b746a50dd718d2a8104160ce2c25af3f877ff88b
[dragonfly.git] / crypto / openssl-0.9 / 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
127 /* XDTLS:  figure out the right values */
128 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
129
130 static unsigned int dtls1_min_mtu(void);
131 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
132 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off, 
133         unsigned long frag_len);
134 static unsigned char *dtls1_write_message_header(SSL *s,
135         unsigned char *p);
136 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
137         unsigned long len, unsigned short seq_num, unsigned long frag_off, 
138         unsigned long frag_len);
139 static int dtls1_retransmit_buffered_messages(SSL *s);
140 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, 
141     long max, int *ok);
142 static void dtls1_process_handshake_fragment(SSL *s, int frag_len);
143
144 static hm_fragment *
145 dtls1_hm_fragment_new(unsigned long frag_len)
146     {
147     hm_fragment *frag = NULL;
148     unsigned char *buf = NULL;
149
150     frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
151     if ( frag == NULL)
152         return NULL;
153
154     buf = (unsigned char *)OPENSSL_malloc(frag_len 
155         + DTLS1_HM_HEADER_LENGTH);
156     if ( buf == NULL)
157         {
158         OPENSSL_free(frag);
159         return NULL;
160         }
161     
162     frag->fragment = buf;
163
164     return frag;
165     }
166
167 static void
168 dtls1_hm_fragment_free(hm_fragment *frag)
169     {
170     OPENSSL_free(frag->fragment);
171     OPENSSL_free(frag);
172     }
173
174 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
175 int dtls1_do_write(SSL *s, int type)
176         {
177         int ret;
178         int curr_mtu;
179         unsigned int len, frag_off;
180
181         /* AHA!  Figure out the MTU, and stick to the right size */
182         if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
183         {
184                 s->d1->mtu = 
185                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
186
187                 /* I've seen the kernel return bogus numbers when it doesn't know
188                  * (initial write), so just make sure we have a reasonable number */
189                 if ( s->d1->mtu < dtls1_min_mtu())
190                         {
191                         s->d1->mtu = 0;
192                         s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
193                         BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU, 
194                                 s->d1->mtu, NULL);
195                         }
196                 }
197 #if 0 
198         mtu = s->d1->mtu;
199
200         fprintf(stderr, "using MTU = %d\n", mtu);
201
202         mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
203
204         curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
205
206         if ( curr_mtu > 0)
207                 mtu = curr_mtu;
208         else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
209                 return ret;
210                 
211         if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
212                 {
213                 ret = BIO_flush(SSL_get_wbio(s));
214                 if ( ret <= 0)
215                         return ret;
216                 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
217                 }
218
219         OPENSSL_assert(mtu > 0);  /* should have something reasonable now */
220
221 #endif
222
223         if ( s->init_off == 0  && type == SSL3_RT_HANDSHAKE)
224                 OPENSSL_assert(s->init_num == 
225                         (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
226
227         frag_off = 0;
228         while( s->init_num)
229                 {
230                 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) - 
231                         DTLS1_RT_HEADER_LENGTH;
232
233                 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
234                         {
235                         /* grr.. we could get an error if MTU picked was wrong */
236                         ret = BIO_flush(SSL_get_wbio(s));
237                         if ( ret <= 0)
238                                 return ret;
239                         curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH;
240                         }
241
242                 if ( s->init_num > curr_mtu)
243                         len = curr_mtu;
244                 else
245                         len = s->init_num;
246
247
248                 /* XDTLS: this function is too long.  split out the CCS part */
249                 if ( type == SSL3_RT_HANDSHAKE)
250                         {
251                         if ( s->init_off != 0)
252                                 {
253                                 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
254                                 s->init_off -= DTLS1_HM_HEADER_LENGTH;
255                                 s->init_num += DTLS1_HM_HEADER_LENGTH;
256
257                 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
258                                 if ( len <= DTLS1_HM_HEADER_LENGTH)  
259                                         len += DTLS1_HM_HEADER_LENGTH;
260                                 }
261                         
262                         dtls1_fix_message_header(s, frag_off, 
263                                 len - DTLS1_HM_HEADER_LENGTH);
264
