2 * DTLS implementation written by Nagendra Modadugu
3 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5 /* ====================================================================
6 * Copyright (c) 1999-2005 The OpenSSL Project. All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * openssl-core@OpenSSL.org.
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
34 * 6. Redistributions of any form whatsoever must retain the following
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
61 #include <openssl/objects.h>
62 #include <openssl/rand.h>
65 #if defined(OPENSSL_SYS_VMS)
66 # include <sys/timeb.h>
67 #elif defined(OPENSSL_SYS_VXWORKS)
68 # include <sys/times.h>
69 #elif !defined(OPENSSL_SYS_WIN32)
70 # include <sys/time.h>
73 static void get_current_time(struct timeval
*t
);
74 static int dtls1_set_handshake_header(SSL
*s
, int type
, unsigned long len
);
75 static int dtls1_handshake_write(SSL
*s
);
76 static unsigned int dtls1_link_min_mtu(void);
78 /* XDTLS: figure out the right values */
79 static const unsigned int g_probable_mtu
[] = { 1500, 512, 256 };
81 const SSL3_ENC_METHOD DTLSv1_enc_data
= {
85 tls1_generate_master_secret
,
86 tls1_change_cipher_state
,
87 tls1_final_finish_mac
,
88 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 TLS_MD_CLIENT_FINISH_CONST
, TLS_MD_CLIENT_FINISH_CONST_SIZE
,
108 TLS_MD_SERVER_FINISH_CONST
, TLS_MD_SERVER_FINISH_CONST_SIZE
,
110 tls1_export_keying_material
,
111 SSL_ENC_FLAG_DTLS
| SSL_ENC_FLAG_EXPLICIT_IV
| SSL_ENC_FLAG_SIGALGS
112 | SSL_ENC_FLAG_SHA256_PRF
| SSL_ENC_FLAG_TLS1_2_CIPHERS
,
113 DTLS1_HM_HEADER_LENGTH
,
114 dtls1_set_handshake_header
,
115 dtls1_handshake_write
118 long dtls1_default_timeout(void)
121 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
122 * http, the cache would over fill
124 return (60 * 60 * 2);
127 int dtls1_new(SSL
*s
)
131 if (!DTLS_RECORD_LAYER_new(&s
->rlayer
)) {
137 if ((d1
= OPENSSL_zalloc(sizeof(*d1
))) == NULL
) {
142 d1
->buffered_messages
= pqueue_new();
143 d1
->sent_messages
= pqueue_new();
146 d1
->cookie_len
= sizeof(s
->d1
->cookie
);
152 if (d1
->buffered_messages
== NULL
|| d1
->sent_messages
== NULL
) {
153 pqueue_free(d1
->buffered_messages
);
154 pqueue_free(d1
->sent_messages
);
161 s
->method
->ssl_clear(s
);
165 static void dtls1_clear_queues(SSL
*s
)
168 hm_fragment
*frag
= NULL
;
170 while ((item
= pqueue_pop(s
->d1
->buffered_messages
)) != NULL
) {
171 frag
= (hm_fragment
*)item
->data
;
172 dtls1_hm_fragment_free(frag
);
176 while ((item
= pqueue_pop(s
->d1
->sent_messages
)) != NULL
) {
177 frag
= (hm_fragment
*)item
->data
;
178 dtls1_hm_fragment_free(frag
);
183 void dtls1_free(SSL
*s
)
185 DTLS_RECORD_LAYER_free(&s
->rlayer
);
189 dtls1_clear_queues(s
);
191 pqueue_free(s
->d1
->buffered_messages
);
192 pqueue_free(s
->d1
->sent_messages
);
198 void dtls1_clear(SSL
*s
)
200 pqueue
*buffered_messages
;
201 pqueue
*sent_messages
;
203 unsigned int link_mtu
;
205 DTLS_RECORD_LAYER_clear(&s
->rlayer
);
