1 /* $OpenBSD: d1_pkt.c,v 1.129 2024/07/20 04:04:23 jsing Exp $ */
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 <endian.h>
117 #include <errno.h>
118 #include <limits.h>
119 #include <stdio.h>
120
121 #include <openssl/buffer.h>
122 #include <openssl/evp.h>
123
124 #include "bytestring.h"
125 #include "dtls_local.h"
126 #include "pqueue.h"
127 #include "ssl_local.h"
128 #include "tls_content.h"
129
130 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
131 static int
satsub64be(const unsigned char * v1,const unsigned char * v2)132 satsub64be(const unsigned char *v1, const unsigned char *v2)
133 {
134 int ret, sat, brw, i;
135
136 if (sizeof(long) == 8)
137 do {
138 long l;
139
140 if (BYTE_ORDER == LITTLE_ENDIAN)
141 break;
142 /* not reached on little-endians */
143 /* following test is redundant, because input is
144 * always aligned, but I take no chances... */
145 if (((size_t)v1 | (size_t)v2) & 0x7)
146 break;
147
148 l = *((long *)v1);
149 l -= *((long *)v2);
150 if (l > 128)
151 return 128;
152 else if (l<-128)
153 return -128;
154 else
155 return (int)l;
156 } while (0);
157
158 ret = (int)v1[7] - (int)v2[7];
159 sat = 0;
160 brw = ret >> 8; /* brw is either 0 or -1 */
161 if (ret & 0x80) {
162 for (i = 6; i >= 0; i--) {
163 brw += (int)v1[i]-(int)v2[i];
164 sat |= ~brw;
165 brw >>= 8;
166 }
167 } else {
168 for (i = 6; i >= 0; i--) {
169 brw += (int)v1[i]-(int)v2[i];
170 sat |= brw;
171 brw >>= 8;
172 }
173 }
174 brw <<= 8; /* brw is either 0 or -256 */
175
176 if (sat & 0xff)
177 return brw | 0x80;
178 else
179 return brw + (ret & 0xFF);
180 }
181
182 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
183 const unsigned char *seq);
184 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap,
185 const unsigned char *seq);
186 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr,
187 unsigned int *is_next_epoch);
188 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
189 unsigned char *priority);
190 static int dtls1_process_record(SSL *s);
191
192 /* copy buffered record into SSL structure */
193 static int
dtls1_copy_record(SSL * s,DTLS1_RECORD_DATA_INTERNAL * rdata)194 dtls1_copy_record(SSL *s, DTLS1_RECORD_DATA_INTERNAL *rdata)
195 {
196 ssl3_release_buffer(&s->s3->rbuf);
197
198 s->packet = rdata->packet;
199 s->packet_length = rdata->packet_length;
200 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL));
201 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD_INTERNAL));
202
203 return (1);
204 }
205
206 static int
dtls1_buffer_record(SSL * s,record_pqueue * queue,unsigned char * priority)207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
208 {
209 DTLS1_RECORD_DATA_INTERNAL *rdata = NULL;
210 pitem *item = NULL;
211
212 /* Limit the size of the queue to prevent DOS attacks */
213 if (pqueue_size(queue->q) >= 100)
214 return 0;
215
216 if ((rdata = malloc(sizeof(*rdata))) == NULL)
217 goto init_err;
218 if ((item = pitem_new(priority, rdata)) == NULL)
219 goto init_err;
220
221 rdata->packet = s->packet;
222 rdata->packet_length = s->packet_length;
223 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER_INTERNAL));
224 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD_INTERNAL));
225
226 item->data = rdata;
227
228 s->packet = NULL;
229 s->packet_length = 0;
230 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL));
231 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD_INTERNAL));
232
233 if (!ssl3_setup_buffers(s))
234 goto err;
235
