Make ChangeCipherSpec compliant with DTLS RFC4347.
[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
124 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
125 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
126 {       int ret,sat,brw,i;
127
128         if (sizeof(long) == 8) do
129         {       const union { long one; char little; } is_endian = {1};
130                 long l;
131
132                 if (is_endian.little)                   break;
133                 /* not reached on little-endians */
134                 /* following test is redundant, because input is
135                  * always aligned, but I take no chances... */
136                 if (((size_t)v1|(size_t)v2)&0x7)        break;
137
138                 l  = *((long *)v1);
139                 l -= *((long *)v2);
140                 if (l>128)              return 128;
141                 else if (l<-128)        return -128;
142                 else                    return (int)l;
143         } while (0);
144
145         ret = (int)v1[7]-(int)v2[7];
146         sat = 0;
147         brw = ret>>8;   /* brw is either 0 or -1 */
148         if (ret & 0x80)
149         {       for (i=6;i>=0;i--)
150                 {       brw += (int)v1[i]-(int)v2[i];
151                         sat |= ~brw;
152                         brw >>= 8;
153                 }
154         }
155         else
156         {       for (i=6;i>=0;i--)
157                 {       brw += (int)v1[i]-(int)v2[i];
158                         sat |= brw;
159                         brw >>= 8;
160                 }
161         }
162         brw <<= 8;      /* brw is either 0 or -256 */
163
164         if (sat&0xff)   return brw | 0x80;
165         else            return brw + (ret&0xFF);
166 }
167
168 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
169         int len, int peek);
170 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
171 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
172 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 
173     unsigned int *is_next_epoch);
174 #if 0
175 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
176         unsigned short *priority, unsigned long *offset);
177 #endif
178 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
179         unsigned char *priority);
180 static int dtls1_process_record(SSL *s);
181 static void dtls1_clear_timeouts(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     return(1);
200     }
201
202
203 static int
204 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
205         {
206         DTLS1_RECORD_DATA *rdata;
207         pitem *item;
208
209         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
210         item = pitem_new(priority, rdata);
211         if (rdata == NULL || item == NULL)
212                 {
213                 if (rdata != NULL) OPENSSL_free(rdata);
214                 if (item != NULL) pitem_free(item);
215                 
216                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
217                 return(0);
218                 }
219         
220         rdata->packet = s->packet;
221         rdata->packet_length = s->packet_length;
222         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
223         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
224
225         item->data = rdata;
226
227         /* insert should not fail, since duplicates are dropped */
228         if (pqueue_insert(queue->q, item) == NULL)
229                 {
230                 OPENSSL_free(rdata);
231                 pitem_free(item);
232                 return(0);
233                 }
234
235         s->packet = NULL;
236         s->packet_length = 0;
237         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
238         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
239         
240         if (!ssl3_setup_buffers(s))
241                 {
242                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
243                 OPENSSL_free(rdata);
244                 pitem_free(item);
245                 return(0);
246                 }
247         
248         return(1);
249         }
250
251
252 static int
253 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
254     {
255     pitem *item;
256
257     item = pqueue_pop(queue->q);
258     if (item)
259         {
260         dtls1_copy_record(s, item);
261
262         OPENSSL_free(item->data);
263                 pitem_free(item);
264
265         return(1);
266         }
267
268     return(0);
269     }
270
271
272 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 
273  * yet */
274 #define dtls1_get_unprocessed_record(s) \
275                    dtls1_retrieve_buffered_record((s), \
276                    &((s)->d1->unprocessed_rcds))
277
278 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
279 #define dtls1_get_processed_record(s) \
280                    dtls1_retrieve_buffered_record((s), \
281                    &((s)->d1->processed_rcds))
282
283 static int
284 dtls1_process_buffered_records(SSL *s)
285     {
286     pitem *item;
287     
288     item = pqueue_peek(s->d1->unprocessed_rcds.q);
289     if (item)
290         {
291         DTLS1_RECORD_DATA *rdata;
292         rdata = (DTLS1_RECORD_DATA *)item->data;
293         
294         /* Check if epoch is current. */
295         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
296             return(1);  /* Nothing to do. */
297         
298         /* Process all the records. */
299         while (pqueue_peek(s->d1->unprocessed_rcds.q))
300             {
301             dtls1_get_unprocessed_record(s);
302             if ( ! dtls1_process_record(s))
303                 return(0);
304             dtls1_buffer_record(s, &(s->d1->processed_rcds), 
305                 s->s3->rrec.seq_num);
306             }
307         }
308
309     /* sync epoch numbers once all the unprocessed records 
310      * have been processed */
311     s->d1->processed_rcds.epoch = s->d1->r_epoch;
312     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
313
314     return(1);
315     }
316
317
318 #if 0
319
320 static int
321 dtls1_get_buffered_record(SSL *s)
322         {
323         pitem *item;
324         PQ_64BIT priority = 
325                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 
326                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
327         
328         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating, 
329                                                            nothing buffered */
330                 return 0;
331
332
333         item = pqueue_peek(s->d1->rcvd_records);
334         if (item && item->priority == priority)
335                 {
336                 /* Check if we've received the record of interest.  It must be
337                  * a handshake record, since data records as passed up without
