1 /* $OpenBSD: d1_pkt.c,v 1.82 2020/09/24 17:59:54 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 <machine/endian.h>
117
118 #include <errno.h>
119 #include <stdio.h>
120
121 #include "ssl_locl.h"
122
123 #include <openssl/buffer.h>
124 #include <openssl/evp.h>
125
126 #include "pqueue.h"
127 #include "bytestring.h"
128
129 static int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
130 unsigned int len);
131
132
133 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
134 static int
satsub64be(const unsigned char * v1,const unsigned char * v2)135 satsub64be(const unsigned char *v1, const unsigned char *v2)
136 {
137 int ret, sat, brw, i;
138
139 if (sizeof(long) == 8)
140 do {
141 long l;
142
143 if (BYTE_ORDER == LITTLE_ENDIAN)
144 break;
145 /* not reached on little-endians */
146 /* following test is redundant, because input is
147 * always aligned, but I take no chances... */
148 if (((size_t)v1 | (size_t)v2) & 0x7)
149 break;
150
151 l = *((long *)v1);
152 l -= *((long *)v2);
153 if (l > 128)
154 return 128;
155 else if (l<-128)
156 return -128;
157 else
158 return (int)l;
159 } while (0);
160
161 ret = (int)v1[7] - (int)v2[7];
162 sat = 0;
163 brw = ret >> 8; /* brw is either 0 or -1 */
164 if (ret & 0x80) {
165 for (i = 6; i >= 0; i--) {
166 brw += (int)v1[i]-(int)v2[i];
167 sat |= ~brw;
168 brw >>= 8;
169 }
170 } else {
171 for (i = 6; i >= 0; i--) {
172 brw += (int)v1[i]-(int)v2[i];
173 sat |= brw;
174 brw >>= 8;
175 }
176 }
177 brw <<= 8; /* brw is either 0 or -256 */
178
179 if (sat & 0xff)
180 return brw | 0x80;
181 else
182 return brw + (ret & 0xFF);
183 }
184
185 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
186 int len, int peek);
187 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
188 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
189 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr,
190 unsigned int *is_next_epoch);
191 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
192 unsigned char *priority);
193 static int dtls1_process_record(SSL *s);
194
195 /* copy buffered record into SSL structure */
196 static int
dtls1_copy_record(SSL * s,pitem * item)197 dtls1_copy_record(SSL *s, pitem *item)
198 {
199 DTLS1_RECORD_DATA_INTERNAL *rdata;
200
201 rdata = (DTLS1_RECORD_DATA_INTERNAL *)item->data;
202
203 ssl3_release_buffer(&S3I(s)->rbuf);
204
205 s->internal->packet = rdata->packet;
206 s->internal->packet_length = rdata->packet_length;
207 memcpy(&(S3I(s)->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER_INTERNAL));
208 memcpy(&(S3I(s)->rrec), &(rdata->rrec), sizeof(SSL3_RECORD_INTERNAL));
209
210 /* Set proper sequence number for mac calculation */
211 memcpy(&(S3I(s)->read_sequence[2]), &(rdata->packet[5]), 6);
212
213 return (1);
214 }
215
216
217 static int
dtls1_buffer_record(SSL * s,record_pqueue * queue,unsigned char * priority)218 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
219 {
220 DTLS1_RECORD_DATA_INTERNAL *rdata;
221 pitem *item;
222
223 /* Limit the size of the queue to prevent DOS attacks */
224 if (pqueue_size(queue->q) >= 100)
225 return 0;
226
227 rdata = malloc(sizeof(DTLS1_RECORD_DATA_INTERNAL));
228 item = pitem_new(priority, rdata);
229 if (rdata == NULL || item == NULL)
230 goto init_err;
231
232 rdata->packet = s->internal->packet;
233 rdata->packet_length = s->internal->packet_length;
234 memcpy(&(rdata->rbuf), &(S3I(s)->rbuf), sizeof(SSL3_BUFFER_INTERNAL));
235 memcpy(&(rdata->rrec), &(S3I(s)->rrec), sizeof(SSL3_RECORD_INTERNAL));
236
237 item->data = rdata;
238
239 s->internal->packet = NULL;
240 s->internal->packet_length = 0;
241 memset(&(S3I(s)->rbuf), 0, sizeof(SSL3_BUFFER_INTERNAL));
242 memset(&(S3I(s)->rrec), 0, sizeof(SSL3_RECORD_INTERNAL));
243
244 if (!ssl3_setup_buffers(s))
245 goto err;
246
247 /* insert should not fail, since duplicates are dropped */
248 if (pqueue_insert(queue->q, item) == NULL)
249 goto err;
250
251 return (1);
252
253 err:
254 ssl3_release_buffer(&rdata->rbuf);
255
256 init_err:
257 SSLerror(s, ERR_R_INTERNAL_ERROR);
258 free(rdata);
259 pitem_free(item);
260 return (-1);
261 }
262
263
264 static int
dtls1_retrieve_buffered_record(SSL * s,record_pqueue * queue)265 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
266 {
267 pitem *item;
268
269 item = pqueue_pop(queue->q);
270 if (item) {
271 dtls1_copy_record(s, item);
272
273 free(item->data);
274 pitem_free(item);
275
276 return (1);
277 }
278
279 return (0);
280 }
281
282
283 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
284 * yet */
285 #define dtls1_get_unprocessed_record(s) \
286 dtls1_retrieve_buffered_record((s), \
287 &((D1I(s))->unprocessed_rcds))
288
289 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
290 #define dtls1_get_processed_record(s) \
291 dtls1_retrieve_buffered_record((s), \
292 &((D1I(s))->processed_rcds))
293
294 static int
dtls1_process_buffered_records(SSL * s)295 dtls1_process_buffered_records(SSL *s)
