355d5ed9cdcbeedc59bbe83855cb02a77cbccecf
[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 static void dtls1_clear_timeouts(SSL *s);
183
184 /* copy buffered record into SSL structure */
185 static int
186 dtls1_copy_record(SSL *s, pitem *item)
187     {
188     DTLS1_RECORD_DATA *rdata;
189
190     rdata = (DTLS1_RECORD_DATA *)item->data;
191     
192     if (s->s3->rbuf.buf != NULL)
193         OPENSSL_free(s->s3->rbuf.buf);
194     
195     s->packet = rdata->packet;
196     s->packet_length = rdata->packet_length;
197     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
198     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
199     
200     return(1);
201     }
202
203
204 static int
205 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
206         {
207         DTLS1_RECORD_DATA *rdata;
208         pitem *item;
209
210         /* Limit the size of the queue to prevent DOS attacks */
211         if (pqueue_size(queue->q) >= 100)
212                 return 0;
213                 
214         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
215         item = pitem_new(priority, rdata);
216         if (rdata == NULL || item == NULL)
217                 {
218                 if (rdata != NULL) OPENSSL_free(rdata);
219                 if (item != NULL) pitem_free(item);
220                 
221                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
222                 return(0);
223                 }
224         
225         rdata->packet = s->packet;
226         rdata->packet_length = s->packet_length;
227         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
228         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
229
230         item->data = rdata;
231
232         /* insert should not fail, since duplicates are dropped */
233         if (pqueue_insert(queue->q, item) == NULL)
234                 {
235                 OPENSSL_free(rdata);
236                 pitem_free(item);
237                 return(0);
238                 }
239
240         s->packet = NULL;
241         s->packet_length = 0;
242         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
243         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
244         
245         if (!ssl3_setup_buffers(s))
246                 {
247                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
248                 OPENSSL_free(rdata);
249                 pitem_free(item);
250                 return(0);
251                 }
252         
253         return(1);
254         }
255
256
257 static int
258 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
259     {
260     pitem *item;
261
262     item = pqueue_pop(queue->q);
263     if (item)
264         {
265         dtls1_copy_record(s, item);
266
267         OPENSSL_free(item->data);
268                 pitem_free(item);
269
270         return(1);
271         }
272
273     return(0);
274     }
275
276
277 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 
278  * yet */
279 #define dtls1_get_unprocessed_record(s) \
280                    dtls1_retrieve_buffered_record((s), \
281                    &((s)->d1->unprocessed_rcds))
282
283 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
284 #define dtls1_get_processed_record(s) \
285                    dtls1_retrieve_buffered_record((s), \
286                    &((s)->d1->processed_rcds))
287
288 static int
289 dtls1_process_buffered_records(SSL *s)
290     {
291     pitem *item;
292     
293     item = pqueue_peek(s->d1->unprocessed_rcds.q);
294     if (item)
295         {
296         DTLS1_RECORD_DATA *rdata;
297         rdata = (DTLS1_RECORD_DATA *)item->data;
298         
299         /* Check if epoch is current. */
300         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
301             return(1);  /* Nothing to do. */
302         
303         /* Process all the records. */
304         while (pqueue_peek(s->d1->unprocessed_rcds.q))
305             {
306             dtls1_get_unprocessed_record(s);
307             if ( ! dtls1_process_record(s))
308                 return(0);
309             dtls1_buffer_record(s, &(s->d1->processed_rcds), 
310                 s->s3->rrec.seq_num);
311             }
312         }
313
314     /* sync epoch numbers once all the unprocessed records 
315      * have been processed */
316     s->d1->processed_rcds.epoch = s->d1->r_epoch;
317     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
318
319     return(1);
320     }
321
322
323 #if 0
324
325 static int
326 dtls1_get_buffered_record(SSL *s)
327         {
328         pitem *item;
329         PQ_64BIT priority = 
330                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 
331                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
332         
333         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating, 
334                                                            nothing buffered */
335                 return 0;
336
337
338         item = pqueue_peek(s->d1->rcvd_records);
339         if (item && item->priority == priority)
340                 {
341                 /* Check if we've received the record of interest.  It must be
342                  * a handshake record, since data records as passed up without
343                  * buffering */
344                 DTLS1_RECORD_DATA *rdata;
345                 item = pqueue_pop(s->d1->rcvd_records);
346                 rdata = (DTLS1_RECORD_DATA *)item->data;
347                 
348                 if (s->s3->rbuf.buf != NULL)
349                         OPENSSL_free(s->s3->rbuf.buf);
350                 
351                 s->packet = rdata->packet;
352                 s->packet_length = rdata->packet_length;
353                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
354                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
355                 
356                 OPENSSL_free(item->data);
357                 pitem_free(item);
358                 
359                 /* s->d1->next_expected_seq_num++; */
360                 return(1);
361                 }
362         
363         return 0;
364         }
365
366 #endif
367
368 static int
369 dtls1_process_record(SSL *s)
370 {
371         int i,al;
372         int clear=0;
373         int enc_err;
374         SSL_SESSION *sess;
375         SSL3_RECORD *rr;
376         unsigned int mac_size;
377         unsigned char md[EVP_MAX_MD_SIZE];
378
379
380         rr= &(s->s3->rrec);
381         sess = s->session;
382
383         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
384          * and we have that many bytes in s->packet
385          */
386         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
387
388         /* ok, we can now read from 's->packet' data into 'rr'
389          * rr->input points at rr->length bytes, which
390          * need to be copied into rr->data by either
391          * the decryption or by the decompression
392          * When the data is 'copied' into the rr->data buffer,
393          * rr->input will be pointed at the new buffer */ 
394
395         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
396          * rr->length bytes of encrypted compressed stuff. */
397
398         /* check is not needed I believe */
399         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
400                 {
401                 al=SSL_AD_RECORD_OVERFLOW;
402                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
403                 goto f_err;
404                 }
405
406         /* decrypt in place in 'rr->input' */
407         rr->data=rr->input;
408
409         enc_err = s->method->ssl3_enc->enc(s,0);
410         if (enc_err <= 0)
411                 {
412                 if (enc_err == 0)
