c195159967f5f45504484526695e588ae253109b
[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_min_mtu(void);
162 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
163 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 
164         unsigned long frag_len);
165 static unsigned char *dtls1_write_message_header(SSL *s,
166         unsigned char *p);
167 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
168         unsigned long len, unsigned short seq_num, unsigned long frag_off, 
169         unsigned long frag_len);
170 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 
171         long max, int *ok);
172
173 static hm_fragment *
174 dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
175         {
176         hm_fragment *frag = NULL;
177         unsigned char *buf = NULL;
178         unsigned char *bitmask = NULL;
179
180         frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
181         if ( frag == NULL)
182                 return NULL;
183
184         if (frag_len)
185                 {
186                 buf = (unsigned char *)OPENSSL_malloc(frag_len);
187                 if ( buf == NULL)
188                         {
189                         OPENSSL_free(frag);
190                         return NULL;
191                         }
192                 }
193
194         /* zero length fragment gets zero frag->fragment */
195         frag->fragment = buf;
196
197         /* Initialize reassembly bitmask if necessary */
198         if (reassembly)
199                 {
200                 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
201                 if (bitmask == NULL)
202                         {
203                         if (buf != NULL) OPENSSL_free(buf);
204                         OPENSSL_free(frag);
205                         return NULL;
206                         }
207                 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
208                 }
209
210         frag->reassembly = bitmask;
211
212         return frag;
213         }
214
215 static void
216 dtls1_hm_fragment_free(hm_fragment *frag)
217         {
218         if (frag->fragment) OPENSSL_free(frag->fragment);
219         if (frag->reassembly) OPENSSL_free(frag->reassembly);
220         OPENSSL_free(frag);
221         }
222
223 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
224 int dtls1_do_write(SSL *s, int type)
225         {
226         int ret;
227         int curr_mtu;
228         unsigned int len, frag_off, mac_size, blocksize;
229
230         /* AHA!  Figure out the MTU, and stick to the right size */
231         if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
232                 {
233                 s->d1->mtu = 
234                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
235
236                 /* I've seen the kernel return bogus numbers when it doesn't know
237                  * (initial write), so just make sure we have a reasonable number */
238                 if ( s->d1->mtu < dtls1_min_mtu())
239                         {
240                         s->d1->mtu = 0;
241                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
242                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 
243                                 s->d1->mtu, NULL);
244                         }
245                 }
246 #if 0 
247         mtu = s->d1->mtu;
248
249         fprintf(stderr, "using MTU = %d\n", mtu);
250
251         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
252
253         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
254
255         if ( curr_mtu > 0)
256                 mtu = curr_mtu;
257         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
258                 return ret;
259
260         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
261                 {
262                 ret = BIO_flush(SSL_get_wbio(s));
263                 if ( ret <= 0)
264                         return ret;
265                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
266                 }
267
268         OPENSSL_assert(mtu > 0);  /* should have something reasonable now */
269
270 #endif
271
272         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
273                 OPENSSL_assert(s->init_num == 
274                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
275
276         if (s->write_hash)
277                 mac_size = EVP_MD_CTX_size(s->write_hash);
278         else
279                 mac_size = 0;
280
281         if (s->enc_write_ctx && 
282                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
283                 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
284         else
285                 blocksize = 0;
286
287         frag_off = 0;
288         while( s->init_num)
289                 {
290                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 
291                         DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
292
293                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
294                         {
295                         /* grr.. we could get an error if MTU picked was wrong */
296                         ret = BIO_flush(SSL_get_wbio(s));
297                         if ( ret <= 0)
298                                 return ret;
299                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
300                                 mac_size - blocksize;
301                         }
302
303                 if ( s->init_num > curr_mtu)
304                         len = curr_mtu;
305                 else
306                         len = s->init_num;
307
308
309                 /* XDTLS: this function is too long.  split out the CCS part */
310                 if ( type == SSL3_RT_HANDSHAKE)
311                         {
312                         if ( s->init_off != 0)
313                                 {
314                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
315                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
316                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
317
318                                 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
319                                 if ( len <= DTLS1_HM_HEADER_LENGTH)  
320                                         len += DTLS1_HM_HEADER_LENGTH;
321                                 }
322
323                         dtls1_fix_message_header(s, frag_off, 
324                                 len - DTLS1_HM_HEADER_LENGTH);
325
326                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
327
328                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
329                         }
330