338                  * buffering */
339                 DTLS1_RECORD_DATA *rdata;
340                 item = pqueue_pop(s->d1->rcvd_records);
341                 rdata = (DTLS1_RECORD_DATA *)item->data;
342                 
343                 if (s->s3->rbuf.buf != NULL)
344                         OPENSSL_free(s->s3->rbuf.buf);
345                 
346                 s->packet = rdata->packet;
347                 s->packet_length = rdata->packet_length;
348                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
349                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
350                 
351                 OPENSSL_free(item->data);
352                 pitem_free(item);
353                 
354                 /* s->d1->next_expected_seq_num++; */
355                 return(1);
356                 }
357         
358         return 0;
359         }
360
361 #endif
362
363 static int
364 dtls1_process_record(SSL *s)
365 {
366         int i,al;
367         int clear=0;
368         int enc_err;
369         SSL_SESSION *sess;
370         SSL3_RECORD *rr;
371         unsigned int mac_size;
372         unsigned char md[EVP_MAX_MD_SIZE];
373
374
375         rr= &(s->s3->rrec);
376         sess = s->session;
377
378         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
379          * and we have that many bytes in s->packet
380          */
381         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
382
383         /* ok, we can now read from 's->packet' data into 'rr'
384          * rr->input points at rr->length bytes, which
385          * need to be copied into rr->data by either
386          * the decryption or by the decompression
387          * When the data is 'copied' into the rr->data buffer,
388          * rr->input will be pointed at the new buffer */ 
389
390         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
391          * rr->length bytes of encrypted compressed stuff. */
392
393         /* check is not needed I believe */
394         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
395                 {
396                 al=SSL_AD_RECORD_OVERFLOW;
397                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
398                 goto f_err;
399                 }
400
401         /* decrypt in place in 'rr->input' */
402         rr->data=rr->input;
403
404         enc_err = s->method->ssl3_enc->enc(s,0);
405         if (enc_err <= 0)
406                 {
407                 if (enc_err == 0)
408                         /* SSLerr() and ssl3_send_alert() have been called */
409                         goto err;
410
411                 /* otherwise enc_err == -1 */
412                 goto decryption_failed_or_bad_record_mac;
413                 }
414
415 #ifdef TLS_DEBUG
416 printf("dec %d\n",rr->length);
417 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
418 printf("\n");
419 #endif
420
421         /* r->length is now the compressed data plus mac */
422         if (    (sess == NULL) ||
423                 (s->enc_read_ctx == NULL) ||
424                 (s->read_hash == NULL))
425         clear=1;
426
427         if (!clear)
428                 {
429                 mac_size=EVP_MD_CTX_size(s->read_hash);
430
431                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
432                         {
433 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
434                         al=SSL_AD_RECORD_OVERFLOW;
435                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
436                         goto f_err;
437 #else
438                         goto decryption_failed_or_bad_record_mac;
439 #endif                  
440                         }
441                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
442                 if (rr->length < mac_size)
443                         {
444 #if 0 /* OK only for stream ciphers */
445                         al=SSL_AD_DECODE_ERROR;
446                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
447                         goto f_err;
448 #else
449                         goto decryption_failed_or_bad_record_mac;
450 #endif
451                         }
452                 rr->length-=mac_size;
453                 i=s->method->ssl3_enc->mac(s,md,0);
454                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
455                         {
456                         goto decryption_failed_or_bad_record_mac;
457                         }
458                 }
459
460         /* r->length is now just compressed */
461         if (s->expand != NULL)
462                 {
463                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
464                         {
465                         al=SSL_AD_RECORD_OVERFLOW;
466                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
467                         goto f_err;
468                         }
469                 if (!ssl3_do_uncompress(s))
470                         {
471                         al=SSL_AD_DECOMPRESSION_FAILURE;
472                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
473                         goto f_err;
474                         }
475                 }
476
477         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
478                 {
479                 al=SSL_AD_RECORD_OVERFLOW;
480                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
481                 goto f_err;
482                 }
483
484         rr->off=0;
485         /* So at this point the following is true
486          * ssl->s3->rrec.type   is the type of record
487          * ssl->s3->rrec.length == number of bytes in record
488          * ssl->s3->rrec.off    == offset to first valid byte
489          * ssl->s3->rrec.data   == where to take bytes from, increment
490          *                         after use :-).
491          */
492
493         /* we have pulled in a full packet so zero things */
494         s->packet_length=0;
495         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
496         return(1);
497
498 decryption_failed_or_bad_record_mac:
499         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
500          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
501          * failure is directly visible from the ciphertext anyway,
502          * we should not reveal which kind of error occured -- this
503          * might become visible to an attacker (e.g. via logfile) */
504         al=SSL_AD_BAD_RECORD_MAC;
505         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
506 f_err:
507         ssl3_send_alert(s,SSL3_AL_FATAL,al);
508 err:
509         return(0);
510 }
511
512
513 /* Call this to get a new input record.
514  * It will return <= 0 if more data is needed, normally due to an error
515  * or non-blocking IO.
