP_AUTH_HMAC_ID_RSVD:
  915         default:
  916                 /* unknown HMAC algorithm: can't do anything */
  917                 return (0);
  918         }                       /* end switch */
  919 }
  920 
  921 static void
  922 sctp_hmac_init(uint16_t hmac_algo, sctp_hash_context_t * ctx)
  923 {
  924         switch (hmac_algo) {
  925         case SCTP_AUTH_HMAC_ID_SHA1:
  926                 SHA1_Init(&ctx->sha1);
  927                 break;
  928 #ifdef HAVE_SHA224
  929         case SCTP_AUTH_HMAC_ID_SHA224:
  930                 break;
  931 #endif
  932 #ifdef HAVE_SHA2
  933         case SCTP_AUTH_HMAC_ID_SHA256:
  934                 SHA256_Init(&ctx->sha256);
  935                 break;
  936         case SCTP_AUTH_HMAC_ID_SHA384:
  937                 SHA384_Init(&ctx->sha384);
  938                 break;
  939         case SCTP_AUTH_HMAC_ID_SHA512:
  940                 SHA512_Init(&ctx->sha512);
  941                 break;
  942 #endif
  943         case SCTP_AUTH_HMAC_ID_RSVD:
  944         default:
  945                 /* unknown HMAC algorithm: can't do anything */
  946                 return;
  947         }                       /* end switch */
  948 }
  949 
  950 static void
  951 sctp_hmac_update(uint16_t hmac_algo, sctp_hash_context_t * ctx,
  952     uint8_t * text, uint32_t textlen)
  953 {
  954         switch (hmac_algo) {
  955         case SCTP_AUTH_HMAC_ID_SHA1:
  956                 SHA1_Update(&ctx->sha1, text, textlen);
  957                 break;
  958 #ifdef HAVE_SHA224
  959         case SCTP_AUTH_HMAC_ID_SHA224:
  960                 break;
  961 #endif
  962 #ifdef HAVE_SHA2
  963         case SCTP_AUTH_HMAC_ID_SHA256:
  964                 SHA256_Update(&ctx->sha256, text, textlen);
  965                 break;
  966         case SCTP_AUTH_HMAC_ID_SHA384:
  967                 SHA384_Update(&ctx->sha384, text, textlen);
  968                 break;
  969         case SCTP_AUTH_HMAC_ID_SHA512:
  970                 SHA512_Update(&ctx->sha512, text, textlen);
  971                 break;
  972 #endif
  973         case SCTP_AUTH_HMAC_ID_RSVD:
  974         default:
  975                 /* unknown HMAC algorithm: can't do anything */
  976                 return;
  977         }                       /* end switch */
  978 }
  979 
  980 static void
  981 sctp_hmac_final(uint16_t hmac_algo, sctp_hash_context_t * ctx,
  982     uint8_t * digest)
  983 {
  984         switch (hmac_algo) {
  985         case SCTP_AUTH_HMAC_ID_SHA1:
  986                 SHA1_Final(digest, &ctx->sha1);
  987                 break;
  988 #ifdef HAVE_SHA224
  989         case SCTP_AUTH_HMAC_ID_SHA224:
  990                 break;
  991 #endif
  992 #ifdef HAVE_SHA2
  993         case SCTP_AUTH_HMAC_ID_SHA256:
  994                 SHA256_Final(digest, &ctx->sha256);
  995                 break;
  996         case SCTP_AUTH_HMAC_ID_SHA384:
  997                 /* SHA384 is truncated SHA512 */
  998                 SHA384_Final(digest, &ctx->sha384);
  999                 break;
 1000         case SCTP_AUTH_HMAC_ID_SHA512:
 1001                 SHA512_Final(digest, &ctx->sha512);
 1002                 break;
 1003 #endif
 1004         case SCTP_AUTH_HMAC_ID_RSVD:
 1005         default:
 1006                 /* unknown HMAC algorithm: can't do anything */
 1007                 return;
 1008         }                       /* end switch */
 1009 }
 1010 
 1011 /*-
 1012  * Keyed-Hashing for Message Authentication: FIPS 198 (RFC 2104)
 1013  *
 1014  * Compute the HMAC digest using the desired hash key, text, and HMAC
 1015  * algorithm.  Resulting digest is placed in 'digest' and digest length
 1016  * is returned, if the HMAC was performed.
 1017  *
 1018  * WARNING: it is up to the caller to supply sufficient space to hold the
 1019  * resultant digest.
 1020  */
 1021 uint32_t
 1022 sctp_hmac(uint16_t hmac_algo, uint8_t * key, uint32_t keylen,
 1023     uint8_t * text, uint32_t textlen, uint8_t * digest)
 1024 {
 1025         uint32_t digestlen;
 1026         uint32_t blocklen;
 1027         sctp_hash_context_t ctx;
 1028         uint8_t ipad[128], opad[128];   /* keyed hash inner/outer pads */
 1029         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
 1030         uint32_t i;
 1031 
 1032         /* sanity check the material and length */
 1033         if ((key == NULL) || (keylen == 0) || (text == NULL) ||
 1034             (textlen == 0) || (digest == NULL)) {
 1035                 /* can't do HMAC with empty key or text or digest store */
 1036                 return (0);
 1037         }
 1038         /* validate the hmac algo and get the digest length */
 1039         digestlen = sctp_get_hmac_digest_len(hmac_algo);
 1040         if (digestlen == 0)
 1041                 return (0);
 1042 
 1043         /* hash the key if it is longer than the hash block size */
 1044         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1045         if (keylen > blocklen) {
 1046                 sctp_hmac_init(hmac_algo, &ctx);
 1047                 sctp_hmac_update(hmac_algo, &ctx, key, keylen);
 1048                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1049                 /* set the hashed key as the key */
 1050                 keylen = digestlen;
 1051                 key = temp;
 1052         }
 1053         /* initialize the inner/outer pads with the key and "append" zeroes */
 1054         bzero(ipad, blocklen);
 1055         bzero(opad, blocklen);
 1056         bcopy(key, ipad, keylen);
 1057         bcopy(key, opad, keylen);
 1058 
 1059         /* XOR the key with ipad and opad values */
 1060         for (i = 0; i < blocklen; i++) {
