2 * DTLS implementation written by Nagendra Modadugu
3 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5 /* ====================================================================
6 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in
17 * the documentation and/or other materials provided with the
20 * 3. All advertising materials mentioning features or use of this
21 * software must display the following acknowledgment:
22 * "This product includes software developed by the OpenSSL Project
23 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
25 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
26 * endorse or promote products derived from this software without
27 * prior written permission. For written permission, please contact
28 * openssl-core@openssl.org.
30 * 5. Products derived from this software may not be called "OpenSSL"
31 * nor may "OpenSSL" appear in their names without prior written
32 * permission of the OpenSSL Project.
34 * 6. Redistributions of any form whatsoever must retain the following
36 * "This product includes software developed by the OpenSSL Project
37 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
39 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
40 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
41 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
42 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
43 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
44 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
45 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
46 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
48 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
49 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
50 * OF THE POSSIBILITY OF SUCH DAMAGE.
51 * ====================================================================
53 * This product includes cryptographic software written by Eric Young
54 * (eay@cryptsoft.com). This product includes software written by Tim
55 * Hudson (tjh@cryptsoft.com).
58 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
59 * All rights reserved.
61 * This package is an SSL implementation written
62 * by Eric Young (eay@cryptsoft.com).
63 * The implementation was written so as to conform with Netscapes SSL.
65 * This library is free for commercial and non-commercial use as long as
66 * the following conditions are aheared to. The following conditions
67 * apply to all code found in this distribution, be it the RC4, RSA,
68 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
69 * included with this distribution is covered by the same copyright terms
70 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
72 * Copyright remains Eric Young's, and as such any Copyright notices in
73 * the code are not to be removed.
74 * If this package is used in a product, Eric Young should be given attribution
75 * as the author of the parts of the library used.
76 * This can be in the form of a textual message at program startup or
77 * in documentation (online or textual) provided with the package.
79 * Redistribution and use in source and binary forms, with or without
80 * modification, are permitted provided that the following conditions
82 * 1. Redistributions of source code must retain the copyright
83 * notice, this list of conditions and the following disclaimer.
84 * 2. Redistributions in binary form must reproduce the above copyright
85 * notice, this list of conditions and the following disclaimer in the
86 * documentation and/or other materials provided with the distribution.
87 * 3. All advertising materials mentioning features or use of this software
88 * must display the following acknowledgement:
89 * "This product includes cryptographic software written by
90 * Eric Young (eay@cryptsoft.com)"
91 * The word 'cryptographic' can be left out if the rouines from the library
92 * being used are not cryptographic related :-).
93 * 4. If you include any Windows specific code (or a derivative thereof) from
94 * the apps directory (application code) you must include an acknowledgement:
95 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
97 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
98 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
99 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
100 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
101 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
102 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
103 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
104 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
105 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
106 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
109 * The licence and distribution terms for any publically available version or
110 * derivative of this code cannot be changed. i.e. this code cannot simply be
111 * copied and put under another distribution licence
112 * [including the GNU Public Licence.]
118 #include "../ssl_locl.h"
119 #include "statem_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 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
153 unsigned long frag_len);
154 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p);
155 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
157 unsigned short seq_num,
158 unsigned long frag_off,
159 unsigned long frag_len);
160 static int dtls_get_reassembled_message(SSL *s, long *len);
162 static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len,
165 hm_fragment *frag = NULL;
166 unsigned char *buf = NULL;
167 unsigned char *bitmask = NULL;
169 frag = OPENSSL_malloc(sizeof(*frag));
174 buf = OPENSSL_malloc(frag_len);
181 /* zero length fragment gets zero frag->fragment */
182 frag->fragment = buf;
184 /* Initialize reassembly bitmask if necessary */
186 bitmask = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len));
187 if (bitmask == NULL) {
194 frag->reassembly = bitmask;
199 void dtls1_hm_fragment_free(hm_fragment *frag)
