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
);
80 static unsigned int dtls1_link_min_mtu(void);
82 /* XDTLS: figure out the right values */
83 static const unsigned int g_probable_mtu
[] = { 1500, 512, 256 };
85 const SSL3_ENC_METHOD DTLSv1_enc_data
= {
89 tls1_generate_master_secret
,
90 tls1_change_cipher_state
,
91 tls1_final_finish_mac
,
92 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 TLS_MD_CLIENT_FINISH_CONST
, TLS_MD_CLIENT_FINISH_CONST_SIZE
,
112 TLS_MD_SERVER_FINISH_CONST
, TLS_MD_SERVER_FINISH_CONST_SIZE
,
114 tls1_export_keying_material
,
115 SSL_ENC_FLAG_DTLS
| SSL_ENC_FLAG_EXPLICIT_IV
| SSL_ENC_FLAG_SIGALGS
116 | SSL_ENC_FLAG_SHA256_PRF
| SSL_ENC_FLAG_TLS1_2_CIPHERS
,
117 DTLS1_HM_HEADER_LENGTH
,
118 dtls1_set_handshake_header
,
119 dtls1_handshake_write
122 long dtls1_default_timeout(void)
125 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
126 * http, the cache would over fill
128 return (60 * 60 * 2);
131 int dtls1_new(SSL
*s
)
135 if (!DTLS_RECORD_LAYER_new(&s
->rlayer
)) {
141 if ((d1
= OPENSSL_zalloc(sizeof(*d1
))) == NULL
) {
146 d1
->buffered_messages
= pqueue_new();
147 d1
->sent_messages
= pqueue_new();
150 d1
->cookie_len
= sizeof(s
->d1
->cookie
);
156 if (d1
->buffered_messages
== NULL
|| d1
->sent_messages
== NULL
) {
157 pqueue_free(d1
->buffered_messages
);
158 pqueue_free(d1
->sent_messages
);
165 s
->method
->ssl_clear(s
);
169 static void dtls1_clear_queues(SSL
*s
)
172 hm_fragment
*frag
= NULL
;
174 while ((item
= pqueue_pop(s
->d1
->buffered_messages
)) != NULL
) {
175 frag
= (hm_fragment
*)item
->data
;
176 dtls1_hm_fragment_free(frag
);
180 while ((item
= pqueue_pop(s
->d1
->sent_messages
)) != NULL
) {
181 frag
= (hm_fragment
*)item
->data
;
182 dtls1_hm_fragment_free(frag
);
187 void dtls1_free(SSL
*s
)
189 DTLS_RECORD_LAYER_free(&s
->rlayer
);
193 dtls1_clear_queues(s
);
195 pqueue_free(s
->d1
->buffered_messages
);
196 pqueue_free(s
->d1
->sent_messages
);
202 void dtls1_clear(SSL
*s
)
204 pqueue
*buffered_messages
;
205 pqueue
*sent_messages
;
207 unsigned int link_mtu
;
209 DTLS_RECORD_LAYER_clear(&s
->rlayer
);
212 buffered_messages
= s
->d1
->buffered_messages
;
213 sent_messages
= s
->d1
->sent_messages
;
215 link_mtu
= s
->d1
->link_mtu
;
217 dtls1_clear_queues(s
);
219 memset(s
->d1
, 0, sizeof(*s
->d1
));
222 s
->d1
->cookie_len
= sizeof(s
->d1
->cookie
);
225 if (SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
) {
227 s
->d1
->link_mtu
= link_mtu
;
230 s
->d1
->buffered_messages
= buffered_messages
;
231 s
->d1
->sent_messages
= sent_messages
;
235 if (s
->options
& SSL_OP_CISCO_ANYCONNECT
)
236 s
->client_version
= s
->version
= DTLS1_BAD_VER
;
237 else if (s
->method
->version
== DTLS_ANY_VERSION
)
238 s
->version
= DTLS_MAX_VERSION
;
240 s
->version
= s
->method
->version
;
243 long dtls1_ctrl(SSL
*s
, int cmd