413                         /* SSLerr() and ssl3_send_alert() have been called */
414                         goto err;
415
416                 /* otherwise enc_err == -1 */
417                 goto decryption_failed_or_bad_record_mac;
418                 }
419
420 #ifdef TLS_DEBUG
421 printf("dec %d\n",rr->length);
422 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
423 printf("\n");
424 #endif
425
426         /* r->length is now the compressed data plus mac */
427         if (    (sess == NULL) ||
428                 (s->enc_read_ctx == NULL) ||
429                 (s->read_hash == NULL))
430                 clear=1;
431
432         if (!clear)
433                 {
434                 /* !clear => s->read_hash != NULL => mac_size != -1 */
435                 int t;
436                 t=EVP_MD_CTX_size(s->read_hash);
437                 OPENSSL_assert(t >= 0);
438                 mac_size=t;
439
440                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
441                         {
442 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
443                         al=SSL_AD_RECORD_OVERFLOW;
444                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
445                         goto f_err;
446 #else
447                         goto decryption_failed_or_bad_record_mac;
448 #endif                  
449                         }
450                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
451                 if (rr->length < mac_size)
452                         {
453 #if 0 /* OK only for stream ciphers */
454                         al=SSL_AD_DECODE_ERROR;
455                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
456                         goto f_err;
457 #else
458                         goto decryption_failed_or_bad_record_mac;
459 #endif
460                         }
461                 rr->length-=mac_size;
462                 i=s->method->ssl3_enc->mac(s,md,0);
463                 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
464                         {
465                         goto decryption_failed_or_bad_record_mac;
466                         }
467                 }
468
469         /* r->length is now just compressed */
470         if (s->expand != NULL)
471                 {
472                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
473                         {
474                         al=SSL_AD_RECORD_OVERFLOW;
475                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
476                         goto f_err;
477                         }
478                 if (!ssl3_do_uncompress(s))
479                         {
480                         al=SSL_AD_DECOMPRESSION_FAILURE;
481                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
482                         goto f_err;
483                         }
484                 }
485
486         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
487                 {
488                 al=SSL_AD_RECORD_OVERFLOW;
489                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
490                 goto f_err;
491                 }
492
493         rr->off=0;
494         /* So at this point the following is true
495          * ssl->s3->rrec.type   is the type of record
496          * ssl->s3->rrec.length == number of bytes in record
497          * ssl->s3->rrec.off    == offset to first valid byte
498          * ssl->s3->rrec.data   == where to take bytes from, increment
499          *                         after use :-).
500          */
501
502         /* we have pulled in a full packet so zero things */
503         s->packet_length=0;
504         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
505         return(1);
506
507 decryption_failed_or_bad_record_mac:
508         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
509          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
510          * failure is directly visible from the ciphertext anyway,
511          * we should not reveal which kind of error occured -- this
512          * might become visible to an attacker (e.g. via logfile) */
513         al=SSL_AD_BAD_RECORD_MAC;
514         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
515 f_err:
516         ssl3_send_alert(s,SSL3_AL_FATAL,al);
517 err:
518         return(0);
519 }
520
521
522 /* Call this to get a new input record.
523  * It will return <= 0 if more data is needed, normally due to an error
524  * or non-blocking IO.
525  * When it finishes, one packet has been decoded and can be found in
526  * ssl->s3->rrec.type    - is the type of record
527  * ssl->s3->rrec.data,   - data
528  * ssl->s3->rrec.length, - number of bytes
529  */
530 /* used only by dtls1_read_bytes */
531 int dtls1_get_record(SSL *s)
532         {
533         int ssl_major,ssl_minor;
534         int i,n;
535         SSL3_RECORD *rr;
536         SSL_SESSION *sess;
537         unsigned char *p;
538         unsigned short version;
539         DTLS1_BITMAP *bitmap;
540         unsigned int is_next_epoch;
541
542         rr= &(s->s3->rrec);
543         sess=s->session;
544
545         /* The epoch may have changed.  If so, process all the
546          * pending records.  This is a non-blocking operation. */
547         if ( ! dtls1_process_buffered_records(s))
548             return 0;
549
550         /* if we're renegotiating, then there may be buffered records */
551         if (dtls1_get_processed_record(s))
552                 return 1;
553
554         /* get something from the wire */
555 again:
556         /* check if we have the header */
557         if (    (s->rstate != SSL_ST_READ_BODY) ||
558                 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 
559                 {
560                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
561                 /* read timeout is handled by dtls1_read_bytes */
562                 if (n <= 0) return(n); /* error or non-blocking */
563
564                 /* this packet contained a partial record, dump it */
565                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
566                         {
567                         s->packet_length = 0;
568                         goto again;
569                         }
570
571                 s->rstate=SSL_ST_READ_BODY;
572
573                 p=s->packet;
574
575                 /* Pull apart the header into the DTLS1_RECORD */
576                 rr->type= *(p++);
577                 ssl_major= *(p++);
578                 ssl_minor= *(p++);
579                 version=(ssl_major<<8)|ssl_minor;
580
581                 /* sequence number is 64 bits, with top 2 bytes = epoch */ 
582                 n2s(p,rr->epoch);
583
584                 memcpy(&(s->s3->read_sequence[2]), p, 6);
585                 p+=6;
586
587                 n2s(p,rr->length);
588
589                 /* Lets check version */
590                 if (!s->first_packet)
591                         {
592                         if (version != s->version)
593                                 {
594                                 /* unexpected version, silently discard */
595                                 rr->length = 0;
596                                 s->packet_length = 0;
597                                 goto again;
598                                 }
599                         }
600
601                 if ((version & 0xff00) != (s->version & 0xff00))
602                         {
603                         /* wrong version, silently discard record */
604                         rr->length = 0;
605                         s->packet_length = 0;
606                         goto again;
607                         }
608
609                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
610                         {
