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 size_t dtls1_link_min_mtu(void);
28 /* XDTLS: figure out the right values */
29 static const size_t 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 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
39 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
41 tls1_export_keying_material,
42 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,
43 dtls1_set_handshake_header,
44 dtls1_close_construct_packet,
48 const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
52 tls1_generate_master_secret,
53 tls1_change_cipher_state,
54 tls1_final_finish_mac,
55 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
56 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
58 tls1_export_keying_material,
59 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS
60 | SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
61 dtls1_set_handshake_header,
62 dtls1_close_construct_packet,
66 long dtls1_default_timeout(void)
69 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
70 * http, the cache would over fill
79 if (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
85 if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) {
90 d1->buffered_messages = pqueue_new();
91 d1->sent_messages = pqueue_new();
94 d1->cookie_len = sizeof(s->d1->cookie);
100 if (d1->buffered_messages == NULL || d1->sent_messages == NULL) {
101 pqueue_free(d1->buffered_messages);
102 pqueue_free(d1->sent_messages);
109 s->method->ssl_clear(s);
113 static void dtls1_clear_queues(SSL *s)
115 dtls1_clear_received_buffer(s);
116 dtls1_clear_sent_buffer(s);
119 void dtls1_clear_received_buffer(SSL *s)
122 hm_fragment *frag = NULL;
124 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
125 frag = (hm_fragment *)item->data;
126 dtls1_hm_fragment_free(frag);
131 void dtls1_clear_sent_buffer(SSL *s)
134 hm_fragment *frag = NULL;
136 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
137 frag = (hm_fragment *)item->data;
138 dtls1_hm_fragment_free(frag);
144 void dtls1_free(SSL *s)
146 DTLS_RECORD_LAYER_free(&s->rlayer);
150 dtls1_clear_queues(s);
152 pqueue_free(s->d1->buffered_messages);
153 pqueue_free(s->d1->sent_messages);
159 void dtls1_clear(SSL *s)
161 pqueue *buffered_messages;
162 pqueue *sent_messages;
166 DTLS_RECORD_LAYER_clear(&s->rlayer);
169 buffered_messages = s->d1->buffered_messages;
170 sent_messages = s->d1->sent_messages;
172 link_mtu = s->d1->link_mtu;
174 dtls1_clear_queues(s);
176 memset(s->d1, 0, sizeof(*s->d1));
179 s->d1->cookie_len = sizeof(s->d1->cookie);
182 if (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU) {
184 s->d1->link_mtu = link_mtu;
187 s->d1->buffered_messages = buffered_messages;
188 s->d1->sent_messages = sent_messages;
193 if (s->method->version == DTLS_ANY_VERSION)
194 s->version = DTLS_MAX_VERSION;
195 #ifndef OPENSSL_NO_DTLS1_METHOD
196 else if (s->options & SSL_OP_CISCO_ANYCONNECT)
197 s->client_version = s->version = DTLS1_BAD_VER;
200 s->version = s->method->version;
203 long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
208 case DTLS_CTRL_GET_TIMEOUT:
209 if (dtls1_get_timeout(s, (struct timeval *)parg) != NULL) {
213 case DTLS_CTRL_HANDLE_TIMEOUT:
214 ret = dtls1_handle_timeout(s);
216 case DTLS_CTRL_SET_LINK_MTU:
217 if (larg < (long)dtls1_link_min_mtu())
219 s->d1->link_mtu = larg;
221 case DTLS_CTRL_GET_LINK_MIN_MTU:
222 return (long)dtls1_link_min_mtu();
223 case SSL_CTRL_SET_MTU:
225 * We may not have a BIO set yet so can't call dtls1_min_mtu()
226 * We'll have to make do with dtls1_link_min_mtu() and max overhead
228 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
233 ret = ssl3_ctrl(s, cmd, larg, parg);
239 void dtls1_start_timer(SSL *s)
241 #ifndef OPENSSL_NO_SCTP
242 /* Disable timer for SCTP */
243 if (BIO_dgram_is_sctp(SSL_get_wbio(s))) {
244 memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
249 /* If timer is not set, initialize duration with 1 second */
250 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
251 s->d1->timeout_duration = 1;
254 /* Set timeout to current time */
255 get_current_time(&(s->d1->next_timeout));
257 /* Add duration to current time */
258 s->d1->next_timeout.tv_sec += s->d1->timeout_duration;
259 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
260 &(s->d1->next_timeout));
263 struct timeval *dtls1_get_timeout(SSL *s, struct timeval *timeleft)
265 struct timeval timenow;
267 /* If no timeout is set, just return NULL */
268 if (s->d1->next_timeout.tv_sec == 0 && s->d1->next_timeout.tv_usec == 0) {
272 /* Get current time */
273 get_current_time(&timenow);
275 /* If timer already expired, set remaining time to 0 */
276 if (s->d1->next_timeout.tv_sec < timenow.tv_sec ||
277 (s->d1->next_timeout.tv_sec == timenow.tv_sec &&
278 s->d1->next_timeout.tv_usec <= timenow.tv_usec)) {
279 memset(timeleft, 0, sizeof(*timeleft));
283 /* Calculate time left until timer expires */
284 memcpy(timeleft, &(s->d1->next_timeout), sizeof(struct timeval));
285 timeleft->tv_sec -= timenow.tv_sec;
286 timeleft->tv_usec -= timenow.tv_usec;
287 if (timeleft->tv_usec < 0) {
289 timeleft->tv_usec += 1000000;
293 * If remaining time is less than 15 ms, set it to 0 to prevent issues
294 * because of small divergences with socket timeouts.
