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[thirdparty/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 /* Set proper sequence number for mac calculation */
201 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
202
203 return(1);
204 }
205
206
207 static int
208 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
209 {
210 DTLS1_RECORD_DATA *rdata;
211 pitem *item;
212
213 /* Limit the size of the queue to prevent DOS attacks */
214 if (pqueue_size(queue->q) >= 100)
215 return 0;
216
217 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
218 item = pitem_new(priority, rdata);
219 if (rdata == NULL || item == NULL)
220 {
221 if (rdata != NULL) OPENSSL_free(rdata);
222 if (item != NULL) pitem_free(item);
223
224 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
225 return(0);
226 }
227
228 rdata->packet = s->packet;
229 rdata->packet_length = s->packet_length;
230 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
231 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
232
233 item->data = rdata;
234
235 /* insert should not fail, since duplicates are dropped */
236 if (pqueue_insert(queue->q, item) == NULL)
237 {
238 OPENSSL_free(rdata);
239 pitem_free(item);
240 return(0);
241 }
242
243 s->packet = NULL;
244 s->packet_length = 0;
245 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
246 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
247
248 if (!ssl3_setup_buffers(s))
249 {
250 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
251 OPENSSL_free(rdata);
252 pitem_free(item);
253 return(0);
254 }
255
256 return(1);
257 }
258
259
260 static int
261 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
262 {
263 pitem *item;
264
265 item = pqueue_pop(queue->q);
266 if (item)
267 {
268 dtls1_copy_record(s, item);
269
270 OPENSSL_free(item->data);
271 pitem_free(item);
272
273 return(1);
274 }
275
276 return(0);
277 }
278
279
280 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
281 * yet */
282 #define dtls1_get_unprocessed_record(s) \
283 dtls1_retrieve_buffered_record((s), \
284 &((s)->d1->unprocessed_rcds))
285
286 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
287 #define dtls1_get_processed_record(s) \
288 dtls1_retrieve_buffered_record((s), \
289 &((s)->d1->processed_rcds))
290
291 static int
292 dtls1_process_buffered_records(SSL *s)
293 {
294 pitem *item;
295
296 item = pqueue_peek(s->d1->unprocessed_rcds.q);
297 if (item)
298 {
299 DTLS1_RECORD_DATA *rdata;
300 rdata = (DTLS1_RECORD_DATA *)item->data;
301
302 /* Check if epoch is current. */
303 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
304 return(1); /* Nothing to do. */
305
306 /* Process all the records. */
307 while (pqueue_peek(s->d1->unprocessed_rcds.q))
308 {
309 dtls1_get_unprocessed_record(s);
310 if ( ! dtls1_process_record(s))
311 return(0);
312 dtls1_buffer_record(s, &(s->d1->processed_rcds),
313 s->s3->rrec.seq_num);
314 }
315 }
316
317 /* sync epoch numbers once all the unprocessed records
318 * have been processed */
319 s->d1->processed_rcds.epoch = s->d1->r_epoch;
320 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
321
322 return(1);
323 }
324
325
326 #if 0
327
328 static int
329 dtls1_get_buffered_record(SSL *s)
330 {
331 pitem *item;
332 PQ_64BIT priority =
333 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
334 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
335
336 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating,
337 nothing buffered */
338 return 0;
339
340
341 item = pqueue_peek(s->d1->rcvd_records);
342 if (item && item->priority == priority)
343 {
344 /* Check if we've received the record of interest. It must be
345 * a handshake record, since data records as passed up without
346 * buffering */
347 DTLS1_RECORD_DATA *rdata;
348 item = pqueue_pop(s->d1->rcvd_records);
349 rdata = (DTLS1_RECORD_DATA *)item->data;
350
351 if (s->s3->rbuf.buf != NULL)
352 OPENSSL_free(s->s3->rbuf.buf);
353
354 s->packet = rdata->packet;
355 s->packet_length = rdata->packet_length;
356 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
357 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
358
359 OPENSSL_free(item->data);
360 pitem_free(item);
361
362 /* s->d1->next_expected_seq_num++; */
363 return(1);
364 }
365
366 return 0;
367 }
368
369 #endif
370
371 static int
372 dtls1_process_record(SSL *s)
373 {
374 int i,al;
375 int clear=0;
376 int enc_err;
377 SSL_SESSION *sess;
378 SSL3_RECORD *rr;
379 unsigned int mac_size;
380 unsigned char md[EVP_MAX_MD_SIZE];
381
382
383 rr= &(s->s3->rrec);
384 sess = s->session;
385
386 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
387 * and we have that many bytes in s->packet
388 */
389 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
390
391 /* ok, we can now read from 's->packet' data into 'rr'
392 * rr->input points at rr->length bytes, which
393 * need to be copied into rr->data by either
394 * the decryption or by the decompression
395 * When the data is 'copied' into the rr->data buffer,
396 * rr->input will be pointed at the new buffer */
397
398 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
399 * rr->length bytes of encrypted compressed stuff. */
400
401 /* check is not needed I believe */
402 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
403 {
404 al=SSL_AD_RECORD_OVERFLOW;
405 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
406 goto f_err;
407 }
408
409 /* decrypt in place in 'rr->input' */
410 rr->data=rr->input;
411
412 enc_err = s->method->ssl3_enc->enc(s,0);
413 if (enc_err <= 0)
414 {
415 if (enc_err == 0)
416 /* SSLerr() and ssl3_send_alert() have been called */
417 goto err;
418
419 /* otherwise enc_err == -1 */
420 goto err;
421 }
422
423 #ifdef TLS_DEBUG
424 printf("dec %d\n",rr->length);
