2 * Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
12 #include <openssl/objects.h>
13 #include <openssl/rand.h>
16 #if defined(OPENSSL_SYS_VMS)
17 # include <sys/timeb.h>
18 #elif defined(OPENSSL_SYS_VXWORKS)
19 # include <sys/times.h>
20 #elif !defined(OPENSSL_SYS_WIN32)
21 # include <sys/time.h>
24 static void get_current_time(struct timeval *t);
25 static int dtls1_handshake_write(SSL *s);
26 static unsigned int dtls1_link_min_mtu(void);
28 /* XDTLS: figure out the right values */
29 static const unsigned int g_probable_mtu[] = { 1500, 512, 256 };
31 const SSL3_ENC_METHOD DTLSv1_enc_data = {
35 tls1_generate_master_secret,
36 tls1_change_cipher_state,
37 tls1_final_finish_mac,
38 TLS1_FINISH_MAC_LENGTH,
39 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
40 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
42 tls1_export_keying_material,
43 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,
44 DTLS1_HM_HEADER_LENGTH,
45 dtls1_set_handshake_header,
46 dtls1_close_construct_packet,
50 const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
54 tls1_generate_master_secret,
55 tls1_change_cipher_state,
56 tls1_final_finish_mac,
57 TLS1_FINISH_MAC_LENGTH,
58 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
59 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
61 tls1_export_keying_material,
62 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS
63 | SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
64 DTLS1_HM_HEADER_LENGTH,
65 dtls1_set_handshake_header,
66 dtls1_close_construct_packet,
70 long dtls1_default_timeout(void)
73 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
74 * http, the cache would over fill
83 if (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
89 if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) {
94 d1->buffered_messages = pqueue_new();
95 d1->sent_messages = pqueue_new();
98 d1->cookie_len = sizeof(s->d1->cookie);
104 if (d1->buffered_messages == NULL || d1->sent_messages == NULL) {
105 pqueue_free(d1->buffered_messages);
106 pqueue_free(d1->sent_messages);
113 s->method->ssl_clear(s);
117 static void dtls1_clear_queues(SSL *s)
119 dtls1_clear_received_buffer(s);
120 dtls1_clear_sent_buffer(s);
123 void dtls1_clear_received_buffer(SSL *s)
126 hm_fragment *frag = NULL;
128 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
129 frag = (hm_fragment *)item->data;
130 dtls1_hm_fragment_free(frag);
135 void dtls1_clear_sent_buffer(SSL *s)
138 hm_fragment *frag = NULL;
140 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
141 frag = (hm_fragment *)item->data;
142 dtls1_hm_fragment_free(frag);
148 void dtls1_free(SSL *s)
150 DTLS_RECORD_LAYER_free(&s->rlayer);
154 dtls1_clear_queues(s);
156 pqueue_free(s->d1->buffered_messages);
157 pqueue_free(s->d1->sent_messages);
163 void dtls1_clear(SSL *s)
165 pqueue *buffered_messages;
166 pqueue *sent_messages;
168 unsigned int link_mtu;
170 DTLS_RECORD_LAYER_clear(&s->rlayer);
173 buffered_messages = s->d1->buffered_messages;
174 sent_messages = s->d1->sent_messages;
176 link_mtu = s->d1->link_mtu;
178 dtls1_clear_queues(s);
180 memset(s->d1, 0, sizeof(*s->d1));
183 s->d1->cookie_len = sizeof(s->d1->cookie);
186 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
188 s->d1->link_mtu = link_mtu;
191 s->d1->buffered_messages = buffered_messages;
192 s->d1->sent_messages = sent_messages;
197 if (s->method->version == DTLS_ANY_VERSION)
198 s->version = DTLS_MAX_VERSION;
199 #ifndef OPENSSL_NO_DTLS1_METHOD
200 else if (s->options & SSL_OP_CISCO_ANYCONNECT)
201 s->client_version = s->version = DTLS1_BAD_VER;
204 s->version = s->method->version;
207 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
212 case DTLS_CTRL_GET_TIMEOUT:
213 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
217 case DTLS_CTRL_HANDLE_TIMEOUT:
218 ret = dtls1_handle_timeout(s);
220 case DTLS_CTRL_SET_LINK_MTU:
221 if (larg < (long)dtls1_link_min_mtu())
223 s->d1->link_mtu = larg;
225 case DTLS_CTRL_GET_LINK_MIN_MTU:
226 return (long)dtls1_link_min_mtu();
227 case SSL_CTRL_SET_MTU:
229 * We may not have a BIO set yet so can't call dtls1_min_mtu()
230 * We'll have to make do with dtls1_link_min_mtu() and max overhead
232 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
237 ret = ssl3_ctrl(s, cmd, larg, parg);
243 void dtls1_start_timer(SSL *s)
245 #ifndef OPENSSL_NO_SCTP
246 /* Disable timer for SCTP */
247 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
248 memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
253 /* If timer is not set, initialize duration with 1 second */
254 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
