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
dtls1_copy_record(SSL * s,pitem * item)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
dtls1_buffer_record(SSL * s,record_pqueue * queue,PQ_64BIT priority)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
dtls1_retrieve_buffered_record(SSL * s,record_pqueue * queue)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
dtls1_process_buffered_records(SSL * s)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
dtls1_process_record(SSL * s)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 */
dtls1_get_record(SSL * s)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 s->packet_length=0; /* dump this record */
601 goto again; /* get another record */
602 }
603
604 /* just read a 0 length packet */
605 if (rr->length == 0) goto again;
606
607 /* If this record is from the next epoch (either HM or ALERT), buffer it
608 * since it cannot be processed at this time.
609 * Records from the next epoch are marked as received even though they are
610 * not processed, so as to prevent any potential resource DoS attack */
611 if (is_next_epoch)
612 {
613 dtls1_record_bitmap_update(s, bitmap);
614 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
615 s->packet_length = 0;
616 goto again;
617 }
618
619 if ( ! dtls1_process_record(s))
620 return(0);
621
622 dtls1_clear_timeouts(s); /* done waiting */
623 return(1);
624
625 f_err:
626 ssl3_send_alert(s,SSL3_AL_FATAL,al);
627 err:
628 return(0);
629 }
630
631 /* Return up to 'len' payload bytes received in 'type' records.
632 * 'type' is one of the following:
633 *
634 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
635 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
636 * - 0 (during a shutdown, no data has to be returned)
637 *
638 * If we don't have stored data to work from, read a SSL/TLS record first
639 * (possibly multiple records if we still don't have anything to return).
640 *
641 * This function must handle any surprises the peer may have for us, such as
642 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
643 * a surprise, but handled as if it were), or renegotiation requests.
644 * Also if record payloads contain fragments too small to process, we store
645 * them until there is enough for the respective protocol (the record protocol
646 * may use arbitrary fragmentation and even interleaving):
647 * Change cipher spec protocol
648 * just 1 byte needed, no need for keeping anything stored
649 * Alert protocol
650 * 2 bytes needed (AlertLevel, AlertDescription)
651 * Handshake protocol
652 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
653 * to detect unexpected Client Hello and Hello Request messages
654 * here, anything else is handled by higher layers
655 * Application data protocol
656 * none of our business
657 */
dtls1_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)658 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
659 {
660 int al,i,j,ret;
661 unsigned int n;
662 SSL3_RECORD *rr;
663 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
664
665 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
666 if (!ssl3_setup_buffers(s))
667 return(-1);
668
669 /* XXX: check what the second '&& type' is about */
670 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
671 (type != SSL3_RT_HANDSHAKE) && type) ||
672 (peek && (type != SSL3_RT_APPLICATION_DATA)))
673 {
674 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
675 return -1;
676 }
677
678 /* check whether there's a handshake message (client hello?) waiting */
679 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
680 return ret;
681
682 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
683
684 if (!s->in_handshake && SSL_in_init(s))
685 {
686 /* type == SSL3_RT_APPLICATION_DATA */
687 i=s->handshake_func(s);
688 if (i < 0) return(i);
689 if (i == 0)
690 {
691 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
692 return(-1);
693 }
694 }
695
696 start:
697 s->rwstate=SSL_NOTHING;
698
699 /* s->s3->rrec.type - is the type of record
700 * s->s3->rrec.data, - data
701 * s->s3->rrec.off, - offset into 'data' for next read
702 * s->s3->rrec.length, - number of bytes. */
703 rr = &(s->s3->rrec);
704
705 /* get new packet if necessary */
706 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
707 {
708 ret=dtls1_get_record(s);
709 if (ret <= 0)
710 {
711 ret = dtls1_read_failed(s, ret);
712 /* anything other than a timeout is an error */
713 if (ret <= 0)
714 return(ret);
715 else
716 goto start;
717 }
718 }
719
720 /* we now have a packet which can be read and processed */
721
722 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
723 * reset by ssl3_get_finished */
724 && (rr->type != SSL3_RT_HANDSHAKE))
725 {
726 al=SSL_AD_UNEXPECTED_MESSAGE;
727 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
728 goto err;
729 }
730
731 /* If the other end has shut down, throw anything we read away
732 * (even in 'peek' mode) */
733 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
734 {
735 rr->length=0;
736 s->rwstate=SSL_NOTHING;
737 return(0);
738 }
739
740
741 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
742 {
743 /* make sure that we are not getting application data when we
744 * are doing a handshake for the first time */
745 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
746 (s->enc_read_ctx == NULL))
747 {
748 al=SSL_AD_UNEXPECTED_MESSAGE;
749 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
750 goto f_err;
751 }
752
753 if (len <= 0) return(len);
754
755 if ((unsigned int)len > rr->length)
756 n = rr->length;
757 else
758 n = (unsigned int)len;
759
760 memcpy(buf,&(rr->data[rr->off]),n);
761 if (!peek)
762 {
763 rr->length-=n;
764 rr->off+=n;
765 if (rr->length == 0)
766 {
767 s->rstate=SSL_ST_READ_HEADER;
768 rr->off=0;
769 }
770 }
771 return(n);
772 }
773
774
775 /* If we get here, then type != rr->type; if we have a handshake
776 * message, then it was unexpected (Hello Request or Client Hello). */
777
778 /* In case of record types for which we have 'fragment' storage,
779 * fill that so that we can process the data at a fixed place.