296 {
297 pitem *item;
298
299 item = pqueue_peek(D1I(s)->unprocessed_rcds.q);
300 if (item) {
301 /* Check if epoch is current. */
302 if (D1I(s)->unprocessed_rcds.epoch != D1I(s)->r_epoch)
303 return (1);
304 /* Nothing to do. */
305
306 /* Process all the records. */
307 while (pqueue_peek(D1I(s)->unprocessed_rcds.q)) {
308 dtls1_get_unprocessed_record(s);
309 if (! dtls1_process_record(s))
310 return (0);
311 if (dtls1_buffer_record(s, &(D1I(s)->processed_rcds),
312 S3I(s)->rrec.seq_num) < 0)
313 return (-1);
314 }
315 }
316
317 /* sync epoch numbers once all the unprocessed records
318 * have been processed */
319 D1I(s)->processed_rcds.epoch = D1I(s)->r_epoch;
320 D1I(s)->unprocessed_rcds.epoch = D1I(s)->r_epoch + 1;
321
322 return (1);
323 }
324
325 static int
dtls1_process_record(SSL * s)326 dtls1_process_record(SSL *s)
327 {
328 int i, al;
329 int enc_err;
330 SSL_SESSION *sess;
331 SSL3_RECORD_INTERNAL *rr;
332 unsigned int mac_size, orig_len;
333 unsigned char md[EVP_MAX_MD_SIZE];
334
335 rr = &(S3I(s)->rrec);
336 sess = s->session;
337
338 /* At this point, s->internal->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
339 * and we have that many bytes in s->internal->packet
340 */
341 rr->input = &(s->internal->packet[DTLS1_RT_HEADER_LENGTH]);
342
343 /* ok, we can now read from 's->internal->packet' data into 'rr'
344 * rr->input points at rr->length bytes, which
345 * need to be copied into rr->data by either
346 * the decryption or by the decompression
347 * When the data is 'copied' into the rr->data buffer,
348 * rr->input will be pointed at the new buffer */
349
350 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
351 * rr->length bytes of encrypted compressed stuff. */
352
353 /* check is not needed I believe */
354 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
355 al = SSL_AD_RECORD_OVERFLOW;
356 SSLerror(s, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
357 goto f_err;
358 }
359
360 /* decrypt in place in 'rr->input' */
361 rr->data = rr->input;
362
363 /* enc_err is:
364 * 0: (in non-constant time) if the record is publically invalid.
365 * 1: if the padding is valid
366 * -1: if the padding is invalid */
367 if ((enc_err = tls1_enc(s, 0)) == 0) {
368 /* For DTLS we simply ignore bad packets. */
369 rr->length = 0;
370 s->internal->packet_length = 0;
371 goto err;
372 }
373
374 /* r->length is now the compressed data plus mac */
375 if ((sess != NULL) && (s->enc_read_ctx != NULL) &&
376 (EVP_MD_CTX_md(s->read_hash) != NULL)) {
377 /* s->read_hash != NULL => mac_size != -1 */
378 unsigned char *mac = NULL;
379 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
380 mac_size = EVP_MD_CTX_size(s->read_hash);
381 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
382
383 orig_len = rr->length + rr->padding_length;
384
385 /* orig_len is the length of the record before any padding was
386 * removed. This is public information, as is the MAC in use,
387 * therefore we can safely process the record in a different
388 * amount of time if it's too short to possibly contain a MAC.
389 */
390 if (orig_len < mac_size ||
391 /* CBC records must have a padding length byte too. */
392 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
393 orig_len < mac_size + 1)) {
394 al = SSL_AD_DECODE_ERROR;
395 SSLerror(s, SSL_R_LENGTH_TOO_SHORT);
396 goto f_err;
397 }
398
399 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
400 /* We update the length so that the TLS header bytes
401 * can be constructed correctly but we need to extract
402 * the MAC in constant time from within the record,
403 * without leaking the contents of the padding bytes.
404 * */
405 mac = mac_tmp;
406 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
407 rr->length -= mac_size;
408 } else {
409 /* In this case there's no padding, so |orig_len|
410 * equals |rec->length| and we checked that there's
411 * enough bytes for |mac_size| above. */
412 rr->length -= mac_size;
413 mac = &rr->data[rr->length];
414 }
415
416 i = tls1_mac(s, md, 0 /* not send */);
417 if (i < 0 || mac == NULL || timingsafe_memcmp(md, mac, (size_t)mac_size) != 0)
418 enc_err = -1;
419 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
420 enc_err = -1;
421 }
422
423 if (enc_err < 0) {
424 /* decryption failed, silently discard message */
425 rr->length = 0;
426 s->internal->packet_length = 0;
427 goto err;
428 }
429
430 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
431 al = SSL_AD_RECORD_OVERFLOW;
432 SSLerror(s, SSL_R_DATA_LENGTH_TOO_LONG);
433 goto f_err;
434 }
435
436 rr->off = 0;
437 /* So at this point the following is true
438 * ssl->s3->internal->rrec.type is the type of record
439 * ssl->s3->internal->rrec.length == number of bytes in record
440 * ssl->s3->internal->rrec.off == offset to first valid byte
441 * ssl->s3->internal->rrec.data == where to take bytes from, increment
442 * after use :-).
