2 * Copyright 2005-2020 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
*s
, size_t frag_off
,
48 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
);
49 static void dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
51 unsigned short seq_num
,
54 static int dtls_get_reassembled_message(SSL
*s
, int *errtype
, size_t *len
);
56 static hm_fragment
*dtls1_hm_fragment_new(size_t frag_len
, int reassembly
)
58 hm_fragment
*frag
= NULL
;
59 unsigned char *buf
= NULL
;
60 unsigned char *bitmask
= NULL
;
62 if ((frag
= OPENSSL_malloc(sizeof(*frag
))) == NULL
) {
63 SSLerr(SSL_F_DTLS1_HM_FRAGMENT_NEW
, ERR_R_MALLOC_FAILURE
);
68 if ((buf
= OPENSSL_malloc(frag_len
)) == NULL
) {
69 SSLerr(SSL_F_DTLS1_HM_FRAGMENT_NEW
, ERR_R_MALLOC_FAILURE
);
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
) {
82 SSLerr(SSL_F_DTLS1_HM_FRAGMENT_NEW
, ERR_R_MALLOC_FAILURE
);
89 frag
->reassembly
= bitmask
;
94 void dtls1_hm_fragment_free(hm_fragment
*frag
)
98 if (frag
->msg_header
.is_ccs
) {
99 EVP_CIPHER_CTX_free(frag
->msg_header
.
100 saved_retransmit_state
.enc_write_ctx
);
101 EVP_MD_CTX_free(frag
->msg_header
.saved_retransmit_state
.write_hash
);
103 OPENSSL_free(frag
->fragment
);
104 OPENSSL_free(frag
->reassembly
);
109 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
110 * SSL3_RT_CHANGE_CIPHER_SPEC)
112 int dtls1_do_write(SSL
*s
, int type
)
118 size_t len
, frag_off
, mac_size
, blocksize
, used_len
;
120 if (!dtls1_query_mtu(s
))
123 if (s
->d1
->mtu
< dtls1_min_mtu(s
))
124 /* should have something reasonable now */
127 if (s
->init_off
== 0 && type
== SSL3_RT_HANDSHAKE
) {
128 if (!ossl_assert(s
->init_num
==
129 s
->d1
->w_msg_hdr
.msg_len
+ DTLS1_HM_HEADER_LENGTH
))
135 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s
->enc_write_ctx
)) &
136 EVP_CIPH_FLAG_AEAD_CIPHER
) != 0)
139 mac_size
= EVP_MD_CTX_size(s
->write_hash
);
143 if (s
->enc_write_ctx
&&
144 (EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_CBC_MODE
))
145 blocksize
= 2 * EVP_CIPHER_CTX_block_size(s
->enc_write_ctx
);
150 s
->rwstate
= SSL_NOTHING
;
152 /* s->init_num shouldn't ever be < 0...but just in case */
153 while (s
->init_num
> 0) {
154 if (type
== SSL3_RT_HANDSHAKE
&& s
->init_off
!= 0) {
155 /* We must be writing a fragment other than the first one */
158 /* This is the first attempt at writing out this fragment */
160 if (s
->init_off
<= DTLS1_HM_HEADER_LENGTH
) {
162 * Each fragment that was already sent must at least have
163 * contained the message header plus one other byte.
164 * Therefore |init_off| must have progressed by at least
165 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
172 * Adjust |init_off| and |init_num| to allow room for a new
173 * message header for this fragment.
175 s
->init_off
-= DTLS1_HM_HEADER_LENGTH
;
176 s
->init_num
+= DTLS1_HM_HEADER_LENGTH
;
179 * We must have been called again after a retry so use the
180 * fragment offset from our last attempt. We do not need
181 * to adjust |init_off| and |init_num| as above, because
182 * that should already have been done before the retry.
