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_destroy(frag
->msg_header
.
208 saved_retransmit_state
.write_hash
);
210 OPENSSL_free(frag
->fragment
);
211 OPENSSL_free(frag
->reassembly
);
216 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
217 * SSL3_RT_CHANGE_CIPHER_SPEC)
219 int dtls1_do_write(SSL
*s
, int type
)
222 unsigned int curr_mtu
;
224 unsigned int len
, frag_off
, mac_size
, blocksize
, used_len
;
226 if (!dtls1_query_mtu(s
))
229 OPENSSL_assert(s
->d1
->mtu
>= dtls1_min_mtu(s
)); /* should have something
232 if (s
->init_off
== 0 && type
== SSL3_RT_HANDSHAKE
)
233 OPENSSL_assert(s
->init_num
==
234 (int)s
->d1
->w_msg_hdr
.msg_len
+
235 DTLS1_HM_HEADER_LENGTH
);
239 && ((EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_GCM_MODE
) ||
240 (EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_CCM_MODE
)))
243 mac_size
= EVP_MD_CTX_size(s
->write_hash
);
247 if (s
->enc_write_ctx
&&
248 (EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_CBC_MODE
))
249 blocksize
= 2 * EVP_CIPHER_block_size(s
->enc_write_ctx
->cipher
);
254 /* s->init_num shouldn't ever be < 0...but just in case */
255 while (s
->init_num
> 0) {
256 used_len
= BIO_wpending(SSL_get_wbio(s
)) + DTLS1_RT_HEADER_LENGTH
257 + mac_size
+ blocksize
;
258 if (s
->d1
->mtu
> used_len
)
259 curr_mtu
= s
->d1
->mtu
- used_len
;
263 if (curr_mtu
<= DTLS1_HM_HEADER_LENGTH
) {
265 * grr.. we could get an error if MTU picked was wrong
267 ret
= BIO_flush(SSL_get_wbio(s
));
270 used_len
= DTLS1_RT_HEADER_LENGTH
+ mac_size
+ blocksize
;
271 if (s
->d1
->mtu
> used_len
+ DTLS1_HM_HEADER_LENGTH
) {
272 curr_mtu
= s
->d1
->mtu
- used_len
;
274 /* Shouldn't happen */
280 * We just checked that s->init_num > 0 so this cast should be safe
282 if (((unsigned int)s
->init_num
) > curr_mtu
)
287 /* Shouldn't ever happen */
292 * XDTLS: this function is too long. split out the CCS part
294 if (type
== SSL3_RT_HANDSHAKE
) {
295 if (s
->init_off
!= 0) {
296 OPENSSL_assert(s
->init_off
> DTLS1_HM_HEADER_LENGTH
);
297 s
->init_off
-= DTLS1_HM_HEADER_LENGTH
;
298 s
->init_num
+= DTLS1_HM_HEADER_LENGTH
;
301 * We just checked that s->init_num > 0 so this cast should
304 if (((unsigned int)s
->init_num
) > curr_mtu
)
310 /* Shouldn't ever happen */
314 if (len
< DTLS1_HM_HEADER_LENGTH
) {
316 * len is so small that we really can't do anything sensible
321 dtls1_fix_message_header(s
, frag_off
,
322 len
- DTLS1_HM_HEADER_LENGTH
);
324 dtls1_write_message_header(s
,
325 (unsigned char *)&s
->init_buf
->
329 ret
= dtls1_write_bytes(s
, type
, &s
->init_buf
->data
[s
->init_off
],
333 * might need to update MTU here, but we don't know which
334 * previous packet caused the failure -- so can't really
335 * retransmit anything. continue as if everything is fine and
336 * wait for an alert to handle the retransmit
338 if (retry
&& BIO_ctrl(SSL_get_wbio(s
),
339 BIO_CTRL_DGRAM_MTU_EXCEEDED
, 0, NULL
) > 0) {
340 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
341 if (!dtls1_query_mtu(s
))
343 /* Have one more go */
353 * bad if this assert fails, only part of the handshake message
354 * got sent. but why would this happen?
