Third argument to dtls1_buffer_record is by reference
[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     return(1);
161     }
162
163
164 static int
165 dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT *priority)
166 {
167     DTLS1_RECORD_DATA *rdata;
168         pitem *item;
169
170         /* Limit the size of the queue to prevent DOS attacks */
171         if (pqueue_size(queue->q) >= 100)
172                 return 0;
173                 
174         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
175         item = pitem_new(*priority, rdata);
176         if (rdata == NULL || item == NULL)
177                 {
178                 if (rdata != NULL) OPENSSL_free(rdata);
179                 if (item != NULL) pitem_free(item);
180                 
181                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
182                 return(0);
183                 }
184         
185         rdata->packet = s->packet;
186         rdata->packet_length = s->packet_length;
187         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
188         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
189
190         item->data = rdata;
191
192         /* insert should not fail, since duplicates are dropped */
193         if (pqueue_insert(queue->q, item) == NULL)
194                 {
195                 OPENSSL_free(rdata);
196                 pitem_free(item);
197                 return(0);
198                 }
199
200         s->packet = NULL;
201         s->packet_length = 0;
202         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
203         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
204         
205         if (!ssl3_setup_buffers(s))
206                 {
207                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
208                 OPENSSL_free(rdata);
209                 pitem_free(item);
210                 return(0);
211                 }
212         
213         return(1);
214     }
215
216
217 static int
218 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
219     {
220     pitem *item;
221
222     item = pqueue_pop(queue->q);
223     if (item)
224         {
225         dtls1_copy_record(s, item);
226
227         OPENSSL_free(item->data);
228                 pitem_free(item);
229
230         return(1);
231         }
232
233     return(0);
234     }
235
236
237 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 
238  * yet */
239 #define dtls1_get_unprocessed_record(s) \
240                    dtls1_retrieve_buffered_record((s), \
241                    &((s)->d1->unprocessed_rcds))
242
243 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
244 #define dtls1_get_processed_record(s) \
245                    dtls1_retrieve_buffered_record((s), \
246                    &((s)->d1->processed_rcds))
247
248 static int
249 dtls1_process_buffered_records(SSL *s)
250     {
251     pitem *item;
252     
253     item = pqueue_peek(s->d1->unprocessed_rcds.q);
254     if (item)
255         {
256         DTLS1_RECORD_DATA *rdata;
257         rdata = (DTLS1_RECORD_DATA *)item->data;
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 i,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                 if (enc_err == 0)
373                         /* SSLerr() and ssl3_send_alert() have been called */
374                         goto err;
375
376                 /* otherwise enc_err == -1 */
377                 goto decryption_failed_or_bad_record_mac;
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                         goto decryption_failed_or_bad_record_mac;
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 #if 0 /* OK only for stream ciphers */
410                         al=SSL_AD_DECODE_ERROR;
411                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
412                         goto f_err;
413 #else
414                         goto decryption_failed_or_bad_record_mac;
415 #endif
416                         }
417                 rr->length-=mac_size;
418                 i=s->method->ssl3_enc->mac(s,md,0);
419                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
420                         {
421                         goto decryption_failed_or_bad_record_mac;
422                         }
423                 }
424
425         /* r->length is now just compressed */
426         if (s->expand != NULL)
427                 {
428                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
429                         {
430                         al=SSL_AD_RECORD_OVERFLOW;
431                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
432                         goto f_err;
433                         }
434                 if (!ssl3_do_uncompress(s))
435                         {
436                         al=SSL_AD_DECOMPRESSION_FAILURE;
437                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
438                         goto f_err;
439                         }
440                 }
441
442         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
443                 {
444                 al=SSL_AD_RECORD_OVERFLOW;
445                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
446                 goto f_err;
447                 }
448
449         rr->off=0;
450         /* So at this point the following is true
451          * ssl->s3->rrec.type   is the type of record
452          * ssl->s3->rrec.length == number of bytes in record
453          * ssl->s3->rrec.off    == offset to first valid byte
454          * ssl->s3->rrec.data   == where to take bytes from, increment
455          *                         after use :-).
456          */
457
458         /* we have pulled in a full packet so zero things */
459         s->packet_length=0;
460     dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
461     return(1);
462
463 decryption_failed_or_bad_record_mac:
464         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
465          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
466          * failure is directly visible from the ciphertext anyway,
467          * we should not reveal which kind of error occured -- this
468          * might become visible to an attacker (e.g. via logfile) */
469         al=SSL_AD_BAD_RECORD_MAC;
470         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
471 f_err:
472         ssl3_send_alert(s,SSL3_AL_FATAL,al);
473 err:
474         return(0);
475 }
476
477
478 /* Call this to get a new input record.
479  * It will return <= 0 if more data is needed, normally due to an error
480  * or non-blocking IO.
