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_set_handshake_header(SSL
*s
, int type
, unsigned long len
);
26 static int dtls1_handshake_write(SSL
*s
);
27 static unsigned int dtls1_link_min_mtu(void);
29 /* XDTLS: figure out the right values */
30 static const unsigned int g_probable_mtu
[] = { 1500, 512, 256 };
32 const SSL3_ENC_METHOD DTLSv1_enc_data
= {
36 tls1_generate_master_secret
,
37 tls1_change_cipher_state
,
38 tls1_final_finish_mac
,
39 TLS1_FINISH_MAC_LENGTH
,
40 TLS_MD_CLIENT_FINISH_CONST
, TLS_MD_CLIENT_FINISH_CONST_SIZE
,
41 TLS_MD_SERVER_FINISH_CONST
, TLS_MD_SERVER_FINISH_CONST_SIZE
,
43 tls1_export_keying_material
,
44 SSL_ENC_FLAG_DTLS
| SSL_ENC_FLAG_EXPLICIT_IV
,
45 DTLS1_HM_HEADER_LENGTH
,
46 dtls1_set_handshake_header
,
47 dtls1_set_handshake_header2
,
48 dtls1_close_construct_packet
,
52 const SSL3_ENC_METHOD DTLSv1_2_enc_data
= {
56 tls1_generate_master_secret
,
57 tls1_change_cipher_state
,
58 tls1_final_finish_mac
,
59 TLS1_FINISH_MAC_LENGTH
,
60 TLS_MD_CLIENT_FINISH_CONST
, TLS_MD_CLIENT_FINISH_CONST_SIZE
,
61 TLS_MD_SERVER_FINISH_CONST
, TLS_MD_SERVER_FINISH_CONST_SIZE
,
63 tls1_export_keying_material
,
64 SSL_ENC_FLAG_DTLS
| SSL_ENC_FLAG_EXPLICIT_IV
| SSL_ENC_FLAG_SIGALGS
65 | SSL_ENC_FLAG_SHA256_PRF
| SSL_ENC_FLAG_TLS1_2_CIPHERS
,
66 DTLS1_HM_HEADER_LENGTH
,
67 dtls1_set_handshake_header
,
68 dtls1_set_handshake_header2
,
69 dtls1_close_construct_packet
,
73 long dtls1_default_timeout(void)
76 * 2 hours, the 24 hours mentioned in the DTLSv1 spec is way too long for
77 * http, the cache would over fill
86 if (!DTLS_RECORD_LAYER_new(&s
->rlayer
)) {
92 if ((d1
= OPENSSL_zalloc(sizeof(*d1
))) == NULL
) {
97 d1
->buffered_messages
= pqueue_new();
98 d1
->sent_messages
= pqueue_new();
101 d1
->cookie_len
= sizeof(s
->d1
->cookie
);
107 if (d1
->buffered_messages
== NULL
|| d1
->sent_messages
== NULL
) {
108 pqueue_free(d1
->buffered_messages
);
109 pqueue_free(d1
->sent_messages
);
116 s
->method
->ssl_clear(s
);
120 static void dtls1_clear_queues(SSL
*s
)
122 dtls1_clear_received_buffer(s
);
123 dtls1_clear_sent_buffer(s
);
126 void dtls1_clear_received_buffer(SSL
*s
)
129 hm_fragment
*frag
= NULL
;
131 while ((item
= pqueue_pop(s
->d1
->buffered_messages
)) != NULL
) {
132 frag
= (hm_fragment
*)item
->data
;
133 dtls1_hm_fragment_free(frag
);
138 void dtls1_clear_sent_buffer(SSL
*s
)
141 hm_fragment
*frag
= NULL
;
143 while ((item
= pqueue_pop(s
->d1
->sent_messages
)) != NULL
) {
144 frag
= (hm_fragment
*)item
->data
;
145 dtls1_hm_fragment_free(frag
);
151 void dtls1_free(SSL
*s
)
153 DTLS_RECORD_LAYER_free(&s
->rlayer
);
157 dtls1_clear_queues(s
);
159 pqueue_free(s
->d1
->buffered_messages
);
160 pqueue_free(s
->d1
->sent_messages
);
166 void dtls1_clear(SSL
*s
)
168 pqueue
*buffered_messages
;
169 pqueue
*sent_messages
;
171 unsigned int link_mtu
;
173 DTLS_RECORD_LAYER_clear(&s
->rlayer
);
176 buffered_messages
= s
->d1
->buffered_messages
;
177 sent_messages
= s
->d1
->sent_messages
