2 * Copyright 2005-2024 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
14 #include "../ssl_local.h"
15 #include "statem_local.h"
16 #include "internal/cryptlib.h"
17 #include <openssl/buffer.h>
18 #include <openssl/objects.h>
19 #include <openssl/evp.h>
20 #include <openssl/x509.h>
22 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
24 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
25 if ((end) - (start) <= 8) { \
27 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
30 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
31 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
32 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
35 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
38 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
39 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
40 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
42 static const unsigned char bitmask_start_values
[] =
43 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
44 static const unsigned char bitmask_end_values
[] =
45 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
47 static void dtls1_fix_message_header(SSL_CONNECTION
*s
, size_t frag_off
,
49 static unsigned char *dtls1_write_message_header(SSL_CONNECTION
*s
,
51 static void dtls1_set_message_header_int(SSL_CONNECTION
*s
, unsigned char mt
,
53 unsigned short seq_num
,
56 static int dtls_get_reassembled_message(SSL_CONNECTION
*s
, int *errtype
,
59 static hm_fragment
*dtls1_hm_fragment_new(size_t frag_len
, int reassembly
)
61 hm_fragment
*frag
= NULL
;
62 unsigned char *buf
= NULL
;
63 unsigned char *bitmask
= NULL
;
65 if ((frag
= OPENSSL_zalloc(sizeof(*frag
))) == NULL
)
69 if ((buf
= OPENSSL_malloc(frag_len
)) == NULL
) {
75 /* zero length fragment gets zero frag->fragment */
78 /* Initialize reassembly bitmask if necessary */
80 bitmask
= OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len
));
81 if (bitmask
== NULL
) {
88 frag
->reassembly
= bitmask
;
93 void dtls1_hm_fragment_free(hm_fragment
*frag
)
98 OPENSSL_free(frag
->fragment
);
99 OPENSSL_free(frag
->reassembly
);
104 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
105 * SSL3_RT_CHANGE_CIPHER_SPEC)
107 int dtls1_do_write(SSL_CONNECTION
*s
, uint8_t type
)
113 size_t len
, frag_off
, overhead
, used_len
;
114 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
116 if (!dtls1_query_mtu(s
))
119 if (s
->d1
->mtu
< dtls1_min_mtu(s
))
120 /* should have something reasonable now */
123 if (s
->init_off
== 0 && type
== SSL3_RT_HANDSHAKE
) {
124 if (!ossl_assert(s
->init_num
==
125 s
->d1
->w_msg_hdr
.msg_len
+ DTLS1_HM_HEADER_LENGTH
))
129 overhead
= s
->rlayer
.wrlmethod
->get_max_record_overhead(s
->rlayer
.wrl
);
132 s
->rwstate
= SSL_NOTHING
;
134 /* s->init_num shouldn't ever be < 0...but just in case */
135 while (s
->init_num
> 0) {
136 if (type
== SSL3_RT_HANDSHAKE
&& s
->init_off
!= 0) {
137 /* We must be writing a fragment other than the first one */
140 /* This is the first attempt at writing out this fragment */
142 if (s
->init_off
<= DTLS1_HM_HEADER_LENGTH
) {
144 * Each fragment that was already sent must at least have
145 * contained the message header plus one other byte.
146 * Therefore |init_off| must have progressed by at least
147 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
154 * Adjust |init_off| and |init_num| to allow room for a new
155 * message header for this fragment.
157 s
->init_off
-= DTLS1_HM_HEADER_LENGTH
;
158 s
->init_num
+= DTLS1_HM_HEADER_LENGTH
;
161 * We must have been called again after a retry so use the
162 * fragment offset from our last attempt. We do not need
163 * to adjust |init_off| and |init_num| as above, because
164 * that should already have been done before the retry.
