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 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) {
458 al = SSL_AD_UNEXPECTED_MESSAGE;
459 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
466 * Messages reused from dtls1_listen also have the record header in
467 * the buffer which we need to skip over.
469 if (s->s3->tmp.reuse_message == DTLS1_SKIP_RECORD_HEADER) {
470 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH
471 + DTLS1_RT_HEADER_LENGTH;
473 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
475 s->init_num = (int)s->s3->tmp.message_size;
476 s->s3->tmp.reuse_message = 0;
480 msg_hdr = &s->d1->r_msg_hdr;
481 memset(msg_hdr, 0, sizeof(*msg_hdr));
484 i = dtls1_get_message_fragment(s, st1, stn, mt, 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 if (mt >= 0 && s->s3->tmp.message_type != mt) {
493 al = SSL_AD_UNEXPECTED_MESSAGE;
494 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
498 p = (unsigned char *)s->init_buf->data;
500 if (mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
501 if (s->msg_callback) {
502 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
503 p, 1, s, s->msg_callback_arg);
506 * This isn't a real handshake message so skip the processing below.
507 * dtls1_get_message_fragment() will never return a CCS if mt == -1,
508 * so we are ok to continue in that case.
513 msg_len = msg_hdr->msg_len;
515 /* reconstruct message header */
516 *(p++) = msg_hdr->type;
518 s2n(msg_hdr->seq, p);
521 if (s->version != DTLS1_BAD_VER) {
522 p -= DTLS1_HM_HEADER_LENGTH;
523 msg_len += DTLS1_HM_HEADER_LENGTH;
526 ssl3_finish_mac(s, p, msg_len);
528 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
529 p, msg_len, s, s->msg_callback_arg);
531 memset(msg_hdr, 0, sizeof(*msg_hdr));
533 s->d1->handshake_read_seq++;
536 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
540 ssl3_send_alert(s, SSL3_AL_FATAL, al);
545 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr,
548 size_t frag_off, frag_len, msg_len;
550 msg_len = msg_hdr->msg_len;
551 frag_off = msg_hdr->frag_off;
552 frag_len = msg_hdr->frag_len;
554 /* sanity checking */
555 if ((frag_off + frag_len) > msg_len) {
556 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
557 return SSL_AD_ILLEGAL_PARAMETER;
560 if ((frag_off + frag_len) > (unsigned long)max) {
561 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
562 return SSL_AD_ILLEGAL_PARAMETER;
565 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
567 * msg_len is limited to 2^24, but is effectively checked against max
570 if (!BUF_MEM_grow_clean
571 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
572 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
573 return SSL_AD_INTERNAL_ERROR;
576 s->s3->tmp.message_size = msg_len;
577 s->d1->r_msg_hdr.msg_len = msg_len;
578 s->s3->tmp.message_type = msg_hdr->type;
579 s->d1->r_msg_hdr.type = msg_hdr->type;
580 s->d1->r_msg_hdr.seq = msg_hdr->seq;
581 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
583 * They must be playing with us! BTW, failure to enforce upper limit
584 * would open possibility for buffer overrun.
586 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
587 return SSL_AD_ILLEGAL_PARAMETER;
590 return 0; /* no error */
593 static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
596 * (0) check whether the desired fragment is available
598 * (1) copy over the fragment to s->init_buf->data[]
599 * (2) update s->init_num
606 item = pqueue_peek(s->d1->buffered_messages);
610 frag = (hm_fragment *)item->data;
612 /* Don't return if reassembly still in progress */
613 if (frag->reassembly != NULL)
616 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
617 unsigned long frag_len = frag->msg_header.frag_len;
618 pqueue_pop(s->d1->buffered_messages);
620 al = dtls1_preprocess_fragment(s, &frag->msg_header, max);
622 if (al == 0) { /* no alert */
624 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
625 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
626 frag->msg_header.frag_len);
629 dtls1_hm_fragment_free(frag);
637 ssl3_send_alert(s, SSL3_AL_FATAL, al);
646 * dtls1_max_handshake_message_len returns the maximum number of bytes
647 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
648 * may be greater if the maximum certificate list size requires it.
