2 * Copyright 2005-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (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_locl.h"
14 #include "statem_locl.h"
15 #include <openssl/buffer.h>
16 #include <openssl/rand.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) { \
36 OPENSSL_assert((msg_len) > 0); \
38 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
39 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
40 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
42 static unsigned char bitmask_start_values
[] =
43 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
44 static unsigned char bitmask_end_values
[] =
45 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
47 static void dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
48 unsigned long frag_len
);
49 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
);
50 static void dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
52 unsigned short seq_num
,
53 unsigned long frag_off
,
54 unsigned long frag_len
);
55 static int dtls_get_reassembled_message(SSL
*s
, long *len
);
57 static hm_fragment
*dtls1_hm_fragment_new(unsigned long frag_len
,
60 hm_fragment
*frag
= NULL
;
61 unsigned char *buf
= NULL
;
62 unsigned char *bitmask
= NULL
;
64 frag
= OPENSSL_malloc(sizeof(*frag
));
69 buf
= OPENSSL_malloc(frag_len
);
76 /* zero length fragment gets zero frag->fragment */
79 /* Initialize reassembly bitmask if necessary */
81 bitmask
= OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len
));
82 if (bitmask
== NULL
) {
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
)
115 unsigned int curr_mtu
;
117 unsigned int len
, frag_off
, mac_size
, blocksize
, used_len
;
119 if (!dtls1_query_mtu(s
))
122 if (s
->d1
->mtu
< dtls1_min_mtu(s
))
123 /* should have something reasonable now */
126 if (s
->init_off
== 0 && type
== SSL3_RT_HANDSHAKE
)
127 OPENSSL_assert(s
->init_num
==
128 (int)s
->d1
->w_msg_hdr
.msg_len
+
129 DTLS1_HM_HEADER_LENGTH
);
133 && (EVP_CIPHER_flags(EVP_CIPHER_CTX_cipher(s
->enc_write_ctx
)) &
134 EVP_CIPH_FLAG_AEAD_CIPHER
) != 0)
137 mac_size
= EVP_MD_CTX_size(s
->write_hash
);
141 if (s
->enc_write_ctx
&&
142 (EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_CBC_MODE
))
143 blocksize
= 2 * EVP_CIPHER_CTX_block_size(s
->enc_write_ctx
);
148 s
->rwstate
= SSL_NOTHING
;
150 /* s->init_num shouldn't ever be < 0...but just in case */
151 while (s
->init_num
> 0) {
152 if (type
== SSL3_RT_HANDSHAKE
&& s
->init_off
!= 0) {
153 /* We must be writing a fragment other than the first one */
156 /* This is the first attempt at writing out this fragment */
158 if (s
->init_off
<= DTLS1_HM_HEADER_LENGTH
) {
160 * Each fragment that was already sent must at least have
161 * contained the message header plus one other byte.
162 * Therefore |init_off| must have progressed by at least
163 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
170 * Adjust |init_off| and |init_num| to allow room for a new
171 * message header for this fragment.
173 s
->init_off
-= DTLS1_HM_HEADER_LENGTH
;
174 s
->init_num
+= DTLS1_HM_HEADER_LENGTH
;
177 * We must have been called again after a retry so use the
178 * fragment offset from our last attempt. We do not need
179 * to adjust |init_off| and |init_num| as above, because
180 * that should already have been done before the retry.