443 */
444
445 /* we have pulled in a full packet so zero things */
446 s->internal->packet_length = 0;
447 return (1);
448
449 f_err:
450 ssl3_send_alert(s, SSL3_AL_FATAL, al);
451 err:
452 return (0);
453 }
454
455
456 /* Call this to get a new input record.
457 * It will return <= 0 if more data is needed, normally due to an error
458 * or non-blocking IO.
459 * When it finishes, one packet has been decoded and can be found in
460 * ssl->s3->internal->rrec.type - is the type of record
461 * ssl->s3->internal->rrec.data, - data
462 * ssl->s3->internal->rrec.length, - number of bytes
463 */
464 /* used only by dtls1_read_bytes */
465 int
dtls1_get_record(SSL * s)466 dtls1_get_record(SSL *s)
467 {
468 SSL3_RECORD_INTERNAL *rr;
469 unsigned char *p = NULL;
470 DTLS1_BITMAP *bitmap;
471 unsigned int is_next_epoch;
472 int n;
473
474 rr = &(S3I(s)->rrec);
475
476 /* The epoch may have changed. If so, process all the
477 * pending records. This is a non-blocking operation. */
478 if (dtls1_process_buffered_records(s) < 0)
479 return (-1);
480
481 /* if we're renegotiating, then there may be buffered records */
482 if (dtls1_get_processed_record(s))
483 return 1;
484
485 /* get something from the wire */
486 if (0) {
487 again:
488 /* dump this record on all retries */
489 rr->length = 0;
490 s->internal->packet_length = 0;
491 }
492
493 /* check if we have the header */
494 if ((s->internal->rstate != SSL_ST_READ_BODY) ||
495 (s->internal->packet_length < DTLS1_RT_HEADER_LENGTH)) {
496 CBS header, seq_no;
497 uint16_t epoch, len, ssl_version;
498 uint8_t type;
499
500 n = ssl3_packet_read(s, DTLS1_RT_HEADER_LENGTH);
501 if (n <= 0)
502 return (n);
503
504 /* If this packet contained a partial record, dump it. */
505 if (n != DTLS1_RT_HEADER_LENGTH)
506 goto again;
507
508 s->internal->rstate = SSL_ST_READ_BODY;
509
510 CBS_init(&header, s->internal->packet, s->internal->packet_length);
511
512 /* Pull apart the header into the DTLS1_RECORD */
513 if (!CBS_get_u8(&header, &type))
514 goto again;
515 if (!CBS_get_u16(&header, &ssl_version))
516 goto again;
517
518 /* sequence number is 64 bits, with top 2 bytes = epoch */
519 if (!CBS_get_u16(&header, &epoch) ||
520 !CBS_get_bytes(&header, &seq_no, 6))
521 goto again;
522
523 if (!CBS_write_bytes(&seq_no, &(S3I(s)->read_sequence[2]),
524 sizeof(S3I(s)->read_sequence) - 2, NULL))
525 goto again;
526 if (!CBS_get_u16(&header, &len))
527 goto again;
528
529 rr->type = type;
530 rr->epoch = epoch;
531 rr->length = len;
532
533 /* unexpected version, silently discard */
534 if (!s->internal->first_packet && ssl_version != s->version)
535 goto again;
536
537 /* wrong version, silently discard record */
538 if ((ssl_version & 0xff00) != (s->version & 0xff00))
539 goto again;
540
541 /* record too long, silently discard it */
542 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
543 goto again;
544
545 /* now s->internal->rstate == SSL_ST_READ_BODY */
546 p = (unsigned char *)CBS_data(&header);
547 }
548
549 /* s->internal->rstate == SSL_ST_READ_BODY, get and decode the data */
550
551 n = ssl3_packet_extend(s, DTLS1_RT_HEADER_LENGTH + rr->length);
552 if (n <= 0)
553 return (n);
554
555 /* If this packet contained a partial record, dump it. */
556 if (n != DTLS1_RT_HEADER_LENGTH + rr->length)
557 goto again;
558
559 s->internal->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
560
561 /* match epochs. NULL means the packet is dropped on the floor */
562 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
563 if (bitmap == NULL)
564 goto again;
565
566 /*
567 * Check whether this is a repeat, or aged record.
568 * Don't check if we're listening and this message is
569 * a ClientHello. They can look as if they're replayed,
570 * since they arrive from different connections and
571 * would be dropped unnecessarily.
572 */
573 if (!(D1I(s)->listen && rr->type == SSL3_RT_HANDSHAKE &&
574 p != NULL && *p == SSL3_MT_CLIENT_HELLO) &&
575 !dtls1_record_replay_check(s, bitmap))
576 goto again;
577
578 /* just read a 0 length packet */
579 if (rr->length == 0)
580 goto again;
581
582 /* If this record is from the next epoch (either HM or ALERT),
583 * and a handshake is currently in progress, buffer it since it
584 * cannot be processed at this time. However, do not buffer
585 * anything while listening.