, long larg
, void *parg
)
248 case DTLS_CTRL_GET_TIMEOUT
:
249 if (dtls1_get_timeout(s
, (struct timeval
*)parg
) != NULL
) {
253 case DTLS_CTRL_HANDLE_TIMEOUT
:
254 ret
= dtls1_handle_timeout(s
);
256 case DTLS_CTRL_LISTEN
:
257 ret
= dtls1_listen(s
, parg
);
259 case DTLS_CTRL_SET_LINK_MTU
:
260 if (larg
< (long)dtls1_link_min_mtu())
262 s
->d1
->link_mtu
= larg
;
264 case DTLS_CTRL_GET_LINK_MIN_MTU
:
265 return (long)dtls1_link_min_mtu();
266 case SSL_CTRL_SET_MTU
:
268 * We may not have a BIO set yet so can't call dtls1_min_mtu()
269 * We'll have to make do with dtls1_link_min_mtu() and max overhead
271 if (larg
< (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD
)
276 ret
= ssl3_ctrl(s
, cmd
, larg
, parg
);
283 * As it's impossible to use stream ciphers in "datagram" mode, this
284 * simple filter is designed to disengage them in DTLS. Unfortunately
285 * there is no universal way to identify stream SSL_CIPHER, so we have
286 * to explicitly list their SSL_* codes. Currently RC4 is the only one
287 * available, but if new ones emerge, they will have to be added...
289 const SSL_CIPHER
*dtls1_get_cipher(unsigned int u
)
291 const SSL_CIPHER
*ciph
= ssl3_get_cipher(u
);
294 if (ciph
->algorithm_enc
== SSL_RC4
)
301 void dtls1_start_timer(SSL
*s
)
303 #ifndef OPENSSL_NO_SCTP
304 /* Disable timer for SCTP */
305 if (BIO_dgram_is_sctp(SSL_get_wbio(s
))) {
306 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
311 /* If timer is not set, initialize duration with 1 second */
312 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
313 s
->d1
->timeout_duration
= 1;
316 /* Set timeout to current time */
317 get_current_time(&(s
->d1
->next_timeout
));
319 /* Add duration to current time */
320 s
->d1
->next_timeout
.tv_sec
+= s
->d1
->timeout_duration
;
321 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
322 &(s
->d1
->next_timeout
));
325 struct timeval
*dtls1_get_timeout(SSL
*s
, struct timeval
*timeleft
)
327 struct timeval timenow
;
329 /* If no timeout is set, just return NULL */
330 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
334 /* Get current time */
335 get_current_time(&timenow
);
337 /* If timer already expired, set remaining time to 0 */
338 if (s
->d1
->next_timeout
.tv_sec
< timenow
.tv_sec
||
339 (s
->d1
->next_timeout
.tv_sec
== timenow
.tv_sec
&&
340 s
->d1
->next_timeout
.tv_usec
<= timenow
.tv_usec
)) {
341 memset(timeleft
, 0, sizeof(*timeleft
));
345 /* Calculate time left until timer expires */
346 memcpy(timeleft
, &(s
->d1
->next_timeout
), sizeof(struct timeval
));
347 timeleft
->tv_sec
-= timenow
.tv_sec
;
348 timeleft
->tv_usec
-= timenow
.tv_usec
;
349 if (timeleft
->tv_usec
< 0) {
351 timeleft
->tv_usec
+= 1000000;
355 * If remaining time is less than 15 ms, set it to 0 to prevent issues
356 * because of small devergences with socket timeouts.
