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; } }
147 static unsigned char bitmask_start_values[] =
148 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
149 static unsigned char bitmask_end_values[] =
150 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
152 /* XDTLS: figure out the right values */
153 static const unsigned int g_probable_mtu[] = { 1500, 512, 256 };
155 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
156 unsigned long frag_len);
157 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p);
158 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
160 unsigned short seq_num,
161 unsigned long frag_off,
162 unsigned long frag_len);
163 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, int mt,
166 static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len,
169 hm_fragment *frag = NULL;
170 unsigned char *buf = NULL;
171 unsigned char *bitmask = NULL;
173 frag = OPENSSL_malloc(sizeof(*frag));
178 buf = OPENSSL_malloc(frag_len);
185 /* zero length fragment gets zero frag->fragment */
186 frag->fragment = buf;
188 /* Initialize reassembly bitmask if necessary */
190 bitmask = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len));
191 if (bitmask == NULL) {
198 frag->reassembly = bitmask;
203 void dtls1_hm_fragment_free(hm_fragment *frag)
207 if (frag->msg_header.is_ccs) {
208 EVP_CIPHER_CTX_free(frag->msg_header.
209 saved_retransmit_state.enc_write_ctx);
210 EVP_MD_CTX_destroy(frag->msg_header.
211 saved_retransmit_state.write_hash);
213 OPENSSL_free(frag->fragment);
214 OPENSSL_free(frag->reassembly);
218 static int dtls1_query_mtu(SSL *s)
220 if (s->d1->link_mtu) {
222 s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
226 /* AHA! Figure out the MTU, and stick to the right size */
227 if (s->d1->mtu < dtls1_min_mtu(s)) {
228 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
230 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
233 * I've seen the kernel return bogus numbers when it doesn't know
234 * (initial write), so just make sure we have a reasonable number
236 if (s->d1->mtu < dtls1_min_mtu(s)) {
238 s->d1->mtu = dtls1_min_mtu(s);
239 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
249 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
250 * SSL3_RT_CHANGE_CIPHER_SPEC)
252 int dtls1_do_write(SSL *s, int type)
255 unsigned int curr_mtu;
257 unsigned int len, frag_off, mac_size, blocksize, used_len;
259 if (!dtls1_query_mtu(s))
262 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something
265 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
266 OPENSSL_assert(s->init_num ==
267 (int)s->d1->w_msg_hdr.msg_len +
268 DTLS1_HM_HEADER_LENGTH);
272 && ((EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE) ||
273 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CCM_MODE)))
276 mac_size = EVP_MD_CTX_size(s->write_hash);
280 if (s->enc_write_ctx &&
281 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
282 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
287 /* s->init_num shouldn't ever be < 0...but just in case */
288 while (s->init_num > 0) {
289 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH
290 + mac_size + blocksize;
291 if (s->d1->mtu > used_len)
292 curr_mtu = s->d1->mtu - used_len;
296 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
298 * grr.. we could get an error if MTU picked was wrong
300 ret = BIO_flush(SSL_get_wbio(s));
303 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
304 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
305 curr_mtu = s->d1->mtu - used_len;
307 /* Shouldn't happen */
313 * We just checked that s->init_num > 0 so this cast should be safe
315 if (((unsigned int)s->init_num) > curr_mtu)
320 /* Shouldn't ever happen */
325 * XDTLS: this function is too long. split out the CCS part
327 if (type == SSL3_RT_HANDSHAKE) {
328 if (s->init_off != 0) {
329 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
330 s->init_off -= DTLS1_HM_HEADER_LENGTH;
331 s->init_num += DTLS1_HM_HEADER_LENGTH;
334 * We just checked that s->init_num > 0 so this cast should
337 if (((unsigned int)s->init_num) > curr_mtu)
343 /* Shouldn't ever happen */
347 if (len < DTLS1_HM_HEADER_LENGTH) {
349 * len is so small that we really can't do anything sensible
354 dtls1_fix_message_header(s, frag_off,
355 len - DTLS1_HM_HEADER_LENGTH);
357 dtls1_write_message_header(s,
358 (unsigned char *)&s->init_buf->
362 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off],
366 * might need to update MTU here, but we don't know which
367 * previous packet caused the failure -- so can't really
368 * retransmit anything. continue as if everything is fine and
369 * wait for an alert to handle the retransmit
371 if (retry && BIO_ctrl(SSL_get_wbio(s),
372 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
373 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
374 if (!dtls1_query_mtu(s))
376 /* Have one more go */
386 * bad if this assert fails, only part of the handshake message
387 * got sent. but why would this happen?
