9badc5e3f2d03a30c27b0c7b4d0f04f468412356
[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         /*-
522          * So at this point the following is true
523          * ssl->s3->rrec.type   is the type of record
524          * ssl->s3->rrec.length == number of bytes in record
525          * ssl->s3->rrec.off    == offset to first valid byte
526          * ssl->s3->rrec.data   == where to take bytes from, increment
527          *                         after use :-).
528          */
529
530         /* we have pulled in a full packet so zero things */
531         s->packet_length=0;
532         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
533         return(1);
534
535 f_err:
536         ssl3_send_alert(s,SSL3_AL_FATAL,al);
537 err:
538         return(0);
539 }
540
541
542 /*-
543  * Call this to get a new input record.
544  * It will return <= 0 if more data is needed, normally due to an error
545  * or non-blocking IO.
546  * When it finishes, one packet has been decoded and can be found in
547  * ssl->s3->rrec.type    - is the type of record
548  * ssl->s3->rrec.data,   - data
549  * ssl->s3->rrec.length, - number of bytes
550  */
551 /* used only by dtls1_read_bytes */
552 int dtls1_get_record(SSL *s)
553         {
554         int ssl_major,ssl_minor;
555         int i,n;
556         SSL3_RECORD *rr;
557         unsigned char *p = NULL;
558         unsigned short version;
559         DTLS1_BITMAP *bitmap;
560         unsigned int is_next_epoch;
561
562         rr= &(s->s3->rrec);
563
564         /* The epoch may have changed.  If so, process all the
565          * pending records.  This is a non-blocking operation. */
566         dtls1_process_buffered_records(s);
567
568         /* if we're renegotiating, then there may be buffered records */
569         if (dtls1_get_processed_record(s))
570                 return 1;
571
572         /* get something from the wire */
573 again:
574         /* check if we have the header */
575         if (    (s->rstate != SSL_ST_READ_BODY) ||
576                 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 
577                 {
578                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
579                 /* read timeout is handled by dtls1_read_bytes */
580                 if (n <= 0) return(n); /* error or non-blocking */
581
582                 /* this packet contained a partial record, dump it */
583                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
584                         {
585                         s->packet_length = 0;
586                         goto again;
587                         }
588
589                 s->rstate=SSL_ST_READ_BODY;
590
591                 p=s->packet;
592
593                 if (s->msg_callback)
594                         s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
595
596                 /* Pull apart the header into the DTLS1_RECORD */
597                 rr->type= *(p++);
598                 ssl_major= *(p++);
599                 ssl_minor= *(p++);
600                 version=(ssl_major<<8)|ssl_minor;
601
602                 /* sequence number is 64 bits, with top 2 bytes = epoch */ 
603                 n2s(p,rr->epoch);
604
605                 memcpy(&(s->s3->read_sequence[2]), p, 6);
606                 p+=6;
607
608                 n2s(p,rr->length);
609
610                 /* Lets check version */
611                 if (!s->first_packet)
612                         {
613                         if (version != s->version)
614                                 {
615                                 /* unexpected version, silently discard */
616                                 rr->length = 0;
617                                 s->packet_length = 0;
618                                 goto again;
619                                 }
620                         }
621
622                 if ((version & 0xff00) != (s->version & 0xff00))
623                         {
624                         /* wrong version, silently discard record */
625                         rr->length = 0;
626                         s->packet_length = 0;
627                         goto again;
628                         }
629
630                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
631                         {
632                         /* record too long, silently discard it */
633                         rr->length = 0;
634                         s->packet_length = 0;
635                         goto again;
636                         }
637
638                 /* now s->rstate == SSL_ST_READ_BODY */
639                 }
640
641         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
642
643         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
644                 {
645                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
646                 i=rr->length;
647                 n=ssl3_read_n(s,i,i,1);
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 /*-
724  * Return up to 'len' payload bytes received in 'type' records.
725  * 'type' is one of the following:
726  *
727  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
728  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
729  *   -  0 (during a shutdown, no data has to be returned)
730  *
731  * If we don't have stored data to work from, read a SSL/TLS record first
732  * (possibly multiple records if we still don't have anything to return).
733  *
734  * This function must handle any surprises the peer may have for us, such as
735  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
736  * a surprise, but handled as if it were), or renegotiation requests.
