2 * Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
12 #include <openssl/objects.h>
13 #include <openssl/rand.h>
16 #if defined(OPENSSL_SYS_VMS)
17 # include <sys/timeb.h>
18 #elif defined(OPENSSL_SYS_VXWORKS)
19 # include <sys/times.h>
20 #elif !defined(OPENSSL_SYS_WIN32)
21 # include <sys/time.h>
24 static void get_current_time(struct timeval
*t
);
25 static int dtls1_handshake_write(SSL
*s
);
26 static size_t dtls1_link_min_mtu(void);
28 /* XDTLS: figure out the right values */
29 static const size_t g_probable_mtu
[] = { 1500, 512, 256 };
31 const SSL3_ENC_METHOD DTLSv1_enc_data
= {
35 tls1_generate_master_secret
,
36 tls1_change_cipher_state
,
37 tls1_final_finish_mac
,
38 TLS_MD_CLIENT_FINISH_CONST
, TLS_MD_CLIENT_FINISH_CONST_SIZE
,
39 TLS_MD_SERVER_FINISH_CONST
, TLS_MD_SERVER_FINISH_CONST_SIZE
,
41 tls1_export_keying_material
,
42 SSL_ENC_FLAG_DTLS
| SSL_ENC_FLAG_EXPLICIT_IV
,
43 dtls1_set_handshake_header
,
44 dtls1_close_construct_packet
,
48 const SSL3_ENC_METHOD DTLSv1_2_enc_data
= {
52 tls1_generate_master_secret
,
53 tls1_change_cipher_state
,
54 tls1_final_finish_mac
,
55 TLS_MD_CLIENT_FINISH_CONST
, TLS_MD_CLIENT_FINISH_CONST_SIZE
,
56 TLS_MD_SERVER_FINISH_CONST
, TLS_MD_SERVER_FINISH_CONST_SIZE
,
58 tls1_export_keying_material
,
59 SSL_ENC_FLAG_DTLS
| SSL_ENC_FLAG_EXPLICIT_IV
| SSL_ENC_FLAG_SIGALGS
60 | SSL_ENC_FLAG_SHA256_PRF
| SSL_ENC_FLAG_TLS1_2_CIPHERS
,
61 dtls1_set_handshake_header
,
62 dtls1_close_construct_packet
,
66 long dtls1_default_timeout(void)
69 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
70 * http, the cache would over fill
79 if (!DTLS_RECORD_LAYER_new(&s
->rlayer
)) {
85 if ((d1
= OPENSSL_zalloc(sizeof(*d1
))) == NULL
) {
90 d1
->buffered_messages
= pqueue_new();
91 d1
->sent_messages
= pqueue_new();
94 d1
->cookie_len
= sizeof(s
->d1
->cookie
);
100 if (d1
->buffered_messages
== NULL
|| d1
->sent_messages
== NULL
) {
101 pqueue_free(d1
->buffered_messages
);
102 pqueue_free(d1
->sent_messages
);
109 s
->method
->ssl_clear(s
);
113 static void dtls1_clear_queues(SSL
*s
)
115 dtls1_clear_received_buffer(s
);
116 dtls1_clear_sent_buffer(s
);
119 void dtls1_clear_received_buffer(SSL
*s
)
122 hm_fragment
*frag
= NULL
;
124 while ((item
= pqueue_pop(s
->d1
->buffered_messages
)) != NULL
) {
125 frag
= (hm_fragment
*)item
->data
;
126 dtls1_hm_fragment_free(frag
);
131 void dtls1_clear_sent_buffer(SSL
*s
)
134 hm_fragment
*frag
= NULL
;
136 while ((item
= pqueue_pop(s
->d1
->sent_messages
)) != NULL
) {
137 frag
= (hm_fragment
*)item
->data
;
138 dtls1_hm_fragment_free(frag
);
144 void dtls1_free(SSL
*s
)
146 DTLS_RECORD_LAYER_free(&s
->rlayer
);
150 dtls1_clear_queues(s
);
152 pqueue_free(s
->d1
->buffered_messages
);
153 pqueue_free(s
->d1
->sent_messages
);
159 void dtls1_clear(SSL
*s
)
161 pqueue
*buffered_messages
;
162 pqueue
*sent_messages
;
166 DTLS_RECORD_LAYER_clear(&s
->rlayer
);
169 buffered_messages
= s
->d1
->buffered_messages
;
170 sent_messages
= s
