Added SSLErr call for internal error in dtls1_buffer_record
[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         s->packet = NULL;
243         s->packet_length = 0;
244         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
245         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
246         
247         if (!ssl3_setup_buffers(s))
248                 {
249                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
250                 OPENSSL_free(rdata);
251                 pitem_free(item);
252                 return(0);
253                 }
254
255         /* insert should not fail, since duplicates are dropped */
256         if (pqueue_insert(queue->q, item) == NULL)
257                 {
258                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
259                 OPENSSL_free(rdata);
260                 pitem_free(item);
261                 return(0);
262                 }
263
264         return(1);
265         }
266
267
268 static int
269 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
270     {
271     pitem *item;
272
273     item = pqueue_pop(queue->q);
274     if (item)
275         {
276         dtls1_copy_record(s, item);
277
278         OPENSSL_free(item->data);
279                 pitem_free(item);
280
281         return(1);
282         }
283
284     return(0);
285     }
286
287
288 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 
289  * yet */
290 #define dtls1_get_unprocessed_record(s) \
291                    dtls1_retrieve_buffered_record((s), \
292                    &((s)->d1->unprocessed_rcds))
293
294 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
295 #define dtls1_get_processed_record(s) \
296                    dtls1_retrieve_buffered_record((s), \
297                    &((s)->d1->processed_rcds))
298
299 static int
300 dtls1_process_buffered_records(SSL *s)
301     {
302     pitem *item;
303     
304     item = pqueue_peek(s->d1->unprocessed_rcds.q);
305     if (item)
306         {
307         /* Check if epoch is current. */
308         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
309             return(1);  /* Nothing to do. */
310         
311         /* Process all the records. */
312         while (pqueue_peek(s->d1->unprocessed_rcds.q))
313             {
314             dtls1_get_unprocessed_record(s);
315             if ( ! dtls1_process_record(s))
316                 return(0);
317             dtls1_buffer_record(s, &(s->d1->processed_rcds), 
318                 s->s3->rrec.seq_num);
319             }
320         }
321
322     /* sync epoch numbers once all the unprocessed records 
323      * have been processed */
324     s->d1->processed_rcds.epoch = s->d1->r_epoch;
325     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
326
327     return(1);
328     }
329
330
331 #if 0
332
333 static int
334 dtls1_get_buffered_record(SSL *s)
335         {
336         pitem *item;
337         PQ_64BIT priority = 
338                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 
339                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
340         
341         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating, 
342                                                            nothing buffered */
343                 return 0;
344
345
346         item = pqueue_peek(s->d1->rcvd_records);
347         if (item && item->priority == priority)
348                 {
349                 /* Check if we've received the record of interest.  It must be
350                  * a handshake record, since data records as passed up without
351                  * buffering */
352                 DTLS1_RECORD_DATA *rdata;
353                 item = pqueue_pop(s->d1->rcvd_records);
354                 rdata = (DTLS1_RECORD_DATA *)item->data;
355                 
356                 if (s->s3->rbuf.buf != NULL)
357                         OPENSSL_free(s->s3->rbuf.buf);
358                 
359                 s->packet = rdata->packet;
360                 s->packet_length = rdata->packet_length;
361                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
362                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
363                 
364                 OPENSSL_free(item->data);
365                 pitem_free(item);
366                 
367                 /* s->d1->next_expected_seq_num++; */
368                 return(1);
369                 }
370         
371         return 0;
372         }
373
374 #endif
375
376 static int
377 dtls1_process_record(SSL *s)
378 {
379         int i,al;
380         int enc_err;
381         SSL_SESSION *sess;
382         SSL3_RECORD *rr;
383         unsigned int mac_size;
384         unsigned char md[EVP_MAX_MD_SIZE];
385
386         rr= &(s->s3->rrec);
387         sess = s->session;
388
389         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
390          * and we have that many bytes in s->packet
391          */
392         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
393
394         /* ok, we can now read from 's->packet' data into 'rr'
395          * rr->input points at rr->length bytes, which
396          * need to be copied into rr->data by either
397          * the decryption or by the decompression
398          * When the data is 'copied' into the rr->data buffer,
399          * rr->input will be pointed at the new buffer */ 
400
401         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
402          * rr->length bytes of encrypted compressed stuff. */
403
404         /* check is not needed I believe */
405         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
406                 {
407                 al=SSL_AD_RECORD_OVERFLOW;
408                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
409                 goto f_err;
410                 }
411
412         /* decrypt in place in 'rr->input' */
413         rr->data=rr->input;
414         rr->orig_len=rr->length;
415
416         enc_err = s->method->ssl3_enc->enc(s,0);
417         /* enc_err is:
418          *    0: (in non-constant time) if the record is publically invalid.
419          *    1: if the padding is valid
420          *    -1: if the padding is invalid */
421         if (enc_err == 0)
422                 {
423                 /* For DTLS we simply ignore bad packets. */
424                 rr->length = 0;
425                 s->packet_length = 0;
426                 goto err;
427                 }
428
429 #ifdef TLS_DEBUG
430 printf("dec %d\n",rr->length);
431 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
432 printf("\n");
433 #endif
434
435         /* r->length is now the compressed data plus mac */
436         if ((sess != NULL) &&
437             (s->enc_read_ctx != NULL) &&
438             (EVP_MD_CTX_md(s->read_hash) != NULL))
439                 {
440                 /* s->read_hash != NULL => mac_size != -1 */
441                 unsigned char *mac = NULL;
442                 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
443                 mac_size=EVP_MD_CTX_size(s->read_hash);
444                 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
445
446                 /* orig_len is the length of the record before any padding was
447                  * removed. This is public information, as is the MAC in use,
448                  * therefore we can safely process the record in a different
449                  * amount of time if it's too short to possibly contain a MAC.
450                  */
451                 if (rr->orig_len < mac_size ||
452                     /* CBC records must have a padding length byte too. */
453                     (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
454                      rr->orig_len < mac_size+1))
455                         {
456                         al=SSL_AD_DECODE_ERROR;
457                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
458                         goto f_err;
459                         }
460
461                 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
462                         {
463                         /* We update the length so that the TLS header bytes
464                          * can be constructed correctly but we need to extract
465                          * the MAC in constant time from within the record,
466                          * without leaking the contents of the padding bytes.
