2 * Copyright 2005-2022 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
13 #include "../ssl_local.h"
14 #include "statem_local.h"
15 #include "internal/cryptlib.h"
16 #include <openssl/buffer.h>
17 #include <openssl/objects.h>
18 #include <openssl/evp.h>
19 #include <openssl/x509.h>
21 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
23 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
24 if ((end) - (start) <= 8) { \
26 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
29 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
30 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
31 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
34 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
37 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
38 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
39 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
41 static unsigned char bitmask_start_values
[] =
42 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
43 static unsigned char bitmask_end_values
[] =
44 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
46 static void dtls1_fix_message_header(SSL_CONNECTION
*s
, size_t frag_off
,
48 static unsigned char *dtls1_write_message_header(SSL_CONNECTION
*s
,
50 static void dtls1_set_message_header_int(SSL_CONNECTION
*s
, unsigned char mt
,
52 unsigned short seq_num
,
55 static int dtls_get_reassembled_message(SSL_CONNECTION
*s
, int *errtype
,
58 static hm_fragment
*dtls1_hm_fragment_new(size_t frag_len
, int reassembly
)
60 hm_fragment
*frag
= NULL
;
61 unsigned char *buf
= NULL
;
62 unsigned char *bitmask
= NULL
;
64 if ((frag
= OPENSSL_malloc(sizeof(*frag
))) == NULL
) {
65 ERR_raise(ERR_LIB_SSL
, ERR_R_MALLOC_FAILURE
);
70 if ((buf
= OPENSSL_malloc(frag_len
)) == NULL
) {
71 ERR_raise(ERR_LIB_SSL
, ERR_R_MALLOC_FAILURE
);
77 /* zero length fragment gets zero frag->fragment */
80 /* Initialize reassembly bitmask if necessary */
82 bitmask
= OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len
));
83 if (bitmask
== NULL
) {
84 ERR_raise(ERR_LIB_SSL
, ERR_R_MALLOC_FAILURE
);
91 frag
->reassembly
= bitmask
;
96 void dtls1_hm_fragment_free(hm_fragment
*frag
)
100 if (frag
->msg_header
.is_ccs
) {
101 EVP_CIPHER_CTX_free(frag
->msg_header
.
102 saved_retransmit_state
.enc_write_ctx
);
103 EVP_MD_CTX_free(frag
->msg_header
.saved_retransmit_state
.write_hash
);
105 OPENSSL_free(frag
->fragment
);
106 OPENSSL_free(frag
->reassembly
);
111 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
112 * SSL3_RT_CHANGE_CIPHER_SPEC)
114 int dtls1_do_write(SSL_CONNECTION
*s
, int type
)
120 size_t len
, frag_off
, mac_size
, blocksize
, used_len
;
121 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
123 if (!dtls1_query_mtu(s
))
126 if (s
->d1
->mtu
< dtls1_min_mtu(s
))
127 /* should have something reasonable now */
130 if (s
->init_off
== 0 && type
== SSL3_RT_HANDSHAKE
) {
131 if (!ossl_assert(s
->init_num
==
132 s
->d1
->w_msg_hdr
.msg_len
+ DTLS1_HM_HEADER_LENGTH
))
138 && (EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(s
->enc_write_ctx
)) &
139 EVP_CIPH_FLAG_AEAD_CIPHER
) != 0)
142 mac_size
= EVP_MD_CTX_get_size(s
->write_hash
);
146 if (s
->enc_write_ctx
&&
147 (EVP_CIPHER_CTX_get_mode(s
->enc_write_ctx
) == EVP_CIPH_CBC_MODE
))
148 blocksize
= 2 * EVP_CIPHER_CTX_get_block_size(s
->enc_write_ctx
);
153 s
->rwstate
= SSL_NOTHING
;
155 /* s->init_num shouldn't ever be < 0...but just in case */
156 while (s
->init_num
> 0) {
157 if (type
== SSL3_RT_HANDSHAKE
&& s
->init_off
!= 0) {
158 /* We must be writing a fragment other than the first one */
161 /* This is the first attempt at writing out this fragment */
163 if (s
->init_off
<= DTLS1_HM_HEADER_LENGTH
) {
165 * Each fragment that was already sent must at least have
166 * contained the message header plus one other byte.
167 * Therefore |init_off| must have progressed by at least
168 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
175 * Adjust |init_off| and |init_num| to allow room for a new
176 * message header for this fragment.
178 s
->init_off
-= DTLS1_HM_HEADER_LENGTH
;
179 s
->init_num
+= DTLS1_HM_HEADER_LENGTH
;
182 * We must have been called again after a retry so use the
183 * fragment offset from our last attempt. We do not need
184 * to adjust |init_off| and |init_num| as above, because
185 * that should already have been done before the retry.
