s3_srvr.c: fix typo.
[openssl.git] / ssl / d1_both.c
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
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};
157
158 /* XDTLS:  figure out the right values */
159 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
160
161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 
163         unsigned long frag_len);
164 static unsigned char *dtls1_write_message_header(SSL *s,
165         unsigned char *p);
166 static 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);
169 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 
170         long max, int *ok);
171
172 static hm_fragment *
173 dtls1_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
214 static void
215 dtls1_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) */
223 int 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  */
408 long 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
435 again:
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
472 f_err:
473         ssl3_send_alert(s,SSL3_AL_FATAL,al);
474         *ok = 0;
475         return -1;
476         }
477
478
479 static 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
528 static int
529 dtls1_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
584 static int
585 dtls1_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
679 err:
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
687 static int
688 dtls1_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
764 err:
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
772 static long
773 dtls1_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
890 f_err:
891         ssl3_send_alert(s,SSL3_AL_FATAL,al);
892         s->init_num = 0;
893
894         *ok=0;
895         return(-1);
896         }
897
898 int 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  */
963 int 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
995 unsigned long dtls1_output_cert_chain(SSL *s, CERT_PKEY *cpk)
996         {
997         unsigned char *p;
998         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
999         BUF_MEM *buf=s->init_buf;
1000
1001         if (!ssl_add_cert_chain(s, cpk, &l))
1002                 return 0;
1003
1004         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1005
1006         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1007         l2n3(l,p);
1008         l+=3;
1009         p=(unsigned char *)&(buf->data[0]);
1010         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1011
1012         l+=DTLS1_HM_HEADER_LENGTH;
1013         return(l);
1014         }
1015
1016 int dtls1_read_failed(SSL *s, int code)
1017         {
1018         if ( code > 0)
1019                 {
1020                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1021                 return 1;
1022                 }
1023
1024         if (!dtls1_is_timer_expired(s))
1025                 {
1026                 /* not a timeout, none of our business, 
1027                    let higher layers handle this.  in fact it's probably an error */
1028                 return code;
1029                 }
1030
1031 #ifndef OPENSSL_NO_HEARTBEATS
1032         if (!SSL_in_init(s) && !s->tlsext_hb_pending)  /* done, no need to send a retransmit */
1033 #else
1034         if (!SSL_in_init(s))  /* done, no need to send a retransmit */
1035 #endif
1036                 {
1037                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1038                 return code;
1039                 }
1040
1041 #if 0 /* for now, each alert contains only one record number */
1042         item = pqueue_peek(state->rcvd_records);
1043         if ( item )
1044                 {
1045                 /* send an alert immediately for all the missing records */
1046                 }
1047         else
1048 #endif
1049
1050 #if 0  /* no more alert sending, just retransmit the last set of messages */
1051         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1052                 ssl3_send_alert(s,SSL3_AL_WARNING,
1053                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1054 #endif
1055
1056         return dtls1_handle_timeout(s);
1057         }
1058
1059 int
1060 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1061         {
1062         /* The index of the retransmission queue actually is the message sequence number,
1063          * since the queue only contains messages of a single handshake. However, the
1064          * ChangeCipherSpec has no message sequence number and so using only the sequence
1065          * will result in the CCS and Finished having the same index. To prevent this,
1066          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1067          * This does not only differ CSS and Finished, it also maintains the order of the
1068          * index (important for priority queues) and fits in the unsigned short variable.
