1/* ssl/d1_both.c */
2/*
3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5 */
6/* ====================================================================
7 * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 *    notice, this list of conditions and the following disclaimer.
15 *
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
19 *    distribution.
20 *
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/)"
25 *
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.
30 *
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.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 *    acknowledgment:
37 *    "This product includes software developed by the OpenSSL Project
38 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
39 *
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 * ====================================================================
53 *
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).
57 *
58 */
59/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
61 *
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.
65 *
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).
72 *
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.
79 *
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
82 * are met:
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)"
97 *
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
108 * SUCH DAMAGE.
109 *
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.]
114 */
115
116#include <limits.h>
117#include <string.h>
118#include <stdio.h>
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>
125
126#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
127
128#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
129			if ((end) - (start) <= 8) { \
130				long ii; \
131				for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
132			} else { \
133				long ii; \
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)]; \
137			} }
138
139#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
140			long ii; \
141			OPENSSL_assert((msg_len) > 0); \
142			is_complete = 1; \
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; } }
146
147#if 0
148#define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
149			long ii; \
150			printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
151			printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
152			printf("\n"); }
153#endif
154
155static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
156static unsigned char bitmask_end_values[]   = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
157
158/* XDTLS:  figure out the right values */
159static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
160
161static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
162static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
163	unsigned long frag_len);
164static unsigned char *dtls1_write_message_header(SSL *s,
165	unsigned char *p);
166static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
167	unsigned long len, unsigned short seq_num, unsigned long frag_off,
168	unsigned long frag_len);
169static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
170	long max, int *ok);
171
172static hm_fragment *
173dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
174	{
175	hm_fragment *frag = NULL;
176	unsigned char *buf = NULL;
177	unsigned char *bitmask = NULL;
178
179	frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
180	if ( frag == NULL)
181		return NULL;
182
183	if (frag_len)
184		{
185		buf = (unsigned char *)OPENSSL_malloc(frag_len);
186		if ( buf == NULL)
187			{
188			OPENSSL_free(frag);
189			return NULL;
190			}
191		}
192
193	/* zero length fragment gets zero frag->fragment */
194	frag->fragment = buf;
195
196	/* Initialize reassembly bitmask if necessary */
197	if (reassembly)
198		{
199		bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
200		if (bitmask == NULL)
201			{
202			if (buf != NULL) OPENSSL_free(buf);
203			OPENSSL_free(frag);
204			return NULL;
205			}
206		memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
207		}
208
209	frag->reassembly = bitmask;
210
211	return frag;
212	}
213
214static void
215dtls1_hm_fragment_free(hm_fragment *frag)
216	{
217	if (frag->fragment) OPENSSL_free(frag->fragment);
218	if (frag->reassembly) OPENSSL_free(frag->reassembly);
219	OPENSSL_free(frag);
220	}
221
222/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
223int dtls1_do_write(SSL *s, int type)
224	{
225	int ret;
226	int curr_mtu;
227	unsigned int len, frag_off, mac_size, blocksize;
228
229	/* AHA!  Figure out the MTU, and stick to the right size */
230	if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
231		{
232		s->d1->mtu =
233			BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
234
235		/* I've seen the kernel return bogus numbers when it doesn't know
236		 * (initial write), so just make sure we have a reasonable number */
237		if (s->d1->mtu < dtls1_min_mtu())
238			{
239			s->d1->mtu = 0;
240			s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
241			BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
242				s->d1->mtu, NULL);
243			}
244		}
245#if 0
246	mtu = s->d1->mtu;
247
248	fprintf(stderr, "using MTU = %d\n", mtu);
249
250	mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
251
252	curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
253
254	if ( curr_mtu > 0)
255		mtu = curr_mtu;
256	else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
257		return ret;
258
259	if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
260		{
261		ret = BIO_flush(SSL_get_wbio(s));
262		if ( ret <= 0)
263			return ret;
264		mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
265		}
266#endif
267
268	OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu());  /* should have something reasonable now */
269
270	if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
271		OPENSSL_assert(s->init_num ==
272			(int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
273
274	if (s->write_hash)
275		mac_size = EVP_MD_CTX_size(s->write_hash);
276	else
277		mac_size = 0;
