1 /* ssl/d1_pkt.c */
2 /*
3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5 */
6 /* ====================================================================
7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@openssl.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
61 *
62 * This package is an SSL implementation written
63 * by Eric Young (eay@cryptsoft.com).
64 * The implementation was written so as to conform with Netscapes SSL.
65 *
66 * This library is free for commercial and non-commercial use as long as
67 * the following conditions are aheared to. The following conditions
68 * apply to all code found in this distribution, be it the RC4, RSA,
69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
70 * included with this distribution is covered by the same copyright terms
71 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
72 *
73 * Copyright remains Eric Young's, and as such any Copyright notices in
74 * the code are not to be removed.
75 * If this package is used in a product, Eric Young should be given attribution
76 * as the author of the parts of the library used.
77 * This can be in the form of a textual message at program startup or
78 * in documentation (online or textual) provided with the package.
79 *
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
82 * are met:
83 * 1. Redistributions of source code must retain the copyright
84 * notice, this list of conditions and the following disclaimer.
85 * 2. Redistributions in binary form must reproduce the above copyright
86 * notice, this list of conditions and the following disclaimer in the
87 * documentation and/or other materials provided with the distribution.
88 * 3. All advertising materials mentioning features or use of this software
89 * must display the following acknowledgement:
90 * "This product includes cryptographic software written by
91 * Eric Young (eay@cryptsoft.com)"
92 * The word 'cryptographic' can be left out if the rouines from the library
93 * being used are not cryptographic related :-).
94 * 4. If you include any Windows specific code (or a derivative thereof) from
95 * the apps directory (application code) you must include an acknowledgement:
96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
97 *
98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
108 * SUCH DAMAGE.
109 *
110 * The licence and distribution terms for any publically available version or
111 * derivative of this code cannot be changed. i.e. this code cannot simply be
112 * copied and put under another distribution licence
113 * [including the GNU Public Licence.]
114 */
115
116 #include <stdio.h>
117 #include <errno.h>
118 #define USE_SOCKETS
119 #include "ssl_locl.h"
120 #include <openssl/evp.h>
121 #include <openssl/buffer.h>
122 #include <openssl/pqueue.h>
123 #include <openssl/rand.h>
124
125 /* 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 { int ret,sat,brw,i;
128
129 if (sizeof(long) == 8) do
130 { const union { long one; char little; } is_endian = {1};
131 long l;
132
133 if (is_endian.little) break;
134 /* not reached on little-endians */
135 /* following test is redundant, because input is
136 * always aligned, but I take no chances... */
137 if (((size_t)v1|(size_t)v2)&0x7) break;
138
139 l = *((long *)v1);
140 l -= *((long *)v2);
141 if (l>128) return 128;
142 else if (l<-128) return -128;
143 else return (int)l;
144 } while (0);
145
146 ret = (int)v1[7]-(int)v2[7];
147 sat = 0;
148 brw = ret>>8; /* brw is either 0 or -1 */
149 if (ret & 0x80)
150 { for (i=6;i>=0;i--)
151 { brw += (int)v1[i]-(int)v2[i];
152 sat |= ~brw;
153 brw >>= 8;
154 }
155 }
156 else
157 { for (i=6;i>=0;i--)
158 { brw += (int)v1[i]-(int)v2[i];
159 sat |= brw;
160 brw >>= 8;
161 }
162 }
163 brw <<= 8; /* brw is either 0 or -256 */
164
165 if (sat&0xff) return brw | 0x80;
166 else return brw + (ret&0xFF);
167 }
168
169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
170 int len, int peek);
171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
174 unsigned int *is_next_epoch);
175 #if 0
176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
177 unsigned short *priority, unsigned long *offset);
178 #endif
179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
180 unsigned char *priority);
181 static int dtls1_process_record(SSL *s);
182
183 /* copy buffered record into SSL structure */
184 static int
dtls1_copy_record(SSL * s,pitem * item)185 dtls1_copy_record(SSL *s, pitem *item)
186 {
187 DTLS1_RECORD_DATA *rdata;
188
189 rdata = (DTLS1_RECORD_DATA *)item->data;
190
191 if (s->s3->rbuf.buf != NULL)
192 OPENSSL_free(s->s3->rbuf.buf);
193
194 s->packet = rdata->packet;
195 s->packet_length = rdata->packet_length;
196 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
197 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
198
199 /* Set proper sequence number for mac calculation */
200 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
201
202 return(1);
203 }
204
205
206 static int
dtls1_buffer_record(SSL * s,record_pqueue * queue,unsigned char * priority)207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
208 {
209 DTLS1_RECORD_DATA *rdata;
210 pitem *item;
211
212 /* Limit the size of the queue to prevent DOS attacks */
213 if (pqueue_size(queue->q) >= 100)
214 return 0;
215
216 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
217 item = pitem_new(priority, rdata);
218 if (rdata == NULL || item == NULL)
219 {
220 if (rdata != NULL) OPENSSL_free(rdata);
221 if (item != NULL) pitem_free(item);
222
223 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
224 return(0);
225 }
226
227 rdata->packet = s->packet;
228 rdata->packet_length = s->packet_length;
229 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
230 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
231
232 item->data = rdata;
233
234 #ifndef OPENSSL_NO_SCTP
235 /* Store bio_dgram_sctp_rcvinfo struct */
236 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
237 (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) {
238 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
239 }
240 #endif
241
242 /* insert should not fail, since duplicates are dropped */
243 if (pqueue_insert(queue->q, item) == NULL)
244 {
245 OPENSSL_free(rdata);
