Import of openssl-0.9.8, a feature release.
[dragonfly.git] / crypto / openssl-0.9 / ssl / d1_pkt.c
CommitLineData
56276539
SS
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
124static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
125 int len, int peek);
126static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
127 PQ_64BIT *seq_num);
128static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
129static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
130 unsigned int *is_next_epoch);
131#if 0
132static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
133 unsigned short *priority, unsigned long *offset);
134#endif
135static int dtls1_buffer_record(SSL *s, record_pqueue *q,
136 PQ_64BIT priority);
137static int dtls1_process_record(SSL *s);
138#if PQ_64BIT_IS_INTEGER
139static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);
140#endif
141static void dtls1_clear_timeouts(SSL *s);
142
143/* copy buffered record into SSL structure */
144static int
145dtls1_copy_record(SSL *s, pitem *item)
146 {
147 DTLS1_RECORD_DATA *rdata;
148
149 rdata = (DTLS1_RECORD_DATA *)item->data;
150
151 if (s->s3->rbuf.buf != NULL)
152 OPENSSL_free(s->s3->rbuf.buf);
153
154 s->packet = rdata->packet;
155 s->packet_length = rdata->packet_length;
156 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
157 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
158
159 return(1);
160 }
161
162
163static int
164dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT priority)
165{
166 DTLS1_RECORD_DATA *rdata;
167 pitem *item;
168
169 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
170 item = pitem_new(priority, rdata);
171 if (rdata == NULL || item == NULL)
172 {
173 if (rdata != NULL) OPENSSL_free(rdata);
174 if (item != NULL) pitem_free(item);
175
176 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
177 return(0);
178 }
179
180 rdata->packet = s->packet;
181 rdata->packet_length = s->packet_length;
182 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
183 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
184
185 item->data = rdata;
186
187 /* insert should not fail, since duplicates are dropped */
188 if (pqueue_insert(queue->q, item) == NULL)
189 {
190 OPENSSL_free(rdata);
191 pitem_free(item);
192 return(0);
193 }
194
195 s->packet = NULL;
196 s->packet_length = 0;
197 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
198 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
199
200 ssl3_setup_buffers(s);
201
202 return(1);
203 }
204
205
206static int
207dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
208 {
209 pitem *item;
210
211 item = pqueue_pop(queue->q);
212 if (item)
213 {
214 dtls1_copy_record(s, item);
215
216 OPENSSL_free(item->data);
217 pitem_free(item);
218
219 return(1);
220 }
221
222 return(0);
223 }
224
225
226/* retrieve a buffered record that belongs to the new epoch, i.e., not processed
227 * yet */
228#define dtls1_get_unprocessed_record(s) \
229 dtls1_retrieve_buffered_record((s), \
230 &((s)->d1->unprocessed_rcds))
231
232/* retrieve a buffered record that belongs to the current epoch, ie, processed */
233#define dtls1_get_processed_record(s) \
234 dtls1_retrieve_buffered_record((s), \
235 &((s)->d1->processed_rcds))
236
237static int
238dtls1_process_buffered_records(SSL *s)
239 {
240 pitem *item;
241
242 item = pqueue_peek(s->d1->unprocessed_rcds.q);
243 if (item)
244 {
245 DTLS1_RECORD_DATA *rdata;
246 rdata = (DTLS1_RECORD_DATA *)item->data;
247
248 /* Check if epoch is current. */
249 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
250 return(1); /* Nothing to do. */
251
252 /* Process all the records. */
253 while (pqueue_peek(s->d1->unprocessed_rcds.q))
254 {
255 dtls1_get_unprocessed_record(s);
256 if ( ! dtls1_process_record(s))
257 return(0);
258 dtls1_buffer_record(s, &(s->d1->processed_rcds),
259 s->s3->rrec.seq_num);
260 }
261 }
262
263 /* sync epoch numbers once all the unprocessed records
264 * have been processed */
265 s->d1->processed_rcds.epoch = s->d1->r_epoch;
266 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
267
268 return(1);
269 }
270
271
272#if 0
273
274static int
275dtls1_get_buffered_record(SSL *s)
276 {
277 pitem *item;
278 PQ_64BIT priority =
279 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
280 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
281
282 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating,
283 nothing buffered */
284 return 0;
285
286
287 item = pqueue_peek(s->d1->rcvd_records);
288 if (item && item->priority == priority)
289 {
290 /* Check if we've received the record of interest. It must be
291 * a handshake record, since data records as passed up without
292 * buffering */
293 DTLS1_RECORD_DATA *rdata;
294 item = pqueue_pop(s->d1->rcvd_records);
295 rdata = (DTLS1_RECORD_DATA *)item->data;
296
297 if (s->s3->rbuf.buf != NULL)
298 OPENSSL_free(s->s3->rbuf.buf);
299
300 s->packet = rdata->packet;
301 s->packet_length = rdata->packet_length;
302 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
303 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
304
305 OPENSSL_free(item->data);
306 pitem_free(item);
307
308 /* s->d1->next_expected_seq_num++; */
309 return(1);
310 }
311
312 return 0;
313 }
314
315#endif
316
317static int
318dtls1_process_record(SSL *s)
319{
320 int i,al;
321 int clear=0;
322 int enc_err;
323 SSL_SESSION *sess;
324 SSL3_RECORD *rr;
325 unsigned int mac_size;
326 unsigned char md[EVP_MAX_MD_SIZE];
327
328
329 rr= &(s->s3->rrec);
330 sess = s->session;
331
332 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
333 * and we have that many bytes in s->packet
334 */
335 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
336
337 /* ok, we can now read from 's->packet' data into 'rr'
338 * rr->input points at rr->length bytes, which
339 * need to be copied into rr->data by either
340 * the decryption or by the decompression
341 * When the data is 'copied' into the rr->data buffer,
342 * rr->input will be pointed at the new buffer */
343
344 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
345 * rr->length bytes of encrypted compressed stuff. */
346
347 /* check is not needed I believe */
348 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
349 {
350 al=SSL_AD_RECORD_OVERFLOW;
351 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
352 goto f_err;
353 }
354
355 /* decrypt in place in 'rr->input' */
356 rr->data=rr->input;
357
358 enc_err = s->method->ssl3_enc->enc(s,0);
359 if (enc_err <= 0)
360 {
361 if (enc_err == 0)
362 /* SSLerr() and ssl3_send_alert() have been called */
363 goto err;
364
365 /* otherwise enc_err == -1 */
