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 */
satsub64be(const unsigned char * v1,const unsigned char * v2)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
183 /* copy buffered record into SSL structure */
184 static int
dtls1_copy_record(SSL * s,pitem * item)185 dtls1_copy_record(SSL *s, pitem *item)
186 {
187 DTLS1_RECORD_DATA *rdata;
188
189 rdata = (DTLS1_RECORD_DATA *)item->data;
190
191 if (s->s3->rbuf.buf != NULL)
192 OPENSSL_free(s->s3->rbuf.buf);
193
194 s->packet = rdata->packet;
195 s->packet_length = rdata->packet_length;
196 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
197 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
198
199 /* Set proper sequence number for mac calculation */
200 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
201
202 return(1);
203 }
204
205
206 static int
dtls1_buffer_record(SSL * s,record_pqueue * queue,unsigned char * priority)207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
208 {
209 DTLS1_RECORD_DATA *rdata;
210 pitem *item;
211
212 /* Limit the size of the queue to prevent DOS attacks */
213 if (pqueue_size(queue->q) >= 100)
214 return 0;
215
216 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
217 item = pitem_new(priority, rdata);
218 if (rdata == NULL || item == NULL)
219 {
220 if (rdata != NULL) OPENSSL_free(rdata);
221 if (item != NULL) pitem_free(item);
222
223 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
224 return(0);
225 }
226
227 rdata->packet = s->packet;
228 rdata->packet_length = s->packet_length;
229 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
230 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
231
232 item->data = rdata;
233
234 #ifndef OPENSSL_NO_SCTP
235 /* Store bio_dgram_sctp_rcvinfo struct */
236 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
237 (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) {
238 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
239 }
240 #endif
241
242 /* insert should not fail, since duplicates are dropped */
243 if (pqueue_insert(queue->q, item) == NULL)
244 {
245 OPENSSL_free(rdata);
246 pitem_free(item);
247 return(0);
248 }
249
250 s->packet = NULL;
251 s->packet_length = 0;
252 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
253 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
254
255 if (!ssl3_setup_buffers(s))
256 {
257 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
258 OPENSSL_free(rdata);
259 pitem_free(item);
260 return(0);
261 }
262
263 return(1);
264 }
265
266
267 static int
dtls1_retrieve_buffered_record(SSL * s,record_pqueue * queue)268 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
269 {
270 pitem *item;
271
272 item = pqueue_pop(queue->q);
273 if (item)
274 {
275 dtls1_copy_record(s, item);
276
277 OPENSSL_free(item->data);
278 pitem_free(item);
279
280 return(1);
281 }
282
283 return(0);
284 }
285
286
287 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
288 * yet */
289 #define dtls1_get_unprocessed_record(s) \
290 dtls1_retrieve_buffered_record((s), \
291 &((s)->d1->unprocessed_rcds))
292
293 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
294 #define dtls1_get_processed_record(s) \
295 dtls1_retrieve_buffered_record((s), \
296 &((s)->d1->processed_rcds))
297
298 static int
dtls1_process_buffered_records(SSL * s)299 dtls1_process_buffered_records(SSL *s)
300 {
301 pitem *item;
302
303 item = pqueue_peek(s->d1->unprocessed_rcds.q);
304 if (item)
305 {
306 /* Check if epoch is current. */
307 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
308 return(1); /* Nothing to do. */
309
310 /* Process all the records. */
311 while (pqueue_peek(s->d1->unprocessed_rcds.q))
312 {
313 dtls1_get_unprocessed_record(s);
314 if ( ! dtls1_process_record(s))
315 return(0);
316 dtls1_buffer_record(s, &(s->d1->processed_rcds),
317 s->s3->rrec.seq_num);
318 }
319 }
320
321 /* sync epoch numbers once all the unprocessed records
322 * have been processed */
323 s->d1->processed_rcds.epoch = s->d1->r_epoch;
324 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
325
326 return(1);
327 }
328
329
330 #if 0
331
332 static int
333 dtls1_get_buffered_record(SSL *s)
334 {
335 pitem *item;
336 PQ_64BIT priority =
337 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
338 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
339
340 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating,
341 nothing buffered */
342 return 0;
343
344
345 item = pqueue_peek(s->d1->rcvd_records);
346 if (item && item->priority == priority)
347 {
348 /* Check if we've received the record of interest. It must be
349 * a handshake record, since data records as passed up without
350 * buffering */
351 DTLS1_RECORD_DATA *rdata;
352 item = pqueue_pop(s->d1->rcvd_records);
353 rdata = (DTLS1_RECORD_DATA *)item->data;
354
355 if (s->s3->rbuf.buf != NULL)
356 OPENSSL_free(s->s3->rbuf.buf);
357
358 s->packet = rdata->packet;
359 s->packet_length = rdata->packet_length;
360 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
361 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
362
363 OPENSSL_free(item->data);
364 pitem_free(item);
365
366 /* s->d1->next_expected_seq_num++; */
367 return(1);
368 }
369
370 return 0;
371 }
372
373 #endif
374
375 static int
dtls1_process_record(SSL * s)376 dtls1_process_record(SSL *s)
377 {
378 int i,al;
379 int clear=0;
380 int enc_err;
381 SSL_SESSION *sess;
382 SSL3_RECORD *rr;
383 unsigned int mac_size;
384 unsigned char md[EVP_MAX_MD_SIZE];
385 int decryption_failed_or_bad_record_mac = 0;
386 unsigned char *mac = NULL;
387
388
389 rr= &(s->s3->rrec);
390 sess = s->session;
391
392 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
393 * and we have that many bytes in s->packet
394 */
395 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
396
397 /* ok, we can now read from 's->packet' data into 'rr'
398 * rr->input points at rr->length bytes, which
399 * need to be copied into rr->data by either
400 * the decryption or by the decompression
401 * When the data is 'copied' into the rr->data buffer,
402 * rr->input will be pointed at the new buffer */
403
404 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
405 * rr->length bytes of encrypted compressed stuff. */
406
407 /* check is not needed I believe */
408 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
409 {
410 al=SSL_AD_RECORD_OVERFLOW;
411 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
412 goto f_err;
413 }
414
415 /* decrypt in place in 'rr->input' */
416 rr->data=rr->input;
417
418 enc_err = s->method->ssl3_enc->enc(s,0);
419 if (enc_err <= 0)
420 {
421 /* To minimize information leaked via timing, we will always
422 * perform all computations before discarding the message.