425 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
426 printf("\n");
427 #endif
428
429 /* r->length is now the compressed data plus mac */
430 if ( (sess == NULL) ||
431 (s->enc_read_ctx == NULL) ||
432 (s->read_hash == NULL))
433 clear=1;
434
435 if (!clear)
436 {
437 /* !clear => s->read_hash != NULL => mac_size != -1 */
438 int t;
439 t=EVP_MD_CTX_size(s->read_hash);
440 OPENSSL_assert(t >= 0);
441 mac_size=t;
442
443 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
444 {
445 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
446 al=SSL_AD_RECORD_OVERFLOW;
447 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
448 goto f_err;
449 #else
450 goto err;
451 #endif
452 }
453 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
454 if (rr->length < mac_size)
455 {
456 #if 0 /* OK only for stream ciphers */
457 al=SSL_AD_DECODE_ERROR;
458 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
459 goto f_err;
460 #else
461 goto err;
462 #endif
463 }
464 rr->length-=mac_size;
465 i=s->method->ssl3_enc->mac(s,md,0);
466 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
467 {
468 goto err;
469 }
470 }
471
472 /* r->length is now just compressed */
473 if (s->expand != NULL)
474 {
475 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
476 {
477 al=SSL_AD_RECORD_OVERFLOW;
478 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
479 goto f_err;
480 }
481 if (!ssl3_do_uncompress(s))
482 {
483 al=SSL_AD_DECOMPRESSION_FAILURE;
484 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
485 goto f_err;
486 }
487 }
488
489 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
490 {
491 al=SSL_AD_RECORD_OVERFLOW;
492 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
493 goto f_err;
494 }
495
496 rr->off=0;
497 /* So at this point the following is true
498 * ssl->s3->rrec.type is the type of record
499 * ssl->s3->rrec.length == number of bytes in record
500 * ssl->s3->rrec.off == offset to first valid byte
501 * ssl->s3->rrec.data == where to take bytes from, increment
502 * after use :-).
503 */
504
505 /* we have pulled in a full packet so zero things */
506 s->packet_length=0;
507 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
508 return(1);
509
510 f_err:
511 ssl3_send_alert(s,SSL3_AL_FATAL,al);
512 err:
513 return(0);
514 }
515
516
517 /* Call this to get a new input record.
518 * It will return <= 0 if more data is needed, normally due to an error
519 * or non-blocking IO.
520 * When it finishes, one packet has been decoded and can be found in
521 * ssl->s3->rrec.type - is the type of record
522 * ssl->s3->rrec.data, - data
523 * ssl->s3->rrec.length, - number of bytes
524 */
525 /* used only by dtls1_read_bytes */
526 int dtls1_get_record(SSL *s)
527 {
528 int ssl_major,ssl_minor;
529 int i,n;
530 SSL3_RECORD *rr;
531 SSL_SESSION *sess;
532 unsigned char *p = NULL;
533 unsigned short version;
534 DTLS1_BITMAP *bitmap;
535 unsigned int is_next_epoch;
536
537 rr= &(s->s3->rrec);
538 sess=s->session;
539
540 /* The epoch may have changed. If so, process all the
541 * pending records. This is a non-blocking operation. */
542 dtls1_process_buffered_records(s);
543
544 /* if we're renegotiating, then there may be buffered records */
545 if (dtls1_get_processed_record(s))
546 return 1;
547
548 /* get something from the wire */
549 again:
550 /* check if we have the header */
551 if ( (s->rstate != SSL_ST_READ_BODY) ||
552 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
553 {
554 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
555 /* read timeout is handled by dtls1_read_bytes */
556 if (n <= 0) return(n); /* error or non-blocking */
557
558 /* this packet contained a partial record, dump it */
559 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
560 {
561 s->packet_length = 0;
562 goto again;
563 }
564
565 s->rstate=SSL_ST_READ_BODY;
566
567 p=s->packet;
568
569 /* Pull apart the header into the DTLS1_RECORD */
570 rr->type= *(p++);
571 ssl_major= *(p++);
572 ssl_minor= *(p++);
573 version=(ssl_major<<8)|ssl_minor;
574
575 /* sequence number is 64 bits, with top 2 bytes = epoch */
576 n2s(p,rr->epoch);
577
578 memcpy(&(s->s3->read_sequence[2]), p, 6);
579 p+=6;
580
581 n2s(p,rr->length);
582
583 /* Lets check version */
584 if (!s->first_packet)
585 {
586 if (version != s->version)
587 {
588 /* unexpected version, silently discard */
589 rr->length = 0;
590 s->packet_length = 0;
591 goto again;
592 }
593 }
594
595 if ((version & 0xff00) != (s->version & 0xff00))
596 {
597 /* wrong version, silently discard record */
598 rr->length = 0;
599 s->packet_length = 0;
600 goto again;
601 }
602
603 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
604 {
605 /* record too long, silently discard it */
606 rr->length = 0;
607 s->packet_length = 0;
608 goto again;
609 }
610
611 /* now s->rstate == SSL_ST_READ_BODY */
612 }
613
614 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
615
616 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
617 {
618 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
619 i=rr->length;
620 n=ssl3_read_n(s,i,i,1);
621 if (n <= 0) return(n); /* error or non-blocking io */
622
623 /* this packet contained a partial record, dump it */
624 if ( n != i)
625 {
626 rr->length = 0;
627 s->packet_length = 0;
628 goto again;
629 }
630
631 /* now n == rr->length,
632 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
633 }
634 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
635
636 /* match epochs. NULL means the packet is dropped on the floor */
637 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
638 if ( bitmap == NULL)
639 {
640 rr->length = 0;
641 s->packet_length = 0; /* dump this record */
642 goto again; /* get another record */
643 }
644
645 /* Check whether this is a repeat, or aged record.
