3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1999-2005 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@OpenSSL.org.
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
62 #include <openssl/objects.h>
65 #if defined(OPENSSL_SYS_VMS)
66 # include <sys/timeb.h>
67 #elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_)
68 # include <sys/timeval.h>
69 #elif defined(OPENSSL_SYS_VXWORKS)
70 # include <sys/times.h>
71 #elif !defined(OPENSSL_SYS_WIN32)
72 # include <sys/time.h>
75 static void get_current_time(struct timeval *t);
76 static int dtls1_set_handshake_header(SSL *s, int type, unsigned long len);
77 static int dtls1_handshake_write(SSL *s);
78 int dtls1_listen(SSL *s, struct sockaddr *client);
80 const SSL3_ENC_METHOD DTLSv1_enc_data = {
84 tls1_generate_master_secret,
85 tls1_change_cipher_state,
86 tls1_final_finish_mac,
87 TLS1_FINISH_MAC_LENGTH,
89 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
90 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
92 tls1_export_keying_material,
93 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,
94 DTLS1_HM_HEADER_LENGTH,
95 dtls1_set_handshake_header,
99 const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
102 tls1_setup_key_block,
103 tls1_generate_master_secret,
104 tls1_change_cipher_state,
105 tls1_final_finish_mac,
106 TLS1_FINISH_MAC_LENGTH,
107 tls1_cert_verify_mac,
108 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
109 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
111 tls1_export_keying_material,
112 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS
113 | SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
114 DTLS1_HM_HEADER_LENGTH,
115 dtls1_set_handshake_header,
116 dtls1_handshake_write
119 long dtls1_default_timeout(void)
122 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
123 * http, the cache would over fill
125 return (60 * 60 * 2);
128 int dtls1_new(SSL *s)
132 if (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
138 if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) {
143 d1->buffered_messages = pqueue_new();
144 d1->sent_messages = pqueue_new();
147 d1->cookie_len = sizeof(s->d1->cookie);
153 if (!d1->buffered_messages || !d1->sent_messages) {
154 pqueue_free(d1->buffered_messages);
155 pqueue_free(d1->sent_messages);
162 s->method->ssl_clear(s);
166 static void dtls1_clear_queues(SSL *s)
169 hm_fragment *frag = NULL;
171 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
172 frag = (hm_fragment *)item->data;
173 dtls1_hm_fragment_free(frag);
177 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
178 frag = (hm_fragment *)item->data;
179 dtls1_hm_fragment_free(frag);
184 void dtls1_free(SSL *s)
186 DTLS_RECORD_LAYER_free(&s->rlayer);
190 dtls1_clear_queues(s);
192 pqueue_free(s->d1->buffered_messages);
193 pqueue_free(s->d1->sent_messages);
199 void dtls1_clear(SSL *s)
201 pqueue buffered_messages;
202 pqueue sent_messages;
204 unsigned int link_mtu;
206 DTLS_RECORD_LAYER_clear(&s->rlayer);
209 buffered_messages = s->d1->buffered_messages;
210 sent_messages = s->d1->sent_messages;
212 link_mtu = s->d1->link_mtu;
214 dtls1_clear_queues(s);
216 memset(s->d1, 0, sizeof(*s->d1));
219 s->d1->cookie_len = sizeof(s->d1->cookie);
222 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
224 s->d1->link_mtu = link_mtu;
227 s->d1->buffered_messages = buffered_messages;
228 s->d1->sent_messages = sent_messages;
232 if (s->options & SSL_OP_CISCO_ANYCONNECT)
233 s->client_version = s->version = DTLS1_BAD_VER;
234 else if (s->method->version == DTLS_ANY_VERSION)
235 s->version = DTLS1_2_VERSION;
237 s->version = s->method->version;
240 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
245 case DTLS_CTRL_GET_TIMEOUT:
246 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
250 case DTLS_CTRL_HANDLE_TIMEOUT:
251 ret = dtls1_handle_timeout(s);
253 case DTLS_CTRL_LISTEN:
254 ret = dtls1_listen(s, parg);
256 case SSL_CTRL_CHECK_PROTO_VERSION:
258 * For library-internal use; checks that the current protocol is the
259 * highest enabled version (according to s->ctx->method, as version
260 * negotiation may have changed s->method).