481  * When it finishes, one packet has been decoded and can be found in
482  * ssl->s3->rrec.type    - is the type of record
483  * ssl->s3->rrec.data,   - data
484  * ssl->s3->rrec.length, - number of bytes
485  */
486 /* used only by dtls1_read_bytes */
487 int dtls1_get_record(SSL *s)
488         {
489         int ssl_major,ssl_minor;
490         int i,n;
491         SSL3_RECORD *rr;
492         SSL_SESSION *sess;
493         unsigned char *p = NULL;
494         unsigned short version;
495         DTLS1_BITMAP *bitmap;
496         unsigned int is_next_epoch;
497
498         rr= &(s->s3->rrec);
499         sess=s->session;
500
501     /* The epoch may have changed.  If so, process all the
502      * pending records.  This is a non-blocking operation. */
503     if ( ! dtls1_process_buffered_records(s))
504         return 0;
505
506         /* if we're renegotiating, then there may be buffered records */
507         if (dtls1_get_processed_record(s))
508                 return 1;
509
510         /* get something from the wire */
511 again:
512         /* check if we have the header */
513         if (    (s->rstate != SSL_ST_READ_BODY) ||
514                 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 
515                 {
516                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
517                 /* read timeout is handled by dtls1_read_bytes */
518                 if (n <= 0) return(n); /* error or non-blocking */
519
520                 /* this packet contained a partial record, dump it */
521                 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
522                         {
523                         s->packet_length = 0;
524                         goto again;
525                         }
526
527                 s->rstate=SSL_ST_READ_BODY;
528
529                 p=s->packet;
530
531                 /* Pull apart the header into the DTLS1_RECORD */
532                 rr->type= *(p++);
533                 ssl_major= *(p++);
534                 ssl_minor= *(p++);
535                 version=(ssl_major<<8)|ssl_minor;
536
537                 /* sequence number is 64 bits, with top 2 bytes = epoch */ 
538                 n2s(p,rr->epoch);
539
540                 memcpy(&(s->s3->read_sequence[2]), p, 6);
541                 p+=6;
542
543                 n2s(p,rr->length);
544
545                 /* Lets check version */
546                 if (!s->first_packet)
547                         {
548                         if (version != s->version && version != DTLS1_BAD_VER)
549                                 {
550                                 /* unexpected version, silently discard */
551                                 rr->length = 0;
552                                 s->packet_length = 0;
553                                 goto again;
554                                 }
555                         }
556
557                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
558                     (version & 0xff00) != (DTLS1_BAD_VER & 0xff00))
559                         {
560                         /* wrong version, silently discard record */
561                         rr->length = 0;
562                         s->packet_length = 0;
563                         goto again;
564                         }
565
566                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
567                         {
568                         /* record too long, silently discard it */
569                         rr->length = 0;
570                         s->packet_length = 0;
571                         goto again;
572                         }
573
574                 s->client_version = version;
575                 /* now s->rstate == SSL_ST_READ_BODY */
576                 }
577
578         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
579
580         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
581                 {
582                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
583                 i=rr->length;
584                 n=ssl3_read_n(s,i,i,1);
585                 if (n <= 0) return(n); /* error or non-blocking io */
586
587                 /* this packet contained a partial record, dump it */
588                 if ( n != i)
589                         {
590                         rr->length = 0;
591                         s->packet_length = 0;
592                         goto again;
593                         }
594
595                 /* now n == rr->length,
596                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
597                 }
598         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
599
600         /* match epochs.  NULL means the packet is dropped on the floor */
601         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
602         if ( bitmap == NULL)
603         {
604         rr->length = 0;
605         s->packet_length = 0;  /* dump this record */
606         goto again;   /* get another record */
607                 }
608
609         /* Check whether this is a repeat, or aged record.
610          * Don't check if we're listening and this message is
611          * a ClientHello. They can look as if they're replayed,
612          * since they arrive from different connections and
613          * would be dropped unnecessarily.
614          */
615         if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
616                 *p == SSL3_MT_CLIENT_HELLO) &&
617                 ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
618                 {
619                 rr->length = 0;
620                 s->packet_length=0; /* dump this record */
621                 goto again;     /* get another record */
622                 }
623
624         /* just read a 0 length packet */
625         if (rr->length == 0) goto again;
626
627         /* If this record is from the next epoch (either HM or ALERT),
628          * and a handshake is currently in progress, buffer it since it
629          * cannot be processed at this time. */
630         if (is_next_epoch)
631                 {
632                 if (SSL_in_init(s) || s->in_handshake)
633                         {
634                         dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), &rr->seq_num);
635                         }
636                 rr->length = 0;
637         s->packet_length = 0;
638         goto again;
639         }
640
641     if ( ! dtls1_process_record(s))
642         return(0);
643
644         dtls1_clear_timeouts(s);  /* done waiting */
645         return(1);
646
647         }
648
649 /* Return up to 'len' payload bytes received in 'type' records.
650  * 'type' is one of the following:
651  *
652  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
653  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
654  *   -  0 (during a shutdown, no data has to be returned)
655  *
656  * If we don't have stored data to work from, read a SSL/TLS record first
657  * (possibly multiple records if we still don't have anything to return).
658  *
659  * This function must handle any surprises the peer may have for us, such as
660  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
661  * a surprise, but handled as if it were), or renegotiation requests.
662  * Also if record payloads contain fragments too small to process, we store
663  * them until there is enough for the respective protocol (the record protocol
664  * may use arbitrary fragmentation and even interleaving):
665  *     Change cipher spec protocol
666  *             just 1 byte needed, no need for keeping anything stored
667  *     Alert protocol
668  *             2 bytes needed (AlertLevel, AlertDescription)
669  *     Handshake protocol
670  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
671  *             to detect unexpected Client Hello and Hello Request messages
672  *             here, anything else is handled by higher layers
673  *     Application data protocol
674  *             none of our business
675  */
676 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
677         {
678         int al,i,j,ret;
679         unsigned int n;
680         SSL3_RECORD *rr;
681         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
682
683         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
684                 if (!ssl3_setup_buffers(s))
685                         return(-1);
686
687     /* XXX: check what the second '&& type' is about */
688         if ((type && (type != SSL3_RT_APPLICATION_DATA) && 
689                 (type != SSL3_RT_HANDSHAKE) && type) ||
690             (peek && (type != SSL3_RT_APPLICATION_DATA)))
691                 {
692                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
693                 return -1;
694                 }
695
696         /* check whether there's a handshake message (client hello?) waiting */
697         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
698                 return ret;
699
700         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
701
702         if (!s->in_handshake && SSL_in_init(s))
703                 {
704                 /* type == SSL3_RT_APPLICATION_DATA */
705                 i=s->handshake_func(s);
706                 if (i < 0) return(i);
707                 if (i == 0)
708                         {
709                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
710                         return(-1);
711                         }
712                 }
713
714 start:
715         s->rwstate=SSL_NOTHING;
716
717         /* s->s3->rrec.type         - is the type of record
718          * s->s3->rrec.data,    - data
719          * s->s3->rrec.off,     - offset into 'data' for next read
720          * s->s3->rrec.length,  - number of bytes. */
721         rr = &(s->s3->rrec);
722
723         /* We are not handshaking and have no data yet,
724          * so process data buffered during the last handshake
725          * in advance, if any.