423 */
424 decryption_failed_or_bad_record_mac = 1;
425 }
426
427 #ifdef TLS_DEBUG
428 printf("dec %d\n",rr->length);
429 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
430 printf("\n");
431 #endif
432
433 /* r->length is now the compressed data plus mac */
434 if ( (sess == NULL) ||
435 (s->enc_read_ctx == NULL) ||
436 (s->read_hash == NULL))
437 clear=1;
438
439 if (!clear)
440 {
441 /* !clear => s->read_hash != NULL => mac_size != -1 */
442 int t;
443 t=EVP_MD_CTX_size(s->read_hash);
444 OPENSSL_assert(t >= 0);
445 mac_size=t;
446
447 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
448 {
449 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
450 al=SSL_AD_RECORD_OVERFLOW;
451 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
452 goto f_err;
453 #else
454 decryption_failed_or_bad_record_mac = 1;
455 #endif
456 }
457 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
458 if (rr->length >= mac_size)
459 {
460 rr->length -= mac_size;
461 mac = &rr->data[rr->length];
462 }
463 else
464 rr->length = 0;
465 i=s->method->ssl3_enc->mac(s,md,0);
466 if (i < 0 || mac == NULL || memcmp(md, mac, mac_size) != 0)
467 {
468 decryption_failed_or_bad_record_mac = 1;
469 }
470 }
471
472 if (decryption_failed_or_bad_record_mac)
473 {
474 /* decryption failed, silently discard message */
475 rr->length = 0;
476 s->packet_length = 0;
477 goto err;
478 }
479
480 /* r->length is now just compressed */
481 if (s->expand != NULL)
482 {
483 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
484 {
485 al=SSL_AD_RECORD_OVERFLOW;
486 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
487 goto f_err;
488 }
489 if (!ssl3_do_uncompress(s))
490 {
491 al=SSL_AD_DECOMPRESSION_FAILURE;
492 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
493 goto f_err;
494 }
495 }
496
497 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
498 {
499 al=SSL_AD_RECORD_OVERFLOW;
500 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
501 goto f_err;
502 }
503
504 rr->off=0;
505 /* So at this point the following is true
506 * ssl->s3->rrec.type is the type of record
507 * ssl->s3->rrec.length == number of bytes in record
508 * ssl->s3->rrec.off == offset to first valid byte
509 * ssl->s3->rrec.data == where to take bytes from, increment
510 * after use :-).
511 */
512
513 /* we have pulled in a full packet so zero things */
514 s->packet_length=0;
515 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
516 return(1);
517
518 f_err:
519 ssl3_send_alert(s,SSL3_AL_FATAL,al);
520 err:
521 return(0);
522 }
523
524
525 /* Call this to get a new input record.
526 * It will return <= 0 if more data is needed, normally due to an error
527 * or non-blocking IO.
528 * When it finishes, one packet has been decoded and can be found in
529 * ssl->s3->rrec.type - is the type of record
530 * ssl->s3->rrec.data, - data
531 * ssl->s3->rrec.length, - number of bytes
532 */
533 /* used only by dtls1_read_bytes */
dtls1_get_record(SSL * s)534 int dtls1_get_record(SSL *s)
535 {
536 int ssl_major,ssl_minor;
537 int i,n;
538 SSL3_RECORD *rr;
539 unsigned char *p = NULL;
540 unsigned short version;
541 DTLS1_BITMAP *bitmap;
542 unsigned int is_next_epoch;
543
544 rr= &(s->s3->rrec);
545
546 /* The epoch may have changed. If so, process all the
547 * pending records. This is a non-blocking operation. */
548 dtls1_process_buffered_records(s);
549
550 /* if we're renegotiating, then there may be buffered records */
551 if (dtls1_get_processed_record(s))
552 return 1;
553
554 /* get something from the wire */
555 again:
556 /* check if we have the header */
557 if ( (s->rstate != SSL_ST_READ_BODY) ||
558 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
559 {
560 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
561 /* read timeout is handled by dtls1_read_bytes */
562 if (n <= 0) return(n); /* error or non-blocking */
563
564 /* this packet contained a partial record, dump it */
565 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
566 {
567 s->packet_length = 0;
568 goto again;
569 }
570
571 s->rstate=SSL_ST_READ_BODY;
572
573 p=s->packet;
574
575 /* Pull apart the header into the DTLS1_RECORD */
576 rr->type= *(p++);
577 ssl_major= *(p++);
578 ssl_minor= *(p++);
579 version=(ssl_major<<8)|ssl_minor;
580
581 /* sequence number is 64 bits, with top 2 bytes = epoch */
582 n2s(p,rr->epoch);
583
584 memcpy(&(s->s3->read_sequence[2]), p, 6);
585 p+=6;
586
587 n2s(p,rr->length);
588
589 /* Lets check version */
590 if (!s->first_packet)
591 {
592 if (version != s->version)
593 {
594 /* unexpected version, silently discard */
595 rr->length = 0;
596 s->packet_length = 0;
597 goto again;
598 }
599 }
600
601 if ((version & 0xff00) != (s->version & 0xff00))
602 {
603 /* wrong version, silently discard record */
604 rr->length = 0;
605 s->packet_length = 0;
606 goto again;
607 }
608
609 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
610 {
611 /* record too long, silently discard it */
612 rr->length = 0;
613 s->packet_length = 0;
614 goto again;
615 }
616
617 /* If we receive a valid record larger than the current buffer size,
618 * allocate some memory for it.