265                         dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
266
267                         OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
268                         }
269
270                 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
271                         len);
272                 if (ret < 0)
273                         {
274                         /* might need to update MTU here, but we don't know
275                          * which previous packet caused the failure -- so can't
276                          * really retransmit anything.  continue as if everything
277                          * is fine and wait for an alert to handle the
278                          * retransmit 
279                          */
280                         if ( BIO_ctrl(SSL_get_wbio(s),
281                                 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL))
282                                 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
283                                         BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
284                         else
285                                 return(-1);
286                         }
287                 else
288                         {
289                         
290                         /* bad if this assert fails, only part of the handshake
291                          * message got sent.  but why would this happen? */
292                         OPENSSL_assert(len == (unsigned int)ret); 
293                         
294                         if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
295                                 /* should not be done for 'Hello Request's, but in that case
296                                  * we'll ignore the result anyway */
297                                 ssl3_finish_mac(s, 
298                                         (unsigned char *)&s->init_buf->data[s->init_off + 
299                                                 DTLS1_HM_HEADER_LENGTH], ret - DTLS1_HM_HEADER_LENGTH);
300                         
301                         if (ret == s->init_num)
302                                 {
303                                 if (s->msg_callback)
304                                         s->msg_callback(1, s->version, type, s->init_buf->data, 
305                                                 (size_t)(s->init_off + s->init_num), s, 
306                                                 s->msg_callback_arg);
307
308                                 s->init_off = 0;  /* done writing this message */
309                                 s->init_num = 0;
310                                 
311                                 return(1);
312                                 }
313                         s->init_off+=ret;
314                         s->init_num-=ret;
315                         frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
316                         }
317                 }
318         return(0);
319         }
320
321
322 /* Obtain handshake message of message type 'mt' (any if mt == -1),
323  * maximum acceptable body length 'max'.
324  * Read an entire handshake message.  Handshake messages arrive in
325  * fragments.
326  */
327 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
328         {
329         int i, al;
330
331         /* s3->tmp is used to store messages that are unexpected, caused
332          * by the absence of an optional handshake message */
333         if (s->s3->tmp.reuse_message)
334                 {
335                 s->s3->tmp.reuse_message=0;
336                 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
337                         {
338                         al=SSL_AD_UNEXPECTED_MESSAGE;
339                         SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
340                         goto f_err;
341                         }
342                 *ok=1;
343                 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
344                 s->init_num = (int)s->s3->tmp.message_size;
345                 return s->init_num;
346                 }
347         
348         do
349                 {
350                 if ( s->d1->r_msg_hdr.frag_off == 0)
351                         {
352                         /* s->d1->r_message_header.msg_len = 0; */
353                         memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
354                         }
355
356                 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
357                 if ( i == DTLS1_HM_BAD_FRAGMENT ||
358             i == DTLS1_HM_FRAGMENT_RETRY)  /* bad fragment received */
359                         continue;
360                 else if ( i <= 0 && !*ok)
361                         return i;
362
363                 if (s->d1->r_msg_hdr.msg_len == (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
364                         {
365                         memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
366
367                         s->d1->handshake_read_seq++;
368                         /* we just read a handshake message from the other side:
369                          * this means that we don't need to retransmit of the
370                          * buffered messages.  
371                          * XDTLS: may be able clear out this
372                          * buffer a little sooner (i.e if an out-of-order
373                          * handshake message/record is received at the record
374                          * layer.  