586 */
587 if (is_next_epoch) {
588 if ((SSL_in_init(s) || s->internal->in_handshake) && !D1I(s)->listen) {
589 if (dtls1_buffer_record(s, &(D1I(s)->unprocessed_rcds),
590 rr->seq_num) < 0)
591 return (-1);
592 /* Mark receipt of record. */
593 dtls1_record_bitmap_update(s, bitmap);
594 }
595 goto again;
596 }
597
598 if (!dtls1_process_record(s))
599 goto again;
600
601 /* Mark receipt of record. */
602 dtls1_record_bitmap_update(s, bitmap);
603
604 return (1);
605 }
606
607 /* Return up to 'len' payload bytes received in 'type' records.
608 * 'type' is one of the following:
609 *
610 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
611 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
612 * - 0 (during a shutdown, no data has to be returned)
613 *
614 * If we don't have stored data to work from, read a SSL/TLS record first
615 * (possibly multiple records if we still don't have anything to return).
616 *
617 * This function must handle any surprises the peer may have for us, such as
618 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
619 * a surprise, but handled as if it were), or renegotiation requests.
620 * Also if record payloads contain fragments too small to process, we store
621 * them until there is enough for the respective protocol (the record protocol
622 * may use arbitrary fragmentation and even interleaving):
623 * Change cipher spec protocol
624 * just 1 byte needed, no need for keeping anything stored
625 * Alert protocol
626 * 2 bytes needed (AlertLevel, AlertDescription)
627 * Handshake protocol
628 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
629 * to detect unexpected Client Hello and Hello Request messages
630 * here, anything else is handled by higher layers
631 * Application data protocol
632 * none of our business
633 */
634 int
dtls1_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)635 dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
636 {
637 int al, i, j, ret;
638 unsigned int n;
639 SSL3_RECORD_INTERNAL *rr;
640 void (*cb)(const SSL *ssl, int type2, int val) = NULL;
641
642 if (S3I(s)->rbuf.buf == NULL) /* Not initialized yet */
643 if (!ssl3_setup_buffers(s))
644 return (-1);
645
646 if ((type &&
647 type != SSL3_RT_APPLICATION_DATA && type != SSL3_RT_HANDSHAKE) ||
648 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
649 SSLerror(s, ERR_R_INTERNAL_ERROR);
650 return -1;
651 }
652
653 /* check whether there's a handshake message (client hello?) waiting */
654 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
655 return ret;
656
657 /* Now D1I(s)->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
658
659 if (!s->internal->in_handshake && SSL_in_init(s))
660 {
661 /* type == SSL3_RT_APPLICATION_DATA */
662 i = s->internal->handshake_func(s);
663 if (i < 0)
664 return (i);
665 if (i == 0) {
666 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
667 return (-1);
668 }
669 }
670
671 start:
672 s->internal->rwstate = SSL_NOTHING;
673
674 /* S3I(s)->rrec.type - is the type of record
675 * S3I(s)->rrec.data, - data
676 * S3I(s)->rrec.off, - offset into 'data' for next read
677 * S3I(s)->rrec.length, - number of bytes. */
678 rr = &(S3I(s)->rrec);
679
680 /* We are not handshaking and have no data yet,
681 * so process data buffered during the last handshake
682 * in advance, if any.
683 */
684 if (S3I(s)->hs.state == SSL_ST_OK && rr->length == 0) {
685 pitem *item;
686 item = pqueue_pop(D1I(s)->buffered_app_data.q);
687 if (item) {
688
689 dtls1_copy_record(s, item);
690
691 free(item->data);
692 pitem_free(item);
693 }
694 }
695
696 /* Check for timeout */
697 if (dtls1_handle_timeout(s) > 0)
698 goto start;
699
700 /* get new packet if necessary */
701 if ((rr->length == 0) || (s->internal->rstate == SSL_ST_READ_BODY)) {
702 ret = dtls1_get_record(s);
703 if (ret <= 0) {
704 ret = dtls1_read_failed(s, ret);
705 /* anything other than a timeout is an error */
706 if (ret <= 0)
707 return (ret);
708 else
709 goto start;
710 }
711 }
712
713 if (D1I(s)->listen && rr->type != SSL3_RT_HANDSHAKE) {
714 rr->length = 0;
715 goto start;
716 }
717
718 /* we now have a packet which can be read and processed */
719
720 if (S3I(s)->change_cipher_spec /* set when we receive ChangeCipherSpec,
721 * reset by ssl3_get_finished */
722 && (rr->type != SSL3_RT_HANDSHAKE)) {
723 /* We now have application data between CCS and Finished.
724 * Most likely the packets were reordered on their way, so
725 * buffer the application data for later processing rather
726 * than dropping the connection.
727 */
728 if (dtls1_buffer_record(s, &(D1I(s)->buffered_app_data),
729 rr->seq_num) < 0) {
730 SSLerror(s, ERR_R_INTERNAL_ERROR);
731 return (-1);
732 }
733 rr->length = 0;
734 goto start;
735 }
736
737 /* If the other end has shut down, throw anything we read away
738 * (even in 'peek' mode) */
739 if (s->internal->shutdown & SSL_RECEIVED_SHUTDOWN) {
740 rr->length = 0;
741 s->internal->rwstate = SSL_NOTHING;
742 return (0);
743 }
744
745
746 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
747 {
748 /* make sure that we are not getting application data when we
749 * are doing a handshake for the first time */
750 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
751 (s->enc_read_ctx == NULL)) {
752 al = SSL_AD_UNEXPECTED_MESSAGE;
753 SSLerror(s, SSL_R_APP_DATA_IN_HANDSHAKE);
754 goto f_err;
755 }
756
757 if (len <= 0)
758 return (len);
759
760 if ((unsigned int)len > rr->length)
761 n = rr->length;
762 else
763 n = (unsigned int)len;
764
765 memcpy(buf, &(rr->data[rr->off]), n);
766 if (!peek) {
767 rr->length -= n;
768 rr->off += n;
769 if (rr->length == 0) {
770 s->internal->rstate = SSL_ST_READ_HEADER;
771 rr->off = 0;
772 }
773 }
774
775 return (n);
776 }
777
778
779 /* If we get here, then type != rr->type; if we have a handshake
780 * message, then it was unexpected (Hello Request or Client Hello). */
781
782 /* In case of record types for which we have 'fragment' storage,
783 * fill that so that we can process the data at a fixed place.