187 frag_off
= s
->d1
->w_msg_hdr
.frag_off
;
191 used_len
= BIO_wpending(s
->wbio
) + DTLS1_RT_HEADER_LENGTH
192 + mac_size
+ blocksize
;
193 if (s
->d1
->mtu
> used_len
)
194 curr_mtu
= s
->d1
->mtu
- used_len
;
198 if (curr_mtu
<= DTLS1_HM_HEADER_LENGTH
) {
200 * grr.. we could get an error if MTU picked was wrong
202 ret
= BIO_flush(s
->wbio
);
204 s
->rwstate
= SSL_WRITING
;
207 used_len
= DTLS1_RT_HEADER_LENGTH
+ mac_size
+ blocksize
;
208 if (s
->d1
->mtu
> used_len
+ DTLS1_HM_HEADER_LENGTH
) {
209 curr_mtu
= s
->d1
->mtu
- used_len
;
211 /* Shouldn't happen */
217 * We just checked that s->init_num > 0 so this cast should be safe
219 if (((unsigned int)s
->init_num
) > curr_mtu
)
224 if (len
> ssl_get_max_send_fragment(s
))
225 len
= ssl_get_max_send_fragment(s
);
228 * XDTLS: this function is too long. split out the CCS part
230 if (type
== SSL3_RT_HANDSHAKE
) {
231 if (len
< DTLS1_HM_HEADER_LENGTH
) {
233 * len is so small that we really can't do anything sensible
238 dtls1_fix_message_header(s
, frag_off
, len
- DTLS1_HM_HEADER_LENGTH
);
240 dtls1_write_message_header(s
,
241 (unsigned char *)&s
->init_buf
->
245 ret
= dtls1_write_bytes(s
, type
, &s
->init_buf
->data
[s
->init_off
], len
,
249 * might need to update MTU here, but we don't know which
250 * previous packet caused the failure -- so can't really
251 * retransmit anything. continue as if everything is fine and
252 * wait for an alert to handle the retransmit
254 if (retry
&& BIO_ctrl(SSL_get_wbio(ssl
),
255 BIO_CTRL_DGRAM_MTU_EXCEEDED
, 0, NULL
) > 0) {
256 if (!(SSL_get_options(ssl
) & SSL_OP_NO_QUERY_MTU
)) {
257 if (!dtls1_query_mtu(s
))
259 /* Have one more go */
269 * bad if this assert fails, only part of the handshake message
270 * got sent. but why would this happen?
272 if (!ossl_assert(len
== written
))
275 if (type
== SSL3_RT_HANDSHAKE
&& !s
->d1
->retransmitting
) {
277 * should not be done for 'Hello Request's, but in that case
278 * we'll ignore the result anyway
281 (unsigned char *)&s
->init_buf
->data
[s
->init_off
];
282 const struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
285 if (frag_off
== 0 && s
->version
!= DTLS1_BAD_VER
) {
287 * reconstruct message header is if it is being sent in
290 *p
++ = msg_hdr
->type
;
291 l2n3(msg_hdr
->msg_len
, p
);
292 s2n(msg_hdr
->seq
, p
);
294 l2n3(msg_hdr
->msg_len
, p
);
295 p
-= DTLS1_HM_HEADER_LENGTH
;
298 p
+= DTLS1_HM_HEADER_LENGTH
;
299 xlen
= written
- DTLS1_HM_HEADER_LENGTH
;
302 if (!ssl3_finish_mac(s
, p
, xlen
))
306 if (written
== s
->init_num
) {
308 s
->msg_callback(1, s
->version
, type
, s
->init_buf
->data
,
309 (size_t)(s
->init_off
+ s
->init_num
), ssl
,
310 s
->msg_callback_arg
);
312 s
->init_off
= 0; /* done writing this message */
317 s
->init_off
+= written
;
318 s
->init_num
-= written
;
319 written
-= DTLS1_HM_HEADER_LENGTH
;
323 * We save the fragment offset for the next fragment so we have it
324 * available in case of an IO retry. We don't know the length of the
325 * next fragment yet so just set that to 0 for now. It will be
326 * updated again later.
328 dtls1_fix_message_header(s
, frag_off
, 0);
334 int dtls_get_message(SSL_CONNECTION
*s
, int *mt
)
336 struct hm_header_st
*msg_hdr
;
342 msg_hdr
= &s
->d1
->r_msg_hdr
;
343 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
346 if (!dtls_get_reassembled_message(s
, &errtype
, &tmplen
)) {
347 if (errtype
== DTLS1_HM_BAD_FRAGMENT
348 || errtype
== DTLS1_HM_FRAGMENT_RETRY
) {
349 /* bad fragment received */
355 *mt
= s
->s3
.tmp
.message_type
;
357 p
= (unsigned char *)s
->init_buf
->data
;
359 if (*mt
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
360 if (s
->msg_callback
) {
361 s
->msg_callback(0, s
->version
, SSL3_RT_CHANGE_CIPHER_SPEC
,
362 p
, 1, SSL_CONNECTION_GET_SSL(s
),
363 s
->msg_callback_arg
);
366 * This isn't a real handshake message so skip the processing below.
