3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1999-2005 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)"
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@OpenSSL.org.
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
62 #include <openssl/objects.h>
63 #include <openssl/rand.h>
66 #if defined(OPENSSL_SYS_VMS)
67 # include <sys/timeb.h>
68 #elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_)
69 # include <sys/timeval.h>
70 #elif defined(OPENSSL_SYS_VXWORKS)
71 # include <sys/times.h>
72 #elif !defined(OPENSSL_SYS_WIN32)
73 # include <sys/time.h>
76 static void get_current_time(struct timeval
*t
);
77 static int dtls1_set_handshake_header(SSL
*s
, int type
, unsigned long len
);
78 static int dtls1_handshake_write(SSL
*s
);
79 int dtls1_listen(SSL
*s
, struct sockaddr
*client
);
81 /* XDTLS: figure out the right values */
82 static const unsigned int g_probable_mtu
[] = { 1500, 512, 256 };
84 const SSL3_ENC_METHOD DTLSv1_enc_data
= {
88 tls1_generate_master_secret
,
89 tls1_change_cipher_state
,
90 tls1_final_finish_mac
,
91 TLS1_FINISH_MAC_LENGTH
,
93 TLS_MD_CLIENT_FINISH_CONST
, TLS_MD_CLIENT_FINISH_CONST_SIZE
,
94 TLS_MD_SERVER_FINISH_CONST
, TLS_MD_SERVER_FINISH_CONST_SIZE
,
96 tls1_export_keying_material
,
97 SSL_ENC_FLAG_DTLS
| SSL_ENC_FLAG_EXPLICIT_IV
,
98 DTLS1_HM_HEADER_LENGTH
,
99 dtls1_set_handshake_header
,
100 dtls1_handshake_write
103 const SSL3_ENC_METHOD DTLSv1_2_enc_data
= {
106 tls1_setup_key_block
,
107 tls1_generate_master_secret
,
108 tls1_change_cipher_state
,
109 tls1_final_finish_mac
,
110 TLS1_FINISH_MAC_LENGTH
,
111 tls1_cert_verify_mac
,
112 TLS_MD_CLIENT_FINISH_CONST
, TLS_MD_CLIENT_FINISH_CONST_SIZE
,
113 TLS_MD_SERVER_FINISH_CONST
, TLS_MD_SERVER_FINISH_CONST_SIZE
,
115 tls1_export_keying_material
,
116 SSL_ENC_FLAG_DTLS
| SSL_ENC_FLAG_EXPLICIT_IV
| SSL_ENC_FLAG_SIGALGS
117 | SSL_ENC_FLAG_SHA256_PRF
| SSL_ENC_FLAG_TLS1_2_CIPHERS
,
118 DTLS1_HM_HEADER_LENGTH
,
119 dtls1_set_handshake_header
,
120 dtls1_handshake_write
123 long dtls1_default_timeout(void)
126 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
127 * http, the cache would over fill
129 return (60 * 60 * 2);
132 int dtls1_new(SSL
*s
)
136 if (!DTLS_RECORD_LAYER_new(&s
->rlayer
)) {
142 if ((d1
= OPENSSL_zalloc(sizeof(*d1
))) == NULL
) {
147 d1
->buffered_messages
= pqueue_new();
148 d1
->sent_messages
= pqueue_new();
151 d1
->cookie_len
= sizeof(s
->d1
->cookie
);
157 if (!d1
->buffered_messages
|| !d1
->sent_messages
) {
158 pqueue_free(d1
->buffered_messages
);
159 pqueue_free(d1
->sent_messages
);
166 s
->method
->ssl_clear(s
);
170 static void dtls1_clear_queues(SSL
*s
)
173 hm_fragment
*frag
= NULL
;
175 while ((item
= pqueue_pop(s
->d1
->buffered_messages
)) != NULL
) {
176 frag
= (hm_fragment
*)item
->data
;
177 dtls1_hm_fragment_free(frag
);
181 while ((item
= pqueue_pop(s
->d1
->sent_messages
)) != NULL
) {
182 frag
= (hm_fragment
*)item
->data
;
183 dtls1_hm_fragment_free(frag
);