366 goto decryption_failed_or_bad_record_mac;
367 }
368
369#ifdef TLS_DEBUG
370printf("dec %d\n",rr->length);
371{ unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
372printf("\n");
373#endif
374
375 /* r->length is now the compressed data plus mac */
376if ( (sess == NULL) ||
377 (s->enc_read_ctx == NULL) ||
378 (s->read_hash == NULL))
379 clear=1;
380
381 if (!clear)
382 {
383 mac_size=EVP_MD_size(s->read_hash);
384
385 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
386 {
387#if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
388 al=SSL_AD_RECORD_OVERFLOW;
389 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
390 goto f_err;
391#else
392 goto decryption_failed_or_bad_record_mac;
393#endif
394 }
395 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
396 if (rr->length < mac_size)
397 {
398#if 0 /* OK only for stream ciphers */
399 al=SSL_AD_DECODE_ERROR;
400 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
401 goto f_err;
402#else
403 goto decryption_failed_or_bad_record_mac;
404#endif
405 }
406 rr->length-=mac_size;
407 i=s->method->ssl3_enc->mac(s,md,0);
408 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
409 {
410 goto decryption_failed_or_bad_record_mac;
411 }
412 }
413
414 /* r->length is now just compressed */
415 if (s->expand != NULL)
416 {
417 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
418 {
419 al=SSL_AD_RECORD_OVERFLOW;
420 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
421 goto f_err;
422 }
423 if (!ssl3_do_uncompress(s))
424 {
425 al=SSL_AD_DECOMPRESSION_FAILURE;
426 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
427 goto f_err;
428 }
429 }
430
431 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
432 {
433 al=SSL_AD_RECORD_OVERFLOW;
434 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
435 goto f_err;
436 }
437
438 rr->off=0;
439 /* So at this point the following is true
440 * ssl->s3->rrec.type is the type of record
441 * ssl->s3->rrec.length == number of bytes in record
442 * ssl->s3->rrec.off == offset to first valid byte
443 * ssl->s3->rrec.data == where to take bytes from, increment
444 * after use :-).
445 */
446
447 /* we have pulled in a full packet so zero things */
448 s->packet_length=0;
449 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
450 return(1);
451
452decryption_failed_or_bad_record_mac:
453 /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
454 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
455 * failure is directly visible from the ciphertext anyway,
456 * we should not reveal which kind of error occured -- this
457 * might become visible to an attacker (e.g. via logfile) */
458 al=SSL_AD_BAD_RECORD_MAC;
459 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
460f_err:
461 ssl3_send_alert(s,SSL3_AL_FATAL,al);
462err:
463 return(0);
464}
465
466
467/* Call this to get a new input record.
468 * It will return <= 0 if more data is needed, normally due to an error
469 * or non-blocking IO.
470 * When it finishes, one packet has been decoded and can be found in
471 * ssl->s3->rrec.type - is the type of record
472 * ssl->s3->rrec.data, - data
473 * ssl->s3->rrec.length, - number of bytes
474 */
475/* used only by dtls1_read_bytes */
476int dtls1_get_record(SSL *s)
477 {
478 int ssl_major,ssl_minor,al;
479 int i,n;
480 SSL3_RECORD *rr;
481 SSL_SESSION *sess;
482 unsigned char *p;
483 short version;
484 DTLS1_BITMAP *bitmap;
485 unsigned int is_next_epoch;
486
487 rr= &(s->s3->rrec);
488 sess=s->session;
489
490 /* The epoch may have changed. If so, process all the
491 * pending records. This is a non-blocking operation. */
492 if ( ! dtls1_process_buffered_records(s))
493 return 0;
494
495 /* if we're renegotiating, then there may be buffered records */
496 if (dtls1_get_processed_record(s))
497 return 1;
498
499 /* get something from the wire */
500again:
501 /* check if we have the header */
502 if ( (s->rstate != SSL_ST_READ_BODY) ||
503 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
504 {
505 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
506 /* read timeout is handled by dtls1_read_bytes */
507 if (n <= 0) return(n); /* error or non-blocking */
508
509 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
510
511 s->rstate=SSL_ST_READ_BODY;
512
513 p=s->packet;
514
515 /* Pull apart the header into the DTLS1_RECORD */
516 rr->type= *(p++);
517 ssl_major= *(p++);
518 ssl_minor= *(p++);
519 version=(ssl_major<<8)|ssl_minor;
520
521 /* sequence number is 64 bits, with top 2 bytes = epoch */
522 n2s(p,rr->epoch);
523
524 memcpy(&(s->s3->read_sequence[2]), p, 6);
525 p+=6;
526
527 n2s(p,rr->length);
528
529 /* Lets check version */
530 if (s->first_packet)
531 {
532 s->first_packet=0;
533 }
534 else
535 {
536 if (version != s->version)
537 {
538 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
539 /* Send back error using their
540 * version number :-) */
541 s->version=version;
542 al=SSL_AD_PROTOCOL_VERSION;
543 goto f_err;
544 }
545 }
546
547 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
548 {
549 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
550 goto err;
551 }
552
553 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
554 {
555 al=SSL_AD_RECORD_OVERFLOW;
556 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
557 goto f_err;
558 }
559
560 /* now s->rstate == SSL_ST_READ_BODY */
561 }
562
563 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
564
565 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
566 {
567 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
568 i=rr->length;
569 n=ssl3_read_n(s,i,i,1);
570 if (n <= 0) return(n); /* error or non-blocking io */
571
572 /* this packet contained a partial record, dump it */
573 if ( n != i)
574 {
575 s->packet_length = 0;
576 goto again;
577 }
578
579 /* now n == rr->length,
580 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
581 }
582 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
583
584 /* match epochs. NULL means the packet is dropped on the floor */
585 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
586 if ( bitmap == NULL)
587 {
588 s->packet_length = 0; /* dump this record */
589 goto again; /* get another record */
590 }
591
592 /* check whether this is a repeat, or aged record */
593 if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
594 {
595 s->packet_length=0; /* dump this record */
596 goto again; /* get another record */
597 }
598
599 /* just read a 0 length packet */
600 if (rr->length == 0) goto again;
601
602 /* If this record is from the next epoch (either HM or ALERT), buffer it
603 * since it cannot be processed at this time.
