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 ERR_raise(ERR_LIB_SSL
, ERR_R_MALLOC_FAILURE
);
68 if ((buf
= OPENSSL_malloc(frag_len
)) == NULL
) {
69 ERR_raise(ERR_LIB_SSL
, 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 ERR_raise(ERR_LIB_SSL
, 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_R_EXCESSIVE_MESSAGE_SIZE
);
433 if (s
->d1
->r_msg_hdr
.frag_off
== 0) { /* first fragment */
435 * msg_len is limited to 2^24, but is effectively checked against
436 * dtls_max_handshake_message_len(s) above
438 if (!BUF_MEM_grow_clean(s
->init_buf
, msg_len
+ DTLS1_HM_HEADER_LENGTH
)) {
439 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_BUF_LIB
);
443 s
->s3
.tmp
.message_size
= msg_len
;
444 s
->d1
->r_msg_hdr
.msg_len
= msg_len
;
445 s
->s3
.tmp
.message_type
= msg_hdr
->type
;
446 s
->d1
->r_msg_hdr
.type
= msg_hdr
->type
;
447 s
->d1
->r_msg_hdr
.seq
= msg_hdr
->seq
;
448 } else if (msg_len
!= s
->d1
->r_msg_hdr
.msg_len
) {
450 * They must be playing with us! BTW, failure to enforce upper limit
451 * would open possibility for buffer overrun.
453 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
461 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a
464 static int dtls1_retrieve_buffered_fragment(SSL
*s
, size_t *len
)
467 * (0) check whether the desired fragment is available
469 * (1) copy over the fragment to s->init_buf->data[]
470 * (2) update s->init_num
477 item
= pqueue_peek(s
->d1
->buffered_messages
);
481 frag
= (hm_fragment
*)item
->data
;
483 if (frag
->msg_header
.seq
< s
->d1
->handshake_read_seq
) {
484 /* This is a stale message that has been buffered so clear it */
485 pqueue_pop(s
->d1
->buffered_messages
);
486 dtls1_hm_fragment_free(frag
);
491 } while (item
== NULL
);
493 /* Don't return if reassembly still in progress */
494 if (frag
->reassembly
!= NULL
)
497 if (s
->d1
->handshake_read_seq
== frag
->msg_header
.seq
) {
498 size_t frag_len
= frag
->msg_header
.frag_len
;
499 pqueue_pop(s
->d1
->buffered_messages
);
501 /* Calls SSLfatal() as required */
502 ret
= dtls1_preprocess_fragment(s
, &frag
->msg_header
);
504 if (ret
&& frag
->msg_header
.frag_len
> 0) {
506 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
507 memcpy(&p
[frag
->msg_header
.frag_off
], frag
->fragment
,
508 frag
->msg_header
.frag_len
);
511 dtls1_hm_fragment_free(frag
);
528 dtls1_reassemble_fragment(SSL
*s
, const struct hm_header_st
*msg_hdr
)
530 hm_fragment
*frag
= NULL
;
532 int i
= -1, is_complete
;
533 unsigned char seq64be
[8];
534 size_t frag_len
= msg_hdr
->frag_len
;
537 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
||
538 msg_hdr
->msg_len
> dtls1_max_handshake_message_len(s
))
542 return DTLS1_HM_FRAGMENT_RETRY
;
545 /* Try to find item in queue */
546 memset(seq64be
, 0, sizeof(seq64be
));
547 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
548 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
549 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
552 frag
= dtls1_hm_fragment_new(msg_hdr
->msg_len
, 1);
555 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
556 frag
->msg_header
.frag_len
= frag
->msg_header
.msg_len
;
557 frag
->msg_header
.frag_off
= 0;
559 frag
= (hm_fragment
*)item
->data
;
560 if (frag
->msg_header
.msg_len
!= msg_hdr
->msg_len
) {
568 * If message is already reassembled, this must be a retransmit and can
569 * be dropped. In this case item != NULL and so frag does not need to be
572 if (frag