 1061                 ipad[i] ^= 0x36;
 1062                 opad[i] ^= 0x5c;
 1063         }
 1064 
 1065         /* perform inner hash */
 1066         sctp_hmac_init(hmac_algo, &ctx);
 1067         sctp_hmac_update(hmac_algo, &ctx, ipad, blocklen);
 1068         sctp_hmac_update(hmac_algo, &ctx, text, textlen);
 1069         sctp_hmac_final(hmac_algo, &ctx, temp);
 1070 
 1071         /* perform outer hash */
 1072         sctp_hmac_init(hmac_algo, &ctx);
 1073         sctp_hmac_update(hmac_algo, &ctx, opad, blocklen);
 1074         sctp_hmac_update(hmac_algo, &ctx, temp, digestlen);
 1075         sctp_hmac_final(hmac_algo, &ctx, digest);
 1076 
 1077         return (digestlen);
 1078 }
 1079 
 1080 /* mbuf version */
 1081 uint32_t
 1082 sctp_hmac_m(uint16_t hmac_algo, uint8_t * key, uint32_t keylen,
 1083     struct mbuf *m, uint32_t m_offset, uint8_t * digest, uint32_t trailer)
 1084 {
 1085         uint32_t digestlen;
 1086         uint32_t blocklen;
 1087         sctp_hash_context_t ctx;
 1088         uint8_t ipad[128], opad[128];   /* keyed hash inner/outer pads */
 1089         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
 1090         uint32_t i;
 1091         struct mbuf *m_tmp;
 1092 
 1093         /* sanity check the material and length */
 1094         if ((key == NULL) || (keylen == 0) || (m == NULL) || (digest == NULL)) {
 1095                 /* can't do HMAC with empty key or text or digest store */
 1096                 return (0);
 1097         }
 1098         /* validate the hmac algo and get the digest length */
 1099         digestlen = sctp_get_hmac_digest_len(hmac_algo);
 1100         if (digestlen == 0)
 1101                 return (0);
 1102 
 1103         /* hash the key if it is longer than the hash block size */
 1104         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1105         if (keylen > blocklen) {
 1106                 sctp_hmac_init(hmac_algo, &ctx);
 1107                 sctp_hmac_update(hmac_algo, &ctx, key, keylen);
 1108                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1109                 /* set the hashed key as the key */
 1110                 keylen = digestlen;
 1111                 key = temp;
 1112         }
 1113         /* initialize the inner/outer pads with the key and "append" zeroes */
 1114         bzero(ipad, blocklen);
 1115         bzero(opad, blocklen);
 1116         bcopy(key, ipad, keylen);
 1117         bcopy(key, opad, keylen);
 1118 
 1119         /* XOR the key with ipad and opad values */
 1120         for (i = 0; i < blocklen; i++) {
 1121                 ipad[i] ^= 0x36;
 1122                 opad[i] ^= 0x5c;
 1123         }
 1124 
 1125         /* perform inner hash */
 1126         sctp_hmac_init(hmac_algo, &ctx);
 1127         sctp_hmac_update(hmac_algo, &ctx, ipad, blocklen);
 1128         /* find the correct starting mbuf and offset (get start of text) */
 1129         m_tmp = m;
 1130         while ((m_tmp != NULL) && (m_offset >= (uint32_t) SCTP_BUF_LEN(m_tmp))) {
 1131                 m_offset -= SCTP_BUF_LEN(m_tmp);
 1132                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1133         }
 1134         /* now use the rest of the mbuf chain for the text */
 1135         while (m_tmp != NULL) {
 1136                 if ((SCTP_BUF_NEXT(m_tmp) == NULL) && trailer) {
 1137                         sctp_hmac_update(hmac_algo, &ctx, mtod(m_tmp, uint8_t *) + m_offset,
 1138                             SCTP_BUF_LEN(m_tmp) - (trailer + m_offset));
 1139                 } else {
 1140                         sctp_hmac_update(hmac_algo, &ctx, mtod(m_tmp, uint8_t *) + m_offset,
 1141                             SCTP_BUF_LEN(m_tmp) - m_offset);
 1142                 }
 1143 
 1144                 /* clear the offset since it's only for the first mbuf */
 1145                 m_offset = 0;
 1146                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1147         }
 1148         sctp_hmac_final(hmac_algo, &ctx, temp);
 1149 
 1150         /* perform outer hash */
 1151         sctp_hmac_init(hmac_algo, &ctx);
 1152         sctp_hmac_update(hmac_algo, &ctx, opad, blocklen);
 1153         sctp_hmac_update(hmac_algo, &ctx, temp, digestlen);
 1154         sctp_hmac_final(hmac_algo, &ctx, digest);
 1155 
 1156         return (digestlen);
 1157 }
 1158 
 1159 /*-
 1160  * verify the HMAC digest using the desired hash key, text, and HMAC
 1161  * algorithm.
 1162  * Returns -1 on error, 0 on success.
 1163  */
 1164 int
 1165 sctp_verify_hmac(uint16_t hmac_algo, uint8_t * key, uint32_t keylen,
 1166     uint8_t * text, uint32_t textlen,
 1167     uint8_t * digest, uint32_t digestlen)
 1168 {
 1169         uint32_t len;
 1170         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
 1171 
 1172         /* sanity check the material and length */
 1173         if ((key == NULL) || (keylen == 0) ||
 1174             (text == NULL) || (textlen == 0) || (digest == NULL)) {
 1175                 /* can't do HMAC with empty key or text or digest */
 1176                 return (-1);
 1177         }
 1178         len = sctp_get_hmac_digest_len(hmac_algo);
 1179         if ((len == 0) || (digestlen != len))
 1180                 return (-1);
 1181 
 1182         /* compute the expected hash */
 1183         if (sctp_hmac(hmac_algo, key, keylen, text, textlen, temp) != len)
 1184                 return (-1);
 1185 
 1186         if (memcmp(digest, temp, digestlen) != 0)
 1187                 return (-1);
 1188         else
 1189                 return (0);
 1190 }
 1191 
 1192 
 1193 /*
 1194  * computes the requested HMAC using a key struct (which may be modified if
 1195  * the keylen exceeds the HMAC block len).