619 */
620 if (rr->length > s->s3->rbuf.len - DTLS1_RT_HEADER_LENGTH)
621 {
622 unsigned char *pp;
623 unsigned int newlen = rr->length + DTLS1_RT_HEADER_LENGTH;
624 if ((pp=OPENSSL_realloc(s->s3->rbuf.buf, newlen))==NULL)
625 {
626 SSLerr(SSL_F_DTLS1_GET_RECORD,ERR_R_MALLOC_FAILURE);
627 return(-1);
628 }
629 p = pp + (p - s->s3->rbuf.buf);
630 s->s3->rbuf.buf=pp;
631 s->s3->rbuf.len=newlen;
632 s->packet= &(s->s3->rbuf.buf[0]);
633 }
634
635 /* now s->rstate == SSL_ST_READ_BODY */
636 }
637
638 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
639
640 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
641 {
642 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
643 i=rr->length;
644 n=ssl3_read_n(s,i,i,1);
645 if (n <= 0) return(n); /* error or non-blocking io */
646
647 /* this packet contained a partial record, dump it */
648 if ( n != i)
649 {
650 rr->length = 0;
651 s->packet_length = 0;
652 goto again;
653 }
654
655 /* now n == rr->length,
656 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
657 }
658 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
659
660 /* match epochs. NULL means the packet is dropped on the floor */
661 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
662 if ( bitmap == NULL)
663 {
664 rr->length = 0;
665 s->packet_length = 0; /* dump this record */
666 goto again; /* get another record */
667 }
668
669 #ifndef OPENSSL_NO_SCTP
670 /* Only do replay check if no SCTP bio */
671 if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
672 {
673 #endif
674 /* Check whether this is a repeat, or aged record.
675 * Don't check if we're listening and this message is
676 * a ClientHello. They can look as if they're replayed,
677 * since they arrive from different connections and
678 * would be dropped unnecessarily.
679 */
680 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
681 *p == SSL3_MT_CLIENT_HELLO) &&
682 !dtls1_record_replay_check(s, bitmap))
683 {
684 rr->length = 0;
685 s->packet_length=0; /* dump this record */
686 goto again; /* get another record */
687 }
688 #ifndef OPENSSL_NO_SCTP
689 }
690 #endif
691
692 /* just read a 0 length packet */
693 if (rr->length == 0) goto again;
694
695 /* If this record is from the next epoch (either HM or ALERT),
696 * and a handshake is currently in progress, buffer it since it
697 * cannot be processed at this time. However, do not buffer
698 * anything while listening.
699 */
700 if (is_next_epoch)
701 {
702 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
703 {
704 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
705 }
706 rr->length = 0;
707 s->packet_length = 0;
708 goto again;
709 }
710
711 if (!dtls1_process_record(s))
712 {
713 rr->length = 0;
714 s->packet_length = 0; /* dump this record */
715 goto again; /* get another record */
716 }
717
718 return(1);
719
720 }
721
722 /* Return up to 'len' payload bytes received in 'type' records.
723 * 'type' is one of the following:
724 *
725 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
726 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
727 * - 0 (during a shutdown, no data has to be returned)
728 *
729 * If we don't have stored data to work from, read a SSL/TLS record first
730 * (possibly multiple records if we still don't have anything to return).
731 *
732 * This function must handle any surprises the peer may have for us, such as
733 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
734 * a surprise, but handled as if it were), or renegotiation requests.
735 * Also if record payloads contain fragments too small to process, we store
736 * them until there is enough for the respective protocol (the record protocol
737 * may use arbitrary fragmentation and even interleaving):
738 * Change cipher spec protocol
739 * just 1 byte needed, no need for keeping anything stored
740 * Alert protocol
741 * 2 bytes needed (AlertLevel, AlertDescription)
742 * Handshake protocol
743 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
744 * to detect unexpected Client Hello and Hello Request messages
745 * here, anything else is handled by higher layers
746 * Application data protocol
747 * none of our business
748 */
dtls1_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)749 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
750 {
751 int al,i,j,ret;
752 unsigned int n;
753 SSL3_RECORD *rr;
754 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
755
756 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
757 if (!ssl3_setup_buffers(s))
758 return(-1);
759
760 /* XXX: check what the second '&& type' is about */
761 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
762 (type != SSL3_RT_HANDSHAKE) && type) ||
763 (peek && (type != SSL3_RT_APPLICATION_DATA)))
764 {
765 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
766 return -1;
767 }
768
769 /* check whether there's a handshake message (client hello?) waiting */
770 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
771 return ret;
772
773 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
774
775 #ifndef OPENSSL_NO_SCTP
776 /* Continue handshake if it had to be interrupted to read
777 * app data with SCTP.
778 */
779 if ((!s->in_handshake && SSL_in_init(s)) ||
780 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
781 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
782 s->s3->in_read_app_data != 2))
783 #else
784 if (!s->in_handshake && SSL_in_init(s))
785 #endif
786 {
787 /* type == SSL3_RT_APPLICATION_DATA */
788 i=s->handshake_func(s);
789 if (i < 0) return(i);
790 if (i == 0)
791 {
792 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
793 return(-1);
794 }
795 }
796
797 start:
798 s->rwstate=SSL_NOTHING;
799
800 /* s->s3->rrec.type - is the type of record
801 * s->s3->rrec.data, - data
802 * s->s3->rrec.off, - offset into 'data' for next read
803 * s->s3->rrec.length, - number of bytes. */
804 rr = &(s->s3->rrec);
805
806 /* We are not handshaking and have no data yet,
807 * so process data buffered during the last handshake
808 * in advance, if any.
809 */
810 if (s->state == SSL_ST_OK && rr->length == 0)
811 {
812 pitem *item;
813 item = pqueue_pop(s->d1->buffered_app_data.q);
814 if (item)
815 {
816 #ifndef OPENSSL_NO_SCTP
817 /* Restore bio_dgram_sctp_rcvinfo struct */
818 if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
819 {
820 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
821 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
822 }
823 #endif
824
825 dtls1_copy_record(s, item);
826
827 OPENSSL_free(item->data);
828 pitem_free(item);
829 }
830 }
831
832 /* Check for timeout */
833 if (dtls1_handle_timeout(s) > 0)
834 goto start;
835
836 /* get new packet if necessary */
837 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
838 {
839 ret=dtls1_get_record(s);
840 if (ret <= 0)
841 {
842 ret = dtls1_read_failed(s, ret);
843 /* anything other than a timeout is an error */
844 if (ret <= 0)
845 return(ret);
846 else
847 goto start;
848 }
849 }
850
851 /* we now have a packet which can be read and processed */
852
853 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
854 * reset by ssl3_get_finished */
855 && (rr->type != SSL3_RT_HANDSHAKE))
856 {
857 /* We now have application data between CCS and Finished.
