2 * Copyright 2005-2022 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (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
10 #include "internal/e_os.h"
12 #include <openssl/objects.h>
13 #include <openssl/rand.h>
14 #include "ssl_local.h"
15 #include "internal/time.h"
17 static int dtls1_handshake_write(SSL_CONNECTION *s);
18 static size_t dtls1_link_min_mtu(void);
20 /* XDTLS: figure out the right values */
21 static const size_t g_probable_mtu[] = { 1500, 512, 256 };
23 const SSL3_ENC_METHOD DTLSv1_enc_data = {
25 tls1_generate_master_secret,
26 tls1_change_cipher_state,
27 tls1_final_finish_mac,
28 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
29 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
31 tls1_export_keying_material,
32 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV,
33 dtls1_set_handshake_header,
34 dtls1_close_construct_packet,
38 const SSL3_ENC_METHOD DTLSv1_2_enc_data = {
40 tls1_generate_master_secret,
41 tls1_change_cipher_state,
42 tls1_final_finish_mac,
43 TLS_MD_CLIENT_FINISH_CONST, TLS_MD_CLIENT_FINISH_CONST_SIZE,
44 TLS_MD_SERVER_FINISH_CONST, TLS_MD_SERVER_FINISH_CONST_SIZE,
46 tls1_export_keying_material,
47 SSL_ENC_FLAG_DTLS | SSL_ENC_FLAG_EXPLICIT_IV | SSL_ENC_FLAG_SIGALGS
48 | SSL_ENC_FLAG_SHA256_PRF | SSL_ENC_FLAG_TLS1_2_CIPHERS,
49 dtls1_set_handshake_header,
50 dtls1_close_construct_packet,
54 OSSL_TIME dtls1_default_timeout(void)
57 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
58 * http, the cache would over fill
60 return ossl_seconds2time(60 * 60 * 2);
63 int dtls1_new(SSL *ssl)
66 SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
71 if (!DTLS_RECORD_LAYER_new(&s->rlayer)) {
77 if ((d1 = OPENSSL_zalloc(sizeof(*d1))) == NULL) {
82 d1->buffered_messages = pqueue_new();
83 d1->sent_messages = pqueue_new();
86 d1->cookie_len = sizeof(s->d1->cookie);
92 if (d1->buffered_messages == NULL || d1->sent_messages == NULL) {
93 pqueue_free(d1->buffered_messages);
94 pqueue_free(d1->sent_messages);
102 if (!ssl->method->ssl_clear(ssl))
108 static void dtls1_clear_queues(SSL_CONNECTION *s)
110 dtls1_clear_received_buffer(s);
111 dtls1_clear_sent_buffer(s);
114 void dtls1_clear_received_buffer(SSL_CONNECTION *s)
117 hm_fragment *frag = NULL;
119 while ((item = pqueue_pop(s->d1->buffered_messages)) != NULL) {
120 frag = (hm_fragment *)item->data;
121 dtls1_hm_fragment_free(frag);
126 void dtls1_clear_sent_buffer(SSL_CONNECTION *s)
129 hm_fragment *frag = NULL;
131 while ((item = pqueue_pop(s->d1->sent_messages)) != NULL) {
132 frag = (hm_fragment *)item->data;
133 dtls1_hm_fragment_free(frag);
139 void dtls1_free(SSL *ssl)
141 SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
146 DTLS_RECORD_LAYER_free(&s->rlayer);
151 dtls1_clear_queues(s);
152 pqueue_free(s->d1->buffered_messages);
153 pqueue_free(s->d1->sent_messages);
160 int dtls1_clear(SSL *ssl)
162 pqueue *buffered_messages;
163 pqueue *sent_messages;
167 SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
172 DTLS_RECORD_LAYER_clear(&s->rlayer);
175 DTLS_timer_cb timer_cb = s->d1->timer_cb;
177 buffered_messages = s->d1->buffered_messages;
178 sent_messages = s->d1->sent_messages;
180 link_mtu = s->d1->link_mtu;
182 dtls1_clear_queues(s);
184 memset(s->d1, 0, sizeof(*s->d1));
186 /* Restore the timer callback from previous state */
187 s->d1->timer_cb = timer_cb;
190 s->d1->cookie_len = sizeof(s->d1->cookie);
