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) 1998-2019 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 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
satsub64be(const unsigned char * v1,const unsigned char * v2)126 static int satsub64be(const unsigned char *v1, const unsigned char *v2)
127 {
128 int ret, i;
129
130 if (sizeof(long) == 8)
131 do {
132 const union {
133 long one;
134 char little;
135 } is_endian = {
136 1
137 };
138 long l;
139
140 if (is_endian.little)
141 break;
142 /* not reached on little-endians */
143 /*
144 * following test is redundant, because input is always aligned,
145 * but I take no chances...
146 */
147 if (((size_t)v1 | (size_t)v2) & 0x7)
148 break;
149
150 l = *((long *)v1);
151 l -= *((long *)v2);
152 if (l > 128)
153 return 128;
154 else if (l < -128)
155 return -128;
156 else
157 return (int)l;
158 } while (0);
159
160 ret = 0;
161 for (i=0; i<7; i++) {
162 if (v1[i] > v2[i]) {
163 /* v1 is larger... but by how much? */
164 if (v1[i] != v2[i] + 1)
165 return 128;
166 while (++i <= 6) {
167 if (v1[i] != 0x00 || v2[i] != 0xff)
168 return 128; /* too much */
169 }
170 /* We checked all the way to the penultimate byte,
171 * so despite higher bytes changing we actually
172 * know that it only changed from (e.g.)
173 * ... (xx) ff ff ff ??
174 * to ... (xx+1) 00 00 00 ??
175 * so we add a 'bias' of 256 for the carry that
176 * happened, and will eventually return
177 * 256 + v1[7] - v2[7]. */
178 ret = 256;
179 break;
180 } else if (v2[i] > v1[i]) {
181 /* v2 is larger... but by how much? */
182 if (v2[i] != v1[i] + 1)
183 return -128;
184 while (++i <= 6) {
185 if (v2[i] != 0x00 || v1[i] != 0xff)
186 return -128; /* too much */
187 }
188 /* Similar to the case above, we know it changed
189 * from ... (xx) 00 00 00 ??
190 * to ... (xx-1) ff ff ff ??
191 * so we add a 'bias' of -256 for the borrow,
192 * to return -256 + v1[7] - v2[7]. */
193 ret = -256;
194 }
195 }
196
197 ret += (int)v1[7] - (int)v2[7];
198
199 if (ret > 128)
200 return 128;
201 else if (ret < -128)
202 return -128;
203 else
204 return ret;
205 }
206
207 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
208 int len, int peek);
209 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
210 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
211 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
212 unsigned int *is_next_epoch);
213 #if 0
214 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
215 unsigned short *priority,
216 unsigned long *offset);
217 #endif
218 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
219 unsigned char *priority);
220 static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap);
221
222 /* copy buffered record into SSL structure */
dtls1_copy_record(SSL * s,pitem * item)223 static int dtls1_copy_record(SSL *s, pitem *item)
224 {
225 DTLS1_RECORD_DATA *rdata;
226
227 rdata = (DTLS1_RECORD_DATA *)item->data;
228
229 if (s->s3->rbuf.buf != NULL)
230 OPENSSL_free(s->s3->rbuf.buf);
231
232 s->packet = rdata->packet;
233 s->packet_length = rdata->packet_length;
234 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
235 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
236
237 /* Set proper sequence number for mac calculation */
238 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
239
240 return (1);
241 }
242
243 static int
dtls1_buffer_record(SSL * s,record_pqueue * queue,unsigned char * priority)244 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
245 {
246 DTLS1_RECORD_DATA *rdata;
247 pitem *item;
248
249 /* Limit the size of the queue to prevent DOS attacks */
250 if (pqueue_size(queue->q) >= 100)
251 return 0;
252
253 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
254 item = pitem_new(priority, rdata);
255 if (rdata == NULL || item == NULL) {
256 if (rdata != NULL)
257 OPENSSL_free(rdata);
258 if (item != NULL)
259 pitem_free(item);
260
261 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
262 return -1;
263 }
264
265 rdata->packet = s->packet;
266 rdata->packet_length = s->packet_length;
267 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
268 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
269
270 item->data = rdata;
271
272 #ifndef OPENSSL_NO_SCTP
273 /* Store bio_dgram_sctp_rcvinfo struct */
274 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
275 (s->state == SSL3_ST_SR_FINISHED_A
276 || s->state == SSL3_ST_CR_FINISHED_A)) {
277 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
278 sizeof(rdata->recordinfo), &rdata->recordinfo);
279 }
280 #endif
281
282 s->packet = NULL;
283 s->packet_length = 0;
284 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
285 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
286
287 if (!ssl3_setup_buffers(s)) {
288 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
289 if (rdata->rbuf.buf != NULL)
290 OPENSSL_free(rdata->rbuf.buf);
291 OPENSSL_free(rdata);
292 pitem_free(item);
293 return (-1);
294 }
295
296 if (pqueue_insert(queue->q, item) == NULL) {
297 /* Must be a duplicate so ignore it */
298 if (rdata->rbuf.buf != NULL)
299 OPENSSL_free(rdata->rbuf.buf);
300 OPENSSL_free(rdata);
301 pitem_free(item);
302 }
303
304 return (1);
305 }
306
dtls1_retrieve_buffered_record(SSL * s,record_pqueue * queue)307 static int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
308 {
309 pitem *item;
310
311 item = pqueue_pop(queue->q);
312 if (item) {
313 dtls1_copy_record(s, item);
314
315 OPENSSL_free(item->data);
316 pitem_free(item);
317
318 return (1);
319 }
320
321 return (0);
322 }
323
324 /*
325 * retrieve a buffered record that belongs to the new epoch, i.e., not
326 * processed yet
327 */
328 #define dtls1_get_unprocessed_record(s) \
329 dtls1_retrieve_buffered_record((s), \
330 &((s)->d1->unprocessed_rcds))
331
332 /*
333 * retrieve a buffered record that belongs to the current epoch, ie,
334 * processed
335 */
336 #define dtls1_get_processed_record(s) \
337 dtls1_retrieve_buffered_record((s), \
338 &((s)->d1->processed_rcds))
339
dtls1_process_buffered_records(SSL * s)340 static int dtls1_process_buffered_records(SSL *s)
341 {
342 pitem *item;
343 SSL3_BUFFER *rb;
344 SSL3_RECORD *rr;
345 DTLS1_BITMAP *bitmap;
346 unsigned int is_next_epoch;
347 int replayok = 1;
348
349 item = pqueue_peek(s->d1->unprocessed_rcds.q);
350 if (item) {
351 /* Check if epoch is current. */
352 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
353 return 1; /* Nothing to do. */
354
355 rr = &s->s3->rrec;
356 rb = &s->s3->rbuf;
357
358 if (rb->left > 0) {
359 /*
360 * We've still got data from the current packet to read. There could
361 * be a record from the new epoch in it - so don't overwrite it
362 * with the unprocessed records yet (we'll do it when we've
363 * finished reading the current packet).