726          */
727         if (s->state == SSL_ST_OK && rr->length == 0)
728                 {
729                 pitem *item;
730                 item = pqueue_pop(s->d1->buffered_app_data.q);
731                 if (item)
732                         {
733                         dtls1_copy_record(s, item);
734
735                         OPENSSL_free(item->data);
736                         pitem_free(item);
737                         }
738                 }
739
740         /* Check for timeout */
741         if (dtls1_handle_timeout(s) > 0)
742                 goto start;
743
744         /* get new packet if necessary */
745         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
746                 {
747                 ret=dtls1_get_record(s);
748                 if (ret <= 0) 
749                         {
750                         ret = dtls1_read_failed(s, ret);
751                         /* anything other than a timeout is an error */
752                         if (ret <= 0)  
753                                 return(ret);
754                         else
755                                 goto start;
756                         }
757                 }
758
759         /* we now have a packet which can be read and processed */
760
761         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
762                                        * reset by ssl3_get_finished */
763                 && (rr->type != SSL3_RT_HANDSHAKE))
764                 {
765                 /* We now have application data between CCS and Finished.
766                  * Most likely the packets were reordered on their way, so
767                  * buffer the application data for later processing rather
768                  * than dropping the connection.
769                  */
770                 dtls1_buffer_record(s, &(s->d1->buffered_app_data), &rr->seq_num);
771                 rr->length = 0;
772                 goto start;
773                 }
774
775         /* If the other end has shut down, throw anything we read away
776          * (even in 'peek' mode) */
777         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
778                 {
779                 rr->length=0;
780                 s->rwstate=SSL_NOTHING;
781                 return(0);
782                 }
783
784
785         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
786                 {
787                 /* make sure that we are not getting application data when we
788                  * are doing a handshake for the first time */
789                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
790                         (s->enc_read_ctx == NULL))
791                         {
792                         al=SSL_AD_UNEXPECTED_MESSAGE;
793                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
794                         goto f_err;
795                         }
796
797                 if (len <= 0) return(len);
798
799                 if ((unsigned int)len > rr->length)
800                         n = rr->length;
801                 else
802                         n = (unsigned int)len;
803
804                 memcpy(buf,&(rr->data[rr->off]),n);
805                 if (!peek)
806                         {
807                         rr->length-=n;
808                         rr->off+=n;
809                         if (rr->length == 0)
810                                 {
811                                 s->rstate=SSL_ST_READ_HEADER;
812                                 rr->off=0;
813                                 }
814                         }
815                 return(n);
816                 }
817
818
819         /* If we get here, then type != rr->type; if we have a handshake
820          * message, then it was unexpected (Hello Request or Client Hello). */
821
822         /* In case of record types for which we have 'fragment' storage,
823          * fill that so that we can process the data at a fixed place.
824          */
825                 {
826                 unsigned int k, dest_maxlen = 0;
827                 unsigned char *dest = NULL;
828                 unsigned int *dest_len = NULL;
829
830                 if (rr->type == SSL3_RT_HANDSHAKE)
831                         {
832                         dest_maxlen = sizeof s->d1->handshake_fragment;
833                         dest = s->d1->handshake_fragment;
834                         dest_len = &s->d1->handshake_fragment_len;
835                         }
836                 else if (rr->type == SSL3_RT_ALERT)
837                         {
838                         dest_maxlen = sizeof(s->d1->alert_fragment);
839                         dest = s->d1->alert_fragment;
840                         dest_len = &s->d1->alert_fragment_len;
841                         }
842                 /* else it's a CCS message, or application data or wrong */
843                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
844                         {
845                         /* Application data while renegotiating
846                          * is allowed. Try again reading.
847                          */
848                         if (rr->type == SSL3_RT_APPLICATION_DATA)
849                                 {
850                                 BIO *bio;
851                                 s->s3->in_read_app_data=2;
852                                 bio=SSL_get_rbio(s);
853                                 s->rwstate=SSL_READING;
854                                 BIO_clear_retry_flags(bio);
855                                 BIO_set_retry_read(bio);
856                                 return(-1);
857                                 }
858
859                         /* Not certain if this is the right error handling */
860                         al=SSL_AD_UNEXPECTED_MESSAGE;
861                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
862                         goto f_err;
863                         }
864
865                 if (dest_maxlen > 0)
866                         {
867             /* XDTLS:  In a pathalogical case, the Client Hello
868              *  may be fragmented--don't always expect dest_maxlen bytes */
869                         if ( rr->length < dest_maxlen)
870                                 {
871 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
872                                 /*
873                                  * for normal alerts rr->length is 2, while
874                                  * dest_maxlen is 7 if we were to handle this
875                                  * non-existing alert...
