Reverse incorrect earlier fix.
[openssl.git] / ssl / d1_pkt.c
1 /* ssl/d1_pkt.c */
2 /* 
3  * DTLS implementation written by Nagendra Modadugu
4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.  
5  */
6 /* ====================================================================
7  * Copyright (c) 1998-2005 The OpenSSL Project.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer. 
15  *
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in
18  *    the documentation and/or other materials provided with the
19  *    distribution.
20  *
21  * 3. All advertising materials mentioning features or use of this
22  *    software must display the following acknowledgment:
23  *    "This product includes software developed by the OpenSSL Project
24  *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
25  *
26  * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27  *    endorse or promote products derived from this software without
28  *    prior written permission. For written permission, please contact
29  *    openssl-core@openssl.org.
30  *
31  * 5. Products derived from this software may not be called "OpenSSL"
32  *    nor may "OpenSSL" appear in their names without prior written
33  *    permission of the OpenSSL Project.
34  *
35  * 6. Redistributions of any form whatsoever must retain the following
36  *    acknowledgment:
37  *    "This product includes software developed by the OpenSSL Project
38  *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41  * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
44  * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49  * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51  * OF THE POSSIBILITY OF SUCH DAMAGE.
52  * ====================================================================
53  *
54  * This product includes cryptographic software written by Eric Young
55  * (eay@cryptsoft.com).  This product includes software written by Tim
56  * Hudson (tjh@cryptsoft.com).
57  *
58  */
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60  * All rights reserved.
61  *
62  * This package is an SSL implementation written
63  * by Eric Young (eay@cryptsoft.com).
64  * The implementation was written so as to conform with Netscapes SSL.
65  * 
66  * This library is free for commercial and non-commercial use as long as
67  * the following conditions are aheared to.  The following conditions
68  * apply to all code found in this distribution, be it the RC4, RSA,
69  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
70  * included with this distribution is covered by the same copyright terms
71  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
72  * 
73  * Copyright remains Eric Young's, and as such any Copyright notices in
74  * the code are not to be removed.
75  * If this package is used in a product, Eric Young should be given attribution
76  * as the author of the parts of the library used.
77  * This can be in the form of a textual message at program startup or
78  * in documentation (online or textual) provided with the package.
79  * 
80  * Redistribution and use in source and binary forms, with or without
81  * modification, are permitted provided that the following conditions
82  * are met:
83  * 1. Redistributions of source code must retain the copyright
84  *    notice, this list of conditions and the following disclaimer.
85  * 2. Redistributions in binary form must reproduce the above copyright
86  *    notice, this list of conditions and the following disclaimer in the
87  *    documentation and/or other materials provided with the distribution.
88  * 3. All advertising materials mentioning features or use of this software
89  *    must display the following acknowledgement:
90  *    "This product includes cryptographic software written by
91  *     Eric Young (eay@cryptsoft.com)"
92  *    The word 'cryptographic' can be left out if the rouines from the library
93  *    being used are not cryptographic related :-).
94  * 4. If you include any Windows specific code (or a derivative thereof) from 
95  *    the apps directory (application code) you must include an acknowledgement:
96  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
97  * 
98  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
108  * SUCH DAMAGE.
109  * 
110  * The licence and distribution terms for any publically available version or
111  * derivative of this code cannot be changed.  i.e. this code cannot simply be
112  * copied and put under another distribution licence
113  * [including the GNU Public Licence.]
114  */
115
116 #include <stdio.h>
117 #include <errno.h>
118 #define USE_SOCKETS
119 #include "ssl_locl.h"
120 #include <openssl/evp.h>
121 #include <openssl/buffer.h>
122 #include <openssl/pqueue.h>
123 #include <openssl/rand.h>
124
125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
127 {       int ret,sat,brw,i;
128
129         if (sizeof(long) == 8) do
130         {       const union { long one; char little; } is_endian = {1};
131                 long l;
132
133                 if (is_endian.little)                   break;
134                 /* not reached on little-endians */
135                 /* following test is redundant, because input is
136                  * always aligned, but I take no chances... */
137                 if (((size_t)v1|(size_t)v2)&0x7)        break;
138
139                 l  = *((long *)v1);
140                 l -= *((long *)v2);
141                 if (l>128)              return 128;
142                 else if (l<-128)        return -128;
143                 else                    return (int)l;
144         } while (0);
145
146         ret = (int)v1[7]-(int)v2[7];
147         sat = 0;
148         brw = ret>>8;   /* brw is either 0 or -1 */
149         if (ret & 0x80)
150         {       for (i=6;i>=0;i--)
151                 {       brw += (int)v1[i]-(int)v2[i];
152                         sat |= ~brw;
153                         brw >>= 8;
154                 }
155         }
156         else
157         {       for (i=6;i>=0;i--)
158                 {       brw += (int)v1[i]-(int)v2[i];
159                         sat |= brw;
160                         brw >>= 8;
161                 }
162         }
163         brw <<= 8;      /* brw is either 0 or -256 */
164
165         if (sat&0xff)   return brw | 0x80;
166         else            return brw + (ret&0xFF);
167 }
168
169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
170         int len, int peek);
171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, 
174     unsigned int *is_next_epoch);
175 #if 0
176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
177         unsigned short *priority, unsigned long *offset);
178 #endif
179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
180         unsigned char *priority);
181 static int dtls1_process_record(SSL *s);
182 static void dtls1_clear_timeouts(SSL *s);
183
184 /* copy buffered record into SSL structure */
185 static int
186 dtls1_copy_record(SSL *s, pitem *item)
187     {
188     DTLS1_RECORD_DATA *rdata;
189
190     rdata = (DTLS1_RECORD_DATA *)item->data;
191     
192     if (s->s3->rbuf.buf != NULL)
193         OPENSSL_free(s->s3->rbuf.buf);
194     
195     s->packet = rdata->packet;
196     s->packet_length = rdata->packet_length;
197     memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
198     memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
199     
200     return(1);
201     }
202
203
204 static int
205 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
206         {
207         DTLS1_RECORD_DATA *rdata;
208         pitem *item;
209
210         rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
211         item = pitem_new(priority, rdata);
212         if (rdata == NULL || item == NULL)
213                 {
214                 if (rdata != NULL) OPENSSL_free(rdata);
215                 if (item != NULL) pitem_free(item);
216                 
217                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
218                 return(0);
219                 }
220         
221         rdata->packet = s->packet;
222         rdata->packet_length = s->packet_length;
223         memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
224         memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
225
226         item->data = rdata;
227
228         /* insert should not fail, since duplicates are dropped */
229         if (pqueue_insert(queue->q, item) == NULL)
230                 {
231                 OPENSSL_free(rdata);
232                 pitem_free(item);
233                 return(0);
234                 }
235
236         s->packet = NULL;
237         s->packet_length = 0;
238         memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
239         memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
240         
241         if (!ssl3_setup_buffers(s))
242                 {
243                 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