358 if (timeleft
->tv_sec
== 0 && timeleft
->tv_usec
< 15000) {
359 memset(timeleft
, 0, sizeof(*timeleft
));
365 int dtls1_is_timer_expired(SSL
*s
)
367 struct timeval timeleft
;
369 /* Get time left until timeout, return false if no timer running */
370 if (dtls1_get_timeout(s
, &timeleft
) == NULL
) {
374 /* Return false if timer is not expired yet */
375 if (timeleft
.tv_sec
> 0 || timeleft
.tv_usec
> 0) {
379 /* Timer expired, so return true */
383 void dtls1_double_timeout(SSL
*s
)
385 s
->d1
->timeout_duration
*= 2;
386 if (s
->d1
->timeout_duration
> 60)
387 s
->d1
->timeout_duration
= 60;
388 dtls1_start_timer(s
);
391 void dtls1_stop_timer(SSL
*s
)
393 /* Reset everything */
394 memset(&s
->d1
->timeout
, 0, sizeof(s
->d1
->timeout
));
395 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
396 s
->d1
->timeout_duration
= 1;
397 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
398 &(s
->d1
->next_timeout
));
399 /* Clear retransmission buffer */
400 dtls1_clear_record_buffer(s
);
403 int dtls1_check_timeout_num(SSL
*s
)
407 s
->d1
->timeout
.num_alerts
++;
409 /* Reduce MTU after 2 unsuccessful retransmissions */
410 if (s
->d1
->timeout
.num_alerts
> 2
411 && !(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
413 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_GET_FALLBACK_MTU
, 0,
415 if (mtu
< s
->d1
->mtu
)
419 if (s
->d1
->timeout
.num_alerts
> DTLS1_TMO_ALERT_COUNT
) {
420 /* fail the connection, enough alerts have been sent */
421 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM
, SSL_R_READ_TIMEOUT_EXPIRED
);
428 int dtls1_handle_timeout(SSL
*s
)
430 /* if no timer is expired, don't do anything */
431 if (!dtls1_is_timer_expired(s
)) {
435 dtls1_double_timeout(s
);
437 if (dtls1_check_timeout_num(s
) < 0)
440 s
->d1
->timeout
.read_timeouts
++;
441 if (s
->d1
->timeout
.read_timeouts
> DTLS1_TMO_READ_COUNT
) {
442 s
->d1
->timeout
.read_timeouts
= 1;
444 #ifndef OPENSSL_NO_HEARTBEATS
445 if (s
->tlsext_hb_pending
) {
446 s
->tlsext_hb_pending
= 0;
447 return dtls1_heartbeat(s
);
451 dtls1_start_timer(s
);
452 return dtls1_retransmit_buffered_messages(s
);
455 static void get_current_time(struct timeval
*t
)
465 SystemTimeToFileTime(&st
, &now
.ft
);
467 now
.ul
-= 116444736000000000ULL;
469 now
.ul
-= 116444736000000000UI
64; /* re-bias to 1/1/1970 */
471 t
->tv_sec
= (long)(now
.ul
/ 10000000);
472 t
->tv_usec
= ((int)(now
.ul
% 10000000)) / 10;
473 #elif defined(OPENSSL_SYS_VMS)
476 t
->tv_sec
= (long)tb
.time
;
477 t
->tv_usec
= (long)tb
.millitm
* 1000;
479 gettimeofday(t
, NULL
);
484 #define LISTEN_SUCCESS 2
485 #define LISTEN_SEND_VERIFY_REQUEST 1
488 int dtls1_listen(SSL
*s
, struct sockaddr
*client
)
490 int next
, n
, ret
= 0, clearpkt
= 0;
491 unsigned char cookie
[DTLS1_COOKIE_LENGTH
];
492 unsigned char seq
[SEQ_NUM_SIZE
];
493 unsigned char *data
, *p
, *buf
;
494 unsigned long reclen
, fragoff
, fraglen
, msglen
;
495 unsigned int rectype
, versmajor
, msgseq
, msgtype
, clientvers
, cookielen
;
498 struct sockaddr_storage tmpclient
;
499 PACKET pkt
, msgpkt
, msgpayload
, session
, cookiepkt
;
501 /* Ensure there is no state left over from a previous invocation */
507 rbio
= SSL_get_rbio(s
);
508 wbio
= SSL_get_wbio(s
);
511 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_BIO_NOT_SET
);
516 * We only peek at incoming ClientHello's until we're sure we are going to
517 * to respond with a HelloVerifyRequest. If its a ClientHello with a valid
518 * cookie then we leave it in the BIO for accept to handle.