389 OPENSSL_assert(len == (unsigned int)ret);
391 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
393 * should not be done for 'Hello Request's, but in that case
394 * we'll ignore the result anyway
397 (unsigned char *)&s->init_buf->data[s->init_off];
398 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
401 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
403 * reconstruct message header is if it is being sent in
406 *p++ = msg_hdr->type;
407 l2n3(msg_hdr->msg_len, p);
408 s2n(msg_hdr->seq, p);
410 l2n3(msg_hdr->msg_len, p);
411 p -= DTLS1_HM_HEADER_LENGTH;
414 p += DTLS1_HM_HEADER_LENGTH;
415 xlen = ret - DTLS1_HM_HEADER_LENGTH;
418 ssl3_finish_mac(s, p, xlen);
421 if (ret == s->init_num) {
423 s->msg_callback(1, s->version, type, s->init_buf->data,
424 (size_t)(s->init_off + s->init_num), s,
425 s->msg_callback_arg);
427 s->init_off = 0; /* done writing this message */
434 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
441 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum
442 * acceptable body length 'max'. Read an entire handshake message. Handshake
443 * messages arrive in fragments.
445 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
448 struct hm_header_st *msg_hdr;
450 unsigned long msg_len;
453 * s3->tmp is used to store messages that are unexpected, caused by the
454 * absence of an optional handshake message
456 if (s->s3->tmp.reuse_message) {
457 s->s3->tmp.reuse_message = 0;
458 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) {
459 al = SSL_AD_UNEXPECTED_MESSAGE;
460 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
464 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
465 s->init_num = (int)s->s3->tmp.message_size;
469 msg_hdr = &s->d1->r_msg_hdr;
470 memset(msg_hdr, 0, sizeof(*msg_hdr));
473 i = dtls1_get_message_fragment(s, st1, stn, mt, max, ok);
474 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) {
475 /* bad fragment received */
477 } else if (i <= 0 && !*ok) {
481 if (mt >= 0 && s->s3->tmp.message_type != mt) {
482 al = SSL_AD_UNEXPECTED_MESSAGE;
483 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
487 p = (unsigned char *)s->init_buf->data;
489 if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
490 if (s->msg_callback) {
491 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
492 p, 1, s, s->msg_callback_arg);
495 * This isn't a real handshake message so skip the processing below.
496 * dtls1_get_message_fragment() will never return a CCS if mt == -1,
497 * so we are ok to continue in that case.
502 msg_len = msg_hdr->msg_len;
504 /* reconstruct message header */
505 *(p++) = msg_hdr->type;
507 s2n(msg_hdr->seq, p);
510 if (s->version != DTLS1_BAD_VER) {
511 p -= DTLS1_HM_HEADER_LENGTH;
512 msg_len += DTLS1_HM_HEADER_LENGTH;
515 ssl3_finish_mac(s, p, msg_len);
517 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
518 p, msg_len, s, s->msg_callback_arg);
520 memset(msg_hdr, 0, sizeof(*msg_hdr));
522 /* Don't change sequence numbers while listening */
524 s->d1->handshake_read_seq++;
526 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
530 ssl3_send_alert(s, SSL3_AL_FATAL, al);
535 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr,
538 size_t frag_off, frag_len, msg_len;
540 msg_len = msg_hdr->msg_len;
541 frag_off = msg_hdr->frag_off;
542 frag_len = msg_hdr->frag_len;
544 /* sanity checking */
545 if ((frag_off + frag_len) > msg_len) {
546 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
547 return SSL_AD_ILLEGAL_PARAMETER;
550 if ((frag_off + frag_len) > (unsigned long)max) {
551 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
552 return SSL_AD_ILLEGAL_PARAMETER;
555 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
557 * msg_len is limited to 2^24, but is effectively checked against max
560 if (!BUF_MEM_grow_clean
561 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
562 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
563 return SSL_AD_INTERNAL_ERROR;
566 s->s3->tmp.message_size = msg_len;
567 s->d1->r_msg_hdr.msg_len = msg_len;
568 s->s3->tmp.message_type = msg_hdr->type;
569 s->d1->r_msg_hdr.type = msg_hdr->type;
570 s->d1->r_msg_hdr.seq = msg_hdr->seq;
571 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
573 * They must be playing with us! BTW, failure to enforce upper limit
574 * would open possibility for buffer overrun.