244                 OPENSSL_free(rdata);
245                 pitem_free(item);
246                 return(0);
247                 }
248         
249         return(1);
250         }
251
252
253 static int
254 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
255     {
256     pitem *item;
257
258     item = pqueue_pop(queue->q);
259     if (item)
260         {
261         dtls1_copy_record(s, item);
262
263         OPENSSL_free(item->data);
264                 pitem_free(item);
265
266         return(1);
267         }
268
269     return(0);
270     }
271
272
273 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed 
274  * yet */
275 #define dtls1_get_unprocessed_record(s) \
276                    dtls1_retrieve_buffered_record((s), \
277                    &((s)->d1->unprocessed_rcds))
278
279 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
280 #define dtls1_get_processed_record(s) \
281                    dtls1_retrieve_buffered_record((s), \
282                    &((s)->d1->processed_rcds))
283
284 static int
285 dtls1_process_buffered_records(SSL *s)
286     {
287     pitem *item;
288     
289     item = pqueue_peek(s->d1->unprocessed_rcds.q);
290     if (item)
291         {
292         DTLS1_RECORD_DATA *rdata;
293         rdata = (DTLS1_RECORD_DATA *)item->data;
294         
295         /* Check if epoch is current. */
296         if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
297             return(1);  /* Nothing to do. */
298         
299         /* Process all the records. */
300         while (pqueue_peek(s->d1->unprocessed_rcds.q))
301             {
302             dtls1_get_unprocessed_record(s);
303             if ( ! dtls1_process_record(s))
304                 return(0);
305             dtls1_buffer_record(s, &(s->d1->processed_rcds), 
306                 s->s3->rrec.seq_num);
307             }
308         }
309
310     /* sync epoch numbers once all the unprocessed records 
311      * have been processed */
312     s->d1->processed_rcds.epoch = s->d1->r_epoch;
313     s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
314
315     return(1);
316     }
317
318
319 #if 0
320
321 static int
322 dtls1_get_buffered_record(SSL *s)
323         {
324         pitem *item;
325         PQ_64BIT priority = 
326                 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) | 
327                 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
328         
329         if ( ! SSL_in_init(s))  /* if we're not (re)negotiating, 
330                                                            nothing buffered */
331                 return 0;
332
333
334         item = pqueue_peek(s->d1->rcvd_records);
335         if (item && item->priority == priority)
336                 {
337                 /* Check if we've received the record of interest.  It must be
338                  * a handshake record, since data records as passed up without
339                  * buffering */
340                 DTLS1_RECORD_DATA *rdata;
341                 item = pqueue_pop(s->d1->rcvd_records);
342                 rdata = (DTLS1_RECORD_DATA *)item->data;
343                 
344                 if (s->s3->rbuf.buf != NULL)
345                         OPENSSL_free(s->s3->rbuf.buf);
346                 
347                 s->packet = rdata->packet;
348                 s->packet_length = rdata->packet_length;
349                 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
350                 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
351                 
352                 OPENSSL_free(item->data);
353                 pitem_free(item);
354                 
355                 /* s->d1->next_expected_seq_num++; */
356                 return(1);
357                 }
358         
359         return 0;
360         }
361
362 #endif
363
364 static int
365 dtls1_process_record(SSL *s)
366 {
367         int i,al;
368         int clear=0;
369         int enc_err;
370         SSL_SESSION *sess;
371         SSL3_RECORD *rr;
372         unsigned int mac_size;
373         unsigned char md[EVP_MAX_MD_SIZE];
374
375
376         rr= &(s->s3->rrec);
377         sess = s->session;
378
379         /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
380          * and we have that many bytes in s->packet
381          */
382         rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
383
384         /* ok, we can now read from 's->packet' data into 'rr'
385          * rr->input points at rr->length bytes, which
386          * need to be copied into rr->data by either
387          * the decryption or by the decompression
388          * When the data is 'copied' into the rr->data buffer,
389          * rr->input will be pointed at the new buffer */ 
390
391         /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
392          * rr->length bytes of encrypted compressed stuff. */
393
394         /* check is not needed I believe */
395         if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
396                 {
397                 al=SSL_AD_RECORD_OVERFLOW;
398                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
399                 goto f_err;
400                 }
401
402         /* decrypt in place in 'rr->input' */
403         rr->data=rr->input;
404
405         enc_err = s->method->ssl3_enc->enc(s,0);
406         if (enc_err <= 0)
407                 {
408                 if (enc_err == 0)
409                         /* SSLerr() and ssl3_send_alert() have been called */
410                         goto err;
411
412                 /* otherwise enc_err == -1 */
413                 goto decryption_failed_or_bad_record_mac;
414                 }
415
416 #ifdef TLS_DEBUG
417 printf("dec %d\n",rr->length);
418 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
419 printf("\n");
420 #endif
421
422         /* r->length is now the compressed data plus mac */
423         if (    (sess == NULL) ||
424                 (s->enc_read_ctx == NULL) ||
425                 (s->read_hash == NULL))
426                 clear=1;
427
428         if (!clear)
429                 {
430                 /* !clear => s->read_hash != NULL => mac_size != -1 */
431                 mac_size=EVP_MD_CTX_size(s->read_hash);
432
433                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
434                         {
435 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
436                         al=SSL_AD_RECORD_OVERFLOW;
437                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
438                         goto f_err;
439 #else
440                         goto decryption_failed_or_bad_record_mac;
441 #endif                  
442                         }
443                 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
444                 if (rr->length < mac_size)
445                         {
446 #if 0 /* OK only for stream ciphers */
447                         al=SSL_AD_DECODE_ERROR;
448                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
449                         goto f_err;
450 #else
451                         goto decryption_failed_or_bad_record_mac;
452 #endif
453                         }
454                 rr->length-=mac_size;
455                 i=s->method->ssl3_enc->mac(s,md,0);
456                 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
457                         {
458                         goto decryption_failed_or_bad_record_mac;
459                         }
460                 }
461
462         /* r->length is now just compressed */
463         if (s->expand != NULL)
464                 {
465                 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
466                         {
467                         al=SSL_AD_RECORD_OVERFLOW;
468                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
469                         goto f_err;
470                         }
471                 if (!ssl3_do_uncompress(s))
472                         {
473                         al=SSL_AD_DECOMPRESSION_FAILURE;
474                         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
475                         goto f_err;
476                         }
477                 }
478
479         if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
480                 {
481                 al=SSL_AD_RECORD_OVERFLOW;
482                 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
483                 goto f_err;
484                 }
485
486         rr->off=0;
487         /* So at this point the following is true
488          * ssl->s3->rrec.type   is the type of record
489          * ssl->s3->rrec.length == number of bytes in record
490          * ssl->s3->rrec.off    == offset to first valid byte
491          * ssl->s3->rrec.data   == where to take bytes from, increment
492          *                         after use :-).