356 OPENSSL_assert(len
== (unsigned int)ret
);
358 if (type
== SSL3_RT_HANDSHAKE
&& !s
->d1
->retransmitting
) {
360 * should not be done for 'Hello Request's, but in that case
361 * we'll ignore the result anyway
364 (unsigned char *)&s
->init_buf
->data
[s
->init_off
];
365 const struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
368 if (frag_off
== 0 && s
->version
!= DTLS1_BAD_VER
) {
370 * reconstruct message header is if it is being sent in
373 *p
++ = msg_hdr
->type
;
374 l2n3(msg_hdr
->msg_len
, p
);
375 s2n(msg_hdr
->seq
, p
);
377 l2n3(msg_hdr
->msg_len
, p
);
378 p
-= DTLS1_HM_HEADER_LENGTH
;
381 p
+= DTLS1_HM_HEADER_LENGTH
;
382 xlen
= ret
- DTLS1_HM_HEADER_LENGTH
;
385 ssl3_finish_mac(s
, p
, xlen
);
388 if (ret
== s
->init_num
) {
390 s
->msg_callback(1, s
->version
, type
, s
->init_buf
->data
,
391 (size_t)(s
->init_off
+ s
->init_num
), s
,
392 s
->msg_callback_arg
);
394 s
->init_off
= 0; /* done writing this message */
401 frag_off
+= (ret
-= DTLS1_HM_HEADER_LENGTH
);
407 int dtls_get_message(SSL
*s
, int *mt
, unsigned long *len
)
409 struct hm_header_st
*msg_hdr
;
411 unsigned long msg_len
;
415 msg_hdr
= &s
->d1
->r_msg_hdr
;
416 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
419 ok
= dtls_get_reassembled_message(s
, &tmplen
);
420 if (tmplen
== DTLS1_HM_BAD_FRAGMENT
421 || tmplen
== DTLS1_HM_FRAGMENT_RETRY
) {
422 /* bad fragment received */
424 } else if (tmplen
<= 0 && !ok
) {
428 *mt
= s
->s3
->tmp
.message_type
;
430 p
= (unsigned char *)s
->init_buf
->data
;
432 if (*mt
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
433 if (s
->msg_callback
) {
434 s
->msg_callback(0, s
->version
, SSL3_RT_CHANGE_CIPHER_SPEC
,
435 p
, 1, s
, s
->msg_callback_arg
);
438 * This isn't a real handshake message so skip the processing below.
440 *len
= (unsigned long)tmplen
;
444 msg_len
= msg_hdr
->msg_len
;
446 /* reconstruct message header */
447 *(p
++) = msg_hdr
->type
;
449 s2n(msg_hdr
->seq
, p
);
452 if (s
->version
!= DTLS1_BAD_VER
) {
453 p
-= DTLS1_HM_HEADER_LENGTH
;
454 msg_len
+= DTLS1_HM_HEADER_LENGTH
;
457 ssl3_finish_mac(s
, p
, msg_len
);
459 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
460 p
, msg_len
, s
, s
->msg_callback_arg
);
462 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
464 s
->d1
->handshake_read_seq
++;
467 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
473 static int dtls1_preprocess_fragment(SSL
*s
, struct hm_header_st
*msg_hdr
)
475 size_t frag_off
, frag_len
, msg_len
;
477 msg_len
= msg_hdr
->msg_len
;
478 frag_off
= msg_hdr
->frag_off
;
479 frag_len
= msg_hdr
->frag_len
;
481 /* sanity checking */
482 if ((frag_off
+ frag_len
) > msg_len
) {
483 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
484 return SSL_AD_ILLEGAL_PARAMETER
;
487 if (s
->d1
->r_msg_hdr
.frag_off
== 0) { /* first fragment */
489 * msg_len is limited to 2^24, but is effectively checked against max
492 if (!BUF_MEM_grow_clean
493 (s
->init_buf
, msg_len
+ DTLS1_HM_HEADER_LENGTH
)) {
494 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, ERR_R_BUF_LIB
);
495 return SSL_AD_INTERNAL_ERROR
;
498 s
->s3
->tmp
.message_size
= msg_len
;
499 s
->d1
->r_msg_hdr
.msg_len
= msg_len
;
500 s
->s3
->tmp
.message_type
= msg_hdr
->type
;
501 s
->d1
->r_msg_hdr
.type
= msg_hdr
->type
;
502 s
->d1
->r_msg_hdr
.seq
= msg_hdr
->seq
;
503 } else if (msg_len
!= s
->d1
->r_msg_hdr
.msg_len
) {
505 * They must be playing with us! BTW, failure to enforce upper limit
506 * would open possibility for buffer overrun.