262 if (s->version == s->ctx->method->version)
265 * Apparently we're using a version-flexible SSL_METHOD (not at its
266 * highest protocol version).
268 if (s->ctx->method->version == DTLS_method()->version) {
269 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
270 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
272 if (!(s->options & SSL_OP_NO_DTLSv1_2))
273 return s->version == DTLS1_2_VERSION;
274 if (!(s->options & SSL_OP_NO_DTLSv1))
275 return s->version == DTLS1_VERSION;
277 return 0; /* Unexpected state; fail closed. */
278 case DTLS_CTRL_SET_LINK_MTU:
279 if (larg < (long)dtls1_link_min_mtu())
281 s->d1->link_mtu = larg;
283 case DTLS_CTRL_GET_LINK_MIN_MTU:
284 return (long)dtls1_link_min_mtu();
285 case SSL_CTRL_SET_MTU:
287 * We may not have a BIO set yet so can't call dtls1_min_mtu()
288 * We'll have to make do with dtls1_link_min_mtu() and max overhead
290 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
295 ret = ssl3_ctrl(s, cmd, larg, parg);
302 * As it's impossible to use stream ciphers in "datagram" mode, this
303 * simple filter is designed to disengage them in DTLS. Unfortunately
304 * there is no universal way to identify stream SSL_CIPHER, so we have
305 * to explicitly list their SSL_* codes. Currently RC4 is the only one
306 * available, but if new ones emerge, they will have to be added...
308 const SSL_CIPHER *dtls1_get_cipher(unsigned int u)
310 const SSL_CIPHER *ciph = ssl3_get_cipher(u);
313 if (ciph->algorithm_enc == SSL_RC4)
320 void dtls1_start_timer(SSL *s)
322 #ifndef OPENSSL_NO_SCTP
323 /* Disable timer for SCTP */
324 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
325 memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
330 /* If timer is not set, initialize duration with 1 second */
331 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
332 s->d1->timeout_duration = 1;
335 /* Set timeout to current time */
336 get_current_time(&(s->d1->next_timeout));
338 /* Add duration to current time */
339 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
340 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
341 &(s->d1->next_timeout));
344 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
346 struct timeval timenow;
348 /* If no timeout is set, just return NULL */
349 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
353 /* Get current time */
354 get_current_time(&timenow);
356 /* If timer already expired, set remaining time to 0 */
357 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
358 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
359 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
360 memset(timeleft, 0, sizeof(*timeleft));
364 /* Calculate time left until timer expires */
365 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
366 timeleft->tv_sec -= timenow.tv_sec;
367 timeleft->tv_usec -= timenow.tv_usec;
368 if (timeleft->tv_usec < 0) {
370 timeleft->tv_usec += 1000000;
374 * If remaining time is less than 15 ms, set it to 0 to prevent issues
375 * because of small devergences with socket timeouts.