184 frag_off
= s
->d1
->w_msg_hdr
.frag_off
;
188 used_len
= BIO_wpending(s
->wbio
) + DTLS1_RT_HEADER_LENGTH
189 + mac_size
+ blocksize
;
190 if (s
->d1
->mtu
> used_len
)
191 curr_mtu
= s
->d1
->mtu
- used_len
;
195 if (curr_mtu
<= DTLS1_HM_HEADER_LENGTH
) {
197 * grr.. we could get an error if MTU picked was wrong
199 ret
= BIO_flush(s
->wbio
);
201 s
->rwstate
= SSL_WRITING
;
204 used_len
= DTLS1_RT_HEADER_LENGTH
+ mac_size
+ blocksize
;
205 if (s
->d1
->mtu
> used_len
+ DTLS1_HM_HEADER_LENGTH
) {
206 curr_mtu
= s
->d1
->mtu
- used_len
;
208 /* Shouldn't happen */
214 * We just checked that s->init_num > 0 so this cast should be safe
216 if (((unsigned int)s
->init_num
) > curr_mtu
)
221 if (len
> s
->max_send_fragment
)
222 len
= s
->max_send_fragment
;
225 * XDTLS: this function is too long. split out the CCS part
227 if (type
== SSL3_RT_HANDSHAKE
) {
228 if (len
< DTLS1_HM_HEADER_LENGTH
) {
230 * len is so small that we really can't do anything sensible
235 dtls1_fix_message_header(s
, frag_off
, len
- DTLS1_HM_HEADER_LENGTH
);
237 dtls1_write_message_header(s
,
238 (unsigned char *)&s
->init_buf
->
242 ret
= dtls1_write_bytes(s
, type
, &s
->init_buf
->data
[s
->init_off
], len
,
246 * might need to update MTU here, but we don't know which
247 * previous packet caused the failure -- so can't really
248 * retransmit anything. continue as if everything is fine and
249 * wait for an alert to handle the retransmit
251 if (retry
&& BIO_ctrl(SSL_get_wbio(s
),
252 BIO_CTRL_DGRAM_MTU_EXCEEDED
, 0, NULL
) > 0) {
253 if (!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
)) {
254 if (!dtls1_query_mtu(s
))
256 /* Have one more go */
266 * bad if this assert fails, only part of the handshake message
267 * got sent. but why would this happen?
269 if (!ossl_assert(len
== written
))
272 if (type
== SSL3_RT_HANDSHAKE
&& !s
->d1
->retransmitting
) {
274 * should not be done for 'Hello Request's, but in that case
275 * we'll ignore the result anyway
278 (unsigned char *)&s
->init_buf
->data
[s
->init_off
];
279 const struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
282 if (frag_off
== 0 && s
->version
!= DTLS1_BAD_VER
) {
284 * reconstruct message header is if it is being sent in
287 *p
++ = msg_hdr
->type
;
288 l2n3(msg_hdr
->msg_len
, p
);
289 s2n(msg_hdr
->seq
, p
);
291 l2n3(msg_hdr
->msg_len
, p
);
292 p
-= DTLS1_HM_HEADER_LENGTH
;
295 p
+= DTLS1_HM_HEADER_LENGTH
;
296 xlen
= written
- DTLS1_HM_HEADER_LENGTH
;
299 if (!ssl3_finish_mac(s
, p
, xlen
))
303 if (written
== s
->init_num
) {
305 s
->msg_callback(1, s
->version
, type
, s
->init_buf
->data
,
306 (size_t)(s
->init_off
+ s
->init_num
), s
,
307 s
->msg_callback_arg
);
309 s
->init_off
= 0; /* done writing this message */
314 s
->init_off
+= written
;
315 s
->init_num
-= written
;
316 written
-= DTLS1_HM_HEADER_LENGTH
;
320 * We save the fragment offset for the next fragment so we have it
321 * available in case of an IO retry. We don't know the length of the
322 * next fragment yet so just set that to 0 for now. It will be
323 * updated again later.
325 dtls1_fix_message_header(s
, frag_off
, 0);
331 int dtls_get_message(SSL
*s
, int *mt
, size_t *len
)
333 struct hm_header_st
*msg_hdr
;
339 msg_hdr
= &s
->d1
->r_msg_hdr
;
340 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
343 if (!dtls_get_reassembled_message(s
, &errtype
, &tmplen
)) {
344 if (errtype
== DTLS1_HM_BAD_FRAGMENT
345 || errtype
== DTLS1_HM_FRAGMENT_RETRY
) {
346 /* bad fragment received */
352 *mt
= s
->s3
.tmp
.message_type
;
354 p
= (unsigned char *)s
->init_buf
->data
;
357 if (*mt
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
358 if (s
->msg_callback
) {
359 s
->msg_callback(0, s
->version
, SSL3_RT_CHANGE_CIPHER_SPEC
,
360 p
, 1, s
, s
->msg_callback_arg
);
363 * This isn't a real handshake message so skip the processing below.
