Extend DTLS method macros.
[openssl.git] / ssl / d1_pkt.c
1 /* ssl/d1_pkt.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 <stdio.h>
117 #include <errno.h>
118 #define USE_SOCKETS
119 #include "ssl_locl.h"
120 #include <openssl/evp.h>
121 #include <openssl/buffer.h>
122 #include <openssl/pqueue.h>
123 #include <openssl/rand.h>
124
125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
127 {       int ret,sat,brw,i;
128
129         if (sizeof(long) == 8) do
130         {       const union { long one; char little; } is_endian = {1};
131                 long l;
132
133                 if (is_endian.little)                   break;
134                 /* not reached on little-endians */
135                 /* following test is redundant, because input is
136                  * always aligned, but I take no chances... */
137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
138
139                 l  = *((long *)v1);
140                 l -= *((long *)v2);
141                 if (l>128)              return 128;
142                 else if (l<-128)        return -128;
143                 else                    return (int)l;
144         } while (0);
145
146         ret = (int)v1[7]-(int)v2[7];
147         sat = 0;
148         brw = ret>>8;   /* brw is either 0 or -1 */
149         if (ret & 0x80)
150         {       for (i=6;i>=0;i--)
151                 {       brw += (int)v1[i]-(int)v2[i];
152                         sat |= ~brw;
153                         brw >>= 8;
154                 }
155         }
156         else
157         {       for (i=6;i>=0;i--)
158                 {       brw += (int)v1[i]-(int)v2[i];
159                         sat |= brw;
160                         brw >>= 8;
161                 }
162         }
163         brw <<= 8;      /* brw is either 0 or -256 */
164
165         if (sat&0xff)   return brw | 0x80;
166         else            return brw + (ret&0xFF);
167 }
168
169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
170         int len, int peek);
171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 
174     unsigned int *is_next_epoch);
175 #if 0
176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
177         unsigned short *priority, unsigned long *offset);
178 #endif
179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
180         unsigned char *priority);
181 static int dtls1_process_record(SSL *s);
182
183 /* copy buffered record into SSL structure */
184 static int
185 dtls1_copy_record(SSL *s, pitem *item)
186     {
187     DTLS1_RECORD_DATA *rdata;
188
189     rdata = (DTLS1_RECORD_DATA *)item->data;
190     
191     if (s->s3->rbuf.buf != NULL)
192         OPENSSL_free(s->s3->rbuf.buf);
193     
194     s->packet = rdata->packet;
195     s->packet_length = rdata->packet_length;
196     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
197     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
198         
199         /* Set proper sequence number for mac calculation */
200         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
201     
202     return(1);
203     }
204
205
206 static int
207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
208         {
209         DTLS1_RECORD_DATA *rdata;
210         pitem *item;
211
212         /* Limit the size of the queue to prevent DOS attacks */
213         if (pqueue_size(queue->q) >= 100)
214                 return 0;
215                 
216         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
217         item = pitem_new(priority, rdata);
218         if (rdata == NULL || item == NULL)
219                 {
220                 if (rdata != NULL) OPENSSL_free(rdata);
221                 if (item != NULL) pitem_free(item);
222                 
223                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
224                 return(0);
225                 }
226         
227         rdata->packet = s->packet;
228         rdata->packet_length = s->packet_length;
229         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
230         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
231
232         item->data = rdata;
233
234 #ifndef OPENSSL_NO_SCTP
235         /* Store bio_dgram_sctp_rcvinfo struct */
236         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
237             (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) {
238                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
239         }
240 #endif
241
242         /* insert should not fail, since duplicates are dropped */
243         if (pqueue_insert(queue->q, item) == NULL)
244                 {
245                 OPENSSL_free(rdata);
246                 pitem_free(item);
247                 return(0);
248                 }
249
250         s->packet = NULL;
251         s->packet_length = 0;
252         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
253         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
254         
255         if (!ssl3_setup_buffers(s))
256                 {
257                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
258                 OPENSSL_free(rdata);
259                 pitem_free(item);
260                 return(0);
261                 }
262         
263         return(1);
264         }
265
266
267 static int
268 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
269     {
270     pitem *item;
271
272     item = pqueue_pop(queue->q);
273     if (item)
274         {
275         dtls1_copy_record(s, item);
276
277         OPENSSL_free(item->data);
278                 pitem_free(item);
279
280         return(1);
281         }
282
283     return(0);
284     }
285
286
287 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 
288  * yet */
289 #define dtls1_get_unprocessed_record(s) \
290                    dtls1_retrieve_buffered_record((s), \
291                    &((s)->d1->unprocessed_rcds))
292
293 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
294 #define dtls1_get_processed_record(s) \
295                    dtls1_retrieve_buffered_record((s), \
296                    &((s)->d1->processed_rcds))
297
298 static int
299 dtls1_process_buffered_records(SSL *s)
300     {
301     pitem *item;
302     
303     item = pqueue_peek(s->d1->unprocessed_rcds.q);
304     if (item)
305         {
306         /* Check if epoch is current. */
307         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
308             return(1);  /* Nothing to do. */
309         
310         /* Process all the records. */
311         while (pqueue_peek(s->d1->unprocessed_rcds.q))
312             {
313             dtls1_get_unprocessed_record(s);
314             if ( ! dtls1_process_record(s))
315                 return(0);
316             dtls1_buffer_record(s, &(s->d1->processed_rcds), 
317                 s->s3->rrec.seq_num);
318             }
319         }
320
321     /* sync epoch numbers once all the unprocessed records 
322      * have been processed */
323     s->d1->processed_rcds.epoch = s->d1->r_epoch;
324     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
325
326     return(1);
327     }
328
329
330 #if 0
331
332 static int
333 dtls1_get_buffered_record(SSL *s)
334         {
335         pitem *item;
336         PQ_64BIT priority = 
337                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 
338                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
339         
340         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating, 
341                                                            nothing buffered */
342                 return 0;
343
344
345         item = pqueue_peek(s->d1->rcvd_records);
346         if (item && item->priority == priority)
347                 {
348                 /* Check if we've received the record of interest.  It must be
349                  * a handshake record, since data records as passed up without
350                  * buffering */
351                 DTLS1_RECORD_DATA *rdata;
352                 item = pqueue_pop(s->d1->rcvd_records);
353                 rdata = (DTLS1_RECORD_DATA *)item->data;
354                 
355                 if (s->s3->rbuf.buf != NULL)
356                         OPENSSL_free(s->s3->rbuf.buf);
357                 
358                 s->packet = rdata->packet;
359                 s->packet_length = rdata->packet_length;
360                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
361                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
362                 
363                 OPENSSL_free(item->data);
364                 pitem_free(item);
365                 
366                 /* s->d1->next_expected_seq_num++; */
367                 return(1);
368                 }
369         
370         return 0;
371         }
372
373 #endif
374
375 static int
376 dtls1_process_record(SSL *s)
377 {
378         int i,al;
379         int enc_err;
380         SSL_SESSION *sess;
381         SSL3_RECORD *rr;
382         unsigned int mac_size;
383         unsigned char md[EVP_MAX_MD_SIZE];
384
385         rr= &(s->s3->rrec);
386         sess = s->session;
387
388         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
389          * and we have that many bytes in s->packet
390          */
391         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
392
393         /* ok, we can now read from 's->packet' data into 'rr'
394          * rr->input points at rr->length bytes, which
395          * need to be copied into rr->data by either
396          * the decryption or by the decompression
397          * When the data is 'copied' into the rr->data buffer,
398          * rr->input will be pointed at the new buffer */ 
399
400         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
401          * rr->length bytes of encrypted compressed stuff. */
402
403         /* check is not needed I believe */
404         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
405                 {
406                 al=SSL_AD_RECORD_OVERFLOW;
407                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
408                 goto f_err;
409                 }
410
411         /* decrypt in place in 'rr->input' */
412         rr->data=rr->input;
413         rr->orig_len=rr->length;
414
415         enc_err = s->method->ssl3_enc->enc(s,0);
416         /* enc_err is:
417          *    0: (in non-constant time) if the record is publically invalid.