;
179 link_mtu
= s
->d1
->link_mtu
;
181 dtls1_clear_queues(s
);
183 memset(s
->d1
, 0, sizeof(*s
->d1
));
186 s
->d1
->cookie_len
= sizeof(s
->d1
->cookie
);
189 if (SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
) {
191 s
->d1
->link_mtu
= link_mtu
;
194 s
->d1
->buffered_messages
= buffered_messages
;
195 s
->d1
->sent_messages
= sent_messages
;
200 if (s
->method
->version
== DTLS_ANY_VERSION
)
201 s
->version
= DTLS_MAX_VERSION
;
202 #ifndef OPENSSL_NO_DTLS1_METHOD
203 else if (s
->options
& SSL_OP_CISCO_ANYCONNECT
)
204 s
->client_version
= s
->version
= DTLS1_BAD_VER
;
207 s
->version
= s
->method
->version
;
210 long dtls1_ctrl(SSL
*s
, int cmd
, long larg
, void *parg
)
215 case DTLS_CTRL_GET_TIMEOUT
:
216 if (dtls1_get_timeout(s
, (struct timeval
*)parg
) != NULL
) {
220 case DTLS_CTRL_HANDLE_TIMEOUT
:
221 ret
= dtls1_handle_timeout(s
);
223 case DTLS_CTRL_SET_LINK_MTU
:
224 if (larg
< (long)dtls1_link_min_mtu())
226 s
->d1
->link_mtu
= larg
;
228 case DTLS_CTRL_GET_LINK_MIN_MTU
:
229 return (long)dtls1_link_min_mtu();
230 case SSL_CTRL_SET_MTU
:
232 * We may not have a BIO set yet so can't call dtls1_min_mtu()
233 * We'll have to make do with dtls1_link_min_mtu() and max overhead
235 if (larg
< (long)dtls1_link_min_mtu() - DTLS1_MAX_MTU_OVERHEAD
)
240 ret
= ssl3_ctrl(s
, cmd
, larg
, parg
);
246 void dtls1_start_timer(SSL
*s
)
248 #ifndef OPENSSL_NO_SCTP
249 /* Disable timer for SCTP */
250 if (BIO_dgram_is_sctp(SSL_get_wbio(s
))) {
251 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
256 /* If timer is not set, initialize duration with 1 second */
257 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
258 s
->d1
->timeout_duration
= 1;
261 /* Set timeout to current time */
262 get_current_time(&(s
->d1
->next_timeout
));
264 /* Add duration to current time */
265 s
->d1
->next_timeout
.tv_sec
+= s
->d1
->timeout_duration
;
266 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
267 &(s
->d1
->next_timeout
));
270 struct timeval
*dtls1_get_timeout(SSL
*s
, struct timeval
*timeleft
)
272 struct timeval timenow
;
274 /* If no timeout is set, just return NULL */
275 if (s
->d1
->next_timeout
.tv_sec
== 0 && s
->d1
->next_timeout
.tv_usec
== 0) {
279 /* Get current time */
280 get_current_time(&timenow
);
282 /* If timer already expired, set remaining time to 0 */
283 if (s
->d1
->next_timeout
.tv_sec
< timenow
.tv_sec
||
284 (s
->d1
->next_timeout
.tv_sec
== timenow
.tv_sec
&&
285 s
->d1
->next_timeout
.tv_usec
<= timenow
.tv_usec
)) {
286 memset(timeleft
, 0, sizeof(*timeleft
));
290 /* Calculate time left until timer expires */
291 memcpy(timeleft
, &(s
->d1
->next_timeout
), sizeof(struct timeval
));
292 timeleft
->tv_sec
-= timenow
.tv_sec
;
293 timeleft
->tv_usec
-= timenow
.tv_usec
;
294 if (timeleft
->tv_usec
< 0) {
296 timeleft
->tv_usec
+= 1000000;
300 * If remaining time is less than 15 ms, set it to 0 to prevent issues
301 * because of small divergences with socket timeouts.