364 */
365 return 1;
366 }
367
368
369 /* Process all the records. */
370 while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
371 dtls1_get_unprocessed_record(s);
372 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
373 if (bitmap == NULL) {
374 /*
375 * Should not happen. This will only ever be NULL when the
376 * current record is from a different epoch. But that cannot
377 * be the case because we already checked the epoch above
378 */
379 SSLerr(SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS,
380 ERR_R_INTERNAL_ERROR);
381 return 0;
382 }
383 #ifndef OPENSSL_NO_SCTP
384 /* Only do replay check if no SCTP bio */
385 if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
386 #endif
387 {
388 /*
389 * Check whether this is a repeat, or aged record. We did this
390 * check once already when we first received the record - but
391 * we might have updated the window since then due to
392 * records we subsequently processed.
393 */
394 replayok = dtls1_record_replay_check(s, bitmap);
395 }
396
397 if (!replayok || !dtls1_process_record(s, bitmap)) {
398 /* dump this record */
399 rr->length = 0;
400 s->packet_length = 0;
401 continue;
402 }
403
404 if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
405 s->s3->rrec.seq_num) < 0)
406 return 0;
407 }
408 }
409
410 /*
411 * sync epoch numbers once all the unprocessed records have been
412 * processed
413 */
414 s->d1->processed_rcds.epoch = s->d1->r_epoch;
415 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
416
417 return 1;
418 }
419
420 #if 0
421
422 static int dtls1_get_buffered_record(SSL *s)
423 {
424 pitem *item;
425 PQ_64BIT priority =
426 (((PQ_64BIT) s->d1->handshake_read_seq) << 32) |
427 ((PQ_64BIT) s->d1->r_msg_hdr.frag_off);
428
429 /* if we're not (re)negotiating, nothing buffered */
430 if (!SSL_in_init(s))
431 return 0;
432
433 item = pqueue_peek(s->d1->rcvd_records);
434 if (item && item->priority == priority) {
435 /*
436 * Check if we've received the record of interest. It must be a
437 * handshake record, since data records as passed up without
438 * buffering
439 */
440 DTLS1_RECORD_DATA *rdata;
441 item = pqueue_pop(s->d1->rcvd_records);
442 rdata = (DTLS1_RECORD_DATA *)item->data;
443
444 if (s->s3->rbuf.buf != NULL)
445 OPENSSL_free(s->s3->rbuf.buf);
446
447 s->packet = rdata->packet;
448 s->packet_length = rdata->packet_length;
449 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
450 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
451
452 OPENSSL_free(item->data);
453 pitem_free(item);
454
455 /* s->d1->next_expected_seq_num++; */
456 return (1);
457 }
458
459 return 0;
460 }
461
462 #endif
463
dtls1_process_record(SSL * s,DTLS1_BITMAP * bitmap)464 static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
465 {
466 int i, al;
467 int enc_err;
468 SSL_SESSION *sess;
469 SSL3_RECORD *rr;
470 unsigned int mac_size, orig_len;
471 unsigned char md[EVP_MAX_MD_SIZE];
472
473 rr = &(s->s3->rrec);
474 sess = s->session;
475
476 /*
477 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
478 * and we have that many bytes in s->packet
479 */
480 rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]);
481
482 /*
483 * ok, we can now read from 's->packet' data into 'rr' rr->input points
484 * at rr->length bytes, which need to be copied into rr->data by either
485 * the decryption or by the decompression When the data is 'copied' into
486 * the rr->data buffer, rr->input will be pointed at the new buffer
487 */
488
489 /*
490 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
491 * bytes of encrypted compressed stuff.
492 */
493
494 /* check is not needed I believe */
495 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
496 al = SSL_AD_RECORD_OVERFLOW;
497 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
498 goto f_err;
499 }
500
501 /* decrypt in place in 'rr->input' */
502 rr->data = rr->input;
503
504 enc_err = s->method->ssl3_enc->enc(s, 0);
505 /*-
506 * enc_err is:
507 * 0: (in non-constant time) if the record is publically invalid.
508 * 1: if the padding is valid
509 * -1: if the padding is invalid
510 */
511 if (enc_err == 0) {
512 /* For DTLS we simply ignore bad packets. */
513 rr->length = 0;
514 s->packet_length = 0;
515 goto err;
516 }
517 #ifdef TLS_DEBUG
518 printf("dec %d\n", rr->length);
519 {
520 unsigned int z;
521 for (z = 0; z < rr->length; z++)
522 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
523 }
524 printf("\n");
525 #endif
526
527 /* r->length is now the compressed data plus mac */
528 if ((sess != NULL) &&
529 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
530 /* s->read_hash != NULL => mac_size != -1 */
531 unsigned char *mac = NULL;
532 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
533 mac_size = EVP_MD_CTX_size(s->read_hash);
534 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
535
536 /*
537 * kludge: *_cbc_remove_padding passes padding length in rr->type
538 */
539 orig_len = rr->length + ((unsigned int)rr->type >> 8);
540
541 /*
542 * orig_len is the length of the record before any padding was
543 * removed. This is public information, as is the MAC in use,
544 * therefore we can safely process the record in a different amount
545 * of time if it's too short to possibly contain a MAC.
546 */
547 if (orig_len < mac_size ||
548 /* CBC records must have a padding length byte too. */
549 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
550 orig_len < mac_size + 1)) {
551 al = SSL_AD_DECODE_ERROR;
552 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
553 goto f_err;
554 }
555
556 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
557 /*
558 * We update the length so that the TLS header bytes can be
559 * constructed correctly but we need to extract the MAC in
560 * constant time from within the record, without leaking the
561 * contents of the padding bytes.
562 */
563 mac = mac_tmp;
564 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
565 rr->length -= mac_size;
566 } else {
567 /*
568 * In this case there's no padding, so |orig_len| equals
569 * |rec->length| and we checked that there's enough bytes for
570 * |mac_size| above.
571 */
572 rr->length -= mac_size;
573 mac = &rr->data[rr->length];
574 }
575
576 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
577 if (i < 0 || mac == NULL
578 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
579 enc_err = -1;
580 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
581 enc_err = -1;
582 }
583
584 if (enc_err < 0) {
585 /* decryption failed, silently discard message */
586 rr->length = 0;
587 s->packet_length = 0;
588 goto err;
589 }
590
591 /* r->length is now just compressed */
592 if (s->expand != NULL) {
593 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
594 al = SSL_AD_RECORD_OVERFLOW;
595 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
596 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
597 goto f_err;
598 }
599 if (!ssl3_do_uncompress(s)) {
600 al = SSL_AD_DECOMPRESSION_FAILURE;
601 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
602 goto f_err;
603 }
604 }
605
606 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
607 al = SSL_AD_RECORD_OVERFLOW;
608 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
609 goto f_err;
610 }
611
612 rr->off = 0;
613 /*-
614 * So at this point the following is true
615 * ssl->s3->rrec.type is the type of record
616 * ssl->s3->rrec.length == number of bytes in record
617 * ssl->s3->rrec.off == offset to first valid byte
618 * ssl->s3->rrec.data == where to take bytes from, increment
619 * after use :-).