278
279	if (s->enc_write_ctx &&
280		(EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
281		blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
282	else
283		blocksize = 0;
284
285	frag_off = 0;
286	while( s->init_num)
287		{
288		curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
289			DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
290
291		if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
292			{
293			/* grr.. we could get an error if MTU picked was wrong */
294			ret = BIO_flush(SSL_get_wbio(s));
295			if ( ret <= 0)
296				return ret;
297			curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
298				mac_size - blocksize;
299			}
300
301		if ( s->init_num > curr_mtu)
302			len = curr_mtu;
303		else
304			len = s->init_num;
305
306
307		/* XDTLS: this function is too long.  split out the CCS part */
308		if ( type == SSL3_RT_HANDSHAKE)
309			{
310			if ( s->init_off != 0)
311				{
312				OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
313				s->init_off -= DTLS1_HM_HEADER_LENGTH;
314				s->init_num += DTLS1_HM_HEADER_LENGTH;
315
316				/* write atleast DTLS1_HM_HEADER_LENGTH bytes */
317				if ( len <= DTLS1_HM_HEADER_LENGTH)
318					len += DTLS1_HM_HEADER_LENGTH;
319				}
320
321			dtls1_fix_message_header(s, frag_off,
322				len - DTLS1_HM_HEADER_LENGTH);
323
324			dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
325
326			OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
327			}
328
329		ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
330			len);
331		if (ret < 0)
332			{
333			/* might need to update MTU here, but we don't know
334			 * which previous packet caused the failure -- so can't
335			 * really retransmit anything.  continue as if everything
336			 * is fine and wait for an alert to handle the
337			 * retransmit
338			 */
339			if ( BIO_ctrl(SSL_get_wbio(s),
340				BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
341				s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
342					BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
343			else
344				return(-1);
345			}
346		else
347			{
348
349			/* bad if this assert fails, only part of the handshake
350			 * message got sent.  but why would this happen? */
351			OPENSSL_assert(len == (unsigned int)ret);
352
353			if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
354				{
355				/* should not be done for 'Hello Request's, but in that case
356				 * we'll ignore the result anyway */
357				unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
358				const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
359				int xlen;
360
361				if (frag_off == 0 && s->version != DTLS1_BAD_VER)
362					{
363					/* reconstruct message header is if it
364					 * is being sent in single fragment */
365					*p++ = msg_hdr->type;
366					l2n3(msg_hdr->msg_len,p);
367					s2n (msg_hdr->seq,p);
368					l2n3(0,p);
369					l2n3(msg_hdr->msg_len,p);
370					p  -= DTLS1_HM_HEADER_LENGTH;
371					xlen = ret;
372					}
373				else
374					{
375					p  += DTLS1_HM_HEADER_LENGTH;
376					xlen = ret - DTLS1_HM_HEADER_LENGTH;
377					}
378
379				ssl3_finish_mac(s, p, xlen);
380				}
381
382			if (ret == s->init_num)
383				{
384				if (s->msg_callback)
385					s->msg_callback(1, s->version, type, s->init_buf->data,
386						(size_t)(s->init_off + s->init_num), s,
387						s->msg_callback_arg);
388
389				s->init_off = 0;  /* done writing this message */
390				s->init_num = 0;
391
392				return(1);
393				}
394			s->init_off+=ret;
395			s->init_num-=ret;
396			frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
397			}
398		}
399	return(0);
400	}
401
402
403/* Obtain handshake message of message type 'mt' (any if mt == -1),
404 * maximum acceptable body length 'max'.
405 * Read an entire handshake message.  Handshake messages arrive in
406 * fragments.
407 */
408long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
409	{
410	int i, al;
411	struct hm_header_st *msg_hdr;
412	unsigned char *p;
413	unsigned long msg_len;
414
415	/* s3->tmp is used to store messages that are unexpected, caused
416	 * by the absence of an optional handshake message */
417	if (s->s3->tmp.reuse_message)
418		{
419		s->s3->tmp.reuse_message=0;
420		if ((mt >= 0) && (s->s3->tmp.message_type != mt))
421			{
422			al=SSL_AD_UNEXPECTED_MESSAGE;
423			SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
424			goto f_err;
425			}
426		*ok=1;
427		s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
428		s->init_num = (int)s->s3->tmp.message_size;
429		return s->init_num;
430		}
431
432	msg_hdr = &s->d1->r_msg_hdr;
433	memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
434
435again:
436	i = dtls1_get_message_fragment(s, st1, stn, max, ok);
437	if ( i == DTLS1_HM_BAD_FRAGMENT ||
438		i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
439		goto again;
440	else if ( i <= 0 && !*ok)
441		return i;
442
443	p = (unsigned char *)s->init_buf->data;
444	msg_len = msg_hdr->msg_len;
445
446	/* reconstruct message header */
447	*(p++) = msg_hdr->type;
448	l2n3(msg_len,p);
449	s2n (msg_hdr->seq,p);
450	l2n3(0,p);
451	l2n3(msg_len,p);
452	if (s->version != DTLS1_BAD_VER) {
453		p       -= DTLS1_HM_HEADER_LENGTH;
454		msg_len += DTLS1_HM_HEADER_LENGTH;
455	}
456
457	ssl3_finish_mac(s, p, msg_len);
458	if (s->msg_callback)
459		s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
460			p, msg_len,
461			s, s->msg_callback_arg);
462
463	memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
464
465	/* Don't change sequence numbers while listening */
466	if (!s->d1->listen)
467		s->d1->handshake_read_seq++;
468
469	s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
470	return s->init_num;
471
472f_err:
473	ssl3_send_alert(s,SSL3_AL_FATAL,al);
474	*ok = 0;
475	return -1;
476	}
477
478
479static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
480	{
481	size_t frag_off,frag_len,msg_len;
482
483	msg_len  = msg_hdr->msg_len;
484	frag_off = msg_hdr->frag_off;
485	frag_len = msg_hdr->frag_len;
486
487	/* sanity checking */