516  * When it finishes, one packet has been decoded and can be found in
517  * ssl->s3->rrec.type    - is the type of record
518  * ssl->s3->rrec.data,   - data
519  * ssl->s3->rrec.length, - number of bytes
520  */
521 /* used only by dtls1_read_bytes */
522 int dtls1_get_record(SSL *s)
523         {
524         int ssl_major,ssl_minor,al;
525         int i,n;
526         SSL3_RECORD *rr;
527         SSL_SESSION *sess;
528         unsigned char *p;
529         unsigned short version;
530         DTLS1_BITMAP *bitmap;
531         unsigned int is_next_epoch;
532
533         rr= &(s->s3->rrec);
534         sess=s->session;
535
536         /* The epoch may have changed.  If so, process all the
537          * pending records.  This is a non-blocking operation. */
538         if ( ! dtls1_process_buffered_records(s))
539             return 0;
540
541         /* if we're renegotiating, then there may be buffered records */
542         if (dtls1_get_processed_record(s))
543                 return 1;
544
545         /* get something from the wire */
546 again:
547         /* check if we have the header */
548         if (    (s->rstate != SSL_ST_READ_BODY) ||
549                 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 
550                 {
551                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
552                 /* read timeout is handled by dtls1_read_bytes */
553                 if (n <= 0) return(n); /* error or non-blocking */
554
555                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
556
557                 s->rstate=SSL_ST_READ_BODY;
558
559                 p=s->packet;
560
561                 /* Pull apart the header into the DTLS1_RECORD */
562                 rr->type= *(p++);
563                 ssl_major= *(p++);
564                 ssl_minor= *(p++);
565                 version=(ssl_major<<8)|ssl_minor;
566
567                 /* sequence number is 64 bits, with top 2 bytes = epoch */ 
568                 n2s(p,rr->epoch);
569
570                 memcpy(&(s->s3->read_sequence[2]), p, 6);
571                 p+=6;
572
573                 n2s(p,rr->length);
574
575                 /* Lets check version */
576                 if (!s->first_packet)
577                         {
578                         if (version != s->version)
579                                 {
580                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
581                                 /* Send back error using their
582                                  * version number :-) */
583                                 s->version=version;
584                                 al=SSL_AD_PROTOCOL_VERSION;
585                                 goto f_err;
586                                 }
587                         }
588
589                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
590                         {
591                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
592                         goto err;
593                         }
594
595                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
596                         {
597                         al=SSL_AD_RECORD_OVERFLOW;
598                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
599                         goto f_err;
600                         }
601
602                 /* now s->rstate == SSL_ST_READ_BODY */
603                 }
604
605         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
606
607         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
608                 {
609                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
610                 i=rr->length;
611                 n=ssl3_read_n(s,i,i,1);
612                 if (n <= 0) return(n); /* error or non-blocking io */
613
614                 /* this packet contained a partial record, dump it */
615                 if ( n != i)
616                         {
617                         s->packet_length = 0;
618                         goto again;
619                         }
620
621                 /* now n == rr->length,
622                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
623                 }
624         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
625
626         /* match epochs.  NULL means the packet is dropped on the floor */
627         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
628         if ( bitmap == NULL)
629                 {
630                 s->packet_length = 0;  /* dump this record */
631                 goto again;   /* get another record */
632                 }
633
634         /* check whether this is a repeat, or aged record */
635         if ( ! dtls1_record_replay_check(s, bitmap))
636                 {
637                 s->packet_length=0; /* dump this record */
638                 goto again;     /* get another record */
639                 }
640
641         /* just read a 0 length packet */
642         if (rr->length == 0) goto again;
643
644         /* If this record is from the next epoch (either HM or ALERT),
645          * buffer it since it cannot be processed at this time. Records
646          * from the next epoch are marked as received even though they
647          * are not processed, so as to prevent any potential resource
648          * DoS attack */
649         if (is_next_epoch)
650                 {
651                 dtls1_record_bitmap_update(s, bitmap);
652                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
653                 s->packet_length = 0;
654                 goto again;
655                 }
656
657         if ( ! dtls1_process_record(s))
658                 return(0);
659
660         dtls1_clear_timeouts(s);  /* done waiting */
661         return(1);
662
663 f_err:
664         ssl3_send_alert(s,SSL3_AL_FATAL,al);
665 err:
666         return(0);
667         }
668
669 /* Return up to 'len' payload bytes received in 'type' records.
670  * 'type' is one of the following:
671  *
672  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
673  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
674  *   -  0 (during a shutdown, no data has to be returned)
675  *
676  * If we don't have stored data to work from, read a SSL/TLS record first
677  * (possibly multiple records if we still don't have anything to return).
678  *
679  * This function must handle any surprises the peer may have for us, such as
680  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
681  * a surprise, but handled as if it were), or renegotiation requests.
682  * Also if record payloads contain fragments too small to process, we store
683  * them until there is enough for the respective protocol (the record protocol
684  * may use arbitrary fragmentation and even interleaving):
685  *     Change cipher spec protocol
686  *             just 1 byte needed, no need for keeping anything stored
687  *     Alert protocol
688  *             2 bytes needed (AlertLevel, AlertDescription)
689  *     Handshake protocol
690  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
691  *             to detect unexpected Client Hello and Hello Request messages
692  *             here, anything else is handled by higher layers
693  *     Application data protocol
694  *             none of our business
695  */
696 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
697         {
698         int al,i,j,ret;
699         unsigned int n;
700         SSL3_RECORD *rr;
701         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
702
703         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
704                 if (!ssl3_setup_buffers(s))
705                         return(-1);
706
707     /* XXX: check what the second '&& type' is about */
708         if ((type && (type != SSL3_RT_APPLICATION_DATA) && 
709                 (type != SSL3_RT_HANDSHAKE) && type) ||
710             (peek && (type != SSL3_RT_APPLICATION_DATA)))
711                 {
712                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
713                 return -1;
714                 }
715
716         /* check whether there's a handshake message (client hello?) waiting */
717         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
718                 return ret;
719
720         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
721
722         if (!s->in_handshake && SSL_in_init(s))
723                 {
724                 /* type == SSL3_RT_APPLICATION_DATA */
725                 i=s->handshake_func(s);
726                 if (i < 0) return(i);
727                 if (i == 0)
728                         {
729                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
730                         return(-1);
731                         }
732                 }
733
734 start:
735         s->rwstate=SSL_NOTHING;
736
737         /* s->s3->rrec.type         - is the type of record
738          * s->s3->rrec.data,    - data
739          * s->s3->rrec.off,     - offset into 'data' for next read
740          * s->s3->rrec.length,  - number of bytes. */
741         rr = &(s->s3->rrec);
742
743         /* get new packet if necessary */