188 void dtls1_free(SSL
*s
)
190 DTLS_RECORD_LAYER_free(&s
->rlayer
);
194 dtls1_clear_queues(s
);
196 pqueue_free(s
->d1
->buffered_messages
);
197 pqueue_free(s
->d1
->sent_messages
);
203 void dtls1_clear(SSL
*s
)
205 pqueue buffered_messages
;
206 pqueue sent_messages
;
208 unsigned int link_mtu
;
210 DTLS_RECORD_LAYER_clear(&s
->rlayer
);
213 buffered_messages
= s
->d1
->buffered_messages
;
214 sent_messages
= s
->d1
->sent_messages
;
216 link_mtu
= s
->d1
->link_mtu
;
218 dtls1_clear_queues(s
);
220 memset(s
->d1
, 0, sizeof(*s
->d1
));
223 s
->d1
->cookie_len
= sizeof(s
->d1
->cookie
);
226 if (SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
) {
228 s
->d1
->link_mtu
= link_mtu
;
231 s
->d1
->buffered_messages
= buffered_messages
;
232 s
->d1
->sent_messages
= sent_messages
;
236 if (s
->options
& SSL_OP_CISCO_ANYCONNECT
)
237 s
->client_version
= s
->version
= DTLS1_BAD_VER
;
238 else if (s
->method
->version
== DTLS_ANY_VERSION
)
239 s
->version
= DTLS1_2_VERSION
;
241 s
->version
= s
->method
->version
;
244 long dtls1_ctrl(SSL
*s
, int cmd
, long larg
, void *parg
)
249 case DTLS_CTRL_GET_TIMEOUT
:
250 if (dtls1_get_timeout(s
, (struct timeval
*)parg
) != NULL
) {
254 case DTLS_CTRL_HANDLE_TIMEOUT
:
255 ret
= dtls1_handle_timeout(s
);
257 case DTLS_CTRL_LISTEN
:
258 ret
= dtls1_listen(s
, parg
);
260 case SSL_CTRL_CHECK_PROTO_VERSION
:
262 * For library-internal use; checks that the current protocol is the
263 * highest enabled version (according to s->ctx->method, as version
264 * negotiation may have changed s->method).
266 if (s
->version
== s
->ctx
->method
->version
)
269 * Apparently we're using a version-flexible SSL_METHOD (not at its
270 * highest protocol version).
272 if (s
->ctx
->method
->version
== DTLS_method()->version
) {
273 #if DTLS_MAX_VERSION != DTLS1_2_VERSION
274 # error Code needs update for DTLS_method() support beyond DTLS1_2_VERSION.
276 if (!(s
->options
& SSL_OP_NO_DTLSv1_2
))
277 return s
->version
== DTLS1_2_VERSION
;
278 if (!(s
->options
& SSL_OP_NO_DTLSv1
))
279 return s
->version
== DTLS1_VERSION
;
281 return 0; /* Unexpected state; fail closed. */
282 case DTLS_CTRL_SET_LINK_MTU
:
283 if (larg
< (long)dtls1_link_min_mtu())
285 s
->d1
->link_mtu
= larg
;
287 case DTLS_CTRL_GET_LINK_MIN_MTU
:
288 return (long)dtls1_link_min_mtu();
289 case SSL_CTRL_SET_MTU
:
291 * We may not have a BIO set yet so can't call dtls1_min_mtu()
292 * We'll have to make do with dtls1_link_min_mtu() and max overhead
294 if (larg
< (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD
)
299 ret
= ssl3_ctrl(s
, cmd
, larg
, parg
);
306 * As it's impossible to use stream ciphers in "datagram" mode, this
307 * simple filter is designed to disengage them in DTLS. Unfortunately
308 * there is no universal way to identify stream SSL_CIPHER, so we have
309 * to explicitly list their SSL_* codes. Currently RC4 is the only one
310 * available, but if new ones emerge, they will have to be added...