->d1
->sent_messages
;
172 link_mtu
= s
->d1
->link_mtu
;
174 dtls1_clear_queues(s
);
176 memset(s
->d1
, 0, sizeof(*s
->d1
));
179 s
->d1
->cookie_len
= sizeof(s
->d1
->cookie
);
182 if (SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
) {
184 s
->d1
->link_mtu
= link_mtu
;
187 s
->d1
->buffered_messages
= buffered_messages
;
188 s
->d1
->sent_messages
= sent_messages
;
193 if (s
->method
->version
== DTLS_ANY_VERSION
)
194 s
->version
= DTLS_MAX_VERSION
;
195 #ifndef OPENSSL_NO_DTLS1_METHOD
196 else if (s
->options
& SSL_OP_CISCO_ANYCONNECT
)
197 s
->client_version
= s
->version
= DTLS1_BAD_VER
;
200 s
->version
= s
->method
->version
;
203 long dtls1_ctrl(SSL
*s
, int cmd
, long larg
, void *parg
)
208 case DTLS_CTRL_GET_TIMEOUT
:
209 if (dtls1_get_timeout(s
, (struct timeval
*)parg
) != NULL
) {
213 case DTLS_CTRL_HANDLE_TIMEOUT
:
214 ret
= dtls1_handle_timeout(s
);
216 case DTLS_CTRL_SET_LINK_MTU
:
217 if (larg
< (long)dtls1_link_min_mtu())
219 s
->d1
->link_mtu
= larg
;
221 case DTLS_CTRL_GET_LINK_MIN_MTU
:
222 return (long)dtls1_link_min_mtu();
223 case SSL_CTRL_SET_MTU
:
225 * We may not have a BIO set yet so can't call dtls1_min_mtu()
226 * We'll have to make do with dtls1_link_min_mtu() and max overhead
228 if (larg
< (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD
)
233 ret
= ssl3_ctrl(s
, cmd
, larg
, parg
);
239 void dtls1_start_timer(SSL
*s
)
241 #ifndef OPENSSL_NO_SCTP
242 /* Disable timer for SCTP */
243 if (BIO_dgram_is_sctp(SSL_get_wbio(s
))) {
244 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
249 /* If timer is not set, initialize duration with 1 second */
250 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
251 s
->d1
->timeout_duration
= 1;
254 /* Set timeout to current time */
255 get_current_time(&(s
->d1
->next_timeout
));
257 /* Add duration to current time */
258 s
->d1
->next_timeout
.tv_sec
+= s
->d1
->timeout_duration
;
259 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
260 &(s
->d1
->next_timeout
));
263 struct timeval
*dtls1_get_timeout(SSL
*s
, struct timeval
*timeleft
)
265 struct timeval timenow
;
267 /* If no timeout is set, just return NULL */
268 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
272 /* Get current time */
273 get_current_time(&timenow
);
275 /* If timer already expired, set remaining time to 0 */
276 if (s
->d1
->next_timeout
.tv_sec
< timenow
.tv_sec
||
277 (s
->d1
->next_timeout
.tv_sec
== timenow
.tv_sec
&&
278 s
->d1
->next_timeout
.tv_usec
<= timenow
.tv_usec
)) {
279 memset(timeleft
, 0, sizeof(*timeleft
));
283 /* Calculate time left until timer expires */
284 memcpy(timeleft
, &(s
->d1
->next_timeout
), sizeof(struct timeval
));
285 timeleft
->tv_sec
-= timenow
.tv_sec
;
286 timeleft
->tv_usec
-= timenow
.tv_usec
;
287 if (timeleft
->tv_usec
< 0) {
289 timeleft
->tv_usec
+= 1000000;
293 * If remaining time is less than 15 ms, set it to 0 to prevent issues
294 * because of small divergences with socket timeouts.
