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A forgotten module...
[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 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
126 int len, int peek);
127 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
128 PQ_64BIT *seq_num);
129 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
130 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
131 unsigned int *is_next_epoch);
132 #if 0
133 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
134 unsigned short *priority, unsigned long *offset);
135 #endif
136 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
137 PQ_64BIT priority);
138 static int dtls1_process_record(SSL *s);
139 #if PQ_64BIT_IS_INTEGER
140 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);
141 #endif
142 static void dtls1_clear_timeouts(SSL *s);
143
144 /* copy buffered record into SSL structure */
145 static int
146 dtls1_copy_record(SSL *s, pitem *item)
147 {
148 DTLS1_RECORD_DATA *rdata;
149
150 rdata = (DTLS1_RECORD_DATA *)item->data;
151
152 if (s->s3->rbuf.buf != NULL)
153 OPENSSL_free(s->s3->rbuf.buf);
154
155 s->packet = rdata->packet;
156 s->packet_length = rdata->packet_length;
157 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
158 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
159
160 return(1);
161 }
162
163
164 static int
165 dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT priority)
166 {
167 DTLS1_RECORD_DATA *rdata;
168 pitem *item;
169
170 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
171 item = pitem_new(priority, rdata);
172 if (rdata == NULL || item == NULL)
173 {
174 if (rdata != NULL) OPENSSL_free(rdata);
175 if (item != NULL) pitem_free(item);
176
177 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
178 return(0);
179 }
180
181 rdata->packet = s->packet;
182 rdata->packet_length = s->packet_length;
183 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
184 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
185
186 item->data = rdata;
187
188 /* insert should not fail, since duplicates are dropped */
189 if (pqueue_insert(queue->q, item) == NULL)
190 {
191 OPENSSL_free(rdata);
192 pitem_free(item);
193 return(0);
194 }
195
196 s->packet = NULL;
197 s->packet_length = 0;
198 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
199 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
200
201 if (!ssl3_setup_buffers(s))
202 {
203 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
204 OPENSSL_free(rdata);
205 pitem_free(item);
206 return(0);
207 }
208
209 return(1);
210 }
211
212
213 static int
214 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
215 {
216 pitem *item;
217
218 item = pqueue_pop(queue->q);
219 if (item)
220 {
221 dtls1_copy_record(s, item);
222
223 OPENSSL_free(item->data);
224 pitem_free(item);
225
226 return(1);
227 }
228
229 return(0);
230 }
231
232
233 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
234 * yet */
235 #define dtls1_get_unprocessed_record(s) \
236 dtls1_retrieve_buffered_record((s), \
237 &((s)->d1->unprocessed_rcds))
238
239 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
240 #define dtls1_get_processed_record(s) \
241 dtls1_retrieve_buffered_record((s), \
242 &((s)->d1->processed_rcds))
243
244 static int
245 dtls1_process_buffered_records(SSL *s)
246 {
247 pitem *item;
248
249 item = pqueue_peek(s->d1->unprocessed_rcds.q);
250 if (item)
251 {
252 DTLS1_RECORD_DATA *rdata;
253 rdata = (DTLS1_RECORD_DATA *)item->data;
254
255 /* Check if epoch is current. */
256 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
257 return(1); /* Nothing to do. */
258
259 /* Process all the records. */
260 while (pqueue_peek(s->d1->unprocessed_rcds.q))
261 {
262 dtls1_get_unprocessed_record(s);
263 if ( ! dtls1_process_record(s))
264 return(0);
265 dtls1_buffer_record(s, &(s->d1->processed_rcds),
266 s->s3->rrec.seq_num);
267 }
268 }
269
270 /* sync epoch numbers once all the unprocessed records
271 * have been processed */
272 s->d1->processed_rcds.epoch = s->d1->r_epoch;
273 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
274
275 return(1);
276 }
277
278
279 #if 0
280
281 static int
282 dtls1_get_buffered_record(SSL *s)
283 {
284 pitem *item;
285 PQ_64BIT priority =
286 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
287 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
288
289 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating,
290 nothing buffered */
291 return 0;
292
293
294 item = pqueue_peek(s->d1->rcvd_records);
295 if (item && item->priority == priority)
296 {
297 /* Check if we've received the record of interest. It must be
298 * a handshake record, since data records as passed up without
299 * buffering */
300 DTLS1_RECORD_DATA *rdata;
301 item = pqueue_pop(s->d1->rcvd_records);
302 rdata = (DTLS1_RECORD_DATA *)item->data;
303
304 if (s->s3->rbuf.buf != NULL)
305 OPENSSL_free(s->s3->rbuf.buf);
306
307 s->packet = rdata->packet;
308 s->packet_length = rdata->packet_length;
309 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
310 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
311
312 OPENSSL_free(item->data);
313 pitem_free(item);
314
315 /* s->d1->next_expected_seq_num++; */
316 return(1);
317 }
318
319 return 0;
320 }
321
322 #endif
323
324 static int
325 dtls1_process_record(SSL *s)
326 {
327 int i,al;
328 int clear=0;
329 int enc_err;
330 SSL_SESSION *sess;
331 SSL3_RECORD *rr;
332 unsigned int mac_size;
333 unsigned char md[EVP_MAX_MD_SIZE];
334
335
336 rr= &(s->s3->rrec);
337 sess = s->session;
338
339 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
340 * and we have that many bytes in s->packet
341 */
342 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
343
344 /* ok, we can now read from 's->packet' data into 'rr'
345 * rr->input points at rr->length bytes, which
346 * need to be copied into rr->data by either
347 * the decryption or by the decompression
348 * When the data is 'copied' into the rr->data buffer,
349 * rr->input will be pointed at the new buffer */
350
351 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
352 * rr->length bytes of encrypted compressed stuff. */
353
354 /* check is not needed I believe */
355 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
356 {
357 al=SSL_AD_RECORD_OVERFLOW;
358 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
359 goto f_err;
360 }
361
362 /* decrypt in place in 'rr->input' */
363 rr->data=rr->input;
364
365 enc_err = s->method->ssl3_enc->enc(s,0);
366 if (enc_err <= 0)
367 {
368 if (enc_err == 0)
369 /* SSLerr() and ssl3_send_alert() have been called */
370 goto err;
371
372 /* otherwise enc_err == -1 */
373 goto decryption_failed_or_bad_record_mac;