858 * Most likely the packets were reordered on their way, so
859 * buffer the application data for later processing rather
860 * than dropping the connection.
861 */
862 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
863 rr->length = 0;
864 goto start;
865 }
866
867 /* If the other end has shut down, throw anything we read away
868 * (even in 'peek' mode) */
869 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
870 {
871 rr->length=0;
872 s->rwstate=SSL_NOTHING;
873 return(0);
874 }
875
876
877 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
878 {
879 /* make sure that we are not getting application data when we
880 * are doing a handshake for the first time */
881 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
882 (s->enc_read_ctx == NULL))
883 {
884 al=SSL_AD_UNEXPECTED_MESSAGE;
885 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
886 goto f_err;
887 }
888
889 if (len <= 0) return(len);
890
891 if ((unsigned int)len > rr->length)
892 n = rr->length;
893 else
894 n = (unsigned int)len;
895
896 memcpy(buf,&(rr->data[rr->off]),n);
897 if (!peek)
898 {
899 rr->length-=n;
900 rr->off+=n;
901 if (rr->length == 0)
902 {
903 s->rstate=SSL_ST_READ_HEADER;
904 rr->off=0;
905 }
906 }
907
908 #ifndef OPENSSL_NO_SCTP
909 /* We were about to renegotiate but had to read
910 * belated application data first, so retry.
911 */
912 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
913 rr->type == SSL3_RT_APPLICATION_DATA &&
914 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
915 {
916 s->rwstate=SSL_READING;
917 BIO_clear_retry_flags(SSL_get_rbio(s));
918 BIO_set_retry_read(SSL_get_rbio(s));
919 }
920
921 /* We might had to delay a close_notify alert because
922 * of reordered app data. If there was an alert and there
923 * is no message to read anymore, finally set shutdown.
924 */
925 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
926 s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
927 {
928 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
929 return(0);
930 }
931 #endif
932 return(n);
933 }
934
935
936 /* If we get here, then type != rr->type; if we have a handshake
937 * message, then it was unexpected (Hello Request or Client Hello). */
938
939 /* In case of record types for which we have 'fragment' storage,
940 * fill that so that we can process the data at a fixed place.
941 */
942 {
943 unsigned int k, dest_maxlen = 0;
944 unsigned char *dest = NULL;
945 unsigned int *dest_len = NULL;
946
947 if (rr->type == SSL3_RT_HANDSHAKE)
948 {
949 dest_maxlen = sizeof s->d1->handshake_fragment;
950 dest = s->d1->handshake_fragment;
951 dest_len = &s->d1->handshake_fragment_len;
952 }
953 else if (rr->type == SSL3_RT_ALERT)
954 {
955 dest_maxlen = sizeof(s->d1->alert_fragment);
956 dest = s->d1->alert_fragment;
957 dest_len = &s->d1->alert_fragment_len;
958 }
959 #ifndef OPENSSL_NO_HEARTBEATS
960 else if (rr->type == TLS1_RT_HEARTBEAT)
961 {
962 dtls1_process_heartbeat(s);
963
964 /* Exit and notify application to read again */
965 rr->length = 0;
966 s->rwstate=SSL_READING;
967 BIO_clear_retry_flags(SSL_get_rbio(s));
968 BIO_set_retry_read(SSL_get_rbio(s));
969 return(-1);
970 }
971 #endif
972 /* else it's a CCS message, or application data or wrong */
973 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
974 {
975 /* Application data while renegotiating
976 * is allowed. Try again reading.
977 */
978 if (rr->type == SSL3_RT_APPLICATION_DATA)
979 {
980 BIO *bio;
981 s->s3->in_read_app_data=2;
982 bio=SSL_get_rbio(s);
983 s->rwstate=SSL_READING;
984 BIO_clear_retry_flags(bio);
985 BIO_set_retry_read(bio);
986 return(-1);
987 }
988
989 /* Not certain if this is the right error handling */
990 al=SSL_AD_UNEXPECTED_MESSAGE;
991 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
992 goto f_err;
993 }
994
995 if (dest_maxlen > 0)
996 {
997 /* XDTLS: In a pathalogical case, the Client Hello
998 * may be fragmented--don't always expect dest_maxlen bytes */
999 if ( rr->length < dest_maxlen)
1000 {
1001 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1002 /*
1003 * for normal alerts rr->length is 2, while
1004 * dest_maxlen is 7 if we were to handle this
1005 * non-existing alert...