296 if (timeleft
->tv_sec
== 0 && timeleft
->tv_usec
< 15000) {
297 memset(timeleft
, 0, sizeof(*timeleft
));
303 int dtls1_is_timer_expired(SSL
*s
)
305 struct timeval timeleft
;
307 /* Get time left until timeout, return false if no timer running */
308 if (dtls1_get_timeout(s
, &timeleft
) == NULL
) {
312 /* Return false if timer is not expired yet */
313 if (timeleft
.tv_sec
> 0 || timeleft
.tv_usec
> 0) {
317 /* Timer expired, so return true */
321 void dtls1_double_timeout(SSL
*s
)
323 s
->d1
->timeout_duration
*= 2;
324 if (s
->d1
->timeout_duration
> 60)
325 s
->d1
->timeout_duration
= 60;
326 dtls1_start_timer(s
);
329 void dtls1_stop_timer(SSL
*s
)
331 /* Reset everything */
332 memset(&s
->d1
->timeout
, 0, sizeof(s
->d1
->timeout
));
333 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
334 s
->d1
->timeout_duration
= 1;
335 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
336 &(s
->d1
->next_timeout
));
337 /* Clear retransmission buffer */
338 dtls1_clear_sent_buffer(s
);
341 int dtls1_check_timeout_num(SSL
*s
)
345 s
->d1
->timeout
.num_alerts
++;
347 /* Reduce MTU after 2 unsuccessful retransmissions */
348 if (s
->d1
->timeout
.num_alerts
> 2
349 && !(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
351 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_GET_FALLBACK_MTU
, 0, NULL
);
352 if (mtu
< s
->d1
->mtu
)
356 if (s
->d1
->timeout
.num_alerts
> DTLS1_TMO_ALERT_COUNT
) {
357 /* fail the connection, enough alerts have been sent */
358 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM
, SSL_R_READ_TIMEOUT_EXPIRED
);
365 int dtls1_handle_timeout(SSL
*s
)
367 /* if no timer is expired, don't do anything */
368 if (!dtls1_is_timer_expired(s
)) {
372 dtls1_double_timeout(s
);
374 if (dtls1_check_timeout_num(s
) < 0)
377 s
->d1
->timeout
.read_timeouts
++;
378 if (s
->d1
->timeout
.read_timeouts
> DTLS1_TMO_READ_COUNT
) {
379 s
->d1
->timeout
.read_timeouts
= 1;
381 #ifndef OPENSSL_NO_HEARTBEATS
382 if (s
->tlsext_hb_pending
) {
383 s
->tlsext_hb_pending
= 0;
384 return dtls1_heartbeat(s
);
388 dtls1_start_timer(s
);
389 return dtls1_retransmit_buffered_messages(s
);
392 static void get_current_time(struct timeval
*t
)
402 SystemTimeToFileTime(&st
, &now
.ft
);
403 /* re-bias to 1/1/1970 */
405 now
.ul
-= 116444736000000000ULL;
408 now
.ul
-= 116444736000000000UI
64;
411 t
->tv_sec
= (long)(now
.ul
/ 10000000);
412 t
->tv_usec
= ((int)(now
.ul
% 10000000)) / 10;
413 #elif defined(OPENSSL_SYS_VMS)
416 t
->tv_sec
= (long)tb
.time
;
417 t
->tv_usec
= (long)tb
.millitm
* 1000;
419 gettimeofday(t
, NULL
);
423 #define LISTEN_SUCCESS 2
424 #define LISTEN_SEND_VERIFY_REQUEST 1
426 #ifndef OPENSSL_NO_SOCK
427 int DTLSv1_listen(SSL
*s
, BIO_ADDR
*client
)
429 int next
, n
, ret
= 0, clearpkt
= 0;
430 unsigned char cookie
[DTLS1_COOKIE_LENGTH
];
431 unsigned char seq
[SEQ_NUM_SIZE
];
432 const unsigned char *data
;
434 size_t fragoff
, fraglen
, msglen
;
435 unsigned int rectype
, versmajor
, msgseq
, msgtype
, clientvers
, cookielen
;
438 BIO_ADDR
*tmpclient
= NULL
;
439 PACKET pkt
, msgpkt
, msgpayload
, session
, cookiepkt
;
441 /* Ensure there is no state left over from a previous invocation */
447 rbio
= SSL_get_rbio(s
);
448 wbio
= SSL_get_wbio(s
);
450 if (!rbio
|| !wbio
) {
451 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_BIO_NOT_SET
);
456 * We only peek at incoming ClientHello's until we're sure we are going to
457 * to respond with a HelloVerifyRequest. If its a ClientHello with a valid
458 * cookie then we leave it in the BIO for accept to handle.