->reassembly
== NULL
) {
573 unsigned char devnull
[256];
576 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
579 sizeof(devnull
) ? sizeof(devnull
) :
580 frag_len
, 0, &readbytes
);
583 frag_len
-= readbytes
;
585 return DTLS1_HM_FRAGMENT_RETRY
;
588 /* read the body of the fragment (header has already been read */
589 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
590 frag
->fragment
+ msg_hdr
->frag_off
,
591 frag_len
, 0, &readbytes
);
592 if (i
<= 0 || readbytes
!= frag_len
)
597 RSMBLY_BITMASK_MARK(frag
->reassembly
, (long)msg_hdr
->frag_off
,
598 (long)(msg_hdr
->frag_off
+ frag_len
));
600 if (!ossl_assert(msg_hdr
->msg_len
> 0))
602 RSMBLY_BITMASK_IS_COMPLETE(frag
->reassembly
, (long)msg_hdr
->msg_len
,
606 OPENSSL_free(frag
->reassembly
);
607 frag
->reassembly
= NULL
;
611 item
= pitem_new(seq64be
, frag
);
617 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
619 * pqueue_insert fails iff a duplicate item is inserted. However,
620 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
621 * would have returned it and control would never have reached this
624 if (!ossl_assert(item
!= NULL
))
628 return DTLS1_HM_FRAGMENT_RETRY
;
632 dtls1_hm_fragment_free(frag
);
637 dtls1_process_out_of_seq_message(SSL
*s
, const struct hm_header_st
*msg_hdr
)
640 hm_fragment
*frag
= NULL
;
642 unsigned char seq64be
[8];
643 size_t frag_len
= msg_hdr
->frag_len
;
646 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
)
649 /* Try to find item in queue, to prevent duplicate entries */
650 memset(seq64be
, 0, sizeof(seq64be
));
651 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
652 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
653 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
656 * If we already have an entry and this one is a fragment, don't discard
657 * it and rather try to reassemble it.
659 if (item
!= NULL
&& frag_len
!= msg_hdr
->msg_len
)
663 * Discard the message if sequence number was already there, is too far
664 * in the future, already in the queue or if we received a FINISHED
665 * before the SERVER_HELLO, which then must be a stale retransmit.
667 if (msg_hdr
->seq
<= s
->d1
->handshake_read_seq
||
668 msg_hdr
->seq
> s
->d1
->handshake_read_seq
+ 10 || item
!= NULL
||
669 (s
->d1
->handshake_read_seq
== 0 && msg_hdr
->type
== SSL3_MT_FINISHED
)) {
670 unsigned char devnull
[256];
673 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
676 sizeof(devnull
) ? sizeof(devnull
) :
677 frag_len
, 0, &readbytes
);
680 frag_len
-= readbytes
;
683 if (frag_len
!= msg_hdr
->msg_len
) {
684 return dtls1_reassemble_fragment(s
, msg_hdr
);
687 if (frag_len
> dtls1_max_handshake_message_len(s
))
690 frag
= dtls1_hm_fragment_new(frag_len
, 0);
694 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
698 * read the body of the fragment (header has already been read
700 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
701 frag
->fragment
, frag_len
, 0,
703 if (i
<=0 || readbytes
!= frag_len
)
709 item
= pitem_new(seq64be
, frag
);
713 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
715 * pqueue_insert fails iff a duplicate item is inserted. However,
716 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
717 * would have returned it. Then, either |frag_len| !=
718 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
719 * have been processed with |dtls1_reassemble_fragment|, above, or
720 * the record will have been discarded.