576 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
577 return SSL_AD_ILLEGAL_PARAMETER;
580 return 0; /* no error */
583 static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
586 * (0) check whether the desired fragment is available
588 * (1) copy over the fragment to s->init_buf->data[]
589 * (2) update s->init_num
596 item = pqueue_peek(s->d1->buffered_messages);
600 frag = (hm_fragment *)item->data;
602 /* Don't return if reassembly still in progress */
603 if (frag->reassembly != NULL)
606 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
607 unsigned long frag_len = frag->msg_header.frag_len;
608 pqueue_pop(s->d1->buffered_messages);
610 al = dtls1_preprocess_fragment(s, &frag->msg_header, max);
612 if (al == 0) { /* no alert */
614 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
615 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
616 frag->msg_header.frag_len);
619 dtls1_hm_fragment_free(frag);
627 ssl3_send_alert(s, SSL3_AL_FATAL, al);
636 * dtls1_max_handshake_message_len returns the maximum number of bytes
637 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
638 * may be greater if the maximum certificate list size requires it.
640 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
642 unsigned long max_len =
643 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
644 if (max_len < (unsigned long)s->max_cert_list)
645 return s->max_cert_list;
650 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
652 hm_fragment *frag = NULL;
654 int i = -1, is_complete;
655 unsigned char seq64be[8];
656 unsigned long frag_len = msg_hdr->frag_len;
658 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
659 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
663 return DTLS1_HM_FRAGMENT_RETRY;
665 /* Try to find item in queue */
666 memset(seq64be, 0, sizeof(seq64be));
667 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
668 seq64be[7] = (unsigned char)msg_hdr->seq;
669 item = pqueue_find(s->d1->buffered_messages, seq64be);
672 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
675 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
676 frag->msg_header.frag_len = frag->msg_header.msg_len;
677 frag->msg_header.frag_off = 0;
679 frag = (hm_fragment *)item->data;
680 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
688 * If message is already reassembled, this must be a retransmit and can
689 * be dropped. In this case item != NULL and so frag does not need to be
692 if (frag->reassembly == NULL) {
693 unsigned char devnull[256];
696 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
699 sizeof(devnull) ? sizeof(devnull) :
705 return DTLS1_HM_FRAGMENT_RETRY;
708 /* read the body of the fragment (header has already been read */
709 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
710 frag->fragment + msg_hdr->frag_off,
712 if ((unsigned long)i != frag_len)
717 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
718 (long)(msg_hdr->frag_off + frag_len));
720 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
724 OPENSSL_free(frag->reassembly);
725 frag->reassembly = NULL;
729 item = pitem_new(seq64be, frag);
735 item = pqueue_insert(s->d1->buffered_messages, item);
737 * pqueue_insert fails iff a duplicate item is inserted. However,
738 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
739 * would have returned it and control would never have reached this
742 OPENSSL_assert(item != NULL);
745 return DTLS1_HM_FRAGMENT_RETRY;
749 dtls1_hm_fragment_free(frag);
755 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr,
759 hm_fragment *frag = NULL;
761 unsigned char seq64be[8];
762 unsigned long frag_len = msg_hdr->frag_len;
764 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
767 /* Try to find item in queue, to prevent duplicate entries */
768 memset(seq64be, 0, sizeof(seq64be));
769 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
770 seq64be[7] = (unsigned char)msg_hdr->seq;
771 item = pqueue_find(s->d1->buffered_messages, seq64be);
774 * If we already have an entry and this one is a fragment, don't discard
775 * it and rather try to reassemble it.
777 if (item != NULL && frag_len != msg_hdr->msg_len)
781 * Discard the message if sequence number was already there, is too far
782 * in the future, already in the queue or if we received a FINISHED
783 * before the SERVER_HELLO, which then must be a stale retransmit.
