Fix for DTLS DoS issue introduced by fix for CVE-2011-4109.
[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         int decryption_failed_or_bad_record_mac = 0;
339         unsigned char *mac = NULL;
340
341
342         rr= &(s->s3->rrec);
343     sess = s->session;
344
345         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
346          * and we have that many bytes in s->packet
347          */
348         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
349
350         /* ok, we can now read from 's->packet' data into 'rr'
351          * rr->input points at rr->length bytes, which
352          * need to be copied into rr->data by either
353          * the decryption or by the decompression
354          * When the data is 'copied' into the rr->data buffer,
355          * rr->input will be pointed at the new buffer */ 
356
357         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
358          * rr->length bytes of encrypted compressed stuff. */
359
360         /* check is not needed I believe */
361         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
362                 {
363                 al=SSL_AD_RECORD_OVERFLOW;
364                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
365                 goto f_err;
366                 }
367
368         /* decrypt in place in 'rr->input' */
369         rr->data=rr->input;
370
371         enc_err = s->method->ssl3_enc->enc(s,0);
372         if (enc_err <= 0)
373                 {
374                 /* To minimize information leaked via timing, we will always
375                  * perform all computations before discarding the message.
376                  */
377                 decryption_failed_or_bad_record_mac = 1;
378                 }
379
380 #ifdef TLS_DEBUG
381 printf("dec %d\n",rr->length);
382 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
383 printf("\n");
384 #endif
385
386         /* r->length is now the compressed data plus mac */
387 if (    (sess == NULL) ||
388                 (s->enc_read_ctx == NULL) ||
389                 (s->read_hash == NULL))
390     clear=1;
391
392         if (!clear)
393                 {
394                 mac_size=EVP_MD_size(s->read_hash);
395
396                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
397                         {
398 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
399                         al=SSL_AD_RECORD_OVERFLOW;
400                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
401                         goto f_err;
402 #else
403                         decryption_failed_or_bad_record_mac = 1;
404 #endif                  
405                         }
406                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
407                 if (rr->length >= mac_size)
408                         {
409                         rr->length -= mac_size;
410                         mac = &rr->data[rr->length];
411                         }
412                 else
413                         rr->length = 0;
414                 s->method->ssl3_enc->mac(s,md,0);
415                 if (mac == NULL || memcmp(md, mac, mac_size) != 0)
416                         {
417                         decryption_failed_or_bad_record_mac = 1;
418                         }
419                 }
420
421         if (decryption_failed_or_bad_record_mac)
422                 {
423                 /* decryption failed, silently discard message */
424                 rr->length = 0;
425                 s->packet_length = 0;
426                 goto err;
427                 }
428
429         /* r->length is now just compressed */
430         if (s->expand != NULL)
431                 {
432                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
433                         {
434                         al=SSL_AD_RECORD_OVERFLOW;
435                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
436                         goto f_err;
437                         }
438                 if (!ssl3_do_uncompress(s))
439                         {
440                         al=SSL_AD_DECOMPRESSION_FAILURE;
441                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
442                         goto f_err;
443                         }
444                 }
445
446         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
447                 {
448                 al=SSL_AD_RECORD_OVERFLOW;
449                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
450                 goto f_err;
451                 }
452
453         rr->off=0;
454         /* So at this point the following is true
455          * ssl->s3->rrec.type   is the type of record
456          * ssl->s3->rrec.length == number of bytes in record
457          * ssl->s3->rrec.off    == offset to first valid byte
458          * ssl->s3->rrec.data   == where to take bytes from, increment
459          *                         after use :-).
460          */
461
462         /* we have pulled in a full packet so zero things */
463         s->packet_length=0;
464     dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
465     return(1);
466
467 f_err:
468         ssl3_send_alert(s,SSL3_AL_FATAL,al);
469 err:
470         return(0);
471 }
472
473
474 /* Call this to get a new input record.
475  * It will return <= 0 if more data is needed, normally due to an error
476  * or non-blocking IO.