377 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
378 memset(timeleft, 0, sizeof(*timeleft));
384 int dtls1_is_timer_expired(SSL *s)
386 struct timeval timeleft;
388 /* Get time left until timeout, return false if no timer running */
389 if (dtls1_get_timeout(s, &timeleft) == NULL) {
393 /* Return false if timer is not expired yet */
394 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
398 /* Timer expired, so return true */
402 void dtls1_double_timeout(SSL *s)
404 s->d1->timeout_duration *= 2;
405 if (s->d1->timeout_duration > 60)
406 s->d1->timeout_duration = 60;
407 dtls1_start_timer(s);
410 void dtls1_stop_timer(SSL *s)
412 /* Reset everything */
413 memset(&s->d1->timeout, 0, sizeof(s->d1->timeout));
414 memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
415 s->d1->timeout_duration = 1;
416 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
417 &(s->d1->next_timeout));
418 /* Clear retransmission buffer */
419 dtls1_clear_record_buffer(s);
422 int dtls1_check_timeout_num(SSL *s)
426 s->d1->timeout.num_alerts++;
428 /* Reduce MTU after 2 unsuccessful retransmissions */
429 if (s->d1->timeout.num_alerts > 2
430 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
432 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0,
434 if (mtu < s->d1->mtu)
438 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
439 /* fail the connection, enough alerts have been sent */
440 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
447 int dtls1_handle_timeout(SSL *s)
449 /* if no timer is expired, don't do anything */
450 if (!dtls1_is_timer_expired(s)) {
454 dtls1_double_timeout(s);
456 if (dtls1_check_timeout_num(s) < 0)
459 s->d1->timeout.read_timeouts++;
460 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
461 s->d1->timeout.read_timeouts = 1;
463 #ifndef OPENSSL_NO_HEARTBEATS
464 if (s->tlsext_hb_pending) {
465 s->tlsext_hb_pending = 0;
466 return dtls1_heartbeat(s);
470 dtls1_start_timer(s);
471 return dtls1_retransmit_buffered_messages(s);
474 static void get_current_time(struct timeval *t)
484 SystemTimeToFileTime(&st, &now.ft);
486 now.ul -= 116444736000000000ULL;
488 now.ul -= 116444736000000000UI64; /* re-bias to 1/1/1970 */
490 t->tv_sec = (long)(now.ul / 10000000);
491 t->tv_usec = ((int)(now.ul % 10000000)) / 10;
492 #elif defined(OPENSSL_SYS_VMS)
495 t->tv_sec = (long)tb.time;
496 t->tv_usec = (long)tb.millitm * 1000;
498 gettimeofday(t, NULL);
503 #define LISTEN_SUCCESS 2
504 #define LISTEN_SEND_VERIFY_REQUEST 1
507 int dtls1_listen(SSL *s, struct sockaddr *client)
509 int next, n, ret = 0, clearpkt = 0;
510 unsigned char cookie[DTLS1_COOKIE_LENGTH];
511 unsigned char seq[SEQ_NUM_SIZE];
512 unsigned char *data, *p, *buf;
513 unsigned long reclen, fragoff, fraglen, msglen;
514 unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen;
517 struct sockaddr_storage tmpclient;
518 PACKET pkt, msgpkt, msgpayload, session, cookiepkt;
520 /* Ensure there is no state left over from a previous invocation */
526 rbio = SSL_get_rbio(s);
527 wbio = SSL_get_wbio(s);
530 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_BIO_NOT_SET);
535 * We only peek at incoming ClientHello's until we're sure we are going to
536 * to respond with a HelloVerifyRequest. If its a ClientHello with a valid
537 * cookie then we leave it in the BIO for dtls1_accept to handle.
539 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
542 * Note: This check deliberately excludes DTLS1_BAD_VER because that version
543 * requires the MAC to be calculated *including* the first ClientHello
544 * (without the cookie). Since DTLSv1_listen is stateless that cannot be
545 * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
548 if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
549 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_UNSUPPORTED_SSL_VERSION);
553 if (s->init_buf == NULL) {
554 if ((bufm = BUF_MEM_new()) == NULL) {
555 SSLerr(SSL_F_DTLS1_LISTEN, ERR_R_MALLOC_FAILURE);
559 if (!BUF_MEM_grow(bufm, SSL3_RT_MAX_PLAIN_LENGTH)) {
561 SSLerr(SSL_F_DTLS1_LISTEN, ERR_R_MALLOC_FAILURE);
566 buf = (unsigned char *)s->init_buf->data;
573 * Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
574 * + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
575 * the record header as well, but we do here. We've set up init_buf to
576 * be the standard size for simplicity. In practice we shouldn't ever
577 * receive a ClientHello as long as this. If we do it will get dropped
578 * in the record length check below.