208 buffered_messages
= s
->d1
->buffered_messages
;
209 sent_messages
= s
->d1
->sent_messages
;
211 link_mtu
= s
->d1
->link_mtu
;
213 dtls1_clear_queues(s
);
215 memset(s
->d1
, 0, sizeof(*s
->d1
));
218 s
->d1
->cookie_len
= sizeof(s
->d1
->cookie
);
221 if (SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
) {
223 s
->d1
->link_mtu
= link_mtu
;
226 s
->d1
->buffered_messages
= buffered_messages
;
227 s
->d1
->sent_messages
= sent_messages
;
231 if (s
->options
& SSL_OP_CISCO_ANYCONNECT
)
232 s
->client_version
= s
->version
= DTLS1_BAD_VER
;
233 else if (s
->method
->version
== DTLS_ANY_VERSION
)
234 s
->version
= DTLS_MAX_VERSION
;
236 s
->version
= s
->method
->version
;
239 long dtls1_ctrl(SSL
*s
, int cmd
, long larg
, void *parg
)
244 case DTLS_CTRL_GET_TIMEOUT
:
245 if (dtls1_get_timeout(s
, (struct timeval
*)parg
) != NULL
) {
249 case DTLS_CTRL_HANDLE_TIMEOUT
:
250 ret
= dtls1_handle_timeout(s
);
252 case DTLS_CTRL_SET_LINK_MTU
:
253 if (larg
< (long)dtls1_link_min_mtu())
255 s
->d1
->link_mtu
= larg
;
257 case DTLS_CTRL_GET_LINK_MIN_MTU
:
258 return (long)dtls1_link_min_mtu();
259 case SSL_CTRL_SET_MTU
:
261 * We may not have a BIO set yet so can't call dtls1_min_mtu()
262 * We'll have to make do with dtls1_link_min_mtu() and max overhead
264 if (larg
< (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD
)
269 ret
= ssl3_ctrl(s
, cmd
, larg
, parg
);
275 void dtls1_start_timer(SSL
*s
)
277 #ifndef OPENSSL_NO_SCTP
278 /* Disable timer for SCTP */
279 if (BIO_dgram_is_sctp(SSL_get_wbio(s
))) {
280 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
285 /* If timer is not set, initialize duration with 1 second */
286 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
287 s
->d1
->timeout_duration
= 1;
290 /* Set timeout to current time */
291 get_current_time(&(s
->d1
->next_timeout
));
293 /* Add duration to current time */
294 s
->d1
->next_timeout
.tv_sec
+= s
->d1
->timeout_duration
;
295 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
296 &(s
->d1
->next_timeout
));
299 struct timeval
*dtls1_get_timeout(SSL
*s
, struct timeval
*timeleft
)
301 struct timeval timenow
;
303 /* If no timeout is set, just return NULL */
304 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
308 /* Get current time */
309 get_current_time(&timenow
);
311 /* If timer already expired, set remaining time to 0 */
312 if (s
->d1
->next_timeout
.tv_sec
< timenow
.tv_sec
||
313 (s
->d1
->next_timeout
.tv_sec
== timenow
.tv_sec
&&
314 s
->d1
->next_timeout
.tv_usec
<= timenow
.tv_usec
)) {
315 memset(timeleft
, 0, sizeof(*timeleft
));
319 /* Calculate time left until timer expires */
320 memcpy(timeleft
, &(s
->d1
->next_timeout
), sizeof(struct timeval
));
321 timeleft
->tv_sec
-= timenow
.tv_sec
;
322 timeleft
->tv_usec
-= timenow
.tv_usec
;
323 if (timeleft
->tv_usec
< 0) {
325 timeleft
->tv_usec
+= 1000000;
329 * If remaining time is less than 15 ms, set it to 0 to prevent issues
330 * because of small devergences with socket timeouts.