331                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
332                         len);
333                 if (ret < 0)
334                         {
335                         /* might need to update MTU here, but we don't know
336                          * which previous packet caused the failure -- so can't
337                          * really retransmit anything.  continue as if everything
338                          * is fine and wait for an alert to handle the
339                          * retransmit 
340                          */
341                         if ( BIO_ctrl(SSL_get_wbio(s),
342                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
343                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
344                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
345                         else
346                                 return(-1);
347                         }
348                 else
349                         {
350
351                         /* bad if this assert fails, only part of the handshake
352                          * message got sent.  but why would this happen? */
353                         OPENSSL_assert(len == (unsigned int)ret);
354
355                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
356                                 {
357                                 /* should not be done for 'Hello Request's, but in that case
358                                  * we'll ignore the result anyway */
359                                 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
360                                 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
361                                 int xlen;
362
363                                 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
364                                         {
365                                         /* reconstruct message header is if it
366                                          * is being sent in single fragment */
367                                         *p++ = msg_hdr->type;
368                                         l2n3(msg_hdr->msg_len,p);
369                                         s2n (msg_hdr->seq,p);
370                                         l2n3(0,p);
371                                         l2n3(msg_hdr->msg_len,p);
372                                         p  -= DTLS1_HM_HEADER_LENGTH;
373                                         xlen = ret;
374                                         }
375                                 else
376                                         {
377                                         p  += DTLS1_HM_HEADER_LENGTH;
378                                         xlen = ret - DTLS1_HM_HEADER_LENGTH;
379                                         }
380
381                                 ssl3_finish_mac(s, p, xlen);
382                                 }
383
384                         if (ret == s->init_num)
385                                 {
386                                 if (s->msg_callback)
387                                         s->msg_callback(1, s->version, type, s->init_buf->data, 
388                                                 (size_t)(s->init_off + s->init_num), s, 
389                                                 s->msg_callback_arg);
390
391                                 s->init_off = 0;  /* done writing this message */
392                                 s->init_num = 0;
393
394                                 return(1);
395                                 }
396                         s->init_off+=ret;
397                         s->init_num-=ret;
398                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
399                         }
400                 }
401         return(0);
402         }
403
404
405 /* Obtain handshake message of message type 'mt' (any if mt == -1),
406  * maximum acceptable body length 'max'.
407  * Read an entire handshake message.  Handshake messages arrive in
408  * fragments.
409  */
410 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
411         {
412         int i, al;
413         struct hm_header_st *msg_hdr;
414         unsigned char *p;
415         unsigned long msg_len;
416
417         /* s3->tmp is used to store messages that are unexpected, caused
418          * by the absence of an optional handshake message */
419         if (s->s3->tmp.reuse_message)
420                 {
421                 s->s3->tmp.reuse_message=0;
422                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
423                         {
424                         al=SSL_AD_UNEXPECTED_MESSAGE;
425                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
426                         goto f_err;
427                         }
428                 *ok=1;
429                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
430                 s->init_num = (int)s->s3->tmp.message_size;
431                 return s->init_num;
432                 }
433
434         msg_hdr = &s->d1->r_msg_hdr;
435         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
436
437 again:
438         i = dtls1_get_message_fragment(s, st1, stn, max, ok);
439         if ( i == DTLS1_HM_BAD_FRAGMENT ||
440                 i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
441                 goto again;
442         else if ( i <= 0 && !*ok)
443                 return i;
444
445         p = (unsigned char *)s->init_buf->data;
446         msg_len = msg_hdr->msg_len;
447
448         /* reconstruct message header */
449         *(p++) = msg_hdr->type;
450         l2n3(msg_len,p);
451         s2n (msg_hdr->seq,p);
452         l2n3(0,p);
453         l2n3(msg_len,p);
454         if (s->version != DTLS1_BAD_VER) {
455                 p       -= DTLS1_HM_HEADER_LENGTH;
456                 msg_len += DTLS1_HM_HEADER_LENGTH;
457         }
458
459         ssl3_finish_mac(s, p, msg_len);
460         if (s->msg_callback)
461                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
462                         p, msg_len,
463                         s, s->msg_callback_arg);
464
465         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
466
467         /* Don't change sequence numbers while listening */
468         if (!s->d1->listen)
469                 s->d1->handshake_read_seq++;
470
471         /* we just read a handshake message from the other side:
472          * this means that we don't need to retransmit of the
473          * buffered messages.  
474          * XDTLS: may be able clear out this
475          * buffer a little sooner (i.e if an out-of-order
476          * handshake message/record is received at the record
477          * layer.  