508 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
509 return SSL_AD_ILLEGAL_PARAMETER
;
512 return 0; /* no error */
515 static int dtls1_retrieve_buffered_fragment(SSL
*s
, int *ok
)
518 * (0) check whether the desired fragment is available
520 * (1) copy over the fragment to s->init_buf->data[]
521 * (2) update s->init_num
528 item
= pqueue_peek(s
->d1
->buffered_messages
);
532 frag
= (hm_fragment
*)item
->data
;
534 /* Don't return if reassembly still in progress */
535 if (frag
->reassembly
!= NULL
)
538 if (s
->d1
->handshake_read_seq
== frag
->msg_header
.seq
) {
539 unsigned long frag_len
= frag
->msg_header
.frag_len
;
540 pqueue_pop(s
->d1
->buffered_messages
);
542 al
= dtls1_preprocess_fragment(s
, &frag
->msg_header
);
544 if (al
== 0) { /* no alert */
546 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
547 memcpy(&p
[frag
->msg_header
.frag_off
], frag
->fragment
,
548 frag
->msg_header
.frag_len
);
551 dtls1_hm_fragment_free(frag
);
559 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
568 * dtls1_max_handshake_message_len returns the maximum number of bytes
569 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
570 * may be greater if the maximum certificate list size requires it.
572 static unsigned long dtls1_max_handshake_message_len(const SSL
*s
)
574 unsigned long max_len
=
575 DTLS1_HM_HEADER_LENGTH
+ SSL3_RT_MAX_ENCRYPTED_LENGTH
;
576 if (max_len
< (unsigned long)s
->max_cert_list
)
577 return s
->max_cert_list
;
582 dtls1_reassemble_fragment(SSL
*s
, const struct hm_header_st
*msg_hdr
, int *ok
)
584 hm_fragment
*frag
= NULL
;
586 int i
= -1, is_complete
;
587 unsigned char seq64be
[8];
588 unsigned long frag_len
= msg_hdr
->frag_len
;
590 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
||
591 msg_hdr
->msg_len
> dtls1_max_handshake_message_len(s
))
595 return DTLS1_HM_FRAGMENT_RETRY
;
597 /* Try to find item in queue */
598 memset(seq64be
, 0, sizeof(seq64be
));
599 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
600 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
601 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
604 frag
= dtls1_hm_fragment_new(msg_hdr
->msg_len
, 1);
607 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
608 frag
->msg_header
.frag_len
= frag
->msg_header
.msg_len
;
609 frag
->msg_header
.frag_off
= 0;
611 frag
= (hm_fragment
*)item
->data
;
612 if (frag
->msg_header
.msg_len
!= msg_hdr
->msg_len
) {
620 * If message is already reassembled, this must be a retransmit and can
621 * be dropped. In this case item != NULL and so frag does not need to be
624 if (frag
->reassembly
== NULL
) {
625 unsigned char devnull
[256];
628 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
631 sizeof(devnull
) ? sizeof(devnull
) :
637 return DTLS1_HM_FRAGMENT_RETRY
;
640 /* read the body of the fragment (header has already been read */
641 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
642 frag
->fragment
+ msg_hdr
->frag_off
,
644 if ((unsigned long)i
!= frag_len
)
649 RSMBLY_BITMASK_MARK(frag
->reassembly
, (long)msg_hdr
->frag_off
,
650 (long)(msg_hdr
->frag_off
+ frag_len
));
652 RSMBLY_BITMASK_IS_COMPLETE(frag
->reassembly
, (long)msg_hdr
->msg_len
,
656 OPENSSL_free(frag
->reassembly
);
657 frag
->reassembly
= NULL
;
661 item
= pitem_new(seq64be
, frag
);
667 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
669 * pqueue_insert fails iff a duplicate item is inserted. However,
670 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
671 * would have returned it and control would never have reached this
674 OPENSSL_assert(item
!= NULL
);
677 return DTLS1_HM_FRAGMENT_RETRY
;
681 dtls1_hm_fragment_free(frag
);
687 dtls1_process_out_of_seq_message(SSL
*s
, const struct hm_header_st
*msg_hdr
,
691 hm_fragment
*frag
= NULL
;
693 unsigned char seq64be
[8];
694 unsigned long frag_len
= msg_hdr
->frag_len
;
696 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
)
699 /* Try to find item in queue, to prevent duplicate entries */
700 memset(seq64be
, 0, sizeof(seq64be
));
701 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
702 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
703 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
706 * If we already have an entry and this one is a fragment, don't discard
707 * it and rather try to reassemble it.
