PR: 2573
[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 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
126         int len, int peek);
127 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
128         PQ_64BIT *seq_num);
129 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
130 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 
131     unsigned int *is_next_epoch);
132 #if 0
133 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
134         unsigned short *priority, unsigned long *offset);
135 #endif
136 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
137         PQ_64BIT *priority);
138 static int dtls1_process_record(SSL *s);
139 #if PQ_64BIT_IS_INTEGER
140 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);
141 #endif
142 static void dtls1_clear_timeouts(SSL *s);
143
144 /* copy buffered record into SSL structure */
145 static int
146 dtls1_copy_record(SSL *s, pitem *item)
147     {
148     DTLS1_RECORD_DATA *rdata;
149
150     rdata = (DTLS1_RECORD_DATA *)item->data;
151     
152     if (s->s3->rbuf.buf != NULL)
153         OPENSSL_free(s->s3->rbuf.buf);
154     
155     s->packet = rdata->packet;
156     s->packet_length = rdata->packet_length;
157     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
158     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
159         
160         /* Set proper sequence number for mac calculation */
161         memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
162     
163     return(1);
164     }
165
166
167 static int
168 dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT *priority)
169 {
170     DTLS1_RECORD_DATA *rdata;
171         pitem *item;
172
173         /* Limit the size of the queue to prevent DOS attacks */
174         if (pqueue_size(queue->q) >= 100)
175                 return 0;
176                 
177         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
178         item = pitem_new(*priority, rdata);
179         if (rdata == NULL || item == NULL)
180                 {
181                 if (rdata != NULL) OPENSSL_free(rdata);
182                 if (item != NULL) pitem_free(item);
183                 
184                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
185                 return(0);
186                 }
187         
188         rdata->packet = s->packet;
189         rdata->packet_length = s->packet_length;
190         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
191         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
192
193         item->data = rdata;
194
195         /* insert should not fail, since duplicates are dropped */
196         if (pqueue_insert(queue->q, item) == NULL)
197                 {
198                 OPENSSL_free(rdata);
199                 pitem_free(item);
200                 return(0);
201                 }
202
203         s->packet = NULL;
204         s->packet_length = 0;
205         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
206         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
207         
208         if (!ssl3_setup_buffers(s))
209                 {
210                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
211                 OPENSSL_free(rdata);
212                 pitem_free(item);
213                 return(0);
214                 }
215         
216         return(1);
217     }
218
219
220 static int
221 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
222     {
223     pitem *item;
224
225     item = pqueue_pop(queue->q);
226     if (item)
227         {
228         dtls1_copy_record(s, item);
229
230         OPENSSL_free(item->data);
231                 pitem_free(item);
232
233         return(1);
234         }
235
236     return(0);
237     }
238
239
240 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 
241  * yet */
242 #define dtls1_get_unprocessed_record(s) \
243                    dtls1_retrieve_buffered_record((s), \
244                    &((s)->d1->unprocessed_rcds))
245
246 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
247 #define dtls1_get_processed_record(s) \
248                    dtls1_retrieve_buffered_record((s), \
249                    &((s)->d1->processed_rcds))
250
251 static int
252 dtls1_process_buffered_records(SSL *s)
253     {
254     pitem *item;
255     
256     item = pqueue_peek(s->d1->unprocessed_rcds.q);
257     if (item)
258         {
259         /* Check if epoch is current. */
260         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
261             return(1);  /* Nothing to do. */
262         
263         /* Process all the records. */
264         while (pqueue_peek(s->d1->unprocessed_rcds.q))
265             {
266             dtls1_get_unprocessed_record(s);
267             if ( ! dtls1_process_record(s))
268                 return(0);
269             dtls1_buffer_record(s, &(s->d1->processed_rcds), 
270                 &s->s3->rrec.seq_num);
271             }
272         }
273
274     /* sync epoch numbers once all the unprocessed records 
275      * have been processed */
276     s->d1->processed_rcds.epoch = s->d1->r_epoch;
277     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
278
279     return(1);
280     }
281
282
283 #if 0
284
285 static int
286 dtls1_get_buffered_record(SSL *s)
287         {
288         pitem *item;
289         PQ_64BIT priority = 
290                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 
291                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
292         
293         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating, 
294                                                            nothing buffered */
295                 return 0;
296
297
298         item = pqueue_peek(s->d1->rcvd_records);
299         if (item && item->priority == priority)
300                 {
301                 /* Check if we've received the record of interest.  It must be
302                  * a handshake record, since data records as passed up without
303                  * buffering */
304                 DTLS1_RECORD_DATA *rdata;
305                 item = pqueue_pop(s->d1->rcvd_records);
306                 rdata = (DTLS1_RECORD_DATA *)item->data;
307                 
308                 if (s->s3->rbuf.buf != NULL)
309                         OPENSSL_free(s->s3->rbuf.buf);
310                 
311                 s->packet = rdata->packet;
312                 s->packet_length = rdata->packet_length;
313                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
314                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
315                 
316                 OPENSSL_free(item->data);
317                 pitem_free(item);
318                 
319                 /* s->d1->next_expected_seq_num++; */
320                 return(1);
321                 }
322         
323         return 0;
324         }
325
326 #endif
327
328 static int
329 dtls1_process_record(SSL *s)
330 {
331     int al;
332         int clear=0;
333     int enc_err;
334         SSL_SESSION *sess;
335     SSL3_RECORD *rr;
336         unsigned int mac_size;
337         unsigned char md[EVP_MAX_MD_SIZE];
338
339
340         rr= &(s->s3->rrec);
341     sess = s->session;
342
343         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
344          * and we have that many bytes in s->packet
345          */
346         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
347
348         /* ok, we can now read from 's->packet' data into 'rr'
349          * rr->input points at rr->length bytes, which
350          * need to be copied into rr->data by either
351          * the decryption or by the decompression
352          * When the data is 'copied' into the rr->data buffer,
353          * rr->input will be pointed at the new buffer */ 
354
355         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
356          * rr->length bytes of encrypted compressed stuff. */
357
358         /* check is not needed I believe */
359         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
360                 {
361                 al=SSL_AD_RECORD_OVERFLOW;
362                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
363                 goto f_err;
364                 }
365
366         /* decrypt in place in 'rr->input' */
367         rr->data=rr->input;
368
369         enc_err = s->method->ssl3_enc->enc(s,0);
370         if (enc_err <= 0)
371                 {
372                 /* decryption failed, silently discard message */
373                 if (enc_err < 0)
374                         {
375                         rr->length = 0;