303 if (timeleft
->tv_sec
== 0 && timeleft
->tv_usec
< 15000) {
304 memset(timeleft
, 0, sizeof(*timeleft
));
310 int dtls1_is_timer_expired(SSL
*s
)
312 struct timeval timeleft
;
314 /* Get time left until timeout, return false if no timer running */
315 if (dtls1_get_timeout(s
, &timeleft
) == NULL
) {
319 /* Return false if timer is not expired yet */
320 if (timeleft
.tv_sec
> 0 || timeleft
.tv_usec
> 0) {
324 /* Timer expired, so return true */
328 void dtls1_double_timeout(SSL
*s
)
330 s
->d1
->timeout_duration
*= 2;
331 if (s
->d1
->timeout_duration
> 60)
332 s
->d1
->timeout_duration
= 60;
333 dtls1_start_timer(s
);
336 void dtls1_stop_timer(SSL
*s
)
338 /* Reset everything */
339 memset(&s
->d1
->timeout
, 0, sizeof(s
->d1
->timeout
));
340 memset(&s
->d1
->next_timeout
, 0, sizeof(s
->d1
->next_timeout
));
341 s
->d1
->timeout_duration
= 1;
342 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_NEXT_TIMEOUT
, 0,
343 &(s
->d1
->next_timeout
));
344 /* Clear retransmission buffer */
345 dtls1_clear_sent_buffer(s
);
348 int dtls1_check_timeout_num(SSL
*s
)
352 s
->d1
->timeout
.num_alerts
++;
354 /* Reduce MTU after 2 unsuccessful retransmissions */
355 if (s
->d1
->timeout
.num_alerts
> 2
356 && !(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
358 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_GET_FALLBACK_MTU
, 0, NULL
);
359 if (mtu
< s
->d1
->mtu
)
363 if (s
->d1
->timeout
.num_alerts
> DTLS1_TMO_ALERT_COUNT
) {
364 /* fail the connection, enough alerts have been sent */
365 SSLerr(SSL_F_DTLS1_CHECK_TIMEOUT_NUM
, SSL_R_READ_TIMEOUT_EXPIRED
);
372 int dtls1_handle_timeout(SSL
*s
)
374 /* if no timer is expired, don't do anything */
375 if (!dtls1_is_timer_expired(s
)) {
379 dtls1_double_timeout(s
);
381 if (dtls1_check_timeout_num(s
) < 0)
384 s
->d1
->timeout
.read_timeouts
++;
385 if (s
->d1
->timeout
.read_timeouts
> DTLS1_TMO_READ_COUNT
) {
386 s
->d1
->timeout
.read_timeouts
= 1;
388 #ifndef OPENSSL_NO_HEARTBEATS
389 if (s
->tlsext_hb_pending
) {
390 s
->tlsext_hb_pending
= 0;
391 return dtls1_heartbeat(s
);
395 dtls1_start_timer(s
);
396 return dtls1_retransmit_buffered_messages(s
);
399 static void get_current_time(struct timeval
*t
)
409 SystemTimeToFileTime(&st
, &now
.ft
);
410 /* re-bias to 1/1/1970 */
412 now
.ul
-= 116444736000000000ULL;
415 now
.ul
-= 116444736000000000UI
64;
418 t
->tv_sec
= (long)(now
.ul
/ 10000000);
419 t
->tv_usec
= ((int)(now
.ul
% 10000000)) / 10;
420 #elif defined(OPENSSL_SYS_VMS)
423 t
->tv_sec
= (long)tb
.time
;
424 t
->tv_usec
= (long)tb
.millitm
* 1000;
426 gettimeofday(t
, NULL
);
430 #define LISTEN_SUCCESS 2
431 #define LISTEN_SEND_VERIFY_REQUEST 1
433 #ifndef OPENSSL_NO_SOCK
434 int DTLSv1_listen(SSL
*s
, BIO_ADDR
*client
)
436 int next
, n
, ret
= 0, clearpkt