709 if (item
!= NULL
&& frag_len
!= msg_hdr
->msg_len
)
713 * Discard the message if sequence number was already there, is too far
714 * in the future, already in the queue or if we received a FINISHED
715 * before the SERVER_HELLO, which then must be a stale retransmit.
717 if (msg_hdr
->seq
<= s
->d1
->handshake_read_seq
||
718 msg_hdr
->seq
> s
->d1
->handshake_read_seq
+ 10 || item
!= NULL
||
719 (s
->d1
->handshake_read_seq
== 0 && msg_hdr
->type
== SSL3_MT_FINISHED
))
721 unsigned char devnull
[256];
724 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
727 sizeof(devnull
) ? sizeof(devnull
) :
734 if (frag_len
!= msg_hdr
->msg_len
)
735 return dtls1_reassemble_fragment(s
, msg_hdr
, ok
);
737 if (frag_len
> dtls1_max_handshake_message_len(s
))
740 frag
= dtls1_hm_fragment_new(frag_len
, 0);
744 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
748 * read the body of the fragment (header has already been read
750 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
751 frag
->fragment
, frag_len
, 0);
752 if ((unsigned long)i
!= frag_len
)
758 item
= pitem_new(seq64be
, frag
);
762 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
764 * pqueue_insert fails iff a duplicate item is inserted. However,
765 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
766 * would have returned it. Then, either |frag_len| !=
767 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
768 * have been processed with |dtls1_reassemble_fragment|, above, or
769 * the record will have been discarded.
771 OPENSSL_assert(item
!= NULL
);
774 return DTLS1_HM_FRAGMENT_RETRY
;
778 dtls1_hm_fragment_free(frag
);
783 static int dtls_get_reassembled_message(SSL
*s
, long *len
)
785 unsigned char wire
[DTLS1_HM_HEADER_LENGTH
];
786 unsigned long mlen
, frag_off
, frag_len
;
787 int i
, al
, recvd_type
;
788 struct hm_header_st msg_hdr
;
792 /* see if we have the required fragment already */
793 if ((frag_len
= dtls1_retrieve_buffered_fragment(s
, &ok
)) || ok
) {
795 s
->init_num
= frag_len
;
800 /* read handshake message header */
801 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, &recvd_type
, wire
,
802 DTLS1_HM_HEADER_LENGTH
, 0);
803 if (i
<= 0) { /* nbio, or an error */
804 s
->rwstate
= SSL_READING
;
808 if(recvd_type
== SSL3_RT_CHANGE_CIPHER_SPEC
) {
809 if (wire
[0] != SSL3_MT_CCS
) {
810 al
= SSL_AD_UNEXPECTED_MESSAGE
;
811 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
,
812 SSL_R_BAD_CHANGE_CIPHER_SPEC
);
816 memcpy(s
->init_buf
->data
, wire
, i
);
818 s
->init_msg
= s
->init_buf
->data
+ 1;
819 s
->s3
->tmp
.message_type
= SSL3_MT_CHANGE_CIPHER_SPEC
;
820 s
->s3
->tmp
.message_size
= i
- 1;
825 /* Handshake fails if message header is incomplete */
826 if (i
!= DTLS1_HM_HEADER_LENGTH
) {
827 al
= SSL_AD_UNEXPECTED_MESSAGE
;
828 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
832 /* parse the message fragment header */
833 dtls1_get_message_header(wire
, &msg_hdr
);
835 mlen
= msg_hdr
.msg_len
;
836 frag_off
= msg_hdr
.frag_off
;
837 frag_len
= msg_hdr
.frag_len
;
840 * We must have at least frag_len bytes left in the record to be read.
841 * Fragments must not span records.