182 frag_off
= s
->d1
->w_msg_hdr
.frag_off
;
186 used_len
= BIO_wpending(SSL_get_wbio(s
)) + DTLS1_RT_HEADER_LENGTH
187 + mac_size
+ blocksize
;
188 if (s
->d1
->mtu
> used_len
)
189 curr_mtu
= s
->d1
->mtu
- used_len
;
193 if (curr_mtu
<= DTLS1_HM_HEADER_LENGTH
) {
195 * grr.. we could get an error if MTU picked was wrong
197 ret
= BIO_flush(SSL_get_wbio(s
));
199 s
->rwstate
= SSL_WRITING
;
202 used_len
= DTLS1_RT_HEADER_LENGTH
+ mac_size
+ blocksize
;
203 if (s
->d1
->mtu
> used_len
+ DTLS1_HM_HEADER_LENGTH
) {
204 curr_mtu
= s
->d1
->mtu
- used_len
;
206 /* Shouldn't happen */
212 * We just checked that s->init_num > 0 so this cast should be safe
214 if (((unsigned int)s
->init_num
) > curr_mtu
)
219 /* Shouldn't ever happen */
224 * XDTLS: this function is too long. split out the CCS part
226 if (type
== SSL3_RT_HANDSHAKE
) {
227 if (len
< DTLS1_HM_HEADER_LENGTH
) {
229 * len is so small that we really can't do anything sensible
234 dtls1_fix_message_header(s
, frag_off
,
235 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
],
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 OPENSSL_assert(len
== (unsigned int)ret
);
271 if (type
== SSL3_RT_HANDSHAKE
&& !s
->d1
->retransmitting
) {
273 * should not be done for 'Hello Request's, but in that case
274 * we'll ignore the result anyway
277 (unsigned char *)&s
->init_buf
->data
[s
->init_off
];
278 const struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
281 if (frag_off
== 0 && s
->version
!= DTLS1_BAD_VER
) {
283 * reconstruct message header is if it is being sent in
286 *p
++ = msg_hdr
->type
;
287 l2n3(msg_hdr
->msg_len
, p
);
288 s2n(msg_hdr
->seq
, p
);
290 l2n3(msg_hdr
->msg_len
, p
);
291 p
-= DTLS1_HM_HEADER_LENGTH
;
294 p
+= DTLS1_HM_HEADER_LENGTH
;
295 xlen
= ret
- DTLS1_HM_HEADER_LENGTH
;
298 ssl3_finish_mac(s
, p
, xlen
);
301 if (ret
== s
->init_num
) {
303 s
->msg_callback(1, s
->version
, type
, s
->init_buf
->data
,
304 (size_t)(s
->init_off
+ s
->init_num
), s
,
305 s
->msg_callback_arg
);
307 s
->init_off
= 0; /* done writing this message */
314 ret
-= DTLS1_HM_HEADER_LENGTH
;
318 * We save the fragment offset for the next fragment so we have it
319 * available in case of an IO retry. We don't know the length of the
320 * next fragment yet so just set that to 0 for now. It will be
321 * updated again later.
323 dtls1_fix_message_header(s
, frag_off
, 0);
329 int dtls_get_message(SSL
*s
, int *mt
, unsigned long *len
)
331 struct hm_header_st
*msg_hdr
;
333 unsigned long msg_len
;
337 msg_hdr
= &s
->d1
->r_msg_hdr
;
338 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
341 ok
= dtls_get_reassembled_message(s
, &tmplen
);
342 if (tmplen
== DTLS1_HM_BAD_FRAGMENT
343 || tmplen
== DTLS1_HM_FRAGMENT_RETRY
) {
344 /* bad fragment received */
346 } else if (tmplen
<= 0 && !ok
) {
350 *mt
= s
->s3
->tmp
.message_type
;
352 p
= (unsigned char *)s
->init_buf
->data
;
354 if (*mt
== SSL3_MT_CHANGE_CIPHER_SPEC
) {
355 if (s
->msg_callback
) {
356 s
->msg_callback(0, s
->version
, SSL3_RT_CHANGE_CIPHER_SPEC
,
357 p
, 1, s
, s
->msg_callback_arg
);
360 * This isn't a real handshake message so skip the processing below.