371 msg_len
= msg_hdr
->msg_len
;
373 /* reconstruct message header */
374 *(p
++) = msg_hdr
->type
;
376 s2n(msg_hdr
->seq
, p
);
380 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
382 s
->d1
->handshake_read_seq
++;
384 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
390 * Actually we already have the message body - but this is an opportunity for
391 * DTLS to do any further processing it wants at the same point that TLS would
392 * be asked for the message body.
394 int dtls_get_message_body(SSL_CONNECTION
*s
, size_t *len
)
396 unsigned char *msg
= (unsigned char *)s
->init_buf
->data
;
397 size_t msg_len
= s
->init_num
+ DTLS1_HM_HEADER_LENGTH
;
399 if (s
->s3
.tmp
.message_type
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
400 /* Nothing to be done */
404 * If receiving Finished, record MAC of prior handshake messages for
405 * Finished verification.
407 if (*(s
->init_buf
->data
) == SSL3_MT_FINISHED
&& !ssl3_take_mac(s
)) {
408 /* SSLfatal() already called */
412 if (s
->version
== DTLS1_BAD_VER
) {
413 msg
+= DTLS1_HM_HEADER_LENGTH
;
414 msg_len
-= DTLS1_HM_HEADER_LENGTH
;
417 if (!ssl3_finish_mac(s
, msg
, msg_len
))
421 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
422 s
->init_buf
->data
, s
->init_num
+ DTLS1_HM_HEADER_LENGTH
,
423 SSL_CONNECTION_GET_SSL(s
), s
->msg_callback_arg
);
431 * dtls1_max_handshake_message_len returns the maximum number of bytes
432 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
433 * may be greater if the maximum certificate list size requires it.
435 static size_t dtls1_max_handshake_message_len(const SSL_CONNECTION
*s
)
437 size_t max_len
= DTLS1_HM_HEADER_LENGTH
+ SSL3_RT_MAX_ENCRYPTED_LENGTH
;
438 if (max_len
< s
->max_cert_list
)
439 return s
->max_cert_list
;
443 static int dtls1_preprocess_fragment(SSL_CONNECTION
*s
,
444 struct hm_header_st
*msg_hdr
)
446 size_t frag_off
, frag_len
, msg_len
;
448 msg_len
= msg_hdr
->msg_len
;
449 frag_off
= msg_hdr
->frag_off
;
450 frag_len
= msg_hdr
->frag_len
;
452 /* sanity checking */
453 if ((frag_off
+ frag_len
) > msg_len
454 || msg_len
> dtls1_max_handshake_message_len(s
)) {
455 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
459 if (s
->d1
->r_msg_hdr
.frag_off
== 0) { /* first fragment */
461 * msg_len is limited to 2^24, but is effectively checked against
462 * dtls_max_handshake_message_len(s) above
464 if (!BUF_MEM_grow_clean(s
->init_buf
, msg_len
+ DTLS1_HM_HEADER_LENGTH
)) {
465 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_BUF_LIB
);
469 s
->s3
.tmp
.message_size
= msg_len
;
470 s
->d1
->r_msg_hdr
.msg_len
= msg_len
;
471 s
->s3
.tmp
.message_type
= msg_hdr
->type
;
472 s
->d1
->r_msg_hdr
.type
= msg_hdr
->type
;
473 s
->d1
->r_msg_hdr
.seq
= msg_hdr
->seq
;
474 } else if (msg_len
!= s
->d1
->r_msg_hdr
.msg_len
) {
476 * They must be playing with us! BTW, failure to enforce upper limit
477 * would open possibility for buffer overrun.
479 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
487 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a
490 static int dtls1_retrieve_buffered_fragment(SSL_CONNECTION
*s
, size_t *len
)
493 * (0) check whether the desired fragment is available
495 * (1) copy over the fragment to s->init_buf->data[]
496 * (2) update s->init_num
504 iter
= pqueue_iterator(s
->d1
->buffered_messages
);
506 item
= pqueue_next(&iter
);
510 frag
= (hm_fragment
*)item
->data
;
512 if (frag
->msg_header
.seq
< s
->d1
->handshake_read_seq
) {
514 hm_fragment
*nextfrag
;
517 || frag
->msg_header
.seq
!= 0
518 || s
->d1
->handshake_read_seq
!= 1
519 || s
->statem
.hand_state
!= DTLS_ST_SW_HELLO_VERIFY_REQUEST
) {
521 * This is a stale message that has been buffered so clear it.