650 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
652 unsigned long max_len =
653 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
654 if (max_len < (unsigned long)s->max_cert_list)
655 return s->max_cert_list;
660 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
662 hm_fragment *frag = NULL;
664 int i = -1, is_complete;
665 unsigned char seq64be[8];
666 unsigned long frag_len = msg_hdr->frag_len;
668 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
669 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
673 return DTLS1_HM_FRAGMENT_RETRY;
675 /* Try to find item in queue */
676 memset(seq64be, 0, sizeof(seq64be));
677 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
678 seq64be[7] = (unsigned char)msg_hdr->seq;
679 item = pqueue_find(s->d1->buffered_messages, seq64be);
682 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
685 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
686 frag->msg_header.frag_len = frag->msg_header.msg_len;
687 frag->msg_header.frag_off = 0;
689 frag = (hm_fragment *)item->data;
690 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
698 * If message is already reassembled, this must be a retransmit and can
699 * be dropped. In this case item != NULL and so frag does not need to be
702 if (frag->reassembly == NULL) {
703 unsigned char devnull[256];
706 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
709 sizeof(devnull) ? sizeof(devnull) :
715 return DTLS1_HM_FRAGMENT_RETRY;
718 /* read the body of the fragment (header has already been read */
719 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
720 frag->fragment + msg_hdr->frag_off,
722 if ((unsigned long)i != frag_len)
727 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
728 (long)(msg_hdr->frag_off + frag_len));
730 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
734 OPENSSL_free(frag->reassembly);
735 frag->reassembly = NULL;
739 item = pitem_new(seq64be, frag);
745 item = pqueue_insert(s->d1->buffered_messages, item);
747 * pqueue_insert fails iff a duplicate item is inserted. However,
748 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
749 * would have returned it and control would never have reached this
752 OPENSSL_assert(item != NULL);
755 return DTLS1_HM_FRAGMENT_RETRY;
759 dtls1_hm_fragment_free(frag);
765 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr,
769 hm_fragment *frag = NULL;
771 unsigned char seq64be[8];
772 unsigned long frag_len = msg_hdr->frag_len;
774 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
777 /* Try to find item in queue, to prevent duplicate entries */
778 memset(seq64be, 0, sizeof(seq64be));
779 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
780 seq64be[7] = (unsigned char)msg_hdr->seq;
781 item = pqueue_find(s->d1->buffered_messages, seq64be);
784 * If we already have an entry and this one is a fragment, don't discard
785 * it and rather try to reassemble it.
787 if (item != NULL && frag_len != msg_hdr->msg_len)
791 * Discard the message if sequence number was already there, is too far
792 * in the future, already in the queue or if we received a FINISHED
793 * before the SERVER_HELLO, which then must be a stale retransmit.
795 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
796 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
797 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
799 unsigned char devnull[256];
802 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
805 sizeof(devnull) ? sizeof(devnull) :
812 if (frag_len != msg_hdr->msg_len)
813 return dtls1_reassemble_fragment(s, msg_hdr, ok);
815 if (frag_len > dtls1_max_handshake_message_len(s))
818 frag = dtls1_hm_fragment_new(frag_len, 0);
822 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
826 * read the body of the fragment (header has already been read
828 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
829 frag->fragment, frag_len, 0);
830 if ((unsigned long)i != frag_len)
836 item = pitem_new(seq64be, frag);
840 item = pqueue_insert(s->d1->buffered_messages, item);
842 * pqueue_insert fails iff a duplicate item is inserted. However,
843 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
844 * would have returned it. Then, either |frag_len| !=
845 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
846 * have been processed with |dtls1_reassemble_fragment|, above, or
847 * the record will have been discarded.