332 if (timeleft
->tv_sec
== 0 && timeleft
->tv_usec
< 15000) {
333 memset(timeleft
, 0, sizeof(*timeleft
));
339 int dtls1_is_timer_expired(SSL
*s
)
341 struct timeval timeleft
;
343 /* Get time left until timeout, return false if no timer running */
344 if (dtls1_get_timeout(s
, &timeleft
) == NULL
) {
348 /* Return false if timer is not expired yet */
349 if (timeleft
.tv_sec
> 0 || timeleft
.tv_usec
> 0) {
353 /* Timer expired, so return true */
357 void dtls1_double_timeout(SSL
*s
)
359 s
->d1
->timeout_duration
*= 2;
360 if (s
->d1
->timeout_duration
> 60)
361 s
->d1
->timeout_duration
= 60;
362 dtls1_start_timer(s
);
365 void dtls1_stop_timer(SSL
*s
)
367 /* Reset everything */
368 memset(&s
->d1
->timeout
, 0, sizeof(s
->d1
->timeout
));
369 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
370 s
->d1
->timeout_duration
= 1;
371 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
372 &(s
->d1
->next_timeout
));
373 /* Clear retransmission buffer */
374 dtls1_clear_record_buffer(s
);
377 int dtls1_check_timeout_num(SSL
*s
)
381 s
->d1
->timeout
.num_alerts
++;
383 /* Reduce MTU after 2 unsuccessful retransmissions */
384 if (s
->d1
->timeout
.num_alerts
> 2
385 && !(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
387 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_GET_FALLBACK_MTU
, 0,
389 if (mtu
< s
->d1
->mtu
)
393 if (s
->d1
->timeout
.num_alerts
> DTLS1_TMO_ALERT_COUNT
) {
394 /* fail the connection, enough alerts have been sent */
395 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM
, SSL_R_READ_TIMEOUT_EXPIRED
);
402 int dtls1_handle_timeout(SSL
*s
)
404 /* if no timer is expired, don't do anything */
405 if (!dtls1_is_timer_expired(s
)) {
409 dtls1_double_timeout(s
);
411 if (dtls1_check_timeout_num(s
) < 0)
414 s
->d1
->timeout
.read_timeouts
++;
415 if (s
->d1
->timeout
.read_timeouts
> DTLS1_TMO_READ_COUNT
) {
416 s
->d1
->timeout
.read_timeouts
= 1;
418 #ifndef OPENSSL_NO_HEARTBEATS
419 if (s
->tlsext_hb_pending
) {
420 s
->tlsext_hb_pending
= 0;
421 return dtls1_heartbeat(s
);
425 dtls1_start_timer(s
);
426 return dtls1_retransmit_buffered_messages(s
);
429 static void get_current_time(struct timeval
*t
)
439 SystemTimeToFileTime(&st
, &now
.ft
);
441 now
.ul
-= 116444736000000000ULL;
443 now
.ul
-= 116444736000000000UI
64; /* re-bias to 1/1/1970 */
445 t
->tv_sec
= (long)(now
.ul
/ 10000000);
446 t
->tv_usec
= ((int)(now
.ul
% 10000000)) / 10;
447 #elif defined(OPENSSL_SYS_VMS)
450 t
->tv_sec
= (long)tb
.time
;
451 t
->tv_usec
= (long)tb
.millitm
* 1000;
453 gettimeofday(t
, NULL
);
458 #define LISTEN_SUCCESS 2
459 #define LISTEN_SEND_VERIFY_REQUEST 1
461 #ifndef OPENSSL_NO_SOCK
462 int DTLSv1_listen(SSL
*s
, BIO_ADDR
*client
)
464 int next
, n
, ret
= 0, clearpkt
= 0;
465 unsigned char cookie
[DTLS1_COOKIE_LENGTH
];
466 unsigned char seq
[SEQ_NUM_SIZE
];
467 const unsigned char *data
;
468 unsigned char *p
, *buf
;
469 unsigned long reclen
, fragoff
, fraglen
, msglen
;
470 unsigned int rectype
, versmajor
, msgseq
, msgtype
, clientvers
, cookielen
;
473 BIO_ADDR
*tmpclient
= NULL
;
474 PACKET pkt
, msgpkt
, msgpayload
, session
, cookiepkt
;
476 /* Ensure there is no state left over from a previous invocation */
482 rbio
= SSL_get_rbio(s
);
483 wbio
= SSL_get_wbio(s
);
486 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_BIO_NOT_SET
);
491 * We only peek at incoming ClientHello's until we're sure we are going to
492 * to respond with a HelloVerifyRequest. If its a ClientHello with a valid
493 * cookie then we leave it in the BIO for accept to handle.
