3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1998-2005 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).
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
62 * This package is an SSL implementation written
63 * by Eric Young (eay@cryptsoft.com).
64 * The implementation was written so as to conform with Netscapes SSL.
66 * This library is free for commercial and non-commercial use as long as
67 * the following conditions are aheared to. The following conditions
68 * apply to all code found in this distribution, be it the RC4, RSA,
69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
70 * included with this distribution is covered by the same copyright terms
71 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
73 * Copyright remains Eric Young's, and as such any Copyright notices in
74 * the code are not to be removed.
75 * If this package is used in a product, Eric Young should be given attribution
76 * as the author of the parts of the library used.
77 * This can be in the form of a textual message at program startup or
78 * in documentation (online or textual) provided with the package.
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
83 * 1. Redistributions of source code must retain the copyright
84 * notice, this list of conditions and the following disclaimer.
85 * 2. Redistributions in binary form must reproduce the above copyright
86 * notice, this list of conditions and the following disclaimer in the
87 * documentation and/or other materials provided with the distribution.
88 * 3. All advertising materials mentioning features or use of this software
89 * must display the following acknowledgement:
90 * "This product includes cryptographic software written by
91 * Eric Young (eay@cryptsoft.com)"
92 * The word 'cryptographic' can be left out if the rouines from the library
93 * being used are not cryptographic related :-).
94 * 4. If you include any Windows specific code (or a derivative thereof) from
95 * the apps directory (application code) you must include an acknowledgement:
96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
110 * The licence and distribution terms for any publically available version or
111 * derivative of this code cannot be changed. i.e. this code cannot simply be
112 * copied and put under another distribution licence
113 * [including the GNU Public Licence.]
119 #include "ssl_locl.h"
120 #include <openssl/buffer.h>
121 #include <openssl/rand.h>
122 #include <openssl/objects.h>
123 #include <openssl/evp.h>
124 #include <openssl/x509.h>
126 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
129 if ((end) - (start) <= 8) { \
131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
141 OPENSSL_assert((msg_len) > 0); \
143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
148 # define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
155 static unsigned char bitmask_start_values
[] =
156 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
157 static unsigned char bitmask_end_values
[] =
158 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
160 /* XDTLS: figure out the right values */
161 static const unsigned int g_probable_mtu
[] = { 1500, 512, 256 };
163 static void dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
164 unsigned long frag_len
);
165 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
);
166 static void dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
168 unsigned short seq_num
,
169 unsigned long frag_off
,
170 unsigned long frag_len
);
171 static long dtls1_get_message_fragment(SSL
*s
, int st1
, int stn
, long max
,
174 static hm_fragment
*dtls1_hm_fragment_new(unsigned long frag_len
,
177 hm_fragment
*frag
= NULL
;
178 unsigned char *buf
= NULL
;
179 unsigned char *bitmask
= NULL
;
181 frag
= (hm_fragment
*)OPENSSL_malloc(sizeof(hm_fragment
));
186 buf
= (unsigned char *)OPENSSL_malloc(frag_len
);
193 /* zero length fragment gets zero frag->fragment */
194 frag
->fragment
= buf
;
196 /* Initialize reassembly bitmask if necessary */
199 (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len
));
200 if (bitmask
== NULL
) {
206 memset(bitmask
, 0, RSMBLY_BITMASK_SIZE(frag_len
));
209 frag
->reassembly
= bitmask
;
214 void dtls1_hm_fragment_free(hm_fragment
*frag
)
217 if (frag
->msg_header
.is_ccs
) {
218 EVP_CIPHER_CTX_free(frag
->msg_header
.
219 saved_retransmit_state
.enc_write_ctx
);
220 EVP_MD_CTX_destroy(frag
->msg_header
.