784 */
785 {
786 unsigned int k, dest_maxlen = 0;
787 unsigned char *dest = NULL;
788 unsigned int *dest_len = NULL;
789
790 if (rr->type == SSL3_RT_HANDSHAKE) {
791 dest_maxlen = sizeof D1I(s)->handshake_fragment;
792 dest = D1I(s)->handshake_fragment;
793 dest_len = &D1I(s)->handshake_fragment_len;
794 } else if (rr->type == SSL3_RT_ALERT) {
795 dest_maxlen = sizeof(D1I(s)->alert_fragment);
796 dest = D1I(s)->alert_fragment;
797 dest_len = &D1I(s)->alert_fragment_len;
798 }
799 /* else it's a CCS message, or application data or wrong */
800 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
801 /* Application data while renegotiating
802 * is allowed. Try again reading.
803 */
804 if (rr->type == SSL3_RT_APPLICATION_DATA) {
805 BIO *bio;
806 S3I(s)->in_read_app_data = 2;
807 bio = SSL_get_rbio(s);
808 s->internal->rwstate = SSL_READING;
809 BIO_clear_retry_flags(bio);
810 BIO_set_retry_read(bio);
811 return (-1);
812 }
813
814 /* Not certain if this is the right error handling */
815 al = SSL_AD_UNEXPECTED_MESSAGE;
816 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
817 goto f_err;
818 }
819
820 if (dest_maxlen > 0) {
821 /* XDTLS: In a pathalogical case, the Client Hello
822 * may be fragmented--don't always expect dest_maxlen bytes */
823 if (rr->length < dest_maxlen) {
824 s->internal->rstate = SSL_ST_READ_HEADER;
825 rr->length = 0;
826 goto start;
827 }
828
829 /* now move 'n' bytes: */
830 for ( k = 0; k < dest_maxlen; k++) {
831 dest[k] = rr->data[rr->off++];
832 rr->length--;
833 }
834 *dest_len = dest_maxlen;
835 }
836 }
837
838 /* D1I(s)->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
839 * D1I(s)->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 (D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
845 (D1I(s)->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
846 (s->session != NULL) && (s->session->cipher != NULL)) {
847 D1I(s)->handshake_fragment_len = 0;
848
849 if ((D1I(s)->handshake_fragment[1] != 0) ||
850 (D1I(s)->handshake_fragment[2] != 0) ||
851 (D1I(s)->handshake_fragment[3] != 0)) {
852 al = SSL_AD_DECODE_ERROR;
853 SSLerror(s, SSL_R_BAD_HELLO_REQUEST);
854 goto f_err;
855 }
856
857 /* no need to check sequence number on HELLO REQUEST messages */
858
859 if (s->internal->msg_callback)
860 s->internal->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
861 D1I(s)->handshake_fragment, 4, s, s->internal->msg_callback_arg);
862
863 if (SSL_is_init_finished(s) &&
864 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
865 !S3I(s)->renegotiate) {
866 D1I(s)->handshake_read_seq++;
867 s->internal->new_session = 1;
868 ssl3_renegotiate(s);
869 if (ssl3_renegotiate_check(s)) {
870 i = s->internal->handshake_func(s);
871 if (i < 0)
872 return (i);
873 if (i == 0) {
874 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
875 return (-1);
876 }
877
878 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) {
879 if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */
880 {
881 BIO *bio;
882 /* In the case where we try to read application data,
883 * but we trigger an SSL handshake, we return -1 with
884 * the retry option set. Otherwise renegotiation may
885 * cause nasty problems in the blocking world */
886 s->internal->rwstate = SSL_READING;
887 bio = SSL_get_rbio(s);
888 BIO_clear_retry_flags(bio);
889 BIO_set_retry_read(bio);
890 return (-1);
891 }
892 }
893 }
894 }
895 /* we either finished a handshake or ignored the request,
896 * now try again to obtain the (application) data we were asked for */
897 goto start;
898 }
899
900 if (D1I(s)->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
901 int alert_level = D1I(s)->alert_fragment[0];
902 int alert_descr = D1I(s)->alert_fragment[1];
903
904 D1I(s)->alert_fragment_len = 0;
905
906 if (s->internal->msg_callback)
907 s->internal->msg_callback(0, s->version, SSL3_RT_ALERT,
908 D1I(s)->alert_fragment, 2, s, s->internal->msg_callback_arg);
909
910 if (s->internal->info_callback != NULL)
911 cb = s->internal->info_callback;
912 else if (s->ctx->internal->info_callback != NULL)
913 cb = s->ctx->internal->info_callback;
914
915 if (cb != NULL) {
916 j = (alert_level << 8) | alert_descr;
917 cb(s, SSL_CB_READ_ALERT, j);
918 }
919
920 if (alert_level == 1) /* warning */
921 {
922 S3I(s)->warn_alert = alert_descr;
923 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
924 s->internal->shutdown |= SSL_RECEIVED_SHUTDOWN;
925 return (0);
926 }
927 } else if (alert_level == 2) /* fatal */
928 {
929 s->internal->rwstate = SSL_NOTHING;
930 S3I(s)->fatal_alert = alert_descr;