493          */
494
495         /* we have pulled in a full packet so zero things */
496         s->packet_length=0;
497         dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
498         return(1);
499
500 decryption_failed_or_bad_record_mac:
501         /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
502          * SSL 3.0 only has 'bad_record_mac'.  But unless a decryption
503          * failure is directly visible from the ciphertext anyway,
504          * we should not reveal which kind of error occured -- this
505          * might become visible to an attacker (e.g. via logfile) */
506         al=SSL_AD_BAD_RECORD_MAC;
507         SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
508 f_err:
509         ssl3_send_alert(s,SSL3_AL_FATAL,al);
510 err:
511         return(0);
512 }
513
514
515 /* Call this to get a new input record.
516  * It will return <= 0 if more data is needed, normally due to an error
517  * or non-blocking IO.
518  * When it finishes, one packet has been decoded and can be found in
519  * ssl->s3->rrec.type    - is the type of record
520  * ssl->s3->rrec.data,   - data
521  * ssl->s3->rrec.length, - number of bytes
522  */
523 /* used only by dtls1_read_bytes */
524 int dtls1_get_record(SSL *s)
525         {
526         int ssl_major,ssl_minor,al;
527         int i,n;
528         SSL3_RECORD *rr;
529         SSL_SESSION *sess;
530         unsigned char *p;
531         unsigned short version;
532         DTLS1_BITMAP *bitmap;
533         unsigned int is_next_epoch;
534
535         rr= &(s->s3->rrec);
536         sess=s->session;
537
538         /* The epoch may have changed.  If so, process all the
539          * pending records.  This is a non-blocking operation. */
540         if ( ! dtls1_process_buffered_records(s))
541             return 0;
542
543         /* if we're renegotiating, then there may be buffered records */
544         if (dtls1_get_processed_record(s))
545                 return 1;
546
547         /* get something from the wire */
548 again:
549         /* check if we have the header */
550         if (    (s->rstate != SSL_ST_READ_BODY) ||
551                 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) 
552                 {
553                 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
554                 /* read timeout is handled by dtls1_read_bytes */
555                 if (n <= 0) return(n); /* error or non-blocking */
556
557                 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
558
559                 s->rstate=SSL_ST_READ_BODY;
560
561                 p=s->packet;
562
563                 /* Pull apart the header into the DTLS1_RECORD */
564                 rr->type= *(p++);
565                 ssl_major= *(p++);
566                 ssl_minor= *(p++);
567                 version=(ssl_major<<8)|ssl_minor;
568
569                 /* sequence number is 64 bits, with top 2 bytes = epoch */ 
570                 n2s(p,rr->epoch);
571
572                 memcpy(&(s->s3->read_sequence[2]), p, 6);
573                 p+=6;
574
575                 n2s(p,rr->length);
576
577                 /* Lets check version */
578                 if (!s->first_packet)
579                         {
580                         if (version != s->version)
581                                 {
582                                 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
583                                 /* Send back error using their
584                                  * version number :-) */
585                                 s->version=version;
586                                 al=SSL_AD_PROTOCOL_VERSION;
587                                 goto f_err;
588                                 }
589                         }
590
591                 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
592                         {
593                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
594                         goto err;
595                         }
596
597                 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
598                         {
599                         al=SSL_AD_RECORD_OVERFLOW;
600                         SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
601                         goto f_err;
602                         }
603
604                 /* now s->rstate == SSL_ST_READ_BODY */
605                 }
606
607         /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
608
609         if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
610                 {
611                 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
612                 i=rr->length;
613                 n=ssl3_read_n(s,i,i,1);
614                 if (n <= 0) return(n); /* error or non-blocking io */
615
616                 /* this packet contained a partial record, dump it */
617                 if ( n != i)
618                         {
619                         s->packet_length = 0;
620                         goto again;
621                         }
622
623                 /* now n == rr->length,
624                  * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
625                 }
626         s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
627
628         /* match epochs.  NULL means the packet is dropped on the floor */
629         bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
630         if ( bitmap == NULL)
631                 {
632                 s->packet_length = 0;  /* dump this record */
633                 goto again;   /* get another record */
634                 }
635
636         /* check whether this is a repeat, or aged record */
637         if ( ! dtls1_record_replay_check(s, bitmap))
638                 {
639                 rr->length = 0;
640                 s->packet_length=0; /* dump this record */
641                 goto again;     /* get another record */
642                 }
643
644         /* just read a 0 length packet */
645         if (rr->length == 0) goto again;
646
647         /* If this record is from the next epoch (either HM or ALERT),
648          * buffer it since it cannot be processed at this time. Records
649          * from the next epoch are marked as received even though they
650          * are not processed, so as to prevent any potential resource
651          * DoS attack */
652         if (is_next_epoch)
653                 {
654                 dtls1_record_bitmap_update(s, bitmap);
655                 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
656                 s->packet_length = 0;
657                 goto again;
658                 }
659
660         if ( ! dtls1_process_record(s))
661                 return(0);
662
663         dtls1_clear_timeouts(s);  /* done waiting */
664         return(1);
665
666 f_err:
667         ssl3_send_alert(s,SSL3_AL_FATAL,al);
668 err:
669         return(0);
670         }
671
672 /* Return up to 'len' payload bytes received in 'type' records.
673  * 'type' is one of the following:
674  *
675  *   -  SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
676  *   -  SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
677  *   -  0 (during a shutdown, no data has to be returned)
678  *
679  * If we don't have stored data to work from, read a SSL/TLS record first
680  * (possibly multiple records if we still don't have anything to return).