488	if ( (frag_off+frag_len) > msg_len)
489		{
490		SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
491		return SSL_AD_ILLEGAL_PARAMETER;
492		}
493
494	if ( (frag_off+frag_len) > (unsigned long)max)
495		{
496		SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
497		return SSL_AD_ILLEGAL_PARAMETER;
498		}
499
500	if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
501		{
502		/* msg_len is limited to 2^24, but is effectively checked
503		 * against max above */
504		if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
505			{
506			SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
507			return SSL_AD_INTERNAL_ERROR;
508			}
509
510		s->s3->tmp.message_size  = msg_len;
511		s->d1->r_msg_hdr.msg_len = msg_len;
512		s->s3->tmp.message_type  = msg_hdr->type;
513		s->d1->r_msg_hdr.type    = msg_hdr->type;
514		s->d1->r_msg_hdr.seq     = msg_hdr->seq;
515		}
516	else if (msg_len != s->d1->r_msg_hdr.msg_len)
517		{
518		/* They must be playing with us! BTW, failure to enforce
519		 * upper limit would open possibility for buffer overrun. */
520		SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
521		return SSL_AD_ILLEGAL_PARAMETER;
522		}
523
524	return 0; /* no error */
525	}
526
527
528static int
529dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
530	{
531	/* (0) check whether the desired fragment is available
532	 * if so:
533	 * (1) copy over the fragment to s->init_buf->data[]
534	 * (2) update s->init_num
535	 */
536	pitem *item;
537	hm_fragment *frag;
538	int al;
539
540	*ok = 0;
541	item = pqueue_peek(s->d1->buffered_messages);
542	if ( item == NULL)
543		return 0;
544
545	frag = (hm_fragment *)item->data;
546
547	/* Don't return if reassembly still in progress */
548	if (frag->reassembly != NULL)
549		return 0;
550
551	if ( s->d1->handshake_read_seq == frag->msg_header.seq)
552		{
553		unsigned long frag_len = frag->msg_header.frag_len;
554		pqueue_pop(s->d1->buffered_messages);
555
556		al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
557
558		if (al==0) /* no alert */
559			{
560			unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
561			memcpy(&p[frag->msg_header.frag_off],
562				frag->fragment,frag->msg_header.frag_len);
563			}
564
565		dtls1_hm_fragment_free(frag);
566		pitem_free(item);
567
568		if (al==0)
569			{
570			*ok = 1;
571			return frag_len;
572			}
573
574		ssl3_send_alert(s,SSL3_AL_FATAL,al);
575		s->init_num = 0;
576		*ok = 0;
577		return -1;
578		}
579	else
580		return 0;
581	}
582
583
584static int
585dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
586	{
587	hm_fragment *frag = NULL;
588	pitem *item = NULL;
589	int i = -1, is_complete;
590	unsigned char seq64be[8];
591	unsigned long frag_len = msg_hdr->frag_len, max_len;
592
593	if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
594		goto err;
595
596	/* Determine maximum allowed message size. Depends on (user set)
597	 * maximum certificate length, but 16k is minimum.
598	 */
599	if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
600		max_len = s->max_cert_list;
601	else
602		max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
603
604	if ((msg_hdr->frag_off+frag_len) > max_len)
605		goto err;
606
607	/* Try to find item in queue */
608	memset(seq64be,0,sizeof(seq64be));
609	seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
610	seq64be[7] = (unsigned char) msg_hdr->seq;
611	item = pqueue_find(s->d1->buffered_messages, seq64be);
612
613	if (item == NULL)
614		{
615		frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
616		if ( frag == NULL)
617			goto err;
618		memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
619		frag->msg_header.frag_len = frag->msg_header.msg_len;
620		frag->msg_header.frag_off = 0;
621		}
622	else
623		frag = (hm_fragment*) item->data;
624
625	/* If message is already reassembled, this must be a
626	 * retransmit and can be dropped.
627	 */
628	if (frag->reassembly == NULL)
629		{
630		unsigned char devnull [256];
631
632		while (frag_len)
633			{
634			i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
635				devnull,
636				frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
637			if (i<=0) goto err;
638			frag_len -= i;
639			}
640		return DTLS1_HM_FRAGMENT_RETRY;
641		}
642
643	/* read the body of the fragment (header has already been read */
644	i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
645		frag->fragment + msg_hdr->frag_off,frag_len,0);
646	if (i<=0 || (unsigned long)i!=frag_len)
647		goto err;
648
649	RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
650	                    (long)(msg_hdr->frag_off + frag_len));
651
652	RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
653	                           is_complete);
654
655	if (is_complete)
656		{
657		OPENSSL_free(frag->reassembly);
658		frag->reassembly = NULL;
659		}
660
661	if (item == NULL)
662		{
663		memset(seq64be,0,sizeof(seq64be));
664		seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
665		seq64be[7] = (unsigned char)(msg_hdr->seq);
666
667		item = pitem_new(seq64be, frag);
668		if (item == NULL)
669			{
670			goto err;
671			i = -1;
672			}
673
674		pqueue_insert(s->d1->buffered_messages, item);
675		}
676
677	return DTLS1_HM_FRAGMENT_RETRY;
678
679err:
680	if (frag != NULL) dtls1_hm_fragment_free(frag);
681	if (item != NULL) OPENSSL_free(item);
682	*ok = 0;
683	return i;
684	}
685
686
687static int
688dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
689{
690	int i=-1;
691	hm_fragment *frag = NULL;
692	pitem *item = NULL;
693	unsigned char seq64be[8];
694	unsigned long frag_len = msg_hdr->frag_len;
695
696	if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
697		goto err;
698
699	/* Try to find item in queue, to prevent duplicate entries */
700	memset(seq64be,0,sizeof(seq64be));
701	seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
702	seq64be[7] = (unsigned char) msg_hdr->seq;
703	item = pqueue_find(s->d1->buffered_messages, seq64be);
704
705	/* If we already have an entry and this one is a fragment,
706	 * don't discard it and rather try to reassemble it.