478          * XDTLS: exception is that the server needs to
479          * know that change cipher spec and finished messages
480          * have been received by the client before clearing this
481          * buffer.  this can simply be done by waiting for the
482          * first data  segment, but is there a better way?  */
483         dtls1_clear_record_buffer(s);
484
485         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
486         return s->init_num;
487
488 f_err:
489         ssl3_send_alert(s,SSL3_AL_FATAL,al);
490         *ok = 0;
491         return -1;
492         }
493
494
495 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
496         {
497         size_t frag_off,frag_len,msg_len;
498
499         msg_len  = msg_hdr->msg_len;
500         frag_off = msg_hdr->frag_off;
501         frag_len = msg_hdr->frag_len;
502
503         /* sanity checking */
504         if ( (frag_off+frag_len) > msg_len)
505                 {
506                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
507                 return SSL_AD_ILLEGAL_PARAMETER;
508                 }
509
510         if ( (frag_off+frag_len) > (unsigned long)max)
511                 {
512                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
513                 return SSL_AD_ILLEGAL_PARAMETER;
514                 }
515
516         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
517                 {
518                 /* msg_len is limited to 2^24, but is effectively checked
519                  * against max above */
520                 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
521                         {
522                         SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
523                         return SSL_AD_INTERNAL_ERROR;
524                         }
525
526                 s->s3->tmp.message_size  = msg_len;
527                 s->d1->r_msg_hdr.msg_len = msg_len;
528                 s->s3->tmp.message_type  = msg_hdr->type;
529                 s->d1->r_msg_hdr.type    = msg_hdr->type;
530                 s->d1->r_msg_hdr.seq     = msg_hdr->seq;
531                 }
532         else if (msg_len != s->d1->r_msg_hdr.msg_len)
533                 {
534                 /* They must be playing with us! BTW, failure to enforce
535                  * upper limit would open possibility for buffer overrun. */
536                 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
537                 return SSL_AD_ILLEGAL_PARAMETER;
538                 }
539
540         return 0; /* no error */
541         }
542
543
544 static int
545 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
546         {
547         /* (0) check whether the desired fragment is available
548          * if so:
549          * (1) copy over the fragment to s->init_buf->data[]
550          * (2) update s->init_num
551          */
552         pitem *item;
553         hm_fragment *frag;
554         int al;
555
556         *ok = 0;
557         item = pqueue_peek(s->d1->buffered_messages);
558         if ( item == NULL)
559                 return 0;
560
561         frag = (hm_fragment *)item->data;
562         
563         /* Don't return if reassembly still in progress */
564         if (frag->reassembly != NULL)
565                 return 0;
566
567         if ( s->d1->handshake_read_seq == frag->msg_header.seq)
568                 {
569                 unsigned long frag_len = frag->msg_header.frag_len;
570                 pqueue_pop(s->d1->buffered_messages);
571
572                 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
573
574                 if (al==0) /* no alert */
575                         {
576                         unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
577                         memcpy(&p[frag->msg_header.frag_off],
578                                 frag->fragment,frag->msg_header.frag_len);
579                         }
580
581                 dtls1_hm_fragment_free(frag);
582                 pitem_free(item);
583
584                 if (al==0)
585                         {
586                         *ok = 1;
587                         return frag_len;
588                         }
589
590                 ssl3_send_alert(s,SSL3_AL_FATAL,al);
591                 s->init_num = 0;
592                 *ok = 0;
593                 return -1;
594                 }
595         else
596                 return 0;
597         }
598
599
600 static int
601 dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
602         {
603         hm_fragment *frag = NULL;
604         pitem *item = NULL;
605         int i = -1, is_complete;
606         unsigned char seq64be[8];
607         unsigned long frag_len = msg_hdr->frag_len, max_len;
608
609         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
610                 goto err;
611
612         /* Determine maximum allowed message size. Depends on (user set)
613          * maximum certificate length, but 16k is minimum.
614          */
615         if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
616                 max_len = s->max_cert_list;
617         else
618                 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
619
620         if ((msg_hdr->frag_off+frag_len) > max_len)
621                 goto err;
622
623         /* Try to find item in queue */
624         memset(seq64be,0,sizeof(seq64be));
625         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
626         seq64be[7] = (unsigned char) msg_hdr->seq;
627         item = pqueue_find(s->d1->buffered_messages, seq64be);
628
629         if (item == NULL)
630                 {
631                 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
632                 if ( frag == NULL)
633                         goto err;
634                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
635                 frag->msg_header.frag_len = frag->msg_header.msg_len;
636                 frag->msg_header.frag_off = 0;
637                 }
638         else
639                 frag = (hm_fragment*) item->data;
640
641         /* If message is already reassembled, this must be a
642          * retransmit and can be dropped.
