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, long max,
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 = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
178 buf = (unsigned char *)OPENSSL_malloc(frag_len);
185 /* zero length fragment gets zero frag->fragment */
186 frag->fragment = buf;
188 /* Initialize reassembly bitmask if necessary */
191 (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
192 if (bitmask == NULL) {
198 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
201 frag->reassembly = bitmask;
206 void dtls1_hm_fragment_free(hm_fragment *frag)
209 if (frag->msg_header.is_ccs) {
210 EVP_CIPHER_CTX_free(frag->msg_header.
211 saved_retransmit_state.enc_write_ctx);
212 EVP_MD_CTX_destroy(frag->msg_header.
213 saved_retransmit_state.write_hash);
216 OPENSSL_free(frag->fragment);
217 if (frag->reassembly)
218 OPENSSL_free(frag->reassembly);
222 static int dtls1_query_mtu(SSL *s)
224 if (s->d1->link_mtu) {
226 s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
230 /* AHA! Figure out the MTU, and stick to the right size */
231 if (s->d1->mtu < dtls1_min_mtu(s)) {
232 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
234 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
237 * I've seen the kernel return bogus numbers when it doesn't know
238 * (initial write), so just make sure we have a reasonable number
240 if (s->d1->mtu < dtls1_min_mtu(s)) {
242 s->d1->mtu = dtls1_min_mtu(s);
243 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
253 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
254 * SSL3_RT_CHANGE_CIPHER_SPEC)
256 int dtls1_do_write(SSL *s, int type)
259 unsigned int curr_mtu;
261 unsigned int len, frag_off, mac_size, blocksize, used_len;
263 if (!dtls1_query_mtu(s))
266 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something
269 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
270 OPENSSL_assert(s->init_num ==
271 (int)s->d1->w_msg_hdr.msg_len +
272 DTLS1_HM_HEADER_LENGTH);
276 && EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_GCM_MODE)
279 mac_size = EVP_MD_CTX_size(s->write_hash);
283 if (s->enc_write_ctx &&
284 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
285 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
290 /* s->init_num shouldn't ever be < 0...but just in case */
291 while (s->init_num > 0) {
292 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH
293 + mac_size + blocksize;
294 if (s->d1->mtu > used_len)
295 curr_mtu = s->d1->mtu - used_len;
299 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
301 * grr.. we could get an error if MTU picked was wrong
303 ret = BIO_flush(SSL_get_wbio(s));
306 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
307 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
308 curr_mtu = s->d1->mtu - used_len;
310 /* Shouldn't happen */
316 * We just checked that s->init_num > 0 so this cast should be safe
318 if (((unsigned int)s->init_num) > curr_mtu)
323 /* Shouldn't ever happen */
328 * XDTLS: this function is too long. split out the CCS part
330 if (type == SSL3_RT_HANDSHAKE) {
331 if (s->init_off != 0) {
332 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
333 s->init_off -= DTLS1_HM_HEADER_LENGTH;
334 s->init_num += DTLS1_HM_HEADER_LENGTH;
337 * We just checked that s->init_num > 0 so this cast should
340 if (((unsigned int)s->init_num) > curr_mtu)
346 /* Shouldn't ever happen */
350 if (len < DTLS1_HM_HEADER_LENGTH) {
352 * len is so small that we really can't do anything sensible
357 dtls1_fix_message_header(s, frag_off,
358 len - DTLS1_HM_HEADER_LENGTH);
360 dtls1_write_message_header(s,
361 (unsigned char *)&s->init_buf->
365 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off],
369 * might need to update MTU here, but we don't know which
370 * previous packet caused the failure -- so can't really
371 * retransmit anything. continue as if everything is fine and
372 * wait for an alert to handle the retransmit
374 if (retry && BIO_ctrl(SSL_get_wbio(s),
375 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
376 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
377 if (!dtls1_query_mtu(s))
379 /* Have one more go */
389 * bad if this assert fails, only part of the handshake message
390 * got sent. but why would this happen?
