3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@openssl.org.
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
62 * This package is an SSL implementation written
63 * by Eric Young (eay@cryptsoft.com).
64 * The implementation was written so as to conform with Netscapes SSL.
66 * This library is free for commercial and non-commercial use as long as
67 * the following conditions are aheared to. The following conditions
68 * apply to all code found in this distribution, be it the RC4, RSA,
69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
70 * included with this distribution is covered by the same copyright terms
71 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
73 * Copyright remains Eric Young's, and as such any Copyright notices in
74 * the code are not to be removed.
75 * If this package is used in a product, Eric Young should be given attribution
76 * as the author of the parts of the library used.
77 * This can be in the form of a textual message at program startup or
78 * in documentation (online or textual) provided with the package.
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
83 * 1. Redistributions of source code must retain the copyright
84 * notice, this list of conditions and the following disclaimer.
85 * 2. Redistributions in binary form must reproduce the above copyright
86 * notice, this list of conditions and the following disclaimer in the
87 * documentation and/or other materials provided with the distribution.
88 * 3. All advertising materials mentioning features or use of this software
89 * must display the following acknowledgement:
90 * "This product includes cryptographic software written by
91 * Eric Young (eay@cryptsoft.com)"
92 * The word 'cryptographic' can be left out if the rouines from the library
93 * being used are not cryptographic related :-).
94 * 4. If you include any Windows specific code (or a derivative thereof) from
95 * the apps directory (application code) you must include an acknowledgement:
96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
110 * The licence and distribution terms for any publically available version or
111 * derivative of this code cannot be changed. i.e. this code cannot simply be
112 * copied and put under another distribution licence
113 * [including the GNU Public Licence.]
119 #include "ssl_locl.h"
120 #include <openssl/buffer.h>
121 #include <openssl/rand.h>
122 #include <openssl/objects.h>
123 #include <openssl/evp.h>
124 #include <openssl/x509.h>
126 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
128 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
129 if ((end) - (start) <= 8) { \
131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
139 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
141 OPENSSL_assert((msg_len) > 0); \
143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
148 #define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
155 static unsigned char bitmask_start_values
[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
156 static unsigned char bitmask_end_values
[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
158 /* XDTLS: figure out the right values */
159 static const unsigned int g_probable_mtu
[] = {1500, 512, 256};
161 static void dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
162 unsigned long frag_len
);
163 static unsigned char *dtls1_write_message_header(SSL
*s
,
165 static void dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
166 unsigned long len
, unsigned short seq_num
, unsigned long frag_off
,
167 unsigned long frag_len
);
168 static long dtls1_get_message_fragment(SSL
*s
, int st1
, int stn
,
172 dtls1_hm_fragment_new(unsigned long frag_len
, int reassembly
)
174 hm_fragment
*frag
= NULL
;
175 unsigned char *buf
= NULL
;
176 unsigned char *bitmask
= NULL
;
178 frag
= (hm_fragment
*)OPENSSL_malloc(sizeof(hm_fragment
));
184 buf
= (unsigned char *)OPENSSL_malloc(frag_len
);
192 /* zero length fragment gets zero frag->fragment */
193 frag
->fragment
= buf
;
195 /* Initialize reassembly bitmask if necessary */
198 bitmask
= (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len
));
201 if (buf
!= NULL
) OPENSSL_free(buf
);
205 memset(bitmask
, 0, RSMBLY_BITMASK_SIZE(frag_len
));
208 frag
->reassembly
= bitmask
;
213 void dtls1_hm_fragment_free(hm_fragment
*frag
)
216 if (frag
->msg_header
.is_ccs
)
218 EVP_CIPHER_CTX_free(frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
);
219 EVP_MD_CTX_destroy(frag
->msg_header
.saved_retransmit_state
.write_hash
);
221 if (frag
->fragment
) OPENSSL_free(frag
->fragment
);
222 if (frag
->reassembly
) OPENSSL_free(frag
->reassembly
);
226 static int dtls1_query_mtu(SSL
*s
)