876                                  */
877                                 FIX ME
878 #endif
879                                 s->rstate=SSL_ST_READ_HEADER;
880                                 rr->length = 0;
881                                 goto start;
882                                 }
883
884                         /* now move 'n' bytes: */
885                         for ( k = 0; k < dest_maxlen; k++)
886                                 {
887                                 dest[k] = rr->data[rr->off++];
888                                 rr->length--;
889                                 }
890                         *dest_len = dest_maxlen;
891                         }
892                 }
893
894         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
895          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
896          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
897
898         /* If we are a client, check for an incoming 'Hello Request': */
899         if ((!s->server) &&
900                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
901                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
902                 (s->session != NULL) && (s->session->cipher != NULL))
903                 {
904                 s->d1->handshake_fragment_len = 0;
905
906                 if ((s->d1->handshake_fragment[1] != 0) ||
907                         (s->d1->handshake_fragment[2] != 0) ||
908                         (s->d1->handshake_fragment[3] != 0))
909                         {
910                         al=SSL_AD_DECODE_ERROR;
911                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
912                         goto err;
913                         }
914
915                 /* no need to check sequence number on HELLO REQUEST messages */
916
917                 if (s->msg_callback)
918                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
919                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
920
921                 if (SSL_is_init_finished(s) &&
922                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
923                         !s->s3->renegotiate)
924                         {
925                         ssl3_renegotiate(s);
926                         if (ssl3_renegotiate_check(s))
927                                 {
928                                 i=s->handshake_func(s);
929                                 if (i < 0) return(i);
930                                 if (i == 0)
931                                         {
932                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
933                                         return(-1);
934                                         }
935
936                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
937                                         {
938                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
939                                                 {
940                                                 BIO *bio;
941                                                 /* In the case where we try to read application data,
942                                                  * but we trigger an SSL handshake, we return -1 with
943                                                  * the retry option set.  Otherwise renegotiation may
944                                                  * cause nasty problems in the blocking world */
945                                                 s->rwstate=SSL_READING;
946                                                 bio=SSL_get_rbio(s);
947                                                 BIO_clear_retry_flags(bio);
948                                                 BIO_set_retry_read(bio);
949                                                 return(-1);
950                                                 }
951                                         }
952                                 }
953                         }
954                 /* we either finished a handshake or ignored the request,
955                  * now try again to obtain the (application) data we were asked for */
956                 goto start;
957                 }
958
959         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
960                 {
961                 int alert_level = s->d1->alert_fragment[0];
962                 int alert_descr = s->d1->alert_fragment[1];
963
964                 s->d1->alert_fragment_len = 0;
965
966                 if (s->msg_callback)
967                         s->msg_callback(0, s->version, SSL3_RT_ALERT, 
968                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
969
970                 if (s->info_callback != NULL)
971                         cb=s->info_callback;
972                 else if (s->ctx->info_callback != NULL)
973                         cb=s->ctx->info_callback;
974
975                 if (cb != NULL)
976                         {
977                         j = (alert_level << 8) | alert_descr;
978                         cb(s, SSL_CB_READ_ALERT, j);
979                         }
980
981                 if (alert_level == 1) /* warning */
982                         {
983                         s->s3->warn_alert = alert_descr;
984                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
985                                 {
986                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
987                                 return(0);
988                                 }
989 #if 0
990             /* XXX: this is a possible improvement in the future */
991                         /* now check if it's a missing record */
992                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
993                                 {
994                                 unsigned short seq;
995                                 unsigned int frag_off;
996                                 unsigned char *p = &(s->d1->alert_fragment[2]);
997
998                                 n2s(p, seq);
999                                 n2l3(p, frag_off);
1000
1001                                 dtls1_retransmit_message(s,
1002                                                                                  dtls1_get_queue_priority(frag->msg_header.seq, 0),
1003                                                                                  frag_off, &found);
1004                                 if ( ! found  && SSL_in_init(s))
1005                                         {
1006                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1007                                         /* requested a message not yet sent, 
1008                                            send an alert ourselves */
1009                                         ssl3_send_alert(s,SSL3_AL_WARNING,
1010                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1011                                         }
1012                                 }
1013 #endif
1014                         }
1015                 else if (alert_level == 2) /* fatal */
1016                         {
1017                         char tmp[16];
1018
1019                         s->rwstate=SSL_NOTHING;
1020                         s->s3->fatal_alert = alert_descr;
1021                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1022                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1023                         ERR_add_error_data(2,"SSL alert number ",tmp);
1024                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1025                         SSL_CTX_remove_session(s->ctx,s->session);
1026                         return(0);
1027                         }
1028                 else
1029                         {
1030                         al=SSL_AD_ILLEGAL_PARAMETER;
1031                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1032                         goto f_err;
1033                         }
1034
1035                 goto start;
1036                 }
1037
1038         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1039                 {
1040                 s->rwstate=SSL_NOTHING;
1041                 rr->length=0;
1042                 return(0);
1043                 }
1044
1045         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1046                 {
1047                 struct ccs_header_st ccs_hdr;
1048                 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1049
1050                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1051
1052                 /* 'Change Cipher Spec' is just a single byte, so we know
1053                  * exactly what the record payload has to look like */
1054                 /* XDTLS: check that epoch is consistent */
1055                 if (s->client_version == DTLS1_BAD_VER || s->version == DTLS1_BAD_VER)
1056                         ccs_hdr_len = 3;
1057
1058                 if ((rr->length != ccs_hdr_len) || (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1059                         {
1060                         i=SSL_AD_ILLEGAL_PARAMETER;
1061                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1062                         goto err;
1063                         }
1064
1065                 rr->length=0;
1066
1067                 if (s->msg_callback)
1068                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
1069                                 rr->data, 1, s, s->msg_callback_arg);
1070
1071                 /* We can't process a CCS now, because previous handshake
1072                  * messages are still missing, so just drop it.