375                          * XDTLS: exception is that the server needs to
376                          * know that change cipher spec and finished messages
377                          * have been received by the client before clearing this
378                          * buffer.  this can simply be done by waiting for the
379                          * first data  segment, but is there a better way?  */
380                         dtls1_clear_record_buffer(s);
381
382             s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
383                         return s->init_num - DTLS1_HM_HEADER_LENGTH;
384                         }
385                 else
386                         s->d1->r_msg_hdr.frag_off = i;
387                 } while(1) ;
388
389 f_err:
390         ssl3_send_alert(s,SSL3_AL_FATAL,al);
391         *ok = 0;
392         return -1;
393         }
394
395
396 static int
397 dtls1_retrieve_buffered_fragment(SSL *s, unsigned long *copied)
398     {
399     /* (0) check whether the desired fragment is available
400      * if so:
401      * (1) copy over the fragment to s->init_buf->data[]
402      * (2) update s->init_num
403      */
404     pitem *item;
405     hm_fragment *frag;
406     unsigned long overlap;
407     unsigned char *p;
408
409     item = pqueue_peek(s->d1->buffered_messages);
410     if ( item == NULL)
411         return 0;
412
413     frag = (hm_fragment *)item->data;
414     
415     if ( s->d1->handshake_read_seq == frag->msg_header.seq &&
416         frag->msg_header.frag_off <= (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
417         {
418         pqueue_pop(s->d1->buffered_messages);
419         overlap = s->init_num - DTLS1_HM_HEADER_LENGTH 
420             - frag->msg_header.frag_off;
421
422         p = frag->fragment;
423
424         memcpy(&s->init_buf->data[s->init_num],
425             p + DTLS1_HM_HEADER_LENGTH + overlap,
426             frag->msg_header.frag_len - overlap);
427     
428         OPENSSL_free(frag->fragment);
429         OPENSSL_free(frag);
430         pitem_free(item);
431
432         *copied = frag->msg_header.frag_len - overlap;
433         return *copied;
434         }
435     else
436         return 0;
437     }
438
439
440 static int
441 dtls1_buffer_handshake_fragment(SSL *s, struct hm_header_st* msg_hdr)
442 {
443     hm_fragment *frag = NULL;
444     pitem *item = NULL;
445         PQ_64BIT seq64;
446
447     frag = dtls1_hm_fragment_new(msg_hdr->frag_len);
448     if ( frag == NULL)
449         goto err;
450
451     memcpy(frag->fragment, &(s->init_buf->data[s->init_num]),
452         msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH);
453
454     memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
455
456     pq_64bit_init(&seq64);
457     pq_64bit_assign_word(&seq64, msg_hdr->seq);
458
459     item = pitem_new(seq64, frag);
460     if ( item == NULL)
461         goto err;
462
463     pq_64bit_free(&seq64);
464
465     pqueue_insert(s->d1->buffered_messages, item);
466     return 1;
467
468 err:
469     if ( frag != NULL) dtls1_hm_fragment_free(frag);
470     if ( item != NULL) OPENSSL_free(item);
471     return 0;
472 }
473
474
475 static void
476 dtls1_process_handshake_fragment(SSL *s, int frag_len)
477     {
478     unsigned char *p;
479
480     p = (unsigned char *)s->init_buf->data;
481
482         ssl3_finish_mac(s, &p[s->init_num - frag_len], frag_len);
483     }
484
485
486 static int
487 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st *msg_hdr, int *ok)
488     {
489     int i;
490     unsigned char *p;
491
492     /* make sure there's enough room to read this fragment */
493     if ( (int)msg_hdr->frag_len && !BUF_MEM_grow_clean(s->init_buf, 
494              (int)msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH + s->init_num))
495         {
496         SSLerr(SSL_F_DTLS1_PROCESS_OUT_OF_SEQ_MESSAGE,ERR_R_BUF_LIB);
497         goto err;
498         }
499
500     p = (unsigned char *)s->init_buf->data;
501
502     /* read the body of the fragment (header has already been read */
503     if ( msg_hdr->frag_len > 0)
504                 {
505                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
506             &p[s->init_num], 
507             msg_hdr->frag_len,0);
508                 if (i <= 0)
509                         {
510                         *ok = 0;
511                         return i;
512                         }
513                 }
514
515     if ( msg_hdr->seq > s->d1->handshake_read_seq)
516         dtls1_buffer_handshake_fragment(s, msg_hdr);
517     else
518         OPENSSL_assert(msg_hdr->seq < s->d1->handshake_read_seq);
519
520     return DTLS1_HM_FRAGMENT_RETRY;
521 err:
522     *ok = 0;
523     return -1;
524     }
525
526
527 static long
528 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
529         {
530         unsigned char *p;
531         unsigned long l, frag_off, frag_len;
532         int i,al;
533         struct hm_header_st msg_hdr;
534     unsigned long overlap;
535     
536     /* see if we have the required fragment already */
537     if (dtls1_retrieve_buffered_fragment(s, &l))
538     {
539         /* compute MAC, remove fragment headers */
540         dtls1_process_handshake_fragment(s, l);
541         s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
542         s->state = stn;
543         return 1;
544     }
545
546     /* get a handshake fragment from the record layer */
547         p = (unsigned char *)s->init_buf->data;
548
549     /* read handshake message header */