477  * When it finishes, one packet has been decoded and can be found in
478  * ssl->s3->rrec.type    - is the type of record
479  * ssl->s3->rrec.data,   - data
480  * ssl->s3->rrec.length, - number of bytes
481  */
482 /* used only by dtls1_read_bytes */
483 int dtls1_get_record(SSL *s)
484         {
485         int ssl_major,ssl_minor;
486         int i,n;
487         SSL3_RECORD *rr;
488         unsigned char *p = NULL;
489         unsigned short version;
490         DTLS1_BITMAP *bitmap;
491         unsigned int is_next_epoch;
492
493         rr= &(s->s3->rrec);
494
495     /* The epoch may have changed.  If so, process all the
496      * pending records.  This is a non-blocking operation. */
497     dtls1_process_buffered_records(s);
498
499         /* if we're renegotiating, then there may be buffered records */
500         if (dtls1_get_processed_record(s))
501                 return 1;
502
503         /* get something from the wire */
504 again:
505         /* check if we have the header */
506         if (    (s->rstate != SSL_ST_READ_BODY) ||
507                 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 
508                 {
509                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
510                 /* read timeout is handled by dtls1_read_bytes */
511                 if (n <= 0) return(n); /* error or non-blocking */
512
513                 /* this packet contained a partial record, dump it */
514                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
515                         {
516                         s->packet_length = 0;
517                         goto again;
518                         }
519
520                 s->rstate=SSL_ST_READ_BODY;
521
522                 p=s->packet;
523
524                 /* Pull apart the header into the DTLS1_RECORD */
525                 rr->type= *(p++);
526                 ssl_major= *(p++);
527                 ssl_minor= *(p++);
528                 version=(ssl_major<<8)|ssl_minor;
529
530                 /* sequence number is 64 bits, with top 2 bytes = epoch */ 
531                 n2s(p,rr->epoch);
532
533                 memcpy(&(s->s3->read_sequence[2]), p, 6);
534                 p+=6;
535
536                 n2s(p,rr->length);
537
538                 /* Lets check version */
539                 if (!s->first_packet)
540                         {
541                         if (version != s->version && version != DTLS1_BAD_VER)
542                                 {
543                                 /* unexpected version, silently discard */
544                                 rr->length = 0;
545                                 s->packet_length = 0;
546                                 goto again;
547                                 }
548                         }
549
550                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
551                     (version & 0xff00) != (DTLS1_BAD_VER & 0xff00))
552                         {
553                         /* wrong version, silently discard record */
554                         rr->length = 0;
555                         s->packet_length = 0;
556                         goto again;
557                         }
558
559                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
560                         {
561                         /* record too long, silently discard it */
562                         rr->length = 0;
563                         s->packet_length = 0;
564                         goto again;
565                         }
566
567                 s->client_version = version;
568                 /* now s->rstate == SSL_ST_READ_BODY */
569                 }
570
571         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
572
573         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
574                 {
575                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
576                 i=rr->length;
577                 n=ssl3_read_n(s,i,i,1);
578                 if (n <= 0) return(n); /* error or non-blocking io */
579
580                 /* this packet contained a partial record, dump it */
581                 if ( n != i)
582                         {
583                         rr->length = 0;
584                         s->packet_length = 0;
585                         goto again;
586                         }
587
588                 /* now n == rr->length,
589                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
590                 }
591         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
592
593         /* match epochs.  NULL means the packet is dropped on the floor */
594         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
595         if ( bitmap == NULL)
596         {
597         rr->length = 0;
598         s->packet_length = 0;  /* dump this record */
599         goto again;   /* get another record */
600                 }
601
602         /* Check whether this is a repeat, or aged record.
603          * Don't check if we're listening and this message is
604          * a ClientHello. They can look as if they're replayed,
605          * since they arrive from different connections and
606          * would be dropped unnecessarily.
607          */
608         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
609                 *p == SSL3_MT_CLIENT_HELLO) &&
610                 ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
611                 {
612                 rr->length = 0;
613                 s->packet_length=0; /* dump this record */
614                 goto again;     /* get another record */
615                 }
616
617         /* just read a 0 length packet */
618         if (rr->length == 0) goto again;
619
620         /* If this record is from the next epoch (either HM or ALERT),
621          * and a handshake is currently in progress, buffer it since it
622          * cannot be processed at this time. However, do not buffer
623          * anything while listening.
624          */
625         if (is_next_epoch)
626                 {
627                 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
628                         {
629                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), &rr->seq_num);
630                         }
631                 rr->length = 0;
632         s->packet_length = 0;
633         goto again;
634         }
635
636     if (!dtls1_process_record(s))
637                 {
638                 rr->length = 0;
639                 s->packet_length=0; /* dump this record */
640                 goto again;     /* get another record */
641                 }
642
643         dtls1_clear_timeouts(s);  /* done waiting */
644         return(1);
645
646         }
647
648 /* Return up to 'len' payload bytes received in 'type' records.
649  * 'type' is one of the following:
650  *
651  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
652  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
653  *   -  0 (during a shutdown, no data has to be returned)
654  *
655  * If we don't have stored data to work from, read a SSL/TLS record first
656  * (possibly multiple records if we still don't have anything to return).
657  *
658  * This function must handle any surprises the peer may have for us, such as
659  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
660  * a surprise, but handled as if it were), or renegotiation requests.