193 if (SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU) {
195 s->d1->link_mtu = link_mtu;
198 s->d1->buffered_messages = buffered_messages;
199 s->d1->sent_messages = sent_messages;
202 if (!ssl3_clear(ssl))
205 if (ssl->method->version == DTLS_ANY_VERSION)
206 s->version = DTLS_MAX_VERSION_INTERNAL;
207 #ifndef OPENSSL_NO_DTLS1_METHOD
208 else if (s->options & SSL_OP_CISCO_ANYCONNECT)
209 s->client_version = s->version = DTLS1_BAD_VER;
212 s->version = ssl->method->version;
217 long dtls1_ctrl(SSL *ssl, int cmd, long larg, void *parg)
221 SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
227 case DTLS_CTRL_GET_TIMEOUT:
228 if (dtls1_get_timeout(s, &t) != NULL) {
229 *(struct timeval *)parg = ossl_time_to_timeval(t);
233 case DTLS_CTRL_HANDLE_TIMEOUT:
234 ret = dtls1_handle_timeout(s);
236 case DTLS_CTRL_SET_LINK_MTU:
237 if (larg < (long)dtls1_link_min_mtu())
239 s->d1->link_mtu = larg;
241 case DTLS_CTRL_GET_LINK_MIN_MTU:
242 return (long)dtls1_link_min_mtu();
243 case SSL_CTRL_SET_MTU:
245 * We may not have a BIO set yet so can't call dtls1_min_mtu()
246 * We'll have to make do with dtls1_link_min_mtu() and max overhead
248 if (larg < (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD)
253 ret = ssl3_ctrl(ssl, cmd, larg, parg);
259 void dtls1_start_timer(SSL_CONNECTION *s)
263 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
265 #ifndef OPENSSL_NO_SCTP
266 /* Disable timer for SCTP */
267 if (BIO_dgram_is_sctp(SSL_get_wbio(ssl))) {
268 s->d1->next_timeout = ossl_time_zero();
274 * If timer is not set, initialize duration with 1 second or
275 * a user-specified value if the timer callback is installed.
277 if (ossl_time_is_zero(s->d1->next_timeout)) {
278 if (s->d1->timer_cb != NULL)
279 s->d1->timeout_duration_us = s->d1->timer_cb(ssl, 0);
281 s->d1->timeout_duration_us = 1000000;
284 /* Set timeout to current time plus duration */
285 duration = ossl_us2time(s->d1->timeout_duration_us);
286 s->d1->next_timeout = ossl_time_add(ossl_time_now(), duration);
288 tv = ossl_time_to_timeval(s->d1->next_timeout);
289 BIO_ctrl(SSL_get_rbio(ssl), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &tv);
292 OSSL_TIME *dtls1_get_timeout(SSL_CONNECTION *s, OSSL_TIME *timeleft)
296 /* If no timeout is set, just return NULL */
297 if (ossl_time_is_zero(s->d1->next_timeout))
300 /* Get current time */
301 timenow = ossl_time_now();
304 * If timer already expired or if remaining time is less than 15 ms,
305 * set it to 0 to prevent issues because of small divergences with
308 *timeleft = ossl_time_subtract(s->d1->next_timeout, timenow);
309 if (ossl_time_compare(*timeleft, ossl_ms2time(15)) <= 0)
310 *timeleft = ossl_time_zero();
314 int dtls1_is_timer_expired(SSL_CONNECTION *s)
318 /* Get time left until timeout, return false if no timer running */
319 if (dtls1_get_timeout(s, &timeleft) == NULL) {
323 /* Return false if timer is not expired yet */
324 if (!ossl_time_is_zero(timeleft)) {
328 /* Timer expired, so return true */
332 static void dtls1_double_timeout(SSL_CONNECTION *s)
334 s->d1->timeout_duration_us *= 2;
335 if (s->d1->timeout_duration_us > 60000000)
336 s->d1->timeout_duration_us = 60000000;
339 void dtls1_stop_timer(SSL_CONNECTION *s)
343 /* Reset everything */
344 s->d1->timeout_num_alerts = 0;
345 s->d1->next_timeout = ossl_time_zero();
346 s->d1->timeout_duration_us = 1000000;