418          *    1: if the padding is valid
419          *    -1: if the padding is invalid */
420         if (enc_err == 0)
421                 {
422                 /* For DTLS we simply ignore bad packets. */
423                 rr->length = 0;
424                 s->packet_length = 0;
425                 goto err;
426                 }
427
428 #ifdef TLS_DEBUG
429 printf("dec %d\n",rr->length);
430 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
431 printf("\n");
432 #endif
433
434         /* r->length is now the compressed data plus mac */
435         if ((sess != NULL) &&
436             (s->enc_read_ctx != NULL) &&
437             (EVP_MD_CTX_md(s->read_hash) != NULL))
438                 {
439                 /* s->read_hash != NULL => mac_size != -1 */
440                 unsigned char *mac = NULL;
441                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
442                 mac_size=EVP_MD_CTX_size(s->read_hash);
443                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
444
445                 /* orig_len is the length of the record before any padding was
446                  * removed. This is public information, as is the MAC in use,
447                  * therefore we can safely process the record in a different
448                  * amount of time if it's too short to possibly contain a MAC.
449                  */
450                 if (rr->orig_len < mac_size ||
451                     /* CBC records must have a padding length byte too. */
452                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
453                      rr->orig_len < mac_size+1))
454                         {
455                         al=SSL_AD_DECODE_ERROR;
456                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
457                         goto f_err;
458                         }
459
460                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
461                         {
462                         /* We update the length so that the TLS header bytes
463                          * can be constructed correctly but we need to extract
464                          * the MAC in constant time from within the record,
465                          * without leaking the contents of the padding bytes.
466                          * */
467                         mac = mac_tmp;
468                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
469                         rr->length -= mac_size;
470                         }
471                 else
472                         {
473                         /* In this case there's no padding, so |rec->orig_len|
474                          * equals |rec->length| and we checked that there's
475                          * enough bytes for |mac_size| above. */
476                         rr->length -= mac_size;
477                         mac = &rr->data[rr->length];
478                         }
479
480                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
481                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
482                         enc_err = -1;
483                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
484                         enc_err = -1;
485                 }
486
487         if (enc_err < 0)
488                 {
489                 /* decryption failed, silently discard message */
490                 rr->length = 0;
491                 s->packet_length = 0;
492                 goto err;
493                 }
494
495         /* r->length is now just compressed */
496         if (s->expand != NULL)
497                 {
498                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
499                         {
500                         al=SSL_AD_RECORD_OVERFLOW;
501                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
502                         goto f_err;
503                         }
504                 if (!ssl3_do_uncompress(s))
505                         {
506                         al=SSL_AD_DECOMPRESSION_FAILURE;
507                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
508                         goto f_err;
509                         }
510                 }
511
512         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
513                 {
514                 al=SSL_AD_RECORD_OVERFLOW;
515                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
516                 goto f_err;
517                 }
518
519         rr->off=0;
520         /* So at this point the following is true
521          * ssl->s3->rrec.type   is the type of record
522          * ssl->s3->rrec.length == number of bytes in record
523          * ssl->s3->rrec.off    == offset to first valid byte
524          * ssl->s3->rrec.data   == where to take bytes from, increment
525          *                         after use :-).
526          */
527
528         /* we have pulled in a full packet so zero things */
529         s->packet_length=0;
530         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
531         return(1);
532
533 f_err:
534         ssl3_send_alert(s,SSL3_AL_FATAL,al);
535 err:
536         return(0);
537 }
538
539
540 /* Call this to get a new input record.
541  * It will return <= 0 if more data is needed, normally due to an error
542  * or non-blocking IO.