661  * Also if record payloads contain fragments too small to process, we store
662  * them until there is enough for the respective protocol (the record protocol
663  * may use arbitrary fragmentation and even interleaving):
664  *     Change cipher spec protocol
665  *             just 1 byte needed, no need for keeping anything stored
666  *     Alert protocol
667  *             2 bytes needed (AlertLevel, AlertDescription)
668  *     Handshake protocol
669  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
670  *             to detect unexpected Client Hello and Hello Request messages
671  *             here, anything else is handled by higher layers
672  *     Application data protocol
673  *             none of our business
674  */
675 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
676         {
677         int al,i,j,ret;
678         unsigned int n;
679         SSL3_RECORD *rr;
680         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
681
682         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
683                 if (!ssl3_setup_buffers(s))
684                         return(-1);
685
686     /* XXX: check what the second '&& type' is about */
687         if ((type && (type != SSL3_RT_APPLICATION_DATA) && 
688                 (type != SSL3_RT_HANDSHAKE) && type) ||
689             (peek && (type != SSL3_RT_APPLICATION_DATA)))
690                 {
691                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
692                 return -1;
693                 }
694
695         /* check whether there's a handshake message (client hello?) waiting */
696         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
697                 return ret;
698
699         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
700
701         if (!s->in_handshake && SSL_in_init(s))
702                 {
703                 /* type == SSL3_RT_APPLICATION_DATA */
704                 i=s->handshake_func(s);
705                 if (i < 0) return(i);
706                 if (i == 0)
707                         {
708                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
709                         return(-1);
710                         }
711                 }
712
713 start:
714         s->rwstate=SSL_NOTHING;
715
716         /* s->s3->rrec.type         - is the type of record
717          * s->s3->rrec.data,    - data
718          * s->s3->rrec.off,     - offset into 'data' for next read
719          * s->s3->rrec.length,  - number of bytes. */
720         rr = &(s->s3->rrec);
721
722         /* We are not handshaking and have no data yet,
723          * so process data buffered during the last handshake
724          * in advance, if any.
725          */
726         if (s->state == SSL_ST_OK && rr->length == 0)
727                 {
728                 pitem *item;
729                 item = pqueue_pop(s->d1->buffered_app_data.q);
730                 if (item)
731                         {
732                         dtls1_copy_record(s, item);
733
734                         OPENSSL_free(item->data);
735                         pitem_free(item);
736                         }
737                 }
738
739         /* Check for timeout */
740         if (dtls1_handle_timeout(s) > 0)
741                 goto start;
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                 /* We now have application data between CCS and Finished.
765                  * Most likely the packets were reordered on their way, so
766                  * buffer the application data for later processing rather
767                  * than dropping the connection.
768                  */
769                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), &rr->seq_num);
770                 rr->length = 0;
771                 goto start;
772                 }
773
774         /* If the other end has shut down, throw anything we read away
775          * (even in 'peek' mode) */
776         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
777                 {
778                 rr->length=0;
779                 s->rwstate=SSL_NOTHING;
780                 return(0);
781                 }
782
783
784         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
785                 {
786                 /* make sure that we are not getting application data when we
787                  * are doing a handshake for the first time */
788                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
789                         (s->enc_read_ctx == NULL))
790                         {
791                         al=SSL_AD_UNEXPECTED_MESSAGE;
792                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
793                         goto f_err;
794                         }
795
796                 if (len <= 0) return(len);
797
798                 if ((unsigned int)len > rr->length)
799                         n = rr->length;
800                 else
801                         n = (unsigned int)len;
802
803                 memcpy(buf,&(rr->data[rr->off]),n);
804                 if (!peek)
805                         {
806                         rr->length-=n;
807                         rr->off+=n;
808                         if (rr->length == 0)
809                                 {
810                                 s->rstate=SSL_ST_READ_HEADER;
811                                 rr->off=0;
812                                 }
813                         }
814                 return(n);
815                 }
816
817
818         /* If we get here, then type != rr->type; if we have a handshake
819          * message, then it was unexpected (Hello Request or Client Hello). */
820
821         /* In case of record types for which we have 'fragment' storage,
822          * fill that so that we can process the data at a fixed place.
823          */
824                 {
825                 unsigned int k, dest_maxlen = 0;
826                 unsigned char *dest = NULL;
827                 unsigned int *dest_len = NULL;
828
829                 if (rr->type == SSL3_RT_HANDSHAKE)
830                         {
831                         dest_maxlen = sizeof s->d1->handshake_fragment;
832                         dest = s->d1->handshake_fragment;
833                         dest_len = &s->d1->handshake_fragment_len;
834                         }
835                 else if (rr->type == SSL3_RT_ALERT)
836                         {
837                         dest_maxlen = sizeof(s->d1->alert_fragment);
838                         dest = s->d1->alert_fragment;
839                         dest_len = &s->d1->alert_fragment_len;
840                         }
841                 /* else it's a CCS message, or application data or wrong */
842                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
843                         {
844                         /* Application data while renegotiating
845                          * is allowed. Try again reading.
846                          */
847                         if (rr->type == SSL3_RT_APPLICATION_DATA)
848                                 {
849                                 BIO *bio;
850                                 s->s3->in_read_app_data=2;
851                                 bio=SSL_get_rbio(s);
852                                 s->rwstate=SSL_READING;
853                                 BIO_clear_retry_flags(bio);
854                                 BIO_set_retry_read(bio);
855                                 return(-1);
856                                 }
857
858                         /* Not certain if this is the right error handling */
859                         al=SSL_AD_UNEXPECTED_MESSAGE;
860                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
861                         goto f_err;
862                         }
863
864                 if (dest_maxlen > 0)
865                         {
866             /* XDTLS:  In a pathalogical case, the Client Hello
867              *  may be fragmented--don't always expect dest_maxlen bytes */
868                         if ( rr->length < dest_maxlen)
869                                 {
870 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
871                                 /*
872                                  * for normal alerts rr->length is 2, while
873                                  * dest_maxlen is 7 if we were to handle this
874                                  * non-existing alert...