246 pitem_free(item);
247 return(0);
248 }
249
250 s->packet = NULL;
251 s->packet_length = 0;
252 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
253 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
254
255 if (!ssl3_setup_buffers(s))
256 {
257 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
258 OPENSSL_free(rdata);
259 pitem_free(item);
260 return(0);
261 }
262
263 return(1);
264 }
265
266
267 static int
dtls1_retrieve_buffered_record(SSL * s,record_pqueue * queue)268 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
269 {
270 pitem *item;
271
272 item = pqueue_pop(queue->q);
273 if (item)
274 {
275 dtls1_copy_record(s, item);
276
277 OPENSSL_free(item->data);
278 pitem_free(item);
279
280 return(1);
281 }
282
283 return(0);
284 }
285
286
287 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
288 * yet */
289 #define dtls1_get_unprocessed_record(s) \
290 dtls1_retrieve_buffered_record((s), \
291 &((s)->d1->unprocessed_rcds))
292
293 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
294 #define dtls1_get_processed_record(s) \
295 dtls1_retrieve_buffered_record((s), \
296 &((s)->d1->processed_rcds))
297
298 static int
dtls1_process_buffered_records(SSL * s)299 dtls1_process_buffered_records(SSL *s)
300 {
301 pitem *item;
302
303 item = pqueue_peek(s->d1->unprocessed_rcds.q);
304 if (item)
305 {
306 /* Check if epoch is current. */
307 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
308 return(1); /* Nothing to do. */
309
310 /* Process all the records. */
311 while (pqueue_peek(s->d1->unprocessed_rcds.q))
312 {
313 dtls1_get_unprocessed_record(s);
314 if ( ! dtls1_process_record(s))
315 return(0);
316 dtls1_buffer_record(s, &(s->d1->processed_rcds),
317 s->s3->rrec.seq_num);
318 }
319 }
320
321 /* sync epoch numbers once all the unprocessed records
322 * have been processed */
323 s->d1->processed_rcds.epoch = s->d1->r_epoch;
324 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
325
326 return(1);
327 }
328
329
330 #if 0
331
332 static int
333 dtls1_get_buffered_record(SSL *s)
334 {
335 pitem *item;
336 PQ_64BIT priority =
337 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
338 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
339
340 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating,
341 nothing buffered */
342 return 0;
343
344
345 item = pqueue_peek(s->d1->rcvd_records);
346 if (item && item->priority == priority)
347 {
348 /* Check if we've received the record of interest. It must be
349 * a handshake record, since data records as passed up without
350 * buffering */
351 DTLS1_RECORD_DATA *rdata;
352 item = pqueue_pop(s->d1->rcvd_records);
353 rdata = (DTLS1_RECORD_DATA *)item->data;
354
355 if (s->s3->rbuf.buf != NULL)
356 OPENSSL_free(s->s3->rbuf.buf);
357
358 s->packet = rdata->packet;
359 s->packet_length = rdata->packet_length;
360 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
361 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
362
363 OPENSSL_free(item->data);
364 pitem_free(item);
365
366 /* s->d1->next_expected_seq_num++; */
367 return(1);
368 }
369
370 return 0;
371 }
372
373 #endif
374
375 static int
dtls1_process_record(SSL * s)376 dtls1_process_record(SSL *s)
377 {
378 int i,al;
379 int enc_err;
380 SSL_SESSION *sess;
381 SSL3_RECORD *rr;
382 unsigned int mac_size, orig_len;
383 unsigned char md[EVP_MAX_MD_SIZE];
384
385 rr= &(s->s3->rrec);
386 sess = s->session;
387
388 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
389 * and we have that many bytes in s->packet
390 */
391 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
392
393 /* ok, we can now read from 's->packet' data into 'rr'
394 * rr->input points at rr->length bytes, which
395 * need to be copied into rr->data by either
396 * the decryption or by the decompression
397 * When the data is 'copied' into the rr->data buffer,
398 * rr->input will be pointed at the new buffer */
399
400 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
401 * rr->length bytes of encrypted compressed stuff. */
402
403 /* check is not needed I believe */
404 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
405 {
406 al=SSL_AD_RECORD_OVERFLOW;
407 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
408 goto f_err;
409 }
410
411 /* decrypt in place in 'rr->input' */
412 rr->data=rr->input;
413
414 enc_err = s->method->ssl3_enc->enc(s,0);
415 /* enc_err is:
416 * 0: (in non-constant time) if the record is publically invalid.
417 * 1: if the padding is valid
418 * -1: if the padding is invalid */
419 if (enc_err == 0)
420 {
421 /* For DTLS we simply ignore bad packets. */
422 rr->length = 0;
423 s->packet_length = 0;
424 goto err;
425 }
426
427 #ifdef TLS_DEBUG
428 printf("dec %d\n",rr->length);
429 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
430 printf("\n");
431 #endif
432
433 /* r->length is now the compressed data plus mac */
434 if ((sess != NULL) &&
435 (s->enc_read_ctx != NULL) &&
436 (EVP_MD_CTX_md(s->read_hash) != NULL))
437 {
438 /* s->read_hash != NULL => mac_size != -1 */
439 unsigned char *mac = NULL;
440 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
441 mac_size=EVP_MD_CTX_size(s->read_hash);
442 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
443
444 /* kludge: *_cbc_remove_padding passes padding length in rr->type */
445 orig_len = rr->length+((unsigned int)rr->type>>8);
446
447 /* orig_len is the length of the record before any padding was
448 * removed. This is public information, as is the MAC in use,
449 * therefore we can safely process the record in a different
450 * amount of time if it's too short to possibly contain a MAC.
451 */
452 if (orig_len < mac_size ||
453 /* CBC records must have a padding length byte too. */
454 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
455 orig_len < mac_size+1))
456 {
457 al=SSL_AD_DECODE_ERROR;
458 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
459 goto f_err;
460 }
461
462 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
463 {
464 /* We update the length so that the TLS header bytes
465 * can be constructed correctly but we need to extract
466 * the MAC in constant time from within the record,
467 * without leaking the contents of the padding bytes.