1006 */
1007 FIX ME
1008 #endif
1009 s->rstate=SSL_ST_READ_HEADER;
1010 rr->length = 0;
1011 goto start;
1012 }
1013
1014 /* now move 'n' bytes: */
1015 for ( k = 0; k < dest_maxlen; k++)
1016 {
1017 dest[k] = rr->data[rr->off++];
1018 rr->length--;
1019 }
1020 *dest_len = dest_maxlen;
1021 }
1022 }
1023
1024 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
1025 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
1026 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1027
1028 /* If we are a client, check for an incoming 'Hello Request': */
1029 if ((!s->server) &&
1030 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1031 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1032 (s->session != NULL) && (s->session->cipher != NULL))
1033 {
1034 s->d1->handshake_fragment_len = 0;
1035
1036 if ((s->d1->handshake_fragment[1] != 0) ||
1037 (s->d1->handshake_fragment[2] != 0) ||
1038 (s->d1->handshake_fragment[3] != 0))
1039 {
1040 al=SSL_AD_DECODE_ERROR;
1041 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1042 goto err;
1043 }
1044
1045 /* no need to check sequence number on HELLO REQUEST messages */
1046
1047 if (s->msg_callback)
1048 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1049 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1050
1051 if (SSL_is_init_finished(s) &&
1052 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1053 !s->s3->renegotiate)
1054 {
1055 s->new_session = 1;
1056 ssl3_renegotiate(s);
1057 if (ssl3_renegotiate_check(s))
1058 {
1059 i=s->handshake_func(s);
1060 if (i < 0) return(i);
1061 if (i == 0)
1062 {
1063 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1064 return(-1);
1065 }
1066
1067 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1068 {
1069 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1070 {
1071 BIO *bio;
1072 /* In the case where we try to read application data,
1073 * but we trigger an SSL handshake, we return -1 with
1074 * the retry option set. Otherwise renegotiation may
1075 * cause nasty problems in the blocking world */
1076 s->rwstate=SSL_READING;
1077 bio=SSL_get_rbio(s);
1078 BIO_clear_retry_flags(bio);
1079 BIO_set_retry_read(bio);
1080 return(-1);
1081 }
1082 }
1083 }
1084 }
1085 /* we either finished a handshake or ignored the request,
1086 * now try again to obtain the (application) data we were asked for */
1087 goto start;
1088 }
1089
1090 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1091 {
1092 int alert_level = s->d1->alert_fragment[0];
1093 int alert_descr = s->d1->alert_fragment[1];
1094
1095 s->d1->alert_fragment_len = 0;
1096
1097 if (s->msg_callback)
1098 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1099 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1100
1101 if (s->info_callback != NULL)
1102 cb=s->info_callback;
1103 else if (s->ctx->info_callback != NULL)
1104 cb=s->ctx->info_callback;
1105
1106 if (cb != NULL)
1107 {
1108 j = (alert_level << 8) | alert_descr;
1109 cb(s, SSL_CB_READ_ALERT, j);
1110 }
1111
1112 if (alert_level == 1) /* warning */
1113 {
1114 s->s3->warn_alert = alert_descr;
1115 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1116 {
1117 #ifndef OPENSSL_NO_SCTP
1118 /* With SCTP and streams the socket may deliver app data
1119 * after a close_notify alert. We have to check this
1120 * first so that nothing gets discarded.
1121 */
1122 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1123 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1124 {
1125 s->d1->shutdown_received = 1;
1126 s->rwstate=SSL_READING;
1127 BIO_clear_retry_flags(SSL_get_rbio(s));
1128 BIO_set_retry_read(SSL_get_rbio(s));
1129 return -1;
1130 }
1131 #endif
1132 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1133 return(0);
1134 }
1135 #if 0
1136 /* XXX: this is a possible improvement in the future */
1137 /* now check if it's a missing record */
1138 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1139 {
1140 unsigned short seq;
1141 unsigned int frag_off;
1142 unsigned char *p = &(s->d1->alert_fragment[2]);
1143
1144 n2s(p, seq);
1145 n2l3(p, frag_off);
1146
1147 dtls1_retransmit_message(s,
1148 dtls1_get_queue_priority(frag->msg_header.seq, 0),
1149 frag_off, &found);
1150 if ( ! found && SSL_in_init(s))
1151 {
1152 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1153 /* requested a message not yet sent,
1154 send an alert ourselves */
1155 ssl3_send_alert(s,SSL3_AL_WARNING,
1156 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1157 }
1158 }
1159 #endif
1160 }
1161 else if (alert_level == 2) /* fatal */
1162 {
1163 char tmp[16];
1164
1165 s->rwstate=SSL_NOTHING;
1166 s->s3->fatal_alert = alert_descr;
1167 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1168 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1169 ERR_add_error_data(2,"SSL alert number ",tmp);
1170 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1171 SSL_CTX_remove_session(s->ctx,s->session);
1172 return(0);
1173 }
1174 else
1175 {
1176 al=SSL_AD_ILLEGAL_PARAMETER;
1177 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1178 goto f_err;
1179 }
1180
1181 goto start;
1182 }
1183
1184 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1185 {
1186 s->rwstate=SSL_NOTHING;
1187 rr->length=0;
1188 return(0);
1189 }
1190
1191 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1192 {
1193 struct ccs_header_st ccs_hdr;
1194 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1195
1196 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1197
1198 if (s->version == DTLS1_BAD_VER)
1199 ccs_hdr_len = 3;
1200
1201 /* 'Change Cipher Spec' is just a single byte, so we know
1202 * exactly what the record payload has to look like */
1203 /* XDTLS: check that epoch is consistent */
1204 if ( (rr->length != ccs_hdr_len) ||
1205 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1206 {
1207 i=SSL_AD_ILLEGAL_PARAMETER;
1208 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1209 goto err;
1210 }
1211
1212 rr->length=0;
1213
1214 if (s->msg_callback)
1215 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1216 rr->data, 1, s, s->msg_callback_arg);
1217
1218 /* We can't process a CCS now, because previous handshake
1219 * messages are still missing, so just drop it.
1220 */
1221 if (!s->d1->change_cipher_spec_ok)
1222 {
1223 goto start;
1224 }
1225
1226 s->d1->change_cipher_spec_ok = 0;
1227
1228 s->s3->change_cipher_spec=1;
1229 if (!ssl3_do_change_cipher_spec(s))
1230 goto err;
1231
1232 /* do this whenever CCS is processed */
1233 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1234
1235 if (s->version == DTLS1_BAD_VER)
1236 s->d1->handshake_read_seq++;
1237
1238 #ifndef OPENSSL_NO_SCTP
1239 /* Remember that a CCS has been received,
1240 * so that an old key of SCTP-Auth can be
1241 * deleted when a CCS is sent. Will be ignored
1242 * if no SCTP is used
1243 */
1244 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1245 #endif
1246
1247 goto start;
1248 }
1249
1250 /* Unexpected handshake message (Client Hello, or protocol violation) */
1251 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1252 !s->in_handshake)
1253 {
1254 struct hm_header_st msg_hdr;
1255
1256 /* this may just be a stale retransmit */
1257 dtls1_get_message_header(rr->data, &msg_hdr);
1258 if( rr->epoch != s->d1->r_epoch)
1259 {
1260 rr->length = 0;
1261 goto start;
1262 }
1263
1264 /* If we are server, we may have a repeated FINISHED of the
1265 * client here, then retransmit our CCS and FINISHED.