785 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
786 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
787 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
789 unsigned char devnull[256];
792 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
795 sizeof(devnull) ? sizeof(devnull) :
802 if (frag_len != msg_hdr->msg_len)
803 return dtls1_reassemble_fragment(s, msg_hdr, ok);
805 if (frag_len > dtls1_max_handshake_message_len(s))
808 frag = dtls1_hm_fragment_new(frag_len, 0);
812 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
816 * read the body of the fragment (header has already been read
818 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
819 frag->fragment, frag_len, 0);
820 if ((unsigned long)i != frag_len)
826 item = pitem_new(seq64be, frag);
830 item = pqueue_insert(s->d1->buffered_messages, item);
832 * pqueue_insert fails iff a duplicate item is inserted. However,
833 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
834 * would have returned it. Then, either |frag_len| !=
835 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
836 * have been processed with |dtls1_reassemble_fragment|, above, or
837 * the record will have been discarded.
839 OPENSSL_assert(item != NULL);
842 return DTLS1_HM_FRAGMENT_RETRY;
846 dtls1_hm_fragment_free(frag);
852 dtls1_get_message_fragment(SSL *s, int st1, int stn, int mt, long max, int *ok)
854 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
855 unsigned long len, frag_off, frag_len;
856 int i, al, recvd_type;
857 struct hm_header_st msg_hdr;
860 /* see if we have the required fragment already */
861 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) {
863 s->init_num = frag_len;
867 /* read handshake message header */
868 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
869 DTLS1_HM_HEADER_LENGTH, 0);
870 if (i <= 0) { /* nbio, or an error */
871 s->rwstate = SSL_READING;
875 if(recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
876 /* This isn't a real handshake message - its a CCS.
877 * There is no message sequence number in a CCS to give us confidence
878 * that this was really intended to be at this point in the handshake
879 * sequence. Therefore we only allow this if we were explicitly looking
880 * for it (i.e. if |mt| is -1 we still don't allow it).
882 if(mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
883 if (wire[0] != SSL3_MT_CCS) {
884 al = SSL_AD_UNEXPECTED_MESSAGE;
885 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_CHANGE_CIPHER_SPEC);
889 memcpy(s->init_buf->data, wire, i);
891 s->init_msg = s->init_buf->data + 1;
892 s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
893 s->s3->tmp.message_size = i - 1;
899 * We weren't expecting a CCS yet. Probably something got
900 * re-ordered or this is a retransmit. We should drop this and try
908 /* Handshake fails if message header is incomplete */
909 if (i != DTLS1_HM_HEADER_LENGTH) {
910 al = SSL_AD_UNEXPECTED_MESSAGE;
911 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE);
915 /* parse the message fragment header */
916 dtls1_get_message_header(wire, &msg_hdr);
918 len = msg_hdr.msg_len;
919 frag_off = msg_hdr.frag_off;
920 frag_len = msg_hdr.frag_len;
923 * We must have at least frag_len bytes left in the record to be read.
924 * Fragments must not span records.
926 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
927 al = SSL3_AD_ILLEGAL_PARAMETER;
928 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH);
933 * if this is a future (or stale) message it gets buffered
934 * (or dropped)--no further processing at this time
935 * While listening, we accept seq 1 (ClientHello with cookie)
936 * although we're still expecting seq 0 (ClientHello)
938 if (msg_hdr.seq != s->d1->handshake_read_seq
939 && !(s->d1->listen && msg_hdr.seq == 1))
940 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
942 if (frag_len && frag_len < len)
943 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
945 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
946 wire[0] == SSL3_MT_HELLO_REQUEST) {
948 * The server may always send 'Hello Request' messages -- we are
949 * doing a handshake anyway now, so ignore them if their format is
950 * correct. Does not count for 'Finished' MAC.
952 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
954 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
955 wire, DTLS1_HM_HEADER_LENGTH, s,
956 s->msg_callback_arg);
960 } else { /* Incorrectly formated Hello request */
962 al = SSL_AD_UNEXPECTED_MESSAGE;
963 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,
964 SSL_R_UNEXPECTED_MESSAGE);
969 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max)))
974 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
976 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
977 &p[frag_off], frag_len, 0);
980 * This shouldn't ever fail due to NBIO because we already checked
981 * that we have enough data in the record
984 s->rwstate = SSL_READING;
992 * XDTLS: an incorrectly formatted fragment should cause the handshake
995 if (i != (int)frag_len) {
996 al = SSL3_AD_ILLEGAL_PARAMETER;
997 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER);
1005 * Note that s->init_num is *not* used as current offset in
1006 * s->init_buf->data, but as a counter summing up fragments' lengths: as
1007 * soon as they sum up to handshake packet length, we assume we have got
1008 * all the fragments.