643          */
644         if (frag->reassembly == NULL)
645                 {
646                 unsigned char devnull [256];
647
648                 while (frag_len)
649                         {
650                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
651                                 devnull,
652                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
653                         if (i<=0) goto err;
654                         frag_len -= i;
655                         }
656                 return DTLS1_HM_FRAGMENT_RETRY;
657                 }
658
659         /* read the body of the fragment (header has already been read */
660         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
661                 frag->fragment + msg_hdr->frag_off,frag_len,0);
662         if (i<=0 || (unsigned long)i!=frag_len)
663                 goto err;
664
665         RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
666                             (long)(msg_hdr->frag_off + frag_len));
667
668         RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
669                                    is_complete);
670
671         if (is_complete)
672                 {
673                 OPENSSL_free(frag->reassembly);
674                 frag->reassembly = NULL;
675                 }
676
677         if (item == NULL)
678                 {
679                 memset(seq64be,0,sizeof(seq64be));
680                 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
681                 seq64be[7] = (unsigned char)(msg_hdr->seq);
682
683                 item = pitem_new(seq64be, frag);
684                 if (item == NULL)
685                         {
686                         goto err;
687                         i = -1;
688                         }
689
690                 pqueue_insert(s->d1->buffered_messages, item);
691                 }
692
693         return DTLS1_HM_FRAGMENT_RETRY;
694
695 err:
696         if (frag != NULL) dtls1_hm_fragment_free(frag);
697         if (item != NULL) OPENSSL_free(item);
698         *ok = 0;
699         return i;
700         }
701
702
703 static int
704 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
705 {
706         int i=-1;
707         hm_fragment *frag = NULL;
708         pitem *item = NULL;
709         unsigned char seq64be[8];
710         unsigned long frag_len = msg_hdr->frag_len;
711
712         if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
713                 goto err;
714
715         /* Try to find item in queue, to prevent duplicate entries */
716         memset(seq64be,0,sizeof(seq64be));
717         seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
718         seq64be[7] = (unsigned char) msg_hdr->seq;
719         item = pqueue_find(s->d1->buffered_messages, seq64be);
720
721         /* If we already have an entry and this one is a fragment,
722          * don't discard it and rather try to reassemble it.
723          */
724         if (item != NULL && frag_len < msg_hdr->msg_len)
725                 item = NULL;
726
727         /* Discard the message if sequence number was already there, is
728          * too far in the future, already in the queue or if we received
729          * a FINISHED before the SERVER_HELLO, which then must be a stale
730          * retransmit.
731          */
732         if (msg_hdr->seq <= s->d1->handshake_read_seq ||
733                 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
734                 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
735                 {
736                 unsigned char devnull [256];
737
738                 while (frag_len)
739                         {
740                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
741                                 devnull,
742                                 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
743                         if (i<=0) goto err;
744                         frag_len -= i;
745                         }
746                 }
747         else
748                 {
749                 if (frag_len && frag_len < msg_hdr->msg_len)
750                         return dtls1_reassemble_fragment(s, msg_hdr, ok);
751
752                 frag = dtls1_hm_fragment_new(frag_len, 0);
753                 if ( frag == NULL)
754                         goto err;
755
756                 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
757
758                 if (frag_len)
759                         {
760                         /* read the body of the fragment (header has already been read */
761                         i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
762                                 frag->fragment,frag_len,0);
763                         if (i<=0 || (unsigned long)i!=frag_len)
764                                 goto err;
765                         }
766
767                 memset(seq64be,0,sizeof(seq64be));
768                 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
769                 seq64be[7] = (unsigned char)(msg_hdr->seq);
770
771                 item = pitem_new(seq64be, frag);
772                 if ( item == NULL)
773                         goto err;
774
775                 pqueue_insert(s->d1->buffered_messages, item);
776                 }
777
778         return DTLS1_HM_FRAGMENT_RETRY;
779
780 err:
781         if ( frag != NULL) dtls1_hm_fragment_free(frag);
782         if ( item != NULL) OPENSSL_free(item);
783         *ok = 0;
784         return i;
785         }
786
787
788 static long
789 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
790         {
791         unsigned char wire[DTLS1_HM_HEADER_LENGTH];
792         unsigned long len, frag_off, frag_len;
793         int i,al;
794         struct hm_header_st msg_hdr;
795
796         /* see if we have the required fragment already */