543  * When it finishes, one packet has been decoded and can be found in
544  * ssl->s3->rrec.type    - is the type of record
545  * ssl->s3->rrec.data,   - data
546  * ssl->s3->rrec.length, - number of bytes
547  */
548 /* used only by dtls1_read_bytes */
549 int dtls1_get_record(SSL *s)
550         {
551         int ssl_major,ssl_minor;
552         int i,n;
553         SSL3_RECORD *rr;
554         unsigned char *p = NULL;
555         unsigned short version;
556         DTLS1_BITMAP *bitmap;
557         unsigned int is_next_epoch;
558
559         rr= &(s->s3->rrec);
560
561         /* The epoch may have changed.  If so, process all the
562          * pending records.  This is a non-blocking operation. */
563         dtls1_process_buffered_records(s);
564
565         /* if we're renegotiating, then there may be buffered records */
566         if (dtls1_get_processed_record(s))
567                 return 1;
568
569         /* get something from the wire */
570 again:
571         /* check if we have the header */
572         if (    (s->rstate != SSL_ST_READ_BODY) ||
573                 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 
574                 {
575                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
576                 /* read timeout is handled by dtls1_read_bytes */
577                 if (n <= 0) return(n); /* error or non-blocking */
578
579                 /* this packet contained a partial record, dump it */
580                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
581                         {
582                         s->packet_length = 0;
583                         goto again;
584                         }
585
586                 s->rstate=SSL_ST_READ_BODY;
587
588                 p=s->packet;
589
590                 if (s->msg_callback)
591                         s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
592
593                 /* Pull apart the header into the DTLS1_RECORD */
594                 rr->type= *(p++);
595                 ssl_major= *(p++);
596                 ssl_minor= *(p++);
597                 version=(ssl_major<<8)|ssl_minor;
598
599                 /* sequence number is 64 bits, with top 2 bytes = epoch */ 
600                 n2s(p,rr->epoch);
601
602                 memcpy(&(s->s3->read_sequence[2]), p, 6);
603                 p+=6;
604
605                 n2s(p,rr->length);
606
607                 /* Lets check version */
608                 if (!s->first_packet)
609                         {
610                         if (version != s->version)
611                                 {
612                                 /* unexpected version, silently discard */
613                                 rr->length = 0;
614                                 s->packet_length = 0;
615                                 goto again;
616                                 }
617                         }
618
619                 if ((version & 0xff00) != (s->version & 0xff00))
620                         {
621                         /* wrong version, silently discard record */
622                         rr->length = 0;
623                         s->packet_length = 0;
624                         goto again;
625                         }
626
627                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
628                         {
629                         /* record too long, silently discard it */
630                         rr->length = 0;
631                         s->packet_length = 0;
632                         goto again;
633                         }
634
635                 /* now s->rstate == SSL_ST_READ_BODY */
636                 }
637
638         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
639
640         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
641                 {
642                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
643                 i=rr->length;
644                 n=ssl3_read_n(s,i,i,1);
645                 if (n <= 0) return(n); /* error or non-blocking io */
646
647                 /* this packet contained a partial record, dump it */
648                 if ( n != i)
649                         {
650                         rr->length = 0;
651                         s->packet_length = 0;
652                         goto again;
653                         }
654
655                 /* now n == rr->length,
656                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
657                 }
658         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
659
660         /* match epochs.  NULL means the packet is dropped on the floor */
661         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
662         if ( bitmap == NULL)
663                 {
664                 rr->length = 0;
665                 s->packet_length = 0;  /* dump this record */
666                 goto again;   /* get another record */
667                 }
668
669 #ifndef OPENSSL_NO_SCTP
670         /* Only do replay check if no SCTP bio */
671         if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
672                 {
673 #endif
674                 /* Check whether this is a repeat, or aged record.
675                  * Don't check if we're listening and this message is
676                  * a ClientHello. They can look as if they're replayed,
677                  * since they arrive from different connections and
678                  * would be dropped unnecessarily.
679                  */
680                 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
681                     *p == SSL3_MT_CLIENT_HELLO) &&
682                     !dtls1_record_replay_check(s, bitmap))
683                         {
684                         rr->length = 0;
685                         s->packet_length=0; /* dump this record */
686                         goto again;     /* get another record */
687                         }
688 #ifndef OPENSSL_NO_SCTP
689                 }
690 #endif
691
692         /* just read a 0 length packet */
693         if (rr->length == 0) goto again;
694
695         /* If this record is from the next epoch (either HM or ALERT),
696          * and a handshake is currently in progress, buffer it since it
697          * cannot be processed at this time. However, do not buffer
698          * anything while listening.
699          */
700         if (is_next_epoch)
701                 {
702                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
703                         {
704                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
705                         }
706                 rr->length = 0;
707                 s->packet_length = 0;
708                 goto again;
709                 }
710
711         if (!dtls1_process_record(s))
712                 {
713                 rr->length = 0;
714                 s->packet_length = 0;  /* dump this record */
715                 goto again;   /* get another record */
716                 }
717
718         return(1);
719
720         }
721
722 /* Return up to 'len' payload bytes received in 'type' records.
723  * 'type' is one of the following:
724  *
725  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
726  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
727  *   -  0 (during a shutdown, no data has to be returned)
728  *
729  * If we don't have stored data to work from, read a SSL/TLS record first
730  * (possibly multiple records if we still don't have anything to return).
731  *
732  * This function must handle any surprises the peer may have for us, such as
733  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
734  * a surprise, but handled as if it were), or renegotiation requests.
735  * Also if record payloads contain fragments too small to process, we store
736  * them until there is enough for the respective protocol (the record protocol
737  * may use arbitrary fragmentation and even interleaving):
738  *     Change cipher spec protocol
739  *             just 1 byte needed, no need for keeping anything stored
740  *     Alert protocol
741  *             2 bytes needed (AlertLevel, AlertDescription)
742  *     Handshake protocol
743  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
744  *             to detect unexpected Client Hello and Hello Request messages
745  *             here, anything else is handled by higher layers
746  *     Application data protocol
747  *             none of our business
748  */
749 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
750         {
751         int al,i,j,ret;
752         unsigned int n;
753         SSL3_RECORD *rr;
754         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
755
756         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
757                 if (!ssl3_setup_buffers(s))
758                         return(-1);
759
760     /* XXX: check what the second '&& type' is about */
761         if ((type && (type != SSL3_RT_APPLICATION_DATA) && 
762                 (type != SSL3_RT_HANDSHAKE) && type) ||
763             (peek && (type != SSL3_RT_APPLICATION_DATA)))
764                 {
765                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
766                 return -1;
767                 }
768
769         /* check whether there's a handshake message (client hello?) waiting */
770         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
771                 return ret;
772
773         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
774
775 #ifndef OPENSSL_NO_SCTP
776         /* Continue handshake if it had to be interrupted to read
777          * app data with SCTP.
778          */
779         if ((!s->in_handshake && SSL_in_init(s)) ||
780             (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
781              (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
782              s->s3->in_read_app_data != 2))
783 #else
784         if (!s->in_handshake && SSL_in_init(s))
785 #endif
786                 {
787                 /* type == SSL3_RT_APPLICATION_DATA */
788                 i=s->handshake_func(s);
789                 if (i < 0) return(i);
790                 if (i == 0)
791                         {
792                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
793                         return(-1);
794                         }
795                 }
796
797 start:
798         s->rwstate=SSL_NOTHING;
799
800         /* s->s3->rrec.type         - is the type of record
801          * s->s3->rrec.data,    - data
802          * s->s3->rrec.off,     - offset into 'data' for next read
803          * s->s3->rrec.length,  - number of bytes. */
804         rr = &(s->s3->rrec);
805
806         /* We are not handshaking and have no data yet,
807          * so process data buffered during the last handshake
808          * in advance, if any.