1010 s->init_num = frag_len;
1014 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1022 * for these 2 messages, we need to
1023 * ssl->enc_read_ctx re-init
1024 * ssl->rlayer.read_sequence zero
1025 * ssl->s3->read_mac_secret re-init
1026 * ssl->session->read_sym_enc assign
1027 * ssl->session->read_compression assign
1028 * ssl->session->read_hash assign
1030 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
1034 if (s->state == a) {
1035 p = (unsigned char *)s->init_buf->data;
1037 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1038 s->init_num = DTLS1_CCS_HEADER_LENGTH;
1040 if (s->version == DTLS1_BAD_VER) {
1041 s->d1->next_handshake_write_seq++;
1042 s2n(s->d1->handshake_write_seq, p);
1048 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1049 s->d1->handshake_write_seq, 0, 0);
1051 /* buffer the message to handle re-xmits */
1052 if (!dtls1_buffer_message(s, 1)) {
1053 SSLerr(SSL_F_DTLS1_SEND_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
1060 /* SSL3_ST_CW_CHANGE_B */
1061 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
1064 int dtls1_read_failed(SSL *s, int code)
1067 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1071 if (!dtls1_is_timer_expired(s)) {
1073 * not a timeout, none of our business, let higher layers handle
1074 * this. in fact it's probably an error
1078 #ifndef OPENSSL_NO_HEARTBEATS
1079 /* done, no need to send a retransmit */
1080 if (!SSL_in_init(s) && !s->tlsext_hb_pending)
1082 /* done, no need to send a retransmit */
1083 if (!SSL_in_init(s))
1086 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1090 return dtls1_handle_timeout(s);
1093 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1096 * The index of the retransmission queue actually is the message sequence
1097 * number, since the queue only contains messages of a single handshake.
1098 * However, the ChangeCipherSpec has no message sequence number and so
1099 * using only the sequence will result in the CCS and Finished having the
1100 * same index. To prevent this, the sequence number is multiplied by 2.
1101 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1102 * Finished, it also maintains the order of the index (important for
1103 * priority queues) and fits in the unsigned short variable.
1105 return seq * 2 - is_ccs;
1108 int dtls1_retransmit_buffered_messages(SSL *s)
1110 pqueue sent = s->d1->sent_messages;
1116 iter = pqueue_iterator(sent);
1118 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1119 frag = (hm_fragment *)item->data;
1120 if (dtls1_retransmit_message(s, (unsigned short)
1121 dtls1_get_queue_priority
1122 (frag->msg_header.seq,
1123 frag->msg_header.is_ccs), 0,
1124 &found) <= 0 && found) {
1125 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1133 int dtls1_buffer_message(SSL *s, int is_ccs)
1137 unsigned char seq64be[8];
1140 * this function is called immediately after a message has been
1143 OPENSSL_assert(s->init_off == 0);
1145 frag = dtls1_hm_fragment_new(s->init_num, 0);
1149 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1152 /* For DTLS1_BAD_VER the header length is non-standard */
1153 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1154 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH)
1155 == (unsigned int)s->init_num);
1157 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1158 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1161 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1162 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1163 frag->msg_header.type = s->d1->w_msg_hdr.type;
1164 frag->msg_header.frag_off = 0;
1165 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1166 frag->msg_header.is_ccs = is_ccs;
1168 /* save current state */
1169 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1170 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1171 frag->msg_header.saved_retransmit_state.compress = s->compress;
1172 frag->msg_header.saved_retransmit_state.session = s->session;
1173 frag->msg_header.saved_retransmit_state.epoch =
1174 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1176 memset(seq64be, 0, sizeof(seq64be));
1179 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1180 frag->msg_header.is_ccs) >> 8);
1183 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1184 frag->msg_header.is_ccs));
1186 item = pitem_new(seq64be, frag);