520 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
523 * Note: This check deliberately excludes DTLS1_BAD_VER because that version
524 * requires the MAC to be calculated *including* the first ClientHello
525 * (without the cookie). Since DTLSv1_listen is stateless that cannot be
526 * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
529 if ((s
->version
& 0xff00) != (DTLS1_VERSION
& 0xff00)) {
530 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_UNSUPPORTED_SSL_VERSION
);
534 if (s
->init_buf
== NULL
) {
535 if ((bufm
= BUF_MEM_new()) == NULL
) {
536 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_MALLOC_FAILURE
);
540 if (!BUF_MEM_grow(bufm
, SSL3_RT_MAX_PLAIN_LENGTH
)) {
542 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_MALLOC_FAILURE
);
547 buf
= (unsigned char *)s
->init_buf
->data
;
554 * Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
555 * + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
556 * the record header as well, but we do here. We've set up init_buf to
557 * be the standard size for simplicity. In practice we shouldn't ever
558 * receive a ClientHello as long as this. If we do it will get dropped
559 * in the record length check below.
561 n
= BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
564 if(BIO_should_retry(rbio
)) {
565 /* Non-blocking IO */
571 /* If we hit any problems we need to clear this packet from the BIO */
574 if (!PACKET_buf_init(&pkt
, buf
, n
)) {
575 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_INTERNAL_ERROR
);
580 * Parse the received record. If there are any problems with it we just
581 * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
582 * resilient in the face of invalid records (e.g., invalid formatting,
583 * length, MAC, etc.). In general, invalid records SHOULD be silently
584 * discarded, thus preserving the association; however, an error MAY be
585 * logged for diagnostic purposes."
588 /* this packet contained a partial record, dump it */
589 if (n
< DTLS1_RT_HEADER_LENGTH
) {
590 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_RECORD_TOO_SMALL
);
595 s
->msg_callback(0, 0, SSL3_RT_HEADER
, buf
,
596 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
598 /* Get the record header */
599 if (!PACKET_get_1(&pkt
, &rectype
)
600 || !PACKET_get_1(&pkt
, &versmajor
)) {
601 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
605 if (rectype
!= SSL3_RT_HANDSHAKE
) {
606 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
611 * Check record version number. We only check that the major version is
614 if (versmajor
!= DTLS1_VERSION_MAJOR
) {
615 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_BAD_PROTOCOL_VERSION_NUMBER
);
619 if (!PACKET_forward(&pkt
, 1)
620 /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
621 || !PACKET_copy_bytes(&pkt
, seq
, SEQ_NUM_SIZE
)
622 || !PACKET_get_length_prefixed_2(&pkt
, &msgpkt
)
623 || PACKET_remaining(&pkt
) != 0) {
624 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
628 /* This is an initial ClientHello so the epoch has to be 0 */
629 if (seq
[0] != 0 || seq
[1] != 0) {
630 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
634 /* Get a pointer to the raw message for the later callback */
635 data
= PACKET_data(&msgpkt
);
637 /* Finished processing the record header, now process the message */
638 if (!PACKET_get_1(&msgpkt
, &msgtype
)
639 || !PACKET_get_net_3(&msgpkt
, &msglen
)
640 || !PACKET_get_net_2(&msgpkt
, &msgseq
)
641 || !PACKET_get_net_3(&msgpkt
, &fragoff
)
642 || !PACKET_get_net_3(&msgpkt
, &fraglen
)
643 || !PACKET_get_sub_packet(&msgpkt
, &msgpayload
, msglen
)
644 || PACKET_remaining(&msgpkt
) != 0) {
645 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
649 if (msgtype
!= SSL3_MT_CLIENT_HELLO
) {
650 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
654 /* Message sequence number can only be 0 or 1 */
656 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_INVALID_SEQUENCE_NUMBER
);
660 /* We don't support a fragmented ClientHello whilst listening */
661 if (fragoff
!= 0 || fraglen
!= msglen
) {
662 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_FRAGMENTED_CLIENT_HELLO
);
667 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
, data
,
668 msglen
+ DTLS1_HM_HEADER_LENGTH
, s
,
669 s
->msg_callback_arg
);
671 if (!PACKET_get_net_2(&msgpayload
, &clientvers
)) {
672 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
677 * Verify client version is supported
679 if (DTLS_VERSION_LT(clientvers
, (unsigned int)s
->method
->version
) &&
680 s
->method
->version
!= DTLS_ANY_VERSION
) {
681 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_WRONG_VERSION_NUMBER
);
685 if (!PACKET_forward(&msgpayload
, SSL3_RANDOM_SIZE
)
686 || !PACKET_get_length_prefixed_1(&msgpayload
, &session
)
687 || !PACKET_get_length_prefixed_1(&msgpayload
, &cookiepkt
)) {
688 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
693 * Check if we have a cookie or not. If not we need to send a
694 * HelloVerifyRequest.