 1196  */
 1197 uint32_t
 1198 sctp_compute_hmac(uint16_t hmac_algo, sctp_key_t * key, uint8_t * text,
 1199     uint32_t textlen, uint8_t * digest)
 1200 {
 1201         uint32_t digestlen;
 1202         uint32_t blocklen;
 1203         sctp_hash_context_t ctx;
 1204         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
 1205 
 1206         /* sanity check */
 1207         if ((key == NULL) || (text == NULL) || (textlen == 0) ||
 1208             (digest == NULL)) {
 1209                 /* can't do HMAC with empty key or text or digest store */
 1210                 return (0);
 1211         }
 1212         /* validate the hmac algo and get the digest length */
 1213         digestlen = sctp_get_hmac_digest_len(hmac_algo);
 1214         if (digestlen == 0)
 1215                 return (0);
 1216 
 1217         /* hash the key if it is longer than the hash block size */
 1218         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1219         if (key->keylen > blocklen) {
 1220                 sctp_hmac_init(hmac_algo, &ctx);
 1221                 sctp_hmac_update(hmac_algo, &ctx, key->key, key->keylen);
 1222                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1223                 /* save the hashed key as the new key */
 1224                 key->keylen = digestlen;
 1225                 bcopy(temp, key->key, key->keylen);
 1226         }
 1227         return (sctp_hmac(hmac_algo, key->key, key->keylen, text, textlen,
 1228             digest));
 1229 }
 1230 
 1231 /* mbuf version */
 1232 uint32_t
 1233 sctp_compute_hmac_m(uint16_t hmac_algo, sctp_key_t * key, struct mbuf *m,
 1234     uint32_t m_offset, uint8_t * digest)
 1235 {
 1236         uint32_t digestlen;
 1237         uint32_t blocklen;
 1238         sctp_hash_context_t ctx;
 1239         uint8_t temp[SCTP_AUTH_DIGEST_LEN_MAX];
 1240 
 1241         /* sanity check */
 1242         if ((key == NULL) || (m == NULL) || (digest == NULL)) {
 1243                 /* can't do HMAC with empty key or text or digest store */
 1244                 return (0);
 1245         }
 1246         /* validate the hmac algo and get the digest length */
 1247         digestlen = sctp_get_hmac_digest_len(hmac_algo);
 1248         if (digestlen == 0)
 1249                 return (0);
 1250 
 1251         /* hash the key if it is longer than the hash block size */
 1252         blocklen = sctp_get_hmac_block_len(hmac_algo);
 1253         if (key->keylen > blocklen) {
 1254                 sctp_hmac_init(hmac_algo, &ctx);
 1255                 sctp_hmac_update(hmac_algo, &ctx, key->key, key->keylen);
 1256                 sctp_hmac_final(hmac_algo, &ctx, temp);
 1257                 /* save the hashed key as the new key */
 1258                 key->keylen = digestlen;
 1259                 bcopy(temp, key->key, key->keylen);
 1260         }
 1261         return (sctp_hmac_m(hmac_algo, key->key, key->keylen, m, m_offset, digest, 0));
 1262 }
 1263 
 1264 int
 1265 sctp_auth_is_supported_hmac(sctp_hmaclist_t * list, uint16_t id)
 1266 {
 1267         int i;
 1268 
 1269         if ((list == NULL) || (id == SCTP_AUTH_HMAC_ID_RSVD))
 1270                 return (0);
 1271 
 1272         for (i = 0; i < list->num_algo; i++)
 1273                 if (list->hmac[i] == id)
 1274                         return (1);
 1275 
 1276         /* not in the list */
 1277         return (0);
 1278 }
 1279 
 1280 
 1281 /*-
 1282  * clear any cached key(s) if they match the given key id on an association.
 1283  * the cached key(s) will be recomputed and re-cached at next use.
 1284  * ASSUMES TCB_LOCK is already held
 1285  */
 1286 void
 1287 sctp_clear_cachedkeys(struct sctp_tcb *stcb, uint16_t keyid)
 1288 {
 1289         if (stcb == NULL)
 1290                 return;
 1291 
 1292         if (keyid == stcb->asoc.authinfo.assoc_keyid) {
 1293                 sctp_free_key(stcb->asoc.authinfo.assoc_key);
 1294                 stcb->asoc.authinfo.assoc_key = NULL;
 1295         }
 1296         if (keyid == stcb->asoc.authinfo.recv_keyid) {
 1297                 sctp_free_key(stcb->asoc.authinfo.recv_key);
 1298                 stcb->asoc.authinfo.recv_key = NULL;
 1299         }
 1300 }
 1301 
 1302 /*-
 1303  * clear any cached key(s) if they match the given key id for all assocs on
 1304  * an endpoint.
 1305  * ASSUMES INP_WLOCK is already held
 1306  */
 1307 void
 1308 sctp_clear_cachedkeys_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1309 {
 1310         struct sctp_tcb *stcb;
 1311 
 1312         if (inp == NULL)
 1313                 return;
 1314 
 1315         /* clear the cached keys on all assocs on this instance */
 1316         LIST_FOREACH(stcb, &inp->sctp_asoc_list, sctp_tcblist) {
 1317                 SCTP_TCB_LOCK(stcb);
 1318                 sctp_clear_cachedkeys(stcb, keyid);
 1319                 SCTP_TCB_UNLOCK(stcb);
 1320         }
 1321 }
 1322 
 1323 /*-
 1324  * delete a shared key from an association
 1325  * ASSUMES TCB_LOCK is already held
 1326  */
 1327 int
 1328 sctp_delete_sharedkey(struct sctp_tcb *stcb, uint16_t keyid)
 1329 {
 1330         sctp_sharedkey_t *skey;
 1331 
 1332         if (stcb == NULL)
 1333                 return (-1);
 1334 
 1335         /* is the keyid the assoc active sending key */
 1336         if (keyid == stcb->asoc.authinfo.active_keyid)
 1337                 return (-1);
 1338 
 1339         /* does the key exist? */
 1340         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1341         if (skey == NULL)
 1342                 return (-1);
 1343 
 1344         /* are there other refcount holders on the key? */
 1345         if (skey->refcount > 1)
 1346                 return (-1);
 1347 
 1348         /* remove it */
 1349         LIST_REMOVE(skey, next);
 1350         sctp_free_sharedkey(skey);      /* frees skey->key as well */
 1351 
 1352         /* clear any cached keys */
 1353         sctp_clear_cachedkeys(stcb, keyid);
 1354         return (0);
 1355 }
 1356 
 1357 /*-
 1358  * deletes a shared key from the endpoint
 1359  * ASSUMES INP_WLOCK is already held
 1360  */
 1361 int
 1362 sctp_delete_sharedkey_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1363 {
 1364         sctp_sharedkey_t *skey;
 1365 
 1366         if (inp == NULL)
 1367                 return (-1);
 1368 
 1369         /* is the keyid the active sending key on the endpoint */
 1370         if (keyid == inp->sctp_ep.default_keyid)
 1371                 return (-1);
 1372 
 1373         /* does the key exist? */
 1374         skey = sctp_find_sharedkey(&inp->sctp_ep.shared_keys, keyid);
 1375         if (skey == NULL)
 1376                 return (-1);
 1377 
 1378         /* endpoint keys are not refcounted */
 1379 
 1380         /* remove it */
 1381         LIST_REMOVE(skey, next);
 1382         sctp_free_sharedkey(skey);      /* frees skey->key as well */
 1383 
 1384         /* clear any cached keys */
 1385         sctp_clear_cachedkeys_ep(inp, keyid);
 1386         return (0);
 1387 }
 1388 
 1389 /*-
 1390  * set the active key on an association