468 * */
469 mac = mac_tmp;
470 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
471 rr->length -= mac_size;
472 }
473 else
474 {
475 /* In this case there's no padding, so |orig_len|
476 * equals |rec->length| and we checked that there's
477 * enough bytes for |mac_size| above. */
478 rr->length -= mac_size;
479 mac = &rr->data[rr->length];
480 }
481
482 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
483 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
484 enc_err = -1;
485 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
486 enc_err = -1;
487 }
488
489 if (enc_err < 0)
490 {
491 /* decryption failed, silently discard message */
492 rr->length = 0;
493 s->packet_length = 0;
494 goto err;
495 }
496
497 /* r->length is now just compressed */
498 if (s->expand != NULL)
499 {
500 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
501 {
502 al=SSL_AD_RECORD_OVERFLOW;
503 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
504 goto f_err;
505 }
506 if (!ssl3_do_uncompress(s))
507 {
508 al=SSL_AD_DECOMPRESSION_FAILURE;
509 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
510 goto f_err;
511 }
512 }
513
514 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
515 {
516 al=SSL_AD_RECORD_OVERFLOW;
517 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
518 goto f_err;
519 }
520
521 rr->off=0;
522 /* So at this point the following is true
523 * ssl->s3->rrec.type is the type of record
524 * ssl->s3->rrec.length == number of bytes in record
525 * ssl->s3->rrec.off == offset to first valid byte
526 * ssl->s3->rrec.data == where to take bytes from, increment
527 * after use :-).
528 */
529
530 /* we have pulled in a full packet so zero things */
531 s->packet_length=0;
532 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
533 return(1);
534
535 f_err:
536 ssl3_send_alert(s,SSL3_AL_FATAL,al);
537 err:
538 return(0);
539 }
540
541
542 /* Call this to get a new input record.
543 * It will return <= 0 if more data is needed, normally due to an error
544 * or non-blocking IO.
545 * When it finishes, one packet has been decoded and can be found in
546 * ssl->s3->rrec.type - is the type of record
547 * ssl->s3->rrec.data, - data
548 * ssl->s3->rrec.length, - number of bytes
549 */
550 /* used only by dtls1_read_bytes */
dtls1_get_record(SSL * s)551 int dtls1_get_record(SSL *s)
552 {
553 int ssl_major,ssl_minor;
554 int i,n;
555 SSL3_RECORD *rr;
556 unsigned char *p = NULL;
557 unsigned short version;
558 DTLS1_BITMAP *bitmap;
559 unsigned int is_next_epoch;
560
561 rr= &(s->s3->rrec);
562
563 /* The epoch may have changed. If so, process all the
564 * pending records. This is a non-blocking operation. */
565 dtls1_process_buffered_records(s);
566
567 /* if we're renegotiating, then there may be buffered records */
568 if (dtls1_get_processed_record(s))
569 return 1;
570
571 /* get something from the wire */
572 again:
573 /* check if we have the header */
574 if ( (s->rstate != SSL_ST_READ_BODY) ||
575 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
576 {
577 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
578 /* read timeout is handled by dtls1_read_bytes */
579 if (n <= 0) return(n); /* error or non-blocking */
580
581 /* this packet contained a partial record, dump it */
582 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
583 {
584 s->packet_length = 0;
585 goto again;
586 }
587
588 s->rstate=SSL_ST_READ_BODY;
589
590 p=s->packet;
591
592 /* Pull apart the header into the DTLS1_RECORD */
593 rr->type= *(p++);
594 ssl_major= *(p++);
595 ssl_minor= *(p++);
596 version=(ssl_major<<8)|ssl_minor;
597
598 /* sequence number is 64 bits, with top 2 bytes = epoch */
599 n2s(p,rr->epoch);
600
601 memcpy(&(s->s3->read_sequence[2]), p, 6);
602 p+=6;
603
604 n2s(p,rr->length);
605
606 /* Lets check version */
607 if (!s->first_packet)
608 {
609 if (version != s->version)
610 {
611 /* unexpected version, silently discard */
612 rr->length = 0;
613 s->packet_length = 0;
614 goto again;
615 }
616 }
617
618 if ((version & 0xff00) != (s->version & 0xff00))
619 {
620 /* wrong version, silently discard record */
621 rr->length = 0;
622 s->packet_length = 0;
623 goto again;
624 }
625
626 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
627 {
628 /* record too long, silently discard it */
629 rr->length = 0;
630 s->packet_length = 0;
631 goto again;
632 }
633
634 /* now s->rstate == SSL_ST_READ_BODY */
635 }
636
637 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
638
639 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
640 {
641 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
642 i=rr->length;
643 n=ssl3_read_n(s,i,i,1);
644 if (n <= 0) return(n); /* error or non-blocking io */
645
646 /* this packet contained a partial record, dump it */
647 if ( n != i)
648 {
649 rr->length = 0;
650 s->packet_length = 0;
651 goto again;
652 }
653
654 /* now n == rr->length,
655 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
656 }
657 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
658
659 /* match epochs. NULL means the packet is dropped on the floor */
660 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
661 if ( bitmap == NULL)
662 {
663 rr->length = 0;
664 s->packet_length = 0; /* dump this record */
665 goto again; /* get another record */
666 }
667
668 #ifndef OPENSSL_NO_SCTP
669 /* Only do replay check if no SCTP bio */
670 if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
671 {
672 #endif
673 /* Check whether this is a repeat, or aged record.
674 * Don't check if we're listening and this message is
675 * a ClientHello. They can look as if they're replayed,
676 * since they arrive from different connections and
677 * would be dropped unnecessarily.
678 */
679 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
680 *p == SSL3_MT_CLIENT_HELLO) &&
681 !dtls1_record_replay_check(s, bitmap))
682 {
683 rr->length = 0;
684 s->packet_length=0; /* dump this record */
685 goto again; /* get another record */
686 }
687 #ifndef OPENSSL_NO_SCTP
688 }
689 #endif
690
691 /* just read a 0 length packet */
692 if (rr->length == 0) goto again;
693
694 /* If this record is from the next epoch (either HM or ALERT),
695 * and a handshake is currently in progress, buffer it since it
696 * cannot be processed at this time. However, do not buffer
697 * anything while listening.