467                          * */
468                         mac = mac_tmp;
469                         ssl3_cbc_copy_mac(mac_tmp, rr, mac_size);
470                         rr->length -= mac_size;
471                         }
472                 else
473                         {
474                         /* In this case there's no padding, so |rec->orig_len|
475                          * equals |rec->length| and we checked that there's
476                          * enough bytes for |mac_size| above. */
477                         rr->length -= mac_size;
478                         mac = &rr->data[rr->length];
479                         }
480
481                 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
482                 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
483                         enc_err = -1;
484                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
485                         enc_err = -1;
486                 }
487
488         if (enc_err < 0)
489                 {
490                 /* decryption failed, silently discard message */
491                 rr->length = 0;
492                 s->packet_length = 0;
493                 goto err;
494                 }
495
496         /* r->length is now just compressed */
497         if (s->expand != NULL)
498                 {
499                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
500                         {
501                         al=SSL_AD_RECORD_OVERFLOW;
502                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
503                         goto f_err;
504                         }
505                 if (!ssl3_do_uncompress(s))
506                         {
507                         al=SSL_AD_DECOMPRESSION_FAILURE;
508                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
509                         goto f_err;
510                         }
511                 }
512
513         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
514                 {
515                 al=SSL_AD_RECORD_OVERFLOW;
516                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
517                 goto f_err;
518                 }
519
520         rr->off=0;
521         /* So at this point the following is true
522          * ssl->s3->rrec.type   is the type of record
523          * ssl->s3->rrec.length == number of bytes in record
524          * ssl->s3->rrec.off    == offset to first valid byte
525          * ssl->s3->rrec.data   == where to take bytes from, increment
526          *                         after use :-).
527          */
528
529         /* we have pulled in a full packet so zero things */
530         s->packet_length=0;
531         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
532         return(1);
533
534 f_err:
535         ssl3_send_alert(s,SSL3_AL_FATAL,al);
536 err:
537         return(0);
538 }
539
540
541 /* Call this to get a new input record.
542  * It will return <= 0 if more data is needed, normally due to an error
543  * or non-blocking IO.
544  * When it finishes, one packet has been decoded and can be found in
545  * ssl->s3->rrec.type    - is the type of record
546  * ssl->s3->rrec.data,   - data
547  * ssl->s3->rrec.length, - number of bytes
548  */
549 /* used only by dtls1_read_bytes */
550 int dtls1_get_record(SSL *s)
551         {
552         int ssl_major,ssl_minor;
553         int i,n;
554         SSL3_RECORD *rr;
555         unsigned char *p = NULL;
556         unsigned short version;
557         DTLS1_BITMAP *bitmap;
558         unsigned int is_next_epoch;
559
560         rr= &(s->s3->rrec);
561
562         /* The epoch may have changed.  If so, process all the
563          * pending records.  This is a non-blocking operation. */
564         dtls1_process_buffered_records(s);
565
566         /* if we're renegotiating, then there may be buffered records */
567         if (dtls1_get_processed_record(s))
568                 return 1;
569
570         /* get something from the wire */
571 again:
572         /* check if we have the header */
573         if (    (s->rstate != SSL_ST_READ_BODY) ||
574                 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 
575                 {
576                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
577                 /* read timeout is handled by dtls1_read_bytes */
578                 if (n <= 0) return(n); /* error or non-blocking */
579
580                 /* this packet contained a partial record, dump it */
581                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
582                         {
583                         s->packet_length = 0;
584                         goto again;
585                         }
586
587                 s->rstate=SSL_ST_READ_BODY;
588
589                 p=s->packet;
590
591                 if (s->msg_callback)
592                         s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
593
594                 /* Pull apart the header into the DTLS1_RECORD */
595                 rr->type= *(p++);
596                 ssl_major= *(p++);
597                 ssl_minor= *(p++);
598                 version=(ssl_major<<8)|ssl_minor;
599
600                 /* sequence number is 64 bits, with top 2 bytes = epoch */ 
601                 n2s(p,rr->epoch);
602
603                 memcpy(&(s->s3->read_sequence[2]), p, 6);
604                 p+=6;
605
606                 n2s(p,rr->length);
607
608                 /* Lets check version */
609                 if (!s->first_packet)
610                         {
611                         if (version != s->version)
612                                 {
613                                 /* unexpected version, silently discard */
614                                 rr->length = 0;
615                                 s->packet_length = 0;
616                                 goto again;
617                                 }
618                         }
619
620                 if ((version & 0xff00) != (s->version & 0xff00))
621                         {
622                         /* wrong version, silently discard record */
623                         rr->length = 0;
624                         s->packet_length = 0;
625                         goto again;
626                         }
627
628                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
629                         {
630                         /* record too long, silently discard it */
631                         rr->length = 0;
632                         s->packet_length = 0;
633                         goto again;
634                         }
635
636                 /* now s->rstate == SSL_ST_READ_BODY */
637                 }
638
639         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
640
641         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
642                 {
643                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
644                 i=rr->length;
645                 n=ssl3_read_n(s,i,i,1);
646                 if (n <= 0) return(n); /* error or non-blocking io */
647
648                 /* this packet contained a partial record, dump it */
649                 if ( n != i)
650                         {
651                         rr->length = 0;
652                         s->packet_length = 0;
653                         goto again;
654                         }
655
656                 /* now n == rr->length,
657                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
658                 }
659         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
660
661         /* match epochs.  NULL means the packet is dropped on the floor */
662         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
663         if ( bitmap == NULL)
664                 {
665                 rr->length = 0;
666                 s->packet_length = 0;  /* dump this record */
667                 goto again;   /* get another record */
668                 }
669
670 #ifndef OPENSSL_NO_SCTP
671         /* Only do replay check if no SCTP bio */
672         if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
673                 {
674 #endif
675                 /* Check whether this is a repeat, or aged record.
676                  * Don't check if we're listening and this message is
677                  * a ClientHello. They can look as if they're replayed,
678                  * since they arrive from different connections and
679                  * would be dropped unnecessarily.