460 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
463 * Note: This check deliberately excludes DTLS1_BAD_VER because that version
464 * requires the MAC to be calculated *including* the first ClientHello
465 * (without the cookie). Since DTLSv1_listen is stateless that cannot be
466 * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
469 if ((s
->version
& 0xff00) != (DTLS1_VERSION
& 0xff00)) {
470 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNSUPPORTED_SSL_VERSION
);
474 if (s
->init_buf
== NULL
) {
475 if ((bufm
= BUF_MEM_new()) == NULL
) {
476 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_MALLOC_FAILURE
);
480 if (!BUF_MEM_grow(bufm
, SSL3_RT_MAX_PLAIN_LENGTH
)) {
482 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_MALLOC_FAILURE
);
487 buf
= (unsigned char *)s
->init_buf
->data
;
494 * Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
495 * + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
496 * the record header as well, but we do here. We've set up init_buf to
497 * be the standard size for simplicity. In practice we shouldn't ever
498 * receive a ClientHello as long as this. If we do it will get dropped
499 * in the record length check below.
501 n
= BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
504 if (BIO_should_retry(rbio
)) {
505 /* Non-blocking IO */
511 /* If we hit any problems we need to clear this packet from the BIO */
514 if (!PACKET_buf_init(&pkt
, buf
, n
)) {
515 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_INTERNAL_ERROR
);
520 * Parse the received record. If there are any problems with it we just
521 * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
522 * resilient in the face of invalid records (e.g., invalid formatting,
523 * length, MAC, etc.). In general, invalid records SHOULD be silently
524 * discarded, thus preserving the association; however, an error MAY be
525 * logged for diagnostic purposes."
528 /* this packet contained a partial record, dump it */
529 if (n
< DTLS1_RT_HEADER_LENGTH
) {
530 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_RECORD_TOO_SMALL
);
535 s
->msg_callback(0, 0, SSL3_RT_HEADER
, buf
,
536 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
538 /* Get the record header */
539 if (!PACKET_get_1(&pkt
, &rectype
)
540 || !PACKET_get_1(&pkt
, &versmajor
)) {
541 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
545 if (rectype
!= SSL3_RT_HANDSHAKE
) {
546 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
551 * Check record version number. We only check that the major version is
554 if (versmajor
!= DTLS1_VERSION_MAJOR
) {
555 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_BAD_PROTOCOL_VERSION_NUMBER
);
559 if (!PACKET_forward(&pkt
, 1)
560 /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
561 || !PACKET_copy_bytes(&pkt
, seq
, SEQ_NUM_SIZE
)
562 || !PACKET_get_length_prefixed_2(&pkt
, &msgpkt
)) {
563 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
567 * We allow data remaining at the end of the packet because there could
568 * be a second record (but we ignore it)
571 /* This is an initial ClientHello so the epoch has to be 0 */
572 if (seq
[0] != 0 || seq
[1] != 0) {
573 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
577 /* Get a pointer to the raw message for the later callback */
578 data
= PACKET_data(&msgpkt
);
580 /* Finished processing the record header, now process the message */
581 if (!PACKET_get_1(&msgpkt
, &msgtype
)
582 || !PACKET_get_net_3(&msgpkt
, &msglen
)
583 || !PACKET_get_net_2(&msgpkt
, &msgseq
)
584 || !PACKET_get_net_3(&msgpkt
, &fragoff
)
585 || !PACKET_get_net_3(&msgpkt
, &fraglen
)
586 || !PACKET_get_sub_packet(&msgpkt
, &msgpayload
, fraglen
)
587 || PACKET_remaining(&msgpkt
) != 0) {
588 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
592 if (msgtype
!= SSL3_MT_CLIENT_HELLO
) {
593 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
597 /* Message sequence number can only be 0 or 1 */
599 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_INVALID_SEQUENCE_NUMBER
);
604 * We don't support fragment reassembly for ClientHellos whilst
605 * listening because that would require server side state (which is
606 * against the whole point of the ClientHello/HelloVerifyRequest
607 * mechanism). Instead we only look at the first ClientHello fragment
608 * and require that the cookie must be contained within it.