744         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
745                 {
746                 ret=dtls1_get_record(s);
747                 if (ret <= 0) 
748                         {
749                         ret = dtls1_read_failed(s, ret);
750                         /* anything other than a timeout is an error */
751                         if (ret <= 0)  
752                                 return(ret);
753                         else
754                                 goto start;
755                         }
756                 }
757
758         /* we now have a packet which can be read and processed */
759
760         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
761                                        * reset by ssl3_get_finished */
762                 && (rr->type != SSL3_RT_HANDSHAKE))
763                 {
764                 al=SSL_AD_UNEXPECTED_MESSAGE;
765                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
766                 goto err;
767                 }
768
769         /* If the other end has shut down, throw anything we read away
770          * (even in 'peek' mode) */
771         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
772                 {
773                 rr->length=0;
774                 s->rwstate=SSL_NOTHING;
775                 return(0);
776                 }
777
778
779         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
780                 {
781                 /* make sure that we are not getting application data when we
782                  * are doing a handshake for the first time */
783                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
784                         (s->enc_read_ctx == NULL))
785                         {
786                         al=SSL_AD_UNEXPECTED_MESSAGE;
787                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
788                         goto f_err;
789                         }
790
791                 if (len <= 0) return(len);
792
793                 if ((unsigned int)len > rr->length)
794                         n = rr->length;
795                 else
796                         n = (unsigned int)len;
797
798                 memcpy(buf,&(rr->data[rr->off]),n);
799                 if (!peek)
800                         {
801                         rr->length-=n;
802                         rr->off+=n;
803                         if (rr->length == 0)
804                                 {
805                                 s->rstate=SSL_ST_READ_HEADER;
806                                 rr->off=0;
807                                 }
808                         }
809                 return(n);
810                 }
811
812
813         /* If we get here, then type != rr->type; if we have a handshake
814          * message, then it was unexpected (Hello Request or Client Hello). */
815
816         /* In case of record types for which we have 'fragment' storage,
817          * fill that so that we can process the data at a fixed place.
818          */
819                 {
820                 unsigned int k, dest_maxlen = 0;
821                 unsigned char *dest = NULL;
822                 unsigned int *dest_len = NULL;
823
824                 if (rr->type == SSL3_RT_HANDSHAKE)
825                         {
826                         dest_maxlen = sizeof s->d1->handshake_fragment;
827                         dest = s->d1->handshake_fragment;
828                         dest_len = &s->d1->handshake_fragment_len;
829                         }
830                 else if (rr->type == SSL3_RT_ALERT)
831                         {
832                         dest_maxlen = sizeof(s->d1->alert_fragment);
833                         dest = s->d1->alert_fragment;
834                         dest_len = &s->d1->alert_fragment_len;
835                         }
836                 /* else it's a CCS message, or it's wrong */
837                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
838                         {
839                           /* Not certain if this is the right error handling */
840                           al=SSL_AD_UNEXPECTED_MESSAGE;
841                           SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
842                           goto f_err;
843                         }
844
845
846                 if (dest_maxlen > 0)
847                         {
848             /* XDTLS:  In a pathalogical case, the Client Hello
849              *  may be fragmented--don't always expect dest_maxlen bytes */
850                         if ( rr->length < dest_maxlen)
851                                 {
852                                 s->rstate=SSL_ST_READ_HEADER;
853                                 rr->length = 0;
854                                 goto start;
855                                 }
856
857                         /* now move 'n' bytes: */
858                         for ( k = 0; k < dest_maxlen; k++)
859                                 {
860                                 dest[k] = rr->data[rr->off++];
861                                 rr->length--;
862                                 }
863                         *dest_len = dest_maxlen;
864                         }
865                 }
866
867         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
868          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
869          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
870
871         /* If we are a client, check for an incoming 'Hello Request': */
872         if ((!s->server) &&
873                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
874                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
875                 (s->session != NULL) && (s->session->cipher != NULL))
876                 {
877                 s->d1->handshake_fragment_len = 0;
878
879                 if ((s->d1->handshake_fragment[1] != 0) ||
880                         (s->d1->handshake_fragment[2] != 0) ||
881                         (s->d1->handshake_fragment[3] != 0))
882                         {
883                         al=SSL_AD_DECODE_ERROR;
884                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
885                         goto err;
886                         }
887
888                 /* no need to check sequence number on HELLO REQUEST messages */
889
890                 if (s->msg_callback)
891                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
892                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
893
894                 if (SSL_is_init_finished(s) &&
895                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
896                         !s->s3->renegotiate)
897                         {
898                         ssl3_renegotiate(s);
899                         if (ssl3_renegotiate_check(s))
900                                 {
901                                 i=s->handshake_func(s);
902                                 if (i < 0) return(i);
903                                 if (i == 0)
904                                         {
905                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
906                                         return(-1);
907                                         }
908
909                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
910                                         {
911                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
912                                                 {
913                                                 BIO *bio;
914                                                 /* In the case where we try to read application data,
915                                                  * but we trigger an SSL handshake, we return -1 with
916                                                  * the retry option set.  Otherwise renegotiation may
917                                                  * cause nasty problems in the blocking world */
918                                                 s->rwstate=SSL_READING;
919                                                 bio=SSL_get_rbio(s);
920                                                 BIO_clear_retry_flags(bio);
921                                                 BIO_set_retry_read(bio);
922                                                 return(-1);
923                                                 }
924                                         }
925                                 }
926                         }
927                 /* we either finished a handshake or ignored the request,
928                  * now try again to obtain the (application) data we were asked for */
929                 goto start;
930                 }
931
932         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
933                 {
934                 int alert_level = s->d1->alert_fragment[0];
935                 int alert_descr = s->d1->alert_fragment[1];
936
937                 s->d1->alert_fragment_len = 0;
938
939                 if (s->msg_callback)
940                         s->msg_callback(0, s->version, SSL3_RT_ALERT, 