495 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
498 * Note: This check deliberately excludes DTLS1_BAD_VER because that version
499 * requires the MAC to be calculated *including* the first ClientHello
500 * (without the cookie). Since DTLSv1_listen is stateless that cannot be
501 * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
504 if ((s
->version
& 0xff00) != (DTLS1_VERSION
& 0xff00)) {
505 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNSUPPORTED_SSL_VERSION
);
509 if (s
->init_buf
== NULL
) {
510 if ((bufm
= BUF_MEM_new()) == NULL
) {
511 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_MALLOC_FAILURE
);
515 if (!BUF_MEM_grow(bufm
, SSL3_RT_MAX_PLAIN_LENGTH
)) {
517 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_MALLOC_FAILURE
);
522 buf
= (unsigned char *)s
->init_buf
->data
;
529 * Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
530 * + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
531 * the record header as well, but we do here. We've set up init_buf to
532 * be the standard size for simplicity. In practice we shouldn't ever
533 * receive a ClientHello as long as this. If we do it will get dropped
534 * in the record length check below.
536 n
= BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
539 if(BIO_should_retry(rbio
)) {
540 /* Non-blocking IO */
546 /* If we hit any problems we need to clear this packet from the BIO */
549 if (!PACKET_buf_init(&pkt
, buf
, n
)) {
550 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_INTERNAL_ERROR
);
555 * Parse the received record. If there are any problems with it we just
556 * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
557 * resilient in the face of invalid records (e.g., invalid formatting,
558 * length, MAC, etc.). In general, invalid records SHOULD be silently
559 * discarded, thus preserving the association; however, an error MAY be
560 * logged for diagnostic purposes."
563 /* this packet contained a partial record, dump it */
564 if (n
< DTLS1_RT_HEADER_LENGTH
) {
565 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_RECORD_TOO_SMALL
);
570 s
->msg_callback(0, 0, SSL3_RT_HEADER
, buf
,
571 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
573 /* Get the record header */
574 if (!PACKET_get_1(&pkt
, &rectype
)
575 || !PACKET_get_1(&pkt
, &versmajor
)) {
576 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
580 if (rectype
!= SSL3_RT_HANDSHAKE
) {
581 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
586 * Check record version number. We only check that the major version is
589 if (versmajor
!= DTLS1_VERSION_MAJOR
) {
590 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_BAD_PROTOCOL_VERSION_NUMBER
);
594 if (!PACKET_forward(&pkt
, 1)
595 /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
596 || !PACKET_copy_bytes(&pkt
, seq
, SEQ_NUM_SIZE
)
597 || !PACKET_get_length_prefixed_2(&pkt
, &msgpkt
)) {
598 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
602 * We allow data remaining at the end of the packet because there could
603 * be a second record (but we ignore it)
606 /* This is an initial ClientHello so the epoch has to be 0 */
607 if (seq
[0] != 0 || seq
[1] != 0) {
608 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
612 /* Get a pointer to the raw message for the later callback */
613 data
= PACKET_data(&msgpkt
);
615 /* Finished processing the record header, now process the message */
616 if (!PACKET_get_1(&msgpkt
, &msgtype
)
617 || !PACKET_get_net_3(&msgpkt
, &msglen
)
618 || !PACKET_get_net_2(&msgpkt
, &msgseq
)
619 || !PACKET_get_net_3(&msgpkt
, &fragoff
)
620 || !PACKET_get_net_3(&msgpkt
, &fraglen
)
621 || !PACKET_get_sub_packet(&msgpkt
, &msgpayload
, fraglen
)
622 || PACKET_remaining(&msgpkt
) != 0) {
623 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
627 if (msgtype
!= SSL3_MT_CLIENT_HELLO
) {
628 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
632 /* Message sequence number can only be 0 or 1 */
634 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_INVALID_SEQUENCE_NUMBER
);
639 * We don't support fragment reassembly for ClientHellos whilst
640 * listening because that would require server side state (which is
641 * against the whole point of the ClientHello/HelloVerifyRequest
642 * mechanism). Instead we only look at the first ClientHello fragment
643 * and require that the cookie must be contained within it.