312 const SSL_CIPHER
*dtls1_get_cipher(unsigned int u
)
314 const SSL_CIPHER
*ciph
= ssl3_get_cipher(u
);
317 if (ciph
->algorithm_enc
== SSL_RC4
)
324 void dtls1_start_timer(SSL
*s
)
326 #ifndef OPENSSL_NO_SCTP
327 /* Disable timer for SCTP */
328 if (BIO_dgram_is_sctp(SSL_get_wbio(s
))) {
329 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
334 /* If timer is not set, initialize duration with 1 second */
335 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
336 s
->d1
->timeout_duration
= 1;
339 /* Set timeout to current time */
340 get_current_time(&(s
->d1
->next_timeout
));
342 /* Add duration to current time */
343 s
->d1
->next_timeout
.tv_sec
+= s
->d1
->timeout_duration
;
344 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
345 &(s
->d1
->next_timeout
));
348 struct timeval
*dtls1_get_timeout(SSL
*s
, struct timeval
*timeleft
)
350 struct timeval timenow
;
352 /* If no timeout is set, just return NULL */
353 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
357 /* Get current time */
358 get_current_time(&timenow
);
360 /* If timer already expired, set remaining time to 0 */
361 if (s
->d1
->next_timeout
.tv_sec
< timenow
.tv_sec
||
362 (s
->d1
->next_timeout
.tv_sec
== timenow
.tv_sec
&&
363 s
->d1
->next_timeout
.tv_usec
<= timenow
.tv_usec
)) {
364 memset(timeleft
, 0, sizeof(*timeleft
));
368 /* Calculate time left until timer expires */
369 memcpy(timeleft
, &(s
->d1
->next_timeout
), sizeof(struct timeval
));
370 timeleft
->tv_sec
-= timenow
.tv_sec
;
371 timeleft
->tv_usec
-= timenow
.tv_usec
;
372 if (timeleft
->tv_usec
< 0) {
374 timeleft
->tv_usec
+= 1000000;
378 * If remaining time is less than 15 ms, set it to 0 to prevent issues
379 * because of small devergences with socket timeouts.
381 if (timeleft
->tv_sec
== 0 && timeleft
->tv_usec
< 15000) {
382 memset(timeleft
, 0, sizeof(*timeleft
));
388 int dtls1_is_timer_expired(SSL
*s
)
390 struct timeval timeleft
;
392 /* Get time left until timeout, return false if no timer running */
393 if (dtls1_get_timeout(s
, &timeleft
) == NULL
) {
397 /* Return false if timer is not expired yet */
398 if (timeleft
.tv_sec
> 0 || timeleft
.tv_usec
> 0) {
402 /* Timer expired, so return true */
406 void dtls1_double_timeout(SSL
*s
)
408 s
->d1
->timeout_duration
*= 2;
409 if (s
->d1
->timeout_duration
> 60)
410 s
->d1
->timeout_duration
= 60;
411 dtls1_start_timer(s
);
414 void dtls1_stop_timer(SSL
*s
)
416 /* Reset everything */
417 memset(&s
->d1
->timeout
, 0, sizeof(s
->d1
->timeout
));
418 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
419 s
->d1
->timeout_duration
= 1;
420 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
421 &(s
->d1
->next_timeout
));
422 /* Clear retransmission buffer */
423 dtls1_clear_record_buffer(s
);
426 int dtls1_check_timeout_num(SSL
*s
)
430 s
->d1
->timeout
.num_alerts
++;
432 /* Reduce MTU after 2 unsuccessful retransmissions */
433 if (s
->d1
->timeout
.num_alerts
> 2
434 && !(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
436 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_GET_FALLBACK_MTU
, 0,
438 if (mtu
< s
->d1
->mtu
)
442 if (s
->d1
->timeout
.num_alerts
> DTLS1_TMO_ALERT_COUNT
) {
443 /* fail the connection, enough alerts have been sent */