236 /* insert should not fail, since duplicates are dropped */
237 if (pqueue_insert(queue->q, item) == NULL)
238 goto err;
239
240 return (1);
241
242 err:
243 ssl3_release_buffer(&rdata->rbuf);
244
245 init_err:
246 SSLerror(s, ERR_R_INTERNAL_ERROR);
247 free(rdata);
248 pitem_free(item);
249 return (-1);
250 }
251
252 static int
dtls1_buffer_rcontent(SSL * s,rcontent_pqueue * queue,unsigned char * priority)253 dtls1_buffer_rcontent(SSL *s, rcontent_pqueue *queue, unsigned char *priority)
254 {
255 DTLS1_RCONTENT_DATA_INTERNAL *rdata = NULL;
256 pitem *item = NULL;
257
258 /* Limit the size of the queue to prevent DOS attacks */
259 if (pqueue_size(queue->q) >= 100)
260 return 0;
261
262 if ((rdata = malloc(sizeof(*rdata))) == NULL)
263 goto init_err;
264 if ((item = pitem_new(priority, rdata)) == NULL)
265 goto init_err;
266
267 rdata->rcontent = s->s3->rcontent;
268 s->s3->rcontent = NULL;
269
270 item->data = rdata;
271
272 /* insert should not fail, since duplicates are dropped */
273 if (pqueue_insert(queue->q, item) == NULL)
274 goto err;
275
276 if ((s->s3->rcontent = tls_content_new()) == NULL)
277 goto err;
278
279 return (1);
280
281 err:
282 tls_content_free(rdata->rcontent);
283
284 init_err:
285 SSLerror(s, ERR_R_INTERNAL_ERROR);
286 free(rdata);
287 pitem_free(item);
288 return (-1);
289 }
290
291 static int
dtls1_retrieve_buffered_record(SSL * s,record_pqueue * queue)292 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
293 {
294 pitem *item;
295
296 item = pqueue_pop(queue->q);
297 if (item) {
298 dtls1_copy_record(s, item->data);
299
300 free(item->data);
301 pitem_free(item);
302
303 return (1);
304 }
305
306 return (0);
307 }
308
309 static int
dtls1_retrieve_buffered_rcontent(SSL * s,rcontent_pqueue * queue)310 dtls1_retrieve_buffered_rcontent(SSL *s, rcontent_pqueue *queue)
311 {
312 DTLS1_RCONTENT_DATA_INTERNAL *rdata;
313 pitem *item;
314
315 item = pqueue_pop(queue->q);
316 if (item) {
317 rdata = item->data;
318
319 tls_content_free(s->s3->rcontent);
320 s->s3->rcontent = rdata->rcontent;
321 s->s3->rrec.epoch = tls_content_epoch(s->s3->rcontent);
322
323 free(item->data);
324 pitem_free(item);
325
326 return (1);
327 }
328
329 return (0);
330 }
331
332 static int
dtls1_process_buffered_record(SSL * s)333 dtls1_process_buffered_record(SSL *s)
334 {
335 /* Check if epoch is current. */
336 if (s->d1->unprocessed_rcds.epoch !=
337 tls12_record_layer_read_epoch(s->rl))
338 return (0);
339
340 /* Update epoch once all unprocessed records have been processed. */
341 if (pqueue_peek(s->d1->unprocessed_rcds.q) == NULL) {
342 s->d1->unprocessed_rcds.epoch =
343 tls12_record_layer_read_epoch(s->rl) + 1;
344 return (0);
345 }
346
347 /* Process one of the records. */
348 if (!dtls1_retrieve_buffered_record(s, &s->d1->unprocessed_rcds))
349 return (-1);
350 if (!dtls1_process_record(s))
351 return (-1);
352
353 return (1);
354 }
355
356 static int
dtls1_process_record(SSL * s)357 dtls1_process_record(SSL *s)
358 {
359 SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec);
360 uint8_t alert_desc;
361
362 tls12_record_layer_set_version(s->rl, s->version);
363
364 if (!tls12_record_layer_open_record(s->rl, s->packet, s->packet_length,
365 s->s3->rcontent)) {
366 tls12_record_layer_alert(s->rl, &alert_desc);
367
368 if (alert_desc == 0)
369 goto err;
370
371 /*
372 * DTLS should silently discard invalid records, including those
373 * with a bad MAC, as per RFC 6347 section 4.1.2.1.
