Function sctp_negotiate_hmacid

freebsd/netinet/sctp_auth.c:721–742

- * HMAC algos are listed in priority/preference order * find the best HMAC id to use for the peer based on local support */

 * find the best HMAC id to use for the peer based on local support
 */
uint16_t
sctp_negotiate_hmacid(sctp_hmaclist_t *peer, sctp_hmaclist_t *local)
{
	int i, j;

	if ((local == NULL) || (peer == NULL))
		return (SCTP_AUTH_HMAC_ID_RSVD);

	for (i = 0; i < peer->num_algo; i++) {
		for (j = 0; j < local->num_algo; j++) {
			if (peer->hmac[i] == local->hmac[j]) {
				/* found the "best" one */
				SCTPDBG(SCTP_DEBUG_AUTH1,
				    "SCTP: negotiated peer HMAC id %u\n",
				    peer->hmac[i]);
				return (peer->hmac[i]);
			}
		}
	}
	/* didn't find one! */
	return (SCTP_AUTH_HMAC_ID_RSVD);
}

/*-
 * serialize the HMAC algo list and return space used