620 */
621
622 /* we have pulled in a full packet so zero things */
623 s->packet_length = 0;
624
625 /* Mark receipt of record. */
626 dtls1_record_bitmap_update(s, bitmap);
627
628 return (1);
629
630 f_err:
631 ssl3_send_alert(s, SSL3_AL_FATAL, al);
632 err:
633 return (0);
634 }
635
636 /*-
637 * Call this to get a new input record.
638 * It will return <= 0 if more data is needed, normally due to an error
639 * or non-blocking IO.
640 * When it finishes, one packet has been decoded and can be found in
641 * ssl->s3->rrec.type - is the type of record
642 * ssl->s3->rrec.data, - data
643 * ssl->s3->rrec.length, - number of bytes
644 */
645 /* used only by dtls1_read_bytes */
dtls1_get_record(SSL * s)646 int dtls1_get_record(SSL *s)
647 {
648 int ssl_major, ssl_minor;
649 int i, n;
650 SSL3_RECORD *rr;
651 unsigned char *p = NULL;
652 unsigned short version;
653 DTLS1_BITMAP *bitmap;
654 unsigned int is_next_epoch;
655
656 rr = &(s->s3->rrec);
657
658 again:
659 /*
660 * The epoch may have changed. If so, process all the pending records.
661 * This is a non-blocking operation.
662 */
663 if (!dtls1_process_buffered_records(s))
664 return -1;
665
666 /* if we're renegotiating, then there may be buffered records */
667 if (dtls1_get_processed_record(s))
668 return 1;
669
670 /* get something from the wire */
671 /* check if we have the header */
672 if ((s->rstate != SSL_ST_READ_BODY) ||
673 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) {
674 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
675 /* read timeout is handled by dtls1_read_bytes */
676 if (n <= 0)
677 return (n); /* error or non-blocking */
678
679 /* this packet contained a partial record, dump it */
680 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) {
681 s->packet_length = 0;
682 goto again;
683 }
684
685 s->rstate = SSL_ST_READ_BODY;
686
687 p = s->packet;
688
689 if (s->msg_callback)
690 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
691 s, s->msg_callback_arg);
692
693 /* Pull apart the header into the DTLS1_RECORD */
694 rr->type = *(p++);
695 ssl_major = *(p++);
696 ssl_minor = *(p++);
697 version = (ssl_major << 8) | ssl_minor;
698
699 /* sequence number is 64 bits, with top 2 bytes = epoch */
700 n2s(p, rr->epoch);
701
702 memcpy(&(s->s3->read_sequence[2]), p, 6);
703 p += 6;
704
705 n2s(p, rr->length);
706
707 /*
708 * Lets check the version. We tolerate alerts that don't have the exact
709 * version number (e.g. because of protocol version errors)
710 */
711 if (!s->first_packet && rr->type != SSL3_RT_ALERT) {
712 if (version != s->version) {
713 /* unexpected version, silently discard */
714 rr->length = 0;
715 s->packet_length = 0;
716 goto again;
717 }
718 }
719
720 if ((version & 0xff00) != (s->version & 0xff00)) {
721 /* wrong version, silently discard record */
722 rr->length = 0;
723 s->packet_length = 0;
724 goto again;
725 }
726
727 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
728 /* record too long, silently discard it */
729 rr->length = 0;
730 s->packet_length = 0;
731 goto again;
732 }
733
734 /* now s->rstate == SSL_ST_READ_BODY */
735 }
736
737 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
738
739 if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) {
740 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
741 i = rr->length;
742 n = ssl3_read_n(s, i, i, 1);
743 /* this packet contained a partial record, dump it */
744 if (n != i) {
745 rr->length = 0;
746 s->packet_length = 0;
747 goto again;
748 }
749
750 /*
751 * now n == rr->length, and s->packet_length ==
752 * DTLS1_RT_HEADER_LENGTH + rr->length
753 */
754 }
755 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
756
757 /* match epochs. NULL means the packet is dropped on the floor */
758 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
759 if (bitmap == NULL) {
760 rr->length = 0;
761 s->packet_length = 0; /* dump this record */
762 goto again; /* get another record */
763 }
764 #ifndef OPENSSL_NO_SCTP
765 /* Only do replay check if no SCTP bio */
766 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
767 #endif
768 /*
769 * Check whether this is a repeat, or aged record. Don't check if
770 * we're listening and this message is a ClientHello. They can look
771 * as if they're replayed, since they arrive from different
772 * connections and would be dropped unnecessarily.
773 */
774 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
775 s->packet_length > DTLS1_RT_HEADER_LENGTH &&
776 s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
777 !dtls1_record_replay_check(s, bitmap)) {
778 rr->length = 0;
779 s->packet_length = 0; /* dump this record */
780 goto again; /* get another record */
781 }
782 #ifndef OPENSSL_NO_SCTP
783 }
784 #endif
785
786 /* just read a 0 length packet */
787 if (rr->length == 0)
788 goto again;
789
790 /*
791 * If this record is from the next epoch (either HM or ALERT), and a
792 * handshake is currently in progress, buffer it since it cannot be
793 * processed at this time. However, do not buffer anything while
794 * listening.
795 */
796 if (is_next_epoch) {
797 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) {
798 if (dtls1_buffer_record
799 (s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0)
800 return -1;
801 }
802 rr->length = 0;
803 s->packet_length = 0;
804 goto again;
805 }
806
807 if (!dtls1_process_record(s, bitmap)) {
808 rr->length = 0;
809 s->packet_length = 0; /* dump this record */
810 goto again; /* get another record */
811 }
812
813 return (1);
814
815 }
816
817 /*-
818 * Return up to 'len' payload bytes received in 'type' records.
819 * 'type' is one of the following:
820 *
821 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
822 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
823 * - 0 (during a shutdown, no data has to be returned)
824 *
825 * If we don't have stored data to work from, read a SSL/TLS record first
826 * (possibly multiple records if we still don't have anything to return).
827 *
828 * This function must handle any surprises the peer may have for us, such as
829 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
830 * a surprise, but handled as if it were), or renegotiation requests.
831 * Also if record payloads contain fragments too small to process, we store
832 * them until there is enough for the respective protocol (the record protocol
833 * may use arbitrary fragmentation and even interleaving):
834 * Change cipher spec protocol
835 * just 1 byte needed, no need for keeping anything stored
836 * Alert protocol
837 * 2 bytes needed (AlertLevel, AlertDescription)
838 * Handshake protocol
839 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
840 * to detect unexpected Client Hello and Hello Request messages
841 * here, anything else is handled by higher layers
842 * Application data protocol
843 * none of our business
844 */
dtls1_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)845 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
846 {
847 int al, i, j, ret;
848 unsigned int n;
849 SSL3_RECORD *rr;
850 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
851
852 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
853 if (!ssl3_setup_buffers(s))
854 return (-1);
855
856 /* XXX: check what the second '&& type' is about */
857 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
858 (type != SSL3_RT_HANDSHAKE) && type) ||
859 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
860 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
861 return -1;
862 }
863
864 /*
865 * check whether there's a handshake message (client hello?) waiting
866 */
867 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
868 return ret;
869
870 /*
871 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
872 */
873
874 #ifndef OPENSSL_NO_SCTP
875 /*
876 * Continue handshake if it had to be interrupted to read app data with
877 * SCTP.