843 if (frag_len
> RECORD_LAYER_get_rrec_length(&s
->rlayer
)) {
844 al
= SSL3_AD_ILLEGAL_PARAMETER
;
845 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL_R_BAD_LENGTH
);
850 * if this is a future (or stale) message it gets buffered
851 * (or dropped)--no further processing at this time
852 * While listening, we accept seq 1 (ClientHello with cookie)
853 * although we're still expecting seq 0 (ClientHello)
855 if (msg_hdr
.seq
!= s
->d1
->handshake_read_seq
) {
856 *len
= dtls1_process_out_of_seq_message(s
, &msg_hdr
, &ok
);
860 if (frag_len
&& frag_len
< mlen
) {
861 *len
= dtls1_reassemble_fragment(s
, &msg_hdr
, &ok
);
865 if (!s
->server
&& s
->d1
->r_msg_hdr
.frag_off
== 0 &&
866 wire
[0] == SSL3_MT_HELLO_REQUEST
) {
868 * The server may always send 'Hello Request' messages -- we are
869 * doing a handshake anyway now, so ignore them if their format is
870 * correct. Does not count for 'Finished' MAC.
872 if (wire
[1] == 0 && wire
[2] == 0 && wire
[3] == 0) {
874 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
875 wire
, DTLS1_HM_HEADER_LENGTH
, s
,
876 s
->msg_callback_arg
);
880 } else { /* Incorrectly formated Hello request */
882 al
= SSL_AD_UNEXPECTED_MESSAGE
;
883 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
,
884 SSL_R_UNEXPECTED_MESSAGE
);
889 if ((al
= dtls1_preprocess_fragment(s
, &msg_hdr
)))
894 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
896 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
897 &p
[frag_off
], frag_len
, 0);
900 * This shouldn't ever fail due to NBIO because we already checked
901 * that we have enough data in the record
904 s
->rwstate
= SSL_READING
;
912 * XDTLS: an incorrectly formatted fragment should cause the handshake
915 if (i
!= (int)frag_len
) {
916 al
= SSL3_AD_ILLEGAL_PARAMETER
;
917 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL3_AD_ILLEGAL_PARAMETER
);
922 * Note that s->init_num is *not* used as current offset in
923 * s->init_buf->data, but as a counter summing up fragments' lengths: as
924 * soon as they sum up to handshake packet length, we assume we have got
927 *len
= s
->init_num
= frag_len
;
931 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
938 * for these 2 messages, we need to
939 * ssl->enc_read_ctx re-init
940 * ssl->rlayer.read_sequence zero
941 * ssl->s3->read_mac_secret re-init
942 * ssl->session->read_sym_enc assign
943 * ssl->session->read_compression assign
944 * ssl->session->read_hash assign
946 int dtls_construct_change_cipher_spec(SSL
*s
)
950 p
= (unsigned char *)s
->init_buf
->data
;
952 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
953 s
->init_num
= DTLS1_CCS_HEADER_LENGTH
;
955 if (s
->version
== DTLS1_BAD_VER
) {
956 s
->d1
->next_handshake_write_seq
++;
957 s2n(s
->d1
->handshake_write_seq
, p
);
963 dtls1_set_message_header_int(s
, SSL3_MT_CCS
, 0,
964 s
->d1
->handshake_write_seq
, 0, 0);
966 /* buffer the message to handle re-xmits */
967 if (!dtls1_buffer_message(s
, 1)) {
968 SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC
, ERR_R_INTERNAL_ERROR
);
975 #ifndef OPENSSL_NO_SCTP
976 WORK_STATE
dtls_wait_for_dry(SSL
*s
)
980 /* read app data until dry event */
981 ret
= BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s
));
986 s
->s3
->in_read_app_data
= 2;
987 s
->rwstate
= SSL_READING
;
988 BIO_clear_retry_flags(SSL_get_rbio(s
));
989 BIO_set_retry_read(SSL_get_rbio(s
));
992 return WORK_FINISHED_CONTINUE
;
996 int dtls1_read_failed(SSL
*s
, int code
)
999 fprintf(stderr
, "invalid state reached %s:%d", __FILE__
, __LINE__
);
1003 if (!dtls1_is_timer_expired(s
)) {
1005 * not a timeout, none of our business, let higher layers handle
1006 * this. in fact it's probably an error
1010 #ifndef OPENSSL_NO_HEARTBEATS
1011 /* done, no need to send a retransmit */
1012 if (!SSL_in_init(s
) && !s
->tlsext_hb_pending
)
1014 /* done, no need to send a retransmit */
1015 if (!SSL_in_init(s
))
1018 BIO_set_flags(SSL_get_rbio(s
), BIO_FLAGS_READ
);
1022 return dtls1_handle_timeout(s
);
1025 int dtls1_get_queue_priority(unsigned short seq
, int is_ccs
)
1028 * The index of the retransmission queue actually is the message sequence
1029 * number, since the queue only contains messages of a single handshake.