203 if (frag->msg_header.is_ccs) {
204 EVP_CIPHER_CTX_free(frag->msg_header.
205 saved_retransmit_state.enc_write_ctx);
206 EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash);
208 OPENSSL_free(frag->fragment);
209 OPENSSL_free(frag->reassembly);
214 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
215 * SSL3_RT_CHANGE_CIPHER_SPEC)
217 int dtls1_do_write(SSL *s, int type)
220 unsigned int curr_mtu;
222 unsigned int len, frag_off, mac_size, blocksize, used_len;
224 if (!dtls1_query_mtu(s))
227 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something
230 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
231 OPENSSL_assert(s->init_num ==
232 (int)s->d1->w_msg_hdr.msg_len +
233 DTLS1_HM_HEADER_LENGTH);
237 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s->enc_write_ctx)) &
238 EVP_CIPH_FLAG_AEAD_CIPHER) != 0)
241 mac_size = EVP_MD_CTX_size(s->write_hash);
245 if (s->enc_write_ctx &&
246 (EVP_CIPHER_CTX_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
247 blocksize = 2 * EVP_CIPHER_CTX_block_size(s->enc_write_ctx);
252 s->rwstate = SSL_NOTHING;
254 /* s->init_num shouldn't ever be < 0...but just in case */
255 while (s->init_num > 0) {
256 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
257 /* We must be writing a fragment other than the first one */
260 /* This is the first attempt at writing out this fragment */
262 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
264 * Each fragment that was already sent must at least have
265 * contained the message header plus one other byte.
266 * Therefore |init_off| must have progressed by at least
267 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
274 * Adjust |init_off| and |init_num| to allow room for a new
275 * message header for this fragment.
277 s->init_off -= DTLS1_HM_HEADER_LENGTH;
278 s->init_num += DTLS1_HM_HEADER_LENGTH;
281 * We must have been called again after a retry so use the
282 * fragment offset from our last attempt. We do not need
283 * to adjust |init_off| and |init_num| as above, because
284 * that should already have been done before the retry.
286 frag_off = s->d1->w_msg_hdr.frag_off;
290 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH
291 + mac_size + blocksize;
292 if (s->d1->mtu > used_len)
293 curr_mtu = s->d1->mtu - used_len;
297 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
299 * grr.. we could get an error if MTU picked was wrong
301 ret = BIO_flush(SSL_get_wbio(s));
303 s->rwstate = SSL_WRITING;
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 (len < DTLS1_HM_HEADER_LENGTH) {
333 * len is so small that we really can't do anything sensible
338 dtls1_fix_message_header(s, frag_off,
339 len - DTLS1_HM_HEADER_LENGTH);
341 dtls1_write_message_header(s,
342 (unsigned char *)&s->init_buf->
346 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off],
350 * might need to update MTU here, but we don't know which
351 * previous packet caused the failure -- so can't really
352 * retransmit anything. continue as if everything is fine and
353 * wait for an alert to handle the retransmit
355 if (retry && BIO_ctrl(SSL_get_wbio(s),
356 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
357 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
358 if (!dtls1_query_mtu(s))
360 /* Have one more go */
370 * bad if this assert fails, only part of the handshake message
371 * got sent. but why would this happen?
373 OPENSSL_assert(len == (unsigned int)ret);
375 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
377 * should not be done for 'Hello Request's, but in that case
378 * we'll ignore the result anyway
381 (unsigned char *)&s->init_buf->data[s->init_off];
382 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
385 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
387 * reconstruct message header is if it is being sent in
390 *p++ = msg_hdr->type;
391 l2n3(msg_hdr->msg_len, p);
392 s2n(msg_hdr->seq, p);
394 l2n3(msg_hdr->msg_len, p);
395 p -= DTLS1_HM_HEADER_LENGTH;
398 p += DTLS1_HM_HEADER_LENGTH;
399 xlen = ret - DTLS1_HM_HEADER_LENGTH;
402 ssl3_finish_mac(s, p, xlen);
405 if (ret == s->init_num) {
407 s->msg_callback(1, s->version, type, s->init_buf->data,
408 (size_t)(s->init_off + s->init_num), s,
409 s->msg_callback_arg);
411 s->init_off = 0; /* done writing this message */
418 ret -= DTLS1_HM_HEADER_LENGTH;
422 * We save the fragment offset for the next fragment so we have it
423 * available in case of an IO retry. We don't know the length of the
424 * next fragment yet so just set that to 0 for now. It will be
425 * updated again later.