780 */
781 {
782 unsigned int k, dest_maxlen = 0;
783 unsigned char *dest = NULL;
784 unsigned int *dest_len = NULL;
785
786 if (rr->type == SSL3_RT_HANDSHAKE)
787 {
788 dest_maxlen = sizeof s->d1->handshake_fragment;
789 dest = s->d1->handshake_fragment;
790 dest_len = &s->d1->handshake_fragment_len;
791 }
792 else if (rr->type == SSL3_RT_ALERT)
793 {
794 dest_maxlen = sizeof(s->d1->alert_fragment);
795 dest = s->d1->alert_fragment;
796 dest_len = &s->d1->alert_fragment_len;
797 }
798 /* else it's a CCS message, or it's wrong */
799 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
800 {
801 /* Not certain if this is the right error handling */
802 al=SSL_AD_UNEXPECTED_MESSAGE;
803 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
804 goto f_err;
805 }
806
807
808 if (dest_maxlen > 0)
809 {
810 /* XDTLS: In a pathalogical case, the Client Hello
811 * may be fragmented--don't always expect dest_maxlen bytes */
812 if ( rr->length < dest_maxlen)
813 {
814 s->rstate=SSL_ST_READ_HEADER;
815 rr->length = 0;
816 goto start;
817 }
818
819 /* now move 'n' bytes: */
820 for ( k = 0; k < dest_maxlen; k++)
821 {
822 dest[k] = rr->data[rr->off++];
823 rr->length--;
824 }
825 *dest_len = dest_maxlen;
826 }
827 }
828
829 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
830 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
831 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
832
833 /* If we are a client, check for an incoming 'Hello Request': */
834 if ((!s->server) &&
835 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
836 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
837 (s->session != NULL) && (s->session->cipher != NULL))
838 {
839 s->d1->handshake_fragment_len = 0;
840
841 if ((s->d1->handshake_fragment[1] != 0) ||
842 (s->d1->handshake_fragment[2] != 0) ||
843 (s->d1->handshake_fragment[3] != 0))
844 {
845 al=SSL_AD_DECODE_ERROR;
846 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
847 goto err;
848 }
849
850 /* no need to check sequence number on HELLO REQUEST messages */
851
852 if (s->msg_callback)
853 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
854 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
855
856 if (SSL_is_init_finished(s) &&
857 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
858 !s->s3->renegotiate)
859 {
860 ssl3_renegotiate(s);
861 if (ssl3_renegotiate_check(s))
862 {
863 i=s->handshake_func(s);
864 if (i < 0) return(i);
865 if (i == 0)
866 {
867 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
868 return(-1);
869 }
870
871 if (!(s->mode & SSL_MODE_AUTO_RETRY))
872 {
873 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
874 {
875 BIO *bio;
876 /* In the case where we try to read application data,
877 * but we trigger an SSL handshake, we return -1 with
878 * the retry option set. Otherwise renegotiation may
879 * cause nasty problems in the blocking world */
880 s->rwstate=SSL_READING;
881 bio=SSL_get_rbio(s);
882 BIO_clear_retry_flags(bio);
883 BIO_set_retry_read(bio);
884 return(-1);
885 }
886 }
887 }
888 }
889 /* we either finished a handshake or ignored the request,
890 * now try again to obtain the (application) data we were asked for */
891 goto start;
892 }
893
894 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
895 {
896 int alert_level = s->d1->alert_fragment[0];
897 int alert_descr = s->d1->alert_fragment[1];
898
899 s->d1->alert_fragment_len = 0;
900
901 if (s->msg_callback)
902 s->msg_callback(0, s->version, SSL3_RT_ALERT,
903 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
904
905 if (s->info_callback != NULL)
906 cb=s->info_callback;
907 else if (s->ctx->info_callback != NULL)
908 cb=s->ctx->info_callback;
909
910 if (cb != NULL)
911 {
912 j = (alert_level << 8) | alert_descr;
913 cb(s, SSL_CB_READ_ALERT, j);
914 }
915
916 if (alert_level == 1) /* warning */
917 {
918 s->s3->warn_alert = alert_descr;
919 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
920 {
921 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
922 return(0);
923 }
924 #if 0