680                  */
681                 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
682                     *p == SSL3_MT_CLIENT_HELLO) &&
683                     !dtls1_record_replay_check(s, bitmap))
684                         {
685                         rr->length = 0;
686                         s->packet_length=0; /* dump this record */
687                         goto again;     /* get another record */
688                         }
689 #ifndef OPENSSL_NO_SCTP
690                 }
691 #endif
692
693         /* just read a 0 length packet */
694         if (rr->length == 0) goto again;
695
696         /* If this record is from the next epoch (either HM or ALERT),
697          * and a handshake is currently in progress, buffer it since it
698          * cannot be processed at this time. However, do not buffer
699          * anything while listening.
700          */
701         if (is_next_epoch)
702                 {
703                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
704                         {
705                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
706                         }
707                 rr->length = 0;
708                 s->packet_length = 0;
709                 goto again;
710                 }
711
712         if (!dtls1_process_record(s))
713                 {
714                 rr->length = 0;
715                 s->packet_length = 0;  /* dump this record */
716                 goto again;   /* get another record */
717                 }
718
719         return(1);
720
721         }
722
723 /* Return up to 'len' payload bytes received in 'type' records.
724  * 'type' is one of the following:
725  *
726  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
727  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
728  *   -  0 (during a shutdown, no data has to be returned)
729  *
730  * If we don't have stored data to work from, read a SSL/TLS record first
731  * (possibly multiple records if we still don't have anything to return).
732  *
733  * This function must handle any surprises the peer may have for us, such as
734  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
735  * a surprise, but handled as if it were), or renegotiation requests.
736  * Also if record payloads contain fragments too small to process, we store
737  * them until there is enough for the respective protocol (the record protocol
738  * may use arbitrary fragmentation and even interleaving):
739  *     Change cipher spec protocol
740  *             just 1 byte needed, no need for keeping anything stored
741  *     Alert protocol
742  *             2 bytes needed (AlertLevel, AlertDescription)
743  *     Handshake protocol
744  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
745  *             to detect unexpected Client Hello and Hello Request messages
746  *             here, anything else is handled by higher layers
747  *     Application data protocol
748  *             none of our business
749  */
750 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
751         {
752         int al,i,j,ret;
753         unsigned int n;
754         SSL3_RECORD *rr;
755         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
756
757         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
758                 if (!ssl3_setup_buffers(s))
759                         return(-1);
760
761     /* XXX: check what the second '&& type' is about */
762         if ((type && (type != SSL3_RT_APPLICATION_DATA) && 
763                 (type != SSL3_RT_HANDSHAKE) && type) ||
764             (peek && (type != SSL3_RT_APPLICATION_DATA)))
765                 {
766                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
767                 return -1;
768                 }
769
770         /* check whether there's a handshake message (client hello?) waiting */
771         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
772                 return ret;
773
774         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
775
776 #ifndef OPENSSL_NO_SCTP
777         /* Continue handshake if it had to be interrupted to read
778          * app data with SCTP.
779          */
780         if ((!s->in_handshake && SSL_in_init(s)) ||
781             (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
782              (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
783              s->s3->in_read_app_data != 2))
784 #else
785         if (!s->in_handshake && SSL_in_init(s))
786 #endif
787                 {
788                 /* type == SSL3_RT_APPLICATION_DATA */
789                 i=s->handshake_func(s);
790                 if (i < 0) return(i);
791                 if (i == 0)
792                         {
793                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
794                         return(-1);
795                         }
796                 }
797
798 start:
799         s->rwstate=SSL_NOTHING;
800
801         /* s->s3->rrec.type         - is the type of record
802          * s->s3->rrec.data,    - data
803          * s->s3->rrec.off,     - offset into 'data' for next read
804          * s->s3->rrec.length,  - number of bytes. */
805         rr = &(s->s3->rrec);
806
807         /* We are not handshaking and have no data yet,
808          * so process data buffered during the last handshake
809          * in advance, if any.
810          */
811         if (s->state == SSL_ST_OK && rr->length == 0)
812                 {
813                 pitem *item;
814                 item = pqueue_pop(s->d1->buffered_app_data.q);
815                 if (item)
816                         {
817 #ifndef OPENSSL_NO_SCTP
818                         /* Restore bio_dgram_sctp_rcvinfo struct */
819                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
820                                 {
821                                 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
822                                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
823                                 }
824 #endif
825
826                         dtls1_copy_record(s, item);
827
828                         OPENSSL_free(item->data);
829                         pitem_free(item);
830                         }
831                 }
832
833         /* Check for timeout */
834         if (dtls1_handle_timeout(s) > 0)
835                 goto start;
836
837         /* get new packet if necessary */
838         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
839                 {
840                 ret=dtls1_get_record(s);
841                 if (ret <= 0) 
842                         {
843                         ret = dtls1_read_failed(s, ret);
844                         /* anything other than a timeout is an error */
845                         if (ret <= 0)  
846                                 return(ret);
847                         else
848                                 goto start;
849                         }
850                 }
851
852         if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE)
853                 {
854                 rr->length = 0;
855                 goto start;
856                 }
857
858         /* we now have a packet which can be read and processed */
859
860         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
861                                        * reset by ssl3_get_finished */
862                 && (rr->type != SSL3_RT_HANDSHAKE))
863                 {
864                 /* We now have application data between CCS and Finished.
865                  * Most likely the packets were reordered on their way, so
866                  * buffer the application data for later processing rather
867                  * than dropping the connection.