 1391  * ASSUMES TCB_LOCK is already held
 1392  */
 1393 int
 1394 sctp_auth_setactivekey(struct sctp_tcb *stcb, uint16_t keyid)
 1395 {
 1396         sctp_sharedkey_t *skey = NULL;
 1397 
 1398         /* find the key on the assoc */
 1399         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1400         if (skey == NULL) {
 1401                 /* that key doesn't exist */
 1402                 return (-1);
 1403         }
 1404         if ((skey->deactivated) && (skey->refcount > 1)) {
 1405                 /* can't reactivate a deactivated key with other refcounts */
 1406                 return (-1);
 1407         }
 1408         /* set the (new) active key */
 1409         stcb->asoc.authinfo.active_keyid = keyid;
 1410         /* reset the deactivated flag */
 1411         skey->deactivated = 0;
 1412 
 1413         return (0);
 1414 }
 1415 
 1416 /*-
 1417  * set the active key on an endpoint
 1418  * ASSUMES INP_WLOCK is already held
 1419  */
 1420 int
 1421 sctp_auth_setactivekey_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1422 {
 1423         sctp_sharedkey_t *skey;
 1424 
 1425         /* find the key */
 1426         skey = sctp_find_sharedkey(&inp->sctp_ep.shared_keys, keyid);
 1427         if (skey == NULL) {
 1428                 /* that key doesn't exist */
 1429                 return (-1);
 1430         }
 1431         inp->sctp_ep.default_keyid = keyid;
 1432         return (0);
 1433 }
 1434 
 1435 /*-
 1436  * deactivates a shared key from the association
 1437  * ASSUMES INP_WLOCK is already held
 1438  */
 1439 int
 1440 sctp_deact_sharedkey(struct sctp_tcb *stcb, uint16_t keyid)
 1441 {
 1442         sctp_sharedkey_t *skey;
 1443 
 1444         if (stcb == NULL)
 1445                 return (-1);
 1446 
 1447         /* is the keyid the assoc active sending key */
 1448         if (keyid == stcb->asoc.authinfo.active_keyid)
 1449                 return (-1);
 1450 
 1451         /* does the key exist? */
 1452         skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1453         if (skey == NULL)
 1454                 return (-1);
 1455 
 1456         /* are there other refcount holders on the key? */
 1457         if (skey->refcount == 1) {
 1458                 /* no other users, send a notification for this key */
 1459                 sctp_ulp_notify(SCTP_NOTIFY_AUTH_FREE_KEY, stcb, keyid, 0,
 1460                     SCTP_SO_LOCKED);
 1461         }
 1462         /* mark the key as deactivated */
 1463         skey->deactivated = 1;
 1464 
 1465         return (0);
 1466 }
 1467 
 1468 /*-
 1469  * deactivates a shared key from the endpoint
 1470  * ASSUMES INP_WLOCK is already held
 1471  */
 1472 int
 1473 sctp_deact_sharedkey_ep(struct sctp_inpcb *inp, uint16_t keyid)
 1474 {
 1475         sctp_sharedkey_t *skey;
 1476 
 1477         if (inp == NULL)
 1478                 return (-1);
 1479 
 1480         /* is the keyid the active sending key on the endpoint */
 1481         if (keyid == inp->sctp_ep.default_keyid)
 1482                 return (-1);
 1483 
 1484         /* does the key exist? */
 1485         skey = sctp_find_sharedkey(&inp->sctp_ep.shared_keys, keyid);
 1486         if (skey == NULL)
 1487                 return (-1);
 1488 
 1489         /* endpoint keys are not refcounted */
 1490 
 1491         /* remove it */
 1492         LIST_REMOVE(skey, next);
 1493         sctp_free_sharedkey(skey);      /* frees skey->key as well */
 1494 
 1495         return (0);
 1496 }
 1497 
 1498 /*
 1499  * get local authentication parameters from cookie (from INIT-ACK)
 1500  */
 1501 void
 1502 sctp_auth_get_cookie_params(struct sctp_tcb *stcb, struct mbuf *m,
 1503     uint32_t offset, uint32_t length)
 1504 {
 1505         struct sctp_paramhdr *phdr, tmp_param;
 1506         uint16_t plen, ptype;
 1507         uint8_t random_store[SCTP_PARAM_BUFFER_SIZE];
 1508         struct sctp_auth_random *p_random = NULL;
 1509         uint16_t random_len = 0;
 1510         uint8_t hmacs_store[SCTP_PARAM_BUFFER_SIZE];
 1511         struct sctp_auth_hmac_algo *hmacs = NULL;
 1512         uint16_t hmacs_len = 0;
 1513         uint8_t chunks_store[SCTP_PARAM_BUFFER_SIZE];
 1514         struct sctp_auth_chunk_list *chunks = NULL;
 1515         uint16_t num_chunks = 0;
 1516         sctp_key_t *new_key;
 1517         uint32_t keylen;
 1518 
 1519         /* convert to upper bound */
 1520         length += offset;
 1521 
 1522         phdr = (struct sctp_paramhdr *)sctp_m_getptr(m, offset,
 1523             sizeof(struct sctp_paramhdr), (uint8_t *) & tmp_param);
 1524         while (phdr != NULL) {
 1525                 ptype = ntohs(phdr->param_type);
 1526                 plen = ntohs(phdr->param_length);
 1527 
 1528                 if ((plen == 0) || (offset + plen > length))
 1529                         break;
 1530 
 1531                 if (ptype == SCTP_RANDOM) {
 1532                         if (plen > sizeof(random_store))
 1533                                 break;
 1534                         phdr = sctp_get_next_param(m, offset,
 1535                             (struct sctp_paramhdr *)random_store, min(plen, sizeof(random_store)));
 1536                         if (phdr == NULL)
 1537                                 return;
 1538                         /* save the random and length for the key */
 1539                         p_random = (struct sctp_auth_random *)phdr;
 1540                         random_len = plen - sizeof(*p_random);
 1541                 } else if (ptype == SCTP_HMAC_LIST) {
 1542                         int num_hmacs;
 1543                         int i;
 1544 
 1545                         if (plen > sizeof(hmacs_store))
 1546                                 break;
 1547                         phdr = sctp_get_next_param(m, offset,
 1548                             (struct sctp_paramhdr *)hmacs_store, min(plen, sizeof(hmacs_store)));
 1549                         if (phdr == NULL)
 1550                                 return;
 1551                         /* save the hmacs list and num for the key */
 1552                         hmacs = (struct sctp_auth_hmac_algo *)phdr;
 1553                         hmacs_len = plen - sizeof(*hmacs);
 1554                         num_hmacs = hmacs_len / sizeof(hmacs->hmac_ids[0]);
 1555                         if (stcb->asoc.local_hmacs != NULL)
 1556                                 sctp_free_hmaclist(stcb->asoc.local_hmacs);
 1557                         stcb->asoc.local_hmacs = sctp_alloc_hmaclist(num_hmacs);
 1558                         if (stcb->asoc.local_hmacs != NULL) {
 1559                                 for (i = 0; i < num_hmacs; i++) {
 1560                                         (void)sctp_auth_add_hmacid(stcb->asoc.local_hmacs,
 1561                                             ntohs(hmacs->hmac_ids[i]));
 1562                                 }
 1563                         }
 1564                 } else if (ptype == SCTP_CHUNK_LIST) {
 1565                         int i;
 1566 
 1567                         if (plen > sizeof(chunks_store))
