1 /* ssl/statem/statem_dtls.c */
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 "statem_locl.h"
121 #include <openssl/buffer.h>
122 #include <openssl/rand.h>
123 #include <openssl/objects.h>
124 #include <openssl/evp.h>
125 #include <openssl/x509.h>
127 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
129 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
130 if ((end) - (start) <= 8) { \
132 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
135 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
136 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
137 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
140 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
142 OPENSSL_assert((msg_len) > 0); \
144 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
145 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
146 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
148 static unsigned char bitmask_start_values
[] =
149 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
150 static unsigned char bitmask_end_values
[] =
151 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
153 static void dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
154 unsigned long frag_len
);
155 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
);
156 static void dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
158 unsigned short seq_num
,
159 unsigned long frag_off
,
160 unsigned long frag_len
);
161 static int dtls_get_reassembled_message(SSL
*s
, long *len
);
163 static hm_fragment
*dtls1_hm_fragment_new(unsigned long frag_len
,
166 hm_fragment
*frag
= NULL
;
167 unsigned char *buf
= NULL
;
168 unsigned char *bitmask
= NULL
;
170 frag
= OPENSSL_malloc(sizeof(*frag
));
175 buf
= OPENSSL_malloc(frag_len
);
182 /* zero length fragment gets zero frag->fragment */
183 frag
->fragment
= buf
;
185 /* Initialize reassembly bitmask if necessary */
187 bitmask
= OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len
));
188 if (bitmask
== NULL
) {
195 frag
->reassembly
= bitmask
;
200 void dtls1_hm_fragment_free(hm_fragment
*frag
)
204 if (frag
->msg_header
.is_ccs
) {
205 EVP_CIPHER_CTX_free(frag
->msg_header
.
206 saved_retransmit_state
.enc_write_ctx
);
207 EVP_MD_CTX_free(frag
->msg_header
.saved_retransmit_state
.write_hash
);
209 OPENSSL_free(frag
->fragment
);
210 OPENSSL_free(frag
->reassembly
);
215 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
216 * SSL3_RT_CHANGE_CIPHER_SPEC)
218 int dtls1_do_write(SSL
*s
, int type
)
221 unsigned int curr_mtu
;
223 unsigned int len
, frag_off
, mac_size
, blocksize
, used_len
;
225 if (!dtls1_query_mtu(s
))
228 OPENSSL_assert(s
->d1
->mtu
>= dtls1_min_mtu(s
)); /* should have something
231 if (s
->init_off
== 0 && type
== SSL3_RT_HANDSHAKE
)
232 OPENSSL_assert(s
->init_num
==
233 (int)s
->d1
->w_msg_hdr
.msg_len
+
234 DTLS1_HM_HEADER_LENGTH
);
238 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s
->enc_write_ctx
)) &
239 EVP_CIPH_FLAG_AEAD_CIPHER
) != 0)
242 mac_size
= EVP_MD_CTX_size(s
->write_hash
);
246 if (s
->enc_write_ctx
&&
247 (EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_CBC_MODE
))
248 blocksize
= 2 * EVP_CIPHER_CTX_block_size(s
->enc_write_ctx
);
253 s
->rwstate
= SSL_NOTHING
;
255 /* s->init_num shouldn't ever be < 0...but just in case */
256 while (s
->init_num
> 0) {
257 if (type
== SSL3_RT_HANDSHAKE
&& s
->init_off
!= 0) {
258 /* We must be writing a fragment other than the first one */
261 /* This is the first attempt at writing out this fragment */
263 if (s
->init_off
<= DTLS1_HM_HEADER_LENGTH
) {
265 * Each fragment that was already sent must at least have
266 * contained the message header plus one other byte.
267 * Therefore |init_off| must have progressed by at least
268 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
275 * Adjust |init_off| and |init_num| to allow room for a new
276 * message header for this fragment.
278 s
->init_off
-= DTLS1_HM_HEADER_LENGTH
;
279 s
->init_num
+= DTLS1_HM_HEADER_LENGTH
;
282 * We must have been called again after a retry so use the
283 * fragment offset from our last attempt. We do not need
284 * to adjust |init_off| and |init_num| as above, because
285 * that should already have been done before the retry.