809          */
810         if (s->state == SSL_ST_OK && rr->length == 0)
811                 {
812                 pitem *item;
813                 item = pqueue_pop(s->d1->buffered_app_data.q);
814                 if (item)
815                         {
816 #ifndef OPENSSL_NO_SCTP
817                         /* Restore bio_dgram_sctp_rcvinfo struct */
818                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
819                                 {
820                                 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
821                                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
822                                 }
823 #endif
824
825                         dtls1_copy_record(s, item);
826
827                         OPENSSL_free(item->data);
828                         pitem_free(item);
829                         }
830                 }
831
832         /* Check for timeout */
833         if (dtls1_handle_timeout(s) > 0)
834                 goto start;
835
836         /* get new packet if necessary */
837         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
838                 {
839                 ret=dtls1_get_record(s);
840                 if (ret <= 0) 
841                         {
842                         ret = dtls1_read_failed(s, ret);
843                         /* anything other than a timeout is an error */
844                         if (ret <= 0)  
845                                 return(ret);
846                         else
847                                 goto start;
848                         }
849                 }
850
851         /* we now have a packet which can be read and processed */
852
853         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
854                                        * reset by ssl3_get_finished */
855                 && (rr->type != SSL3_RT_HANDSHAKE))
856                 {
857                 /* We now have application data between CCS and Finished.
858                  * Most likely the packets were reordered on their way, so
859                  * buffer the application data for later processing rather
860                  * than dropping the connection.
861                  */
862                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
863                 rr->length = 0;
864                 goto start;
865                 }
866
867         /* If the other end has shut down, throw anything we read away
868          * (even in 'peek' mode) */
869         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
870                 {
871                 rr->length=0;
872                 s->rwstate=SSL_NOTHING;
873                 return(0);
874                 }
875
876
877         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
878                 {
879                 /* make sure that we are not getting application data when we
880                  * are doing a handshake for the first time */
881                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
882                         (s->enc_read_ctx == NULL))
883                         {
884                         al=SSL_AD_UNEXPECTED_MESSAGE;
885                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
886                         goto f_err;
887                         }
888
889                 if (len <= 0) return(len);
890
891                 if ((unsigned int)len > rr->length)
892                         n = rr->length;
893                 else
894                         n = (unsigned int)len;
895
896                 memcpy(buf,&(rr->data[rr->off]),n);
897                 if (!peek)
898                         {
899                         rr->length-=n;
900                         rr->off+=n;
901                         if (rr->length == 0)
902                                 {
903                                 s->rstate=SSL_ST_READ_HEADER;
904                                 rr->off=0;
905                                 }
906                         }
907
908 #ifndef OPENSSL_NO_SCTP
909                         /* We were about to renegotiate but had to read
910                          * belated application data first, so retry.
911                          */
912                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
913                             rr->type == SSL3_RT_APPLICATION_DATA &&
914                             (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
915                                 {
916                                 s->rwstate=SSL_READING;
917                                 BIO_clear_retry_flags(SSL_get_rbio(s));
918                                 BIO_set_retry_read(SSL_get_rbio(s));
919                                 }
920
921                         /* We might had to delay a close_notify alert because
922                          * of reordered app data. If there was an alert and there
923                          * is no message to read anymore, finally set shutdown.
924                          */
925                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
926                             s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
927                                 {
928                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
929                                 return(0);
930                                 }
931 #endif                  
932                 return(n);
933                 }
934
935
936         /* If we get here, then type != rr->type; if we have a handshake
937          * message, then it was unexpected (Hello Request or Client Hello). */
938
939         /* In case of record types for which we have 'fragment' storage,
940          * fill that so that we can process the data at a fixed place.
941          */
942                 {
943                 unsigned int k, dest_maxlen = 0;
944                 unsigned char *dest = NULL;
945                 unsigned int *dest_len = NULL;
946
947                 if (rr->type == SSL3_RT_HANDSHAKE)
948                         {
949                         dest_maxlen = sizeof s->d1->handshake_fragment;
950                         dest = s->d1->handshake_fragment;
951                         dest_len = &s->d1->handshake_fragment_len;
952                         }
953                 else if (rr->type == SSL3_RT_ALERT)
954                         {
955                         dest_maxlen = sizeof(s->d1->alert_fragment);
956                         dest = s->d1->alert_fragment;
957                         dest_len = &s->d1->alert_fragment_len;
958                         }
959 #ifndef OPENSSL_NO_HEARTBEATS
960                 else if (rr->type == TLS1_RT_HEARTBEAT)
961                         {
962                         dtls1_process_heartbeat(s);
963
964                         /* Exit and notify application to read again */
965                         rr->length = 0;
966                         s->rwstate=SSL_READING;
967                         BIO_clear_retry_flags(SSL_get_rbio(s));
968                         BIO_set_retry_read(SSL_get_rbio(s));
969                         return(-1);
970                         }
971 #endif
972                 /* else it's a CCS message, or application data or wrong */
973                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
974                         {
975                         /* Application data while renegotiating
976                          * is allowed. Try again reading.
977                          */
978                         if (rr->type == SSL3_RT_APPLICATION_DATA)
979                                 {
980                                 BIO *bio;
981                                 s->s3->in_read_app_data=2;
982                                 bio=SSL_get_rbio(s);
983                                 s->rwstate=SSL_READING;
984                                 BIO_clear_retry_flags(bio);
985                                 BIO_set_retry_read(bio);
986                                 return(-1);
987                                 }
988
989                         /* Not certain if this is the right error handling */
990                         al=SSL_AD_UNEXPECTED_MESSAGE;
991                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
992                         goto f_err;
993                         }
994
995                 if (dest_maxlen > 0)
996                         {
997             /* XDTLS:  In a pathalogical case, the Client Hello
998              *  may be fragmented--don't always expect dest_maxlen bytes */
999                         if ( rr->length < dest_maxlen)
1000                                 {
1001 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1002                                 /*
1003                                  * for normal alerts rr->length is 2, while
1004                                  * dest_maxlen is 7 if we were to handle this
1005                                  * non-existing alert...