722 if (!ossl_assert(item
!= NULL
))
726 return DTLS1_HM_FRAGMENT_RETRY
;
730 dtls1_hm_fragment_free(frag
);
734 static int dtls_get_reassembled_message(SSL
*s
, int *errtype
, size_t *len
)
736 unsigned char wire
[DTLS1_HM_HEADER_LENGTH
];
737 size_t mlen
, frag_off
, frag_len
;
738 int i
, ret
, recvd_type
;
739 struct hm_header_st msg_hdr
;
745 /* see if we have the required fragment already */
746 ret
= dtls1_retrieve_buffered_fragment(s
, &frag_len
);
748 /* SSLfatal() already called */
752 s
->init_num
= frag_len
;
757 /* read handshake message header */
758 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, &recvd_type
, wire
,
759 DTLS1_HM_HEADER_LENGTH
, 0, &readbytes
);
760 if (i
<= 0) { /* nbio, or an error */
761 s
->rwstate
= SSL_READING
;
765 if (recvd_type
== SSL3_RT_CHANGE_CIPHER_SPEC
) {
766 if (wire
[0] != SSL3_MT_CCS
) {
767 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
,
768 SSL_R_BAD_CHANGE_CIPHER_SPEC
);
772 memcpy(s
->init_buf
->data
, wire
, readbytes
);
773 s
->init_num
= readbytes
- 1;
774 s
->init_msg
= s
->init_buf
->data
+ 1;
775 s
->s3
.tmp
.message_type
= SSL3_MT_CHANGE_CIPHER_SPEC
;
776 s
->s3
.tmp
.message_size
= readbytes
- 1;
777 *len
= readbytes
- 1;
781 /* Handshake fails if message header is incomplete */
782 if (readbytes
!= DTLS1_HM_HEADER_LENGTH
) {
783 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
787 /* parse the message fragment header */
788 dtls1_get_message_header(wire
, &msg_hdr
);
790 mlen
= msg_hdr
.msg_len
;
791 frag_off
= msg_hdr
.frag_off
;
792 frag_len
= msg_hdr
.frag_len
;
795 * We must have at least frag_len bytes left in the record to be read.
796 * Fragments must not span records.
798 if (frag_len
> RECORD_LAYER_get_rrec_length(&s
->rlayer
)) {
799 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_BAD_LENGTH
);
804 * if this is a future (or stale) message it gets buffered
805 * (or dropped)--no further processing at this time
806 * While listening, we accept seq 1 (ClientHello with cookie)
807 * although we're still expecting seq 0 (ClientHello)
809 if (msg_hdr
.seq
!= s
->d1
->handshake_read_seq
) {
810 *errtype
= dtls1_process_out_of_seq_message(s
, &msg_hdr
);
814 if (frag_len
&& frag_len
< mlen
) {
815 *errtype
= dtls1_reassemble_fragment(s
, &msg_hdr
);
820 && s
->d1
->r_msg_hdr
.frag_off
== 0
821 && s
->statem
.hand_state
!= TLS_ST_OK
822 && wire
[0] == SSL3_MT_HELLO_REQUEST
) {
824 * The server may always send 'Hello Request' messages -- we are
825 * doing a handshake anyway now, so ignore them if their format is
826 * correct. Does not count for 'Finished' MAC.
828 if (wire
[1] == 0 && wire
[2] == 0 && wire
[3] == 0) {
830 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
831 wire
, DTLS1_HM_HEADER_LENGTH
, s
,
832 s
->msg_callback_arg
);
836 } else { /* Incorrectly formatted Hello request */
838 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
843 if (!dtls1_preprocess_fragment(s
, &msg_hdr
)) {
844 /* SSLfatal() already called */
850 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
852 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
853 &p
[frag_off
], frag_len
, 0, &readbytes
);
856 * This shouldn't ever fail due to NBIO because we already checked
857 * that we have enough data in the record
860 s
->rwstate
= SSL_READING
;
869 * XDTLS: an incorrectly formatted fragment should cause the handshake
872 if (readbytes
!= frag_len
) {
873 SSLfatal(s
, SSL_AD_ILLEGAL_PARAMETER
, SSL_R_BAD_LENGTH
);
878 * Note that s->init_num is *not* used as current offset in
879 * s->init_buf->data, but as a counter summing up fragments' lengths: as
880 * soon as they sum up to handshake packet length, we assume we have got
883 *len
= s
->init_num
= frag_len
;
893 * for these 2 messages, we need to
894 * ssl->enc_read_ctx re-init
895 * ssl->rlayer.read_sequence zero
896 * ssl->s3.read_mac_secret re-init
897 * ssl->session->read_sym_enc assign
898 * ssl->session->read_compression assign
899 * ssl->session->read_hash assign
901 int dtls_construct_change_cipher_spec(SSL
*s
, WPACKET
*pkt
)
903 if (s
->version
== DTLS1_BAD_VER
) {
904 s
->d1
->next_handshake_write_seq
++;
906 if (!WPACKET_put_bytes_u16(pkt
, s
->d1
->handshake_write_seq
)) {
907 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
915 #ifndef OPENSSL_NO_SCTP
917 * Wait for a dry event. Should only be called at a point in the handshake
918 * where we are not expecting any data from the peer except an alert.
