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
, "invalid state reached %s:%d", __FILE__
, __LINE__
);
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
), 0,
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
, unsigned long frag_off
,
1159 /* XDTLS: for now assuming that read/writes are blocking */
1162 unsigned long header_length
;
1163 unsigned char seq64be
[8];
1164 struct dtls1_retransmit_state saved_state
;
1167 OPENSSL_assert(s->init_num == 0);
1168 OPENSSL_assert(s->init_off == 0);
1171 /* XDTLS: the requested message ought to be found, otherwise error */
1172 memset(seq64be
, 0, sizeof(seq64be
));
1173 seq64be
[6] = (unsigned char)(seq
>> 8);
1174 seq64be
[7] = (unsigned char)seq
;
1176 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1178 fprintf(stderr
, "retransmit: message %d non-existant\n", seq
);
1184 frag
= (hm_fragment
*)item
->data
;
1186 if (frag
->msg_header
.is_ccs
)
1187 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1189 header_length
= DTLS1_HM_HEADER_LENGTH
;
1191 memcpy(s
->init_buf
->data
, frag
->fragment
,
1192 frag
->msg_header
.msg_len
+ header_length
);
1193 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1195 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1196 frag
->msg_header
.msg_len
,
1197 frag
->msg_header
.seq
, 0,
1198 frag
->msg_header
.frag_len
);
1200 /* save current state */
1201 saved_state
.enc_write_ctx
= s
->enc_write_ctx
;
1202 saved_state
.write_hash
= s
->write_hash
;
1203 saved_state
.compress
= s
->compress
;
1204 saved_state
.session
= s
->session
;
1205 saved_state
.epoch
= DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1207 s
->d1
->retransmitting
= 1;
1209 /* restore state in which the message was originally sent */
1210 s
->enc_write_ctx
= frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
;
1211 s
->write_hash
= frag
->msg_header
.saved_retransmit_state
.write_hash
;
1212 s
->compress
= frag
->msg_header
.saved_retransmit_state
.compress
;
1213 s
->session
= frag
->msg_header
.saved_retransmit_state
.session
;
1214 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
,
1215 frag
->msg_header
.saved_retransmit_state
.epoch
);
1217 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1218 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1220 /* restore current state */
1221 s
->enc_write_ctx
= saved_state
.enc_write_ctx
;
1222 s
->write_hash
= saved_state
.write_hash
;
1223 s
->compress
= saved_state
.compress
;
1224 s
->session
= saved_state
.session
;
1225 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
, saved_state
.epoch
);
1227 s
->d1
->retransmitting
= 0;
1229 (void)BIO_flush(SSL_get_wbio(s
));
1233 /* call this function when the buffered messages are no longer needed */
1234 void dtls1_clear_record_buffer(SSL
*s
)
1238 for (item
= pqueue_pop(s
->d1
->sent_messages
);
1239 item
!= NULL
; item
= pqueue_pop(s
->d1
->sent_messages
)) {
1240 dtls1_hm_fragment_free((hm_fragment
*)item
->data
);
1245 void dtls1_set_message_header(SSL
*s
, unsigned char *p
,
1246 unsigned char mt
, unsigned long len
,
1247 unsigned long frag_off
,
1248 unsigned long frag_len
)
1250 if (frag_off
== 0) {
1251 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1252 s
->d1
->next_handshake_write_seq
++;
1255 dtls1_set_message_header_int(s
, mt
, len
, s
->d1
->handshake_write_seq
,
1256 frag_off
, frag_len
);
1259 /* don't actually do the writing, wait till the MTU has been retrieved */
1261 dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
1262 unsigned long len
, unsigned short seq_num
,
1263 unsigned long frag_off
, unsigned long frag_len
)
1265 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1268 msg_hdr
->msg_len
= len
;
1269 msg_hdr
->seq
= seq_num
;
1270 msg_hdr
->frag_off
= frag_off
;
1271 msg_hdr
->frag_len
= frag_len
;
1275 dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
1276 unsigned long frag_len
)
1278 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1280 msg_hdr
->frag_off
= frag_off
;
1281 msg_hdr
->frag_len
= frag_len
;
1284 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
)
1286 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1288 *p
++ = msg_hdr
->type
;
1289 l2n3(msg_hdr
->msg_len
, p
);
1291 s2n(msg_hdr
->seq
, p
);
1292 l2n3(msg_hdr
->frag_off
, p
);
1293 l2n3(msg_hdr
->frag_len
, p
);
1299 dtls1_get_message_header(unsigned char *data
, struct hm_header_st
*msg_hdr
)
1301 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
1302 msg_hdr
->type
= *(data
++);
1303 n2l3(data
, msg_hdr
->msg_len
);
1305 n2s(data
, msg_hdr
->seq
);
1306 n2l3(data
, msg_hdr
->frag_off
);
1307 n2l3(data
, msg_hdr
->frag_len
);