925 /* XXX: this is a possible improvement in the future */
926 /* now check if it's a missing record */
927 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
928 {
929 unsigned short seq;
930 unsigned int frag_off;
931 unsigned char *p = &(s->d1->alert_fragment[2]);
932
933 n2s(p, seq);
934 n2l3(p, frag_off);
935
936 dtls1_retransmit_message(s, seq, frag_off, &found);
937 if ( ! found && SSL_in_init(s))
938 {
939 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
940 /* requested a message not yet sent,
941 send an alert ourselves */
942 ssl3_send_alert(s,SSL3_AL_WARNING,
943 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
944 }
945 }
946 #endif
947 }
948 else if (alert_level == 2) /* fatal */
949 {
950 char tmp[16];
951
952 s->rwstate=SSL_NOTHING;
953 s->s3->fatal_alert = alert_descr;
954 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
955 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
956 ERR_add_error_data(2,"SSL alert number ",tmp);
957 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
958 SSL_CTX_remove_session(s->ctx,s->session);
959 return(0);
960 }
961 else
962 {
963 al=SSL_AD_ILLEGAL_PARAMETER;
964 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
965 goto f_err;
966 }
967
968 goto start;
969 }
970
971 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
972 {
973 s->rwstate=SSL_NOTHING;
974 rr->length=0;
975 return(0);
976 }
977
978 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
979 {
980 struct ccs_header_st ccs_hdr;
981
982 dtls1_get_ccs_header(rr->data, &ccs_hdr);
983
984 /* 'Change Cipher Spec' is just a single byte, so we know
985 * exactly what the record payload has to look like */
986 /* XDTLS: check that epoch is consistent */
987 if ( (s->client_version == DTLS1_BAD_VER && rr->length != 3) ||
988 (s->client_version != DTLS1_BAD_VER && rr->length != DTLS1_CCS_HEADER_LENGTH) ||
989 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
990 {
991 i=SSL_AD_ILLEGAL_PARAMETER;
992 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
993 goto err;
994 }
995
996 rr->length=0;
997
998 if (s->msg_callback)
999 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1000 rr->data, 1, s, s->msg_callback_arg);
1001
1002 s->s3->change_cipher_spec=1;
1003 if (!ssl3_do_change_cipher_spec(s))
1004 goto err;
1005
1006 /* do this whenever CCS is processed */
1007 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1008
1009 if (s->client_version == DTLS1_BAD_VER)
1010 s->d1->handshake_read_seq++;
1011
1012 goto start;
1013 }
1014
1015 /* Unexpected handshake message (Client Hello, or protocol violation) */
1016 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1017 !s->in_handshake)
1018 {
1019 struct hm_header_st msg_hdr;
1020
1021 /* this may just be a stale retransmit */
1022 dtls1_get_message_header(rr->data, &msg_hdr);
1023 if( rr->epoch != s->d1->r_epoch)
1024 {
1025 rr->length = 0;
1026 goto start;
1027 }
1028
1029 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1030 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1031 {
1032 #if 0 /* worked only because C operator preferences are not as expected (and
1033 * because this is not really needed for clients except for detecting
1034 * protocol violations): */
1035 s->state=SSL_ST_BEFORE|(s->server)
1036 ?SSL_ST_ACCEPT
1037 :SSL_ST_CONNECT;
1038 #else
1039 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1040 #endif
1041 s->new_session=1;
1042 }
1043 i=s->handshake_func(s);
1044 if (i < 0) return(i);
1045 if (i == 0)
1046 {
1047 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1048 return(-1);
1049 }
1050
1051 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1052 {
1053 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1054 {
1055 BIO *bio;
1056 /* In the case where we try to read application data,
1057 * but we trigger an SSL handshake, we return -1 with
1058 * the retry option set. Otherwise renegotiation may
1059 * cause nasty problems in the blocking world */
1060 s->rwstate=SSL_READING;
1061 bio=SSL_get_rbio(s);
1062 BIO_clear_retry_flags(bio);