230 s
->d1
->mtu
= s
->d1
->link_mtu
-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
234 /* AHA! Figure out the MTU, and stick to the right size */
235 if (s
->d1
->mtu
< dtls1_min_mtu(s
))
237 if(!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
))
240 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_QUERY_MTU
, 0, NULL
);
242 /* I've seen the kernel return bogus numbers when it doesn't know
243 * (initial write), so just make sure we have a reasonable number */
244 if (s
->d1
->mtu
< dtls1_min_mtu(s
))
247 s
->d1
->mtu
= dtls1_min_mtu(s
);
248 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SET_MTU
,
258 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
259 int dtls1_do_write(SSL
*s
, int type
)
262 unsigned int curr_mtu
;
264 unsigned int len
, frag_off
, mac_size
, blocksize
, used_len
;
266 if(!dtls1_query_mtu(s
))
269 OPENSSL_assert(s
->d1
->mtu
>= dtls1_min_mtu(s
)); /* should have something reasonable now */
271 if ( s
->init_off
== 0 && type
== SSL3_RT_HANDSHAKE
)
272 OPENSSL_assert(s
->init_num
==
273 (int)s
->d1
->w_msg_hdr
.msg_len
+ DTLS1_HM_HEADER_LENGTH
);
277 if (s
->enc_write_ctx
&& EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_GCM_MODE
)
280 mac_size
= EVP_MD_CTX_size(s
->write_hash
);
285 if (s
->enc_write_ctx
&&
286 (EVP_CIPHER_CTX_mode(s
->enc_write_ctx
) == EVP_CIPH_CBC_MODE
))
287 blocksize
= 2 * EVP_CIPHER_block_size(s
->enc_write_ctx
->cipher
);
292 /* s->init_num shouldn't ever be < 0...but just in case */
293 while(s
->init_num
> 0)
295 used_len
= BIO_wpending(SSL_get_wbio(s
)) + DTLS1_RT_HEADER_LENGTH
296 + mac_size
+ blocksize
;
297 if(s
->d1
->mtu
> used_len
)
298 curr_mtu
= s
->d1
->mtu
- used_len
;
302 if ( curr_mtu
<= DTLS1_HM_HEADER_LENGTH
)
304 /* grr.. we could get an error if MTU picked was wrong */
305 ret
= BIO_flush(SSL_get_wbio(s
));
308 used_len
= DTLS1_RT_HEADER_LENGTH
+ mac_size
+ blocksize
;
309 if(s
->d1
->mtu
> used_len
+ DTLS1_HM_HEADER_LENGTH
)
311 curr_mtu
= s
->d1
->mtu
- used_len
;
315 /* Shouldn't happen */
320 /* We just checked that s->init_num > 0 so this cast should be safe */
321 if (((unsigned int)s
->init_num
) > curr_mtu
)
326 /* Shouldn't ever happen */
330 /* XDTLS: this function is too long. split out the CCS part */
331 if ( type
== SSL3_RT_HANDSHAKE
)
333 if ( s
->init_off
!= 0)
335 OPENSSL_assert(s
->init_off
> DTLS1_HM_HEADER_LENGTH
);
336 s
->init_off
-= DTLS1_HM_HEADER_LENGTH
;
337 s
->init_num
+= DTLS1_HM_HEADER_LENGTH
;
339 /* We just checked that s->init_num > 0 so this cast should be safe */
340 if (((unsigned int)s
->init_num
) > curr_mtu
)
346 /* Shouldn't ever happen */
350 if ( len
< DTLS1_HM_HEADER_LENGTH
)
353 * len is so small that we really can't do anything sensible
358 dtls1_fix_message_header(s
, frag_off
,
359 len
- DTLS1_HM_HEADER_LENGTH
);
361 dtls1_write_message_header(s
, (unsigned char *)&s
->init_buf
->data
[s
->init_off
]);
364 ret
=dtls1_write_bytes(s
,type
,&s
->init_buf
->data
[s
->init_off
],
368 /* might need to update MTU here, but we don't know
369 * which previous packet caused the failure -- so can't
370 * really retransmit anything. continue as if everything
371 * is fine and wait for an alert to handle the
374 if ( retry
&& BIO_ctrl(SSL_get_wbio(s
),
375 BIO_CTRL_DGRAM_MTU_EXCEEDED
, 0, NULL
) > 0 )
377 if(!(SSL_get_options(s
) & SSL_OP_NO_QUERY_MTU
))
379 if(!dtls1_query_mtu(s
))
381 /* Have one more go */
395 /* bad if this assert fails, only part of the handshake
396 * message got sent. but why would this happen? */
397 OPENSSL_assert(len
== (unsigned int)ret
);
399 if (type
== SSL3_RT_HANDSHAKE
&& ! s
->d1
->retransmitting
)
401 /* should not be done for 'Hello Request's, but in that case
402 * we'll ignore the result anyway */
403 unsigned char *p
= (unsigned char *)&s
->init_buf
->data
[s
->init_off
];
404 const struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
407 if (frag_off
== 0 && s
->version
!= DTLS1_BAD_VER
)
409 /* reconstruct message header is if it
410 * is being sent in single fragment */
411 *p
++ = msg_hdr
->type
;
412 l2n3(msg_hdr
->msg_len
,p
);
413 s2n (msg_hdr
->seq
,p
);
415 l2n3(msg_hdr
->msg_len
,p
);
416 p
-= DTLS1_HM_HEADER_LENGTH
;
421 p
+= DTLS1_HM_HEADER_LENGTH
;
422 xlen
= ret
- DTLS1_HM_HEADER_LENGTH
;
425 ssl3_finish_mac(s
, p
, xlen
);
428 if (ret
== s
->init_num
)
431 s
->msg_callback(1, s
->version
, type
, s
->init_buf
->data
,
432 (size_t)(s
->init_off
+ s
->init_num
), s
,
433 s
->msg_callback_arg
);
435 s
->init_off
= 0; /* done writing this message */
442 frag_off
+= (ret
-= DTLS1_HM_HEADER_LENGTH
);
449 /* Obtain handshake message of message type 'mt' (any if mt == -1),
450 * maximum acceptable body length 'max'.