347 tv = ossl_time_to_timeval(s->d1->next_timeout);
348 BIO_ctrl(s->rbio, BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT, 0, &tv);
349 /* Clear retransmission buffer */
350 dtls1_clear_sent_buffer(s);
353 int dtls1_check_timeout_num(SSL_CONNECTION *s)
356 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
358 s->d1->timeout_num_alerts++;
360 /* Reduce MTU after 2 unsuccessful retransmissions */
361 if (s->d1->timeout_num_alerts > 2
362 && !(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
364 BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_GET_FALLBACK_MTU, 0, NULL);
365 if (mtu < s->d1->mtu)
369 if (s->d1->timeout_num_alerts > DTLS1_TMO_ALERT_COUNT) {
370 /* fail the connection, enough alerts have been sent */
371 SSLfatal(s, SSL_AD_NO_ALERT, SSL_R_READ_TIMEOUT_EXPIRED);
378 int dtls1_handle_timeout(SSL_CONNECTION *s)
380 /* if no timer is expired, don't do anything */
381 if (!dtls1_is_timer_expired(s)) {
385 if (s->d1->timer_cb != NULL)
386 s->d1->timeout_duration_us = s->d1->timer_cb(SSL_CONNECTION_GET_SSL(s),
387 s->d1->timeout_duration_us);
389 dtls1_double_timeout(s);
391 if (dtls1_check_timeout_num(s) < 0) {
392 /* SSLfatal() already called */
396 dtls1_start_timer(s);
397 /* Calls SSLfatal() if required */
398 return dtls1_retransmit_buffered_messages(s);
401 #define LISTEN_SUCCESS 2
402 #define LISTEN_SEND_VERIFY_REQUEST 1
404 #ifndef OPENSSL_NO_SOCK
405 int DTLSv1_listen(SSL *ssl, BIO_ADDR *client)
407 int next, n, ret = 0;
408 unsigned char cookie[DTLS1_COOKIE_LENGTH];
409 unsigned char seq[SEQ_NUM_SIZE];
410 const unsigned char *data;
411 unsigned char *buf = NULL, *wbuf;
412 size_t fragoff, fraglen, msglen;
413 unsigned int rectype, versmajor, msgseq, msgtype, clientvers, cookielen;
415 BIO_ADDR *tmpclient = NULL;
416 PACKET pkt, msgpkt, msgpayload, session, cookiepkt;
417 SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
422 if (s->handshake_func == NULL) {
423 /* Not properly initialized yet */
424 SSL_set_accept_state(ssl);
427 /* Ensure there is no state left over from a previous invocation */
433 rbio = SSL_get_rbio(ssl);
434 wbio = SSL_get_wbio(ssl);
436 if (!rbio || !wbio) {
437 ERR_raise(ERR_LIB_SSL, SSL_R_BIO_NOT_SET);
442 * Note: This check deliberately excludes DTLS1_BAD_VER because that version
443 * requires the MAC to be calculated *including* the first ClientHello
444 * (without the cookie). Since DTLSv1_listen is stateless that cannot be
445 * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
448 if ((s->version & 0xff00) != (DTLS1_VERSION & 0xff00)) {
449 ERR_raise(ERR_LIB_SSL, SSL_R_UNSUPPORTED_SSL_VERSION);
453 buf = OPENSSL_malloc(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH);
456 wbuf = OPENSSL_malloc(DTLS1_RT_HEADER_LENGTH + SSL3_RT_MAX_PLAIN_LENGTH);
466 n = BIO_read(rbio, buf, SSL3_RT_MAX_PLAIN_LENGTH
467 + DTLS1_RT_HEADER_LENGTH);
469 if (BIO_should_retry(rbio)) {
470 /* Non-blocking IO */
477 if (!PACKET_buf_init(&pkt, buf, n)) {
478 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
484 * Parse the received record. If there are any problems with it we just
485 * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
486 * resilient in the face of invalid records (e.g., invalid formatting,
487 * length, MAC, etc.). In general, invalid records SHOULD be silently
488 * discarded, thus preserving the association; however, an error MAY be
489 * logged for diagnostic purposes."