374 */
375 if (alert_desc == SSL_AD_BAD_RECORD_MAC)
376 goto done;
377
378 if (alert_desc == SSL_AD_RECORD_OVERFLOW)
379 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
380
381 goto fatal_err;
382 }
383
384 /* XXX move to record layer. */
385 tls_content_set_epoch(s->s3->rcontent, rr->epoch);
386
387 done:
388 s->packet_length = 0;
389
390 return (1);
391
392 fatal_err:
393 ssl3_send_alert(s, SSL3_AL_FATAL, alert_desc);
394 err:
395 return (0);
396 }
397
398 /* Call this to get a new input record.
399 * It will return <= 0 if more data is needed, normally due to an error
400 * or non-blocking IO.
401 * When it finishes, one packet has been decoded and can be found in
402 * ssl->s3->rrec.type - is the type of record
403 * ssl->s3->rrec.data, - data
404 * ssl->s3->rrec.length, - number of bytes
405 */
406 /* used only by dtls1_read_bytes */
407 int
dtls1_get_record(SSL * s)408 dtls1_get_record(SSL *s)
409 {
410 SSL3_RECORD_INTERNAL *rr = &(s->s3->rrec);
411 unsigned char *p = NULL;
412 DTLS1_BITMAP *bitmap;
413 unsigned int is_next_epoch;
414 int ret, n;
415
416 /* See if there are pending records that can now be processed. */
417 if ((ret = dtls1_process_buffered_record(s)) != 0)
418 return (ret);
419
420 /* get something from the wire */
421 if (0) {
422 again:
423 /* dump this record on all retries */
424 rr->length = 0;
425 s->packet_length = 0;
426 }
427
428 /* check if we have the header */
429 if ((s->rstate != SSL_ST_READ_BODY) ||
430 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) {
431 CBS header, seq_no;
432 uint16_t epoch, len, ssl_version;
433 uint8_t type;
434
435 n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH);
436 if (n <= 0)
437 return (n);
438
439 /* If this packet contained a partial record, dump it. */
440 if (n != DTLS1_RT_HEADER_LENGTH)
441 goto again;
442
443 s->rstate = SSL_ST_READ_BODY;
444
445 CBS_init(&header, s->packet, s->packet_length);
446
447 /* Pull apart the header into the DTLS1_RECORD */
448 if (!CBS_get_u8(&header, &type))
449 goto again;
450 if (!CBS_get_u16(&header, &ssl_version))
451 goto again;
452
453 /* Sequence number is 64 bits, with top 2 bytes = epoch. */
454 if (!CBS_get_bytes(&header, &seq_no, SSL3_SEQUENCE_SIZE))
455 goto again;
456 if (!CBS_get_u16(&seq_no, &epoch))
457 goto again;
458 if (!CBS_write_bytes(&seq_no, &rr->seq_num[2],
459 sizeof(rr->seq_num) - 2, NULL))
460 goto again;
461
462 if (!CBS_get_u16(&header, &len))
463 goto again;
464
465 rr->type = type;
466 rr->epoch = epoch;
467 rr->length = len;
468
469 /* unexpected version, silently discard */
470 if (!s->first_packet && ssl_version != s->version)
471 goto again;
472
473 /* wrong version, silently discard record */
474 if ((ssl_version & 0xff00) != (s->version & 0xff00))
475 goto again;
476
477 /* record too long, silently discard it */
478 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
479 goto again;
480
481 /* now s->rstate == SSL_ST_READ_BODY */
482 p = (unsigned char *)CBS_data(&header);
483 }
484
485 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
486
487 n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length);
488 if (n <= 0)
489 return (n);
490
491 /* If this packet contained a partial record, dump it. */
492 if (n != DTLS1_RT_HEADER_LENGTH + rr->length)
493 goto again;
494
495 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
496
497 /* match epochs. NULL means the packet is dropped on the floor */
498 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
499 if (bitmap == NULL)
500 goto again;
501
502 /*
503 * Check whether this is a repeat, or aged record.
504 * Don't check if we're listening and this message is
505 * a ClientHello. They can look as if they're replayed,
506 * since they arrive from different connections and
507 * would be dropped unnecessarily.