451 * Read an entire handshake message. Handshake messages arrive in
454 long dtls1_get_message(SSL
*s
, int st1
, int stn
, int mt
, long max
, int *ok
)
457 struct hm_header_st
*msg_hdr
;
459 unsigned long msg_len
;
461 /* s3->tmp is used to store messages that are unexpected, caused
462 * by the absence of an optional handshake message */
463 if (s
->s3
->tmp
.reuse_message
)
465 s
->s3
->tmp
.reuse_message
=0;
466 if ((mt
>= 0) && (s
->s3
->tmp
.message_type
!= mt
))
468 al
=SSL_AD_UNEXPECTED_MESSAGE
;
469 SSLerr(SSL_F_DTLS1_GET_MESSAGE
,SSL_R_UNEXPECTED_MESSAGE
);
473 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
474 s
->init_num
= (int)s
->s3
->tmp
.message_size
;
478 msg_hdr
= &s
->d1
->r_msg_hdr
;
479 memset(msg_hdr
, 0x00, sizeof(struct hm_header_st
));
482 i
= dtls1_get_message_fragment(s
, st1
, stn
, max
, ok
);
483 if ( i
== DTLS1_HM_BAD_FRAGMENT
||
484 i
== DTLS1_HM_FRAGMENT_RETRY
) /* bad fragment received */
486 else if ( i
<= 0 && !*ok
)
489 p
= (unsigned char *)s
->init_buf
->data
;
490 msg_len
= msg_hdr
->msg_len
;
492 /* reconstruct message header */
493 *(p
++) = msg_hdr
->type
;
495 s2n (msg_hdr
->seq
,p
);
498 if (s
->version
!= DTLS1_BAD_VER
) {
499 p
-= DTLS1_HM_HEADER_LENGTH
;
500 msg_len
+= DTLS1_HM_HEADER_LENGTH
;
503 ssl3_finish_mac(s
, p
, msg_len
);
505 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
507 s
, s
->msg_callback_arg
);
509 memset(msg_hdr
, 0x00, sizeof(struct hm_header_st
));
511 /* Don't change sequence numbers while listening */
513 s
->d1
->handshake_read_seq
++;
515 s
->init_msg
= s
->init_buf
->data
+ DTLS1_HM_HEADER_LENGTH
;
519 ssl3_send_alert(s
,SSL3_AL_FATAL
,al
);
525 static int dtls1_preprocess_fragment(SSL
*s
,struct hm_header_st
*msg_hdr
,int max
)
527 size_t frag_off
,frag_len
,msg_len
;
529 msg_len
= msg_hdr
->msg_len
;
530 frag_off
= msg_hdr
->frag_off
;
531 frag_len
= msg_hdr
->frag_len
;
533 /* sanity checking */
534 if ( (frag_off
+frag_len
) > msg_len
)
536 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
,SSL_R_EXCESSIVE_MESSAGE_SIZE
);
537 return SSL_AD_ILLEGAL_PARAMETER
;
540 if ( (frag_off
+frag_len
) > (unsigned long)max
)
542 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
,SSL_R_EXCESSIVE_MESSAGE_SIZE
);
543 return SSL_AD_ILLEGAL_PARAMETER
;
546 if ( s
->d1
->r_msg_hdr
.frag_off
== 0) /* first fragment */
548 /* msg_len is limited to 2^24, but is effectively checked
549 * against max above */
550 if (!BUF_MEM_grow_clean(s
->init_buf
,msg_len
+DTLS1_HM_HEADER_LENGTH
))
552 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
,ERR_R_BUF_LIB
);
553 return SSL_AD_INTERNAL_ERROR
;
556 s
->s3
->tmp
.message_size
= msg_len
;
557 s
->d1
->r_msg_hdr
.msg_len
= msg_len
;
558 s
->s3
->tmp
.message_type
= msg_hdr
->type
;
559 s
->d1
->r_msg_hdr
.type
= msg_hdr
->type
;
560 s
->d1
->r_msg_hdr
.seq
= msg_hdr
->seq
;
562 else if (msg_len
!= s
->d1
->r_msg_hdr
.msg_len
)
564 /* They must be playing with us! BTW, failure to enforce
565 * upper limit would open possibility for buffer overrun. */
566 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT
,SSL_R_EXCESSIVE_MESSAGE_SIZE
);
567 return SSL_AD_ILLEGAL_PARAMETER
;
570 return 0; /* no error */
575 dtls1_retrieve_buffered_fragment(SSL
*s
, long max
, int *ok
)
578 * (0) check whether the desired fragment is available
580 * (1) copy over the fragment to s->init_buf->data[]
581 * (2) update s->init_num
588 item
= pqueue_peek(s
->d1
->buffered_messages
);
592 frag
= (hm_fragment
*)item
->data
;
594 /* Don't return if reassembly still in progress */
595 if (frag
->reassembly
!= NULL
)
598 if ( s
->d1
->handshake_read_seq
== frag
->msg_header
.seq
)
600 unsigned long frag_len
= frag
->msg_header
.frag_len
;
601 pqueue_pop(s
->d1
->buffered_messages
);
603 al
=dtls1_preprocess_fragment(s
,&frag
->msg_header
,max
);
605 if (al
==0) /* no alert */
607 unsigned char *p
= (unsigned char *)s
->init_buf
->data
+DTLS1_HM_HEADER_LENGTH
;
608 memcpy(&p
[frag
->msg_header
.frag_off
],
609 frag
->fragment
,frag
->msg_header
.frag_len
);
612 dtls1_hm_fragment_free(frag
);
621 ssl3_send_alert(s
,SSL3_AL_FATAL
,al
);
630 /* dtls1_max_handshake_message_len returns the maximum number of bytes
631 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
632 * be greater if the maximum certificate list size requires it. */
633 static unsigned long dtls1_max_handshake_message_len(const SSL
*s
)
635 unsigned long max_len
= DTLS1_HM_HEADER_LENGTH
+ SSL3_RT_MAX_ENCRYPTED_LENGTH
;
636 if (max_len
< (unsigned long)s
->max_cert_list
)
637 return s
->max_cert_list
;
642 dtls1_reassemble_fragment(SSL
*s
, const struct hm_header_st
* msg_hdr
, int *ok
)
644 hm_fragment
*frag
= NULL
;
646 int i
= -1, is_complete
;
647 unsigned char seq64be
[8];
648 unsigned long frag_len
= msg_hdr
->frag_len
;
650 if ((msg_hdr
->frag_off
+frag_len
) > msg_hdr
->msg_len
||
651 msg_hdr
->msg_len
> dtls1_max_handshake_message_len(s
))
655 return DTLS1_HM_FRAGMENT_RETRY
;
657 /* Try to find item in queue */
658 memset(seq64be
,0,sizeof(seq64be
));
659 seq64be
[6] = (unsigned char) (msg_hdr
->seq
>>8);
660 seq64be
[7] = (unsigned char) msg_hdr
->seq
;
661 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
665 frag
= dtls1_hm_fragment_new(msg_hdr
->msg_len
, 1);
668 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
669 frag
->msg_header
.frag_len
= frag
->msg_header
.msg_len
;
670 frag
->msg_header
.frag_off
= 0;
674 frag
= (hm_fragment
*) item
->data
;
675 if (frag
->msg_header
.msg_len
!= msg_hdr
->msg_len
)
684 /* If message is already reassembled, this must be a
685 * retransmit and can be dropped. In this case item != NULL and so frag
686 * does not need to be freed.