444 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM
, SSL_R_READ_TIMEOUT_EXPIRED
);
451 int dtls1_handle_timeout(SSL
*s
)
453 /* if no timer is expired, don't do anything */
454 if (!dtls1_is_timer_expired(s
)) {
458 dtls1_double_timeout(s
);
460 if (dtls1_check_timeout_num(s
) < 0)
463 s
->d1
->timeout
.read_timeouts
++;
464 if (s
->d1
->timeout
.read_timeouts
> DTLS1_TMO_READ_COUNT
) {
465 s
->d1
->timeout
.read_timeouts
= 1;
467 #ifndef OPENSSL_NO_HEARTBEATS
468 if (s
->tlsext_hb_pending
) {
469 s
->tlsext_hb_pending
= 0;
470 return dtls1_heartbeat(s
);
474 dtls1_start_timer(s
);
475 return dtls1_retransmit_buffered_messages(s
);
478 static void get_current_time(struct timeval
*t
)
488 SystemTimeToFileTime(&st
, &now
.ft
);
490 now
.ul
-= 116444736000000000ULL;
492 now
.ul
-= 116444736000000000UI
64; /* re-bias to 1/1/1970 */
494 t
->tv_sec
= (long)(now
.ul
/ 10000000);
495 t
->tv_usec
= ((int)(now
.ul
% 10000000)) / 10;
496 #elif defined(OPENSSL_SYS_VMS)
499 t
->tv_sec
= (long)tb
.time
;
500 t
->tv_usec
= (long)tb
.millitm
* 1000;
502 gettimeofday(t
, NULL
);
507 #define LISTEN_SUCCESS 2
508 #define LISTEN_SEND_VERIFY_REQUEST 1
511 int dtls1_listen(SSL
*s
, struct sockaddr
*client
)
513 int next
, n
, ret
= 0, clearpkt
= 0;
514 unsigned char cookie
[DTLS1_COOKIE_LENGTH
];
515 unsigned char seq
[SEQ_NUM_SIZE
];
516 unsigned char *data
, *p
, *buf
;
517 unsigned long reclen
, fragoff
, fraglen
, msglen
;
518 unsigned int rectype
, versmajor
, msgseq
, msgtype
, clientvers
, cookielen
;
521 struct sockaddr_storage tmpclient
;
522 PACKET pkt
, msgpkt
, msgpayload
, session
, cookiepkt
;
524 /* Ensure there is no state left over from a previous invocation */
530 rbio
= SSL_get_rbio(s
);
531 wbio
= SSL_get_wbio(s
);
534 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_BIO_NOT_SET
);
539 * We only peek at incoming ClientHello's until we're sure we are going to
540 * to respond with a HelloVerifyRequest. If its a ClientHello with a valid
541 * cookie then we leave it in the BIO for dtls1_accept to handle.
543 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
546 * Note: This check deliberately excludes DTLS1_BAD_VER because that version
547 * requires the MAC to be calculated *including* the first ClientHello
548 * (without the cookie). Since DTLSv1_listen is stateless that cannot be
549 * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
552 if ((s
->version
& 0xff00) != (DTLS1_VERSION
& 0xff00)) {
553 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_UNSUPPORTED_SSL_VERSION
);
557 if (s
->init_buf
== NULL
) {
558 if ((bufm
= BUF_MEM_new()) == NULL
) {
559 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_MALLOC_FAILURE
);
563 if (!BUF_MEM_grow(bufm
, SSL3_RT_MAX_PLAIN_LENGTH
)) {
565 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_MALLOC_FAILURE
);
570 buf
= (unsigned char *)s
->init_buf
->data
;
577 * Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
578 * + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
579 * the record header as well, but we do here. We've set up init_buf to
580 * be the standard size for simplicity. In practice we shouldn't ever
581 * receive a ClientHello as long as this. If we do it will get dropped
582 * in the record length check below.