550         i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],
551                 DTLS1_HM_HEADER_LENGTH, 0);
552         if (i <= 0)     /* nbio, or an error */
553                 {
554                 s->rwstate=SSL_READING;
555                 *ok = 0;
556                 return i;
557                 }
558
559         OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
560
561         p += s->init_num;
562     /* parse the message fragment header */
563     
564     dtls1_get_message_header(p, &msg_hdr);
565
566     /* 
567      * if this is a future (or stale) message it gets buffered
568      * (or dropped)--no further processing at this time 
569      */
570     if ( msg_hdr.seq != s->d1->handshake_read_seq)
571         return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
572
573     l = msg_hdr.msg_len;
574     frag_off = msg_hdr.frag_off;
575         frag_len = msg_hdr.frag_len;
576
577     /* sanity checking */
578     if ( frag_off + frag_len > l)
579         {
580         al=SSL_AD_ILLEGAL_PARAMETER;
581         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
582         goto f_err;
583         }
584
585         if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
586         p[0] == SSL3_MT_HELLO_REQUEST)
587         {
588         /* The server may always send 'Hello Request' messages --
589          * we are doing a handshake anyway now, so ignore them
590          * if their format is correct. Does not count for
591          * 'Finished' MAC. */
592         if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
593             {
594             if (s->msg_callback)
595                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
596                     p, DTLS1_HM_HEADER_LENGTH, s, 
597                     s->msg_callback_arg);
598             
599             s->init_num = 0;
600             return dtls1_get_message_fragment(s, st1, stn,
601                 max, ok);
602             }
603         else /* Incorrectly formated Hello request */
604             {
605             al=SSL_AD_UNEXPECTED_MESSAGE;
606             SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
607             goto f_err;
608             }
609         }
610
611     /* XDTLS: do a sanity check on the fragment */
612
613     s->init_num += i;
614
615         if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
616                 {
617                 /* BUF_MEM_grow takes an 'int' parameter */
618                 if (l > (INT_MAX-DTLS1_HM_HEADER_LENGTH)) 
619                         {
620                         al=SSL_AD_ILLEGAL_PARAMETER;
621                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
622                         goto f_err;
623                         }
624                 if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l
625                         + DTLS1_HM_HEADER_LENGTH))
626                         {
627                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
628                         goto err;
629                         }
630         /* Only do this test when we're reading the expected message.
631          * Stale messages will be dropped and future messages will be buffered */
632         if ( l > (unsigned long)max)
633                         {
634                         al=SSL_AD_ILLEGAL_PARAMETER;
635                         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
636                         goto f_err;
637                         }
638
639                 s->s3->tmp.message_size=l;
640                 }
641
642     if ( frag_len > (unsigned long)max)
643         {
644         al=SSL_AD_ILLEGAL_PARAMETER;
645         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
646         goto f_err;
647         }
648     if ( frag_len + s->init_num > (INT_MAX - DTLS1_HM_HEADER_LENGTH))
649         {
650         al=SSL_AD_ILLEGAL_PARAMETER;
651         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
652         goto f_err;
653         }
654
655     if ( frag_len & !BUF_MEM_grow_clean(s->init_buf, (int)frag_len 
656              + DTLS1_HM_HEADER_LENGTH + s->init_num))
657         {
658         SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
659         goto err;
660         }
661
662         if ( s->d1->r_msg_hdr.frag_off == 0)
663                 {
664                 s->s3->tmp.message_type = msg_hdr.type;
665                 s->d1->r_msg_hdr.type = msg_hdr.type;
666                 s->d1->r_msg_hdr.msg_len = l;
667                 /* s->d1->r_msg_hdr.seq = seq_num; */
668                 }
669
670         /* XDTLS:  ressurect this when restart is in place */
671         s->state=stn;
672         
673         /* next state (stn) */
674         p = (unsigned char *)s->init_buf->data;
675
676         if ( frag_len > 0)
677                 {
678                 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
679             &p[s->init_num], 
680             frag_len,0);
681         /* XDTLS:  fix this--message fragments cannot span multiple packets */
682                 if (i <= 0)
683                         {
684                         s->rwstate=SSL_READING;
685                         *ok = 0;
686                         return i;
687                         }
688                 }
689         else
690                 i = 0;
691
692     /* XDTLS:  an incorrectly formatted fragment should cause the 
693      * handshake to fail */
694         OPENSSL_assert(i == (int)frag_len);
695
696 #if 0
697     /* Successfully read a fragment.