287 frag_off
= s
->d1
->w_msg_hdr
.frag_off
;
291 used_len
= BIO_wpending(SSL_get_wbio(s
)) + DTLS1_RT_HEADER_LENGTH
292 + mac_size
+ blocksize
;
293 if (s
->d1
->mtu
> used_len
)
294 curr_mtu
= s
->d1
->mtu
- used_len
;
298 if (curr_mtu
<= DTLS1_HM_HEADER_LENGTH
) {
300 * grr.. we could get an error if MTU picked was wrong
302 ret
= BIO_flush(SSL_get_wbio(s
));
304 s
->rwstate
= SSL_WRITING
;
307 used_len
= DTLS1_RT_HEADER_LENGTH
+ mac_size
+ blocksize
;
308 if (s
->d1
->mtu
> used_len
+ DTLS1_HM_HEADER_LENGTH
) {
309 curr_mtu
= s
->d1
->mtu
- used_len
;
311 /* Shouldn't happen */
317 * We just checked that s->init_num > 0 so this cast should be safe
319 if (((unsigned int)s
->init_num
) > curr_mtu
)
324 /* Shouldn't ever happen */
329 * XDTLS: this function is too long. split out the CCS part
331 if (type
== SSL3_RT_HANDSHAKE
) {
332 if (len
< DTLS1_HM_HEADER_LENGTH
) {
334 * len is so small that we really can't do anything sensible
339 dtls1_fix_message_header(s
, frag_off
,
340 len
- DTLS1_HM_HEADER_LENGTH
);
342 dtls1_write_message_header(s
,
343 (unsigned char *)&s
->init_buf
->
347 ret
= dtls1_write_bytes(s
, type
, &s
->init_buf
->data
[s
->init_off
],
351 * might need to update MTU here, but we don't know which
352 * previous packet caused the failure -- so can't really
353 * retransmit anything. continue as if everything is fine and
354 * wait for an alert to handle the retransmit
356 if (retry
&& BIO_ctrl(SSL_get_wbio(s
),
357 BIO_CTRL_DGRAM_MTU_EXCEEDED
, 0, NULL
) > 0) {
358 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
359 if (!dtls1_query_mtu(s
))
361 /* Have one more go */
371 * bad if this assert fails, only part of the handshake message
372 * got sent. but why would this happen?
374 OPENSSL_assert(len
== (unsigned int)ret
);
376 if (type
== SSL3_RT_HANDSHAKE
&& !s
->d1
->retransmitting
) {
378 * should not be done for 'Hello Request's, but in that case
379 * we'll ignore the result anyway
382 (unsigned char *)&s
->init_buf
->data
[s
->init_off
];
383 const struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
386 if (frag_off
== 0 && s
->version
!= DTLS1_BAD_VER
) {
388 * reconstruct message header is if it is being sent in
391 *p
++ = msg_hdr
->type
;
392 l2n3(msg_hdr
->msg_len
, p
);
393 s2n(msg_hdr
->seq
, p
);
395 l2n3(msg_hdr
->msg_len
, p
);
396 p
-= DTLS1_HM_HEADER_LENGTH
;
399 p
+= DTLS1_HM_HEADER_LENGTH
;
400 xlen
= ret
- DTLS1_HM_HEADER_LENGTH
;
403 ssl3_finish_mac(s
, p
, xlen
);
406 if (ret
== s
->init_num
) {
408 s
->msg_callback(1, s
->version
, type
, s
->init_buf
->data
,
409 (size_t)(s
->init_off
+ s
->init_num
), s
,
410 s
->msg_callback_arg
);
412 s
->init_off
= 0; /* done writing this message */
419 ret
-= DTLS1_HM_HEADER_LENGTH
;
423 * We save the fragment offset for the next fragment so we have it
424 * available in case of an IO retry. We don't know the length of the
425 * next fragment yet so just set that to 0 for now. It will be
426 * updated again later.