374 }
375
376 #ifdef TLS_DEBUG
377 printf("dec %d\n",rr->length);
378 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
379 printf("\n");
380 #endif
381
382 /* r->length is now the compressed data plus mac */
383 if ( (sess == NULL) ||
384 (s->enc_read_ctx == NULL) ||
385 (s->read_hash == NULL))
386 clear=1;
387
388 if (!clear)
389 {
390 mac_size=EVP_MD_size(s->read_hash);
391
392 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
393 {
394 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
395 al=SSL_AD_RECORD_OVERFLOW;
396 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
397 goto f_err;
398 #else
399 goto decryption_failed_or_bad_record_mac;
400 #endif
401 }
402 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
403 if (rr->length < mac_size)
404 {
405 #if 0 /* OK only for stream ciphers */
406 al=SSL_AD_DECODE_ERROR;
407 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
408 goto f_err;
409 #else
410 goto decryption_failed_or_bad_record_mac;
411 #endif
412 }
413 rr->length-=mac_size;
414 i=s->method->ssl3_enc->mac(s,md,0);
415 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
416 {
417 goto decryption_failed_or_bad_record_mac;
418 }
419 }
420
421 /* r->length is now just compressed */
422 if (s->expand != NULL)
423 {
424 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
425 {
426 al=SSL_AD_RECORD_OVERFLOW;
427 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
428 goto f_err;
429 }
430 if (!ssl3_do_uncompress(s))
431 {
432 al=SSL_AD_DECOMPRESSION_FAILURE;
433 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
434 goto f_err;
435 }
436 }
437
438 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
439 {
440 al=SSL_AD_RECORD_OVERFLOW;
441 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
442 goto f_err;
443 }
444
445 rr->off=0;
446 /* So at this point the following is true
447 * ssl->s3->rrec.type is the type of record
448 * ssl->s3->rrec.length == number of bytes in record
449 * ssl->s3->rrec.off == offset to first valid byte
450 * ssl->s3->rrec.data == where to take bytes from, increment
451 * after use :-).
452 */
453
454 /* we have pulled in a full packet so zero things */
455 s->packet_length=0;
456 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
457 return(1);
458
459 decryption_failed_or_bad_record_mac:
460 /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
461 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
462 * failure is directly visible from the ciphertext anyway,
463 * we should not reveal which kind of error occured -- this
464 * might become visible to an attacker (e.g. via logfile) */
465 al=SSL_AD_BAD_RECORD_MAC;
466 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
467 f_err:
468 ssl3_send_alert(s,SSL3_AL_FATAL,al);
469 err:
470 return(0);
471 }
472
473
474 /* Call this to get a new input record.
475 * It will return <= 0 if more data is needed, normally due to an error
476 * or non-blocking IO.
477 * When it finishes, one packet has been decoded and can be found in
478 * ssl->s3->rrec.type - is the type of record
479 * ssl->s3->rrec.data, - data
480 * ssl->s3->rrec.length, - number of bytes
481 */
482 /* used only by dtls1_read_bytes */
483 int dtls1_get_record(SSL *s)
484 {
485 int ssl_major,ssl_minor,al;
486 int i,n;
487 SSL3_RECORD *rr;
488 SSL_SESSION *sess;
489 unsigned char *p;
490 unsigned short version;
491 DTLS1_BITMAP *bitmap;
492 unsigned int is_next_epoch;
493
494 rr= &(s->s3->rrec);
495 sess=s->session;
496
497 /* The epoch may have changed. If so, process all the
498 * pending records. This is a non-blocking operation. */
499 if ( ! dtls1_process_buffered_records(s))
500 return 0;
501
502 /* if we're renegotiating, then there may be buffered records */
503 if (dtls1_get_processed_record(s))
504 return 1;
505
506 /* get something from the wire */
507 again:
508 /* check if we have the header */
509 if ( (s->rstate != SSL_ST_READ_BODY) ||
510 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
511 {
512 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
513 /* read timeout is handled by dtls1_read_bytes */
514 if (n <= 0) return(n); /* error or non-blocking */
515
516 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
517
518 s->rstate=SSL_ST_READ_BODY;
519
520 p=s->packet;
521
522 /* Pull apart the header into the DTLS1_RECORD */
523 rr->type= *(p++);
524 ssl_major= *(p++);
525 ssl_minor= *(p++);
526 version=(ssl_major<<8)|ssl_minor;
527
528 /* sequence number is 64 bits, with top 2 bytes = epoch */
529 n2s(p,rr->epoch);
530
531 memcpy(&(s->s3->read_sequence[2]), p, 6);
532 p+=6;
533
534 n2s(p,rr->length);
535
536 /* Lets check version */
537 if (!s->first_packet)
538 {
539 if (version != s->version && version != DTLS1_BAD_VER)
540 {
541 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
542 /* Send back error using their
543 * version number :-) */
544 s->version=version;
545 al=SSL_AD_PROTOCOL_VERSION;
546 goto f_err;
547 }
548 }
549
550 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00) &&
551 (version & 0xff00) != (DTLS1_BAD_VER & 0xff00))
552 {
553 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
554 goto err;
555 }
556
557 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
558 {
559 al=SSL_AD_RECORD_OVERFLOW;
560 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
561 goto f_err;
562 }
563
564 s->client_version = version;
565 /* now s->rstate == SSL_ST_READ_BODY */
566 }
567
568 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
569
570 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
571 {
572 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
573 i=rr->length;
574 n=ssl3_read_n(s,i,i,1);
575 if (n <= 0) return(n); /* error or non-blocking io */
576
577 /* this packet contained a partial record, dump it */
578 if ( n != i)
579 {
580 s->packet_length = 0;
581 goto again;
582 }
583
584 /* now n == rr->length,
585 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
586 }
587 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
588
589 /* match epochs. NULL means the packet is dropped on the floor */
590 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
591 if ( bitmap == NULL)
592 {
593 s->packet_length = 0; /* dump this record */
594 goto again; /* get another record */
595 }
596
597 /* check whether this is a repeat, or aged record */
598 if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
599 {
600 rr->length = 0;
601 s->packet_length=0; /* dump this record */
602 goto again; /* get another record */
603 }
604
605 /* just read a 0 length packet */
606 if (rr->length == 0) goto again;
607
608 /* If this record is from the next epoch (either HM or ALERT), buffer it
609 * since it cannot be processed at this time.