931 SSLerror(s, SSL_AD_REASON_OFFSET + alert_descr);
932 ERR_asprintf_error_data("SSL alert number %d",
933 alert_descr);
934 s->internal->shutdown|=SSL_RECEIVED_SHUTDOWN;
935 SSL_CTX_remove_session(s->ctx, s->session);
936 return (0);
937 } else {
938 al = SSL_AD_ILLEGAL_PARAMETER;
939 SSLerror(s, SSL_R_UNKNOWN_ALERT_TYPE);
940 goto f_err;
941 }
942
943 goto start;
944 }
945
946 if (s->internal->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
947 {
948 s->internal->rwstate = SSL_NOTHING;
949 rr->length = 0;
950 return (0);
951 }
952
953 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
954 struct ccs_header_st ccs_hdr;
955 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
956
957 dtls1_get_ccs_header(rr->data, &ccs_hdr);
958
959 /* 'Change Cipher Spec' is just a single byte, so we know
960 * exactly what the record payload has to look like */
961 /* XDTLS: check that epoch is consistent */
962 if ((rr->length != ccs_hdr_len) ||
963 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
964 al = SSL_AD_DECODE_ERROR;
965 SSLerror(s, SSL_R_BAD_CHANGE_CIPHER_SPEC);
966 goto f_err;
967 }
968
969 rr->length = 0;
970
971 if (s->internal->msg_callback)
972 s->internal->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
973 rr->data, 1, s, s->internal->msg_callback_arg);
974
975 /* We can't process a CCS now, because previous handshake
976 * messages are still missing, so just drop it.
977 */
978 if (!D1I(s)->change_cipher_spec_ok) {
979 goto start;
980 }
981
982 D1I(s)->change_cipher_spec_ok = 0;
983
984 S3I(s)->change_cipher_spec = 1;
985 if (!ssl3_do_change_cipher_spec(s))
986 goto err;
987
988 /* do this whenever CCS is processed */
989 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
990
991 goto start;
992 }
993
994 /* Unexpected handshake message (Client Hello, or protocol violation) */
995 if ((D1I(s)->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
996 !s->internal->in_handshake) {
997 struct hm_header_st msg_hdr;
998
999 /* this may just be a stale retransmit */
1000 if (!dtls1_get_message_header(rr->data, &msg_hdr))
1001 return -1;
1002 if (rr->epoch != D1I(s)->r_epoch) {
1003 rr->length = 0;
1004 goto start;
1005 }
1006
1007 /* If we are server, we may have a repeated FINISHED of the
1008 * client here, then retransmit our CCS and FINISHED.
1009 */
1010 if (msg_hdr.type == SSL3_MT_FINISHED) {
1011 if (dtls1_check_timeout_num(s) < 0)
1012 return -1;
1013
1014 dtls1_retransmit_buffered_messages(s);
1015 rr->length = 0;
1016 goto start;
1017 }
1018
1019 if (((S3I(s)->hs.state&SSL_ST_MASK) == SSL_ST_OK) &&
1020 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
1021 S3I(s)->hs.state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1022 s->internal->renegotiate = 1;
1023 s->internal->new_session = 1;
1024 }
1025 i = s->internal->handshake_func(s);
1026 if (i < 0)
1027 return (i);
1028 if (i == 0) {
1029 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
1030 return (-1);
1031 }
1032
1033 if (!(s->internal->mode & SSL_MODE_AUTO_RETRY)) {
1034 if (S3I(s)->rbuf.left == 0) /* no read-ahead left? */
1035 {
1036 BIO *bio;
1037 /* In the case where we try to read application data,
1038 * but we trigger an SSL handshake, we return -1 with
1039 * the retry option set. Otherwise renegotiation may
1040 * cause nasty problems in the blocking world */
1041 s->internal->rwstate = SSL_READING;
1042 bio = SSL_get_rbio(s);
1043 BIO_clear_retry_flags(bio);
1044 BIO_set_retry_read(bio);
1045 return (-1);
1046 }
1047 }
1048 goto start;
1049 }
1050
1051 switch (rr->type) {
1052 default:
1053 /* TLS just ignores unknown message types */
1054 if (s->version == TLS1_VERSION) {
1055 rr->length = 0;
1056 goto start;
1057 }
1058 al = SSL_AD_UNEXPECTED_MESSAGE;
1059 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
1060 goto f_err;
1061 case SSL3_RT_CHANGE_CIPHER_SPEC:
1062 case SSL3_RT_ALERT:
1063 case SSL3_RT_HANDSHAKE:
1064 /* we already handled all of these, with the possible exception
1065 * of SSL3_RT_HANDSHAKE when s->internal->in_handshake is set, but that
1066 * should not happen when type != rr->type */
1067 al = SSL_AD_UNEXPECTED_MESSAGE;
1068 SSLerror(s, ERR_R_INTERNAL_ERROR);
1069 goto f_err;
1070 case SSL3_RT_APPLICATION_DATA:
1071 /* At this point, we were expecting handshake data,
1072 * but have application data. If the library was
1073 * running inside ssl3_read() (i.e. in_read_app_data
1074 * is set) and it makes sense to read application data
1075 * at this point (session renegotiation not yet started),
1076 * we will indulge it.