1188 dtls1_hm_fragment_free(frag);
1192 pqueue_insert(s->d1->sent_messages, item);
1197 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1201 /* XDTLS: for now assuming that read/writes are blocking */
1204 unsigned long header_length;
1205 unsigned char seq64be[8];
1206 struct dtls1_retransmit_state saved_state;
1209 OPENSSL_assert(s->init_num == 0);
1210 OPENSSL_assert(s->init_off == 0);
1213 /* XDTLS: the requested message ought to be found, otherwise error */
1214 memset(seq64be, 0, sizeof(seq64be));
1215 seq64be[6] = (unsigned char)(seq >> 8);
1216 seq64be[7] = (unsigned char)seq;
1218 item = pqueue_find(s->d1->sent_messages, seq64be);
1220 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1226 frag = (hm_fragment *)item->data;
1228 if (frag->msg_header.is_ccs)
1229 header_length = DTLS1_CCS_HEADER_LENGTH;
1231 header_length = DTLS1_HM_HEADER_LENGTH;
1233 memcpy(s->init_buf->data, frag->fragment,
1234 frag->msg_header.msg_len + header_length);
1235 s->init_num = frag->msg_header.msg_len + header_length;
1237 dtls1_set_message_header_int(s, frag->msg_header.type,
1238 frag->msg_header.msg_len,
1239 frag->msg_header.seq, 0,
1240 frag->msg_header.frag_len);
1242 /* save current state */
1243 saved_state.enc_write_ctx = s->enc_write_ctx;
1244 saved_state.write_hash = s->write_hash;
1245 saved_state.compress = s->compress;
1246 saved_state.session = s->session;
1247 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1249 s->d1->retransmitting = 1;
1251 /* restore state in which the message was originally sent */
1252 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1253 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1254 s->compress = frag->msg_header.saved_retransmit_state.compress;
1255 s->session = frag->msg_header.saved_retransmit_state.session;
1256 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1257 frag->msg_header.saved_retransmit_state.epoch);
1259 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1260 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1262 /* restore current state */
1263 s->enc_write_ctx = saved_state.enc_write_ctx;
1264 s->write_hash = saved_state.write_hash;
1265 s->compress = saved_state.compress;
1266 s->session = saved_state.session;
1267 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1269 s->d1->retransmitting = 0;
1271 (void)BIO_flush(SSL_get_wbio(s));
1275 /* call this function when the buffered messages are no longer needed */
1276 void dtls1_clear_record_buffer(SSL *s)
1280 for (item = pqueue_pop(s->d1->sent_messages);
1281 item != NULL; item = pqueue_pop(s->d1->sent_messages)) {
1282 dtls1_hm_fragment_free((hm_fragment *)item->data);
1287 void dtls1_set_message_header(SSL *s, unsigned char *p,
1288 unsigned char mt, unsigned long len,
1289 unsigned long frag_off,
1290 unsigned long frag_len)
1292 /* Don't change sequence numbers while listening */
1293 if (frag_off == 0 && !s->d1->listen) {
1294 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1295 s->d1->next_handshake_write_seq++;
1298 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1299 frag_off, frag_len);
1302 /* don't actually do the writing, wait till the MTU has been retrieved */
1304 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1305 unsigned long len, unsigned short seq_num,
1306 unsigned long frag_off, unsigned long frag_len)
1308 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1311 msg_hdr->msg_len = len;
1312 msg_hdr->seq = seq_num;
1313 msg_hdr->frag_off = frag_off;
1314 msg_hdr->frag_len = frag_len;
1318 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1319 unsigned long frag_len)
1321 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1323 msg_hdr->frag_off = frag_off;
1324 msg_hdr->frag_len = frag_len;
1327 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1329 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1331 *p++ = msg_hdr->type;
1332 l2n3(msg_hdr->msg_len, p);
1334 s2n(msg_hdr->seq, p);
1335 l2n3(msg_hdr->frag_off, p);
1336 l2n3(msg_hdr->frag_len, p);
1341 unsigned int dtls1_link_min_mtu(void)
1343 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1344 sizeof(g_probable_mtu[0])) - 1]);
1347 unsigned int dtls1_min_mtu(SSL *s)
1349 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1353 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1355 memset(msg_hdr, 0, sizeof(*msg_hdr));