797         if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
798                 {
799                 if (*ok)        s->init_num = frag_len;
800                 return frag_len;
801                 }
802
803         /* read handshake message header */
804         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
805                 DTLS1_HM_HEADER_LENGTH, 0);
806         if (i <= 0)     /* nbio, or an error */
807                 {
808                 s->rwstate=SSL_READING;
809                 *ok = 0;
810                 return i;
811                 }
812         OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
813
814         /* parse the message fragment header */
815         dtls1_get_message_header(wire, &msg_hdr);
816
817         /* 
818          * if this is a future (or stale) message it gets buffered
819          * (or dropped)--no further processing at this time
820          * While listening, we accept seq 1 (ClientHello with cookie)
821          * although we're still expecting seq 0 (ClientHello)
822          */
823         if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
824                 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
825
826         len = msg_hdr.msg_len;
827         frag_off = msg_hdr.frag_off;
828         frag_len = msg_hdr.frag_len;
829
830         if (frag_len && frag_len < len)
831                 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
832
833         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
834                 wire[0] == SSL3_MT_HELLO_REQUEST)
835                 {
836                 /* The server may always send 'Hello Request' messages --
837                  * we are doing a handshake anyway now, so ignore them
838                  * if their format is correct. Does not count for
839                  * 'Finished' MAC. */
840                 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
841                         {
842                         if (s->msg_callback)
843                                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
844                                         wire, DTLS1_HM_HEADER_LENGTH, s, 
845                                         s->msg_callback_arg);
846                         
847                         s->init_num = 0;
848                         return dtls1_get_message_fragment(s, st1, stn,
849                                 max, ok);
850                         }
851                 else /* Incorrectly formated Hello request */
852                         {
853                         al=SSL_AD_UNEXPECTED_MESSAGE;
854                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
855                         goto f_err;
856                         }
857                 }
858
859         if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
860                 goto f_err;
861
862         /* XDTLS:  ressurect this when restart is in place */
863         s->state=stn;
864
865         if ( frag_len > 0)
866                 {
867                 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
868
869                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
870                         &p[frag_off],frag_len,0);
871                 /* XDTLS:  fix this--message fragments cannot span multiple packets */
872                 if (i <= 0)
873                         {
874                         s->rwstate=SSL_READING;
875                         *ok = 0;
876                         return i;
877                         }
878                 }
879         else
880                 i = 0;
881
882         /* XDTLS:  an incorrectly formatted fragment should cause the 
883          * handshake to fail */
884         OPENSSL_assert(i == (int)frag_len);
885
886         *ok = 1;
887
888         /* Note that s->init_num is *not* used as current offset in
889          * s->init_buf->data, but as a counter summing up fragments'
890          * lengths: as soon as they sum up to handshake packet
891          * length, we assume we have got all the fragments. */
892         s->init_num = frag_len;
893         return frag_len;
894
895 f_err:
896         ssl3_send_alert(s,SSL3_AL_FATAL,al);
897         s->init_num = 0;
898
899         *ok=0;
900         return(-1);
901         }
902
903 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
904         {
905         unsigned char *p,*d;
906         int i;
907         unsigned long l;
908
909         if (s->state == a)
910                 {
911                 d=(unsigned char *)s->init_buf->data;
912                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
913
914                 i=s->method->ssl3_enc->final_finish_mac(s,
915                         sender,slen,s->s3->tmp.finish_md);
916                 s->s3->tmp.finish_md_len = i;
917                 memcpy(p, s->s3->tmp.finish_md, i);
918                 p+=i;
919                 l=i;
920
921         /* Copy the finished so we can use it for
922          * renegotiation checks
923          */
924         if(s->type == SSL_ST_CONNECT)
925                 {
926                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
927                 memcpy(s->s3->previous_client_finished, 
928                        s->s3->tmp.finish_md, i);
929                 s->s3->previous_client_finished_len=i;
930                 }
931         else
932                 {
933                 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
934                 memcpy(s->s3->previous_server_finished, 
935                        s->s3->tmp.finish_md, i);
936                 s->s3->previous_server_finished_len=i;
937                 }
938
939 #ifdef OPENSSL_SYS_WIN16
940                 /* MSVC 1.5 does not clear the top bytes of the word unless
941                  * I do this.