1063 BIO_set_retry_read(bio);
1064 return(-1);
1065 }
1066 }
1067 goto start;
1068 }
1069
1070 switch (rr->type)
1071 {
1072 default:
1073 #ifndef OPENSSL_NO_TLS
1074 /* TLS just ignores unknown message types */
1075 if (s->version == TLS1_VERSION)
1076 {
1077 rr->length = 0;
1078 goto start;
1079 }
1080 #endif
1081 al=SSL_AD_UNEXPECTED_MESSAGE;
1082 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1083 goto f_err;
1084 case SSL3_RT_CHANGE_CIPHER_SPEC:
1085 case SSL3_RT_ALERT:
1086 case SSL3_RT_HANDSHAKE:
1087 /* we already handled all of these, with the possible exception
1088 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1089 * should not happen when type != rr->type */
1090 al=SSL_AD_UNEXPECTED_MESSAGE;
1091 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1092 goto f_err;
1093 case SSL3_RT_APPLICATION_DATA:
1094 /* At this point, we were expecting handshake data,
1095 * but have application data. If the library was
1096 * running inside ssl3_read() (i.e. in_read_app_data
1097 * is set) and it makes sense to read application data
1098 * at this point (session renegotiation not yet started),
1099 * we will indulge it.
1100 */
1101 if (s->s3->in_read_app_data &&
1102 (s->s3->total_renegotiations != 0) &&
1103 ((
1104 (s->state & SSL_ST_CONNECT) &&
1105 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1106 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1107 ) || (
1108 (s->state & SSL_ST_ACCEPT) &&
1109 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1110 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1111 )
1112 ))
1113 {
1114 s->s3->in_read_app_data=2;
1115 return(-1);
1116 }
1117 else
1118 {
1119 al=SSL_AD_UNEXPECTED_MESSAGE;
1120 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1121 goto f_err;
1122 }
1123 }
1124 /* not reached */
1125
1126 f_err:
1127 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1128 err:
1129 return(-1);
1130 }
1131
1132 int
dtls1_write_app_data_bytes(SSL * s,int type,const void * buf_,int len)1133 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1134 {
1135 unsigned int n,tot;
1136 int i;
1137
1138 if (SSL_in_init(s) && !s->in_handshake)
1139 {
1140 i=s->handshake_func(s);
1141 if (i < 0) return(i);
1142 if (i == 0)
1143 {
1144 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1145 return -1;
1146 }
1147 }
1148
1149 tot = s->s3->wnum;
1150 n = len - tot;
1151
1152 while( n)
1153 {
1154 /* dtls1_write_bytes sends one record at a time, sized according to
1155 * the currently known MTU */
1156 i = dtls1_write_bytes(s, type, buf_, len);
1157 if (i <= 0) return i;
1158
1159 if ((i == (int)n) ||
1160 (type == SSL3_RT_APPLICATION_DATA &&
1161 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1162 {
1163 /* next chunk of data should get another prepended empty fragment
1164 * in ciphersuites with known-IV weakness: */
1165 s->s3->empty_fragment_done = 0;
1166 return tot+i;
1167 }
1168
1169 tot += i;
1170 n-=i;
1171 }
1172
1173 return tot;
1174 }
1175
1176
1177 /* this only happens when a client hello is received and a handshake
1178 * is started. */
1179 static int
have_handshake_fragment(SSL * s,int type,unsigned char * buf,int len,int peek)1180 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1181 int len, int peek)
1182 {
1183
1184 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1185 /* (partially) satisfy request from storage */
1186 {
1187 unsigned char *src = s->d1->handshake_fragment;
1188 unsigned char *dst = buf;
1189 unsigned int k,n;
1190
1191 /* peek == 0 */
1192 n = 0;
1193 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1194 {
1195 *dst++ = *src++;
1196 len--; s->d1->handshake_fragment_len--;
1197 n++;
1198 }
1199 /* move any remaining fragment bytes: */
1200 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1201 s->d1->handshake_fragment[k] = *src++;
1202 return n;
1203 }
1204
1205 return 0;
1206 }
1207
1208
1209
1210
1211 /* Call this to write data in records of type 'type'
1212 * It will return <= 0 if not all data has been sent or non-blocking IO.