646 * Don't check if we're listening and this message is
647 * a ClientHello. They can look as if they're replayed,
648 * since they arrive from different connections and
649 * would be dropped unnecessarily.
650 */
651 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
652 *p == SSL3_MT_CLIENT_HELLO) &&
653 !dtls1_record_replay_check(s, bitmap))
654 {
655 rr->length = 0;
656 s->packet_length=0; /* dump this record */
657 goto again; /* get another record */
658 }
659
660 /* just read a 0 length packet */
661 if (rr->length == 0) goto again;
662
663 /* If this record is from the next epoch (either HM or ALERT),
664 * and a handshake is currently in progress, buffer it since it
665 * cannot be processed at this time. */
666 if (is_next_epoch)
667 {
668 if (SSL_in_init(s) || s->in_handshake)
669 {
670 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
671 }
672 rr->length = 0;
673 s->packet_length = 0;
674 goto again;
675 }
676
677 if (!dtls1_process_record(s))
678 {
679 rr->length = 0;
680 s->packet_length = 0; /* dump this record */
681 goto again; /* get another record */
682 }
683
684 dtls1_clear_timeouts(s); /* done waiting */
685 return(1);
686
687 }
688
689 /* Return up to 'len' payload bytes received in 'type' records.
690 * 'type' is one of the following:
691 *
692 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
693 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
694 * - 0 (during a shutdown, no data has to be returned)
695 *
696 * If we don't have stored data to work from, read a SSL/TLS record first
697 * (possibly multiple records if we still don't have anything to return).
698 *
699 * This function must handle any surprises the peer may have for us, such as
700 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
701 * a surprise, but handled as if it were), or renegotiation requests.
702 * Also if record payloads contain fragments too small to process, we store
703 * them until there is enough for the respective protocol (the record protocol
704 * may use arbitrary fragmentation and even interleaving):
705 * Change cipher spec protocol
706 * just 1 byte needed, no need for keeping anything stored
707 * Alert protocol
708 * 2 bytes needed (AlertLevel, AlertDescription)
709 * Handshake protocol
710 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
711 * to detect unexpected Client Hello and Hello Request messages
712 * here, anything else is handled by higher layers
713 * Application data protocol
714 * none of our business
715 */
716 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
717 {
718 int al,i,j,ret;
719 unsigned int n;
720 SSL3_RECORD *rr;
721 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
722
723 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
724 if (!ssl3_setup_buffers(s))
725 return(-1);
726
727 /* XXX: check what the second '&& type' is about */
728 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
729 (type != SSL3_RT_HANDSHAKE) && type) ||
730 (peek && (type != SSL3_RT_APPLICATION_DATA)))
731 {
732 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
733 return -1;
734 }
735
736 /* check whether there's a handshake message (client hello?) waiting */
737 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
738 return ret;
739
740 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
741
742 if (!s->in_handshake && SSL_in_init(s))
743 {
744 /* type == SSL3_RT_APPLICATION_DATA */
745 i=s->handshake_func(s);
746 if (i < 0) return(i);
747 if (i == 0)
748 {
749 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
750 return(-1);
751 }
752 }
753
754 start:
755 s->rwstate=SSL_NOTHING;
756
757 /* s->s3->rrec.type - is the type of record
758 * s->s3->rrec.data, - data
759 * s->s3->rrec.off, - offset into 'data' for next read
760 * s->s3->rrec.length, - number of bytes. */
761 rr = &(s->s3->rrec);
762
763 /* We are not handshaking and have no data yet,
764 * so process data buffered during the last handshake
765 * in advance, if any.
766 */
767 if (s->state == SSL_ST_OK && rr->length == 0)
768 {
769 pitem *item;
770 item = pqueue_pop(s->d1->buffered_app_data.q);
771 if (item)
772 {
773 dtls1_copy_record(s, item);
774
775 OPENSSL_free(item->data);
776 pitem_free(item);
777 }
778 }
779
780 /* Check for timeout */
781 if (dtls1_handle_timeout(s) > 0)
782 goto start;
783
784 /* get new packet if necessary */
785 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
786 {
787 ret=dtls1_get_record(s);
788 if (ret <= 0)
789 {
790 ret = dtls1_read_failed(s, ret);
791 /* anything other than a timeout is an error */
792 if (ret <= 0)
793 return(ret);
794 else
795 goto start;
796 }
797 }
798
799 /* we now have a packet which can be read and processed */
800
801 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
802 * reset by ssl3_get_finished */
803 && (rr->type != SSL3_RT_HANDSHAKE))
804 {
805 /* We now have application data between CCS and Finished.
806 * Most likely the packets were reordered on their way, so
807 * buffer the application data for later processing rather
808 * than dropping the connection.