737  * Also if record payloads contain fragments too small to process, we store
738  * them until there is enough for the respective protocol (the record protocol
739  * may use arbitrary fragmentation and even interleaving):
740  *     Change cipher spec protocol
741  *             just 1 byte needed, no need for keeping anything stored
742  *     Alert protocol
743  *             2 bytes needed (AlertLevel, AlertDescription)
744  *     Handshake protocol
745  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
746  *             to detect unexpected Client Hello and Hello Request messages
747  *             here, anything else is handled by higher layers
748  *     Application data protocol
749  *             none of our business
750  */
751 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
752         {
753         int al,i,j,ret;
754         unsigned int n;
755         SSL3_RECORD *rr;
756         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
757
758         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
759                 if (!ssl3_setup_buffers(s))
760                         return(-1);
761
762         if ((type && (type != SSL3_RT_APPLICATION_DATA) && 
763                 (type != SSL3_RT_HANDSHAKE)) ||
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         /*-
802          * s->s3->rrec.type         - is the type of record
803          * s->s3->rrec.data,    - data
804          * s->s3->rrec.off,     - offset into 'data' for next read
805          * s->s3->rrec.length,  - number of bytes. 
806          */
807         rr = &(s->s3->rrec);
808
809         /* We are not handshaking and have no data yet,
810          * so process data buffered during the last handshake
811          * in advance, if any.
812          */
813         if (s->state == SSL_ST_OK && rr->length == 0)
814                 {
815                 pitem *item;
816                 item = pqueue_pop(s->d1->buffered_app_data.q);
817                 if (item)
818                         {
819 #ifndef OPENSSL_NO_SCTP
820                         /* Restore bio_dgram_sctp_rcvinfo struct */
821                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
822                                 {
823                                 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
824                                 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
825                                 }
826 #endif
827
828                         dtls1_copy_record(s, item);
829
830                         OPENSSL_free(item->data);
831                         pitem_free(item);
832                         }
833                 }
834
835         /* Check for timeout */
836         if (dtls1_handle_timeout(s) > 0)
837                 goto start;
838
839         /* get new packet if necessary */
840         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
841                 {
842                 ret=dtls1_get_record(s);
843                 if (ret <= 0) 
844                         {
845                         ret = dtls1_read_failed(s, ret);
846                         /* anything other than a timeout is an error */
847                         if (ret <= 0)  
848                                 return(ret);
849                         else
850                                 goto start;
851                         }
852                 }
853
854         if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE)
855                 {
856                 rr->length = 0;
857                 goto start;
858                 }
859
860         /* we now have a packet which can be read and processed */
861
862         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
863                                        * reset by ssl3_get_finished */
864                 && (rr->type != SSL3_RT_HANDSHAKE))
865                 {
866                 /* We now have application data between CCS and Finished.
867                  * Most likely the packets were reordered on their way, so
868                  * buffer the application data for later processing rather
869                  * than dropping the connection.
870                  */
871                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
872                 rr->length = 0;
873                 goto start;
874                 }
875
876         /* If the other end has shut down, throw anything we read away
877          * (even in 'peek' mode) */
878         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
879                 {
880                 rr->length=0;
881                 s->rwstate=SSL_NOTHING;
882                 return(0);
883                 }
884
885
886         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
887                 {
888                 /* make sure that we are not getting application data when we
889                  * are doing a handshake for the first time */
890                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
891                         (s->enc_read_ctx == NULL))
892                         {
893                         al=SSL_AD_UNEXPECTED_MESSAGE;
894                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
895                         goto f_err;
896                         }
897
898                 if (len <= 0) return(len);
899
900                 if ((unsigned int)len > rr->length)
901                         n = rr->length;
902                 else
903                         n = (unsigned int)len;
904
905                 memcpy(buf,&(rr->data[rr->off]),n);
906                 if (!peek)
907                         {
908                         rr->length-=n;
909                         rr->off+=n;
910                         if (rr->length == 0)
911                                 {
912                                 s->rstate=SSL_ST_READ_HEADER;
913                                 rr->off=0;
914                                 }
915                         }
916
917 #ifndef OPENSSL_NO_SCTP
918                         /* We were about to renegotiate but had to read
919                          * belated application data first, so retry.
920                          */
921                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
922                             rr->type == SSL3_RT_APPLICATION_DATA &&
923                             (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
924                                 {
925                                 s->rwstate=SSL_READING;
926                                 BIO_clear_retry_flags(SSL_get_rbio(s));
927                                 BIO_set_retry_read(SSL_get_rbio(s));
928                                 }
929
930                         /* We might had to delay a close_notify alert because
931                          * of reordered app data. If there was an alert and there
932                          * is no message to read anymore, finally set shutdown.
933                          */
934                         if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
935                             s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
936                                 {
937                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
938                                 return(0);
939                                 }
940 #endif                  
941                 return(n);
942                 }
943
944
945         /* If we get here, then type != rr->type; if we have a handshake
946          * message, then it was unexpected (Hello Request or Client Hello). */
947
948         /* In case of record types for which we have 'fragment' storage,
949          * fill that so that we can process the data at a fixed place.