362 *len
= (unsigned long)tmplen
;
366 msg_len
= msg_hdr
->msg_len
;
368 /* reconstruct message header */
369 *(p
++) = msg_hdr
->type
;
371 s2n(msg_hdr
->seq
, p
);
374 if (s
->version
!= DTLS1_BAD_VER
) {
375 p
-= DTLS1_HM_HEADER_LENGTH
;
376 msg_len
+= DTLS1_HM_HEADER_LENGTH
;
379 ssl3_finish_mac(s
, p
, msg_len
);
381 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
382 p
, msg_len
, s
, s
->msg_callback_arg
);
384 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
386 s
->d1
->handshake_read_seq
++;
389 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
395 static int dtls1_preprocess_fragment(SSL
*s
, struct hm_header_st
*msg_hdr
)
397 size_t frag_off
, frag_len
, msg_len
;
399 msg_len
= msg_hdr
->msg_len
;
400 frag_off
= msg_hdr
->frag_off
;
401 frag_len
= msg_hdr
->frag_len
;
403 /* sanity checking */
404 if ((frag_off
+ frag_len
) > msg_len
) {
405 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
406 return SSL_AD_ILLEGAL_PARAMETER
;
409 if (s
->d1
->r_msg_hdr
.frag_off
== 0) { /* first fragment */
411 * msg_len is limited to 2^24, but is effectively checked against max
414 if (!BUF_MEM_grow_clean
415 (s
->init_buf
, msg_len
+ DTLS1_HM_HEADER_LENGTH
)) {
416 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, ERR_R_BUF_LIB
);
417 return SSL_AD_INTERNAL_ERROR
;
420 s
->s3
->tmp
.message_size
= msg_len
;
421 s
->d1
->r_msg_hdr
.msg_len
= msg_len
;
422 s
->s3
->tmp
.message_type
= msg_hdr
->type
;
423 s
->d1
->r_msg_hdr
.type
= msg_hdr
->type
;
424 s
->d1
->r_msg_hdr
.seq
= msg_hdr
->seq
;
425 } else if (msg_len
!= s
->d1
->r_msg_hdr
.msg_len
) {
427 * They must be playing with us! BTW, failure to enforce upper limit
428 * would open possibility for buffer overrun.
430 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
, SSL_R_EXCESSIVE_MESSAGE_SIZE
);
431 return SSL_AD_ILLEGAL_PARAMETER
;
434 return 0; /* no error */
437 static int dtls1_retrieve_buffered_fragment(SSL
*s
, int *ok
)
440 * (0) check whether the desired fragment is available
442 * (1) copy over the fragment to s->init_buf->data[]
443 * (2) update s->init_num
450 item
= pqueue_peek(s
->d1
->buffered_messages
);
454 frag
= (hm_fragment
*)item
->data
;
456 /* Don't return if reassembly still in progress */
457 if (frag
->reassembly
!= NULL
)
460 if (s
->d1
->handshake_read_seq
== frag
->msg_header
.seq
) {
461 unsigned long frag_len
= frag
->msg_header
.frag_len
;
462 pqueue_pop(s
->d1
->buffered_messages
);
464 al
= dtls1_preprocess_fragment(s
, &frag
->msg_header
);
466 if (al
== 0) { /* no alert */
468 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
469 memcpy(&p
[frag
->msg_header
.frag_off
], frag
->fragment
,
470 frag
->msg_header
.frag_len
);
473 dtls1_hm_fragment_free(frag
);
481 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
490 * dtls1_max_handshake_message_len returns the maximum number of bytes
491 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
492 * may be greater if the maximum certificate list size requires it.