809 */
810 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
811 rr->length = 0;
812 goto start;
813 }
814
815 /* If the other end has shut down, throw anything we read away
816 * (even in 'peek' mode) */
817 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
818 {
819 rr->length=0;
820 s->rwstate=SSL_NOTHING;
821 return(0);
822 }
823
824
825 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
826 {
827 /* make sure that we are not getting application data when we
828 * are doing a handshake for the first time */
829 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
830 (s->enc_read_ctx == NULL))
831 {
832 al=SSL_AD_UNEXPECTED_MESSAGE;
833 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
834 goto f_err;
835 }
836
837 if (len <= 0) return(len);
838
839 if ((unsigned int)len > rr->length)
840 n = rr->length;
841 else
842 n = (unsigned int)len;
843
844 memcpy(buf,&(rr->data[rr->off]),n);
845 if (!peek)
846 {
847 rr->length-=n;
848 rr->off+=n;
849 if (rr->length == 0)
850 {
851 s->rstate=SSL_ST_READ_HEADER;
852 rr->off=0;
853 }
854 }
855 return(n);
856 }
857
858
859 /* If we get here, then type != rr->type; if we have a handshake
860 * message, then it was unexpected (Hello Request or Client Hello). */
861
862 /* In case of record types for which we have 'fragment' storage,
863 * fill that so that we can process the data at a fixed place.
864 */
865 {
866 unsigned int k, dest_maxlen = 0;
867 unsigned char *dest = NULL;
868 unsigned int *dest_len = NULL;
869
870 if (rr->type == SSL3_RT_HANDSHAKE)
871 {
872 dest_maxlen = sizeof s->d1->handshake_fragment;
873 dest = s->d1->handshake_fragment;
874 dest_len = &s->d1->handshake_fragment_len;
875 }
876 else if (rr->type == SSL3_RT_ALERT)
877 {
878 dest_maxlen = sizeof(s->d1->alert_fragment);
879 dest = s->d1->alert_fragment;
880 dest_len = &s->d1->alert_fragment_len;
881 }
882 /* else it's a CCS message, or application data or wrong */
883 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
884 {
885 /* Application data while renegotiating
886 * is allowed. Try again reading.
887 */
888 if (rr->type == SSL3_RT_APPLICATION_DATA)
889 {
890 BIO *bio;
891 s->s3->in_read_app_data=2;
892 bio=SSL_get_rbio(s);
893 s->rwstate=SSL_READING;
894 BIO_clear_retry_flags(bio);
895 BIO_set_retry_read(bio);
896 return(-1);
897 }
898
899 /* Not certain if this is the right error handling */
900 al=SSL_AD_UNEXPECTED_MESSAGE;
901 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
902 goto f_err;
903 }
904
905 if (dest_maxlen > 0)
906 {
907 /* XDTLS: In a pathalogical case, the Client Hello
908 * may be fragmented--don't always expect dest_maxlen bytes */
909 if ( rr->length < dest_maxlen)
910 {
911 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
912 /*
913 * for normal alerts rr->length is 2, while
914 * dest_maxlen is 7 if we were to handle this
915 * non-existing alert...
916 */
917 FIX ME
918 #endif
919 s->rstate=SSL_ST_READ_HEADER;
920 rr->length = 0;
921 goto start;
922 }
923
924 /* now move 'n' bytes: */
925 for ( k = 0; k < dest_maxlen; k++)
926 {
927 dest[k] = rr->data[rr->off++];
928 rr->length--;
929 }
930 *dest_len = dest_maxlen;
931 }
932 }
933
934 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
935 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
936 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
937
938 /* If we are a client, check for an incoming 'Hello Request': */
939 if ((!s->server) &&
940 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
941 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
942 (s->session != NULL) && (s->session->cipher != NULL))
943 {
944 s->d1->handshake_fragment_len = 0;
945
946 if ((s->d1->handshake_fragment[1] != 0) ||
947 (s->d1->handshake_fragment[2] != 0) ||
948 (s->d1->handshake_fragment[3] != 0))
949 {
950 al=SSL_AD_DECODE_ERROR;
951 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
952 goto err;
953 }
954
955 /* no need to check sequence number on HELLO REQUEST messages */
956
957 if (s->msg_callback)
958 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
959 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
960
961 if (SSL_is_init_finished(s) &&
962 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
963 !s->s3->renegotiate)
964 {
965 ssl3_renegotiate(s);
966 if (ssl3_renegotiate_check(s))
967 {
968 i=s->handshake_func(s);
969 if (i < 0) return(i);
970 if (i == 0)
971 {
972 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
973 return(-1);
974 }
975
976 if (!(s->mode & SSL_MODE_AUTO_RETRY))
977 {
978 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
979 {
980 BIO *bio;
981 /* In the case where we try to read application data,
982 * but we trigger an SSL handshake, we return -1 with