950          */
951                 {
952                 unsigned int k, dest_maxlen = 0;
953                 unsigned char *dest = NULL;
954                 unsigned int *dest_len = NULL;
955
956                 if (rr->type == SSL3_RT_HANDSHAKE)
957                         {
958                         dest_maxlen = sizeof s->d1->handshake_fragment;
959                         dest = s->d1->handshake_fragment;
960                         dest_len = &s->d1->handshake_fragment_len;
961                         }
962                 else if (rr->type == SSL3_RT_ALERT)
963                         {
964                         dest_maxlen = sizeof(s->d1->alert_fragment);
965                         dest = s->d1->alert_fragment;
966                         dest_len = &s->d1->alert_fragment_len;
967                         }
968 #ifndef OPENSSL_NO_HEARTBEATS
969                 else if (rr->type == TLS1_RT_HEARTBEAT)
970                         {
971                         dtls1_process_heartbeat(s);
972
973                         /* Exit and notify application to read again */
974                         rr->length = 0;
975                         s->rwstate=SSL_READING;
976                         BIO_clear_retry_flags(SSL_get_rbio(s));
977                         BIO_set_retry_read(SSL_get_rbio(s));
978                         return(-1);
979                         }
980 #endif
981                 /* else it's a CCS message, or application data or wrong */
982                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
983                         {
984                         /* Application data while renegotiating
985                          * is allowed. Try again reading.
986                          */
987                         if (rr->type == SSL3_RT_APPLICATION_DATA)
988                                 {
989                                 BIO *bio;
990                                 s->s3->in_read_app_data=2;
991                                 bio=SSL_get_rbio(s);
992                                 s->rwstate=SSL_READING;
993                                 BIO_clear_retry_flags(bio);
994                                 BIO_set_retry_read(bio);
995                                 return(-1);
996                                 }
997
998                         /* Not certain if this is the right error handling */
999                         al=SSL_AD_UNEXPECTED_MESSAGE;
1000                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1001                         goto f_err;
1002                         }
1003
1004                 if (dest_maxlen > 0)
1005                         {
1006             /* XDTLS:  In a pathalogical case, the Client Hello
1007              *  may be fragmented--don't always expect dest_maxlen bytes */
1008                         if ( rr->length < dest_maxlen)
1009                                 {
1010 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1011                                 /*
1012                                  * for normal alerts rr->length is 2, while
1013                                  * dest_maxlen is 7 if we were to handle this
1014                                  * non-existing alert...
1015                                  */
1016                                 FIX ME
1017 #endif
1018                                 s->rstate=SSL_ST_READ_HEADER;
1019                                 rr->length = 0;
1020                                 goto start;
1021                                 }
1022
1023                         /* now move 'n' bytes: */
1024                         for ( k = 0; k < dest_maxlen; k++)
1025                                 {
1026                                 dest[k] = rr->data[rr->off++];
1027                                 rr->length--;
1028                                 }
1029                         *dest_len = dest_maxlen;
1030                         }
1031                 }
1032
1033         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
1034          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
1035          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1036
1037         /* If we are a client, check for an incoming 'Hello Request': */
1038         if ((!s->server) &&
1039                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1040                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1041                 (s->session != NULL) && (s->session->cipher != NULL))
1042                 {
1043                 s->d1->handshake_fragment_len = 0;
1044
1045                 if ((s->d1->handshake_fragment[1] != 0) ||
1046                         (s->d1->handshake_fragment[2] != 0) ||
1047                         (s->d1->handshake_fragment[3] != 0))
1048                         {
1049                         al=SSL_AD_DECODE_ERROR;
1050                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1051                         goto err;
1052                         }
1053
1054                 /* no need to check sequence number on HELLO REQUEST messages */
1055
1056                 if (s->msg_callback)
1057                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
1058                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1059
1060                 if (SSL_is_init_finished(s) &&
1061                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1062                         !s->s3->renegotiate)
1063                         {
1064                         s->d1->handshake_read_seq++;
1065                         s->new_session = 1;
1066                         ssl3_renegotiate(s);
1067                         if (ssl3_renegotiate_check(s))
1068                                 {
1069                                 i=s->handshake_func(s);
1070                                 if (i < 0) return(i);
1071                                 if (i == 0)
1072                                         {
1073                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1074                                         return(-1);
1075                                         }
1076
1077                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1078                                         {
1079                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1080                                                 {
1081                                                 BIO *bio;
1082                                                 /* In the case where we try to read application data,
1083                                                  * but we trigger an SSL handshake, we return -1 with
1084                                                  * the retry option set.  Otherwise renegotiation may
1085                                                  * cause nasty problems in the blocking world */
1086                                                 s->rwstate=SSL_READING;
1087                                                 bio=SSL_get_rbio(s);
1088                                                 BIO_clear_retry_flags(bio);
1089                                                 BIO_set_retry_read(bio);
1090                                                 return(-1);
1091                                                 }
1092                                         }
1093                                 }
1094                         }
1095                 /* we either finished a handshake or ignored the request,
1096                  * now try again to obtain the (application) data we were asked for */
1097                 goto start;
1098                 }
1099
1100         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1101                 {
1102                 int alert_level = s->d1->alert_fragment[0];
1103                 int alert_descr = s->d1->alert_fragment[1];
1104
1105                 s->d1->alert_fragment_len = 0;
1106
1107                 if (s->msg_callback)
1108                         s->msg_callback(0, s->version, SSL3_RT_ALERT, 
1109                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1110
1111                 if (s->info_callback != NULL)
1112                         cb=s->info_callback;
1113                 else if (s->ctx->info_callback != NULL)
1114                         cb=s->ctx->info_callback;
1115
1116                 if (cb != NULL)
1117                         {
1118                         j = (alert_level << 8) | alert_descr;
1119                         cb(s, SSL_CB_READ_ALERT, j);
1120                         }
1121
1122                 if (alert_level == 1) /* warning */
1123                         {
1124                         s->s3->warn_alert = alert_descr;
1125                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1126                                 {
1127 #ifndef OPENSSL_NO_SCTP
1128                                 /* With SCTP and streams the socket may deliver app data
1129                                  * after a close_notify alert. We have to check this
1130                                  * first so that nothing gets discarded.