920 WORK_STATE
dtls_wait_for_dry(SSL
*s
)
925 /* read app data until dry event */
926 ret
= BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s
));
928 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
934 * We're not expecting any more messages from the peer at this point -
935 * but we could get an alert. If an alert is waiting then we will never
936 * return successfully. Therefore we attempt to read a message. This
937 * should never succeed but will process any waiting alerts.
939 if (dtls_get_reassembled_message(s
, &errtype
, &len
)) {
940 /* The call succeeded! This should never happen */
941 SSLfatal(s
, SSL_AD_UNEXPECTED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
945 s
->s3
.in_read_app_data
= 2;
946 s
->rwstate
= SSL_READING
;
947 BIO_clear_retry_flags(SSL_get_rbio(s
));
948 BIO_set_retry_read(SSL_get_rbio(s
));
951 return WORK_FINISHED_CONTINUE
;
955 int dtls1_read_failed(SSL
*s
, int code
)
958 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
962 if (!dtls1_is_timer_expired(s
) || ossl_statem_in_error(s
)) {
964 * not a timeout, none of our business, let higher layers handle
965 * this. in fact it's probably an error
969 /* done, no need to send a retransmit */
972 BIO_set_flags(SSL_get_rbio(s
), BIO_FLAGS_READ
);
976 return dtls1_handle_timeout(s
);
979 int dtls1_get_queue_priority(unsigned short seq
, int is_ccs
)
982 * The index of the retransmission queue actually is the message sequence
983 * number, since the queue only contains messages of a single handshake.
984 * However, the ChangeCipherSpec has no message sequence number and so
985 * using only the sequence will result in the CCS and Finished having the
986 * same index. To prevent this, the sequence number is multiplied by 2.
987 * In case of a CCS 1 is subtracted. This does not only differ CSS and
988 * Finished, it also maintains the order of the index (important for
989 * priority queues) and fits in the unsigned short variable.
991 return seq
* 2 - is_ccs
;
994 int dtls1_retransmit_buffered_messages(SSL
*s
)
996 pqueue
*sent
= s
->d1
->sent_messages
;
1002 iter
= pqueue_iterator(sent
);
1004 for (item
= pqueue_next(&iter
); item
!= NULL
; item
= pqueue_next(&iter
)) {
1005 frag
= (hm_fragment
*)item
->data
;
1006 if (dtls1_retransmit_message(s
, (unsigned short)
1007 dtls1_get_queue_priority
1008 (frag
->msg_header
.seq
,
1009 frag
->msg_header
.is_ccs
), &found
) <= 0)
1016 int dtls1_buffer_message(SSL
*s
, int is_ccs
)
1020 unsigned char seq64be
[8];
1023 * this function is called immediately after a message has been
1026 if (!ossl_assert(s
->init_off
== 0))
1029 frag
= dtls1_hm_fragment_new(s
->init_num
, 0);
1033 memcpy(frag
->fragment
, s
->init_buf
->data
, s
->init_num
);
1036 /* For DTLS1_BAD_VER the header length is non-standard */
1037 if (!ossl_assert(s
->d1
->w_msg_hdr
.msg_len
+
1039 DTLS1_BAD_VER
) ? 3 : DTLS1_CCS_HEADER_LENGTH
)
1040 == (unsigned int)s
->init_num
)) {
1041 dtls1_hm_fragment_free(frag
);
1045 if (!ossl_assert(s
->d1
->w_msg_hdr
.msg_len
+
1046 DTLS1_HM_HEADER_LENGTH
== (unsigned int)s
->init_num
)) {
1047 dtls1_hm_fragment_free(frag
);
1052 frag
->msg_header
.msg_len