221 saved_retransmit_state
.write_hash
);
224 OPENSSL_free(frag
->fragment
);
225 if (frag
->reassembly
)
226 OPENSSL_free(frag
->reassembly
);
230 static int dtls1_query_mtu(SSL
*s
)
232 if (s
->d1
->link_mtu
) {
234 s
->d1
->link_mtu
- BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
238 /* AHA! Figure out the MTU, and stick to the right size */
239 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
240 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
242 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_QUERY_MTU
, 0, NULL
);
245 * I've seen the kernel return bogus numbers when it doesn't know
246 * (initial write), so just make sure we have a reasonable number
248 if (s
->d1
->mtu
< dtls1_min_mtu(s
)) {
250 s
->d1
->mtu
= dtls1_min_mtu(s
);
251 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SET_MTU
,
261 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
262 * SSL3_RT_CHANGE_CIPHER_SPEC)
264 int dtls1_do_write(SSL
*s
, int type
)
267 unsigned int curr_mtu
;
269 unsigned int len
, frag_off
, mac_size
, blocksize
, used_len
;
271 if (!dtls1_query_mtu(s
))
274 OPENSSL_assert(s
->d1
->mtu
>= dtls1_min_mtu(s
)); /* should have something
277 if (s
->init_off
== 0 && type
== SSL3_RT_HANDSHAKE
)
278 OPENSSL_assert(s
->init_num
==
279 (int)s
->d1
->w_msg_hdr
.msg_len
+
280 DTLS1_HM_HEADER_LENGTH
);
284 && EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_GCM_MODE
)
287 mac_size
= EVP_MD_CTX_size(s
->write_hash
);
291 if (s
->enc_write_ctx
&&
292 (EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_CBC_MODE
))
293 blocksize
= 2 * EVP_CIPHER_block_size(s
->enc_write_ctx
->cipher
);
298 /* s->init_num shouldn't ever be < 0...but just in case */
299 while (s
->init_num
> 0) {
300 used_len
= BIO_wpending(SSL_get_wbio(s
)) + DTLS1_RT_HEADER_LENGTH
301 + mac_size
+ blocksize
;
302 if (s
->d1
->mtu
> used_len
)
303 curr_mtu
= s
->d1
->mtu
- used_len
;
307 if (curr_mtu
<= DTLS1_HM_HEADER_LENGTH
) {
309 * grr.. we could get an error if MTU picked was wrong
311 ret
= BIO_flush(SSL_get_wbio(s
));
314 used_len
= DTLS1_RT_HEADER_LENGTH
+ mac_size
+ blocksize
;
315 if (s
->d1
->mtu
> used_len
+ DTLS1_HM_HEADER_LENGTH
) {
316 curr_mtu
= s
->d1
->mtu
- used_len
;
318 /* Shouldn't happen */
324 * We just checked that s->init_num > 0 so this cast should be safe
326 if (((unsigned int)s
->init_num
) > curr_mtu
)
331 /* Shouldn't ever happen */
336 * XDTLS: this function is too long. split out the CCS part
338 if (type
== SSL3_RT_HANDSHAKE
) {
339 if (s
->init_off
!= 0) {
340 OPENSSL_assert(s
->init_off
> DTLS1_HM_HEADER_LENGTH
);
341 s
->init_off
-= DTLS1_HM_HEADER_LENGTH
;
342 s
->init_num
+= DTLS1_HM_HEADER_LENGTH
;
345 * We just checked that s->init_num > 0 so this cast should
348 if (((unsigned int)s
->init_num
) > curr_mtu
)
354 /* Shouldn't ever happen */
358 if (len
< DTLS1_HM_HEADER_LENGTH
) {
360 * len is so small that we really can't do anything sensible
365 dtls1_fix_message_header(s
, frag_off
,
366 len
- DTLS1_HM_HEADER_LENGTH
);
368 dtls1_write_message_header(s
,
369 (unsigned char *)&s
->init_buf
->
373 ret
= dtls1_write_bytes(s
, type
, &s
->init_buf
->data
[s
->init_off
],
377 * might need to update MTU here, but we don't know which
378 * previous packet caused the failure -- so can't really
379 * retransmit anything. continue as if everything is fine and
380 * wait for an alert to handle the retransmit
382 if (retry
&& BIO_ctrl(SSL_get_wbio(s
),
383 BIO_CTRL_DGRAM_MTU_EXCEEDED
, 0, NULL
) > 0) {
384 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
385 if (!dtls1_query_mtu(s
))
387 /* Have one more go */
397 * bad if this assert fails, only part of the handshake message
398 * got sent. but why would this happen?
400 OPENSSL_assert(len
== (unsigned int)ret
);
402 if (type
== SSL3_RT_HANDSHAKE
&& !s
->d1
->retransmitting
) {
404 * should not be done for 'Hello Request's, but in that case
405 * we'll ignore the result anyway
408 (unsigned char *)&s
->init_buf
->data
[s
->init_off
];
409 const struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
412 if (frag_off
== 0 && s
->version
!= DTLS1_BAD_VER
) {
414 * reconstruct message header is if it is being sent in
417 *p
++ = msg_hdr
->type
;
418 l2n3(msg_hdr
->msg_len
, p
);
419 s2n(msg_hdr
->seq
, p
);
421 l2n3(msg_hdr
->msg_len
, p
);
422 p
-= DTLS1_HM_HEADER_LENGTH
;
425 p
+= DTLS1_HM_HEADER_LENGTH
;
426 xlen
= ret
- DTLS1_HM_HEADER_LENGTH
;
429 ssl3_finish_mac(s
, p
, xlen
);
432 if (ret
== s
->init_num
) {
434 s
->msg_callback(1, s
->version
, type
, s
->init_buf
->data
,
435 (size_t)(s
->init_off
+ s
->init_num
), s
,
436 s
->msg_callback_arg
);
438 s
->init_off
= 0; /* done writing this message */
445 frag_off
+= (ret
-= DTLS1_HM_HEADER_LENGTH
);
452 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum
453 * acceptable body length 'max'. Read an entire handshake message. Handshake
454 * messages arrive in fragments.