522 * It is safe to pop this message from the queue even though
523 * we have an active iterator
525 pqueue_pop(s
->d1
->buffered_messages
);
526 dtls1_hm_fragment_free(frag
);
532 * We have fragments for a ClientHello without a cookie,
533 * even though we have sent a HelloVerifyRequest. It is possible
534 * that the HelloVerifyRequest got lost and this is a
535 * retransmission of the original ClientHello
537 next
= pqueue_next(&iter
);
539 nextfrag
= (hm_fragment
*)next
->data
;
540 if (nextfrag
->msg_header
.seq
== s
->d1
->handshake_read_seq
) {
542 * We have fragments for both a ClientHello without
543 * cookie and one with. Ditch the one without.
545 pqueue_pop(s
->d1
->buffered_messages
);
546 dtls1_hm_fragment_free(frag
);
558 } while (item
== NULL
);
560 /* Don't return if reassembly still in progress */
561 if (frag
->reassembly
!= NULL
)
564 if (s
->d1
->handshake_read_seq
== frag
->msg_header
.seq
|| chretran
) {
565 size_t frag_len
= frag
->msg_header
.frag_len
;
566 pqueue_pop(s
->d1
->buffered_messages
);
568 /* Calls SSLfatal() as required */
569 ret
= dtls1_preprocess_fragment(s
, &frag
->msg_header
);
571 if (ret
&& frag
->msg_header
.frag_len
> 0) {
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
);
584 * We got a new ClientHello with a message sequence of 0.
585 * Reset the read/write sequences back to the beginning.
586 * We process it like this is the first time we've seen a
587 * ClientHello from the client.
589 s
->d1
->handshake_read_seq
= 0;
590 s
->d1
->next_handshake_write_seq
= 0;
604 static int dtls1_reassemble_fragment(SSL_CONNECTION
*s
,
605 const struct hm_header_st
*msg_hdr
)
607 hm_fragment
*frag
= NULL
;
609 int i
= -1, is_complete
;
610 unsigned char seq64be
[8];
611 size_t frag_len
= msg_hdr
->frag_len
;
613 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
615 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
||
616 msg_hdr
->msg_len
> dtls1_max_handshake_message_len(s
))
620 return DTLS1_HM_FRAGMENT_RETRY
;
623 /* Try to find item in queue */
624 memset(seq64be
, 0, sizeof(seq64be
));
625 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
626 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
627 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
630 frag
= dtls1_hm_fragment_new(msg_hdr
->msg_len
, 1);
633 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
634 frag
->msg_header
.frag_len
= frag
->msg_header
.msg_len
;
635 frag
->msg_header
.frag_off
= 0;
637 frag
= (hm_fragment
*)item
->data
;
638 if (frag
->msg_header
.msg_len
!= msg_hdr
->msg_len
) {
646 * If message is already reassembled, this must be a retransmit and can
647 * be dropped. In this case item != NULL and so frag does not need to be
650 if (frag
->reassembly
== NULL
) {
651 unsigned char devnull
[256];
654 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
657 sizeof(devnull
) ? sizeof(devnull
) :
658 frag_len
, 0, &readbytes
);
661 frag_len
-= readbytes
;
663 return DTLS1_HM_FRAGMENT_RETRY
;
666 /* read the body of the fragment (header has already been read */
667 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
668 frag
->fragment
+ msg_hdr
->frag_off
,
669 frag_len
, 0, &readbytes
);
670 if (i
<= 0 || readbytes
!= frag_len
)
675 RSMBLY_BITMASK_MARK(frag
->reassembly
, (long)msg_hdr
->frag_off
,
676 (long)(msg_hdr
->frag_off
+ frag_len
));
678 if (!ossl_assert(msg_hdr
->msg_len
> 0))
680 RSMBLY_BITMASK_IS_COMPLETE(frag
->reassembly
, (long)msg_hdr
->msg_len
,
684 OPENSSL_free(frag
->reassembly
);
685 frag
->reassembly
= NULL
;
689 item
= pitem_new(seq64be
, frag
);
695 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
697 * pqueue_insert fails iff a duplicate item is inserted. However,
698 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
699 * would have returned it and control would never have reached this
702 if (!ossl_assert(item
!= NULL
))
706 return DTLS1_HM_FRAGMENT_RETRY
;
710 dtls1_hm_fragment_free(frag
);
714 static int dtls1_process_out_of_seq_message(SSL_CONNECTION
*s
,
715 const struct hm_header_st
*msg_hdr
)
718 hm_fragment
*frag
= NULL
;
720 unsigned char seq64be
[8];
721 size_t frag_len
= msg_hdr
->frag_len
;
723 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
725 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
)
728 /* Try to find item in queue, to prevent duplicate entries */
729 memset(seq64be
, 0, sizeof(seq64be
));
730 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
731 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
732 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
735 * If we already have an entry and this one is a fragment, don't discard
736 * it and rather try to reassemble it.