508 */
509 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
510 p != NULL && *p == SSL3_MT_CLIENT_HELLO) &&
511 !dtls1_record_replay_check(s, bitmap, rr->seq_num))
512 goto again;
513
514 /* just read a 0 length packet */
515 if (rr->length == 0)
516 goto again;
517
518 /* If this record is from the next epoch (either HM or ALERT),
519 * and a handshake is currently in progress, buffer it since it
520 * cannot be processed at this time. However, do not buffer
521 * anything while listening.
522 */
523 if (is_next_epoch) {
524 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) {
525 if (dtls1_buffer_record(s, &(s->d1->unprocessed_rcds),
526 rr->seq_num) < 0)
527 return (-1);
528 /* Mark receipt of record. */
529 dtls1_record_bitmap_update(s, bitmap, rr->seq_num);
530 }
531 goto again;
532 }
533
534 if (!dtls1_process_record(s))
535 goto again;
536
537 /* Mark receipt of record. */
538 dtls1_record_bitmap_update(s, bitmap, rr->seq_num);
539
540 return (1);
541 }
542
543 static int
dtls1_read_handshake_unexpected(SSL * s)544 dtls1_read_handshake_unexpected(SSL *s)
545 {
546 struct hm_header_st hs_msg_hdr;
547 CBS cbs;
548 int ret;
549
550 if (s->in_handshake) {
551 SSLerror(s, ERR_R_INTERNAL_ERROR);
552 return -1;
553 }
554
555 /* Parse handshake message header. */
556 CBS_dup(tls_content_cbs(s->s3->rcontent), &cbs);
557 if (!dtls1_get_message_header(&cbs, &hs_msg_hdr))
558 return -1; /* XXX - probably should drop/continue. */
559
560 /* This may just be a stale retransmit. */
561 if (tls_content_epoch(s->s3->rcontent) !=
562 tls12_record_layer_read_epoch(s->rl)) {
563 tls_content_clear(s->s3->rcontent);
564 s->s3->rrec.length = 0;
565 return 1;
566 }
567
568 if (hs_msg_hdr.type == SSL3_MT_HELLO_REQUEST) {
569 /*
570 * Incoming HelloRequest messages should only be received by a
571 * client. A server may send these at any time - a client should
572 * ignore the message if received in the middle of a handshake.
573 * See RFC 5246 sections 7.4 and 7.4.1.1.
574 */
575 if (s->server) {
576 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
577 ssl3_send_alert(s, SSL3_AL_FATAL,
578 SSL_AD_UNEXPECTED_MESSAGE);
579 return -1;
580 }
581
582 /* XXX - should also check frag offset/length. */
583 if (hs_msg_hdr.msg_len != 0) {
584 SSLerror(s, SSL_R_BAD_HELLO_REQUEST);
585 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_DECODE_ERROR);
586 return -1;
587 }
588
589 ssl_msg_callback_cbs(s, 0, SSL3_RT_HANDSHAKE,
590 tls_content_cbs(s->s3->rcontent));
591
592 tls_content_clear(s->s3->rcontent);
593 s->s3->rrec.length = 0;
594
595 /*
596 * It should be impossible to hit this, but keep the safety
597 * harness for now...
598 */
599 if (s->session == NULL || s->s3->hs.cipher == NULL)
600 return 1;
601
602 /*
603 * Ignore this message if we're currently handshaking,
604 * renegotiation is already pending or renegotiation is disabled
605 * via flags.
606 */
607 if (!SSL_is_init_finished(s) || s->s3->renegotiate ||
608 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0)
609 return 1;
610
611 s->d1->handshake_read_seq++;
612
613 /* XXX - why is this set here but not in ssl3? */
614 s->new_session = 1;
615
616 if (!ssl3_renegotiate(s))
617 return 1;
618 if (!ssl3_renegotiate_check(s))
619 return 1;
620
621 } else if (hs_msg_hdr.type == SSL3_MT_CLIENT_HELLO) {
622 /*
623 * Incoming ClientHello messages should only be received by a
624 * server. A client may send these in response to server
625 * initiated renegotiation (HelloRequest) or in order to
626 * initiate renegotiation by the client. See RFC 5246 section
627 * 7.4.1.2.