698      * It may be (1) out of order, or
699      *           (2) it's a repeat, in which case we dump it
700      *           (3) the one we are expecting next (maybe with overlap)
701      * If it is next one, it may overlap with previously read bytes
702      */
703
704     /* case (1): buffer the future fragment 
705      * (we can treat fragments from a future message the same
706      * as future fragments from the message being currently read, since
707      * they are sematically simply out of order.
708      */
709     if ( msg_hdr.seq > s->d1->handshake_read_seq ||
710         frag_off > s->init_num - DTLS1_HM_HEADER_LENGTH)
711     {
712         dtls1_buffer_handshake_fragment(s, &msg_hdr);
713         return DTLS1_HM_FRAGMENT_RETRY;
714     }
715
716     /* case (2):  drop the entire fragment, and try again */
717     if ( msg_hdr.seq < s->d1->handshake_read_seq ||
718         frag_off + frag_len < s->init_num - DTLS1_HM_HEADER_LENGTH)
719         {
720         s->init_num -= DTLS1_HM_HEADER_LENGTH;
721         return DTLS1_HM_FRAGMENT_RETRY;
722         }
723 #endif
724
725     /* case (3): received a immediately useful fragment.  Determine the 
726      * possible overlap and copy the fragment.
727      */
728     overlap = (s->init_num - DTLS1_HM_HEADER_LENGTH) - frag_off;
729         
730     /* retain the header for the first fragment */
731     if ( s->init_num > DTLS1_HM_HEADER_LENGTH)
732         {
733         memmove(&(s->init_buf->data[s->init_num]),
734             &(s->init_buf->data[s->init_num + DTLS1_HM_HEADER_LENGTH + overlap]),
735             frag_len - overlap);
736
737         s->init_num += frag_len - overlap;
738         }
739     else
740         s->init_num += frag_len;
741
742     dtls1_process_handshake_fragment(s, frag_len - overlap);
743
744         if (s->msg_callback)
745                 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data, 
746                         (size_t)s->init_num, s, 
747                         s->msg_callback_arg);
748         *ok=1;
749
750         return s->init_num;
751
752 f_err:
753         ssl3_send_alert(s,SSL3_AL_FATAL,al);
754     s->init_num = 0;
755 err:
756         *ok=0;
757         return(-1);
758         }
759
760 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
761         {
762         unsigned char *p,*d;
763         int i;
764         unsigned long l;
765
766         if (s->state == a)
767                 {
768                 d=(unsigned char *)s->init_buf->data;
769                 p= &(d[DTLS1_HM_HEADER_LENGTH]);
770
771                 i=s->method->ssl3_enc->final_finish_mac(s,
772                         &(s->s3->finish_dgst1),
773                         &(s->s3->finish_dgst2),
774                         sender,slen,s->s3->tmp.finish_md);
775                 s->s3->tmp.finish_md_len = i;
776                 memcpy(p, s->s3->tmp.finish_md, i);
777                 p+=i;
778                 l=i;
779
780 #ifdef OPENSSL_SYS_WIN16
781                 /* MSVC 1.5 does not clear the top bytes of the word unless
782                  * I do this.
