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->rwstate = SSL_NOTHING;
300 /* s->init_num shouldn't ever be < 0...but just in case */
301 while (s->init_num > 0) {
302 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
303 /* We must be writing a fragment other than the first one */
306 /* This is the first attempt at writing out this fragment */
308 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
310 * Each fragment that was already sent must at least have
311 * contained the message header plus one other byte.
312 * Therefore |init_off| must have progressed by at least
313 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
320 * Adjust |init_off| and |init_num| to allow room for a new
321 * message header for this fragment.
323 s->init_off -= DTLS1_HM_HEADER_LENGTH;
324 s->init_num += DTLS1_HM_HEADER_LENGTH;
327 * We must have been called again after a retry so use the
328 * fragment offset from our last attempt. We do not need
329 * to adjust |init_off| and |init_num| as above, because
330 * that should already have been done before the retry.
332 frag_off = s->d1->w_msg_hdr.frag_off;
336 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH
337 + mac_size + blocksize;
338 if (s->d1->mtu > used_len)
339 curr_mtu = s->d1->mtu - used_len;
343 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
345 * grr.. we could get an error if MTU picked was wrong
347 ret = BIO_flush(SSL_get_wbio(s));
349 s->rwstate = SSL_WRITING;
352 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
353 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
354 curr_mtu = s->d1->mtu - used_len;
356 /* Shouldn't happen */
362 * We just checked that s->init_num > 0 so this cast should be safe
364 if (((unsigned int)s->init_num) > curr_mtu)
369 /* Shouldn't ever happen */
374 * XDTLS: this function is too long. split out the CCS part
376 if (type == SSL3_RT_HANDSHAKE) {
377 if (len < DTLS1_HM_HEADER_LENGTH) {
379 * len is so small that we really can't do anything sensible
384 dtls1_fix_message_header(s, frag_off,
385 len - DTLS1_HM_HEADER_LENGTH);
387 dtls1_write_message_header(s,
388 (unsigned char *)&s->init_buf->
392 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off],
396 * might need to update MTU here, but we don't know which
397 * previous packet caused the failure -- so can't really
398 * retransmit anything. continue as if everything is fine and
399 * wait for an alert to handle the retransmit
401 if (retry && BIO_ctrl(SSL_get_wbio(s),
402 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
403 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
404 if (!dtls1_query_mtu(s))
406 /* Have one more go */
416 * bad if this assert fails, only part of the handshake message
417 * got sent. but why would this happen?
419 OPENSSL_assert(len == (unsigned int)ret);
421 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
423 * should not be done for 'Hello Request's, but in that case
424 * we'll ignore the result anyway
427 (unsigned char *)&s->init_buf->data[s->init_off];
428 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
431 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
433 * reconstruct message header is if it is being sent in
436 *p++ = msg_hdr->type;
437 l2n3(msg_hdr->msg_len, p);
438 s2n(msg_hdr->seq, p);
440 l2n3(msg_hdr->msg_len, p);
441 p -= DTLS1_HM_HEADER_LENGTH;
444 p += DTLS1_HM_HEADER_LENGTH;
445 xlen = ret - DTLS1_HM_HEADER_LENGTH;
448 ssl3_finish_mac(s, p, xlen);
451 if (ret == s->init_num) {
453 s->msg_callback(1, s->version, type, s->init_buf->data,
454 (size_t)(s->init_off + s->init_num), s,
455 s->msg_callback_arg);
457 s->init_off = 0; /* done writing this message */
464 ret -= DTLS1_HM_HEADER_LENGTH;
468 * We save the fragment offset for the next fragment so we have it
469 * available in case of an IO retry. We don't know the length of the
470 * next fragment yet so just set that to 0 for now. It will be
471 * updated again later.
473 dtls1_fix_message_header(s, frag_off, 0);
480 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum
481 * acceptable body length 'max'. Read an entire handshake message. Handshake
482 * messages arrive in fragments.