 1568                                 break;
 1569                         phdr = sctp_get_next_param(m, offset,
 1570                             (struct sctp_paramhdr *)chunks_store, min(plen, sizeof(chunks_store)));
 1571                         if (phdr == NULL)
 1572                                 return;
 1573                         chunks = (struct sctp_auth_chunk_list *)phdr;
 1574                         num_chunks = plen - sizeof(*chunks);
 1575                         /* save chunks list and num for the key */
 1576                         if (stcb->asoc.local_auth_chunks != NULL)
 1577                                 sctp_clear_chunklist(stcb->asoc.local_auth_chunks);
 1578                         else
 1579                                 stcb->asoc.local_auth_chunks = sctp_alloc_chunklist();
 1580                         for (i = 0; i < num_chunks; i++) {
 1581                                 (void)sctp_auth_add_chunk(chunks->chunk_types[i],
 1582                                     stcb->asoc.local_auth_chunks);
 1583                         }
 1584                 }
 1585                 /* get next parameter */
 1586                 offset += SCTP_SIZE32(plen);
 1587                 if (offset + sizeof(struct sctp_paramhdr) > length)
 1588                         break;
 1589                 phdr = (struct sctp_paramhdr *)sctp_m_getptr(m, offset, sizeof(struct sctp_paramhdr),
 1590                     (uint8_t *) & tmp_param);
 1591         }
 1592         /* concatenate the full random key */
 1593         keylen = sizeof(*p_random) + random_len + sizeof(*hmacs) + hmacs_len;
 1594         if (chunks != NULL) {
 1595                 keylen += sizeof(*chunks) + num_chunks;
 1596         }
 1597         new_key = sctp_alloc_key(keylen);
 1598         if (new_key != NULL) {
 1599                 /* copy in the RANDOM */
 1600                 if (p_random != NULL) {
 1601                         keylen = sizeof(*p_random) + random_len;
 1602                         bcopy(p_random, new_key->key, keylen);
 1603                 }
 1604                 /* append in the AUTH chunks */
 1605                 if (chunks != NULL) {
 1606                         bcopy(chunks, new_key->key + keylen,
 1607                             sizeof(*chunks) + num_chunks);
 1608                         keylen += sizeof(*chunks) + num_chunks;
 1609                 }
 1610                 /* append in the HMACs */
 1611                 if (hmacs != NULL) {
 1612                         bcopy(hmacs, new_key->key + keylen,
 1613                             sizeof(*hmacs) + hmacs_len);
 1614                 }
 1615         }
 1616         if (stcb->asoc.authinfo.random != NULL)
 1617                 sctp_free_key(stcb->asoc.authinfo.random);
 1618         stcb->asoc.authinfo.random = new_key;
 1619         stcb->asoc.authinfo.random_len = random_len;
 1620         sctp_clear_cachedkeys(stcb, stcb->asoc.authinfo.assoc_keyid);
 1621         sctp_clear_cachedkeys(stcb, stcb->asoc.authinfo.recv_keyid);
 1622 
 1623         /* negotiate what HMAC to use for the peer */
 1624         stcb->asoc.peer_hmac_id = sctp_negotiate_hmacid(stcb->asoc.peer_hmacs,
 1625             stcb->asoc.local_hmacs);
 1626 
 1627         /* copy defaults from the endpoint */
 1628         /* FIX ME: put in cookie? */
 1629         stcb->asoc.authinfo.active_keyid = stcb->sctp_ep->sctp_ep.default_keyid;
 1630         /* copy out the shared key list (by reference) from the endpoint */
 1631         (void)sctp_copy_skeylist(&stcb->sctp_ep->sctp_ep.shared_keys,
 1632             &stcb->asoc.shared_keys);
 1633 }
 1634 
 1635 /*
 1636  * compute and fill in the HMAC digest for a packet
 1637  */
 1638 void
 1639 sctp_fill_hmac_digest_m(struct mbuf *m, uint32_t auth_offset,
 1640     struct sctp_auth_chunk *auth, struct sctp_tcb *stcb, uint16_t keyid)
 1641 {
 1642         uint32_t digestlen;
 1643         sctp_sharedkey_t *skey;
 1644         sctp_key_t *key;
 1645 
 1646         if ((stcb == NULL) || (auth == NULL))
 1647                 return;
 1648 
 1649         /* zero the digest + chunk padding */
 1650         digestlen = sctp_get_hmac_digest_len(stcb->asoc.peer_hmac_id);
 1651         bzero(auth->hmac, SCTP_SIZE32(digestlen));
 1652 
 1653         /* is the desired key cached? */
 1654         if ((keyid != stcb->asoc.authinfo.assoc_keyid) ||
 1655             (stcb->asoc.authinfo.assoc_key == NULL)) {
 1656                 if (stcb->asoc.authinfo.assoc_key != NULL) {
 1657                         /* free the old cached key */
 1658                         sctp_free_key(stcb->asoc.authinfo.assoc_key);
 1659                 }
 1660                 skey = sctp_find_sharedkey(&stcb->asoc.shared_keys, keyid);
 1661                 /* the only way skey is NULL is if null key id 0 is used */
 1662                 if (skey != NULL)
 1663                         key = skey->key;
 1664                 else
 1665                         key = NULL;
 1666                 /* compute a new assoc key and cache it */
 1667                 stcb->asoc.authinfo.assoc_key =
 1668                     sctp_compute_hashkey(stcb->asoc.authinfo.random,
 1669                     stcb->asoc.authinfo.peer_random, key);
 1670                 stcb->asoc.authinfo.assoc_keyid = keyid;
 1671                 SCTPDBG(SCTP_DEBUG_AUTH1, "caching key id %u\n",
 1672                     stcb->asoc.authinfo.assoc_keyid);
 1673 #ifdef SCTP_DEBUG
 1674                 if (SCTP_AUTH_DEBUG)
 1675                         sctp_print_key(stcb->asoc.authinfo.assoc_key,
 1676                             "Assoc Key");
 1677 #endif
 1678         }
 1679         /* set in the active key id */
 1680         auth->shared_key_id = htons(keyid);
 1681 
 1682         /* compute and fill in the digest */
 1683         (void)sctp_compute_hmac_m(stcb->asoc.peer_hmac_id, stcb->asoc.authinfo.assoc_key,
 1684             m, auth_offset, auth->hmac);
 1685 }
 1686 
 1687 
 1688 static void
 1689 sctp_bzero_m(struct mbuf *m, uint32_t m_offset, uint32_t size)
 1690 {
 1691         struct mbuf *m_tmp;
 1692         uint8_t *data;
 1693 
 1694         /* sanity check */
 1695         if (m == NULL)
 1696                 return;
 1697 
 1698         /* find the correct starting mbuf and offset (get start position) */
 1699         m_tmp = m;
 1700         while ((m_tmp != NULL) && (m_offset >= (uint32_t) SCTP_BUF_LEN(m_tmp))) {
 1701                 m_offset -= SCTP_BUF_LEN(m_tmp);
 1702                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1703         }
 1704         /* now use the rest of the mbuf chain */
 1705         while ((m_tmp != NULL) && (size > 0)) {
 1706                 data = mtod(m_tmp, uint8_t *) + m_offset;
 1707                 if (size > (uint32_t) SCTP_BUF_LEN(m_tmp)) {
 1708                         bzero(data, SCTP_BUF_LEN(m_tmp));
 1709                         size -= SCTP_BUF_LEN(m_tmp);
 1710                 } else {
 1711                         bzero(data, size);
 1712                         size = 0;
 1713                 }