783                  */
784                 l&=0xffff;
785 #endif
786
787                 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
788                 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
789                 s->init_off=0;
790
791                 /* buffer the message to handle re-xmits */
792                 dtls1_buffer_message(s, 0);
793                 
794                 s->state=b;
795                 }
796
797         /* SSL3_ST_SEND_xxxxxx_HELLO_B */
798         return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
799         }
800
801 /* for these 2 messages, we need to
802  * ssl->enc_read_ctx                    re-init
803  * ssl->s3->read_sequence               zero
804  * ssl->s3->read_mac_secret             re-init
805  * ssl->session->read_sym_enc           assign
806  * ssl->session->read_compression       assign
807  * ssl->session->read_hash              assign
808  */
809 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
810         { 
811         unsigned char *p;
812
813         if (s->state == a)
814                 {
815                 p=(unsigned char *)s->init_buf->data;
816                 *p++=SSL3_MT_CCS;
817                 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
818                 s->d1->next_handshake_write_seq++;
819                 s2n(s->d1->handshake_write_seq,p);
820
821                 s->init_num=DTLS1_CCS_HEADER_LENGTH;
822                 s->init_off=0;
823
824                 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0, 
825                         s->d1->handshake_write_seq, 0, 0);
826
827                 /* buffer the message to handle re-xmits */
828                 dtls1_buffer_message(s, 1);
829
830                 s->state=b;
831                 }
832
833         /* SSL3_ST_CW_CHANGE_B */
834         return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
835         }
836
837 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
838         {
839         unsigned char *p;
840         int n,i;
841         unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
842         BUF_MEM *buf;
843         X509_STORE_CTX xs_ctx;
844         X509_OBJECT obj;
845
846         /* TLSv1 sends a chain with nothing in it, instead of an alert */
847         buf=s->init_buf;
848         if (!BUF_MEM_grow_clean(buf,10))
849                 {
850                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
851                 return(0);
852                 }
853         if (x != NULL)
854                 {
855                 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
856                         {
857                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
858                         return(0);
859                         }
860
861                 for (;;)
862                         {
863                         n=i2d_X509(x,NULL);
864                         if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
865                                 {
866                                 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
867                                 return(0);
868                                 }
869                         p=(unsigned char *)&(buf->data[l]);
870                         l2n3(n,p);
871                         i2d_X509(x,&p);
872                         l+=n+3;
873                         if (X509_NAME_cmp(X509_get_subject_name(x),
874                                 X509_get_issuer_name(x)) == 0) break;
875
876                         i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
877                                 X509_get_issuer_name(x),&obj);
878                         if (i <= 0) break;
879                         x=obj.data.x509;
880                         /* Count is one too high since the X509_STORE_get uped the
881                          * ref count */
882                         X509_free(x);
883                         }
884
885                 X509_STORE_CTX_cleanup(&xs_ctx);
886                 }
887
888         /* Thawte special :-) */
889         if (s->ctx->extra_certs != NULL)
890         for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
891                 {
892                 x=sk_X509_value(s->ctx->extra_certs,i);
893                 n=i2d_X509(x,NULL);
894                 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
895                         {
896                         SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
897                         return(0);
898                         }
899                 p=(unsigned char *)&(buf->data[l]);
900                 l2n3(n,p);
901                 i2d_X509(x,&p);
902                 l+=n+3;
903                 }
904
905         l-= (3 + DTLS1_HM_HEADER_LENGTH);
906
907         p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
908         l2n3(l,p);
909         l+=3;
910         p=(unsigned char *)&(buf->data[0]);
911         p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
912
913         l+=DTLS1_HM_HEADER_LENGTH;
914         return(l);
915         }
916
917 int dtls1_read_failed(SSL *s, int code)
918     {
919     DTLS1_STATE *state;
920     BIO *bio;
921     int send_alert = 0;
922
923     if ( code > 0)
924         {
925         fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
926         return 1;
927         }
928
929     bio = SSL_get_rbio(s);
930     if ( ! BIO_dgram_recv_timedout(bio))
931         {
932         /* not a timeout, none of our business, 
933            let higher layers handle this.  in fact it's probably an error */
934         return code;
935         }
936
937     if ( ! SSL_in_init(s))  /* done, no need to send a retransmit */
938         {
939         BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
940         return code;
941         }
942
943     state = s->d1;
944     state->timeout.num_alerts++;