604 * Records from the next epoch are marked as received even though they are
605 * not processed, so as to prevent any potential resource DoS attack */
606 if (is_next_epoch)
607 {
608 dtls1_record_bitmap_update(s, bitmap);
609 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
610 s->packet_length = 0;
611 goto again;
612 }
613
614 if ( ! dtls1_process_record(s))
615 return(0);
616
617 dtls1_clear_timeouts(s); /* done waiting */
618 return(1);
619
620f_err:
621 ssl3_send_alert(s,SSL3_AL_FATAL,al);
622err:
623 return(0);
624 }
625
626/* Return up to 'len' payload bytes received in 'type' records.
627 * 'type' is one of the following:
628 *
629 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
630 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
631 * - 0 (during a shutdown, no data has to be returned)
632 *
633 * If we don't have stored data to work from, read a SSL/TLS record first
634 * (possibly multiple records if we still don't have anything to return).
635 *
636 * This function must handle any surprises the peer may have for us, such as
637 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
638 * a surprise, but handled as if it were), or renegotiation requests.
639 * Also if record payloads contain fragments too small to process, we store
640 * them until there is enough for the respective protocol (the record protocol
641 * may use arbitrary fragmentation and even interleaving):
642 * Change cipher spec protocol
643 * just 1 byte needed, no need for keeping anything stored
644 * Alert protocol
645 * 2 bytes needed (AlertLevel, AlertDescription)
646 * Handshake protocol
647 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
648 * to detect unexpected Client Hello and Hello Request messages
649 * here, anything else is handled by higher layers
650 * Application data protocol
651 * none of our business
652 */
653int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
654 {
655 int al,i,j,ret;
656 unsigned int n;
657 SSL3_RECORD *rr;
658 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
659
660 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
661 if (!ssl3_setup_buffers(s))
662 return(-1);
663
664 /* XXX: check what the second '&& type' is about */
665 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
666 (type != SSL3_RT_HANDSHAKE) && type) ||
667 (peek && (type != SSL3_RT_APPLICATION_DATA)))
668 {
669 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
670 return -1;
671 }
672
673 /* check whether there's a handshake message (client hello?) waiting */
674 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
675 return ret;
676
677 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
678
679 if (!s->in_handshake && SSL_in_init(s))
680 {
681 /* type == SSL3_RT_APPLICATION_DATA */
682 i=s->handshake_func(s);
683 if (i < 0) return(i);
684 if (i == 0)
685 {
686 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
687 return(-1);
688 }
689 }
690
691start:
692 s->rwstate=SSL_NOTHING;
693
694 /* s->s3->rrec.type - is the type of record
695 * s->s3->rrec.data, - data
696 * s->s3->rrec.off, - offset into 'data' for next read
697 * s->s3->rrec.length, - number of bytes. */
698 rr = &(s->s3->rrec);
699
700 /* get new packet if necessary */
701 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
702 {
703 ret=dtls1_get_record(s);
704 if (ret <= 0)
705 {
706 ret = dtls1_read_failed(s, ret);
707 /* anything other than a timeout is an error */
708 if (ret <= 0)
709 return(ret);
710 else
711 goto start;
712 }
713 }
714
715 /* we now have a packet which can be read and processed */
716
717 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
718 * reset by ssl3_get_finished */
719 && (rr->type != SSL3_RT_HANDSHAKE))
720 {
721 al=SSL_AD_UNEXPECTED_MESSAGE;
722 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
723 goto err;
724 }
725
726 /* If the other end has shut down, throw anything we read away
727 * (even in 'peek' mode) */
728 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
729 {
730 rr->length=0;
731 s->rwstate=SSL_NOTHING;
732 return(0);
733 }
734
735
736 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
737 {
738 /* make sure that we are not getting application data when we
739 * are doing a handshake for the first time */
740 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
741 (s->enc_read_ctx == NULL))
742 {
743 al=SSL_AD_UNEXPECTED_MESSAGE;
744 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
745 goto f_err;
746 }
747
748 if (len <= 0) return(len);
749
750 if ((unsigned int)len > rr->length)
751 n = rr->length;
752 else
753 n = (unsigned int)len;
754
755 memcpy(buf,&(rr->data[rr->off]),n);
756 if (!peek)
757 {
758 rr->length-=n;
759 rr->off+=n;
760 if (rr->length == 0)
761 {
762 s->rstate=SSL_ST_READ_HEADER;
763 rr->off=0;
764 }
765 }
766 return(n);
767 }
768
769
770 /* If we get here, then type != rr->type; if we have a handshake
771 * message, then it was unexpected (Hello Request or Client Hello). */
772
773 /* In case of record types for which we have 'fragment' storage,
774 * fill that so that we can process the data at a fixed place.