427 dtls1_fix_message_header(s, frag_off, 0);
433 int dtls_get_message(SSL *s, int *mt, unsigned long *len)
435 struct hm_header_st *msg_hdr;
437 unsigned long msg_len;
441 msg_hdr = &s->d1->r_msg_hdr;
442 memset(msg_hdr, 0, sizeof(*msg_hdr));
445 ok = dtls_get_reassembled_message(s, &tmplen);
446 if (tmplen == DTLS1_HM_BAD_FRAGMENT
447 || tmplen == DTLS1_HM_FRAGMENT_RETRY) {
448 /* bad fragment received */
450 } else if (tmplen <= 0 && !ok) {
454 *mt = s->s3->tmp.message_type;
456 p = (unsigned char *)s->init_buf->data;
458 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
459 if (s->msg_callback) {
460 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
461 p, 1, s, s->msg_callback_arg);
464 * This isn't a real handshake message so skip the processing below.
466 *len = (unsigned long)tmplen;
470 msg_len = msg_hdr->msg_len;
472 /* reconstruct message header */
473 *(p++) = msg_hdr->type;
475 s2n(msg_hdr->seq, p);
478 if (s->version != DTLS1_BAD_VER) {
479 p -= DTLS1_HM_HEADER_LENGTH;
480 msg_len += DTLS1_HM_HEADER_LENGTH;
483 ssl3_finish_mac(s, p, msg_len);
485 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
486 p, msg_len, s, s->msg_callback_arg);
488 memset(msg_hdr, 0, sizeof(*msg_hdr));
490 s->d1->handshake_read_seq++;
493 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
499 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
501 size_t frag_off, frag_len, msg_len;
503 msg_len = msg_hdr->msg_len;
504 frag_off = msg_hdr->frag_off;
505 frag_len = msg_hdr->frag_len;
507 /* sanity checking */
508 if ((frag_off + frag_len) > msg_len) {
509 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
510 return SSL_AD_ILLEGAL_PARAMETER;
513 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
515 * msg_len is limited to 2^24, but is effectively checked against max
518 if (!BUF_MEM_grow_clean
519 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
520 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
521 return SSL_AD_INTERNAL_ERROR;
524 s->s3->tmp.message_size = msg_len;
525 s->d1->r_msg_hdr.msg_len = msg_len;
526 s->s3->tmp.message_type = msg_hdr->type;
527 s->d1->r_msg_hdr.type = msg_hdr->type;
528 s->d1->r_msg_hdr.seq = msg_hdr->seq;
529 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
531 * They must be playing with us! BTW, failure to enforce upper limit
532 * would open possibility for buffer overrun.
534 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
535 return SSL_AD_ILLEGAL_PARAMETER;
538 return 0; /* no error */
541 static int dtls1_retrieve_buffered_fragment(SSL *s, int *ok)
544 * (0) check whether the desired fragment is available
546 * (1) copy over the fragment to s->init_buf->data[]
547 * (2) update s->init_num
554 item = pqueue_peek(s->d1->buffered_messages);
558 frag = (hm_fragment *)item->data;
560 /* Don't return if reassembly still in progress */
561 if (frag->reassembly != NULL)
564 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
565 unsigned long frag_len = frag->msg_header.frag_len;
566 pqueue_pop(s->d1->buffered_messages);
568 al = dtls1_preprocess_fragment(s, &frag->msg_header);
570 if (al == 0) { /* no alert */
572 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
573 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
574 frag->msg_header.frag_len);
577 dtls1_hm_fragment_free(frag);
585 ssl3_send_alert(s, SSL3_AL_FATAL, al);
594 * dtls1_max_handshake_message_len returns the maximum number of bytes
595 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
596 * may be greater if the maximum certificate list size requires it.