392 OPENSSL_assert(len == (unsigned int)ret);
394 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
396 * should not be done for 'Hello Request's, but in that case
397 * we'll ignore the result anyway
400 (unsigned char *)&s->init_buf->data[s->init_off];
401 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
404 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
406 * reconstruct message header is if it is being sent in
409 *p++ = msg_hdr->type;
410 l2n3(msg_hdr->msg_len, p);
411 s2n(msg_hdr->seq, p);
413 l2n3(msg_hdr->msg_len, p);
414 p -= DTLS1_HM_HEADER_LENGTH;
417 p += DTLS1_HM_HEADER_LENGTH;
418 xlen = ret - DTLS1_HM_HEADER_LENGTH;
421 ssl3_finish_mac(s, p, xlen);
424 if (ret == s->init_num) {
426 s->msg_callback(1, s->version, type, s->init_buf->data,
427 (size_t)(s->init_off + s->init_num), s,
428 s->msg_callback_arg);
430 s->init_off = 0; /* done writing this message */
437 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
444 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum
445 * acceptable body length 'max'. Read an entire handshake message. Handshake
446 * messages arrive in fragments.
448 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
451 struct hm_header_st *msg_hdr;
453 unsigned long msg_len;
456 * s3->tmp is used to store messages that are unexpected, caused by the
457 * absence of an optional handshake message
459 if (s->s3->tmp.reuse_message) {
460 s->s3->tmp.reuse_message = 0;
461 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) {
462 al = SSL_AD_UNEXPECTED_MESSAGE;
463 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
467 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
468 s->init_num = (int)s->s3->tmp.message_size;
472 msg_hdr = &s->d1->r_msg_hdr;
473 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
476 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
477 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) {
478 /* bad fragment received */
480 } else if (i <= 0 && !*ok) {
484 p = (unsigned char *)s->init_buf->data;
485 msg_len = msg_hdr->msg_len;
487 /* reconstruct message header */
488 *(p++) = msg_hdr->type;
490 s2n(msg_hdr->seq, p);
493 if (s->version != DTLS1_BAD_VER) {
494 p -= DTLS1_HM_HEADER_LENGTH;
495 msg_len += DTLS1_HM_HEADER_LENGTH;
498 ssl3_finish_mac(s, p, msg_len);
500 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
501 p, msg_len, s, s->msg_callback_arg);
503 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
505 /* Don't change sequence numbers while listening */
507 s->d1->handshake_read_seq++;
509 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
513 ssl3_send_alert(s, SSL3_AL_FATAL, al);
518 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr,
521 size_t frag_off, frag_len, msg_len;
523 msg_len = msg_hdr->msg_len;
524 frag_off = msg_hdr->frag_off;
525 frag_len = msg_hdr->frag_len;
527 /* sanity checking */
528 if ((frag_off + frag_len) > msg_len) {
529 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
530 return SSL_AD_ILLEGAL_PARAMETER;
533 if ((frag_off + frag_len) > (unsigned long)max) {
534 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
535 return SSL_AD_ILLEGAL_PARAMETER;
538 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
540 * msg_len is limited to 2^24, but is effectively checked against max
543 if (!BUF_MEM_grow_clean
544 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
545 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
546 return SSL_AD_INTERNAL_ERROR;
549 s->s3->tmp.message_size = msg_len;
550 s->d1->r_msg_hdr.msg_len = msg_len;
551 s->s3->tmp.message_type = msg_hdr->type;
552 s->d1->r_msg_hdr.type = msg_hdr->type;
553 s->d1->r_msg_hdr.seq = msg_hdr->seq;
554 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
556 * They must be playing with us! BTW, failure to enforce upper limit
557 * would open possibility for buffer overrun.