942                  */
943                 l&=0xffff;
944 #endif
945
946                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
947                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
948                 s->init_off=0;
949
950                 /* buffer the message to handle re-xmits */
951                 dtls1_buffer_message(s, 0);
952
953                 s->state=b;
954                 }
955
956         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
957         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
958         }
959
960 /* for these 2 messages, we need to
961  * ssl->enc_read_ctx                    re-init
962  * ssl->s3->read_sequence               zero
963  * ssl->s3->read_mac_secret             re-init
964  * ssl->session->read_sym_enc           assign
965  * ssl->session->read_compression       assign
966  * ssl->session->read_hash              assign
967  */
968 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
969         { 
970         unsigned char *p;
971
972         if (s->state == a)
973                 {
974                 p=(unsigned char *)s->init_buf->data;
975                 *p++=SSL3_MT_CCS;
976                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
977                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
978
979                 if (s->version == DTLS1_BAD_VER) {
980                         s->d1->next_handshake_write_seq++;
981                         s2n(s->d1->handshake_write_seq,p);
982                         s->init_num+=2;
983                 }
984
985                 s->init_off=0;
986
987                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 
988                         s->d1->handshake_write_seq, 0, 0);
989
990                 /* buffer the message to handle re-xmits */
991                 dtls1_buffer_message(s, 1);
992
993                 s->state=b;
994                 }
995
996         /* SSL3_ST_CW_CHANGE_B */
997         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
998         }
999
1000 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1001         {
1002         int n;
1003         unsigned char *p;
1004
1005         n=i2d_X509(x,NULL);
1006         if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1007                 {
1008                 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1009                 return 0;
1010                 }
1011         p=(unsigned char *)&(buf->data[*l]);
1012         l2n3(n,p);
1013         i2d_X509(x,&p);
1014         *l+=n+3;
1015
1016         return 1;
1017         }
1018 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1019         {
1020         unsigned char *p;
1021         int i;
1022         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1023         BUF_MEM *buf;
1024
1025         /* TLSv1 sends a chain with nothing in it, instead of an alert */
1026         buf=s->init_buf;
1027         if (!BUF_MEM_grow_clean(buf,10))
1028                 {
1029                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1030                 return(0);
1031                 }
1032         if (x != NULL)
1033                 {
1034                 X509_STORE_CTX xs_ctx;
1035
1036                 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1037                         {
1038                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1039                         return(0);
1040                         }
1041   
1042                 X509_verify_cert(&xs_ctx);
1043                 /* Don't leave errors in the queue */
1044                 ERR_clear_error();
1045                 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1046                         {
1047                         x = sk_X509_value(xs_ctx.chain, i);
1048
1049                         if (!dtls1_add_cert_to_buf(buf, &l, x))
1050                                 {
1051                                 X509_STORE_CTX_cleanup(&xs_ctx);
1052                                 return 0;
1053                                 }
1054                         }
1055                 X509_STORE_CTX_cleanup(&xs_ctx);
1056                 }
1057         /* Thawte special :-) */
1058         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1059                 {
1060                 x=sk_X509_value(s->ctx->extra_certs,i);
1061                 if (!dtls1_add_cert_to_buf(buf, &l, x))
1062                         return 0;
1063                 }
1064
1065         l-= (3 + DTLS1_HM_HEADER_LENGTH);
1066
1067         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1068         l2n3(l,p);
1069         l+=3;
1070         p=(unsigned char *)&(buf->data[0]);
1071         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1072
1073         l+=DTLS1_HM_HEADER_LENGTH;
1074         return(l);
1075         }
1076
1077 int dtls1_read_failed(SSL *s, int code)
1078         {
1079         if ( code > 0)
1080                 {
1081                 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1082                 return 1;
1083                 }
1084
1085         if (!dtls1_is_timer_expired(s))
1086                 {
1087                 /* not a timeout, none of our business, 
1088                    let higher layers handle this.  in fact it's probably an error */
1089                 return code;
1090                 }
1091
1092         if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
1093                 {
1094                 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1095                 return code;
1096                 }
1097
1098 #if 0 /* for now, each alert contains only one record number */
1099         item = pqueue_peek(state->rcvd_records);
1100         if ( item )
1101                 {
1102                 /* send an alert immediately for all the missing records */
1103                 }
1104         else
1105 #endif
1106
1107 #if 0  /* no more alert sending, just retransmit the last set of messages */
1108         if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1109                 ssl3_send_alert(s,SSL3_AL_WARNING,
1110                         DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1111 #endif
1112
1113         return dtls1_handle_timeout(s);
1114         }
1115
1116 int
1117 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1118         {
1119         /* The index of the retransmission queue actually is the message sequence number,
1120          * since the queue only contains messages of a single handshake. However, the
1121          * ChangeCipherSpec has no message sequence number and so using only the sequence
1122          * will result in the CCS and Finished having the same index. To prevent this,
1123          * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1124          * This does not only differ CSS and Finished, it also maintains the order of the
1125          * index (important for priority queues) and fits in the unsigned short variable.