255 s->d1->timeout_duration = 1;
258 /* Set timeout to current time */
259 get_current_time(&(s->d1->next_timeout));
261 /* Add duration to current time */
262 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
263 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
264 &(s->d1->next_timeout));
267 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
269 struct timeval timenow;
271 /* If no timeout is set, just return NULL */
272 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
276 /* Get current time */
277 get_current_time(&timenow);
279 /* If timer already expired, set remaining time to 0 */
280 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
281 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
282 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
283 memset(timeleft, 0, sizeof(*timeleft));
287 /* Calculate time left until timer expires */
288 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
289 timeleft->tv_sec -= timenow.tv_sec;
290 timeleft->tv_usec -= timenow.tv_usec;
291 if (timeleft->tv_usec < 0) {
293 timeleft->tv_usec += 1000000;
297 * If remaining time is less than 15 ms, set it to 0 to prevent issues
298 * because of small divergences with socket timeouts.
300 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
301 memset(timeleft, 0, sizeof(*timeleft));
307 int dtls1_is_timer_expired(SSL *s)
309 struct timeval timeleft;
311 /* Get time left until timeout, return false if no timer running */
312 if (dtls1_get_timeout(s, &timeleft) == NULL) {
316 /* Return false if timer is not expired yet */
317 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
321 /* Timer expired, so return true */
325 void dtls1_double_timeout(SSL *s)
327 s->d1->timeout_duration *= 2;
328 if (s->d1->timeout_duration > 60)
329 s->d1->timeout_duration = 60;
330 dtls1_start_timer(s);
333 void dtls1_stop_timer(SSL *s)
335 /* Reset everything */
336 memset(&s->d1->timeout, 0, sizeof(s->d1->timeout));
337 memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
338 s->d1->timeout_duration = 1;
339 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
340 &(s->d1->next_timeout));
341 /* Clear retransmission buffer */
342 dtls1_clear_sent_buffer(s);
345 int dtls1_check_timeout_num(SSL *s)
349 s->d1->timeout.num_alerts++;
351 /* Reduce MTU after 2 unsuccessful retransmissions */
352 if (s->d1->timeout.num_alerts > 2
353 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
355 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
356 if (mtu < s->d1->mtu)
360 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
361 /* fail the connection, enough alerts have been sent */
362 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
369 int dtls1_handle_timeout(SSL *s)
371 /* if no timer is expired, don't do anything */
372 if (!dtls1_is_timer_expired(s)) {
376 dtls1_double_timeout(s);
378 if (dtls1_check_timeout_num(s) < 0)
381 s->d1->timeout.read_timeouts++;
382 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
383 s->d1->timeout.read_timeouts = 1;
385 #ifndef OPENSSL_NO_HEARTBEATS
386 if (s->tlsext_hb_pending) {
387 s->tlsext_hb_pending = 0;
388 return dtls1_heartbeat(s);
392 dtls1_start_timer(s);
393 return dtls1_retransmit_buffered_messages(s);
396 static void get_current_time(struct timeval *t)
406 SystemTimeToFileTime(&st, &now.ft);
407 /* re-bias to 1/1/1970 */
409 now.ul -= 116444736000000000ULL;
412 now.ul -= 116444736000000000UI64;
415 t->tv_sec = (long)(now.ul / 10000000);
416 t->tv_usec = ((int)(now.ul % 10000000)) / 10;
417 #elif defined(OPENSSL_SYS_VMS)
420 t->tv_sec = (long)tb.time;
421 t->tv_usec = (long)tb.millitm * 1000;
423 gettimeofday(t, NULL);
427 #define LISTEN_SUCCESS 2
428 #define LISTEN_SEND_VERIFY_REQUEST 1
430 #ifndef OPENSSL_NO_SOCK
431 int DTLSv1_listen(SSL *s, BIO_ADDR *client)
433 int next, n, ret = 0, clearpkt = 0;
434 unsigned char cookie[DTLS1_COOKIE_LENGTH];
435 unsigned char seq[SEQ_NUM_SIZE];
436 const unsigned char *data;
438 unsigned long fragoff, fraglen, msglen;
439 unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen;
442 BIO_ADDR *tmpclient = NULL;
443 PACKET pkt, msgpkt, msgpayload, session, cookiepkt;
445 /* Ensure there is no state left over from a previous invocation */
451 rbio = SSL_get_rbio(s);
452 wbio = SSL_get_wbio(s);
454 if (!rbio || !wbio) {
455 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BIO_NOT_SET);
460 * We only peek at incoming ClientHello's until we're sure we are going to
461 * to respond with a HelloVerifyRequest. If its a ClientHello with a valid
462 * cookie then we leave it in the BIO for accept to handle.