1131                                  */
1132                                 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1133                                         BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1134                                         {
1135                                         s->d1->shutdown_received = 1;
1136                                         s->rwstate=SSL_READING;
1137                                         BIO_clear_retry_flags(SSL_get_rbio(s));
1138                                         BIO_set_retry_read(SSL_get_rbio(s));
1139                                         return -1;
1140                                         }
1141 #endif
1142                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1143                                 return(0);
1144                                 }
1145 #if 0
1146             /* XXX: this is a possible improvement in the future */
1147                         /* now check if it's a missing record */
1148                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1149                                 {
1150                                 unsigned short seq;
1151                                 unsigned int frag_off;
1152                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1153
1154                                 n2s(p, seq);
1155                                 n2l3(p, frag_off);
1156
1157                                 dtls1_retransmit_message(s,
1158                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1159                                                                                  frag_off, &found);
1160                                 if ( ! found  && SSL_in_init(s))
1161                                         {
1162                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1163                                         /* requested a message not yet sent, 
1164                                            send an alert ourselves */
1165                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1166                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1167                                         }
1168                                 }
1169 #endif
1170                         }
1171                 else if (alert_level == 2) /* fatal */
1172                         {
1173                         char tmp[16];
1174
1175                         s->rwstate=SSL_NOTHING;
1176                         s->s3->fatal_alert = alert_descr;
1177                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1178                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1179                         ERR_add_error_data(2,"SSL alert number ",tmp);
1180                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1181                         SSL_CTX_remove_session(s->ctx,s->session);
1182                         return(0);
1183                         }
1184                 else
1185                         {
1186                         al=SSL_AD_ILLEGAL_PARAMETER;
1187                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1188                         goto f_err;
1189                         }
1190
1191                 goto start;
1192                 }
1193
1194         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1195                 {
1196                 s->rwstate=SSL_NOTHING;
1197                 rr->length=0;
1198                 return(0);
1199                 }
1200
1201         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1202                 {
1203                 struct ccs_header_st ccs_hdr;
1204                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1205
1206                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1207
1208                 if (s->version == DTLS1_BAD_VER)
1209                         ccs_hdr_len = 3;
1210
1211                 /* 'Change Cipher Spec' is just a single byte, so we know
1212                  * exactly what the record payload has to look like */
1213                 /* XDTLS: check that epoch is consistent */
1214                 if (    (rr->length != ccs_hdr_len) || 
1215                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1216                         {
1217                         i=SSL_AD_ILLEGAL_PARAMETER;
1218                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1219                         goto err;
1220                         }
1221
1222                 rr->length=0;
1223
1224                 if (s->msg_callback)
1225                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
1226                                 rr->data, 1, s, s->msg_callback_arg);
1227
1228                 /* We can't process a CCS now, because previous handshake
1229                  * messages are still missing, so just drop it.