849 OPENSSL_assert(item != NULL);
852 return DTLS1_HM_FRAGMENT_RETRY;
856 dtls1_hm_fragment_free(frag);
862 dtls1_get_message_fragment(SSL *s, int st1, int stn, int mt, long max, int *ok)
864 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
865 unsigned long len, frag_off, frag_len;
866 int i, al, recvd_type;
867 struct hm_header_st msg_hdr;
870 /* see if we have the required fragment already */
871 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) {
873 s->init_num = frag_len;
877 /* read handshake message header */
878 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
879 DTLS1_HM_HEADER_LENGTH, 0);
880 if (i <= 0) { /* nbio, or an error */
881 s->rwstate = SSL_READING;
885 if(recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
886 /* This isn't a real handshake message - its a CCS.
887 * There is no message sequence number in a CCS to give us confidence
888 * that this was really intended to be at this point in the handshake
889 * sequence. Therefore we only allow this if we were explicitly looking
890 * for it (i.e. if |mt| is -1 we still don't allow it).
892 if(mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
893 if (wire[0] != SSL3_MT_CCS) {
894 al = SSL_AD_UNEXPECTED_MESSAGE;
895 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_CHANGE_CIPHER_SPEC);
899 memcpy(s->init_buf->data, wire, i);
901 s->init_msg = s->init_buf->data + 1;
902 s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
903 s->s3->tmp.message_size = i - 1;
909 * We weren't expecting a CCS yet. Probably something got
910 * re-ordered or this is a retransmit. We should drop this and try
918 /* Handshake fails if message header is incomplete */
919 if (i != DTLS1_HM_HEADER_LENGTH) {
920 al = SSL_AD_UNEXPECTED_MESSAGE;
921 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE);
925 /* parse the message fragment header */
926 dtls1_get_message_header(wire, &msg_hdr);
928 len = msg_hdr.msg_len;
929 frag_off = msg_hdr.frag_off;
930 frag_len = msg_hdr.frag_len;
933 * We must have at least frag_len bytes left in the record to be read.
934 * Fragments must not span records.
936 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
937 al = SSL3_AD_ILLEGAL_PARAMETER;
938 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH);
943 * if this is a future (or stale) message it gets buffered
944 * (or dropped)--no further processing at this time
945 * While listening, we accept seq 1 (ClientHello with cookie)
946 * although we're still expecting seq 0 (ClientHello)
948 if (msg_hdr.seq != s->d1->handshake_read_seq)
949 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
951 if (frag_len && frag_len < len)
952 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
954 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
955 wire[0] == SSL3_MT_HELLO_REQUEST) {
957 * The server may always send 'Hello Request' messages -- we are
958 * doing a handshake anyway now, so ignore them if their format is
959 * correct. Does not count for 'Finished' MAC.
961 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
963 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
964 wire, DTLS1_HM_HEADER_LENGTH, s,
965 s->msg_callback_arg);
969 } else { /* Incorrectly formated Hello request */
971 al = SSL_AD_UNEXPECTED_MESSAGE;
972 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,
973 SSL_R_UNEXPECTED_MESSAGE);
978 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max)))
983 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
985 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
986 &p[frag_off], frag_len, 0);
989 * This shouldn't ever fail due to NBIO because we already checked
990 * that we have enough data in the record
993 s->rwstate = SSL_READING;
1001 * XDTLS: an incorrectly formatted fragment should cause the handshake
1004 if (i != (int)frag_len) {
1005 al = SSL3_AD_ILLEGAL_PARAMETER;
1006 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER);
1014 * Note that s->init_num is *not* used as current offset in
1015 * s->init_buf->data, but as a counter summing up fragments' lengths: as
1016 * soon as they sum up to handshake packet length, we assume we have got
1017 * all the fragments.