645 if (fragoff
!= 0 || fraglen
> msglen
) {
646 /* Non initial ClientHello fragment (or bad fragment) */
647 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_FRAGMENTED_CLIENT_HELLO
);
652 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
, data
,
653 fraglen
+ DTLS1_HM_HEADER_LENGTH
, s
,
654 s
->msg_callback_arg
);
656 if (!PACKET_get_net_2(&msgpayload
, &clientvers
)) {
657 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
662 * Verify client version is supported
664 if (DTLS_VERSION_LT(clientvers
, (unsigned int)s
->method
->version
) &&
665 s
->method
->version
!= DTLS_ANY_VERSION
) {
666 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_WRONG_VERSION_NUMBER
);
670 if (!PACKET_forward(&msgpayload
, SSL3_RANDOM_SIZE
)
671 || !PACKET_get_length_prefixed_1(&msgpayload
, &session
)
672 || !PACKET_get_length_prefixed_1(&msgpayload
, &cookiepkt
)) {
674 * Could be malformed or the cookie does not fit within the initial
675 * ClientHello fragment. Either way we can't handle it.
677 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
682 * Check if we have a cookie or not. If not we need to send a
683 * HelloVerifyRequest.
685 if (PACKET_remaining(&cookiepkt
) == 0) {
686 next
= LISTEN_SEND_VERIFY_REQUEST
;
689 * We have a cookie, so lets check it.
691 if (s
->ctx
->app_verify_cookie_cb
== NULL
) {
692 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_NO_VERIFY_COOKIE_CALLBACK
);
696 if (s
->ctx
->app_verify_cookie_cb(s
, PACKET_data(&cookiepkt
),
697 PACKET_remaining(&cookiepkt
)) ==
700 * We treat invalid cookies in the same was as no cookie as
703 next
= LISTEN_SEND_VERIFY_REQUEST
;
705 /* Cookie verification succeeded */
706 next
= LISTEN_SUCCESS
;
710 if (next
== LISTEN_SEND_VERIFY_REQUEST
) {
712 * There was no cookie in the ClientHello so we need to send a
713 * HelloVerifyRequest. If this fails we do not worry about trying
714 * to resend, we just drop it.
718 * Dump the read packet, we don't need it any more. Ignore return
721 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
722 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
723 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
725 /* Generate the cookie */
726 if (s
->ctx
->app_gen_cookie_cb
== NULL
||
727 s
->ctx
->app_gen_cookie_cb(s
, cookie
, &cookielen
) == 0 ||
729 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_COOKIE_GEN_CALLBACK_FAILURE
);
734 p
= &buf
[DTLS1_RT_HEADER_LENGTH
];
735 msglen
= dtls_raw_hello_verify_request(p
+ DTLS1_HM_HEADER_LENGTH
,
738 *p
++ = DTLS1_MT_HELLO_VERIFY_REQUEST
;
743 /* Message sequence number is always 0 for a HelloVerifyRequest */
747 * We never fragment a HelloVerifyRequest, so fragment offset is 0
748 * and fragment length is message length
753 /* Set reclen equal to length of whole handshake message */
754 reclen
= msglen
+ DTLS1_HM_HEADER_LENGTH
;
756 /* Add the record header */
759 *(p
++) = SSL3_RT_HANDSHAKE
;
761 * Special case: for hello verify request, client version 1.0 and we
762 * haven't decided which version to use yet send back using version
763 * 1.0 header: otherwise some clients will ignore it.
765 if (s
->method
->version
== DTLS_ANY_VERSION
) {
766 *(p
++) = DTLS1_VERSION
>> 8;
767 *(p
++) = DTLS1_VERSION
& 0xff;
769 *(p
++) = s
->version
>> 8;
770 *(p
++) = s
->version
& 0xff;
774 * Record sequence number is always the same as in the received
777 memcpy(p
, seq
, SEQ_NUM_SIZE
);
784 * Set reclen equal to length of whole record including record
787 reclen
+= DTLS1_RT_HEADER_LENGTH
;
790 s
->msg_callback(1, 0, SSL3_RT_HEADER
, buf
,
791 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
794 if ((tmpclient
= BIO_ADDR_new()) == NULL
) {
795 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_MALLOC_FAILURE
);
800 * This is unnecessary if rbio and wbio are one and the same - but
801 * maybe they're not. We ignore errors here - some BIOs do not
804 if(BIO_dgram_get_peer(rbio
, tmpclient
) > 0) {
805 (void)BIO_dgram_set_peer(wbio
, tmpclient
);
807 BIO_ADDR_free(tmpclient
);
810 if (BIO_write(wbio
, buf
, reclen
) < (int)reclen
) {
811 if(BIO_should_retry(wbio
)) {
813 * Non-blocking IO...but we're stateless, so we're just
814 * going to drop this packet.