610 if (fragoff
!= 0 || fraglen
> msglen
) {
611 /* Non initial ClientHello fragment (or bad fragment) */
612 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_FRAGMENTED_CLIENT_HELLO
);
617 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
, data
,
618 fraglen
+ DTLS1_HM_HEADER_LENGTH
, s
,
619 s
->msg_callback_arg
);
621 if (!PACKET_get_net_2(&msgpayload
, &clientvers
)) {
622 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
627 * Verify client version is supported
629 if (DTLS_VERSION_LT(clientvers
, (unsigned int)s
->method
->version
) &&
630 s
->method
->version
!= DTLS_ANY_VERSION
) {
631 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_WRONG_VERSION_NUMBER
);
635 if (!PACKET_forward(&msgpayload
, SSL3_RANDOM_SIZE
)
636 || !PACKET_get_length_prefixed_1(&msgpayload
, &session
)
637 || !PACKET_get_length_prefixed_1(&msgpayload
, &cookiepkt
)) {
639 * Could be malformed or the cookie does not fit within the initial
640 * ClientHello fragment. Either way we can't handle it.
642 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
647 * Check if we have a cookie or not. If not we need to send a
648 * HelloVerifyRequest.
650 if (PACKET_remaining(&cookiepkt
) == 0) {
651 next
= LISTEN_SEND_VERIFY_REQUEST
;
654 * We have a cookie, so lets check it.
656 if (s
->ctx
->app_verify_cookie_cb
== NULL
) {
657 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_NO_VERIFY_COOKIE_CALLBACK
);
661 if (s
->ctx
->app_verify_cookie_cb(s
, PACKET_data(&cookiepkt
),
662 (unsigned int)PACKET_remaining(&cookiepkt
)) == 0) {
664 * We treat invalid cookies in the same was as no cookie as
667 next
= LISTEN_SEND_VERIFY_REQUEST
;
669 /* Cookie verification succeeded */
670 next
= LISTEN_SUCCESS
;
674 if (next
== LISTEN_SEND_VERIFY_REQUEST
) {
676 unsigned int version
;
680 * There was no cookie in the ClientHello so we need to send a
681 * HelloVerifyRequest. If this fails we do not worry about trying
682 * to resend, we just drop it.
686 * Dump the read packet, we don't need it any more. Ignore return
689 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
690 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
691 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
693 /* Generate the cookie */
694 if (s
->ctx
->app_gen_cookie_cb
== NULL
||
695 s
->ctx
->app_gen_cookie_cb(s
, cookie
, &cookielen
) == 0 ||
697 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_COOKIE_GEN_CALLBACK_FAILURE
);
703 * Special case: for hello verify request, client version 1.0 and we
704 * haven't decided which version to use yet send back using version
705 * 1.0 header: otherwise some clients will ignore it.