983 * the retry option set. Otherwise renegotiation may
984 * cause nasty problems in the blocking world */
985 s->rwstate=SSL_READING;
986 bio=SSL_get_rbio(s);
987 BIO_clear_retry_flags(bio);
988 BIO_set_retry_read(bio);
989 return(-1);
990 }
991 }
992 }
993 }
994 /* we either finished a handshake or ignored the request,
995 * now try again to obtain the (application) data we were asked for */
996 goto start;
997 }
998
999 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1000 {
1001 int alert_level = s->d1->alert_fragment[0];
1002 int alert_descr = s->d1->alert_fragment[1];
1003
1004 s->d1->alert_fragment_len = 0;
1005
1006 if (s->msg_callback)
1007 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1008 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1009
1010 if (s->info_callback != NULL)
1011 cb=s->info_callback;
1012 else if (s->ctx->info_callback != NULL)
1013 cb=s->ctx->info_callback;
1014
1015 if (cb != NULL)
1016 {
1017 j = (alert_level << 8) | alert_descr;
1018 cb(s, SSL_CB_READ_ALERT, j);
1019 }
1020
1021 if (alert_level == 1) /* warning */
1022 {
1023 s->s3->warn_alert = alert_descr;
1024 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1025 {
1026 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1027 return(0);
1028 }
1029 #if 0
1030 /* XXX: this is a possible improvement in the future */
1031 /* now check if it's a missing record */
1032 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1033 {
1034 unsigned short seq;
1035 unsigned int frag_off;
1036 unsigned char *p = &(s->d1->alert_fragment[2]);
1037
1038 n2s(p, seq);
1039 n2l3(p, frag_off);
1040
1041 dtls1_retransmit_message(s,
1042 dtls1_get_queue_priority(frag->msg_header.seq, 0),
1043 frag_off, &found);
1044 if ( ! found && SSL_in_init(s))
1045 {
1046 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1047 /* requested a message not yet sent,
1048 send an alert ourselves */
1049 ssl3_send_alert(s,SSL3_AL_WARNING,
1050 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1051 }
1052 }
1053 #endif
1054 }
1055 else if (alert_level == 2) /* fatal */
1056 {
1057 char tmp[16];
1058
1059 s->rwstate=SSL_NOTHING;
1060 s->s3->fatal_alert = alert_descr;
1061 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1062 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1063 ERR_add_error_data(2,"SSL alert number ",tmp);
1064 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1065 SSL_CTX_remove_session(s->ctx,s->session);
1066 return(0);
1067 }
1068 else
1069 {
1070 al=SSL_AD_ILLEGAL_PARAMETER;
1071 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1072 goto f_err;
1073 }
1074
1075 goto start;
1076 }
1077
1078 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1079 {
1080 s->rwstate=SSL_NOTHING;
1081 rr->length=0;
1082 return(0);
1083 }
1084
1085 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1086 {
1087 struct ccs_header_st ccs_hdr;
1088 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1089
1090 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1091
1092 if (s->version == DTLS1_BAD_VER)
1093 ccs_hdr_len = 3;
1094
1095 /* 'Change Cipher Spec' is just a single byte, so we know
1096 * exactly what the record payload has to look like */
1097 /* XDTLS: check that epoch is consistent */
1098 if ( (rr->length != ccs_hdr_len) ||
1099 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1100 {
1101 i=SSL_AD_ILLEGAL_PARAMETER;
1102 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1103 goto err;
1104 }
1105
1106 rr->length=0;
1107
1108 if (s->msg_callback)
1109 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1110 rr->data, 1, s, s->msg_callback_arg);
1111
1112 /* We can't process a CCS now, because previous handshake
1113 * messages are still missing, so just drop it.
1114 */
1115 if (!s->d1->change_cipher_spec_ok)
1116 {
1117 goto start;
1118 }
1119
1120 s->d1->change_cipher_spec_ok = 0;
1121
1122 s->s3->change_cipher_spec=1;
1123 if (!ssl3_do_change_cipher_spec(s))
1124 goto err;
1125
1126 /* do this whenever CCS is processed */
1127 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1128
1129 if (s->version == DTLS1_BAD_VER)
1130 s->d1->handshake_read_seq++;
1131
1132 goto start;
1133 }
1134
1135 /* Unexpected handshake message (Client Hello, or protocol violation) */
1136 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1137 !s->in_handshake)
1138 {
1139 struct hm_header_st msg_hdr;
1140
1141 /* this may just be a stale retransmit */
1142 dtls1_get_message_header(rr->data, &msg_hdr);
1143 if( rr->epoch != s->d1->r_epoch)
1144 {
1145 rr->length = 0;
1146 goto start;
1147 }
1148
1149 /* If we are server, we may have a repeated FINISHED of the
1150 * client here, then retransmit our CCS and FINISHED.