878 */
879 if ((!s->in_handshake && SSL_in_init(s)) ||
880 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
881 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
882 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
883 && s->s3->in_read_app_data != 2))
884 #else
885 if (!s->in_handshake && SSL_in_init(s))
886 #endif
887 {
888 /* type == SSL3_RT_APPLICATION_DATA */
889 i = s->handshake_func(s);
890 if (i < 0)
891 return (i);
892 if (i == 0) {
893 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
894 return (-1);
895 }
896 }
897
898 start:
899 s->rwstate = SSL_NOTHING;
900
901 /*-
902 * s->s3->rrec.type - is the type of record
903 * s->s3->rrec.data, - data
904 * s->s3->rrec.off, - offset into 'data' for next read
905 * s->s3->rrec.length, - number of bytes.
906 */
907 rr = &(s->s3->rrec);
908
909 /*
910 * We are not handshaking and have no data yet, so process data buffered
911 * during the last handshake in advance, if any.
912 */
913 if (s->state == SSL_ST_OK && rr->length == 0) {
914 pitem *item;
915 item = pqueue_pop(s->d1->buffered_app_data.q);
916 if (item) {
917 #ifndef OPENSSL_NO_SCTP
918 /* Restore bio_dgram_sctp_rcvinfo struct */
919 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
920 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
921 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
922 sizeof(rdata->recordinfo), &rdata->recordinfo);
923 }
924 #endif
925
926 dtls1_copy_record(s, item);
927
928 OPENSSL_free(item->data);
929 pitem_free(item);
930 }
931 }
932
933 /* Check for timeout */
934 if (dtls1_handle_timeout(s) > 0)
935 goto start;
936
937 /* get new packet if necessary */
938 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) {
939 ret = dtls1_get_record(s);
940 if (ret <= 0) {
941 ret = dtls1_read_failed(s, ret);
942 /* anything other than a timeout is an error */
943 if (ret <= 0)
944 return (ret);
945 else
946 goto start;
947 }
948 }
949
950 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
951 rr->length = 0;
952 goto start;
953 }
954
955 /*
956 * Reset the count of consecutive warning alerts if we've got a non-empty
957 * record that isn't an alert.
958 */
959 if (rr->type != SSL3_RT_ALERT && rr->length != 0)
960 s->cert->alert_count = 0;
961
962 /* we now have a packet which can be read and processed */
963
964 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
965 * reset by ssl3_get_finished */
966 && (rr->type != SSL3_RT_HANDSHAKE)) {
967 /*
968 * We now have application data between CCS and Finished. Most likely
969 * the packets were reordered on their way, so buffer the application
970 * data for later processing rather than dropping the connection.
971 */
972 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) <
973 0) {
974 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
975 return -1;
976 }
977 rr->length = 0;
978 goto start;
979 }
980
981 /*
982 * If the other end has shut down, throw anything we read away (even in
983 * 'peek' mode)
984 */
985 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
986 rr->length = 0;
987 s->rwstate = SSL_NOTHING;
988 return (0);
989 }
990
991 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or
992 * SSL3_RT_HANDSHAKE */
993 /*
994 * make sure that we are not getting application data when we are
995 * doing a handshake for the first time
996 */
997 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
998 (s->enc_read_ctx == NULL)) {
999 al = SSL_AD_UNEXPECTED_MESSAGE;
1000 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
1001 goto f_err;
1002 }
1003
1004 if (len <= 0)
1005 return (len);
1006
1007 if ((unsigned int)len > rr->length)
1008 n = rr->length;
1009 else
1010 n = (unsigned int)len;
1011
1012 memcpy(buf, &(rr->data[rr->off]), n);
1013 if (!peek) {
1014 rr->length -= n;
1015 rr->off += n;
1016 if (rr->length == 0) {
1017 s->rstate = SSL_ST_READ_HEADER;
1018 rr->off = 0;
1019 }
1020 }
1021 #ifndef OPENSSL_NO_SCTP
1022 /*
1023 * We were about to renegotiate but had to read belated application
1024 * data first, so retry.
1025 */
1026 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1027 rr->type == SSL3_RT_APPLICATION_DATA &&
1028 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
1029 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
1030 s->rwstate = SSL_READING;
1031 BIO_clear_retry_flags(SSL_get_rbio(s));
1032 BIO_set_retry_read(SSL_get_rbio(s));
1033 }
1034
1035 /*
1036 * We might had to delay a close_notify alert because of reordered
1037 * app data. If there was an alert and there is no message to read
1038 * anymore, finally set shutdown.
1039 */
1040 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1041 s->d1->shutdown_received
1042 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
1043 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1044 return (0);
1045 }
1046 #endif
1047 return (n);
1048 }
1049
1050 /*
1051 * If we get here, then type != rr->type; if we have a handshake message,
1052 * then it was unexpected (Hello Request or Client Hello).
1053 */
1054
1055 /*
1056 * In case of record types for which we have 'fragment' storage, fill
1057 * that so that we can process the data at a fixed place.
1058 */
1059 {
1060 unsigned int k, dest_maxlen = 0;
1061 unsigned char *dest = NULL;
1062 unsigned int *dest_len = NULL;
1063
1064 if (rr->type == SSL3_RT_HANDSHAKE) {
1065 dest_maxlen = sizeof(s->d1->handshake_fragment);
1066 dest = s->d1->handshake_fragment;
1067 dest_len = &s->d1->handshake_fragment_len;
1068 } else if (rr->type == SSL3_RT_ALERT) {
1069 dest_maxlen = sizeof(s->d1->alert_fragment);
1070 dest = s->d1->alert_fragment;
1071 dest_len = &s->d1->alert_fragment_len;
1072 }
1073 #ifndef OPENSSL_NO_HEARTBEATS
1074 else if (rr->type == TLS1_RT_HEARTBEAT) {
1075 dtls1_process_heartbeat(s);
1076
1077 /* Exit and notify application to read again */
1078 rr->length = 0;
1079 s->rwstate = SSL_READING;
1080 BIO_clear_retry_flags(SSL_get_rbio(s));
1081 BIO_set_retry_read(SSL_get_rbio(s));
1082 return (-1);
1083 }
1084 #endif
1085 /* else it's a CCS message, or application data or wrong */
1086 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
1087 /*
1088 * Application data while renegotiating is allowed. Try again
1089 * reading.
1090 */
1091 if (rr->type == SSL3_RT_APPLICATION_DATA) {
1092 BIO *bio;
1093 s->s3->in_read_app_data = 2;
1094 bio = SSL_get_rbio(s);
1095 s->rwstate = SSL_READING;
1096 BIO_clear_retry_flags(bio);
1097 BIO_set_retry_read(bio);
1098 return (-1);
1099 }
1100
1101 /* Not certain if this is the right error handling */
1102 al = SSL_AD_UNEXPECTED_MESSAGE;
1103 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1104 goto f_err;
1105 }
1106
1107 if (dest_maxlen > 0) {
1108 /*
1109 * XDTLS: In a pathalogical case, the Client Hello may be
1110 * fragmented--don't always expect dest_maxlen bytes
1111 */
1112 if (rr->length < dest_maxlen) {
1113 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1114 /*
1115 * for normal alerts rr->length is 2, while
1116 * dest_maxlen is 7 if we were to handle this
1117 * non-existing alert...