875                                  */
876                                 FIX ME
877 #endif
878                                 s->rstate=SSL_ST_READ_HEADER;
879                                 rr->length = 0;
880                                 goto start;
881                                 }
882
883                         /* now move 'n' bytes: */
884                         for ( k = 0; k < dest_maxlen; k++)
885                                 {
886                                 dest[k] = rr->data[rr->off++];
887                                 rr->length--;
888                                 }
889                         *dest_len = dest_maxlen;
890                         }
891                 }
892
893         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
894          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
895          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
896
897         /* If we are a client, check for an incoming 'Hello Request': */
898         if ((!s->server) &&
899                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
900                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
901                 (s->session != NULL) && (s->session->cipher != NULL))
902                 {
903                 s->d1->handshake_fragment_len = 0;
904
905                 if ((s->d1->handshake_fragment[1] != 0) ||
906                         (s->d1->handshake_fragment[2] != 0) ||
907                         (s->d1->handshake_fragment[3] != 0))
908                         {
909                         al=SSL_AD_DECODE_ERROR;
910                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
911                         goto err;
912                         }
913
914                 /* no need to check sequence number on HELLO REQUEST messages */
915
916                 if (s->msg_callback)
917                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
918                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
919
920                 if (SSL_is_init_finished(s) &&
921                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
922                         !s->s3->renegotiate)
923                         {
924                         ssl3_renegotiate(s);
925                         if (ssl3_renegotiate_check(s))
926                                 {
927                                 i=s->handshake_func(s);
928                                 if (i < 0) return(i);
929                                 if (i == 0)
930                                         {
931                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
932                                         return(-1);
933                                         }
934
935                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
936                                         {
937                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
938                                                 {
939                                                 BIO *bio;
940                                                 /* In the case where we try to read application data,
941                                                  * but we trigger an SSL handshake, we return -1 with
942                                                  * the retry option set.  Otherwise renegotiation may
943                                                  * cause nasty problems in the blocking world */
944                                                 s->rwstate=SSL_READING;
945                                                 bio=SSL_get_rbio(s);
946                                                 BIO_clear_retry_flags(bio);
947                                                 BIO_set_retry_read(bio);
948                                                 return(-1);
949                                                 }
950                                         }
951                                 }
952                         }
953                 /* we either finished a handshake or ignored the request,
954                  * now try again to obtain the (application) data we were asked for */
955                 goto start;
956                 }
957
958         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
959                 {
960                 int alert_level = s->d1->alert_fragment[0];
961                 int alert_descr = s->d1->alert_fragment[1];
962
963                 s->d1->alert_fragment_len = 0;
964
965                 if (s->msg_callback)
966                         s->msg_callback(0, s->version, SSL3_RT_ALERT, 
967                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
968
969                 if (s->info_callback != NULL)
970                         cb=s->info_callback;
971                 else if (s->ctx->info_callback != NULL)
972                         cb=s->ctx->info_callback;
973
974                 if (cb != NULL)
975                         {
976                         j = (alert_level << 8) | alert_descr;
977                         cb(s, SSL_CB_READ_ALERT, j);
978                         }
979
980                 if (alert_level == 1) /* warning */
981                         {
982                         s->s3->warn_alert = alert_descr;
983                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
984                                 {
985                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
986                                 return(0);
987                                 }
988 #if 0
989             /* XXX: this is a possible improvement in the future */
990                         /* now check if it's a missing record */
991                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
992                                 {
993                                 unsigned short seq;
994                                 unsigned int frag_off;
995                                 unsigned char *p = &(s->d1->alert_fragment[2]);
996
997                                 n2s(p, seq);
998                                 n2l3(p, frag_off);
999
1000                                 dtls1_retransmit_message(s,
1001                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1002                                                                                  frag_off, &found);
1003                                 if ( ! found  && SSL_in_init(s))
1004                                         {
1005                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1006                                         /* requested a message not yet sent, 
1007                                            send an alert ourselves */
1008                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1009                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1010                                         }
1011                                 }
1012 #endif
1013                         }
1014                 else if (alert_level == 2) /* fatal */
1015                         {
1016                         char tmp[16];
1017
1018                         s->rwstate=SSL_NOTHING;
1019                         s->s3->fatal_alert = alert_descr;
1020                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1021                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1022                         ERR_add_error_data(2,"SSL alert number ",tmp);
1023                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1024                         SSL_CTX_remove_session(s->ctx,s->session);
1025                         return(0);
1026                         }
1027                 else
1028                         {
1029                         al=SSL_AD_ILLEGAL_PARAMETER;
1030                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1031                         goto f_err;
1032                         }
1033
1034                 goto start;
1035                 }
1036
1037         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1038                 {
1039                 s->rwstate=SSL_NOTHING;
1040                 rr->length=0;
1041                 return(0);
1042                 }
1043
1044         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1045                 {
1046                 struct ccs_header_st ccs_hdr;
1047                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1048
1049                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1050
1051                 /* 'Change Cipher Spec' is just a single byte, so we know
1052                  * exactly what the record payload has to look like */
1053                 /* XDTLS: check that epoch is consistent */
1054                 if (s->client_version == DTLS1_BAD_VER || s->version == DTLS1_BAD_VER)
1055                         ccs_hdr_len = 3;
1056
1057                 if ((rr->length != ccs_hdr_len) || (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1058                         {
1059                         i=SSL_AD_ILLEGAL_PARAMETER;
1060                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1061                         goto err;
1062                         }
1063
1064                 rr->length=0;
1065
1066                 if (s->msg_callback)
1067                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
1068                                 rr->data, 1, s, s->msg_callback_arg);
1069
1070                 /* We can't process a CCS now, because previous handshake
1071                  * messages are still missing, so just drop it.