= 0;
437 unsigned char cookie
[DTLS1_COOKIE_LENGTH
];
438 unsigned char seq
[SEQ_NUM_SIZE
];
439 const unsigned char *data
;
441 unsigned long fragoff
, fraglen
, msglen
;
442 unsigned int rectype
, versmajor
, msgseq
, msgtype
, clientvers
, cookielen
;
445 BIO_ADDR
*tmpclient
= NULL
;
446 PACKET pkt
, msgpkt
, msgpayload
, session
, cookiepkt
;
448 /* Ensure there is no state left over from a previous invocation */
454 rbio
= SSL_get_rbio(s
);
455 wbio
= SSL_get_wbio(s
);
457 if (!rbio
|| !wbio
) {
458 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_BIO_NOT_SET
);
463 * We only peek at incoming ClientHello's until we're sure we are going to
464 * to respond with a HelloVerifyRequest. If its a ClientHello with a valid
465 * cookie then we leave it in the BIO for accept to handle.
467 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
470 * Note: This check deliberately excludes DTLS1_BAD_VER because that version
471 * requires the MAC to be calculated *including* the first ClientHello
472 * (without the cookie). Since DTLSv1_listen is stateless that cannot be
473 * supported. DTLS1_BAD_VER must use cookies in a stateful manner (e.g. via
476 if ((s
->version
& 0xff00) != (DTLS1_VERSION
& 0xff00)) {
477 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNSUPPORTED_SSL_VERSION
);
481 if (s
->init_buf
== NULL
) {
482 if ((bufm
= BUF_MEM_new()) == NULL
) {
483 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_MALLOC_FAILURE
);
487 if (!BUF_MEM_grow(bufm
, SSL3_RT_MAX_PLAIN_LENGTH
)) {
489 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_MALLOC_FAILURE
);
494 buf
= (unsigned char *)s
->init_buf
->data
;
501 * Technically a ClientHello could be SSL3_RT_MAX_PLAIN_LENGTH
502 * + DTLS1_RT_HEADER_LENGTH bytes long. Normally init_buf does not store
503 * the record header as well, but we do here. We've set up init_buf to
504 * be the standard size for simplicity. In practice we shouldn't ever
505 * receive a ClientHello as long as this. If we do it will get dropped
506 * in the record length check below.
508 n
= BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
511 if (BIO_should_retry(rbio
)) {
512 /* Non-blocking IO */
518 /* If we hit any problems we need to clear this packet from the BIO */
521 if (!PACKET_buf_init(&pkt
, buf
, n
)) {
522 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_INTERNAL_ERROR
);
527 * Parse the received record. If there are any problems with it we just
528 * dump it - with no alert. RFC6347 says this "Unlike TLS, DTLS is
529 * resilient in the face of invalid records (e.g., invalid formatting,
530 * length, MAC, etc.). In general, invalid records SHOULD be silently
531 * discarded, thus preserving the association; however, an error MAY be
532 * logged for diagnostic purposes."