707	 */
708	if (item != NULL && frag_len < msg_hdr->msg_len)
709		item = NULL;
710
711	/* Discard the message if sequence number was already there, is
712	 * too far in the future, already in the queue or if we received
713	 * a FINISHED before the SERVER_HELLO, which then must be a stale
714	 * retransmit.
715	 */
716	if (msg_hdr->seq <= s->d1->handshake_read_seq ||
717		msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
718		(s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
719		{
720		unsigned char devnull [256];
721
722		while (frag_len)
723			{
724			i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
725				devnull,
726				frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
727			if (i<=0) goto err;
728			frag_len -= i;
729			}
730		}
731	else
732		{
733		if (frag_len && frag_len < msg_hdr->msg_len)
734			return dtls1_reassemble_fragment(s, msg_hdr, ok);
735
736		frag = dtls1_hm_fragment_new(frag_len, 0);
737		if ( frag == NULL)
738			goto err;
739
740		memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
741
742		if (frag_len)
743			{
744			/* read the body of the fragment (header has already been read */
745			i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
746				frag->fragment,frag_len,0);
747			if (i<=0 || (unsigned long)i!=frag_len)
748				goto err;
749			}
750
751		memset(seq64be,0,sizeof(seq64be));
752		seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
753		seq64be[7] = (unsigned char)(msg_hdr->seq);
754
755		item = pitem_new(seq64be, frag);
756		if ( item == NULL)
757			goto err;
758
759		pqueue_insert(s->d1->buffered_messages, item);
760		}
761
762	return DTLS1_HM_FRAGMENT_RETRY;
763
764err:
765	if ( frag != NULL) dtls1_hm_fragment_free(frag);
766	if ( item != NULL) OPENSSL_free(item);
767	*ok = 0;
768	return i;
769	}
770
771
772static long
773dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
774	{
775	unsigned char wire[DTLS1_HM_HEADER_LENGTH];
776	unsigned long len, frag_off, frag_len;
777	int i,al;
778	struct hm_header_st msg_hdr;
779
780	/* see if we have the required fragment already */
781	if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
782		{
783		if (*ok)	s->init_num = frag_len;
784		return frag_len;
785		}
786
787	/* read handshake message header */
788	i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
789		DTLS1_HM_HEADER_LENGTH, 0);
790	if (i <= 0) 	/* nbio, or an error */
791		{
792		s->rwstate=SSL_READING;
793		*ok = 0;
794		return i;
795		}
796	/* Handshake fails if message header is incomplete */
797	if (i != DTLS1_HM_HEADER_LENGTH)
798		{
799		al=SSL_AD_UNEXPECTED_MESSAGE;
800		SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
801		goto f_err;
802		}
803
804	/* parse the message fragment header */
805	dtls1_get_message_header(wire, &msg_hdr);
806
807	/*
808	 * if this is a future (or stale) message it gets buffered
809	 * (or dropped)--no further processing at this time
810	 * While listening, we accept seq 1 (ClientHello with cookie)
811	 * although we're still expecting seq 0 (ClientHello)
812	 */
813	if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
814		return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
815
816	len = msg_hdr.msg_len;
817	frag_off = msg_hdr.frag_off;
818	frag_len = msg_hdr.frag_len;
819
820	if (frag_len && frag_len < len)
821		return dtls1_reassemble_fragment(s, &msg_hdr, ok);
822
823	if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
824		wire[0] == SSL3_MT_HELLO_REQUEST)
825		{
826		/* The server may always send 'Hello Request' messages --
827		 * we are doing a handshake anyway now, so ignore them
828		 * if their format is correct. Does not count for
829		 * 'Finished' MAC. */
830		if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
831			{
832			if (s->msg_callback)
833				s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
834					wire, DTLS1_HM_HEADER_LENGTH, s,
835					s->msg_callback_arg);
836
837			s->init_num = 0;
838			return dtls1_get_message_fragment(s, st1, stn,
839				max, ok);
840			}
841		else /* Incorrectly formated Hello request */
842			{
843			al=SSL_AD_UNEXPECTED_MESSAGE;
844			SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
845			goto f_err;
846			}
847		}
848
849	if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
850		goto f_err;
851
852	/* XDTLS:  ressurect this when restart is in place */
853	s->state=stn;
854
855	if ( frag_len > 0)
856		{
857		unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
858
859		i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
860			&p[frag_off],frag_len,0);
861		/* XDTLS:  fix this--message fragments cannot span multiple packets */
862		if (i <= 0)
863			{
864			s->rwstate=SSL_READING;
865			*ok = 0;
866			return i;
867			}
868		}
869	else
870		i = 0;
871
872	/* XDTLS:  an incorrectly formatted fragment should cause the
873	 * handshake to fail */
874	if (i != (int)frag_len)
875		{
876		al=SSL3_AD_ILLEGAL_PARAMETER;
877		SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
878		goto f_err;
879		}
880
881	*ok = 1;
882