821 if (BIO_flush(wbio
) <= 0) {
822 if(BIO_should_retry(wbio
)) {
824 * Non-blocking IO...but we're stateless, so we're just
825 * going to drop this packet.
832 } while (next
!= LISTEN_SUCCESS
);
835 * Set expected sequence numbers to continue the handshake.
837 s
->d1
->handshake_read_seq
= 1;
838 s
->d1
->handshake_write_seq
= 1;
839 s
->d1
->next_handshake_write_seq
= 1;
840 DTLS_RECORD_LAYER_set_write_sequence(&s
->rlayer
, seq
);
843 * We are doing cookie exchange, so make sure we set that option in the
846 SSL_set_options(s
, SSL_OP_COOKIE_EXCHANGE
);
849 * Tell the state machine that we've done the initial hello verify
852 ossl_statem_set_hello_verify_done(s
);
854 /* Some BIOs may not support this. If we fail we clear the client address */
855 if (BIO_dgram_get_peer(rbio
, client
) <= 0)
856 BIO_ADDR_clear(client
);
861 BIO_ADDR_free(tmpclient
);
862 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
864 /* Dump this packet. Ignore return value */
865 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
871 static int dtls1_set_handshake_header(SSL
*s
, int htype
, unsigned long len
)
873 dtls1_set_message_header(s
, htype
, len
, 0, len
);
874 s
->init_num
= (int)len
+ DTLS1_HM_HEADER_LENGTH
;
876 /* Buffer the message to handle re-xmits */
878 if (!dtls1_buffer_message(s
, 0))
884 static int dtls1_handshake_write(SSL
*s
)
886 return dtls1_do_write(s
, SSL3_RT_HANDSHAKE
);
889 #ifndef OPENSSL_NO_HEARTBEATS
891 #define HEARTBEAT_SIZE(payload, padding) ( \
892 1 /* heartbeat type */ + \
893 2 /* heartbeat length */ + \
894 (payload) + (padding))
896 #define HEARTBEAT_SIZE_STD(payload) HEARTBEAT_SIZE(payload, 16)
898 int dtls1_process_heartbeat(SSL
*s
, unsigned char *p
, unsigned int length
)
901 unsigned short hbtype
;
902 unsigned int payload
;
903 unsigned int padding
= 16; /* Use minimum padding */
906 s
->msg_callback(0, s
->version
, DTLS1_RT_HEARTBEAT
,
907 p
, length
, s
, s
->msg_callback_arg
);
909 /* Read type and payload length */
910 if (HEARTBEAT_SIZE_STD(0) > length
)
911 return 0; /* silently discard */
912 if (length
> SSL3_RT_MAX_PLAIN_LENGTH
)
913 return 0; /* silently discard per RFC 6520 sec. 4 */
917 if (HEARTBEAT_SIZE_STD(payload
) > length
)
918 return 0; /* silently discard per RFC 6520 sec. 4 */
921 if (hbtype
== TLS1_HB_REQUEST
) {
922 unsigned char *buffer
, *bp
;
923 unsigned int write_length
= HEARTBEAT_SIZE(payload
, padding
);
926 if (write_length
> SSL3_RT_MAX_PLAIN_LENGTH
)
929 /* Allocate memory for the response. */
930 buffer
= OPENSSL_malloc(write_length
);
935 /* Enter response type, length and copy payload */
936 *bp
++ = TLS1_HB_RESPONSE
;
938 memcpy(bp
, pl
, payload
);
941 if (RAND_bytes(bp
, padding
) <= 0) {
942 OPENSSL_free(buffer
);
946 r
= dtls1_write_bytes(s
, DTLS1_RT_HEARTBEAT
, buffer
, write_length
);
948 if (r
>= 0 && s
->msg_callback
)
949 s
->msg_callback(1, s
->version
, DTLS1_RT_HEARTBEAT
,
950 buffer
, write_length
, s
, s
->msg_callback_arg
);
952 OPENSSL_free(buffer
);
956 } else if (hbtype
== TLS1_HB_RESPONSE
) {
960 * We only send sequence numbers (2 bytes unsigned int), and 16
961 * random bytes, so we just try to read the sequence number
965 if (payload
== 18 && seq
== s