1230                  */
1231                 if (!s->d1->change_cipher_spec_ok)
1232                         {
1233                         goto start;
1234                         }
1235
1236                 s->d1->change_cipher_spec_ok = 0;
1237
1238                 s->s3->change_cipher_spec=1;
1239                 if (!ssl3_do_change_cipher_spec(s))
1240                         goto err;
1241
1242                 /* do this whenever CCS is processed */
1243                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1244
1245                 if (s->version == DTLS1_BAD_VER)
1246                         s->d1->handshake_read_seq++;
1247
1248 #ifndef OPENSSL_NO_SCTP
1249                 /* Remember that a CCS has been received,
1250                  * so that an old key of SCTP-Auth can be
1251                  * deleted when a CCS is sent. Will be ignored
1252                  * if no SCTP is used
1253                  */
1254                 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1255 #endif
1256
1257                 goto start;
1258                 }
1259
1260         /* Unexpected handshake message (Client Hello, or protocol violation) */
1261         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 
1262                 !s->in_handshake)
1263                 {
1264                 struct hm_header_st msg_hdr;
1265                 
1266                 /* this may just be a stale retransmit */
1267                 dtls1_get_message_header(rr->data, &msg_hdr);
1268                 if( rr->epoch != s->d1->r_epoch)
1269                         {
1270                         rr->length = 0;
1271                         goto start;
1272                         }
1273
1274                 /* If we are server, we may have a repeated FINISHED of the
1275                  * client here, then retransmit our CCS and FINISHED.
1276                  */
1277                 if (msg_hdr.type == SSL3_MT_FINISHED)
1278                         {
1279                         if (dtls1_check_timeout_num(s) < 0)
1280                                 return -1;
1281
1282                         dtls1_retransmit_buffered_messages(s);
1283                         rr->length = 0;
1284                         goto start;
1285                         }
1286
1287                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1288                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1289                         {
1290 #if 0 /* worked only because C operator preferences are not as expected (and
1291        * because this is not really needed for clients except for detecting
1292        * protocol violations): */
1293                         s->state=SSL_ST_BEFORE|(s->server)
1294                                 ?SSL_ST_ACCEPT
1295                                 :SSL_ST_CONNECT;
1296 #else
1297                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1298 #endif
1299                         s->renegotiate=1;
1300                         s->new_session=1;
1301                         }
1302                 i=s->handshake_func(s);
1303                 if (i < 0) return(i);
1304                 if (i == 0)
1305                         {
1306                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1307                         return(-1);
1308                         }
1309
1310                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1311                         {
1312                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1313                                 {
1314                                 BIO *bio;
1315                                 /* In the case where we try to read application data,
1316                                  * but we trigger an SSL handshake, we return -1 with
1317                                  * the retry option set.  Otherwise renegotiation may
1318                                  * cause nasty problems in the blocking world */
1319                                 s->rwstate=SSL_READING;
1320                                 bio=SSL_get_rbio(s);
1321                                 BIO_clear_retry_flags(bio);
1322                                 BIO_set_retry_read(bio);
1323                                 return(-1);
1324                                 }
1325                         }
1326                 goto start;
1327                 }
1328
1329         switch (rr->type)
1330                 {
1331         default:
1332 #ifndef OPENSSL_NO_TLS
1333                 /* TLS just ignores unknown message types */
1334                 if (s->version == TLS1_VERSION)
1335                         {
1336                         rr->length = 0;
1337                         goto start;
1338                         }
1339 #endif
1340                 al=SSL_AD_UNEXPECTED_MESSAGE;
1341                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1342                 goto f_err;
1343         case SSL3_RT_CHANGE_CIPHER_SPEC:
1344         case SSL3_RT_ALERT:
1345         case SSL3_RT_HANDSHAKE:
1346                 /* we already handled all of these, with the possible exception
1347                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1348                  * should not happen when type != rr->type */
1349                 al=SSL_AD_UNEXPECTED_MESSAGE;
1350                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1351                 goto f_err;
1352         case SSL3_RT_APPLICATION_DATA:
1353                 /* At this point, we were expecting handshake data,
1354                  * but have application data.  If the library was
1355                  * running inside ssl3_read() (i.e. in_read_app_data
1356                  * is set) and it makes sense to read application data
1357                  * at this point (session renegotiation not yet started),
1358                  * we will indulge it.
1359                  */
1360                 if (s->s3->in_read_app_data &&
1361                         (s->s3->total_renegotiations != 0) &&
1362                         ((
1363                                 (s->state & SSL_ST_CONNECT) &&
1364                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1365                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1366                                 ) || (
1367                                         (s->state & SSL_ST_ACCEPT) &&
1368                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1369                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1370                                         )
1371                                 ))
1372                         {
1373                         s->s3->in_read_app_data=2;
1374                         return(-1);
1375                         }
1376                 else
1377                         {
1378                         al=SSL_AD_UNEXPECTED_MESSAGE;
1379                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1380                         goto f_err;
1381                         }
1382                 }
1383         /* not reached */
1384
1385 f_err:
1386         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1387 err:
1388         return(-1);
1389         }
1390
1391 int
1392 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1393         {
1394         int i;
1395
1396 #ifndef OPENSSL_NO_SCTP
1397                 /* Check if we have to continue an interrupted handshake
1398                  * for reading belated app data with SCTP.