611                         /* record too long, silently discard it */
612                         rr->length = 0;
613                         s->packet_length = 0;
614                         goto again;
615                         }
616
617                 /* now s->rstate == SSL_ST_READ_BODY */
618                 }
619
620         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
621
622         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
623                 {
624                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
625                 i=rr->length;
626                 n=ssl3_read_n(s,i,i,1);
627                 if (n <= 0) return(n); /* error or non-blocking io */
628
629                 /* this packet contained a partial record, dump it */
630                 if ( n != i)
631                         {
632                         rr->length = 0;
633                         s->packet_length = 0;
634                         goto again;
635                         }
636
637                 /* now n == rr->length,
638                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
639                 }
640         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
641
642         /* match epochs.  NULL means the packet is dropped on the floor */
643         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
644         if ( bitmap == NULL)
645                 {
646                 rr->length = 0;
647                 s->packet_length = 0;  /* dump this record */
648                 goto again;   /* get another record */
649                 }
650
651         /* check whether this is a repeat, or aged record */
652         if ( ! dtls1_record_replay_check(s, bitmap))
653                 {
654                 rr->length = 0;
655                 s->packet_length=0; /* dump this record */
656                 goto again;     /* get another record */
657                 }
658
659         /* just read a 0 length packet */
660         if (rr->length == 0) goto again;
661
662         /* If this record is from the next epoch (either HM or ALERT),
663          * buffer it since it cannot be processed at this time. Records
664          * from the next epoch are marked as received even though they
665          * are not processed, so as to prevent any potential resource
666          * DoS attack */
667         if (is_next_epoch)
668                 {
669                 dtls1_record_bitmap_update(s, bitmap);
670                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
671                 rr->length = 0;
672                 s->packet_length = 0;
673                 goto again;
674                 }
675
676         if ( ! dtls1_process_record(s))
677                 return(0);
678
679         dtls1_clear_timeouts(s);  /* done waiting */
680         return(1);
681
682         }
683
684 /* Return up to 'len' payload bytes received in 'type' records.
685  * 'type' is one of the following:
686  *
687  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
688  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
689  *   -  0 (during a shutdown, no data has to be returned)
690  *
691  * If we don't have stored data to work from, read a SSL/TLS record first
692  * (possibly multiple records if we still don't have anything to return).
693  *
694  * This function must handle any surprises the peer may have for us, such as
695  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
696  * a surprise, but handled as if it were), or renegotiation requests.
697  * Also if record payloads contain fragments too small to process, we store
698  * them until there is enough for the respective protocol (the record protocol
699  * may use arbitrary fragmentation and even interleaving):
700  *     Change cipher spec protocol
701  *             just 1 byte needed, no need for keeping anything stored
702  *     Alert protocol
703  *             2 bytes needed (AlertLevel, AlertDescription)
704  *     Handshake protocol
705  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
706  *             to detect unexpected Client Hello and Hello Request messages
707  *             here, anything else is handled by higher layers
708  *     Application data protocol
709  *             none of our business
710  */
711 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
712         {
713         int al,i,j,ret;
714         unsigned int n;
715         SSL3_RECORD *rr;
716         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
717
718         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
719                 if (!ssl3_setup_buffers(s))
720                         return(-1);
721
722     /* XXX: check what the second '&& type' is about */
723         if ((type && (type != SSL3_RT_APPLICATION_DATA) && 
724                 (type != SSL3_RT_HANDSHAKE) && type) ||
725             (peek && (type != SSL3_RT_APPLICATION_DATA)))
726                 {
727                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
728                 return -1;
729                 }
730
731         /* check whether there's a handshake message (client hello?) waiting */
732         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
733                 return ret;
734
735         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
736
737         if (!s->in_handshake && SSL_in_init(s))
738                 {
739                 /* type == SSL3_RT_APPLICATION_DATA */
740                 i=s->handshake_func(s);
741                 if (i < 0) return(i);
742                 if (i == 0)
743                         {
744                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
745                         return(-1);
746                         }
747                 }
748
749 start:
750         s->rwstate=SSL_NOTHING;
751
752         /* s->s3->rrec.type         - is the type of record
753          * s->s3->rrec.data,    - data
754          * s->s3->rrec.off,     - offset into 'data' for next read
755          * s->s3->rrec.length,  - number of bytes. */
756         rr = &(s->s3->rrec);
757
758         /* We are not handshaking and have no data yet,
759          * so process data buffered during the last handshake
760          * in advance, if any.
761          */
762         if (s->state == SSL_ST_OK && rr->length == 0)
763                 {
764                 pitem *item;
765                 item = pqueue_pop(s->d1->buffered_app_data.q);
766                 if (item)
767                         {
768                         dtls1_copy_record(s, item);
769
770                         OPENSSL_free(item->data);
771                         pitem_free(item);
772                         }
773                 }
774
775         /* Check for timeout */
776         if (dtls1_handle_timeout(s) > 0)
777                 goto start;
778
779         /* get new packet if necessary */
780         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
781                 {
782                 ret=dtls1_get_record(s);
783                 if (ret <= 0) 
784                         {
785                         ret = dtls1_read_failed(s, ret);
786                         /* anything other than a timeout is an error */
787                         if (ret <= 0)  
788                                 return(ret);
789                         else
790                                 goto start;
791                         }
792                 }
793
794         /* we now have a packet which can be read and processed */
795
796         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
797                                        * reset by ssl3_get_finished */
798                 && (rr->type != SSL3_RT_HANDSHAKE))
799                 {
800                 /* We now have application data between CCS and Finished.