610 * Records from the next epoch are marked as received even though they are
611 * not processed, so as to prevent any potential resource DoS attack */
612 if (is_next_epoch)
613 {
614 dtls1_record_bitmap_update(s, bitmap);
615 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
616 s->packet_length = 0;
617 goto again;
618 }
619
620 if ( ! dtls1_process_record(s))
621 return(0);
622
623 dtls1_clear_timeouts(s); /* done waiting */
624 return(1);
625
626 f_err:
627 ssl3_send_alert(s,SSL3_AL_FATAL,al);
628 err:
629 return(0);
630 }
631
632 /* Return up to 'len' payload bytes received in 'type' records.
633 * 'type' is one of the following:
634 *
635 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
636 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
637 * - 0 (during a shutdown, no data has to be returned)
638 *
639 * If we don't have stored data to work from, read a SSL/TLS record first
640 * (possibly multiple records if we still don't have anything to return).
641 *
642 * This function must handle any surprises the peer may have for us, such as
643 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
644 * a surprise, but handled as if it were), or renegotiation requests.
645 * Also if record payloads contain fragments too small to process, we store
646 * them until there is enough for the respective protocol (the record protocol
647 * may use arbitrary fragmentation and even interleaving):
648 * Change cipher spec protocol
649 * just 1 byte needed, no need for keeping anything stored
650 * Alert protocol
651 * 2 bytes needed (AlertLevel, AlertDescription)
652 * Handshake protocol
653 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
654 * to detect unexpected Client Hello and Hello Request messages
655 * here, anything else is handled by higher layers
656 * Application data protocol
657 * none of our business
658 */
659 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
660 {
661 int al,i,j,ret;
662 unsigned int n;
663 SSL3_RECORD *rr;
664 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
665
666 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
667 if (!ssl3_setup_buffers(s))
668 return(-1);
669
670 /* XXX: check what the second '&& type' is about */
671 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
672 (type != SSL3_RT_HANDSHAKE) && type) ||
673 (peek && (type != SSL3_RT_APPLICATION_DATA)))
674 {
675 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
676 return -1;
677 }
678
679 /* check whether there's a handshake message (client hello?) waiting */
680 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
681 return ret;
682
683 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
684
685 if (!s->in_handshake && SSL_in_init(s))
686 {
687 /* type == SSL3_RT_APPLICATION_DATA */
688 i=s->handshake_func(s);
689 if (i < 0) return(i);
690 if (i == 0)
691 {
692 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
693 return(-1);
694 }
695 }
696
697 start:
698 s->rwstate=SSL_NOTHING;
699
700 /* s->s3->rrec.type - is the type of record
701 * s->s3->rrec.data, - data
702 * s->s3->rrec.off, - offset into 'data' for next read
703 * s->s3->rrec.length, - number of bytes. */
704 rr = &(s->s3->rrec);
705
706 /* get new packet if necessary */
707 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
708 {
709 ret=dtls1_get_record(s);
710 if (ret <= 0)
711 {
712 ret = dtls1_read_failed(s, ret);
713 /* anything other than a timeout is an error */
714 if (ret <= 0)
715 return(ret);
716 else
717 goto start;
718 }
719 }
720
721 /* we now have a packet which can be read and processed */
722
723 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
724 * reset by ssl3_get_finished */
725 && (rr->type != SSL3_RT_HANDSHAKE))
726 {
727 al=SSL_AD_UNEXPECTED_MESSAGE;
728 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
729 goto err;
730 }
731
732 /* If the other end has shut down, throw anything we read away
733 * (even in 'peek' mode) */
734 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
735 {
736 rr->length=0;
737 s->rwstate=SSL_NOTHING;
738 return(0);
739 }
740
741
742 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
743 {
744 /* make sure that we are not getting application data when we
745 * are doing a handshake for the first time */
746 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
747 (s->enc_read_ctx == NULL))
748 {
749 al=SSL_AD_UNEXPECTED_MESSAGE;
750 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
751 goto f_err;
752 }
753
754 if (len <= 0) return(len);
755
756 if ((unsigned int)len > rr->length)
757 n = rr->length;
758 else
759 n = (unsigned int)len;
760
761 memcpy(buf,&(rr->data[rr->off]),n);
762 if (!peek)
763 {
764 rr->length-=n;
765 rr->off+=n;
766 if (rr->length == 0)
767 {
768 s->rstate=SSL_ST_READ_HEADER;
769 rr->off=0;
770 }
771 }
772 return(n);
773 }
774
775
776 /* If we get here, then type != rr->type; if we have a handshake
777 * message, then it was unexpected (Hello Request or Client Hello). */
778
779 /* In case of record types for which we have 'fragment' storage,
780 * fill that so that we can process the data at a fixed place.