696 if (PACKET_remaining(&cookiepkt
) == 0) {
697 next
= LISTEN_SEND_VERIFY_REQUEST
;
700 * We have a cookie, so lets check it.
702 if (s
->ctx
->app_verify_cookie_cb
== NULL
) {
703 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_NO_VERIFY_COOKIE_CALLBACK
);
707 if (s
->ctx
->app_verify_cookie_cb(s
, PACKET_data(&cookiepkt
),
708 PACKET_remaining(&cookiepkt
)) ==
711 * We treat invalid cookies in the same was as no cookie as
714 next
= LISTEN_SEND_VERIFY_REQUEST
;
716 /* Cookie verification succeeded */
717 next
= LISTEN_SUCCESS
;
721 if (next
== LISTEN_SEND_VERIFY_REQUEST
) {
723 * There was no cookie in the ClientHello so we need to send a
724 * HelloVerifyRequest. If this fails we do not worry about trying
725 * to resend, we just drop it.
729 * Dump the read packet, we don't need it any more. Ignore return
732 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
733 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
734 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
736 /* Generate the cookie */
737 if (s
->ctx
->app_gen_cookie_cb
== NULL
||
738 s
->ctx
->app_gen_cookie_cb(s
, cookie
, &cookielen
) == 0 ||
740 SSLerr(SSL_F_DTLS1_LISTEN
, SSL_R_COOKIE_GEN_CALLBACK_FAILURE
);
745 p
= &buf
[DTLS1_RT_HEADER_LENGTH
];
746 msglen
= dtls_raw_hello_verify_request(p
+ DTLS1_HM_HEADER_LENGTH
,
749 *p
++ = DTLS1_MT_HELLO_VERIFY_REQUEST
;
754 /* Message sequence number is always 0 for a HelloVerifyRequest */
758 * We never fragment a HelloVerifyRequest, so fragment offset is 0
759 * and fragment length is message length
764 /* Set reclen equal to length of whole handshake message */
765 reclen
= msglen
+ DTLS1_HM_HEADER_LENGTH
;
767 /* Add the record header */
770 *(p
++) = SSL3_RT_HANDSHAKE
;
772 * Special case: for hello verify request, client version 1.0 and we
773 * haven't decided which version to use yet send back using version
774 * 1.0 header: otherwise some clients will ignore it.
776 if (s
->method
->version
== DTLS_ANY_VERSION
) {
777 *(p
++) = DTLS1_VERSION
>> 8;
778 *(p
++) = DTLS1_VERSION
& 0xff;
780 *(p
++) = s
->version
>> 8;
781 *(p
++) = s
->version
& 0xff;
785 * Record sequence number is always the same as in the received
788 memcpy(p
, seq
, SEQ_NUM_SIZE
);
795 * Set reclen equal to length of whole record including record
798 reclen
+= DTLS1_RT_HEADER_LENGTH
;
801 s
->msg_callback(1, 0, SSL3_RT_HEADER
, buf
,
802 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
805 * This is unneccessary if rbio and wbio are one and the same - but
808 if(BIO_dgram_get_peer(rbio
, &tmpclient
) <= 0
809 || BIO_dgram_set_peer(wbio
, &tmpclient
) <= 0) {
810 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_INTERNAL_ERROR
);
814 if (BIO_write(wbio
, buf
, reclen
) < (int)reclen
) {
815 if(BIO_should_retry(wbio
)) {
817 * Non-blocking IO...but we're stateless, so we're just
818 * going to drop this packet.