296 if (timeleft->tv_sec == 0 && timeleft->tv_usec < 15000) {
297 memset(timeleft, 0, sizeof(*timeleft));
303 int dtls1_is_timer_expired(SSL *s)
305 struct timeval timeleft;
307 /* Get time left until timeout, return false if no timer running */
308 if (dtls1_get_timeout(s, &timeleft) == NULL) {
312 /* Return false if timer is not expired yet */
313 if (timeleft.tv_sec > 0 || timeleft.tv_usec > 0) {
317 /* Timer expired, so return true */
321 void dtls1_double_timeout(SSL *s)
323 s->d1->timeout_duration *= 2;
324 if (s->d1->timeout_duration > 60)
325 s->d1->timeout_duration = 60;
326 dtls1_start_timer(s);
329 void dtls1_stop_timer(SSL *s)
331 /* Reset everything */
332 memset(&s->d1->timeout, 0, sizeof(s->d1->timeout));
333 memset(&s->d1->next_timeout, 0, sizeof(s->d1->next_timeout));
334 s->d1->timeout_duration = 1;
335 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0,
336 &(s->d1->next_timeout));
337 /* Clear retransmission buffer */
338 dtls1_clear_sent_buffer(s);
341 int dtls1_check_timeout_num(SSL *s)
345 s->d1->timeout.num_alerts++;
347 /* Reduce MTU after 2 unsuccessful retransmissions */
348 if (s->d1->timeout.num_alerts > 2
349 && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
351 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
352 if (mtu < s->d1->mtu)
356 if (s->d1->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT) {
357 /* fail the connection, enough alerts have been sent */
358 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM, SSL_R_READ_TIMEOUT_EXPIRED);
365 int dtls1_handle_timeout(SSL *s)
367 /* if no timer is expired, don't do anything */
368 if (!dtls1_is_timer_expired(s)) {
372 dtls1_double_timeout(s);
374 if (dtls1_check_timeout_num(s) < 0)
377 s->d1->timeout.read_timeouts++;
378 if (s->d1->timeout.read_timeouts > DTLS1_TMO_READ_COUNT) {
379 s->d1->timeout.read_timeouts = 1;
382 dtls1_start_timer(s);
383 return dtls1_retransmit_buffered_messages(s);
386 static void get_current_time(struct timeval *t)
396 SystemTimeToFileTime(&st, &now.ft);
397 /* re-bias to 1/1/1970 */
399 now.ul -= 116444736000000000ULL;
402 now.ul -= 116444736000000000UI64;
405 t->tv_sec = (long)(now.ul / 10000000);
406 t->tv_usec = ((int)(now.ul % 10000000)) / 10;
407 #elif defined(OPENSSL_SYS_VMS)
410 t->tv_sec = (long)tb.time;
411 t->tv_usec = (long)tb.millitm * 1000;
413 gettimeofday(t, NULL);
417 #define LISTEN_SUCCESS 2
418 #define LISTEN_SEND_VERIFY_REQUEST 1
420 #ifndef OPENSSL_NO_SOCK
421 int DTLSv1_listen(SSL *s, BIO_ADDR *client)
423 int next, n, ret = 0, clearpkt = 0;
424 unsigned char cookie[DTLS1_COOKIE_LENGTH];
425 unsigned char seq[SEQ_NUM_SIZE];
426 const unsigned char *data;
428 size_t fragoff, fraglen, msglen;
429 unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen;
432 BIO_ADDR *tmpclient = NULL;
433 PACKET pkt, msgpkt, msgpayload, session, cookiepkt;
435 /* Ensure there is no state left over from a previous invocation */
441 rbio = SSL_get_rbio(s);
442 wbio = SSL_get_wbio(s);
444 if (!rbio || !wbio) {
445 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BIO_NOT_SET);
450 * We only peek at incoming ClientHello's until we're sure we are going to
451 * to respond with a HelloVerifyRequest. If its a ClientHello with a valid
452 * cookie then we leave it in the BIO for accept to handle.