598 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
600 unsigned long max_len =
601 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
602 if (max_len < (unsigned long)s->max_cert_list)
603 return s->max_cert_list;
608 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
610 hm_fragment *frag = NULL;
612 int i = -1, is_complete;
613 unsigned char seq64be[8];
614 unsigned long frag_len = msg_hdr->frag_len;
616 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
617 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
621 return DTLS1_HM_FRAGMENT_RETRY;
623 /* Try to find item in queue */
624 memset(seq64be, 0, sizeof(seq64be));
625 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
626 seq64be[7] = (unsigned char)msg_hdr->seq;
627 item = pqueue_find(s->d1->buffered_messages, seq64be);
630 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
633 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
634 frag->msg_header.frag_len = frag->msg_header.msg_len;
635 frag->msg_header.frag_off = 0;
637 frag = (hm_fragment *)item->data;
638 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
646 * If message is already reassembled, this must be a retransmit and can
647 * be dropped. In this case item != NULL and so frag does not need to be
650 if (frag->reassembly == NULL) {
651 unsigned char devnull[256];
654 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
657 sizeof(devnull) ? sizeof(devnull) :
663 return DTLS1_HM_FRAGMENT_RETRY;
666 /* read the body of the fragment (header has already been read */
667 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
668 frag->fragment + msg_hdr->frag_off,
670 if ((unsigned long)i != frag_len)
675 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
676 (long)(msg_hdr->frag_off + frag_len));
678 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
682 OPENSSL_free(frag->reassembly);
683 frag->reassembly = NULL;
687 item = pitem_new(seq64be, frag);
693 item = pqueue_insert(s->d1->buffered_messages, item);
695 * pqueue_insert fails iff a duplicate item is inserted. However,
696 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
697 * would have returned it and control would never have reached this
700 OPENSSL_assert(item != NULL);
703 return DTLS1_HM_FRAGMENT_RETRY;
707 dtls1_hm_fragment_free(frag);
713 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr,
717 hm_fragment *frag = NULL;
719 unsigned char seq64be[8];
720 unsigned long frag_len = msg_hdr->frag_len;
722 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
725 /* Try to find item in queue, to prevent duplicate entries */
726 memset(seq64be, 0, sizeof(seq64be));
727 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
728 seq64be[7] = (unsigned char)msg_hdr->seq;
729 item = pqueue_find(s->d1->buffered_messages, seq64be);
732 * If we already have an entry and this one is a fragment, don't discard
733 * it and rather try to reassemble it.
735 if (item != NULL && frag_len != msg_hdr->msg_len)
739 * Discard the message if sequence number was already there, is too far
740 * in the future, already in the queue or if we received a FINISHED
741 * before the SERVER_HELLO, which then must be a stale retransmit.
743 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
744 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
745 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
747 unsigned char devnull[256];
750 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
753 sizeof(devnull) ? sizeof(devnull) :
760 if (frag_len != msg_hdr->msg_len)
761 return dtls1_reassemble_fragment(s, msg_hdr, ok);
763 if (frag_len > dtls1_max_handshake_message_len(s))
766 frag = dtls1_hm_fragment_new(frag_len, 0);
770 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
774 * read the body of the fragment (header has already been read
776 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
777 frag->fragment, frag_len, 0);
778 if ((unsigned long)i != frag_len)
784 item = pitem_new(seq64be, frag);
788 item = pqueue_insert(s->d1->buffered_messages, item);
790 * pqueue_insert fails iff a duplicate item is inserted. However,
791 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
792 * would have returned it. Then, either |frag_len| !=
793 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
794 * have been processed with |dtls1_reassemble_fragment|, above, or
795 * the record will have been discarded.