535 /* this packet contained a partial record, dump it */
536 if (n
< DTLS1_RT_HEADER_LENGTH
) {
537 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_RECORD_TOO_SMALL
);
542 s
->msg_callback(0, 0, SSL3_RT_HEADER
, buf
,
543 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
545 /* Get the record header */
546 if (!PACKET_get_1(&pkt
, &rectype
)
547 || !PACKET_get_1(&pkt
, &versmajor
)) {
548 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
552 if (rectype
!= SSL3_RT_HANDSHAKE
) {
553 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
558 * Check record version number. We only check that the major version is
561 if (versmajor
!= DTLS1_VERSION_MAJOR
) {
562 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_BAD_PROTOCOL_VERSION_NUMBER
);
566 if (!PACKET_forward(&pkt
, 1)
567 /* Save the sequence number: 64 bits, with top 2 bytes = epoch */
568 || !PACKET_copy_bytes(&pkt
, seq
, SEQ_NUM_SIZE
)
569 || !PACKET_get_length_prefixed_2(&pkt
, &msgpkt
)) {
570 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
574 * We allow data remaining at the end of the packet because there could
575 * be a second record (but we ignore it)
578 /* This is an initial ClientHello so the epoch has to be 0 */
579 if (seq
[0] != 0 || seq
[1] != 0) {
580 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
584 /* Get a pointer to the raw message for the later callback */
585 data
= PACKET_data(&msgpkt
);
587 /* Finished processing the record header, now process the message */
588 if (!PACKET_get_1(&msgpkt
, &msgtype
)
589 || !PACKET_get_net_3(&msgpkt
, &msglen
)
590 || !PACKET_get_net_2(&msgpkt
, &msgseq
)
591 || !PACKET_get_net_3(&msgpkt
, &fragoff
)
592 || !PACKET_get_net_3(&msgpkt
, &fraglen
)
593 || !PACKET_get_sub_packet(&msgpkt
, &msgpayload
, fraglen
)
594 || PACKET_remaining(&msgpkt
) != 0) {
595 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
599 if (msgtype
!= SSL3_MT_CLIENT_HELLO
) {
600 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_UNEXPECTED_MESSAGE
);
604 /* Message sequence number can only be 0 or 1 */
606 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_INVALID_SEQUENCE_NUMBER
);
611 * We don't support fragment reassembly for ClientHellos whilst
612 * listening because that would require server side state (which is
613 * against the whole point of the ClientHello/HelloVerifyRequest
614 * mechanism). Instead we only look at the first ClientHello fragment
615 * and require that the cookie must be contained within it.
617 if (fragoff
!= 0 || fraglen
> msglen
) {
618 /* Non initial ClientHello fragment (or bad fragment) */
619 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_FRAGMENTED_CLIENT_HELLO
);
624 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
, data
,
625 fraglen
+ DTLS1_HM_HEADER_LENGTH
, s
,
626 s
->msg_callback_arg
);
628 if (!PACKET_get_net_2(&msgpayload
, &clientvers
)) {
629 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
634 * Verify client version is supported
636 if (DTLS_VERSION_LT(clientvers
, (unsigned int)s
->method
->version
) &&
637 s
->method
->version
!= DTLS_ANY_VERSION
) {
638 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_WRONG_VERSION_NUMBER
);
642 if (!PACKET_forward(&msgpayload
, SSL3_RANDOM_SIZE
)
643 || !PACKET_get_length_prefixed_1(&msgpayload
, &session
)
644 || !PACKET_get_length_prefixed_1(&msgpayload
, &cookiepkt
)) {
646 * Could be malformed or the cookie does not fit within the initial
647 * ClientHello fragment. Either way we can't handle it.
649 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_LENGTH_MISMATCH
);
654 * Check if we have a cookie or not. If not we need to send a
655 * HelloVerifyRequest.
657 if (PACKET_remaining(&cookiepkt
) == 0) {
658 next
= LISTEN_SEND_VERIFY_REQUEST
;
661 * We have a cookie, so lets check it.
663 if (s
->ctx
->app_verify_cookie_cb
== NULL
) {
664 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_NO_VERIFY_COOKIE_CALLBACK
);
668 if (s
->ctx
->app_verify_cookie_cb(s
, PACKET_data(&cookiepkt
),
669 PACKET_remaining(&cookiepkt
)) ==
672 * We treat invalid cookies in the same was as no cookie as
675 next
= LISTEN_SEND_VERIFY_REQUEST
;
677 /* Cookie verification succeeded */
678 next
= LISTEN_SUCCESS
;
682 if (next
== LISTEN_SEND_VERIFY_REQUEST
) {
684 unsigned int version
;
688 * There was no cookie in the ClientHello so we need to send a
689 * HelloVerifyRequest. If this fails we do not worry about trying
690 * to resend, we just drop it.