492 /* this packet contained a partial record, dump it */
493 if (n < DTLS1_RT_HEADER_LENGTH) {
494 ERR_raise(ERR_LIB_SSL, SSL_R_RECORD_TOO_SMALL);
499 s->msg_callback(0, 0, SSL3_RT_HEADER, buf,
500 DTLS1_RT_HEADER_LENGTH, ssl, s->msg_callback_arg);
502 /* Get the record header */
503 if (!PACKET_get_1(&pkt, &rectype)
504 || !PACKET_get_1(&pkt, &versmajor)) {
505 ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
509 if (rectype != SSL3_RT_HANDSHAKE) {
510 ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE);
515 * Check record version number. We only check that the major version is
518 if (versmajor != DTLS1_VERSION_MAJOR) {
519 ERR_raise(ERR_LIB_SSL, SSL_R_BAD_PROTOCOL_VERSION_NUMBER);
523 if (!PACKET_forward(&pkt, 1)
524 /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
525 || !PACKET_copy_bytes(&pkt, seq, SEQ_NUM_SIZE)
526 || !PACKET_get_length_prefixed_2(&pkt, &msgpkt)) {
527 ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
531 * We allow data remaining at the end of the packet because there could
532 * be a second record (but we ignore it)
535 /* This is an initial ClientHello so the epoch has to be 0 */
536 if (seq[0] != 0 || seq[1] != 0) {
537 ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE);
541 /* Get a pointer to the raw message for the later callback */
542 data = PACKET_data(&msgpkt);
544 /* Finished processing the record header, now process the message */
545 if (!PACKET_get_1(&msgpkt, &msgtype)
546 || !PACKET_get_net_3_len(&msgpkt, &msglen)
547 || !PACKET_get_net_2(&msgpkt, &msgseq)
548 || !PACKET_get_net_3_len(&msgpkt, &fragoff)
549 || !PACKET_get_net_3_len(&msgpkt, &fraglen)
550 || !PACKET_get_sub_packet(&msgpkt, &msgpayload, fraglen)
551 || PACKET_remaining(&msgpkt) != 0) {
552 ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
556 if (msgtype != SSL3_MT_CLIENT_HELLO) {
557 ERR_raise(ERR_LIB_SSL, SSL_R_UNEXPECTED_MESSAGE);
561 /* Message sequence number can only be 0 or 1 */
563 ERR_raise(ERR_LIB_SSL, SSL_R_INVALID_SEQUENCE_NUMBER);
568 * We don't support fragment reassembly for ClientHellos whilst
569 * listening because that would require server side state (which is
570 * against the whole point of the ClientHello/HelloVerifyRequest
571 * mechanism). Instead we only look at the first ClientHello fragment
572 * and require that the cookie must be contained within it.
574 if (fragoff != 0 || fraglen > msglen) {
575 /* Non initial ClientHello fragment (or bad fragment) */
576 ERR_raise(ERR_LIB_SSL, SSL_R_FRAGMENTED_CLIENT_HELLO);
581 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, data,
582 fraglen + DTLS1_HM_HEADER_LENGTH, ssl,
583 s->msg_callback_arg);
585 if (!PACKET_get_net_2(&msgpayload, &clientvers)) {
586 ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
591 * Verify client version is supported
593 if (DTLS_VERSION_LT(clientvers, (unsigned int)ssl->method->version) &&
594 ssl->method->version != DTLS_ANY_VERSION) {
595 ERR_raise(ERR_LIB_SSL, SSL_R_WRONG_VERSION_NUMBER);
599 if (!PACKET_forward(&msgpayload, SSL3_RANDOM_SIZE)
600 || !PACKET_get_length_prefixed_1(&msgpayload, &session)
601 || !PACKET_get_length_prefixed_1(&msgpayload, &cookiepkt)) {
603 * Could be malformed or the cookie does not fit within the initial
604 * ClientHello fragment. Either way we can't handle it.
606 ERR_raise(ERR_LIB_SSL, SSL_R_LENGTH_MISMATCH);
611 * Check if we have a cookie or not. If not we need to send a
612 * HelloVerifyRequest.
614 if (PACKET_remaining(&cookiepkt) == 0) {
615 next = LISTEN_SEND_VERIFY_REQUEST;
618 * We have a cookie, so lets check it.
620 if (ssl->ctx->app_verify_cookie_cb == NULL) {
621 ERR_raise(ERR_LIB_SSL, SSL_R_NO_VERIFY_COOKIE_CALLBACK);
626 if (ssl->ctx->app_verify_cookie_cb(ssl, PACKET_data(&cookiepkt),
627 (unsigned int)PACKET_remaining(&cookiepkt)) == 0) {
629 * We treat invalid cookies in the same was as no cookie as
632 next = LISTEN_SEND_VERIFY_REQUEST;
634 /* Cookie verification succeeded */
635 next = LISTEN_SUCCESS;
639 if (next == LISTEN_SEND_VERIFY_REQUEST) {
641 unsigned int version;
645 * There was no cookie in the ClientHello so we need to send a
646 * HelloVerifyRequest. If this fails we do not worry about trying
647 * to resend, we just drop it.