797 OPENSSL_assert(item != NULL);
800 return DTLS1_HM_FRAGMENT_RETRY;
804 dtls1_hm_fragment_free(frag);
809 static int dtls_get_reassembled_message(SSL *s, long *len)
811 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
812 unsigned long mlen, frag_off, frag_len;
813 int i, al, recvd_type;
814 struct hm_header_st msg_hdr;
818 /* see if we have the required fragment already */
819 if ((frag_len = dtls1_retrieve_buffered_fragment(s, &ok)) || ok) {
821 s->init_num = frag_len;
826 /* read handshake message header */
827 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
828 DTLS1_HM_HEADER_LENGTH, 0);
829 if (i <= 0) { /* nbio, or an error */
830 s->rwstate = SSL_READING;
834 if(recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
835 if (wire[0] != SSL3_MT_CCS) {
836 al = SSL_AD_UNEXPECTED_MESSAGE;
837 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
838 SSL_R_BAD_CHANGE_CIPHER_SPEC);
842 memcpy(s->init_buf->data, wire, i);
844 s->init_msg = s->init_buf->data + 1;
845 s->s3->tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
846 s->s3->tmp.message_size = i - 1;
851 /* Handshake fails if message header is incomplete */
852 if (i != DTLS1_HM_HEADER_LENGTH) {
853 al = SSL_AD_UNEXPECTED_MESSAGE;
854 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
858 /* parse the message fragment header */
859 dtls1_get_message_header(wire, &msg_hdr);
861 mlen = msg_hdr.msg_len;
862 frag_off = msg_hdr.frag_off;
863 frag_len = msg_hdr.frag_len;
866 * We must have at least frag_len bytes left in the record to be read.
867 * Fragments must not span records.
869 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
870 al = SSL3_AD_ILLEGAL_PARAMETER;
871 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL_R_BAD_LENGTH);
876 * if this is a future (or stale) message it gets buffered
877 * (or dropped)--no further processing at this time
878 * While listening, we accept seq 1 (ClientHello with cookie)
879 * although we're still expecting seq 0 (ClientHello)
881 if (msg_hdr.seq != s->d1->handshake_read_seq) {
882 *len = dtls1_process_out_of_seq_message(s, &msg_hdr, &ok);
886 if (frag_len && frag_len < mlen) {
887 *len = dtls1_reassemble_fragment(s, &msg_hdr, &ok);
891 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
892 wire[0] == SSL3_MT_HELLO_REQUEST) {
894 * The server may always send 'Hello Request' messages -- we are
895 * doing a handshake anyway now, so ignore them if their format is
896 * correct. Does not count for 'Finished' MAC.
898 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
900 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
901 wire, DTLS1_HM_HEADER_LENGTH, s,
902 s->msg_callback_arg);
906 } else { /* Incorrectly formated Hello request */
908 al = SSL_AD_UNEXPECTED_MESSAGE;
909 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE,
910 SSL_R_UNEXPECTED_MESSAGE);
915 if ((al = dtls1_preprocess_fragment(s, &msg_hdr)))
920 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
922 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
923 &p[frag_off], frag_len, 0);
926 * This shouldn't ever fail due to NBIO because we already checked
927 * that we have enough data in the record
930 s->rwstate = SSL_READING;
938 * XDTLS: an incorrectly formatted fragment should cause the handshake
941 if (i != (int)frag_len) {
942 al = SSL3_AD_ILLEGAL_PARAMETER;
943 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE, SSL3_AD_ILLEGAL_PARAMETER);
948 * Note that s->init_num is *not* used as current offset in
949 * s->init_buf->data, but as a counter summing up fragments' lengths: as
950 * soon as they sum up to handshake packet length, we assume we have got
953 *len = s->init_num = frag_len;
957 ssl3_send_alert(s, SSL3_AL_FATAL, al);
964 * for these 2 messages, we need to
965 * ssl->enc_read_ctx re-init
966 * ssl->rlayer.read_sequence zero
967 * ssl->s3->read_mac_secret re-init
968 * ssl->session->read_sym_enc assign
969 * ssl->session->read_compression assign
970 * ssl->session->read_hash assign
972 int dtls_construct_change_cipher_spec(SSL *s)
976 p = (unsigned char *)s->init_buf->data;
978 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