428 dtls1_fix_message_header(s
, frag_off
, 0);
434 int dtls_get_message(SSL
*s
, int *mt
, unsigned long *len
)
436 struct hm_header_st
*msg_hdr
;
438 unsigned long msg_len
;
442 msg_hdr
= &s
->d1
->r_msg_hdr
;
443 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
446 ok
= dtls_get_reassembled_message(s
, &tmplen
);
447 if (tmplen
== DTLS1_HM_BAD_FRAGMENT
448 || tmplen
== DTLS1_HM_FRAGMENT_RETRY
) {
449 /* bad fragment received */
451 } else if (tmplen
<= 0 && !ok
) {
455 *mt
= s
->s3
->tmp
.message_type
;
457 p
= (unsigned char *)s
->init_buf
->data
;
459 if (*mt
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
460 if (s
->msg_callback
) {
461 s
->msg_callback(0, s
->version
, SSL3_RT_CHANGE_CIPHER_SPEC
,
462 p
, 1, s
, s
->msg_callback_arg
);
465 * This isn't a real handshake message so skip the processing below.
467 *len
= (unsigned long)tmplen
;
471 msg_len
= msg_hdr
->msg_len
;
473 /* reconstruct message header */
474 *(p
++) = msg_hdr
->type
;
476 s2n(msg_hdr
->seq
, p
);
479 if (s
->version
!= DTLS1_BAD_VER
) {
480 p
-= DTLS1_HM_HEADER_LENGTH
;
481 msg_len
+= DTLS1_HM_HEADER_LENGTH
;
484 ssl3_finish_mac(s
, p
, msg_len
);
486 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
487 p
, msg_len
, s
, s
->msg_callback_arg
);
489 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
491 s
->d1
->handshake_read_seq
++;
494 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
500 static int dtls1_preprocess_fragment(SSL
*s
, struct hm_header_st
*msg_hdr
)
502 size_t frag_off
, frag_len
, msg_len
;
504 msg_len
= msg_hdr
->msg_len
;
505 frag_off
= msg_hdr
->frag_off
;
506 frag_len
= msg_hdr
->frag_len
;
508 /* sanity checking */
509 if ((frag_off
+ frag_len
) > msg_len
) {
510 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
511 return SSL_AD_ILLEGAL_PARAMETER
;
514 if (s
->d1
->r_msg_hdr
.frag_off
== 0) { /* first fragment */
516 * msg_len is limited to 2^24, but is effectively checked against max
519 if (!BUF_MEM_grow_clean
520 (s
->init_buf
, msg_len
+ DTLS1_HM_HEADER_LENGTH
)) {
521 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, ERR_R_BUF_LIB
);
522 return SSL_AD_INTERNAL_ERROR
;
525 s
->s3
->tmp
.message_size
= msg_len
;
526 s
->d1
->r_msg_hdr
.msg_len
= msg_len
;
527 s
->s3
->tmp
.message_type
= msg_hdr
->type
;
528 s
->d1
->r_msg_hdr
.type
= msg_hdr
->type
;
529 s
->d1
->r_msg_hdr
.seq
= msg_hdr
->seq
;
530 } else if (msg_len
!= s
->d1
->r_msg_hdr
.msg_len
) {
532 * They must be playing with us! BTW, failure to enforce upper limit
533 * would open possibility for buffer overrun.
535 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
536 return SSL_AD_ILLEGAL_PARAMETER
;
539 return 0; /* no error */
542 static int dtls1_retrieve_buffered_fragment(SSL
*s
, int *ok
)
545 * (0) check whether the desired fragment is available
547 * (1) copy over the fragment to s->init_buf->data[]
548 * (2) update s->init_num
555 item
= pqueue_peek(s
->d1
->buffered_messages
);
559 frag
= (hm_fragment
*)item
->data
;
561 /* Don't return if reassembly still in progress */
562 if (frag
->reassembly
!= NULL
)
565 if (s
->d1
->handshake_read_seq
== frag
->msg_header
.seq
) {
566 unsigned long frag_len
= frag
->msg_header
.frag_len
;
567 pqueue_pop(s
->d1
->buffered_messages
);
569 al
= dtls1_preprocess_fragment(s
, &frag
->msg_header
);
571 if (al
== 0) { /* no alert */
573 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
574 memcpy(&p
[frag
->msg_header
.frag_off
], frag
->fragment
,
575 frag
->msg_header
.frag_len
);
578 dtls1_hm_fragment_free(frag
);
586 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
595 * dtls1_max_handshake_message_len returns the maximum number of bytes
596 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
597 * may be greater if the maximum certificate list size requires it.