1118 */
1119 FIX ME
1120 #endif
1121 s->rstate = SSL_ST_READ_HEADER;
1122 rr->length = 0;
1123 goto start;
1124 }
1125
1126 /* now move 'n' bytes: */
1127 for (k = 0; k < dest_maxlen; k++) {
1128 dest[k] = rr->data[rr->off++];
1129 rr->length--;
1130 }
1131 *dest_len = dest_maxlen;
1132 }
1133 }
1134
1135 /*-
1136 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
1137 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
1138 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
1139 */
1140
1141 /* If we are a client, check for an incoming 'Hello Request': */
1142 if ((!s->server) &&
1143 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1144 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1145 (s->session != NULL) && (s->session->cipher != NULL)) {
1146 s->d1->handshake_fragment_len = 0;
1147
1148 if ((s->d1->handshake_fragment[1] != 0) ||
1149 (s->d1->handshake_fragment[2] != 0) ||
1150 (s->d1->handshake_fragment[3] != 0)) {
1151 al = SSL_AD_DECODE_ERROR;
1152 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
1153 goto f_err;
1154 }
1155
1156 /*
1157 * no need to check sequence number on HELLO REQUEST messages
1158 */
1159
1160 if (s->msg_callback)
1161 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1162 s->d1->handshake_fragment, 4, s,
1163 s->msg_callback_arg);
1164
1165 if (SSL_is_init_finished(s) &&
1166 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1167 !s->s3->renegotiate) {
1168 s->d1->handshake_read_seq++;
1169 s->new_session = 1;
1170 ssl3_renegotiate(s);
1171 if (ssl3_renegotiate_check(s)) {
1172 i = s->handshake_func(s);
1173 if (i < 0)
1174 return (i);
1175 if (i == 0) {
1176 SSLerr(SSL_F_DTLS1_READ_BYTES,
1177 SSL_R_SSL_HANDSHAKE_FAILURE);
1178 return (-1);
1179 }
1180
1181 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
1182 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
1183 BIO *bio;
1184 /*
1185 * In the case where we try to read application data,
1186 * but we trigger an SSL handshake, we return -1 with
1187 * the retry option set. Otherwise renegotiation may
1188 * cause nasty problems in the blocking world
1189 */
1190 s->rwstate = SSL_READING;
1191 bio = SSL_get_rbio(s);
1192 BIO_clear_retry_flags(bio);
1193 BIO_set_retry_read(bio);
1194 return (-1);
1195 }
1196 }
1197 }
1198 }
1199 /*
1200 * we either finished a handshake or ignored the request, now try
1201 * again to obtain the (application) data we were asked for
1202 */
1203 goto start;
1204 }
1205
1206 /*
1207 * If we are a server and get a client hello when renegotiation isn't
1208 * allowed send back a no renegotiation alert and carry on.
1209 */
1210 if (s->server
1211 && SSL_is_init_finished(s)
1212 && !s->s3->send_connection_binding
1213 && s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH
1214 && s->d1->handshake_fragment[0] == SSL3_MT_CLIENT_HELLO
1215 && s->s3->previous_client_finished_len != 0
1216 && (s->options & SSL_OP_ALLOW_UNSAFE_LEGACY_RENEGOTIATION) == 0) {
1217 s->d1->handshake_fragment_len = 0;
1218 rr->length = 0;
1219 ssl3_send_alert(s, SSL3_AL_WARNING, SSL_AD_NO_RENEGOTIATION);
1220 goto start;
1221 }
1222
1223
1224 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
1225 int alert_level = s->d1->alert_fragment[0];
1226 int alert_descr = s->d1->alert_fragment[1];
1227
1228 s->d1->alert_fragment_len = 0;
1229
1230 if (s->msg_callback)
1231 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1232 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1233
1234 if (s->info_callback != NULL)
1235 cb = s->info_callback;
1236 else if (s->ctx->info_callback != NULL)
1237 cb = s->ctx->info_callback;
1238
1239 if (cb != NULL) {
1240 j = (alert_level << 8) | alert_descr;
1241 cb(s, SSL_CB_READ_ALERT, j);
1242 }
1243
1244 if (alert_level == SSL3_AL_WARNING) {
1245 s->s3->warn_alert = alert_descr;
1246
1247 s->cert->alert_count++;
1248 if (s->cert->alert_count == MAX_WARN_ALERT_COUNT) {
1249 al = SSL_AD_UNEXPECTED_MESSAGE;
1250 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_TOO_MANY_WARN_ALERTS);
1251 goto f_err;
1252 }
1253
1254 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
1255 #ifndef OPENSSL_NO_SCTP
1256 /*
1257 * With SCTP and streams the socket may deliver app data
1258 * after a close_notify alert. We have to check this first so
1259 * that nothing gets discarded.
1260 */
1261 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1262 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
1263 s->d1->shutdown_received = 1;
1264 s->rwstate = SSL_READING;
1265 BIO_clear_retry_flags(SSL_get_rbio(s));
1266 BIO_set_retry_read(SSL_get_rbio(s));
1267 return -1;
1268 }
1269 #endif
1270 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1271 return (0);
1272 }
1273 #if 0
1274 /* XXX: this is a possible improvement in the future */
1275 /* now check if it's a missing record */
1276 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
1277 unsigned short seq;
1278 unsigned int frag_off;
1279 unsigned char *p = &(s->d1->alert_fragment[2]);
1280
1281 n2s(p, seq);
1282 n2l3(p, frag_off);
1283
1284 dtls1_retransmit_message(s,
1285 dtls1_get_queue_priority
1286 (frag->msg_header.seq, 0), frag_off,
1287 &found);
1288 if (!found && SSL_in_init(s)) {
1289 /*
1290 * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
1291 */
1292 /*
1293 * requested a message not yet sent, send an alert
1294 * ourselves
1295 */
1296 ssl3_send_alert(s, SSL3_AL_WARNING,
1297 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1298 }
1299 }
1300 #endif
1301 } else if (alert_level == SSL3_AL_FATAL) {
1302 char tmp[16];
1303
1304 s->rwstate = SSL_NOTHING;
1305 s->s3->fatal_alert = alert_descr;
1306 SSLerr(SSL_F_DTLS1_READ_BYTES,
1307 SSL_AD_REASON_OFFSET + alert_descr);
1308 BIO_snprintf(tmp, sizeof(tmp), "%d", alert_descr);
1309 ERR_add_error_data(2, "SSL alert number ", tmp);
1310 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1311 SSL_CTX_remove_session(s->session_ctx, s->session);
1312 s->state = SSL_ST_ERR;
1313 return (0);
1314 } else {
1315 al = SSL_AD_ILLEGAL_PARAMETER;
1316 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
1317 goto f_err;
1318 }
1319
1320 goto start;
1321 }
1322
1323 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
1324 * shutdown */
1325 s->rwstate = SSL_NOTHING;
1326 rr->length = 0;
1327 return (0);
1328 }
1329
1330 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
1331 struct ccs_header_st ccs_hdr;
1332 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1333
1334 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1335
1336 if (s->version == DTLS1_BAD_VER)
1337 ccs_hdr_len = 3;
1338
1339 /*
1340 * 'Change Cipher Spec' is just a single byte, so we know exactly
1341 * what the record payload has to look like
1342 */
1343 /* XDTLS: check that epoch is consistent */
1344 if ((rr->length != ccs_hdr_len) ||
1345 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
1346 al = SSL_AD_ILLEGAL_PARAMETER;
1347 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
1348 goto f_err;
1349 }
1350
1351 rr->length = 0;
1352
1353 if (s->msg_callback)
1354 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1355 rr->data, 1, s, s->msg_callback_arg);
1356
1357 /*
1358 * We can't process a CCS now, because previous handshake messages
1359 * are still missing, so just drop it.