1073                  */
1074                 if (!s->d1->change_cipher_spec_ok)
1075                         {
1076                         goto start;
1077                         }
1078
1079                 s->d1->change_cipher_spec_ok = 0;
1080
1081                 s->s3->change_cipher_spec=1;
1082                 if (!ssl3_do_change_cipher_spec(s))
1083                         goto err;
1084
1085                 /* do this whenever CCS is processed */
1086                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1087
1088                 if (s->client_version == DTLS1_BAD_VER)
1089                         s->d1->handshake_read_seq++;
1090
1091                 goto start;
1092                 }
1093
1094         /* Unexpected handshake message (Client Hello, or protocol violation) */
1095         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 
1096                 !s->in_handshake)
1097                 {
1098                 struct hm_header_st msg_hdr;
1099                 
1100                 /* this may just be a stale retransmit */
1101                 dtls1_get_message_header(rr->data, &msg_hdr);
1102                 if( rr->epoch != s->d1->r_epoch)
1103                         {
1104                         rr->length = 0;
1105                         goto start;
1106                         }
1107
1108                 /* If we are server, we may have a repeated FINISHED of the
1109                  * client here, then retransmit our CCS and FINISHED.
1110                  */
1111                 if (msg_hdr.type == SSL3_MT_FINISHED)
1112                         {
1113                         dtls1_retransmit_buffered_messages(s);
1114                         rr->length = 0;
1115                         goto start;
1116                         }
1117
1118                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1119                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1120                         {
1121 #if 0 /* worked only because C operator preferences are not as expected (and
1122        * because this is not really needed for clients except for detecting
1123        * protocol violations): */
1124                         s->state=SSL_ST_BEFORE|(s->server)
1125                                 ?SSL_ST_ACCEPT
1126                                 :SSL_ST_CONNECT;
1127 #else
1128                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1129 #endif
1130                         s->new_session=1;
1131                         }
1132                 i=s->handshake_func(s);
1133                 if (i < 0) return(i);
1134                 if (i == 0)
1135                         {
1136                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1137                         return(-1);
1138                         }
1139
1140                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1141                         {
1142                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1143                                 {
1144                                 BIO *bio;
1145                                 /* In the case where we try to read application data,
1146                                  * but we trigger an SSL handshake, we return -1 with
1147                                  * the retry option set.  Otherwise renegotiation may
1148                                  * cause nasty problems in the blocking world */
1149                                 s->rwstate=SSL_READING;
1150                                 bio=SSL_get_rbio(s);
1151                                 BIO_clear_retry_flags(bio);
1152                                 BIO_set_retry_read(bio);
1153                                 return(-1);
1154                                 }
1155                         }
1156                 goto start;
1157                 }
1158
1159         switch (rr->type)
1160                 {
1161         default:
1162 #ifndef OPENSSL_NO_TLS
1163                 /* TLS just ignores unknown message types */
1164                 if (s->version == TLS1_VERSION)
1165                         {
1166                         rr->length = 0;
1167                         goto start;
1168                         }
1169 #endif
1170                 al=SSL_AD_UNEXPECTED_MESSAGE;
1171                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1172                 goto f_err;
1173         case SSL3_RT_CHANGE_CIPHER_SPEC:
1174         case SSL3_RT_ALERT:
1175         case SSL3_RT_HANDSHAKE:
1176                 /* we already handled all of these, with the possible exception
1177                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1178                  * should not happen when type != rr->type */
1179                 al=SSL_AD_UNEXPECTED_MESSAGE;
1180                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1181                 goto f_err;
1182         case SSL3_RT_APPLICATION_DATA:
1183                 /* At this point, we were expecting handshake data,
1184                  * but have application data.  If the library was
1185                  * running inside ssl3_read() (i.e. in_read_app_data
1186                  * is set) and it makes sense to read application data
1187                  * at this point (session renegotiation not yet started),
1188                  * we will indulge it.
1189                  */
1190                 if (s->s3->in_read_app_data &&
1191                         (s->s3->total_renegotiations != 0) &&
1192                         ((
1193                                 (s->state & SSL_ST_CONNECT) &&
1194                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1195                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1196                                 ) || (
1197                                         (s->state & SSL_ST_ACCEPT) &&
1198                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1199                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1200                                         )
1201                                 ))
1202                         {
1203                         s->s3->in_read_app_data=2;
1204                         return(-1);
1205                         }
1206                 else
1207                         {
1208                         al=SSL_AD_UNEXPECTED_MESSAGE;
1209                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1210                         goto f_err;
1211                         }
1212                 }
1213         /* not reached */
1214
1215 f_err:
1216         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1217 err:
1218         return(-1);
1219         }
1220
1221 int
1222 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1223         {
1224         int i;
1225
1226         if (SSL_in_init(s) && !s->in_handshake)
1227                 {
1228                 i=s->handshake_func(s);
1229                 if (i < 0) return(i);
1230                 if (i == 0)
1231                         {
1232                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1233                         return -1;
1234                         }
1235                 }
1236
1237         if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1238                 {
1239                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1240                         return -1;
1241                 }
1242
1243         i = dtls1_write_bytes(s, type, buf_, len);
1244         return i;
1245         }
1246
1247
1248         /* this only happens when a client hello is received and a handshake 
1249          * is started. */
1250 static int
1251 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
1252         int len, int peek)
1253         {
1254         
1255         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1256                 /* (partially) satisfy request from storage */
1257                 {
1258                 unsigned char *src = s->d1->handshake_fragment;
1259                 unsigned char *dst = buf;
1260                 unsigned int k,n;
1261                 
1262                 /* peek == 0 */
1263                 n = 0;
1264                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1265                         {
1266                         *dst++ = *src++;
1267                         len--; s->d1->handshake_fragment_len--;
1268                         n++;
1269                         }
1270                 /* move any remaining fragment bytes: */
1271                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1272                         s->d1->handshake_fragment[k] = *src++;
1273                 return n;
1274                 }
1275         
1276         return 0;
1277         }
1278
1279
1280
1281
1282 /* Call this to write data in records of type 'type'
1283  * It will return <= 0 if not all data has been sent or non-blocking IO.