559 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
560 return SSL_AD_ILLEGAL_PARAMETER;
563 return 0; /* no error */
566 static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
569 * (0) check whether the desired fragment is available
571 * (1) copy over the fragment to s->init_buf->data[]
572 * (2) update s->init_num
579 item = pqueue_peek(s->d1->buffered_messages);
583 frag = (hm_fragment *)item->data;
585 /* Don't return if reassembly still in progress */
586 if (frag->reassembly != NULL)
589 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
590 unsigned long frag_len = frag->msg_header.frag_len;
591 pqueue_pop(s->d1->buffered_messages);
593 al = dtls1_preprocess_fragment(s, &frag->msg_header, max);
595 if (al == 0) { /* no alert */
597 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
598 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
599 frag->msg_header.frag_len);
602 dtls1_hm_fragment_free(frag);
610 ssl3_send_alert(s, SSL3_AL_FATAL, al);
619 * dtls1_max_handshake_message_len returns the maximum number of bytes
620 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
621 * may be greater if the maximum certificate list size requires it.
623 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
625 unsigned long max_len =
626 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
627 if (max_len < (unsigned long)s->max_cert_list)
628 return s->max_cert_list;
633 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
635 hm_fragment *frag = NULL;
637 int i = -1, is_complete;
638 unsigned char seq64be[8];
639 unsigned long frag_len = msg_hdr->frag_len;
641 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
642 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
646 return DTLS1_HM_FRAGMENT_RETRY;
648 /* Try to find item in queue */
649 memset(seq64be, 0, sizeof(seq64be));
650 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
651 seq64be[7] = (unsigned char)msg_hdr->seq;
652 item = pqueue_find(s->d1->buffered_messages, seq64be);
655 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
658 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
659 frag->msg_header.frag_len = frag->msg_header.msg_len;
660 frag->msg_header.frag_off = 0;
662 frag = (hm_fragment *)item->data;
663 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
671 * If message is already reassembled, this must be a retransmit and can
672 * be dropped. In this case item != NULL and so frag does not need to be
675 if (frag->reassembly == NULL) {
676 unsigned char devnull[256];
679 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
682 sizeof(devnull) ? sizeof(devnull) :
688 return DTLS1_HM_FRAGMENT_RETRY;
691 /* read the body of the fragment (header has already been read */
692 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
693 frag->fragment + msg_hdr->frag_off,
695 if ((unsigned long)i != frag_len)
700 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
701 (long)(msg_hdr->frag_off + frag_len));
703 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
707 OPENSSL_free(frag->reassembly);
708 frag->reassembly = NULL;
712 item = pitem_new(seq64be, frag);
718 item = pqueue_insert(s->d1->buffered_messages, item);
720 * pqueue_insert fails iff a duplicate item is inserted. However,
721 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
722 * would have returned it and control would never have reached this
725 OPENSSL_assert(item != NULL);
728 return DTLS1_HM_FRAGMENT_RETRY;
731 if (frag != NULL && item == NULL)
732 dtls1_hm_fragment_free(frag);
738 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr,
742 hm_fragment *frag = NULL;
744 unsigned char seq64be[8];
745 unsigned long frag_len = msg_hdr->frag_len;
747 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
750 /* Try to find item in queue, to prevent duplicate entries */
751 memset(seq64be, 0, sizeof(seq64be));
752 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
753 seq64be[7] = (unsigned char)msg_hdr->seq;
754 item = pqueue_find(s->d1->buffered_messages, seq64be);
757 * If we already have an entry and this one is a fragment, don't discard
758 * it and rather try to reassemble it.
760 if (item != NULL && frag_len != msg_hdr->msg_len)
764 * Discard the message if sequence number was already there, is too far
765 * in the future, already in the queue or if we received a FINISHED
766 * before the SERVER_HELLO, which then must be a stale retransmit.