1072                  */
1073                 if (!s->d1->change_cipher_spec_ok)
1074                         {
1075                         goto start;
1076                         }
1077
1078                 s->d1->change_cipher_spec_ok = 0;
1079
1080                 s->s3->change_cipher_spec=1;
1081                 if (!ssl3_do_change_cipher_spec(s))
1082                         goto err;
1083
1084                 /* do this whenever CCS is processed */
1085                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1086
1087                 if (s->client_version == DTLS1_BAD_VER)
1088                         s->d1->handshake_read_seq++;
1089
1090                 goto start;
1091                 }
1092
1093         /* Unexpected handshake message (Client Hello, or protocol violation) */
1094         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 
1095                 !s->in_handshake)
1096                 {
1097                 struct hm_header_st msg_hdr;
1098                 
1099                 /* this may just be a stale retransmit */
1100                 dtls1_get_message_header(rr->data, &msg_hdr);
1101                 if( rr->epoch != s->d1->r_epoch)
1102                         {
1103                         rr->length = 0;
1104                         goto start;
1105                         }
1106
1107                 /* If we are server, we may have a repeated FINISHED of the
1108                  * client here, then retransmit our CCS and FINISHED.
1109                  */
1110                 if (msg_hdr.type == SSL3_MT_FINISHED)
1111                         {
1112                         dtls1_retransmit_buffered_messages(s);
1113                         rr->length = 0;
1114                         goto start;
1115                         }
1116
1117                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1118                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1119                         {
1120 #if 0 /* worked only because C operator preferences are not as expected (and
1121        * because this is not really needed for clients except for detecting
1122        * protocol violations): */
1123                         s->state=SSL_ST_BEFORE|(s->server)
1124                                 ?SSL_ST_ACCEPT
1125                                 :SSL_ST_CONNECT;
1126 #else
1127                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1128 #endif
1129                         s->new_session=1;
1130                         }
1131                 i=s->handshake_func(s);
1132                 if (i < 0) return(i);
1133                 if (i == 0)
1134                         {
1135                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1136                         return(-1);
1137                         }
1138
1139                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1140                         {
1141                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1142                                 {
1143                                 BIO *bio;
1144                                 /* In the case where we try to read application data,
1145                                  * but we trigger an SSL handshake, we return -1 with
1146                                  * the retry option set.  Otherwise renegotiation may
1147                                  * cause nasty problems in the blocking world */
1148                                 s->rwstate=SSL_READING;
1149                                 bio=SSL_get_rbio(s);
1150                                 BIO_clear_retry_flags(bio);
1151                                 BIO_set_retry_read(bio);
1152                                 return(-1);
1153                                 }
1154                         }
1155                 goto start;
1156                 }
1157
1158         switch (rr->type)
1159                 {
1160         default:
1161 #ifndef OPENSSL_NO_TLS
1162                 /* TLS just ignores unknown message types */
1163                 if (s->version == TLS1_VERSION)
1164                         {
1165                         rr->length = 0;
1166                         goto start;
1167                         }
1168 #endif
1169                 al=SSL_AD_UNEXPECTED_MESSAGE;
1170                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1171                 goto f_err;
1172         case SSL3_RT_CHANGE_CIPHER_SPEC:
1173         case SSL3_RT_ALERT:
1174         case SSL3_RT_HANDSHAKE:
1175                 /* we already handled all of these, with the possible exception
1176                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1177                  * should not happen when type != rr->type */
1178                 al=SSL_AD_UNEXPECTED_MESSAGE;
1179                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1180                 goto f_err;
1181         case SSL3_RT_APPLICATION_DATA:
1182                 /* At this point, we were expecting handshake data,
1183                  * but have application data.  If the library was
1184                  * running inside ssl3_read() (i.e. in_read_app_data
1185                  * is set) and it makes sense to read application data
1186                  * at this point (session renegotiation not yet started),
1187                  * we will indulge it.