368 msg_len
= msg_hdr
->msg_len
;
370 /* reconstruct message header */
371 *(p
++) = msg_hdr
->type
;
373 s2n(msg_hdr
->seq
, p
);
376 if (s
->version
!= DTLS1_BAD_VER
) {
377 p
-= DTLS1_HM_HEADER_LENGTH
;
378 msg_len
+= DTLS1_HM_HEADER_LENGTH
;
382 * If receiving Finished, record MAC of prior handshake messages for
383 * Finished verification.
385 if (*mt
== SSL3_MT_FINISHED
&& !ssl3_take_mac(s
)) {
386 /* SSLfatal() already called */
390 if (!ssl3_finish_mac(s
, p
, msg_len
))
393 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
394 p
, msg_len
, s
, s
->msg_callback_arg
);
396 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
398 s
->d1
->handshake_read_seq
++;
400 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
406 * dtls1_max_handshake_message_len returns the maximum number of bytes
407 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
408 * may be greater if the maximum certificate list size requires it.
410 static size_t dtls1_max_handshake_message_len(const SSL
*s
)
412 size_t max_len
= DTLS1_HM_HEADER_LENGTH
+ SSL3_RT_MAX_ENCRYPTED_LENGTH
;
413 if (max_len
< s
->max_cert_list
)
414 return s
->max_cert_list
;
418 static int dtls1_preprocess_fragment(SSL
*s
, struct hm_header_st
*msg_hdr
)
420 size_t frag_off
, frag_len
, msg_len
;
422 msg_len
= msg_hdr
->msg_len
;
423 frag_off
= msg_hdr
->frag_off
;
424 frag_len
= msg_hdr
->frag_len
;
426 /* sanity checking */
427 if ((frag_off
+ frag_len
) > msg_len
428 || msg_len
> dtls1_max_handshake_message_len(s
)) {
429 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_F_DTLS1_PREPROCESS_FRAGMENT
,
430 SSL_R_EXCESSIVE_MESSAGE_SIZE
);
434 if (s
->d1
->r_msg_hdr
.frag_off
== 0) { /* first fragment */
436 * msg_len is limited to 2^24, but is effectively checked against
437 * dtls_max_handshake_message_len(s) above
439 if (!BUF_MEM_grow_clean(s
->init_buf
, msg_len
+ DTLS1_HM_HEADER_LENGTH
)) {
440 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_DTLS1_PREPROCESS_FRAGMENT
,
445 s
->s3
.tmp
.message_size
= msg_len
;
446 s
->d1
->r_msg_hdr
.msg_len
= msg_len
;
447 s
->s3
.tmp
.message_type
= msg_hdr
->type
;
448 s
->d1
->r_msg_hdr
.type
= msg_hdr
->type
;
449 s
->d1
->r_msg_hdr
.seq
= msg_hdr
->seq
;
450 } else if (msg_len
!= s
->d1
->r_msg_hdr
.msg_len
) {
452 * They must be playing with us! BTW, failure to enforce upper limit
453 * would open possibility for buffer overrun.