781 */
782 {
783 unsigned int k, dest_maxlen = 0;
784 unsigned char *dest = NULL;
785 unsigned int *dest_len = NULL;
786
787 if (rr->type == SSL3_RT_HANDSHAKE)
788 {
789 dest_maxlen = sizeof s->d1->handshake_fragment;
790 dest = s->d1->handshake_fragment;
791 dest_len = &s->d1->handshake_fragment_len;
792 }
793 else if (rr->type == SSL3_RT_ALERT)
794 {
795 dest_maxlen = sizeof(s->d1->alert_fragment);
796 dest = s->d1->alert_fragment;
797 dest_len = &s->d1->alert_fragment_len;
798 }
799 /* else it's a CCS message, or it's wrong */
800 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
801 {
802 /* Not certain if this is the right error handling */
803 al=SSL_AD_UNEXPECTED_MESSAGE;
804 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
805 goto f_err;
806 }
807
808
809 if (dest_maxlen > 0)
810 {
811 /* XDTLS: In a pathalogical case, the Client Hello
812 * may be fragmented--don't always expect dest_maxlen bytes */
813 if ( rr->length < dest_maxlen)
814 {
815 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
816 /*
817 * for normal alerts rr->length is 2, while
818 * dest_maxlen is 7 if we were to handle this
819 * non-existing alert...
820 */
821 FIX ME
822 #endif
823 s->rstate=SSL_ST_READ_HEADER;
824 rr->length = 0;
825 goto start;
826 }
827
828 /* now move 'n' bytes: */
829 for ( k = 0; k < dest_maxlen; k++)
830 {
831 dest[k] = rr->data[rr->off++];
832 rr->length--;
833 }
834 *dest_len = dest_maxlen;
835 }
836 }
837
838 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
839 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
840 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
841
842 /* If we are a client, check for an incoming 'Hello Request': */
843 if ((!s->server) &&
844 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
845 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
846 (s->session != NULL) && (s->session->cipher != NULL))
847 {
848 s->d1->handshake_fragment_len = 0;
849
850 if ((s->d1->handshake_fragment[1] != 0) ||
851 (s->d1->handshake_fragment[2] != 0) ||
852 (s->d1->handshake_fragment[3] != 0))
853 {
854 al=SSL_AD_DECODE_ERROR;
855 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
856 goto err;
857 }
858
859 /* no need to check sequence number on HELLO REQUEST messages */
860
861 if (s->msg_callback)
862 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
863 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
864
865 if (SSL_is_init_finished(s) &&
866 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
867 !s->s3->renegotiate)
868 {
869 ssl3_renegotiate(s);
870 if (ssl3_renegotiate_check(s))
871 {
872 i=s->handshake_func(s);
873 if (i < 0) return(i);
874 if (i == 0)
875 {
876 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
877 return(-1);
878 }
879
880 if (!(s->mode & SSL_MODE_AUTO_RETRY))
881 {
882 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
883 {
884 BIO *bio;
885 /* In the case where we try to read application data,
886 * but we trigger an SSL handshake, we return -1 with
887 * the retry option set. Otherwise renegotiation may
888 * cause nasty problems in the blocking world */
889 s->rwstate=SSL_READING;
890 bio=SSL_get_rbio(s);
891 BIO_clear_retry_flags(bio);
892 BIO_set_retry_read(bio);
893 return(-1);
894 }
895 }
896 }
897 }
898 /* we either finished a handshake or ignored the request,
899 * now try again to obtain the (application) data we were asked for */
900 goto start;
901 }
902
903 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
904 {
905 int alert_level = s->d1->alert_fragment[0];
906 int alert_descr = s->d1->alert_fragment[1];
907
908 s->d1->alert_fragment_len = 0;
909
910 if (s->msg_callback)
911 s->msg_callback(0, s->version, SSL3_RT_ALERT,
912 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
913
914 if (s->info_callback != NULL)
915 cb=s->info_callback;
916 else if (s->ctx->info_callback != NULL)
917 cb=s->ctx->info_callback;
918
919 if (cb != NULL)
920 {
921 j = (alert_level << 8) | alert_descr;
922 cb(s, SSL_CB_READ_ALERT, j);
923 }
924
925 if (alert_level == 1) /* warning */
926 {
927 s->s3->warn_alert = alert_descr;
928 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
929 {
930 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
931 return(0);
932 }
933 #if 0
934 /* XXX: this is a possible improvement in the future */
935 /* now check if it's a missing record */
936 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
937 {
938 unsigned short seq;
939 unsigned int frag_off;
940 unsigned char *p = &(s->d1->alert_fragment[2]);
941
942 n2s(p, seq);
943 n2l3(p, frag_off);
944
945 dtls1_retransmit_message(s, seq, frag_off, &found);
946 if ( ! found && SSL_in_init(s))
947 {
948 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
949 /* requested a message not yet sent,
950 send an alert ourselves */
951 ssl3_send_alert(s,SSL3_AL_WARNING,
952 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
953 }
954 }
955 #endif
956 }
957 else if (alert_level == 2) /* fatal */
958 {
959 char tmp[16];
960
961 s->rwstate=SSL_NOTHING;
962 s->s3->fatal_alert = alert_descr;
963 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
964 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
965 ERR_add_error_data(2,"SSL alert number ",tmp);
966 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
967 SSL_CTX_remove_session(s->ctx,s->session);
968 return(0);
969 }
970 else
971 {
972 al=SSL_AD_ILLEGAL_PARAMETER;
973 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
974 goto f_err;
975 }
976
977 goto start;
978 }
979
980 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
981 {
982 s->rwstate=SSL_NOTHING;
983 rr->length=0;
984 return(0);
985 }
986
987 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
988 {
989 struct ccs_header_st ccs_hdr;
990
991 dtls1_get_ccs_header(rr->data, &ccs_hdr);
992
993 /* 'Change Cipher Spec' is just a single byte, so we know
994 * exactly what the record payload has to look like */
995 /* XDTLS: check that epoch is consistent */
996 if ( (s->client_version == DTLS1_BAD_VER && rr->length != 3) ||
997 (s->client_version != DTLS1_BAD_VER && rr->length != DTLS1_CCS_HEADER_LENGTH) ||