1284  */
1285 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1286         {
1287         int i;
1288
1289         OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1290         s->rwstate=SSL_NOTHING;
1291         i=do_dtls1_write(s, type, buf, len, 0);
1292         return i;
1293         }
1294
1295 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1296         {
1297         unsigned char *p,*pseq;
1298         int i,mac_size,clear=0;
1299         int prefix_len = 0;
1300         SSL3_RECORD *wr;
1301         SSL3_BUFFER *wb;
1302         SSL_SESSION *sess;
1303         int bs;
1304
1305         /* first check if there is a SSL3_BUFFER still being written
1306          * out.  This will happen with non blocking IO */
1307         if (s->s3->wbuf.left != 0)
1308                 {
1309                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1310                 return(ssl3_write_pending(s,type,buf,len));
1311                 }
1312
1313         /* If we have an alert to send, lets send it */
1314         if (s->s3->alert_dispatch)
1315                 {
1316                 i=s->method->ssl_dispatch_alert(s);
1317                 if (i <= 0)
1318                         return(i);
1319                 /* if it went, fall through and send more stuff */
1320                 }
1321
1322         if (len == 0 && !create_empty_fragment)
1323                 return 0;
1324
1325         wr= &(s->s3->wrec);
1326         wb= &(s->s3->wbuf);
1327         sess=s->session;
1328
1329         if (    (sess == NULL) ||
1330                 (s->enc_write_ctx == NULL) ||
1331                 (s->write_hash == NULL))
1332                 clear=1;
1333
1334         if (clear)
1335                 mac_size=0;
1336         else
1337                 mac_size=EVP_MD_size(s->write_hash);
1338
1339         /* DTLS implements explicit IV, so no need for empty fragments */
1340 #if 0
1341         /* 'create_empty_fragment' is true only when this function calls itself */
1342         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1343             && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1344                 {
1345                 /* countermeasure against known-IV weakness in CBC ciphersuites
1346                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
1347                  */
1348
1349                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1350                         {
1351                         /* recursive function call with 'create_empty_fragment' set;
1352                          * this prepares and buffers the data for an empty fragment
1353                          * (these 'prefix_len' bytes are sent out later
1354                          * together with the actual payload) */
1355                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1356                         if (prefix_len <= 0)
1357                                 goto err;
1358
1359                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1360                                 {
1361                                 /* insufficient space */
1362                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1363                                 goto err;
1364                                 }
1365                         }
1366                 
1367                 s->s3->empty_fragment_done = 1;
1368                 }
1369 #endif
1370
1371         p = wb->buf + prefix_len;
1372
1373         /* write the header */
1374
1375         *(p++)=type&0xff;
1376         wr->type=type;
1377
1378         if (s->client_version == DTLS1_BAD_VER)
1379                 *(p++) = DTLS1_BAD_VER>>8,
1380                 *(p++) = DTLS1_BAD_VER&0xff;
1381         else
1382                 *(p++)=(s->version>>8),
1383                 *(p++)=s->version&0xff;
1384
1385         /* field where we are to write out packet epoch, seq num and len */
1386         pseq=p; 
1387         p+=10;
1388
1389         /* lets setup the record stuff. */
1390
1391         /* Make space for the explicit IV in case of CBC.
1392          * (this is a bit of a boundary violation, but what the heck).
1393          */
1394         if ( s->enc_write_ctx && 
1395                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1396                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1397         else
1398                 bs = 0;
1399
1400         wr->data=p + bs;  /* make room for IV in case of CBC */
1401         wr->length=(int)len;
1402         wr->input=(unsigned char *)buf;
1403
1404         /* we now 'read' from wr->input, wr->length bytes into
1405          * wr->data */
1406
1407         /* first we compress */
1408         if (s->compress != NULL)
1409                 {
1410                 if (!ssl3_do_compress(s))
1411                         {
1412                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1413                         goto err;
1414                         }
1415                 }
1416         else
1417                 {
1418                 memcpy(wr->data,wr->input,wr->length);
1419                 wr->input=wr->data;
1420                 }
1421
1422         /* we should still have the output to wr->data and the input
1423          * from wr->input.  Length should be wr->length.