945     if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
946         {
947         /* fail the connection, enough alerts have been sent */
948         SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
949         return 0;
950         }
951         
952     state->timeout.read_timeouts++;
953     if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
954         {
955         send_alert = 1;
956         state->timeout.read_timeouts = 1;
957         }
958
959         
960 #if 0 /* for now, each alert contains only one record number */
961     item = pqueue_peek(state->rcvd_records);
962     if ( item )
963         {
964         /* send an alert immediately for all the missing records */
965         }
966     else
967 #endif
968
969 #if 0  /* no more alert sending, just retransmit the last set of messages */
970         if ( send_alert)
971             ssl3_send_alert(s,SSL3_AL_WARNING,
972                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
973 #endif
974
975     return dtls1_retransmit_buffered_messages(s) ;
976     }
977
978
979 static int
980 dtls1_retransmit_buffered_messages(SSL *s)
981     {
982     pqueue sent = s->d1->sent_messages;
983     piterator iter;
984     pitem *item;
985     hm_fragment *frag;
986     int found = 0;
987
988     iter = pqueue_iterator(sent);
989
990     for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
991         {
992         frag = (hm_fragment *)item->data;
993         if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 &&
994             found)
995             {
996             fprintf(stderr, "dtls1_retransmit_message() failed\n");
997             return -1;
998             }
999         }
1000
1001     return 1;
1002     }
1003
1004 #if 0
1005 static dtls1_message_buffer *
1006 dtls1_message_buffer_new(unsigned int len)
1007     {
1008     dtls1_message_buffer *msg_buf;
1009
1010     msg_buf = (dtls1_message_buffer *) 
1011         OPENSSL_malloc(sizeof(dtls1_message_buffer)); 
1012     if ( msg_buf == NULL)
1013         return NULL;
1014
1015     memset(msg_buf, 0x00, sizeof(dtls1_message_buffer));
1016
1017     msg_buf->data = (unsigned char *) OPENSSL_malloc(len);
1018     if ( msg_buf->data == NULL)
1019         {
1020         OPENSSL_free(msg_buf);
1021         return NULL;
1022         }
1023
1024     memset(msg_buf->data, 0x00, len);
1025     return msg_buf;
1026     }
1027 #endif
1028
1029 #if 0
1030 static void
1031 dtls1_message_buffer_free(dtls1_message_buffer *msg_buf)
1032     {
1033     if (msg_buf != NULL)
1034         {
1035         OPENSSL_free(msg_buf->data);
1036         OPENSSL_free(msg_buf);
1037         }
1038     }
1039 #endif
1040
1041 int
1042 dtls1_buffer_message(SSL *s, int is_ccs)
1043     {
1044     pitem *item;
1045     hm_fragment *frag;
1046         PQ_64BIT seq64;
1047
1048     /* this function is called immediately after a message has 
1049      * been serialized */
1050     OPENSSL_assert(s->init_off == 0);
1051
1052     frag = dtls1_hm_fragment_new(s->init_num);
1053
1054     memcpy(frag->fragment, s->init_buf->data, s->init_num);
1055
1056     if ( is_ccs)
1057         {
1058         OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
1059             DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1060         }
1061     else
1062         {
1063         OPENSSL_assert(s->d1->w_msg_hdr.msg_len + 
1064             DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1065         }
1066
1067     frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1068     frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1069     frag->msg_header.type = s->d1->w_msg_hdr.type;
1070     frag->msg_header.frag_off = 0;
1071     frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1072     frag->msg_header.is_ccs = is_ccs;
1073
1074     pq_64bit_init(&seq64);
1075     pq_64bit_assign_word(&seq64, frag->msg_header.seq);
1076
1077     item = pitem_new(seq64, frag);
1078     pq_64bit_free(&seq64);
1079     if ( item == NULL)
1080         {
1081         dtls1_hm_fragment_free(frag);
1082         return 0;
1083         }
1084
1085 #if 0
1086     fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1087     fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1088     fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1089 #endif
1090
1091     pqueue_insert(s->d1->sent_messages, item);
1092     return 1;
1093     }
1094
1095 int
1096 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1097     int *found)
1098     {
1099     int ret;
1100     /* XDTLS: for now assuming that read/writes are blocking */
1101     pitem *item;
1102     hm_fragment *frag ;
1103     unsigned long header_length;
1104         PQ_64BIT seq64;
1105
1106     /*
1107       OPENSSL_assert(s->init_num == 0);
1108       OPENSSL_assert(s->init_off == 0);
1109      */
1110
1111     /* XDTLS:  the requested message ought to be found, otherwise error */
1112     pq_64bit_init(&seq64);
1113     pq_64bit_assign_word(&seq64, seq);
1114
1115     item = pqueue_find(s->d1->sent_messages, seq64);
1116     pq_64bit_free(&seq64);
1117     if ( item == NULL)
1118         {
1119         fprintf(stderr, "retransmit:  message %d non-existant\n", seq);
1120         *found = 0;
1121         return 0;
1122         }
1123
1124     *found = 1;
1125     frag = (hm_fragment *)item->data;
1126
1127     if ( frag->msg_header.is_ccs)
1128         header_length = DTLS1_CCS_HEADER_LENGTH;
1129     else
1130         header_length = DTLS1_HM_HEADER_LENGTH;
1131
1132     memcpy(s->init_buf->data, frag->fragment, 
1133         frag->msg_header.msg_len + header_length);
1134         s->init_num = frag->msg_header.msg_len + header_length;
1135     
1136     dtls1_set_message_header_int(s, frag->msg_header.type, 
1137         frag->msg_header.msg_len, frag->msg_header.seq, 0, 
1138         frag->msg_header.frag_len);
1139
1140     s->d1->retransmitting = 1;
1141     ret = dtls1_do_write(s, frag->msg_header.is_ccs ? 