1077 */
1078 if (S3I(s)->in_read_app_data &&
1079 (S3I(s)->total_renegotiations != 0) &&
1080 (((S3I(s)->hs.state & SSL_ST_CONNECT) &&
1081 (S3I(s)->hs.state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1082 (S3I(s)->hs.state <= SSL3_ST_CR_SRVR_HELLO_A)) || (
1083 (S3I(s)->hs.state & SSL_ST_ACCEPT) &&
1084 (S3I(s)->hs.state <= SSL3_ST_SW_HELLO_REQ_A) &&
1085 (S3I(s)->hs.state >= SSL3_ST_SR_CLNT_HELLO_A)))) {
1086 S3I(s)->in_read_app_data = 2;
1087 return (-1);
1088 } else {
1089 al = SSL_AD_UNEXPECTED_MESSAGE;
1090 SSLerror(s, SSL_R_UNEXPECTED_RECORD);
1091 goto f_err;
1092 }
1093 }
1094 /* not reached */
1095
1096 f_err:
1097 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1098 err:
1099 return (-1);
1100 }
1101
1102 int
dtls1_write_app_data_bytes(SSL * s,int type,const void * buf_,int len)1103 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1104 {
1105 int i;
1106
1107 if (SSL_in_init(s) && !s->internal->in_handshake)
1108 {
1109 i = s->internal->handshake_func(s);
1110 if (i < 0)
1111 return (i);
1112 if (i == 0) {
1113 SSLerror(s, SSL_R_SSL_HANDSHAKE_FAILURE);
1114 return -1;
1115 }
1116 }
1117
1118 if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
1119 SSLerror(s, SSL_R_DTLS_MESSAGE_TOO_BIG);
1120 return -1;
1121 }
1122
1123 i = dtls1_write_bytes(s, type, buf_, len);
1124 return i;
1125 }
1126
1127
1128 /* this only happens when a client hello is received and a handshake
1129 * is started. */
1130 static int
have_handshake_fragment(SSL * s,int type,unsigned char * buf,int len,int peek)1131 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1132 int len, int peek)
1133 {
1134
1135 if ((type == SSL3_RT_HANDSHAKE) && (D1I(s)->handshake_fragment_len > 0))
1136 /* (partially) satisfy request from storage */
1137 {
1138 unsigned char *src = D1I(s)->handshake_fragment;
1139 unsigned char *dst = buf;
1140 unsigned int k, n;
1141
1142 /* peek == 0 */
1143 n = 0;
1144 while ((len > 0) && (D1I(s)->handshake_fragment_len > 0)) {
1145 *dst++ = *src++;
1146 len--;
1147 D1I(s)->handshake_fragment_len--;
1148 n++;
1149 }
1150 /* move any remaining fragment bytes: */
1151 for (k = 0; k < D1I(s)->handshake_fragment_len; k++)
1152 D1I(s)->handshake_fragment[k] = *src++;
1153 return n;
1154 }
1155
1156 return 0;
1157 }
1158
1159
1160 /* Call this to write data in records of type 'type'
1161 * It will return <= 0 if not all data has been sent or non-blocking IO.
1162 */
1163 int
dtls1_write_bytes(SSL * s,int type,const void * buf,int len)1164 dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1165 {
1166 int i;
1167
1168 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1169 s->internal->rwstate = SSL_NOTHING;
1170 i = do_dtls1_write(s, type, buf, len);
1171 return i;
1172 }
1173
1174 int
do_dtls1_write(SSL * s,int type,const unsigned char * buf,unsigned int len)1175 do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len)
1176 {
1177 SSL3_BUFFER_INTERNAL *wb = &(S3I(s)->wbuf);
1178 size_t out_len;
1179 CBB cbb;
1180 int ret;
1181
1182 memset(&cbb, 0, sizeof(cbb));
1183
1184 /*
1185 * First check if there is a SSL3_BUFFER_INTERNAL still being written
1186 * out. This will happen with non blocking IO.
1187 */
1188 if (wb->left != 0) {
1189 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1190 return (ssl3_write_pending(s, type, buf, len));
1191 }
1192
1193 /* If we have an alert to send, let's send it */
1194 if (S3I(s)->alert_dispatch) {
1195 if ((ret = s->method->ssl_dispatch_alert(s)) <= 0)
1196 return (ret);
1197 /* If it went, fall through and send more stuff. */
1198 }
1199
1200 if (len == 0)
1201 return 0;
1202
1203 wb->offset = 0;
1204
1205 if (!CBB_init_fixed(&cbb, wb->buf, wb->len))
1206 goto err;
1207
1208 tls12_record_layer_set_version(s->internal->rl, s->version);
1209 tls12_record_layer_set_write_epoch(s->internal->rl, D1I(s)->w_epoch);
1210
1211 if (!tls12_record_layer_seal_record(s->internal->rl, type, buf, len, &cbb))
1212 goto err;
1213
1214 if (!CBB_finish(&cbb, NULL, &out_len))
1215 goto err;
1216
1217 wb->left = out_len;
1218
1219 /*
1220 * Memorize arguments so that ssl3_write_pending can detect
1221 * bad write retries later.