1424          * wr->data still points in the wb->buf */
1425
1426         if (mac_size != 0)
1427                 {
1428                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1429                 wr->length+=mac_size;
1430                 }
1431
1432         /* this is true regardless of mac size */
1433         wr->input=p;
1434         wr->data=p;
1435
1436
1437         /* ssl3_enc can only have an error on read */
1438         if (bs) /* bs != 0 in case of CBC */
1439                 {
1440                 RAND_pseudo_bytes(p,bs);
1441                 /* master IV and last CBC residue stand for
1442                  * the rest of randomness */
1443                 wr->length += bs;
1444                 }
1445
1446         s->method->ssl3_enc->enc(s,1);
1447
1448         /* record length after mac and block padding */
1449 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1450         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1451         
1452         /* there's only one epoch between handshake and app data */
1453         
1454         s2n(s->d1->w_epoch, pseq);
1455
1456         /* XDTLS: ?? */
1457 /*      else
1458         s2n(s->d1->handshake_epoch, pseq); */
1459
1460         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1461         pseq+=6;
1462         s2n(wr->length,pseq);
1463
1464         /* we should now have
1465          * wr->data pointing to the encrypted data, which is
1466          * wr->length long */
1467         wr->type=type; /* not needed but helps for debugging */
1468         wr->length+=DTLS1_RT_HEADER_LENGTH;
1469
1470 #if 0  /* this is now done at the message layer */
1471         /* buffer the record, making it easy to handle retransmits */
1472         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1473                 dtls1_buffer_record(s, wr->data, wr->length, 
1474                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1475 #endif
1476
1477         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1478
1479         if (create_empty_fragment)
1480                 {
1481                 /* we are in a recursive call;
1482                  * just return the length, don't write out anything here
1483                  */
1484                 return wr->length;
1485                 }
1486
1487         /* now let's set up wb */
1488         wb->left = prefix_len + wr->length;
1489         wb->offset = 0;
1490
1491         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1492         s->s3->wpend_tot=len;
1493         s->s3->wpend_buf=buf;
1494         s->s3->wpend_type=type;
1495         s->s3->wpend_ret=len;
1496
1497         /* we now just need to write the buffer */
1498         return ssl3_write_pending(s,type,buf,len);
1499 err:
1500         return -1;
1501         }
1502
1503
1504
1505 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1506         PQ_64BIT *seq_num)
1507         {
1508 #if PQ_64BIT_IS_INTEGER
1509         PQ_64BIT mask = 0x0000000000000001L;
1510 #endif
1511         PQ_64BIT rcd_num, tmp;
1512
1513         pq_64bit_init(&rcd_num);
1514         pq_64bit_init(&tmp);
1515
1516         /* this is the sequence number for the record just read */
1517         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1518
1519         
1520         if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1521                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1522                 {
1523                 pq_64bit_assign(seq_num, &rcd_num);
1524                 pq_64bit_free(&rcd_num);
1525                 pq_64bit_free(&tmp);
1526                 return 1;  /* this record is new */
1527                 }
1528
1529         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1530
1531         if ( pq_64bit_get_word(&tmp) > bitmap->length)
1532                 {
1533                 pq_64bit_free(&rcd_num);
1534                 pq_64bit_free(&tmp);
1535                 return 0;  /* stale, outside the window */
1536                 }
1537
1538 #if PQ_64BIT_IS_BIGNUM
1539         {
1540         int offset;
1541         pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1542         pq_64bit_sub_word(&tmp, 1);
1543         offset = pq_64bit_get_word(&tmp);
1544         if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1545                 {
1546                 pq_64bit_free(&rcd_num);
1547                 pq_64bit_free(&tmp);
1548                 return 0;
1549                 }
1550         }
1551 #else
1552         mask <<= (bitmap->max_seq_num - rcd_num - 1);
1553         if (bitmap->map & mask)
1554                 return 0; /* record previously received */
1555 #endif
1556         
1557         pq_64bit_assign(seq_num, &rcd_num);
1558         pq_64bit_free(&rcd_num);
1559         pq_64bit_free(&tmp);
1560         return 1;
1561         }
1562
1563
1564 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1565         {
1566         unsigned int shift;
1567         PQ_64BIT rcd_num;
1568         PQ_64BIT tmp;
1569         PQ_64BIT_CTX *ctx;
1570
1571         pq_64bit_init(&rcd_num);
1572         pq_64bit_init(&tmp);
1573
1574         pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1575
1576         /* unfortunate code complexity due to 64-bit manipulation support
1577          * on 32-bit machines */
1578         if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1579                 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1580                 {
1581                 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1582                 pq_64bit_add_word(&tmp, 1);
1583
1584                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1585
1586                 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1587                 pq_64bit_assign(&(bitmap->map), &tmp);
1588
1589                 pq_64bit_set_bit(&(bitmap->map), 0);
1590                 pq_64bit_add_word(&rcd_num, 1);
1591                 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1592
1593                 pq_64bit_assign_word(&tmp, 1);
1594                 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1595                 ctx = pq_64bit_ctx_new(&ctx);
1596                 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1597                 pq_64bit_ctx_free(ctx);
1598                 }
1599         else
1600                 {
1601                 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1602                 pq_64bit_sub_word(&tmp, 1);
1603                 shift = (unsigned int)pq_64bit_get_word(&tmp);
1604
1605                 pq_64bit_set_bit(&(bitmap->map), shift);
1606                 }
1607
1608         pq_64bit_free(&rcd_num);
1609         pq_64bit_free(&tmp);
1610         }
1611
1612
1613 int dtls1_dispatch_alert(SSL *s)
1614         {
1615         int i,j;
1616         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1617         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1618         unsigned char *ptr = &buf[0];
1619
1620         s->s3->alert_dispatch=0;
1621
1622         memset(buf, 0x00, sizeof(buf));
1623         *ptr++ = s->s3->send_alert[0];
1624         *ptr++ = s->s3->send_alert[1];
1625
1626 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1627         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1628                 {       
1629                 s2n(s->d1->handshake_read_seq, ptr);
1630 #if 0