650 /* Generate the cookie */
651 if (ssl->ctx->app_gen_cookie_cb == NULL ||
652 ssl->ctx->app_gen_cookie_cb(ssl, cookie, &cookielen) == 0 ||
654 ERR_raise(ERR_LIB_SSL, SSL_R_COOKIE_GEN_CALLBACK_FAILURE);
661 * Special case: for hello verify request, client version 1.0 and we
662 * haven't decided which version to use yet send back using version
663 * 1.0 header: otherwise some clients will ignore it.
665 version = (ssl->method->version == DTLS_ANY_VERSION) ? DTLS1_VERSION
668 /* Construct the record and message headers */
669 if (!WPACKET_init_static_len(&wpkt,
671 ssl_get_max_send_fragment(s)
672 + DTLS1_RT_HEADER_LENGTH,
674 || !WPACKET_put_bytes_u8(&wpkt, SSL3_RT_HANDSHAKE)
675 || !WPACKET_put_bytes_u16(&wpkt, version)
677 * Record sequence number is always the same as in the
678 * received ClientHello
680 || !WPACKET_memcpy(&wpkt, seq, SEQ_NUM_SIZE)
681 /* End of record, start sub packet for message */
682 || !WPACKET_start_sub_packet_u16(&wpkt)
684 || !WPACKET_put_bytes_u8(&wpkt,
685 DTLS1_MT_HELLO_VERIFY_REQUEST)
687 * Message length - doesn't follow normal TLS convention:
688 * the length isn't the last thing in the message header.
689 * We'll need to fill this in later when we know the
690 * length. Set it to zero for now
692 || !WPACKET_put_bytes_u24(&wpkt, 0)
694 * Message sequence number is always 0 for a
697 || !WPACKET_put_bytes_u16(&wpkt, 0)
699 * We never fragment a HelloVerifyRequest, so fragment
702 || !WPACKET_put_bytes_u24(&wpkt, 0)
704 * Fragment length is the same as message length, but
705 * this *is* the last thing in the message header so we
706 * can just start a sub-packet. No need to come back
707 * later for this one.
709 || !WPACKET_start_sub_packet_u24(&wpkt)
710 /* Create the actual HelloVerifyRequest body */
711 || !dtls_raw_hello_verify_request(&wpkt, cookie, cookielen)
712 /* Close message body */
713 || !WPACKET_close(&wpkt)
714 /* Close record body */
715 || !WPACKET_close(&wpkt)
716 || !WPACKET_get_total_written(&wpkt, &wreclen)
717 || !WPACKET_finish(&wpkt)) {
718 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
719 WPACKET_cleanup(&wpkt);
726 * Fix up the message len in the message header. Its the same as the
727 * fragment len which has been filled in by WPACKET, so just copy
728 * that. Destination for the message len is after the record header
729 * plus one byte for the message content type. The source is the
730 * last 3 bytes of the message header
732 memcpy(&wbuf[DTLS1_RT_HEADER_LENGTH + 1],
733 &wbuf[DTLS1_RT_HEADER_LENGTH + DTLS1_HM_HEADER_LENGTH - 3],
737 s->msg_callback(1, 0, SSL3_RT_HEADER, buf,
738 DTLS1_RT_HEADER_LENGTH, ssl,
739 s->msg_callback_arg);
741 if ((tmpclient = BIO_ADDR_new()) == NULL) {
742 ERR_raise(ERR_LIB_SSL, ERR_R_BIO_LIB);
747 * This is unnecessary if rbio and wbio are one and the same - but
748 * maybe they're not. We ignore errors here - some BIOs do not
751 if (BIO_dgram_get_peer(rbio, tmpclient) > 0) {
752 (void)BIO_dgram_set_peer(wbio, tmpclient);
754 BIO_ADDR_free(tmpclient);
757 if (BIO_write(wbio, wbuf, wreclen) < (int)wreclen) {
758 if (BIO_should_retry(wbio)) {
760 * Non-blocking IO...but we're stateless, so we're just
761 * going to drop this packet.
769 if (BIO_flush(wbio) <= 0) {
770 if (BIO_should_retry(wbio)) {
772 * Non-blocking IO...but we're stateless, so we're just
773 * going to drop this packet.
781 } while (next != LISTEN_SUCCESS);
784 * Set expected sequence numbers to continue the handshake.