376                         s->packet_length = 0;
377                         }
378                 goto err;
379                 }
380
381 #ifdef TLS_DEBUG
382 printf("dec %d\n",rr->length);
383 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
384 printf("\n");
385 #endif
386
387         /* r->length is now the compressed data plus mac */
388 if (    (sess == NULL) ||
389                 (s->enc_read_ctx == NULL) ||
390                 (s->read_hash == NULL))
391     clear=1;
392
393         if (!clear)
394                 {
395                 mac_size=EVP_MD_size(s->read_hash);
396
397                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
398                         {
399 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
400                         al=SSL_AD_RECORD_OVERFLOW;
401                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
402                         goto f_err;
403 #else
404                         goto err;
405 #endif                  
406                         }
407                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
408                 if (rr->length < mac_size)
409                         {
410 #if 0 /* OK only for stream ciphers */
411                         al=SSL_AD_DECODE_ERROR;
412                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
413                         goto f_err;
414 #else
415                         goto err;
416 #endif
417                         }
418                 rr->length-=mac_size;
419                 s->method->ssl3_enc->mac(s,md,0);
420                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
421                         {
422                         goto err;
423                         }
424                 }
425
426         /* r->length is now just compressed */
427         if (s->expand != NULL)
428                 {
429                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
430                         {
431                         al=SSL_AD_RECORD_OVERFLOW;
432                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
433                         goto f_err;
434                         }
435                 if (!ssl3_do_uncompress(s))
436                         {
437                         al=SSL_AD_DECOMPRESSION_FAILURE;
438                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
439                         goto f_err;
440                         }
441                 }
442
443         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
444                 {
445                 al=SSL_AD_RECORD_OVERFLOW;
446                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
447                 goto f_err;
448                 }
449
450         rr->off=0;
451         /* So at this point the following is true
452          * ssl->s3->rrec.type   is the type of record
453          * ssl->s3->rrec.length == number of bytes in record
454          * ssl->s3->rrec.off    == offset to first valid byte
455          * ssl->s3->rrec.data   == where to take bytes from, increment
456          *                         after use :-).
457          */
458
459         /* we have pulled in a full packet so zero things */
460         s->packet_length=0;
461     dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
462     return(1);
463
464 f_err:
465         ssl3_send_alert(s,SSL3_AL_FATAL,al);
466 err:
467         return(0);
468 }
469
470
471 /* Call this to get a new input record.
472  * It will return <= 0 if more data is needed, normally due to an error
473  * or non-blocking IO.
474  * When it finishes, one packet has been decoded and can be found in
475  * ssl->s3->rrec.type    - is the type of record
476  * ssl->s3->rrec.data,   - data
477  * ssl->s3->rrec.length, - number of bytes
478  */
479 /* used only by dtls1_read_bytes */
480 int dtls1_get_record(SSL *s)
481         {
482         int ssl_major,ssl_minor;
483         int i,n;
484         SSL3_RECORD *rr;
485         unsigned char *p = NULL;
486         unsigned short version;
487         DTLS1_BITMAP *bitmap;
488         unsigned int is_next_epoch;
489
490         rr= &(s->s3->rrec);
491
492     /* The epoch may have changed.  If so, process all the
493      * pending records.  This is a non-blocking operation. */
494     dtls1_process_buffered_records(s);
495
496         /* if we're renegotiating, then there may be buffered records */
497         if (dtls1_get_processed_record(s))
498                 return 1;
499
500         /* get something from the wire */
501 again:
502         /* check if we have the header */
503         if (    (s->rstate != SSL_ST_READ_BODY) ||
504                 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 
505                 {
506                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
507                 /* read timeout is handled by dtls1_read_bytes */
508                 if (n <= 0) return(n); /* error or non-blocking */
509
510                 /* this packet contained a partial record, dump it */
511                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
512                         {
513                         s->packet_length = 0;
514                         goto again;
515                         }
516
517                 s->rstate=SSL_ST_READ_BODY;
518
519                 p=s->packet;
520
521                 /* Pull apart the header into the DTLS1_RECORD */
522                 rr->type= *(p++);
523                 ssl_major= *(p++);
524                 ssl_minor= *(p++);
525                 version=(ssl_major<<8)|ssl_minor;
526
527                 /* sequence number is 64 bits, with top 2 bytes = epoch */ 
528                 n2s(p,rr->epoch);
529
530                 memcpy(&(s->s3->read_sequence[2]), p, 6);
531                 p+=6;
532
533                 n2s(p,rr->length);
534
535                 /* Lets check version */
536                 if (!s->first_packet)
537                         {
538                         if (version != s->version && version != DTLS1_BAD_VER)
539                                 {
540                                 /* unexpected version, silently discard */
541                                 rr->length = 0;
542                                 s->packet_length = 0;
543                                 goto again;
544                                 }
545                         }
546
547                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
548                     (version & 0xff00) != (DTLS1_BAD_VER & 0xff00))
549                         {
550                         /* wrong version, silently discard record */
551                         rr->length = 0;
552                         s->packet_length = 0;
553                         goto again;
554                         }
555
556                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
557                         {
558                         /* record too long, silently discard it */
559                         rr->length = 0;
560                         s->packet_length = 0;
561                         goto again;
562                         }
563
564                 s->client_version = version;
565                 /* now s->rstate == SSL_ST_READ_BODY */
566                 }
567
568         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
569
570         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
571                 {
572                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
573                 i=rr->length;
574                 n=ssl3_read_n(s,i,i,1);
575                 if (n <= 0) return(n); /* error or non-blocking io */
576
577                 /* this packet contained a partial record, dump it */
578                 if ( n != i)
579                         {
580                         rr->length = 0;
581                         s->packet_length = 0;
582                         goto again;
583                         }
584
585                 /* now n == rr->length,
586                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
587                 }
588         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
589
590         /* match epochs.  NULL means the packet is dropped on the floor */
591         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
592         if ( bitmap == NULL)
593         {
594         rr->length = 0;
595         s->packet_length = 0;  /* dump this record */
596         goto again;   /* get another record */
597                 }
598
599         /* Check whether this is a repeat, or aged record.