883	/* Note that s->init_num is *not* used as current offset in
884	 * s->init_buf->data, but as a counter summing up fragments'
885	 * lengths: as soon as they sum up to handshake packet
886	 * length, we assume we have got all the fragments. */
887	s->init_num = frag_len;
888	return frag_len;
889
890f_err:
891	ssl3_send_alert(s,SSL3_AL_FATAL,al);
892	s->init_num = 0;
893
894	*ok=0;
895	return(-1);
896	}
897
898int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
899	{
900	unsigned char *p,*d;
901	int i;
902	unsigned long l;
903
904	if (s->state == a)
905		{
906		d=(unsigned char *)s->init_buf->data;
907		p= &(d[DTLS1_HM_HEADER_LENGTH]);
908
909		i=s->method->ssl3_enc->final_finish_mac(s,
910			sender,slen,s->s3->tmp.finish_md);
911		s->s3->tmp.finish_md_len = i;
912		memcpy(p, s->s3->tmp.finish_md, i);
913		p+=i;
914		l=i;
915
916	/* Copy the finished so we can use it for
917	 * renegotiation checks
918	 */
919	if(s->type == SSL_ST_CONNECT)
920		{
921		OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
922		memcpy(s->s3->previous_client_finished,
923		       s->s3->tmp.finish_md, i);
924		s->s3->previous_client_finished_len=i;
925		}
926	else
927		{
928		OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
929		memcpy(s->s3->previous_server_finished,
930		       s->s3->tmp.finish_md, i);
931		s->s3->previous_server_finished_len=i;
932		}
933
934#ifdef OPENSSL_SYS_WIN16
935		/* MSVC 1.5 does not clear the top bytes of the word unless
936		 * I do this.
937		 */
938		l&=0xffff;
939#endif
940
941		d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
942		s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
943		s->init_off=0;
944
945		/* buffer the message to handle re-xmits */
946		dtls1_buffer_message(s, 0);
947
948		s->state=b;
949		}
950
951	/* SSL3_ST_SEND_xxxxxx_HELLO_B */
952	return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
953	}
954
955/* for these 2 messages, we need to
956 * ssl->enc_read_ctx			re-init
957 * ssl->s3->read_sequence		zero
958 * ssl->s3->read_mac_secret		re-init
959 * ssl->session->read_sym_enc		assign
960 * ssl->session->read_compression	assign
961 * ssl->session->read_hash		assign
962 */
963int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
964	{
965	unsigned char *p;
966
967	if (s->state == a)
968		{
969		p=(unsigned char *)s->init_buf->data;
970		*p++=SSL3_MT_CCS;
971		s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
972		s->init_num=DTLS1_CCS_HEADER_LENGTH;
973
974		if (s->version == DTLS1_BAD_VER) {
975			s->d1->next_handshake_write_seq++;
976			s2n(s->d1->handshake_write_seq,p);
977			s->init_num+=2;
978		}
979
980		s->init_off=0;
981
982		dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
983			s->d1->handshake_write_seq, 0, 0);
984
985		/* buffer the message to handle re-xmits */
986		dtls1_buffer_message(s, 1);
987
988		s->state=b;
989		}
990
991	/* SSL3_ST_CW_CHANGE_B */
992	return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
993	}
994
995static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
996	{
997	int n;
998	unsigned char *p;
999
1000	n=i2d_X509(x,NULL);
1001	if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1002		{
1003		SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1004		return 0;
1005		}
1006	p=(unsigned char *)&(buf->data[*l]);
1007	l2n3(n,p);
1008	i2d_X509(x,&p);
1009	*l+=n+3;
1010
1011	return 1;
1012	}
1013unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1014	{
1015	unsigned char *p;
1016	int i;
1017	unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1018	BUF_MEM *buf;
1019
1020	/* TLSv1 sends a chain with nothing in it, instead of an alert */
1021	buf=s->init_buf;
1022	if (!BUF_MEM_grow_clean(buf,10))
1023		{
1024		SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1025		return(0);
1026		}
1027	if (x != NULL)
1028		{
1029		X509_STORE_CTX xs_ctx;
1030
1031		if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1032  			{
1033  			SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1034  			return(0);
1035  			}
1036
1037		X509_verify_cert(&xs_ctx);
1038		/* Don't leave errors in the queue */
1039		ERR_clear_error();
1040		for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1041  			{
1042			x = sk_X509_value(xs_ctx.chain, i);
1043
1044			if (!dtls1_add_cert_to_buf(buf, &l, x))
1045  				{
1046				X509_STORE_CTX_cleanup(&xs_ctx);
1047				return 0;
1048  				}
1049  			}
1050  		X509_STORE_CTX_cleanup(&xs_ctx);
1051  		}
1052  	/* Thawte special :-) */
1053	for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1054		{
1055		x=sk_X509_value(s->ctx->extra_certs,i);
1056		if (!dtls1_add_cert_to_buf(buf, &l, x))
1057			return 0;
1058		}
1059
1060	l-= (3 + DTLS1_HM_HEADER_LENGTH);
1061
1062	p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1063	l2n3(l,p);
1064	l+=3;
1065	p=(unsigned char *)&(buf->data[0]);
1066	p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1067
1068	l+=DTLS1_HM_HEADER_LENGTH;
1069	return(l);
1070	}
1071
1072int dtls1_read_failed(SSL *s, int code)
1073	{
1074	if ( code > 0)
1075		{