801                  * Most likely the packets were reordered on their way, so
802                  * buffer the application data for later processing rather
803                  * than dropping the connection.
804                  */
805                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), 0);
806                 rr->length = 0;
807                 goto start;
808                 }
809
810         /* If the other end has shut down, throw anything we read away
811          * (even in 'peek' mode) */
812         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
813                 {
814                 rr->length=0;
815                 s->rwstate=SSL_NOTHING;
816                 return(0);
817                 }
818
819
820         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
821                 {
822                 /* make sure that we are not getting application data when we
823                  * are doing a handshake for the first time */
824                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
825                         (s->enc_read_ctx == NULL))
826                         {
827                         al=SSL_AD_UNEXPECTED_MESSAGE;
828                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
829                         goto f_err;
830                         }
831
832                 if (len <= 0) return(len);
833
834                 if ((unsigned int)len > rr->length)
835                         n = rr->length;
836                 else
837                         n = (unsigned int)len;
838
839                 memcpy(buf,&(rr->data[rr->off]),n);
840                 if (!peek)
841                         {
842                         rr->length-=n;
843                         rr->off+=n;
844                         if (rr->length == 0)
845                                 {
846                                 s->rstate=SSL_ST_READ_HEADER;
847                                 rr->off=0;
848                                 }
849                         }
850                 return(n);
851                 }
852
853
854         /* If we get here, then type != rr->type; if we have a handshake
855          * message, then it was unexpected (Hello Request or Client Hello). */
856
857         /* In case of record types for which we have 'fragment' storage,
858          * fill that so that we can process the data at a fixed place.
859          */
860                 {
861                 unsigned int k, dest_maxlen = 0;
862                 unsigned char *dest = NULL;
863                 unsigned int *dest_len = NULL;
864
865                 if (rr->type == SSL3_RT_HANDSHAKE)
866                         {
867                         dest_maxlen = sizeof s->d1->handshake_fragment;
868                         dest = s->d1->handshake_fragment;
869                         dest_len = &s->d1->handshake_fragment_len;
870                         }
871                 else if (rr->type == SSL3_RT_ALERT)
872                         {
873                         dest_maxlen = sizeof(s->d1->alert_fragment);
874                         dest = s->d1->alert_fragment;
875                         dest_len = &s->d1->alert_fragment_len;
876                         }
877                 /* else it's a CCS message, or application data or wrong */
878                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
879                         {
880                         /* Application data while renegotiating
881                          * is allowed. Try again reading.
882                          */
883                         if (rr->type == SSL3_RT_APPLICATION_DATA)
884                                 {
885                                 BIO *bio;
886                                 s->s3->in_read_app_data=2;
887                                 bio=SSL_get_rbio(s);
888                                 s->rwstate=SSL_READING;
889                                 BIO_clear_retry_flags(bio);
890                                 BIO_set_retry_read(bio);
891                                 return(-1);
892                                 }
893
894                         /* Not certain if this is the right error handling */
895                         al=SSL_AD_UNEXPECTED_MESSAGE;
896                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
897                         goto f_err;
898                         }
899
900                 if (dest_maxlen > 0)
901                         {
902             /* XDTLS:  In a pathalogical case, the Client Hello
903              *  may be fragmented--don't always expect dest_maxlen bytes */
904                         if ( rr->length < dest_maxlen)
905                                 {
906 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
907                                 /*
908                                  * for normal alerts rr->length is 2, while
909                                  * dest_maxlen is 7 if we were to handle this
910                                  * non-existing alert...
911                                  */
912                                 FIX ME
913 #endif
914                                 s->rstate=SSL_ST_READ_HEADER;
915                                 rr->length = 0;
916                                 goto start;
917                                 }
918
919                         /* now move 'n' bytes: */
920                         for ( k = 0; k < dest_maxlen; k++)
921                                 {
922                                 dest[k] = rr->data[rr->off++];
923                                 rr->length--;
924                                 }
925                         *dest_len = dest_maxlen;
926                         }
927                 }
928
929         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
930          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
931          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
932
933         /* If we are a client, check for an incoming 'Hello Request': */
934         if ((!s->server) &&
935                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
936                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
937                 (s->session != NULL) && (s->session->cipher != NULL))
938                 {
939                 s->d1->handshake_fragment_len = 0;
940
941                 if ((s->d1->handshake_fragment[1] != 0) ||
942                         (s->d1->handshake_fragment[2] != 0) ||
943                         (s->d1->handshake_fragment[3] != 0))
944                         {
945                         al=SSL_AD_DECODE_ERROR;
946                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
947                         goto err;
948                         }
949
950                 /* no need to check sequence number on HELLO REQUEST messages */
951
952                 if (s->msg_callback)
953                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
954                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
955
956                 if (SSL_is_init_finished(s) &&
957                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
958                         !s->s3->renegotiate)
959                         {
960                         ssl3_renegotiate(s);
961                         if (ssl3_renegotiate_check(s))
962                                 {
963                                 i=s->handshake_func(s);
964                                 if (i < 0) return(i);
965                                 if (i == 0)
966                                         {
967                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
968                                         return(-1);
969                                         }
970
971                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
972                                         {
973                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
974                                                 {
975                                                 BIO *bio;