599 static unsigned long dtls1_max_handshake_message_len(const SSL
*s
)
601 unsigned long max_len
=
602 DTLS1_HM_HEADER_LENGTH
+ SSL3_RT_MAX_ENCRYPTED_LENGTH
;
603 if (max_len
< (unsigned long)s
->max_cert_list
)
604 return s
->max_cert_list
;
609 dtls1_reassemble_fragment(SSL
*s
, const struct hm_header_st
*msg_hdr
, int *ok
)
611 hm_fragment
*frag
= NULL
;
613 int i
= -1, is_complete
;
614 unsigned char seq64be
[8];
615 unsigned long frag_len
= msg_hdr
->frag_len
;
617 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
||
618 msg_hdr
->msg_len
> dtls1_max_handshake_message_len(s
))
622 return DTLS1_HM_FRAGMENT_RETRY
;
624 /* Try to find item in queue */
625 memset(seq64be
, 0, sizeof(seq64be
));
626 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
627 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
628 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
631 frag
= dtls1_hm_fragment_new(msg_hdr
->msg_len
, 1);
634 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
635 frag
->msg_header
.frag_len
= frag
->msg_header
.msg_len
;
636 frag
->msg_header
.frag_off
= 0;
638 frag
= (hm_fragment
*)item
->data
;
639 if (frag
->msg_header
.msg_len
!= msg_hdr
->msg_len
) {
647 * If message is already reassembled, this must be a retransmit and can
648 * be dropped. In this case item != NULL and so frag does not need to be
651 if (frag
->reassembly
== NULL
) {
652 unsigned char devnull
[256];
655 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
658 sizeof(devnull
) ? sizeof(devnull
) :
664 return DTLS1_HM_FRAGMENT_RETRY
;
667 /* read the body of the fragment (header has already been read */
668 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
669 frag
->fragment
+ msg_hdr
->frag_off
,
671 if ((unsigned long)i
!= frag_len
)
676 RSMBLY_BITMASK_MARK(frag
->reassembly
, (long)msg_hdr
->frag_off
,
677 (long)(msg_hdr
->frag_off
+ frag_len
));
679 RSMBLY_BITMASK_IS_COMPLETE(frag
->reassembly
, (long)msg_hdr
->msg_len
,
683 OPENSSL_free(frag
->reassembly
);
684 frag
->reassembly
= NULL
;
688 item
= pitem_new(seq64be
, frag
);
694 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
696 * pqueue_insert fails iff a duplicate item is inserted. However,
697 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
698 * would have returned it and control would never have reached this
701 OPENSSL_assert(item
!= NULL
);
704 return DTLS1_HM_FRAGMENT_RETRY
;
708 dtls1_hm_fragment_free(frag
);
714 dtls1_process_out_of_seq_message(SSL
*s
, const struct hm_header_st
*msg_hdr
,
718 hm_fragment
*frag
= NULL
;
720 unsigned char seq64be
[8];
721 unsigned long frag_len
= msg_hdr
->frag_len
;
723 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
)
726 /* Try to find item in queue, to prevent duplicate entries */
727 memset(seq64be
, 0, sizeof(seq64be
));
728 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
729 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
730 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
733 * If we already have an entry and this one is a fragment, don't discard
734 * it and rather try to reassemble it.
736 if (item
!= NULL
&& frag_len
!= msg_hdr
->msg_len
)
740 * Discard the message if sequence number was already there, is too far
741 * in the future, already in the queue or if we received a FINISHED
742 * before the SERVER_HELLO, which then must be a stale retransmit.