738 if (item
!= NULL
&& frag_len
!= msg_hdr
->msg_len
)
742 * Discard the message if sequence number was already there, is too far
743 * in the future, already in the queue or if we received a FINISHED
744 * before the SERVER_HELLO, which then must be a stale retransmit.
746 if (msg_hdr
->seq
<= s
->d1
->handshake_read_seq
||
747 msg_hdr
->seq
> s
->d1
->handshake_read_seq
+ 10 || item
!= NULL
||
748 (s
->d1
->handshake_read_seq
== 0 && msg_hdr
->type
== SSL3_MT_FINISHED
)) {
749 unsigned char devnull
[256];
752 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
755 sizeof(devnull
) ? sizeof(devnull
) :
756 frag_len
, 0, &readbytes
);
759 frag_len
-= readbytes
;
762 if (frag_len
!= msg_hdr
->msg_len
) {
763 return dtls1_reassemble_fragment(s
, msg_hdr
);
766 if (frag_len
> dtls1_max_handshake_message_len(s
))
769 frag
= dtls1_hm_fragment_new(frag_len
, 0);
773 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
777 * read the body of the fragment (header has already been read
779 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
780 frag
->fragment
, frag_len
, 0,
782 if (i
<=0 || readbytes
!= frag_len
)
788 item
= pitem_new(seq64be
, frag
);
792 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
794 * pqueue_insert fails iff a duplicate item is inserted. However,
795 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
796 * would have returned it. Then, either |frag_len| !=
797 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
798 * have been processed with |dtls1_reassemble_fragment|, above, or
799 * the record will have been discarded.
801 if (!ossl_assert(item
!= NULL
))
805 return DTLS1_HM_FRAGMENT_RETRY
;
809 dtls1_hm_fragment_free(frag
);
813 static int dtls_get_reassembled_message(SSL_CONNECTION
*s
, int *errtype
,
816 unsigned char wire
[DTLS1_HM_HEADER_LENGTH
];
817 size_t mlen
, frag_off
, frag_len
;
818 int i
, ret
, recvd_type
;
819 struct hm_header_st msg_hdr
;
821 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
827 /* see if we have the required fragment already */
828 ret
= dtls1_retrieve_buffered_fragment(s
, &frag_len
);
830 /* SSLfatal() already called */
834 s
->init_num
= frag_len
;
839 /* read handshake message header */
840 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, &recvd_type
, wire
,
841 DTLS1_HM_HEADER_LENGTH
, 0, &readbytes
);
842 if (i
<= 0) { /* nbio, or an error */
843 s
->rwstate
= SSL_READING
;
847 if (recvd_type
== SSL3_RT_CHANGE_CIPHER_SPEC
) {
848 if (wire
[0] != SSL3_MT_CCS
) {
849 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
,
850 SSL_R_BAD_CHANGE_CIPHER_SPEC
);
854 memcpy(s
->init_buf
->data
, wire
, readbytes
);
855 s
->init_num
= readbytes
- 1;
856 s
->init_msg
= s
->init_buf
->data
+ 1;
857 s
->s3
.tmp
.message_type
= SSL3_MT_CHANGE_CIPHER_SPEC
;
858 s
->s3
.tmp
.message_size
= readbytes
- 1;
859 *len
= readbytes
- 1;
863 /* Handshake fails if message header is incomplete */
864 if (readbytes
!= DTLS1_HM_HEADER_LENGTH
) {
865 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
869 /* parse the message fragment header */
870 dtls1_get_message_header(wire
, &msg_hdr
);
872 mlen
= msg_hdr
.msg_len
;
873 frag_off
= msg_hdr
.frag_off
;
874 frag_len
= msg_hdr
.frag_len
;
877 * We must have at least frag_len bytes left in the record to be read.
878 * Fragments must not span records.
880 if (frag_len
> s
->rlayer
.tlsrecs
[s
->rlayer
.curr_rec
].length
) {
881 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_BAD_LENGTH
);
886 * if this is a future (or stale) message it gets buffered
887 * (or dropped)--no further processing at this time
888 * While listening, we accept seq 1 (ClientHello with cookie)
889 * although we're still expecting seq 0 (ClientHello)
891 if (msg_hdr
.seq
!= s
->d1
->handshake_read_seq
) {
894 || s
->d1
->handshake_read_seq
!= 1
895 || wire
[0] != SSL3_MT_CLIENT_HELLO
896 || s
->statem
.hand_state
!= DTLS_ST_SW_HELLO_VERIFY_REQUEST
) {
897 *errtype
= dtls1_process_out_of_seq_message(s
, &msg_hdr
);
901 * We received a ClientHello and sent back a HelloVerifyRequest. We
902 * now seem to have received a retransmitted initial ClientHello. That
903 * is allowed (possibly our HelloVerifyRequest got lost).