1019 s->init_num = frag_len;
1023 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1031 * for these 2 messages, we need to
1032 * ssl->enc_read_ctx re-init
1033 * ssl->rlayer.read_sequence zero
1034 * ssl->s3->read_mac_secret re-init
1035 * ssl->session->read_sym_enc assign
1036 * ssl->session->read_compression assign
1037 * ssl->session->read_hash assign
1039 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
1043 if (s->state == a) {
1044 p = (unsigned char *)s->init_buf->data;
1046 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1047 s->init_num = DTLS1_CCS_HEADER_LENGTH;
1049 if (s->version == DTLS1_BAD_VER) {
1050 s->d1->next_handshake_write_seq++;
1051 s2n(s->d1->handshake_write_seq, p);
1057 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1058 s->d1->handshake_write_seq, 0, 0);
1060 /* buffer the message to handle re-xmits */
1061 if (!dtls1_buffer_message(s, 1)) {
1062 SSLerr(SSL_F_DTLS1_SEND_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
1069 /* SSL3_ST_CW_CHANGE_B */
1070 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
1073 int dtls1_read_failed(SSL *s, int code)
1076 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1080 if (!dtls1_is_timer_expired(s)) {
1082 * not a timeout, none of our business, let higher layers handle
1083 * this. in fact it's probably an error
1087 #ifndef OPENSSL_NO_HEARTBEATS
1088 /* done, no need to send a retransmit */
1089 if (!SSL_in_init(s) && !s->tlsext_hb_pending)
1091 /* done, no need to send a retransmit */
1092 if (!SSL_in_init(s))
1095 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1099 return dtls1_handle_timeout(s);
1102 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1105 * The index of the retransmission queue actually is the message sequence
1106 * number, since the queue only contains messages of a single handshake.
1107 * However, the ChangeCipherSpec has no message sequence number and so
1108 * using only the sequence will result in the CCS and Finished having the
1109 * same index. To prevent this, the sequence number is multiplied by 2.
1110 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1111 * Finished, it also maintains the order of the index (important for
1112 * priority queues) and fits in the unsigned short variable.
1114 return seq * 2 - is_ccs;
1117 int dtls1_retransmit_buffered_messages(SSL *s)
1119 pqueue sent = s->d1->sent_messages;
1125 iter = pqueue_iterator(sent);
1127 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1128 frag = (hm_fragment *)item->data;
1129 if (dtls1_retransmit_message(s, (unsigned short)
1130 dtls1_get_queue_priority
1131 (frag->msg_header.seq,
1132 frag->msg_header.is_ccs), 0,
1133 &found) <= 0 && found) {
1134 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1142 int dtls1_buffer_message(SSL *s, int is_ccs)
1146 unsigned char seq64be[8];
1149 * this function is called immediately after a message has been
1152 OPENSSL_assert(s->init_off == 0);
1154 frag = dtls1_hm_fragment_new(s->init_num, 0);
1158 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1161 /* For DTLS1_BAD_VER the header length is non-standard */
1162 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1163 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH)
1164 == (unsigned int)s->init_num);
1166 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1167 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1170 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1171 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1172 frag->msg_header.type = s->d1->w_msg_hdr.type;
1173 frag->msg_header.frag_off = 0;
1174 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1175 frag->msg_header.is_ccs = is_ccs;
1177 /* save current state */
1178 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1179 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1180 frag->msg_header.saved_retransmit_state.compress = s->compress;
1181 frag->msg_header.saved_retransmit_state.session = s->session;
1182 frag->msg_header.saved_retransmit_state.epoch =
1183 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1185 memset(seq64be, 0, sizeof(seq64be));
1188 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1189 frag->msg_header.is_ccs) >> 8);
1192 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1193 frag->msg_header.is_ccs));