= s
->d1
->w_msg_hdr
.msg_len
;
1053 frag
->msg_header
.seq
= s
->d1
->w_msg_hdr
.seq
;
1054 frag
->msg_header
.type
= s
->d1
->w_msg_hdr
.type
;
1055 frag
->msg_header
.frag_off
= 0;
1056 frag
->msg_header
.frag_len
= s
->d1
->w_msg_hdr
.msg_len
;
1057 frag
->msg_header
.is_ccs
= is_ccs
;
1059 /* save current state */
1060 frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
= s
->enc_write_ctx
;
1061 frag
->msg_header
.saved_retransmit_state
.write_hash
= s
->write_hash
;
1062 frag
->msg_header
.saved_retransmit_state
.compress
= s
->compress
;
1063 frag
->msg_header
.saved_retransmit_state
.session
= s
->session
;
1064 frag
->msg_header
.saved_retransmit_state
.epoch
=
1065 DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1067 memset(seq64be
, 0, sizeof(seq64be
));
1070 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1071 frag
->msg_header
.is_ccs
) >> 8);
1074 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1075 frag
->msg_header
.is_ccs
));
1077 item
= pitem_new(seq64be
, frag
);
1079 dtls1_hm_fragment_free(frag
);
1083 pqueue_insert(s
->d1
->sent_messages
, item
);
1087 int dtls1_retransmit_message(SSL
*s
, unsigned short seq
, int *found
)
1090 /* XDTLS: for now assuming that read/writes are blocking */
1093 unsigned long header_length
;
1094 unsigned char seq64be
[8];
1095 struct dtls1_retransmit_state saved_state
;
1097 /* XDTLS: the requested message ought to be found, otherwise error */
1098 memset(seq64be
, 0, sizeof(seq64be
));
1099 seq64be
[6] = (unsigned char)(seq
>> 8);
1100 seq64be
[7] = (unsigned char)seq
;
1102 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1104 SSLfatal(s
, SSL_AD_INTERNAL_ERROR
, ERR_R_INTERNAL_ERROR
);
1110 frag
= (hm_fragment
*)item
->data
;
1112 if (frag
->msg_header
.is_ccs
)
1113 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1115 header_length
= DTLS1_HM_HEADER_LENGTH
;
1117 memcpy(s
->init_buf
->data
, frag
->fragment
,
1118 frag
->msg_header
.msg_len
+ header_length
);
1119 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1121 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1122 frag
->msg_header
.msg_len
,
1123 frag
->msg_header
.seq
, 0,
1124 frag
->msg_header
.frag_len
);
1126 /* save current state */
1127 saved_state
.enc_write_ctx
= s
->enc_write_ctx
;
1128 saved_state
.write_hash
= s
->write_hash
;
1129 saved_state
.compress
= s
->compress
;
1130 saved_state
.session
= s
->session
;
1131 saved_state
.epoch
= DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1133 s
->d1
->retransmitting
= 1;
1135 /* restore state in which the message was originally sent */
1136 s
->enc_write_ctx
= frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
;
1137 s
->write_hash
= frag
->msg_header
.saved_retransmit_state
.write_hash
;
1138 s
->compress
= frag
->msg_header
.saved_retransmit_state
.compress
;
1139 s
->session
= frag
->msg_header
.saved_retransmit_state
.session
;
1140 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
,
1142 saved_retransmit_state
.epoch
);
1144 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1145 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1147 /* restore current state */
1148 s