1126          */     
1127         return seq * 2 - is_ccs;
1128         }
1129
1130 int
1131 dtls1_retransmit_buffered_messages(SSL *s)
1132         {
1133         pqueue sent = s->d1->sent_messages;
1134         piterator iter;
1135         pitem *item;
1136         hm_fragment *frag;
1137         int found = 0;
1138
1139         iter = pqueue_iterator(sent);
1140
1141         for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1142                 {
1143                 frag = (hm_fragment *)item->data;
1144                         if ( dtls1_retransmit_message(s,
1145                                 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1146                                 0, &found) <= 0 && found)
1147                         {
1148                         fprintf(stderr, "dtls1_retransmit_message() failed\n");
1149                         return -1;
1150                         }
1151                 }
1152
1153         return 1;
1154         }
1155
1156 int
1157 dtls1_buffer_message(SSL *s, int is_ccs)
1158         {
1159         pitem *item;
1160         hm_fragment *frag;
1161         unsigned char seq64be[8];
1162
1163         /* this function is called immediately after a message has 
1164          * been serialized */
1165         OPENSSL_assert(s->init_off == 0);
1166
1167         frag = dtls1_hm_fragment_new(s->init_num, 0);
1168
1169         memcpy(frag->fragment, s->init_buf->data, s->init_num);
1170
1171         if ( is_ccs)
1172                 {
1173                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
1174                                ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
1175                 }
1176         else
1177                 {
1178                 OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
1179                         DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1180                 }
1181
1182         frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1183         frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1184         frag->msg_header.type = s->d1->w_msg_hdr.type;
1185         frag->msg_header.frag_off = 0;
1186         frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1187         frag->msg_header.is_ccs = is_ccs;
1188
1189         /* save current state*/
1190         frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1191         frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1192         frag->msg_header.saved_retransmit_state.compress = s->compress;
1193         frag->msg_header.saved_retransmit_state.session = s->session;
1194         frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1195         
1196         memset(seq64be,0,sizeof(seq64be));
1197         seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1198                                                                                                                   frag->msg_header.is_ccs)>>8);
1199         seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1200                                                                                                                   frag->msg_header.is_ccs));
1201
1202         item = pitem_new(seq64be, frag);
1203         if ( item == NULL)
1204                 {
1205                 dtls1_hm_fragment_free(frag);
1206                 return 0;
1207                 }
1208
1209 #if 0
1210         fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1211         fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1212         fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1213 #endif
1214
1215         pqueue_insert(s->d1->sent_messages, item);
1216         return 1;
1217         }
1218
1219 int
1220 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1221         int *found)
1222         {
1223         int ret;
1224         /* XDTLS: for now assuming that read/writes are blocking */
1225         pitem *item;
1226         hm_fragment *frag ;
1227         unsigned long header_length;
1228         unsigned char seq64be[8];
1229         struct dtls1_retransmit_state saved_state;
1230         unsigned char save_write_sequence[8];
1231
1232         /*
1233           OPENSSL_assert(s->init_num == 0);
1234           OPENSSL_assert(s->init_off == 0);
1235          */
1236
1237         /* XDTLS:  the requested message ought to be found, otherwise error */
1238         memset(seq64be,0,sizeof(seq64be));
1239         seq64be[6] = (unsigned char)(seq>>8);
1240         seq64be[7] = (unsigned char)seq;
1241
1242         item = pqueue_find(s->d1->sent_messages, seq64be);
1243         if ( item == NULL)
1244                 {
1245                 fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1246                 *found = 0;
1247                 return 0;
1248                 }
1249
1250         *found = 1;
1251         frag = (hm_fragment *)item->data;
1252
1253         if ( frag->msg_header.is_ccs)
1254                 header_length = DTLS1_CCS_HEADER_LENGTH;
1255         else
1256                 header_length = DTLS1_HM_HEADER_LENGTH;
1257
1258         memcpy(s->init_buf->data, frag->fragment, 
1259                 frag->msg_header.msg_len + header_length);
1260                 s->init_num = frag->msg_header.msg_len + header_length;
1261
1262         dtls1_set_message_header_int(s, frag->msg_header.type, 
1263                 frag->msg_header.msg_len, frag->msg_header.seq, 0, 
1264                 frag->msg_header.frag_len);
1265
1266         /* save current state */
1267         saved_state.enc_write_ctx = s->enc_write_ctx;
1268         saved_state.write_hash = s->write_hash;