1006                                  */
1007                                 FIX ME
1008 #endif
1009                                 s->rstate=SSL_ST_READ_HEADER;
1010                                 rr->length = 0;
1011                                 goto start;
1012                                 }
1013
1014                         /* now move 'n' bytes: */
1015                         for ( k = 0; k < dest_maxlen; k++)
1016                                 {
1017                                 dest[k] = rr->data[rr->off++];
1018                                 rr->length--;
1019                                 }
1020                         *dest_len = dest_maxlen;
1021                         }
1022                 }
1023
1024         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
1025          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
1026          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1027
1028         /* If we are a client, check for an incoming 'Hello Request': */
1029         if ((!s->server) &&
1030                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1031                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1032                 (s->session != NULL) && (s->session->cipher != NULL))
1033                 {
1034                 s->d1->handshake_fragment_len = 0;
1035
1036                 if ((s->d1->handshake_fragment[1] != 0) ||
1037                         (s->d1->handshake_fragment[2] != 0) ||
1038                         (s->d1->handshake_fragment[3] != 0))
1039                         {
1040                         al=SSL_AD_DECODE_ERROR;
1041                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1042                         goto err;
1043                         }
1044
1045                 /* no need to check sequence number on HELLO REQUEST messages */
1046
1047                 if (s->msg_callback)
1048                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
1049                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1050
1051                 if (SSL_is_init_finished(s) &&
1052                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1053                         !s->s3->renegotiate)
1054                         {
1055                         s->new_session = 1;
1056                         ssl3_renegotiate(s);
1057                         if (ssl3_renegotiate_check(s))
1058                                 {
1059                                 i=s->handshake_func(s);
1060                                 if (i < 0) return(i);
1061                                 if (i == 0)
1062                                         {
1063                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1064                                         return(-1);
1065                                         }
1066
1067                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1068                                         {
1069                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1070                                                 {
1071                                                 BIO *bio;
1072                                                 /* In the case where we try to read application data,
1073                                                  * but we trigger an SSL handshake, we return -1 with
1074                                                  * the retry option set.  Otherwise renegotiation may
1075                                                  * cause nasty problems in the blocking world */
1076                                                 s->rwstate=SSL_READING;
1077                                                 bio=SSL_get_rbio(s);
1078                                                 BIO_clear_retry_flags(bio);
1079                                                 BIO_set_retry_read(bio);
1080                                                 return(-1);
1081                                                 }
1082                                         }
1083                                 }
1084                         }
1085                 /* we either finished a handshake or ignored the request,
1086                  * now try again to obtain the (application) data we were asked for */
1087                 goto start;
1088                 }
1089
1090         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1091                 {
1092                 int alert_level = s->d1->alert_fragment[0];
1093                 int alert_descr = s->d1->alert_fragment[1];
1094
1095                 s->d1->alert_fragment_len = 0;
1096
1097                 if (s->msg_callback)
1098                         s->msg_callback(0, s->version, SSL3_RT_ALERT, 
1099                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1100
1101                 if (s->info_callback != NULL)
1102                         cb=s->info_callback;
1103                 else if (s->ctx->info_callback != NULL)
1104                         cb=s->ctx->info_callback;
1105
1106                 if (cb != NULL)
1107                         {
1108                         j = (alert_level << 8) | alert_descr;
1109                         cb(s, SSL_CB_READ_ALERT, j);
1110                         }
1111
1112                 if (alert_level == 1) /* warning */
1113                         {
1114                         s->s3->warn_alert = alert_descr;
1115                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1116                                 {
1117 #ifndef OPENSSL_NO_SCTP
1118                                 /* With SCTP and streams the socket may deliver app data
1119                                  * after a close_notify alert. We have to check this
1120                                  * first so that nothing gets discarded.
1121                                  */
1122                                 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1123                                         BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1124                                         {
1125                                         s->d1->shutdown_received = 1;
1126                                         s->rwstate=SSL_READING;
1127                                         BIO_clear_retry_flags(SSL_get_rbio(s));
1128                                         BIO_set_retry_read(SSL_get_rbio(s));
1129                                         return -1;
1130                                         }
1131 #endif
1132                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1133                                 return(0);
1134                                 }
1135 #if 0
1136             /* XXX: this is a possible improvement in the future */
1137                         /* now check if it's a missing record */
1138                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1139                                 {
1140                                 unsigned short seq;
1141                                 unsigned int frag_off;
1142                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1143
1144                                 n2s(p, seq);
1145                                 n2l3(p, frag_off);
1146
1147                                 dtls1_retransmit_message(s,
1148                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1149                                                                                  frag_off, &found);
1150                                 if ( ! found  && SSL_in_init(s))
1151                                         {
1152                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1153                                         /* requested a message not yet sent, 
1154                                            send an alert ourselves */
1155                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1156                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1157                                         }
1158                                 }
1159 #endif
1160                         }
1161                 else if (alert_level == 2) /* fatal */
1162                         {
1163                         char tmp[16];
1164
1165                         s->rwstate=SSL_NOTHING;
1166                         s->s3->fatal_alert = alert_descr;
1167                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1168                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1169                         ERR_add_error_data(2,"SSL alert number ",tmp);
1170                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1171                         SSL_CTX_remove_session(s->ctx,s->session);
1172                         return(0);
1173                         }
1174                 else
1175                         {
1176                         al=SSL_AD_ILLEGAL_PARAMETER;
1177                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1178                         goto f_err;
1179                         }
1180
1181                 goto start;
1182                 }
1183
1184         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1185                 {
1186                 s->rwstate=SSL_NOTHING;
1187                 rr->length=0;
1188                 return(0);
1189                 }
1190
1191         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1192                 {
1193                 struct ccs_header_st ccs_hdr;
1194                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1195
1196                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1197
1198                 if (s->version == DTLS1_BAD_VER)
1199                         ccs_hdr_len = 3;
1200
1201                 /* 'Change Cipher Spec' is just a single byte, so we know
1202                  * exactly what the record payload has to look like */
1203                 /* XDTLS: check that epoch is consistent */
1204                 if (    (rr->length != ccs_hdr_len) || 
1205                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1206                         {
1207                         i=SSL_AD_ILLEGAL_PARAMETER;
1208                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1209                         goto err;
1210                         }
1211
1212                 rr->length=0;
1213
1214                 if (s->msg_callback)
1215                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
1216                                 rr->data, 1, s, s->msg_callback_arg);
1217
1218                 /* We can't process a CCS now, because previous handshake
1219                  * messages are still missing, so just drop it.