941                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
942
943                 if (s->info_callback != NULL)
944                         cb=s->info_callback;
945                 else if (s->ctx->info_callback != NULL)
946                         cb=s->ctx->info_callback;
947
948                 if (cb != NULL)
949                         {
950                         j = (alert_level << 8) | alert_descr;
951                         cb(s, SSL_CB_READ_ALERT, j);
952                         }
953
954                 if (alert_level == 1) /* warning */
955                         {
956                         s->s3->warn_alert = alert_descr;
957                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
958                                 {
959                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
960                                 return(0);
961                                 }
962 #if 0
963             /* XXX: this is a possible improvement in the future */
964                         /* now check if it's a missing record */
965                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
966                                 {
967                                 unsigned short seq;
968                                 unsigned int frag_off;
969                                 unsigned char *p = &(s->d1->alert_fragment[2]);
970
971                                 n2s(p, seq);
972                                 n2l3(p, frag_off);
973
974                                 dtls1_retransmit_message(s, seq, frag_off, &found);
975                                 if ( ! found  && SSL_in_init(s))
976                                         {
977                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
978                                         /* requested a message not yet sent, 
979                                            send an alert ourselves */
980                                         ssl3_send_alert(s,SSL3_AL_WARNING,
981                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
982                                         }
983                                 }
984 #endif
985                         }
986                 else if (alert_level == 2) /* fatal */
987                         {
988                         char tmp[16];
989
990                         s->rwstate=SSL_NOTHING;
991                         s->s3->fatal_alert = alert_descr;
992                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
993                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
994                         ERR_add_error_data(2,"SSL alert number ",tmp);
995                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
996                         SSL_CTX_remove_session(s->ctx,s->session);
997                         return(0);
998                         }
999                 else
1000                         {
1001                         al=SSL_AD_ILLEGAL_PARAMETER;
1002                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1003                         goto f_err;
1004                         }
1005
1006                 goto start;
1007                 }
1008
1009         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1010                 {
1011                 s->rwstate=SSL_NOTHING;
1012                 rr->length=0;
1013                 return(0);
1014                 }
1015
1016         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1017                 {
1018                 struct ccs_header_st ccs_hdr;
1019
1020                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1021
1022                 /* 'Change Cipher Spec' is just a single byte, so we know
1023                  * exactly what the record payload has to look like */
1024                 /* XDTLS: check that epoch is consistent */
1025                 if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) || 
1026                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1027                         {
1028                         i=SSL_AD_ILLEGAL_PARAMETER;
1029                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1030                         goto err;
1031                         }
1032
1033                 rr->length=0;
1034
1035                 if (s->msg_callback)
1036                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
1037                                 rr->data, 1, s, s->msg_callback_arg);
1038
1039                 s->s3->change_cipher_spec=1;
1040                 if (!ssl3_do_change_cipher_spec(s))
1041                         goto err;
1042
1043                 /* do this whenever CCS is processed */
1044                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1045
1046                 /* handshake read seq is reset upon handshake completion */
1047                 s->d1->handshake_read_seq++;
1048
1049                 goto start;
1050                 }
1051
1052         /* Unexpected handshake message (Client Hello, or protocol violation) */
1053         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 
1054                 !s->in_handshake)
1055                 {
1056                 struct hm_header_st msg_hdr;
1057                 
1058                 /* this may just be a stale retransmit */
1059                 dtls1_get_message_header(rr->data, &msg_hdr);
1060                 if( rr->epoch != s->d1->r_epoch)
1061                         {
1062                         rr->length = 0;
1063                         goto start;
1064                         }
1065
1066                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1067                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1068                         {
1069 #if 0 /* worked only because C operator preferences are not as expected (and
1070        * because this is not really needed for clients except for detecting
1071        * protocol violations): */
1072                         s->state=SSL_ST_BEFORE|(s->server)
1073                                 ?SSL_ST_ACCEPT
1074                                 :SSL_ST_CONNECT;
1075 #else
1076                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1077 #endif
1078                         s->new_session=1;
1079                         }
1080                 i=s->handshake_func(s);
1081                 if (i < 0) return(i);
1082                 if (i == 0)
1083                         {
1084                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1085                         return(-1);
1086                         }
1087
1088                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1089                         {
1090                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1091                                 {
1092                                 BIO *bio;
1093                                 /* In the case where we try to read application data,
1094                                  * but we trigger an SSL handshake, we return -1 with
1095                                  * the retry option set.  Otherwise renegotiation may
1096                                  * cause nasty problems in the blocking world */
1097                                 s->rwstate=SSL_READING;
1098                                 bio=SSL_get_rbio(s);
1099                                 BIO_clear_retry_flags(bio);
1100                                 BIO_set_retry_read(bio);
1101                                 return(-1);
1102                                 }
1103                         }
1104                 goto start;
1105                 }
1106
1107         switch (rr->type)
1108                 {
1109         default:
1110 #ifndef OPENSSL_NO_TLS
1111                 /* TLS just ignores unknown message types */
1112                 if (s->version == TLS1_VERSION)
1113                         {
1114                         rr->length = 0;
1115                         goto start;
1116                         }
1117 #endif
1118                 al=SSL_AD_UNEXPECTED_MESSAGE;
1119                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1120                 goto f_err;
1121         case SSL3_RT_CHANGE_CIPHER_SPEC:
1122         case SSL3_RT_ALERT:
1123         case SSL3_RT_HANDSHAKE:
1124                 /* we already handled all of these, with the possible exception
1125                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1126                  * should not happen when type != rr->type */
1127                 al=SSL_AD_UNEXPECTED_MESSAGE;
1128                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1129                 goto f_err;
1130         case SSL3_RT_APPLICATION_DATA:
1131                 /* At this point, we were expecting handshake data,
1132                  * but have application data.  If the library was
1133                  * running inside ssl3_read() (i.e. in_read_app_data
1134                  * is set) and it makes sense to read application data
1135                  * at this point (session renegotiation not yet started),
1136                  * we will indulge it.