628 */
629 if (!s->server) {
630 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
631 ssl3_send_alert(s, SSL3_AL_FATAL,
632 SSL_AD_UNEXPECTED_MESSAGE);
633 return -1;
634 }
635
636 /*
637 * A client should not be sending a ClientHello unless we're not
638 * currently handshaking.
639 */
640 if (!SSL_is_init_finished(s)) {
641 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
642 ssl3_send_alert(s, SSL3_AL_FATAL,
643 SSL_AD_UNEXPECTED_MESSAGE);
644 return -1;
645 }
646
647 if ((s->options & SSL_OP_NO_CLIENT_RENEGOTIATION) != 0) {
648 ssl3_send_alert(s, SSL3_AL_FATAL,
649 SSL_AD_NO_RENEGOTIATION);
650 return -1;
651 }
652
653 if (s->session == NULL || s->s3->hs.cipher == NULL) {
654 SSLerror(s, ERR_R_INTERNAL_ERROR);
655 return -1;
656 }
657
658 /* Client requested renegotiation but it is not permitted. */
659 if (!s->s3->send_connection_binding ||
660 (s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) != 0) {
661 ssl3_send_alert(s, SSL3_AL_WARNING,
662 SSL_AD_NO_RENEGOTIATION);
663 return 1;
664 }
665
666 s->s3->hs.state = SSL_ST_ACCEPT;
667 s->renegotiate = 1;
668 s->new_session = 1;
669
670 } else if (hs_msg_hdr.type == SSL3_MT_FINISHED && s->server) {
671 /*
672 * If we are server, we may have a repeated FINISHED of the
673 * client here, then retransmit our CCS and FINISHED.
674 */
675 if (dtls1_check_timeout_num(s) < 0)
676 return -1;
677
678 /* XXX - should this be calling ssl_msg_callback()? */
679
680 dtls1_retransmit_buffered_messages(s);
681
682 tls_content_clear(s->s3->rcontent);
683 s->s3->rrec.length = 0;
684
685 return 1;
686
687 } else {
688 SSLerror(s, SSL_R_UNEXPECTED_MESSAGE);
689 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
690 return -1;
691 }
692
693 if ((ret = s->handshake_func(s)) < 0)
694 return ret;
695 if (ret == 0) {
696 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
697 return -1;
698 }
699
700 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
701 if (s->s3->rbuf.left == 0) {
702 ssl_force_want_read(s);
703 return -1;
704 }
705 }
706
707 /*
708 * We either finished a handshake or ignored the request, now try again
709 * to obtain the (application) data we were asked for.
710 */
711 return 1;
712 }
713
714 /* Return up to 'len' payload bytes received in 'type' records.
715 * 'type' is one of the following:
716 *
717 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
718 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
719 * - 0 (during a shutdown, no data has to be returned)
720 *
721 * If we don't have stored data to work from, read a SSL/TLS record first
722 * (possibly multiple records if we still don't have anything to return).
723 *
724 * This function must handle any surprises the peer may have for us, such as
725 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
726 * a surprise, but handled as if it were), or renegotiation requests.