580 n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
583 if(BIO_should_retry(rbio)) {
584 /* Non-blocking IO */
590 /* If we hit any problems we need to clear this packet from the BIO */
593 if (!PACKET_buf_init(&pkt, buf, n)) {
594 SSLerr(SSL_F_DTLS1_LISTEN, ERR_R_INTERNAL_ERROR);
599 * Parse the received record. If there are any problems with it we just
600 * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
601 * resilient in the face of invalid records (e.g., invalid formatting,
602 * length, MAC, etc.). In general, invalid records SHOULD be silently
603 * discarded, thus preserving the association; however, an error MAY be
604 * logged for diagnostic purposes."
607 /* this packet contained a partial record, dump it */
608 if (n < DTLS1_RT_HEADER_LENGTH) {
609 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_RECORD_TOO_SMALL);
614 s->msg_callback(0, 0, SSL3_RT_HEADER, buf,
615 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
617 /* Get the record header */
618 if (!PACKET_get_1(&pkt, &rectype)
619 || !PACKET_get_1(&pkt, &versmajor)) {
620 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_LENGTH_MISMATCH);
624 if (rectype != SSL3_RT_HANDSHAKE) {
625 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
630 * Check record version number. We only check that the major version is
633 if (versmajor != DTLS1_VERSION_MAJOR) {
634 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
638 if (!PACKET_forward(&pkt, 1)
639 /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
640 || !PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)
641 || !PACKET_get_length_prefixed_2(&pkt, &msgpkt)
642 || PACKET_remaining(&pkt) != 0) {
643 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_LENGTH_MISMATCH);
647 /* This is an initial ClientHello so the epoch has to be 0 */
648 if (seq[0] != 0 || seq[1] != 0) {
649 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
653 /* Get a pointer to the raw message for the later callback */
654 data = PACKET_data(&msgpkt);
656 /* Finished processing the record header, now process the message */
657 if (!PACKET_get_1(&msgpkt, &msgtype)
658 || !PACKET_get_net_3(&msgpkt, &msglen)
659 || !PACKET_get_net_2(&msgpkt, &msgseq)
660 || !PACKET_get_net_3(&msgpkt, &fragoff)
661 || !PACKET_get_net_3(&msgpkt, &fraglen)
662 || !PACKET_get_sub_packet(&msgpkt, &msgpayload, msglen)
663 || PACKET_remaining(&msgpkt) != 0) {
664 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_LENGTH_MISMATCH);
668 if (msgtype != SSL3_MT_CLIENT_HELLO) {
669 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
673 /* Message sequence number can only be 0 or 1 */
675 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_INVALID_SEQUENCE_NUMBER);
679 /* We don't support a fragmented ClientHello whilst listening */
680 if (fragoff != 0 || fraglen != msglen) {
681 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_FRAGMENTED_CLIENT_HELLO);
686 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, data,
687 msglen + DTLS1_HM_HEADER_LENGTH, s,
688 s->msg_callback_arg);
690 if (!PACKET_get_net_2(&msgpayload, &clientvers)) {
691 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_LENGTH_MISMATCH);
696 * Verify client version is supported
698 if ((clientvers > (unsigned int)s->method->version &&
699 s->method->version != DTLS_ANY_VERSION)) {
700 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_WRONG_VERSION_NUMBER);
704 if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
705 || !PACKET_get_length_prefixed_1(&msgpayload, &session)
706 || !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)) {
707 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_LENGTH_MISMATCH);
712 * Check if we have a cookie or not. If not we need to send a
713 * HelloVerifyRequest.
715 if (PACKET_remaining(&cookiepkt) == 0) {
716 next = LISTEN_SEND_VERIFY_REQUEST;
719 * We have a cookie, so lets check it.
721 if (s->ctx->app_verify_cookie_cb == NULL) {
722 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_NO_VERIFY_COOKIE_CALLBACK);
726 if (PACKET_remaining(&cookiepkt) > sizeof(s->d1->rcvd_cookie)
727 || s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookiepkt),
728 PACKET_remaining(&cookiepkt)) == 0) {
730 * We treat invalid cookies in the same was as no cookie as
733 next = LISTEN_SEND_VERIFY_REQUEST;
735 /* Cookie verification succeeded */
736 next = LISTEN_SUCCESS;
740 if (next == LISTEN_SEND_VERIFY_REQUEST) {
742 * There was no cookie in the ClientHello so we need to send a
743 * HelloVerifyRequest. If this fails we do not worry about trying
744 * to resend, we just drop it.