744 if (msg_hdr
->seq
<= s
->d1
->handshake_read_seq
||
745 msg_hdr
->seq
> s
->d1
->handshake_read_seq
+ 10 || item
!= NULL
||
746 (s
->d1
->handshake_read_seq
== 0 && msg_hdr
->type
== SSL3_MT_FINISHED
))
748 unsigned char devnull
[256];
751 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
754 sizeof(devnull
) ? sizeof(devnull
) :
761 if (frag_len
!= msg_hdr
->msg_len
)
762 return dtls1_reassemble_fragment(s
, msg_hdr
, ok
);
764 if (frag_len
> dtls1_max_handshake_message_len(s
))
767 frag
= dtls1_hm_fragment_new(frag_len
, 0);
771 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
775 * read the body of the fragment (header has already been read
777 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
778 frag
->fragment
, frag_len
, 0);
779 if ((unsigned long)i
!= frag_len
)
785 item
= pitem_new(seq64be
, frag
);
789 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
791 * pqueue_insert fails iff a duplicate item is inserted. However,
792 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
793 * would have returned it. Then, either |frag_len| !=
794 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
795 * have been processed with |dtls1_reassemble_fragment|, above, or
796 * the record will have been discarded.
798 OPENSSL_assert(item
!= NULL
);
801 return DTLS1_HM_FRAGMENT_RETRY
;
805 dtls1_hm_fragment_free(frag
);
810 static int dtls_get_reassembled_message(SSL
*s
, long *len
)
812 unsigned char wire
[DTLS1_HM_HEADER_LENGTH
];
813 unsigned long mlen
, frag_off
, frag_len
;
814 int i
, al
, recvd_type
;
815 struct hm_header_st msg_hdr
;
819 /* see if we have the required fragment already */
820 if ((frag_len
= dtls1_retrieve_buffered_fragment(s
, &ok
)) || ok
) {
822 s
->init_num
= frag_len
;
827 /* read handshake message header */
828 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, &recvd_type
, wire
,
829 DTLS1_HM_HEADER_LENGTH
, 0);
830 if (i
<= 0) { /* nbio, or an error */
831 s
->rwstate
= SSL_READING
;
835 if(recvd_type
== SSL3_RT_CHANGE_CIPHER_SPEC
) {
836 if (wire
[0] != SSL3_MT_CCS
) {
837 al
= SSL_AD_UNEXPECTED_MESSAGE
;
838 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
,
839 SSL_R_BAD_CHANGE_CIPHER_SPEC
);
843 memcpy(s
->init_buf
->data
, wire
, i
);
845 s
->init_msg
= s
->init_buf
->data
+ 1;
846 s
->s3
->tmp
.message_type
= SSL3_MT_CHANGE_CIPHER_SPEC
;
847 s
->s3
->tmp
.message_size
= i
- 1;
852 /* Handshake fails if message header is incomplete */
853 if (i
!= DTLS1_HM_HEADER_LENGTH
) {
854 al
= SSL_AD_UNEXPECTED_MESSAGE
;
855 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
859 /* parse the message fragment header */
860 dtls1_get_message_header(wire
, &msg_hdr
);
862 mlen
= msg_hdr
.msg_len
;
863 frag_off
= msg_hdr
.frag_off
;
864 frag_len
= msg_hdr
.frag_len
;
867 * We must have at least frag_len bytes left in the record to be read.
868 * Fragments must not span records.
870 if (frag_len
> RECORD_LAYER_get_rrec_length(&s
->rlayer
)) {
871 al
= SSL3_AD_ILLEGAL_PARAMETER
;
872 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL_R_BAD_LENGTH
);
877 * if this is a future (or stale) message it gets buffered
878 * (or dropped)--no further processing at this time
879 * While listening, we accept seq 1 (ClientHello with cookie)
880 * although we're still expecting seq 0 (ClientHello)
882 if (msg_hdr
.seq
!= s
->d1
->handshake_read_seq
) {
883 *len
= dtls1_process_out_of_seq_message(s
, &msg_hdr
, &ok
);
887 if (frag_len
&& frag_len
< mlen
) {
888 *len
= dtls1_reassemble_fragment(s
, &msg_hdr
, &ok
);
892 if (!s
->server
&& s
->d1
->r_msg_hdr
.frag_off
== 0 &&
893 wire
[0] == SSL3_MT_HELLO_REQUEST
) {
895 * The server may always send 'Hello Request' messages -- we are
896 * doing a handshake anyway now, so ignore them if their format is
897 * correct. Does not count for 'Finished' MAC.