775 */
776 {
777 unsigned int k, dest_maxlen = 0;
778 unsigned char *dest = NULL;
779 unsigned int *dest_len = NULL;
780
781 if (rr->type == SSL3_RT_HANDSHAKE)
782 {
783 dest_maxlen = sizeof s->d1->handshake_fragment;
784 dest = s->d1->handshake_fragment;
785 dest_len = &s->d1->handshake_fragment_len;
786 }
787 else if (rr->type == SSL3_RT_ALERT)
788 {
789 dest_maxlen = sizeof(s->d1->alert_fragment);
790 dest = s->d1->alert_fragment;
791 dest_len = &s->d1->alert_fragment_len;
792 }
793 else /* else it's a CCS message */
794 OPENSSL_assert(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC);
795
796
797 if (dest_maxlen > 0)
798 {
799 /* XDTLS: In a pathalogical case, the Client Hello
800 * may be fragmented--don't always expect dest_maxlen bytes */
801 if ( rr->length < dest_maxlen)
802 {
803 s->rstate=SSL_ST_READ_HEADER;
804 rr->length = 0;
805 goto start;
806 }
807
808 /* now move 'n' bytes: */
809 for ( k = 0; k < dest_maxlen; k++)
810 {
811 dest[k] = rr->data[rr->off++];
812 rr->length--;
813 }
814 *dest_len = dest_maxlen;
815 }
816 }
817
818 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
819 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
820 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
821
822 /* If we are a client, check for an incoming 'Hello Request': */
823 if ((!s->server) &&
824 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
825 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
826 (s->session != NULL) && (s->session->cipher != NULL))
827 {
828 s->d1->handshake_fragment_len = 0;
829
830 if ((s->d1->handshake_fragment[1] != 0) ||
831 (s->d1->handshake_fragment[2] != 0) ||
832 (s->d1->handshake_fragment[3] != 0))
833 {
834 al=SSL_AD_DECODE_ERROR;
835 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
836 goto err;
837 }
838
839 /* no need to check sequence number on HELLO REQUEST messages */
840
841 if (s->msg_callback)
842 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
843 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
844
845 if (SSL_is_init_finished(s) &&
846 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
847 !s->s3->renegotiate)
848 {
849 ssl3_renegotiate(s);
850 if (ssl3_renegotiate_check(s))
851 {
852 i=s->handshake_func(s);
853 if (i < 0) return(i);
854 if (i == 0)
855 {
856 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
857 return(-1);
858 }
859
860 if (!(s->mode & SSL_MODE_AUTO_RETRY))
861 {
862 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
863 {
864 BIO *bio;
865 /* In the case where we try to read application data,
866 * but we trigger an SSL handshake, we return -1 with
867 * the retry option set. Otherwise renegotiation may
868 * cause nasty problems in the blocking world */
869 s->rwstate=SSL_READING;
870 bio=SSL_get_rbio(s);
871 BIO_clear_retry_flags(bio);
872 BIO_set_retry_read(bio);
873 return(-1);
874 }
875 }
876 }
877 }
878 /* we either finished a handshake or ignored the request,
879 * now try again to obtain the (application) data we were asked for */
880 goto start;
881 }
882
883 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
884 {
885 int alert_level = s->d1->alert_fragment[0];
886 int alert_descr = s->d1->alert_fragment[1];
887
888 s->d1->alert_fragment_len = 0;
889
890 if (s->msg_callback)
891 s->msg_callback(0, s->version, SSL3_RT_ALERT,
892 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
893
894 if (s->info_callback != NULL)
895 cb=s->info_callback;
896 else if (s->ctx->info_callback != NULL)
897 cb=s->ctx->info_callback;
898
899 if (cb != NULL)
900 {
901 j = (alert_level << 8) | alert_descr;
902 cb(s, SSL_CB_READ_ALERT, j);
903 }
904
905 if (alert_level == 1) /* warning */
906 {
907 s->s3->warn_alert = alert_descr;
908 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
909 {
910 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
911 return(0);
912 }
913#if 0
914 /* XXX: this is a possible improvement in the future */
915 /* now check if it's a missing record */
916 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
917 {
918 unsigned short seq;
919 unsigned int frag_off;
920 unsigned char *p = &(s->d1->alert_fragment[2]);
921
922 n2s(p, seq);
923 n2l3(p, frag_off);
924
925 dtls1_retransmit_message(s, seq, frag_off, &found);
926 if ( ! found && SSL_in_init(s))
927 {
928 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
929 /* requested a message not yet sent,
930 send an alert ourselves */
931 ssl3_send_alert(s,SSL3_AL_WARNING,
932 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
933 }
934 }
935#endif
936 }
937 else if (alert_level == 2) /* fatal */
938 {
939 char tmp[16];
940
941 s->rwstate=SSL_NOTHING;
942 s->s3->fatal_alert = alert_descr;
943 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
944 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
945 ERR_add_error_data(2,"SSL alert number ",tmp);
946 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
947 SSL_CTX_remove_session(s->ctx,s->session);
948 return(0);
949 }
950 else
951 {
952 al=SSL_AD_ILLEGAL_PARAMETER;
953 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
954 goto f_err;
955 }
956
957 goto start;
958 }
959
960 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
961 {
962 s->rwstate=SSL_NOTHING;
963 rr->length=0;
964 return(0);
965 }
966
967 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
968 {
969 struct ccs_header_st ccs_hdr;
970
971 dtls1_get_ccs_header(rr->data, &ccs_hdr);
972
973 if ( ccs_hdr.seq == s->d1->handshake_read_seq)
974 {
975 /* 'Change Cipher Spec' is just a single byte, so we know
976 * exactly what the record payload has to look like */
977 /* XDTLS: check that epoch is consistent */
978 if ( (rr->length != DTLS1_CCS_HEADER_LENGTH) ||
979 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
980 {
981 i=SSL_AD_ILLEGAL_PARAMETER;
982 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
983 goto err;
984 }
985
986 rr->length=0;
987
988 if (s->msg_callback)