976                                                 /* In the case where we try to read application data,
977                                                  * but we trigger an SSL handshake, we return -1 with
978                                                  * the retry option set.  Otherwise renegotiation may
979                                                  * cause nasty problems in the blocking world */
980                                                 s->rwstate=SSL_READING;
981                                                 bio=SSL_get_rbio(s);
982                                                 BIO_clear_retry_flags(bio);
983                                                 BIO_set_retry_read(bio);
984                                                 return(-1);
985                                                 }
986                                         }
987                                 }
988                         }
989                 /* we either finished a handshake or ignored the request,
990                  * now try again to obtain the (application) data we were asked for */
991                 goto start;
992                 }
993
994         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
995                 {
996                 int alert_level = s->d1->alert_fragment[0];
997                 int alert_descr = s->d1->alert_fragment[1];
998
999                 s->d1->alert_fragment_len = 0;
1000
1001                 if (s->msg_callback)
1002                         s->msg_callback(0, s->version, SSL3_RT_ALERT, 
1003                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1004
1005                 if (s->info_callback != NULL)
1006                         cb=s->info_callback;
1007                 else if (s->ctx->info_callback != NULL)
1008                         cb=s->ctx->info_callback;
1009
1010                 if (cb != NULL)
1011                         {
1012                         j = (alert_level << 8) | alert_descr;
1013                         cb(s, SSL_CB_READ_ALERT, j);
1014                         }
1015
1016                 if (alert_level == 1) /* warning */
1017                         {
1018                         s->s3->warn_alert = alert_descr;
1019                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1020                                 {
1021                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1022                                 return(0);
1023                                 }
1024 #if 0
1025             /* XXX: this is a possible improvement in the future */
1026                         /* now check if it's a missing record */
1027                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1028                                 {
1029                                 unsigned short seq;
1030                                 unsigned int frag_off;
1031                                 unsigned char *p = &(s->d1->alert_fragment[2]);
1032
1033                                 n2s(p, seq);
1034                                 n2l3(p, frag_off);
1035
1036                                 dtls1_retransmit_message(s,
1037                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1038                                                                                  frag_off, &found);
1039                                 if ( ! found  && SSL_in_init(s))
1040                                         {
1041                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1042                                         /* requested a message not yet sent, 
1043                                            send an alert ourselves */
1044                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1045                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1046                                         }
1047                                 }
1048 #endif
1049                         }
1050                 else if (alert_level == 2) /* fatal */
1051                         {
1052                         char tmp[16];
1053
1054                         s->rwstate=SSL_NOTHING;
1055                         s->s3->fatal_alert = alert_descr;
1056                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1057                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1058                         ERR_add_error_data(2,"SSL alert number ",tmp);
1059                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1060                         SSL_CTX_remove_session(s->ctx,s->session);
1061                         return(0);
1062                         }
1063                 else
1064                         {
1065                         al=SSL_AD_ILLEGAL_PARAMETER;
1066                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1067                         goto f_err;
1068                         }
1069
1070                 goto start;
1071                 }
1072
1073         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1074                 {
1075                 s->rwstate=SSL_NOTHING;
1076                 rr->length=0;
1077                 return(0);
1078                 }
1079
1080         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1081                 {
1082                 struct ccs_header_st ccs_hdr;
1083                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1084
1085                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1086
1087                 if (s->version == DTLS1_BAD_VER)
1088                         ccs_hdr_len = 3;
1089
1090                 /* 'Change Cipher Spec' is just a single byte, so we know
1091                  * exactly what the record payload has to look like */
1092                 /* XDTLS: check that epoch is consistent */
1093                 if (    (rr->length != ccs_hdr_len) || 
1094                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1095                         {
1096                         i=SSL_AD_ILLEGAL_PARAMETER;
1097                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1098                         goto err;
1099                         }
1100
1101                 rr->length=0;
1102
1103                 if (s->msg_callback)
1104                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
1105                                 rr->data, 1, s, s->msg_callback_arg);
1106
1107                 /* We can't process a CCS now, because previous handshake
1108                  * messages are still missing, so just drop it.
1109                  */
1110                 if (!s->d1->change_cipher_spec_ok)
1111                         {
1112                         goto start;
1113                         }
1114
1115                 s->d1->change_cipher_spec_ok = 0;
1116
1117                 s->s3->change_cipher_spec=1;
1118                 if (!ssl3_do_change_cipher_spec(s))
1119                         goto err;
1120
1121                 /* do this whenever CCS is processed */
1122                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1123
1124                 if (s->version == DTLS1_BAD_VER)
1125                         s->d1->handshake_read_seq++;
1126
1127                 goto start;
1128                 }
1129
1130         /* Unexpected handshake message (Client Hello, or protocol violation) */
1131         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 
1132                 !s->in_handshake)
1133                 {
1134                 struct hm_header_st msg_hdr;
1135                 
1136                 /* this may just be a stale retransmit */
1137                 dtls1_get_message_header(rr->data, &msg_hdr);
1138                 if( rr->epoch != s->d1->r_epoch)
1139                         {
1140                         rr->length = 0;
1141                         goto start;
1142                         }
1143
1144                 /* If we are server, we may have a repeated FINISHED of the
1145                  * client here, then retransmit our CCS and FINISHED.