166 frag_off
= s
->d1
->w_msg_hdr
.frag_off
;
170 used_len
= BIO_wpending(s
->wbio
) + overhead
;
171 if (s
->d1
->mtu
> used_len
)
172 curr_mtu
= s
->d1
->mtu
- used_len
;
176 if (curr_mtu
<= DTLS1_HM_HEADER_LENGTH
) {
178 * grr.. we could get an error if MTU picked was wrong
180 ret
= BIO_flush(s
->wbio
);
182 s
->rwstate
= SSL_WRITING
;
185 if (s
->d1
->mtu
> overhead
+ DTLS1_HM_HEADER_LENGTH
) {
186 curr_mtu
= s
->d1
->mtu
- overhead
;
188 /* Shouldn't happen */
194 * We just checked that s->init_num > 0 so this cast should be safe
196 if (((unsigned int)s
->init_num
) > curr_mtu
)
201 if (len
> ssl_get_max_send_fragment(s
))
202 len
= ssl_get_max_send_fragment(s
);
205 * XDTLS: this function is too long. split out the CCS part
207 if (type
== SSL3_RT_HANDSHAKE
) {
208 if (len
< DTLS1_HM_HEADER_LENGTH
) {
210 * len is so small that we really can't do anything sensible
215 dtls1_fix_message_header(s
, frag_off
, len
- DTLS1_HM_HEADER_LENGTH
);
217 dtls1_write_message_header(s
,
218 (unsigned char *)&s
->init_buf
->
222 ret
= dtls1_write_bytes(s
, type
, &s
->init_buf
->data
[s
->init_off
], len
,
226 * might need to update MTU here, but we don't know which
227 * previous packet caused the failure -- so can't really
228 * retransmit anything. continue as if everything is fine and
229 * wait for an alert to handle the retransmit
231 if (retry
&& BIO_ctrl(SSL_get_wbio(ssl
),
232 BIO_CTRL_DGRAM_MTU_EXCEEDED
, 0, NULL
) > 0) {
233 if (!(SSL_get_options(ssl
) & SSL_OP_NO_QUERY_MTU
)) {
234 if (!dtls1_query_mtu(s
))
236 /* Have one more go */
246 * bad if this assert fails, only part of the handshake message
247 * got sent. but why would this happen?
249 if (!ossl_assert(len
== written
))
253 * We should not exceed the MTU size. If compression is in use
254 * then the max record overhead calculation is unreliable so we do
255 * not check in that case. We use assert rather than ossl_assert
256 * because in a production build, if this assert were ever to fail,
257 * then the best thing to do is probably carry on regardless.
259 assert(s
->s3
.tmp
.new_compression
!= NULL
260 || BIO_wpending(s
->wbio
) <= (int)s
->d1
->mtu
);
262 if (type
== SSL3_RT_HANDSHAKE
&& !s
->d1
->retransmitting
) {
264 * should not be done for 'Hello Request's, but in that case
265 * we'll ignore the result anyway
268 (unsigned char *)&s
->init_buf
->data
[s
->init_off
];
269 const struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
272 if (frag_off
== 0 && s
->version
!= DTLS1_BAD_VER
) {
274 * reconstruct message header is if it is being sent in
277 *p
++ = msg_hdr
->type
;
278 l2n3(msg_hdr
->msg_len
, p
);
279 s2n(msg_hdr
->seq
, p
);
281 l2n3(msg_hdr
->msg_len
, p
);
282 p
-= DTLS1_HM_HEADER_LENGTH
;
285 p
+= DTLS1_HM_HEADER_LENGTH
;
286 xlen
= written
- DTLS1_HM_HEADER_LENGTH
;
289 if (!ssl3_finish_mac(s
, p
, xlen
))
293 if (written
== s
->init_num
) {
295 s
->msg_callback(1, s
->version
, type
, s
->init_buf
->data
,
296 (size_t)(s
->init_off
+ s
->init_num
), ssl
,
297 s
->msg_callback_arg
);
299 s
->init_off
= 0; /* done writing this message */
304 s
->init_off
+= written
;
305 s
->init_num
-= written
;
306 written
-= DTLS1_HM_HEADER_LENGTH
;
310 * We save the fragment offset for the next fragment so we have it
311 * available in case of an IO retry. We don't know the length of the
312 * next fragment yet so just set that to 0 for now. It will be
313 * updated again later.
315 dtls1_fix_message_header(s
, frag_off
, 0);
321 int dtls_get_message(SSL_CONNECTION
*s
, int *mt
)
323 struct hm_header_st
*msg_hdr
;
329 msg_hdr
= &s
->d1
->r_msg_hdr
;
330 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
333 if (!dtls_get_reassembled_message(s
, &errtype
, &tmplen
)) {
334 if (errtype
== DTLS1_HM_BAD_FRAGMENT
335 || errtype
== DTLS1_HM_FRAGMENT_RETRY
) {
336 /* bad fragment received */
342 *mt
= s
->s3
.tmp
.message_type
;
344 p
= (unsigned char *)s
->init_buf
->data
;
346 if (*mt
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
347 if (s
->msg_callback
) {
348 s
->msg_callback(0, s
->version
, SSL3_RT_CHANGE_CIPHER_SPEC
,
349 p
, 1, SSL_CONNECTION_GET_SSL(s
),
350 s
->msg_callback_arg
);
353 * This isn't a real handshake message so skip the processing below.