688 if (frag
->reassembly
== NULL
)
690 unsigned char devnull
[256];
694 i
= s
->method
->ssl_read_bytes(s
,SSL3_RT_HANDSHAKE
,
696 frag_len
>sizeof(devnull
)?sizeof(devnull
):frag_len
,0);
700 return DTLS1_HM_FRAGMENT_RETRY
;
703 /* read the body of the fragment (header has already been read */
704 i
= s
->method
->ssl_read_bytes(s
,SSL3_RT_HANDSHAKE
,
705 frag
->fragment
+ msg_hdr
->frag_off
,frag_len
,0);
706 if ((unsigned long)i
!=frag_len
)
711 RSMBLY_BITMASK_MARK(frag
->reassembly
, (long)msg_hdr
->frag_off
,
712 (long)(msg_hdr
->frag_off
+ frag_len
));
714 RSMBLY_BITMASK_IS_COMPLETE(frag
->reassembly
, (long)msg_hdr
->msg_len
,
719 OPENSSL_free(frag
->reassembly
);
720 frag
->reassembly
= NULL
;
725 item
= pitem_new(seq64be
, frag
);
732 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
733 /* pqueue_insert fails iff a duplicate item is inserted.
734 * However, |item| cannot be a duplicate. If it were,
735 * |pqueue_find|, above, would have returned it and control
736 * would never have reached this branch. */
737 OPENSSL_assert(item
!= NULL
);
740 return DTLS1_HM_FRAGMENT_RETRY
;
743 if (frag
!= NULL
&& item
== NULL
) dtls1_hm_fragment_free(frag
);
750 dtls1_process_out_of_seq_message(SSL
*s
, const struct hm_header_st
* msg_hdr
, int *ok
)
753 hm_fragment
*frag
= NULL
;
755 unsigned char seq64be
[8];
756 unsigned long frag_len
= msg_hdr
->frag_len
;
758 if ((msg_hdr
->frag_off
+frag_len
) > msg_hdr
->msg_len
)
761 /* Try to find item in queue, to prevent duplicate entries */
762 memset(seq64be
,0,sizeof(seq64be
));
763 seq64be
[6] = (unsigned char) (msg_hdr
->seq
>>8);
764 seq64be
[7] = (unsigned char) msg_hdr
->seq
;
765 item
= pqueue_find(s
->d1
->buffered_messages
, seq64be
);
767 /* If we already have an entry and this one is a fragment,
768 * don't discard it and rather try to reassemble it.
770 if (item
!= NULL
&& frag_len
!= msg_hdr
->msg_len
)
773 /* Discard the message if sequence number was already there, is
774 * too far in the future, already in the queue or if we received
775 * a FINISHED before the SERVER_HELLO, which then must be a stale
778 if (msg_hdr
->seq
<= s
->d1
->handshake_read_seq
||
779 msg_hdr
->seq
> s
->d1
->handshake_read_seq
+ 10 || item
!= NULL
||
780 (s
->d1
->handshake_read_seq
== 0 && msg_hdr
->type
== SSL3_MT_FINISHED
))
782 unsigned char devnull
[256];
786 i
= s
->method
->ssl_read_bytes(s
,SSL3_RT_HANDSHAKE
,
788 frag_len
>sizeof(devnull
)?sizeof(devnull
):frag_len
,0);
795 if (frag_len
!= msg_hdr
->msg_len
)
796 return dtls1_reassemble_fragment(s
, msg_hdr
, ok
);
798 if (frag_len
> dtls1_max_handshake_message_len(s
))
801 frag
= dtls1_hm_fragment_new(frag_len
, 0);
805 memcpy(&(frag
->msg_header
), msg_hdr
, sizeof(*msg_hdr
));
809 /* read the body of the fragment (header has already been read */
810 i
= s
->method
->ssl_read_bytes(s
,SSL3_RT_HANDSHAKE
,
811 frag
->fragment
,frag_len
,0);
812 if ((unsigned long)i
!=frag_len
)
818 item
= pitem_new(seq64be
, frag
);
822 item
= pqueue_insert(s
->d1
->buffered_messages
, item
);
823 /* pqueue_insert fails iff a duplicate item is inserted.