484 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
487 struct hm_header_st *msg_hdr;
489 unsigned long msg_len;
492 * s3->tmp is used to store messages that are unexpected, caused by the
493 * absence of an optional handshake message
495 if (s->s3->tmp.reuse_message) {
496 s->s3->tmp.reuse_message = 0;
497 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) {
498 al = SSL_AD_UNEXPECTED_MESSAGE;
499 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
503 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
504 s->init_num = (int)s->s3->tmp.message_size;
508 msg_hdr = &s->d1->r_msg_hdr;
509 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
512 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
513 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) {
514 /* bad fragment received */
516 } else if (i <= 0 && !*ok) {
521 * Don't change the *message* read sequence number while listening. For
522 * the *record* write sequence we reflect the ClientHello sequence number
526 memcpy(s->s3->write_sequence, s->s3->read_sequence,
527 sizeof(s->s3->write_sequence));
529 s->d1->handshake_read_seq++;
531 if (mt >= 0 && s->s3->tmp.message_type != mt) {
532 al = SSL_AD_UNEXPECTED_MESSAGE;
533 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
537 p = (unsigned char *)s->init_buf->data;
538 msg_len = msg_hdr->msg_len;
540 /* reconstruct message header */
541 *(p++) = msg_hdr->type;
543 s2n(msg_hdr->seq, p);
546 if (s->version != DTLS1_BAD_VER) {
547 p -= DTLS1_HM_HEADER_LENGTH;
548 msg_len += DTLS1_HM_HEADER_LENGTH;
551 ssl3_finish_mac(s, p, msg_len);
553 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
554 p, msg_len, s, s->msg_callback_arg);
556 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
558 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
562 ssl3_send_alert(s, SSL3_AL_FATAL, al);
567 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr,
570 size_t frag_off, frag_len, msg_len;
572 msg_len = msg_hdr->msg_len;
573 frag_off = msg_hdr->frag_off;
574 frag_len = msg_hdr->frag_len;
576 /* sanity checking */
577 if ((frag_off + frag_len) > msg_len) {
578 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
579 return SSL_AD_ILLEGAL_PARAMETER;
582 if ((frag_off + frag_len) > (unsigned long)max) {
583 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
584 return SSL_AD_ILLEGAL_PARAMETER;
587 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
589 * msg_len is limited to 2^24, but is effectively checked against max
592 * Make buffer slightly larger than message length as a precaution
593 * against small OOB reads e.g. CVE-2016-6306
595 if (!BUF_MEM_grow_clean
596 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH + 16)) {
597 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
598 return SSL_AD_INTERNAL_ERROR;
601 s->s3->tmp.message_size = msg_len;
602 s->d1->r_msg_hdr.msg_len = msg_len;
603 s->s3->tmp.message_type = msg_hdr->type;
604 s->d1->r_msg_hdr.type = msg_hdr->type;
605 s->d1->r_msg_hdr.seq = msg_hdr->seq;
606 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
608 * They must be playing with us! BTW, failure to enforce upper limit
609 * would open possibility for buffer overrun.
611 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
612 return SSL_AD_ILLEGAL_PARAMETER;
615 return 0; /* no error */
618 static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
621 * (0) check whether the desired fragment is available
623 * (1) copy over the fragment to s->init_buf->data[]
624 * (2) update s->init_num
632 item = pqueue_peek(s->d1->buffered_messages);
636 frag = (hm_fragment *)item->data;
638 if (frag->msg_header.seq < s->d1->handshake_read_seq) {
639 /* This is a stale message that has been buffered so clear it */
640 pqueue_pop(s->d1->buffered_messages);
641 dtls1_hm_fragment_free(frag);
646 } while (item == NULL);
649 /* Don't return if reassembly still in progress */
650 if (frag->reassembly != NULL)
653 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
654 unsigned long frag_len = frag->msg_header.frag_len;
655 pqueue_pop(s->d1->buffered_messages);
657 al = dtls1_preprocess_fragment(s, &frag->msg_header, max);
659 if (al == 0) { /* no alert */
661 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
662 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
663 frag->msg_header.frag_len);
666 dtls1_hm_fragment_free(frag);
674 ssl3_send_alert(s, SSL3_AL_FATAL, al);
683 * dtls1_max_handshake_message_len returns the maximum number of bytes
684 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
685 * may be greater if the maximum certificate list size requires it.