358 msg_len
= msg_hdr
->msg_len
;
360 /* reconstruct message header */
361 *(p
++) = msg_hdr
->type
;
363 s2n(msg_hdr
->seq
, p
);
367 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
369 s
->d1
->handshake_read_seq
++;
371 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
377 * Actually we already have the message body - but this is an opportunity for
378 * DTLS to do any further processing it wants at the same point that TLS would
379 * be asked for the message body.
381 int dtls_get_message_body(SSL_CONNECTION
*s
, size_t *len
)
383 unsigned char *msg
= (unsigned char *)s
->init_buf
->data
;
384 size_t msg_len
= s
->init_num
+ DTLS1_HM_HEADER_LENGTH
;
386 if (s
->s3
.tmp
.message_type
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
387 /* Nothing to be done */
391 * If receiving Finished, record MAC of prior handshake messages for
392 * Finished verification.
394 if (*(s
->init_buf
->data
) == SSL3_MT_FINISHED
&& !ssl3_take_mac(s
)) {
395 /* SSLfatal() already called */
399 if (s
->version
== DTLS1_BAD_VER
) {
400 msg
+= DTLS1_HM_HEADER_LENGTH
;
401 msg_len
-= DTLS1_HM_HEADER_LENGTH
;
404 if (!ssl3_finish_mac(s
, msg
, msg_len
))
408 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
409 s
->init_buf
->data
, s
->init_num
+ DTLS1_HM_HEADER_LENGTH
,
410 SSL_CONNECTION_GET_SSL(s
), s
->msg_callback_arg
);
418 * dtls1_max_handshake_message_len returns the maximum number of bytes
419 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
420 * may be greater if the maximum certificate list size requires it.
422 static size_t dtls1_max_handshake_message_len(const SSL_CONNECTION
*s
)
424 size_t max_len
= DTLS1_HM_HEADER_LENGTH
+ SSL3_RT_MAX_ENCRYPTED_LENGTH
;
425 if (max_len
< s
->max_cert_list
)
426 return s
->max_cert_list
;
430 static int dtls1_preprocess_fragment(SSL_CONNECTION
*s
,
431 struct hm_header_st
*msg_hdr
)
433 size_t frag_off
, frag_len
, msg_len
;
435 msg_len
= msg_hdr
->msg_len
;
436 frag_off
= msg_hdr
->frag_off
;
437 frag_len
= msg_hdr
->frag_len
;
439 /* sanity checking */
440 if ((frag_off
+ frag_len
) > msg_len
441 || msg_len
> dtls1_max_handshake_message_len(s
)) {
442 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
446 if (s
->d1
->r_msg_hdr
.frag_off
== 0) { /* first fragment */
448 * msg_len is limited to 2^24, but is effectively checked against
449 * dtls_max_handshake_message_len(s) above
451 if (!BUF_MEM_grow_clean(s
->init_buf
, msg_len
+ DTLS1_HM_HEADER_LENGTH
)) {
452 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_BUF_LIB
);
456 s
->s3
.tmp
.message_size
= msg_len
;
457 s
->d1
->r_msg_hdr
.msg_len
= msg_len
;
458 s
->s3
.tmp
.message_type
= msg_hdr
->type
;
459 s
->d1
->r_msg_hdr
.type
= msg_hdr
->type
;
460 s
->d1
->r_msg_hdr
.seq
= msg_hdr
->seq
;
461 } else if (msg_len
!= s
->d1
->r_msg_hdr
.msg_len
) {
463 * They must be playing with us! BTW, failure to enforce upper limit
464 * would open possibility for buffer overrun.
466 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
474 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a
477 static int dtls1_retrieve_buffered_fragment(SSL_CONNECTION
*s
, size_t *len
)
480 * (0) check whether the desired fragment is available
482 * (1) copy over the fragment to s->init_buf->data[]
483 * (2) update s->init_num
491 iter
= pqueue_iterator(s
->d1
->buffered_messages
);
493 item
= pqueue_next(&iter
);
497 frag
= (hm_fragment
*)item
->data
;
499 if (frag
->msg_header
.seq
< s
->d1
->handshake_read_seq
) {
501 hm_fragment
*nextfrag
;
504 || frag
->msg_header
.seq
!= 0
505 || s
->d1
->handshake_read_seq
!= 1
506 || s
->statem
.hand_state
!= DTLS_ST_SW_HELLO_VERIFY_REQUEST
) {
508 * This is a stale message that has been buffered so clear it.