868                  */
869                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
870                 rr->length = 0;
871                 goto start;
872                 }
873
874         /* If the other end has shut down, throw anything we read away
875          * (even in 'peek' mode) */
876         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
877                 {
878                 rr->length=0;
879                 s->rwstate=SSL_NOTHING;
880                 return(0);
881                 }
882
883
884         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
885                 {
886                 /* make sure that we are not getting application data when we
887                  * are doing a handshake for the first time */
888                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
889                         (s->enc_read_ctx == NULL))
890                         {
891                         al=SSL_AD_UNEXPECTED_MESSAGE;
892                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
893                         goto f_err;
894                         }
895
896                 if (len <= 0) return(len);
897
898                 if ((unsigned int)len > rr->length)
899                         n = rr->length;
900                 else
901                         n = (unsigned int)len;
902
903                 memcpy(buf,&(rr->data[rr->off]),n);
904                 if (!peek)
905                         {
906                         rr->length-=n;
907                         rr->off+=n;
908                         if (rr->length == 0)
909                                 {
910                                 s->rstate=SSL_ST_READ_HEADER;
911                                 rr->off=0;
912                                 }
913                         }
914
915 #ifndef OPENSSL_NO_SCTP
916                         /* We were about to renegotiate but had to read
917                          * belated application data first, so retry.
918                          */
919                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
920                             rr->type == SSL3_RT_APPLICATION_DATA &&
921                             (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
922                                 {
923                                 s->rwstate=SSL_READING;
924                                 BIO_clear_retry_flags(SSL_get_rbio(s));
925                                 BIO_set_retry_read(SSL_get_rbio(s));
926                                 }
927
928                         /* We might had to delay a close_notify alert because
929                          * of reordered app data. If there was an alert and there
930                          * is no message to read anymore, finally set shutdown.
931                          */
932                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
933                             s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
934                                 {
935                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
936                                 return(0);
937                                 }
938 #endif                  
939                 return(n);
940                 }
941
942
943         /* If we get here, then type != rr->type; if we have a handshake
944          * message, then it was unexpected (Hello Request or Client Hello). */
945
946         /* In case of record types for which we have 'fragment' storage,
947          * fill that so that we can process the data at a fixed place.
948          */
949                 {
950                 unsigned int k, dest_maxlen = 0;
951                 unsigned char *dest = NULL;
952                 unsigned int *dest_len = NULL;
953
954                 if (rr->type == SSL3_RT_HANDSHAKE)
955                         {
956                         dest_maxlen = sizeof s->d1->handshake_fragment;
957                         dest = s->d1->handshake_fragment;
958                         dest_len = &s->d1->handshake_fragment_len;
959                         }
960                 else if (rr->type == SSL3_RT_ALERT)
961                         {
962                         dest_maxlen = sizeof(s->d1->alert_fragment);
963                         dest = s->d1->alert_fragment;
964                         dest_len = &s->d1->alert_fragment_len;
965                         }
966 #ifndef OPENSSL_NO_HEARTBEATS
967                 else if (rr->type == TLS1_RT_HEARTBEAT)
968                         {
969                         dtls1_process_heartbeat(s);
970
971                         /* Exit and notify application to read again */
972                         rr->length = 0;
973                         s->rwstate=SSL_READING;
974                         BIO_clear_retry_flags(SSL_get_rbio(s));
975                         BIO_set_retry_read(SSL_get_rbio(s));
976                         return(-1);
977                         }
978 #endif
979                 /* else it's a CCS message, or application data or wrong */
980                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
981                         {
982                         /* Application data while renegotiating
983                          * is allowed. Try again reading.
984                          */
985                         if (rr->type == SSL3_RT_APPLICATION_DATA)
986                                 {
987                                 BIO *bio;
988                                 s->s3->in_read_app_data=2;
989                                 bio=SSL_get_rbio(s);
990                                 s->rwstate=SSL_READING;
991                                 BIO_clear_retry_flags(bio);
992                                 BIO_set_retry_read(bio);
993                                 return(-1);
994                                 }
995
996                         /* Not certain if this is the right error handling */
997                         al=SSL_AD_UNEXPECTED_MESSAGE;
998                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
999                         goto f_err;
1000                         }
1001
1002                 if (dest_maxlen > 0)
1003                         {
1004             /* XDTLS:  In a pathalogical case, the Client Hello
1005              *  may be fragmented--don't always expect dest_maxlen bytes */
1006                         if ( rr->length < dest_maxlen)
1007                                 {
1008 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1009                                 /*
1010                                  * for normal alerts rr->length is 2, while
1011                                  * dest_maxlen is 7 if we were to handle this
1012                                  * non-existing alert...
1013                                  */
1014                                 FIX ME
1015 #endif
1016                                 s->rstate=SSL_ST_READ_HEADER;
1017                                 rr->length = 0;
1018                                 goto start;
1019                                 }
1020
1021                         /* now move 'n' bytes: */
1022                         for ( k = 0; k < dest_maxlen; k++)
1023                                 {
1024                                 dest[k] = rr->data[rr->off++];
1025                                 rr->length--;
1026                                 }
1027                         *dest_len = dest_maxlen;
1028                         }
1029                 }
1030
1031         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
1032          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
1033          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1034
1035         /* If we are a client, check for an incoming 'Hello Request': */
1036         if ((!s->server) &&
1037                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1038                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1039                 (s->session != NULL) && (s->session->cipher != NULL))
1040                 {
1041                 s->d1->handshake_fragment_len = 0;
1042
1043                 if ((s->d1->handshake_fragment[1] != 0) ||
1044                         (s->d1->handshake_fragment[2] != 0) ||
1045                         (s->d1->handshake_fragment[3] != 0))
1046                         {
1047                         al=SSL_AD_DECODE_ERROR;
1048                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1049                         goto err;
1050                         }
1051
1052                 /* no need to check sequence number on HELLO REQUEST messages */
1053
1054                 if (s->msg_callback)
1055                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
1056                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1057
1058                 if (SSL_is_init_finished(s) &&
1059                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1060                         !s->s3->renegotiate)
1061                         {
1062                         s->d1->handshake_read_seq++;
1063                         s->new_session = 1;
1064                         ssl3_renegotiate(s);
1065                         if (ssl3_renegotiate_check(s))
1066                                 {
1067                                 i=s->handshake_func(s);
1068                                 if (i < 0) return(i);
1069                                 if (i == 0)
1070                                         {
1071                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1072                                         return(-1);
1073                                         }
1074
1075                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1076                                         {
1077                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1078                                                 {
1079                                                 BIO *bio;
1080                                                 /* In the case where we try to read application data,
1081                                                  * but we trigger an SSL handshake, we return -1 with
1082                                                  * the retry option set.  Otherwise renegotiation may
1083                                                  * cause nasty problems in the blocking world */
1084                                                 s->rwstate=SSL_READING;
1085                                                 bio=SSL_get_rbio(s);
1086                                                 BIO_clear_retry_flags(bio);
1087                                                 BIO_set_retry_read(bio);
1088                                                 return(-1);
1089                                                 }
1090                                         }
1091                                 }
1092                         }
1093                 /* we either finished a handshake or ignored the request,
1094                  * now try again to obtain the (application) data we were asked for */
1095                 goto start;
1096                 }
1097
1098         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1099                 {
1100                 int alert_level = s->d1->alert_fragment[0];
1101                 int alert_descr = s->d1->alert_fragment[1];
1102
1103                 s->d1->alert_fragment_len = 0;
1104
1105                 if (s->msg_callback)
1106                         s->msg_callback(0, s->version, SSL3_RT_ALERT, 
1107                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1108
1109                 if (s->info_callback != NULL)
1110                         cb=s->info_callback;
1111                 else if (s->ctx->info_callback != NULL)
1112                         cb=s->ctx->info_callback;
1113
1114                 if (cb != NULL)
1115                         {
1116                         j = (alert_level << 8) | alert_descr;
1117                         cb(s, SSL_CB_READ_ALERT, j);
1118                         }
1119
1120                 if (alert_level == 1) /* warning */
1121                         {
1122                         s->s3->warn_alert = alert_descr;
1123                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1124                                 {
1125 #ifndef OPENSSL_NO_SCTP
1126                                 /* With SCTP and streams the socket may deliver app data
1127                                  * after a close_notify alert. We have to check this
1128                                  * first so that nothing gets discarded.