454 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
457 * Note: This check deliberately excludes DTLS1_BAD_VER because that version
458 * requires the MAC to be calculated *including* the first ClientHello
459 * (without the cookie). Since DTLSv1_listen is stateless that cannot be
460 * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
463 if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
464 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNSUPPORTED_SSL_VERSION);
468 if (s->init_buf == NULL) {
469 if ((bufm = BUF_MEM_new()) == NULL) {
470 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
474 if (!BUF_MEM_grow(bufm, SSL3_RT_MAX_PLAIN_LENGTH)) {
476 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
481 buf = (unsigned char *)s->init_buf->data;
488 * Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
489 * + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
490 * the record header as well, but we do here. We've set up init_buf to
491 * be the standard size for simplicity. In practice we shouldn't ever
492 * receive a ClientHello as long as this. If we do it will get dropped
493 * in the record length check below.
495 n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
498 if (BIO_should_retry(rbio)) {
499 /* Non-blocking IO */
505 /* If we hit any problems we need to clear this packet from the BIO */
508 if (!PACKET_buf_init(&pkt, buf, n)) {
509 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);
514 * Parse the received record. If there are any problems with it we just
515 * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
516 * resilient in the face of invalid records (e.g., invalid formatting,
517 * length, MAC, etc.). In general, invalid records SHOULD be silently
518 * discarded, thus preserving the association; however, an error MAY be
519 * logged for diagnostic purposes."
522 /* this packet contained a partial record, dump it */
523 if (n < DTLS1_RT_HEADER_LENGTH) {
524 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_RECORD_TOO_SMALL);
529 s->msg_callback(0, 0, SSL3_RT_HEADER, buf,
530 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
532 /* Get the record header */
533 if (!PACKET_get_1(&pkt, &rectype)
534 || !PACKET_get_1(&pkt, &versmajor)) {
535 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
539 if (rectype != SSL3_RT_HANDSHAKE) {
540 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
545 * Check record version number. We only check that the major version is
548 if (versmajor != DTLS1_VERSION_MAJOR) {
549 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
553 if (!PACKET_forward(&pkt, 1)
554 /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
555 || !PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)
556 || !PACKET_get_length_prefixed_2(&pkt, &msgpkt)) {
557 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
561 * We allow data remaining at the end of the packet because there could
562 * be a second record (but we ignore it)
565 /* This is an initial ClientHello so the epoch has to be 0 */
566 if (seq[0] != 0 || seq[1] != 0) {
567 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
571 /* Get a pointer to the raw message for the later callback */
572 data = PACKET_data(&msgpkt);
574 /* Finished processing the record header, now process the message */
575 if (!PACKET_get_1(&msgpkt, &msgtype)
576 || !PACKET_get_net_3_len(&msgpkt, &msglen)
577 || !PACKET_get_net_2(&msgpkt, &msgseq)
578 || !PACKET_get_net_3_len(&msgpkt, &fragoff)
579 || !PACKET_get_net_3_len(&msgpkt, &fraglen)
580 || !PACKET_get_sub_packet(&msgpkt, &msgpayload, fraglen)
581 || PACKET_remaining(&msgpkt) != 0) {
582 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
586 if (msgtype != SSL3_MT_CLIENT_HELLO) {
587 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_UNEXPECTED_MESSAGE);
591 /* Message sequence number can only be 0 or 1 */
593 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_INVALID_SEQUENCE_NUMBER);
598 * We don't support fragment reassembly for ClientHellos whilst
599 * listening because that would require server side state (which is
600 * against the whole point of the ClientHello/HelloVerifyRequest
601 * mechanism). Instead we only look at the first ClientHello fragment
602 * and require that the cookie must be contained within it.