899 if (wire
[1] == 0 && wire
[2] == 0 && wire
[3] == 0) {
901 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
902 wire
, DTLS1_HM_HEADER_LENGTH
, s
,
903 s
->msg_callback_arg
);
907 } else { /* Incorrectly formated Hello request */
909 al
= SSL_AD_UNEXPECTED_MESSAGE
;
910 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
,
911 SSL_R_UNEXPECTED_MESSAGE
);
916 if ((al
= dtls1_preprocess_fragment(s
, &msg_hdr
)))
921 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
923 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
924 &p
[frag_off
], frag_len
, 0);
927 * This shouldn't ever fail due to NBIO because we already checked
928 * that we have enough data in the record
931 s
->rwstate
= SSL_READING
;
939 * XDTLS: an incorrectly formatted fragment should cause the handshake
942 if (i
!= (int)frag_len
) {
943 al
= SSL3_AD_ILLEGAL_PARAMETER
;
944 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL3_AD_ILLEGAL_PARAMETER
);
949 * Note that s->init_num is *not* used as current offset in
950 * s->init_buf->data, but as a counter summing up fragments' lengths: as
951 * soon as they sum up to handshake packet length, we assume we have got
954 *len
= s
->init_num
= frag_len
;
958 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
965 * for these 2 messages, we need to
966 * ssl->enc_read_ctx re-init
967 * ssl->rlayer.read_sequence zero
968 * ssl->s3->read_mac_secret re-init
969 * ssl->session->read_sym_enc assign
970 * ssl->session->read_compression assign
971 * ssl->session->read_hash assign
973 int dtls_construct_change_cipher_spec(SSL
*s
)
977 p
= (unsigned char *)s
->init_buf
->data
;
979 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
980 s
->init_num
= DTLS1_CCS_HEADER_LENGTH
;
982 if (s
->version
== DTLS1_BAD_VER
) {
983 s
->d1
->next_handshake_write_seq
++;
984 s2n(s
->d1
->handshake_write_seq
, p
);
990 dtls1_set_message_header_int(s
, SSL3_MT_CCS
, 0,
991 s
->d1
->handshake_write_seq
, 0, 0);
993 /* buffer the message to handle re-xmits */
994 if (!dtls1_buffer_message(s
, 1)) {
995 SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC
, ERR_R_INTERNAL_ERROR
);
1002 #ifndef OPENSSL_NO_SCTP
1003 WORK_STATE
dtls_wait_for_dry(SSL
*s
)
1007 /* read app data until dry event */
1008 ret
= BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s
));
1013 s
->s3
->in_read_app_data
= 2;
1014 s
->rwstate
= SSL_READING
;
1015 BIO_clear_retry_flags(SSL_get_rbio(s
));
1016 BIO_set_retry_read(SSL_get_rbio(s
));
1019 return WORK_FINISHED_CONTINUE
;
1023 int dtls1_read_failed(SSL
*s
, int code
)
1026 fprintf(stderr
, "invalid state reached %s:%d", __FILE__
, __LINE__
);
1030 if (!dtls1_is_timer_expired(s
)) {
1032 * not a timeout, none of our business, let higher layers handle
1033 * this. in fact it's probably an error
1037 #ifndef OPENSSL_NO_HEARTBEATS
1038 /* done, no need to send a retransmit */
1039 if (!SSL_in_init(s
) && !s
->tlsext_hb_pending
)
1041 /* done, no need to send a retransmit */
1042 if (!SSL_in_init(s
))
1045 BIO_set_flags(SSL_get_rbio(s
), BIO_FLAGS_READ
);
1049 return dtls1_handle_timeout(s
);
1052 int dtls1_get_queue_priority(unsigned short seq
, int is_ccs
)
1055 * The index of the retransmission queue actually is the message sequence
1056 * number, since the queue only contains messages of a single handshake.