1129                                  */
1130                                 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1131                                         BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1132                                         {
1133                                         s->d1->shutdown_received = 1;
1134                                         s->rwstate=SSL_READING;
1135                                         BIO_clear_retry_flags(SSL_get_rbio(s));
1136                                         BIO_set_retry_read(SSL_get_rbio(s));
1137                                         return -1;
1138                                         }
1139 #endif
1140                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1141                                 return(0);
1142                                 }
1143 #if 0
1144             /* XXX: this is a possible improvement in the future */
1145                         /* now check if it's a missing record */
1146                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1147                                 {
1148                                 unsigned short seq;
1149                                 unsigned int frag_off;
1150                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1151
1152                                 n2s(p, seq);
1153                                 n2l3(p, frag_off);
1154
1155                                 dtls1_retransmit_message(s,
1156                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1157                                                                                  frag_off, &found);
1158                                 if ( ! found  && SSL_in_init(s))
1159                                         {
1160                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1161                                         /* requested a message not yet sent, 
1162                                            send an alert ourselves */
1163                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1164                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1165                                         }
1166                                 }
1167 #endif
1168                         }
1169                 else if (alert_level == 2) /* fatal */
1170                         {
1171                         char tmp[16];
1172
1173                         s->rwstate=SSL_NOTHING;
1174                         s->s3->fatal_alert = alert_descr;
1175                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1176                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1177                         ERR_add_error_data(2,"SSL alert number ",tmp);
1178                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1179                         SSL_CTX_remove_session(s->ctx,s->session);
1180                         return(0);
1181                         }
1182                 else
1183                         {
1184                         al=SSL_AD_ILLEGAL_PARAMETER;
1185                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1186                         goto f_err;
1187                         }
1188
1189                 goto start;
1190                 }
1191
1192         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1193                 {
1194                 s->rwstate=SSL_NOTHING;
1195                 rr->length=0;
1196                 return(0);
1197                 }
1198
1199         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1200                 {
1201                 struct ccs_header_st ccs_hdr;
1202                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1203
1204                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1205
1206                 if (s->version == DTLS1_BAD_VER)
1207                         ccs_hdr_len = 3;
1208
1209                 /* 'Change Cipher Spec' is just a single byte, so we know
1210                  * exactly what the record payload has to look like */
1211                 /* XDTLS: check that epoch is consistent */
1212                 if (    (rr->length != ccs_hdr_len) || 
1213                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1214                         {
1215                         i=SSL_AD_ILLEGAL_PARAMETER;
1216                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1217                         goto err;
1218                         }
1219
1220                 rr->length=0;
1221
1222                 if (s->msg_callback)
1223                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
1224                                 rr->data, 1, s, s->msg_callback_arg);
1225
1226                 /* We can't process a CCS now, because previous handshake
1227                  * messages are still missing, so just drop it.
1228                  */
1229                 if (!s->d1->change_cipher_spec_ok)
1230                         {
1231                         goto start;
1232                         }
1233
1234                 s->d1->change_cipher_spec_ok = 0;
1235
1236                 s->s3->change_cipher_spec=1;
1237                 if (!ssl3_do_change_cipher_spec(s))
1238                         goto err;
1239
1240                 /* do this whenever CCS is processed */
1241                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1242
1243                 if (s->version == DTLS1_BAD_VER)
1244                         s->d1->handshake_read_seq++;
1245
1246 #ifndef OPENSSL_NO_SCTP
1247                 /* Remember that a CCS has been received,
1248                  * so that an old key of SCTP-Auth can be
1249                  * deleted when a CCS is sent. Will be ignored
1250                  * if no SCTP is used
1251                  */
1252                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1253 #endif
1254
1255                 goto start;
1256                 }
1257
1258         /* Unexpected handshake message (Client Hello, or protocol violation) */
1259         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 
1260                 !s->in_handshake)
1261                 {
1262                 struct hm_header_st msg_hdr;
1263                 
1264                 /* this may just be a stale retransmit */
1265                 dtls1_get_message_header(rr->data, &msg_hdr);
1266                 if( rr->epoch != s->d1->r_epoch)
1267                         {
1268                         rr->length = 0;
1269                         goto start;
1270                         }
1271
1272                 /* If we are server, we may have a repeated FINISHED of the
1273                  * client here, then retransmit our CCS and FINISHED.