509 * It is safe to pop this message from the queue even though
510 * we have an active iterator
512 pqueue_pop(s
->d1
->buffered_messages
);
513 dtls1_hm_fragment_free(frag
);
519 * We have fragments for a ClientHello without a cookie,
520 * even though we have sent a HelloVerifyRequest. It is possible
521 * that the HelloVerifyRequest got lost and this is a
522 * retransmission of the original ClientHello
524 next
= pqueue_next(&iter
);
526 nextfrag
= (hm_fragment
*)next
->data
;
527 if (nextfrag
->msg_header
.seq
== s
->d1
->handshake_read_seq
) {
529 * We have fragments for both a ClientHello without
530 * cookie and one with. Ditch the one without.
532 pqueue_pop(s
->d1
->buffered_messages
);
533 dtls1_hm_fragment_free(frag
);
545 } while (item
== NULL
);
547 /* Don't return if reassembly still in progress */
548 if (frag
->reassembly
!= NULL
)
551 if (s
->d1
->handshake_read_seq
== frag
->msg_header
.seq
|| chretran
) {
552 size_t frag_len
= frag
->msg_header
.frag_len
;
553 pqueue_pop(s
->d1
->buffered_messages
);
555 /* Calls SSLfatal() as required */
556 ret
= dtls1_preprocess_fragment(s
, &frag
->msg_header
);
558 if (ret
&& frag
->msg_header
.frag_len
> 0) {
560 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
561 memcpy(&p
[frag
->msg_header
.frag_off
], frag
->fragment
,
562 frag
->msg_header
.frag_len
);
565 dtls1_hm_fragment_free(frag
);
571 * We got a new ClientHello with a message sequence of 0.
572 * Reset the read/write sequences back to the beginning.
573 * We process it like this is the first time we've seen a
574 * ClientHello from the client.
576 s
->d1
->handshake_read_seq
= 0;
577 s
->d1
->next_handshake_write_seq
= 0;
591 static int dtls1_reassemble_fragment(SSL_CONNECTION
*s
,
592 const struct hm_header_st
*msg_hdr
)
594 hm_fragment
*frag
= NULL
;
596 int i
= -1, is_complete
;
597 unsigned char seq64be
[8];
598 size_t frag_len
= msg_hdr
->frag_len
;
600 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
602 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
||
603 msg_hdr
->msg_len
> dtls1_max_handshake_message_len(s
))
607 return DTLS1_HM_FRAGMENT_RETRY
;
610 /* Try to find item in queue */
611 memset(seq64be
, 0, sizeof(seq64be
));
612 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
613 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
614 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
617 frag
= dtls1_hm_fragment_new(msg_hdr
->msg_len
, 1);
620 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
621 frag
->msg_header
.frag_len
= frag
->msg_header
.msg_len
;
622 frag
->msg_header
.frag_off
= 0;
624 frag
= (hm_fragment
*)item
->data
;
625 if (frag
->msg_header
.msg_len
!= msg_hdr
->msg_len
) {
633 * If message is already reassembled, this must be a retransmit and can
634 * be dropped. In this case item != NULL and so frag does not need to be
637 if (frag
->reassembly
== NULL
) {
638 unsigned char devnull
[256];
641 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
644 sizeof(devnull
) ? sizeof(devnull
) :
645 frag_len
, 0, &readbytes
);
648 frag_len
-= readbytes
;
650 return DTLS1_HM_FRAGMENT_RETRY
;
653 /* read the body of the fragment (header has already been read */
654 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
655 frag
->fragment
+ msg_hdr
->frag_off
,
656 frag_len
, 0, &readbytes
);
657 if (i
<= 0 || readbytes
!= frag_len
)
662 RSMBLY_BITMASK_MARK(frag
->reassembly
, (long)msg_hdr
->frag_off
,
663 (long)(msg_hdr
->frag_off
+ frag_len
));
665 if (!ossl_assert(msg_hdr
->msg_len
> 0))
667 RSMBLY_BITMASK_IS_COMPLETE(frag
->reassembly
, (long)msg_hdr
->msg_len
,
671 OPENSSL_free(frag
->reassembly
);
672 frag
->reassembly
= NULL
;
676 item
= pitem_new(seq64be
, frag
);
682 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
684 * pqueue_insert fails iff a duplicate item is inserted. However,
685 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
686 * would have returned it and control would never have reached this
689 if (!ossl_assert(item
!= NULL
))
693 return DTLS1_HM_FRAGMENT_RETRY
;
697 dtls1_hm_fragment_free(frag
);
701 static int dtls1_process_out_of_seq_message(SSL_CONNECTION
*s
,
702 const struct hm_header_st
*msg_hdr
)
705 hm_fragment
*frag
= NULL
;
707 unsigned char seq64be
[8];
708 size_t frag_len
= msg_hdr
->frag_len
;
710 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
712 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
)
715 /* Try to find item in queue, to prevent duplicate entries */
716 memset(seq64be
, 0, sizeof(seq64be
));
717 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
718 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
719 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
722 * If we already have an entry and this one is a fragment, don't discard
723 * it and rather try to reassemble it.