464 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
467 * Note: This check deliberately excludes DTLS1_BAD_VER because that version
468 * requires the MAC to be calculated *including* the first ClientHello
469 * (without the cookie). Since DTLSv1_listen is stateless that cannot be
470 * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
473 if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
474 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNSUPPORTED_SSL_VERSION);
478 if (s->init_buf == NULL) {
479 if ((bufm = BUF_MEM_new()) == NULL) {
480 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
484 if (!BUF_MEM_grow(bufm, SSL3_RT_MAX_PLAIN_LENGTH)) {
486 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
491 buf = (unsigned char *)s->init_buf->data;
498 * Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
499 * + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
500 * the record header as well, but we do here. We've set up init_buf to
501 * be the standard size for simplicity. In practice we shouldn't ever
502 * receive a ClientHello as long as this. If we do it will get dropped
503 * in the record length check below.
505 n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
508 if (BIO_should_retry(rbio)) {
509 /* Non-blocking IO */
515 /* If we hit any problems we need to clear this packet from the BIO */
518 if (!PACKET_buf_init(&pkt, buf, n)) {
519 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);
524 * Parse the received record. If there are any problems with it we just
525 * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
526 * resilient in the face of invalid records (e.g., invalid formatting,
527 * length, MAC, etc.). In general, invalid records SHOULD be silently
528 * discarded, thus preserving the association; however, an error MAY be
529 * logged for diagnostic purposes."
532 /* this packet contained a partial record, dump it */
533 if (n < DTLS1_RT_HEADER_LENGTH) {
534 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_RECORD_TOO_SMALL);
539 s->msg_callback(0, 0, SSL3_RT_HEADER, buf,
540 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
542 /* Get the record header */
543 if (!PACKET_get_1(&pkt, &rectype)
544 || !PACKET_get_1(&pkt, &versmajor)) {
545 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
549 if (rectype != SSL3_RT_HANDSHAKE) {
550 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
555 * Check record version number. We only check that the major version is
558 if (versmajor != DTLS1_VERSION_MAJOR) {
559 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
563 if (!PACKET_forward(&pkt, 1)
564 /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
565 || !PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)
566 || !PACKET_get_length_prefixed_2(&pkt, &msgpkt)) {
567 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
571 * We allow data remaining at the end of the packet because there could
572 * be a second record (but we ignore it)
575 /* This is an initial ClientHello so the epoch has to be 0 */
576 if (seq[0] != 0 || seq[1] != 0) {
577 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
581 /* Get a pointer to the raw message for the later callback */
582 data = PACKET_data(&msgpkt);
584 /* Finished processing the record header, now process the message */
585 if (!PACKET_get_1(&msgpkt, &msgtype)
586 || !PACKET_get_net_3(&msgpkt, &msglen)
587 || !PACKET_get_net_2(&msgpkt, &msgseq)
588 || !PACKET_get_net_3(&msgpkt, &fragoff)
589 || !PACKET_get_net_3(&msgpkt, &fraglen)
590 || !PACKET_get_sub_packet(&msgpkt, &msgpayload, fraglen)
591 || PACKET_remaining(&msgpkt) != 0) {
592 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
596 if (msgtype != SSL3_MT_CLIENT_HELLO) {
597 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
601 /* Message sequence number can only be 0 or 1 */
603 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_INVALID_SEQUENCE_NUMBER);
608 * We don't support fragment reassembly for ClientHellos whilst
609 * listening because that would require server side state (which is
610 * against the whole point of the ClientHello/HelloVerifyRequest
611 * mechanism). Instead we only look at the first ClientHello fragment
612 * and require that the cookie must be contained within it.