681  *
682  * This function must handle any surprises the peer may have for us, such as
683  * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
684  * a surprise, but handled as if it were), or renegotiation requests.
685  * Also if record payloads contain fragments too small to process, we store
686  * them until there is enough for the respective protocol (the record protocol
687  * may use arbitrary fragmentation and even interleaving):
688  *     Change cipher spec protocol
689  *             just 1 byte needed, no need for keeping anything stored
690  *     Alert protocol
691  *             2 bytes needed (AlertLevel, AlertDescription)
692  *     Handshake protocol
693  *             4 bytes needed (HandshakeType, uint24 length) -- we just have
694  *             to detect unexpected Client Hello and Hello Request messages
695  *             here, anything else is handled by higher layers
696  *     Application data protocol
697  *             none of our business
698  */
699 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
700         {
701         int al,i,j,ret;
702         unsigned int n;
703         SSL3_RECORD *rr;
704         void (*cb)(const SSL *ssl,int type2,int val)=NULL;
705
706         if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
707                 if (!ssl3_setup_buffers(s))
708                         return(-1);
709
710     /* XXX: check what the second '&& type' is about */
711         if ((type && (type != SSL3_RT_APPLICATION_DATA) && 
712                 (type != SSL3_RT_HANDSHAKE) && type) ||
713             (peek && (type != SSL3_RT_APPLICATION_DATA)))
714                 {
715                 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
716                 return -1;
717                 }
718
719         /* check whether there's a handshake message (client hello?) waiting */
720         if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
721                 return ret;
722
723         /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
724
725         if (!s->in_handshake && SSL_in_init(s))
726                 {
727                 /* type == SSL3_RT_APPLICATION_DATA */
728                 i=s->handshake_func(s);
729                 if (i < 0) return(i);
730                 if (i == 0)
731                         {
732                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
733                         return(-1);
734                         }
735                 }
736
737 start:
738         s->rwstate=SSL_NOTHING;
739
740         /* s->s3->rrec.type         - is the type of record
741          * s->s3->rrec.data,    - data
742          * s->s3->rrec.off,     - offset into 'data' for next read
743          * s->s3->rrec.length,  - number of bytes. */
744         rr = &(s->s3->rrec);
745
746         /* get new packet if necessary */
747         if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
748                 {
749                 ret=dtls1_get_record(s);
750                 if (ret <= 0) 
751                         {
752                         ret = dtls1_read_failed(s, ret);
753                         /* anything other than a timeout is an error */
754                         if (ret <= 0)  
755                                 return(ret);
756                         else
757                                 goto start;
758                         }
759                 }
760
761         /* we now have a packet which can be read and processed */
762
763         if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
764                                        * reset by ssl3_get_finished */
765                 && (rr->type != SSL3_RT_HANDSHAKE))
766                 {
767                 al=SSL_AD_UNEXPECTED_MESSAGE;
768                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
769                 goto err;
770                 }
771
772         /* If the other end has shut down, throw anything we read away
773          * (even in 'peek' mode) */
774         if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
775                 {
776                 rr->length=0;
777                 s->rwstate=SSL_NOTHING;
778                 return(0);
779                 }
780
781
782         if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
783                 {
784                 /* make sure that we are not getting application data when we
785                  * are doing a handshake for the first time */
786                 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
787                         (s->enc_read_ctx == NULL))
788                         {
789                         al=SSL_AD_UNEXPECTED_MESSAGE;
790                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
791                         goto f_err;
792                         }
793
794                 if (len <= 0) return(len);
795
796                 if ((unsigned int)len > rr->length)
797                         n = rr->length;
798                 else
799                         n = (unsigned int)len;
800
801                 memcpy(buf,&(rr->data[rr->off]),n);
802                 if (!peek)
803                         {
804                         rr->length-=n;
805                         rr->off+=n;
806                         if (rr->length == 0)
807                                 {
808                                 s->rstate=SSL_ST_READ_HEADER;
809                                 rr->off=0;
810                                 }
811                         }
812                 return(n);
813                 }
814
815
816         /* If we get here, then type != rr->type; if we have a handshake
817          * message, then it was unexpected (Hello Request or Client Hello). */
818
819         /* In case of record types for which we have 'fragment' storage,
820          * fill that so that we can process the data at a fixed place.
821          */
822                 {
823                 unsigned int k, dest_maxlen = 0;
824                 unsigned char *dest = NULL;
825                 unsigned int *dest_len = NULL;
826
827                 if (rr->type == SSL3_RT_HANDSHAKE)
828                         {
829                         dest_maxlen = sizeof s->d1->handshake_fragment;
830                         dest = s->d1->handshake_fragment;
831                         dest_len = &s->d1->handshake_fragment_len;
832                         }
833                 else if (rr->type == SSL3_RT_ALERT)
834                         {
835                         dest_maxlen = sizeof(s->d1->alert_fragment);
836                         dest = s->d1->alert_fragment;
837                         dest_len = &s->d1->alert_fragment_len;
838                         }
839                 /* else it's a CCS message, or it's wrong */
840                 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
841                         {
842                           /* Not certain if this is the right error handling */
843                           al=SSL_AD_UNEXPECTED_MESSAGE;
844                           SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
845                           goto f_err;
846                         }
847
848
849                 if (dest_maxlen > 0)
850                         {
851             /* XDTLS:  In a pathalogical case, the Client Hello
852              *  may be fragmented--don't always expect dest_maxlen bytes */
853                         if ( rr->length < dest_maxlen)
854                                 {
855 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
856                                 /*
857                                  * for normal alerts rr->length is 2, while
858                                  * dest_maxlen is 7 if we were to handle this
859                                  * non-existing alert...
860                                  */
861                                 FIX ME
862 #endif
863                                 s->rstate=SSL_ST_READ_HEADER;
864                                 rr->length = 0;
865                                 goto start;
866                                 }
867
868                         /* now move 'n' bytes: */
869                         for ( k = 0; k < dest_maxlen; k++)
870                                 {
871                                 dest[k] = rr->data[rr->off++];
872                                 rr->length--;
873                                 }
874                         *dest_len = dest_maxlen;
875                         }
876                 }
877
878         /* s->d1->handshake_fragment_len == 12  iff  rr->type == SSL3_RT_HANDSHAKE;
879          * s->d1->alert_fragment_len == 7      iff  rr->type == SSL3_RT_ALERT.