1188                  */
1189                 if (s->s3->in_read_app_data &&
1190                         (s->s3->total_renegotiations != 0) &&
1191                         ((
1192                                 (s->state & SSL_ST_CONNECT) &&
1193                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1194                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1195                                 ) || (
1196                                         (s->state & SSL_ST_ACCEPT) &&
1197                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1198                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1199                                         )
1200                                 ))
1201                         {
1202                         s->s3->in_read_app_data=2;
1203                         return(-1);
1204                         }
1205                 else
1206                         {
1207                         al=SSL_AD_UNEXPECTED_MESSAGE;
1208                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1209                         goto f_err;
1210                         }
1211                 }
1212         /* not reached */
1213
1214 f_err:
1215         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1216 err:
1217         return(-1);
1218         }
1219
1220 int
1221 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1222         {
1223         int i;
1224
1225         if (SSL_in_init(s) && !s->in_handshake)
1226                 {
1227                 i=s->handshake_func(s);
1228                 if (i < 0) return(i);
1229                 if (i == 0)
1230                         {
1231                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1232                         return -1;
1233                         }
1234                 }
1235
1236         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1237                 {
1238                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1239                         return -1;
1240                 }
1241
1242         i = dtls1_write_bytes(s, type, buf_, len);
1243         return i;
1244         }
1245
1246
1247         /* this only happens when a client hello is received and a handshake 
1248          * is started. */
1249 static int
1250 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
1251         int len, int peek)
1252         {
1253         
1254         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1255                 /* (partially) satisfy request from storage */
1256                 {
1257                 unsigned char *src = s->d1->handshake_fragment;
1258                 unsigned char *dst = buf;
1259                 unsigned int k,n;
1260                 
1261                 /* peek == 0 */
1262                 n = 0;
1263                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1264                         {
1265                         *dst++ = *src++;
1266                         len--; s->d1->handshake_fragment_len--;
1267                         n++;
1268                         }
1269                 /* move any remaining fragment bytes: */
1270                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1271                         s->d1->handshake_fragment[k] = *src++;
1272                 return n;
1273                 }
1274         
1275         return 0;
1276         }
1277
1278
1279
1280
1281 /* Call this to write data in records of type 'type'
1282  * It will return <= 0 if not all data has been sent or non-blocking IO.
1283  */
1284 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1285         {
1286         int i;
1287
1288         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1289         s->rwstate=SSL_NOTHING;
1290         i=do_dtls1_write(s, type, buf, len, 0);
1291         return 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                 (s->write_hash == NULL))
1331                 clear=1;
1332
1333         if (clear)
1334                 mac_size=0;
1335         else
1336                 mac_size=EVP_MD_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 && SSL_version(s) != DTLS1_BAD_VER)
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         if (s->client_version == DTLS1_BAD_VER)
1378                 *(p++) = DTLS1_BAD_VER>>8,
1379                 *(p++) = DTLS1_BAD_VER&0xff;
1380         else
1381                 *(p++)=(s->version>>8),
1382                 *(p++)=s->version&0xff;
1383
1384         /* field where we are to write out packet epoch, seq num and len */
1385         pseq=p; 
1386         p+=10;
1387
1388         /* lets setup the record stuff. */
1389
1390         /* Make space for the explicit IV in case of CBC.
1391          * (this is a bit of a boundary violation, but what the heck).
1392          */
1393         if ( s->enc_write_ctx && 
1394                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1395                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1396         else
1397                 bs = 0;
1398
1399         wr->data=p + bs;  /* make room for IV in case of CBC */
1400         wr->length=(int)len;
1401         wr->input=(unsigned char *)buf;
1402
1403         /* we now 'read' from wr->input, wr->length bytes into
1404          * wr->data */
1405
1406         /* first we compress */
1407         if (s->compress != NULL)
1408                 {
1409                 if (!ssl3_do_compress(s))
1410                         {
1411                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1412                         goto err;
1413                         }
1414                 }
1415         else
1416                 {
1417                 memcpy(wr->data,wr->input,wr->length);
1418                 wr->input=wr->data;
1419                 }
1420
1421         /* we should still have the output to wr->data and the input
1422          * from wr->input.  Length should be wr->length.