1151 */
1152 if (msg_hdr.type == SSL3_MT_FINISHED)
1153 {
1154 dtls1_retransmit_buffered_messages(s);
1155 rr->length = 0;
1156 goto start;
1157 }
1158
1159 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1160 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1161 {
1162 #if 0 /* worked only because C operator preferences are not as expected (and
1163 * because this is not really needed for clients except for detecting
1164 * protocol violations): */
1165 s->state=SSL_ST_BEFORE|(s->server)
1166 ?SSL_ST_ACCEPT
1167 :SSL_ST_CONNECT;
1168 #else
1169 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1170 #endif
1171 s->new_session=1;
1172 }
1173 i=s->handshake_func(s);
1174 if (i < 0) return(i);
1175 if (i == 0)
1176 {
1177 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1178 return(-1);
1179 }
1180
1181 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1182 {
1183 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1184 {
1185 BIO *bio;
1186 /* In the case where we try to read application data,
1187 * but we trigger an SSL handshake, we return -1 with
1188 * the retry option set. Otherwise renegotiation may
1189 * cause nasty problems in the blocking world */
1190 s->rwstate=SSL_READING;
1191 bio=SSL_get_rbio(s);
1192 BIO_clear_retry_flags(bio);
1193 BIO_set_retry_read(bio);
1194 return(-1);
1195 }
1196 }
1197 goto start;
1198 }
1199
1200 switch (rr->type)
1201 {
1202 default:
1203 #ifndef OPENSSL_NO_TLS
1204 /* TLS just ignores unknown message types */
1205 if (s->version == TLS1_VERSION)
1206 {
1207 rr->length = 0;
1208 goto start;
1209 }
1210 #endif
1211 al=SSL_AD_UNEXPECTED_MESSAGE;
1212 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1213 goto f_err;
1214 case SSL3_RT_CHANGE_CIPHER_SPEC:
1215 case SSL3_RT_ALERT:
1216 case SSL3_RT_HANDSHAKE:
1217 /* we already handled all of these, with the possible exception
1218 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1219 * should not happen when type != rr->type */
1220 al=SSL_AD_UNEXPECTED_MESSAGE;
1221 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1222 goto f_err;
1223 case SSL3_RT_APPLICATION_DATA:
1224 /* At this point, we were expecting handshake data,
1225 * but have application data. If the library was
1226 * running inside ssl3_read() (i.e. in_read_app_data
1227 * is set) and it makes sense to read application data
1228 * at this point (session renegotiation not yet started),
1229 * we will indulge it.
1230 */
1231 if (s->s3->in_read_app_data &&
1232 (s->s3->total_renegotiations != 0) &&
1233 ((
1234 (s->state & SSL_ST_CONNECT) &&
1235 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1236 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1237 ) || (
1238 (s->state & SSL_ST_ACCEPT) &&
1239 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1240 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1241 )
1242 ))
1243 {
1244 s->s3->in_read_app_data=2;
1245 return(-1);
1246 }
1247 else
1248 {
1249 al=SSL_AD_UNEXPECTED_MESSAGE;
1250 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1251 goto f_err;
1252 }
1253 }
1254 /* not reached */
1255
1256 f_err:
1257 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1258 err:
1259 return(-1);
1260 }
1261
1262 int
1263 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1264 {
1265 int i;
1266
1267 if (SSL_in_init(s) && !s->in_handshake)
1268 {
1269 i=s->handshake_func(s);
1270 if (i < 0) return(i);
1271 if (i == 0)
1272 {
1273 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1274 return -1;
1275 }
1276 }
1277
1278 if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1279 {
1280 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1281 return -1;
1282 }
1283
1284 i = dtls1_write_bytes(s, type, buf_, len);
1285 return i;
1286 }
1287
1288
1289 /* this only happens when a client hello is received and a handshake
1290 * is started. */
1291 static int
1292 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1293 int len, int peek)
1294 {
1295
1296 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1297 /* (partially) satisfy request from storage */
1298 {
1299 unsigned char *src = s->d1->handshake_fragment;
1300 unsigned char *dst = buf;
1301 unsigned int k,n;
1302
1303 /* peek == 0 */
1304 n = 0;
1305 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1306 {
1307 *dst++ = *src++;
1308 len--; s->d1->handshake_fragment_len--;
1309 n++;
1310 }
1311 /* move any remaining fragment bytes: */
1312 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1313 s->d1->handshake_fragment[k] = *src++;
1314 return n;
1315 }
1316
1317 return 0;
1318 }
1319
1320
1321
1322
1323 /* Call this to write data in records of type 'type'
1324 * It will return <= 0 if not all data has been sent or non-blocking IO.
1325 */
1326 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1327 {
1328 int i;
1329
1330 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1331 s->rwstate=SSL_NOTHING;
1332 i=do_dtls1_write(s, type, buf, len, 0);
1333 return i;
1334 }
1335
1336 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1337 {
1338 unsigned char *p,*pseq;
1339 int i,mac_size,clear=0;
1340 int prefix_len = 0;
1341 SSL3_RECORD *wr;
1342 SSL3_BUFFER *wb;
1343 SSL_SESSION *sess;
1344 int bs;
1345
1346 /* first check if there is a SSL3_BUFFER still being written
1347 * out. This will happen with non blocking IO */
1348 if (s->s3->wbuf.left != 0)
1349 {
1350 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1351 return(ssl3_write_pending(s,type,buf,len));
1352 }
1353
1354 /* If we have an alert to send, lets send it */
1355 if (s->s3->alert_dispatch)
1356 {
1357 i=s->method->ssl_dispatch_alert(s);
1358 if (i <= 0)
1359 return(i);
1360 /* if it went, fall through and send more stuff */
1361 }
1362
1363 if (len == 0 && !create_empty_fragment)
1364 return 0;
1365
1366 wr= &(s->s3->wrec);
1367 wb= &(s->s3->wbuf);
1368 sess=s->session;
1369
1370 if ( (sess == NULL) ||
1371 (s->enc_write_ctx == NULL) ||
1372 (EVP_MD_CTX_md(s->write_hash) == NULL))
1373 clear=1;
1374
1375 if (clear)
1376 mac_size=0;
1377 else
1378 {
1379 mac_size=EVP_MD_CTX_size(s->write_hash);
1380 if (mac_size < 0)
1381 goto err;
1382 }
1383
1384 /* DTLS implements explicit IV, so no need for empty fragments */
1385 #if 0
1386 /* 'create_empty_fragment' is true only when this function calls itself */
1387 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1388 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1389 {
1390 /* countermeasure against known-IV weakness in CBC ciphersuites
1391 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1392 */
1393
1394 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1395 {
1396 /* recursive function call with 'create_empty_fragment' set;
1397 * this prepares and buffers the data for an empty fragment
1398 * (these 'prefix_len' bytes are sent out later
1399 * together with the actual payload) */
1400 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1401 if (prefix_len <= 0)
1402 goto err;
1403
1404 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1405 {
1406 /* insufficient space */
1407 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1408 goto err;
1409 }
1410 }
1411
1412 s->s3->empty_fragment_done = 1;
1413 }
1414 #endif
1415 p = wb->buf + prefix_len;
1416
1417 /* write the header */
1418
1419 *(p++)=type&0xff;
1420 wr->type=type;
1421
1422 *(p++)=(s->version>>8);
1423 *(p++)=s->version&0xff;
1424
1425 /* field where we are to write out packet epoch, seq num and len */
1426 pseq=p;
1427 p+=10;
1428
1429 /* lets setup the record stuff. */
1430
1431 /* Make space for the explicit IV in case of CBC.