989 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
990 rr->data, 1, s, s->msg_callback_arg);
991
992 s->s3->change_cipher_spec=1;
993 if (!ssl3_do_change_cipher_spec(s))
994 goto err;
995
996 /* do this whenever CCS is processed */
997 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
998
999 /* handshake read seq is reset upon handshake completion */
1000 s->d1->handshake_read_seq++;
1001
1002 goto start;
1003 }
1004 else
1005 {
1006 rr->length = 0;
1007 goto start;
1008 }
1009 }
1010
1011 /* Unexpected handshake message (Client Hello, or protocol violation) */
1012 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1013 !s->in_handshake)
1014 {
1015 struct hm_header_st msg_hdr;
1016
1017 /* this may just be a stale retransmit */
1018 dtls1_get_message_header(rr->data, &msg_hdr);
1019 if( rr->epoch != s->d1->r_epoch)
1020 {
1021 rr->length = 0;
1022 goto start;
1023 }
1024
1025 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1026 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1027 {
1028#if 0 /* worked only because C operator preferences are not as expected (and
1029 * because this is not really needed for clients except for detecting
1030 * protocol violations): */
1031 s->state=SSL_ST_BEFORE|(s->server)
1032 ?SSL_ST_ACCEPT
1033 :SSL_ST_CONNECT;
1034#else
1035 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1036#endif
1037 s->new_session=1;
1038 }
1039 i=s->handshake_func(s);
1040 if (i < 0) return(i);
1041 if (i == 0)
1042 {
1043 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1044 return(-1);
1045 }
1046
1047 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1048 {
1049 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1050 {
1051 BIO *bio;
1052 /* In the case where we try to read application data,
1053 * but we trigger an SSL handshake, we return -1 with
1054 * the retry option set. Otherwise renegotiation may
1055 * cause nasty problems in the blocking world */
1056 s->rwstate=SSL_READING;
1057 bio=SSL_get_rbio(s);
1058 BIO_clear_retry_flags(bio);
1059 BIO_set_retry_read(bio);
1060 return(-1);
1061 }
1062 }
1063 goto start;
1064 }
1065
1066 switch (rr->type)
1067 {
1068 default:
1069#ifndef OPENSSL_NO_TLS
1070 /* TLS just ignores unknown message types */
1071 if (s->version == TLS1_VERSION)
1072 {
1073 rr->length = 0;
1074 goto start;
1075 }
1076#endif
1077 al=SSL_AD_UNEXPECTED_MESSAGE;
1078 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1079 goto f_err;
1080 case SSL3_RT_CHANGE_CIPHER_SPEC:
1081 case SSL3_RT_ALERT:
1082 case SSL3_RT_HANDSHAKE:
1083 /* we already handled all of these, with the possible exception
1084 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1085 * should not happen when type != rr->type */
1086 al=SSL_AD_UNEXPECTED_MESSAGE;
1087 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1088 goto f_err;
1089 case SSL3_RT_APPLICATION_DATA:
1090 /* At this point, we were expecting handshake data,
1091 * but have application data. If the library was
1092 * running inside ssl3_read() (i.e. in_read_app_data
1093 * is set) and it makes sense to read application data
1094 * at this point (session renegotiation not yet started),
1095 * we will indulge it.
1096 */
1097 if (s->s3->in_read_app_data &&
1098 (s->s3->total_renegotiations != 0) &&
1099 ((
1100 (s->state & SSL_ST_CONNECT) &&
1101 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1102 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1103 ) || (
1104 (s->state & SSL_ST_ACCEPT) &&
1105 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1106 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1107 )
1108 ))
1109 {
1110 s->s3->in_read_app_data=2;
1111 return(-1);
1112 }
1113 else
1114 {
1115 al=SSL_AD_UNEXPECTED_MESSAGE;
1116 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1117 goto f_err;
1118 }
1119 }
1120 /* not reached */
1121
1122f_err:
1123 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1124err:
1125 return(-1);
1126 }
1127
1128int
1129dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1130 {
1131 unsigned int n,tot;
1132 int i;
1133
1134 if (SSL_in_init(s) && !s->in_handshake)
1135 {
1136 i=s->handshake_func(s);
1137 if (i < 0) return(i);
1138 if (i == 0)
1139 {
1140 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1141 return -1;
1142 }
1143 }
1144
1145 tot = s->s3->wnum;
1146 n = len - tot;
1147
1148 while( n)
1149 {
1150 /* dtls1_write_bytes sends one record at a time, sized according to
1151 * the currently known MTU */
1152 i = dtls1_write_bytes(s, type, buf_, len);
1153 if (i <= 0) return i;
1154
1155 if ((i == (int)n) ||
1156 (type == SSL3_RT_APPLICATION_DATA &&
1157 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1158 {
1159 /* next chunk of data should get another prepended empty fragment
1160 * in ciphersuites with known-IV weakness: */
1161 s->s3->empty_fragment_done = 0;
1162 return tot+i;
1163 }
1164
1165 tot += i;
1166 n-=i;
1167 }
1168
1169 return tot;
1170 }
1171
1172
1173 /* this only happens when a client hello is received and a handshake
1174 * is started. */
1175static int
1176have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1177 int len, int peek)
1178 {
1179
1180 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1181 /* (partially) satisfy request from storage */
1182 {
1183 unsigned char *src = s->d1->handshake_fragment;
1184 unsigned char *dst = buf;
1185 unsigned int k,n;
1186
1187 /* peek == 0 */
1188 n = 0;
1189 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1190 {
1191 *dst++ = *src++;
1192 len--; s->d1->handshake_fragment_len--;
1193 n++;
1194 }
1195 /* move any remaining fragment bytes: */
1196 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1197 s->d1->handshake_fragment[k] = *src++;
1198 return n;
1199 }
1200
1201 return 0;
1202 }
1203
1204
1205
1206
1207/* Call this to write data in records of type 'type'
1208 * It will return <= 0 if not all data has been sent or non-blocking IO.