1274                  */
1275                 if (msg_hdr.type == SSL3_MT_FINISHED)
1276                         {
1277                         if (dtls1_check_timeout_num(s) < 0)
1278                                 return -1;
1279
1280                         dtls1_retransmit_buffered_messages(s);
1281                         rr->length = 0;
1282                         goto start;
1283                         }
1284
1285                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1286                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1287                         {
1288 #if 0 /* worked only because C operator preferences are not as expected (and
1289        * because this is not really needed for clients except for detecting
1290        * protocol violations): */
1291                         s->state=SSL_ST_BEFORE|(s->server)
1292                                 ?SSL_ST_ACCEPT
1293                                 :SSL_ST_CONNECT;
1294 #else
1295                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1296 #endif
1297                         s->renegotiate=1;
1298                         s->new_session=1;
1299                         }
1300                 i=s->handshake_func(s);
1301                 if (i < 0) return(i);
1302                 if (i == 0)
1303                         {
1304                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1305                         return(-1);
1306                         }
1307
1308                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1309                         {
1310                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1311                                 {
1312                                 BIO *bio;
1313                                 /* In the case where we try to read application data,
1314                                  * but we trigger an SSL handshake, we return -1 with
1315                                  * the retry option set.  Otherwise renegotiation may
1316                                  * cause nasty problems in the blocking world */
1317                                 s->rwstate=SSL_READING;
1318                                 bio=SSL_get_rbio(s);
1319                                 BIO_clear_retry_flags(bio);
1320                                 BIO_set_retry_read(bio);
1321                                 return(-1);
1322                                 }
1323                         }
1324                 goto start;
1325                 }
1326
1327         switch (rr->type)
1328                 {
1329         default:
1330 #ifndef OPENSSL_NO_TLS
1331                 /* TLS just ignores unknown message types */
1332                 if (s->version == TLS1_VERSION)
1333                         {
1334                         rr->length = 0;
1335                         goto start;
1336                         }
1337 #endif
1338                 al=SSL_AD_UNEXPECTED_MESSAGE;
1339                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1340                 goto f_err;
1341         case SSL3_RT_CHANGE_CIPHER_SPEC:
1342         case SSL3_RT_ALERT:
1343         case SSL3_RT_HANDSHAKE:
1344                 /* we already handled all of these, with the possible exception
1345                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1346                  * should not happen when type != rr->type */
1347                 al=SSL_AD_UNEXPECTED_MESSAGE;
1348                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1349                 goto f_err;
1350         case SSL3_RT_APPLICATION_DATA:
1351                 /* At this point, we were expecting handshake data,
1352                  * but have application data.  If the library was
1353                  * running inside ssl3_read() (i.e. in_read_app_data
1354                  * is set) and it makes sense to read application data
1355                  * at this point (session renegotiation not yet started),
1356                  * we will indulge it.
1357                  */
1358                 if (s->s3->in_read_app_data &&
1359                         (s->s3->total_renegotiations != 0) &&
1360                         ((
1361                                 (s->state & SSL_ST_CONNECT) &&
1362                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1363                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1364                                 ) || (
1365                                         (s->state & SSL_ST_ACCEPT) &&
1366                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1367                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1368                                         )
1369                                 ))
1370                         {
1371                         s->s3->in_read_app_data=2;
1372                         return(-1);
1373                         }
1374                 else
1375                         {
1376                         al=SSL_AD_UNEXPECTED_MESSAGE;
1377                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1378                         goto f_err;
1379                         }
1380                 }
1381         /* not reached */
1382
1383 f_err:
1384         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1385 err:
1386         return(-1);
1387         }
1388
1389 int
1390 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1391         {
1392         int i;
1393
1394 #ifndef OPENSSL_NO_SCTP
1395                 /* Check if we have to continue an interrupted handshake
1396                  * for reading belated app data with SCTP.
1397                  */
1398                 if ((SSL_in_init(s) && !s->in_handshake) ||
1399                     (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1400                      (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1401 #else
1402                 if (SSL_in_init(s) && !s->in_handshake)
1403 #endif
1404                 {
1405                 i=s->handshake_func(s);
1406                 if (i < 0) return(i);
1407                 if (i == 0)
1408                         {
1409                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1410                         return -1;
1411                         }
1412                 }
1413
1414         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1415                 {
1416                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1417                         return -1;
1418                 }
1419
1420         i = dtls1_write_bytes(s, type, buf_, len);
1421         return i;
1422         }
1423
1424
1425         /* this only happens when a client hello is received and a handshake 
1426          * is started. */
1427 static int
1428 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
1429         int len, int peek)
1430         {
1431         
1432         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1433                 /* (partially) satisfy request from storage */
1434                 {
1435                 unsigned char *src = s->d1->handshake_fragment;
1436                 unsigned char *dst = buf;
1437                 unsigned int k,n;
1438                 
1439                 /* peek == 0 */
1440                 n = 0;
1441                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1442                         {
1443                         *dst++ = *src++;
1444                         len--; s->d1->handshake_fragment_len--;
1445                         n++;
1446                         }
1447                 /* move any remaining fragment bytes: */
1448                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1449                         s->d1->handshake_fragment[k] = *src++;
1450                 return n;
1451                 }
1452         
1453         return 0;
1454         }
1455
1456
1457
1458
1459 /* Call this to write data in records of type 'type'
1460  * It will return <= 0 if not all data has been sent or non-blocking IO.