725 if (item
!= NULL
&& frag_len
!= msg_hdr
->msg_len
)
729 * Discard the message if sequence number was already there, is too far
730 * in the future, already in the queue or if we received a FINISHED
731 * before the SERVER_HELLO, which then must be a stale retransmit.
733 if (msg_hdr
->seq
<= s
->d1
->handshake_read_seq
||
734 msg_hdr
->seq
> s
->d1
->handshake_read_seq
+ 10 || item
!= NULL
||
735 (s
->d1
->handshake_read_seq
== 0 && msg_hdr
->type
== SSL3_MT_FINISHED
)) {
736 unsigned char devnull
[256];
739 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
742 sizeof(devnull
) ? sizeof(devnull
) :
743 frag_len
, 0, &readbytes
);
746 frag_len
-= readbytes
;
749 if (frag_len
!= msg_hdr
->msg_len
) {
750 return dtls1_reassemble_fragment(s
, msg_hdr
);
753 if (frag_len
> dtls1_max_handshake_message_len(s
))
756 frag
= dtls1_hm_fragment_new(frag_len
, 0);
760 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
764 * read the body of the fragment (header has already been read
766 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
767 frag
->fragment
, frag_len
, 0,
769 if (i
<=0 || readbytes
!= frag_len
)
775 item
= pitem_new(seq64be
, frag
);
779 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
781 * pqueue_insert fails iff a duplicate item is inserted. However,
782 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
783 * would have returned it. Then, either |frag_len| !=
784 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
785 * have been processed with |dtls1_reassemble_fragment|, above, or
786 * the record will have been discarded.
788 if (!ossl_assert(item
!= NULL
))
792 return DTLS1_HM_FRAGMENT_RETRY
;
796 dtls1_hm_fragment_free(frag
);
800 static int dtls_get_reassembled_message(SSL_CONNECTION
*s
, int *errtype
,
803 size_t mlen
, frag_off
, frag_len
;
806 struct hm_header_st msg_hdr
;
808 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
814 p
= (unsigned char *)s
->init_buf
->data
;
817 /* see if we have the required fragment already */
818 ret
= dtls1_retrieve_buffered_fragment(s
, &frag_len
);
820 /* SSLfatal() already called */
824 s
->init_num
= frag_len
;
829 /* read handshake message header */
830 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, &recvd_type
, p
,
831 DTLS1_HM_HEADER_LENGTH
, 0, &readbytes
);
832 if (i
<= 0) { /* nbio, or an error */
833 s
->rwstate
= SSL_READING
;
837 if (recvd_type
== SSL3_RT_CHANGE_CIPHER_SPEC
) {
838 if (p
[0] != SSL3_MT_CCS
) {
839 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
,
840 SSL_R_BAD_CHANGE_CIPHER_SPEC
);
844 s
->init_num
= readbytes
- 1;
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
= readbytes
- 1;
848 *len
= readbytes
- 1;
852 /* Handshake fails if message header is incomplete */
853 if (readbytes
!= DTLS1_HM_HEADER_LENGTH
) {
854 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
858 /* parse the message fragment header */
859 dtls1_get_message_header(p
, &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
> s
->rlayer
.tlsrecs
[s
->rlayer
.curr_rec
].length
) {
870 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_BAD_LENGTH
);
875 * if this is a future (or stale) message it gets buffered
876 * (or dropped)--no further processing at this time
877 * While listening, we accept seq 1 (ClientHello with cookie)
878 * although we're still expecting seq 0 (ClientHello)
880 if (msg_hdr
.seq
!= s
->d1
->handshake_read_seq
) {
883 || s
->d1
->handshake_read_seq
!= 1
884 || p
[0] != SSL3_MT_CLIENT_HELLO
885 || s
->statem
.hand_state
!= DTLS_ST_SW_HELLO_VERIFY_REQUEST
) {
886 *errtype
= dtls1_process_out_of_seq_message(s
, &msg_hdr
);
890 * We received a ClientHello and sent back a HelloVerifyRequest. We
891 * now seem to have received a retransmitted initial ClientHello. That
892 * is allowed (possibly our HelloVerifyRequest got lost).