494 static unsigned long dtls1_max_handshake_message_len(const SSL
*s
)
496 unsigned long max_len
=
497 DTLS1_HM_HEADER_LENGTH
+ SSL3_RT_MAX_ENCRYPTED_LENGTH
;
498 if (max_len
< (unsigned long)s
->max_cert_list
)
499 return s
->max_cert_list
;
504 dtls1_reassemble_fragment(SSL
*s
, const struct hm_header_st
*msg_hdr
, int *ok
)
506 hm_fragment
*frag
= NULL
;
508 int i
= -1, is_complete
;
509 unsigned char seq64be
[8];
510 unsigned long frag_len
= msg_hdr
->frag_len
;
512 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
||
513 msg_hdr
->msg_len
> dtls1_max_handshake_message_len(s
))
517 return DTLS1_HM_FRAGMENT_RETRY
;
519 /* Try to find item in queue */
520 memset(seq64be
, 0, sizeof(seq64be
));
521 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
522 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
523 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
526 frag
= dtls1_hm_fragment_new(msg_hdr
->msg_len
, 1);
529 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
530 frag
->msg_header
.frag_len
= frag
->msg_header
.msg_len
;
531 frag
->msg_header
.frag_off
= 0;
533 frag
= (hm_fragment
*)item
->data
;
534 if (frag
->msg_header
.msg_len
!= msg_hdr
->msg_len
) {
542 * If message is already reassembled, this must be a retransmit and can
543 * be dropped. In this case item != NULL and so frag does not need to be
546 if (frag
->reassembly
== NULL
) {
547 unsigned char devnull
[256];
550 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
553 sizeof(devnull
) ? sizeof(devnull
) :
559 return DTLS1_HM_FRAGMENT_RETRY
;
562 /* read the body of the fragment (header has already been read */
563 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
564 frag
->fragment
+ msg_hdr
->frag_off
,
566 if ((unsigned long)i
!= frag_len
)
571 RSMBLY_BITMASK_MARK(frag
->reassembly
, (long)msg_hdr
->frag_off
,
572 (long)(msg_hdr
->frag_off
+ frag_len
));
574 RSMBLY_BITMASK_IS_COMPLETE(frag
->reassembly
, (long)msg_hdr
->msg_len
,
578 OPENSSL_free(frag
->reassembly
);
579 frag
->reassembly
= NULL
;
583 item
= pitem_new(seq64be
, frag
);
589 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
591 * pqueue_insert fails iff a duplicate item is inserted. However,
592 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
593 * would have returned it and control would never have reached this
596 OPENSSL_assert(item
!= NULL
);
599 return DTLS1_HM_FRAGMENT_RETRY
;
603 dtls1_hm_fragment_free(frag
);
609 dtls1_process_out_of_seq_message(SSL
*s
, const struct hm_header_st
*msg_hdr
,
613 hm_fragment
*frag
= NULL
;
615 unsigned char seq64be
[8];
616 unsigned long frag_len
= msg_hdr
->frag_len
;
618 if ((msg_hdr
->frag_off
+ frag_len
) > msg_hdr
->msg_len
)
621 /* Try to find item in queue, to prevent duplicate entries */
622 memset(seq64be
, 0, sizeof(seq64be
));
623 seq64be
[6] = (unsigned char)(msg_hdr
->seq
>> 8);
624 seq64be
[7] = (unsigned char)msg_hdr
->seq
;
625 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
628 * If we already have an entry and this one is a fragment, don't discard
629 * it and rather try to reassemble it.
631 if (item
!= NULL
&& frag_len
!= msg_hdr
->msg_len
)
635 * Discard the message if sequence number was already there, is too far
636 * in the future, already in the queue or if we received a FINISHED
637 * before the SERVER_HELLO, which then must be a stale retransmit.
639 if (msg_hdr
->seq
<= s
->d1
->handshake_read_seq
||
640 msg_hdr
->seq
> s
->d1
->handshake_read_seq
+ 10 || item
!= NULL
||
641 (s
->d1
->handshake_read_seq
== 0 && msg_hdr
->type
== SSL3_MT_FINISHED
))
643 unsigned char devnull
[256];
646 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
649 sizeof(devnull
) ? sizeof(devnull
) :
656 if (frag_len
!= msg_hdr
->msg_len
)
657 return dtls1_reassemble_fragment(s
, msg_hdr
, ok
);
659 if (frag_len
> dtls1_max_handshake_message_len(s
))
662 frag
= dtls1_hm_fragment_new(frag_len
, 0);
666 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
670 * read the body of the fragment (header has already been read
672 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
673 frag
->fragment
, frag_len
, 0);
674 if ((unsigned long)i
!= frag_len
)
680 item
= pitem_new(seq64be
, frag
);
684 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
686 * pqueue_insert fails iff a duplicate item is inserted. However,
687 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
688 * would have returned it. Then, either |frag_len| !=
689 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
690 * have been processed with |dtls1_reassemble_fragment|, above, or
691 * the record will have been discarded.