1220                  */
1221                 if (!s->d1->change_cipher_spec_ok)
1222                         {
1223                         goto start;
1224                         }
1225
1226                 s->d1->change_cipher_spec_ok = 0;
1227
1228                 s->s3->change_cipher_spec=1;
1229                 if (!ssl3_do_change_cipher_spec(s))
1230                         goto err;
1231
1232                 /* do this whenever CCS is processed */
1233                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1234
1235                 if (s->version == DTLS1_BAD_VER)
1236                         s->d1->handshake_read_seq++;
1237
1238 #ifndef OPENSSL_NO_SCTP
1239                 /* Remember that a CCS has been received,
1240                  * so that an old key of SCTP-Auth can be
1241                  * deleted when a CCS is sent. Will be ignored
1242                  * if no SCTP is used
1243                  */
1244                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1245 #endif
1246
1247                 goto start;
1248                 }
1249
1250         /* Unexpected handshake message (Client Hello, or protocol violation) */
1251         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 
1252                 !s->in_handshake)
1253                 {
1254                 struct hm_header_st msg_hdr;
1255                 
1256                 /* this may just be a stale retransmit */
1257                 dtls1_get_message_header(rr->data, &msg_hdr);
1258                 if( rr->epoch != s->d1->r_epoch)
1259                         {
1260                         rr->length = 0;
1261                         goto start;
1262                         }
1263
1264                 /* If we are server, we may have a repeated FINISHED of the
1265                  * client here, then retransmit our CCS and FINISHED.
1266                  */
1267                 if (msg_hdr.type == SSL3_MT_FINISHED)
1268                         {
1269                         if (dtls1_check_timeout_num(s) < 0)
1270                                 return -1;
1271
1272                         dtls1_retransmit_buffered_messages(s);
1273                         rr->length = 0;
1274                         goto start;
1275                         }
1276
1277                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1278                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1279                         {
1280 #if 0 /* worked only because C operator preferences are not as expected (and
1281        * because this is not really needed for clients except for detecting
1282        * protocol violations): */
1283                         s->state=SSL_ST_BEFORE|(s->server)
1284                                 ?SSL_ST_ACCEPT
1285                                 :SSL_ST_CONNECT;
1286 #else
1287                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1288 #endif
1289                         s->renegotiate=1;
1290                         s->new_session=1;
1291                         }
1292                 i=s->handshake_func(s);
1293                 if (i < 0) return(i);
1294                 if (i == 0)
1295                         {
1296                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1297                         return(-1);
1298                         }
1299
1300                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1301                         {
1302                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1303                                 {
1304                                 BIO *bio;
1305                                 /* In the case where we try to read application data,
1306                                  * but we trigger an SSL handshake, we return -1 with
1307                                  * the retry option set.  Otherwise renegotiation may
1308                                  * cause nasty problems in the blocking world */
1309                                 s->rwstate=SSL_READING;
1310                                 bio=SSL_get_rbio(s);
1311                                 BIO_clear_retry_flags(bio);
1312                                 BIO_set_retry_read(bio);
1313                                 return(-1);
1314                                 }
1315                         }
1316                 goto start;
1317                 }
1318
1319         switch (rr->type)
1320                 {
1321         default:
1322 #ifndef OPENSSL_NO_TLS
1323                 /* TLS just ignores unknown message types */
1324                 if (s->version == TLS1_VERSION)
1325                         {
1326                         rr->length = 0;
1327                         goto start;
1328                         }
1329 #endif
1330                 al=SSL_AD_UNEXPECTED_MESSAGE;
1331                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1332                 goto f_err;
1333         case SSL3_RT_CHANGE_CIPHER_SPEC:
1334         case SSL3_RT_ALERT:
1335         case SSL3_RT_HANDSHAKE:
1336                 /* we already handled all of these, with the possible exception
1337                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1338                  * should not happen when type != rr->type */
1339                 al=SSL_AD_UNEXPECTED_MESSAGE;
1340                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1341                 goto f_err;
1342         case SSL3_RT_APPLICATION_DATA:
1343                 /* At this point, we were expecting handshake data,
1344                  * but have application data.  If the library was
1345                  * running inside ssl3_read() (i.e. in_read_app_data
1346                  * is set) and it makes sense to read application data
1347                  * at this point (session renegotiation not yet started),
1348                  * we will indulge it.
1349                  */
1350                 if (s->s3->in_read_app_data &&
1351                         (s->s3->total_renegotiations != 0) &&
1352                         ((
1353                                 (s->state & SSL_ST_CONNECT) &&
1354                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1355                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1356                                 ) || (
1357                                         (s->state & SSL_ST_ACCEPT) &&
1358                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1359                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1360                                         )
1361                                 ))
1362                         {
1363                         s->s3->in_read_app_data=2;
1364                         return(-1);
1365                         }
1366                 else
1367                         {
1368                         al=SSL_AD_UNEXPECTED_MESSAGE;
1369                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1370                         goto f_err;
1371                         }
1372                 }
1373         /* not reached */
1374
1375 f_err:
1376         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1377 err:
1378         return(-1);
1379         }
1380
1381 int
1382 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1383         {
1384         int i;
1385
1386 #ifndef OPENSSL_NO_SCTP
1387                 /* Check if we have to continue an interrupted handshake
1388                  * for reading belated app data with SCTP.
1389                  */
1390                 if ((SSL_in_init(s) && !s->in_handshake) ||
1391                     (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1392                      (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1393 #else
1394                 if (SSL_in_init(s) && !s->in_handshake)
1395 #endif
1396                 {
1397                 i=s->handshake_func(s);
1398                 if (i < 0) return(i);
1399                 if (i == 0)
1400                         {
1401                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1402                         return -1;
1403                         }
1404                 }
1405
1406         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1407                 {
1408                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1409                         return -1;
1410                 }
1411
1412         i = dtls1_write_bytes(s, type, buf_, len);
1413         return i;
1414         }
1415
1416
1417         /* this only happens when a client hello is received and a handshake 
1418          * is started. */
1419 static int
1420 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
1421         int len, int peek)
1422         {
1423         
1424         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1425                 /* (partially) satisfy request from storage */
1426                 {
1427                 unsigned char *src = s->d1->handshake_fragment;
1428                 unsigned char *dst = buf;
1429                 unsigned int k,n;
1430                 
1431                 /* peek == 0 */
1432                 n = 0;
1433                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1434                         {
1435                         *dst++ = *src++;
1436                         len--; s->d1->handshake_fragment_len--;
1437                         n++;
1438                         }
1439                 /* move any remaining fragment bytes: */
1440                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1441                         s->d1->handshake_fragment[k] = *src++;
1442                 return n;
1443                 }
1444         
1445         return 0;
1446         }
1447
1448
1449
1450
1451 /* Call this to write data in records of type 'type'
1452  * It will return <= 0 if not all data has been sent or non-blocking IO.