1137                  */
1138                 if (s->s3->in_read_app_data &&
1139                         (s->s3->total_renegotiations != 0) &&
1140                         ((
1141                                 (s->state & SSL_ST_CONNECT) &&
1142                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1143                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1144                                 ) || (
1145                                         (s->state & SSL_ST_ACCEPT) &&
1146                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1147                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1148                                         )
1149                                 ))
1150                         {
1151                         s->s3->in_read_app_data=2;
1152                         return(-1);
1153                         }
1154                 else
1155                         {
1156                         al=SSL_AD_UNEXPECTED_MESSAGE;
1157                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1158                         goto f_err;
1159                         }
1160                 }
1161         /* not reached */
1162
1163 f_err:
1164         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1165 err:
1166         return(-1);
1167         }
1168
1169 int
1170 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1171         {
1172         unsigned int n,tot;
1173         int i;
1174
1175         if (SSL_in_init(s) && !s->in_handshake)
1176                 {
1177                 i=s->handshake_func(s);
1178                 if (i < 0) return(i);
1179                 if (i == 0)
1180                         {
1181                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1182                         return -1;
1183                         }
1184                 }
1185
1186         tot = s->s3->wnum;
1187         n = len - tot;
1188
1189         while( n)
1190                 {
1191                 /* dtls1_write_bytes sends one record at a time, sized according to 
1192                  * the currently known MTU */
1193                 i = dtls1_write_bytes(s, type, buf_, len);
1194                 if (i <= 0) return i;
1195                 
1196                 if ((i == (int)n) ||
1197                         (type == SSL3_RT_APPLICATION_DATA &&
1198                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1199                         {
1200                         /* next chunk of data should get another prepended empty fragment
1201                          * in ciphersuites with known-IV weakness: */
1202                         s->s3->empty_fragment_done = 0;
1203                         return tot+i;
1204                         }
1205
1206                 tot += i;
1207                 n-=i;
1208                 }
1209
1210         return tot;
1211         }
1212
1213
1214         /* this only happens when a client hello is received and a handshake 
1215          * is started. */
1216 static int
1217 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
1218         int len, int peek)
1219         {
1220         
1221         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1222                 /* (partially) satisfy request from storage */
1223                 {
1224                 unsigned char *src = s->d1->handshake_fragment;
1225                 unsigned char *dst = buf;
1226                 unsigned int k,n;
1227                 
1228                 /* peek == 0 */
1229                 n = 0;
1230                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1231                         {
1232                         *dst++ = *src++;
1233                         len--; s->d1->handshake_fragment_len--;
1234                         n++;
1235                         }
1236                 /* move any remaining fragment bytes: */
1237                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1238                         s->d1->handshake_fragment[k] = *src++;
1239                 return n;
1240                 }
1241         
1242         return 0;
1243         }
1244
1245
1246
1247
1248 /* Call this to write data in records of type 'type'
1249  * It will return <= 0 if not all data has been sent or non-blocking IO.
1250  */
1251 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1252         {
1253         const unsigned char *buf=buf_;
1254         unsigned int tot,n,nw;
1255         int i;
1256         unsigned int mtu;
1257
1258         s->rwstate=SSL_NOTHING;
1259         tot=s->s3->wnum;
1260
1261         n=(len-tot);
1262
1263         /* handshake layer figures out MTU for itself, but data records
1264          * are also sent through this interface, so need to figure out MTU */
1265 #if 0
1266         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1267         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1268 #endif
1269         mtu = s->d1->mtu;
1270
1271         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1272                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1273
1274         if (n > mtu)
1275                 nw=mtu;
1276         else
1277                 nw=n;
1278         
1279         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1280         if (i <= 0)
1281                 {
1282                 s->s3->wnum=tot;
1283                 return i;
1284                 }
1285
1286         if ( (int)s->s3->wnum + i == len)
1287                 s->s3->wnum = 0;
1288         else 
1289                 s->s3->wnum += i;
1290
1291         return tot + i;
1292         }
1293
1294 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1295         {
1296         unsigned char *p,*pseq;
1297         int i,mac_size,clear=0;
1298         int prefix_len = 0;
1299         SSL3_RECORD *wr;
1300         SSL3_BUFFER *wb;
1301         SSL_SESSION *sess;
1302         int bs;
1303
1304         /* first check if there is a SSL3_BUFFER still being written
1305          * out.  This will happen with non blocking IO */
1306         if (s->s3->wbuf.left != 0)
1307                 {
1308                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1309                 return(ssl3_write_pending(s,type,buf,len));
1310                 }
1311
1312         /* If we have an alert to send, lets send it */
1313         if (s->s3->alert_dispatch)
1314                 {
1315                 i=s->method->ssl_dispatch_alert(s);
1316                 if (i <= 0)
1317                         return(i);
1318                 /* if it went, fall through and send more stuff */
1319                 }
1320
1321         if (len == 0 && !create_empty_fragment)
1322                 return 0;
1323
1324         wr= &(s->s3->wrec);
1325         wb= &(s->s3->wbuf);
1326         sess=s->session;
1327
1328         if (    (sess == NULL) ||
1329                 (s->enc_write_ctx == NULL) ||
1330                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1331                 clear=1;
1332
1333         if (clear)
1334                 mac_size=0;
1335         else
1336                 mac_size=EVP_MD_CTX_size(s->write_hash);
1337
1338         /* DTLS implements explicit IV, so no need for empty fragments */