694 * Dump the read packet, we don't need it any more. Ignore return
697 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
698 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
699 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 1, NULL
);
701 /* Generate the cookie */
702 if (s
->ctx
->app_gen_cookie_cb
== NULL
||
703 s
->ctx
->app_gen_cookie_cb(s
, cookie
, &cookielen
) == 0 ||
705 SSLerr(SSL_F_DTLSV1_LISTEN
, SSL_R_COOKIE_GEN_CALLBACK_FAILURE
);
711 * Special case: for hello verify request, client version 1.0 and we
712 * haven't decided which version to use yet send back using version
713 * 1.0 header: otherwise some clients will ignore it.
715 version
= (s
->method
->version
== DTLS_ANY_VERSION
) ? DTLS1_VERSION
718 /* Construct the record and message headers */
719 if (!WPACKET_init(&wpkt
, s
->init_buf
)
720 || !WPACKET_put_bytes_u8(&wpkt
, SSL3_RT_HANDSHAKE
)
721 || !WPACKET_put_bytes_u16(&wpkt
, version
)
723 * Record sequence number is always the same as in the
724 * received ClientHello
726 || !WPACKET_memcpy(&wpkt
, seq
, SEQ_NUM_SIZE
)
727 /* End of record, start sub packet for message */
728 || !WPACKET_start_sub_packet_u16(&wpkt
)
730 || !WPACKET_put_bytes_u8(&wpkt
,
731 DTLS1_MT_HELLO_VERIFY_REQUEST
)
733 * Message length - doesn't follow normal TLS convention:
734 * the length isn't the last thing in the message header.
735 * We'll need to fill this in later when we know the
736 * length. Set it to zero for now
738 || !WPACKET_put_bytes_u24(&wpkt
, 0)
740 * Message sequence number is always 0 for a
743 || !WPACKET_put_bytes_u16(&wpkt
, 0)
745 * We never fragment a HelloVerifyRequest, so fragment
748 || !WPACKET_put_bytes_u24(&wpkt
, 0)
750 * Fragment length is the same as message length, but
751 * this *is* the last thing in the message header so we
752 * can just start a sub-packet. No need to come back
753 * later for this one.
755 || !WPACKET_start_sub_packet_u24(&wpkt
)
756 /* Create the actual HelloVerifyRequest body */
757 || !dtls_raw_hello_verify_request(&wpkt
, cookie
, cookielen
)
758 /* Close message body */
759 || !WPACKET_close(&wpkt
)
760 /* Close record body */
761 || !WPACKET_close(&wpkt
)
762 || !WPACKET_get_total_written(&wpkt
, &wreclen
)
763 || !WPACKET_finish(&wpkt
)) {
764 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_INTERNAL_ERROR
);
765 WPACKET_cleanup(&wpkt
);
771 * Fix up the message len in the message header. Its the same as the
772 * fragment len which has been filled in by WPACKET, so just copy
773 * that. Destination for the message len is after the record header
774 * plus one byte for the message content type. The source is the
775 * last 3 bytes of the message header
777 memcpy(&buf
[DTLS1_RT_HEADER_LENGTH
+ 1],
778 &buf
[DTLS1_RT_HEADER_LENGTH
+ DTLS1_HM_HEADER_LENGTH
- 3],
782 s
->msg_callback(1, 0, SSL3_RT_HEADER
, buf
,
783 DTLS1_RT_HEADER_LENGTH
, s
, s
->msg_callback_arg
);
785 if ((tmpclient
= BIO_ADDR_new()) == NULL
) {
786 SSLerr(SSL_F_DTLSV1_LISTEN
, ERR_R_MALLOC_FAILURE
);
791 * This is unnecessary if rbio and wbio are one and the same - but
792 * maybe they're not. We ignore errors here - some BIOs do not
795 if (BIO_dgram_get_peer(rbio
, tmpclient
) > 0) {
796 (void)BIO_dgram_set_peer(wbio
, tmpclient
);
798 BIO_ADDR_free(tmpclient
);
801 if (BIO_write(wbio
, buf
, wreclen
) < (int)wreclen
) {
802 if (BIO_should_retry(wbio
)) {
804 * Non-blocking IO...but we're stateless, so we're just
805 * going to drop this packet.