698 */
699 if (is_next_epoch)
700 {
701 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
702 {
703 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
704 }
705 rr->length = 0;
706 s->packet_length = 0;
707 goto again;
708 }
709
710 if (!dtls1_process_record(s))
711 {
712 rr->length = 0;
713 s->packet_length = 0; /* dump this record */
714 goto again; /* get another record */
715 }
716
717 return(1);
718
719 }
720
721 /* Return up to 'len' payload bytes received in 'type' records.
722 * 'type' is one of the following:
723 *
724 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
725 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
726 * - 0 (during a shutdown, no data has to be returned)
727 *
728 * If we don't have stored data to work from, read a SSL/TLS record first
729 * (possibly multiple records if we still don't have anything to return).
730 *
731 * This function must handle any surprises the peer may have for us, such as
732 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
733 * a surprise, but handled as if it were), or renegotiation requests.
734 * Also if record payloads contain fragments too small to process, we store
735 * them until there is enough for the respective protocol (the record protocol
736 * may use arbitrary fragmentation and even interleaving):
737 * Change cipher spec protocol
738 * just 1 byte needed, no need for keeping anything stored
739 * Alert protocol
740 * 2 bytes needed (AlertLevel, AlertDescription)
741 * Handshake protocol
742 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
743 * to detect unexpected Client Hello and Hello Request messages
744 * here, anything else is handled by higher layers
745 * Application data protocol
746 * none of our business
747 */
dtls1_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)748 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
749 {
750 int al,i,j,ret;
751 unsigned int n;
752 SSL3_RECORD *rr;
753 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
754
755 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
756 if (!ssl3_setup_buffers(s))
757 return(-1);
758
759 /* XXX: check what the second '&& type' is about */
760 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
761 (type != SSL3_RT_HANDSHAKE) && type) ||
762 (peek && (type != SSL3_RT_APPLICATION_DATA)))
763 {
764 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
765 return -1;
766 }
767
768 /* check whether there's a handshake message (client hello?) waiting */
769 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
770 return ret;
771
772 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
773
774 #ifndef OPENSSL_NO_SCTP
775 /* Continue handshake if it had to be interrupted to read
776 * app data with SCTP.
777 */
778 if ((!s->in_handshake && SSL_in_init(s)) ||
779 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
780 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
781 s->s3->in_read_app_data != 2))
782 #else
783 if (!s->in_handshake && SSL_in_init(s))
784 #endif
785 {
786 /* type == SSL3_RT_APPLICATION_DATA */
787 i=s->handshake_func(s);
788 if (i < 0) return(i);
789 if (i == 0)
790 {
791 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
792 return(-1);
793 }
794 }
795
796 start:
797 s->rwstate=SSL_NOTHING;
798
799 /* s->s3->rrec.type - is the type of record
800 * s->s3->rrec.data, - data
801 * s->s3->rrec.off, - offset into 'data' for next read
802 * s->s3->rrec.length, - number of bytes. */
803 rr = &(s->s3->rrec);
804
805 /* We are not handshaking and have no data yet,
806 * so process data buffered during the last handshake
807 * in advance, if any.
808 */
809 if (s->state == SSL_ST_OK && rr->length == 0)
810 {
811 pitem *item;
812 item = pqueue_pop(s->d1->buffered_app_data.q);
813 if (item)
814 {
815 #ifndef OPENSSL_NO_SCTP
816 /* Restore bio_dgram_sctp_rcvinfo struct */
817 if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
818 {
819 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
820 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
821 }
822 #endif
823
824 dtls1_copy_record(s, item);
825
826 OPENSSL_free(item->data);
827 pitem_free(item);
828 }
829 }
830
831 /* Check for timeout */
832 if (dtls1_handle_timeout(s) > 0)
833 goto start;
834
835 /* get new packet if necessary */
836 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
837 {
838 ret=dtls1_get_record(s);
839 if (ret <= 0)
840 {
841 ret = dtls1_read_failed(s, ret);
842 /* anything other than a timeout is an error */
843 if (ret <= 0)
844 return(ret);
845 else
846 goto start;
847 }
848 }
849
850 /* we now have a packet which can be read and processed */
851
852 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
853 * reset by ssl3_get_finished */
854 && (rr->type != SSL3_RT_HANDSHAKE))
855 {
856 /* We now have application data between CCS and Finished.
857 * Most likely the packets were reordered on their way, so
858 * buffer the application data for later processing rather
859 * than dropping the connection.
860 */
861 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
862 rr->length = 0;
863 goto start;
864 }
865
866 /* If the other end has shut down, throw anything we read away
867 * (even in 'peek' mode) */
868 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
869 {
870 rr->length=0;
871 s->rwstate=SSL_NOTHING;
872 return(0);
873 }
874
875
876 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
877 {
878 /* make sure that we are not getting application data when we
879 * are doing a handshake for the first time */
880 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
881 (s->enc_read_ctx == NULL))
882 {
883 al=SSL_AD_UNEXPECTED_MESSAGE;
884 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
885 goto f_err;
886 }
887
888 if (len <= 0) return(len);
889
890 if ((unsigned int)len > rr->length)
891 n = rr->length;
892 else
893 n = (unsigned int)len;
894
895 memcpy(buf,&(rr->data[rr->off]),n);
896 if (!peek)
897 {
898 rr->length-=n;
899 rr->off+=n;
900 if (rr->length == 0)
901 {
902 s->rstate=SSL_ST_READ_HEADER;
903 rr->off=0;
904 }
905 }
906
907 #ifndef OPENSSL_NO_SCTP
908 /* We were about to renegotiate but had to read
909 * belated application data first, so retry.