727 * Also if record payloads contain fragments too small to process, we store
728 * them until there is enough for the respective protocol (the record protocol
729 * may use arbitrary fragmentation and even interleaving):
730 * Change cipher spec protocol
731 * just 1 byte needed, no need for keeping anything stored
732 * Alert protocol
733 * 2 bytes needed (AlertLevel, AlertDescription)
734 * Handshake protocol
735 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
736 * to detect unexpected Client Hello and Hello Request messages
737 * here, anything else is handled by higher layers
738 * Application data protocol
739 * none of our business
740 */
741 int
dtls1_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)742 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
743 {
744 int rrcount = 0;
745 ssize_t ssret;
746 int ret;
747
748 if (s->s3->rbuf.buf == NULL) {
749 if (!ssl3_setup_buffers(s))
750 return -1;
751 }
752
753 if (s->s3->rcontent == NULL) {
754 if ((s->s3->rcontent = tls_content_new()) == NULL)
755 return -1;
756 }
757
758 if (len < 0) {
759 SSLerror(s, ERR_R_INTERNAL_ERROR);
760 return -1;
761 }
762
763 if (type != 0 && type != SSL3_RT_APPLICATION_DATA &&
764 type != SSL3_RT_HANDSHAKE) {
765 SSLerror(s, ERR_R_INTERNAL_ERROR);
766 return -1;
767 }
768 if (peek && type != SSL3_RT_APPLICATION_DATA) {
769 SSLerror(s, ERR_R_INTERNAL_ERROR);
770 return -1;
771 }
772
773 if (SSL_in_init(s) && !s->in_handshake) {
774 if ((ret = s->handshake_func(s)) < 0)
775 return ret;
776 if (ret == 0) {
777 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
778 return -1;
779 }
780 }
781
782 start:
783 /*
784 * Do not process more than three consecutive records, otherwise the
785 * peer can cause us to loop indefinitely. Instead, return with an
786 * SSL_ERROR_WANT_READ so the caller can choose when to handle further
787 * processing. In the future, the total number of non-handshake and
788 * non-application data records per connection should probably also be
789 * limited...
790 */
791 if (rrcount++ >= 3) {
792 ssl_force_want_read(s);
793 return -1;
794 }
795
796 s->rwstate = SSL_NOTHING;
797
798 /*
799 * We are not handshaking and have no data yet, so process data buffered
800 * during the last handshake in advance, if any.
801 */
802 if (s->s3->hs.state == SSL_ST_OK &&
803 tls_content_remaining(s->s3->rcontent) == 0)
804 dtls1_retrieve_buffered_rcontent(s, &s->d1->buffered_app_data);
805
806 if (dtls1_handle_timeout(s) > 0)
807 goto start;
808
809 if (tls_content_remaining(s->s3->rcontent) == 0) {
810 if ((ret = dtls1_get_record(s)) <= 0) {
811 /* Anything other than a timeout is an error. */
812 if ((ret = dtls1_read_failed(s, ret)) <= 0)
813 return ret;
814 goto start;
815 }
816 }
817
818 if (s->d1->listen &&
819 tls_content_type(s->s3->rcontent) != SSL3_RT_HANDSHAKE) {
820 tls_content_clear(s->s3->rcontent);
821 s->s3->rrec.length = 0;
822 goto start;
823 }
824
825 /* We now have a packet which can be read and processed. */
826
827 if (s->s3->change_cipher_spec &&
828 tls_content_type(s->s3->rcontent) != SSL3_RT_HANDSHAKE) {
829 /*
830 * We now have application data between CCS and Finished.
831 * Most likely the packets were reordered on their way, so
832 * buffer the application data for later processing rather
833 * than dropping the connection.
834 */
835 if (dtls1_buffer_rcontent(s, &s->d1->buffered_app_data,
836 s->s3->rrec.seq_num) < 0) {
837 SSLerror(s, ERR_R_INTERNAL_ERROR);
838 return (-1);
839 }
840 tls_content_clear(s->s3->rcontent);
841 s->s3->rrec.length = 0;
842 goto start;
843 }
844
845 /*
846 * If the other end has shut down, throw anything we read away (even in
847 * 'peek' mode).
848 */
849 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
850 s->rwstate = SSL_NOTHING;
851 tls_content_clear(s->s3->rcontent);
852 s->s3->rrec.length = 0;
853 return 0;
854 }
855
856 /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
857 if (tls_content_type(s->s3->rcontent) == type) {
858 /*
859 * Make sure that we are not getting application data when we
860 * are doing a handshake for the first time.