768 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
769 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
770 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
772 unsigned char devnull[256];
775 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
778 sizeof(devnull) ? sizeof(devnull) :
785 if (frag_len != msg_hdr->msg_len)
786 return dtls1_reassemble_fragment(s, msg_hdr, ok);
788 if (frag_len > dtls1_max_handshake_message_len(s))
791 frag = dtls1_hm_fragment_new(frag_len, 0);
795 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
799 * read the body of the fragment (header has already been read
801 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
802 frag->fragment, frag_len, 0);
803 if ((unsigned long)i != frag_len)
809 item = pitem_new(seq64be, frag);
813 item = pqueue_insert(s->d1->buffered_messages, item);
815 * pqueue_insert fails iff a duplicate item is inserted. However,
816 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
817 * would have returned it. Then, either |frag_len| !=
818 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
819 * have been processed with |dtls1_reassemble_fragment|, above, or
820 * the record will have been discarded.
822 OPENSSL_assert(item != NULL);
825 return DTLS1_HM_FRAGMENT_RETRY;
828 if (frag != NULL && item == NULL)
829 dtls1_hm_fragment_free(frag);
835 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
837 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
838 unsigned long len, frag_off, frag_len;
840 struct hm_header_st msg_hdr;
843 /* see if we have the required fragment already */
844 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) {
846 s->init_num = frag_len;
850 /* read handshake message header */
851 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire,
852 DTLS1_HM_HEADER_LENGTH, 0);
853 if (i <= 0) { /* nbio, or an error */
854 s->rwstate = SSL_READING;
858 /* Handshake fails if message header is incomplete */
859 if (i != DTLS1_HM_HEADER_LENGTH) {
860 al = SSL_AD_UNEXPECTED_MESSAGE;
861 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE);
865 /* parse the message fragment header */
866 dtls1_get_message_header(wire, &msg_hdr);
869 * if this is a future (or stale) message it gets buffered
870 * (or dropped)--no further processing at this time
871 * While listening, we accept seq 1 (ClientHello with cookie)
872 * although we're still expecting seq 0 (ClientHello)
874 if (msg_hdr.seq != s->d1->handshake_read_seq
875 && !(s->d1->listen && msg_hdr.seq == 1))
876 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
878 len = msg_hdr.msg_len;
879 frag_off = msg_hdr.frag_off;
880 frag_len = msg_hdr.frag_len;
882 if (frag_len && frag_len < len)
883 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
885 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
886 wire[0] == SSL3_MT_HELLO_REQUEST) {
888 * The server may always send 'Hello Request' messages -- we are
889 * doing a handshake anyway now, so ignore them if their format is
890 * correct. Does not count for 'Finished' MAC.
892 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
894 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
895 wire, DTLS1_HM_HEADER_LENGTH, s,
896 s->msg_callback_arg);
900 } else { /* Incorrectly formated Hello request */
902 al = SSL_AD_UNEXPECTED_MESSAGE;
903 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,
904 SSL_R_UNEXPECTED_MESSAGE);
909 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max)))
912 /* XDTLS: ressurect this when restart is in place */
917 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
919 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
920 &p[frag_off], frag_len, 0);
922 * XDTLS: fix this--message fragments cannot span multiple packets
925 s->rwstate = SSL_READING;
933 * XDTLS: an incorrectly formatted fragment should cause the handshake
936 if (i != (int)frag_len) {
937 al = SSL3_AD_ILLEGAL_PARAMETER;
938 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER);
945 * Note that s->init_num is *not* used as current offset in
946 * s->init_buf->data, but as a counter summing up fragments' lengths: as
947 * soon as they sum up to handshake packet length, we assume we have got
950 s->init_num = frag_len;
954 ssl3_send_alert(s, SSL3_AL_FATAL, al);
962 * for these 2 messages, we need to
963 * ssl->enc_read_ctx re-init
964 * ssl->rlayer.read_sequence zero
965 * ssl->s3->read_mac_secret re-init
966 * ssl->session->read_sym_enc assign
967 * ssl->session->read_compression assign
968 * ssl->session->read_hash assign
970 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
975 p = (unsigned char *)s->init_buf->data;
977 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
978 s->init_num = DTLS1_CCS_HEADER_LENGTH;
980 if (s->version == DTLS1_BAD_VER) {
981 s->d1->next_handshake_write_seq++;
982 s2n(s->d1->handshake_write_seq, p);
988 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
989 s->d1->handshake_write_seq, 0, 0);
991 /* buffer the message to handle re-xmits */
992 if (!dtls1_buffer_message(s, 1)) {
993 SSLerr(SSL_F_DTLS1_SEND_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
1000 /* SSL3_ST_CW_CHANGE_B */
1001 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
1004 int dtls1_read_failed(SSL *s, int code)
1007 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1011 if (!dtls1_is_timer_expired(s)) {
1013 * not a timeout, none of our business, let higher layers handle
1014 * this. in fact it's probably an error
1018 #ifndef OPENSSL_NO_HEARTBEATS
1019 /* done, no need to send a retransmit */
1020 if (!SSL_in_init(s) && !s->tlsext_hb_pending)
1022 /* done, no need to send a retransmit */
1023 if (!SSL_in_init(s))
1026 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1030 return dtls1_handle_timeout(s);
1033 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1036 * The index of the retransmission queue actually is the message sequence
1037 * number, since the queue only contains messages of a single handshake.