687 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
689 unsigned long max_len =
690 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
691 if (max_len < (unsigned long)s->max_cert_list)
692 return s->max_cert_list;
697 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
699 hm_fragment *frag = NULL;
701 int i = -1, is_complete;
702 unsigned char seq64be[8];
703 unsigned long frag_len = msg_hdr->frag_len;
705 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
706 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
710 return DTLS1_HM_FRAGMENT_RETRY;
712 /* Try to find item in queue */
713 memset(seq64be, 0, sizeof(seq64be));
714 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
715 seq64be[7] = (unsigned char)msg_hdr->seq;
716 item = pqueue_find(s->d1->buffered_messages, seq64be);
719 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
722 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
723 frag->msg_header.frag_len = frag->msg_header.msg_len;
724 frag->msg_header.frag_off = 0;
726 frag = (hm_fragment *)item->data;
727 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
735 * If message is already reassembled, this must be a retransmit and can
736 * be dropped. In this case item != NULL and so frag does not need to be
739 if (frag->reassembly == NULL) {
740 unsigned char devnull[256];
743 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
746 sizeof(devnull) ? sizeof(devnull) :
752 return DTLS1_HM_FRAGMENT_RETRY;
755 /* read the body of the fragment (header has already been read */
756 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
757 frag->fragment + msg_hdr->frag_off,
759 if ((unsigned long)i != frag_len)
764 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
765 (long)(msg_hdr->frag_off + frag_len));
767 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
771 OPENSSL_free(frag->reassembly);
772 frag->reassembly = NULL;
776 item = pitem_new(seq64be, frag);
782 item = pqueue_insert(s->d1->buffered_messages, item);
784 * pqueue_insert fails iff a duplicate item is inserted. However,
785 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
786 * would have returned it and control would never have reached this
789 OPENSSL_assert(item != NULL);
792 return DTLS1_HM_FRAGMENT_RETRY;
795 if (frag != NULL && item == NULL)
796 dtls1_hm_fragment_free(frag);
802 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr,
806 hm_fragment *frag = NULL;
808 unsigned char seq64be[8];
809 unsigned long frag_len = msg_hdr->frag_len;
811 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
814 /* Try to find item in queue, to prevent duplicate entries */
815 memset(seq64be, 0, sizeof(seq64be));
816 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
817 seq64be[7] = (unsigned char)msg_hdr->seq;
818 item = pqueue_find(s->d1->buffered_messages, seq64be);
821 * If we already have an entry and this one is a fragment, don't discard
822 * it and rather try to reassemble it.
824 if (item != NULL && frag_len != msg_hdr->msg_len)
828 * Discard the message if sequence number was already there, is too far
829 * in the future, already in the queue or if we received a FINISHED
830 * before the SERVER_HELLO, which then must be a stale retransmit.
832 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
833 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
834 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
836 unsigned char devnull[256];
839 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
842 sizeof(devnull) ? sizeof(devnull) :
849 if (frag_len != msg_hdr->msg_len)
850 return dtls1_reassemble_fragment(s, msg_hdr, ok);
852 if (frag_len > dtls1_max_handshake_message_len(s))
855 frag = dtls1_hm_fragment_new(frag_len, 0);
859 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
863 * read the body of the fragment (header has already been read
865 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
866 frag->fragment, frag_len, 0);
867 if ((unsigned long)i != frag_len)
873 item = pitem_new(seq64be, frag);
877 item = pqueue_insert(s->d1->buffered_messages, item);
879 * pqueue_insert fails iff a duplicate item is inserted. However,
880 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
881 * would have returned it. Then, either |frag_len| !=
882 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
883 * have been processed with |dtls1_reassemble_fragment|, above, or
884 * the record will have been discarded.