908 if (frag_len
&& frag_len
< mlen
) {
909 *errtype
= dtls1_reassemble_fragment(s
, &msg_hdr
);
914 && s
->d1
->r_msg_hdr
.frag_off
== 0
915 && s
->statem
.hand_state
!= TLS_ST_OK
916 && wire
[0] == SSL3_MT_HELLO_REQUEST
) {
918 * The server may always send 'Hello Request' messages -- we are
919 * doing a handshake anyway now, so ignore them if their format is
920 * correct. Does not count for 'Finished' MAC.
922 if (wire
[1] == 0 && wire
[2] == 0 && wire
[3] == 0) {
924 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
925 wire
, DTLS1_HM_HEADER_LENGTH
, ssl
,
926 s
->msg_callback_arg
);
930 } else { /* Incorrectly formatted Hello request */
932 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
937 if (!dtls1_preprocess_fragment(s
, &msg_hdr
)) {
938 /* SSLfatal() already called */
944 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
946 i
= ssl
->method
->ssl_read_bytes(ssl
, SSL3_RT_HANDSHAKE
, NULL
,
947 &p
[frag_off
], frag_len
, 0, &readbytes
);
950 * This shouldn't ever fail due to NBIO because we already checked
951 * that we have enough data in the record
954 s
->rwstate
= SSL_READING
;
963 * XDTLS: an incorrectly formatted fragment should cause the handshake
966 if (readbytes
!= frag_len
) {
967 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_BAD_LENGTH
);
973 * We got a new ClientHello with a message sequence of 0.
974 * Reset the read/write sequences back to the beginning.
975 * We process it like this is the first time we've seen a ClientHello
978 s
->d1
->handshake_read_seq
= 0;
979 s
->d1
->next_handshake_write_seq
= 0;
983 * Note that s->init_num is *not* used as current offset in
984 * s->init_buf->data, but as a counter summing up fragments' lengths: as
985 * soon as they sum up to handshake packet length, we assume we have got
988 *len
= s
->init_num
= frag_len
;
998 * for these 2 messages, we need to
999 * ssl->enc_read_ctx re-init
1000 * ssl->s3.read_mac_secret re-init
1001 * ssl->session->read_sym_enc assign
1002 * ssl->session->read_compression assign
1003 * ssl->session->read_hash assign
1005 CON_FUNC_RETURN
dtls_construct_change_cipher_spec(SSL_CONNECTION
*s
,
1008 if (s
->version
== DTLS1_BAD_VER
) {
1009 s
->d1
->next_handshake_write_seq
++;
1011 if (!WPACKET_put_bytes_u16(pkt
, s
->d1
->handshake_write_seq
)) {
1012 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1013 return CON_FUNC_ERROR
;
1017 return CON_FUNC_SUCCESS
;
1020 #ifndef OPENSSL_NO_SCTP
1022 * Wait for a dry event. Should only be called at a point in the handshake
1023 * where we are not expecting any data from the peer except an alert.
1025 WORK_STATE
dtls_wait_for_dry(SSL_CONNECTION
*s
)
1029 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
1031 /* read app data until dry event */
1032 ret
= BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(ssl
));
1034 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1040 * We're not expecting any more messages from the peer at this point -
1041 * but we could get an alert. If an alert is waiting then we will never
1042 * return successfully. Therefore we attempt to read a message. This
1043 * should never succeed but will process any waiting alerts.
1045 if (dtls_get_reassembled_message(s
, &errtype
, &len
)) {
1046 /* The call succeeded! This should never happen */
1047 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
1051 s
->s3
.in_read_app_data
= 2;
1052 s
->rwstate
= SSL_READING
;
1053 BIO_clear_retry_flags(SSL_get_rbio(ssl
));
1054 BIO_set_retry_read(SSL_get_rbio(ssl
));
1057 return WORK_FINISHED_CONTINUE
;
1061 int dtls1_read_failed(SSL_CONNECTION
*s
, int code
)
1063 SSL
*ssl
= SSL_CONNECTION_GET_SSL(s
);
1066 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1070 if (!dtls1_is_timer_expired(s
) || ossl_statem_in_error(s
)) {
1072 * not a timeout, none of our business, let higher layers handle
1073 * this. in fact it's probably an error
1077 /* done, no need to send a retransmit */
1078 if (!SSL_in_init(ssl
))
1080 BIO_set_flags(SSL_get_rbio(ssl
), BIO_FLAGS_READ
);
1084 return dtls1_handle_timeout(s
);
1087 int dtls1_get_queue_priority(unsigned short seq
, int is_ccs
)
1090 * The index of the retransmission queue actually is the message sequence
1091 * number, since the queue only contains messages of a single handshake.