1399                  */
1400                 if ((SSL_in_init(s) && !s->in_handshake) ||
1401                     (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1402                      (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1403 #else
1404                 if (SSL_in_init(s) && !s->in_handshake)
1405 #endif
1406                 {
1407                 i=s->handshake_func(s);
1408                 if (i < 0) return(i);
1409                 if (i == 0)
1410                         {
1411                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1412                         return -1;
1413                         }
1414                 }
1415
1416         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1417                 {
1418                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1419                         return -1;
1420                 }
1421
1422         i = dtls1_write_bytes(s, type, buf_, len);
1423         return i;
1424         }
1425
1426
1427         /* this only happens when a client hello is received and a handshake 
1428          * is started. */
1429 static int
1430 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
1431         int len, int peek)
1432         {
1433         
1434         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1435                 /* (partially) satisfy request from storage */
1436                 {
1437                 unsigned char *src = s->d1->handshake_fragment;
1438                 unsigned char *dst = buf;
1439                 unsigned int k,n;
1440                 
1441                 /* peek == 0 */
1442                 n = 0;
1443                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1444                         {
1445                         *dst++ = *src++;
1446                         len--; s->d1->handshake_fragment_len--;
1447                         n++;
1448                         }
1449                 /* move any remaining fragment bytes: */
1450                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1451                         s->d1->handshake_fragment[k] = *src++;
1452                 return n;
1453                 }
1454         
1455         return 0;
1456         }
1457
1458
1459
1460
1461 /* Call this to write data in records of type 'type'
1462  * It will return <= 0 if not all data has been sent or non-blocking IO.
1463  */
1464 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1465         {
1466         int i;
1467
1468         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1469         s->rwstate=SSL_NOTHING;
1470         i=do_dtls1_write(s, type, buf, len, 0);
1471         return i;
1472         }
1473
1474 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1475         {
1476         unsigned char *p,*pseq;
1477         int i,mac_size,clear=0;
1478         int prefix_len = 0;
1479         int eivlen;
1480         SSL3_RECORD *wr;
1481         SSL3_BUFFER *wb;
1482         SSL_SESSION *sess;
1483
1484         /* first check if there is a SSL3_BUFFER still being written
1485          * out.  This will happen with non blocking IO */
1486         if (s->s3->wbuf.left != 0)
1487                 {
1488                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1489                 return(ssl3_write_pending(s,type,buf,len));
1490                 }
1491
1492         /* If we have an alert to send, lets send it */
1493         if (s->s3->alert_dispatch)
1494                 {
1495                 i=s->method->ssl_dispatch_alert(s);
1496                 if (i <= 0)
1497                         return(i);
1498                 /* if it went, fall through and send more stuff */
1499                 }
1500
1501         if (len == 0 && !create_empty_fragment)
1502                 return 0;
1503
1504         wr= &(s->s3->wrec);
1505         wb= &(s->s3->wbuf);
1506         sess=s->session;
1507
1508         if (    (sess == NULL) ||
1509                 (s->enc_write_ctx == NULL) ||
1510                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1511                 clear=1;
1512
1513         if (clear)
1514                 mac_size=0;
1515         else
1516                 {
1517                 mac_size=EVP_MD_CTX_size(s->write_hash);
1518                 if (mac_size < 0)
1519                         goto err;
1520                 }
1521
1522         /* DTLS implements explicit IV, so no need for empty fragments */
1523 #if 0
1524         /* 'create_empty_fragment' is true only when this function calls itself */
1525         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1526             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1527                 {
1528                 /* countermeasure against known-IV weakness in CBC ciphersuites
1529                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
1530                  */
1531
1532                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1533                         {
1534                         /* recursive function call with 'create_empty_fragment' set;
1535                          * this prepares and buffers the data for an empty fragment
1536                          * (these 'prefix_len' bytes are sent out later
1537                          * together with the actual payload) */
1538                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1539                         if (prefix_len <= 0)
1540                                 goto err;
1541
1542                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1543                                 {
1544                                 /* insufficient space */
1545                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1546                                 goto err;
1547                                 }
1548                         }
1549                 
1550                 s->s3->empty_fragment_done = 1;
1551                 }
1552 #endif
1553         p = wb->buf + prefix_len;
1554
1555         /* write the header */
1556
1557         *(p++)=type&0xff;
1558         wr->type=type;
1559         /* Special case: for hello verify request, client version 1.0 and
1560          * we haven't decided which version to use yet send back using 
1561          * version 1.0 header: otherwise some clients will ignore it.