 1714                 /* clear the offset since it's only for the first mbuf */
 1715                 m_offset = 0;
 1716                 m_tmp = SCTP_BUF_NEXT(m_tmp);
 1717         }
 1718 }
 1719 
 1720 /*-
 1721  * process the incoming Authentication chunk
 1722  * return codes:
 1723  *   -1 on any authentication error
 1724  *    0 on authentication verification
 1725  */
 1726 int
 1727 sctp_handle_auth(struct sctp_tcb *stcb, struct sctp_auth_chunk *auth,
 1728     struct mbuf *m, uint32_t offset)
 1729 {
 1730         uint16_t chunklen;
 1731         uint16_t shared_key_id;
 1732         uint16_t hmac_id;
 1733         sctp_sharedkey_t *skey;
 1734         uint32_t digestlen;
 1735         uint8_t digest[SCTP_AUTH_DIGEST_LEN_MAX];
 1736         uint8_t computed_digest[SCTP_AUTH_DIGEST_LEN_MAX];
 1737 
 1738         /* auth is checked for NULL by caller */
 1739         chunklen = ntohs(auth->ch.chunk_length);
 1740         if (chunklen < sizeof(*auth)) {
 1741                 SCTP_STAT_INCR(sctps_recvauthfailed);
 1742                 return (-1);
 1743         }
 1744         SCTP_STAT_INCR(sctps_recvauth);
 1745 
 1746         /* get the auth params */
 1747         shared_key_id = ntohs(auth->shared_key_id);
 1748         hmac_id = ntohs(auth->hmac_id);
 1749         SCTPDBG(SCTP_DEBUG_AUTH1,
 1750             "SCTP AUTH Chunk: shared key %u, HMAC id %u\n",
 1751             shared_key_id, hmac_id);
 1752 
 1753         /* is the indicated HMAC supported? */
 1754         if (!sctp_auth_is_supported_hmac(stcb->asoc.local_hmacs, hmac_id)) {
 1755                 struct mbuf *m_err;
 1756                 struct sctp_auth_invalid_hmac *err;
 1757 
 1758                 SCTP_STAT_INCR(sctps_recvivalhmacid);
 1759                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1760                     "SCTP Auth: unsupported HMAC id %u\n",
 1761                     hmac_id);
 1762                 /*
 1763                  * report this in an Error Chunk: Unsupported HMAC
 1764                  * Identifier
 1765                  */
 1766                 m_err = sctp_get_mbuf_for_msg(sizeof(*err), 0, M_DONTWAIT,
 1767                     1, MT_HEADER);
 1768                 if (m_err != NULL) {
 1769                         /* pre-reserve some space */
 1770                         SCTP_BUF_RESV_UF(m_err, sizeof(struct sctp_chunkhdr));
 1771                         /* fill in the error */
 1772                         err = mtod(m_err, struct sctp_auth_invalid_hmac *);
 1773                         bzero(err, sizeof(*err));
 1774                         err->ph.param_type = htons(SCTP_CAUSE_UNSUPPORTED_HMACID);
 1775                         err->ph.param_length = htons(sizeof(*err));
 1776                         err->hmac_id = ntohs(hmac_id);
 1777                         SCTP_BUF_LEN(m_err) = sizeof(*err);
 1778                         /* queue it */
 1779                         sctp_queue_op_err(stcb, m_err);
 1780                 }
 1781                 return (-1);
 1782         }
 1783         /* get the indicated shared key, if available */
 1784         if ((stcb->asoc.authinfo.recv_key == NULL) ||
 1785             (stcb->asoc.authinfo.recv_keyid != shared_key_id)) {
 1786                 /* find the shared key on the assoc first */
 1787                 skey = sctp_find_sharedkey(&stcb->asoc.shared_keys,
 1788                     shared_key_id);
 1789                 /* if the shared key isn't found, discard the chunk */
 1790                 if (skey == NULL) {
 1791                         SCTP_STAT_INCR(sctps_recvivalkeyid);
 1792                         SCTPDBG(SCTP_DEBUG_AUTH1,
 1793                             "SCTP Auth: unknown key id %u\n",
 1794                             shared_key_id);
 1795                         return (-1);
 1796                 }
 1797                 /* generate a notification if this is a new key id */
 1798                 if (stcb->asoc.authinfo.recv_keyid != shared_key_id)
 1799                         /*
 1800                          * sctp_ulp_notify(SCTP_NOTIFY_AUTH_NEW_KEY, stcb,
 1801                          * shared_key_id, (void
 1802                          * *)stcb->asoc.authinfo.recv_keyid);
 1803                          */
 1804                         sctp_notify_authentication(stcb, SCTP_AUTH_NEW_KEY,
 1805                             shared_key_id, stcb->asoc.authinfo.recv_keyid,
 1806                             SCTP_SO_NOT_LOCKED);
 1807                 /* compute a new recv assoc key and cache it */
 1808                 if (stcb->asoc.authinfo.recv_key != NULL)
 1809                         sctp_free_key(stcb->asoc.authinfo.recv_key);
 1810                 stcb->asoc.authinfo.recv_key =
 1811                     sctp_compute_hashkey(stcb->asoc.authinfo.random,
 1812                     stcb->asoc.authinfo.peer_random, skey->key);
 1813                 stcb->asoc.authinfo.recv_keyid = shared_key_id;
 1814 #ifdef SCTP_DEBUG
 1815                 if (SCTP_AUTH_DEBUG)
 1816                         sctp_print_key(stcb->asoc.authinfo.recv_key, "Recv Key");
 1817 #endif
 1818         }
 1819         /* validate the digest length */
 1820         digestlen = sctp_get_hmac_digest_len(hmac_id);
 1821         if (chunklen < (sizeof(*auth) + digestlen)) {
 1822                 /* invalid digest length */
 1823                 SCTP_STAT_INCR(sctps_recvauthfailed);
 1824                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1825                     "SCTP Auth: chunk too short for HMAC\n");
 1826                 return (-1);
 1827         }
 1828         /* save a copy of the digest, zero the pseudo header, and validate */
 1829         bcopy(auth->hmac, digest, digestlen);
 1830         sctp_bzero_m(m, offset + sizeof(*auth), SCTP_SIZE32(digestlen));
 1831         (void)sctp_compute_hmac_m(hmac_id, stcb->asoc.authinfo.recv_key,
 1832             m, offset, computed_digest);
 1833 
 1834         /* compare the computed digest with the one in the AUTH chunk */
 1835         if (memcmp(digest, computed_digest, digestlen) != 0) {
 1836                 SCTP_STAT_INCR(sctps_recvauthfailed);
 1837                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1838                     "SCTP Auth: HMAC digest check failed\n");
 1839                 return (-1);
 1840         }
 1841         return (0);
 1842 }
 1843 
 1844 /*
 1845  * Generate NOTIFICATION
 1846  */
 1847 void
 1848 sctp_notify_authentication(struct sctp_tcb *stcb, uint32_t indication,
 1849     uint16_t keyid, uint16_t alt_keyid, int so_locked
 1850 #if !defined(__APPLE__) && !defined(SCTP_SO_LOCK_TESTING)
 1851     SCTP_UNUSED
 1852 #endif
 1853 )
 1854 {
 1855         struct mbuf *m_notify;
 1856         struct sctp_authkey_event *auth;
 1857         struct sctp_queued_to_read *control;
 1858 
 1859         if ((stcb == NULL) ||
 1860             (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_GONE) ||
 1861             (stcb->sctp_ep->sctp_flags & SCTP_PCB_FLAGS_SOCKET_ALLGONE) ||
 1862             (stcb->asoc.state & SCTP_STATE_CLOSED_SOCKET)