693 OPENSSL_assert(item
!= NULL
);
696 return DTLS1_HM_FRAGMENT_RETRY
;
700 dtls1_hm_fragment_free(frag
);
705 static int dtls_get_reassembled_message(SSL
*s
, long *len
)
707 unsigned char wire
[DTLS1_HM_HEADER_LENGTH
];
708 unsigned long mlen
, frag_off
, frag_len
;
709 int i
, al
, recvd_type
;
710 struct hm_header_st msg_hdr
;
714 /* see if we have the required fragment already */
715 if ((frag_len
= dtls1_retrieve_buffered_fragment(s
, &ok
)) || ok
) {
717 s
->init_num
= frag_len
;
722 /* read handshake message header */
723 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, &recvd_type
, wire
,
724 DTLS1_HM_HEADER_LENGTH
, 0);
725 if (i
<= 0) { /* nbio, or an error */
726 s
->rwstate
= SSL_READING
;
730 if(recvd_type
== SSL3_RT_CHANGE_CIPHER_SPEC
) {
731 if (wire
[0] != SSL3_MT_CCS
) {
732 al
= SSL_AD_UNEXPECTED_MESSAGE
;
733 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
,
734 SSL_R_BAD_CHANGE_CIPHER_SPEC
);
738 memcpy(s
->init_buf
->data
, wire
, i
);
740 s
->init_msg
= s
->init_buf
->data
+ 1;
741 s
->s3
->tmp
.message_type
= SSL3_MT_CHANGE_CIPHER_SPEC
;
742 s
->s3
->tmp
.message_size
= i
- 1;
747 /* Handshake fails if message header is incomplete */
748 if (i
!= DTLS1_HM_HEADER_LENGTH
) {
749 al
= SSL_AD_UNEXPECTED_MESSAGE
;
750 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL_R_UNEXPECTED_MESSAGE
);
754 /* parse the message fragment header */
755 dtls1_get_message_header(wire
, &msg_hdr
);
757 mlen
= msg_hdr
.msg_len
;
758 frag_off
= msg_hdr
.frag_off
;
759 frag_len
= msg_hdr
.frag_len
;
762 * We must have at least frag_len bytes left in the record to be read.
763 * Fragments must not span records.
765 if (frag_len
> RECORD_LAYER_get_rrec_length(&s
->rlayer
)) {
766 al
= SSL3_AD_ILLEGAL_PARAMETER
;
767 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL_R_BAD_LENGTH
);
772 * if this is a future (or stale) message it gets buffered
773 * (or dropped)--no further processing at this time
774 * While listening, we accept seq 1 (ClientHello with cookie)
775 * although we're still expecting seq 0 (ClientHello)
777 if (msg_hdr
.seq
!= s
->d1
->handshake_read_seq
) {
778 *len
= dtls1_process_out_of_seq_message(s
, &msg_hdr
, &ok
);
782 if (frag_len
&& frag_len
< mlen
) {
783 *len
= dtls1_reassemble_fragment(s
, &msg_hdr
, &ok
);
787 if (!s
->server
&& s
->d1
->r_msg_hdr
.frag_off
== 0 &&
788 wire
[0] == SSL3_MT_HELLO_REQUEST
) {
790 * The server may always send 'Hello Request' messages -- we are
791 * doing a handshake anyway now, so ignore them if their format is
792 * correct. Does not count for 'Finished' MAC.