1069          */     
1070         return seq * 2 - is_ccs;
1071         }
1072
1073 int
1074 dtls1_retransmit_buffered_messages(SSL *s)
1075         {
1076         pqueue sent = s->d1->sent_messages;
1077         piterator iter;
1078         pitem *item;
1079         hm_fragment *frag;
1080         int found = 0;
1081
1082         iter = pqueue_iterator(sent);
1083
1084         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1085                 {
1086                 frag = (hm_fragment *)item->data;
1087                         if ( dtls1_retransmit_message(s,
1088                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1089                                 0, &found) <= 0 && found)
1090                         {
1091                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1092                         return -1;
1093                         }
1094                 }
1095
1096         return 1;
1097         }
1098
1099 int
1100 dtls1_buffer_message(SSL *s, int is_ccs)
1101         {
1102         pitem *item;
1103         hm_fragment *frag;
1104         unsigned char seq64be[8];
1105
1106         /* this function is called immediately after a message has 
1107          * been serialized */
1108         OPENSSL_assert(s->init_off == 0);
1109
1110         frag = dtls1_hm_fragment_new(s->init_num, 0);
1111
1112         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1113
1114         if ( is_ccs)
1115                 {
1116                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
1117                                ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
1118                 }
1119         else
1120                 {
1121                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
1122                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1123                 }
1124
1125         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1126         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1127         frag->msg_header.type = s->d1->w_msg_hdr.type;
1128         frag->msg_header.frag_off = 0;
1129         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1130         frag->msg_header.is_ccs = is_ccs;
1131
1132         /* save current state*/
1133         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1134         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1135         frag->msg_header.saved_retransmit_state.compress = s->compress;
1136         frag->msg_header.saved_retransmit_state.session = s->session;
1137         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1138         
1139         memset(seq64be,0,sizeof(seq64be));
1140         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1141                                                                                                                   frag->msg_header.is_ccs)>>8);
1142         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1143                                                                                                                   frag->msg_header.is_ccs));
1144
1145         item = pitem_new(seq64be, frag);
1146         if ( item == NULL)
1147                 {
1148                 dtls1_hm_fragment_free(frag);
1149                 return 0;
1150                 }
1151
1152 #if 0
1153         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1154         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1155         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1156 #endif
1157
1158         pqueue_insert(s->d1->sent_messages, item);
1159         return 1;
1160         }
1161
1162 int
1163 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1164         int *found)
1165         {
1166         int ret;
1167         /* XDTLS: for now assuming that read/writes are blocking */
1168         pitem *item;
1169         hm_fragment *frag ;
1170         unsigned long header_length;
1171         unsigned char seq64be[8];
1172         struct dtls1_retransmit_state saved_state;
1173         unsigned char save_write_sequence[8];
1174
1175         /*
1176           OPENSSL_assert(s->init_num == 0);
1177           OPENSSL_assert(s->init_off == 0);
1178          */
1179
1180         /* XDTLS:  the requested message ought to be found, otherwise error */
1181         memset(seq64be,0,sizeof(seq64be));
1182         seq64be[6] = (unsigned char)(seq>>8);
1183         seq64be[7] = (unsigned char)seq;
1184
1185         item = pqueue_find(s->d1->sent_messages, seq64be);
1186         if ( item == NULL)
1187                 {
1188                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1189                 *found = 0;
1190                 return 0;
1191                 }
1192
1193         *found = 1;
1194         frag = (hm_fragment *)item->data;
1195
1196         if ( frag->msg_header.is_ccs)
1197                 header_length = DTLS1_CCS_HEADER_LENGTH;
1198         else
1199                 header_length = DTLS1_HM_HEADER_LENGTH;
1200
1201         memcpy(s->init_buf->data, frag->fragment, 
1202                 frag->msg_header.msg_len + header_length);
1203                 s->init_num = frag->msg_header.msg_len + header_length;
1204
1205         dtls1_set_message_header_int(s, frag->msg_header.type, 
1206                 frag->msg_header.msg_len, frag->msg_header.seq, 0, 
1207                 frag->msg_header.frag_len);
1208
1209         /* save current state */
1210         saved_state.enc_write_ctx = s->enc_write_ctx;
1211         saved_state.write_hash = s->write_hash;
1212         saved_state.compress = s->compress;
1213         saved_state.session = s->session;
1214         saved_state.epoch = s->d1->w_epoch;
1215         saved_state.epoch = s->d1->w_epoch;
1216         