455 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_F_DTLS1_PREPROCESS_FRAGMENT
,
456 SSL_R_EXCESSIVE_MESSAGE_SIZE
);
464 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a
467 static int dtls1_retrieve_buffered_fragment(SSL
*s
, size_t *len
)
470 * (0) check whether the desired fragment is available
472 * (1) copy over the fragment to s->init_buf->data[]
473 * (2) update s->init_num
480 item
= pqueue_peek(s
->d1
->buffered_messages
);
484 frag
= (hm_fragment
*)item
->data
;
486 if (frag
->msg_header
.seq
< s
->d1
->handshake_read_seq
) {
487 /* This is a stale message that has been buffered so clear it */
488 pqueue_pop(s
->d1
->buffered_messages
);
489 dtls1_hm_fragment_free(frag
);
494 } while (item
== NULL
);
496 /* Don't return if reassembly still in progress */
497 if (frag
->reassembly
!= NULL
)
500 if (s
->d1
->handshake_read_seq
== frag
->msg_header
.seq
) {
501 size_t frag_len
= frag
->msg_header
.frag_len
;
502 pqueue_pop(s
->d1
->buffered_messages
);
504 /* Calls SSLfatal() as required */
505 ret
= dtls1_preprocess_fragment(s
, &frag
->msg_header
);
507 if (ret
&& frag
->msg_header
.frag_len
> 0) {
509 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
510 memcpy(&p
[frag
->msg_header
.frag_off
], frag
->fragment
,
511 frag
->msg_header
.frag_len
);
514 dtls1_hm_fragment_free(frag
);
531 dtls1_reassemble_fragment(SSL
*s
, const struct hm_header_st
*msg_hdr
)
533 hm_fragment
*frag
= NULL
;
535 int i
= -1, is_complete
;
536 unsigned char seq64be
[8];
537 size_t frag_len
= msg_hdr
->frag_len
;
540 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
||
541 msg_hdr
->msg_len
> dtls1_max_handshake_message_len(s
))
545 return DTLS1_HM_FRAGMENT_RETRY
;
548 /* Try to find item in queue */
549 memset(seq64be
, 0, sizeof(seq64be
));
550 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
551 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
552 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
555 frag
= dtls1_hm_fragment_new(msg_hdr
->msg_len
, 1);
558 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
559 frag
->msg_header
.frag_len
= frag
->msg_header
.msg_len
;
560 frag
->msg_header
.frag_off
= 0;
562 frag
= (hm_fragment
*)item
->data
;
563 if (frag
->msg_header
.msg_len
!= msg_hdr
->msg_len
) {
571 * If message is already reassembled, this must be a retransmit and can
572 * be dropped. In this case item != NULL and so frag does not need to be
575 if (frag
->reassembly
== NULL
) {
576 unsigned char devnull
[256];
579 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
582 sizeof(devnull
) ? sizeof(devnull
) :
583 frag_len
, 0, &readbytes
);
586 frag_len
-= readbytes
;
588 return DTLS1_HM_FRAGMENT_RETRY
;
591 /* read the body of the fragment (header has already been read */
592 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
593 frag
->fragment
+ msg_hdr
->frag_off
,
594 frag_len
, 0, &readbytes
);
595 if (i
<= 0 || readbytes
!= frag_len
)
600 RSMBLY_BITMASK_MARK(frag
->reassembly
, (long)msg_hdr
->frag_off
,
601 (long)(msg_hdr
->frag_off
+ frag_len
));
603 if (!ossl_assert(msg_hdr
->msg_len
> 0))
605 RSMBLY_BITMASK_IS_COMPLETE(frag
->reassembly
, (long)msg_hdr
->msg_len
,
609 OPENSSL_free(frag
->reassembly
);
610 frag
->reassembly
= NULL
;
614 item
= pitem_new(seq64be
, frag
);
620 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
622 * pqueue_insert fails iff a duplicate item is inserted. However,
623 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
624 * would have returned it and control would never have reached this
627 if (!ossl_assert(item
!= NULL
))
631 return DTLS1_HM_FRAGMENT_RETRY
;
635 dtls1_hm_fragment_free(frag
);
640 dtls1_process_out_of_seq_message(SSL
*s
, const struct hm_header_st
*msg_hdr
)
643 hm_fragment
*frag
= NULL
;
645 unsigned char seq64be
[8];
646 size_t frag_len
= msg_hdr
->frag_len
;
649 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
)
652 /* Try to find item in queue, to prevent duplicate entries */
653 memset(seq64be
, 0, sizeof(seq64be
));
654 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
655 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
656 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
659 * If we already have an entry and this one is a fragment, don't discard
660 * it and rather try to reassemble it.
662 if (item
!= NULL
&& frag_len
!= msg_hdr
->msg_len
)
666 * Discard the message if sequence number was already there, is too far
667 * in the future, already in the queue or if we received a FINISHED
668 * before the SERVER_HELLO, which then must be a stale retransmit.
670 if (msg_hdr
->seq
<= s
->d1
->handshake_read_seq
||
671 msg_hdr
->seq
> s
->d1
->handshake_read_seq
+ 10 || item
!= NULL
||
672 (s
->d1
->handshake_read_seq
== 0 && msg_hdr
->type
== SSL3_MT_FINISHED
)) {
673 unsigned char devnull
[256];
676 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
679 sizeof(devnull
) ? sizeof(devnull
) :
680 frag_len
, 0, &readbytes
);
683 frag_len
-= readbytes
;
686 if (frag_len
!= msg_hdr
->msg_len
) {
687 return dtls1_reassemble_fragment(s
, msg_hdr
);
690 if (frag_len
> dtls1_max_handshake_message_len(s
))
693 frag
= dtls1_hm_fragment_new(frag_len
, 0);
697 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
701 * read the body of the fragment (header has already been read
703 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
704 frag
->fragment
, frag_len
, 0,
706 if (i
<=0 || readbytes
!= frag_len
)
712 item
= pitem_new(seq64be
, frag
);
716 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
718 * pqueue_insert fails iff a duplicate item is inserted. However,
719 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
720 * would have returned it. Then, either |frag_len| !=
721 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
722 * have been processed with |dtls1_reassemble_fragment|, above, or
723 * the record will have been discarded.