1146                  */
1147                 if (msg_hdr.type == SSL3_MT_FINISHED)
1148                         {
1149                         dtls1_retransmit_buffered_messages(s);
1150                         rr->length = 0;
1151                         goto start;
1152                         }
1153
1154                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1155                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1156                         {
1157 #if 0 /* worked only because C operator preferences are not as expected (and
1158        * because this is not really needed for clients except for detecting
1159        * protocol violations): */
1160                         s->state=SSL_ST_BEFORE|(s->server)
1161                                 ?SSL_ST_ACCEPT
1162                                 :SSL_ST_CONNECT;
1163 #else
1164                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1165 #endif
1166                         s->new_session=1;
1167                         }
1168                 i=s->handshake_func(s);
1169                 if (i < 0) return(i);
1170                 if (i == 0)
1171                         {
1172                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1173                         return(-1);
1174                         }
1175
1176                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1177                         {
1178                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1179                                 {
1180                                 BIO *bio;
1181                                 /* In the case where we try to read application data,
1182                                  * but we trigger an SSL handshake, we return -1 with
1183                                  * the retry option set.  Otherwise renegotiation may
1184                                  * cause nasty problems in the blocking world */
1185                                 s->rwstate=SSL_READING;
1186                                 bio=SSL_get_rbio(s);
1187                                 BIO_clear_retry_flags(bio);
1188                                 BIO_set_retry_read(bio);
1189                                 return(-1);
1190                                 }
1191                         }
1192                 goto start;
1193                 }
1194
1195         switch (rr->type)
1196                 {
1197         default:
1198 #ifndef OPENSSL_NO_TLS
1199                 /* TLS just ignores unknown message types */
1200                 if (s->version == TLS1_VERSION)
1201                         {
1202                         rr->length = 0;
1203                         goto start;
1204                         }
1205 #endif
1206                 al=SSL_AD_UNEXPECTED_MESSAGE;
1207                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1208                 goto f_err;
1209         case SSL3_RT_CHANGE_CIPHER_SPEC:
1210         case SSL3_RT_ALERT:
1211         case SSL3_RT_HANDSHAKE:
1212                 /* we already handled all of these, with the possible exception
1213                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1214                  * should not happen when type != rr->type */
1215                 al=SSL_AD_UNEXPECTED_MESSAGE;
1216                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1217                 goto f_err;
1218         case SSL3_RT_APPLICATION_DATA:
1219                 /* At this point, we were expecting handshake data,
1220                  * but have application data.  If the library was
1221                  * running inside ssl3_read() (i.e. in_read_app_data
1222                  * is set) and it makes sense to read application data
1223                  * at this point (session renegotiation not yet started),
1224                  * we will indulge it.
1225                  */
1226                 if (s->s3->in_read_app_data &&
1227                         (s->s3->total_renegotiations != 0) &&
1228                         ((
1229                                 (s->state & SSL_ST_CONNECT) &&
1230                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1231                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1232                                 ) || (
1233                                         (s->state & SSL_ST_ACCEPT) &&
1234                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1235                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1236                                         )
1237                                 ))
1238                         {
1239                         s->s3->in_read_app_data=2;
1240                         return(-1);
1241                         }
1242                 else
1243                         {
1244                         al=SSL_AD_UNEXPECTED_MESSAGE;
1245                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1246                         goto f_err;
1247                         }
1248                 }
1249         /* not reached */
1250
1251 f_err:
1252         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1253 err:
1254         return(-1);
1255         }
1256
1257 int
1258 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1259         {
1260         int i;
1261
1262         if (SSL_in_init(s) && !s->in_handshake)
1263                 {
1264                 i=s->handshake_func(s);
1265                 if (i < 0) return(i);
1266                 if (i == 0)
1267                         {
1268                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1269                         return -1;
1270                         }
1271                 }
1272
1273         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1274                 {
1275                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1276                         return -1;
1277                 }
1278
1279         i = dtls1_write_bytes(s, type, buf_, len);
1280         return i;
1281         }
1282
1283
1284         /* this only happens when a client hello is received and a handshake 
1285          * is started. */
1286 static int
1287 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
1288         int len, int peek)
1289         {
1290         
1291         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1292                 /* (partially) satisfy request from storage */
1293                 {
1294                 unsigned char *src = s->d1->handshake_fragment;
1295                 unsigned char *dst = buf;
1296                 unsigned int k,n;
1297                 
1298                 /* peek == 0 */
1299                 n = 0;
1300                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1301                         {
1302                         *dst++ = *src++;
1303                         len--; s->d1->handshake_fragment_len--;
1304                         n++;
1305                         }
1306                 /* move any remaining fragment bytes: */
1307                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1308                         s->d1->handshake_fragment[k] = *src++;
1309                 return n;
1310                 }
1311         
1312         return 0;
1313         }
1314
1315
1316
1317
1318 /* Call this to write data in records of type 'type'
1319  * It will return <= 0 if not all data has been sent or non-blocking IO.