1057 * However, the ChangeCipherSpec has no message sequence number and so
1058 * using only the sequence will result in the CCS and Finished having the
1059 * same index. To prevent this, the sequence number is multiplied by 2.
1060 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1061 * Finished, it also maintains the order of the index (important for
1062 * priority queues) and fits in the unsigned short variable.
1064 return seq
* 2 - is_ccs
;
1067 int dtls1_retransmit_buffered_messages(SSL
*s
)
1069 pqueue
*sent
= s
->d1
->sent_messages
;
1075 iter
= pqueue_iterator(sent
);
1077 for (item
= pqueue_next(&iter
); item
!= NULL
; item
= pqueue_next(&iter
)) {
1078 frag
= (hm_fragment
*)item
->data
;
1079 if (dtls1_retransmit_message(s
, (unsigned short)
1080 dtls1_get_queue_priority
1081 (frag
->msg_header
.seq
,
1082 frag
->msg_header
.is_ccs
), 0,
1083 &found
) <= 0 && found
) {
1084 fprintf(stderr
, "dtls1_retransmit_message() failed\n");
1092 int dtls1_buffer_message(SSL
*s
, int is_ccs
)
1096 unsigned char seq64be
[8];
1099 * this function is called immediately after a message has been
1102 OPENSSL_assert(s
->init_off
== 0);
1104 frag
= dtls1_hm_fragment_new(s
->init_num
, 0);
1108 memcpy(frag
->fragment
, s
->init_buf
->data
, s
->init_num
);
1111 /* For DTLS1_BAD_VER the header length is non-standard */
1112 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1113 ((s
->version
==DTLS1_BAD_VER
)?3:DTLS1_CCS_HEADER_LENGTH
)
1114 == (unsigned int)s
->init_num
);
1116 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1117 DTLS1_HM_HEADER_LENGTH
== (unsigned int)s
->init_num
);
1120 frag
->msg_header
.msg_len
= s
->d1
->w_msg_hdr
.msg_len
;
1121 frag
->msg_header
.seq
= s
->d1
->w_msg_hdr
.seq
;
1122 frag
->msg_header
.type
= s
->d1
->w_msg_hdr
.type
;
1123 frag
->msg_header
.frag_off
= 0;
1124 frag
->msg_header
.frag_len
= s
->d1
->w_msg_hdr
.msg_len
;
1125 frag
->msg_header
.is_ccs
= is_ccs
;
1127 /* save current state */
1128 frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
= s
->enc_write_ctx
;
1129 frag
->msg_header
.saved_retransmit_state
.write_hash
= s
->write_hash
;
1130 frag
->msg_header
.saved_retransmit_state
.compress
= s
->compress
;
1131 frag
->msg_header
.saved_retransmit_state
.session
= s
->session
;
1132 frag
->msg_header
.saved_retransmit_state
.epoch
=
1133 DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1135 memset(seq64be
, 0, sizeof(seq64be
));
1138 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1139 frag
->msg_header
.is_ccs
) >> 8);
1142 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1143 frag
->msg_header
.is_ccs
));
1145 item
= pitem_new(seq64be
, frag
);
1147 dtls1_hm_fragment_free(frag
);
1151 pqueue_insert(s
->d1
->sent_messages
, item
);
1156 dtls1_retransmit_message(SSL
*s
, unsigned short seq
, unsigned long frag_off
,
1160 /* XDTLS: for now assuming that read/writes are blocking */
1163 unsigned long header_length
;
1164 unsigned char seq64be
[8];
1165 struct dtls1_retransmit_state saved_state
;
1168 OPENSSL_assert(s->init_num == 0);
1169 OPENSSL_assert(s->init_off == 0);
1172 /* XDTLS: the requested message ought to be found, otherwise error */
1173 memset(seq64be
, 0, sizeof(seq64be
));
1174 seq64be
[6] = (unsigned char)(seq
>> 8);
1175 seq64be
[7] = (unsigned char)seq
;
1177 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1179 fprintf(stderr
, "retransmit: message %d non-existant\n", seq
);
1185 frag
= (hm_fragment
*)item
->data
;
1187 if (frag
->msg_header
.is_ccs
)
1188 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1190 header_length
= DTLS1_HM_HEADER_LENGTH