725 if (!ossl_assert(item
!= NULL
))
729 return DTLS1_HM_FRAGMENT_RETRY
;
733 dtls1_hm_fragment_free(frag
);
737 static int dtls_get_reassembled_message(SSL
*s
, int *errtype
, size_t *len
)
739 unsigned char wire
[DTLS1_HM_HEADER_LENGTH
];
740 size_t mlen
, frag_off
, frag_len
;
741 int i
, ret
, recvd_type
;
742 struct hm_header_st msg_hdr
;
748 /* see if we have the required fragment already */
749 ret
= dtls1_retrieve_buffered_fragment(s
, &frag_len
);
751 /* SSLfatal() already called */
755 s
->init_num
= frag_len
;
760 /* read handshake message header */
761 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, &recvd_type
, wire
,
762 DTLS1_HM_HEADER_LENGTH
, 0, &readbytes
);
763 if (i
<= 0) { /* nbio, or an error */
764 s
->rwstate
= SSL_READING
;
768 if (recvd_type
== SSL3_RT_CHANGE_CIPHER_SPEC
) {
769 if (wire
[0] != SSL3_MT_CCS
) {
770 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
,
771 SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
,
772 SSL_R_BAD_CHANGE_CIPHER_SPEC
);
776 memcpy(s
->init_buf
->data
, wire
, readbytes
);
777 s
->init_num
= readbytes
- 1;
778 s
->init_msg
= s
->init_buf
->data
+ 1;
779 s
->s3
.tmp
.message_type
= SSL3_MT_CHANGE_CIPHER_SPEC
;
780 s
->s3
.tmp
.message_size
= readbytes
- 1;
781 *len
= readbytes
- 1;
785 /* Handshake fails if message header is incomplete */
786 if (readbytes
!= DTLS1_HM_HEADER_LENGTH
) {
787 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
,
788 SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
792 /* parse the message fragment header */
793 dtls1_get_message_header(wire
, &msg_hdr
);
795 mlen
= msg_hdr
.msg_len
;
796 frag_off
= msg_hdr
.frag_off
;
797 frag_len
= msg_hdr
.frag_len
;
800 * We must have at least frag_len bytes left in the record to be read.
801 * Fragments must not span records.
803 if (frag_len
> RECORD_LAYER_get_rrec_length(&s
->rlayer
)) {
804 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
,
805 SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL_R_BAD_LENGTH
);
810 * if this is a future (or stale) message it gets buffered
811 * (or dropped)--no further processing at this time
812 * While listening, we accept seq 1 (ClientHello with cookie)
813 * although we're still expecting seq 0 (ClientHello)
815 if (msg_hdr
.seq
!= s
->d1
->handshake_read_seq
) {
816 *errtype
= dtls1_process_out_of_seq_message(s
, &msg_hdr
);
820 if (frag_len
&& frag_len
< mlen
) {
821 *errtype
= dtls1_reassemble_fragment(s
, &msg_hdr
);
826 && s
->d1
->r_msg_hdr
.frag_off
== 0
827 && s
->statem
.hand_state
!= TLS_ST_OK
828 && wire
[0] == SSL3_MT_HELLO_REQUEST
) {
830 * The server may always send 'Hello Request' messages -- we are
831 * doing a handshake anyway now, so ignore them if their format is
832 * correct. Does not count for 'Finished' MAC.