910 */
911 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
912 rr->type == SSL3_RT_APPLICATION_DATA &&
913 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
914 {
915 s->rwstate=SSL_READING;
916 BIO_clear_retry_flags(SSL_get_rbio(s));
917 BIO_set_retry_read(SSL_get_rbio(s));
918 }
919
920 /* We might had to delay a close_notify alert because
921 * of reordered app data. If there was an alert and there
922 * is no message to read anymore, finally set shutdown.
923 */
924 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
925 s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
926 {
927 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
928 return(0);
929 }
930 #endif
931 return(n);
932 }
933
934
935 /* If we get here, then type != rr->type; if we have a handshake
936 * message, then it was unexpected (Hello Request or Client Hello). */
937
938 /* In case of record types for which we have 'fragment' storage,
939 * fill that so that we can process the data at a fixed place.
940 */
941 {
942 unsigned int k, dest_maxlen = 0;
943 unsigned char *dest = NULL;
944 unsigned int *dest_len = NULL;
945
946 if (rr->type == SSL3_RT_HANDSHAKE)
947 {
948 dest_maxlen = sizeof s->d1->handshake_fragment;
949 dest = s->d1->handshake_fragment;
950 dest_len = &s->d1->handshake_fragment_len;
951 }
952 else if (rr->type == SSL3_RT_ALERT)
953 {
954 dest_maxlen = sizeof(s->d1->alert_fragment);
955 dest = s->d1->alert_fragment;
956 dest_len = &s->d1->alert_fragment_len;
957 }
958 #ifndef OPENSSL_NO_HEARTBEATS
959 else if (rr->type == TLS1_RT_HEARTBEAT)
960 {
961 dtls1_process_heartbeat(s);
962
963 /* Exit and notify application to read again */
964 rr->length = 0;
965 s->rwstate=SSL_READING;
966 BIO_clear_retry_flags(SSL_get_rbio(s));
967 BIO_set_retry_read(SSL_get_rbio(s));
968 return(-1);
969 }
970 #endif
971 /* else it's a CCS message, or application data or wrong */
972 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
973 {
974 /* Application data while renegotiating
975 * is allowed. Try again reading.
976 */
977 if (rr->type == SSL3_RT_APPLICATION_DATA)
978 {
979 BIO *bio;
980 s->s3->in_read_app_data=2;
981 bio=SSL_get_rbio(s);
982 s->rwstate=SSL_READING;
983 BIO_clear_retry_flags(bio);
984 BIO_set_retry_read(bio);
985 return(-1);
986 }
987
988 /* Not certain if this is the right error handling */
989 al=SSL_AD_UNEXPECTED_MESSAGE;
990 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
991 goto f_err;
992 }
993
994 if (dest_maxlen > 0)
995 {
996 /* XDTLS: In a pathalogical case, the Client Hello
997 * may be fragmented--don't always expect dest_maxlen bytes */
998 if ( rr->length < dest_maxlen)
999 {
1000 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1001 /*
1002 * for normal alerts rr->length is 2, while
1003 * dest_maxlen is 7 if we were to handle this
1004 * non-existing alert...
1005 */
1006 FIX ME
1007 #endif
1008 s->rstate=SSL_ST_READ_HEADER;
1009 rr->length = 0;
1010 goto start;
1011 }
1012
1013 /* now move 'n' bytes: */
1014 for ( k = 0; k < dest_maxlen; k++)
1015 {
1016 dest[k] = rr->data[rr->off++];
1017 rr->length--;
1018 }
1019 *dest_len = dest_maxlen;
1020 }
1021 }
1022
1023 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
1024 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
1025 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1026
1027 /* If we are a client, check for an incoming 'Hello Request': */
1028 if ((!s->server) &&
1029 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1030 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1031 (s->session != NULL) && (s->session->cipher != NULL))
1032 {
1033 s->d1->handshake_fragment_len = 0;
1034
1035 if ((s->d1->handshake_fragment[1] != 0) ||
1036 (s->d1->handshake_fragment[2] != 0) ||
1037 (s->d1->handshake_fragment[3] != 0))
1038 {
1039 al=SSL_AD_DECODE_ERROR;
1040 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1041 goto err;
1042 }
1043
1044 /* no need to check sequence number on HELLO REQUEST messages */
1045
1046 if (s->msg_callback)
1047 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1048 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1049
1050 if (SSL_is_init_finished(s) &&
1051 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1052 !s->s3->renegotiate)
1053 {
1054 s->new_session = 1;
1055 ssl3_renegotiate(s);
1056 if (ssl3_renegotiate_check(s))
1057 {
1058 i=s->handshake_func(s);
1059 if (i < 0) return(i);
1060 if (i == 0)
1061 {
1062 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1063 return(-1);
1064 }
1065
1066 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1067 {
1068 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1069 {
1070 BIO *bio;
1071 /* In the case where we try to read application data,
1072 * but we trigger an SSL handshake, we return -1 with
1073 * the retry option set. Otherwise renegotiation may
1074 * cause nasty problems in the blocking world */
1075 s->rwstate=SSL_READING;
1076 bio=SSL_get_rbio(s);
1077 BIO_clear_retry_flags(bio);
1078 BIO_set_retry_read(bio);
1079 return(-1);
1080 }
1081 }
1082 }
1083 }
1084 /* we either finished a handshake or ignored the request,
1085 * now try again to obtain the (application) data we were asked for */
1086 goto start;
1087 }
1088
1089 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1090 {
1091 int alert_level = s->d1->alert_fragment[0];
1092 int alert_descr = s->d1->alert_fragment[1];
1093
1094 s->d1->alert_fragment_len = 0;
1095
1096 if (s->msg_callback)
1097 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1098 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1099
1100 if (s->info_callback != NULL)
1101 cb=s->info_callback;
1102 else if (s->ctx->info_callback != NULL)
1103 cb=s->ctx->info_callback;
1104
1105 if (cb != NULL)
1106 {
1107 j = (alert_level << 8) | alert_descr;
1108 cb(s, SSL_CB_READ_ALERT, j);
1109 }
1110
1111 if (alert_level == 1) /* warning */
1112 {
1113 s->s3->warn_alert = alert_descr;
1114 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1115 {
1116 #ifndef OPENSSL_NO_SCTP
1117 /* With SCTP and streams the socket may deliver app data
1118 * after a close_notify alert. We have to check this
1119 * first so that nothing gets discarded.