1631                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1632
1633                 else
1634                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1635 #endif
1636
1637 #if 0
1638                 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);
1639 #endif
1640                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1641                 }
1642 #endif
1643
1644         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1645         if (i <= 0)
1646                 {
1647                 s->s3->alert_dispatch=1;
1648                 /* fprintf( stderr, "not done with alert\n" ); */
1649                 }
1650         else
1651                 {
1652                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1653 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1654                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1655 #endif
1656                    )
1657                         (void)BIO_flush(s->wbio);
1658
1659                 if (s->msg_callback)
1660                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 
1661                                 2, s, s->msg_callback_arg);
1662
1663                 if (s->info_callback != NULL)
1664                         cb=s->info_callback;
1665                 else if (s->ctx->info_callback != NULL)
1666                         cb=s->ctx->info_callback;
1667
1668                 if (cb != NULL)
1669                         {
1670                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1671                         cb(s,SSL_CB_WRITE_ALERT,j);
1672                         }
1673                 }
1674         return(i);
1675         }
1676
1677
1678 static DTLS1_BITMAP *
1679 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1680     {
1681     
1682     *is_next_epoch = 0;
1683
1684     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1685     if (rr->epoch == s->d1->r_epoch)
1686         return &s->d1->bitmap;
1687
1688     /* Only HM and ALERT messages can be from the next epoch */
1689     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1690         (rr->type == SSL3_RT_HANDSHAKE ||
1691             rr->type == SSL3_RT_ALERT))
1692         {
1693         *is_next_epoch = 1;
1694         return &s->d1->next_bitmap;
1695         }
1696
1697     return NULL;
1698     }
1699
1700 #if 0
1701 static int
1702 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1703         unsigned long *offset)
1704         {
1705
1706         /* alerts are passed up immediately */
1707         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1708                 rr->type == SSL3_RT_ALERT)
1709                 return 0;
1710
1711         /* Only need to buffer if a handshake is underway.
1712          * (this implies that Hello Request and Client Hello are passed up
1713          * immediately) */
1714         if ( SSL_in_init(s))
1715                 {
1716                 unsigned char *data = rr->data;
1717                 /* need to extract the HM/CCS sequence number here */
1718                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1719                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1720                         {
1721                         unsigned short seq_num;
1722                         struct hm_header_st msg_hdr;
1723                         struct ccs_header_st ccs_hdr;
1724
1725                         if ( rr->type == SSL3_RT_HANDSHAKE)
1726                                 {
1727                                 dtls1_get_message_header(data, &msg_hdr);
1728                                 seq_num = msg_hdr.seq;
1729                                 *offset = msg_hdr.frag_off;
1730                                 }
1731                         else
1732                                 {
1733                                 dtls1_get_ccs_header(data, &ccs_hdr);
1734                                 seq_num = ccs_hdr.seq;
1735                                 *offset = 0;
1736                                 }
1737                                 
1738                         /* this is either a record we're waiting for, or a
1739                          * retransmit of something we happened to previously 
1740                          * receive (higher layers will drop the repeat silently */
1741                         if ( seq_num < s->d1->handshake_read_seq)
1742                                 return 0;
1743                         if (rr->type == SSL3_RT_HANDSHAKE && 
1744                                 seq_num == s->d1->handshake_read_seq &&
1745                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1746                                 return 0;
1747                         else if ( seq_num == s->d1->handshake_read_seq &&
1748                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1749                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1750                                 return 0;
1751                         else
1752                                 {
1753                                 *priority = seq_num;
1754                                 return 1;
1755                                 }
1756                         }
1757                 else /* unknown record type */
1758                         return 0;
1759                 }
1760
1761         return 0;
1762         }
1763 #endif
1764
1765 void
1766 dtls1_reset_seq_numbers(SSL *s, int rw)
1767         {
1768         unsigned char *seq;
1769         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1770
1771         if ( rw & SSL3_CC_READ)
1772                 {
1773                 seq = s->s3->read_sequence;
1774                 s->d1->r_epoch++;
1775
1776                 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1777                 s->d1->bitmap.length = s->d1->next_bitmap.length;
1778                 pq_64bit_assign(&(s->d1->bitmap.max_seq_num), 
1779                         &(s->d1->next_bitmap.max_seq_num));
1780
1781                 pq_64bit_free(&(s->d1->next_bitmap.map));
1782                 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1783                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1784                 pq_64bit_init(&(s->d1->next_bitmap.map));
1785                 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1786                 }
1787         else
1788                 {
1789                 seq = s->s3->write_sequence;
1790                 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1791                 s->d1->w_epoch++;
1792                 }
1793
1794         memset(seq, 0x00, seq_bytes);
1795         }
1796
1797 #if PQ_64BIT_IS_INTEGER
1798 static PQ_64BIT
1799 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1800        {
1801        PQ_64BIT _num;
1802
1803        _num = (((PQ_64BIT)bytes[0]) << 56) |
1804                (((PQ_64BIT)bytes[1]) << 48) |
1805                (((PQ_64BIT)bytes[2]) << 40) |
1806                (((PQ_64BIT)bytes[3]) << 32) |
1807                (((PQ_64BIT)bytes[4]) << 24) |
1808                (((PQ_64BIT)bytes[5]) << 16) |
1809                (((PQ_64BIT)bytes[6]) <<  8) |
1810                (((PQ_64BIT)bytes[7])      );
1811
1812            *num = _num ;
1813        return _num;
1814        }
1815 #endif
1816
1817
1818 static void
1819 dtls1_clear_timeouts(SSL *s)
1820         {
1821         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1822         }