600          * Don't check if we're listening and this message is
601          * a ClientHello. They can look as if they're replayed,
602          * since they arrive from different connections and
603          * would be dropped unnecessarily.
604          */
605         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
606                 *p == SSL3_MT_CLIENT_HELLO) &&
607                 ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
608                 {
609                 rr->length = 0;
610                 s->packet_length=0; /* dump this record */
611                 goto again;     /* get another record */
612                 }
613
614         /* just read a 0 length packet */
615         if (rr->length == 0) goto again;
616
617         /* If this record is from the next epoch (either HM or ALERT),
618          * and a handshake is currently in progress, buffer it since it
619          * cannot be processed at this time. However, do not buffer
620          * anything while listening.
621          */
622         if (is_next_epoch)
623                 {
624                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
625                         {
626                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), &rr->seq_num);
627                         }
628                 rr->length = 0;
629         s->packet_length = 0;
630         goto again;
631         }
632
633     if (!dtls1_process_record(s))
634                 {
635                 rr->length = 0;
636                 s->packet_length=0; /* dump this record */
637                 goto again;     /* get another record */
638                 }
639
640         dtls1_clear_timeouts(s);  /* done waiting */
641         return(1);
642
643         }
644
645 /* Return up to 'len' payload bytes received in 'type' records.
646  * 'type' is one of the following:
647  *
648  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
649  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
650  *   -  0 (during a shutdown, no data has to be returned)
651  *
652  * If we don't have stored data to work from, read a SSL/TLS record first
653  * (possibly multiple records if we still don't have anything to return).
654  *
655  * This function must handle any surprises the peer may have for us, such as
656  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
657  * a surprise, but handled as if it were), or renegotiation requests.
658  * Also if record payloads contain fragments too small to process, we store
659  * them until there is enough for the respective protocol (the record protocol
660  * may use arbitrary fragmentation and even interleaving):
661  *     Change cipher spec protocol
662  *             just 1 byte needed, no need for keeping anything stored
663  *     Alert protocol
664  *             2 bytes needed (AlertLevel, AlertDescription)
665  *     Handshake protocol
666  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
667  *             to detect unexpected Client Hello and Hello Request messages
668  *             here, anything else is handled by higher layers
669  *     Application data protocol
670  *             none of our business
671  */
672 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
673         {
674         int al,i,j,ret;
675         unsigned int n;
676         SSL3_RECORD *rr;
677         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
678
679         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
680                 if (!ssl3_setup_buffers(s))
681                         return(-1);
682
683     /* XXX: check what the second '&& type' is about */
684         if ((type && (type != SSL3_RT_APPLICATION_DATA) && 
685                 (type != SSL3_RT_HANDSHAKE) && type) ||
686             (peek && (type != SSL3_RT_APPLICATION_DATA)))
687                 {
688                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
689                 return -1;
690                 }
691
692         /* check whether there's a handshake message (client hello?) waiting */
693         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
694                 return ret;
695
696         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
697
698         if (!s->in_handshake && SSL_in_init(s))
699                 {
700                 /* type == SSL3_RT_APPLICATION_DATA */
701                 i=s->handshake_func(s);
702                 if (i < 0) return(i);
703                 if (i == 0)
704                         {
705                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
706                         return(-1);
707                         }
708                 }
709
710 start:
711         s->rwstate=SSL_NOTHING;
712
713         /* s->s3->rrec.type         - is the type of record
714          * s->s3->rrec.data,    - data
715          * s->s3->rrec.off,     - offset into 'data' for next read
716          * s->s3->rrec.length,  - number of bytes. */
717         rr = &(s->s3->rrec);
718
719         /* We are not handshaking and have no data yet,
720          * so process data buffered during the last handshake
721          * in advance, if any.
722          */
723         if (s->state == SSL_ST_OK && rr->length == 0)
724                 {
725                 pitem *item;
726                 item = pqueue_pop(s->d1->buffered_app_data.q);
727                 if (item)
728                         {
729                         dtls1_copy_record(s, item);
730
731                         OPENSSL_free(item->data);
732                         pitem_free(item);
733                         }
734                 }
735
736         /* Check for timeout */
737         if (dtls1_handle_timeout(s) > 0)
738                 goto start;
739
740         /* get new packet if necessary */
741         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
742                 {
743                 ret=dtls1_get_record(s);
744                 if (ret <= 0) 
745                         {
746                         ret = dtls1_read_failed(s, ret);
747                         /* anything other than a timeout is an error */
748                         if (ret <= 0)  
749                                 return(ret);
750                         else
751                                 goto start;
752                         }
753                 }
754
755         /* we now have a packet which can be read and processed */
756
757         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
758                                        * reset by ssl3_get_finished */
759                 && (rr->type != SSL3_RT_HANDSHAKE))
760                 {
761                 /* We now have application data between CCS and Finished.
762                  * Most likely the packets were reordered on their way, so
763                  * buffer the application data for later processing rather
764                  * than dropping the connection.