1360 */
1361 if (!s->d1->change_cipher_spec_ok) {
1362 goto start;
1363 }
1364
1365 s->d1->change_cipher_spec_ok = 0;
1366
1367 s->s3->change_cipher_spec = 1;
1368 if (!ssl3_do_change_cipher_spec(s))
1369 goto err;
1370
1371 /* do this whenever CCS is processed */
1372 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1373
1374 if (s->version == DTLS1_BAD_VER)
1375 s->d1->handshake_read_seq++;
1376
1377 #ifndef OPENSSL_NO_SCTP
1378 /*
1379 * Remember that a CCS has been received, so that an old key of
1380 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
1381 * SCTP is used
1382 */
1383 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1384 #endif
1385
1386 goto start;
1387 }
1388
1389 /*
1390 * Unexpected handshake message (Client Hello, or protocol violation)
1391 */
1392 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1393 !s->in_handshake) {
1394 struct hm_header_st msg_hdr;
1395
1396 /* this may just be a stale retransmit */
1397 dtls1_get_message_header(rr->data, &msg_hdr);
1398 if (rr->epoch != s->d1->r_epoch) {
1399 rr->length = 0;
1400 goto start;
1401 }
1402
1403 /*
1404 * If we are server, we may have a repeated FINISHED of the client
1405 * here, then retransmit our CCS and FINISHED.
1406 */
1407 if (msg_hdr.type == SSL3_MT_FINISHED) {
1408 if (dtls1_check_timeout_num(s) < 0)
1409 return -1;
1410
1411 dtls1_retransmit_buffered_messages(s);
1412 rr->length = 0;
1413 goto start;
1414 }
1415
1416 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
1417 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
1418 #if 0 /* worked only because C operator preferences
1419 * are not as expected (and because this is
1420 * not really needed for clients except for
1421 * detecting protocol violations): */
1422 s->state = SSL_ST_BEFORE | (s->server)
1423 ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1424 #else
1425 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1426 #endif
1427 s->renegotiate = 1;
1428 s->new_session = 1;
1429 }
1430 i = s->handshake_func(s);
1431 if (i < 0)
1432 return (i);
1433 if (i == 0) {
1434 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
1435 return (-1);
1436 }
1437
1438 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
1439 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
1440 BIO *bio;
1441 /*
1442 * In the case where we try to read application data, but we
1443 * trigger an SSL handshake, we return -1 with the retry
1444 * option set. Otherwise renegotiation may cause nasty
1445 * problems in the blocking world
1446 */
1447 s->rwstate = SSL_READING;
1448 bio = SSL_get_rbio(s);
1449 BIO_clear_retry_flags(bio);
1450 BIO_set_retry_read(bio);
1451 return (-1);
1452 }
1453 }
1454 goto start;
1455 }
1456
1457 switch (rr->type) {
1458 default:
1459 #ifndef OPENSSL_NO_TLS
1460 /* TLS just ignores unknown message types */
1461 if (s->version == TLS1_VERSION) {
1462 rr->length = 0;
1463 goto start;
1464 }
1465 #endif
1466 al = SSL_AD_UNEXPECTED_MESSAGE;
1467 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1468 goto f_err;
1469 case SSL3_RT_CHANGE_CIPHER_SPEC:
1470 case SSL3_RT_ALERT:
1471 case SSL3_RT_HANDSHAKE:
1472 /*
1473 * we already handled all of these, with the possible exception of
1474 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
1475 * happen when type != rr->type
1476 */
1477 al = SSL_AD_UNEXPECTED_MESSAGE;
1478 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
1479 goto f_err;
1480 case SSL3_RT_APPLICATION_DATA:
1481 /*
1482 * At this point, we were expecting handshake data, but have
1483 * application data. If the library was running inside ssl3_read()
1484 * (i.e. in_read_app_data is set) and it makes sense to read
1485 * application data at this point (session renegotiation not yet
1486 * started), we will indulge it.
1487 */
1488 if (s->s3->in_read_app_data &&
1489 (s->s3->total_renegotiations != 0) &&
1490 (((s->state & SSL_ST_CONNECT) &&
1491 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1492 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1493 ) || ((s->state & SSL_ST_ACCEPT) &&
1494 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1495 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1496 )
1497 )) {
1498 s->s3->in_read_app_data = 2;
1499 return (-1);
1500 } else {
1501 al = SSL_AD_UNEXPECTED_MESSAGE;
1502 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1503 goto f_err;
1504 }
1505 }
1506 /* not reached */
1507
1508 f_err:
1509 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1510 err:
1511 return (-1);
1512 }
1513
dtls1_write_app_data_bytes(SSL * s,int type,const void * buf_,int len)1514 int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1515 {
1516 int i;
1517
1518 #ifndef OPENSSL_NO_SCTP
1519 /*
1520 * Check if we have to continue an interrupted handshake for reading
1521 * belated app data with SCTP.
1522 */
1523 if ((SSL_in_init(s) && !s->in_handshake) ||
1524 (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1525 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
1526 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1527 #else
1528 if (SSL_in_init(s) && !s->in_handshake)
1529 #endif
1530 {
1531 i = s->handshake_func(s);
1532 if (i < 0)
1533 return (i);
1534 if (i == 0) {
1535 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,
1536 SSL_R_SSL_HANDSHAKE_FAILURE);
1537 return -1;
1538 }
1539 }
1540
1541 if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
1542 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG);
1543 return -1;
1544 }
1545
1546 i = dtls1_write_bytes(s, type, buf_, len);
1547 return i;
1548 }
1549
1550 /*
1551 * this only happens when a client hello is received and a handshake
1552 * is started.
1553 */
1554 static int
have_handshake_fragment(SSL * s,int type,unsigned char * buf,int len,int peek)1555 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1556 int len, int peek)
1557 {
1558
1559 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1560 /* (partially) satisfy request from storage */
1561 {
1562 unsigned char *src = s->d1->handshake_fragment;
1563 unsigned char *dst = buf;
1564 unsigned int k, n;
1565
1566 /* peek == 0 */
1567 n = 0;
1568 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) {
1569 *dst++ = *src++;
1570 len--;
1571 s->d1->handshake_fragment_len--;
1572 n++;
1573 }
1574 /* move any remaining fragment bytes: */
1575 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1576 s->d1->handshake_fragment[k] = *src++;
1577 return n;
1578 }
1579
1580 return 0;
1581 }
1582
1583 /*
1584 * Call this to write data in records of type 'type' It will return <= 0 if
1585 * not all data has been sent or non-blocking IO.