->tlsext_hb_seq
) {
968 s
->tlsext_hb_pending
= 0;
975 int dtls1_heartbeat(SSL
*s
)
977 unsigned char *buf
, *p
;
979 unsigned int payload
= 18; /* Sequence number + random bytes */
980 unsigned int padding
= 16; /* Use minimum padding */
983 /* Only send if peer supports and accepts HB requests... */
984 if (!(s
->tlsext_heartbeat
& SSL_DTLSEXT_HB_ENABLED
) ||
985 s
->tlsext_heartbeat
& SSL_DTLSEXT_HB_DONT_SEND_REQUESTS
) {
986 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT
);
990 /* ...and there is none in flight yet... */
991 if (s
->tlsext_hb_pending
) {
992 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PENDING
);
996 /* ...and no handshake in progress. */
997 if (SSL_in_init(s
) || ossl_statem_get_in_handshake(s
)) {
998 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_UNEXPECTED_MESSAGE
);
1003 * Create HeartBeat message, we just use a sequence number
1004 * as payload to distuingish different messages and add
1005 * some random stuff.
1007 size
= HEARTBEAT_SIZE(payload
, padding
);
1008 buf
= OPENSSL_malloc(size
);
1010 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_MALLOC_FAILURE
);
1015 *p
++ = TLS1_HB_REQUEST
;
1016 /* Payload length (18 bytes here) */
1018 /* Sequence number */
1019 s2n(s
->tlsext_hb_seq
, p
);
1020 /* 16 random bytes */
1021 if (RAND_bytes(p
, 16) <= 0) {
1022 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1026 /* Random padding */
1027 if (RAND_bytes(p
, padding
) <= 0) {
1028 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1032 ret
= dtls1_write_bytes(s
, DTLS1_RT_HEARTBEAT
, buf
, size
);
1034 if (s
->msg_callback
)
1035 s
->msg_callback(1, s
->version
, DTLS1_RT_HEARTBEAT
,
1037 s
, s
->msg_callback_arg
);
1039 dtls1_start_timer(s
);
1040 s
->tlsext_hb_pending
= 1;
1050 int dtls1_shutdown(SSL
*s
)
1053 #ifndef OPENSSL_NO_SCTP
1056 wbio
= SSL_get_wbio(s
);
1057 if (wbio
!= NULL
&& BIO_dgram_is_sctp(wbio
) &&
1058 !(s
->shutdown
& SSL_SENT_SHUTDOWN
)) {
1059 ret
= BIO_dgram_sctp_wait_for_dry(wbio
);
1064 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 1,
1068 ret
= ssl3_shutdown(s
);
1069 #ifndef OPENSSL_NO_SCTP
1070 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 0, NULL
);
1075 int dtls1_query_mtu(SSL
*s
)
1077 if (s
->d1
->link_mtu
) {
1079 s
->d1
->link_mtu
- BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
1080 s
->d1
->link_mtu
= 0;
1083 /* AHA! Figure out the MTU, and stick to the right size */
1084 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1085 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
1087 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_QUERY_MTU
, 0, NULL
);
1090 * I've seen the kernel return bogus numbers when it doesn't know
1091 * (initial write), so just make sure we have a reasonable number
1093 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1094 /* Set to min mtu */
1095 s
->d1
->mtu
= dtls1_min_mtu(s
);
1096 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SET_MTU
,
1105 static unsigned int dtls1_link_min_mtu(void)
1107 return (g_probable_mtu
[(sizeof(g_probable_mtu
) /
1108 sizeof(g_probable_mtu
[0])) - 1]);
1111 unsigned int dtls1_min_mtu(SSL
*s
)
1113 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));