765                  */
766                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), &rr->seq_num);
767                 rr->length = 0;
768                 goto start;
769                 }
770
771         /* If the other end has shut down, throw anything we read away
772          * (even in 'peek' mode) */
773         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
774                 {
775                 rr->length=0;
776                 s->rwstate=SSL_NOTHING;
777                 return(0);
778                 }
779
780
781         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
782                 {
783                 /* make sure that we are not getting application data when we
784                  * are doing a handshake for the first time */
785                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
786                         (s->enc_read_ctx == NULL))
787                         {
788                         al=SSL_AD_UNEXPECTED_MESSAGE;
789                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
790                         goto f_err;
791                         }
792
793                 if (len <= 0) return(len);
794
795                 if ((unsigned int)len > rr->length)
796                         n = rr->length;
797                 else
798                         n = (unsigned int)len;
799
800                 memcpy(buf,&(rr->data[rr->off]),n);
801                 if (!peek)
802                         {
803                         rr->length-=n;
804                         rr->off+=n;
805                         if (rr->length == 0)
806                                 {
807                                 s->rstate=SSL_ST_READ_HEADER;
808                                 rr->off=0;
809                                 }
810                         }
811                 return(n);
812                 }
813
814
815         /* If we get here, then type != rr->type; if we have a handshake
816          * message, then it was unexpected (Hello Request or Client Hello). */
817
818         /* In case of record types for which we have 'fragment' storage,
819          * fill that so that we can process the data at a fixed place.
820          */
821                 {
822                 unsigned int k, dest_maxlen = 0;
823                 unsigned char *dest = NULL;
824                 unsigned int *dest_len = NULL;
825
826                 if (rr->type == SSL3_RT_HANDSHAKE)
827                         {
828                         dest_maxlen = sizeof s->d1->handshake_fragment;
829                         dest = s->d1->handshake_fragment;
830                         dest_len = &s->d1->handshake_fragment_len;
831                         }
832                 else if (rr->type == SSL3_RT_ALERT)
833                         {
834                         dest_maxlen = sizeof(s->d1->alert_fragment);
835                         dest = s->d1->alert_fragment;
836                         dest_len = &s->d1->alert_fragment_len;
837                         }
838                 /* else it's a CCS message, or application data or wrong */
839                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
840                         {
841                         /* Application data while renegotiating
842                          * is allowed. Try again reading.
843                          */
844                         if (rr->type == SSL3_RT_APPLICATION_DATA)
845                                 {
846                                 BIO *bio;
847                                 s->s3->in_read_app_data=2;
848                                 bio=SSL_get_rbio(s);
849                                 s->rwstate=SSL_READING;
850                                 BIO_clear_retry_flags(bio);
851                                 BIO_set_retry_read(bio);
852                                 return(-1);
853                                 }
854
855                         /* Not certain if this is the right error handling */
856                         al=SSL_AD_UNEXPECTED_MESSAGE;
857                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
858                         goto f_err;
859                         }
860
861                 if (dest_maxlen > 0)
862                         {
863             /* XDTLS:  In a pathalogical case, the Client Hello
864              *  may be fragmented--don't always expect dest_maxlen bytes */
865                         if ( rr->length < dest_maxlen)
866                                 {
867 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
868                                 /*
869                                  * for normal alerts rr->length is 2, while
870                                  * dest_maxlen is 7 if we were to handle this
871                                  * non-existing alert...
872                                  */
873                                 FIX ME
874 #endif
875                                 s->rstate=SSL_ST_READ_HEADER;
876                                 rr->length = 0;
877                                 goto start;
878                                 }
879
880                         /* now move 'n' bytes: */
881                         for ( k = 0; k < dest_maxlen; k++)
882                                 {
883                                 dest[k] = rr->data[rr->off++];
884                                 rr->length--;
885                                 }
886                         *dest_len = dest_maxlen;
887                         }
888                 }
889
890         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
891          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
892          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
893
894         /* If we are a client, check for an incoming 'Hello Request': */
895         if ((!s->server) &&
896                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
897                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
898                 (s->session != NULL) && (s->session->cipher != NULL))
899                 {
900                 s->d1->handshake_fragment_len = 0;
901
902                 if ((s->d1->handshake_fragment[1] != 0) ||
903                         (s->d1->handshake_fragment[2] != 0) ||
904                         (s->d1->handshake_fragment[3] != 0))
905                         {
906                         al=SSL_AD_DECODE_ERROR;
907                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
908                         goto err;
909                         }
910
911                 /* no need to check sequence number on HELLO REQUEST messages */
912
913                 if (s->msg_callback)
914                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
915                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
916
917                 if (SSL_is_init_finished(s) &&
918                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
919                         !s->s3->renegotiate)
920                         {
921                         ssl3_renegotiate(s);
922                         if (ssl3_renegotiate_check(s))
923                                 {
924                                 i=s->handshake_func(s);
925                                 if (i < 0) return(i);
926                                 if (i == 0)
927                                         {
928                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
929                                         return(-1);
930                                         }
931
932                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
933                                         {
934                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
935                                                 {
936                                                 BIO *bio;
937                                                 /* In the case where we try to read application data,
938                                                  * but we trigger an SSL handshake, we return -1 with
939                                                  * the retry option set.  Otherwise renegotiation may
940                                                  * cause nasty problems in the blocking world */
941                                                 s->rwstate=SSL_READING;
942                                                 bio=SSL_get_rbio(s);
943                                                 BIO_clear_retry_flags(bio);
944                                                 BIO_set_retry_read(bio);
945                                                 return(-1);
946                                                 }
947                                         }
948                                 }
949                         }
950                 /* we either finished a handshake or ignored the request,
951                  * now try again to obtain the (application) data we were asked for */
952                 goto start;
953                 }
954
955         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
956                 {
957                 int alert_level = s->d1->alert_fragment[0];
958                 int alert_descr = s->d1->alert_fragment[1];
959
960                 s->d1->alert_fragment_len = 0;
961
962                 if (s->msg_callback)
963                         s->msg_callback(0, s->version, SSL3_RT_ALERT, 
964                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
965
966                 if (s->info_callback != NULL)
967                         cb=s->info_callback;
968                 else if (s->ctx->info_callback != NULL)
969                         cb=s->ctx->info_callback;
970
971                 if (cb != NULL)
972                         {
973                         j = (alert_level << 8) | alert_descr;