1120 */
1121 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1122 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1123 {
1124 s->d1->shutdown_received = 1;
1125 s->rwstate=SSL_READING;
1126 BIO_clear_retry_flags(SSL_get_rbio(s));
1127 BIO_set_retry_read(SSL_get_rbio(s));
1128 return -1;
1129 }
1130 #endif
1131 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1132 return(0);
1133 }
1134 #if 0
1135 /* XXX: this is a possible improvement in the future */
1136 /* now check if it's a missing record */
1137 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1138 {
1139 unsigned short seq;
1140 unsigned int frag_off;
1141 unsigned char *p = &(s->d1->alert_fragment[2]);
1142
1143 n2s(p, seq);
1144 n2l3(p, frag_off);
1145
1146 dtls1_retransmit_message(s,
1147 dtls1_get_queue_priority(frag->msg_header.seq, 0),
1148 frag_off, &found);
1149 if ( ! found && SSL_in_init(s))
1150 {
1151 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1152 /* requested a message not yet sent,
1153 send an alert ourselves */
1154 ssl3_send_alert(s,SSL3_AL_WARNING,
1155 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1156 }
1157 }
1158 #endif
1159 }
1160 else if (alert_level == 2) /* fatal */
1161 {
1162 char tmp[16];
1163
1164 s->rwstate=SSL_NOTHING;
1165 s->s3->fatal_alert = alert_descr;
1166 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1167 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1168 ERR_add_error_data(2,"SSL alert number ",tmp);
1169 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1170 SSL_CTX_remove_session(s->ctx,s->session);
1171 return(0);
1172 }
1173 else
1174 {
1175 al=SSL_AD_ILLEGAL_PARAMETER;
1176 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1177 goto f_err;
1178 }
1179
1180 goto start;
1181 }
1182
1183 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1184 {
1185 s->rwstate=SSL_NOTHING;
1186 rr->length=0;
1187 return(0);
1188 }
1189
1190 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1191 {
1192 struct ccs_header_st ccs_hdr;
1193 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1194
1195 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1196
1197 if (s->version == DTLS1_BAD_VER)
1198 ccs_hdr_len = 3;
1199
1200 /* 'Change Cipher Spec' is just a single byte, so we know
1201 * exactly what the record payload has to look like */
1202 /* XDTLS: check that epoch is consistent */
1203 if ( (rr->length != ccs_hdr_len) ||
1204 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1205 {
1206 i=SSL_AD_ILLEGAL_PARAMETER;
1207 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1208 goto err;
1209 }
1210
1211 rr->length=0;
1212
1213 if (s->msg_callback)
1214 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1215 rr->data, 1, s, s->msg_callback_arg);
1216
1217 /* We can't process a CCS now, because previous handshake
1218 * messages are still missing, so just drop it.
1219 */
1220 if (!s->d1->change_cipher_spec_ok)
1221 {
1222 goto start;
1223 }
1224
1225 s->d1->change_cipher_spec_ok = 0;
1226
1227 s->s3->change_cipher_spec=1;
1228 if (!ssl3_do_change_cipher_spec(s))
1229 goto err;
1230
1231 /* do this whenever CCS is processed */
1232 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1233
1234 if (s->version == DTLS1_BAD_VER)
1235 s->d1->handshake_read_seq++;
1236
1237 #ifndef OPENSSL_NO_SCTP
1238 /* Remember that a CCS has been received,
1239 * so that an old key of SCTP-Auth can be
1240 * deleted when a CCS is sent. Will be ignored
1241 * if no SCTP is used
1242 */
1243 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1244 #endif
1245
1246 goto start;
1247 }
1248
1249 /* Unexpected handshake message (Client Hello, or protocol violation) */
1250 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1251 !s->in_handshake)
1252 {
1253 struct hm_header_st msg_hdr;
1254
1255 /* this may just be a stale retransmit */
1256 dtls1_get_message_header(rr->data, &msg_hdr);
1257 if( rr->epoch != s->d1->r_epoch)
1258 {
1259 rr->length = 0;
1260 goto start;
1261 }
1262
1263 /* If we are server, we may have a repeated FINISHED of the
1264 * client here, then retransmit our CCS and FINISHED.