614 if (fragoff != 0 || fraglen > msglen) {
615 /* Non initial ClientHello fragment (or bad fragment) */
616 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_FRAGMENTED_CLIENT_HELLO);
621 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, data,
622 fraglen + DTLS1_HM_HEADER_LENGTH, s,
623 s->msg_callback_arg);
625 if (!PACKET_get_net_2(&msgpayload, &clientvers)) {
626 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
631 * Verify client version is supported
633 if (DTLS_VERSION_LT(clientvers, (unsigned int)s->method->version) &&
634 s->method->version != DTLS_ANY_VERSION) {
635 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_WRONG_VERSION_NUMBER);
639 if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
640 || !PACKET_get_length_prefixed_1(&msgpayload, &session)
641 || !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)) {
643 * Could be malformed or the cookie does not fit within the initial
644 * ClientHello fragment. Either way we can't handle it.
646 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
651 * Check if we have a cookie or not. If not we need to send a
652 * HelloVerifyRequest.
654 if (PACKET_remaining(&cookiepkt) == 0) {
655 next = LISTEN_SEND_VERIFY_REQUEST;
658 * We have a cookie, so lets check it.
660 if (s->ctx->app_verify_cookie_cb == NULL) {
661 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_NO_VERIFY_COOKIE_CALLBACK);
665 if (s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookiepkt),
666 PACKET_remaining(&cookiepkt)) ==
669 * We treat invalid cookies in the same was as no cookie as
672 next = LISTEN_SEND_VERIFY_REQUEST;
674 /* Cookie verification succeeded */
675 next = LISTEN_SUCCESS;
679 if (next == LISTEN_SEND_VERIFY_REQUEST) {
681 unsigned int version;
685 * There was no cookie in the ClientHello so we need to send a
686 * HelloVerifyRequest. If this fails we do not worry about trying
687 * to resend, we just drop it.
691 * Dump the read packet, we don't need it any more. Ignore return
694 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL);
695 BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
696 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
698 /* Generate the cookie */
699 if (s->ctx->app_gen_cookie_cb == NULL ||
700 s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0 ||
702 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
708 * Special case: for hello verify request, client version 1.0 and we
709 * haven't decided which version to use yet send back using version
710 * 1.0 header: otherwise some clients will ignore it.
712 version = (s->method->version == DTLS_ANY_VERSION) ? DTLS1_VERSION
715 /* Construct the record and message headers */
716 if (!WPACKET_init(&wpkt, s->init_buf)
717 || !WPACKET_put_bytes_u8(&wpkt, SSL3_RT_HANDSHAKE)
718 || !WPACKET_put_bytes_u16(&wpkt, version)
720 * Record sequence number is always the same as in the
721 * received ClientHello
723 || !WPACKET_memcpy(&wpkt, seq, SEQ_NUM_SIZE)
724 /* End of record, start sub packet for message */
725 || !WPACKET_start_sub_packet_u16(&wpkt)
727 || !WPACKET_put_bytes_u8(&wpkt,
728 DTLS1_MT_HELLO_VERIFY_REQUEST)
730 * Message length - doesn't follow normal TLS convention:
731 * the length isn't the last thing in the message header.
732 * We'll need to fill this in later when we know the
733 * length. Set it to zero for now
735 || !WPACKET_put_bytes_u24(&wpkt, 0)
737 * Message sequence number is always 0 for a
740 || !WPACKET_put_bytes_u16(&wpkt, 0)
742 * We never fragment a HelloVerifyRequest, so fragment
745 || !WPACKET_put_bytes_u24(&wpkt, 0)
747 * Fragment length is the same as message length, but
748 * this *is* the last thing in the message header so we
749 * can just start a sub-packet. No need to come back
750 * later for this one.