998 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
999 {
1000 i=SSL_AD_ILLEGAL_PARAMETER;
1001 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1002 goto err;
1003 }
1004
1005 rr->length=0;
1006
1007 if (s->msg_callback)
1008 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1009 rr->data, 1, s, s->msg_callback_arg);
1010
1011 s->s3->change_cipher_spec=1;
1012 if (!ssl3_do_change_cipher_spec(s))
1013 goto err;
1014
1015 /* do this whenever CCS is processed */
1016 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1017
1018 if (s->client_version == DTLS1_BAD_VER)
1019 s->d1->handshake_read_seq++;
1020
1021 goto start;
1022 }
1023
1024 /* Unexpected handshake message (Client Hello, or protocol violation) */
1025 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1026 !s->in_handshake)
1027 {
1028 struct hm_header_st msg_hdr;
1029
1030 /* this may just be a stale retransmit */
1031 dtls1_get_message_header(rr->data, &msg_hdr);
1032 if( rr->epoch != s->d1->r_epoch)
1033 {
1034 rr->length = 0;
1035 goto start;
1036 }
1037
1038 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1039 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1040 {
1041 #if 0 /* worked only because C operator preferences are not as expected (and
1042 * because this is not really needed for clients except for detecting
1043 * protocol violations): */
1044 s->state=SSL_ST_BEFORE|(s->server)
1045 ?SSL_ST_ACCEPT
1046 :SSL_ST_CONNECT;
1047 #else
1048 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1049 #endif
1050 s->new_session=1;
1051 }
1052 i=s->handshake_func(s);
1053 if (i < 0) return(i);
1054 if (i == 0)
1055 {
1056 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1057 return(-1);
1058 }
1059
1060 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1061 {
1062 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1063 {
1064 BIO *bio;
1065 /* In the case where we try to read application data,
1066 * but we trigger an SSL handshake, we return -1 with
1067 * the retry option set. Otherwise renegotiation may
1068 * cause nasty problems in the blocking world */
1069 s->rwstate=SSL_READING;
1070 bio=SSL_get_rbio(s);
1071 BIO_clear_retry_flags(bio);
1072 BIO_set_retry_read(bio);
1073 return(-1);
1074 }
1075 }
1076 goto start;
1077 }
1078
1079 switch (rr->type)
1080 {
1081 default:
1082 #ifndef OPENSSL_NO_TLS
1083 /* TLS just ignores unknown message types */
1084 if (s->version == TLS1_VERSION)
1085 {
1086 rr->length = 0;
1087 goto start;
1088 }
1089 #endif
1090 al=SSL_AD_UNEXPECTED_MESSAGE;
1091 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1092 goto f_err;
1093 case SSL3_RT_CHANGE_CIPHER_SPEC:
1094 case SSL3_RT_ALERT:
1095 case SSL3_RT_HANDSHAKE:
1096 /* we already handled all of these, with the possible exception
1097 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1098 * should not happen when type != rr->type */
1099 al=SSL_AD_UNEXPECTED_MESSAGE;
1100 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1101 goto f_err;
1102 case SSL3_RT_APPLICATION_DATA:
1103 /* At this point, we were expecting handshake data,
1104 * but have application data. If the library was
1105 * running inside ssl3_read() (i.e. in_read_app_data
1106 * is set) and it makes sense to read application data
1107 * at this point (session renegotiation not yet started),
1108 * we will indulge it.
1109 */
1110 if (s->s3->in_read_app_data &&
1111 (s->s3->total_renegotiations != 0) &&
1112 ((
1113 (s->state & SSL_ST_CONNECT) &&
1114 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1115 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1116 ) || (
1117 (s->state & SSL_ST_ACCEPT) &&
1118 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1119 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1120 )
1121 ))
1122 {
1123 s->s3->in_read_app_data=2;
1124 return(-1);
1125 }
1126 else
1127 {
1128 al=SSL_AD_UNEXPECTED_MESSAGE;
1129 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1130 goto f_err;
1131 }
1132 }
1133 /* not reached */
1134
1135 f_err:
1136 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1137 err:
1138 return(-1);
1139 }
1140
1141 int
1142 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1143 {
1144 unsigned int n,tot;
1145 int i;
1146
1147 if (SSL_in_init(s) && !s->in_handshake)
1148 {
1149 i=s->handshake_func(s);
1150 if (i < 0) return(i);
1151 if (i == 0)
1152 {
1153 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1154 return -1;
1155 }
1156 }
1157
1158 tot = s->s3->wnum;
1159 n = len - tot;
1160
1161 while( n)
1162 {
1163 /* dtls1_write_bytes sends one record at a time, sized according to
1164 * the currently known MTU */
1165 i = dtls1_write_bytes(s, type, buf_, len);
1166 if (i <= 0) return i;
1167
1168 if ((i == (int)n) ||
1169 (type == SSL3_RT_APPLICATION_DATA &&
1170 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1171 {
1172 /* next chunk of data should get another prepended empty fragment
1173 * in ciphersuites with known-IV weakness: */
1174 s->s3->empty_fragment_done = 0;
1175 return tot+i;
1176 }
1177
1178 tot += i;
1179 n-=i;
1180 }
1181
1182 return tot;
1183 }
1184
1185
1186 /* this only happens when a client hello is received and a handshake
1187 * is started. */
1188 static int
1189 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1190 int len, int peek)
1191 {
1192
1193 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1194 /* (partially) satisfy request from storage */
1195 {
1196 unsigned char *src = s->d1->handshake_fragment;
1197 unsigned char *dst = buf;
1198 unsigned int k,n;
1199
1200 /* peek == 0 */
1201 n = 0;
1202 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1203 {
1204 *dst++ = *src++;
1205 len--; s->d1->handshake_fragment_len--;
1206 n++;
1207 }
1208 /* move any remaining fragment bytes: */
1209 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1210 s->d1->handshake_fragment[k] = *src++;
1211 return n;
1212 }
1213
1214 return 0;
1215 }
1216
1217
1218
1219
1220 /* Call this to write data in records of type 'type'
1221 * It will return <= 0 if not all data has been sent or non-blocking IO.