1213 */
dtls1_write_bytes(SSL * s,int type,const void * buf_,int len)1214 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1215 {
1216 const unsigned char *buf=buf_;
1217 unsigned int tot,n,nw;
1218 int i;
1219 unsigned int mtu;
1220
1221 s->rwstate=SSL_NOTHING;
1222 tot=s->s3->wnum;
1223
1224 n=(len-tot);
1225
1226 /* handshake layer figures out MTU for itself, but data records
1227 * are also sent through this interface, so need to figure out MTU */
1228 #if 0
1229 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1230 mtu += DTLS1_HM_HEADER_LENGTH; /* HM already inserted */
1231 #endif
1232 mtu = s->d1->mtu;
1233
1234 if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1235 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1236
1237 if (n > mtu)
1238 nw=mtu;
1239 else
1240 nw=n;
1241
1242 i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1243 if (i <= 0)
1244 {
1245 s->s3->wnum=tot;
1246 return i;
1247 }
1248
1249 if ( (int)s->s3->wnum + i == len)
1250 s->s3->wnum = 0;
1251 else
1252 s->s3->wnum += i;
1253
1254 return tot + i;
1255 }
1256
do_dtls1_write(SSL * s,int type,const unsigned char * buf,unsigned int len,int create_empty_fragment)1257 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1258 {
1259 unsigned char *p,*pseq;
1260 int i,mac_size,clear=0;
1261 int prefix_len = 0;
1262 SSL3_RECORD *wr;
1263 SSL3_BUFFER *wb;
1264 SSL_SESSION *sess;
1265 int bs;
1266
1267 /* first check if there is a SSL3_BUFFER still being written
1268 * out. This will happen with non blocking IO */
1269 if (s->s3->wbuf.left != 0)
1270 {
1271 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1272 return(ssl3_write_pending(s,type,buf,len));
1273 }
1274
1275 /* If we have an alert to send, lets send it */
1276 if (s->s3->alert_dispatch)
1277 {
1278 i=s->method->ssl_dispatch_alert(s);
1279 if (i <= 0)
1280 return(i);
1281 /* if it went, fall through and send more stuff */
1282 }
1283
1284 if (len == 0 && !create_empty_fragment)
1285 return 0;
1286
1287 wr= &(s->s3->wrec);
1288 wb= &(s->s3->wbuf);
1289 sess=s->session;
1290
1291 if ( (sess == NULL) ||
1292 (s->enc_write_ctx == NULL) ||
1293 (s->write_hash == NULL))
1294 clear=1;
1295
1296 if (clear)
1297 mac_size=0;
1298 else
1299 mac_size=EVP_MD_size(s->write_hash);
1300
1301 /* DTLS implements explicit IV, so no need for empty fragments */
1302 #if 0
1303 /* 'create_empty_fragment' is true only when this function calls itself */
1304 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1305 && SSL_version(s) != DTLS1_VERSION)
1306 {
1307 /* countermeasure against known-IV weakness in CBC ciphersuites
1308 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1309 */
1310
1311 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1312 {
1313 /* recursive function call with 'create_empty_fragment' set;
1314 * this prepares and buffers the data for an empty fragment
1315 * (these 'prefix_len' bytes are sent out later
1316 * together with the actual payload) */
1317 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1318 if (prefix_len <= 0)
1319 goto err;
1320
1321 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1322 {
1323 /* insufficient space */
1324 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1325 goto err;
1326 }
1327 }
1328
1329 s->s3->empty_fragment_done = 1;
1330 }
1331 #endif
1332
1333 p = wb->buf + prefix_len;
1334
1335 /* write the header */
1336
1337 *(p++)=type&0xff;
1338 wr->type=type;
1339
1340 if (s->client_version == DTLS1_BAD_VER)
1341 *(p++) = DTLS1_BAD_VER>>8,
1342 *(p++) = DTLS1_BAD_VER&0xff;
1343 else
1344 *(p++)=(s->version>>8),
1345 *(p++)=s->version&0xff;
1346
1347 /* field where we are to write out packet epoch, seq num and len */
1348 pseq=p;
1349 p+=10;
1350
1351 /* lets setup the record stuff. */
1352
1353 /* Make space for the explicit IV in case of CBC.