604 if (fragoff != 0 || fraglen > msglen) {
605 /* Non initial ClientHello fragment (or bad fragment) */
606 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_FRAGMENTED_CLIENT_HELLO);
611 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, data,
612 fraglen + DTLS1_HM_HEADER_LENGTH, s,
613 s->msg_callback_arg);
615 if (!PACKET_get_net_2(&msgpayload, &clientvers)) {
616 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
621 * Verify client version is supported
623 if (DTLS_VERSION_LT(clientvers, (unsigned int)s->method->version) &&
624 s->method->version != DTLS_ANY_VERSION) {
625 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_WRONG_VERSION_NUMBER);
629 if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
630 || !PACKET_get_length_prefixed_1(&msgpayload, &session)
631 || !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)) {
633 * Could be malformed or the cookie does not fit within the initial
634 * ClientHello fragment. Either way we can't handle it.
636 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_LENGTH_MISMATCH);
641 * Check if we have a cookie or not. If not we need to send a
642 * HelloVerifyRequest.
644 if (PACKET_remaining(&cookiepkt) == 0) {
645 next = LISTEN_SEND_VERIFY_REQUEST;
648 * We have a cookie, so lets check it.
650 if (s->ctx->app_verify_cookie_cb == NULL) {
651 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_NO_VERIFY_COOKIE_CALLBACK);
655 if (s->ctx->app_verify_cookie_cb(s, PACKET_data(&cookiepkt),
656 (unsigned int)PACKET_remaining(&cookiepkt)) == 0) {
658 * We treat invalid cookies in the same was as no cookie as
661 next = LISTEN_SEND_VERIFY_REQUEST;
663 /* Cookie verification succeeded */
664 next = LISTEN_SUCCESS;
668 if (next == LISTEN_SEND_VERIFY_REQUEST) {
670 unsigned int version;
674 * There was no cookie in the ClientHello so we need to send a
675 * HelloVerifyRequest. If this fails we do not worry about trying
676 * to resend, we just drop it.
680 * Dump the read packet, we don't need it any more. Ignore return
683 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL);
684 BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
685 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 1, NULL);
687 /* Generate the cookie */
688 if (s->ctx->app_gen_cookie_cb == NULL ||
689 s->ctx->app_gen_cookie_cb(s, cookie, &cookielen) == 0 ||
691 SSLerr(SSL_F_DTLSV1_LISTEN, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
697 * Special case: for hello verify request, client version 1.0 and we
698 * haven't decided which version to use yet send back using version
699 * 1.0 header: otherwise some clients will ignore it.
701 version = (s->method->version == DTLS_ANY_VERSION) ? DTLS1_VERSION
704 /* Construct the record and message headers */
705 if (!WPACKET_init(&wpkt, s->init_buf)
706 || !WPACKET_put_bytes_u8(&wpkt, SSL3_RT_HANDSHAKE)
707 || !WPACKET_put_bytes_u16(&wpkt, version)
709 * Record sequence number is always the same as in the
710 * received ClientHello
712 || !WPACKET_memcpy(&wpkt, seq, SEQ_NUM_SIZE)
713 /* End of record, start sub packet for message */
714 || !WPACKET_start_sub_packet_u16(&wpkt)
716 || !WPACKET_put_bytes_u8(&wpkt,
717 DTLS1_MT_HELLO_VERIFY_REQUEST)
719 * Message length - doesn't follow normal TLS convention:
720 * the length isn't the last thing in the message header.
721 * We'll need to fill this in later when we know the
722 * length. Set it to zero for now
724 || !WPACKET_put_bytes_u24(&wpkt, 0)
726 * Message sequence number is always 0 for a
729 || !WPACKET_put_bytes_u16(&wpkt, 0)
731 * We never fragment a HelloVerifyRequest, so fragment
734 || !WPACKET_put_bytes_u24(&wpkt, 0)
736 * Fragment length is the same as message length, but
737 * this *is* the last thing in the message header so we
738 * can just start a sub-packet. No need to come back
739 * later for this one.