897 if (frag_len
&& frag_len
< mlen
) {
898 *errtype
= dtls1_reassemble_fragment(s
, &msg_hdr
);
903 && s
->d1
->r_msg_hdr
.frag_off
== 0
904 && s
->statem
.hand_state
!= TLS_ST_OK
905 && p
[0] == SSL3_MT_HELLO_REQUEST
) {
907 * The server may always send 'Hello Request' messages -- we are
908 * doing a handshake anyway now, so ignore them if their format is
909 * correct. Does not count for 'Finished' MAC.
911 if (p
[1] == 0 && p
[2] == 0 && p
[3] == 0) {
913 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
914 p
, DTLS1_HM_HEADER_LENGTH
, ssl
,
915 s
->msg_callback_arg
);
919 } else { /* Incorrectly formatted Hello request */
921 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
926 if (!dtls1_preprocess_fragment(s
, &msg_hdr
)) {
927 /* SSLfatal() already called */
932 p
+= DTLS1_HM_HEADER_LENGTH
;
934 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
935 &p
[frag_off
], frag_len
, 0, &readbytes
);
938 * This shouldn't ever fail due to NBIO because we already checked
939 * that we have enough data in the record
942 s
->rwstate
= SSL_READING
;
951 * XDTLS: an incorrectly formatted fragment should cause the handshake
954 if (readbytes
!= frag_len
) {
955 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_BAD_LENGTH
);
961 * We got a new ClientHello with a message sequence of 0.
962 * Reset the read/write sequences back to the beginning.
963 * We process it like this is the first time we've seen a ClientHello
966 s
->d1
->handshake_read_seq
= 0;
967 s
->d1
->next_handshake_write_seq
= 0;
971 * Note that s->init_num is *not* used as current offset in
972 * s->init_buf->data, but as a counter summing up fragments' lengths: as
973 * soon as they sum up to handshake packet length, we assume we have got
976 *len
= s
->init_num
= frag_len
;
986 * for these 2 messages, we need to
987 * ssl->session->read_sym_enc assign
988 * ssl->session->read_compression assign
989 * ssl->session->read_hash assign
991 CON_FUNC_RETURN
dtls_construct_change_cipher_spec(SSL_CONNECTION
*s
,
994 if (s
->version
== DTLS1_BAD_VER
) {
995 s
->d1
->next_handshake_write_seq
++;
997 if (!WPACKET_put_bytes_u16(pkt
, s
->d1
->handshake_write_seq
)) {
998 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
999 return CON_FUNC_ERROR
;
1003 return CON_FUNC_SUCCESS
;
1006 #ifndef OPENSSL_NO_SCTP
1008 * Wait for a dry event. Should only be called at a point in the handshake
1009 * where we are not expecting any data from the peer except an alert.
1011 WORK_STATE
dtls_wait_for_dry(SSL_CONNECTION
*s
)
1015 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
1017 /* read app data until dry event */
1018 ret
= BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(ssl
));
1020 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1026 * We're not expecting any more messages from the peer at this point -
1027 * but we could get an alert. If an alert is waiting then we will never
1028 * return successfully. Therefore we attempt to read a message. This
1029 * should never succeed but will process any waiting alerts.