752 || !WPACKET_start_sub_packet_u24(&wpkt)
753 /* Create the actual HelloVerifyRequest body */
754 || !dtls_raw_hello_verify_request(&wpkt, cookie, cookielen)
755 /* Close message body */
756 || !WPACKET_close(&wpkt)
757 /* Close record body */
758 || !WPACKET_close(&wpkt)
759 || !WPACKET_get_total_written(&wpkt, &wreclen)
760 || !WPACKET_finish(&wpkt)) {
761 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);
762 WPACKET_cleanup(&wpkt);
768 * Fix up the message len in the message header. Its the same as the
769 * fragment len which has been filled in by WPACKET, so just copy
770 * that. Destination for the message len is after the record header
771 * plus one byte for the message content type. The source is the
772 * last 3 bytes of the message header
774 memcpy(&buf[DTLS1_RT_HEADER_LENGTH + 1],
775 &buf[DTLS1_RT_HEADER_LENGTH + DTLS1_HM_HEADER_LENGTH - 3],
779 s->msg_callback(1, 0, SSL3_RT_HEADER, buf,
780 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
782 if ((tmpclient = BIO_ADDR_new()) == NULL) {
783 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
788 * This is unnecessary if rbio and wbio are one and the same - but
789 * maybe they're not. We ignore errors here - some BIOs do not
792 if (BIO_dgram_get_peer(rbio, tmpclient) > 0) {
793 (void)BIO_dgram_set_peer(wbio, tmpclient);
795 BIO_ADDR_free(tmpclient);
798 if (BIO_write(wbio, buf, wreclen) < (int)wreclen) {
799 if (BIO_should_retry(wbio)) {
801 * Non-blocking IO...but we're stateless, so we're just
802 * going to drop this packet.
809 if (BIO_flush(wbio) <= 0) {
810 if (BIO_should_retry(wbio)) {
812 * Non-blocking IO...but we're stateless, so we're just
813 * going to drop this packet.
820 } while (next != LISTEN_SUCCESS);
823 * Set expected sequence numbers to continue the handshake.
825 s->d1->handshake_read_seq = 1;
826 s->d1->handshake_write_seq = 1;
827 s->d1->next_handshake_write_seq = 1;
828 DTLS_RECORD_LAYER_set_write_sequence(&s->rlayer, seq);
831 * We are doing cookie exchange, so make sure we set that option in the
834 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
837 * Tell the state machine that we've done the initial hello verify
840 ossl_statem_set_hello_verify_done(s);
843 * Some BIOs may not support this. If we fail we clear the client address
845 if (BIO_dgram_get_peer(rbio, client) <= 0)
846 BIO_ADDR_clear(client);
851 BIO_ADDR_free(tmpclient);
852 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL);
854 /* Dump this packet. Ignore return value */
855 BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
861 static int dtls1_handshake_write(SSL *s)
863 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
866 #ifndef OPENSSL_NO_HEARTBEATS
868 # define HEARTBEAT_SIZE(payload, padding) ( \
869 1 /* heartbeat type */ + \
870 2 /* heartbeat length */ + \
871 (payload) + (padding))
873 # define HEARTBEAT_SIZE_STD(payload) HEARTBEAT_SIZE(payload, 16)
875 int dtls1_process_heartbeat(SSL *s, unsigned char *p, unsigned int length)
878 unsigned short hbtype;
879 unsigned int payload;
880 unsigned int padding = 16; /* Use minimum padding */
883 s->msg_callback(0, s->version, DTLS1_RT_HEARTBEAT,
884 p, length, s, s->msg_callback_arg);
886 /* Read type and payload length */
887 if (HEARTBEAT_SIZE_STD(0) > length)
888 return 0; /* silently discard */
889 if (length > SSL3_RT_MAX_PLAIN_LENGTH)
890 return 0; /* silently discard per RFC 6520 sec. 4 */
894 if (HEARTBEAT_SIZE_STD(payload) > length)
895 return 0; /* silently discard per RFC 6520 sec. 4 */
898 if (hbtype == TLS1_HB_REQUEST) {
899 unsigned char *buffer, *bp;
900 unsigned int write_length = HEARTBEAT_SIZE(payload, padding);
903 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