1423          * wr->data still points in the wb->buf */
1424
1425         if (mac_size != 0)
1426                 {
1427                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1428                 wr->length+=mac_size;
1429                 }
1430
1431         /* this is true regardless of mac size */
1432         wr->input=p;
1433         wr->data=p;
1434
1435
1436         /* ssl3_enc can only have an error on read */
1437         if (bs) /* bs != 0 in case of CBC */
1438                 {
1439                 RAND_pseudo_bytes(p,bs);
1440                 /* master IV and last CBC residue stand for
1441                  * the rest of randomness */
1442                 wr->length += bs;
1443                 }
1444
1445         s->method->ssl3_enc->enc(s,1);
1446
1447         /* record length after mac and block padding */
1448 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1449         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1450         
1451         /* there's only one epoch between handshake and app data */
1452         
1453         s2n(s->d1->w_epoch, pseq);
1454
1455         /* XDTLS: ?? */
1456 /*      else
1457         s2n(s->d1->handshake_epoch, pseq); */
1458
1459         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1460         pseq+=6;
1461         s2n(wr->length,pseq);
1462
1463         /* we should now have
1464          * wr->data pointing to the encrypted data, which is
1465          * wr->length long */
1466         wr->type=type; /* not needed but helps for debugging */
1467         wr->length+=DTLS1_RT_HEADER_LENGTH;
1468
1469 #if 0  /* this is now done at the message layer */
1470         /* buffer the record, making it easy to handle retransmits */
1471         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1472                 dtls1_buffer_record(s, wr->data, wr->length, 
1473                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1474 #endif
1475
1476         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1477
1478         if (create_empty_fragment)
1479                 {
1480                 /* we are in a recursive call;
1481                  * just return the length, don't write out anything here
1482                  */
1483                 return wr->length;
1484                 }
1485
1486         /* now let's set up wb */
1487         wb->left = prefix_len + wr->length;
1488         wb->offset = 0;
1489
1490         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1491         s->s3->wpend_tot=len;
1492         s->s3->wpend_buf=buf;
1493         s->s3->wpend_type=type;
1494         s->s3->wpend_ret=len;
1495
1496         /* we now just need to write the buffer */
1497         return ssl3_write_pending(s,type,buf,len);
1498 err:
1499         return -1;
1500         }
1501
1502
1503
1504 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1505         PQ_64BIT *seq_num)
1506         {
1507 #if PQ_64BIT_IS_INTEGER
1508         PQ_64BIT mask = 0x0000000000000001L;
1509 #endif
1510         PQ_64BIT rcd_num, tmp;
1511
1512         pq_64bit_init(&rcd_num);
1513         pq_64bit_init(&tmp);
1514
1515         /* this is the sequence number for the record just read */
1516         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1517
1518         
1519         if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1520                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1521                 {
1522                 pq_64bit_assign(seq_num, &rcd_num);
1523                 pq_64bit_free(&rcd_num);
1524                 pq_64bit_free(&tmp);
1525                 return 1;  /* this record is new */
1526                 }
1527
1528         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1529
1530         if ( pq_64bit_get_word(&tmp) > bitmap->length)
1531                 {
1532                 pq_64bit_free(&rcd_num);
1533                 pq_64bit_free(&tmp);
1534                 return 0;  /* stale, outside the window */
1535                 }
1536
1537 #if PQ_64BIT_IS_BIGNUM
1538         {
1539         int offset;
1540         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1541         pq_64bit_sub_word(&tmp, 1);
1542         offset = pq_64bit_get_word(&tmp);
1543         if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1544                 {
1545                 pq_64bit_free(&rcd_num);
1546                 pq_64bit_free(&tmp);
1547                 return 0;
1548                 }
1549         }
1550 #else
1551         mask <<= (bitmap->max_seq_num - rcd_num - 1);
1552         if (bitmap->map & mask)
1553                 return 0; /* record previously received */
1554 #endif
1555         
1556         pq_64bit_assign(seq_num, &rcd_num);
1557         pq_64bit_free(&rcd_num);
1558         pq_64bit_free(&tmp);
1559         return 1;
1560         }
1561
1562
1563 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1564         {
1565         unsigned int shift;
1566         PQ_64BIT rcd_num;
1567         PQ_64BIT tmp;
1568         PQ_64BIT_CTX *ctx;
1569
1570         pq_64bit_init(&rcd_num);
1571         pq_64bit_init(&tmp);
1572
1573         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1574
1575         /* unfortunate code complexity due to 64-bit manipulation support
1576          * on 32-bit machines */
1577         if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1578                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1579                 {
1580                 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1581                 pq_64bit_add_word(&tmp, 1);
1582
1583                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1584
1585                 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1586                 pq_64bit_assign(&(bitmap->map), &tmp);
1587
1588                 pq_64bit_set_bit(&(bitmap->map), 0);
1589                 pq_64bit_add_word(&rcd_num, 1);
1590                 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1591
1592                 pq_64bit_assign_word(&tmp, 1);
1593                 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1594                 ctx = pq_64bit_ctx_new(&ctx);
1595                 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1596                 pq_64bit_ctx_free(ctx);
1597                 }
1598         else
1599                 {
1600                 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1601                 pq_64bit_sub_word(&tmp, 1);
1602                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1603
1604                 pq_64bit_set_bit(&(bitmap->map), shift);
1605                 }
1606
1607         pq_64bit_free(&rcd_num);
1608         pq_64bit_free(&tmp);
1609         }
1610
1611
1612 int dtls1_dispatch_alert(SSL *s)
1613         {
1614         int i,j;
1615         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1616         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1617         unsigned char *ptr = &buf[0];
1618
1619         s->s3->alert_dispatch=0;
1620
1621         memset(buf, 0x00, sizeof(buf));
1622         *ptr++ = s->s3->send_alert[0];
1623         *ptr++ = s->s3->send_alert[1];
1624
1625 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1626         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1627                 {       
1628                 s2n(s->d1->handshake_read_seq, ptr);
1629 #if 0
1630                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1631
1632                 else
1633                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1634 #endif
1635
1636 #if 0
1637                 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);
1638 #endif
1639                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1640                 }
1641 #endif
1642
1643         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1644         if (i <= 0)
1645                 {
1646                 s->s3->alert_dispatch=1;
1647                 /* fprintf( stderr, "not done with alert\n" ); */
1648                 }
1649         else
1650                 {
1651                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1652 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1653                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1654 #endif
1655                    )
1656                         (void)BIO_flush(s->wbio);
1657
1658                 if (s->msg_callback)
1659                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 
1660                                 2, s, s->msg_callback_arg);
1661
1662                 if (s->info_callback != NULL)
1663                         cb=s->info_callback;
1664                 else if (s->ctx->info_callback != NULL)
1665                         cb=s->ctx->info_callback;
1666
1667                 if (cb != NULL)
1668                         {
1669                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1670                         cb(s,SSL_CB_WRITE_ALERT,j);
1671                         }
1672                 }
1673         return(i);
1674         }
1675
1676
1677 static DTLS1_BITMAP *
1678 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1679     {
1680     
1681     *is_next_epoch = 0;
1682
1683     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1684     if (rr->epoch == s->d1->r_epoch)
1685         return &s->d1->bitmap;
1686
1687     /* Only HM and ALERT messages can be from the next epoch */
1688     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1689         (rr->type == SSL3_RT_HANDSHAKE ||
1690             rr->type == SSL3_RT_ALERT))
1691         {
1692         *is_next_epoch = 1;
1693         return &s->d1->next_bitmap;
1694         }
1695
1696     return NULL;
1697     }
1698
1699 #if 0
1700 static int
1701 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1702         unsigned long *offset)
1703         {
1704
1705         /* alerts are passed up immediately */
1706         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1707                 rr->type == SSL3_RT_ALERT)
1708                 return 0;
1709
1710         /* Only need to buffer if a handshake is underway.