1076		fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1077		return 1;
1078		}
1079
1080	if (!dtls1_is_timer_expired(s))
1081		{
1082		/* not a timeout, none of our business,
1083		   let higher layers handle this.  in fact it's probably an error */
1084		return code;
1085		}
1086
1087#ifndef OPENSSL_NO_HEARTBEATS
1088	if (!SSL_in_init(s) && !s->tlsext_hb_pending)  /* done, no need to send a retransmit */
1089#else
1090	if (!SSL_in_init(s))  /* done, no need to send a retransmit */
1091#endif
1092		{
1093		BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1094		return code;
1095		}
1096
1097#if 0 /* for now, each alert contains only one record number */
1098	item = pqueue_peek(state->rcvd_records);
1099	if ( item )
1100		{
1101		/* send an alert immediately for all the missing records */
1102		}
1103	else
1104#endif
1105
1106#if 0  /* no more alert sending, just retransmit the last set of messages */
1107	if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1108		ssl3_send_alert(s,SSL3_AL_WARNING,
1109			DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1110#endif
1111
1112	return dtls1_handle_timeout(s);
1113	}
1114
1115int
1116dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1117	{
1118	/* The index of the retransmission queue actually is the message sequence number,
1119	 * since the queue only contains messages of a single handshake. However, the
1120	 * ChangeCipherSpec has no message sequence number and so using only the sequence
1121	 * will result in the CCS and Finished having the same index. To prevent this,
1122	 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1123	 * This does not only differ CSS and Finished, it also maintains the order of the
1124	 * index (important for priority queues) and fits in the unsigned short variable.
1125	 */
1126	return seq * 2 - is_ccs;
1127	}
1128
1129int
1130dtls1_retransmit_buffered_messages(SSL *s)
1131	{
1132	pqueue sent = s->d1->sent_messages;
1133	piterator iter;
1134	pitem *item;
1135	hm_fragment *frag;
1136	int found = 0;
1137
1138	iter = pqueue_iterator(sent);
1139
1140	for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1141		{
1142		frag = (hm_fragment *)item->data;
1143			if ( dtls1_retransmit_message(s,
1144				(unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1145				0, &found) <= 0 && found)
1146			{
1147			fprintf(stderr, "dtls1_retransmit_message() failed\n");
1148			return -1;
1149			}
1150		}
1151
1152	return 1;
1153	}
1154
1155int
1156dtls1_buffer_message(SSL *s, int is_ccs)
1157	{
1158	pitem *item;
1159	hm_fragment *frag;
1160	unsigned char seq64be[8];
1161
1162	/* this function is called immediately after a message has
1163	 * been serialized */
1164	OPENSSL_assert(s->init_off == 0);
1165
1166	frag = dtls1_hm_fragment_new(s->init_num, 0);
1167
1168	memcpy(frag->fragment, s->init_buf->data, s->init_num);
1169
1170	if ( is_ccs)
1171		{
1172		OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1173			       ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
1174		}
1175	else
1176		{
1177		OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1178			DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1179		}
1180
1181	frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1182	frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1183	frag->msg_header.type = s->d1->w_msg_hdr.type;
1184	frag->msg_header.frag_off = 0;
1185	frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1186	frag->msg_header.is_ccs = is_ccs;
1187
1188	/* save current state*/
1189	frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1190	frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1191	frag->msg_header.saved_retransmit_state.compress = s->compress;
1192	frag->msg_header.saved_retransmit_state.session = s->session;
1193	frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1194
1195	memset(seq64be,0,sizeof(seq64be));
1196	seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1197														  frag->msg_header.is_ccs)>>8);
1198	seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1199														  frag->msg_header.is_ccs));
1200
1201	item = pitem_new(seq64be, frag);
1202	if ( item == NULL)
1203		{
1204		dtls1_hm_fragment_free(frag);
1205		return 0;
1206		}
1207
1208#if 0
1209	fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1210	fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1211	fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1212#endif
1213
1214	pqueue_insert(s->d1->sent_messages, item);
1215	return 1;
1216	}
1217
1218int
1219dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1220	int *found)
1221	{
1222	int ret;
1223	/* XDTLS: for now assuming that read/writes are blocking */
1224	pitem *item;
1225	hm_fragment *frag ;
1226	unsigned long header_length;
1227	unsigned char seq64be[8];
1228	struct dtls1_retransmit_state saved_state;
1229	unsigned char save_write_sequence[8];
1230
1231	/*
1232	  OPENSSL_assert(s->init_num == 0);
1233	  OPENSSL_assert(s->init_off == 0);
1234	 */
1235
1236	/* XDTLS:  the requested message ought to be found, otherwise error */