1030 * However, the ChangeCipherSpec has no message sequence number and so
1031 * using only the sequence will result in the CCS and Finished having the
1032 * same index. To prevent this, the sequence number is multiplied by 2.
1033 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1034 * Finished, it also maintains the order of the index (important for
1035 * priority queues) and fits in the unsigned short variable.
1037 return seq
* 2 - is_ccs
;
1040 int dtls1_retransmit_buffered_messages(SSL
*s
)
1042 pqueue sent
= s
->d1
->sent_messages
;
1048 iter
= pqueue_iterator(sent
);
1050 for (item
= pqueue_next(&iter
); item
!= NULL
; item
= pqueue_next(&iter
)) {
1051 frag
= (hm_fragment
*)item
->data
;
1052 if (dtls1_retransmit_message(s
, (unsigned short)
1053 dtls1_get_queue_priority
1054 (frag
->msg_header
.seq
,
1055 frag
->msg_header
.is_ccs
), 0,
1056 &found
) <= 0 && found
) {
1057 fprintf(stderr
, "dtls1_retransmit_message() failed\n");
1065 int dtls1_buffer_message(SSL
*s
, int is_ccs
)
1069 unsigned char seq64be
[8];
1072 * this function is called immediately after a message has been
1075 OPENSSL_assert(s
->init_off
== 0);
1077 frag
= dtls1_hm_fragment_new(s
->init_num
, 0);
1081 memcpy(frag
->fragment
, s
->init_buf
->data
, s
->init_num
);
1084 /* For DTLS1_BAD_VER the header length is non-standard */
1085 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1086 ((s
->version
==DTLS1_BAD_VER
)?3:DTLS1_CCS_HEADER_LENGTH
)
1087 == (unsigned int)s
->init_num
);
1089 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1090 DTLS1_HM_HEADER_LENGTH
== (unsigned int)s
->init_num
);
1093 frag
->msg_header
.msg_len
= s
->d1
->w_msg_hdr
.msg_len
;
1094 frag
->msg_header
.seq
= s
->d1
->w_msg_hdr
.seq
;
1095 frag
->msg_header
.type
= s
->d1
->w_msg_hdr
.type
;
1096 frag
->msg_header
.frag_off
= 0;
1097 frag
->msg_header
.frag_len
= s
->d1
->w_msg_hdr
.msg_len
;
1098 frag
->msg_header
.is_ccs
= is_ccs
;
1100 /* save current state */
1101 frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
= s
->enc_write_ctx
;
1102 frag
->msg_header
.saved_retransmit_state
.write_hash
= s
->write_hash
;
1103 frag
->msg_header
.saved_retransmit_state
.compress
= s
->compress
;
1104 frag
->msg_header
.saved_retransmit_state
.session
= s
->session
;
1105 frag
->msg_header
.saved_retransmit_state
.epoch
=
1106 DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1108 memset(seq64be
, 0, sizeof(seq64be
));
1111 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1112 frag
->msg_header
.is_ccs
) >> 8);
1115 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1116 frag
->msg_header
.is_ccs
));
1118 item
= pitem_new(seq64be
, frag
);
1120 dtls1_hm_fragment_free(frag
);
1124 pqueue_insert(s
->d1
->sent_messages
, item
);
1129 dtls1_retransmit_message(SSL
*s
, unsigned short seq
, unsigned long frag_off
,
1133 /* XDTLS: for now assuming that read/writes are blocking */
1136 unsigned long header_length
;
1137 unsigned char seq64be
[8];
1138 struct dtls1_retransmit_state saved_state
;
1141 OPENSSL_assert(s->init_num == 0);
1142 OPENSSL_assert(s->init_off == 0);
1145 /* XDTLS: the requested message ought to be found, otherwise error */
1146 memset(seq64be
, 0, sizeof(seq64be
));
1147 seq64be
[6] = (unsigned char)(seq
>> 8);
1148 seq64be
[7] = (unsigned char)seq
;
1150 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1152 fprintf(stderr
, "retransmit: message %d non-existant\n", seq
);
1158 frag
= (hm_fragment
*)item
->data
;
1160 if (frag
->msg_header
.is_ccs
)
1161 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1163 header_length
= DTLS1_HM_HEADER_LENGTH
;