834 if (wire
[1] == 0 && wire
[2] == 0 && wire
[3] == 0) {
836 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
837 wire
, DTLS1_HM_HEADER_LENGTH
, s
,
838 s
->msg_callback_arg
);
842 } else { /* Incorrectly formatted Hello request */
844 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
,
845 SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
,
846 SSL_R_UNEXPECTED_MESSAGE
);
851 if (!dtls1_preprocess_fragment(s
, &msg_hdr
)) {
852 /* SSLfatal() already called */
858 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
860 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
861 &p
[frag_off
], frag_len
, 0, &readbytes
);
864 * This shouldn't ever fail due to NBIO because we already checked
865 * that we have enough data in the record
868 s
->rwstate
= SSL_READING
;
877 * XDTLS: an incorrectly formatted fragment should cause the handshake
880 if (readbytes
!= frag_len
) {
881 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
,
882 SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL_R_BAD_LENGTH
);
887 * Note that s->init_num is *not* used as current offset in
888 * s->init_buf->data, but as a counter summing up fragments' lengths: as
889 * soon as they sum up to handshake packet length, we assume we have got
892 *len
= s
->init_num
= frag_len
;
902 * for these 2 messages, we need to
903 * ssl->enc_read_ctx re-init
904 * ssl->rlayer.read_sequence zero
905 * ssl->s3.read_mac_secret re-init
906 * ssl->session->read_sym_enc assign
907 * ssl->session->read_compression assign
908 * ssl->session->read_hash assign
910 int dtls_construct_change_cipher_spec(SSL
*s
, WPACKET
*pkt
)
912 if (s
->version
== DTLS1_BAD_VER
) {
913 s
->d1
->next_handshake_write_seq
++;
915 if (!WPACKET_put_bytes_u16(pkt
, s
->d1
->handshake_write_seq
)) {
916 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
917 SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC
,
918 ERR_R_INTERNAL_ERROR
);
926 #ifndef OPENSSL_NO_SCTP
928 * Wait for a dry event. Should only be called at a point in the handshake
929 * where we are not expecting any data from the peer except an alert.
931 WORK_STATE
dtls_wait_for_dry(SSL
*s
)
936 /* read app data until dry event */
937 ret
= BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s
));
939 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_DTLS_WAIT_FOR_DRY
,
940 ERR_R_INTERNAL_ERROR
);
946 * We're not expecting any more messages from the peer at this point -
947 * but we could get an alert. If an alert is waiting then we will never
948 * return successfully. Therefore we attempt to read a message. This
949 * should never succeed but will process any waiting alerts.
951 if (dtls_get_reassembled_message(s
, &errtype
, &len
)) {
952 /* The call succeeded! This should never happen */
953 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_F_DTLS_WAIT_FOR_DRY
,
954 SSL_R_UNEXPECTED_MESSAGE
);
958 s
->s3
.in_read_app_data
= 2;
959 s
->rwstate
= SSL_READING
;
960 BIO_clear_retry_flags(SSL_get_rbio(s
));
961 BIO_set_retry_read(SSL_get_rbio(s
));
964 return WORK_FINISHED_CONTINUE
;
968 int dtls1_read_failed(SSL
*s
, int code
)
971 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
,
972 SSL_F_DTLS1_READ_FAILED
, ERR_R_INTERNAL_ERROR
);
976 if (!dtls1_is_timer_expired(s
) || ossl_statem_in_error(s
)) {
978 * not a timeout, none of our business, let higher layers handle
979 * this. in fact it's probably an error
983 /* done, no need to send a retransmit */
986 BIO_set_flags(SSL_get_rbio(s
), BIO_FLAGS_READ
);
990 return dtls1_handle_timeout(s
);
993 int dtls1_get_queue_priority(unsigned short seq
, int is_ccs
)
996 * The index of the retransmission queue actually is the message sequence
997 * number, since the queue only contains messages of a single handshake.
998 * However, the ChangeCipherSpec has no message sequence number and so
999 * using only the sequence will result in the CCS and Finished having the
1000 * same index. To prevent this, the sequence number is multiplied by 2.
1001 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1002 * Finished, it also maintains the order of the index (important for
1003 * priority queues) and fits in the unsigned short variable.