1339 #if 0
1340         /* 'create_empty_fragment' is true only when this function calls itself */
1341         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1342                 && SSL_version(s) != DTLS1_VERSION)
1343                 {
1344                 /* countermeasure against known-IV weakness in CBC ciphersuites
1345                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
1346                  */
1347
1348                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1349                         {
1350                         /* recursive function call with 'create_empty_fragment' set;
1351                          * this prepares and buffers the data for an empty fragment
1352                          * (these 'prefix_len' bytes are sent out later
1353                          * together with the actual payload) */
1354                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1355                         if (prefix_len <= 0)
1356                                 goto err;
1357
1358                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1359                                 {
1360                                 /* insufficient space */
1361                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1362                                 goto err;
1363                                 }
1364                         }
1365                 
1366                 s->s3->empty_fragment_done = 1;
1367                 }
1368 #endif
1369
1370         p = wb->buf + prefix_len;
1371
1372         /* write the header */
1373
1374         *(p++)=type&0xff;
1375         wr->type=type;
1376
1377         *(p++)=(s->version>>8);
1378         *(p++)=s->version&0xff;
1379
1380         /* field where we are to write out packet epoch, seq num and len */
1381         pseq=p; 
1382         p+=10;
1383
1384         /* lets setup the record stuff. */
1385
1386         /* Make space for the explicit IV in case of CBC.
1387          * (this is a bit of a boundary violation, but what the heck).
1388          */
1389         if ( s->enc_write_ctx && 
1390                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1391                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1392         else
1393                 bs = 0;
1394
1395         wr->data=p + bs;  /* make room for IV in case of CBC */
1396         wr->length=(int)len;
1397         wr->input=(unsigned char *)buf;
1398
1399         /* we now 'read' from wr->input, wr->length bytes into
1400          * wr->data */
1401
1402         /* first we compress */
1403         if (s->compress != NULL)
1404                 {
1405                 if (!ssl3_do_compress(s))
1406                         {
1407                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1408                         goto err;
1409                         }
1410                 }
1411         else
1412                 {
1413                 memcpy(wr->data,wr->input,wr->length);
1414                 wr->input=wr->data;
1415                 }
1416
1417         /* we should still have the output to wr->data and the input
1418          * from wr->input.  Length should be wr->length.
1419          * wr->data still points in the wb->buf */
1420
1421         if (mac_size != 0)
1422                 {
1423                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1424                 wr->length+=mac_size;
1425                 }
1426
1427         /* this is true regardless of mac size */
1428         wr->input=p;
1429         wr->data=p;
1430
1431
1432         /* ssl3_enc can only have an error on read */
1433         wr->length += bs;  /* bs != 0 in case of CBC.  The enc fn provides
1434                                                 * the randomness */ 
1435         s->method->ssl3_enc->enc(s,1);
1436
1437         /* record length after mac and block padding */
1438 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1439         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1440         
1441         /* there's only one epoch between handshake and app data */
1442         
1443         s2n(s->d1->w_epoch, pseq);
1444
1445         /* XDTLS: ?? */
1446 /*      else
1447         s2n(s->d1->handshake_epoch, pseq); */
1448
1449         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1450         pseq+=6;
1451         s2n(wr->length,pseq);
1452
1453         /* we should now have
1454          * wr->data pointing to the encrypted data, which is
1455          * wr->length long */
1456         wr->type=type; /* not needed but helps for debugging */
1457         wr->length+=DTLS1_RT_HEADER_LENGTH;
1458
1459 #if 0  /* this is now done at the message layer */
1460         /* buffer the record, making it easy to handle retransmits */
1461         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1462                 dtls1_buffer_record(s, wr->data, wr->length, 
1463                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1464 #endif
1465
1466         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1467
1468         if (create_empty_fragment)
1469                 {
1470                 /* we are in a recursive call;
1471                  * just return the length, don't write out anything here
1472                  */
1473                 return wr->length;
1474                 }
1475
1476         /* now let's set up wb */
1477         wb->left = prefix_len + wr->length;
1478         wb->offset = 0;
1479
1480         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1481         s->s3->wpend_tot=len;
1482         s->s3->wpend_buf=buf;
1483         s->s3->wpend_type=type;
1484         s->s3->wpend_ret=len;
1485
1486         /* we now just need to write the buffer */
1487         return ssl3_write_pending(s,type,buf,len);
1488 err:
1489         return -1;
1490         }
1491
1492
1493
1494 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1495         {
1496         int cmp;
1497         unsigned int shift;
1498         const unsigned char *seq = s->s3->read_sequence;
1499
1500         cmp = satsub64be(seq,bitmap->max_seq_num);
1501         if (cmp > 0)
1502                 {
1503                 memcpy (s->s3->rrec.seq_num,seq,8);
1504                 return 1; /* this record in new */
1505                 }
1506         shift = -cmp;
1507         if (shift >= sizeof(bitmap->map)*8)
1508                 return 0; /* stale, outside the window */
1509         else if (bitmap->map & (1UL<<shift))
1510                 return 0; /* record previously received */
1511
1512         memcpy (s->s3->rrec.seq_num,seq,8);
1513         return 1;
1514         }
1515
1516
1517 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1518         {
1519         int cmp;
1520         unsigned int shift;
1521         const unsigned char *seq = s->s3->read_sequence;
1522
1523         cmp = satsub64be(seq,bitmap->max_seq_num);
1524         if (cmp > 0)
1525                 {
1526                 shift = cmp;
1527                 if (shift < sizeof(bitmap->map)*8)
1528                         bitmap->map <<= shift, bitmap->map |= 1UL;
1529                 else
1530                         bitmap->map = 1UL;