1453  */
1454 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1455         {
1456         int i;
1457
1458         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1459         s->rwstate=SSL_NOTHING;
1460         i=do_dtls1_write(s, type, buf, len, 0);
1461         return i;
1462         }
1463
1464 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1465         {
1466         unsigned char *p,*pseq;
1467         int i,mac_size,clear=0;
1468         int prefix_len = 0;
1469         SSL3_RECORD *wr;
1470         SSL3_BUFFER *wb;
1471         SSL_SESSION *sess;
1472         int bs;
1473
1474         /* first check if there is a SSL3_BUFFER still being written
1475          * out.  This will happen with non blocking IO */
1476         if (s->s3->wbuf.left != 0)
1477                 {
1478                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1479                 return(ssl3_write_pending(s,type,buf,len));
1480                 }
1481
1482         /* If we have an alert to send, lets send it */
1483         if (s->s3->alert_dispatch)
1484                 {
1485                 i=s->method->ssl_dispatch_alert(s);
1486                 if (i <= 0)
1487                         return(i);
1488                 /* if it went, fall through and send more stuff */
1489                 }
1490
1491         if (len == 0 && !create_empty_fragment)
1492                 return 0;
1493
1494         wr= &(s->s3->wrec);
1495         wb= &(s->s3->wbuf);
1496         sess=s->session;
1497
1498         if (    (sess == NULL) ||
1499                 (s->enc_write_ctx == NULL) ||
1500                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1501                 clear=1;
1502
1503         if (clear)
1504                 mac_size=0;
1505         else
1506                 {
1507                 mac_size=EVP_MD_CTX_size(s->write_hash);
1508                 if (mac_size < 0)
1509                         goto err;
1510                 }
1511
1512         /* DTLS implements explicit IV, so no need for empty fragments */
1513 #if 0
1514         /* 'create_empty_fragment' is true only when this function calls itself */
1515         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1516             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1517                 {
1518                 /* countermeasure against known-IV weakness in CBC ciphersuites
1519                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
1520                  */
1521
1522                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1523                         {
1524                         /* recursive function call with 'create_empty_fragment' set;
1525                          * this prepares and buffers the data for an empty fragment
1526                          * (these 'prefix_len' bytes are sent out later
1527                          * together with the actual payload) */
1528                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1529                         if (prefix_len <= 0)
1530                                 goto err;
1531
1532                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1533                                 {
1534                                 /* insufficient space */
1535                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1536                                 goto err;
1537                                 }
1538                         }
1539                 
1540                 s->s3->empty_fragment_done = 1;
1541                 }
1542 #endif
1543         p = wb->buf + prefix_len;
1544
1545         /* write the header */
1546
1547         *(p++)=type&0xff;
1548         wr->type=type;
1549
1550         *(p++)=(s->version>>8);
1551         *(p++)=s->version&0xff;
1552
1553         /* field where we are to write out packet epoch, seq num and len */
1554         pseq=p; 
1555         p+=10;
1556
1557         /* lets setup the record stuff. */
1558
1559         /* Make space for the explicit IV in case of CBC.
1560          * (this is a bit of a boundary violation, but what the heck).
1561          */
1562         if ( s->enc_write_ctx && 
1563                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1564                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1565         else
1566                 bs = 0;
1567
1568         wr->data=p + bs;  /* make room for IV in case of CBC */
1569         wr->length=(int)len;
1570         wr->input=(unsigned char *)buf;
1571
1572         /* we now 'read' from wr->input, wr->length bytes into
1573          * wr->data */
1574
1575         /* first we compress */
1576         if (s->compress != NULL)
1577                 {
1578                 if (!ssl3_do_compress(s))
1579                         {
1580                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1581                         goto err;
1582                         }
1583                 }
1584         else
1585                 {
1586                 memcpy(wr->data,wr->input,wr->length);
1587                 wr->input=wr->data;
1588                 }
1589
1590         /* we should still have the output to wr->data and the input
1591          * from wr->input.  Length should be wr->length.
1592          * wr->data still points in the wb->buf */
1593
1594         if (mac_size != 0)
1595                 {
1596                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1597                         goto err;
1598                 wr->length+=mac_size;
1599                 }
1600
1601         /* this is true regardless of mac size */
1602         wr->input=p;
1603         wr->data=p;
1604
1605
1606         /* ssl3_enc can only have an error on read */
1607         if (bs) /* bs != 0 in case of CBC */
1608                 {
1609                 RAND_pseudo_bytes(p,bs);
1610                 /* master IV and last CBC residue stand for
1611                  * the rest of randomness */
1612                 wr->length += bs;
1613                 }
1614
1615         s->method->ssl3_enc->enc(s,1);
1616
1617         /* record length after mac and block padding */
1618 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1619         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1620         
1621         /* there's only one epoch between handshake and app data */
1622         
1623         s2n(s->d1->w_epoch, pseq);
1624
1625         /* XDTLS: ?? */
1626 /*      else
1627         s2n(s->d1->handshake_epoch, pseq); */
1628
1629         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1630         pseq+=6;
1631         s2n(wr->length,pseq);
1632
1633         if (s->msg_callback)
1634                 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1635
1636         /* we should now have
1637          * wr->data pointing to the encrypted data, which is
1638          * wr->length long */
1639         wr->type=type; /* not needed but helps for debugging */
1640         wr->length+=DTLS1_RT_HEADER_LENGTH;
1641
1642 #if 0  /* this is now done at the message layer */
1643         /* buffer the record, making it easy to handle retransmits */
1644         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1645                 dtls1_buffer_record(s, wr->data, wr->length, 
1646                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1647 #endif
1648
1649         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1650
1651         if (create_empty_fragment)
1652                 {
1653                 /* we are in a recursive call;
1654                  * just return the length, don't write out anything here
1655                  */
1656                 return wr->length;
1657                 }
1658
1659         /* now let's set up wb */
1660         wb->left = prefix_len + wr->length;
1661         wb->offset = 0;
1662
1663         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1664         s->s3->wpend_tot=len;
1665         s->s3->wpend_buf=buf;
1666         s->s3->wpend_type=type;
1667         s->s3->wpend_ret=len;
1668
1669         /* we now just need to write the buffer */
1670         return ssl3_write_pending(s,type,buf,len);
1671 err:
1672         return -1;
1673         }
1674
1675
1676
1677 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1678         {
1679         int cmp;
1680         unsigned int shift;