584 n
= BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
587 if(BIO_should_retry(rbio
)) {
588 /* Non-blocking IO */
594 /* If we hit any problems we need to clear this packet from the BIO */
597 if (!PACKET_buf_init(&pkt
, buf
, n
)) {
598 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_INTERNAL_ERROR
);
603 * Parse the received record. If there are any problems with it we just
604 * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
605 * resilient in the face of invalid records (e.g., invalid formatting,
606 * length, MAC, etc.). In general, invalid records SHOULD be silently
607 * discarded, thus preserving the association; however, an error MAY be
608 * logged for diagnostic purposes."
611 /* this packet contained a partial record, dump it */
612 if (n
< DTLS1_RT_HEADER_LENGTH
) {
613 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_RECORD_TOO_SMALL
);
618 s
->msg_callback(0, 0, SSL3_RT_HEADER
, buf
,
619 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
621 /* Get the record header */
622 if (!PACKET_get_1(&pkt
, &rectype
)
623 || !PACKET_get_1(&pkt
, &versmajor
)) {
624 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
628 if (rectype
!= SSL3_RT_HANDSHAKE
) {
629 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
634 * Check record version number. We only check that the major version is
637 if (versmajor
!= DTLS1_VERSION_MAJOR
) {
638 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_BAD_PROTOCOL_VERSION_NUMBER
);
642 if (!PACKET_forward(&pkt
, 1)
643 /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
644 || !PACKET_copy_bytes(&pkt
, seq
, SEQ_NUM_SIZE
)
645 || !PACKET_get_length_prefixed_2(&pkt
, &msgpkt
)
646 || PACKET_remaining(&pkt
) != 0) {
647 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
651 /* This is an initial ClientHello so the epoch has to be 0 */
652 if (seq
[0] != 0 || seq
[1] != 0) {
653 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
657 /* Get a pointer to the raw message for the later callback */
658 data
= PACKET_data(&msgpkt
);
660 /* Finished processing the record header, now process the message */
661 if (!PACKET_get_1(&msgpkt
, &msgtype
)
662 || !PACKET_get_net_3(&msgpkt
, &msglen
)
663 || !PACKET_get_net_2(&msgpkt
, &msgseq
)
664 || !PACKET_get_net_3(&msgpkt
, &fragoff
)
665 || !PACKET_get_net_3(&msgpkt
, &fraglen
)
666 || !PACKET_get_sub_packet(&msgpkt
, &msgpayload
, msglen
)
667 || PACKET_remaining(&msgpkt
) != 0) {
668 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
672 if (msgtype
!= SSL3_MT_CLIENT_HELLO
) {
673 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
677 /* Message sequence number can only be 0 or 1 */
679 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_INVALID_SEQUENCE_NUMBER
);
683 /* We don't support a fragmented ClientHello whilst listening */
684 if (fragoff
!= 0 || fraglen
!= msglen
) {
685 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_FRAGMENTED_CLIENT_HELLO
);
690 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
, data
,
691 msglen
+ DTLS1_HM_HEADER_LENGTH
, s
,
692 s
->msg_callback_arg
);
694 if (!PACKET_get_net_2(&msgpayload
, &clientvers
)) {
695 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
700 * Verify client version is supported
702 if ((clientvers
> (unsigned int)s
->method
->version
&&
703 s
->method
->version
!= DTLS_ANY_VERSION
)) {
704 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_WRONG_VERSION_NUMBER
);
708 if (!PACKET_forward(&msgpayload
, SSL3_RANDOM_SIZE
)
709 || !PACKET_get_length_prefixed_1(&msgpayload
, &session
)
710 || !PACKET_get_length_prefixed_1(&msgpayload
, &cookiepkt
)) {
711 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
716 * Check if we have a cookie or not. If not we need to send a
717 * HelloVerifyRequest.