825 if (BIO_flush(wbio
) <= 0) {
826 if(BIO_should_retry(wbio
)) {
828 * Non-blocking IO...but we're stateless, so we're just
829 * going to drop this packet.
836 } while (next
!= LISTEN_SUCCESS
);
839 * Set expected sequence numbers to continue the handshake.
841 s
->d1
->handshake_read_seq
= 1;
842 s
->d1
->handshake_write_seq
= 1;
843 s
->d1
->next_handshake_write_seq
= 1;
844 DTLS_RECORD_LAYER_set_write_sequence(&s
->rlayer
, seq
);
847 * We are doing cookie exchange, so make sure we set that option in the
850 SSL_set_options(s
, SSL_OP_COOKIE_EXCHANGE
);
853 * Tell the state machine that we've done the initial hello verify
856 ossl_statem_set_hello_verify_done(s
);
858 if(BIO_dgram_get_peer(rbio
, client
) <= 0) {
859 SSLerr(SSL_F_DTLS1_LISTEN
, ERR_R_INTERNAL_ERROR
);
866 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
868 /* Dump this packet. Ignore return value */
869 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
874 static int dtls1_set_handshake_header(SSL
*s
, int htype
, unsigned long len
)
876 unsigned char *p
= (unsigned char *)s
->init_buf
->data
;
877 dtls1_set_message_header(s
, p
, htype
, len
, 0, len
);
878 s
->init_num
= (int)len
+ DTLS1_HM_HEADER_LENGTH
;
880 /* Buffer the message to handle re-xmits */
882 if (!dtls1_buffer_message(s
, 0))
888 static int dtls1_handshake_write(SSL
*s
)
890 return dtls1_do_write(s
, SSL3_RT_HANDSHAKE
);
893 #ifndef OPENSSL_NO_HEARTBEATS
894 int dtls1_process_heartbeat(SSL
*s
, unsigned char *p
, unsigned int length
)
897 unsigned short hbtype
;
898 unsigned int payload
;
899 unsigned int padding
= 16; /* Use minimum padding */
902 s
->msg_callback(0, s
->version
, TLS1_RT_HEARTBEAT
,
903 p
, length
, s
, s
->msg_callback_arg
);
905 /* Read type and payload length first */
906 if (1 + 2 + 16 > length
)
907 return 0; /* silently discard */
908 if (length
> SSL3_RT_MAX_PLAIN_LENGTH
)
909 return 0; /* silently discard per RFC 6520 sec. 4 */
913 if (1 + 2 + payload
+ 16 > length
)
914 return 0; /* silently discard per RFC 6520 sec. 4 */
917 if (hbtype
== TLS1_HB_REQUEST
) {
918 unsigned char *buffer
, *bp
;
919 unsigned int write_length
= 1 /* heartbeat type */ +
920 2 /* heartbeat length */ +
924 if (write_length
> SSL3_RT_MAX_PLAIN_LENGTH
)
928 * Allocate memory for the response, size is 1 byte message type,
929 * plus 2 bytes payload length, plus payload, plus padding
931 buffer
= OPENSSL_malloc(write_length
);
936 /* Enter response type, length and copy payload */
937 *bp
++ = TLS1_HB_RESPONSE
;
939 memcpy(bp
, pl
, payload
);
942 if (RAND_bytes(bp
, padding
) <= 0) {
943 OPENSSL_free(buffer
);
947 r
= dtls1_write_bytes(s
, TLS1_RT_HEARTBEAT
, buffer
, write_length
);
949 if (r
>= 0 && s
->msg_callback
)
950 s
->msg_callback(1, s
->version
, TLS1_RT_HEARTBEAT
,
951 buffer
, write_length
, s
, s
->msg_callback_arg
);
953 OPENSSL_free(buffer
);
957 } else if (hbtype
== TLS1_HB_RESPONSE
) {
961 * We only send sequence numbers (2 bytes unsigned int), and 16
962 * random bytes, so we just try to read the sequence number
966 if (payload
== 18 && seq
== s
->tlsext_hb_seq
) {
969 s
->tlsext_hb_pending
= 0;
976 int dtls1_heartbeat(SSL
*s
)
978 unsigned char *buf
, *p
;
980 unsigned int payload
= 18; /* Sequence number + random bytes */
981 unsigned int padding
= 16; /* Use minimum padding */
983 /* Only send if peer supports and accepts HB requests... */
984 if (!(s
->tlsext_heartbeat
& SSL_TLSEXT_HB_ENABLED
) ||
985 s
->tlsext_heartbeat
& SSL_TLSEXT_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.