1038 * However, the ChangeCipherSpec has no message sequence number and so
1039 * using only the sequence will result in the CCS and Finished having the
1040 * same index. To prevent this, the sequence number is multiplied by 2.
1041 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1042 * Finished, it also maintains the order of the index (important for
1043 * priority queues) and fits in the unsigned short variable.
1045 return seq * 2 - is_ccs;
1048 int dtls1_retransmit_buffered_messages(SSL *s)
1050 pqueue sent = s->d1->sent_messages;
1056 iter = pqueue_iterator(sent);
1058 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1059 frag = (hm_fragment *)item->data;
1060 if (dtls1_retransmit_message(s, (unsigned short)
1061 dtls1_get_queue_priority
1062 (frag->msg_header.seq,
1063 frag->msg_header.is_ccs), 0,
1064 &found) <= 0 && found) {
1065 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1073 int dtls1_buffer_message(SSL *s, int is_ccs)
1077 unsigned char seq64be[8];
1080 * this function is called immediately after a message has been
1083 OPENSSL_assert(s->init_off == 0);
1085 frag = dtls1_hm_fragment_new(s->init_num, 0);
1089 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1092 /* For DTLS1_BAD_VER the header length is non-standard */
1093 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1094 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH)
1095 == (unsigned int)s->init_num);
1097 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1098 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1101 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1102 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1103 frag->msg_header.type = s->d1->w_msg_hdr.type;
1104 frag->msg_header.frag_off = 0;
1105 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1106 frag->msg_header.is_ccs = is_ccs;
1108 /* save current state */
1109 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1110 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1111 frag->msg_header.saved_retransmit_state.compress = s->compress;
1112 frag->msg_header.saved_retransmit_state.session = s->session;
1113 frag->msg_header.saved_retransmit_state.epoch =
1114 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1116 memset(seq64be, 0, sizeof(seq64be));
1119 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1120 frag->msg_header.is_ccs) >> 8);
1123 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1124 frag->msg_header.is_ccs));
1126 item = pitem_new(seq64be, frag);
1128 dtls1_hm_fragment_free(frag);
1132 pqueue_insert(s->d1->sent_messages, item);
1137 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1141 /* XDTLS: for now assuming that read/writes are blocking */
1144 unsigned long header_length;
1145 unsigned char seq64be[8];
1146 struct dtls1_retransmit_state saved_state;
1149 OPENSSL_assert(s->init_num == 0);
1150 OPENSSL_assert(s->init_off == 0);
1153 /* XDTLS: the requested message ought to be found, otherwise error */
1154 memset(seq64be, 0, sizeof(seq64be));
1155 seq64be[6] = (unsigned char)(seq >> 8);
1156 seq64be[7] = (unsigned char)seq;
1158 item = pqueue_find(s->d1->sent_messages, seq64be);
1160 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1166 frag = (hm_fragment *)item->data;
1168 if (frag->msg_header.is_ccs)
1169 header_length = DTLS1_CCS_HEADER_LENGTH;
1171 header_length = DTLS1_HM_HEADER_LENGTH;
1173 memcpy(s->init_buf->data, frag->fragment,
1174 frag->msg_header.msg_len + header_length);
1175 s->init_num = frag->msg_header.msg_len + header_length;
1177 dtls1_set_message_header_int(s, frag->msg_header.type,
1178 frag->msg_header.msg_len,
1179 frag->msg_header.seq, 0,
1180 frag->msg_header.frag_len);
1182 /* save current state */
1183 saved_state.enc_write_ctx = s->enc_write_ctx;