1222 */
1223 S3I(s)->wpend_tot = len;
1224 S3I(s)->wpend_buf = buf;
1225 S3I(s)->wpend_type = type;
1226 S3I(s)->wpend_ret = len;
1227
1228 /* We now just need to write the buffer. */
1229 return ssl3_write_pending(s, type, buf, len);
1230
1231 err:
1232 CBB_cleanup(&cbb);
1233
1234 return -1;
1235 }
1236
1237 static int
dtls1_record_replay_check(SSL * s,DTLS1_BITMAP * bitmap)1238 dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1239 {
1240 int cmp;
1241 unsigned int shift;
1242 const unsigned char *seq = S3I(s)->read_sequence;
1243
1244 cmp = satsub64be(seq, bitmap->max_seq_num);
1245 if (cmp > 0) {
1246 memcpy (S3I(s)->rrec.seq_num, seq, 8);
1247 return 1; /* this record in new */
1248 }
1249 shift = -cmp;
1250 if (shift >= sizeof(bitmap->map)*8)
1251 return 0; /* stale, outside the window */
1252 else if (bitmap->map & (1UL << shift))
1253 return 0; /* record previously received */
1254
1255 memcpy(S3I(s)->rrec.seq_num, seq, 8);
1256 return 1;
1257 }
1258
1259
1260 static void
dtls1_record_bitmap_update(SSL * s,DTLS1_BITMAP * bitmap)1261 dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1262 {
1263 int cmp;
1264 unsigned int shift;
1265 const unsigned char *seq = S3I(s)->read_sequence;
1266
1267 cmp = satsub64be(seq, bitmap->max_seq_num);
1268 if (cmp > 0) {
1269 shift = cmp;
1270 if (shift < sizeof(bitmap->map)*8)
1271 bitmap->map <<= shift, bitmap->map |= 1UL;
1272 else
1273 bitmap->map = 1UL;
1274 memcpy(bitmap->max_seq_num, seq, 8);
1275 } else {
1276 shift = -cmp;
1277 if (shift < sizeof(bitmap->map) * 8)
1278 bitmap->map |= 1UL << shift;
1279 }
1280 }
1281
1282
1283 int
dtls1_dispatch_alert(SSL * s)1284 dtls1_dispatch_alert(SSL *s)
1285 {
1286 int i, j;
1287 void (*cb)(const SSL *ssl, int type, int val) = NULL;
1288 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1289 unsigned char *ptr = &buf[0];
1290
1291 S3I(s)->alert_dispatch = 0;
1292
1293 memset(buf, 0, sizeof(buf));
1294 *ptr++ = S3I(s)->send_alert[0];
1295 *ptr++ = S3I(s)->send_alert[1];
1296
1297 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf));
1298 if (i <= 0) {
1299 S3I(s)->alert_dispatch = 1;
1300 /* fprintf( stderr, "not done with alert\n" ); */
1301 } else {
1302 if (S3I(s)->send_alert[0] == SSL3_AL_FATAL)
1303 (void)BIO_flush(s->wbio);
1304
1305 if (s->internal->msg_callback)
1306 s->internal->msg_callback(1, s->version, SSL3_RT_ALERT,
1307 S3I(s)->send_alert, 2, s, s->internal->msg_callback_arg);
1308
1309 if (s->internal->info_callback != NULL)
1310 cb = s->internal->info_callback;
1311 else if (s->ctx->internal->info_callback != NULL)
1312 cb = s->ctx->internal->info_callback;
1313
1314 if (cb != NULL) {
1315 j = (S3I(s)->send_alert[0]<<8)|S3I(s)->send_alert[1];
1316 cb(s, SSL_CB_WRITE_ALERT, j);
1317 }
1318 }
1319 return (i);
1320 }
1321
1322
1323 static DTLS1_BITMAP *
dtls1_get_bitmap(SSL * s,SSL3_RECORD_INTERNAL * rr,unsigned int * is_next_epoch)1324 dtls1_get_bitmap(SSL *s, SSL3_RECORD_INTERNAL *rr, unsigned int *is_next_epoch)
1325 {
1326
1327 *is_next_epoch = 0;
1328
1329 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1330 if (rr->epoch == D1I(s)->r_epoch)
1331 return &D1I(s)->bitmap;
1332
1333 /* Only HM and ALERT messages can be from the next epoch */
1334 else if (rr->epoch == (unsigned long)(D1I(s)->r_epoch + 1) &&
1335 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1336 *is_next_epoch = 1;
1337 return &D1I(s)->next_bitmap;
1338 }
1339
1340 return NULL;
1341 }
1342
1343 void
dtls1_reset_seq_numbers(SSL * s,int rw)1344 dtls1_reset_seq_numbers(SSL *s, int rw)
1345 {
1346 unsigned char *seq;
1347 unsigned int seq_bytes = sizeof(S3I(s)->read_sequence);
1348
1349 if (rw & SSL3_CC_READ) {
1350 D1I(s)->r_epoch++;
1351 seq = S3I(s)->read_sequence;
1352 memcpy(&(D1I(s)->bitmap), &(D1I(s)->next_bitmap), sizeof(DTLS1_BITMAP));
1353 memset(&(D1I(s)->next_bitmap), 0, sizeof(DTLS1_BITMAP));
1354 } else {
1355 D1I(s)->w_epoch++;
1356 seq = S3I(s)->write_sequence;
1357 memcpy(D1I(s)->last_write_sequence, seq, sizeof(S3I(s)->write_sequence));
1358 }
1359
1360 memset(seq, 0, seq_bytes);
1361 }
1362