1586 */
dtls1_write_bytes(SSL * s,int type,const void * buf,int len)1587 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1588 {
1589 int i;
1590
1591 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1592 s->rwstate = SSL_NOTHING;
1593 i = do_dtls1_write(s, type, buf, len, 0);
1594 return i;
1595 }
1596
do_dtls1_write(SSL * s,int type,const unsigned char * buf,unsigned int len,int create_empty_fragment)1597 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
1598 unsigned int len, int create_empty_fragment)
1599 {
1600 unsigned char *p, *pseq;
1601 int i, mac_size, clear = 0;
1602 int prefix_len = 0;
1603 int eivlen;
1604 SSL3_RECORD *wr;
1605 SSL3_BUFFER *wb;
1606 SSL_SESSION *sess;
1607
1608 /*
1609 * first check if there is a SSL3_BUFFER still being written out. This
1610 * will happen with non blocking IO
1611 */
1612 if (s->s3->wbuf.left != 0) {
1613 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1614 return (ssl3_write_pending(s, type, buf, len));
1615 }
1616
1617 /* If we have an alert to send, lets send it */
1618 if (s->s3->alert_dispatch) {
1619 i = s->method->ssl_dispatch_alert(s);
1620 if (i <= 0)
1621 return (i);
1622 /* if it went, fall through and send more stuff */
1623 }
1624
1625 if (len == 0 && !create_empty_fragment)
1626 return 0;
1627
1628 wr = &(s->s3->wrec);
1629 wb = &(s->s3->wbuf);
1630 sess = s->session;
1631
1632 if ((sess == NULL) ||
1633 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
1634 clear = 1;
1635
1636 if (clear)
1637 mac_size = 0;
1638 else {
1639 mac_size = EVP_MD_CTX_size(s->write_hash);
1640 if (mac_size < 0)
1641 goto err;
1642 }
1643
1644 /* DTLS implements explicit IV, so no need for empty fragments */
1645 #if 0
1646 /*
1647 * 'create_empty_fragment' is true only when this function calls itself
1648 */
1649 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1650 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1651 {
1652 /*
1653 * countermeasure against known-IV weakness in CBC ciphersuites (see
1654 * http://www.openssl.org/~bodo/tls-cbc.txt)
1655 */
1656
1657 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) {
1658 /*
1659 * recursive function call with 'create_empty_fragment' set; this
1660 * prepares and buffers the data for an empty fragment (these
1661 * 'prefix_len' bytes are sent out later together with the actual
1662 * payload)
1663 */
1664 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1665 if (prefix_len <= 0)
1666 goto err;
1667
1668 if (s->s3->wbuf.len <
1669 (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) {
1670 /* insufficient space */
1671 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1672 goto err;
1673 }
1674 }
1675
1676 s->s3->empty_fragment_done = 1;
1677 }
1678 #endif
1679 p = wb->buf + prefix_len;
1680
1681 /* write the header */
1682
1683 *(p++) = type & 0xff;
1684 wr->type = type;
1685 /*
1686 * Special case: for hello verify request, client version 1.0 and we
1687 * haven't decided which version to use yet send back using version 1.0
1688 * header: otherwise some clients will ignore it.
1689 */
1690 if (s->method->version == DTLS_ANY_VERSION) {
1691 *(p++) = DTLS1_VERSION >> 8;
1692 *(p++) = DTLS1_VERSION & 0xff;
1693 } else {
1694 *(p++) = s->version >> 8;
1695 *(p++) = s->version & 0xff;
1696 }
1697
1698 /* field where we are to write out packet epoch, seq num and len */
1699 pseq = p;
1700 p += 10;
1701
1702 /* Explicit IV length, block ciphers appropriate version flag */
1703 if (s->enc_write_ctx) {
1704 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1705 if (mode == EVP_CIPH_CBC_MODE) {
1706 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1707 if (eivlen <= 1)
1708 eivlen = 0;
1709 }
1710 /* Need explicit part of IV for GCM mode */
1711 else if (mode == EVP_CIPH_GCM_MODE)
1712 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1713 else
1714 eivlen = 0;
1715 } else
1716 eivlen = 0;
1717
1718 /* lets setup the record stuff. */
1719 wr->data = p + eivlen; /* make room for IV in case of CBC */
1720 wr->length = (int)len;
1721 wr->input = (unsigned char *)buf;
1722
1723 /*
1724 * we now 'read' from wr->input, wr->length bytes into wr->data
1725 */
1726
1727 /* first we compress */
1728 if (s->compress != NULL) {
1729 if (!ssl3_do_compress(s)) {
1730 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
1731 goto err;
1732 }
1733 } else {
1734 memcpy(wr->data, wr->input, wr->length);
1735 wr->input = wr->data;
1736 }
1737
1738 /*
1739 * we should still have the output to wr->data and the input from
1740 * wr->input. Length should be wr->length. wr->data still points in the
1741 * wb->buf
1742 */
1743
1744 if (mac_size != 0) {
1745 if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
1746 goto err;
1747 wr->length += mac_size;
1748 }
1749
1750 /* this is true regardless of mac size */
1751 wr->input = p;
1752 wr->data = p;
1753
1754 if (eivlen)
1755 wr->length += eivlen;
1756
1757 if (s->method->ssl3_enc->enc(s, 1) < 1)
1758 goto err;
1759
1760 /* record length after mac and block padding */
1761 /*
1762 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
1763 * SSL_in_init(s)))
1764 */
1765
1766 /* there's only one epoch between handshake and app data */
1767
1768 s2n(s->d1->w_epoch, pseq);
1769
1770 /* XDTLS: ?? */
1771 /*
1772 * else s2n(s->d1->handshake_epoch, pseq);
1773 */
1774
1775 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1776 pseq += 6;
1777 s2n(wr->length, pseq);
1778
1779 if (s->msg_callback)
1780 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
1781 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1782
1783 /*
1784 * we should now have wr->data pointing to the encrypted data, which is
1785 * wr->length long
1786 */
1787 wr->type = type; /* not needed but helps for debugging */
1788 wr->length += DTLS1_RT_HEADER_LENGTH;
1789
1790 #if 0 /* this is now done at the message layer */
1791 /* buffer the record, making it easy to handle retransmits */
1792 if (type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1793 dtls1_buffer_record(s, wr->data, wr->length,
1794 *((PQ_64BIT *) & (s->s3->write_sequence[0])));
1795 #endif
1796
1797 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1798
1799 if (create_empty_fragment) {
1800 /*
1801 * we are in a recursive call; just return the length, don't write
1802 * out anything here
1803 */
1804 return wr->length;
1805 }
1806
1807 /* now let's set up wb */
1808 wb->left = prefix_len + wr->length;
1809 wb->offset = 0;
1810
1811 /*
1812 * memorize arguments so that ssl3_write_pending can detect bad write
1813 * retries later
1814 */
1815 s->s3->wpend_tot = len;
1816 s->s3->wpend_buf = buf;