707 version
= (s
->method
->version
== DTLS_ANY_VERSION
) ? DTLS1_VERSION
710 /* Construct the record and message headers */
711 if (!WPACKET_init(&wpkt
, s
->init_buf
)
712 || !WPACKET_put_bytes_u8(&wpkt
, SSL3_RT_HANDSHAKE
)
713 || !WPACKET_put_bytes_u16(&wpkt
, version
)
715 * Record sequence number is always the same as in the
716 * received ClientHello
718 || !WPACKET_memcpy(&wpkt
, seq
, SEQ_NUM_SIZE
)
719 /* End of record, start sub packet for message */
720 || !WPACKET_start_sub_packet_u16(&wpkt
)
722 || !WPACKET_put_bytes_u8(&wpkt
,
723 DTLS1_MT_HELLO_VERIFY_REQUEST
)
725 * Message length - doesn't follow normal TLS convention:
726 * the length isn't the last thing in the message header.
727 * We'll need to fill this in later when we know the
728 * length. Set it to zero for now
730 || !WPACKET_put_bytes_u24(&wpkt
, 0)
732 * Message sequence number is always 0 for a
735 || !WPACKET_put_bytes_u16(&wpkt
, 0)
737 * We never fragment a HelloVerifyRequest, so fragment
740 || !WPACKET_put_bytes_u24(&wpkt
, 0)
742 * Fragment length is the same as message length, but
743 * this *is* the last thing in the message header so we
744 * can just start a sub-packet. No need to come back
745 * later for this one.
747 || !WPACKET_start_sub_packet_u24(&wpkt
)
748 /* Create the actual HelloVerifyRequest body */
749 || !dtls_raw_hello_verify_request(&wpkt
, cookie
, cookielen
)
750 /* Close message body */
751 || !WPACKET_close(&wpkt
)
752 /* Close record body */
753 || !WPACKET_close(&wpkt
)
754 || !WPACKET_get_total_written(&wpkt
, &wreclen
)
755 || !WPACKET_finish(&wpkt
)) {
756 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_INTERNAL_ERROR
);
757 WPACKET_cleanup(&wpkt
);
763 * Fix up the message len in the message header. Its the same as the
764 * fragment len which has been filled in by WPACKET, so just copy
765 * that. Destination for the message len is after the record header
766 * plus one byte for the message content type. The source is the
767 * last 3 bytes of the message header
769 memcpy(&buf
[DTLS1_RT_HEADER_LENGTH
+ 1],
770 &buf
[DTLS1_RT_HEADER_LENGTH
+ DTLS1_HM_HEADER_LENGTH
- 3],
774 s
->msg_callback(1, 0, SSL3_RT_HEADER
, buf
,
775 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
777 if ((tmpclient
= BIO_ADDR_new()) == NULL
) {
778 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_MALLOC_FAILURE
);
783 * This is unnecessary if rbio and wbio are one and the same - but
784 * maybe they're not. We ignore errors here - some BIOs do not
787 if (BIO_dgram_get_peer(rbio
, tmpclient
) > 0) {
788 (void)BIO_dgram_set_peer(wbio
, tmpclient
);
790 BIO_ADDR_free(tmpclient
);
793 /* TODO(size_t): convert this call */
794 if (BIO_write(wbio
, buf
, wreclen
) < (int)wreclen
) {
795 if (BIO_should_retry(wbio
)) {
797 * Non-blocking IO...but we're stateless, so we're just
798 * going to drop this packet.
805 if (BIO_flush(wbio
) <= 0) {
806 if (BIO_should_retry(wbio
)) {
808 * Non-blocking IO...but we're stateless, so we're just
809 * going to drop this packet.
816 } while (next
!= LISTEN_SUCCESS
);
819 * Set expected sequence numbers to continue the handshake.