1209 */
1210int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1211 {
1212 const unsigned char *buf=buf_;
1213 unsigned int tot,n,nw;
1214 int i;
1215 unsigned int mtu;
1216
1217 s->rwstate=SSL_NOTHING;
1218 tot=s->s3->wnum;
1219
1220 n=(len-tot);
1221
1222 /* handshake layer figures out MTU for itself, but data records
1223 * are also sent through this interface, so need to figure out MTU */
1224#if 0
1225 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1226 mtu += DTLS1_HM_HEADER_LENGTH; /* HM already inserted */
1227#endif
1228 mtu = s->d1->mtu;
1229
1230 if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1231 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1232
1233 if (n > mtu)
1234 nw=mtu;
1235 else
1236 nw=n;
1237
1238 i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1239 if (i <= 0)
1240 {
1241 s->s3->wnum=tot;
1242 return i;
1243 }
1244
1245 if ( (int)s->s3->wnum + i == len)
1246 s->s3->wnum = 0;
1247 else
1248 s->s3->wnum += i;
1249
1250 return tot + i;
1251 }
1252
1253int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1254 {
1255 unsigned char *p,*pseq;
1256 int i,mac_size,clear=0;
1257 int prefix_len = 0;
1258 SSL3_RECORD *wr;
1259 SSL3_BUFFER *wb;
1260 SSL_SESSION *sess;
1261 int bs;
1262
1263 /* first check if there is a SSL3_BUFFER still being written
1264 * out. This will happen with non blocking IO */
1265 if (s->s3->wbuf.left != 0)
1266 {
1267 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1268 return(ssl3_write_pending(s,type,buf,len));
1269 }
1270
1271 /* If we have an alert to send, lets send it */
1272 if (s->s3->alert_dispatch)
1273 {
1274 i=s->method->ssl_dispatch_alert(s);
1275 if (i <= 0)
1276 return(i);
1277 /* if it went, fall through and send more stuff */
1278 }
1279
1280 if (len == 0 && !create_empty_fragment)
1281 return 0;
1282
1283 wr= &(s->s3->wrec);
1284 wb= &(s->s3->wbuf);
1285 sess=s->session;
1286
1287 if ( (sess == NULL) ||
1288 (s->enc_write_ctx == NULL) ||
1289 (s->write_hash == NULL))
1290 clear=1;
1291
1292 if (clear)
1293 mac_size=0;
1294 else
1295 mac_size=EVP_MD_size(s->write_hash);
1296
1297 /* DTLS implements explicit IV, so no need for empty fragments */
1298#if 0
1299 /* 'create_empty_fragment' is true only when this function calls itself */
1300 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1301 && SSL_version(s) != DTLS1_VERSION)
1302 {
1303 /* countermeasure against known-IV weakness in CBC ciphersuites
1304 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1305 */
1306
1307 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1308 {
1309 /* recursive function call with 'create_empty_fragment' set;
1310 * this prepares and buffers the data for an empty fragment
1311 * (these 'prefix_len' bytes are sent out later
1312 * together with the actual payload) */
1313 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1314 if (prefix_len <= 0)
1315 goto err;
1316
1317 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1318 {
1319 /* insufficient space */
1320 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1321 goto err;
1322 }
1323 }
1324
1325 s->s3->empty_fragment_done = 1;
1326 }
1327#endif
1328
1329 p = wb->buf + prefix_len;
1330
1331 /* write the header */
1332
1333 *(p++)=type&0xff;
1334 wr->type=type;
1335
1336 *(p++)=(s->version>>8);
1337 *(p++)=s->version&0xff;
1338
1339 /* field where we are to write out packet epoch, seq num and len */
1340 pseq=p;
1341 p+=10;
1342
1343 /* lets setup the record stuff. */
1344
1345 /* Make space for the explicit IV in case of CBC.
1346 * (this is a bit of a boundary violation, but what the heck).
1347 */
1348 if ( s->enc_write_ctx &&
1349 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1350 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1351 else
1352 bs = 0;
1353
1354 wr->data=p + bs; /* make room for IV in case of CBC */
1355 wr->length=(int)len;
1356 wr->input=(unsigned char *)buf;
1357
1358 /* we now 'read' from wr->input, wr->length bytes into
1359 * wr->data */
1360
1361 /* first we compress */
1362 if (s->compress != NULL)
1363 {
1364 if (!ssl3_do_compress(s))
1365 {
1366 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1367 goto err;
1368 }
1369 }
1370 else
1371 {
1372 memcpy(wr->data,wr->input,wr->length);
1373 wr->input=wr->data;
1374 }
1375
1376 /* we should still have the output to wr->data and the input
1377 * from wr->input. Length should be wr->length.