719 if (PACKET_remaining(&cookiepkt
) == 0) {
720 next
= LISTEN_SEND_VERIFY_REQUEST
;
723 * We have a cookie, so lets check it.
725 if (s
->ctx
->app_verify_cookie_cb
== NULL
) {
726 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_NO_VERIFY_COOKIE_CALLBACK
);
730 if (s
->ctx
->app_verify_cookie_cb(s
, PACKET_data(&cookiepkt
),
731 PACKET_remaining(&cookiepkt
)) ==
734 * We treat invalid cookies in the same was as no cookie as
737 next
= LISTEN_SEND_VERIFY_REQUEST
;
739 /* Cookie verification succeeded */
740 next
= LISTEN_SUCCESS
;
744 if (next
== LISTEN_SEND_VERIFY_REQUEST
) {
746 * There was no cookie in the ClientHello so we need to send a
747 * HelloVerifyRequest. If this fails we do not worry about trying
748 * to resend, we just drop it.
752 * Dump the read packet, we don't need it any more. Ignore return
755 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
756 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
757 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
759 /* Generate the cookie */
760 if (s
->ctx
->app_gen_cookie_cb
== NULL
||
761 s
->ctx
->app_gen_cookie_cb(s
, cookie
, &cookielen
) == 0 ||
763 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_COOKIE_GEN_CALLBACK_FAILURE
);
768 p
= &buf
[DTLS1_RT_HEADER_LENGTH
];
769 msglen
= dtls_raw_hello_verify_request(p
+ DTLS1_HM_HEADER_LENGTH
,
772 *p
++ = DTLS1_MT_HELLO_VERIFY_REQUEST
;
777 /* Message sequence number is always 0 for a HelloVerifyRequest */
781 * We never fragment a HelloVerifyRequest, so fragment offset is 0
782 * and fragment length is message length
787 /* Set reclen equal to length of whole handshake message */
788 reclen
= msglen
+ DTLS1_HM_HEADER_LENGTH
;
790 /* Add the record header */
793 *(p
++) = SSL3_RT_HANDSHAKE
;
795 * Special case: for hello verify request, client version 1.0 and we
796 * haven't decided which version to use yet send back using version
797 * 1.0 header: otherwise some clients will ignore it.
799 if (s
->method
->version
== DTLS_ANY_VERSION
) {
800 *(p
++) = DTLS1_VERSION
>> 8;
801 *(p
++) = DTLS1_VERSION
& 0xff;
803 *(p
++) = s
->version
>> 8;
804 *(p
++) = s
->version
& 0xff;
808 * Record sequence number is always the same as in the received
811 memcpy(p
, seq
, SEQ_NUM_SIZE
);
818 * Set reclen equal to length of whole record including record
821 reclen
+= DTLS1_RT_HEADER_LENGTH
;
824 s
->msg_callback(1, 0, SSL3_RT_HEADER
, buf
,
825 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
828 * This is unneccessary if rbio and wbio are one and the same - but
831 if(BIO_dgram_get_peer(rbio
, &tmpclient
) <= 0
832 || BIO_dgram_set_peer(wbio
, &tmpclient
) <= 0) {
833 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_INTERNAL_ERROR
);
837 if (BIO_write(wbio
, buf
, reclen
) < (int)reclen
) {
838 if(BIO_should_retry(wbio
)) {
840 * Non-blocking IO...but we're stateless, so we're just
841 * going to drop this packet.
848 if (BIO_flush(wbio
) <= 0) {
849 if(BIO_should_retry(wbio
)) {
851 * Non-blocking IO...but we're stateless, so we're just
852 * going to drop this packet.
859 } while (next
!= LISTEN_SUCCESS
);
862 * Set expected sequence numbers to continue the handshake.