880          * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
881
882         /* If we are a client, check for an incoming 'Hello Request': */
883         if ((!s->server) &&
884                 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
885                 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
886                 (s->session != NULL) && (s->session->cipher != NULL))
887                 {
888                 s->d1->handshake_fragment_len = 0;
889
890                 if ((s->d1->handshake_fragment[1] != 0) ||
891                         (s->d1->handshake_fragment[2] != 0) ||
892                         (s->d1->handshake_fragment[3] != 0))
893                         {
894                         al=SSL_AD_DECODE_ERROR;
895                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
896                         goto err;
897                         }
898
899                 /* no need to check sequence number on HELLO REQUEST messages */
900
901                 if (s->msg_callback)
902                         s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, 
903                                 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
904
905                 if (SSL_is_init_finished(s) &&
906                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
907                         !s->s3->renegotiate)
908                         {
909                         ssl3_renegotiate(s);
910                         if (ssl3_renegotiate_check(s))
911                                 {
912                                 i=s->handshake_func(s);
913                                 if (i < 0) return(i);
914                                 if (i == 0)
915                                         {
916                                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
917                                         return(-1);
918                                         }
919
920                                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
921                                         {
922                                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
923                                                 {
924                                                 BIO *bio;
925                                                 /* In the case where we try to read application data,
926                                                  * but we trigger an SSL handshake, we return -1 with
927                                                  * the retry option set.  Otherwise renegotiation may
928                                                  * cause nasty problems in the blocking world */
929                                                 s->rwstate=SSL_READING;
930                                                 bio=SSL_get_rbio(s);
931                                                 BIO_clear_retry_flags(bio);
932                                                 BIO_set_retry_read(bio);
933                                                 return(-1);
934                                                 }
935                                         }
936                                 }
937                         }
938                 /* we either finished a handshake or ignored the request,
939                  * now try again to obtain the (application) data we were asked for */
940                 goto start;
941                 }
942
943         if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
944                 {
945                 int alert_level = s->d1->alert_fragment[0];
946                 int alert_descr = s->d1->alert_fragment[1];
947
948                 s->d1->alert_fragment_len = 0;
949
950                 if (s->msg_callback)
951                         s->msg_callback(0, s->version, SSL3_RT_ALERT, 
952                                 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
953
954                 if (s->info_callback != NULL)
955                         cb=s->info_callback;
956                 else if (s->ctx->info_callback != NULL)
957                         cb=s->ctx->info_callback;
958
959                 if (cb != NULL)
960                         {
961                         j = (alert_level << 8) | alert_descr;
962                         cb(s, SSL_CB_READ_ALERT, j);
963                         }
964
965                 if (alert_level == 1) /* warning */
966                         {
967                         s->s3->warn_alert = alert_descr;
968                         if (alert_descr == SSL_AD_CLOSE_NOTIFY)
969                                 {
970                                 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
971                                 return(0);
972                                 }
973 #if 0
974             /* XXX: this is a possible improvement in the future */
975                         /* now check if it's a missing record */
976                         if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
977                                 {
978                                 unsigned short seq;
979                                 unsigned int frag_off;
980                                 unsigned char *p = &(s->d1->alert_fragment[2]);
981
982                                 n2s(p, seq);
983                                 n2l3(p, frag_off);
984
985                                 dtls1_retransmit_message(s, seq, frag_off, &found);
986                                 if ( ! found  && SSL_in_init(s))
987                                         {
988                                         /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
989                                         /* requested a message not yet sent, 
990                                            send an alert ourselves */
991                                         ssl3_send_alert(s,SSL3_AL_WARNING,
992                                                 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
993                                         }
994                                 }
995 #endif
996                         }
997                 else if (alert_level == 2) /* fatal */
998                         {
999                         char tmp[16];
1000
1001                         s->rwstate=SSL_NOTHING;
1002                         s->s3->fatal_alert = alert_descr;
1003                         SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1004                         BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1005                         ERR_add_error_data(2,"SSL alert number ",tmp);
1006                         s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1007                         SSL_CTX_remove_session(s->ctx,s->session);
1008                         return(0);
1009                         }
1010                 else
1011                         {
1012                         al=SSL_AD_ILLEGAL_PARAMETER;
1013                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1014                         goto f_err;
1015                         }
1016
1017                 goto start;
1018                 }
1019
1020         if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1021                 {
1022                 s->rwstate=SSL_NOTHING;
1023                 rr->length=0;
1024                 return(0);
1025                 }
1026
1027         if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1028                 {
1029                 struct ccs_header_st ccs_hdr;
1030
1031                 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1032
1033                 /* 'Change Cipher Spec' is just a single byte, so we know
1034                  * exactly what the record payload has to look like */
1035                 /* XDTLS: check that epoch is consistent */
1036                 if (    (rr->length != DTLS1_CCS_HEADER_LENGTH) || 
1037                         (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1038                         {
1039                         i=SSL_AD_ILLEGAL_PARAMETER;
1040                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1041                         goto err;
1042                         }
1043
1044                 rr->length=0;
1045
1046                 if (s->msg_callback)
1047                         s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC, 
1048                                 rr->data, 1, s, s->msg_callback_arg);
1049
1050                 s->s3->change_cipher_spec=1;
1051                 if (!ssl3_do_change_cipher_spec(s))
1052                         goto err;
1053
1054                 /* do this whenever CCS is processed */