1562          */
1563         if (s->method->version == DTLS_ANY_VERSION)
1564                 {
1565                 *(p++)=DTLS1_VERSION>>8;
1566                 *(p++)=DTLS1_VERSION&0xff;
1567                 }
1568         else
1569                 {
1570                 *(p++)=s->version>>8;
1571                 *(p++)=s->version&0xff;
1572                 }
1573
1574         /* field where we are to write out packet epoch, seq num and len */
1575         pseq=p; 
1576         p+=10;
1577
1578         /* Explicit IV length, block ciphers appropriate version flag */
1579         if (s->enc_write_ctx)
1580                 {
1581                 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1582                 if (mode == EVP_CIPH_CBC_MODE)
1583                         {
1584                         eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1585                         if (eivlen <= 1)
1586                                 eivlen = 0;
1587                         }
1588                 /* Need explicit part of IV for GCM mode */
1589                 else if (mode == EVP_CIPH_GCM_MODE)
1590                         eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1591                 else
1592                         eivlen = 0;
1593                 }
1594         else 
1595                 eivlen = 0;
1596
1597         /* lets setup the record stuff. */
1598         wr->data=p + eivlen;  /* make room for IV in case of CBC */
1599         wr->length=(int)len;
1600         wr->input=(unsigned char *)buf;
1601
1602         /* we now 'read' from wr->input, wr->length bytes into
1603          * wr->data */
1604
1605         /* first we compress */
1606         if (s->compress != NULL)
1607                 {
1608                 if (!ssl3_do_compress(s))
1609                         {
1610                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1611                         goto err;
1612                         }
1613                 }
1614         else
1615                 {
1616                 memcpy(wr->data,wr->input,wr->length);
1617                 wr->input=wr->data;
1618                 }
1619
1620         /* we should still have the output to wr->data and the input
1621          * from wr->input.  Length should be wr->length.
1622          * wr->data still points in the wb->buf */
1623
1624         if (mac_size != 0)
1625                 {
1626                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
1627                         goto err;
1628                 wr->length+=mac_size;
1629                 }
1630
1631         /* this is true regardless of mac size */
1632         wr->input=p;
1633         wr->data=p;
1634
1635         if (eivlen)
1636                 wr->length += eivlen;
1637
1638         if(s->method->ssl3_enc->enc(s,1) < 1) goto err;
1639
1640         /* record length after mac and block padding */
1641 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1642         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1643         
1644         /* there's only one epoch between handshake and app data */
1645         
1646         s2n(s->d1->w_epoch, pseq);
1647
1648         /* XDTLS: ?? */
1649 /*      else
1650         s2n(s->d1->handshake_epoch, pseq); */
1651
1652         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1653         pseq+=6;
1654         s2n(wr->length,pseq);
1655
1656         if (s->msg_callback)
1657                 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1658
1659         /* we should now have
1660          * wr->data pointing to the encrypted data, which is
1661          * wr->length long */
1662         wr->type=type; /* not needed but helps for debugging */
1663         wr->length+=DTLS1_RT_HEADER_LENGTH;
1664
1665 #if 0  /* this is now done at the message layer */
1666         /* buffer the record, making it easy to handle retransmits */
1667         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1668                 dtls1_buffer_record(s, wr->data, wr->length, 
1669                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1670 #endif
1671
1672         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1673
1674         if (create_empty_fragment)
1675                 {
1676                 /* we are in a recursive call;
1677                  * just return the length, don't write out anything here
1678                  */
1679                 return wr->length;
1680                 }
1681
1682         /* now let's set up wb */
1683         wb->left = prefix_len + wr->length;
1684         wb->offset = 0;
1685
1686         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1687         s->s3->wpend_tot=len;
1688         s->s3->wpend_buf=buf;
1689         s->s3->wpend_type=type;
1690         s->s3->wpend_ret=len;
1691
1692         /* we now just need to write the buffer */
1693         return ssl3_write_pending(s,type,buf,len);
1694 err:
1695         return -1;
1696         }
1697
1698
1699
1700 static int dtls1_record_replay_check(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                 memcpy (s->s3->rrec.seq_num,seq,8);
1710                 return 1; /* this record in new */
1711                 }
1712         shift = -cmp;
1713         if (shift >= sizeof(bitmap->map)*8)
1714                 return 0; /* stale, outside the window */
1715         else if (bitmap->map & (1UL<<shift))
1716                 return 0; /* record previously received */
1717
1718         memcpy (s->s3->rrec.seq_num,seq,8);
1719         return 1;
1720         }
1721
1722
1723 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1724         {
1725         int cmp;
1726         unsigned int shift;
1727         const unsigned char *seq = s->s3->read_sequence;
1728
1729         cmp = satsub64be(seq,bitmap->max_seq_num);
1730         if (cmp > 0)
1731                 {
1732                 shift = cmp;
1733                 if (shift < sizeof(bitmap->map)*8)
1734                         bitmap->map <<= shift, bitmap->map |= 1UL;
1735                 else
1736                         bitmap->map = 1UL;
1737                 memcpy(bitmap->max_seq_num,seq,8);
1738                 }
1739         else    {
1740                 shift = -cmp;
1741                 if (shift < sizeof(bitmap->map)*8)
1742                         bitmap->map |= 1UL<<shift;
1743                 }
1744         }
1745
1746
1747 int dtls1_dispatch_alert(SSL *s)
1748         {
1749         int i,j;
1750         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1751         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1752         unsigned char *ptr = &buf[0];