974                         cb(s, SSL_CB_READ_ALERT, j);
975                         }
976
977                 if (alert_level == 1) /* warning */
978                         {
979                         s->s3->warn_alert = alert_descr;
980                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
981                                 {
982                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
983                                 return(0);
984                                 }
985 #if 0
986             /* XXX: this is a possible improvement in the future */
987                         /* now check if it's a missing record */
988                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
989                                 {
990                                 unsigned short seq;
991                                 unsigned int frag_off;
992                                 unsigned char *p = &(s->d1->alert_fragment[2]);
993
994                                 n2s(p, seq);
995                                 n2l3(p, frag_off);
996
997                                 dtls1_retransmit_message(s,
998                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
999                                                                                  frag_off, &found);
1000                                 if ( ! found  && SSL_in_init(s))
1001                                         {
1002                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1003                                         /* requested a message not yet sent, 
1004                                            send an alert ourselves */
1005                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1006                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1007                                         }
1008                                 }
1009 #endif
1010                         }
1011                 else if (alert_level == 2) /* fatal */
1012                         {
1013                         char tmp[16];
1014
1015                         s->rwstate=SSL_NOTHING;
1016                         s->s3->fatal_alert = alert_descr;
1017                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1018                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1019                         ERR_add_error_data(2,"SSL alert number ",tmp);
1020                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1021                         SSL_CTX_remove_session(s->ctx,s->session);
1022                         return(0);
1023                         }
1024                 else
1025                         {
1026                         al=SSL_AD_ILLEGAL_PARAMETER;
1027                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1028                         goto f_err;
1029                         }
1030
1031                 goto start;
1032                 }
1033
1034         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1035                 {
1036                 s->rwstate=SSL_NOTHING;
1037                 rr->length=0;
1038                 return(0);
1039                 }
1040
1041         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1042                 {
1043                 struct ccs_header_st ccs_hdr;
1044                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1045
1046                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1047
1048                 /* 'Change Cipher Spec' is just a single byte, so we know
1049                  * exactly what the record payload has to look like */
1050                 /* XDTLS: check that epoch is consistent */
1051                 if (s->client_version == DTLS1_BAD_VER || s->version == DTLS1_BAD_VER)
1052                         ccs_hdr_len = 3;
1053
1054                 if ((rr->length != ccs_hdr_len) || (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1055                         {
1056                         i=SSL_AD_ILLEGAL_PARAMETER;
1057                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1058                         goto err;
1059                         }
1060
1061                 rr->length=0;
1062
1063                 if (s->msg_callback)
1064                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
1065                                 rr->data, 1, s, s->msg_callback_arg);
1066
1067                 /* We can't process a CCS now, because previous handshake
1068                  * messages are still missing, so just drop it.
1069                  */
1070                 if (!s->d1->change_cipher_spec_ok)
1071                         {
1072                         goto start;
1073                         }
1074
1075                 s->d1->change_cipher_spec_ok = 0;
1076
1077                 s->s3->change_cipher_spec=1;
1078                 if (!ssl3_do_change_cipher_spec(s))
1079                         goto err;
1080
1081                 /* do this whenever CCS is processed */
1082                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1083
1084                 if (s->client_version == DTLS1_BAD_VER)
1085                         s->d1->handshake_read_seq++;
1086
1087                 goto start;
1088                 }
1089
1090         /* Unexpected handshake message (Client Hello, or protocol violation) */
1091         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 
1092                 !s->in_handshake)
1093                 {
1094                 struct hm_header_st msg_hdr;
1095                 
1096                 /* this may just be a stale retransmit */
1097                 dtls1_get_message_header(rr->data, &msg_hdr);
1098                 if( rr->epoch != s->d1->r_epoch)
1099                         {
1100                         rr->length = 0;
1101                         goto start;
1102                         }
1103
1104                 /* If we are server, we may have a repeated FINISHED of the
1105                  * client here, then retransmit our CCS and FINISHED.
1106                  */
1107                 if (msg_hdr.type == SSL3_MT_FINISHED)
1108                         {
1109                         dtls1_retransmit_buffered_messages(s);
1110                         rr->length = 0;
1111                         goto start;
1112                         }
1113
1114                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1115                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1116                         {
1117 #if 0 /* worked only because C operator preferences are not as expected (and
1118        * because this is not really needed for clients except for detecting
1119        * protocol violations): */
1120                         s->state=SSL_ST_BEFORE|(s->server)
1121                                 ?SSL_ST_ACCEPT
1122                                 :SSL_ST_CONNECT;
1123 #else
1124                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1125 #endif
1126                         s->new_session=1;
1127                         }
1128                 i=s->handshake_func(s);
1129                 if (i < 0) return(i);
1130                 if (i == 0)
1131                         {
1132                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1133                         return(-1);
1134                         }
1135
1136                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1137                         {
1138                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1139                                 {
1140                                 BIO *bio;
1141                                 /* In the case where we try to read application data,
1142                                  * but we trigger an SSL handshake, we return -1 with
1143                                  * the retry option set.  Otherwise renegotiation may
1144                                  * cause nasty problems in the blocking world */
1145                                 s->rwstate=SSL_READING;
1146                                 bio=SSL_get_rbio(s);
1147                                 BIO_clear_retry_flags(bio);
1148                                 BIO_set_retry_read(bio);
1149                                 return(-1);
1150                                 }
1151                         }
1152                 goto start;
1153                 }
1154
1155         switch (rr->type)
1156                 {
1157         default:
1158 #ifndef OPENSSL_NO_TLS
1159                 /* TLS just ignores unknown message types */
1160                 if (s->version == TLS1_VERSION)
1161                         {
1162                         rr->length = 0;
1163                         goto start;
1164                         }
1165 #endif
1166                 al=SSL_AD_UNEXPECTED_MESSAGE;
1167                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1168                 goto f_err;
1169         case SSL3_RT_CHANGE_CIPHER_SPEC:
1170         case SSL3_RT_ALERT:
1171         case SSL3_RT_HANDSHAKE:
1172                 /* we already handled all of these, with the possible exception
1173                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1174                  * should not happen when type != rr->type */
1175                 al=SSL_AD_UNEXPECTED_MESSAGE;
1176                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1177                 goto f_err;
1178         case SSL3_RT_APPLICATION_DATA:
1179                 /* At this point, we were expecting handshake data,
1180                  * but have application data.  If the library was
1181                  * running inside ssl3_read() (i.e. in_read_app_data
1182                  * is set) and it makes sense to read application data
1183                  * at this point (session renegotiation not yet started),
1184                  * we will indulge it.