1165 memcpy(s
->init_buf
->data
, frag
->fragment
,
1166 frag
->msg_header
.msg_len
+ header_length
);
1167 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1169 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1170 frag
->msg_header
.msg_len
,
1171 frag
->msg_header
.seq
, 0,
1172 frag
->msg_header
.frag_len
);
1174 /* save current state */
1175 saved_state
.enc_write_ctx
= s
->enc_write_ctx
;
1176 saved_state
.write_hash
= s
->write_hash
;
1177 saved_state
.compress
= s
->compress
;
1178 saved_state
.session
= s
->session
;
1179 saved_state
.epoch
= DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1181 s
->d1
->retransmitting
= 1;
1183 /* restore state in which the message was originally sent */
1184 s
->enc_write_ctx
= frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
;
1185 s
->write_hash
= frag
->msg_header
.saved_retransmit_state
.write_hash
;
1186 s
->compress
= frag
->msg_header
.saved_retransmit_state
.compress
;
1187 s
->session
= frag
->msg_header
.saved_retransmit_state
.session
;
1188 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
,
1189 frag
->msg_header
.saved_retransmit_state
.epoch
);
1191 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1192 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1194 /* restore current state */
1195 s
->enc_write_ctx
= saved_state
.enc_write_ctx
;
1196 s
->write_hash
= saved_state
.write_hash
;
1197 s
->compress
= saved_state
.compress
;
1198 s
->session
= saved_state
.session
;
1199 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
, saved_state
.epoch
);
1201 s
->d1
->retransmitting
= 0;
1203 (void)BIO_flush(SSL_get_wbio(s
));
1207 /* call this function when the buffered messages are no longer needed */
1208 void dtls1_clear_record_buffer(SSL
*s
)
1212 for (item
= pqueue_pop(s
->d1
->sent_messages
);
1213 item
!= NULL
; item
= pqueue_pop(s
->d1
->sent_messages
)) {
1214 dtls1_hm_fragment_free((hm_fragment
*)item
->data
);
1219 void dtls1_set_message_header(SSL
*s
, unsigned char *p
,
1220 unsigned char mt
, unsigned long len
,
1221 unsigned long frag_off
,
1222 unsigned long frag_len
)
1224 if (frag_off
== 0) {
1225 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1226 s
->d1
->next_handshake_write_seq
++;
1229 dtls1_set_message_header_int(s
, mt
, len
, s
->d1
->handshake_write_seq
,
1230 frag_off
, frag_len
);
1233 /* don't actually do the writing, wait till the MTU has been retrieved */
1235 dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
1236 unsigned long len
, unsigned short seq_num
,
1237 unsigned long frag_off
, unsigned long frag_len
)
1239 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1242 msg_hdr
->msg_len
= len
;
1243 msg_hdr
->seq
= seq_num
;
1244 msg_hdr
->frag_off
= frag_off
;
1245 msg_hdr
->frag_len
= frag_len
;
1249 dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
1250 unsigned long frag_len
)
1252 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1254 msg_hdr
->frag_off
= frag_off
;
1255 msg_hdr
->frag_len
= frag_len
;
1258 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
)
1260 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1262 *p
++ = msg_hdr
->type
;
1263 l2n3(msg_hdr
->msg_len
, p
);
1265 s2n(msg_hdr
->seq
, p
);
1266 l2n3(msg_hdr
->frag_off
, p
);
1267 l2n3(msg_hdr
->frag_len
, p
);
1273 dtls1_get_message_header(unsigned char *data
, struct hm_header_st
*msg_hdr
)
1275 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
1276 msg_hdr
->type
= *(data
++);
1277 n2l3(data
, msg_hdr
->msg_len
);
1279 n2s(data
, msg_hdr
->seq
);
1280 n2l3(data
, msg_hdr
->frag_off
);
1281 n2l3(data
, msg_hdr
->frag_len
);