1711          * (this implies that Hello Request and Client Hello are passed up
1712          * immediately) */
1713         if ( SSL_in_init(s))
1714                 {
1715                 unsigned char *data = rr->data;
1716                 /* need to extract the HM/CCS sequence number here */
1717                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1718                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1719                         {
1720                         unsigned short seq_num;
1721                         struct hm_header_st msg_hdr;
1722                         struct ccs_header_st ccs_hdr;
1723
1724                         if ( rr->type == SSL3_RT_HANDSHAKE)
1725                                 {
1726                                 dtls1_get_message_header(data, &msg_hdr);
1727                                 seq_num = msg_hdr.seq;
1728                                 *offset = msg_hdr.frag_off;
1729                                 }
1730                         else
1731                                 {
1732                                 dtls1_get_ccs_header(data, &ccs_hdr);
1733                                 seq_num = ccs_hdr.seq;
1734                                 *offset = 0;
1735                                 }
1736                                 
1737                         /* this is either a record we're waiting for, or a
1738                          * retransmit of something we happened to previously 
1739                          * receive (higher layers will drop the repeat silently */
1740                         if ( seq_num < s->d1->handshake_read_seq)
1741                                 return 0;
1742                         if (rr->type == SSL3_RT_HANDSHAKE && 
1743                                 seq_num == s->d1->handshake_read_seq &&
1744                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1745                                 return 0;
1746                         else if ( seq_num == s->d1->handshake_read_seq &&
1747                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1748                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1749                                 return 0;
1750                         else
1751                                 {
1752                                 *priority = seq_num;
1753                                 return 1;
1754                                 }
1755                         }
1756                 else /* unknown record type */
1757                         return 0;
1758                 }
1759
1760         return 0;
1761         }
1762 #endif
1763
1764 void
1765 dtls1_reset_seq_numbers(SSL *s, int rw)
1766         {
1767         unsigned char *seq;
1768         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1769
1770         if ( rw & SSL3_CC_READ)
1771                 {
1772                 seq = s->s3->read_sequence;
1773                 s->d1->r_epoch++;
1774
1775                 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1776                 s->d1->bitmap.length = s->d1->next_bitmap.length;
1777                 pq_64bit_assign(&(s->d1->bitmap.max_seq_num), 
1778                         &(s->d1->next_bitmap.max_seq_num));
1779
1780                 pq_64bit_free(&(s->d1->next_bitmap.map));
1781                 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1782                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1783                 pq_64bit_init(&(s->d1->next_bitmap.map));
1784                 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1785                 }
1786         else
1787                 {
1788                 seq = s->s3->write_sequence;
1789                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1790                 s->d1->w_epoch++;
1791                 }
1792
1793         memset(seq, 0x00, seq_bytes);
1794         }
1795
1796 #if PQ_64BIT_IS_INTEGER
1797 static PQ_64BIT
1798 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1799        {
1800        PQ_64BIT _num;
1801
1802        _num = (((PQ_64BIT)bytes[0]) << 56) |
1803                (((PQ_64BIT)bytes[1]) << 48) |
1804                (((PQ_64BIT)bytes[2]) << 40) |
1805                (((PQ_64BIT)bytes[3]) << 32) |
1806                (((PQ_64BIT)bytes[4]) << 24) |
1807                (((PQ_64BIT)bytes[5]) << 16) |
1808                (((PQ_64BIT)bytes[6]) <<  8) |
1809                (((PQ_64BIT)bytes[7])      );
1810
1811            *num = _num ;
1812        return _num;
1813        }
1814 #endif
1815
1816
1817 static void
1818 dtls1_clear_timeouts(SSL *s)
1819         {
1820         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1821         }