864 s
->d1
->handshake_read_seq
= 1;
865 s
->d1
->handshake_write_seq
= 1;
866 s
->d1
->next_handshake_write_seq
= 1;
867 DTLS_RECORD_LAYER_set_write_sequence(&s
->rlayer
, seq
);
870 * We are doing cookie exchange, so make sure we set that option in the
873 SSL_set_options(s
, SSL_OP_COOKIE_EXCHANGE
);
876 * Tell the state machine that we've done the initial hello verify
879 ossl_statem_set_hello_verify_done(s
);
881 if(BIO_dgram_get_peer(rbio
, client
) <= 0) {
882 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_INTERNAL_ERROR
);
889 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
891 /* Dump this packet. Ignore return value */
892 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
897 static int dtls1_set_handshake_header(SSL
*s
, int htype
, unsigned long len
)
899 unsigned char *p
= (unsigned char *)s
->init_buf
->data
;
900 dtls1_set_message_header(s
, p
, htype
, len
, 0, len
);
901 s
->init_num
= (int)len
+ DTLS1_HM_HEADER_LENGTH
;
903 /* Buffer the message to handle re-xmits */
905 if (!dtls1_buffer_message(s
, 0))
911 static int dtls1_handshake_write(SSL
*s
)
913 return dtls1_do_write(s
, SSL3_RT_HANDSHAKE
);
916 #ifndef OPENSSL_NO_HEARTBEATS
917 int dtls1_process_heartbeat(SSL
*s
, unsigned char *p
, unsigned int length
)
920 unsigned short hbtype
;
921 unsigned int payload
;
922 unsigned int padding
= 16; /* Use minimum padding */
925 s
->msg_callback(0, s
->version
, TLS1_RT_HEARTBEAT
,
926 p
, length
, s
, s
->msg_callback_arg
);
928 /* Read type and payload length first */
929 if (1 + 2 + 16 > length
)
930 return 0; /* silently discard */
931 if (length
> SSL3_RT_MAX_PLAIN_LENGTH
)
932 return 0; /* silently discard per RFC 6520 sec. 4 */
936 if (1 + 2 + payload
+ 16 > length
)
937 return 0; /* silently discard per RFC 6520 sec. 4 */
940 if (hbtype
== TLS1_HB_REQUEST
) {
941 unsigned char *buffer
, *bp
;
942 unsigned int write_length
= 1 /* heartbeat type */ +
943 2 /* heartbeat length */ +
947 if (write_length
> SSL3_RT_MAX_PLAIN_LENGTH
)
951 * Allocate memory for the response, size is 1 byte message type,
952 * plus 2 bytes payload length, plus payload, plus padding
954 buffer
= OPENSSL_malloc(write_length
);
959 /* Enter response type, length and copy payload */
960 *bp
++ = TLS1_HB_RESPONSE
;
962 memcpy(bp
, pl
, payload
);
965 if (RAND_bytes(bp
, padding
) <= 0) {
966 OPENSSL_free(buffer
);
970 r
= dtls1_write_bytes(s
, TLS1_RT_HEARTBEAT
, buffer
, write_length
);
972 if (r
>= 0 && s
->msg_callback
)
973 s
->msg_callback(1, s
->version
, TLS1_RT_HEARTBEAT
,
974 buffer
, write_length
, s
, s
->msg_callback_arg
);
976 OPENSSL_free(buffer
);
980 } else if (hbtype
== TLS1_HB_RESPONSE
) {
984 * We only send sequence numbers (2 bytes unsigned int), and 16
985 * random bytes, so we just try to read the sequence number
989 if (payload
== 18 && seq
== s
->tlsext_hb_seq
) {
992 s
->tlsext_hb_pending
= 0;
999 int dtls1_heartbeat(SSL
*s
)
1001 unsigned char *buf
, *p
;
1003 unsigned int payload
= 18; /* Sequence number + random bytes */
1004 unsigned int padding
= 16; /* Use minimum padding */
1006 /* Only send if peer supports and accepts HB requests... */
1007 if (!(s
->tlsext_heartbeat
& SSL_TLSEXT_HB_ENABLED
) ||
1008 s
->tlsext_heartbeat
& SSL_TLSEXT_HB_DONT_SEND_REQUESTS
) {
1009 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT
);
1013 /* ...and there is none in flight yet... */
1014 if (s
->tlsext_hb_pending
) {
1015 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PENDING
);
1019 /* ...and no handshake in progress. */
1020 if (SSL_in_init(s
) || s
->in_handshake
) {
1021 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_UNEXPECTED_MESSAGE
);
1026 * Check if padding is too long, payload and padding must not exceed 2^14
1027 * - 3 = 16381 bytes in total.