748 * Dump the read packet, we don't need it any more. Ignore return
751 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL);
752 BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
753 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
755 /* Generate the cookie */
756 if (s->ctx->app_gen_cookie_cb == NULL ||
757 s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0) {
758 SSLerr(SSL_F_DTLS1_LISTEN, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
763 p = &buf[DTLS1_RT_HEADER_LENGTH];
764 msglen = dtls1_raw_hello_verify_request(p + DTLS1_HM_HEADER_LENGTH,
767 *p++ = DTLS1_MT_HELLO_VERIFY_REQUEST;
772 /* Message sequence number is always 0 for a HelloVerifyRequest */
776 * We never fragment a HelloVerifyRequest, so fragment offset is 0
777 * and fragment length is message length
782 /* Set reclen equal to length of whole handshake message */
783 reclen = msglen + DTLS1_HM_HEADER_LENGTH;
785 /* Add the record header */
788 *(p++) = SSL3_RT_HANDSHAKE;
790 * Special case: for hello verify request, client version 1.0 and we
791 * haven't decided which version to use yet send back using version
792 * 1.0 header: otherwise some clients will ignore it.
794 if (s->method->version == DTLS_ANY_VERSION) {
795 *(p++) = DTLS1_VERSION >> 8;
796 *(p++) = DTLS1_VERSION & 0xff;
798 *(p++) = s->version >> 8;
799 *(p++) = s->version & 0xff;
803 * Record sequence number is always the same as in the received
806 memcpy(p, seq, SEQ_NUM_SIZE);
813 * Set reclen equal to length of whole record including record
816 reclen += DTLS1_RT_HEADER_LENGTH;
819 s->msg_callback(1, 0, SSL3_RT_HEADER, buf,
820 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
823 * This is unneccessary if rbio and wbio are one and the same - but
826 if(BIO_dgram_get_peer(rbio, &tmpclient) <= 0
827 || BIO_dgram_set_peer(wbio, &tmpclient) <= 0) {
828 SSLerr(SSL_F_DTLS1_LISTEN, ERR_R_INTERNAL_ERROR);
832 if (BIO_write(wbio, buf, reclen) < (int)reclen) {
833 if(BIO_should_retry(wbio)) {
835 * Non-blocking IO...but we're stateless, so we're just
836 * going to drop this packet.
843 if (BIO_flush(wbio) <= 0) {
844 if(BIO_should_retry(wbio)) {
846 * Non-blocking IO...but we're stateless, so we're just
847 * going to drop this packet.
854 } while (next != LISTEN_SUCCESS);
857 * Set expected sequence numbers to continue the handshake.
859 s->d1->handshake_read_seq = 1;
860 s->d1->handshake_write_seq = 1;
861 s->d1->next_handshake_write_seq = 1;
862 DTLS_RECORD_LAYER_set_write_sequence(&s->rlayer, seq);
865 * We are doing cookie exchange, so make sure we set that option in the
868 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
871 * Put us into the "init" state so that dtls1_accept doesn't clear our
874 s->state = SSL_ST_ACCEPT;
876 if(BIO_dgram_get_peer(rbio, client) <= 0) {
877 SSLerr(SSL_F_DTLS1_LISTEN, ERR_R_INTERNAL_ERROR);
884 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL);
886 /* Dump this packet. Ignore return value */
887 BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
892 static int dtls1_set_handshake_header(SSL *s, int htype, unsigned long len)
894 unsigned char *p = (unsigned char *)s->init_buf->data;
895 dtls1_set_message_header(s, p, htype, len, 0, len);
896 s->init_num = (int)len + DTLS1_HM_HEADER_LENGTH;
898 /* Buffer the message to handle re-xmits */
900 if (!dtls1_buffer_message(s, 0))
906 static int dtls1_handshake_write(SSL *s)
908 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);