821 s
->d1
->handshake_read_seq
= 1;
822 s
->d1
->handshake_write_seq
= 1;
823 s
->d1
->next_handshake_write_seq
= 1;
824 DTLS_RECORD_LAYER_set_write_sequence(&s
->rlayer
, seq
);
827 * We are doing cookie exchange, so make sure we set that option in the
830 SSL_set_options(s
, SSL_OP_COOKIE_EXCHANGE
);
833 * Tell the state machine that we've done the initial hello verify
836 ossl_statem_set_hello_verify_done(s
);
839 * Some BIOs may not support this. If we fail we clear the client address
841 if (BIO_dgram_get_peer(rbio
, client
) <= 0)
842 BIO_ADDR_clear(client
);
847 BIO_ADDR_free(tmpclient
);
848 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
850 /* Dump this packet. Ignore return value */
851 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
857 static int dtls1_handshake_write(SSL
*s
)
859 return dtls1_do_write(s
, SSL3_RT_HANDSHAKE
);
862 #ifndef OPENSSL_NO_HEARTBEATS
864 # define HEARTBEAT_SIZE(payload, padding) ( \
865 1 /* heartbeat type */ + \
866 2 /* heartbeat length */ + \
867 (payload) + (padding))
869 # define HEARTBEAT_SIZE_STD(payload) HEARTBEAT_SIZE(payload, 16)
871 int dtls1_process_heartbeat(SSL
*s
, unsigned char *p
, size_t length
)
874 unsigned short hbtype
;
875 unsigned int payload
;
876 unsigned int padding
= 16; /* Use minimum padding */
880 s
->msg_callback(0, s
->version
, DTLS1_RT_HEARTBEAT
,
881 p
, length
, s
, s
->msg_callback_arg
);
883 /* Read type and payload length */
884 if (HEARTBEAT_SIZE_STD(0) > length
)
885 return 0; /* silently discard */
886 if (length
> SSL3_RT_MAX_PLAIN_LENGTH
)
887 return 0; /* silently discard per RFC 6520 sec. 4 */
891 if (HEARTBEAT_SIZE_STD(payload
) > length
)
892 return 0; /* silently discard per RFC 6520 sec. 4 */
895 if (hbtype
== TLS1_HB_REQUEST
) {
896 unsigned char *buffer
, *bp
;
897 size_t write_length
= HEARTBEAT_SIZE(payload
, padding
);
900 if (write_length
> SSL3_RT_MAX_PLAIN_LENGTH
)
903 /* Allocate memory for the response. */
904 buffer
= OPENSSL_malloc(write_length
);
909 /* Enter response type, length and copy payload */
910 *bp
++ = TLS1_HB_RESPONSE
;
912 memcpy(bp
, pl
, payload
);
915 if (RAND_bytes(bp
, padding
) <= 0) {
916 OPENSSL_free(buffer
);
920 r
= dtls1_write_bytes(s
, DTLS1_RT_HEARTBEAT
, buffer
, write_length
,
923 if (r
> 0 && s
->msg_callback
)
924 s
->msg_callback(1, s
->version
, DTLS1_RT_HEARTBEAT
,
925 buffer
, write_length
, s
, s
->msg_callback_arg
);
927 OPENSSL_free(buffer
);
931 } else if (hbtype
== TLS1_HB_RESPONSE
) {
935 * We only send sequence numbers (2 bytes unsigned int), and 16
936 * random bytes, so we just try to read the sequence number
940 if (payload
== 18 && seq
== s
->tlsext_hb_seq
) {
943 s
->tlsext_hb_pending
= 0;
950 int dtls1_heartbeat(SSL
*s
)
952 unsigned char *buf
, *p
;
954 size_t payload
= 18; /* Sequence number + random bytes */
955 size_t padding
= 16; /* Use minimum padding */
956 size_t size
, written
;
958 /* Only send if peer supports and accepts HB requests... */
959 if (!(s
->tlsext_heartbeat
& SSL_DTLSEXT_HB_ENABLED
) ||
960 s
->tlsext_heartbeat
& SSL_DTLSEXT_HB_DONT_SEND_REQUESTS
) {
961 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT
);
965 /* ...and there is none in flight yet... */
966 if (s
->tlsext_hb_pending
) {
967 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PENDING
);
971 /* ...and no handshake in progress. */
972 if (SSL_in_init(s