;
1192 memcpy(s
->init_buf
->data
, frag
->fragment
,
1193 frag
->msg_header
.msg_len
+ header_length
);
1194 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1196 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1197 frag
->msg_header
.msg_len
,
1198 frag
->msg_header
.seq
, 0,
1199 frag
->msg_header
.frag_len
);
1201 /* save current state */
1202 saved_state
.enc_write_ctx
= s
->enc_write_ctx
;
1203 saved_state
.write_hash
= s
->write_hash
;
1204 saved_state
.compress
= s
->compress
;
1205 saved_state
.session
= s
->session
;
1206 saved_state
.epoch
= DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1208 s
->d1
->retransmitting
= 1;
1210 /* restore state in which the message was originally sent */
1211 s
->enc_write_ctx
= frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
;
1212 s
->write_hash
= frag
->msg_header
.saved_retransmit_state
.write_hash
;
1213 s
->compress
= frag
->msg_header
.saved_retransmit_state
.compress
;
1214 s
->session
= frag
->msg_header
.saved_retransmit_state
.session
;
1215 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
,
1216 frag
->msg_header
.saved_retransmit_state
.epoch
);
1218 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1219 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1221 /* restore current state */
1222 s
->enc_write_ctx
= saved_state
.enc_write_ctx
;
1223 s
->write_hash
= saved_state
.write_hash
;
1224 s
->compress
= saved_state
.compress
;
1225 s
->session
= saved_state
.session
;
1226 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
, saved_state
.epoch
);
1228 s
->d1
->retransmitting
= 0;
1230 (void)BIO_flush(SSL_get_wbio(s
));
1234 /* call this function when the buffered messages are no longer needed */
1235 void dtls1_clear_record_buffer(SSL
*s
)
1239 for (item
= pqueue_pop(s
->d1
->sent_messages
);
1240 item
!= NULL
; item
= pqueue_pop(s
->d1
->sent_messages
)) {
1241 dtls1_hm_fragment_free((hm_fragment
*)item
->data
);
1246 void dtls1_set_message_header(SSL
*s
, unsigned char *p
,
1247 unsigned char mt
, unsigned long len
,
1248 unsigned long frag_off
,
1249 unsigned long frag_len
)
1251 if (frag_off
== 0) {
1252 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1253 s
->d1
->next_handshake_write_seq
++;
1256 dtls1_set_message_header_int(s
, mt
, len
, s
->d1
->handshake_write_seq
,
1257 frag_off
, frag_len
);
1260 /* don't actually do the writing, wait till the MTU has been retrieved */
1262 dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
1263 unsigned long len
, unsigned short seq_num
,
1264 unsigned long frag_off
, unsigned long frag_len
)
1266 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1269 msg_hdr
->msg_len
= len
;
1270 msg_hdr
->seq
= seq_num
;
1271 msg_hdr
->frag_off
= frag_off
;
1272 msg_hdr
->frag_len
= frag_len
;
1276 dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
1277 unsigned long frag_len
)
1279 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1281 msg_hdr
->frag_off
= frag_off
;
1282 msg_hdr
->frag_len
= frag_len
;
1285 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
)
1287 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1289 *p
++ = msg_hdr
->type
;
1290 l2n3(msg_hdr
->msg_len
, p
);
1292 s2n(msg_hdr
->seq
, p
);
1293 l2n3(msg_hdr
->frag_off
, p
);
1294 l2n3(msg_hdr
->frag_len
, p
);
1300 dtls1_get_message_header(unsigned char *data
, struct hm_header_st
*msg_hdr
)
1302 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
1303 msg_hdr
->type
= *(data
++);
1304 n2l3(data
, msg_hdr
->msg_len
);
1306 n2s(data
, msg_hdr
->seq
);
1307 n2l3(data
, msg_hdr
->frag_off
);
1308 n2l3(data
, msg_hdr
->frag_len
);