1184 saved_state.write_hash = s->write_hash;
1185 saved_state.compress = s->compress;
1186 saved_state.session = s->session;
1187 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1189 s->d1->retransmitting = 1;
1191 /* restore state in which the message was originally sent */
1192 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1193 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1194 s->compress = frag->msg_header.saved_retransmit_state.compress;
1195 s->session = frag->msg_header.saved_retransmit_state.session;
1196 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1197 frag->msg_header.saved_retransmit_state.epoch);
1199 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1200 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1202 /* restore current state */
1203 s->enc_write_ctx = saved_state.enc_write_ctx;
1204 s->write_hash = saved_state.write_hash;
1205 s->compress = saved_state.compress;
1206 s->session = saved_state.session;
1207 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1209 s->d1->retransmitting = 0;
1211 (void)BIO_flush(SSL_get_wbio(s));
1215 /* call this function when the buffered messages are no longer needed */
1216 void dtls1_clear_record_buffer(SSL *s)
1220 for (item = pqueue_pop(s->d1->sent_messages);
1221 item != NULL; item = pqueue_pop(s->d1->sent_messages)) {
1222 dtls1_hm_fragment_free((hm_fragment *)item->data);
1227 void dtls1_set_message_header(SSL *s, unsigned char *p,
1228 unsigned char mt, unsigned long len,
1229 unsigned long frag_off,
1230 unsigned long frag_len)
1232 /* Don't change sequence numbers while listening */
1233 if (frag_off == 0 && !s->d1->listen) {
1234 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1235 s->d1->next_handshake_write_seq++;
1238 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1239 frag_off, frag_len);
1242 /* don't actually do the writing, wait till the MTU has been retrieved */
1244 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1245 unsigned long len, unsigned short seq_num,
1246 unsigned long frag_off, unsigned long frag_len)
1248 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1251 msg_hdr->msg_len = len;
1252 msg_hdr->seq = seq_num;
1253 msg_hdr->frag_off = frag_off;
1254 msg_hdr->frag_len = frag_len;
1258 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1259 unsigned long frag_len)
1261 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1263 msg_hdr->frag_off = frag_off;
1264 msg_hdr->frag_len = frag_len;
1267 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1269 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1271 *p++ = msg_hdr->type;
1272 l2n3(msg_hdr->msg_len, p);
1274 s2n(msg_hdr->seq, p);
1275 l2n3(msg_hdr->frag_off, p);
1276 l2n3(msg_hdr->frag_len, p);
1281 unsigned int dtls1_link_min_mtu(void)
1283 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1284 sizeof(g_probable_mtu[0])) - 1]);
1287 unsigned int dtls1_min_mtu(SSL *s)
1289 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1293 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1295 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1296 msg_hdr->type = *(data++);
1297 n2l3(data, msg_hdr->msg_len);
1299 n2s(data, msg_hdr->seq);
1300 n2l3(data, msg_hdr->frag_off);
1301 n2l3(data, msg_hdr->frag_len);
1304 void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1306 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1308 ccs_hdr->type = *(data++);
1311 int dtls1_shutdown(SSL *s)
1314 #ifndef OPENSSL_NO_SCTP
1315 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1316 !(s->shutdown & SSL_SENT_SHUTDOWN)) {
1317 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1322 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
1326 ret = ssl3_shutdown(s);
1327 #ifndef OPENSSL_NO_SCTP