794 if (wire
[1] == 0 && wire
[2] == 0 && wire
[3] == 0) {
796 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
797 wire
, DTLS1_HM_HEADER_LENGTH
, s
,
798 s
->msg_callback_arg
);
802 } else { /* Incorrectly formated Hello request */
804 al
= SSL_AD_UNEXPECTED_MESSAGE
;
805 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
,
806 SSL_R_UNEXPECTED_MESSAGE
);
811 if ((al
= dtls1_preprocess_fragment(s
, &msg_hdr
)))
816 (unsigned char *)s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
818 i
= s
->method
->ssl_read_bytes(s
, SSL3_RT_HANDSHAKE
, NULL
,
819 &p
[frag_off
], frag_len
, 0);
822 * This shouldn't ever fail due to NBIO because we already checked
823 * that we have enough data in the record
826 s
->rwstate
= SSL_READING
;
834 * XDTLS: an incorrectly formatted fragment should cause the handshake
837 if (i
!= (int)frag_len
) {
838 al
= SSL3_AD_ILLEGAL_PARAMETER
;
839 SSLerr(SSL_F_DTLS_GET_REASSEMBLED_MESSAGE
, SSL3_AD_ILLEGAL_PARAMETER
);
844 * Note that s->init_num is *not* used as current offset in
845 * s->init_buf->data, but as a counter summing up fragments' lengths: as
846 * soon as they sum up to handshake packet length, we assume we have got
849 *len
= s
->init_num
= frag_len
;
853 ssl3_send_alert(s
, SSL3_AL_FATAL
, al
);
860 * for these 2 messages, we need to
861 * ssl->enc_read_ctx re-init
862 * ssl->rlayer.read_sequence zero
863 * ssl->s3->read_mac_secret re-init
864 * ssl->session->read_sym_enc assign
865 * ssl->session->read_compression assign
866 * ssl->session->read_hash assign
868 int dtls_construct_change_cipher_spec(SSL
*s
)
872 p
= (unsigned char *)s
->init_buf
->data
;
874 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
875 s
->init_num
= DTLS1_CCS_HEADER_LENGTH
;
877 if (s
->version
== DTLS1_BAD_VER
) {
878 s
->d1
->next_handshake_write_seq
++;
879 s2n(s
->d1
->handshake_write_seq
, p
);
885 dtls1_set_message_header_int(s
, SSL3_MT_CCS
, 0,
886 s
->d1
->handshake_write_seq
, 0, 0);
888 /* buffer the message to handle re-xmits */
889 if (!dtls1_buffer_message(s
, 1)) {
890 SSLerr(SSL_F_DTLS_CONSTRUCT_CHANGE_CIPHER_SPEC
, ERR_R_INTERNAL_ERROR
);
897 #ifndef OPENSSL_NO_SCTP
898 WORK_STATE
dtls_wait_for_dry(SSL
*s
)
902 /* read app data until dry event */
903 ret
= BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s
));
908 s
->s3
->in_read_app_data
= 2;
909 s
->rwstate
= SSL_READING
;
910 BIO_clear_retry_flags(SSL_get_rbio(s
));
911 BIO_set_retry_read(SSL_get_rbio(s
));
914 return WORK_FINISHED_CONTINUE
;
918 int dtls1_read_failed(SSL
*s
, int code
)
921 SSLerr(SSL_F_DTLS1_READ_FAILED
, ERR_R_INTERNAL_ERROR
);
925 if (!dtls1_is_timer_expired(s
)) {
927 * not a timeout, none of our business, let higher layers handle
928 * this. in fact it's probably an error
932 #ifndef OPENSSL_NO_HEARTBEATS
933 /* done, no need to send a retransmit */
934 if (!SSL_in_init(s
) && !s
->tlsext_hb_pending
)
936 /* done, no need to send a retransmit */
940 BIO_set_flags(SSL_get_rbio(s
), BIO_FLAGS_READ
);
944 return dtls1_handle_timeout(s
);
947 int dtls1_get_queue_priority(unsigned short seq
, int is_ccs
)
950 * The index of the retransmission queue actually is the message sequence
951 * number, since the queue only contains messages of a single handshake.
952 * However, the ChangeCipherSpec has no message sequence number and so
953 * using only the sequence will result in the CCS and Finished having the
954 * same index. To prevent this, the sequence number is multiplied by 2.
955 * In case of a CCS 1 is subtracted. This does not only differ CSS and
956 * Finished, it also maintains the order of the index (important for
957 * priority queues) and fits in the unsigned short variable.