824 * However, |item| cannot be a duplicate. If it were,
825 * |pqueue_find|, above, would have returned it. Then, either
826 * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
827 * to NULL and it will have been processed with
828 * |dtls1_reassemble_fragment|, above, or the record will have
830 OPENSSL_assert(item
!= NULL
);
833 return DTLS1_HM_FRAGMENT_RETRY
;
836 if (frag
!= NULL
&& item
== NULL
) dtls1_hm_fragment_free(frag
);
843 dtls1_get_message_fragment(SSL
*s
, int st1
, int stn
, long max
, int *ok
)
845 unsigned char wire
[DTLS1_HM_HEADER_LENGTH
];
846 unsigned long len
, frag_off
, frag_len
;
848 struct hm_header_st msg_hdr
;
851 /* see if we have the required fragment already */
852 if ((frag_len
= dtls1_retrieve_buffered_fragment(s
,max
,ok
)) || *ok
)
854 if (*ok
) s
->init_num
= frag_len
;
858 /* read handshake message header */
859 i
=s
->method
->ssl_read_bytes(s
,SSL3_RT_HANDSHAKE
,wire
,
860 DTLS1_HM_HEADER_LENGTH
, 0);
861 if (i
<= 0) /* nbio, or an error */
863 s
->rwstate
=SSL_READING
;
867 /* Handshake fails if message header is incomplete */
868 if (i
!= DTLS1_HM_HEADER_LENGTH
)
870 al
=SSL_AD_UNEXPECTED_MESSAGE
;
871 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT
,SSL_R_UNEXPECTED_MESSAGE
);
875 /* parse the message fragment header */
876 dtls1_get_message_header(wire
, &msg_hdr
);
879 * if this is a future (or stale) message it gets buffered
880 * (or dropped)--no further processing at this time
881 * While listening, we accept seq 1 (ClientHello with cookie)
882 * although we're still expecting seq 0 (ClientHello)
884 if (msg_hdr
.seq
!= s
->d1
->handshake_read_seq
&& !(s
->d1
->listen
&& msg_hdr
.seq
== 1))
885 return dtls1_process_out_of_seq_message(s
, &msg_hdr
, ok
);
887 len
= msg_hdr
.msg_len
;
888 frag_off
= msg_hdr
.frag_off
;
889 frag_len
= msg_hdr
.frag_len
;
891 if (frag_len
&& frag_len
< len
)
892 return dtls1_reassemble_fragment(s
, &msg_hdr
, ok
);
894 if (!s
->server
&& s
->d1
->r_msg_hdr
.frag_off
== 0 &&
895 wire
[0] == SSL3_MT_HELLO_REQUEST
)
897 /* The server may always send 'Hello Request' messages --
898 * we are doing a handshake anyway now, so ignore them
899 * if their format is correct. Does not count for
901 if (wire
[1] == 0 && wire
[2] == 0 && wire
[3] == 0)
904 s
->msg_callback(0, s
->version
, SSL3_RT_HANDSHAKE
,
905 wire
, DTLS1_HM_HEADER_LENGTH
, s
,
906 s
->msg_callback_arg
);
911 else /* Incorrectly formated Hello request */
913 al
=SSL_AD_UNEXPECTED_MESSAGE
;
914 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT
,SSL_R_UNEXPECTED_MESSAGE
);
919 if ((al
=dtls1_preprocess_fragment(s
,&msg_hdr
,max
)))
922 /* XDTLS: ressurect this when restart is in place */
927 unsigned char *p
=(unsigned char *)s
->init_buf
->data
+DTLS1_HM_HEADER_LENGTH
;
929 i
=s
->method
->ssl_read_bytes(s
,SSL3_RT_HANDSHAKE
,
930 &p
[frag_off
],frag_len
,0);
931 /* XDTLS: fix this--message fragments cannot span multiple packets */
934 s
->rwstate
=SSL_READING
;
942 /* XDTLS: an incorrectly formatted fragment should cause the
943 * handshake to fail */
944 if (i
!= (int)frag_len
)
946 al
=SSL3_AD_ILLEGAL_PARAMETER
;
947 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT
,SSL3_AD_ILLEGAL_PARAMETER
);
953 /* Note that s->init_num is *not* used as current offset in
954 * s->init_buf->data, but as a counter summing up fragments'
955 * lengths: as soon as they sum up to handshake packet
956 * length, we assume we have got all the fragments. */
957 s
->init_num
= frag_len
;
961 ssl3_send_alert(s
,SSL3_AL_FATAL
,al
);
969 * for these 2 messages, we need to
970 * ssl->enc_read_ctx re-init
971 * ssl->s3->read_sequence zero
972 * ssl->s3->read_mac_secret re-init
973 * ssl->session->read_sym_enc assign
974 * ssl->session->read_compression assign
975 * ssl->session->read_hash assign
977 int dtls1_send_change_cipher_spec(SSL
*s
, int a
, int b
)
983 p
=(unsigned char *)s
->init_buf
->data
;
985 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
986 s
->init_num
=DTLS1_CCS_HEADER_LENGTH
;
988 if (s
->version
== DTLS1_BAD_VER
) {
989 s
->d1
->next_handshake_write_seq
++;
990 s2n(s
->d1
->handshake_write_seq
,p
);
996 dtls1_set_message_header_int(s
, SSL3_MT_CCS
, 0,
997 s
->d1
->handshake_write_seq
, 0, 0);
999 /* buffer the message to handle re-xmits */
1000 dtls1_buffer_message(s
, 1);
1005 /* SSL3_ST_CW_CHANGE_B */
1006 return(dtls1_do_write(s
,SSL3_RT_CHANGE_CIPHER_SPEC
));
1009 int dtls1_read_failed(SSL
*s
, int code
)
1013 fprintf( stderr
, "invalid state reached %s:%d", __FILE__
, __LINE__
);
1017 if (!dtls1_is_timer_expired(s
))
1019 /* not a timeout, none of our business,
1020 let higher layers handle this. in fact it's probably an error */
1024 #ifndef OPENSSL_NO_HEARTBEATS
1025 if (!SSL_in_init(s
) && !s
->tlsext_hb_pending
) /* done, no need to send a retransmit */
1027 if (!SSL_in_init(s
)) /* done, no need to send a retransmit */
1030 BIO_set_flags(SSL_get_rbio(s
), BIO_FLAGS_READ
);
1034 #if 0 /* for now, each alert contains only one record number */
1035 item
= pqueue_peek(state
->rcvd_records
);
1038 /* send an alert immediately for all the missing records */
1043 #if 0 /* no more alert sending, just retransmit the last set of messages */
1044 if ( state
->timeout
.read_timeouts
>= DTLS1_TMO_READ_COUNT
)
1045 ssl3_send_alert(s
,SSL3_AL_WARNING
,
1046 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
);
1049 return dtls1_handle_timeout(s
);
1053 dtls1_get_queue_priority(unsigned short seq
, int is_ccs
)
1055 /* The index of the retransmission queue actually is the message sequence number,
1056 * since the queue only contains messages of a single handshake. However, the
1057 * ChangeCipherSpec has no message sequence number and so using only the sequence
1058 * will result in the CCS and Finished having the same index. To prevent this,
1059 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1060 * This does not only differ CSS and Finished, it also maintains the order of the
1061 * index (important for priority queues) and fits in the unsigned short variable.