1354 * (this is a bit of a boundary violation, but what the heck).
1355 */
1356 if ( s->enc_write_ctx &&
1357 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1358 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1359 else
1360 bs = 0;
1361
1362 wr->data=p + bs; /* make room for IV in case of CBC */
1363 wr->length=(int)len;
1364 wr->input=(unsigned char *)buf;
1365
1366 /* we now 'read' from wr->input, wr->length bytes into
1367 * wr->data */
1368
1369 /* first we compress */
1370 if (s->compress != NULL)
1371 {
1372 if (!ssl3_do_compress(s))
1373 {
1374 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1375 goto err;
1376 }
1377 }
1378 else
1379 {
1380 memcpy(wr->data,wr->input,wr->length);
1381 wr->input=wr->data;
1382 }
1383
1384 /* we should still have the output to wr->data and the input
1385 * from wr->input. Length should be wr->length.
1386 * wr->data still points in the wb->buf */
1387
1388 if (mac_size != 0)
1389 {
1390 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1391 wr->length+=mac_size;
1392 }
1393
1394 /* this is true regardless of mac size */
1395 wr->input=p;
1396 wr->data=p;
1397
1398
1399 /* ssl3_enc can only have an error on read */
1400 if (bs) /* bs != 0 in case of CBC */
1401 {
1402 RAND_pseudo_bytes(p,bs);
1403 /* master IV and last CBC residue stand for
1404 * the rest of randomness */
1405 wr->length += bs;
1406 }
1407
1408 s->method->ssl3_enc->enc(s,1);
1409
1410 /* record length after mac and block padding */
1411 /* if (type == SSL3_RT_APPLICATION_DATA ||
1412 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1413
1414 /* there's only one epoch between handshake and app data */
1415
1416 s2n(s->d1->w_epoch, pseq);
1417
1418 /* XDTLS: ?? */
1419 /* else
1420 s2n(s->d1->handshake_epoch, pseq); */
1421
1422 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1423 pseq+=6;
1424 s2n(wr->length,pseq);
1425
1426 /* we should now have
1427 * wr->data pointing to the encrypted data, which is
1428 * wr->length long */
1429 wr->type=type; /* not needed but helps for debugging */
1430 wr->length+=DTLS1_RT_HEADER_LENGTH;
1431
1432 #if 0 /* this is now done at the message layer */
1433 /* buffer the record, making it easy to handle retransmits */
1434 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1435 dtls1_buffer_record(s, wr->data, wr->length,
1436 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1437 #endif
1438
1439 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1440
1441 if (create_empty_fragment)
1442 {
1443 /* we are in a recursive call;
1444 * just return the length, don't write out anything here
1445 */
1446 return wr->length;
1447 }
1448
1449 /* now let's set up wb */
1450 wb->left = prefix_len + wr->length;
1451 wb->offset = 0;
1452
1453 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1454 s->s3->wpend_tot=len;
1455 s->s3->wpend_buf=buf;
1456 s->s3->wpend_type=type;
1457 s->s3->wpend_ret=len;
1458
1459 /* we now just need to write the buffer */
1460 return ssl3_write_pending(s,type,buf,len);
1461 err:
1462 return -1;
1463 }
1464
1465
1466
dtls1_record_replay_check(SSL * s,DTLS1_BITMAP * bitmap,PQ_64BIT * seq_num)1467 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1468 PQ_64BIT *seq_num)
1469 {
1470 #if PQ_64BIT_IS_INTEGER
1471 PQ_64BIT mask = 0x0000000000000001L;
1472 #endif
1473 PQ_64BIT rcd_num, tmp;
1474
1475 pq_64bit_init(&rcd_num);
1476 pq_64bit_init(&tmp);
1477
1478 /* this is the sequence number for the record just read */
1479 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1480
1481
1482 if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1483 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1484 {
1485 pq_64bit_assign(seq_num, &rcd_num);
1486 pq_64bit_free(&rcd_num);
1487 pq_64bit_free(&tmp);
1488 return 1; /* this record is new */
1489 }
1490
1491 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1492
1493 if ( pq_64bit_get_word(&tmp) > bitmap->length)
1494 {
1495 pq_64bit_free(&rcd_num);
1496 pq_64bit_free(&tmp);
1497 return 0; /* stale, outside the window */
1498 }
1499
1500 #if PQ_64BIT_IS_BIGNUM
1501 {
1502 int offset;
1503 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1504 pq_64bit_sub_word(&tmp, 1);
1505 offset = pq_64bit_get_word(&tmp);
1506 if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1507 {
1508 pq_64bit_free(&rcd_num);
1509 pq_64bit_free(&tmp);