1328 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1333 #ifndef OPENSSL_NO_HEARTBEATS
1334 int dtls1_process_heartbeat(SSL *s, unsigned char *p, unsigned int length)
1337 unsigned short hbtype;
1338 unsigned int payload;
1339 unsigned int padding = 16; /* Use minimum padding */
1341 if (s->msg_callback)
1342 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1343 p, length, s, s->msg_callback_arg);
1345 /* Read type and payload length first */
1346 if (1 + 2 + 16 > length)
1347 return 0; /* silently discard */
1348 if (length > SSL3_RT_MAX_PLAIN_LENGTH)
1349 return 0; /* silently discard per RFC 6520 sec. 4 */
1353 if (1 + 2 + payload + 16 > length)
1354 return 0; /* silently discard per RFC 6520 sec. 4 */
1357 if (hbtype == TLS1_HB_REQUEST) {
1358 unsigned char *buffer, *bp;
1359 unsigned int write_length = 1 /* heartbeat type */ +
1360 2 /* heartbeat length */ +
1364 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1368 * Allocate memory for the response, size is 1 byte message type,
1369 * plus 2 bytes payload length, plus payload, plus padding
1371 buffer = OPENSSL_malloc(write_length);
1376 /* Enter response type, length and copy payload */
1377 *bp++ = TLS1_HB_RESPONSE;
1379 memcpy(bp, pl, payload);
1381 /* Random padding */
1382 if (RAND_bytes(bp, padding) <= 0) {
1383 OPENSSL_free(buffer);
1387 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1389 if (r >= 0 && s->msg_callback)
1390 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1391 buffer, write_length, s, s->msg_callback_arg);
1393 OPENSSL_free(buffer);
1397 } else if (hbtype == TLS1_HB_RESPONSE) {
1401 * We only send sequence numbers (2 bytes unsigned int), and 16
1402 * random bytes, so we just try to read the sequence number
1406 if (payload == 18 && seq == s->tlsext_hb_seq) {
1407 dtls1_stop_timer(s);
1409 s->tlsext_hb_pending = 0;
1416 int dtls1_heartbeat(SSL *s)
1418 unsigned char *buf, *p;
1420 unsigned int payload = 18; /* Sequence number + random bytes */
1421 unsigned int padding = 16; /* Use minimum padding */
1423 /* Only send if peer supports and accepts HB requests... */
1424 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1425 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) {
1426 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1430 /* ...and there is none in flight yet... */
1431 if (s->tlsext_hb_pending) {
1432 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
1436 /* ...and no handshake in progress. */
1437 if (SSL_in_init(s) || s->in_handshake) {
1438 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
1443 * Check if padding is too long, payload and padding must not exceed 2^14
1444 * - 3 = 16381 bytes in total.
1446 OPENSSL_assert(payload + padding <= 16381);
1449 * Create HeartBeat message, we just use a sequence number
1450 * as payload to distuingish different messages and add
1451 * some random stuff.
1452 * - Message Type, 1 byte
1453 * - Payload Length, 2 bytes (unsigned int)
1454 * - Payload, the sequence number (2 bytes uint)
1455 * - Payload, random bytes (16 bytes uint)
1458 buf = OPENSSL_malloc(1 + 2 + payload + padding);
1460 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_MALLOC_FAILURE);
1465 *p++ = TLS1_HB_REQUEST;
1466 /* Payload length (18 bytes here) */
1468 /* Sequence number */
1469 s2n(s->tlsext_hb_seq, p);
1470 /* 16 random bytes */
1471 if (RAND_bytes(p, 16) <= 0) {
1472 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
1476 /* Random padding */
1477 if (RAND_bytes(p, padding) <= 0) {
1478 SSLerr(SSL_F_DTLS1_HEARTBEAT, ERR_R_INTERNAL_ERROR);
1482 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1484 if (s->msg_callback)
1485 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1486 buf, 3 + payload + padding,
1487 s, s->msg_callback_arg);
1489 dtls1_start_timer(s);
1490 s->tlsext_hb_pending = 1;