1432 * (this is a bit of a boundary violation, but what the heck).
1433 */
1434 if ( s->enc_write_ctx &&
1435 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1436 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1437 else
1438 bs = 0;
1439
1440 wr->data=p + bs; /* make room for IV in case of CBC */
1441 wr->length=(int)len;
1442 wr->input=(unsigned char *)buf;
1443
1444 /* we now 'read' from wr->input, wr->length bytes into
1445 * wr->data */
1446
1447 /* first we compress */
1448 if (s->compress != NULL)
1449 {
1450 if (!ssl3_do_compress(s))
1451 {
1452 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1453 goto err;
1454 }
1455 }
1456 else
1457 {
1458 memcpy(wr->data,wr->input,wr->length);
1459 wr->input=wr->data;
1460 }
1461
1462 /* we should still have the output to wr->data and the input
1463 * from wr->input. Length should be wr->length.
1464 * wr->data still points in the wb->buf */
1465
1466 if (mac_size != 0)
1467 {
1468 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1469 goto err;
1470 wr->length+=mac_size;
1471 }
1472
1473 /* this is true regardless of mac size */
1474 wr->input=p;
1475 wr->data=p;
1476
1477
1478 /* ssl3_enc can only have an error on read */
1479 if (bs) /* bs != 0 in case of CBC */
1480 {
1481 RAND_pseudo_bytes(p,bs);
1482 /* master IV and last CBC residue stand for
1483 * the rest of randomness */
1484 wr->length += bs;
1485 }
1486
1487 s->method->ssl3_enc->enc(s,1);
1488
1489 /* record length after mac and block padding */
1490 /* if (type == SSL3_RT_APPLICATION_DATA ||
1491 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1492
1493 /* there's only one epoch between handshake and app data */
1494
1495 s2n(s->d1->w_epoch, pseq);
1496
1497 /* XDTLS: ?? */
1498 /* else
1499 s2n(s->d1->handshake_epoch, pseq); */
1500
1501 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1502 pseq+=6;
1503 s2n(wr->length,pseq);
1504
1505 /* we should now have
1506 * wr->data pointing to the encrypted data, which is
1507 * wr->length long */
1508 wr->type=type; /* not needed but helps for debugging */
1509 wr->length+=DTLS1_RT_HEADER_LENGTH;
1510
1511 #if 0 /* this is now done at the message layer */
1512 /* buffer the record, making it easy to handle retransmits */
1513 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1514 dtls1_buffer_record(s, wr->data, wr->length,
1515 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1516 #endif
1517
1518 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1519
1520 if (create_empty_fragment)
1521 {
1522 /* we are in a recursive call;
1523 * just return the length, don't write out anything here
1524 */
1525 return wr->length;
1526 }
1527
1528 /* now let's set up wb */
1529 wb->left = prefix_len + wr->length;
1530 wb->offset = 0;
1531
1532 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1533 s->s3->wpend_tot=len;
1534 s->s3->wpend_buf=buf;
1535 s->s3->wpend_type=type;
1536 s->s3->wpend_ret=len;
1537
1538 /* we now just need to write the buffer */
1539 return ssl3_write_pending(s,type,buf,len);
1540 err:
1541 return -1;
1542 }
1543
1544
1545
1546 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1547 {
1548 int cmp;
1549 unsigned int shift;
1550 const unsigned char *seq = s->s3->read_sequence;
1551
1552 cmp = satsub64be(seq,bitmap->max_seq_num);
1553 if (cmp > 0)
1554 {
1555 memcpy (s->s3->rrec.seq_num,seq,8);
1556 return 1; /* this record in new */
1557 }
1558 shift = -cmp;
1559 if (shift >= sizeof(bitmap->map)*8)
1560 return 0; /* stale, outside the window */
1561 else if (bitmap->map & (1UL<<shift))
1562 return 0; /* record previously received */
1563
1564 memcpy (s->s3->rrec.seq_num,seq,8);
1565 return 1;
1566 }
1567
1568
1569 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1570 {
1571 int cmp;
1572 unsigned int shift;
1573 const unsigned char *seq = s->s3->read_sequence;
1574
1575 cmp = satsub64be(seq,bitmap->max_seq_num);
1576 if (cmp > 0)
1577 {
1578 shift = cmp;
1579 if (shift < sizeof(bitmap->map)*8)
1580 bitmap->map <<= shift, bitmap->map |= 1UL;
1581 else
1582 bitmap->map = 1UL;
1583 memcpy(bitmap->max_seq_num,seq,8);
1584 }
1585 else {
1586 shift = -cmp;
1587 if (shift < sizeof(bitmap->map)*8)
1588 bitmap->map |= 1UL<<shift;
1589 }
1590 }
1591
1592
1593 int dtls1_dispatch_alert(SSL *s)
1594 {
1595 int i,j;
1596 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1597 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1598 unsigned char *ptr = &buf[0];
1599
1600 s->s3->alert_dispatch=0;
1601
1602 memset(buf, 0x00, sizeof(buf));