1055                 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1056
1057                 goto start;
1058                 }
1059
1060         /* Unexpected handshake message (Client Hello, or protocol violation) */
1061         if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) && 
1062                 !s->in_handshake)
1063                 {
1064                 struct hm_header_st msg_hdr;
1065                 
1066                 /* this may just be a stale retransmit */
1067                 dtls1_get_message_header(rr->data, &msg_hdr);
1068                 if( rr->epoch != s->d1->r_epoch)
1069                         {
1070                         rr->length = 0;
1071                         goto start;
1072                         }
1073
1074                 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1075                         !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1076                         {
1077 #if 0 /* worked only because C operator preferences are not as expected (and
1078        * because this is not really needed for clients except for detecting
1079        * protocol violations): */
1080                         s->state=SSL_ST_BEFORE|(s->server)
1081                                 ?SSL_ST_ACCEPT
1082                                 :SSL_ST_CONNECT;
1083 #else
1084                         s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1085 #endif
1086                         s->new_session=1;
1087                         }
1088                 i=s->handshake_func(s);
1089                 if (i < 0) return(i);
1090                 if (i == 0)
1091                         {
1092                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1093                         return(-1);
1094                         }
1095
1096                 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1097                         {
1098                         if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1099                                 {
1100                                 BIO *bio;
1101                                 /* In the case where we try to read application data,
1102                                  * but we trigger an SSL handshake, we return -1 with
1103                                  * the retry option set.  Otherwise renegotiation may
1104                                  * cause nasty problems in the blocking world */
1105                                 s->rwstate=SSL_READING;
1106                                 bio=SSL_get_rbio(s);
1107                                 BIO_clear_retry_flags(bio);
1108                                 BIO_set_retry_read(bio);
1109                                 return(-1);
1110                                 }
1111                         }
1112                 goto start;
1113                 }
1114
1115         switch (rr->type)
1116                 {
1117         default:
1118 #ifndef OPENSSL_NO_TLS
1119                 /* TLS just ignores unknown message types */
1120                 if (s->version == TLS1_VERSION)
1121                         {
1122                         rr->length = 0;
1123                         goto start;
1124                         }
1125 #endif
1126                 al=SSL_AD_UNEXPECTED_MESSAGE;
1127                 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1128                 goto f_err;
1129         case SSL3_RT_CHANGE_CIPHER_SPEC:
1130         case SSL3_RT_ALERT:
1131         case SSL3_RT_HANDSHAKE:
1132                 /* we already handled all of these, with the possible exception
1133                  * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1134                  * should not happen when type != rr->type */
1135                 al=SSL_AD_UNEXPECTED_MESSAGE;
1136                 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1137                 goto f_err;
1138         case SSL3_RT_APPLICATION_DATA:
1139                 /* At this point, we were expecting handshake data,
1140                  * but have application data.  If the library was
1141                  * running inside ssl3_read() (i.e. in_read_app_data
1142                  * is set) and it makes sense to read application data
1143                  * at this point (session renegotiation not yet started),
1144                  * we will indulge it.
1145                  */
1146                 if (s->s3->in_read_app_data &&
1147                         (s->s3->total_renegotiations != 0) &&
1148                         ((
1149                                 (s->state & SSL_ST_CONNECT) &&
1150                                 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1151                                 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1152                                 ) || (
1153                                         (s->state & SSL_ST_ACCEPT) &&
1154                                         (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1155                                         (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1156                                         )
1157                                 ))
1158                         {
1159                         s->s3->in_read_app_data=2;
1160                         return(-1);
1161                         }
1162                 else
1163                         {
1164                         al=SSL_AD_UNEXPECTED_MESSAGE;
1165                         SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1166                         goto f_err;
1167                         }
1168                 }
1169         /* not reached */
1170
1171 f_err:
1172         ssl3_send_alert(s,SSL3_AL_FATAL,al);
1173 err:
1174         return(-1);
1175         }
1176
1177 int
1178 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1179         {
1180         unsigned int n,tot;
1181         int i;
1182
1183         if (SSL_in_init(s) && !s->in_handshake)
1184                 {
1185                 i=s->handshake_func(s);
1186                 if (i < 0) return(i);
1187                 if (i == 0)
1188                         {
1189                         SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1190                         return -1;
1191                         }
1192                 }
1193
1194         tot = s->s3->wnum;
1195         n = len - tot;
1196
1197         while( n)
1198                 {
1199                 /* dtls1_write_bytes sends one record at a time, sized according to 
1200                  * the currently known MTU */
1201                 i = dtls1_write_bytes(s, type, buf_, len);
1202                 if (i <= 0) return i;
1203                 
1204                 if ((i == (int)n) ||
1205                         (type == SSL3_RT_APPLICATION_DATA &&
1206                                 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1207                         {
1208                         /* next chunk of data should get another prepended empty fragment
1209                          * in ciphersuites with known-IV weakness: */
1210                         s->s3->empty_fragment_done = 0;
1211                         return tot+i;
1212                         }
1213
1214                 tot += i;
1215                 n-=i;
1216                 }
1217
1218         return tot;
1219         }
1220
1221
1222         /* this only happens when a client hello is received and a handshake 
1223          * is started. */
1224 static int
1225 have_handshake_fragment(SSL *s, int type, unsigned char *buf, 
1226         int len, int peek)
1227         {
1228         
1229         if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1230                 /* (partially) satisfy request from storage */
1231                 {
1232                 unsigned char *src = s->d1->handshake_fragment;
1233                 unsigned char *dst = buf;
1234                 unsigned int k,n;
1235                 
1236                 /* peek == 0 */
1237                 n = 0;
1238                 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1239                         {
1240                         *dst++ = *src++;
1241                         len--; s->d1->handshake_fragment_len--;
1242                         n++;
1243                         }
1244                 /* move any remaining fragment bytes: */
1245                 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1246                         s->d1->handshake_fragment[k] = *src++;
1247                 return n;
1248                 }
1249         
1250         return 0;
1251         }
1252
1253
1254
1255
1256 /* Call this to write data in records of type 'type'
1257  * It will return <= 0 if not all data has been sent or non-blocking IO.