1222 */
1223 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1224 {
1225 const unsigned char *buf=buf_;
1226 unsigned int tot,n,nw;
1227 int i;
1228 unsigned int mtu;
1229
1230 s->rwstate=SSL_NOTHING;
1231 tot=s->s3->wnum;
1232
1233 n=(len-tot);
1234
1235 /* handshake layer figures out MTU for itself, but data records
1236 * are also sent through this interface, so need to figure out MTU */
1237 #if 0
1238 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1239 mtu += DTLS1_HM_HEADER_LENGTH; /* HM already inserted */
1240 #endif
1241 mtu = s->d1->mtu;
1242
1243 if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1244 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1245
1246 if (n > mtu)
1247 nw=mtu;
1248 else
1249 nw=n;
1250
1251 i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1252 if (i <= 0)
1253 {
1254 s->s3->wnum=tot;
1255 return i;
1256 }
1257
1258 if ( (int)s->s3->wnum + i == len)
1259 s->s3->wnum = 0;
1260 else
1261 s->s3->wnum += i;
1262
1263 return i;
1264 }
1265
1266 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1267 {
1268 unsigned char *p,*pseq;
1269 int i,mac_size,clear=0;
1270 int prefix_len = 0;
1271 SSL3_RECORD *wr;
1272 SSL3_BUFFER *wb;
1273 SSL_SESSION *sess;
1274 int bs;
1275
1276 /* first check if there is a SSL3_BUFFER still being written
1277 * out. This will happen with non blocking IO */
1278 if (s->s3->wbuf.left != 0)
1279 {
1280 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1281 return(ssl3_write_pending(s,type,buf,len));
1282 }
1283
1284 /* If we have an alert to send, lets send it */
1285 if (s->s3->alert_dispatch)
1286 {
1287 i=s->method->ssl_dispatch_alert(s);
1288 if (i <= 0)
1289 return(i);
1290 /* if it went, fall through and send more stuff */
1291 }
1292
1293 if (len == 0 && !create_empty_fragment)
1294 return 0;
1295
1296 wr= &(s->s3->wrec);
1297 wb= &(s->s3->wbuf);
1298 sess=s->session;
1299
1300 if ( (sess == NULL) ||
1301 (s->enc_write_ctx == NULL) ||
1302 (s->write_hash == NULL))
1303 clear=1;
1304
1305 if (clear)
1306 mac_size=0;
1307 else
1308 mac_size=EVP_MD_size(s->write_hash);
1309
1310 /* DTLS implements explicit IV, so no need for empty fragments */
1311 #if 0
1312 /* 'create_empty_fragment' is true only when this function calls itself */
1313 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1314 && SSL_version(s) != DTLS1_VERSION)
1315 {
1316 /* countermeasure against known-IV weakness in CBC ciphersuites
1317 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1318 */
1319
1320 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1321 {
1322 /* recursive function call with 'create_empty_fragment' set;
1323 * this prepares and buffers the data for an empty fragment
1324 * (these 'prefix_len' bytes are sent out later
1325 * together with the actual payload) */
1326 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1327 if (prefix_len <= 0)
1328 goto err;
1329
1330 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1331 {
1332 /* insufficient space */
1333 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1334 goto err;
1335 }
1336 }
1337
1338 s->s3->empty_fragment_done = 1;
1339 }
1340 #endif
1341
1342 p = wb->buf + prefix_len;
1343
1344 /* write the header */
1345
1346 *(p++)=type&0xff;
1347 wr->type=type;
1348
1349 if (s->client_version == DTLS1_BAD_VER)
1350 *(p++) = DTLS1_BAD_VER>>8,
1351 *(p++) = DTLS1_BAD_VER&0xff;
1352 else
1353 *(p++)=(s->version>>8),
1354 *(p++)=s->version&0xff;
1355
1356 /* field where we are to write out packet epoch, seq num and len */
1357 pseq=p;
1358 p+=10;
1359
1360 /* lets setup the record stuff. */
1361
1362 /* Make space for the explicit IV in case of CBC.
1363 * (this is a bit of a boundary violation, but what the heck).
1364 */
1365 if ( s->enc_write_ctx &&
1366 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1367 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1368 else
1369 bs = 0;
1370
1371 wr->data=p + bs; /* make room for IV in case of CBC */
1372 wr->length=(int)len;
1373 wr->input=(unsigned char *)buf;
1374
1375 /* we now 'read' from wr->input, wr->length bytes into
1376 * wr->data */
1377
1378 /* first we compress */
1379 if (s->compress != NULL)
1380 {
1381 if (!ssl3_do_compress(s))
1382 {
1383 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1384 goto err;
1385 }
1386 }
1387 else
1388 {
1389 memcpy(wr->data,wr->input,wr->length);
1390 wr->input=wr->data;
1391 }
1392
1393 /* we should still have the output to wr->data and the input
1394 * from wr->input. Length should be wr->length.