456 long dtls1_get_message(SSL
*s
, int st1
, int stn
, int mt
, long max
, int *ok
)
459 struct hm_header_st
*msg_hdr
;
461 unsigned long msg_len
;
464 * s3->tmp is used to store messages that are unexpected, caused by the
465 * absence of an optional handshake message
467 if (s
->s3
->tmp
.reuse_message
) {
468 s
->s3
->tmp
.reuse_message
= 0;
469 if ((mt
>= 0) && (s
->s3
->tmp
.message_type
!= mt
)) {
470 al
= SSL_AD_UNEXPECTED_MESSAGE
;
471 SSLerr(SSL_F_DTLS1_GET_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
475 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
476 s
->init_num
= (int)s
->s3
->tmp
.message_size
;
480 msg_hdr
= &s
->d1
->r_msg_hdr
;
481 memset(msg_hdr
, 0x00, sizeof(struct hm_header_st
));
484 i
= dtls1_get_message_fragment(s
, st1
, stn
, max
, ok
);
485 if (i
== DTLS1_HM_BAD_FRAGMENT
|| i
== DTLS1_HM_FRAGMENT_RETRY
) {
486 /* bad fragment received */
488 } else if (i
<= 0 && !*ok
) {
492 p
= (unsigned char *)s
->init_buf
->data
;
493 msg_len
= msg_hdr
->msg_len
;
495 /* reconstruct message header */
496 *(p
++) = msg_hdr
->type
;
498 s2n(msg_hdr
->seq
, p
);
501 if (s
->version
!= DTLS1_BAD_VER
) {
502 p
-= DTLS1_HM_HEADER_LENGTH
;
503 msg_len
+= DTLS1_HM_HEADER_LENGTH
;
506 ssl3_finish_mac(s
, p
, msg_len
);
508 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
509 p
, msg_len
, s
, s
->msg_callback_arg
);
511 memset(msg_hdr
, 0x00, sizeof(struct hm_header_st
));
513 /* Don't change sequence numbers while listening */
515 s
->d1
->handshake_read_seq
++;
517 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
521 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
526 static int dtls1_preprocess_fragment(SSL
*s
, struct hm_header_st
*msg_hdr
,
529 size_t frag_off
, frag_len
, msg_len
;
531 msg_len
= msg_hdr
->msg_len
;
532 frag_off
= msg_hdr
->frag_off
;
533 frag_len
= msg_hdr
->frag_len
;
535 /* sanity checking */
536 if ((frag_off
+ frag_len
) > msg_len
) {
537 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
538 return SSL_AD_ILLEGAL_PARAMETER
;
541 if ((frag_off
+ frag_len
) > (unsigned long)max
) {
542 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
543 return SSL_AD_ILLEGAL_PARAMETER
;
546 if (s
->d1
->r_msg_hdr
.frag_off
== 0) { /* first fragment */
548 * msg_len is limited to 2^24, but is effectively checked against max
551 if (!BUF_MEM_grow_clean
552 (s
->init_buf
, msg_len
+ DTLS1_HM_HEADER_LENGTH
)) {
553 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, ERR_R_BUF_LIB
);
554 return SSL_AD_INTERNAL_ERROR
;
557 s
->s3
->tmp
.message_size
= msg_len
;
558 s
->d1
->r_msg_hdr
.msg_len
= msg_len
;
559 s
->s3
->tmp
.message_type
= msg_hdr
->type
;
560 s
->d1
->r_msg_hdr
.type
= msg_hdr
->type
;
561 s
->d1
->r_msg_hdr
.seq
= msg_hdr
->seq
;
562 } else if (msg_len
!= s
->d1
->r_msg_hdr
.msg_len
) {
564 * They must be playing with us! BTW, failure to enforce upper limit
565 * would open possibility for buffer overrun.
567 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
568 return SSL_AD_ILLEGAL_PARAMETER
;
571 return 0; /* no error */
574 static int dtls1_retrieve_buffered_fragment(SSL
*s
, long max
, int *ok
)
577 * (0) check whether the desired fragment is available
579 * (1) copy over the fragment to s->init_buf->data[]
580 * (2) update s->init_num
587 item
= pqueue_peek(s
->d1
->buffered_messages
);
591 frag
= (hm_fragment
*)item
->data
;
593 /* Don't return if reassembly still in progress */
594 if (frag
->reassembly
!= NULL
)
597 if (s
->d1
->handshake_read_seq
== frag
->msg_header
.seq
) {
598 unsigned long frag_len
= frag
->msg_header
.frag_len
;
599 pqueue_pop(s
->d1
->buffered_messages
);
601 al
= dtls1_preprocess_fragment(s
, &frag
->msg_header
, max
);
603 if (al
== 0) { /* no alert */
605 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
606 memcpy(&p
[frag
->msg_header
.frag_off
], frag
->fragment
,
607 frag
->msg_header
.frag_len
);
610 dtls1_hm_fragment_free(frag
);
618 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
627 * dtls1_max_handshake_message_len returns the maximum number of bytes
628 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
629 * may be greater if the maximum certificate list size requires it.