959 return seq
* 2 - is_ccs
;
962 int dtls1_retransmit_buffered_messages(SSL
*s
)
964 pqueue
*sent
= s
->d1
->sent_messages
;
970 iter
= pqueue_iterator(sent
);
972 for (item
= pqueue_next(&iter
); item
!= NULL
; item
= pqueue_next(&iter
)) {
973 frag
= (hm_fragment
*)item
->data
;
974 if (dtls1_retransmit_message(s
, (unsigned short)
975 dtls1_get_queue_priority
976 (frag
->msg_header
.seq
,
977 frag
->msg_header
.is_ccs
),
985 int dtls1_buffer_message(SSL
*s
, int is_ccs
)
989 unsigned char seq64be
[8];
992 * this function is called immediately after a message has been
995 OPENSSL_assert(s
->init_off
== 0);
997 frag
= dtls1_hm_fragment_new(s
->init_num
, 0);
1001 memcpy(frag
->fragment
, s
->init_buf
->data
, s
->init_num
);
1004 /* For DTLS1_BAD_VER the header length is non-standard */
1005 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1006 ((s
->version
==DTLS1_BAD_VER
)?3:DTLS1_CCS_HEADER_LENGTH
)
1007 == (unsigned int)s
->init_num
);
1009 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1010 DTLS1_HM_HEADER_LENGTH
== (unsigned int)s
->init_num
);
1013 frag
->msg_header
.msg_len
= s
->d1
->w_msg_hdr
.msg_len
;
1014 frag
->msg_header
.seq
= s
->d1
->w_msg_hdr
.seq
;
1015 frag
->msg_header
.type
= s
->d1
->w_msg_hdr
.type
;
1016 frag
->msg_header
.frag_off
= 0;
1017 frag
->msg_header
.frag_len
= s
->d1
->w_msg_hdr
.msg_len
;
1018 frag
->msg_header
.is_ccs
= is_ccs
;
1020 /* save current state */
1021 frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
= s
->enc_write_ctx
;
1022 frag
->msg_header
.saved_retransmit_state
.write_hash
= s
->write_hash
;
1023 frag
->msg_header
.saved_retransmit_state
.compress
= s
->compress
;
1024 frag
->msg_header
.saved_retransmit_state
.session
= s
->session
;
1025 frag
->msg_header
.saved_retransmit_state
.epoch
=
1026 DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1028 memset(seq64be
, 0, sizeof(seq64be
));
1031 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1032 frag
->msg_header
.is_ccs
) >> 8);
1035 char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1036 frag
->msg_header
.is_ccs
));
1038 item
= pitem_new(seq64be
, frag
);
1040 dtls1_hm_fragment_free(frag
);
1044 pqueue_insert(s
->d1
->sent_messages
, item
);
1049 dtls1_retransmit_message(SSL
*s
, unsigned short seq
, int *found
)
1052 /* XDTLS: for now assuming that read/writes are blocking */
1055 unsigned long header_length
;
1056 unsigned char seq64be
[8];
1057 struct dtls1_retransmit_state saved_state
;
1060 OPENSSL_assert(s->init_num == 0);
1061 OPENSSL_assert(s->init_off == 0);
1064 /* XDTLS: the requested message ought to be found, otherwise error */
1065 memset(seq64be
, 0, sizeof(seq64be
));
1066 seq64be
[6] = (unsigned char)(seq
>> 8);
1067 seq64be
[7] = (unsigned char)seq
;
1069 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1071 SSLerr(SSL_F_DTLS1_RETRANSMIT_MESSAGE
, ERR_R_INTERNAL_ERROR
);
1077 frag
= (hm_fragment
*)item
->data
;
1079 if (frag
->msg_header
.is_ccs
)
1080 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1082 header_length
= DTLS1_HM_HEADER_LENGTH
;
1084 memcpy(s
->init_buf
->data
, frag
->fragment
,
1085 frag
->msg_header
.msg_len
+ header_length
);
1086 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1088 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1089 frag
->msg_header
.msg_len
,
1090 frag