1195 item = pitem_new(seq64be, frag);
1197 dtls1_hm_fragment_free(frag);
1201 pqueue_insert(s->d1->sent_messages, item);
1206 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1210 /* XDTLS: for now assuming that read/writes are blocking */
1213 unsigned long header_length;
1214 unsigned char seq64be[8];
1215 struct dtls1_retransmit_state saved_state;
1218 OPENSSL_assert(s->init_num == 0);
1219 OPENSSL_assert(s->init_off == 0);
1222 /* XDTLS: the requested message ought to be found, otherwise error */
1223 memset(seq64be, 0, sizeof(seq64be));
1224 seq64be[6] = (unsigned char)(seq >> 8);
1225 seq64be[7] = (unsigned char)seq;
1227 item = pqueue_find(s->d1->sent_messages, seq64be);
1229 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1235 frag = (hm_fragment *)item->data;
1237 if (frag->msg_header.is_ccs)
1238 header_length = DTLS1_CCS_HEADER_LENGTH;
1240 header_length = DTLS1_HM_HEADER_LENGTH;
1242 memcpy(s->init_buf->data, frag->fragment,
1243 frag->msg_header.msg_len + header_length);
1244 s->init_num = frag->msg_header.msg_len + header_length;
1246 dtls1_set_message_header_int(s, frag->msg_header.type,
1247 frag->msg_header.msg_len,
1248 frag->msg_header.seq, 0,
1249 frag->msg_header.frag_len);
1251 /* save current state */
1252 saved_state.enc_write_ctx = s->enc_write_ctx;
1253 saved_state.write_hash = s->write_hash;
1254 saved_state.compress = s->compress;
1255 saved_state.session = s->session;
1256 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1258 s->d1->retransmitting = 1;
1260 /* restore state in which the message was originally sent */
1261 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1262 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1263 s->compress = frag->msg_header.saved_retransmit_state.compress;
1264 s->session = frag->msg_header.saved_retransmit_state.session;
1265 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1266 frag->msg_header.saved_retransmit_state.epoch);
1268 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1269 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1271 /* restore current state */
1272 s->enc_write_ctx = saved_state.enc_write_ctx;
1273 s->write_hash = saved_state.write_hash;
1274 s->compress = saved_state.compress;
1275 s->session = saved_state.session;
1276 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1278 s->d1->retransmitting = 0;
1280 (void)BIO_flush(SSL_get_wbio(s));
1284 /* call this function when the buffered messages are no longer needed */
1285 void dtls1_clear_record_buffer(SSL *s)
1289 for (item = pqueue_pop(s->d1->sent_messages);
1290 item != NULL; item = pqueue_pop(s->d1->sent_messages)) {
1291 dtls1_hm_fragment_free((hm_fragment *)item->data);
1296 void dtls1_set_message_header(SSL *s, unsigned char *p,
1297 unsigned char mt, unsigned long len,
1298 unsigned long frag_off,
1299 unsigned long frag_len)
1301 if (frag_off == 0) {
1302 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1303 s->d1->next_handshake_write_seq++;
1306 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1307 frag_off, frag_len);
1310 /* don't actually do the writing, wait till the MTU has been retrieved */
1312 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1313 unsigned long len, unsigned short seq_num,
1314 unsigned long frag_off, unsigned long frag_len)
1316 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1319 msg_hdr->msg_len = len;
1320 msg_hdr->seq = seq_num;
1321 msg_hdr->frag_off = frag_off;
1322 msg_hdr->frag_len = frag_len;
1326 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1327 unsigned long frag_len)
1329 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1331 msg_hdr->frag_off = frag_off;
1332 msg_hdr->frag_len = frag_len;
1335 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1337 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1339 *p++ = msg_hdr->type;
1340 l2n3(msg_hdr->msg_len, p);
1342 s2n(msg_hdr->seq, p);
1343 l2n3(msg_hdr->frag_off, p);
1344 l2n3(msg_hdr->frag_len, p);
1349 unsigned int dtls1_link_min_mtu(void)
1351 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1352 sizeof(g_probable_mtu[0])) - 1]);
1355 unsigned int dtls1_min_mtu(SSL *s)
1357 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1361 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1363 memset(msg_hdr, 0, sizeof(*msg_hdr));
1364 msg_hdr->type = *(data++);