979 s->init_num = DTLS1_CCS_HEADER_LENGTH;
981 if (s->version == DTLS1_BAD_VER) {
982 s->d1->next_handshake_write_seq++;
983 s2n(s->d1->handshake_write_seq, p);
989 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
990 s->d1->handshake_write_seq, 0, 0);
992 /* buffer the message to handle re-xmits */
993 if (!dtls1_buffer_message(s, 1)) {
994 SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC, ERR_R_INTERNAL_ERROR);
1001 #ifndef OPENSSL_NO_SCTP
1002 WORK_STATE dtls_wait_for_dry(SSL *s)
1006 /* read app data until dry event */
1007 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1012 s->s3->in_read_app_data = 2;
1013 s->rwstate = SSL_READING;
1014 BIO_clear_retry_flags(SSL_get_rbio(s));
1015 BIO_set_retry_read(SSL_get_rbio(s));
1018 return WORK_FINISHED_CONTINUE;
1022 int dtls1_read_failed(SSL *s, int code)
1025 fprintf(stderr, "dtls1_read_failed(); invalid state reached\n");
1029 if (!dtls1_is_timer_expired(s)) {
1031 * not a timeout, none of our business, let higher layers handle
1032 * this. in fact it's probably an error
1036 #ifndef OPENSSL_NO_HEARTBEATS
1037 /* done, no need to send a retransmit */
1038 if (!SSL_in_init(s) && !s->tlsext_hb_pending)
1040 /* done, no need to send a retransmit */
1041 if (!SSL_in_init(s))
1044 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1048 return dtls1_handle_timeout(s);
1051 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1054 * The index of the retransmission queue actually is the message sequence
1055 * number, since the queue only contains messages of a single handshake.
1056 * However, the ChangeCipherSpec has no message sequence number and so
1057 * using only the sequence will result in the CCS and Finished having the
1058 * same index. To prevent this, the sequence number is multiplied by 2.
1059 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1060 * Finished, it also maintains the order of the index (important for
1061 * priority queues) and fits in the unsigned short variable.
1063 return seq * 2 - is_ccs;
1066 int dtls1_retransmit_buffered_messages(SSL *s)
1068 pqueue *sent = s->d1->sent_messages;
1074 iter = pqueue_iterator(sent);
1076 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1077 frag = (hm_fragment *)item->data;
1078 if (dtls1_retransmit_message(s, (unsigned short)
1079 dtls1_get_queue_priority
1080 (frag->msg_header.seq,
1081 frag->msg_header.is_ccs),
1082 &found) <= 0 && found) {
1083 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1091 int dtls1_buffer_message(SSL *s, int is_ccs)
1095 unsigned char seq64be[8];
1098 * this function is called immediately after a message has been
1101 OPENSSL_assert(s->init_off == 0);
1103 frag = dtls1_hm_fragment_new(s->init_num, 0);
1107 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1110 /* For DTLS1_BAD_VER the header length is non-standard */
1111 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1112 ((s->version==DTLS1_BAD_VER)?3:DTLS1_CCS_HEADER_LENGTH)
1113 == (unsigned int)s->init_num);
1115 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1116 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1119 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1120 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1121 frag->msg_header.type = s->d1->w_msg_hdr.type;
1122 frag->msg_header.frag_off = 0;
1123 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1124 frag->msg_header.is_ccs = is_ccs;
1126 /* save current state */
1127 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1128 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1129 frag->msg_header.saved_retransmit_state.compress = s->compress;
1130 frag->msg_header.saved_retransmit_state.session = s->session;
1131 frag->msg_header.saved_retransmit_state.epoch =
1132 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1134 memset(seq64be, 0, sizeof(seq64be));
1137 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1138 frag->msg_header.is_ccs) >> 8);
1141 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1142 frag->msg_header.is_ccs));
1144 item = pitem_new(seq64be, frag);
1146 dtls1_hm_fragment_free(frag);
1150 pqueue_insert(s->d1->sent_messages, item);