1265 */
1266 if (msg_hdr.type == SSL3_MT_FINISHED)
1267 {
1268 if (dtls1_check_timeout_num(s) < 0)
1269 return -1;
1270
1271 dtls1_retransmit_buffered_messages(s);
1272 rr->length = 0;
1273 goto start;
1274 }
1275
1276 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1277 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1278 {
1279 #if 0 /* worked only because C operator preferences are not as expected (and
1280 * because this is not really needed for clients except for detecting
1281 * protocol violations): */
1282 s->state=SSL_ST_BEFORE|(s->server)
1283 ?SSL_ST_ACCEPT
1284 :SSL_ST_CONNECT;
1285 #else
1286 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1287 #endif
1288 s->renegotiate=1;
1289 s->new_session=1;
1290 }
1291 i=s->handshake_func(s);
1292 if (i < 0) return(i);
1293 if (i == 0)
1294 {
1295 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1296 return(-1);
1297 }
1298
1299 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1300 {
1301 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1302 {
1303 BIO *bio;
1304 /* In the case where we try to read application data,
1305 * but we trigger an SSL handshake, we return -1 with
1306 * the retry option set. Otherwise renegotiation may
1307 * cause nasty problems in the blocking world */
1308 s->rwstate=SSL_READING;
1309 bio=SSL_get_rbio(s);
1310 BIO_clear_retry_flags(bio);
1311 BIO_set_retry_read(bio);
1312 return(-1);
1313 }
1314 }
1315 goto start;
1316 }
1317
1318 switch (rr->type)
1319 {
1320 default:
1321 #ifndef OPENSSL_NO_TLS
1322 /* TLS just ignores unknown message types */
1323 if (s->version == TLS1_VERSION)
1324 {
1325 rr->length = 0;
1326 goto start;
1327 }
1328 #endif
1329 al=SSL_AD_UNEXPECTED_MESSAGE;
1330 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1331 goto f_err;
1332 case SSL3_RT_CHANGE_CIPHER_SPEC:
1333 case SSL3_RT_ALERT:
1334 case SSL3_RT_HANDSHAKE:
1335 /* we already handled all of these, with the possible exception
1336 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1337 * should not happen when type != rr->type */
1338 al=SSL_AD_UNEXPECTED_MESSAGE;
1339 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1340 goto f_err;
1341 case SSL3_RT_APPLICATION_DATA:
1342 /* At this point, we were expecting handshake data,
1343 * but have application data. If the library was
1344 * running inside ssl3_read() (i.e. in_read_app_data
1345 * is set) and it makes sense to read application data
1346 * at this point (session renegotiation not yet started),
1347 * we will indulge it.
1348 */
1349 if (s->s3->in_read_app_data &&
1350 (s->s3->total_renegotiations != 0) &&
1351 ((
1352 (s->state & SSL_ST_CONNECT) &&
1353 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1354 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1355 ) || (
1356 (s->state & SSL_ST_ACCEPT) &&
1357 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1358 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1359 )
1360 ))
1361 {
1362 s->s3->in_read_app_data=2;
1363 return(-1);
1364 }
1365 else
1366 {
1367 al=SSL_AD_UNEXPECTED_MESSAGE;
1368 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1369 goto f_err;
1370 }
1371 }
1372 /* not reached */
1373
1374 f_err:
1375 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1376 err:
1377 return(-1);
1378 }
1379
1380 int
dtls1_write_app_data_bytes(SSL * s,int type,const void * buf_,int len)1381 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1382 {
1383 int i;
1384
1385 #ifndef OPENSSL_NO_SCTP
1386 /* Check if we have to continue an interrupted handshake
1387 * for reading belated app data with SCTP.
1388 */
1389 if ((SSL_in_init(s) && !s->in_handshake) ||
1390 (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1391 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1392 #else
1393 if (SSL_in_init(s) && !s->in_handshake)
1394 #endif
1395 {
1396 i=s->handshake_func(s);
1397 if (i < 0) return(i);
1398 if (i == 0)
1399 {
1400 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1401 return -1;
1402 }
1403 }
1404
1405 if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1406 {
1407 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1408 return -1;
1409 }
1410
1411 i = dtls1_write_bytes(s, type, buf_, len);
1412 return i;
1413 }
1414
1415
1416 /* this only happens when a client hello is received and a handshake
1417 * is started. */
1418 static int
have_handshake_fragment(SSL * s,int type,unsigned char * buf,int len,int peek)1419 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1420 int len, int peek)
1421 {
1422
1423 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1424 /* (partially) satisfy request from storage */
1425 {
1426 unsigned char *src = s->d1->handshake_fragment;
1427 unsigned char *dst = buf;
1428 unsigned int k,n;
1429
1430 /* peek == 0 */
1431 n = 0;
1432 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1433 {
1434 *dst++ = *src++;
1435 len--; s->d1->handshake_fragment_len--;
1436 n++;
1437 }
1438 /* move any remaining fragment bytes: */
1439 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1440 s->d1->handshake_fragment[k] = *src++;
1441 return n;
1442 }
1443
1444 return 0;
1445 }
1446
1447
1448
1449
1450 /* Call this to write data in records of type 'type'
1451 * It will return <= 0 if not all data has been sent or non-blocking IO.
1452 */
dtls1_write_bytes(SSL * s,int type,const void * buf,int len)1453 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1454 {
1455 int i;
1456
1457 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1458 s->rwstate=SSL_NOTHING;
1459 i=do_dtls1_write(s, type, buf, len, 0);
1460 return i;
1461 }
1462
do_dtls1_write(SSL * s,int type,const unsigned char * buf,unsigned int len,int create_empty_fragment)1463 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1464 {
1465 unsigned char *p,*pseq;
1466 int i,mac_size,clear=0;
1467 int prefix_len = 0;
1468 SSL3_RECORD *wr;
1469 SSL3_BUFFER *wb;
1470 SSL_SESSION *sess;
1471 int bs;
1472
1473 /* first check if there is a SSL3_BUFFER still being written
1474 * out. This will happen with non blocking IO */
1475 if (s->s3->wbuf.left != 0)
1476 {
1477 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1478 return(ssl3_write_pending(s,type,buf,len));
1479 }
1480
1481 /* If we have an alert to send, lets send it */
1482 if (s->s3->alert_dispatch)
1483 {
1484 i=s->method->ssl_dispatch_alert(s);
1485 if (i <= 0)
1486 return(i);
1487 /* if it went, fall through and send more stuff */
1488 }
1489
1490 if (len == 0 && !create_empty_fragment)
1491 return 0;
1492
1493 wr= &(s->s3->wrec);
1494 wb= &(s->s3->wbuf);
1495 sess=s->session;
1496
1497 if ( (sess == NULL) ||
1498 (s->enc_write_ctx == NULL) ||
1499 (EVP_MD_CTX_md(s->write_hash) == NULL))
1500 clear=1;
1501
1502 if (clear)
1503 mac_size=0;
1504 else
1505 {
1506 mac_size=EVP_MD_CTX_size(s->write_hash);
1507 if (mac_size < 0)
1508 goto err;
1509 }
1510
1511 /* DTLS implements explicit IV, so no need for empty fragments */
1512 #if 0
1513 /* 'create_empty_fragment' is true only when this function calls itself */
1514 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1515 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1516 {
1517 /* countermeasure against known-IV weakness in CBC ciphersuites
1518 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1519 */
1520
1521 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1522 {
1523 /* recursive function call with 'create_empty_fragment' set;
1524 * this prepares and buffers the data for an empty fragment
1525 * (these 'prefix_len' bytes are sent out later
1526 * together with the actual payload) */
1527 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1528 if (prefix_len <= 0)
1529 goto err;
1530
1531 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1532 {
1533 /* insufficient space */
1534 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1535 goto err;
1536 }
1537 }
1538
1539 s->s3->empty_fragment_done = 1;
1540 }
1541 #endif
1542 p = wb->buf + prefix_len;
1543
1544 /* write the header */
1545
1546 *(p++)=type&0xff;
1547 wr->type=type;
1548
1549 *(p++)=(s->version>>8);
1550 *(p++)=s->version&0xff;
1551
1552 /* field where we are to write out packet epoch, seq num and len */
1553 pseq=p;
1554 p+=10;
1555
1556 /* lets setup the record stuff. */
1557
1558 /* Make space for the explicit IV in case of CBC.