631 static unsigned long dtls1_max_handshake_message_len(const SSL
*s
)
633 unsigned long max_len
=
634 DTLS1_HM_HEADER_LENGTH
+ SSL3_RT_MAX_ENCRYPTED_LENGTH
;
635 if (max_len
< (unsigned long)s
->max_cert_list
)
636 return s
->max_cert_list
;
641 dtls1_reassemble_fragment(SSL
*s
, const struct hm_header_st
*msg_hdr
, int *ok
)
643 hm_fragment
*frag
= NULL
;
645 int i
= -1, is_complete
;
646 unsigned char seq64be
[8];
647 unsigned long frag_len
= msg_hdr
->frag_len
;
649 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
||
650 msg_hdr
->msg_len
> dtls1_max_handshake_message_len(s
))
654 return DTLS1_HM_FRAGMENT_RETRY
;
656 /* Try to find item in queue */
657 memset(seq64be
, 0, sizeof(seq64be
));
658 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
659 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
660 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
663 frag
= dtls1_hm_fragment_new(msg_hdr
->msg_len
, 1);
666 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
667 frag
->msg_header
.frag_len
= frag
->msg_header
.msg_len
;
668 frag
->msg_header
.frag_off
= 0;
670 frag
= (hm_fragment
*)item
->data
;
671 if (frag
->msg_header
.msg_len
!= msg_hdr
->msg_len
) {
679 * If message is already reassembled, this must be a retransmit and can
680 * be dropped. In this case item != NULL and so frag does not need to be
683 if (frag
->reassembly
== NULL
) {
684 unsigned char devnull
[256];
687 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
,
690 sizeof(devnull
) ? sizeof(devnull
) :
696 return DTLS1_HM_FRAGMENT_RETRY
;
699 /* read the body of the fragment (header has already been read */
700 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
,
701 frag
->fragment
+ msg_hdr
->frag_off
,
703 if ((unsigned long)i
!= frag_len
)
708 RSMBLY_BITMASK_MARK(frag
->reassembly
, (long)msg_hdr
->frag_off
,
709 (long)(msg_hdr
->frag_off
+ frag_len
));
711 RSMBLY_BITMASK_IS_COMPLETE(frag
->reassembly
, (long)msg_hdr
->msg_len
,
715 OPENSSL_free(frag
->reassembly
);
716 frag
->reassembly
= NULL
;
720 item
= pitem_new(seq64be
, frag
);
726 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
728 * pqueue_insert fails iff a duplicate item is inserted. However,
729 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
730 * would have returned it and control would never have reached this
733 OPENSSL_assert(item
!= NULL
);
736 return DTLS1_HM_FRAGMENT_RETRY
;
739 if (frag
!= NULL
&& item
== NULL
)
740 dtls1_hm_fragment_free(frag
);
746 dtls1_process_out_of_seq_message(SSL
*s
, const struct hm_header_st
*msg_hdr
,
750 hm_fragment
*frag
= NULL
;
752 unsigned char seq64be
[8];
753 unsigned long frag_len
= msg_hdr
->frag_len
;
755 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
)
758 /* Try to find item in queue, to prevent duplicate entries */
759 memset(seq64be
, 0, sizeof(seq64be
));
760 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
761 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
762 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
765 * If we already have an entry and this one is a fragment, don't discard
766 * it and rather try to reassemble it.
768 if (item
!= NULL
&& frag_len
!= msg_hdr
->msg_len
)
772 * Discard the message if sequence number was already there, is too far
773 * in the future, already in the queue or if we received a FINISHED
774 * before the SERVER_HELLO, which then must be a stale retransmit.
776 if (msg_hdr
->seq
<= s
->d1
->handshake_read_seq
||
777 msg_hdr
->seq
> s
->d1
->handshake_read_seq
+ 10 || item
!= NULL
||
778 (s
->d1
->handshake_read_seq
== 0 && msg_hdr
->type
== SSL3_MT_FINISHED
))
780 unsigned char devnull
[256];
783 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
,
786 sizeof(devnull
) ? sizeof(devnull
) :
793 if (frag_len
!= msg_hdr
->msg_len
)
794 return dtls1_reassemble_fragment(s
, msg_hdr
, ok
);
796 if (frag_len
> dtls1_max_handshake_message_len(s
))
799 frag
= dtls1_hm_fragment_new(frag_len
, 0);
803 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
807 * read the body of the fragment (header has already been read
809 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
,
810 frag
->fragment
, frag_len
, 0);
811 if ((unsigned long)i
!= frag_len
)
817 item
= pitem_new(seq64be
, frag
);
821 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
823 * pqueue_insert fails iff a duplicate item is inserted. However,
824 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
825 * would have returned it. Then, either |frag_len| !=
826 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
827 * have been processed with |dtls1_reassemble_fragment|, above, or
828 * the record will have been discarded.
830 OPENSSL_assert(item
!= NULL
);
833 return DTLS1_HM_FRAGMENT_RETRY
;
836 if (frag
!= NULL
&& item
== NULL
)
837 dtls1_hm_fragment_free(frag
);
843 dtls1_get_message_fragment(SSL
*s
, int st1
, int stn
, long max
, int *ok
)
845 unsigned char wire
[DTLS1_HM_HEADER_LENGTH
];
846 unsigned long len
, frag_off
, frag_len
;
848 struct hm_header_st msg_hdr
;
851 /* see if we have the required fragment already */
852 if ((frag_len
= dtls1_retrieve_buffered_fragment(s
, max
, ok
)) || *ok
) {
854 s
->init_num
= frag_len
;
858 /* read handshake message header */
859 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, wire
,
860 DTLS1_HM_HEADER_LENGTH
, 0);
861 if (i
<= 0) { /* nbio, or an error */
862 s
->rwstate
= SSL_READING
;
866 /* Handshake fails if message header is incomplete */
867 if (i
!= DTLS1_HM_HEADER_LENGTH
) {
868 al
= SSL_AD_UNEXPECTED_MESSAGE
;
869 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT
, SSL_R_UNEXPECTED_MESSAGE
);
873 /* parse the message fragment header */
874 dtls1_get_message_header(wire
, &msg_hdr
);
877 * if this is a future (or stale) message it gets buffered
878 * (or dropped)--no further processing at this time
879 * While listening, we accept seq 1 (ClientHello with cookie)
880 * although we're still expecting seq 0 (ClientHello)
882 if (msg_hdr
.seq
!= s
->d1
->handshake_read_seq
883 && !(s
->d1
->listen
&& msg_hdr
.seq
== 1))
884 return dtls1_process_out_of_seq_message(s
, &msg_hdr
, ok
);
886 len
= msg_hdr
.msg_len
;
887 frag_off
= msg_hdr
.frag_off
;
888 frag_len
= msg_hdr
.frag_len
;
890 if (frag_len
&& frag_len
< len
)
891 return dtls1_reassemble_fragment(s
, &msg_hdr
, ok
);
893 if (!s
->server
&& s
->d1
->r_msg_hdr
.frag_off
== 0 &&
894 wire
[0] == SSL3_MT_HELLO_REQUEST
) {
896 * The server may always send 'Hello Request' messages -- we are
897 * doing a handshake anyway now, so ignore them if their format is
898 * correct. Does not count for 'Finished' MAC.