1817 s->s3->wpend_type = type;
1818 s->s3->wpend_ret = len;
1819
1820 /* we now just need to write the buffer */
1821 return ssl3_write_pending(s, type, buf, len);
1822 err:
1823 return -1;
1824 }
1825
dtls1_record_replay_check(SSL * s,DTLS1_BITMAP * bitmap)1826 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1827 {
1828 int cmp;
1829 unsigned int shift;
1830 const unsigned char *seq = s->s3->read_sequence;
1831
1832 cmp = satsub64be(seq, bitmap->max_seq_num);
1833 if (cmp > 0) {
1834 memcpy(s->s3->rrec.seq_num, seq, 8);
1835 return 1; /* this record in new */
1836 }
1837 shift = -cmp;
1838 if (shift >= sizeof(bitmap->map) * 8)
1839 return 0; /* stale, outside the window */
1840 else if (bitmap->map & (1UL << shift))
1841 return 0; /* record previously received */
1842
1843 memcpy(s->s3->rrec.seq_num, seq, 8);
1844 return 1;
1845 }
1846
dtls1_record_bitmap_update(SSL * s,DTLS1_BITMAP * bitmap)1847 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1848 {
1849 int cmp;
1850 unsigned int shift;
1851 const unsigned char *seq = s->s3->read_sequence;
1852
1853 cmp = satsub64be(seq, bitmap->max_seq_num);
1854 if (cmp > 0) {
1855 shift = cmp;
1856 if (shift < sizeof(bitmap->map) * 8)
1857 bitmap->map <<= shift, bitmap->map |= 1UL;
1858 else
1859 bitmap->map = 1UL;
1860 memcpy(bitmap->max_seq_num, seq, 8);
1861 } else {
1862 shift = -cmp;
1863 if (shift < sizeof(bitmap->map) * 8)
1864 bitmap->map |= 1UL << shift;
1865 }
1866 }
1867
dtls1_dispatch_alert(SSL * s)1868 int dtls1_dispatch_alert(SSL *s)
1869 {
1870 int i, j;
1871 void (*cb) (const SSL *ssl, int type, int val) = NULL;
1872 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1873 unsigned char *ptr = &buf[0];
1874
1875 s->s3->alert_dispatch = 0;
1876
1877 memset(buf, 0x00, sizeof(buf));
1878 *ptr++ = s->s3->send_alert[0];
1879 *ptr++ = s->s3->send_alert[1];
1880
1881 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1882 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
1883 s2n(s->d1->handshake_read_seq, ptr);
1884 # if 0
1885 if (s->d1->r_msg_hdr.frag_off == 0)
1886 /*
1887 * waiting for a new msg
1888 */
1889 else
1890 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1891 # endif
1892
1893 # if 0
1894 fprintf(stderr,
1895 "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",
1896 s->d1->handshake_read_seq, s->d1->r_msg_hdr.seq);
1897 # endif
1898 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1899 }
1900 #endif
1901
1902 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1903 if (i <= 0) {
1904 s->s3->alert_dispatch = 1;
1905 /* fprintf( stderr, "not done with alert\n" ); */
1906 } else {
1907 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1908 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1909 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1910 #endif
1911 )
1912 (void)BIO_flush(s->wbio);
1913
1914 if (s->msg_callback)
1915 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1916 2, s, s->msg_callback_arg);
1917
1918 if (s->info_callback != NULL)
1919 cb = s->info_callback;
1920 else if (s->ctx->info_callback != NULL)
1921 cb = s->ctx->info_callback;
1922
1923 if (cb != NULL) {
1924 j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1];
1925 cb(s, SSL_CB_WRITE_ALERT, j);
1926 }
1927 }
1928 return (i);
1929 }
1930
dtls1_get_bitmap(SSL * s,SSL3_RECORD * rr,unsigned int * is_next_epoch)1931 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1932 unsigned int *is_next_epoch)
1933 {
1934
1935 *is_next_epoch = 0;
1936
1937 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1938 if (rr->epoch == s->d1->r_epoch)
1939 return &s->d1->bitmap;
1940
1941 /*
1942 * Only HM and ALERT messages can be from the next epoch and only if we
1943 * have already processed all of the unprocessed records from the last
1944 * epoch
1945 */
1946 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1947 s->d1->unprocessed_rcds.epoch != s->d1->r_epoch &&
1948 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1949 *is_next_epoch = 1;
1950 return &s->d1->next_bitmap;
1951 }
1952
1953 return NULL;
1954 }
1955
1956 #if 0
1957 static int
1958 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
1959 unsigned short *priority, unsigned long *offset)
1960 {
1961
1962 /* alerts are passed up immediately */
1963 if (rr->type == SSL3_RT_APPLICATION_DATA || rr->type == SSL3_RT_ALERT)
1964 return 0;
1965
1966 /*
1967 * Only need to buffer if a handshake is underway. (this implies that
1968 * Hello Request and Client Hello are passed up immediately)
1969 */
1970 if (SSL_in_init(s)) {
1971 unsigned char *data = rr->data;
1972 /* need to extract the HM/CCS sequence number here */
1973 if (rr->type == SSL3_RT_HANDSHAKE ||
1974 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
1975 unsigned short seq_num;
1976 struct hm_header_st msg_hdr;
1977 struct ccs_header_st ccs_hdr;
1978
1979 if (rr->type == SSL3_RT_HANDSHAKE) {
1980 dtls1_get_message_header(data, &msg_hdr);
1981 seq_num = msg_hdr.seq;
1982 *offset = msg_hdr.frag_off;
1983 } else {
1984 dtls1_get_ccs_header(data, &ccs_hdr);
1985 seq_num = ccs_hdr.seq;
1986 *offset = 0;
1987 }
1988
1989 /*
1990 * this is either a record we're waiting for, or a retransmit of
1991 * something we happened to previously receive (higher layers
1992 * will drop the repeat silently
1993 */
1994 if (seq_num < s->d1->handshake_read_seq)
1995 return 0;
1996 if (rr->type == SSL3_RT_HANDSHAKE &&
1997 seq_num == s->d1->handshake_read_seq &&
1998 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1999 return 0;
2000 else if (seq_num == s->d1->handshake_read_seq &&
2001 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
2002 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
2003 return 0;
2004 else {
2005 *priority = seq_num;
2006 return 1;
2007 }
2008 } else /* unknown record type */
2009 return 0;
2010 }
2011
2012 return 0;
2013 }
2014 #endif
2015
dtls1_reset_seq_numbers(SSL * s,int rw)2016 void dtls1_reset_seq_numbers(SSL *s, int rw)
2017 {
2018 unsigned char *seq;
2019 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
2020
2021 if (rw & SSL3_CC_READ) {
2022 seq = s->s3->read_sequence;
2023 s->d1->r_epoch++;
2024 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
2025 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
2026
2027 /*
2028 * We must not use any buffered messages received from the previous
2029 * epoch
2030 */
2031 dtls1_clear_received_buffer(s);
2032 } else {
2033 seq = s->s3->write_sequence;
2034 memcpy(s->d1->last_write_sequence, seq,
2035 sizeof(s->s3->write_sequence));
2036 s->d1->w_epoch++;
2037 }
2038
2039 memset(seq, 0x00, seq_bytes);
2040 }
2041