1531                 memcpy(bitmap->max_seq_num,seq,8);
1532                 }
1533         else    {
1534                 shift = -cmp;
1535                 if (shift < sizeof(bitmap->map)*8)
1536                         bitmap->map |= 1UL<<shift;
1537                 }
1538         }
1539
1540
1541 int dtls1_dispatch_alert(SSL *s)
1542         {
1543         int i,j;
1544         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1545         unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1546         unsigned char *ptr = &buf[0];
1547
1548         s->s3->alert_dispatch=0;
1549
1550         memset(buf, 0x00, sizeof(buf));
1551         *ptr++ = s->s3->send_alert[0];
1552         *ptr++ = s->s3->send_alert[1];
1553
1554 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1555         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1556                 {       
1557                 s2n(s->d1->handshake_read_seq, ptr);
1558 #if 0
1559                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1560
1561                 else
1562                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1563 #endif
1564
1565 #if 0
1566                 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);
1567 #endif
1568                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1569                 }
1570 #endif
1571
1572         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1573         if (i <= 0)
1574                 {
1575                 s->s3->alert_dispatch=1;
1576                 /* fprintf( stderr, "not done with alert\n" ); */
1577                 }
1578         else
1579                 {
1580                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1581 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1582                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1583 #endif
1584                     )
1585                         (void)BIO_flush(s->wbio);
1586
1587                 if (s->msg_callback)
1588                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 
1589                                 2, s, s->msg_callback_arg);
1590
1591                 if (s->info_callback != NULL)
1592                         cb=s->info_callback;
1593                 else if (s->ctx->info_callback != NULL)
1594                         cb=s->ctx->info_callback;
1595
1596                 if (cb != NULL)
1597                         {
1598                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1599                         cb(s,SSL_CB_WRITE_ALERT,j);
1600                         }
1601                 }
1602         return(i);
1603         }
1604
1605
1606 static DTLS1_BITMAP *
1607 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1608     {
1609     
1610     *is_next_epoch = 0;
1611
1612     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1613     if (rr->epoch == s->d1->r_epoch)
1614         return &s->d1->bitmap;
1615
1616     /* Only HM and ALERT messages can be from the next epoch */
1617     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1618         (rr->type == SSL3_RT_HANDSHAKE ||
1619             rr->type == SSL3_RT_ALERT))
1620         {
1621         *is_next_epoch = 1;
1622         return &s->d1->next_bitmap;
1623         }
1624
1625     return NULL;
1626     }
1627
1628 #if 0
1629 static int
1630 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1631         unsigned long *offset)
1632         {
1633
1634         /* alerts are passed up immediately */
1635         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1636                 rr->type == SSL3_RT_ALERT)
1637                 return 0;
1638
1639         /* Only need to buffer if a handshake is underway.
1640          * (this implies that Hello Request and Client Hello are passed up
1641          * immediately) */
1642         if ( SSL_in_init(s))
1643                 {
1644                 unsigned char *data = rr->data;
1645                 /* need to extract the HM/CCS sequence number here */
1646                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1647                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1648                         {
1649                         unsigned short seq_num;
1650                         struct hm_header_st msg_hdr;
1651                         struct ccs_header_st ccs_hdr;
1652
1653                         if ( rr->type == SSL3_RT_HANDSHAKE)
1654                                 {
1655                                 dtls1_get_message_header(data, &msg_hdr);
1656                                 seq_num = msg_hdr.seq;
1657                                 *offset = msg_hdr.frag_off;
1658                                 }
1659                         else
1660                                 {
1661                                 dtls1_get_ccs_header(data, &ccs_hdr);
1662                                 seq_num = ccs_hdr.seq;
1663                                 *offset = 0;
1664                                 }
1665                                 
1666                         /* this is either a record we're waiting for, or a
1667                          * retransmit of something we happened to previously 
1668                          * receive (higher layers will drop the repeat silently */
1669                         if ( seq_num < s->d1->handshake_read_seq)
1670                                 return 0;
1671                         if (rr->type == SSL3_RT_HANDSHAKE && 
1672                                 seq_num == s->d1->handshake_read_seq &&
1673                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1674                                 return 0;
1675                         else if ( seq_num == s->d1->handshake_read_seq &&
1676                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1677                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1678                                 return 0;
1679                         else
1680                                 {
1681                                 *priority = seq_num;
1682                                 return 1;
1683                                 }
1684                         }
1685                 else /* unknown record type */
1686                         return 0;
1687                 }
1688
1689         return 0;
1690         }
1691 #endif
1692
1693 void
1694 dtls1_reset_seq_numbers(SSL *s, int rw)
1695         {
1696         unsigned char *seq;
1697         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1698
1699         if ( rw & SSL3_CC_READ)
1700                 {
1701                 seq = s->s3->read_sequence;
1702                 s->d1->r_epoch++;
1703                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1704                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1705                 }
1706         else
1707                 {
1708                 seq = s->s3->write_sequence;
1709                 s->d1->w_epoch++;
1710                 }
1711
1712         memset(seq, 0x00, seq_bytes);
1713         }
1714
1715
1716 static void
1717 dtls1_clear_timeouts(SSL *s)
1718         {
1719         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1720         }