900 if (wire
[1] == 0 && wire
[2] == 0 && wire
[3] == 0) {
902 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
903 wire
, DTLS1_HM_HEADER_LENGTH
, s
,
904 s
->msg_callback_arg
);
908 } else { /* Incorrectly formated Hello request */
910 al
= SSL_AD_UNEXPECTED_MESSAGE
;
911 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT
,
912 SSL_R_UNEXPECTED_MESSAGE
);
917 if ((al
= dtls1_preprocess_fragment(s
, &msg_hdr
, max
)))
920 /* XDTLS: ressurect this when restart is in place */
925 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
927 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
,
928 &p
[frag_off
], frag_len
, 0);
930 * XDTLS: fix this--message fragments cannot span multiple packets
933 s
->rwstate
= SSL_READING
;
941 * XDTLS: an incorrectly formatted fragment should cause the handshake
944 if (i
!= (int)frag_len
) {
945 al
= SSL3_AD_ILLEGAL_PARAMETER
;
946 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT
, SSL3_AD_ILLEGAL_PARAMETER
);
953 * Note that s->init_num is *not* used as current offset in
954 * s->init_buf->data, but as a counter summing up fragments' lengths: as
955 * soon as they sum up to handshake packet length, we assume we have got
958 s
->init_num
= frag_len
;
962 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
970 * for these 2 messages, we need to
971 * ssl->enc_read_ctx re-init
972 * ssl->s3->read_sequence zero
973 * ssl->s3->read_mac_secret re-init
974 * ssl->session->read_sym_enc assign
975 * ssl->session->read_compression assign
976 * ssl->session->read_hash assign
978 int dtls1_send_change_cipher_spec(SSL
*s
, int a
, int b
)
983 p
= (unsigned char *)s
->init_buf
->data
;
985 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
986 s
->init_num
= DTLS1_CCS_HEADER_LENGTH
;
988 if (s
->version
== DTLS1_BAD_VER
) {
989 s
->d1
->next_handshake_write_seq
++;
990 s2n(s
->d1
->handshake_write_seq
, p
);
996 dtls1_set_message_header_int(s
, SSL3_MT_CCS
, 0,
997 s
->d1
->handshake_write_seq
, 0, 0);
999 /* buffer the message to handle re-xmits */
1000 dtls1_buffer_message(s
, 1);
1005 /* SSL3_ST_CW_CHANGE_B */
1006 return (dtls1_do_write(s
, SSL3_RT_CHANGE_CIPHER_SPEC
));
1009 int dtls1_read_failed(SSL
*s
, int code
)
1012 fprintf(stderr
, "invalid state reached %s:%d", __FILE__
, __LINE__
);
1016 if (!dtls1_is_timer_expired(s
)) {
1018 * not a timeout, none of our business, let higher layers handle
1019 * this. in fact it's probably an error
1023 #ifndef OPENSSL_NO_HEARTBEATS
1024 /* done, no need to send a retransmit */
1025 if (!SSL_in_init(s
) && !s
->tlsext_hb_pending
)
1027 /* done, no need to send a retransmit */
1028 if (!SSL_in_init(s
))
1031 BIO_set_flags(SSL_get_rbio(s
), BIO_FLAGS_READ
);
1034 #if 0 /* for now, each alert contains only one
1036 item
= pqueue_peek(state
->rcvd_records
);
1038 /* send an alert immediately for all the missing records */
1042 #if 0 /* no more alert sending, just retransmit the
1043 * last set of messages */
1044 if (state
->timeout
.read_timeouts
>= DTLS1_TMO_READ_COUNT
)
1045 ssl3_send_alert(s
, SSL3_AL_WARNING
,
1046 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
);
1049 return dtls1_handle_timeout(s
);
1052 int dtls1_get_queue_priority(unsigned short seq
, int is_ccs
)
1055 * The index of the retransmission queue actually is the message sequence
1056 * number, since the queue only contains messages of a single handshake.
1057 * However, the ChangeCipherSpec has no message sequence number and so
1058 * using only the sequence will result in the CCS and Finished having the
1059 * same index. To prevent this, the sequence number is multiplied by 2.