1005 return seq
* 2 - is_ccs
;
1008 int dtls1_retransmit_buffered_messages(SSL
*s
)
1010 pqueue
*sent
= s
->d1
->sent_messages
;
1016 iter
= pqueue_iterator(sent
);
1018 for (item
= pqueue_next(&iter
); item
!= NULL
; item
= pqueue_next(&iter
)) {
1019 frag
= (hm_fragment
*)item
->data
;
1020 if (dtls1_retransmit_message(s
, (unsigned short)
1021 dtls1_get_queue_priority
1022 (frag
->msg_header
.seq
,
1023 frag
->msg_header
.is_ccs
), &found
) <= 0)
1030 int dtls1_buffer_message(SSL
*s
, int is_ccs
)
1034 unsigned char seq64be
[8];
1037 * this function is called immediately after a message has been
1040 if (!ossl_assert(s
->init_off
== 0))
1043 frag
= dtls1_hm_fragment_new(s
->init_num
, 0);
1047 memcpy(frag
->fragment
, s
->init_buf
->data
, s
->init_num
);
1050 /* For DTLS1_BAD_VER the header length is non-standard */
1051 if (!ossl_assert(s
->d1
->w_msg_hdr
.msg_len
+
1053 DTLS1_BAD_VER
) ? 3 : DTLS1_CCS_HEADER_LENGTH
)
1054 == (unsigned int)s
->init_num
)) {
1055 dtls1_hm_fragment_free(frag
);
1059 if (!ossl_assert(s
->d1
->w_msg_hdr
.msg_len
+
1060 DTLS1_HM_HEADER_LENGTH
== (unsigned int)s
->init_num
)) {
1061 dtls1_hm_fragment_free(frag
);
1066 frag
->msg_header
.msg_len
= s
->d1
->w_msg_hdr
.msg_len
;
1067 frag
->msg_header
.seq
= s
->d1
->w_msg_hdr
.seq
;
1068 frag
->msg_header
.type
= s
->d1
->w_msg_hdr
.type
;
1069 frag
->msg_header
.frag_off
= 0;
1070 frag
->msg_header
.frag_len
= s
->d1
->w_msg_hdr
.msg_len
;
1071 frag
->msg_header
.is_ccs
= is_ccs
;
1073 /* save current state */
1074 frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
= s
->enc_write_ctx
;
1075 frag
->msg_header
.saved_retransmit_state
.write_hash
= s
->write_hash
;
1076 frag
->msg_header
.saved_retransmit_state
.compress
= s
->compress
;
1077 frag
->msg_header
.saved_retransmit_state
.session
= s
->session
;
1078 frag
->msg_header
.saved_retransmit_state
.epoch
=
1079 DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1081 memset(seq64be
, 0, sizeof(seq64be
));
1084 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1085 frag
->msg_header
.is_ccs
) >> 8);
1088 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1089 frag
->msg_header
.is_ccs
));
1091 item
= pitem_new(seq64be
, frag
);
1093 dtls1_hm_fragment_free(frag
);
1097 pqueue_insert(s
->d1
->sent_messages
, item
);
1101 int dtls1_retransmit_message(SSL
*s
, unsigned short seq
, int *found
)
1104 /* XDTLS: for now assuming that read/writes are blocking */
1107 unsigned long header_length
;
1108 unsigned char seq64be
[8];
1109 struct dtls1_retransmit_state saved_state
;
1111 /* XDTLS: the requested message ought to be found, otherwise error */
1112 memset(seq64be
, 0, sizeof(seq64be
));
1113 seq64be
[6] = (unsigned char)(seq
>> 8);
1114 seq64be
[7] = (unsigned char)seq
;
1116 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1118 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, SSL_F_DTLS1_RETRANSMIT_MESSAGE
,
1119 ERR_R_INTERNAL_ERROR
);
1125 frag
= (hm_fragment
*)item
->data
;
1127 if (frag
->msg_header
.is_ccs
)
1128 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1130 header_length
= DTLS1_HM_HEADER_LENGTH
;
1132 memcpy(s
->init_buf
->data
, frag
->fragment
,
1133 frag
->msg_header
.msg_len
+ header_length
);
1134 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1136 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1137 frag
->msg_header
.msg_len
,
1138 frag
->msg_header
.seq
, 0,
1139 frag
->msg_header
.frag_len
);
1141 /* save current state */
1142 saved_state
.enc_write_ctx
= s
->enc_write_ctx
;
1143 saved_state
.write_hash
= s
->write_hash
;
1144 saved_state
.compress
= s
->compress
;
1145 saved_state
.session
= s
->session
;
1146 saved_state
.epoch
= DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1148 s
->d1
->retransmitting
= 1;