1142         SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1143     s->d1->retransmitting = 0;
1144
1145     BIO_flush(SSL_get_wbio(s));
1146     return ret;
1147     }
1148
1149 /* call this function when the buffered messages are no longer needed */
1150 void
1151 dtls1_clear_record_buffer(SSL *s)
1152     {
1153     pitem *item;
1154     
1155     for(item = pqueue_pop(s->d1->sent_messages);
1156         item != NULL; item = pqueue_pop(s->d1->sent_messages))
1157         {
1158         dtls1_hm_fragment_free((hm_fragment *)item->data);
1159         pitem_free(item);
1160         }
1161     }
1162
1163
1164 unsigned char *
1165 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1166     unsigned long len, unsigned long frag_off, unsigned long frag_len)
1167     {
1168     if ( frag_off == 0)
1169         {
1170         s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1171         s->d1->next_handshake_write_seq++;
1172         }
1173     
1174     dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1175         frag_off, frag_len);
1176     
1177     return p += DTLS1_HM_HEADER_LENGTH;
1178     }
1179
1180
1181 /* don't actually do the writing, wait till the MTU has been retrieved */
1182 static void
1183 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1184     unsigned long len, unsigned short seq_num, unsigned long frag_off, 
1185     unsigned long frag_len)
1186     {
1187     struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1188     
1189     msg_hdr->type = mt;
1190     msg_hdr->msg_len = len;
1191     msg_hdr->seq = seq_num;
1192     msg_hdr->frag_off = frag_off;
1193     msg_hdr->frag_len = frag_len;
1194 }
1195
1196 static void
1197 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1198         unsigned long frag_len)
1199     {
1200     struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1201     
1202     msg_hdr->frag_off = frag_off;
1203     msg_hdr->frag_len = frag_len;
1204     }
1205
1206 static unsigned char *
1207 dtls1_write_message_header(SSL *s, unsigned char *p)
1208     {
1209     struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1210     
1211     *p++ = msg_hdr->type;
1212     l2n3(msg_hdr->msg_len, p);
1213     
1214     s2n(msg_hdr->seq, p);
1215     l2n3(msg_hdr->frag_off, p);
1216     l2n3(msg_hdr->frag_len, p);
1217     
1218     return p;
1219     }
1220
1221 static unsigned int 
1222 dtls1_min_mtu(void)
1223     {
1224     return 
1225         g_probable_mtu[(sizeof(g_probable_mtu) / 
1226            sizeof(g_probable_mtu[0])) - 1];
1227     }
1228
1229 static unsigned int 
1230 dtls1_guess_mtu(unsigned int curr_mtu)
1231         {
1232         size_t i;
1233
1234         if ( curr_mtu == 0 )
1235                 return g_probable_mtu[0] ;
1236
1237         for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1238                 if ( curr_mtu > g_probable_mtu[i])
1239                         return g_probable_mtu[i];
1240         
1241         return curr_mtu;
1242         }
1243
1244 void
1245 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1246     {
1247     memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1248     msg_hdr->type = *(data++);
1249     n2l3(data, msg_hdr->msg_len);
1250     
1251     n2s(data, msg_hdr->seq);
1252     n2l3(data, msg_hdr->frag_off);
1253     n2l3(data, msg_hdr->frag_len);
1254     }
1255
1256 void
1257 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1258     {
1259     memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1260     
1261     ccs_hdr->type = *(data++);
1262     n2s(data, ccs_hdr->seq);
1263 }