1258  */
1259 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1260         {
1261         const unsigned char *buf=buf_;
1262         unsigned int tot,n,nw;
1263         int i;
1264         unsigned int mtu;
1265
1266         s->rwstate=SSL_NOTHING;
1267         tot=s->s3->wnum;
1268
1269         n=(len-tot);
1270
1271         /* handshake layer figures out MTU for itself, but data records
1272          * are also sent through this interface, so need to figure out MTU */
1273 #if 0
1274         mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1275         mtu += DTLS1_HM_HEADER_LENGTH;  /* HM already inserted */
1276 #endif
1277         mtu = s->d1->mtu;
1278
1279         if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1280                 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1281
1282         if (n > mtu)
1283                 nw=mtu;
1284         else
1285                 nw=n;
1286         
1287         i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1288         if (i <= 0)
1289                 {
1290                 s->s3->wnum=tot;
1291                 return i;
1292                 }
1293
1294         if ( (int)s->s3->wnum + i == len)
1295                 s->s3->wnum = 0;
1296         else 
1297                 s->s3->wnum += i;
1298
1299         return i;
1300         }
1301
1302 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1303         {
1304         unsigned char *p,*pseq;
1305         int i,mac_size,clear=0;
1306         int prefix_len = 0;
1307         SSL3_RECORD *wr;
1308         SSL3_BUFFER *wb;
1309         SSL_SESSION *sess;
1310         int bs;
1311
1312         /* first check if there is a SSL3_BUFFER still being written
1313          * out.  This will happen with non blocking IO */
1314         if (s->s3->wbuf.left != 0)
1315                 {
1316                 OPENSSL_assert(0); /* XDTLS:  want to see if we ever get here */
1317                 return(ssl3_write_pending(s,type,buf,len));
1318                 }
1319
1320         /* If we have an alert to send, lets send it */
1321         if (s->s3->alert_dispatch)
1322                 {
1323                 i=s->method->ssl_dispatch_alert(s);
1324                 if (i <= 0)
1325                         return(i);
1326                 /* if it went, fall through and send more stuff */
1327                 }
1328
1329         if (len == 0 && !create_empty_fragment)
1330                 return 0;
1331
1332         wr= &(s->s3->wrec);
1333         wb= &(s->s3->wbuf);
1334         sess=s->session;
1335
1336         if (    (sess == NULL) ||
1337                 (s->enc_write_ctx == NULL) ||
1338                 (EVP_MD_CTX_md(s->write_hash) == NULL))
1339                 clear=1;
1340
1341         if (clear)
1342                 mac_size=0;
1343         else
1344                 mac_size=EVP_MD_CTX_size(s->write_hash);
1345
1346         /* DTLS implements explicit IV, so no need for empty fragments */
1347 #if 0
1348         /* 'create_empty_fragment' is true only when this function calls itself */
1349         if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1350                 && SSL_version(s) != DTLS1_VERSION)
1351                 {
1352                 /* countermeasure against known-IV weakness in CBC ciphersuites
1353                  * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
1354                  */
1355
1356                 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1357                         {
1358                         /* recursive function call with 'create_empty_fragment' set;
1359                          * this prepares and buffers the data for an empty fragment
1360                          * (these 'prefix_len' bytes are sent out later
1361                          * together with the actual payload) */
1362                         prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1363                         if (prefix_len <= 0)
1364                                 goto err;
1365
1366                         if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1367                                 {
1368                                 /* insufficient space */
1369                                 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1370                                 goto err;
1371                                 }
1372                         }
1373                 
1374                 s->s3->empty_fragment_done = 1;
1375                 }
1376 #endif
1377
1378         p = wb->buf + prefix_len;
1379
1380         /* write the header */
1381
1382         *(p++)=type&0xff;
1383         wr->type=type;
1384
1385         *(p++)=(s->version>>8);
1386         *(p++)=s->version&0xff;
1387
1388         /* field where we are to write out packet epoch, seq num and len */
1389         pseq=p; 
1390         p+=10;
1391
1392         /* lets setup the record stuff. */
1393
1394         /* Make space for the explicit IV in case of CBC.
1395          * (this is a bit of a boundary violation, but what the heck).
1396          */
1397         if ( s->enc_write_ctx && 
1398                 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1399                 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1400         else
1401                 bs = 0;
1402
1403         wr->data=p + bs;  /* make room for IV in case of CBC */
1404         wr->length=(int)len;
1405         wr->input=(unsigned char *)buf;
1406
1407         /* we now 'read' from wr->input, wr->length bytes into
1408          * wr->data */
1409
1410         /* first we compress */
1411         if (s->compress != NULL)
1412                 {
1413                 if (!ssl3_do_compress(s))
1414                         {
1415                         SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1416                         goto err;
1417                         }
1418                 }
1419         else
1420                 {
1421                 memcpy(wr->data,wr->input,wr->length);
1422                 wr->input=wr->data;
1423                 }
1424
1425         /* we should still have the output to wr->data and the input
1426          * from wr->input.  Length should be wr->length.
1427          * wr->data still points in the wb->buf */
1428
1429         if (mac_size != 0)
1430                 {
1431                 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1432                 wr->length+=mac_size;
1433                 }
1434
1435         /* this is true regardless of mac size */
1436         wr->input=p;
1437         wr->data=p;
1438
1439
1440         /* ssl3_enc can only have an error on read */
1441         if (bs) /* bs != 0 in case of CBC */
1442                 {
1443                 RAND_pseudo_bytes(p,bs);
1444                 /* master IV and last CBC residue stand for
1445                  * the rest of randomness */
1446                 wr->length += bs;
1447                 }
1448
1449         s->method->ssl3_enc->enc(s,1);
1450
1451         /* record length after mac and block padding */
1452 /*      if (type == SSL3_RT_APPLICATION_DATA ||
1453         (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1454         
1455         /* there's only one epoch between handshake and app data */
1456         
1457         s2n(s->d1->w_epoch, pseq);
1458
1459         /* XDTLS: ?? */
1460 /*      else
1461         s2n(s->d1->handshake_epoch, pseq); */
1462
1463         memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1464         pseq+=6;
1465         s2n(wr->length,pseq);
1466
1467         /* we should now have
1468          * wr->data pointing to the encrypted data, which is
1469          * wr->length long */
1470         wr->type=type; /* not needed but helps for debugging */
1471         wr->length+=DTLS1_RT_HEADER_LENGTH;
1472
1473 #if 0  /* this is now done at the message layer */
1474         /* buffer the record, making it easy to handle retransmits */
1475         if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1476                 dtls1_buffer_record(s, wr->data, wr->length, 
1477                         *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1478 #endif
1479
1480         ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1481
1482         if (create_empty_fragment)
1483                 {
1484                 /* we are in a recursive call;
1485                  * just return the length, don't write out anything here
1486                  */
1487                 return wr->length;
1488                 }
1489
1490         /* now let's set up wb */
1491         wb->left = prefix_len + wr->length;
1492         wb->offset = 0;
1493
1494         /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1495         s->s3->wpend_tot=len;
1496         s->s3->wpend_buf=buf;
1497         s->s3->wpend_type=type;
1498         s->s3->wpend_ret=len;