1320  */
1321 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1322         {
1323         int i;
1324
1325         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1326         s->rwstate=SSL_NOTHING;
1327         i=do_dtls1_write(s, type, buf, len, 0);
1328         return i;
1329         }
1330
1331 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1332         {
1333         unsigned char *p,*pseq;
1334         int i,mac_size,clear=0;
1335         int prefix_len = 0;
1336         SSL3_RECORD *wr;
1337         SSL3_BUFFER *wb;
1338         SSL_SESSION *sess;
1339         int bs;
1340
1341         /* first check if there is a SSL3_BUFFER still being written
1342          * out.  This will happen with non blocking IO */
1343         if (s->s3->wbuf.left != 0)
1344                 {
1345                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1346                 return(ssl3_write_pending(s,type,buf,len));
1347                 }
1348
1349         /* If we have an alert to send, lets send it */
1350         if (s->s3->alert_dispatch)
1351                 {
1352                 i=s->method->ssl_dispatch_alert(s);
1353                 if (i <= 0)
1354                         return(i);
1355                 /* if it went, fall through and send more stuff */
1356                 }
1357
1358         if (len == 0 && !create_empty_fragment)
1359                 return 0;
1360
1361         wr= &(s->s3->wrec);
1362         wb= &(s->s3->wbuf);
1363         sess=s->session;
1364
1365         if (    (sess == NULL) ||
1366                 (s->enc_write_ctx == NULL) ||
1367                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1368                 clear=1;
1369
1370         if (clear)
1371                 mac_size=0;
1372         else
1373                 {
1374                 mac_size=EVP_MD_CTX_size(s->write_hash);
1375                 if (mac_size < 0)
1376                         goto err;
1377                 }
1378
1379         /* DTLS implements explicit IV, so no need for empty fragments */
1380 #if 0
1381         /* 'create_empty_fragment' is true only when this function calls itself */
1382         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1383             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1384                 {
1385                 /* countermeasure against known-IV weakness in CBC ciphersuites
1386                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
1387                  */
1388
1389                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1390                         {
1391                         /* recursive function call with 'create_empty_fragment' set;
1392                          * this prepares and buffers the data for an empty fragment
1393                          * (these 'prefix_len' bytes are sent out later
1394                          * together with the actual payload) */
1395                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1396                         if (prefix_len <= 0)
1397                                 goto err;
1398
1399                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1400                                 {
1401                                 /* insufficient space */
1402                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1403                                 goto err;
1404                                 }
1405                         }
1406                 
1407                 s->s3->empty_fragment_done = 1;
1408                 }
1409 #endif
1410         p = wb->buf + prefix_len;
1411
1412         /* write the header */
1413
1414         *(p++)=type&0xff;
1415         wr->type=type;
1416
1417         *(p++)=(s->version>>8);
1418         *(p++)=s->version&0xff;
1419
1420         /* field where we are to write out packet epoch, seq num and len */
1421         pseq=p; 
1422         p+=10;
1423
1424         /* lets setup the record stuff. */
1425
1426         /* Make space for the explicit IV in case of CBC.
1427          * (this is a bit of a boundary violation, but what the heck).
1428          */
1429         if ( s->enc_write_ctx && 
1430                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1431                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1432         else
1433                 bs = 0;
1434
1435         wr->data=p + bs;  /* make room for IV in case of CBC */
1436         wr->length=(int)len;
1437         wr->input=(unsigned char *)buf;
1438
1439         /* we now 'read' from wr->input, wr->length bytes into
1440          * wr->data */
1441
1442         /* first we compress */
1443         if (s->compress != NULL)
1444                 {
1445                 if (!ssl3_do_compress(s))
1446                         {
1447                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1448                         goto err;
1449                         }
1450                 }
1451         else
1452                 {
1453                 memcpy(wr->data,wr->input,wr->length);
1454                 wr->input=wr->data;
1455                 }
1456
1457         /* we should still have the output to wr->data and the input
1458          * from wr->input.  Length should be wr->length.
1459          * wr->data still points in the wb->buf */
1460
1461         if (mac_size != 0)
1462                 {
1463                 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1464                         goto err;
1465                 wr->length+=mac_size;
1466                 }
1467
1468         /* this is true regardless of mac size */
1469         wr->input=p;
1470         wr->data=p;
1471
1472
1473         /* ssl3_enc can only have an error on read */
1474         if (bs) /* bs != 0 in case of CBC */
1475                 {
1476                 RAND_pseudo_bytes(p,bs);
1477                 /* master IV and last CBC residue stand for
1478                  * the rest of randomness */
1479                 wr->length += bs;
1480                 }
1481
1482         s->method->ssl3_enc->enc(s,1);
1483
1484         /* record length after mac and block padding */
1485 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1486         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1487         
1488         /* there's only one epoch between handshake and app data */
1489         
1490         s2n(s->d1->w_epoch, pseq);
1491
1492         /* XDTLS: ?? */
1493 /*      else
1494         s2n(s->d1->handshake_epoch, pseq); */
1495
1496         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1497         pseq+=6;
1498         s2n(wr->length,pseq);
1499
1500         /* we should now have
1501          * wr->data pointing to the encrypted data, which is
1502          * wr->length long */
1503         wr->type=type; /* not needed but helps for debugging */
1504         wr->length+=DTLS1_RT_HEADER_LENGTH;
1505
1506 #if 0  /* this is now done at the message layer */
1507         /* buffer the record, making it easy to handle retransmits */
1508         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1509                 dtls1_buffer_record(s, wr->data, wr->length, 
1510                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1511 #endif
1512
1513         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1514
1515         if (create_empty_fragment)
1516                 {
1517                 /* we are in a recursive call;
1518                  * just return the length, don't write out anything here
1519                  */
1520                 return wr->length;
1521                 }
1522
1523         /* now let's set up wb */
1524         wb->left = prefix_len + wr->length;
1525         wb->offset = 0;
1526
1527         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1528         s->s3->wpend_tot=len;
1529         s->s3->wpend_buf=buf;
1530         s->s3->wpend_type=type;
1531         s->s3->wpend_ret=len;
1532
1533         /* we now just need to write the buffer */
1534         return ssl3_write_pending(s,type,buf,len);
1535 err:
1536         return -1;
1537         }
1538
1539
1540
1541 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1542         {
1543         int cmp;
1544         unsigned int shift;
1545         const unsigned char *seq = s->s3->read_sequence;
1546
1547         cmp = satsub64be(seq,bitmap->max_seq_num);