->msg_header
.seq
, 0,
1091 frag
->msg_header
.frag_len
);
1093 /* save current state */
1094 saved_state
.enc_write_ctx
= s
->enc_write_ctx
;
1095 saved_state
.write_hash
= s
->write_hash
;
1096 saved_state
.compress
= s
->compress
;
1097 saved_state
.session
= s
->session
;
1098 saved_state
.epoch
= DTLS_RECORD_LAYER_get_w_epoch(&s
->rlayer
);
1100 s
->d1
->retransmitting
= 1;
1102 /* restore state in which the message was originally sent */
1103 s
->enc_write_ctx
= frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
;
1104 s
->write_hash
= frag
->msg_header
.saved_retransmit_state
.write_hash
;
1105 s
->compress
= frag
->msg_header
.saved_retransmit_state
.compress
;
1106 s
->session
= frag
->msg_header
.saved_retransmit_state
.session
;
1107 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
,
1108 frag
->msg_header
.saved_retransmit_state
.epoch
);
1110 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1111 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1113 /* restore current state */
1114 s
->enc_write_ctx
= saved_state
.enc_write_ctx
;
1115 s
->write_hash
= saved_state
.write_hash
;
1116 s
->compress
= saved_state
.compress
;
1117 s
->session
= saved_state
.session
;
1118 DTLS_RECORD_LAYER_set_saved_w_epoch(&s
->rlayer
, saved_state
.epoch
);
1120 s
->d1
->retransmitting
= 0;
1122 (void)BIO_flush(SSL_get_wbio(s
));
1126 /* call this function when the buffered messages are no longer needed */
1127 void dtls1_clear_record_buffer(SSL
*s
)
1131 for (item
= pqueue_pop(s
->d1
->sent_messages
);
1132 item
!= NULL
; item
= pqueue_pop(s
->d1
->sent_messages
)) {
1133 dtls1_hm_fragment_free((hm_fragment
*)item
->data
);
1138 void dtls1_set_message_header(SSL
*s
,
1139 unsigned char mt
, unsigned long len
,
1140 unsigned long frag_off
,
1141 unsigned long frag_len
)
1143 if (frag_off
== 0) {
1144 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1145 s
->d1
->next_handshake_write_seq
++;
1148 dtls1_set_message_header_int(s
, mt
, len
, s
->d1
->handshake_write_seq
,
1149 frag_off
, frag_len
);
1152 /* don't actually do the writing, wait till the MTU has been retrieved */
1154 dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
1155 unsigned long len
, unsigned short seq_num
,
1156 unsigned long frag_off
, unsigned long frag_len
)
1158 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1161 msg_hdr
->msg_len
= len
;
1162 msg_hdr
->seq
= seq_num
;
1163 msg_hdr
->frag_off
= frag_off
;
1164 msg_hdr
->frag_len
= frag_len
;
1168 dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
1169 unsigned long frag_len
)
1171 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1173 msg_hdr
->frag_off
= frag_off
;
1174 msg_hdr
->frag_len
= frag_len
;
1177 static unsigned char *dtls1_write_message_header(SSL
*s
, unsigned char *p
)
1179 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1181 *p
++ = msg_hdr
->type
;
1182 l2n3(msg_hdr
->msg_len
, p
);
1184 s2n(msg_hdr
->seq
, p
);
1185 l2n3(msg_hdr
->frag_off
, p
);
1186 l2n3(msg_hdr
->frag_len
, p
);
1192 dtls1_get_message_header(unsigned char *data
, struct hm_header_st
*msg_hdr
)
1194 memset(msg_hdr
, 0, sizeof(*msg_hdr
));
1195 msg_hdr
->type
= *(data
++);
1196 n2l3(data
, msg_hdr
->msg_len
);
1198 n2s(data
, msg_hdr
->seq
);
1199 n2l3(data
, msg_hdr
->frag_off
);
1200 n2l3(data
, msg_hdr
->frag_len
);