886 OPENSSL_assert(item != NULL);
889 return DTLS1_HM_FRAGMENT_RETRY;
892 if (frag != NULL && item == NULL)
893 dtls1_hm_fragment_free(frag);
899 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
901 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
902 unsigned long len, frag_off, frag_len;
904 struct hm_header_st msg_hdr;
907 /* see if we have the required fragment already */
908 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) {
910 s->init_num = frag_len;
914 /* read handshake message header */
915 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire,
916 DTLS1_HM_HEADER_LENGTH, 0);
917 if (i <= 0) { /* nbio, or an error */
918 s->rwstate = SSL_READING;
922 /* Handshake fails if message header is incomplete */
923 if (i != DTLS1_HM_HEADER_LENGTH) {
924 al = SSL_AD_UNEXPECTED_MESSAGE;
925 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE);
929 /* parse the message fragment header */
930 dtls1_get_message_header(wire, &msg_hdr);
932 len = msg_hdr.msg_len;
933 frag_off = msg_hdr.frag_off;
934 frag_len = msg_hdr.frag_len;
937 * We must have at least frag_len bytes left in the record to be read.
938 * Fragments must not span records.
940 if (frag_len > s->s3->rrec.length) {
941 al = SSL3_AD_ILLEGAL_PARAMETER;
942 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH);
947 * if this is a future (or stale) message it gets buffered
948 * (or dropped)--no further processing at this time
949 * While listening, we accept seq 1 (ClientHello with cookie)
950 * although we're still expecting seq 0 (ClientHello)
952 if (msg_hdr.seq != s->d1->handshake_read_seq
953 && !(s->d1->listen && msg_hdr.seq == 1))
954 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
956 if (frag_len && frag_len < len)
957 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
959 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
960 wire[0] == SSL3_MT_HELLO_REQUEST) {
962 * The server may always send 'Hello Request' messages -- we are
963 * doing a handshake anyway now, so ignore them if their format is
964 * correct. Does not count for 'Finished' MAC.
966 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
968 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
969 wire, DTLS1_HM_HEADER_LENGTH, s,
970 s->msg_callback_arg);
974 } else { /* Incorrectly formated Hello request */
976 al = SSL_AD_UNEXPECTED_MESSAGE;
977 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,
978 SSL_R_UNEXPECTED_MESSAGE);
983 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max)))
988 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
990 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
991 &p[frag_off], frag_len, 0);
994 * This shouldn't ever fail due to NBIO because we already checked
995 * that we have enough data in the record
998 s->rwstate = SSL_READING;
1006 * XDTLS: an incorrectly formatted fragment should cause the handshake
1009 if (i != (int)frag_len) {
1010 al = SSL3_AD_ILLEGAL_PARAMETER;
1011 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER);
1019 * Note that s->init_num is *not* used as current offset in
1020 * s->init_buf->data, but as a counter summing up fragments' lengths: as
1021 * soon as they sum up to handshake packet length, we assume we have got
1022 * all the fragments.
1024 s->init_num = frag_len;
1028 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1036 * for these 2 messages, we need to
1037 * ssl->enc_read_ctx re-init
1038 * ssl->s3->read_sequence zero
1039 * ssl->s3->read_mac_secret re-init
1040 * ssl->session->read_sym_enc assign
1041 * ssl->session->read_compression assign
1042 * ssl->session->read_hash assign
1044 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
1048 if (s->state == a) {
1049 p = (unsigned char *)s->init_buf->data;
1051 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1052 s->init_num = DTLS1_CCS_HEADER_LENGTH;
1054 if (s->version == DTLS1_BAD_VER) {
1055 s->d1->next_handshake_write_seq++;
1056 s2n(s->d1->handshake_write_seq, p);
1062 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1063 s->d1->handshake_write_seq, 0, 0);
1065 /* buffer the message to handle re-xmits */
1066 dtls1_buffer_message(s, 1);
1071 /* SSL3_ST_CW_CHANGE_B */
1072 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
1075 int dtls1_read_failed(SSL *s, int code)
1079 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1084 if (!dtls1_is_timer_expired(s)) {
1086 * not a timeout, none of our business, let higher layers handle
1087 * this. in fact it's probably an error
1091 #ifndef OPENSSL_NO_HEARTBEATS
1092 /* done, no need to send a retransmit */
1093 if (!SSL_in_init(s) && !s->tlsext_hb_pending)
1095 /* done, no need to send a retransmit */
1096 if (!SSL_in_init(s))
1099 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1102 #if 0 /* for now, each alert contains only one
1104 item = pqueue_peek(state->rcvd_records);
1106 /* send an alert immediately for all the missing records */
1110 #if 0 /* no more alert sending, just retransmit the
1111 * last set of messages */
1112 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1113 ssl3_send_alert(s, SSL3_AL_WARNING,
1114 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1117 return dtls1_handle_timeout(s);
1120 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1123 * The index of the retransmission queue actually is the message sequence
1124 * number, since the queue only contains messages of a single handshake.