1266 */
1267 if (msg_hdr.type == SSL3_MT_FINISHED)
1268 {
1269 if (dtls1_check_timeout_num(s) < 0)
1270 return -1;
1271
1272 dtls1_retransmit_buffered_messages(s);
1273 rr->length = 0;
1274 goto start;
1275 }
1276
1277 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1278 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1279 {
1280 #if 0 /* worked only because C operator preferences are not as expected (and
1281 * because this is not really needed for clients except for detecting
1282 * protocol violations): */
1283 s->state=SSL_ST_BEFORE|(s->server)
1284 ?SSL_ST_ACCEPT
1285 :SSL_ST_CONNECT;
1286 #else
1287 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1288 #endif
1289 s->renegotiate=1;
1290 s->new_session=1;
1291 }
1292 i=s->handshake_func(s);
1293 if (i < 0) return(i);
1294 if (i == 0)
1295 {
1296 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1297 return(-1);
1298 }
1299
1300 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1301 {
1302 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1303 {
1304 BIO *bio;
1305 /* In the case where we try to read application data,
1306 * but we trigger an SSL handshake, we return -1 with
1307 * the retry option set. Otherwise renegotiation may
1308 * cause nasty problems in the blocking world */
1309 s->rwstate=SSL_READING;
1310 bio=SSL_get_rbio(s);
1311 BIO_clear_retry_flags(bio);
1312 BIO_set_retry_read(bio);
1313 return(-1);
1314 }
1315 }
1316 goto start;
1317 }
1318
1319 switch (rr->type)
1320 {
1321 default:
1322 #ifndef OPENSSL_NO_TLS
1323 /* TLS just ignores unknown message types */
1324 if (s->version == TLS1_VERSION)
1325 {
1326 rr->length = 0;
1327 goto start;
1328 }
1329 #endif
1330 al=SSL_AD_UNEXPECTED_MESSAGE;
1331 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1332 goto f_err;
1333 case SSL3_RT_CHANGE_CIPHER_SPEC:
1334 case SSL3_RT_ALERT:
1335 case SSL3_RT_HANDSHAKE:
1336 /* we already handled all of these, with the possible exception
1337 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1338 * should not happen when type != rr->type */
1339 al=SSL_AD_UNEXPECTED_MESSAGE;
1340 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1341 goto f_err;
1342 case SSL3_RT_APPLICATION_DATA:
1343 /* At this point, we were expecting handshake data,
1344 * but have application data. If the library was
1345 * running inside ssl3_read() (i.e. in_read_app_data
1346 * is set) and it makes sense to read application data
1347 * at this point (session renegotiation not yet started),
1348 * we will indulge it.
1349 */
1350 if (s->s3->in_read_app_data &&
1351 (s->s3->total_renegotiations != 0) &&
1352 ((
1353 (s->state & SSL_ST_CONNECT) &&
1354 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1355 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1356 ) || (
1357 (s->state & SSL_ST_ACCEPT) &&
1358 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1359 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1360 )
1361 ))
1362 {
1363 s->s3->in_read_app_data=2;
1364 return(-1);
1365 }
1366 else
1367 {
1368 al=SSL_AD_UNEXPECTED_MESSAGE;
1369 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1370 goto f_err;
1371 }
1372 }
1373 /* not reached */
1374
1375 f_err:
1376 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1377 err:
1378 return(-1);
1379 }
1380
1381 int
dtls1_write_app_data_bytes(SSL * s,int type,const void * buf_,int len)1382 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1383 {
1384 int i;
1385
1386 #ifndef OPENSSL_NO_SCTP
1387 /* Check if we have to continue an interrupted handshake
1388 * for reading belated app data with SCTP.
1389 */
1390 if ((SSL_in_init(s) && !s->in_handshake) ||
1391 (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1392 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1393 #else
1394 if (SSL_in_init(s) && !s->in_handshake)
1395 #endif
1396 {
1397 i=s->handshake_func(s);
1398 if (i < 0) return(i);
1399 if (i == 0)
1400 {
1401 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1402 return -1;
1403 }
1404 }
1405
1406 if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1407 {
1408 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1409 return -1;
1410 }
1411
1412 i = dtls1_write_bytes(s, type, buf_, len);
1413 return i;
1414 }
1415
1416
1417 /* this only happens when a client hello is received and a handshake
1418 * is started. */
1419 static int
have_handshake_fragment(SSL * s,int type,unsigned char * buf,int len,int peek)1420 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1421 int len, int peek)
1422 {
1423
1424 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1425 /* (partially) satisfy request from storage */
1426 {
1427 unsigned char *src = s->d1->handshake_fragment;
1428 unsigned char *dst = buf;
1429 unsigned int k,n;
1430
1431 /* peek == 0 */
1432 n = 0;
1433 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1434 {
1435 *dst++ = *src++;
1436 len--; s->d1->handshake_fragment_len--;
1437 n++;
1438 }
1439 /* move any remaining fragment bytes: */
1440 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1441 s->d1->handshake_fragment[k] = *src++;
1442 return n;
1443 }
1444
1445 return 0;
1446 }
1447
1448
1449
1450
1451 /* Call this to write data in records of type 'type'
1452 * It will return <= 0 if not all data has been sent or non-blocking IO.