1510 return 0;
1511 }
1512 }
1513 #else
1514 mask <<= (bitmap->max_seq_num - rcd_num - 1);
1515 if (bitmap->map & mask)
1516 return 0; /* record previously received */
1517 #endif
1518
1519 pq_64bit_assign(seq_num, &rcd_num);
1520 pq_64bit_free(&rcd_num);
1521 pq_64bit_free(&tmp);
1522 return 1;
1523 }
1524
1525
dtls1_record_bitmap_update(SSL * s,DTLS1_BITMAP * bitmap)1526 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1527 {
1528 unsigned int shift;
1529 PQ_64BIT rcd_num;
1530 PQ_64BIT tmp;
1531 PQ_64BIT_CTX *ctx;
1532
1533 pq_64bit_init(&rcd_num);
1534 pq_64bit_init(&tmp);
1535
1536 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1537
1538 /* unfortunate code complexity due to 64-bit manipulation support
1539 * on 32-bit machines */
1540 if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1541 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1542 {
1543 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1544 pq_64bit_add_word(&tmp, 1);
1545
1546 shift = (unsigned int)pq_64bit_get_word(&tmp);
1547
1548 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1549 pq_64bit_assign(&(bitmap->map), &tmp);
1550
1551 pq_64bit_set_bit(&(bitmap->map), 0);
1552 pq_64bit_add_word(&rcd_num, 1);
1553 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1554
1555 pq_64bit_assign_word(&tmp, 1);
1556 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1557 ctx = pq_64bit_ctx_new(&ctx);
1558 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1559 pq_64bit_ctx_free(ctx);
1560 }
1561 else
1562 {
1563 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1564 pq_64bit_sub_word(&tmp, 1);
1565 shift = (unsigned int)pq_64bit_get_word(&tmp);
1566
1567 pq_64bit_set_bit(&(bitmap->map), shift);
1568 }
1569
1570 pq_64bit_free(&rcd_num);
1571 pq_64bit_free(&tmp);
1572 }
1573
1574
dtls1_dispatch_alert(SSL * s)1575 int dtls1_dispatch_alert(SSL *s)
1576 {
1577 int i,j;
1578 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1579 unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1580 unsigned char *ptr = &buf[0];
1581
1582 s->s3->alert_dispatch=0;
1583
1584 memset(buf, 0x00, sizeof(buf));
1585 *ptr++ = s->s3->send_alert[0];
1586 *ptr++ = s->s3->send_alert[1];
1587
1588 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1589 {
1590 s2n(s->d1->handshake_read_seq, ptr);
1591 #if 0
1592 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1593
1594 else
1595 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1596 #endif
1597
1598 #if 0
1599 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);
1600 #endif
1601 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1602 }
1603
1604 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1605 if (i <= 0)
1606 {
1607 s->s3->alert_dispatch=1;
1608 /* fprintf( stderr, "not done with alert\n" ); */
1609 }
1610 else
1611 {
1612 if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||
1613 s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1614 (void)BIO_flush(s->wbio);
1615
1616 if (s->msg_callback)
1617 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1618 2, s, s->msg_callback_arg);
1619
1620 if (s->info_callback != NULL)
1621 cb=s->info_callback;
1622 else if (s->ctx->info_callback != NULL)
1623 cb=s->ctx->info_callback;
1624
1625 if (cb != NULL)
1626 {
1627 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1628 cb(s,SSL_CB_WRITE_ALERT,j);
1629 }
1630 }
1631 return(i);
1632 }
1633
1634
1635 static DTLS1_BITMAP *
dtls1_get_bitmap(SSL * s,SSL3_RECORD * rr,unsigned int * is_next_epoch)1636 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1637 {
1638
1639 *is_next_epoch = 0;
1640
1641 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1642 if (rr->epoch == s->d1->r_epoch)
1643 return &s->d1->bitmap;
1644
1645 /* Only HM and ALERT messages can be from the next epoch */
1646 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1647 (rr->type == SSL3_RT_HANDSHAKE ||
1648 rr->type == SSL3_RT_ALERT))
1649 {
1650 *is_next_epoch = 1;
1651 return &s->d1->next_bitmap;
1652 }
1653
1654 return NULL;
1655 }
1656
1657 #if 0
1658 static int
1659 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1660 unsigned long *offset)
1661 {
1662
1663 /* alerts are passed up immediately */
1664 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1665 rr->type == SSL3_RT_ALERT)
1666 return 0;
1667
1668 /* Only need to buffer if a handshake is underway.