1395 * wr->data still points in the wb->buf */
1396
1397 if (mac_size != 0)
1398 {
1399 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1400 wr->length+=mac_size;
1401 }
1402
1403 /* this is true regardless of mac size */
1404 wr->input=p;
1405 wr->data=p;
1406
1407
1408 /* ssl3_enc can only have an error on read */
1409 if (bs) /* bs != 0 in case of CBC */
1410 {
1411 RAND_pseudo_bytes(p,bs);
1412 /* master IV and last CBC residue stand for
1413 * the rest of randomness */
1414 wr->length += bs;
1415 }
1416
1417 s->method->ssl3_enc->enc(s,1);
1418
1419 /* record length after mac and block padding */
1420 /* if (type == SSL3_RT_APPLICATION_DATA ||
1421 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1422
1423 /* there's only one epoch between handshake and app data */
1424
1425 s2n(s->d1->w_epoch, pseq);
1426
1427 /* XDTLS: ?? */
1428 /* else
1429 s2n(s->d1->handshake_epoch, pseq); */
1430
1431 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1432 pseq+=6;
1433 s2n(wr->length,pseq);
1434
1435 /* we should now have
1436 * wr->data pointing to the encrypted data, which is
1437 * wr->length long */
1438 wr->type=type; /* not needed but helps for debugging */
1439 wr->length+=DTLS1_RT_HEADER_LENGTH;
1440
1441 #if 0 /* this is now done at the message layer */
1442 /* buffer the record, making it easy to handle retransmits */
1443 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1444 dtls1_buffer_record(s, wr->data, wr->length,
1445 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1446 #endif
1447
1448 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1449
1450 if (create_empty_fragment)
1451 {
1452 /* we are in a recursive call;
1453 * just return the length, don't write out anything here
1454 */
1455 return wr->length;
1456 }
1457
1458 /* now let's set up wb */
1459 wb->left = prefix_len + wr->length;
1460 wb->offset = 0;
1461
1462 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1463 s->s3->wpend_tot=len;
1464 s->s3->wpend_buf=buf;
1465 s->s3->wpend_type=type;
1466 s->s3->wpend_ret=len;
1467
1468 /* we now just need to write the buffer */
1469 return ssl3_write_pending(s,type,buf,len);
1470 err:
1471 return -1;
1472 }
1473
1474
1475
1476 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1477 PQ_64BIT *seq_num)
1478 {
1479 #if PQ_64BIT_IS_INTEGER
1480 PQ_64BIT mask = 0x0000000000000001L;
1481 #endif
1482 PQ_64BIT rcd_num, tmp;
1483
1484 pq_64bit_init(&rcd_num);
1485 pq_64bit_init(&tmp);
1486
1487 /* this is the sequence number for the record just read */
1488 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1489
1490
1491 if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1492 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1493 {
1494 pq_64bit_assign(seq_num, &rcd_num);
1495 pq_64bit_free(&rcd_num);
1496 pq_64bit_free(&tmp);
1497 return 1; /* this record is new */
1498 }
1499
1500 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1501
1502 if ( pq_64bit_get_word(&tmp) > bitmap->length)
1503 {
1504 pq_64bit_free(&rcd_num);
1505 pq_64bit_free(&tmp);
1506 return 0; /* stale, outside the window */
1507 }
1508
1509 #if PQ_64BIT_IS_BIGNUM
1510 {
1511 int offset;
1512 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1513 pq_64bit_sub_word(&tmp, 1);
1514 offset = pq_64bit_get_word(&tmp);
1515 if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1516 {
1517 pq_64bit_free(&rcd_num);
1518 pq_64bit_free(&tmp);
1519 return 0;
1520 }
1521 }
1522 #else
1523 mask <<= (bitmap->max_seq_num - rcd_num - 1);
1524 if (bitmap->map & mask)
1525 return 0; /* record previously received */
1526 #endif
1527
1528 pq_64bit_assign(seq_num, &rcd_num);
1529 pq_64bit_free(&rcd_num);
1530 pq_64bit_free(&tmp);
1531 return 1;
1532 }
1533
1534
1535 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1536 {
1537 unsigned int shift;
1538 PQ_64BIT rcd_num;
1539 PQ_64BIT tmp;
1540 PQ_64BIT_CTX *ctx;
1541
1542 pq_64bit_init(&rcd_num);
1543 pq_64bit_init(&tmp);
1544
1545 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1546
1547 /* unfortunate code complexity due to 64-bit manipulation support
1548 * on 32-bit machines */
1549 if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1550 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1551 {
1552 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1553 pq_64bit_add_word(&tmp, 1);
1554
1555 shift = (unsigned int)pq_64bit_get_word(&tmp);
1556
1557 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1558 pq_64bit_assign(&(bitmap->map), &tmp);
1559
1560 pq_64bit_set_bit(&(bitmap->map), 0);
1561 pq_64bit_add_word(&rcd_num, 1);
1562 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1563
1564 pq_64bit_assign_word(&tmp, 1);
1565 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1566 ctx = pq_64bit_ctx_new(&ctx);
1567 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1568 pq_64bit_ctx_free(ctx);
1569 }
1570 else
1571 {
1572 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1573 pq_64bit_sub_word(&tmp, 1);
1574 shift = (unsigned int)pq_64bit_get_word(&tmp);
1575
1576 pq_64bit_set_bit(&(bitmap->map), shift);
1577 }
1578
1579 pq_64bit_free(&rcd_num);
1580 pq_64bit_free(&tmp);
1581 }
1582
1583
1584 int dtls1_dispatch_alert(SSL *s)
1585 {
1586 int i,j;
1587 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1588 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1589 unsigned char *ptr = &buf[0];
1590