1185                  */
1186                 if (s->s3->in_read_app_data &&
1187                         (s->s3->total_renegotiations != 0) &&
1188                         ((
1189                                 (s->state & SSL_ST_CONNECT) &&
1190                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1191                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1192                                 ) || (
1193                                         (s->state & SSL_ST_ACCEPT) &&
1194                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1195                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1196                                         )
1197                                 ))
1198                         {
1199                         s->s3->in_read_app_data=2;
1200                         return(-1);
1201                         }
1202                 else
1203                         {
1204                         al=SSL_AD_UNEXPECTED_MESSAGE;
1205                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1206                         goto f_err;
1207                         }
1208                 }
1209         /* not reached */
1210
1211 f_err:
1212         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1213 err:
1214         return(-1);
1215         }
1216
1217 int
1218 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1219         {
1220         int i;
1221
1222         if (SSL_in_init(s) && !s->in_handshake)
1223                 {
1224                 i=s->handshake_func(s);
1225                 if (i < 0) return(i);
1226                 if (i == 0)
1227                         {
1228                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1229                         return -1;
1230                         }
1231                 }
1232
1233         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1234                 {
1235                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1236                         return -1;
1237                 }
1238
1239         i = dtls1_write_bytes(s, type, buf_, len);
1240         return i;
1241         }
1242
1243
1244         /* this only happens when a client hello is received and a handshake 
1245          * is started. */
1246 static int
1247 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
1248         int len, int peek)
1249         {
1250         
1251         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1252                 /* (partially) satisfy request from storage */
1253                 {
1254                 unsigned char *src = s->d1->handshake_fragment;
1255                 unsigned char *dst = buf;
1256                 unsigned int k,n;
1257                 
1258                 /* peek == 0 */
1259                 n = 0;
1260                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1261                         {
1262                         *dst++ = *src++;
1263                         len--; s->d1->handshake_fragment_len--;
1264                         n++;
1265                         }
1266                 /* move any remaining fragment bytes: */
1267                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1268                         s->d1->handshake_fragment[k] = *src++;
1269                 return n;
1270                 }
1271         
1272         return 0;
1273         }
1274
1275
1276
1277
1278 /* Call this to write data in records of type 'type'
1279  * It will return <= 0 if not all data has been sent or non-blocking IO.
1280  */
1281 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1282         {
1283         int i;
1284
1285         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1286         s->rwstate=SSL_NOTHING;
1287         i=do_dtls1_write(s, type, buf, len, 0);
1288         return i;
1289         }
1290
1291 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1292         {
1293         unsigned char *p,*pseq;
1294         int i,mac_size,clear=0;
1295         int prefix_len = 0;
1296         SSL3_RECORD *wr;
1297         SSL3_BUFFER *wb;
1298         SSL_SESSION *sess;
1299         int bs;
1300
1301         /* first check if there is a SSL3_BUFFER still being written
1302          * out.  This will happen with non blocking IO */
1303         if (s->s3->wbuf.left != 0)
1304                 {
1305                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1306                 return(ssl3_write_pending(s,type,buf,len));
1307                 }
1308
1309         /* If we have an alert to send, lets send it */
1310         if (s->s3->alert_dispatch)
1311                 {
1312                 i=s->method->ssl_dispatch_alert(s);
1313                 if (i <= 0)
1314                         return(i);
1315                 /* if it went, fall through and send more stuff */
1316                 }
1317
1318         if (len == 0 && !create_empty_fragment)
1319                 return 0;
1320
1321         wr= &(s->s3->wrec);
1322         wb= &(s->s3->wbuf);
1323         sess=s->session;
1324
1325         if (    (sess == NULL) ||
1326                 (s->enc_write_ctx == NULL) ||
1327                 (s->write_hash == NULL))
1328                 clear=1;
1329
1330         if (clear)
1331                 mac_size=0;
1332         else
1333                 mac_size=EVP_MD_size(s->write_hash);
1334
1335         /* DTLS implements explicit IV, so no need for empty fragments */
1336 #if 0
1337         /* 'create_empty_fragment' is true only when this function calls itself */
1338         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1339             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1340                 {
1341                 /* countermeasure against known-IV weakness in CBC ciphersuites
1342                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
1343                  */
1344
1345                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1346                         {
1347                         /* recursive function call with 'create_empty_fragment' set;
1348                          * this prepares and buffers the data for an empty fragment
1349                          * (these 'prefix_len' bytes are sent out later
1350                          * together with the actual payload) */
1351                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1352                         if (prefix_len <= 0)
1353                                 goto err;
1354
1355                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1356                                 {
1357                                 /* insufficient space */
1358                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1359                                 goto err;
1360                                 }
1361                         }
1362                 
1363                 s->s3->empty_fragment_done = 1;
1364                 }
1365 #endif
1366
1367         p = wb->buf + prefix_len;
1368
1369         /* write the header */
1370
1371         *(p++)=type&0xff;
1372         wr->type=type;
1373
1374         if (s->client_version == DTLS1_BAD_VER)
1375                 *(p++) = DTLS1_BAD_VER>>8,
1376                 *(p++) = DTLS1_BAD_VER&0xff;
1377         else
1378                 *(p++)=(s->version>>8),
1379                 *(p++)=s->version&0xff;
1380
1381         /* field where we are to write out packet epoch, seq num and len */
1382         pseq=p; 
1383         p+=10;
1384
1385         /* lets setup the record stuff. */
1386
1387         /* Make space for the explicit IV in case of CBC.
1388          * (this is a bit of a boundary violation, but what the heck).