1669 * (this implies that Hello Request and Client Hello are passed up
1670 * immediately) */
1671 if ( SSL_in_init(s))
1672 {
1673 unsigned char *data = rr->data;
1674 /* need to extract the HM/CCS sequence number here */
1675 if ( rr->type == SSL3_RT_HANDSHAKE ||
1676 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1677 {
1678 unsigned short seq_num;
1679 struct hm_header_st msg_hdr;
1680 struct ccs_header_st ccs_hdr;
1681
1682 if ( rr->type == SSL3_RT_HANDSHAKE)
1683 {
1684 dtls1_get_message_header(data, &msg_hdr);
1685 seq_num = msg_hdr.seq;
1686 *offset = msg_hdr.frag_off;
1687 }
1688 else
1689 {
1690 dtls1_get_ccs_header(data, &ccs_hdr);
1691 seq_num = ccs_hdr.seq;
1692 *offset = 0;
1693 }
1694
1695 /* this is either a record we're waiting for, or a
1696 * retransmit of something we happened to previously
1697 * receive (higher layers will drop the repeat silently */
1698 if ( seq_num < s->d1->handshake_read_seq)
1699 return 0;
1700 if (rr->type == SSL3_RT_HANDSHAKE &&
1701 seq_num == s->d1->handshake_read_seq &&
1702 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1703 return 0;
1704 else if ( seq_num == s->d1->handshake_read_seq &&
1705 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1706 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1707 return 0;
1708 else
1709 {
1710 *priority = seq_num;
1711 return 1;
1712 }
1713 }
1714 else /* unknown record type */
1715 return 0;
1716 }
1717
1718 return 0;
1719 }
1720 #endif
1721
1722 void
dtls1_reset_seq_numbers(SSL * s,int rw)1723 dtls1_reset_seq_numbers(SSL *s, int rw)
1724 {
1725 unsigned char *seq;
1726 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1727
1728 if ( rw & SSL3_CC_READ)
1729 {
1730 seq = s->s3->read_sequence;
1731 s->d1->r_epoch++;
1732
1733 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1734 s->d1->bitmap.length = s->d1->next_bitmap.length;
1735 pq_64bit_assign(&(s->d1->bitmap.max_seq_num),
1736 &(s->d1->next_bitmap.max_seq_num));
1737
1738 pq_64bit_free(&(s->d1->next_bitmap.map));
1739 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1740 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1741 pq_64bit_init(&(s->d1->next_bitmap.map));
1742 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1743 }
1744 else
1745 {
1746 seq = s->s3->write_sequence;
1747 s->d1->w_epoch++;
1748 }
1749
1750 memset(seq, 0x00, seq_bytes);
1751 }
1752
1753 #if PQ_64BIT_IS_INTEGER
1754 static PQ_64BIT
bytes_to_long_long(unsigned char * bytes,PQ_64BIT * num)1755 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1756 {
1757 PQ_64BIT _num;
1758
1759 _num = (((PQ_64BIT)bytes[0]) << 56) |
1760 (((PQ_64BIT)bytes[1]) << 48) |
1761 (((PQ_64BIT)bytes[2]) << 40) |
1762 (((PQ_64BIT)bytes[3]) << 32) |
1763 (((PQ_64BIT)bytes[4]) << 24) |
1764 (((PQ_64BIT)bytes[5]) << 16) |
1765 (((PQ_64BIT)bytes[6]) << 8) |
1766 (((PQ_64BIT)bytes[7]) );
1767
1768 *num = _num ;
1769 return _num;
1770 }
1771 #endif
1772
1773
1774 static void
dtls1_clear_timeouts(SSL * s)1775 dtls1_clear_timeouts(SSL *s)
1776 {
1777 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1778 }
1779