1031 if (dtls_get_reassembled_message(s
, &errtype
, &len
)) {
1032 /* The call succeeded! This should never happen */
1033 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
1037 s
->s3
.in_read_app_data
= 2;
1038 s
->rwstate
= SSL_READING
;
1039 BIO_clear_retry_flags(SSL_get_rbio(ssl
));
1040 BIO_set_retry_read(SSL_get_rbio(ssl
));
1043 return WORK_FINISHED_CONTINUE
;
1047 int dtls1_read_failed(SSL_CONNECTION
*s
, int code
)
1049 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
1052 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1056 if (!dtls1_is_timer_expired(s
) || ossl_statem_in_error(s
)) {
1058 * not a timeout, none of our business, let higher layers handle
1059 * this. in fact it's probably an error
1063 /* done, no need to send a retransmit */
1064 if (!SSL_in_init(ssl
))
1066 BIO_set_flags(SSL_get_rbio(ssl
), BIO_FLAGS_READ
);
1070 return dtls1_handle_timeout(s
);
1073 int dtls1_get_queue_priority(unsigned short seq
, int is_ccs
)
1076 * The index of the retransmission queue actually is the message sequence
1077 * number, since the queue only contains messages of a single handshake.
1078 * However, the ChangeCipherSpec has no message sequence number and so
1079 * using only the sequence will result in the CCS and Finished having the
1080 * same index. To prevent this, the sequence number is multiplied by 2.
1081 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1082 * Finished, it also maintains the order of the index (important for
1083 * priority queues) and fits in the unsigned short variable.
1085 return seq
* 2 - is_ccs
;
1088 int dtls1_retransmit_buffered_messages(SSL_CONNECTION
*s
)
1090 pqueue
*sent
= s
->d1
->sent_messages
;
1096 iter
= pqueue_iterator(sent
);
1098 for (item
= pqueue_next(&iter
); item
!= NULL
; item
= pqueue_next(&iter
)) {
1099 frag
= (hm_fragment
*)item
->data
;
1100 if (dtls1_retransmit_message(s
, (unsigned short)
1101 dtls1_get_queue_priority
1102 (frag
->msg_header
.seq
,
1103 frag
->msg_header
.is_ccs
), &found
) <= 0)
1110 int dtls1_buffer_message(SSL_CONNECTION
*s
, int is_ccs
)
1114 unsigned char seq64be
[8];
1117 * this function is called immediately after a message has been
1120 if (!ossl_assert(s
->init_off
== 0))
1123 frag
= dtls1_hm_fragment_new(s
->init_num
, 0);
1127 memcpy(frag
->fragment
, s
->init_buf
->data
, s
->init_num
);
1130 /* For DTLS1_BAD_VER the header length is non-standard */
1131 if (!ossl_assert(s
->d1
->w_msg_hdr
.msg_len
+
1133 DTLS1_BAD_VER
) ? 3 : DTLS1_CCS_HEADER_LENGTH
)
1134 == (unsigned int)s
->init_num
)) {
1135 dtls1_hm_fragment_free(frag
);
1139 if (!ossl_assert(s
->d1
->w_msg_hdr
.msg_len
+
1140 DTLS1_HM_HEADER_LENGTH
== (unsigned int)s
->init_num
)) {
1141 dtls1_hm_fragment_free(frag
);
1146 frag
->msg_header
.msg_len
= s
->d1
->w_msg_hdr
.msg_len
;
1147 frag
->msg_header
.seq
= s
->d1
->w_msg_hdr
.seq
;
1148 frag
->msg_header
.type
= s
->d1
->w_msg_hdr
.type
;
1149 frag
->msg_header
.frag_off
= 0;
1150 frag
->msg_header
.frag_len
= s
->d1
->w_msg_hdr
.msg_len
;
1151 frag
->msg_header
.is_ccs
= is_ccs
;
1153 /* save current state */
1154 frag
->msg_header
.saved_retransmit_state
.wrlmethod
= s
->rlayer
.wrlmethod
;
1155 frag
->msg_header
.saved_retransmit_state
.wrl
= s
->rlayer
.wrl
;
1158 memset(seq64be
, 0, sizeof(seq64be
));
1161 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1162 frag
->msg_header
.is_ccs
) >> 8);
1165 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1166 frag
->msg_header
.is_ccs
));
1168 item
= pitem_new(seq64be
, frag
);
1170 dtls1_hm_fragment_free(frag
);
1174 pqueue_insert(s
->d1
->sent_messages
, item
);
1178 int dtls1_retransmit_message(SSL_CONNECTION
*s
, unsigned short seq
, int *found
)
1181 /* XDTLS: for now assuming that read/writes are blocking */
1184 unsigned long header_length