1453 */
dtls1_write_bytes(SSL * s,int type,const void * buf,int len)1454 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1455 {
1456 int i;
1457
1458 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1459 s->rwstate=SSL_NOTHING;
1460 i=do_dtls1_write(s, type, buf, len, 0);
1461 return i;
1462 }
1463
do_dtls1_write(SSL * s,int type,const unsigned char * buf,unsigned int len,int create_empty_fragment)1464 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1465 {
1466 unsigned char *p,*pseq;
1467 int i,mac_size,clear=0;
1468 int prefix_len = 0;
1469 SSL3_RECORD *wr;
1470 SSL3_BUFFER *wb;
1471 SSL_SESSION *sess;
1472 int bs;
1473 unsigned int len_with_overhead = len + SSL3_RT_DEFAULT_WRITE_OVERHEAD;
1474
1475 /* first check if there is a SSL3_BUFFER still being written
1476 * out. This will happen with non blocking IO */
1477 if (s->s3->wbuf.left != 0)
1478 {
1479 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1480 return(ssl3_write_pending(s,type,buf,len));
1481 }
1482
1483 if (s->s3->wbuf.len < len_with_overhead)
1484 {
1485 if ((p=OPENSSL_realloc(s->s3->wbuf.buf, len_with_overhead)) == NULL) {
1486 SSLerr(SSL_F_DO_DTLS1_WRITE,ERR_R_MALLOC_FAILURE);
1487 goto err;
1488 }
1489 s->s3->wbuf.buf = p;
1490 s->s3->wbuf.len = len_with_overhead;
1491 }
1492
1493 /* If we have an alert to send, lets send it */
1494 if (s->s3->alert_dispatch)
1495 {
1496 i=s->method->ssl_dispatch_alert(s);
1497 if (i <= 0)
1498 return(i);
1499 /* if it went, fall through and send more stuff */
1500 }
1501
1502 if (len == 0 && !create_empty_fragment)
1503 return 0;
1504
1505 wr= &(s->s3->wrec);
1506 wb= &(s->s3->wbuf);
1507 sess=s->session;
1508
1509 if ( (sess == NULL) ||
1510 (s->enc_write_ctx == NULL) ||
1511 (EVP_MD_CTX_md(s->write_hash) == NULL))
1512 clear=1;
1513
1514 if (clear)
1515 mac_size=0;
1516 else
1517 {
1518 mac_size=EVP_MD_CTX_size(s->write_hash);
1519 if (mac_size < 0)
1520 goto err;
1521 }
1522
1523 /* DTLS implements explicit IV, so no need for empty fragments */
1524 #if 0
1525 /* 'create_empty_fragment' is true only when this function calls itself */
1526 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1527 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1528 {
1529 /* countermeasure against known-IV weakness in CBC ciphersuites
1530 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1531 */
1532
1533 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1534 {
1535 /* recursive function call with 'create_empty_fragment' set;
1536 * this prepares and buffers the data for an empty fragment
1537 * (these 'prefix_len' bytes are sent out later
1538 * together with the actual payload) */
1539 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1540 if (prefix_len <= 0)
1541 goto err;
1542
1543 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1544 {
1545 /* insufficient space */
1546 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1547 goto err;
1548 }
1549 }
1550
1551 s->s3->empty_fragment_done = 1;
1552 }
1553 #endif
1554 p = wb->buf + prefix_len;
1555
1556 /* write the header */
1557
1558 *(p++)=type&0xff;
1559 wr->type=type;
1560
1561 *(p++)=(s->version>>8);
1562 *(p++)=s->version&0xff;
1563
1564 /* field where we are to write out packet epoch, seq num and len */
1565 pseq=p;
1566 p+=10;
1567
1568 /* lets setup the record stuff. */
1569
1570 /* Make space for the explicit IV in case of CBC.
1571 * (this is a bit of a boundary violation, but what the heck).
1572 */
1573 if ( s->enc_write_ctx &&
1574 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1575 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1576 else
1577 bs = 0;
1578
1579 wr->data=p + bs; /* make room for IV in case of CBC */
1580 wr->length=(int)len;
1581 wr->input=(unsigned char *)buf;
1582
1583 /* we now 'read' from wr->input, wr->length bytes into
1584 * wr->data */
1585
1586 /* first we compress */
1587 if (s->compress != NULL)
1588 {
1589 if (!ssl3_do_compress(s))
1590 {
1591 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1592 goto err;
1593 }
1594 }
1595 else
1596 {
1597 memcpy(wr->data,wr->input,wr->length);
1598 wr->input=wr->data;
1599 }
1600
1601 /* we should still have the output to wr->data and the input
1602 * from wr->input. Length should be wr->length.
1603 * wr->data still points in the wb->buf */
1604
1605 if (mac_size != 0)
1606 {
1607 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1608 goto err;
1609 wr->length+=mac_size;
1610 }
1611
1612 /* this is true regardless of mac size */
1613 wr->input=p;
1614 wr->data=p;
1615
1616
1617 /* ssl3_enc can only have an error on read */
1618 if (bs) /* bs != 0 in case of CBC */
1619 {
1620 RAND_pseudo_bytes(p,bs);
1621 /* master IV and last CBC residue stand for
1622 * the rest of randomness */
1623 wr->length += bs;
1624 }
1625
1626 s->method->ssl3_enc->enc(s,1);
1627
1628 /* record length after mac and block padding */
1629 /* if (type == SSL3_RT_APPLICATION_DATA ||
1630 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1631
1632 /* there's only one epoch between handshake and app data */
1633
1634 s2n(s->d1->w_epoch, pseq);
1635
1636 /* XDTLS: ?? */
1637 /* else
1638 s2n(s->d1->handshake_epoch, pseq); */
1639
1640 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1641 pseq+=6;
1642 s2n(wr->length,pseq);
1643
1644 /* we should now have
1645 * wr->data pointing to the encrypted data, which is
1646 * wr->length long */
1647 wr->type=type; /* not needed but helps for debugging */
1648 wr->length+=DTLS1_RT_HEADER_LENGTH;
1649
1650 #if 0 /* this is now done at the message layer */
1651 /* buffer the record, making it easy to handle retransmits */
1652 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1653 dtls1_buffer_record(s, wr->data, wr->length,
1654 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1655 #endif
1656
1657 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1658
1659 if (create_empty_fragment)
1660 {
1661 /* we are in a recursive call;
1662 * just return the length, don't write out anything here
1663 */
1664 return wr->length;
1665 }
1666
1667 /* now let's set up wb */
1668 wb->left = prefix_len + wr->length;
1669 wb->offset = 0;
1670
1671 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1672 s->s3->wpend_tot=len;
1673 s->s3->wpend_buf=buf;