786 s->d1->handshake_read_seq = 1;
787 s->d1->handshake_write_seq = 1;
788 s->d1->next_handshake_write_seq = 1;
789 s->rlayer.wrlmethod->increment_sequence_ctr(s->rlayer.wrl);
792 * We are doing cookie exchange, so make sure we set that option in the
795 SSL_set_options(ssl, SSL_OP_COOKIE_EXCHANGE);
798 * Tell the state machine that we've done the initial hello verify
801 ossl_statem_set_hello_verify_done(s);
804 * Some BIOs may not support this. If we fail we clear the client address
806 if (BIO_dgram_get_peer(rbio, client) <= 0)
807 BIO_ADDR_clear(client);
809 /* Buffer the record for use by the record layer */
810 if (BIO_write(s->rlayer.rrlnext, buf, n) != n) {
811 ERR_raise(ERR_LIB_SSL, ERR_R_INTERNAL_ERROR);
817 * Reset the record layer - but this time we can use the record we just
818 * buffered in s->rlayer.rrlnext
820 if (!ssl_set_new_record_layer(s,
822 OSSL_RECORD_DIRECTION_READ,
823 OSSL_RECORD_PROTECTION_LEVEL_NONE, NULL, 0,
824 NULL, 0, NULL, 0, NULL, 0, NULL, 0,
825 NID_undef, NULL, NULL, NULL)) {
826 /* SSLfatal already called */
833 BIO_ADDR_free(tmpclient);
840 static int dtls1_handshake_write(SSL_CONNECTION *s)
842 return dtls1_do_write(s, SSL3_RT_HANDSHAKE);
845 int dtls1_shutdown(SSL *s)
848 #ifndef OPENSSL_NO_SCTP
850 SSL_CONNECTION *sc = SSL_CONNECTION_FROM_SSL_ONLY(s);
855 wbio = SSL_get_wbio(s);
856 if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
857 !(sc->shutdown & SSL_SENT_SHUTDOWN)) {
858 ret = BIO_dgram_sctp_wait_for_dry(wbio);
863 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
867 ret = ssl3_shutdown(s);
868 #ifndef OPENSSL_NO_SCTP
869 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
874 int dtls1_query_mtu(SSL_CONNECTION *s)
876 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
878 if (s->d1->link_mtu) {
880 s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(ssl));
884 /* AHA! Figure out the MTU, and stick to the right size */
885 if (s->d1->mtu < dtls1_min_mtu(s)) {
886 if (!(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
888 BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
891 * I've seen the kernel return bogus numbers when it doesn't know
892 * (initial write), so just make sure we have a reasonable number
894 if (s->d1->mtu < dtls1_min_mtu(s)) {
896 s->d1->mtu = dtls1_min_mtu(s);
897 BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_SET_MTU,
898 (long)s->d1->mtu, NULL);
906 static size_t dtls1_link_min_mtu(void)
908 return (g_probable_mtu[(sizeof(g_probable_mtu) /
909 sizeof(g_probable_mtu[0])) - 1]);
912 size_t dtls1_min_mtu(SSL_CONNECTION *s)
914 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
916 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(ssl));
919 size_t DTLS_get_data_mtu(const SSL *ssl)
921 size_t mac_overhead, int_overhead, blocksize, ext_overhead;
922 const SSL_CIPHER *ciph = SSL_get_current_cipher(ssl);
924 const SSL_CONNECTION *s = SSL_CONNECTION_FROM_CONST_SSL_ONLY(ssl);
934 if (!ssl_cipher_get_overhead(ciph, &mac_overhead, &int_overhead,
935 &blocksize, &ext_overhead))
939 ext_overhead += mac_overhead;
941 int_overhead += mac_overhead;
943 /* Subtract external overhead (e.g. IV/nonce, separate MAC) */
944 if (ext_overhead + DTLS1_RT_HEADER_LENGTH >= mtu)
946 mtu -= ext_overhead + DTLS1_RT_HEADER_LENGTH;
948 /* Round encrypted payload down to cipher block size (for CBC etc.)
949 * No check for overflow since 'mtu % blocksize' cannot exceed mtu. */
951 mtu -= (mtu % blocksize);
953 /* Subtract internal overhead (e.g. CBC padding len byte) */
954 if (int_overhead >= mtu)
961 void DTLS_set_timer_cb(SSL *ssl, DTLS_timer_cb cb)
963 SSL_CONNECTION *s = SSL_CONNECTION_FROM_SSL_ONLY(ssl);
968 s->d1->timer_cb = cb;