1060 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1061 * Finished, it also maintains the order of the index (important for
1062 * priority queues) and fits in the unsigned short variable.
1064 return seq
* 2 - is_ccs
;
1067 int dtls1_retransmit_buffered_messages(SSL
*s
)
1069 pqueue sent
= s
->d1
->sent_messages
;
1075 iter
= pqueue_iterator(sent
);
1077 for (item
= pqueue_next(&iter
); item
!= NULL
; item
= pqueue_next(&iter
)) {
1078 frag
= (hm_fragment
*)item
->data
;
1079 if (dtls1_retransmit_message(s
, (unsigned short)
1080 dtls1_get_queue_priority
1081 (frag
->msg_header
.seq
,
1082 frag
->msg_header
.is_ccs
), 0,
1083 &found
) <= 0 && found
) {
1084 fprintf(stderr
, "dtls1_retransmit_message() failed\n");
1092 int dtls1_buffer_message(SSL
*s
, int is_ccs
)
1096 unsigned char seq64be
[8];
1099 * this function is called immediately after a message has been
1102 OPENSSL_assert(s
->init_off
== 0);
1104 frag
= dtls1_hm_fragment_new(s
->init_num
, 0);
1108 memcpy(frag
->fragment
, s
->init_buf
->data
, s
->init_num
);
1111 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1112 DTLS1_CCS_HEADER_LENGTH
== (unsigned int)s
->init_num
);
1114 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1115 DTLS1_HM_HEADER_LENGTH
== (unsigned int)s
->init_num
);
1118 frag
->msg_header
.msg_len
= s
->d1
->w_msg_hdr
.msg_len
;
1119 frag
->msg_header
.seq
= s
->d1
->w_msg_hdr
.seq
;
1120 frag
->msg_header
.type
= s
->d1
->w_msg_hdr
.type
;
1121 frag
->msg_header
.frag_off
= 0;
1122 frag
->msg_header
.frag_len
= s
->d1
->w_msg_hdr
.msg_len
;
1123 frag
->msg_header
.is_ccs
= is_ccs
;
1125 /* save current state */
1126 frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
= s
->enc_write_ctx
;
1127 frag
->msg_header
.saved_retransmit_state
.write_hash
= s
->write_hash
;
1128 frag
->msg_header
.saved_retransmit_state
.compress
= s
->compress
;
1129 frag
->msg_header
.saved_retransmit_state
.session
= s
->session
;
1130 frag
->msg_header
.saved_retransmit_state
.epoch
= s
->d1
->w_epoch
;
1132 memset(seq64be
, 0, sizeof(seq64be
));
1135 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1136 frag
->msg_header
.is_ccs
) >> 8);
1139 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1140 frag
->msg_header
.is_ccs
));
1142 item
= pitem_new(seq64be
, frag
);
1144 dtls1_hm_fragment_free(frag
);
1148 fprintf(stderr
, "buffered messge: \ttype = %xx\n", msg_buf
->type
);
1149 fprintf(stderr
, "\t\t\t\t\tlen = %d\n", msg_buf
->len
);
1150 fprintf(stderr
, "\t\t\t\t\tseq_num = %d\n", msg_buf
->seq_num
);
1153 pqueue_insert(s
->d1
->sent_messages
, item
);
1158 dtls1_retransmit_message(SSL
*s
, unsigned short seq
, unsigned long frag_off
,
1162 /* XDTLS: for now assuming that read/writes are blocking */
1165 unsigned long header_length
;
1166 unsigned char seq64be
[8];
1167 struct dtls1_retransmit_state saved_state
;
1168 unsigned char save_write_sequence
[8];
1171 OPENSSL_assert(s->init_num == 0);
1172 OPENSSL_assert(s->init_off == 0);
1175 /* XDTLS: the requested message ought to be found, otherwise error */
1176 memset(seq64be
, 0, sizeof(seq64be
));
1177 seq64be
[6] = (unsigned char)(seq
>> 8);
1178 seq64be
[7] = (unsigned char)seq
;
1180 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1182 fprintf(stderr
, "retransmit: message %d non-existant\n", seq
);
1188 frag
= (hm_fragment
*)item
->data
;
1190 if (frag
->msg_header
.is_ccs
)
1191 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1193 header_length
= DTLS1_HM_HEADER_LENGTH
;
1195 memcpy(s
->init_buf
->data
, frag
->fragment
,
1196 frag
->msg_header
.msg_len
+ header_length
);
1197 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1199 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1200 frag
->msg_header
.msg_len
,
1201 frag
->msg_header
.seq
, 0,
1202 frag
->msg_header
.frag_len
);
1204 /* save current state */
1205 saved_state
.enc_write_ctx
= s
->enc_write_ctx
;
1206 saved_state
.write_hash
= s
->write_hash
;
1207 saved_state
.compress
= s
->compress
;
1208 saved_state
.session
= s
->session
;
1209 saved_state
.epoch
= s
->d1
->w_epoch
;
1210 saved_state
.epoch
= s
->d1
->w_epoch
;
1212 s
->d1
->retransmitting
= 1;