;
1185 unsigned char seq64be
[8];
1186 struct dtls1_retransmit_state saved_state
;
1188 /* XDTLS: the requested message ought to be found, otherwise error */
1189 memset(seq64be
, 0, sizeof(seq64be
));
1190 seq64be
[6] = (unsigned char)(seq
>> 8);
1191 seq64be
[7] = (unsigned char)seq
;
1193 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1195 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1201 frag
= (hm_fragment
*)item
->data
;
1203 if (frag
->msg_header
.is_ccs
)
1204 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1206 header_length
= DTLS1_HM_HEADER_LENGTH
;
1208 memcpy(s
->init_buf
->data
, frag
->fragment
,
1209 frag
->msg_header
.msg_len
+ header_length
);
1210 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1212 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1213 frag
->msg_header
.msg_len
,
1214 frag
->msg_header
.seq
, 0,
1215 frag
->msg_header
.frag_len
);
1217 /* save current state */
1218 saved_state
.wrlmethod
= s
->rlayer
.wrlmethod
;
1219 saved_state
.wrl
= s
->rlayer
.wrl
;
1221 s
->d1
->retransmitting
= 1;
1223 /* restore state in which the message was originally sent */
1224 s
->rlayer
.wrlmethod
= frag
->msg_header
.saved_retransmit_state
.wrlmethod
;
1225 s
->rlayer
.wrl
= frag
->msg_header
.saved_retransmit_state
.wrl
;
1228 * The old wrl may be still pointing at an old BIO. Update it to what we're
1231 s
->rlayer
.wrlmethod
->set1_bio(s
->rlayer
.wrl
, s
->wbio
);
1233 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1234 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1236 /* restore current state */
1237 s
->rlayer
.wrlmethod
= saved_state
.wrlmethod
;
1238 s
->rlayer
.wrl
= saved_state
.wrl
;
1240 s
->d1
->retransmitting
= 0;
1242 (void)BIO_flush(s
->wbio
);
1246 void dtls1_set_message_header(SSL_CONNECTION
*s
,
1247 unsigned char mt
, size_t len
,
1248 size_t frag_off
, size_t 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_CONNECTION
*s
, unsigned char mt
,
1262 size_t len
, unsigned short seq_num
,
1263 size_t frag_off
, size_t 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_CONNECTION
*s
, size_t frag_off
, size_t frag_len
)
1277 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1279 msg_hdr
->frag_off
= frag_off
;
1280 msg_hdr
->frag_len
= frag_len
;
1283 static unsigned char *dtls1_write_message_header(SSL_CONNECTION
*s
,
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
);
1298 void dtls1_get_message_header(const unsigned char *data
, struct
1299 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
);
1310 int dtls1_set_handshake_header(SSL_CONNECTION
*s
, WPACKET
*pkt
, int htype
)
1312 unsigned char *header
;
1314 if (htype
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
1315 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1316 dtls1_set_message_header_int(s
, SSL3_MT_CCS
, 0,
1317 s
->d1
->handshake_write_seq
, 0, 0);
1318 if (!WPACKET_put_bytes_u8(pkt
, SSL3_MT_CCS
))
1321 dtls1_set_message_header(s
, htype
, 0, 0, 0);
1323 * We allocate space at the start for the message header. This gets
1326 if (!WPACKET_allocate_bytes(pkt
, DTLS1_HM_HEADER_LENGTH
, &header
)
1327 || !WPACKET_start_sub_packet(pkt
))
1334 int dtls1_close_construct_packet(SSL_CONNECTION
*s
, WPACKET
*pkt
, int htype
)
1338 if ((htype
!= SSL3_MT_CHANGE_CIPHER_SPEC
&& !WPACKET_close(pkt
))
1339 || !WPACKET_get_length(pkt
, &msglen
)
1340 || msglen
> INT_MAX
)
1343 if (htype
!= SSL3_MT_CHANGE_CIPHER_SPEC
) {
1344 s
->d1
->w_msg_hdr
.msg_len
= msglen
- DTLS1_HM_HEADER_LENGTH
;
1345 s
->d1
->w_msg_hdr
.frag_len
= msglen
- DTLS1_HM_HEADER_LENGTH
;
1347 s
->init_num
= (int)msglen
;
1350 if (htype
!= DTLS1_MT_HELLO_VERIFY_REQUEST
) {
1351 /* Buffer the message to handle re-xmits */
1352 if (!dtls1_buffer_message(s
, htype
== SSL3_MT_CHANGE_CIPHER_SPEC