->enc_write_ctx
= saved_state
.enc_write_ctx
;
1149 s
->write_hash
= saved_state
.write_hash
;
1150 s
->compress
= saved_state
.compress
;
1151 s
->session
= saved_state
.session
;
1152 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
, saved_state
.epoch
);
1154 s
->d1
->retransmitting
= 0;
1156 (void)BIO_flush(s
->wbio
);
1160 void dtls1_set_message_header(SSL
*s
,
1161 unsigned char mt
, size_t len
,
1162 size_t frag_off
, size_t frag_len
)
1164 if (frag_off
== 0) {
1165 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1166 s
->d1
->next_handshake_write_seq
++;
1169 dtls1_set_message_header_int(s
, mt
, len
, s
->d1
->handshake_write_seq
,
1170 frag_off
, frag_len
);
1173 /* don't actually do the writing, wait till the MTU has been retrieved */
1175 dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
1176 size_t len
, unsigned short seq_num
,
1177 size_t frag_off
, size_t frag_len
)
1179 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1182 msg_hdr
->msg_len
= len
;
1183 msg_hdr
->seq
= seq_num
;
1184 msg_hdr
->frag_off
= frag_off
;
1185 msg_hdr
->frag_len
= frag_len
;
1189 dtls1_fix_message_header(SSL
*s
, size_t frag_off
, size_t frag_len
)
1191 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1193 msg_hdr
->frag_off
= frag_off
;
1194 msg_hdr
->frag_len
= frag_len
;
1197 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
)
1199 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1201 *p
++ = msg_hdr
->type
;
1202 l2n3(msg_hdr
->msg_len
, p
);
1204 s2n(msg_hdr
->seq
, p
);
1205 l2n3(msg_hdr
->frag_off
, p
);
1206 l2n3(msg_hdr
->frag_len
, p
);
1211 void dtls1_get_message_header(unsigned char *data
, struct hm_header_st
*msg_hdr
)
1213 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
1214 msg_hdr
->type
= *(data
++);
1215 n2l3(data
, msg_hdr
->msg_len
);
1217 n2s(data
, msg_hdr
->seq
);
1218 n2l3(data
, msg_hdr
->frag_off
);
1219 n2l3(data
, msg_hdr
->frag_len
);
1222 int dtls1_set_handshake_header(SSL
*s
, WPACKET
*pkt
, int htype
)
1224 unsigned char *header
;
1226 if (htype
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
1227 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1228 dtls1_set_message_header_int(s
, SSL3_MT_CCS
, 0,
1229 s
->d1
->handshake_write_seq
, 0, 0);
1230 if (!WPACKET_put_bytes_u8(pkt
, SSL3_MT_CCS
))
1233 dtls1_set_message_header(s
, htype
, 0, 0, 0);
1235 * We allocate space at the start for the message header. This gets
1238 if (!WPACKET_allocate_bytes(pkt
, DTLS1_HM_HEADER_LENGTH
, &header
)
1239 || !WPACKET_start_sub_packet(pkt
))
1246 int dtls1_close_construct_packet(SSL
*s
, WPACKET
*pkt
, int htype
)
1250 if ((htype
!= SSL3_MT_CHANGE_CIPHER_SPEC
&& !WPACKET_close(pkt
))
1251 || !WPACKET_get_length(pkt
, &msglen
)
1252 || msglen
> INT_MAX
)
1255 if (htype
!= SSL3_MT_CHANGE_CIPHER_SPEC
) {
1256 s
->d1
->w_msg_hdr
.msg_len
= msglen
- DTLS1_HM_HEADER_LENGTH
;
1257 s
->d1
->w_msg_hdr
.frag_len
= msglen
- DTLS1_HM_HEADER_LENGTH
;
1259 s
->init_num
= (int)msglen
;
1262 if (htype
!= DTLS1_MT_HELLO_VERIFY_REQUEST
) {
1263 /* Buffer the message to handle re-xmits */
1264 if (!dtls1_buffer_message(s
, htype
== SSL3_MT_CHANGE_CIPHER_SPEC