1006 * - Message Type, 1 byte
1007 * - Payload Length, 2 bytes (unsigned int)
1008 * - Payload, the sequence number (2 bytes uint)
1009 * - Payload, random bytes (16 bytes uint)
1012 buf
= OPENSSL_malloc(1 + 2 + payload
+ padding
);
1014 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_MALLOC_FAILURE
);
1019 *p
++ = TLS1_HB_REQUEST
;
1020 /* Payload length (18 bytes here) */
1022 /* Sequence number */
1023 s2n(s
->tlsext_hb_seq
, p
);
1024 /* 16 random bytes */
1025 if (RAND_bytes(p
, 16) <= 0) {
1026 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1030 /* Random padding */
1031 if (RAND_bytes(p
, padding
) <= 0) {
1032 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1036 ret
= dtls1_write_bytes(s
, TLS1_RT_HEARTBEAT
, buf
, 3 + payload
+ padding
);
1038 if (s
->msg_callback
)
1039 s
->msg_callback(1, s
->version
, TLS1_RT_HEARTBEAT
,
1040 buf
, 3 + payload
+ padding
,
1041 s
, s
->msg_callback_arg
);
1043 dtls1_start_timer(s
);
1044 s
->tlsext_hb_pending
= 1;
1054 int dtls1_shutdown(SSL
*s
)
1057 #ifndef OPENSSL_NO_SCTP
1060 wbio
= SSL_get_wbio(s
);
1061 if (wbio
!= NULL
&& BIO_dgram_is_sctp(wbio
) &&
1062 !(s
->shutdown
& SSL_SENT_SHUTDOWN
)) {
1063 ret
= BIO_dgram_sctp_wait_for_dry(wbio
);
1068 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 1,
1072 ret
= ssl3_shutdown(s
);
1073 #ifndef OPENSSL_NO_SCTP
1074 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 0, NULL
);
1079 int dtls1_query_mtu(SSL
*s
)
1081 if (s
->d1
->link_mtu
) {
1083 s
->d1
->link_mtu
- BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
1084 s
->d1
->link_mtu
= 0;
1087 /* AHA! Figure out the MTU, and stick to the right size */
1088 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1089 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
1091 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_QUERY_MTU
, 0, NULL
);
1094 * I've seen the kernel return bogus numbers when it doesn't know
1095 * (initial write), so just make sure we have a reasonable number
1097 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1098 /* Set to min mtu */
1099 s
->d1
->mtu
= dtls1_min_mtu(s
);
1100 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SET_MTU
,
1109 static unsigned int dtls1_link_min_mtu(void)
1111 return (g_probable_mtu
[(sizeof(g_probable_mtu
) /
1112 sizeof(g_probable_mtu
[0])) - 1]);
1115 unsigned int dtls1_min_mtu(SSL
*s
)
1117 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));