 1863             ) {
 1864                 /* If the socket is gone we are out of here */
 1865                 return;
 1866         }
 1867         if (sctp_stcb_is_feature_off(stcb->sctp_ep, stcb, SCTP_PCB_FLAGS_AUTHEVNT))
 1868                 /* event not enabled */
 1869                 return;
 1870 
 1871         m_notify = sctp_get_mbuf_for_msg(sizeof(struct sctp_authkey_event),
 1872             0, M_DONTWAIT, 1, MT_HEADER);
 1873         if (m_notify == NULL)
 1874                 /* no space left */
 1875                 return;
 1876 
 1877         SCTP_BUF_LEN(m_notify) = 0;
 1878         auth = mtod(m_notify, struct sctp_authkey_event *);
 1879         memset(auth, 0, sizeof(struct sctp_authkey_event));
 1880         auth->auth_type = SCTP_AUTHENTICATION_EVENT;
 1881         auth->auth_flags = 0;
 1882         auth->auth_length = sizeof(*auth);
 1883         auth->auth_keynumber = keyid;
 1884         auth->auth_altkeynumber = alt_keyid;
 1885         auth->auth_indication = indication;
 1886         auth->auth_assoc_id = sctp_get_associd(stcb);
 1887 
 1888         SCTP_BUF_LEN(m_notify) = sizeof(*auth);
 1889         SCTP_BUF_NEXT(m_notify) = NULL;
 1890 
 1891         /* append to socket */
 1892         control = sctp_build_readq_entry(stcb, stcb->asoc.primary_destination,
 1893             0, 0, stcb->asoc.context, 0, 0, 0, m_notify);
 1894         if (control == NULL) {
 1895                 /* no memory */
 1896                 sctp_m_freem(m_notify);
 1897                 return;
 1898         }
 1899         control->spec_flags = M_NOTIFICATION;
 1900         control->length = SCTP_BUF_LEN(m_notify);
 1901         /* not that we need this */
 1902         control->tail_mbuf = m_notify;
 1903         sctp_add_to_readq(stcb->sctp_ep, stcb, control,
 1904             &stcb->sctp_socket->so_rcv, 1, SCTP_READ_LOCK_NOT_HELD, so_locked);
 1905 }
 1906 
 1907 
 1908 /*-
 1909  * validates the AUTHentication related parameters in an INIT/INIT-ACK
 1910  * Note: currently only used for INIT as INIT-ACK is handled inline
 1911  * with sctp_load_addresses_from_init()
 1912  */
 1913 int
 1914 sctp_validate_init_auth_params(struct mbuf *m, int offset, int limit)
 1915 {
 1916         struct sctp_paramhdr *phdr, parm_buf;
 1917         uint16_t ptype, plen;
 1918         int peer_supports_asconf = 0;
 1919         int peer_supports_auth = 0;
 1920         int got_random = 0, got_hmacs = 0, got_chklist = 0;
 1921         uint8_t saw_asconf = 0;
 1922         uint8_t saw_asconf_ack = 0;
 1923 
 1924         /* go through each of the params. */
 1925         phdr = sctp_get_next_param(m, offset, &parm_buf, sizeof(parm_buf));
 1926         while (phdr) {
 1927                 ptype = ntohs(phdr->param_type);
 1928                 plen = ntohs(phdr->param_length);
 1929 
 1930                 if (offset + plen > limit) {
 1931                         break;
 1932                 }
 1933                 if (plen < sizeof(struct sctp_paramhdr)) {
 1934                         break;
 1935                 }
 1936                 if (ptype == SCTP_SUPPORTED_CHUNK_EXT) {
 1937                         /* A supported extension chunk */
 1938                         struct sctp_supported_chunk_types_param *pr_supported;
 1939                         uint8_t local_store[SCTP_PARAM_BUFFER_SIZE];
 1940                         int num_ent, i;
 1941 
 1942                         phdr = sctp_get_next_param(m, offset,
 1943                             (struct sctp_paramhdr *)&local_store, min(plen, sizeof(local_store)));
 1944                         if (phdr == NULL) {
 1945                                 return (-1);
 1946                         }
 1947                         pr_supported = (struct sctp_supported_chunk_types_param *)phdr;
 1948                         num_ent = plen - sizeof(struct sctp_paramhdr);
 1949                         for (i = 0; i < num_ent; i++) {
 1950                                 switch (pr_supported->chunk_types[i]) {
 1951                                 case SCTP_ASCONF:
 1952                                 case SCTP_ASCONF_ACK:
 1953                                         peer_supports_asconf = 1;
 1954                                         break;
 1955                                 default:
 1956                                         /* one we don't care about */
 1957                                         break;
 1958                                 }
 1959                         }
 1960                 } else if (ptype == SCTP_RANDOM) {
 1961                         got_random = 1;
 1962                         /* enforce the random length */
 1963                         if (plen != (sizeof(struct sctp_auth_random) +
 1964                             SCTP_AUTH_RANDOM_SIZE_REQUIRED)) {
 1965                                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1966                                     "SCTP: invalid RANDOM len\n");
 1967                                 return (-1);
 1968                         }
 1969                 } else if (ptype == SCTP_HMAC_LIST) {
 1970                         uint8_t store[SCTP_PARAM_BUFFER_SIZE];
 1971                         struct sctp_auth_hmac_algo *hmacs;
 1972                         int num_hmacs;
 1973 
 1974                         if (plen > sizeof(store))
 1975                                 break;
 1976                         phdr = sctp_get_next_param(m, offset,
 1977                             (struct sctp_paramhdr *)store, min(plen, sizeof(store)));
 1978                         if (phdr == NULL)
 1979                                 return (-1);
 1980                         hmacs = (struct sctp_auth_hmac_algo *)phdr;
 1981                         num_hmacs = (plen - sizeof(*hmacs)) /
 1982                             sizeof(hmacs->hmac_ids[0]);
 1983                         /* validate the hmac list */
 1984                         if (sctp_verify_hmac_param(hmacs, num_hmacs)) {
 1985                                 SCTPDBG(SCTP_DEBUG_AUTH1,
 1986                                     "SCTP: invalid HMAC param\n");
 1987                                 return (-1);
 1988                         }
 1989                         got_hmacs = 1;
 1990                 } else if (ptype == SCTP_CHUNK_LIST) {
 1991                         int i, num_chunks;
 1992                         uint8_t chunks_store[SCTP_SMALL_CHUNK_STORE];
 1993 
 1994                         /* did the peer send a non-empty chunk list? */
 1995                         struct sctp_auth_chunk_list *chunks = NULL;
 1996 
 1997                         phdr = sctp_get_next_param(m, offset,
 1998                             (struct sctp_paramhdr *)chunks_store,
 1999                             min(plen, sizeof(chunks_store)));
 2000                         if (phdr == NULL)
 2001                                 return (-1);
 2002 
 2003                         /*-
 2004                          * Flip through the list and mark that the
 2005                          * peer supports asconf/asconf_ack.