1356 msg_hdr->type = *(data++);
1357 n2l3(data, msg_hdr->msg_len);
1359 n2s(data, msg_hdr->seq);
1360 n2l3(data, msg_hdr->frag_off);
1361 n2l3(data, msg_hdr->frag_len);
1364 int dtls1_shutdown(SSL *s)
1367 #ifndef OPENSSL_NO_SCTP
1370 wbio = SSL_get_wbio(s);
1371 if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
1372 !(s->shutdown & SSL_SENT_SHUTDOWN)) {
1373 ret = BIO_dgram_sctp_wait_for_dry(wbio);
1378 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
1382 ret = ssl3_shutdown(s);
1383 #ifndef OPENSSL_NO_SCTP
1384 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1389 #ifndef OPENSSL_NO_HEARTBEATS
1390 int dtls1_process_heartbeat(SSL *s, unsigned char *p, unsigned int length)
1393 unsigned short hbtype;
1394 unsigned int payload;
1395 unsigned int padding = 16; /* Use minimum padding */
1397 if (s->msg_callback)
1398 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1399 p, length, s, s->msg_callback_arg);
1401 /* Read type and payload length first */
1402 if (1 + 2 + 16 > length)
1403 return 0; /* silently discard */
1404 if (length > SSL3_RT_MAX_PLAIN_LENGTH)
1405 return 0; /* silently discard per RFC 6520 sec. 4 */
1409 if (1 + 2 + payload + 16 > length)
1410 return 0; /* silently discard per RFC 6520 sec. 4 */
1413 if (hbtype == TLS1_HB_REQUEST) {
1414 unsigned char *buffer, *bp;
1415 unsigned int write_length = 1 /* heartbeat type */ +
1416 2 /* heartbeat length */ +
1420 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1424 * Allocate memory for the response, size is 1 byte message type,
1425 * plus 2 bytes payload length, plus payload, plus padding
1427 buffer = OPENSSL_malloc(write_length);
1432 /* Enter response type, length and copy payload */
1433 *bp++ = TLS1_HB_RESPONSE;
1435 memcpy(bp, pl, payload);
1437 /* Random padding */
1438 if (RAND_bytes(bp, padding) <= 0) {
1439 OPENSSL_free(buffer);
1443 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1445 if (r >= 0 && s->msg_callback)
1446 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1447 buffer, write_length, s, s->msg_callback_arg);
1449 OPENSSL_free(buffer);
1453 } else if (hbtype == TLS1_HB_RESPONSE) {
1457 * We only send sequence numbers (2 bytes unsigned int), and 16
1458 * random bytes, so we just try to read the sequence number
1462 if (payload == 18 && seq == s->tlsext_hb_seq) {
1463 dtls1_stop_timer(s);
1465 s->tlsext_hb_pending = 0;
1472 int dtls1_heartbeat(SSL *s)
1474 unsigned char *buf, *p;
1476 unsigned int payload = 18; /* Sequence number + random bytes */
1477 unsigned int padding = 16; /* Use minimum padding */
1479 /* Only send if peer supports and accepts HB requests... */
1480 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1481 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) {
1482 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1486 /* ...and there is none in flight yet... */
1487 if (s->tlsext_hb_pending) {
1488 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
1492 /* ...and no handshake in progress. */
1493 if (SSL_in_init(s) || s->in_handshake) {
1494 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
1499 * Check if padding is too long, payload and padding must not exceed 2^14
1500 * - 3 = 16381 bytes in total.
1502 OPENSSL_assert(payload + padding <= 16381);
1505 * Create HeartBeat message, we just use a sequence number
1506 * as payload to distuingish different messages and add
1507 * some random stuff.
1508 * - Message Type, 1 byte
1509 * - Payload Length, 2 bytes (unsigned int)
1510 * - Payload, the sequence number (2 bytes uint)
1511 * - Payload, random bytes (16 bytes uint)
1514 buf = OPENSSL_malloc(1 + 2 + payload + padding);
1516 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_MALLOC_FAILURE);
1521 *p++ = TLS1_HB_REQUEST;
1522 /* Payload length (18 bytes here) */
1524 /* Sequence number */
1525 s2n(s->tlsext_hb_seq, p);
1526 /* 16 random bytes */
1527 if (RAND_bytes(p, 16) <= 0) {
1528 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
1532 /* Random padding */
1533 if (RAND_bytes(p, padding) <= 0) {
1534 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
1538 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1540 if (s->msg_callback)
1541 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1542 buf, 3 + payload + padding,
1543 s, s->msg_callback_arg);
1545 dtls1_start_timer(s);
1546 s->tlsext_hb_pending = 1;