1389          */
1390         if ( s->enc_write_ctx && 
1391                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1392                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1393         else
1394                 bs = 0;
1395
1396         wr->data=p + bs;  /* make room for IV in case of CBC */
1397         wr->length=(int)len;
1398         wr->input=(unsigned char *)buf;
1399
1400         /* we now 'read' from wr->input, wr->length bytes into
1401          * wr->data */
1402
1403         /* first we compress */
1404         if (s->compress != NULL)
1405                 {
1406                 if (!ssl3_do_compress(s))
1407                         {
1408                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1409                         goto err;
1410                         }
1411                 }
1412         else
1413                 {
1414                 memcpy(wr->data,wr->input,wr->length);
1415                 wr->input=wr->data;
1416                 }
1417
1418         /* we should still have the output to wr->data and the input
1419          * from wr->input.  Length should be wr->length.
1420          * wr->data still points in the wb->buf */
1421
1422         if (mac_size != 0)
1423                 {
1424                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1425                 wr->length+=mac_size;
1426                 }
1427
1428         /* this is true regardless of mac size */
1429         wr->input=p;
1430         wr->data=p;
1431
1432
1433         /* ssl3_enc can only have an error on read */
1434         if (bs) /* bs != 0 in case of CBC */
1435                 {
1436                 RAND_pseudo_bytes(p,bs);
1437                 /* master IV and last CBC residue stand for
1438                  * the rest of randomness */
1439                 wr->length += bs;
1440                 }
1441
1442         s->method->ssl3_enc->enc(s,1);
1443
1444         /* record length after mac and block padding */
1445 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1446         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1447         
1448         /* there's only one epoch between handshake and app data */
1449         
1450         s2n(s->d1->w_epoch, pseq);
1451
1452         /* XDTLS: ?? */
1453 /*      else
1454         s2n(s->d1->handshake_epoch, pseq); */
1455
1456         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1457         pseq+=6;
1458         s2n(wr->length,pseq);
1459
1460         /* we should now have
1461          * wr->data pointing to the encrypted data, which is
1462          * wr->length long */
1463         wr->type=type; /* not needed but helps for debugging */
1464         wr->length+=DTLS1_RT_HEADER_LENGTH;
1465
1466 #if 0  /* this is now done at the message layer */
1467         /* buffer the record, making it easy to handle retransmits */
1468         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1469                 dtls1_buffer_record(s, wr->data, wr->length, 
1470                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1471 #endif
1472
1473         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1474
1475         if (create_empty_fragment)
1476                 {
1477                 /* we are in a recursive call;
1478                  * just return the length, don't write out anything here
1479                  */
1480                 return wr->length;
1481                 }
1482
1483         /* now let's set up wb */
1484         wb->left = prefix_len + wr->length;
1485         wb->offset = 0;
1486
1487         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1488         s->s3->wpend_tot=len;
1489         s->s3->wpend_buf=buf;
1490         s->s3->wpend_type=type;
1491         s->s3->wpend_ret=len;
1492
1493         /* we now just need to write the buffer */
1494         return ssl3_write_pending(s,type,buf,len);
1495 err:
1496         return -1;
1497         }
1498
1499
1500
1501 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1502         PQ_64BIT *seq_num)
1503         {
1504 #if PQ_64BIT_IS_INTEGER
1505         PQ_64BIT mask = 0x0000000000000001L;
1506 #endif
1507         PQ_64BIT rcd_num, tmp;
1508
1509         pq_64bit_init(&rcd_num);
1510         pq_64bit_init(&tmp);
1511
1512         /* this is the sequence number for the record just read */
1513         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1514
1515         
1516         if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1517                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1518                 {
1519                 pq_64bit_assign(seq_num, &rcd_num);
1520                 pq_64bit_free(&rcd_num);
1521                 pq_64bit_free(&tmp);
1522                 return 1;  /* this record is new */
1523                 }
1524
1525         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1526
1527         if ( pq_64bit_get_word(&tmp) > bitmap->length)
1528                 {
1529                 pq_64bit_free(&rcd_num);
1530                 pq_64bit_free(&tmp);
1531                 return 0;  /* stale, outside the window */
1532                 }
1533
1534 #if PQ_64BIT_IS_BIGNUM
1535         {
1536         int offset;
1537         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1538         pq_64bit_sub_word(&tmp, 1);
1539         offset = pq_64bit_get_word(&tmp);
1540         if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1541                 {
1542                 pq_64bit_free(&rcd_num);
1543                 pq_64bit_free(&tmp);
1544                 return 0;
1545                 }
1546         }
1547 #else
1548         mask <<= (bitmap->max_seq_num - rcd_num - 1);
1549         if (bitmap->map & mask)
1550                 return 0; /* record previously received */
1551 #endif
1552         
1553         pq_64bit_assign(seq_num, &rcd_num);
1554         pq_64bit_free(&rcd_num);
1555         pq_64bit_free(&tmp);
1556         return 1;
1557         }
1558
1559
1560 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1561         {
1562         unsigned int shift;
1563         PQ_64BIT rcd_num;
1564         PQ_64BIT tmp;
1565         PQ_64BIT_CTX *ctx;
1566
1567         pq_64bit_init(&rcd_num);
1568         pq_64bit_init(&tmp);
1569
1570         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1571
1572         /* unfortunate code complexity due to 64-bit manipulation support
1573          * on 32-bit machines */
1574         if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1575                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1576                 {
1577                 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1578                 pq_64bit_add_word(&tmp, 1);
1579
1580                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1581
1582                 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1583                 pq_64bit_assign(&(bitmap->map), &tmp);
1584
1585                 pq_64bit_set_bit(&(bitmap->map), 0);
1586                 pq_64bit_add_word(&rcd_num, 1);
1587                 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1588
1589                 pq_64bit_assign_word(&tmp, 1);
1590                 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1591                 ctx = pq_64bit_ctx_new(&ctx);
1592                 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1593                 pq_64bit_ctx_free(ctx);
1594                 }
1595         else
1596                 {
1597                 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1598                 pq_64bit_sub_word(&tmp, 1);
1599                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1600
1601                 pq_64bit_set_bit(&(bitmap->map), shift);
1602                 }
1603
1604         pq_64bit_free(&rcd_num);
1605         pq_64bit_free(&tmp);
1606         }
1607
1608
1609 int dtls1_dispatch_alert(SSL *s)
1610         {
1611         int i,j;