1237	memset(seq64be,0,sizeof(seq64be));
1238	seq64be[6] = (unsigned char)(seq>>8);
1239	seq64be[7] = (unsigned char)seq;
1240
1241	item = pqueue_find(s->d1->sent_messages, seq64be);
1242	if ( item == NULL)
1243		{
1244		fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1245		*found = 0;
1246		return 0;
1247		}
1248
1249	*found = 1;
1250	frag = (hm_fragment *)item->data;
1251
1252	if ( frag->msg_header.is_ccs)
1253		header_length = DTLS1_CCS_HEADER_LENGTH;
1254	else
1255		header_length = DTLS1_HM_HEADER_LENGTH;
1256
1257	memcpy(s->init_buf->data, frag->fragment,
1258		frag->msg_header.msg_len + header_length);
1259		s->init_num = frag->msg_header.msg_len + header_length;
1260
1261	dtls1_set_message_header_int(s, frag->msg_header.type,
1262		frag->msg_header.msg_len, frag->msg_header.seq, 0,
1263		frag->msg_header.frag_len);
1264
1265	/* save current state */
1266	saved_state.enc_write_ctx = s->enc_write_ctx;
1267	saved_state.write_hash = s->write_hash;
1268	saved_state.compress = s->compress;
1269	saved_state.session = s->session;
1270	saved_state.epoch = s->d1->w_epoch;
1271	saved_state.epoch = s->d1->w_epoch;
1272
1273	s->d1->retransmitting = 1;
1274
1275	/* restore state in which the message was originally sent */
1276	s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1277	s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1278	s->compress = frag->msg_header.saved_retransmit_state.compress;
1279	s->session = frag->msg_header.saved_retransmit_state.session;
1280	s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1281
1282	if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1283	{
1284		memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1285		memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1286	}
1287
1288	ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1289						 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1290
1291	/* restore current state */
1292	s->enc_write_ctx = saved_state.enc_write_ctx;
1293	s->write_hash = saved_state.write_hash;
1294	s->compress = saved_state.compress;
1295	s->session = saved_state.session;
1296	s->d1->w_epoch = saved_state.epoch;
1297
1298	if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1299	{
1300		memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1301		memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1302	}
1303
1304	s->d1->retransmitting = 0;
1305
1306	(void)BIO_flush(SSL_get_wbio(s));
1307	return ret;
1308	}
1309
1310/* call this function when the buffered messages are no longer needed */
1311void
1312dtls1_clear_record_buffer(SSL *s)
1313	{
1314	pitem *item;
1315
1316	for(item = pqueue_pop(s->d1->sent_messages);
1317		item != NULL; item = pqueue_pop(s->d1->sent_messages))
1318		{
1319		dtls1_hm_fragment_free((hm_fragment *)item->data);
1320		pitem_free(item);
1321		}
1322	}
1323
1324
1325unsigned char *
1326dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1327			unsigned long len, unsigned long frag_off, unsigned long frag_len)
1328	{
1329	/* Don't change sequence numbers while listening */
1330	if (frag_off == 0 && !s->d1->listen)
1331		{
1332		s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1333		s->d1->next_handshake_write_seq++;
1334		}
1335
1336	dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1337		frag_off, frag_len);
1338
1339	return p += DTLS1_HM_HEADER_LENGTH;
1340	}
1341
1342
1343/* don't actually do the writing, wait till the MTU has been retrieved */
1344static void
1345dtls1_set_message_header_int(SSL *s, unsigned char mt,
1346			    unsigned long len, unsigned short seq_num, unsigned long frag_off,
1347			    unsigned long frag_len)
1348	{
1349	struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1350
1351	msg_hdr->type = mt;
1352	msg_hdr->msg_len = len;
1353	msg_hdr->seq = seq_num;
1354	msg_hdr->frag_off = frag_off;
1355	msg_hdr->frag_len = frag_len;
1356	}
1357
1358static void
1359dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1360			unsigned long frag_len)
1361	{
1362	struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1363
1364	msg_hdr->frag_off = frag_off;
1365	msg_hdr->frag_len = frag_len;
1366	}
1367
1368static unsigned char *
1369dtls1_write_message_header(SSL *s, unsigned char *p)
1370	{
1371	struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1372
1373	*p++ = msg_hdr->type;
1374	l2n3(msg_hdr->msg_len, p);
1375
1376	s2n(msg_hdr->seq, p);
1377	l2n3(msg_hdr->frag_off, p);
1378	l2n3(msg_hdr->frag_len, p);
1379
1380	return p;
1381	}
1382
1383unsigned int
1384dtls1_min_mtu(void)
1385	{
1386	return (g_probable_mtu[(sizeof(g_probable_mtu) /
1387		sizeof(g_probable_mtu[0])) - 1]);
1388	}
1389
1390static unsigned int
1391dtls1_guess_mtu(unsigned int curr_mtu)
1392	{
1393	unsigned int i;
1394
1395	if ( curr_mtu == 0 )
1396		return g_probable_mtu[0] ;
1397
1398	for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1399		if ( curr_mtu > g_probable_mtu[i])
1400			return g_probable_mtu[i];
1401
1402	return curr_mtu;
1403	}
1404
1405void
1406dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1407	{