) || ossl_statem_get_in_handshake(s
)) {
973 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_UNEXPECTED_MESSAGE
);
978 * Create HeartBeat message, we just use a sequence number
979 * as payload to distinguish different messages and add
982 size
= HEARTBEAT_SIZE(payload
, padding
);
983 buf
= OPENSSL_malloc(size
);
985 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_MALLOC_FAILURE
);
990 *p
++ = TLS1_HB_REQUEST
;
991 /* Payload length (18 bytes here) */
993 /* Sequence number */
994 s2n(s
->tlsext_hb_seq
, p
);
995 /* 16 random bytes */
996 if (RAND_bytes(p
, 16) <= 0) {
997 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1001 /* Random padding */
1002 if (RAND_bytes(p
, padding
) <= 0) {
1003 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1007 ret
= dtls1_write_bytes(s
, DTLS1_RT_HEARTBEAT
, buf
, size
, &written
);
1009 if (s
->msg_callback
)
1010 s
->msg_callback(1, s
->version
, DTLS1_RT_HEARTBEAT
,
1011 buf
, size
, s
, s
->msg_callback_arg
);
1013 dtls1_start_timer(s
);
1014 s
->tlsext_hb_pending
= 1;
1024 int dtls1_shutdown(SSL
*s
)
1027 #ifndef OPENSSL_NO_SCTP
1030 wbio
= SSL_get_wbio(s
);
1031 if (wbio
!= NULL
&& BIO_dgram_is_sctp(wbio
) &&
1032 !(s
->shutdown
& SSL_SENT_SHUTDOWN
)) {
1033 ret
= BIO_dgram_sctp_wait_for_dry(wbio
);
1038 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 1,
1042 ret
= ssl3_shutdown(s
);
1043 #ifndef OPENSSL_NO_SCTP
1044 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 0, NULL
);
1049 int dtls1_query_mtu(SSL
*s
)
1051 if (s
->d1
->link_mtu
) {
1053 s
->d1
->link_mtu
- BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
1054 s
->d1
->link_mtu
= 0;
1057 /* AHA! Figure out the MTU, and stick to the right size */
1058 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1059 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
1061 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_QUERY_MTU
, 0, NULL
);
1064 * I've seen the kernel return bogus numbers when it doesn't know
1065 * (initial write), so just make sure we have a reasonable number
1067 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1068 /* Set to min mtu */
1069 s
->d1
->mtu
= dtls1_min_mtu(s
);
1070 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SET_MTU
,
1071 (long)s
->d1
->mtu
, NULL
);
1079 static size_t dtls1_link_min_mtu(void)
1081 return (g_probable_mtu
[(sizeof(g_probable_mtu
) /
1082 sizeof(g_probable_mtu
[0])) - 1]);
1085 size_t dtls1_min_mtu(SSL
*s
)
1087 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
1090 size_t DTLS_get_data_mtu(const SSL
*s
)
1092 size_t mac_overhead
, int_overhead
, blocksize
, ext_overhead
;
1093 const SSL_CIPHER
*ciph
= SSL_get_current_cipher(s
);
1094 size_t mtu
= s
->d1
->mtu
;
1099 if (!ssl_cipher_get_overhead(ciph
, &mac_overhead
, &int_overhead
,
1100 &blocksize
, &ext_overhead
))
1104 ext_overhead
+= mac_overhead
;
1106 int_overhead
+= mac_overhead
;
1108 /* Subtract external overhead (e.g. IV/nonce, separate MAC) */
1109 if (ext_overhead
+ DTLS1_RT_HEADER_LENGTH
>= mtu
)
1111 mtu
-= ext_overhead
+ DTLS1_RT_HEADER_LENGTH
;
1113 /* Round encrypted payload down to cipher block size (for CBC etc.)
1114 * No check for overflow since 'mtu % blocksize' cannot exceed mtu. */
1116 mtu
-= (mtu
% blocksize
);
1118 /* Subtract internal overhead (e.g. CBC padding len byte) */
1119 if (int_overhead
>= mtu
)
1121 mtu
-= int_overhead
;