1125 * However, the ChangeCipherSpec has no message sequence number and so
1126 * using only the sequence will result in the CCS and Finished having the
1127 * same index. To prevent this, the sequence number is multiplied by 2.
1128 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1129 * Finished, it also maintains the order of the index (important for
1130 * priority queues) and fits in the unsigned short variable.
1132 return seq * 2 - is_ccs;
1135 int dtls1_retransmit_buffered_messages(SSL *s)
1137 pqueue sent = s->d1->sent_messages;
1143 iter = pqueue_iterator(sent);
1145 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1146 frag = (hm_fragment *)item->data;
1147 if (dtls1_retransmit_message(s, (unsigned short)
1148 dtls1_get_queue_priority
1149 (frag->msg_header.seq,
1150 frag->msg_header.is_ccs), 0,
1151 &found) <= 0 && found) {
1153 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1162 int dtls1_buffer_message(SSL *s, int is_ccs)
1166 unsigned char seq64be[8];
1169 * this function is called immediately after a message has been
1172 OPENSSL_assert(s->init_off == 0);
1174 frag = dtls1_hm_fragment_new(s->init_num, 0);
1178 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1181 /* For DTLS1_BAD_VER the header length is non-standard */
1182 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1183 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH)
1184 == (unsigned int)s->init_num);
1186 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1187 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1190 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1191 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1192 frag->msg_header.type = s->d1->w_msg_hdr.type;
1193 frag->msg_header.frag_off = 0;
1194 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1195 frag->msg_header.is_ccs = is_ccs;
1197 /* save current state */
1198 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1199 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1200 frag->msg_header.saved_retransmit_state.compress = s->compress;
1201 frag->msg_header.saved_retransmit_state.session = s->session;
1202 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1204 memset(seq64be, 0, sizeof(seq64be));
1207 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1208 frag->msg_header.is_ccs) >> 8);
1211 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1212 frag->msg_header.is_ccs));
1214 item = pitem_new(seq64be, frag);
1216 dtls1_hm_fragment_free(frag);
1220 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1221 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1222 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1225 pqueue_insert(s->d1->sent_messages, item);
1230 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1234 /* XDTLS: for now assuming that read/writes are blocking */
1237 unsigned long header_length;
1238 unsigned char seq64be[8];
1239 struct dtls1_retransmit_state saved_state;
1240 unsigned char save_write_sequence[8] = {0, 0, 0, 0, 0, 0, 0, 0};
1243 OPENSSL_assert(s->init_num == 0);
1244 OPENSSL_assert(s->init_off == 0);
1247 /* XDTLS: the requested message ought to be found, otherwise error */
1248 memset(seq64be, 0, sizeof(seq64be));
1249 seq64be[6] = (unsigned char)(seq >> 8);
1250 seq64be[7] = (unsigned char)seq;
1252 item = pqueue_find(s->d1->sent_messages, seq64be);
1255 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1262 frag = (hm_fragment *)item->data;
1264 if (frag->msg_header.is_ccs)
1265 header_length = DTLS1_CCS_HEADER_LENGTH;
1267 header_length = DTLS1_HM_HEADER_LENGTH;
1269 memcpy(s->init_buf->data, frag->fragment,
1270 frag->msg_header.msg_len + header_length);
1271 s->init_num = frag->msg_header.msg_len + header_length;
1273 dtls1_set_message_header_int(s, frag->msg_header.type,
1274 frag->msg_header.msg_len,
1275 frag->msg_header.seq, 0,
1276 frag->msg_header.frag_len);
1278 /* save current state */