812 if (BIO_flush(wbio
) <= 0) {
813 if (BIO_should_retry(wbio
)) {
815 * Non-blocking IO...but we're stateless, so we're just
816 * going to drop this packet.
823 } while (next
!= LISTEN_SUCCESS
);
826 * Set expected sequence numbers to continue the handshake.
828 s
->d1
->handshake_read_seq
= 1;
829 s
->d1
->handshake_write_seq
= 1;
830 s
->d1
->next_handshake_write_seq
= 1;
831 DTLS_RECORD_LAYER_set_write_sequence(&s
->rlayer
, seq
);
834 * We are doing cookie exchange, so make sure we set that option in the
837 SSL_set_options(s
, SSL_OP_COOKIE_EXCHANGE
);
840 * Tell the state machine that we've done the initial hello verify
843 ossl_statem_set_hello_verify_done(s
);
846 * Some BIOs may not support this. If we fail we clear the client address
848 if (BIO_dgram_get_peer(rbio
, client
) <= 0)
849 BIO_ADDR_clear(client
);
854 BIO_ADDR_free(tmpclient
);
855 BIO_ctrl(SSL_get_rbio(s
), BIO_CTRL_DGRAM_SET_PEEK_MODE
, 0, NULL
);
857 /* Dump this packet. Ignore return value */
858 BIO_read(rbio
, buf
, SSL3_RT_MAX_PLAIN_LENGTH
);
864 static int dtls1_set_handshake_header(SSL
*s
, int htype
, unsigned long len
)
866 dtls1_set_message_header(s
, htype
, len
, 0, len
);
867 s
->init_num
= (int)len
+ DTLS1_HM_HEADER_LENGTH
;
869 /* Buffer the message to handle re-xmits */
871 if (!dtls1_buffer_message(s
, 0))
877 static int dtls1_handshake_write(SSL
*s
)
879 return dtls1_do_write(s
, SSL3_RT_HANDSHAKE
);
882 #ifndef OPENSSL_NO_HEARTBEATS
884 # define HEARTBEAT_SIZE(payload, padding) ( \
885 1 /* heartbeat type */ + \
886 2 /* heartbeat length */ + \
887 (payload) + (padding))
889 # define HEARTBEAT_SIZE_STD(payload) HEARTBEAT_SIZE(payload, 16)
891 int dtls1_process_heartbeat(SSL
*s
, unsigned char *p
, unsigned int length
)
894 unsigned short hbtype
;
895 unsigned int payload
;
896 unsigned int padding
= 16; /* Use minimum padding */
899 s
->msg_callback(0, s
->version
, DTLS1_RT_HEARTBEAT
,
900 p
, length
, s
, s
->msg_callback_arg
);
902 /* Read type and payload length */
903 if (HEARTBEAT_SIZE_STD(0) > length
)
904 return 0; /* silently discard */
905 if (length
> SSL3_RT_MAX_PLAIN_LENGTH
)
906 return 0; /* silently discard per RFC 6520 sec. 4 */
910 if (HEARTBEAT_SIZE_STD(payload
) > length
)
911 return 0; /* silently discard per RFC 6520 sec. 4 */
914 if (hbtype
== TLS1_HB_REQUEST
) {
915 unsigned char *buffer
, *bp
;
916 unsigned int write_length
= HEARTBEAT_SIZE(payload
, padding
);
919 if (write_length
> SSL3_RT_MAX_PLAIN_LENGTH
)
922 /* Allocate memory for the response. */
923 buffer
= OPENSSL_malloc(write_length
);
928 /* Enter response type, length and copy payload */
929 *bp
++ = TLS1_HB_RESPONSE
;
931 memcpy(bp
, pl
, payload
);
934 if (RAND_bytes(bp
, padding
) <= 0) {
935 OPENSSL_free(buffer
);
939 r
= dtls1_write_bytes(s
, DTLS1_RT_HEARTBEAT
, buffer
, write_length
);
941 if (r
>= 0 && s
->msg_callback
)
942 s
->msg_callback(1, s
->version
, DTLS1_RT_HEARTBEAT
,
943 buffer
, write_length
, s
, s
->msg_callback_arg
);
945 OPENSSL_free(buffer
);
949 } else if (hbtype
== TLS1_HB_RESPONSE
) {
953 * We only send sequence numbers (2 bytes unsigned int), and 16
954 * random bytes, so we just try to read the sequence number
958 if (payload
== 18 && seq
== s