1461  */
1462 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1463         {
1464         int i;
1465
1466         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1467         s->rwstate=SSL_NOTHING;
1468         i=do_dtls1_write(s, type, buf, len, 0);
1469         return i;
1470         }
1471
1472 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1473         {
1474         unsigned char *p,*pseq;
1475         int i,mac_size,clear=0;
1476         int prefix_len = 0;
1477         int eivlen;
1478         SSL3_RECORD *wr;
1479         SSL3_BUFFER *wb;
1480         SSL_SESSION *sess;
1481
1482         /* first check if there is a SSL3_BUFFER still being written
1483          * out.  This will happen with non blocking IO */
1484         if (s->s3->wbuf.left != 0)
1485                 {
1486                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1487                 return(ssl3_write_pending(s,type,buf,len));
1488                 }
1489
1490         /* If we have an alert to send, lets send it */
1491         if (s->s3->alert_dispatch)
1492                 {
1493                 i=s->method->ssl_dispatch_alert(s);
1494                 if (i <= 0)
1495                         return(i);
1496                 /* if it went, fall through and send more stuff */
1497                 }
1498
1499         if (len == 0 && !create_empty_fragment)
1500                 return 0;
1501
1502         wr= &(s->s3->wrec);
1503         wb= &(s->s3->wbuf);
1504         sess=s->session;
1505
1506         if (    (sess == NULL) ||
1507                 (s->enc_write_ctx == NULL) ||
1508                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1509                 clear=1;
1510
1511         if (clear)
1512                 mac_size=0;
1513         else
1514                 {
1515                 mac_size=EVP_MD_CTX_size(s->write_hash);
1516                 if (mac_size < 0)
1517                         goto err;
1518                 }
1519
1520         /* DTLS implements explicit IV, so no need for empty fragments */
1521 #if 0
1522         /* 'create_empty_fragment' is true only when this function calls itself */
1523         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1524             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1525                 {
1526                 /* countermeasure against known-IV weakness in CBC ciphersuites
1527                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
1528                  */
1529
1530                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1531                         {
1532                         /* recursive function call with 'create_empty_fragment' set;
1533                          * this prepares and buffers the data for an empty fragment
1534                          * (these 'prefix_len' bytes are sent out later
1535                          * together with the actual payload) */
1536                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1537                         if (prefix_len <= 0)
1538                                 goto err;
1539
1540                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1541                                 {
1542                                 /* insufficient space */
1543                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1544                                 goto err;
1545                                 }
1546                         }
1547                 
1548                 s->s3->empty_fragment_done = 1;
1549                 }
1550 #endif
1551         p = wb->buf + prefix_len;
1552
1553         /* write the header */
1554
1555         *(p++)=type&0xff;
1556         wr->type=type;
1557         /* Special case: for hello verify request, client version 1.0 and
1558          * we haven't decided which version to use yet send back using 
1559          * version 1.0 header: otherwise some clients will ignore it.
1560          */
1561         if (s->method->version == DTLS_ANY_VERSION)
1562                 {
1563                 *(p++)=DTLS1_VERSION>>8;
1564                 *(p++)=DTLS1_VERSION&0xff;
1565                 }
1566         else
1567                 {
1568                 *(p++)=s->version>>8;
1569                 *(p++)=s->version&0xff;
1570                 }
1571
1572         /* field where we are to write out packet epoch, seq num and len */
1573         pseq=p; 
1574         p+=10;
1575
1576         /* Explicit IV length, block ciphers appropriate version flag */
1577         if (s->enc_write_ctx)
1578                 {
1579                 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1580                 if (mode == EVP_CIPH_CBC_MODE)
1581                         {
1582                         eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1583                         if (eivlen <= 1)
1584                                 eivlen = 0;
1585                         }
1586                 /* Need explicit part of IV for GCM mode */
1587                 else if (mode == EVP_CIPH_GCM_MODE)
1588                         eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1589                 else
1590                         eivlen = 0;
1591                 }
1592         else 
1593                 eivlen = 0;
1594
1595         /* lets setup the record stuff. */
1596         wr->data=p + eivlen;  /* make room for IV in case of CBC */
1597         wr->length=(int)len;
1598         wr->input=(unsigned char *)buf;
1599
1600         /* we now 'read' from wr->input, wr->length bytes into
1601          * wr->data */
1602
1603         /* first we compress */
1604         if (s->compress != NULL)
1605                 {
1606                 if (!ssl3_do_compress(s))
1607                         {
1608                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1609                         goto err;
1610                         }
1611                 }
1612         else
1613                 {
1614                 memcpy(wr->data,wr->input,wr->length);
1615                 wr->input=wr->data;
1616                 }
1617
1618         /* we should still have the output to wr->data and the input
1619          * from wr->input.  Length should be wr->length.
1620          * wr->data still points in the wb->buf */
1621
1622         if (mac_size != 0)
1623                 {
1624                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
1625                         goto err;
1626                 wr->length+=mac_size;
1627                 }
1628
1629         /* this is true regardless of mac size */
1630         wr->input=p;
1631         wr->data=p;
1632
1633         if (eivlen)
1634                 wr->length += eivlen;
1635
1636         s->method->ssl3_enc->enc(s,1);
1637
1638         /* record length after mac and block padding */
1639 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1640         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1641         
1642         /* there's only one epoch between handshake and app data */
1643         
1644         s2n(s->d1->w_epoch, pseq);
1645
1646         /* XDTLS: ?? */
1647 /*      else
1648         s2n(s->d1->handshake_epoch, pseq); */
1649
1650         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1651         pseq+=6;
1652         s2n(wr->length,pseq);
1653
1654         if (s->msg_callback)
1655                 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1656
1657         /* we should now have
1658          * wr->data pointing to the encrypted data, which is
1659          * wr->length long */
1660         wr->type=type; /* not needed but helps for debugging */
1661         wr->length+=DTLS1_RT_HEADER_LENGTH;
1662
1663 #if 0  /* this is now done at the message layer */
1664         /* buffer the record, making it easy to handle retransmits */
1665         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1666                 dtls1_buffer_record(s, wr->data, wr->length, 
1667                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1668 #endif
1669
1670         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1671
1672         if (create_empty_fragment)
1673                 {
1674                 /* we are in a recursive call;
1675                  * just return the length, don't write out anything here
1676                  */
1677                 return wr->length;
1678                 }
1679
1680         /* now let's set up wb */
1681         wb->left = prefix_len + wr->length;
1682         wb->offset = 0;
1683
1684         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1685         s->s3->wpend_tot=len;
1686         s->s3->wpend_buf=buf;
1687         s->s3->wpend_type=type;