861 */
862 if (SSL_in_init(s) && type == SSL3_RT_APPLICATION_DATA &&
863 !tls12_record_layer_read_protected(s->rl)) {
864 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE);
865 ssl3_send_alert(s, SSL3_AL_FATAL,
866 SSL_AD_UNEXPECTED_MESSAGE);
867 return -1;
868 }
869
870 if (len <= 0)
871 return len;
872
873 if (peek) {
874 ssret = tls_content_peek(s->s3->rcontent, buf, len);
875 } else {
876 ssret = tls_content_read(s->s3->rcontent, buf, len);
877 }
878 if (ssret < INT_MIN || ssret > INT_MAX)
879 return -1;
880 if (ssret < 0)
881 return (int)ssret;
882
883 if (tls_content_remaining(s->s3->rcontent) == 0)
884 s->rstate = SSL_ST_READ_HEADER;
885
886 return (int)ssret;
887 }
888
889 if (tls_content_type(s->s3->rcontent) == SSL3_RT_ALERT) {
890 if ((ret = ssl3_read_alert(s)) <= 0)
891 return ret;
892 goto start;
893 }
894
895 if (s->shutdown & SSL_SENT_SHUTDOWN) {
896 s->rwstate = SSL_NOTHING;
897 tls_content_clear(s->s3->rcontent);
898 s->s3->rrec.length = 0;
899 return (0);
900 }
901
902 if (tls_content_type(s->s3->rcontent) == SSL3_RT_APPLICATION_DATA) {
903 /*
904 * At this point, we were expecting handshake data, but have
905 * application data. If the library was running inside
906 * ssl3_read() (i.e. in_read_app_data is set) and it makes
907 * sense to read application data at this point (session
908 * renegotiation not yet started), we will indulge it.
909 */
910 if (s->s3->in_read_app_data != 0 &&
911 s->s3->total_renegotiations != 0 &&
912 (((s->s3->hs.state & SSL_ST_CONNECT) &&
913 (s->s3->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) &&
914 (s->s3->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || (
915 (s->s3->hs.state & SSL_ST_ACCEPT) &&
916 (s->s3->hs.state <= SSL3_ST_SW_HELLO_REQ_A) &&
917 (s->s3->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) {
918 s->s3->in_read_app_data = 2;
919 return -1;
920 } else {
921 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
922 ssl3_send_alert(s, SSL3_AL_FATAL,
923 SSL_AD_UNEXPECTED_MESSAGE);
924 return -1;
925 }
926 }
927
928 if (tls_content_type(s->s3->rcontent) == SSL3_RT_CHANGE_CIPHER_SPEC) {
929 if ((ret = ssl3_read_change_cipher_spec(s)) <= 0)
930 return ret;
931 goto start;
932 }
933
934 if (tls_content_type(s->s3->rcontent) == SSL3_RT_HANDSHAKE) {
935 if ((ret = dtls1_read_handshake_unexpected(s)) <= 0)
936 return ret;
937 goto start;
938 }
939
940 /* Unknown record type. */
941 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
942 ssl3_send_alert(s, SSL3_AL_FATAL, SSL_AD_UNEXPECTED_MESSAGE);
943 return -1;
944 }
945
946 int
dtls1_write_app_data_bytes(SSL * s,int type,const void * buf_,int len)947 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
948 {
949 int i;
950
951 if (SSL_in_init(s) && !s->in_handshake) {
952 i = s->handshake_func(s);
953 if (i < 0)
954 return (i);
955 if (i == 0) {
956 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
957 return -1;
958 }
959 }
960
961 if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
962 SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG);
963 return -1;
964 }
965
966 i = dtls1_write_bytes(s, type, buf_, len);
967 return i;
968 }
969
970 /* Call this to write data in records of type 'type'
971 * It will return <= 0 if not all data has been sent or non-blocking IO.
972 */
973 int
dtls1_write_bytes(SSL * s,int type,const void * buf,int len)974 dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
975 {
976 int i;
977
978 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
979 s->rwstate = SSL_NOTHING;
980 i = do_dtls1_write(s, type, buf, len);
981 return i;
982 }
983
984 int
do_dtls1_write(SSL * s,int type,const unsigned char * buf,unsigned int len)985 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len)
986 {
987 SSL3_BUFFER_INTERNAL *wb = &(s->s3->wbuf);
988 size_t out_len;
989 CBB cbb;
990 int ret;
991
992 memset(&cbb, 0, sizeof(cbb));
993
994 /*
995 * First check if there is a SSL3_BUFFER_INTERNAL still being written
996 * out. This will happen with non blocking IO.