1092 * However, the ChangeCipherSpec has no message sequence number and so
1093 * using only the sequence will result in the CCS and Finished having the
1094 * same index. To prevent this, the sequence number is multiplied by 2.
1095 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1096 * Finished, it also maintains the order of the index (important for
1097 * priority queues) and fits in the unsigned short variable.
1099 return seq
* 2 - is_ccs
;
1102 int dtls1_retransmit_buffered_messages(SSL_CONNECTION
*s
)
1104 pqueue
*sent
= s
->d1
->sent_messages
;
1110 iter
= pqueue_iterator(sent
);
1112 for (item
= pqueue_next(&iter
); item
!= NULL
; item
= pqueue_next(&iter
)) {
1113 frag
= (hm_fragment
*)item
->data
;
1114 if (dtls1_retransmit_message(s
, (unsigned short)
1115 dtls1_get_queue_priority
1116 (frag
->msg_header
.seq
,
1117 frag
->msg_header
.is_ccs
), &found
) <= 0)
1124 int dtls1_buffer_message(SSL_CONNECTION
*s
, int is_ccs
)
1128 unsigned char seq64be
[8];
1131 * this function is called immediately after a message has been
1134 if (!ossl_assert(s
->init_off
== 0))
1137 frag
= dtls1_hm_fragment_new(s
->init_num
, 0);
1141 memcpy(frag
->fragment
, s
->init_buf
->data
, s
->init_num
);
1144 /* For DTLS1_BAD_VER the header length is non-standard */
1145 if (!ossl_assert(s
->d1
->w_msg_hdr
.msg_len
+
1147 DTLS1_BAD_VER
) ? 3 : DTLS1_CCS_HEADER_LENGTH
)
1148 == (unsigned int)s
->init_num
)) {
1149 dtls1_hm_fragment_free(frag
);
1153 if (!ossl_assert(s
->d1
->w_msg_hdr
.msg_len
+
1154 DTLS1_HM_HEADER_LENGTH
== (unsigned int)s
->init_num
)) {
1155 dtls1_hm_fragment_free(frag
);
1160 frag
->msg_header
.msg_len
= s
->d1
->w_msg_hdr
.msg_len
;
1161 frag
->msg_header
.seq
= s
->d1
->w_msg_hdr
.seq
;
1162 frag
->msg_header
.type
= s
->d1
->w_msg_hdr
.type
;
1163 frag
->msg_header
.frag_off
= 0;
1164 frag
->msg_header
.frag_len
= s
->d1
->w_msg_hdr
.msg_len
;
1165 frag
->msg_header
.is_ccs
= is_ccs
;
1167 /* save current state */
1168 frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
= s
->enc_write_ctx
;
1169 frag
->msg_header
.saved_retransmit_state
.write_hash
= s
->write_hash
;
1170 frag
->msg_header
.saved_retransmit_state
.compress
= s
->compress
;
1171 frag
->msg_header
.saved_retransmit_state
.session
= s
->session
;
1172 frag
->msg_header
.saved_retransmit_state
.epoch
=
1173 DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1175 memset(seq64be
, 0, sizeof(seq64be
));
1178 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1179 frag
->msg_header
.is_ccs
) >> 8);
1182 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1183 frag
->msg_header
.is_ccs
));
1185 item
= pitem_new(seq64be
, frag
);
1187 dtls1_hm_fragment_free(frag
);
1191 pqueue_insert(s
->d1
->sent_messages
, item
);
1195 int dtls1_retransmit_message(SSL_CONNECTION
*s
, unsigned short seq
, int *found
)
1198 /* XDTLS: for now assuming that read/writes are blocking */
1201 unsigned long header_length
;
1202 unsigned char seq64be
[8];
1203 struct dtls1_retransmit_state saved_state
;
1205 /* XDTLS: the requested message ought to be found, otherwise error */
1206 memset(seq64be
, 0, sizeof(seq64be
));
1207 seq64be
[6] = (unsigned char)(seq
>> 8);
1208 seq64be
[7] = (unsigned char)seq
;
1210 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1212 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1218 frag
= (hm_fragment
*)item
->data
;
1220 if (frag
->msg_header
.is_ccs
)
1221 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1223 header_length
= DTLS1_HM_HEADER_LENGTH
;
1225 memcpy(s
->init_buf
->data
, frag
->fragment
,
1226 frag
->msg_header
.msg_len
+ header_length
);
1227 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1229 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1230 frag
->msg_header
.msg_len
,
1231 frag
->msg_header
.seq
, 0,
1232 frag
->msg_header
.frag_len
);
1234 /* save current state */
1235 saved_state
.enc_write_ctx
= s
->enc_write_ctx
;
1236 saved_state
.write_hash
= s
->write_hash
;
1237 saved_state
.compress
= s
->compress