1688         s->s3->wpend_ret=len;
1689
1690         /* we now just need to write the buffer */
1691         return ssl3_write_pending(s,type,buf,len);
1692 err:
1693         return -1;
1694         }
1695
1696
1697
1698 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1699         {
1700         int cmp;
1701         unsigned int shift;
1702         const unsigned char *seq = s->s3->read_sequence;
1703
1704         cmp = satsub64be(seq,bitmap->max_seq_num);
1705         if (cmp > 0)
1706                 {
1707                 memcpy (s->s3->rrec.seq_num,seq,8);
1708                 return 1; /* this record in new */
1709                 }
1710         shift = -cmp;
1711         if (shift >= sizeof(bitmap->map)*8)
1712                 return 0; /* stale, outside the window */
1713         else if (bitmap->map & (1UL<<shift))
1714                 return 0; /* record previously received */
1715
1716         memcpy (s->s3->rrec.seq_num,seq,8);
1717         return 1;
1718         }
1719
1720
1721 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1722         {
1723         int cmp;
1724         unsigned int shift;
1725         const unsigned char *seq = s->s3->read_sequence;
1726
1727         cmp = satsub64be(seq,bitmap->max_seq_num);
1728         if (cmp > 0)
1729                 {
1730                 shift = cmp;
1731                 if (shift < sizeof(bitmap->map)*8)
1732                         bitmap->map <<= shift, bitmap->map |= 1UL;
1733                 else
1734                         bitmap->map = 1UL;
1735                 memcpy(bitmap->max_seq_num,seq,8);
1736                 }
1737         else    {
1738                 shift = -cmp;
1739                 if (shift < sizeof(bitmap->map)*8)
1740                         bitmap->map |= 1UL<<shift;
1741                 }
1742         }
1743
1744
1745 int dtls1_dispatch_alert(SSL *s)
1746         {
1747         int i,j;
1748         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1749         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1750         unsigned char *ptr = &buf[0];
1751
1752         s->s3->alert_dispatch=0;
1753
1754         memset(buf, 0x00, sizeof(buf));
1755         *ptr++ = s->s3->send_alert[0];
1756         *ptr++ = s->s3->send_alert[1];
1757
1758 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1759         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1760                 {       
1761                 s2n(s->d1->handshake_read_seq, ptr);
1762 #if 0
1763                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1764
1765                 else
1766                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1767 #endif
1768
1769 #if 0
1770                 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);
1771 #endif
1772                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1773                 }
1774 #endif
1775
1776         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1777         if (i <= 0)
1778                 {
1779                 s->s3->alert_dispatch=1;
1780                 /* fprintf( stderr, "not done with alert\n" ); */
1781                 }
1782         else
1783                 {
1784                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1785 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1786                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1787 #endif
1788                     )
1789                         (void)BIO_flush(s->wbio);
1790
1791                 if (s->msg_callback)
1792                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 
1793                                 2, s, s->msg_callback_arg);
1794
1795                 if (s->info_callback != NULL)
1796                         cb=s->info_callback;
1797                 else if (s->ctx->info_callback != NULL)
1798                         cb=s->ctx->info_callback;
1799
1800                 if (cb != NULL)
1801                         {
1802                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1803                         cb(s,SSL_CB_WRITE_ALERT,j);
1804                         }
1805                 }
1806         return(i);
1807         }
1808
1809
1810 static DTLS1_BITMAP *
1811 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1812     {
1813     
1814     *is_next_epoch = 0;
1815
1816     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1817     if (rr->epoch == s->d1->r_epoch)
1818         return &s->d1->bitmap;
1819
1820     /* Only HM and ALERT messages can be from the next epoch */
1821     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1822         (rr->type == SSL3_RT_HANDSHAKE ||
1823             rr->type == SSL3_RT_ALERT))
1824         {
1825         *is_next_epoch = 1;
1826         return &s->d1->next_bitmap;
1827         }
1828
1829     return NULL;
1830     }
1831
1832 #if 0
1833 static int
1834 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1835         unsigned long *offset)
1836         {
1837
1838         /* alerts are passed up immediately */
1839         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1840                 rr->type == SSL3_RT_ALERT)
1841                 return 0;
1842
1843         /* Only need to buffer if a handshake is underway.
1844          * (this implies that Hello Request and Client Hello are passed up
1845          * immediately) */
1846         if ( SSL_in_init(s))
1847                 {
1848                 unsigned char *data = rr->data;
1849                 /* need to extract the HM/CCS sequence number here */
1850                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1851                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1852                         {
1853                         unsigned short seq_num;
1854                         struct hm_header_st msg_hdr;
1855                         struct ccs_header_st ccs_hdr;
1856
1857                         if ( rr->type == SSL3_RT_HANDSHAKE)
1858                                 {
1859                                 dtls1_get_message_header(data, &msg_hdr);
1860                                 seq_num = msg_hdr.seq;
1861                                 *offset = msg_hdr.frag_off;
1862                                 }
1863                         else
1864                                 {
1865                                 dtls1_get_ccs_header(data, &ccs_hdr);
1866                                 seq_num = ccs_hdr.seq;
1867                                 *offset = 0;
1868                                 }
1869                                 
1870                         /* this is either a record we're waiting for, or a
1871                          * retransmit of something we happened to previously 
1872                          * receive (higher layers will drop the repeat silently */
1873                         if ( seq_num < s->d1->handshake_read_seq)
1874                                 return 0;
1875                         if (rr->type == SSL3_RT_HANDSHAKE && 
1876                                 seq_num == s->d1->handshake_read_seq &&
1877                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1878                                 return 0;
1879                         else if ( seq_num == s->d1->handshake_read_seq &&
1880                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1881                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1882                                 return 0;
1883                         else
1884                                 {
1885                                 *priority = seq_num;
1886                                 return 1;
1887                                 }
1888                         }
1889                 else /* unknown record type */
1890                         return 0;
1891                 }
1892
1893         return 0;
1894         }
1895 #endif
1896
1897 void
1898 dtls1_reset_seq_numbers(SSL *s, int rw)
1899         {
1900         unsigned char *seq;
1901         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1902
1903         if ( rw & SSL3_CC_READ)
1904                 {
1905                 seq = s->s3->read_sequence;
1906                 s->d1->r_epoch++;
1907                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1908                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1909                 }
1910         else
1911                 {
1912                 seq = s->s3->write_sequence;
1913                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1914                 s->d1->w_epoch++;
1915                 }
1916
1917         memset(seq, 0x00, seq_bytes);
1918         }