->tlsext_hb_seq
) {
961 s
->tlsext_hb_pending
= 0;
968 int dtls1_heartbeat(SSL
*s
)
970 unsigned char *buf
, *p
;
972 unsigned int payload
= 18; /* Sequence number + random bytes */
973 unsigned int padding
= 16; /* Use minimum padding */
976 /* Only send if peer supports and accepts HB requests... */
977 if (!(s
->tlsext_heartbeat
& SSL_DTLSEXT_HB_ENABLED
) ||
978 s
->tlsext_heartbeat
& SSL_DTLSEXT_HB_DONT_SEND_REQUESTS
) {
979 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT
);
983 /* ...and there is none in flight yet... */
984 if (s
->tlsext_hb_pending
) {
985 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PENDING
);
989 /* ...and no handshake in progress. */
990 if (SSL_in_init(s
) || ossl_statem_get_in_handshake(s
)) {
991 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_UNEXPECTED_MESSAGE
);
996 * Create HeartBeat message, we just use a sequence number
997 * as payload to distinguish different messages and add
1000 size
= HEARTBEAT_SIZE(payload
, padding
);
1001 buf
= OPENSSL_malloc(size
);
1003 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_MALLOC_FAILURE
);
1008 *p
++ = TLS1_HB_REQUEST
;
1009 /* Payload length (18 bytes here) */
1011 /* Sequence number */
1012 s2n(s
->tlsext_hb_seq
, p
);
1013 /* 16 random bytes */
1014 if (RAND_bytes(p
, 16) <= 0) {
1015 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1019 /* Random padding */
1020 if (RAND_bytes(p
, padding
) <= 0) {
1021 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_INTERNAL_ERROR
);
1025 ret
= dtls1_write_bytes(s
, DTLS1_RT_HEARTBEAT
, buf
, size
);
1027 if (s
->msg_callback
)
1028 s
->msg_callback(1, s
->version
, DTLS1_RT_HEARTBEAT
,
1029 buf
, size
, s
, s
->msg_callback_arg
);
1031 dtls1_start_timer(s
);
1032 s
->tlsext_hb_pending
= 1;
1042 int dtls1_shutdown(SSL
*s
)
1045 #ifndef OPENSSL_NO_SCTP
1048 wbio
= SSL_get_wbio(s
);
1049 if (wbio
!= NULL
&& BIO_dgram_is_sctp(wbio
) &&
1050 !(s
->shutdown
& SSL_SENT_SHUTDOWN
)) {
1051 ret
= BIO_dgram_sctp_wait_for_dry(wbio
);
1056 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 1,
1060 ret
= ssl3_shutdown(s
);
1061 #ifndef OPENSSL_NO_SCTP
1062 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 0, NULL
);
1067 int dtls1_query_mtu(SSL
*s
)
1069 if (s
->d1
->link_mtu
) {
1071 s
->d1
->link_mtu
- BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
1072 s
->d1
->link_mtu
= 0;
1075 /* AHA! Figure out the MTU, and stick to the right size */
1076 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1077 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
1079 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_QUERY_MTU
, 0, NULL
);
1082 * I've seen the kernel return bogus numbers when it doesn't know
1083 * (initial write), so just make sure we have a reasonable number
1085 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
1086 /* Set to min mtu */
1087 s
->d1
->mtu
= dtls1_min_mtu(s
);
1088 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SET_MTU
,
1097 static unsigned int dtls1_link_min_mtu(void)
1099 return (g_probable_mtu
[(sizeof(g_probable_mtu
) /
1100 sizeof(g_probable_mtu
[0])) - 1]);
1103 unsigned int dtls1_min_mtu(SSL
*s
)
1105 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));