1365 n2l3(data, msg_hdr->msg_len);
1367 n2s(data, msg_hdr->seq);
1368 n2l3(data, msg_hdr->frag_off);
1369 n2l3(data, msg_hdr->frag_len);
1372 int dtls1_shutdown(SSL *s)
1375 #ifndef OPENSSL_NO_SCTP
1378 wbio = SSL_get_wbio(s);
1379 if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
1380 !(s->shutdown & SSL_SENT_SHUTDOWN)) {
1381 ret = BIO_dgram_sctp_wait_for_dry(wbio);
1386 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
1390 ret = ssl3_shutdown(s);
1391 #ifndef OPENSSL_NO_SCTP
1392 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1397 #ifndef OPENSSL_NO_HEARTBEATS
1398 int dtls1_process_heartbeat(SSL *s, unsigned char *p, unsigned int length)
1401 unsigned short hbtype;
1402 unsigned int payload;
1403 unsigned int padding = 16; /* Use minimum padding */
1405 if (s->msg_callback)
1406 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1407 p, length, s, s->msg_callback_arg);
1409 /* Read type and payload length first */
1410 if (1 + 2 + 16 > length)
1411 return 0; /* silently discard */
1412 if (length > SSL3_RT_MAX_PLAIN_LENGTH)
1413 return 0; /* silently discard per RFC 6520 sec. 4 */
1417 if (1 + 2 + payload + 16 > length)
1418 return 0; /* silently discard per RFC 6520 sec. 4 */
1421 if (hbtype == TLS1_HB_REQUEST) {
1422 unsigned char *buffer, *bp;
1423 unsigned int write_length = 1 /* heartbeat type */ +
1424 2 /* heartbeat length */ +
1428 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1432 * Allocate memory for the response, size is 1 byte message type,
1433 * plus 2 bytes payload length, plus payload, plus padding
1435 buffer = OPENSSL_malloc(write_length);
1440 /* Enter response type, length and copy payload */
1441 *bp++ = TLS1_HB_RESPONSE;
1443 memcpy(bp, pl, payload);
1445 /* Random padding */
1446 if (RAND_bytes(bp, padding) <= 0) {
1447 OPENSSL_free(buffer);
1451 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1453 if (r >= 0 && s->msg_callback)
1454 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1455 buffer, write_length, s, s->msg_callback_arg);
1457 OPENSSL_free(buffer);
1461 } else if (hbtype == TLS1_HB_RESPONSE) {
1465 * We only send sequence numbers (2 bytes unsigned int), and 16
1466 * random bytes, so we just try to read the sequence number
1470 if (payload == 18 && seq == s->tlsext_hb_seq) {
1471 dtls1_stop_timer(s);
1473 s->tlsext_hb_pending = 0;
1480 int dtls1_heartbeat(SSL *s)
1482 unsigned char *buf, *p;
1484 unsigned int payload = 18; /* Sequence number + random bytes */
1485 unsigned int padding = 16; /* Use minimum padding */
1487 /* Only send if peer supports and accepts HB requests... */
1488 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1489 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) {
1490 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1494 /* ...and there is none in flight yet... */
1495 if (s->tlsext_hb_pending) {
1496 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
1500 /* ...and no handshake in progress. */
1501 if (SSL_in_init(s) || s->in_handshake) {
1502 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
1507 * Check if padding is too long, payload and padding must not exceed 2^14
1508 * - 3 = 16381 bytes in total.
1510 OPENSSL_assert(payload + padding <= 16381);
1513 * Create HeartBeat message, we just use a sequence number
1514 * as payload to distuingish different messages and add
1515 * some random stuff.
1516 * - Message Type, 1 byte
1517 * - Payload Length, 2 bytes (unsigned int)
1518 * - Payload, the sequence number (2 bytes uint)
1519 * - Payload, random bytes (16 bytes uint)
1522 buf = OPENSSL_malloc(1 + 2 + payload + padding);
1524 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_MALLOC_FAILURE);
1529 *p++ = TLS1_HB_REQUEST;
1530 /* Payload length (18 bytes here) */
1532 /* Sequence number */
1533 s2n(s->tlsext_hb_seq, p);
1534 /* 16 random bytes */
1535 if (RAND_bytes(p, 16) <= 0) {
1536 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
1540 /* Random padding */
1541 if (RAND_bytes(p, padding) <= 0) {
1542 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
1546 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1548 if (s->msg_callback)
1549 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1550 buf, 3 + payload + padding,
1551 s, s->msg_callback_arg);
1553 dtls1_start_timer(s);
1554 s->tlsext_hb_pending = 1;