1548         if (cmp > 0)
1549                 {
1550                 memcpy (s->s3->rrec.seq_num,seq,8);
1551                 return 1; /* this record in new */
1552                 }
1553         shift = -cmp;
1554         if (shift >= sizeof(bitmap->map)*8)
1555                 return 0; /* stale, outside the window */
1556         else if (bitmap->map & (1UL<<shift))
1557                 return 0; /* record previously received */
1558
1559         memcpy (s->s3->rrec.seq_num,seq,8);
1560         return 1;
1561         }
1562
1563
1564 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1565         {
1566         int cmp;
1567         unsigned int shift;
1568         const unsigned char *seq = s->s3->read_sequence;
1569
1570         cmp = satsub64be(seq,bitmap->max_seq_num);
1571         if (cmp > 0)
1572                 {
1573                 shift = cmp;
1574                 if (shift < sizeof(bitmap->map)*8)
1575                         bitmap->map <<= shift, bitmap->map |= 1UL;
1576                 else
1577                         bitmap->map = 1UL;
1578                 memcpy(bitmap->max_seq_num,seq,8);
1579                 }
1580         else    {
1581                 shift = -cmp;
1582                 if (shift < sizeof(bitmap->map)*8)
1583                         bitmap->map |= 1UL<<shift;
1584                 }
1585         }
1586
1587
1588 int dtls1_dispatch_alert(SSL *s)
1589         {
1590         int i,j;
1591         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1592         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1593         unsigned char *ptr = &buf[0];
1594
1595         s->s3->alert_dispatch=0;
1596
1597         memset(buf, 0x00, sizeof(buf));
1598         *ptr++ = s->s3->send_alert[0];
1599         *ptr++ = s->s3->send_alert[1];
1600
1601 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1602         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1603                 {       
1604                 s2n(s->d1->handshake_read_seq, ptr);
1605 #if 0
1606                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1607
1608                 else
1609                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1610 #endif
1611
1612 #if 0
1613                 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);
1614 #endif
1615                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1616                 }
1617 #endif
1618
1619         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1620         if (i <= 0)
1621                 {
1622                 s->s3->alert_dispatch=1;
1623                 /* fprintf( stderr, "not done with alert\n" ); */
1624                 }
1625         else
1626                 {
1627                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1628 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1629                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1630 #endif
1631                     )
1632                         (void)BIO_flush(s->wbio);
1633
1634                 if (s->msg_callback)
1635                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 
1636                                 2, s, s->msg_callback_arg);
1637
1638                 if (s->info_callback != NULL)
1639                         cb=s->info_callback;
1640                 else if (s->ctx->info_callback != NULL)
1641                         cb=s->ctx->info_callback;
1642
1643                 if (cb != NULL)
1644                         {
1645                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1646                         cb(s,SSL_CB_WRITE_ALERT,j);
1647                         }
1648                 }
1649         return(i);
1650         }
1651
1652
1653 static DTLS1_BITMAP *
1654 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1655     {
1656     
1657     *is_next_epoch = 0;
1658
1659     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1660     if (rr->epoch == s->d1->r_epoch)
1661         return &s->d1->bitmap;
1662
1663     /* Only HM and ALERT messages can be from the next epoch */
1664     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1665         (rr->type == SSL3_RT_HANDSHAKE ||
1666             rr->type == SSL3_RT_ALERT))
1667         {
1668         *is_next_epoch = 1;
1669         return &s->d1->next_bitmap;
1670         }
1671
1672     return NULL;
1673     }
1674
1675 #if 0
1676 static int
1677 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1678         unsigned long *offset)
1679         {
1680
1681         /* alerts are passed up immediately */
1682         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1683                 rr->type == SSL3_RT_ALERT)
1684                 return 0;
1685
1686         /* Only need to buffer if a handshake is underway.
1687          * (this implies that Hello Request and Client Hello are passed up
1688          * immediately) */
1689         if ( SSL_in_init(s))
1690                 {
1691                 unsigned char *data = rr->data;
1692                 /* need to extract the HM/CCS sequence number here */
1693                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1694                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1695                         {
1696                         unsigned short seq_num;
1697                         struct hm_header_st msg_hdr;
1698                         struct ccs_header_st ccs_hdr;
1699
1700                         if ( rr->type == SSL3_RT_HANDSHAKE)
1701                                 {
1702                                 dtls1_get_message_header(data, &msg_hdr);
1703                                 seq_num = msg_hdr.seq;
1704                                 *offset = msg_hdr.frag_off;
1705                                 }
1706                         else
1707                                 {
1708                                 dtls1_get_ccs_header(data, &ccs_hdr);
1709                                 seq_num = ccs_hdr.seq;
1710                                 *offset = 0;
1711                                 }
1712                                 
1713                         /* this is either a record we're waiting for, or a
1714                          * retransmit of something we happened to previously 
1715                          * receive (higher layers will drop the repeat silently */
1716                         if ( seq_num < s->d1->handshake_read_seq)
1717                                 return 0;
1718                         if (rr->type == SSL3_RT_HANDSHAKE && 
1719                                 seq_num == s->d1->handshake_read_seq &&
1720                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1721                                 return 0;
1722                         else if ( seq_num == s->d1->handshake_read_seq &&
1723                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1724                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1725                                 return 0;
1726                         else
1727                                 {
1728                                 *priority = seq_num;
1729                                 return 1;
1730                                 }
1731                         }
1732                 else /* unknown record type */
1733                         return 0;
1734                 }
1735
1736         return 0;
1737         }
1738 #endif
1739
1740 void
1741 dtls1_reset_seq_numbers(SSL *s, int rw)
1742         {
1743         unsigned char *seq;
1744         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1745
1746         if ( rw & SSL3_CC_READ)
1747                 {
1748                 seq = s->s3->read_sequence;
1749                 s->d1->r_epoch++;
1750                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1751                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1752                 }
1753         else
1754                 {
1755                 seq = s->s3->write_sequence;
1756                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1757                 s->d1->w_epoch++;
1758                 }
1759
1760         memset(seq, 0x00, seq_bytes);
1761         }
1762
1763
1764 static void
1765 dtls1_clear_timeouts(SSL *s)
1766         {
1767         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1768         }