1150 /* restore state in which the message was originally sent */
1151 s
->enc_write_ctx
= frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
;
1152 s
->write_hash
= frag
->msg_header
.saved_retransmit_state
.write_hash
;
1153 s
->compress
= frag
->msg_header
.saved_retransmit_state
.compress
;
1154 s
->session
= frag
->msg_header
.saved_retransmit_state
.session
;
1155 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
,
1157 saved_retransmit_state
.epoch
);
1159 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1160 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1162 /* restore current state */
1163 s
->enc_write_ctx
= saved_state
.enc_write_ctx
;
1164 s
->write_hash
= saved_state
.write_hash
;
1165 s
->compress
= saved_state
.compress
;
1166 s
->session
= saved_state
.session
;
1167 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
, saved_state
.epoch
);
1169 s
->d1
->retransmitting
= 0;
1171 (void)BIO_flush(s
->wbio
);
1175 void dtls1_set_message_header(SSL
*s
,
1176 unsigned char mt
, size_t len
,
1177 size_t frag_off
, size_t frag_len
)
1179 if (frag_off
== 0) {
1180 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1181 s
->d1
->next_handshake_write_seq
++;
1184 dtls1_set_message_header_int(s
, mt
, len
, s
->d1
->handshake_write_seq
,
1185 frag_off
, frag_len
);
1188 /* don't actually do the writing, wait till the MTU has been retrieved */
1190 dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
1191 size_t len
, unsigned short seq_num
,
1192 size_t frag_off
, size_t frag_len
)
1194 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1197 msg_hdr
->msg_len
= len
;
1198 msg_hdr
->seq
= seq_num
;
1199 msg_hdr
->frag_off
= frag_off
;
1200 msg_hdr
->frag_len
= frag_len
;
1204 dtls1_fix_message_header(SSL
*s
, size_t frag_off
, size_t frag_len
)
1206 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1208 msg_hdr
->frag_off
= frag_off
;
1209 msg_hdr
->frag_len
= frag_len
;
1212 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
)
1214 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1216 *p
++ = msg_hdr
->type
;
1217 l2n3(msg_hdr
->msg_len
, p
);
1219 s2n(msg_hdr
->seq
, p
);
1220 l2n3(msg_hdr
->frag_off
, p
);
1221 l2n3(msg_hdr
->frag_len
, p
);
1226 void dtls1_get_message_header(unsigned char *data
, struct hm_header_st
*msg_hdr
)
1228 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
1229 msg_hdr
->type
= *(data
++);
1230 n2l3(data
, msg_hdr
->msg_len
);
1232 n2s(data
, msg_hdr
->seq
);
1233 n2l3(data
, msg_hdr
->frag_off
);
1234 n2l3(data
, msg_hdr
->frag_len
);
1237 int dtls1_set_handshake_header(SSL
*s
, WPACKET
*pkt
, int htype
)
1239 unsigned char *header
;
1241 if (htype
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
1242 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1243 dtls1_set_message_header_int(s
, SSL3_MT_CCS
, 0,
1244 s
->d1
->handshake_write_seq
, 0, 0);
1245 if (!WPACKET_put_bytes_u8(pkt
, SSL3_MT_CCS
))
1248 dtls1_set_message_header(s
, htype
, 0, 0, 0);
1250 * We allocate space at the start for the message header. This gets
1253 if (!WPACKET_allocate_bytes(pkt
, DTLS1_HM_HEADER_LENGTH
, &header
)
1254 || !WPACKET_start_sub_packet(pkt
))
1261 int dtls1_close_construct_packet(SSL
*s
, WPACKET
*pkt
, int htype
)
1265 if ((htype
!= SSL3_MT_CHANGE_CIPHER_SPEC
&& !WPACKET_close(pkt
))
1266 || !WPACKET_get_length(pkt
, &msglen
)
1267 || msglen
> INT_MAX
)
1270 if (htype
!= SSL3_MT_CHANGE_CIPHER_SPEC
) {
1271 s
->d1
->w_msg_hdr
.msg_len
= msglen
- DTLS1_HM_HEADER_LENGTH
;
1272 s
->d1
->w_msg_hdr
.frag_len
= msglen
- DTLS1_HM_HEADER_LENGTH
;
1274 s
->init_num
= (int)msglen
;
1277 if (htype
!= DTLS1_MT_HELLO_VERIFY_REQUEST
) {
1278 /* Buffer the message to handle re-xmits */
1279 if (!dtls1_buffer_message(s
, htype
== SSL3_MT_CHANGE_CIPHER_SPEC