;
1238 saved_state
.session
= s
->session
;
1239 saved_state
.epoch
= DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1241 s
->d1
->retransmitting
= 1;
1243 /* restore state in which the message was originally sent */
1244 s
->enc_write_ctx
= frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
;
1245 s
->write_hash
= frag
->msg_header
.saved_retransmit_state
.write_hash
;
1246 s
->compress
= frag
->msg_header
.saved_retransmit_state
.compress
;
1247 s
->session
= frag
->msg_header
.saved_retransmit_state
.session
;
1248 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
,
1250 saved_retransmit_state
.epoch
);
1252 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1253 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1255 /* restore current state */
1256 s
->enc_write_ctx
= saved_state
.enc_write_ctx
;
1257 s
->write_hash
= saved_state
.write_hash
;
1258 s
->compress
= saved_state
.compress
;
1259 s
->session
= saved_state
.session
;
1260 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
, saved_state
.epoch
);
1262 s
->d1
->retransmitting
= 0;
1264 (void)BIO_flush(s
->wbio
);
1268 void dtls1_set_message_header(SSL_CONNECTION
*s
,
1269 unsigned char mt
, size_t len
,
1270 size_t frag_off
, size_t frag_len
)
1272 if (frag_off
== 0) {
1273 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1274 s
->d1
->next_handshake_write_seq
++;
1277 dtls1_set_message_header_int(s
, mt
, len
, s
->d1
->handshake_write_seq
,
1278 frag_off
, frag_len
);
1281 /* don't actually do the writing, wait till the MTU has been retrieved */
1283 dtls1_set_message_header_int(SSL_CONNECTION
*s
, unsigned char mt
,
1284 size_t len
, unsigned short seq_num
,
1285 size_t frag_off
, size_t frag_len
)
1287 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1290 msg_hdr
->msg_len
= len
;
1291 msg_hdr
->seq
= seq_num
;
1292 msg_hdr
->frag_off
= frag_off
;
1293 msg_hdr
->frag_len
= frag_len
;
1297 dtls1_fix_message_header(SSL_CONNECTION
*s
, size_t frag_off
, size_t frag_len
)
1299 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1301 msg_hdr
->frag_off
= frag_off
;
1302 msg_hdr
->frag_len
= frag_len
;
1305 static unsigned char *dtls1_write_message_header(SSL_CONNECTION
*s
,
1308 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1310 *p
++ = msg_hdr
->type
;
1311 l2n3(msg_hdr
->msg_len
, p
);
1313 s2n(msg_hdr
->seq
, p
);
1314 l2n3(msg_hdr
->frag_off
, p
);
1315 l2n3(msg_hdr
->frag_len
, p
);
1320 void dtls1_get_message_header(unsigned char *data
, struct hm_header_st
*msg_hdr
)
1322 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
1323 msg_hdr
->type
= *(data
++);
1324 n2l3(data
, msg_hdr
->msg_len
);
1326 n2s(data
, msg_hdr
->seq
);
1327 n2l3(data
, msg_hdr
->frag_off
);
1328 n2l3(data
, msg_hdr
->frag_len
);
1331 int dtls1_set_handshake_header(SSL_CONNECTION
*s
, WPACKET
*pkt
, int htype
)
1333 unsigned char *header
;
1335 if (htype
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
1336 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1337 dtls1_set_message_header_int(s
, SSL3_MT_CCS
, 0,
1338 s
->d1
->handshake_write_seq
, 0, 0);
1339 if (!WPACKET_put_bytes_u8(pkt
, SSL3_MT_CCS
))
1342 dtls1_set_message_header(s
, htype
, 0, 0, 0);
1344 * We allocate space at the start for the message header. This gets
1347 if (!WPACKET_allocate_bytes(pkt
, DTLS1_HM_HEADER_LENGTH
, &header
)
1348 || !WPACKET_start_sub_packet(pkt
))
1355 int dtls1_close_construct_packet(SSL_CONNECTION
*s
, WPACKET
*pkt
, int htype
)
1359 if ((htype
!= SSL3_MT_CHANGE_CIPHER_SPEC
&& !WPACKET_close(pkt
))
1360 || !WPACKET_get_length(pkt
, &msglen
)
1361 || msglen
> INT_MAX
)
1364 if (htype
!= SSL3_MT_CHANGE_CIPHER_SPEC
) {
1365 s
->d1
->w_msg_hdr
.msg_len
= msglen
- DTLS1_HM_HEADER_LENGTH
;
1366 s
->d1
->w_msg_hdr
.frag_len
= msglen
- DTLS1_HM_HEADER_LENGTH
;
1368 s
->init_num
= (int)msglen
;
1371 if (htype
!= DTLS1_MT_HELLO_VERIFY_REQUEST
) {
1372 /* Buffer the message to handle re-xmits */
1373 if (!dtls1_buffer_message(s
, htype
== SSL3_MT_CHANGE_CIPHER_SPEC