997 */
998 if (wb->left != 0) {
999 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1000 return (ssl3_write_pending(s, type, buf, len));
1001 }
1002
1003 /* If we have an alert to send, let's send it */
1004 if (s->s3->alert_dispatch) {
1005 if ((ret = ssl3_dispatch_alert(s)) <= 0)
1006 return (ret);
1007 /* If it went, fall through and send more stuff. */
1008 }
1009
1010 if (len == 0)
1011 return 0;
1012
1013 wb->offset = 0;
1014
1015 if (!CBB_init_fixed(&cbb, wb->buf, wb->len))
1016 goto err;
1017
1018 tls12_record_layer_set_version(s->rl, s->version);
1019
1020 if (!tls12_record_layer_seal_record(s->rl, type, buf, len, &cbb))
1021 goto err;
1022
1023 if (!CBB_finish(&cbb, NULL, &out_len))
1024 goto err;
1025
1026 wb->left = out_len;
1027
1028 /*
1029 * Memorize arguments so that ssl3_write_pending can detect
1030 * bad write retries later.
1031 */
1032 s->s3->wpend_tot = len;
1033 s->s3->wpend_buf = buf;
1034 s->s3->wpend_type = type;
1035 s->s3->wpend_ret = len;
1036
1037 /* We now just need to write the buffer. */
1038 return ssl3_write_pending(s, type, buf, len);
1039
1040 err:
1041 CBB_cleanup(&cbb);
1042
1043 return -1;
1044 }
1045
1046 static int
dtls1_record_replay_check(SSL * s,DTLS1_BITMAP * bitmap,const unsigned char * seq)1047 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1048 const unsigned char *seq)
1049 {
1050 unsigned int shift;
1051 int cmp;
1052
1053 cmp = satsub64be(seq, bitmap->max_seq_num);
1054 if (cmp > 0)
1055 return 1; /* this record in new */
1056 shift = -cmp;
1057 if (shift >= sizeof(bitmap->map)*8)
1058 return 0; /* stale, outside the window */
1059 else if (bitmap->map & (1UL << shift))
1060 return 0; /* record previously received */
1061
1062 return 1;
1063 }
1064
1065 static void
dtls1_record_bitmap_update(SSL * s,DTLS1_BITMAP * bitmap,const unsigned char * seq)1066 dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap,
1067 const unsigned char *seq)
1068 {
1069 unsigned int shift;
1070 int cmp;
1071
1072 cmp = satsub64be(seq, bitmap->max_seq_num);
1073 if (cmp > 0) {
1074 shift = cmp;
1075 if (shift < sizeof(bitmap->map)*8)
1076 bitmap->map <<= shift, bitmap->map |= 1UL;
1077 else
1078 bitmap->map = 1UL;
1079 memcpy(bitmap->max_seq_num, seq, 8);
1080 } else {
1081 shift = -cmp;
1082 if (shift < sizeof(bitmap->map) * 8)
1083 bitmap->map |= 1UL << shift;
1084 }
1085 }
1086
1087 static DTLS1_BITMAP *
dtls1_get_bitmap(SSL * s,SSL3_RECORD_INTERNAL * rr,unsigned int * is_next_epoch)1088 dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch)
1089 {
1090 uint16_t read_epoch, read_epoch_next;
1091
1092 *is_next_epoch = 0;
1093
1094 read_epoch = tls12_record_layer_read_epoch(s->rl);
1095 read_epoch_next = read_epoch + 1;
1096
1097 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1098 if (rr->epoch == read_epoch)
1099 return &s->d1->bitmap;
1100
1101 /* Only HM and ALERT messages can be from the next epoch */
1102 if (rr->epoch == read_epoch_next &&
1103 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1104 *is_next_epoch = 1;
1105 return &s->d1->next_bitmap;
1106 }
1107
1108 return NULL;
1109 }
1110
1111 void
dtls1_reset_read_seq_numbers(SSL * s)1112 dtls1_reset_read_seq_numbers(SSL *s)
1113 {
1114 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1115 memset(&(s->d1->next_bitmap), 0, sizeof(DTLS1_BITMAP));
1116 }
1117