1499
1500         /* we now just need to write the buffer */
1501         return ssl3_write_pending(s,type,buf,len);
1502 err:
1503         return -1;
1504         }
1505
1506
1507
1508 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1509         {
1510         int cmp;
1511         unsigned int shift;
1512         const unsigned char *seq = s->s3->read_sequence;
1513
1514         cmp = satsub64be(seq,bitmap->max_seq_num);
1515         if (cmp > 0)
1516                 {
1517                 memcpy (s->s3->rrec.seq_num,seq,8);
1518                 return 1; /* this record in new */
1519                 }
1520         shift = -cmp;
1521         if (shift >= sizeof(bitmap->map)*8)
1522                 return 0; /* stale, outside the window */
1523         else if (bitmap->map & (1UL<<shift))
1524                 return 0; /* record previously received */
1525
1526         memcpy (s->s3->rrec.seq_num,seq,8);
1527         return 1;
1528         }
1529
1530
1531 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1532         {
1533         int cmp;
1534         unsigned int shift;
1535         const unsigned char *seq = s->s3->read_sequence;
1536
1537         cmp = satsub64be(seq,bitmap->max_seq_num);
1538         if (cmp > 0)
1539                 {
1540                 shift = cmp;
1541                 if (shift < sizeof(bitmap->map)*8)
1542                         bitmap->map <<= shift, bitmap->map |= 1UL;
1543                 else
1544                         bitmap->map = 1UL;
1545                 memcpy(bitmap->max_seq_num,seq,8);
1546                 }
1547         else    {
1548                 shift = -cmp;
1549                 if (shift < sizeof(bitmap->map)*8)
1550                         bitmap->map |= 1UL<<shift;
1551                 }
1552         }
1553
1554
1555 int dtls1_dispatch_alert(SSL *s)
1556         {
1557         int i,j;
1558         void (*cb)(const SSL *ssl,int type,int val)=NULL;
1559         unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1560         unsigned char *ptr = &buf[0];
1561
1562         s->s3->alert_dispatch=0;
1563
1564         memset(buf, 0x00, sizeof(buf));
1565         *ptr++ = s->s3->send_alert[0];
1566         *ptr++ = s->s3->send_alert[1];
1567
1568 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1569         if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1570                 {       
1571                 s2n(s->d1->handshake_read_seq, ptr);
1572 #if 0
1573                 if ( s->d1->r_msg_hdr.frag_off == 0)  /* waiting for a new msg */
1574
1575                 else
1576                         s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1577 #endif
1578
1579 #if 0
1580                 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);
1581 #endif
1582                 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1583                 }
1584 #endif
1585
1586         i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1587         if (i <= 0)
1588                 {
1589                 s->s3->alert_dispatch=1;
1590                 /* fprintf( stderr, "not done with alert\n" ); */
1591                 }
1592         else
1593                 {
1594                 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1595 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1596                     || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1597 #endif
1598                     )
1599                         (void)BIO_flush(s->wbio);
1600
1601                 if (s->msg_callback)
1602                         s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert, 
1603                                 2, s, s->msg_callback_arg);
1604
1605                 if (s->info_callback != NULL)
1606                         cb=s->info_callback;
1607                 else if (s->ctx->info_callback != NULL)
1608                         cb=s->ctx->info_callback;
1609
1610                 if (cb != NULL)
1611                         {
1612                         j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1613                         cb(s,SSL_CB_WRITE_ALERT,j);
1614                         }
1615                 }
1616         return(i);
1617         }
1618
1619
1620 static DTLS1_BITMAP *
1621 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1622     {
1623     
1624     *is_next_epoch = 0;
1625
1626     /* In current epoch, accept HM, CCS, DATA, & ALERT */
1627     if (rr->epoch == s->d1->r_epoch)
1628         return &s->d1->bitmap;
1629
1630     /* Only HM and ALERT messages can be from the next epoch */
1631     else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1632         (rr->type == SSL3_RT_HANDSHAKE ||
1633             rr->type == SSL3_RT_ALERT))
1634         {
1635         *is_next_epoch = 1;
1636         return &s->d1->next_bitmap;
1637         }
1638
1639     return NULL;
1640     }
1641
1642 #if 0
1643 static int
1644 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1645         unsigned long *offset)
1646         {
1647
1648         /* alerts are passed up immediately */
1649         if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1650                 rr->type == SSL3_RT_ALERT)
1651                 return 0;
1652
1653         /* Only need to buffer if a handshake is underway.
1654          * (this implies that Hello Request and Client Hello are passed up
1655          * immediately) */
1656         if ( SSL_in_init(s))
1657                 {
1658                 unsigned char *data = rr->data;
1659                 /* need to extract the HM/CCS sequence number here */
1660                 if ( rr->type == SSL3_RT_HANDSHAKE ||
1661                         rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1662                         {
1663                         unsigned short seq_num;
1664                         struct hm_header_st msg_hdr;
1665                         struct ccs_header_st ccs_hdr;
1666
1667                         if ( rr->type == SSL3_RT_HANDSHAKE)
1668                                 {
1669                                 dtls1_get_message_header(data, &msg_hdr);
1670                                 seq_num = msg_hdr.seq;
1671                                 *offset = msg_hdr.frag_off;
1672                                 }
1673                         else
1674                                 {
1675                                 dtls1_get_ccs_header(data, &ccs_hdr);
1676                                 seq_num = ccs_hdr.seq;
1677                                 *offset = 0;
1678                                 }
1679                                 
1680                         /* this is either a record we're waiting for, or a
1681                          * retransmit of something we happened to previously 
1682                          * receive (higher layers will drop the repeat silently */
1683                         if ( seq_num < s->d1->handshake_read_seq)
1684                                 return 0;
1685                         if (rr->type == SSL3_RT_HANDSHAKE && 
1686                                 seq_num == s->d1->handshake_read_seq &&
1687                                 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1688                                 return 0;
1689                         else if ( seq_num == s->d1->handshake_read_seq &&
1690                                 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1691                                         msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1692                                 return 0;
1693                         else
1694                                 {
1695                                 *priority = seq_num;
1696                                 return 1;
1697                                 }
1698                         }
1699                 else /* unknown record type */
1700                         return 0;
1701                 }
1702
1703         return 0;
1704         }
1705 #endif
1706
1707 void
1708 dtls1_reset_seq_numbers(SSL *s, int rw)
1709         {
1710         unsigned char *seq;
1711         unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1712
1713         if ( rw & SSL3_CC_READ)
1714                 {
1715                 seq = s->s3->read_sequence;
1716                 s->d1->r_epoch++;
1717                 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1718                 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1719                 }
1720         else
1721                 {
1722                 seq = s->s3->write_sequence;
1723                 s->d1->w_epoch++;
1724                 }
1725
1726         memset(seq, 0x00, seq_bytes);
1727         }
1728
1729
1730 static void
1731 dtls1_clear_timeouts(SSL *s)
1732         {
1733         memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1734         }