741 || !WPACKET_start_sub_packet_u24(&wpkt)
742 /* Create the actual HelloVerifyRequest body */
743 || !dtls_raw_hello_verify_request(&wpkt, cookie, cookielen)
744 /* Close message body */
745 || !WPACKET_close(&wpkt)
746 /* Close record body */
747 || !WPACKET_close(&wpkt)
748 || !WPACKET_get_total_written(&wpkt, &wreclen)
749 || !WPACKET_finish(&wpkt)) {
750 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_INTERNAL_ERROR);
751 WPACKET_cleanup(&wpkt);
757 * Fix up the message len in the message header. Its the same as the
758 * fragment len which has been filled in by WPACKET, so just copy
759 * that. Destination for the message len is after the record header
760 * plus one byte for the message content type. The source is the
761 * last 3 bytes of the message header
763 memcpy(&buf[DTLS1_RT_HEADER_LENGTH + 1],
764 &buf[DTLS1_RT_HEADER_LENGTH + DTLS1_HM_HEADER_LENGTH - 3],
768 s->msg_callback(1, 0, SSL3_RT_HEADER, buf,
769 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
771 if ((tmpclient = BIO_ADDR_new()) == NULL) {
772 SSLerr(SSL_F_DTLSV1_LISTEN, ERR_R_MALLOC_FAILURE);
777 * This is unnecessary if rbio and wbio are one and the same - but
778 * maybe they're not. We ignore errors here - some BIOs do not
781 if (BIO_dgram_get_peer(rbio, tmpclient) > 0) {
782 (void)BIO_dgram_set_peer(wbio, tmpclient);
784 BIO_ADDR_free(tmpclient);
787 /* TODO(size_t): convert this call */
788 if (BIO_write(wbio, buf, wreclen) < (int)wreclen) {
789 if (BIO_should_retry(wbio)) {
791 * Non-blocking IO...but we're stateless, so we're just
792 * going to drop this packet.
799 if (BIO_flush(wbio) <= 0) {
800 if (BIO_should_retry(wbio)) {
802 * Non-blocking IO...but we're stateless, so we're just
803 * going to drop this packet.
810 } while (next != LISTEN_SUCCESS);
813 * Set expected sequence numbers to continue the handshake.
815 s->d1->handshake_read_seq = 1;
816 s->d1->handshake_write_seq = 1;
817 s->d1->next_handshake_write_seq = 1;
818 DTLS_RECORD_LAYER_set_write_sequence(&s->rlayer, seq);
821 * We are doing cookie exchange, so make sure we set that option in the
824 SSL_set_options(s, SSL_OP_COOKIE_EXCHANGE);
827 * Tell the state machine that we've done the initial hello verify
830 ossl_statem_set_hello_verify_done(s);
833 * Some BIOs may not support this. If we fail we clear the client address
835 if (BIO_dgram_get_peer(rbio, client) <= 0)
836 BIO_ADDR_clear(client);
841 BIO_ADDR_free(tmpclient);
842 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SET_PEEK_MODE, 0, NULL);
844 /* Dump this packet. Ignore return value */
845 BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH);
851 static int dtls1_handshake_write(SSL *s)
853 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
856 int dtls1_shutdown(SSL *s)
859 #ifndef OPENSSL_NO_SCTP
862 wbio = SSL_get_wbio(s);
863 if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
864 !(s->shutdown & SSL_SENT_SHUTDOWN)) {
865 ret = BIO_dgram_sctp_wait_for_dry(wbio);
870 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
874 ret = ssl3_shutdown(s);
875 #ifndef OPENSSL_NO_SCTP
876 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
881 int dtls1_query_mtu(SSL *s)
883 if (s->d1->link_mtu) {
885 s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
889 /* AHA! Figure out the MTU, and stick to the right size */
890 if (s->d1->mtu < dtls1_min_mtu(s)) {
891 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
893 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
896 * I've seen the kernel return bogus numbers when it doesn't know
897 * (initial write), so just make sure we have a reasonable number
899 if (s->d1->mtu < dtls1_min_mtu(s)) {
901 s->d1->mtu = dtls1_min_mtu(s);
902 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
903 (long)s->d1->mtu, NULL);
911 static size_t dtls1_link_min_mtu(void)
913 return (g_probable_mtu[(sizeof(g_probable_mtu) /
914 sizeof(g_probable_mtu[0])) - 1]);
917 size_t dtls1_min_mtu(SSL *s)
919 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
922 size_t DTLS_get_data_mtu(const SSL *s)
924 size_t mac_overhead, int_overhead, blocksize, ext_overhead;
925 const SSL_CIPHER *ciph = SSL_get_current_cipher(s);
926 size_t mtu = s->d1->mtu;
931 if (!ssl_cipher_get_overhead(ciph, &mac_overhead, &int_overhead,
932 &blocksize, &ext_overhead))
936 ext_overhead += mac_overhead;
938 int_overhead += mac_overhead;
940 /* Subtract external overhead (e.g. IV/nonce, separate MAC) */
941 if (ext_overhead + DTLS1_RT_HEADER_LENGTH >= mtu)
943 mtu -= ext_overhead + DTLS1_RT_HEADER_LENGTH;
945 /* Round encrypted payload down to cipher block size (for CBC etc.)
946 * No check for overflow since 'mtu % blocksize' cannot exceed mtu. */
948 mtu -= (mtu % blocksize);
950 /* Subtract internal overhead (e.g. CBC padding len byte) */
951 if (int_overhead >= mtu)