1063 return seq
* 2 - is_ccs
;
1067 dtls1_retransmit_buffered_messages(SSL
*s
)
1069 pqueue sent
= s
->d1
->sent_messages
;
1075 iter
= pqueue_iterator(sent
);
1077 for ( item
= pqueue_next(&iter
); item
!= NULL
; item
= pqueue_next(&iter
))
1079 frag
= (hm_fragment
*)item
->data
;
1080 if ( dtls1_retransmit_message(s
,
1081 (unsigned short)dtls1_get_queue_priority(frag
->msg_header
.seq
, frag
->msg_header
.is_ccs
),
1082 0, &found
) <= 0 && found
)
1084 fprintf(stderr
, "dtls1_retransmit_message() failed\n");
1093 dtls1_buffer_message(SSL
*s
, int is_ccs
)
1097 unsigned char seq64be
[8];
1099 /* this function is called immediately after a message has
1100 * been serialized */
1101 OPENSSL_assert(s
->init_off
== 0);
1103 frag
= dtls1_hm_fragment_new(s
->init_num
, 0);
1107 memcpy(frag
->fragment
, s
->init_buf
->data
, s
->init_num
);
1111 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1112 DTLS1_CCS_HEADER_LENGTH
== (unsigned int)s
->init_num
);
1116 OPENSSL_assert(s
->d1
->w_msg_hdr
.msg_len
+
1117 DTLS1_HM_HEADER_LENGTH
== (unsigned int)s
->init_num
);
1120 frag
->msg_header
.msg_len
= s
->d1
->w_msg_hdr
.msg_len
;
1121 frag
->msg_header
.seq
= s
->d1
->w_msg_hdr
.seq
;
1122 frag
->msg_header
.type
= s
->d1
->w_msg_hdr
.type
;
1123 frag
->msg_header
.frag_off
= 0;
1124 frag
->msg_header
.frag_len
= s
->d1
->w_msg_hdr
.msg_len
;
1125 frag
->msg_header
.is_ccs
= is_ccs
;
1127 /* save current state*/
1128 frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
= s
->enc_write_ctx
;
1129 frag
->msg_header
.saved_retransmit_state
.write_hash
= s
->write_hash
;
1130 frag
->msg_header
.saved_retransmit_state
.compress
= s
->compress
;
1131 frag
->msg_header
.saved_retransmit_state
.session
= s
->session
;
1132 frag
->msg_header
.saved_retransmit_state
.epoch
= s
->d1
->w_epoch
;
1134 memset(seq64be
,0,sizeof(seq64be
));
1135 seq64be
[6] = (unsigned char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1136 frag
->msg_header
.is_ccs
)>>8);
1137 seq64be
[7] = (unsigned char)(dtls1_get_queue_priority(frag
->msg_header
.seq
,
1138 frag
->msg_header
.is_ccs
));
1140 item
= pitem_new(seq64be
, frag
);
1143 dtls1_hm_fragment_free(frag
);
1148 fprintf( stderr
, "buffered messge: \ttype = %xx\n", msg_buf
->type
);
1149 fprintf( stderr
, "\t\t\t\t\tlen = %d\n", msg_buf
->len
);
1150 fprintf( stderr
, "\t\t\t\t\tseq_num = %d\n", msg_buf
->seq_num
);
1153 pqueue_insert(s
->d1
->sent_messages
, item
);
1158 dtls1_retransmit_message(SSL
*s
, unsigned short seq
, unsigned long frag_off
,
1162 /* XDTLS: for now assuming that read/writes are blocking */
1165 unsigned long header_length
;
1166 unsigned char seq64be
[8];
1167 struct dtls1_retransmit_state saved_state
;
1168 unsigned char save_write_sequence
[8];
1171 OPENSSL_assert(s->init_num == 0);
1172 OPENSSL_assert(s->init_off == 0);
1175 /* XDTLS: the requested message ought to be found, otherwise error */
1176 memset(seq64be
,0,sizeof(seq64be
));
1177 seq64be
[6] = (unsigned char)(seq
>>8);
1178 seq64be
[7] = (unsigned char)seq
;
1180 item
= pqueue_find(s
->d1
->sent_messages
, seq64be
);
1183 fprintf(stderr
, "retransmit: message %d non-existant\n", seq
);
1189 frag
= (hm_fragment
*)item
->data
;
1191 if ( frag
->msg_header
.is_ccs
)
1192 header_length
= DTLS1_CCS_HEADER_LENGTH
;
1194 header_length
= DTLS1_HM_HEADER_LENGTH
;
1196 memcpy(s
->init_buf
->data
, frag
->fragment
,
1197 frag
->msg_header
.msg_len
+ header_length
);
1198 s
->init_num
= frag
->msg_header
.msg_len
+ header_length
;
1200 dtls1_set_message_header_int(s
, frag
->msg_header
.type
,
1201 frag
->msg_header
.msg_len
, frag
->msg_header
.seq
, 0,
1202 frag
->msg_header
.frag_len
);
1204 /* save current state */
1205 saved_state
.enc_write_ctx
= s
->enc_write_ctx
;
1206 saved_state
.write_hash
= s
->write_hash
;
1207 saved_state
.compress
= s
->compress
;
1208 saved_state
.session
= s
->session
;
1209 saved_state
.epoch
= s
->d1
->w_epoch
;
1210 saved_state
.epoch
= s
->d1
->w_epoch
;
1212 s
->d1
->retransmitting
= 1;
1214 /* restore state in which the message was originally sent */
1215 s
->enc_write_ctx
= frag
->msg_header
.saved_retransmit_state
.enc_write_ctx
;
1216 s
->write_hash
= frag
->msg_header
.saved_retransmit_state
.write_hash
;
1217 s
->compress
= frag
->msg_header
.saved_retransmit_state
.compress
;
1218 s
->session
= frag
->msg_header
.saved_retransmit_state
.session
;
1219 s
->d1
->w_epoch
= frag
->msg_header
.saved_retransmit_state
.epoch
;
1221 if (frag
->msg_header
.saved_retransmit_state
.epoch
== saved_state
.epoch
- 1)
1223 memcpy(save_write_sequence
, s
->s3
->write_sequence
, sizeof(s
->s3
->write_sequence
));
1224 memcpy(s
->s3
->write_sequence
, s
->d1
->last_write_sequence
, sizeof(s
->s3
->write_sequence
));
1227 ret
= dtls1_do_write(s
, frag
->msg_header
.is_ccs
?