1029 OPENSSL_assert(payload
+ padding
<= 16381);
1032 * Create HeartBeat message, we just use a sequence number
1033 * as payload to distuingish different messages and add
1034 * some random stuff.
1035 * - Message Type, 1 byte
1036 * - Payload Length, 2 bytes (unsigned int)
1037 * - Payload, the sequence number (2 bytes uint)
1038 * - Payload, random bytes (16 bytes uint)
1041 buf
= OPENSSL_malloc(1 + 2 + payload
+ padding
);
1043 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_MALLOC_FAILURE
);
1048 *p
++ = TLS1_HB_REQUEST
;
1049 /* Payload length (18 bytes here) */
1051 /* Sequence number */
1052 s2n(s
->tlsext_hb_seq
, p
);
1053 /* 16 random bytes */
1054 if (RAND_bytes(p
, 16) <= 0) {
1055 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1059 /* Random padding */
1060 if (RAND_bytes(p
, padding
) <= 0) {
1061 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1065 ret
= dtls1_write_bytes(s
, TLS1_RT_HEARTBEAT
, buf
, 3 + payload
+ padding
);
1067 if (s
->msg_callback
)
1068 s
->msg_callback(1, s
->version
, TLS1_RT_HEARTBEAT
,
1069 buf
, 3 + payload
+ padding
,
1070 s
, s
->msg_callback_arg
);
1072 dtls1_start_timer(s
);
1073 s
->tlsext_hb_pending
= 1;
1083 int dtls1_shutdown(SSL
*s
)
1086 #ifndef OPENSSL_NO_SCTP
1089 wbio
= SSL_get_wbio(s
);
1090 if (wbio
!= NULL
&& BIO_dgram_is_sctp(wbio
) &&
1091 !(s
->shutdown
& SSL_SENT_SHUTDOWN
)) {
1092 ret
= BIO_dgram_sctp_wait_for_dry(wbio
);
1097 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 1,
1101 ret
= ssl3_shutdown(s
);
1102 #ifndef OPENSSL_NO_SCTP
1103 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 0, NULL
);
1108 int dtls1_query_mtu(SSL
*s
)
1110 if (s
->d1
->link_mtu
) {
1112 s
->d1
->link_mtu
- BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
1113 s
->d1
->link_mtu
= 0;
1116 /* AHA! Figure out the MTU, and stick to the right size */
1117 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1118 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
1120 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_QUERY_MTU
, 0, NULL
);
1123 * I've seen the kernel return bogus numbers when it doesn't know
1124 * (initial write), so just make sure we have a reasonable number
1126 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1127 /* Set to min mtu */
1128 s
->d1
->mtu
= dtls1_min_mtu(s
);
1129 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SET_MTU
,
1138 unsigned int dtls1_link_min_mtu(void)
1140 return (g_probable_mtu
[(sizeof(g_probable_mtu
) /
1141 sizeof(g_probable_mtu
[0])) - 1]);
1144 unsigned int dtls1_min_mtu(SSL
*s
)
1146 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));