1378 * wr->data still points in the wb->buf */
1379
1380 if (mac_size != 0)
1381 {
1382 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1383 wr->length+=mac_size;
1384 }
1385
1386 /* this is true regardless of mac size */
1387 wr->input=p;
1388 wr->data=p;
1389
1390
1391 /* ssl3_enc can only have an error on read */
1392 wr->length += bs; /* bs != 0 in case of CBC. The enc fn provides
1393 * the randomness */
1394 s->method->ssl3_enc->enc(s,1);
1395
1396 /* record length after mac and block padding */
1397/* if (type == SSL3_RT_APPLICATION_DATA ||
1398 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1399
1400 /* there's only one epoch between handshake and app data */
1401
1402 s2n(s->d1->w_epoch, pseq);
1403
1404 /* XDTLS: ?? */
1405/* else
1406 s2n(s->d1->handshake_epoch, pseq); */
1407
1408 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1409 pseq+=6;
1410 s2n(wr->length,pseq);
1411
1412 /* we should now have
1413 * wr->data pointing to the encrypted data, which is
1414 * wr->length long */
1415 wr->type=type; /* not needed but helps for debugging */
1416 wr->length+=DTLS1_RT_HEADER_LENGTH;
1417
1418#if 0 /* this is now done at the message layer */
1419 /* buffer the record, making it easy to handle retransmits */
1420 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1421 dtls1_buffer_record(s, wr->data, wr->length,
1422 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1423#endif
1424
1425 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1426
1427 if (create_empty_fragment)
1428 {
1429 /* we are in a recursive call;
1430 * just return the length, don't write out anything here
1431 */
1432 return wr->length;
1433 }
1434
1435 /* now let's set up wb */
1436 wb->left = prefix_len + wr->length;
1437 wb->offset = 0;
1438
1439 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1440 s->s3->wpend_tot=len;
1441 s->s3->wpend_buf=buf;
1442 s->s3->wpend_type=type;
1443 s->s3->wpend_ret=len;
1444
1445 /* we now just need to write the buffer */
1446 return ssl3_write_pending(s,type,buf,len);
1447err:
1448 return -1;
1449 }
1450
1451
1452
1453static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1454 PQ_64BIT *seq_num)
1455 {
1456#if PQ_64BIT_IS_INTEGER
1457 PQ_64BIT mask = 0x0000000000000001L;
1458#endif
1459 PQ_64BIT rcd_num, tmp;
1460
1461 pq_64bit_init(&rcd_num);
1462 pq_64bit_init(&tmp);
1463
1464 /* this is the sequence number for the record just read */
1465 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1466
1467
1468 if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1469 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1470 {
1471 pq_64bit_assign(seq_num, &rcd_num);
1472 pq_64bit_free(&rcd_num);
1473 pq_64bit_free(&tmp);
1474 return 1; /* this record is new */
1475 }
1476
1477 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1478
1479 if ( pq_64bit_get_word(&tmp) > bitmap->length)
1480 {
1481 pq_64bit_free(&rcd_num);
1482 pq_64bit_free(&tmp);
1483 return 0; /* stale, outside the window */
1484 }
1485
1486#if PQ_64BIT_IS_BIGNUM
1487 {
1488 int offset;
1489 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1490 pq_64bit_sub_word(&tmp, 1);
1491 offset = pq_64bit_get_word(&tmp);
1492 if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1493 {
1494 pq_64bit_free(&rcd_num);
1495 pq_64bit_free(&tmp);
1496 return 0;
1497 }
1498 }
1499#else
1500 mask <<= (bitmap->max_seq_num - rcd_num - 1);
1501 if (bitmap->map & mask)
1502 return 0; /* record previously received */
1503#endif
1504
1505 pq_64bit_assign(seq_num, &rcd_num);
1506 pq_64bit_free(&rcd_num);
1507 pq_64bit_free(&tmp);
1508 return 1;
1509 }
1510
1511
1512static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1513 {
1514 unsigned int shift;
1515 PQ_64BIT rcd_num;
1516 PQ_64BIT tmp;
1517 PQ_64BIT_CTX *ctx;
1518
1519 pq_64bit_init(&rcd_num);
1520 pq_64bit_init(&tmp);
1521
1522 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1523
1524 /* unfortunate code complexity due to 64-bit manipulation support
1525 * on 32-bit machines */
1526 if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1527 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1528 {
1529 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1530 pq_64bit_add_word(&tmp, 1);
1531
1532 shift = (unsigned int)pq_64bit_get_word(&tmp);
1533
1534 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1535 pq_64bit_assign(&(bitmap->map), &tmp);
1536
1537 pq_64bit_set_bit(&(bitmap->map), 0);
1538 pq_64bit_add_word(&rcd_num, 1);
1539 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1540
1541 pq_64bit_assign_word(&tmp, 1);
1542 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1543 ctx = pq_64bit_ctx_new(&ctx);
1544 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1545 pq_64bit_ctx_free(ctx);
1546 }
1547 else
1548 {
1549 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1550 pq_64bit_sub_word(&tmp, 1);
1551 shift = (unsigned int)pq_64bit_get_word(&tmp);
1552
1553 pq_64bit_set_bit(&(bitmap->map), shift);
1554 }
1555
1556 pq_64bit_free(&rcd_num);
1557 pq_64bit_free(&tmp);
1558 }
1559
1560
1561int dtls1_dispatch_alert(SSL *s)
1562 {
1563 int i,j;
1564 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1565 unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1566 unsigned char *ptr = &buf[0];