1228 SSL3_RT_CHANGE_CIPHER_SPEC
: SSL3_RT_HANDSHAKE
);
1230 /* restore current state */
1231 s
->enc_write_ctx
= saved_state
.enc_write_ctx
;
1232 s
->write_hash
= saved_state
.write_hash
;
1233 s
->compress
= saved_state
.compress
;
1234 s
->session
= saved_state
.session
;
1235 s
->d1
->w_epoch
= saved_state
.epoch
;
1237 if (frag
->msg_header
.saved_retransmit_state
.epoch
== saved_state
.epoch
- 1)
1239 memcpy(s
->d1
->last_write_sequence
, s
->s3
->write_sequence
, sizeof(s
->s3
->write_sequence
));
1240 memcpy(s
->s3
->write_sequence
, save_write_sequence
, sizeof(s
->s3
->write_sequence
));
1243 s
->d1
->retransmitting
= 0;
1245 (void)BIO_flush(SSL_get_wbio(s
));
1249 /* call this function when the buffered messages are no longer needed */
1251 dtls1_clear_record_buffer(SSL
*s
)
1255 for(item
= pqueue_pop(s
->d1
->sent_messages
);
1256 item
!= NULL
; item
= pqueue_pop(s
->d1
->sent_messages
))
1258 dtls1_hm_fragment_free((hm_fragment
*)item
->data
);
1265 dtls1_set_message_header(SSL
*s
, unsigned char *p
, unsigned char mt
,
1266 unsigned long len
, unsigned long frag_off
, unsigned long frag_len
)
1268 /* Don't change sequence numbers while listening */
1269 if (frag_off
== 0 && !s
->d1
->listen
)
1271 s
->d1
->handshake_write_seq
= s
->d1
->next_handshake_write_seq
;
1272 s
->d1
->next_handshake_write_seq
++;
1275 dtls1_set_message_header_int(s
, mt
, len
, s
->d1
->handshake_write_seq
,
1276 frag_off
, frag_len
);
1278 return p
+= DTLS1_HM_HEADER_LENGTH
;
1282 /* don't actually do the writing, wait till the MTU has been retrieved */
1284 dtls1_set_message_header_int(SSL
*s
, unsigned char mt
,
1285 unsigned long len
, unsigned short seq_num
, unsigned long frag_off
,
1286 unsigned long frag_len
)
1288 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1291 msg_hdr
->msg_len
= len
;
1292 msg_hdr
->seq
= seq_num
;
1293 msg_hdr
->frag_off
= frag_off
;
1294 msg_hdr
->frag_len
= frag_len
;
1298 dtls1_fix_message_header(SSL
*s
, unsigned long frag_off
,
1299 unsigned long frag_len
)
1301 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1303 msg_hdr
->frag_off
= frag_off
;
1304 msg_hdr
->frag_len
= frag_len
;
1307 static unsigned char *
1308 dtls1_write_message_header(SSL
*s
, unsigned char *p
)
1310 struct hm_header_st
*msg_hdr
= &s
->d1
->w_msg_hdr
;
1312 *p
++ = msg_hdr
->type
;
1313 l2n3(msg_hdr
->msg_len
, p
);
1315 s2n(msg_hdr
->seq
, p
);
1316 l2n3(msg_hdr
->frag_off
, p
);
1317 l2n3(msg_hdr
->frag_len
, p
);
1323 dtls1_link_min_mtu(void)
1325 return (g_probable_mtu
[(sizeof(g_probable_mtu
) /
1326 sizeof(g_probable_mtu
[0])) - 1]);
1330 dtls1_min_mtu(SSL
*s
)
1332 return dtls1_link_min_mtu()-BIO_dgram_get_mtu_overhead(SSL_get_wbio(s
));
1337 dtls1_get_message_header(unsigned char *data
, struct hm_header_st
*msg_hdr
)
1339 memset(msg_hdr
, 0x00, sizeof(struct hm_header_st
));
1340 msg_hdr
->type
= *(data
++);
1341 n2l3(data
, msg_hdr
->msg_len
);
1343 n2s(data
, msg_hdr
->seq
);
1344 n2l3(data
, msg_hdr
->frag_off
);
1345 n2l3(data
, msg_hdr
->frag_len
);
1349 dtls1_get_ccs_header(unsigned char *data
, struct ccs_header_st
*ccs_hdr
)
1351 memset(ccs_hdr
, 0x00, sizeof(struct ccs_header_st
));
1353 ccs_hdr
->type
= *(data
++);
1356 int dtls1_shutdown(SSL
*s
)
1359 #ifndef OPENSSL_NO_SCTP
1360 if (BIO_dgram_is_sctp(SSL_get_wbio(s
)) &&
1361 !(s
->shutdown
& SSL_SENT_SHUTDOWN
))
1363 ret
= BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s
));
1364 if (ret
< 0) return -1;
1367 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 1, NULL
);
1370 ret
= ssl3_shutdown(s
);
1371 #ifndef OPENSSL_NO_SCTP
1372 BIO_ctrl(SSL_get_wbio(s
), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN
, 0, NULL
);
1377 #ifndef OPENSSL_NO_HEARTBEATS
1379 dtls1_process_heartbeat(SSL
*s
)
1381 unsigned char *p