1681         const unsigned char *seq = s->s3->read_sequence;
1682
1683         cmp = satsub64be(seq,bitmap->max_seq_num);
1684         if (cmp > 0)
1685                 {
1686                 memcpy (s->s3->rrec.seq_num,seq,8);
1687                 return 1; /* this record in new */
1688                 }
1689         shift = -cmp;
1690         if (shift >= sizeof(bitmap->map)*8)
1691                 return 0; /* stale, outside the window */
1692         else if (bitmap->map & (1UL<<shift))
1693                 return 0; /* record previously received */
1694
1695         memcpy (s->s3->rrec.seq_num,seq,8);
1696         return 1;
1697         }
1698
1699
1700 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1701         {
1702         int cmp;
1703         unsigned int shift;
1704         const unsigned char *seq = s->s3->read_sequence;
1705
1706         cmp = satsub64be(seq,bitmap->max_seq_num);
1707         if (cmp > 0)
1708                 {
1709                 shift = cmp;
1710                 if (shift < sizeof(bitmap->map)*8)
1711                         bitmap->map <<= shift, bitmap->map |= 1UL;
1712                 else
1713                         bitmap->map = 1UL;
1714                 memcpy(bitmap->max_seq_num,seq,8);
1715                 }
1716         else    {
1717                 shift = -cmp;
1718                 if (shift < sizeof(bitmap->map)*8)
1719                         bitmap->map |= 1UL<<shift;
1720                 }
1721         }
1722
1723
1724 int dtls1_dispatch_alert(SSL *s)
1725         {
1726         int i,j;
1727         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1728         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1729         unsigned char *ptr = &buf[0];
1730
1731         s->s3->alert_dispatch=0;
1732
1733         memset(buf, 0x00, sizeof(buf));
1734         *ptr++ = s->s3->send_alert[0];
1735         *ptr++ = s->s3->send_alert[1];
1736
1737 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1738         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1739                 {       
1740                 s2n(s->d1->handshake_read_seq, ptr);
1741 #if 0
1742                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1743
1744                 else
1745                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1746 #endif
1747
1748 #if 0
1749                 fprintf(stderr, "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",s->d1->handshake_read_seq,s->d1->r_msg_hdr.seq);
1750 #endif
1751                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1752                 }
1753 #endif
1754
1755         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1756         if (i <= 0)
1757                 {
1758                 s->s3->alert_dispatch=1;
1759                 /* fprintf( stderr, "not done with alert\n" ); */
1760                 }
1761         else
1762                 {
1763                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1764 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1765                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1766 #endif
1767                     )
1768                         (void)BIO_flush(s->wbio);
1769
1770                 if (s->msg_callback)
1771                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 
1772                                 2, s, s->msg_callback_arg);
1773
1774                 if (s->info_callback != NULL)
1775                         cb=s->info_callback;
1776                 else if (s->ctx->info_callback != NULL)
1777                         cb=s->ctx->info_callback;
1778
1779                 if (cb != NULL)
1780                         {
1781                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1782                         cb(s,SSL_CB_WRITE_ALERT,j);
1783                         }
1784                 }
1785         return(i);
1786         }
1787
1788
1789 static DTLS1_BITMAP *
1790 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1791     {
1792     
1793     *is_next_epoch = 0;
1794
1795     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1796     if (rr->epoch == s->d1->r_epoch)
1797         return &s->d1->bitmap;
1798
1799     /* Only HM and ALERT messages can be from the next epoch */
1800     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1801         (rr->type == SSL3_RT_HANDSHAKE ||
1802             rr->type == SSL3_RT_ALERT))
1803         {
1804         *is_next_epoch = 1;
1805         return &s->d1->next_bitmap;
1806         }
1807
1808     return NULL;
1809     }
1810
1811 #if 0
1812 static int
1813 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1814         unsigned long *offset)
1815         {
1816
1817         /* alerts are passed up immediately */
1818         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1819                 rr->type == SSL3_RT_ALERT)
1820                 return 0;
1821
1822         /* Only need to buffer if a handshake is underway.
1823          * (this implies that Hello Request and Client Hello are passed up
1824          * immediately) */
1825         if ( SSL_in_init(s))
1826                 {
1827                 unsigned char *data = rr->data;
1828                 /* need to extract the HM/CCS sequence number here */
1829                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1830                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1831                         {
1832                         unsigned short seq_num;
1833                         struct hm_header_st msg_hdr;
1834                         struct ccs_header_st ccs_hdr;
1835
1836                         if ( rr->type == SSL3_RT_HANDSHAKE)
1837                                 {
1838                                 dtls1_get_message_header(data, &msg_hdr);
1839                                 seq_num = msg_hdr.seq;
1840                                 *offset = msg_hdr.frag_off;
1841                                 }
1842                         else
1843                                 {
1844                                 dtls1_get_ccs_header(data, &ccs_hdr);
1845                                 seq_num = ccs_hdr.seq;
1846                                 *offset = 0;
1847                                 }
1848                                 
1849                         /* this is either a record we're waiting for, or a
1850                          * retransmit of something we happened to previously 
1851                          * receive (higher layers will drop the repeat silently */
1852                         if ( seq_num < s->d1->handshake_read_seq)
1853                                 return 0;
1854                         if (rr->type == SSL3_RT_HANDSHAKE && 
1855                                 seq_num == s->d1->handshake_read_seq &&
1856                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1857                                 return 0;
1858                         else if ( seq_num == s->d1->handshake_read_seq &&
1859                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1860                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1861                                 return 0;
1862                         else
1863                                 {
1864                                 *priority = seq_num;
1865                                 return 1;
1866                                 }
1867                         }
1868                 else /* unknown record type */
1869                         return 0;
1870                 }
1871
1872         return 0;
1873         }
1874 #endif
1875
1876 void
1877 dtls1_reset_seq_numbers(SSL *s, int rw)
1878         {
1879         unsigned char *seq;
1880         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1881
1882         if ( rw & SSL3_CC_READ)
1883                 {
1884                 seq = s->s3->read_sequence;
1885                 s->d1->r_epoch++;
1886                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1887                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1888                 }
1889         else
1890                 {
1891                 seq = s->s3->write_sequence;
1892                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1893                 s->d1->w_epoch++;
1894                 }
1895
1896         memset(seq, 0x00, seq_bytes);
1897         }