 2006                          */
 2007                         chunks = (struct sctp_auth_chunk_list *)phdr;
 2008                         num_chunks = plen - sizeof(*chunks);
 2009                         for (i = 0; i < num_chunks; i++) {
 2010                                 /* record asconf/asconf-ack if listed */
 2011                                 if (chunks->chunk_types[i] == SCTP_ASCONF)
 2012                                         saw_asconf = 1;
 2013                                 if (chunks->chunk_types[i] == SCTP_ASCONF_ACK)
 2014                                         saw_asconf_ack = 1;
 2015 
 2016                         }
 2017                         if (num_chunks)
 2018                                 got_chklist = 1;
 2019                 }
 2020                 offset += SCTP_SIZE32(plen);
 2021                 if (offset >= limit) {
 2022                         break;
 2023                 }
 2024                 phdr = sctp_get_next_param(m, offset, &parm_buf,
 2025                     sizeof(parm_buf));
 2026         }
 2027         /* validate authentication required parameters */
 2028         if (got_random && got_hmacs) {
 2029                 peer_supports_auth = 1;
 2030         } else {
 2031                 peer_supports_auth = 0;
 2032         }
 2033         if (!peer_supports_auth && got_chklist) {
 2034                 SCTPDBG(SCTP_DEBUG_AUTH1,
 2035                     "SCTP: peer sent chunk list w/o AUTH\n");
 2036                 return (-1);
 2037         }
 2038         if (!SCTP_BASE_SYSCTL(sctp_asconf_auth_nochk) && peer_supports_asconf &&
 2039             !peer_supports_auth) {
 2040                 SCTPDBG(SCTP_DEBUG_AUTH1,
 2041                     "SCTP: peer supports ASCONF but not AUTH\n");
 2042                 return (-1);
 2043         } else if ((peer_supports_asconf) && (peer_supports_auth) &&
 2044             ((saw_asconf == 0) || (saw_asconf_ack == 0))) {
 2045                 return (-2);
 2046         }
 2047         return (0);
 2048 }
 2049 
 2050 void
 2051 sctp_initialize_auth_params(struct sctp_inpcb *inp, struct sctp_tcb *stcb)
 2052 {
 2053         uint16_t chunks_len = 0;
 2054         uint16_t hmacs_len = 0;
 2055         uint16_t random_len = SCTP_AUTH_RANDOM_SIZE_DEFAULT;
 2056         sctp_key_t *new_key;
 2057         uint16_t keylen;
 2058 
 2059         /* initialize hmac list from endpoint */
 2060         stcb->asoc.local_hmacs = sctp_copy_hmaclist(inp->sctp_ep.local_hmacs);
 2061         if (stcb->asoc.local_hmacs != NULL) {
 2062                 hmacs_len = stcb->asoc.local_hmacs->num_algo *
 2063                     sizeof(stcb->asoc.local_hmacs->hmac[0]);
 2064         }
 2065         /* initialize auth chunks list from endpoint */
 2066         stcb->asoc.local_auth_chunks =
 2067             sctp_copy_chunklist(inp->sctp_ep.local_auth_chunks);
 2068         if (stcb->asoc.local_auth_chunks != NULL) {
 2069                 int i;
 2070 
 2071                 for (i = 0; i < 256; i++) {
 2072                         if (stcb->asoc.local_auth_chunks->chunks[i])
 2073                                 chunks_len++;
 2074                 }
 2075         }
 2076         /* copy defaults from the endpoint */
 2077         stcb->asoc.authinfo.active_keyid = inp->sctp_ep.default_keyid;
 2078 
 2079         /* copy out the shared key list (by reference) from the endpoint */
 2080         (void)sctp_copy_skeylist(&inp->sctp_ep.shared_keys,
 2081             &stcb->asoc.shared_keys);
 2082 
 2083         /* now set the concatenated key (random + chunks + hmacs) */
 2084         /* key includes parameter headers */
 2085         keylen = (3 * sizeof(struct sctp_paramhdr)) + random_len + chunks_len +
 2086             hmacs_len;
 2087         new_key = sctp_alloc_key(keylen);
 2088         if (new_key != NULL) {
 2089                 struct sctp_paramhdr *ph;
 2090                 int plen;
 2091 
 2092                 /* generate and copy in the RANDOM */
 2093                 ph = (struct sctp_paramhdr *)new_key->key;
 2094                 ph->param_type = htons(SCTP_RANDOM);
 2095                 plen = sizeof(*ph) + random_len;
 2096                 ph->param_length = htons(plen);
 2097                 SCTP_READ_RANDOM(new_key->key + sizeof(*ph), random_len);
 2098                 keylen = plen;
 2099 
 2100                 /* append in the AUTH chunks */
 2101                 /* NOTE: currently we always have chunks to list */
 2102                 ph = (struct sctp_paramhdr *)(new_key->key + keylen);
 2103                 ph->param_type = htons(SCTP_CHUNK_LIST);
 2104                 plen = sizeof(*ph) + chunks_len;
 2105                 ph->param_length = htons(plen);
 2106                 keylen += sizeof(*ph);
 2107                 if (stcb->asoc.local_auth_chunks) {
 2108                         int i;
 2109 
 2110                         for (i = 0; i < 256; i++) {
 2111                                 if (stcb->asoc.local_auth_chunks->chunks[i])
 2112                                         new_key->key[keylen++] = i;
 2113                         }
 2114                 }
 2115                 /* append in the HMACs */
 2116                 ph = (struct sctp_paramhdr *)(new_key->key + keylen);
 2117                 ph->param_type = htons(SCTP_HMAC_LIST);
 2118                 plen = sizeof(*ph) + hmacs_len;
 2119                 ph->param_length = htons(plen);
 2120                 keylen += sizeof(*ph);
 2121                 (void)sctp_serialize_hmaclist(stcb->asoc.local_hmacs,
 2122                     new_key->key + keylen);
 2123         }
 2124         if (stcb->asoc.authinfo.random != NULL)
 2125                 sctp_free_key(stcb->asoc.authinfo.random);
 2126         stcb->asoc.authinfo.random = new_key;
 2127         stcb->asoc.authinfo.random_len = random_len;
 2128 }
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FreeBSD/Linux Kernel Cross Reference sys/netinet/sctp_auth.c

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