1279 saved_state.enc_write_ctx = s->enc_write_ctx;
1280 saved_state.write_hash = s->write_hash;
1281 saved_state.compress = s->compress;
1282 saved_state.session = s->session;
1283 saved_state.epoch = s->d1->w_epoch;
1284 saved_state.epoch = s->d1->w_epoch;
1286 s->d1->retransmitting = 1;
1288 /* restore state in which the message was originally sent */
1289 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1290 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1291 s->compress = frag->msg_header.saved_retransmit_state.compress;
1292 s->session = frag->msg_header.saved_retransmit_state.session;
1293 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1295 if (frag->msg_header.saved_retransmit_state.epoch ==
1296 saved_state.epoch - 1) {
1297 memcpy(save_write_sequence, s->s3->write_sequence,
1298 sizeof(s->s3->write_sequence));
1299 memcpy(s->s3->write_sequence, s->d1->last_write_sequence,
1300 sizeof(s->s3->write_sequence));
1303 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1304 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1306 /* restore current state */
1307 s->enc_write_ctx = saved_state.enc_write_ctx;
1308 s->write_hash = saved_state.write_hash;
1309 s->compress = saved_state.compress;
1310 s->session = saved_state.session;
1311 s->d1->w_epoch = saved_state.epoch;
1313 if (frag->msg_header.saved_retransmit_state.epoch ==
1314 saved_state.epoch - 1) {
1315 memcpy(s->d1->last_write_sequence, s->s3->write_sequence,
1316 sizeof(s->s3->write_sequence));
1317 memcpy(s->s3->write_sequence, save_write_sequence,
1318 sizeof(s->s3->write_sequence));
1321 s->d1->retransmitting = 0;
1323 (void)BIO_flush(SSL_get_wbio(s));
1327 unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p,
1328 unsigned char mt, unsigned long len,
1329 unsigned long frag_off,
1330 unsigned long frag_len)
1332 /* Don't change sequence numbers while listening */
1333 if (frag_off == 0 && !s->d1->listen) {
1334 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1335 s->d1->next_handshake_write_seq++;
1338 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1339 frag_off, frag_len);
1341 return p += DTLS1_HM_HEADER_LENGTH;
1344 /* don't actually do the writing, wait till the MTU has been retrieved */
1346 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1347 unsigned long len, unsigned short seq_num,
1348 unsigned long frag_off, unsigned long frag_len)
1350 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1353 msg_hdr->msg_len = len;
1354 msg_hdr->seq = seq_num;
1355 msg_hdr->frag_off = frag_off;
1356 msg_hdr->frag_len = frag_len;
1360 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1361 unsigned long frag_len)
1363 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1365 msg_hdr->frag_off = frag_off;
1366 msg_hdr->frag_len = frag_len;
1369 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1371 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1373 *p++ = msg_hdr->type;
1374 l2n3(msg_hdr->msg_len, p);
1376 s2n(msg_hdr->seq, p);
1377 l2n3(msg_hdr->frag_off, p);
1378 l2n3(msg_hdr->frag_len, p);
1383 unsigned int dtls1_link_min_mtu(void)
1385 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1386 sizeof(g_probable_mtu[0])) - 1]);
1389 unsigned int dtls1_min_mtu(SSL *s)
1391 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1395 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1397 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1398 msg_hdr->type = *(data++);
1399 n2l3(data, msg_hdr->msg_len);
1401 n2s(data, msg_hdr->seq);
1402 n2l3(data, msg_hdr->frag_off);
1403 n2l3(data, msg_hdr->frag_len);
1406 void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1408 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1410 ccs_hdr->type = *(data++);
1413 int dtls1_shutdown(SSL *s)
1416 #ifndef OPENSSL_NO_SCTP
1419 wbio = SSL_get_wbio(s);
1420 if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