1214 /* restore state in which the message was originally sent */
1215 s
->enc_write_ctx
= frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
;
1216 s
->write_hash
= frag
->msg_header
.saved_retransmit_state
.write_hash
;
1217 s
->compress
= frag
->msg_header
.saved_retransmit_state
.compress
;
1218 s
->session
= frag
->msg_header
.saved_retransmit_state
.session
;
1219 s
->d1
->w_epoch
= frag
->msg_header
.saved_retransmit_state
.epoch
;
1221 if (frag
->msg_header
.saved_retransmit_state
.epoch
==
1222 saved_state
.epoch
- 1) {
1223 memcpy(save_write_sequence
, s
->s3
->write_sequence
,
1224 sizeof(s
->s3
->write_sequence
));
1225 memcpy(s
->s3
->write_sequence
, s
->d1
->last_write_sequence
,
1226 sizeof(s
->s3
->write_sequence
));
1229 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1230 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1232 /* restore current state */
1233 s
->enc_write_ctx
= saved_state
.enc_write_ctx
;
1234 s
->write_hash
= saved_state
.write_hash
;
1235 s
->compress
= saved_state
.compress
;
1236 s
->session
= saved_state
.session
;
1237 s
->d1
->w_epoch
= saved_state
.epoch
;
1239 if (frag
->msg_header
.saved_retransmit_state
.epoch
==
1240 saved_state
.epoch
- 1) {
1241 memcpy(s
->d1
->last_write_sequence
, s
->s3
->write_sequence
,
1242 sizeof(s
->s3
->write_sequence
));
1243 memcpy(s
->s3
->write_sequence
, save_write_sequence
,
1244 sizeof(s
->s3
->write_sequence
));
1247 s
->d1
->retransmitting
= 0;
1249 (void)BIO_flush(SSL_get_wbio(s
));
1253 /* call this function when the buffered messages are no longer needed */
1254 void dtls1_clear_record_buffer(SSL
*s
)
1258 for (item
= pqueue_pop(s
->d1
->sent_messages
);
1259 item
!= NULL
; item
= pqueue_pop(s
->d1
->sent_messages
)) {
1260 dtls1_hm_fragment_free((hm_fragment
*)item
->data
);
1265 unsigned char *dtls1_set_message_header(SSL
*s
, unsigned char *p
,
1266 unsigned char mt
, unsigned long len
,
1267 unsigned long frag_off
,
1268 unsigned long frag_len
)
1270 /* Don't change sequence numbers while listening */
1271 if (frag_off
== 0 && !s
->d1
->listen
) {
1272 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1273 s
->d1
->next_handshake_write_seq
++;
1276 dtls1_set_message_header_int(s
, mt
, len
, s
->d1
->handshake_write_seq
,
1277 frag_off
, frag_len
);
1279 return p
+= DTLS1_HM_HEADER_LENGTH
;
1282 /* don't actually do the writing, wait till the MTU has been retrieved */
1284 dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
1285 unsigned long len
, unsigned short seq_num
,
1286 unsigned long frag_off
, unsigned long frag_len
)
1288 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1291 msg_hdr
->msg_len
= len
;
1292 msg_hdr
->seq
= seq_num
;
1293 msg_hdr
->frag_off
= frag_off
;
1294 msg_hdr
->frag_len
= frag_len
;
1298 dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
1299 unsigned long frag_len
)
1301 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1303 msg_hdr
->frag_off
= frag_off
;
1304 msg_hdr
->frag_len
= frag_len
;
1307 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
)
1309 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1311 *p
++ = msg_hdr
->type
;
1312 l2n3(msg_hdr
->msg_len
, p
);
1314 s2n(msg_hdr
->seq
, p
);
1315 l2n3(msg_hdr
->frag_off
, p
);
1316 l2n3(msg_hdr
->frag_len
, p
);
1321 unsigned int dtls1_link_min_mtu(void)
1323 return (g_probable_mtu
[(sizeof(g_probable_mtu
) /
1324 sizeof(g_probable_mtu
[0])) - 1]);
1327 unsigned int dtls1_min_mtu(SSL
*s
)
1329 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
1333 dtls1_get_message_header(unsigned char *data
, struct hm_header_st
*msg_hdr
)
1335 memset(msg_hdr
, 0x00, sizeof(struct hm_header_st
));
1336 msg_hdr
->type
= *(data
++);
1337 n2l3(data
, msg_hdr
->msg_len
);
1339 n2s(data
, msg_hdr
->seq
);
1340 n2l3(data
, msg_hdr
->frag_off
);
1341 n2l3(data
, msg_hdr
->frag_len
);
1344 void dtls1_get_ccs_header(unsigned char *data
, struct ccs_header_st
*ccs_hdr
)
1346 memset(ccs_hdr
, 0x00, sizeof(struct ccs_header_st
));
1348 ccs_hdr
->type
= *(data
++);
1351 int dtls1_shutdown(SSL
*s
)
1354 #ifndef OPENSSL_NO_SCTP
1355 if (BIO_dgram_is_sctp(SSL_get_wbio(s
)) &&
1356 !(s
->shutdown