= &s
->s3
->rrec
.data
[0], *pl
;
1382 unsigned short hbtype
;
1383 unsigned int payload
;
1384 unsigned int padding
= 16; /* Use minimum padding */
1386 if (s
->msg_callback
)
1387 s
->msg_callback(0, s
->version
, TLS1_RT_HEARTBEAT
,
1388 &s
->s3
->rrec
.data
[0], s
->s3
->rrec
.length
,
1389 s
, s
->msg_callback_arg
);
1391 /* Read type and payload length first */
1392 if (1 + 2 + 16 > s
->s3
->rrec
.length
)
1393 return 0; /* silently discard */
1394 if (s
->s3
->rrec
.length
> SSL3_RT_MAX_PLAIN_LENGTH
)
1395 return 0; /* silently discard per RFC 6520 sec. 4 */
1399 if (1 + 2 + payload
+ 16 > s
->s3
->rrec
.length
)
1400 return 0; /* silently discard per RFC 6520 sec. 4 */
1403 if (hbtype
== TLS1_HB_REQUEST
)
1405 unsigned char *buffer
, *bp
;
1406 unsigned int write_length
= 1 /* heartbeat type */ +
1407 2 /* heartbeat length */ +
1411 if (write_length
> SSL3_RT_MAX_PLAIN_LENGTH
)
1414 /* Allocate memory for the response, size is 1 byte
1415 * message type, plus 2 bytes payload length, plus
1416 * payload, plus padding
1418 buffer
= OPENSSL_malloc(write_length
);
1423 /* Enter response type, length and copy payload */
1424 *bp
++ = TLS1_HB_RESPONSE
;
1426 memcpy(bp
, pl
, payload
);
1428 /* Random padding */
1429 RAND_pseudo_bytes(bp
, padding
);
1431 r
= dtls1_write_bytes(s
, TLS1_RT_HEARTBEAT
, buffer
, write_length
);
1433 if (r
>= 0 && s
->msg_callback
)
1434 s
->msg_callback(1, s
->version
, TLS1_RT_HEARTBEAT
,
1435 buffer
, write_length
,
1436 s
, s
->msg_callback_arg
);
1438 OPENSSL_free(buffer
);
1443 else if (hbtype
== TLS1_HB_RESPONSE
)
1447 /* We only send sequence numbers (2 bytes unsigned int),
1448 * and 16 random bytes, so we just try to read the
1449 * sequence number */
1452 if (payload
== 18 && seq
== s
->tlsext_hb_seq
)
1454 dtls1_stop_timer(s
);
1456 s
->tlsext_hb_pending
= 0;
1464 dtls1_heartbeat(SSL
*s
)
1466 unsigned char *buf
, *p
;
1468 unsigned int payload
= 18; /* Sequence number + random bytes */
1469 unsigned int padding
= 16; /* Use minimum padding */
1471 /* Only send if peer supports and accepts HB requests... */
1472 if (!(s
->tlsext_heartbeat
& SSL_TLSEXT_HB_ENABLED
) ||
1473 s
->tlsext_heartbeat
& SSL_TLSEXT_HB_DONT_SEND_REQUESTS
)
1475 SSLerr(SSL_F_DTLS1_HEARTBEAT
,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT
);
1479 /* ...and there is none in flight yet... */
1480 if (s
->tlsext_hb_pending
)
1482 SSLerr(SSL_F_DTLS1_HEARTBEAT
,SSL_R_TLS_HEARTBEAT_PENDING
);
1486 /* ...and no handshake in progress. */
1487 if (SSL_in_init(s
) || s
->in_handshake
)
1489 SSLerr(SSL_F_DTLS1_HEARTBEAT
,SSL_R_UNEXPECTED_MESSAGE
);
1493 /* Check if padding is too long, payload and padding
1494 * must not exceed 2^14 - 3 = 16381 bytes in total.
1496 OPENSSL_assert(payload
+ padding
<= 16381);
1499 * Create HeartBeat message, we just use a sequence number
1500 * as payload to distuingish different messages and add
1501 * some random stuff.
1502 * - Message Type, 1 byte
1503 * - Payload Length, 2 bytes (unsigned int)
1504 * - Payload, the sequence number (2 bytes uint)
1505 * - Payload, random bytes (16 bytes uint)
1508 buf
= OPENSSL_malloc(1 + 2 + payload
+ padding
);
1511 SSLerr(SSL_F_DTLS1_HEARTBEAT
, ERR_R_MALLOC_FAILURE
);
1516 *p
++ = TLS1_HB_REQUEST
;
1517 /* Payload length (18 bytes here) */
1519 /* Sequence number */
1520 s2n(s
->tlsext_hb_seq
, p
);
1521 /* 16 random bytes */
1522 RAND_pseudo_bytes(p
, 16);
1524 /* Random padding */
1525 RAND_pseudo_bytes(p
, padding
);
1527 ret
= dtls1_write_bytes(s
, TLS1_RT_HEARTBEAT
, buf
, 3 + payload
+ padding
);
1530 if (s
->msg_callback
)
1531 s
->msg_callback(1, s
->version
, TLS1_RT_HEARTBEAT
,
1532 buf
, 3 + payload
+ padding
,
1533 s
, s
->msg_callback_arg
);
1535 dtls1_start_timer(s
);
1536 s
->tlsext_hb_pending
= 1;