1603 *ptr++ = s->s3->send_alert[0];
1604 *ptr++ = s->s3->send_alert[1];
1605
1606 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1607 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1608 {
1609 s2n(s->d1->handshake_read_seq, ptr);
1610 #if 0
1611 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1612
1613 else
1614 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1615 #endif
1616
1617 #if 0
1618 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);
1619 #endif
1620 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1621 }
1622 #endif
1623
1624 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1625 if (i <= 0)
1626 {
1627 s->s3->alert_dispatch=1;
1628 /* fprintf( stderr, "not done with alert\n" ); */
1629 }
1630 else
1631 {
1632 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1633 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1634 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1635 #endif
1636 )
1637 (void)BIO_flush(s->wbio);
1638
1639 if (s->msg_callback)
1640 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1641 2, s, s->msg_callback_arg);
1642
1643 if (s->info_callback != NULL)
1644 cb=s->info_callback;
1645 else if (s->ctx->info_callback != NULL)
1646 cb=s->ctx->info_callback;
1647
1648 if (cb != NULL)
1649 {
1650 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1651 cb(s,SSL_CB_WRITE_ALERT,j);
1652 }
1653 }
1654 return(i);
1655 }
1656
1657
1658 static DTLS1_BITMAP *
1659 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1660 {
1661
1662 *is_next_epoch = 0;
1663
1664 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1665 if (rr->epoch == s->d1->r_epoch)
1666 return &s->d1->bitmap;
1667
1668 /* Only HM and ALERT messages can be from the next epoch */
1669 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1670 (rr->type == SSL3_RT_HANDSHAKE ||
1671 rr->type == SSL3_RT_ALERT))
1672 {
1673 *is_next_epoch = 1;
1674 return &s->d1->next_bitmap;
1675 }
1676
1677 return NULL;
1678 }
1679
1680 #if 0
1681 static int
1682 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1683 unsigned long *offset)
1684 {
1685
1686 /* alerts are passed up immediately */
1687 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1688 rr->type == SSL3_RT_ALERT)
1689 return 0;
1690
1691 /* Only need to buffer if a handshake is underway.
1692 * (this implies that Hello Request and Client Hello are passed up
1693 * immediately) */
1694 if ( SSL_in_init(s))
1695 {
1696 unsigned char *data = rr->data;
1697 /* need to extract the HM/CCS sequence number here */
1698 if ( rr->type == SSL3_RT_HANDSHAKE ||
1699 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1700 {
1701 unsigned short seq_num;
1702 struct hm_header_st msg_hdr;
1703 struct ccs_header_st ccs_hdr;
1704
1705 if ( rr->type == SSL3_RT_HANDSHAKE)
1706 {
1707 dtls1_get_message_header(data, &msg_hdr);
1708 seq_num = msg_hdr.seq;
1709 *offset = msg_hdr.frag_off;
1710 }
1711 else
1712 {
1713 dtls1_get_ccs_header(data, &ccs_hdr);
1714 seq_num = ccs_hdr.seq;
1715 *offset = 0;
1716 }
1717
1718 /* this is either a record we're waiting for, or a
1719 * retransmit of something we happened to previously
1720 * receive (higher layers will drop the repeat silently */
1721 if ( seq_num < s->d1->handshake_read_seq)
1722 return 0;
1723 if (rr->type == SSL3_RT_HANDSHAKE &&
1724 seq_num == s->d1->handshake_read_seq &&
1725 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1726 return 0;
1727 else if ( seq_num == s->d1->handshake_read_seq &&
1728 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1729 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1730 return 0;
1731 else
1732 {
1733 *priority = seq_num;
1734 return 1;
1735 }
1736 }
1737 else /* unknown record type */
1738 return 0;
1739 }
1740
1741 return 0;
1742 }
1743 #endif
1744
1745 void
1746 dtls1_reset_seq_numbers(SSL *s, int rw)
1747 {
1748 unsigned char *seq;
1749 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1750
1751 if ( rw & SSL3_CC_READ)
1752 {
1753 seq = s->s3->read_sequence;
1754 s->d1->r_epoch++;
1755 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1756 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1757 }
1758 else
1759 {
1760 seq = s->s3->write_sequence;
1761 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1762 s->d1->w_epoch++;
1763 }
1764
1765 memset(seq, 0x00, seq_bytes);
1766 }
1767
1768
1769 static void
1770 dtls1_clear_timeouts(SSL *s)
1771 {
1772 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1773 }
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