& SSL_SENT_SHUTDOWN
)) {
1357 ret
= BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s
));
1362 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 1,
1366 ret
= ssl3_shutdown(s
);
1367 #ifndef OPENSSL_NO_SCTP
1368 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 0, NULL
);
1373 #ifndef OPENSSL_NO_HEARTBEATS
1374 int dtls1_process_heartbeat(SSL
*s
)
1376 unsigned char *p
= &s
->s3
->rrec
.data
[0], *pl
;
1377 unsigned short hbtype
;
1378 unsigned int payload
;
1379 unsigned int padding
= 16; /* Use minimum padding */
1381 if (s
->msg_callback
)
1382 s
->msg_callback(0, s
->version
, TLS1_RT_HEARTBEAT
,
1383 &s
->s3
->rrec
.data
[0], s
->s3
->rrec
.length
,
1384 s
, s
->msg_callback_arg
);
1386 /* Read type and payload length first */
1387 if (1 + 2 + 16 > s
->s3
->rrec
.length
)
1388 return 0; /* silently discard */
1389 if (s
->s3
->rrec
.length
> SSL3_RT_MAX_PLAIN_LENGTH
)
1390 return 0; /* silently discard per RFC 6520 sec. 4 */
1394 if (1 + 2 + payload
+ 16 > s
->s3
->rrec
.length
)
1395 return 0; /* silently discard per RFC 6520 sec. 4 */
1398 if (hbtype
== TLS1_HB_REQUEST
) {
1399 unsigned char *buffer
, *bp
;
1400 unsigned int write_length
= 1 /* heartbeat type */ +
1401 2 /* heartbeat length */ +
1405 if (write_length
> SSL3_RT_MAX_PLAIN_LENGTH
)
1409 * Allocate memory for the response, size is 1 byte message type,
1410 * plus 2 bytes payload length, plus payload, plus padding
1412 buffer
= OPENSSL_malloc(write_length
);
1417 /* Enter response type, length and copy payload */
1418 *bp
++ = TLS1_HB_RESPONSE
;
1420 memcpy(bp
, pl
, payload
);
1422 /* Random padding */
1423 RAND_pseudo_bytes(bp
, padding
);
1425 r
= dtls1_write_bytes(s
, TLS1_RT_HEARTBEAT
, buffer
, write_length
);
1427 if (r
>= 0 && s
->msg_callback
)
1428 s
->msg_callback(1, s
->version
, TLS1_RT_HEARTBEAT
,
1429 buffer
, write_length
, s
, s
->msg_callback_arg
);
1431 OPENSSL_free(buffer
);
1435 } else if (hbtype
== TLS1_HB_RESPONSE
) {
1439 * We only send sequence numbers (2 bytes unsigned int), and 16
1440 * random bytes, so we just try to read the sequence number
1444 if (payload
== 18 && seq
== s
->tlsext_hb_seq
) {
1445 dtls1_stop_timer(s
);
1447 s
->tlsext_hb_pending
= 0;
1454 int dtls1_heartbeat(SSL
*s
)
1456 unsigned char *buf
, *p
;
1458 unsigned int payload
= 18; /* Sequence number + random bytes */
1459 unsigned int padding
= 16; /* Use minimum padding */
1461 /* Only send if peer supports and accepts HB requests... */
1462 if (!(s
->tlsext_heartbeat
& SSL_TLSEXT_HB_ENABLED
) ||
1463 s
->tlsext_heartbeat
& SSL_TLSEXT_HB_DONT_SEND_REQUESTS
) {
1464 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT
);
1468 /* ...and there is none in flight yet... */
1469 if (s
->tlsext_hb_pending
) {
1470 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_TLS_HEARTBEAT_PENDING
);
1474 /* ...and no handshake in progress. */
1475 if (SSL_in_init(s
) || s
->in_handshake
) {
1476 SSLerr(SSL_F_DTLS1_HEARTBEAT
, SSL_R_UNEXPECTED_MESSAGE
);
1481 * Check if padding is too long, payload and padding must not exceed 2^14
1482 * - 3 = 16381 bytes in total.
1484 OPENSSL_assert(payload
+ padding
<= 16381);
1487 * Create HeartBeat message, we just use a sequence number
1488 * as payload to distuingish different messages and add
1489 * some random stuff.
1490 * - Message Type, 1 byte
1491 * - Payload Length, 2 bytes (unsigned int)
1492 * - Payload, the sequence number (2 bytes uint)
1493 * - Payload, random bytes (16 bytes uint)
1496 buf
= OPENSSL_malloc(1 + 2 + payload
+ padding
);
1498 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_MALLOC_FAILURE
);
1503 *p
++ = TLS1_HB_REQUEST
;
1504 /* Payload length (18 bytes here) */
1506 /* Sequence number */
1507 s2n(s
->tlsext_hb_seq
, p
);
1508 /* 16 random bytes */
1509 RAND_pseudo_bytes(p
, 16);
1511 /* Random padding */
1512 RAND_pseudo_bytes(p
, padding
);
1514 ret
= dtls1_write_bytes(s
, TLS1_RT_HEARTBEAT
, buf
, 3 + payload
+ padding
);
1516 if (s
->msg_callback
)
1517 s
->msg_callback(1, s
->version
, TLS1_RT_HEARTBEAT
,
1518 buf
, 3 + payload
+ padding
,
1519 s
, s
->msg_callback_arg
);
1521 dtls1_start_timer(s
);
1522 s
->tlsext_hb_pending
= 1;