1612         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1613         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1614         unsigned char *ptr = &buf[0];
1615
1616         s->s3->alert_dispatch=0;
1617
1618         memset(buf, 0x00, sizeof(buf));
1619         *ptr++ = s->s3->send_alert[0];
1620         *ptr++ = s->s3->send_alert[1];
1621
1622 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1623         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1624                 {       
1625                 s2n(s->d1->handshake_read_seq, ptr);
1626 #if 0
1627                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1628
1629                 else
1630                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1631 #endif
1632
1633 #if 0
1634                 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);
1635 #endif
1636                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1637                 }
1638 #endif
1639
1640         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1641         if (i <= 0)
1642                 {
1643                 s->s3->alert_dispatch=1;
1644                 /* fprintf( stderr, "not done with alert\n" ); */
1645                 }
1646         else
1647                 {
1648                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1649 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1650                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1651 #endif
1652                    )
1653                         (void)BIO_flush(s->wbio);
1654
1655                 if (s->msg_callback)
1656                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 
1657                                 2, s, s->msg_callback_arg);
1658
1659                 if (s->info_callback != NULL)
1660                         cb=s->info_callback;
1661                 else if (s->ctx->info_callback != NULL)
1662                         cb=s->ctx->info_callback;
1663
1664                 if (cb != NULL)
1665                         {
1666                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1667                         cb(s,SSL_CB_WRITE_ALERT,j);
1668                         }
1669                 }
1670         return(i);
1671         }
1672
1673
1674 static DTLS1_BITMAP *
1675 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1676     {
1677     
1678     *is_next_epoch = 0;
1679
1680     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1681     if (rr->epoch == s->d1->r_epoch)
1682         return &s->d1->bitmap;
1683
1684     /* Only HM and ALERT messages can be from the next epoch */
1685     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1686         (rr->type == SSL3_RT_HANDSHAKE ||
1687             rr->type == SSL3_RT_ALERT))
1688         {
1689         *is_next_epoch = 1;
1690         return &s->d1->next_bitmap;
1691         }
1692
1693     return NULL;
1694     }
1695
1696 #if 0
1697 static int
1698 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1699         unsigned long *offset)
1700         {
1701
1702         /* alerts are passed up immediately */
1703         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1704                 rr->type == SSL3_RT_ALERT)
1705                 return 0;
1706
1707         /* Only need to buffer if a handshake is underway.
1708          * (this implies that Hello Request and Client Hello are passed up
1709          * immediately) */
1710         if ( SSL_in_init(s))
1711                 {
1712                 unsigned char *data = rr->data;
1713                 /* need to extract the HM/CCS sequence number here */
1714                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1715                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1716                         {
1717                         unsigned short seq_num;
1718                         struct hm_header_st msg_hdr;
1719                         struct ccs_header_st ccs_hdr;
1720
1721                         if ( rr->type == SSL3_RT_HANDSHAKE)
1722                                 {
1723                                 dtls1_get_message_header(data, &msg_hdr);
1724                                 seq_num = msg_hdr.seq;
1725                                 *offset = msg_hdr.frag_off;
1726                                 }
1727                         else
1728                                 {
1729                                 dtls1_get_ccs_header(data, &ccs_hdr);
1730                                 seq_num = ccs_hdr.seq;
1731                                 *offset = 0;
1732                                 }
1733                                 
1734                         /* this is either a record we're waiting for, or a
1735                          * retransmit of something we happened to previously 
1736                          * receive (higher layers will drop the repeat silently */
1737                         if ( seq_num < s->d1->handshake_read_seq)
1738                                 return 0;
1739                         if (rr->type == SSL3_RT_HANDSHAKE && 
1740                                 seq_num == s->d1->handshake_read_seq &&
1741                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1742                                 return 0;
1743                         else if ( seq_num == s->d1->handshake_read_seq &&
1744                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1745                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1746                                 return 0;
1747                         else
1748                                 {
1749                                 *priority = seq_num;
1750                                 return 1;
1751                                 }
1752                         }
1753                 else /* unknown record type */
1754                         return 0;
1755                 }
1756
1757         return 0;
1758         }
1759 #endif
1760
1761 void
1762 dtls1_reset_seq_numbers(SSL *s, int rw)
1763         {
1764         unsigned char *seq;
1765         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1766
1767         if ( rw & SSL3_CC_READ)
1768                 {
1769                 seq = s->s3->read_sequence;
1770                 s->d1->r_epoch++;
1771
1772                 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1773                 s->d1->bitmap.length = s->d1->next_bitmap.length;
1774                 pq_64bit_assign(&(s->d1->bitmap.max_seq_num), 
1775                         &(s->d1->next_bitmap.max_seq_num));
1776
1777                 pq_64bit_free(&(s->d1->next_bitmap.map));
1778                 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1779                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1780                 pq_64bit_init(&(s->d1->next_bitmap.map));
1781                 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1782                 }
1783         else
1784                 {
1785                 seq = s->s3->write_sequence;
1786                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1787                 s->d1->w_epoch++;
1788                 }
1789
1790         memset(seq, 0x00, seq_bytes);
1791         }
1792
1793 #if PQ_64BIT_IS_INTEGER
1794 static PQ_64BIT
1795 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1796        {
1797        PQ_64BIT _num;
1798
1799        _num = (((PQ_64BIT)bytes[0]) << 56) |
1800                (((PQ_64BIT)bytes[1]) << 48) |
1801                (((PQ_64BIT)bytes[2]) << 40) |
1802                (((PQ_64BIT)bytes[3]) << 32) |
1803                (((PQ_64BIT)bytes[4]) << 24) |
1804                (((PQ_64BIT)bytes[5]) << 16) |
1805                (((PQ_64BIT)bytes[6]) <<  8) |
1806                (((PQ_64BIT)bytes[7])      );
1807
1808            *num = _num ;
1809        return _num;
1810        }
1811 #endif
1812
1813
1814 static void
1815 dtls1_clear_timeouts(SSL *s)
1816         {
1817         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1818         }