1217         s->d1->retransmitting = 1;
1218         
1219         /* restore state in which the message was originally sent */
1220         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1221         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1222         s->compress = frag->msg_header.saved_retransmit_state.compress;
1223         s->session = frag->msg_header.saved_retransmit_state.session;
1224         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1225         
1226         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1227         {
1228                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1229                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1230         }
1231         
1232         ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 
1233                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1234         
1235         /* restore current state */
1236         s->enc_write_ctx = saved_state.enc_write_ctx;
1237         s->write_hash = saved_state.write_hash;
1238         s->compress = saved_state.compress;
1239         s->session = saved_state.session;
1240         s->d1->w_epoch = saved_state.epoch;
1241         
1242         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1243         {
1244                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1245                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1246         }
1247
1248         s->d1->retransmitting = 0;
1249
1250         (void)BIO_flush(SSL_get_wbio(s));
1251         return ret;
1252         }
1253
1254 /* call this function when the buffered messages are no longer needed */
1255 void
1256 dtls1_clear_record_buffer(SSL *s)
1257         {
1258         pitem *item;
1259
1260         for(item = pqueue_pop(s->d1->sent_messages);
1261                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1262                 {
1263                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1264                 pitem_free(item);
1265                 }
1266         }
1267
1268
1269 unsigned char *
1270 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1271                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1272         {
1273         /* Don't change sequence numbers while listening */
1274         if (frag_off == 0 && !s->d1->listen)
1275                 {
1276                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1277                 s->d1->next_handshake_write_seq++;
1278                 }
1279
1280         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1281                 frag_off, frag_len);
1282
1283         return p += DTLS1_HM_HEADER_LENGTH;
1284         }
1285
1286
1287 /* don't actually do the writing, wait till the MTU has been retrieved */
1288 static void
1289 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1290                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1291                             unsigned long frag_len)
1292         {
1293         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1294
1295         msg_hdr->type = mt;
1296         msg_hdr->msg_len = len;
1297         msg_hdr->seq = seq_num;
1298         msg_hdr->frag_off = frag_off;
1299         msg_hdr->frag_len = frag_len;
1300         }
1301
1302 static void
1303 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1304                         unsigned long frag_len)
1305         {
1306         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1307
1308         msg_hdr->frag_off = frag_off;
1309         msg_hdr->frag_len = frag_len;
1310         }
1311
1312 static unsigned char *
1313 dtls1_write_message_header(SSL *s, unsigned char *p)
1314         {
1315         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1316
1317         *p++ = msg_hdr->type;
1318         l2n3(msg_hdr->msg_len, p);
1319
1320         s2n(msg_hdr->seq, p);
1321         l2n3(msg_hdr->frag_off, p);
1322         l2n3(msg_hdr->frag_len, p);
1323
1324         return p;
1325         }
1326
1327 unsigned int 
1328 dtls1_min_mtu(void)
1329         {
1330         return (g_probable_mtu[(sizeof(g_probable_mtu) / 
1331                 sizeof(g_probable_mtu[0])) - 1]);
1332         }
1333
1334 static unsigned int 
1335 dtls1_guess_mtu(unsigned int curr_mtu)
1336         {
1337         unsigned int i;
1338
1339         if ( curr_mtu == 0 )
1340                 return g_probable_mtu[0] ;
1341
1342         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1343                 if ( curr_mtu > g_probable_mtu[i])
1344                         return g_probable_mtu[i];
1345
1346         return curr_mtu;
1347         }
1348
1349 void
1350 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1351         {
1352         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1353         msg_hdr->type = *(data++);
1354         n2l3(data, msg_hdr->msg_len);
1355
1356         n2s(data, msg_hdr->seq);
1357         n2l3(data, msg_hdr->frag_off);
1358         n2l3(data, msg_hdr->frag_len);
1359         }
1360
1361 void
1362 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1363         {
1364         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1365
1366         ccs_hdr->type = *(data++);
1367         }
1368
1369 int dtls1_shutdown(SSL *s)
1370         {
1371         int ret;
1372 #ifndef OPENSSL_NO_SCTP
1373         if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1374             !(s->shutdown & SSL_SENT_SHUTDOWN))
1375                 {
1376                 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1377                 if (ret < 0) return -1;
1378
1379                 if (ret == 0)
1380                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1381                 }