1567
1568 s->s3->alert_dispatch=0;
1569
1570 memset(buf, 0x00, sizeof(buf));
1571 *ptr++ = s->s3->send_alert[0];
1572 *ptr++ = s->s3->send_alert[1];
1573
1574 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1575 {
1576 s2n(s->d1->handshake_read_seq, ptr);
1577#if 0
1578 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1579
1580 else
1581 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1582#endif
1583
1584#if 0
1585 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);
1586#endif
1587 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1588 }
1589
1590 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1591 if (i <= 0)
1592 {
1593 s->s3->alert_dispatch=1;
1594 /* fprintf( stderr, "not done with alert\n" ); */
1595 }
1596 else
1597 {
1598 if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||
1599 s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1600 (void)BIO_flush(s->wbio);
1601
1602 if (s->msg_callback)
1603 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1604 2, s, s->msg_callback_arg);
1605
1606 if (s->info_callback != NULL)
1607 cb=s->info_callback;
1608 else if (s->ctx->info_callback != NULL)
1609 cb=s->ctx->info_callback;
1610
1611 if (cb != NULL)
1612 {
1613 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1614 cb(s,SSL_CB_WRITE_ALERT,j);
1615 }
1616 }
1617 return(i);
1618 }
1619
1620
1621static DTLS1_BITMAP *
1622dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1623 {
1624
1625 *is_next_epoch = 0;
1626
1627 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1628 if (rr->epoch == s->d1->r_epoch)
1629 return &s->d1->bitmap;
1630
1631 /* Only HM and ALERT messages can be from the next epoch */
1632 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1633 (rr->type == SSL3_RT_HANDSHAKE ||
1634 rr->type == SSL3_RT_ALERT))
1635 {
1636 *is_next_epoch = 1;
1637 return &s->d1->next_bitmap;
1638 }
1639
1640 return NULL;
1641 }
1642
1643#if 0
1644static int
1645dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1646 unsigned long *offset)
1647 {
1648
1649 /* alerts are passed up immediately */
1650 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1651 rr->type == SSL3_RT_ALERT)
1652 return 0;
1653
1654 /* Only need to buffer if a handshake is underway.
1655 * (this implies that Hello Request and Client Hello are passed up
1656 * immediately) */
1657 if ( SSL_in_init(s))
1658 {
1659 unsigned char *data = rr->data;
1660 /* need to extract the HM/CCS sequence number here */
1661 if ( rr->type == SSL3_RT_HANDSHAKE ||
1662 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1663 {
1664 unsigned short seq_num;
1665 struct hm_header_st msg_hdr;
1666 struct ccs_header_st ccs_hdr;
1667
1668 if ( rr->type == SSL3_RT_HANDSHAKE)
1669 {
1670 dtls1_get_message_header(data, &msg_hdr);
1671 seq_num = msg_hdr.seq;
1672 *offset = msg_hdr.frag_off;
1673 }
1674 else
1675 {
1676 dtls1_get_ccs_header(data, &ccs_hdr);
1677 seq_num = ccs_hdr.seq;
1678 *offset = 0;
1679 }
1680
1681 /* this is either a record we're waiting for, or a
1682 * retransmit of something we happened to previously
1683 * receive (higher layers will drop the repeat silently */
1684 if ( seq_num < s->d1->handshake_read_seq)
1685 return 0;
1686 if (rr->type == SSL3_RT_HANDSHAKE &&
1687 seq_num == s->d1->handshake_read_seq &&
1688 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1689 return 0;
1690 else if ( seq_num == s->d1->handshake_read_seq &&
1691 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1692 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1693 return 0;
1694 else
1695 {
1696 *priority = seq_num;
1697 return 1;
1698 }
1699 }
1700 else /* unknown record type */
1701 return 0;
1702 }
1703
1704 return 0;
1705 }
1706#endif
1707
1708void
1709dtls1_reset_seq_numbers(SSL *s, int rw)
1710 {
1711 unsigned char *seq;
1712 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1713
1714 if ( rw & SSL3_CC_READ)
1715 {
1716 seq = s->s3->read_sequence;
1717 s->d1->r_epoch++;
1718
1719 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1720 s->d1->bitmap.length = s->d1->next_bitmap.length;
1721 pq_64bit_assign(&(s->d1->bitmap.max_seq_num),
1722 &(s->d1->next_bitmap.max_seq_num));
1723
1724 pq_64bit_free(&(s->d1->next_bitmap.map));
1725 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1726 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1727 pq_64bit_init(&(s->d1->next_bitmap.map));
1728 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1729 }
1730 else
1731 {
1732 seq = s->s3->write_sequence;
1733 s->d1->w_epoch++;
1734 }
1735
1736 memset(seq, 0x00, seq_bytes);
1737 }
1738
1739#if PQ_64BIT_IS_INTEGER
1740static PQ_64BIT
1741bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1742 {
1743 PQ_64BIT _num;
1744
1745 _num = (((PQ_64BIT)bytes[0]) << 56) |
1746 (((PQ_64BIT)bytes[1]) << 48) |
1747 (((PQ_64BIT)bytes[2]) << 40) |
1748 (((PQ_64BIT)bytes[3]) << 32) |
1749 (((PQ_64BIT)bytes[4]) << 24) |
1750 (((PQ_64BIT)bytes[5]) << 16) |
1751 (((PQ_64BIT)bytes[6]) << 8) |
1752 (((PQ_64BIT)bytes[7]) );
1753
1754 *num = _num ;
1755 return _num;
1756 }
1757#endif
1758
1759
1760static void
1761dtls1_clear_timeouts(SSL *s)
1762 {
1763 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1764 }