1408	memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1409	msg_hdr->type = *(data++);
1410	n2l3(data, msg_hdr->msg_len);
1411
1412	n2s(data, msg_hdr->seq);
1413	n2l3(data, msg_hdr->frag_off);
1414	n2l3(data, msg_hdr->frag_len);
1415	}
1416
1417void
1418dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1419	{
1420	memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1421
1422	ccs_hdr->type = *(data++);
1423	}
1424
1425int dtls1_shutdown(SSL *s)
1426	{
1427	int ret;
1428#ifndef OPENSSL_NO_SCTP
1429	if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1430	    !(s->shutdown & SSL_SENT_SHUTDOWN))
1431		{
1432		ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1433		if (ret < 0) return -1;
1434
1435		if (ret == 0)
1436			BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1437		}
1438#endif
1439	ret = ssl3_shutdown(s);
1440#ifndef OPENSSL_NO_SCTP
1441	BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1442#endif
1443	return ret;
1444	}
1445
1446#ifndef OPENSSL_NO_HEARTBEATS
1447int
1448dtls1_process_heartbeat(SSL *s)
1449	{
1450	unsigned char *p = &s->s3->rrec.data[0], *pl;
1451	unsigned short hbtype;
1452	unsigned int payload;
1453	unsigned int padding = 16; /* Use minimum padding */
1454
1455	/* Read type and payload length first */
1456	hbtype = *p++;
1457	n2s(p, payload);
1458	pl = p;
1459
1460	if (s->msg_callback)
1461		s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1462			&s->s3->rrec.data[0], s->s3->rrec.length,
1463			s, s->msg_callback_arg);
1464
1465	if (hbtype == TLS1_HB_REQUEST)
1466		{
1467		unsigned char *buffer, *bp;
1468		int r;
1469
1470		/* Allocate memory for the response, size is 1 byte
1471		 * message type, plus 2 bytes payload length, plus
1472		 * payload, plus padding
1473		 */
1474		buffer = OPENSSL_malloc(1 + 2 + payload + padding);
1475		bp = buffer;
1476
1477		/* Enter response type, length and copy payload */
1478		*bp++ = TLS1_HB_RESPONSE;
1479		s2n(payload, bp);
1480		memcpy(bp, pl, payload);
1481		bp += payload;
1482		/* Random padding */
1483		RAND_pseudo_bytes(bp, padding);
1484
1485		r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, 3 + payload + padding);
1486
1487		if (r >= 0 && s->msg_callback)
1488			s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1489				buffer, 3 + payload + padding,
1490				s, s->msg_callback_arg);
1491
1492		OPENSSL_free(buffer);
1493
1494		if (r < 0)
1495			return r;
1496		}
1497	else if (hbtype == TLS1_HB_RESPONSE)
1498		{
1499		unsigned int seq;
1500
1501		/* We only send sequence numbers (2 bytes unsigned int),
1502		 * and 16 random bytes, so we just try to read the
1503		 * sequence number */
1504		n2s(pl, seq);
1505
1506		if (payload == 18 && seq == s->tlsext_hb_seq)
1507			{
1508			dtls1_stop_timer(s);
1509			s->tlsext_hb_seq++;
1510			s->tlsext_hb_pending = 0;
1511			}
1512		}
1513
1514	return 0;
1515	}
1516
1517int
1518dtls1_heartbeat(SSL *s)
1519	{
1520	unsigned char *buf, *p;
1521	int ret;
1522	unsigned int payload = 18; /* Sequence number + random bytes */
1523	unsigned int padding = 16; /* Use minimum padding */
1524
1525	/* Only send if peer supports and accepts HB requests... */
1526	if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1527	    s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1528		{
1529		SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1530		return -1;
1531		}
1532
1533	/* ...and there is none in flight yet... */
1534	if (s->tlsext_hb_pending)
1535		{
1536		SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1537		return -1;
1538		}
1539
1540	/* ...and no handshake in progress. */
1541	if (SSL_in_init(s) || s->in_handshake)
1542		{
1543		SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1544		return -1;
1545		}
1546
1547	/* Check if padding is too long, payload and padding
1548	 * must not exceed 2^14 - 3 = 16381 bytes in total.
1549	 */
1550	OPENSSL_assert(payload + padding <= 16381);
1551
1552	/* Create HeartBeat message, we just use a sequence number
1553	 * as payload to distuingish different messages and add
1554	 * some random stuff.
1555	 *  - Message Type, 1 byte
1556	 *  - Payload Length, 2 bytes (unsigned int)
1557	 *  - Payload, the sequence number (2 bytes uint)
1558	 *  - Payload, random bytes (16 bytes uint)
1559	 *  - Padding
1560	 */
1561	buf = OPENSSL_malloc(1 + 2 + payload + padding);
1562	p = buf;
1563	/* Message Type */
1564	*p++ = TLS1_HB_REQUEST;
1565	/* Payload length (18 bytes here) */
1566	s2n(payload, p);
1567	/* Sequence number */
1568	s2n(s->tlsext_hb_seq, p);
1569	/* 16 random bytes */
1570	RAND_pseudo_bytes(p, 16);
1571	p += 16;
1572	/* Random padding */
1573	RAND_pseudo_bytes(p, padding);
1574
1575	ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1576	if (ret >= 0)
1577		{
1578		if (s->msg_callback)
1579			s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1580				buf, 3 + payload + padding,
1581				s, s->msg_callback_arg);
1582
1583		dtls1_start_timer(s);
1584		s->tlsext_hb_pending = 1;
1585		}
1586
1587	OPENSSL_free(buf);
1588
1589	return ret;
1590	}
1591#endif
1592