1269         saved_state.compress = s->compress;
1270         saved_state.session = s->session;
1271         saved_state.epoch = s->d1->w_epoch;
1272         saved_state.epoch = s->d1->w_epoch;
1273         
1274         s->d1->retransmitting = 1;
1275         
1276         /* restore state in which the message was originally sent */
1277         s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1278         s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1279         s->compress = frag->msg_header.saved_retransmit_state.compress;
1280         s->session = frag->msg_header.saved_retransmit_state.session;
1281         s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1282         
1283         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1284         {
1285                 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1286                 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1287         }
1288         
1289         ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 
1290                                                  SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1291         
1292         /* restore current state */
1293         s->enc_write_ctx = saved_state.enc_write_ctx;
1294         s->write_hash = saved_state.write_hash;
1295         s->compress = saved_state.compress;
1296         s->session = saved_state.session;
1297         s->d1->w_epoch = saved_state.epoch;
1298         
1299         if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1300         {
1301                 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1302                 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1303         }
1304
1305         s->d1->retransmitting = 0;
1306
1307         (void)BIO_flush(SSL_get_wbio(s));
1308         return ret;
1309         }
1310
1311 /* call this function when the buffered messages are no longer needed */
1312 void
1313 dtls1_clear_record_buffer(SSL *s)
1314         {
1315         pitem *item;
1316
1317         for(item = pqueue_pop(s->d1->sent_messages);
1318                 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1319                 {
1320                 dtls1_hm_fragment_free((hm_fragment *)item->data);
1321                 pitem_free(item);
1322                 }
1323         }
1324
1325
1326 unsigned char *
1327 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1328                         unsigned long len, unsigned long frag_off, unsigned long frag_len)
1329         {
1330         /* Don't change sequence numbers while listening */
1331         if (frag_off == 0 && !s->d1->listen)
1332                 {
1333                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1334                 s->d1->next_handshake_write_seq++;
1335                 }
1336
1337         dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1338                 frag_off, frag_len);
1339
1340         return p += DTLS1_HM_HEADER_LENGTH;
1341         }
1342
1343
1344 /* don't actually do the writing, wait till the MTU has been retrieved */
1345 static void
1346 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1347                             unsigned long len, unsigned short seq_num, unsigned long frag_off,
1348                             unsigned long frag_len)
1349         {
1350         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1351
1352         msg_hdr->type = mt;
1353         msg_hdr->msg_len = len;
1354         msg_hdr->seq = seq_num;
1355         msg_hdr->frag_off = frag_off;
1356         msg_hdr->frag_len = frag_len;
1357         }
1358
1359 static void
1360 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1361                         unsigned long frag_len)
1362         {
1363         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1364
1365         msg_hdr->frag_off = frag_off;
1366         msg_hdr->frag_len = frag_len;
1367         }
1368
1369 static unsigned char *
1370 dtls1_write_message_header(SSL *s, unsigned char *p)
1371         {
1372         struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1373
1374         *p++ = msg_hdr->type;
1375         l2n3(msg_hdr->msg_len, p);
1376
1377         s2n(msg_hdr->seq, p);
1378         l2n3(msg_hdr->frag_off, p);
1379         l2n3(msg_hdr->frag_len, p);
1380
1381         return p;
1382         }
1383
1384 static unsigned int 
1385 dtls1_min_mtu(void)
1386         {
1387         return (g_probable_mtu[(sizeof(g_probable_mtu) / 
1388                 sizeof(g_probable_mtu[0])) - 1]);
1389         }
1390
1391 static unsigned int 
1392 dtls1_guess_mtu(unsigned int curr_mtu)
1393         {
1394         unsigned int i;
1395
1396         if ( curr_mtu == 0 )
1397                 return g_probable_mtu[0] ;
1398
1399         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1400                 if ( curr_mtu > g_probable_mtu[i])
1401                         return g_probable_mtu[i];
1402
1403         return curr_mtu;
1404         }
1405
1406 void
1407 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1408         {
1409         memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1410         msg_hdr->type = *(data++);
1411         n2l3(data, msg_hdr->msg_len);
1412
1413         n2s(data, msg_hdr->seq);
1414         n2l3(data, msg_hdr->frag_off);
1415         n2l3(data, msg_hdr->frag_len);
1416         }
1417
1418 void
1419 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1420         {
1421         memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1422
1423         ccs_hdr->type = *(data++);
1424         }