1421 !(s->shutdown & SSL_SENT_SHUTDOWN)) {
1422 ret = BIO_dgram_sctp_wait_for_dry(wbio);
1427 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
1431 ret = ssl3_shutdown(s);
1432 #ifndef OPENSSL_NO_SCTP
1433 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1438 #ifndef OPENSSL_NO_HEARTBEATS
1439 int dtls1_process_heartbeat(SSL *s)
1441 unsigned char *p = &s->s3->rrec.data[0], *pl;
1442 unsigned short hbtype;
1443 unsigned int payload;
1444 unsigned int padding = 16; /* Use minimum padding */
1446 if (s->msg_callback)
1447 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1448 &s->s3->rrec.data[0], s->s3->rrec.length,
1449 s, s->msg_callback_arg);
1451 /* Read type and payload length first */
1452 if (1 + 2 + 16 > s->s3->rrec.length)
1453 return 0; /* silently discard */
1454 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH)
1455 return 0; /* silently discard per RFC 6520 sec. 4 */
1459 if (1 + 2 + payload + 16 > s->s3->rrec.length)
1460 return 0; /* silently discard per RFC 6520 sec. 4 */
1463 if (hbtype == TLS1_HB_REQUEST) {
1464 unsigned char *buffer, *bp;
1465 unsigned int write_length = 1 /* heartbeat type */ +
1466 2 /* heartbeat length */ +
1470 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1474 * Allocate memory for the response, size is 1 byte message type,
1475 * plus 2 bytes payload length, plus payload, plus padding
1477 buffer = OPENSSL_malloc(write_length);
1482 /* Enter response type, length and copy payload */
1483 *bp++ = TLS1_HB_RESPONSE;
1485 memcpy(bp, pl, payload);
1487 /* Random padding */
1488 if (RAND_bytes(bp, padding) <= 0) {
1489 OPENSSL_free(buffer);
1493 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1495 if (r >= 0 && s->msg_callback)
1496 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1497 buffer, write_length, s, s->msg_callback_arg);
1499 OPENSSL_free(buffer);
1503 } else if (hbtype == TLS1_HB_RESPONSE) {
1507 * We only send sequence numbers (2 bytes unsigned int), and 16
1508 * random bytes, so we just try to read the sequence number
1512 if (payload == 18 && seq == s->tlsext_hb_seq) {
1513 dtls1_stop_timer(s);
1515 s->tlsext_hb_pending = 0;
1522 int dtls1_heartbeat(SSL *s)
1524 unsigned char *buf, *p;
1526 unsigned int payload = 18; /* Sequence number + random bytes */
1527 unsigned int padding = 16; /* Use minimum padding */
1529 /* Only send if peer supports and accepts HB requests... */
1530 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1531 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) {
1532 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1536 /* ...and there is none in flight yet... */
1537 if (s->tlsext_hb_pending) {
1538 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
1542 /* ...and no handshake in progress. */
1543 if (SSL_in_init(s) || s->in_handshake) {
1544 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
1549 * Check if padding is too long, payload and padding must not exceed 2^14
1550 * - 3 = 16381 bytes in total.
1552 OPENSSL_assert(payload + padding <= 16381);
1555 * Create HeartBeat message, we just use a sequence number
1556 * as payload to distuingish different messages and add
1557 * some random stuff.
1558 * - Message Type, 1 byte
1559 * - Payload Length, 2 bytes (unsigned int)
1560 * - Payload, the sequence number (2 bytes uint)
1561 * - Payload, random bytes (16 bytes uint)
1564 buf = OPENSSL_malloc(1 + 2 + payload + padding);
1569 *p++ = TLS1_HB_REQUEST;
1570 /* Payload length (18 bytes here) */
1572 /* Sequence number */
1573 s2n(s->tlsext_hb_seq, p);
1574 /* 16 random bytes */
1575 if (RAND_bytes(p, 16) <= 0)
1578 /* Random padding */
1579 if (RAND_bytes(p, padding) <= 0)
1582 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1584 if (s->msg_callback)
1585 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1586 buf, 3 + payload + padding,
1587 s, s->msg_callback_arg);
1589 dtls1_start_timer(s);
1590 s->tlsext_hb_pending = 1;