1674 s->s3->wpend_type=type;
1675 s->s3->wpend_ret=len;
1676
1677 /* we now just need to write the buffer */
1678 return ssl3_write_pending(s,type,buf,len);
1679 err:
1680 return -1;
1681 }
1682
1683
1684
dtls1_record_replay_check(SSL * s,DTLS1_BITMAP * bitmap)1685 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1686 {
1687 int cmp;
1688 unsigned int shift;
1689 const unsigned char *seq = s->s3->read_sequence;
1690
1691 cmp = satsub64be(seq,bitmap->max_seq_num);
1692 if (cmp > 0)
1693 {
1694 memcpy (s->s3->rrec.seq_num,seq,8);
1695 return 1; /* this record in new */
1696 }
1697 shift = -cmp;
1698 if (shift >= sizeof(bitmap->map)*8)
1699 return 0; /* stale, outside the window */
1700 else if (bitmap->map & (1UL<<shift))
1701 return 0; /* record previously received */
1702
1703 memcpy (s->s3->rrec.seq_num,seq,8);
1704 return 1;
1705 }
1706
1707
dtls1_record_bitmap_update(SSL * s,DTLS1_BITMAP * bitmap)1708 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1709 {
1710 int cmp;
1711 unsigned int shift;
1712 const unsigned char *seq = s->s3->read_sequence;
1713
1714 cmp = satsub64be(seq,bitmap->max_seq_num);
1715 if (cmp > 0)
1716 {
1717 shift = cmp;
1718 if (shift < sizeof(bitmap->map)*8)
1719 bitmap->map <<= shift, bitmap->map |= 1UL;
1720 else
1721 bitmap->map = 1UL;
1722 memcpy(bitmap->max_seq_num,seq,8);
1723 }
1724 else {
1725 shift = -cmp;
1726 if (shift < sizeof(bitmap->map)*8)
1727 bitmap->map |= 1UL<<shift;
1728 }
1729 }
1730
1731
dtls1_dispatch_alert(SSL * s)1732 int dtls1_dispatch_alert(SSL *s)
1733 {
1734 int i,j;
1735 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1736 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1737 unsigned char *ptr = &buf[0];
1738
1739 s->s3->alert_dispatch=0;
1740
1741 memset(buf, 0x00, sizeof(buf));
1742 *ptr++ = s->s3->send_alert[0];
1743 *ptr++ = s->s3->send_alert[1];
1744
1745 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1746 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1747 {
1748 s2n(s->d1->handshake_read_seq, ptr);
1749 #if 0
1750 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1751
1752 else
1753 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1754 #endif
1755
1756 #if 0
1757 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);
1758 #endif
1759 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1760 }
1761 #endif
1762
1763 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1764 if (i <= 0)
1765 {
1766 s->s3->alert_dispatch=1;
1767 /* fprintf( stderr, "not done with alert\n" ); */
1768 }
1769 else
1770 {
1771 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1772 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1773 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1774 #endif
1775 )
1776 (void)BIO_flush(s->wbio);
1777
1778 if (s->msg_callback)
1779 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1780 2, s, s->msg_callback_arg);
1781
1782 if (s->info_callback != NULL)
1783 cb=s->info_callback;
1784 else if (s->ctx->info_callback != NULL)
1785 cb=s->ctx->info_callback;
1786
1787 if (cb != NULL)
1788 {
1789 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1790 cb(s,SSL_CB_WRITE_ALERT,j);
1791 }
1792 }
1793 return(i);
1794 }
1795
1796
1797 static DTLS1_BITMAP *
dtls1_get_bitmap(SSL * s,SSL3_RECORD * rr,unsigned int * is_next_epoch)1798 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1799 {
1800
1801 *is_next_epoch = 0;
1802
1803 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1804 if (rr->epoch == s->d1->r_epoch)
1805 return &s->d1->bitmap;
1806
1807 /* Only HM and ALERT messages can be from the next epoch */
1808 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1809 (rr->type == SSL3_RT_HANDSHAKE ||
1810 rr->type == SSL3_RT_ALERT))
1811 {
1812 *is_next_epoch = 1;
1813 return &s->d1->next_bitmap;
1814 }
1815
1816 return NULL;
1817 }
1818
1819 #if 0
1820 static int
1821 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1822 unsigned long *offset)
1823 {
1824
1825 /* alerts are passed up immediately */
1826 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1827 rr->type == SSL3_RT_ALERT)
1828 return 0;
1829
1830 /* Only need to buffer if a handshake is underway.
1831 * (this implies that Hello Request and Client Hello are passed up
1832 * immediately) */
1833 if ( SSL_in_init(s))
1834 {
1835 unsigned char *data = rr->data;
1836 /* need to extract the HM/CCS sequence number here */
1837 if ( rr->type == SSL3_RT_HANDSHAKE ||
1838 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1839 {
1840 unsigned short seq_num;
1841 struct hm_header_st msg_hdr;
1842 struct ccs_header_st ccs_hdr;
1843
1844 if ( rr->type == SSL3_RT_HANDSHAKE)
1845 {
1846 dtls1_get_message_header(data, &msg_hdr);
1847 seq_num = msg_hdr.seq;
1848 *offset = msg_hdr.frag_off;
1849 }
1850 else
1851 {
1852 dtls1_get_ccs_header(data, &ccs_hdr);
1853 seq_num = ccs_hdr.seq;
1854 *offset = 0;
1855 }
1856
1857 /* this is either a record we're waiting for, or a
1858 * retransmit of something we happened to previously
1859 * receive (higher layers will drop the repeat silently */
1860 if ( seq_num < s->d1->handshake_read_seq)
1861 return 0;
1862 if (rr->type == SSL3_RT_HANDSHAKE &&
1863 seq_num == s->d1->handshake_read_seq &&
1864 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1865 return 0;
1866 else if ( seq_num == s->d1->handshake_read_seq &&
1867 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1868 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1869 return 0;
1870 else
1871 {
1872 *priority = seq_num;
1873 return 1;
1874 }
1875 }
1876 else /* unknown record type */
1877 return 0;
1878 }
1879
1880 return 0;
1881 }
1882 #endif
1883
1884 void
dtls1_reset_seq_numbers(SSL * s,int rw)1885 dtls1_reset_seq_numbers(SSL *s, int rw)
1886 {
1887 unsigned char *seq;
1888 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1889
1890 if ( rw & SSL3_CC_READ)
1891 {
1892 seq = s->s3->read_sequence;
1893 s->d1->r_epoch++;
1894 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1895 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1896 }
1897 else
1898 {
1899 seq = s->s3->write_sequence;
1900 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1901 s->d1->w_epoch++;
1902 }
1903
1904 memset(seq, 0x00, seq_bytes);
1905 }
1906