906 /* Allocate memory for the response. */
907 buffer = OPENSSL_malloc(write_length);
912 /* Enter response type, length and copy payload */
913 *bp++ = TLS1_HB_RESPONSE;
915 memcpy(bp, pl, payload);
918 if (RAND_bytes(bp, padding) <= 0) {
919 OPENSSL_free(buffer);
923 r = dtls1_write_bytes(s, DTLS1_RT_HEARTBEAT, buffer, write_length);
925 if (r >= 0 && s->msg_callback)
926 s->msg_callback(1, s->version, DTLS1_RT_HEARTBEAT,
927 buffer, write_length, s, s->msg_callback_arg);
929 OPENSSL_free(buffer);
933 } else if (hbtype == TLS1_HB_RESPONSE) {
937 * We only send sequence numbers (2 bytes unsigned int), and 16
938 * random bytes, so we just try to read the sequence number
942 if (payload == 18 && seq == s->tlsext_hb_seq) {
945 s->tlsext_hb_pending = 0;
952 int dtls1_heartbeat(SSL *s)
954 unsigned char *buf, *p;
956 unsigned int payload = 18; /* Sequence number + random bytes */
957 unsigned int padding = 16; /* Use minimum padding */
960 /* Only send if peer supports and accepts HB requests... */
961 if (!(s->tlsext_heartbeat & SSL_DTLSEXT_HB_ENABLED) ||
962 s->tlsext_heartbeat & SSL_DTLSEXT_HB_DONT_SEND_REQUESTS) {
963 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
967 /* ...and there is none in flight yet... */
968 if (s->tlsext_hb_pending) {
969 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
973 /* ...and no handshake in progress. */
974 if (SSL_in_init(s) || ossl_statem_get_in_handshake(s)) {
975 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
980 * Create HeartBeat message, we just use a sequence number
981 * as payload to distinguish different messages and add
984 size = HEARTBEAT_SIZE(payload, padding);
985 buf = OPENSSL_malloc(size);
987 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_MALLOC_FAILURE);
992 *p++ = TLS1_HB_REQUEST;
993 /* Payload length (18 bytes here) */
995 /* Sequence number */
996 s2n(s->tlsext_hb_seq, p);
997 /* 16 random bytes */
998 if (RAND_bytes(p, 16) <= 0) {
999 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
1003 /* Random padding */
1004 if (RAND_bytes(p, padding) <= 0) {
1005 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
1009 ret = dtls1_write_bytes(s, DTLS1_RT_HEARTBEAT, buf, size);
1011 if (s->msg_callback)
1012 s->msg_callback(1, s->version, DTLS1_RT_HEARTBEAT,
1013 buf, size, s, s->msg_callback_arg);
1015 dtls1_start_timer(s);
1016 s->tlsext_hb_pending = 1;
1026 int dtls1_shutdown(SSL *s)
1029 #ifndef OPENSSL_NO_SCTP
1032 wbio = SSL_get_wbio(s);
1033 if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
1034 !(s->shutdown & SSL_SENT_SHUTDOWN)) {
1035 ret = BIO_dgram_sctp_wait_for_dry(wbio);
1040 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
1044 ret = ssl3_shutdown(s);
1045 #ifndef OPENSSL_NO_SCTP
1046 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1051 int dtls1_query_mtu(SSL *s)
1053 if (s->d1->link_mtu) {
1055 s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1056 s->d1->link_mtu = 0;
1059 /* AHA! Figure out the MTU, and stick to the right size */
1060 if (s->d1->mtu < dtls1_min_mtu(s)) {
1061 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
1063 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
1066 * I've seen the kernel return bogus numbers when it doesn't know
1067 * (initial write), so just make sure we have a reasonable number
1069 if (s->d1->mtu < dtls1_min_mtu(s)) {
1070 /* Set to min mtu */
1071 s->d1->mtu = dtls1_min_mtu(s);
1072 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
1081 static unsigned int dtls1_link_min_mtu(void)
1083 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1084 sizeof(g_probable_mtu[0])) - 1]);
1087 unsigned int dtls1_min_mtu(SSL *s)
1089 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));