1591 s->s3->alert_dispatch=0;
1592
1593 memset(buf, 0x00, sizeof(buf));
1594 *ptr++ = s->s3->send_alert[0];
1595 *ptr++ = s->s3->send_alert[1];
1596
1597 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1598 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1599 {
1600 s2n(s->d1->handshake_read_seq, ptr);
1601 #if 0
1602 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1603
1604 else
1605 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1606 #endif
1607
1608 #if 0
1609 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);
1610 #endif
1611 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1612 }
1613 #endif
1614
1615 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1616 if (i <= 0)
1617 {
1618 s->s3->alert_dispatch=1;
1619 /* fprintf( stderr, "not done with alert\n" ); */
1620 }
1621 else
1622 {
1623 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1624 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1625 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1626 #endif
1627 )
1628 (void)BIO_flush(s->wbio);
1629
1630 if (s->msg_callback)
1631 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1632 2, s, s->msg_callback_arg);
1633
1634 if (s->info_callback != NULL)
1635 cb=s->info_callback;
1636 else if (s->ctx->info_callback != NULL)
1637 cb=s->ctx->info_callback;
1638
1639 if (cb != NULL)
1640 {
1641 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1642 cb(s,SSL_CB_WRITE_ALERT,j);
1643 }
1644 }
1645 return(i);
1646 }
1647
1648
1649 static DTLS1_BITMAP *
1650 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1651 {
1652
1653 *is_next_epoch = 0;
1654
1655 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1656 if (rr->epoch == s->d1->r_epoch)
1657 return &s->d1->bitmap;
1658
1659 /* Only HM and ALERT messages can be from the next epoch */
1660 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1661 (rr->type == SSL3_RT_HANDSHAKE ||
1662 rr->type == SSL3_RT_ALERT))
1663 {
1664 *is_next_epoch = 1;
1665 return &s->d1->next_bitmap;
1666 }
1667
1668 return NULL;
1669 }
1670
1671 #if 0
1672 static int
1673 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1674 unsigned long *offset)
1675 {
1676
1677 /* alerts are passed up immediately */
1678 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1679 rr->type == SSL3_RT_ALERT)
1680 return 0;
1681
1682 /* Only need to buffer if a handshake is underway.
1683 * (this implies that Hello Request and Client Hello are passed up
1684 * immediately) */
1685 if ( SSL_in_init(s))
1686 {
1687 unsigned char *data = rr->data;
1688 /* need to extract the HM/CCS sequence number here */
1689 if ( rr->type == SSL3_RT_HANDSHAKE ||
1690 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1691 {
1692 unsigned short seq_num;
1693 struct hm_header_st msg_hdr;
1694 struct ccs_header_st ccs_hdr;
1695
1696 if ( rr->type == SSL3_RT_HANDSHAKE)
1697 {
1698 dtls1_get_message_header(data, &msg_hdr);
1699 seq_num = msg_hdr.seq;
1700 *offset = msg_hdr.frag_off;
1701 }
1702 else
1703 {
1704 dtls1_get_ccs_header(data, &ccs_hdr);
1705 seq_num = ccs_hdr.seq;
1706 *offset = 0;
1707 }
1708
1709 /* this is either a record we're waiting for, or a
1710 * retransmit of something we happened to previously
1711 * receive (higher layers will drop the repeat silently */
1712 if ( seq_num < s->d1->handshake_read_seq)
1713 return 0;
1714 if (rr->type == SSL3_RT_HANDSHAKE &&
1715 seq_num == s->d1->handshake_read_seq &&
1716 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1717 return 0;
1718 else if ( seq_num == s->d1->handshake_read_seq &&
1719 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1720 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1721 return 0;
1722 else
1723 {
1724 *priority = seq_num;
1725 return 1;
1726 }
1727 }
1728 else /* unknown record type */
1729 return 0;
1730 }
1731
1732 return 0;
1733 }
1734 #endif
1735
1736 void
1737 dtls1_reset_seq_numbers(SSL *s, int rw)
1738 {
1739 unsigned char *seq;
1740 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1741
1742 if ( rw & SSL3_CC_READ)
1743 {
1744 seq = s->s3->read_sequence;
1745 s->d1->r_epoch++;
1746
1747 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1748 s->d1->bitmap.length = s->d1->next_bitmap.length;
1749 pq_64bit_assign(&(s->d1->bitmap.max_seq_num),
1750 &(s->d1->next_bitmap.max_seq_num));
1751
1752 pq_64bit_free(&(s->d1->next_bitmap.map));
1753 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1754 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1755 pq_64bit_init(&(s->d1->next_bitmap.map));
1756 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1757 }
1758 else
1759 {
1760 seq = s->s3->write_sequence;
1761 s->d1->w_epoch++;
1762 }
1763
1764 memset(seq, 0x00, seq_bytes);
1765 }
1766
1767 #if PQ_64BIT_IS_INTEGER
1768 static PQ_64BIT
1769 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1770 {
1771 PQ_64BIT _num;
1772
1773 _num = (((PQ_64BIT)bytes[0]) << 56) |
1774 (((PQ_64BIT)bytes[1]) << 48) |
1775 (((PQ_64BIT)bytes[2]) << 40) |
1776 (((PQ_64BIT)bytes[3]) << 32) |
1777 (((PQ_64BIT)bytes[4]) << 24) |
1778 (((PQ_64BIT)bytes[5]) << 16) |
1779 (((PQ_64BIT)bytes[6]) << 8) |
1780 (((PQ_64BIT)bytes[7]) );
1781
1782 *num = _num ;
1783 return _num;
1784 }
1785 #endif
1786
1787
1788 static void
1789 dtls1_clear_timeouts(SSL *s)
1790 {
1791 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1792 }
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