1155 dtls1_retransmit_message(SSL *s, unsigned short seq, int *found)
1158 /* XDTLS: for now assuming that read/writes are blocking */
1161 unsigned long header_length;
1162 unsigned char seq64be[8];
1163 struct dtls1_retransmit_state saved_state;
1166 OPENSSL_assert(s->init_num == 0);
1167 OPENSSL_assert(s->init_off == 0);
1170 /* XDTLS: the requested message ought to be found, otherwise error */
1171 memset(seq64be, 0, sizeof(seq64be));
1172 seq64be[6] = (unsigned char)(seq >> 8);
1173 seq64be[7] = (unsigned char)seq;
1175 item = pqueue_find(s->d1->sent_messages, seq64be);
1177 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1183 frag = (hm_fragment *)item->data;
1185 if (frag->msg_header.is_ccs)
1186 header_length = DTLS1_CCS_HEADER_LENGTH;
1188 header_length = DTLS1_HM_HEADER_LENGTH;
1190 memcpy(s->init_buf->data, frag->fragment,
1191 frag->msg_header.msg_len + header_length);
1192 s->init_num = frag->msg_header.msg_len + header_length;
1194 dtls1_set_message_header_int(s, frag->msg_header.type,
1195 frag->msg_header.msg_len,
1196 frag->msg_header.seq, 0,
1197 frag->msg_header.frag_len);
1199 /* save current state */
1200 saved_state.enc_write_ctx = s->enc_write_ctx;
1201 saved_state.write_hash = s->write_hash;
1202 saved_state.compress = s->compress;
1203 saved_state.session = s->session;
1204 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1206 s->d1->retransmitting = 1;
1208 /* restore state in which the message was originally sent */
1209 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1210 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1211 s->compress = frag->msg_header.saved_retransmit_state.compress;
1212 s->session = frag->msg_header.saved_retransmit_state.session;
1213 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1214 frag->msg_header.saved_retransmit_state.epoch);
1216 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1217 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1219 /* restore current state */
1220 s->enc_write_ctx = saved_state.enc_write_ctx;
1221 s->write_hash = saved_state.write_hash;
1222 s->compress = saved_state.compress;
1223 s->session = saved_state.session;
1224 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1226 s->d1->retransmitting = 0;
1228 (void)BIO_flush(SSL_get_wbio(s));
1232 /* call this function when the buffered messages are no longer needed */
1233 void dtls1_clear_record_buffer(SSL *s)
1237 for (item = pqueue_pop(s->d1->sent_messages);
1238 item != NULL; item = pqueue_pop(s->d1->sent_messages)) {
1239 dtls1_hm_fragment_free((hm_fragment *)item->data);
1244 void dtls1_set_message_header(SSL *s,
1245 unsigned char mt, unsigned long len,
1246 unsigned long frag_off,
1247 unsigned long frag_len)
1249 if (frag_off == 0) {
1250 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1251 s->d1->next_handshake_write_seq++;
1254 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1255 frag_off, frag_len);
1258 /* don't actually do the writing, wait till the MTU has been retrieved */
1260 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1261 unsigned long len, unsigned short seq_num,
1262 unsigned long frag_off, unsigned long frag_len)
1264 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1267 msg_hdr->msg_len = len;
1268 msg_hdr->seq = seq_num;
1269 msg_hdr->frag_off = frag_off;
1270 msg_hdr->frag_len = frag_len;
1274 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1275 unsigned long frag_len)
1277 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1279 msg_hdr->frag_off = frag_off;
1280 msg_hdr->frag_len = frag_len;
1283 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1285 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1287 *p++ = msg_hdr->type;
1288 l2n3(msg_hdr->msg_len, p);
1290 s2n(msg_hdr->seq, p);
1291 l2n3(msg_hdr->frag_off, p);
1292 l2n3(msg_hdr->frag_len, p);
1298 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1300 memset(msg_hdr, 0, sizeof(*msg_hdr));
1301 msg_hdr->type = *(data++);
1302 n2l3(data, msg_hdr->msg_len);
1304 n2s(data, msg_hdr->seq);
1305 n2l3(data, msg_hdr->frag_off);
1306 n2l3(data, msg_hdr->frag_len);