1753
1754         s->s3->alert_dispatch=0;
1755
1756         memset(buf, 0x00, sizeof(buf));
1757         *ptr++ = s->s3->send_alert[0];
1758         *ptr++ = s->s3->send_alert[1];
1759
1760 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1761         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1762                 {       
1763                 s2n(s->d1->handshake_read_seq, ptr);
1764 #if 0
1765                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1766
1767                 else
1768                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1769 #endif
1770
1771 #if 0
1772                 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);
1773 #endif
1774                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1775                 }
1776 #endif
1777
1778         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1779         if (i <= 0)
1780                 {
1781                 s->s3->alert_dispatch=1;
1782                 /* fprintf( stderr, "not done with alert\n" ); */
1783                 }
1784         else
1785                 {
1786                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1787 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1788                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1789 #endif
1790                     )
1791                         (void)BIO_flush(s->wbio);
1792
1793                 if (s->msg_callback)
1794                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 
1795                                 2, s, s->msg_callback_arg);
1796
1797                 if (s->info_callback != NULL)
1798                         cb=s->info_callback;
1799                 else if (s->ctx->info_callback != NULL)
1800                         cb=s->ctx->info_callback;
1801
1802                 if (cb != NULL)
1803                         {
1804                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1805                         cb(s,SSL_CB_WRITE_ALERT,j);
1806                         }
1807                 }
1808         return(i);
1809         }
1810
1811
1812 static DTLS1_BITMAP *
1813 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1814     {
1815     
1816     *is_next_epoch = 0;
1817
1818     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1819     if (rr->epoch == s->d1->r_epoch)
1820         return &s->d1->bitmap;
1821
1822     /* Only HM and ALERT messages can be from the next epoch */
1823     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1824         (rr->type == SSL3_RT_HANDSHAKE ||
1825             rr->type == SSL3_RT_ALERT))
1826         {
1827         *is_next_epoch = 1;
1828         return &s->d1->next_bitmap;
1829         }
1830
1831     return NULL;
1832     }
1833
1834 #if 0
1835 static int
1836 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1837         unsigned long *offset)
1838         {
1839
1840         /* alerts are passed up immediately */
1841         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1842                 rr->type == SSL3_RT_ALERT)
1843                 return 0;
1844
1845         /* Only need to buffer if a handshake is underway.
1846          * (this implies that Hello Request and Client Hello are passed up
1847          * immediately) */
1848         if ( SSL_in_init(s))
1849                 {
1850                 unsigned char *data = rr->data;
1851                 /* need to extract the HM/CCS sequence number here */
1852                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1853                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1854                         {
1855                         unsigned short seq_num;
1856                         struct hm_header_st msg_hdr;
1857                         struct ccs_header_st ccs_hdr;
1858
1859                         if ( rr->type == SSL3_RT_HANDSHAKE)
1860                                 {
1861                                 dtls1_get_message_header(data, &msg_hdr);
1862                                 seq_num = msg_hdr.seq;
1863                                 *offset = msg_hdr.frag_off;
1864                                 }
1865                         else
1866                                 {
1867                                 dtls1_get_ccs_header(data, &ccs_hdr);
1868                                 seq_num = ccs_hdr.seq;
1869                                 *offset = 0;
1870                                 }
1871                                 
1872                         /* this is either a record we're waiting for, or a
1873                          * retransmit of something we happened to previously 
1874                          * receive (higher layers will drop the repeat silently */
1875                         if ( seq_num < s->d1->handshake_read_seq)
1876                                 return 0;
1877                         if (rr->type == SSL3_RT_HANDSHAKE && 
1878                                 seq_num == s->d1->handshake_read_seq &&
1879                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1880                                 return 0;
1881                         else if ( seq_num == s->d1->handshake_read_seq &&
1882                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1883                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1884                                 return 0;
1885                         else
1886                                 {
1887                                 *priority = seq_num;
1888                                 return 1;
1889                                 }
1890                         }
1891                 else /* unknown record type */
1892                         return 0;
1893                 }
1894
1895         return 0;
1896         }
1897 #endif
1898
1899 void
1900 dtls1_reset_seq_numbers(SSL *s, int rw)
1901         {
1902         unsigned char *seq;
1903         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1904
1905         if ( rw & SSL3_CC_READ)
1906                 {
1907                 seq = s->s3->read_sequence;
1908                 s->d1->r_epoch++;
1909                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1910                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1911                 }
1912         else
1913                 {
1914                 seq = s->s3->write_sequence;
1915                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1916                 s->d1->w_epoch++;
1917                 }
1918
1919         memset(seq, 0x00, seq_bytes);
1920         }