1382 #endif
1383         ret = ssl3_shutdown(s);
1384 #ifndef OPENSSL_NO_SCTP
1385         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1386 #endif
1387         return ret;
1388         }
1389
1390 #ifndef OPENSSL_NO_HEARTBEATS
1391 int
1392 dtls1_process_heartbeat(SSL *s)
1393         {
1394         unsigned char *p = &s->s3->rrec.data[0], *pl;
1395         unsigned short hbtype;
1396         unsigned int payload;
1397         unsigned int padding = 16; /* Use minimum padding */
1398
1399         /* Read type and payload length first */
1400         hbtype = *p++;
1401         n2s(p, payload);
1402         pl = p;
1403
1404         if (s->msg_callback)
1405                 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1406                         &s->s3->rrec.data[0], s->s3->rrec.length,
1407                         s, s->msg_callback_arg);
1408
1409         if (hbtype == TLS1_HB_REQUEST)
1410                 {
1411                 unsigned char *buffer, *bp;
1412                 int r;
1413
1414                 /* Allocate memory for the response, size is 1 byte
1415                  * message type, plus 2 bytes payload length, plus
1416                  * payload, plus padding
1417                  */
1418                 buffer = OPENSSL_malloc(1 + 2 + payload + padding);
1419                 bp = buffer;
1420
1421                 /* Enter response type, length and copy payload */
1422                 *bp++ = TLS1_HB_RESPONSE;
1423                 s2n(payload, bp);
1424                 memcpy(bp, pl, payload);
1425                 bp += payload;
1426                 /* Random padding */
1427                 RAND_pseudo_bytes(bp, padding);
1428
1429                 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, 3 + payload + padding);
1430
1431                 if (r >= 0 && s->msg_callback)
1432                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1433                                 buffer, 3 + payload + padding,
1434                                 s, s->msg_callback_arg);
1435
1436                 OPENSSL_free(buffer);
1437
1438                 if (r < 0)
1439                         return r;
1440                 }
1441         else if (hbtype == TLS1_HB_RESPONSE)
1442                 {
1443                 unsigned int seq;
1444
1445                 /* We only send sequence numbers (2 bytes unsigned int),
1446                  * and 16 random bytes, so we just try to read the
1447                  * sequence number */
1448                 n2s(pl, seq);
1449
1450                 if (payload == 18 && seq == s->tlsext_hb_seq)
1451                         {
1452                         dtls1_stop_timer(s);
1453                         s->tlsext_hb_seq++;
1454                         s->tlsext_hb_pending = 0;
1455                         }
1456                 }
1457
1458         return 0;
1459         }
1460
1461 int
1462 dtls1_heartbeat(SSL *s)
1463         {
1464         unsigned char *buf, *p;
1465         int ret;
1466         unsigned int payload = 18; /* Sequence number + random bytes */
1467         unsigned int padding = 16; /* Use minimum padding */
1468
1469         /* Only send if peer supports and accepts HB requests... */
1470         if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1471             s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1472                 {
1473                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1474                 return -1;
1475                 }
1476
1477         /* ...and there is none in flight yet... */
1478         if (s->tlsext_hb_pending)
1479                 {
1480                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1481                 return -1;
1482                 }
1483
1484         /* ...and no handshake in progress. */
1485         if (SSL_in_init(s) || s->in_handshake)
1486                 {
1487                 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1488                 return -1;
1489                 }
1490
1491         /* Check if padding is too long, payload and padding
1492          * must not exceed 2^14 - 3 = 16381 bytes in total.
1493          */
1494         OPENSSL_assert(payload + padding <= 16381);
1495
1496         /* Create HeartBeat message, we just use a sequence number
1497          * as payload to distuingish different messages and add
1498          * some random stuff.
1499          *  - Message Type, 1 byte
1500          *  - Payload Length, 2 bytes (unsigned int)
1501          *  - Payload, the sequence number (2 bytes uint)
1502          *  - Payload, random bytes (16 bytes uint)
1503          *  - Padding
1504          */
1505         buf = OPENSSL_malloc(1 + 2 + payload + padding);
1506         p = buf;
1507         /* Message Type */
1508         *p++ = TLS1_HB_REQUEST;
1509         /* Payload length (18 bytes here) */
1510         s2n(payload, p);
1511         /* Sequence number */
1512         s2n(s->tlsext_hb_seq, p);
1513         /* 16 random bytes */
1514         RAND_pseudo_bytes(p, 16);
1515         p += 16;
1516         /* Random padding */
1517         RAND_pseudo_bytes(p, padding);
1518
1519         ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1520         if (ret >= 0)
1521                 {
1522                 if (s->msg_callback)
1523                         s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1524                                 buf, 3 + payload + padding,
1525                                 s, s->msg_callback_arg);
1526
1527                 dtls1_start_timer(s);
1528                 s->tlsext_hb_pending = 1;
1529                 }
1530
1531         OPENSSL_free(buf);
1532
1533         return ret;
1534         }
1535 #endif