1559 * (this is a bit of a boundary violation, but what the heck).
1560 */
1561 if ( s->enc_write_ctx &&
1562 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1563 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1564 else
1565 bs = 0;
1566
1567 wr->data=p + bs; /* make room for IV in case of CBC */
1568 wr->length=(int)len;
1569 wr->input=(unsigned char *)buf;
1570
1571 /* we now 'read' from wr->input, wr->length bytes into
1572 * wr->data */
1573
1574 /* first we compress */
1575 if (s->compress != NULL)
1576 {
1577 if (!ssl3_do_compress(s))
1578 {
1579 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1580 goto err;
1581 }
1582 }
1583 else
1584 {
1585 memcpy(wr->data,wr->input,wr->length);
1586 wr->input=wr->data;
1587 }
1588
1589 /* we should still have the output to wr->data and the input
1590 * from wr->input. Length should be wr->length.
1591 * wr->data still points in the wb->buf */
1592
1593 if (mac_size != 0)
1594 {
1595 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1596 goto err;
1597 wr->length+=mac_size;
1598 }
1599
1600 /* this is true regardless of mac size */
1601 wr->input=p;
1602 wr->data=p;
1603
1604
1605 /* ssl3_enc can only have an error on read */
1606 if (bs) /* bs != 0 in case of CBC */
1607 {
1608 RAND_pseudo_bytes(p,bs);
1609 /* master IV and last CBC residue stand for
1610 * the rest of randomness */
1611 wr->length += bs;
1612 }
1613
1614 s->method->ssl3_enc->enc(s,1);
1615
1616 /* record length after mac and block padding */
1617 /* if (type == SSL3_RT_APPLICATION_DATA ||
1618 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1619
1620 /* there's only one epoch between handshake and app data */
1621
1622 s2n(s->d1->w_epoch, pseq);
1623
1624 /* XDTLS: ?? */
1625 /* else
1626 s2n(s->d1->handshake_epoch, pseq); */
1627
1628 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1629 pseq+=6;
1630 s2n(wr->length,pseq);
1631
1632 /* we should now have
1633 * wr->data pointing to the encrypted data, which is
1634 * wr->length long */
1635 wr->type=type; /* not needed but helps for debugging */
1636 wr->length+=DTLS1_RT_HEADER_LENGTH;
1637
1638 #if 0 /* this is now done at the message layer */
1639 /* buffer the record, making it easy to handle retransmits */
1640 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1641 dtls1_buffer_record(s, wr->data, wr->length,
1642 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1643 #endif
1644
1645 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1646
1647 if (create_empty_fragment)
1648 {
1649 /* we are in a recursive call;
1650 * just return the length, don't write out anything here
1651 */
1652 return wr->length;
1653 }
1654
1655 /* now let's set up wb */
1656 wb->left = prefix_len + wr->length;
1657 wb->offset = 0;
1658
1659 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1660 s->s3->wpend_tot=len;
1661 s->s3->wpend_buf=buf;
1662 s->s3->wpend_type=type;
1663 s->s3->wpend_ret=len;
1664
1665 /* we now just need to write the buffer */
1666 return ssl3_write_pending(s,type,buf,len);
1667 err:
1668 return -1;
1669 }
1670
1671
1672
dtls1_record_replay_check(SSL * s,DTLS1_BITMAP * bitmap)1673 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1674 {
1675 int cmp;
1676 unsigned int shift;
1677 const unsigned char *seq = s->s3->read_sequence;
1678
1679 cmp = satsub64be(seq,bitmap->max_seq_num);
1680 if (cmp > 0)
1681 {
1682 memcpy (s->s3->rrec.seq_num,seq,8);
1683 return 1; /* this record in new */
1684 }
1685 shift = -cmp;
1686 if (shift >= sizeof(bitmap->map)*8)
1687 return 0; /* stale, outside the window */
1688 else if (bitmap->map & (1UL<<shift))
1689 return 0; /* record previously received */
1690
1691 memcpy (s->s3->rrec.seq_num,seq,8);
1692 return 1;
1693 }
1694
1695
dtls1_record_bitmap_update(SSL * s,DTLS1_BITMAP * bitmap)1696 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1697 {
1698 int cmp;
1699 unsigned int shift;
1700 const unsigned char *seq = s->s3->read_sequence;
1701
1702 cmp = satsub64be(seq,bitmap->max_seq_num);
1703 if (cmp > 0)
1704 {
1705 shift = cmp;
1706 if (shift < sizeof(bitmap->map)*8)
1707 bitmap->map <<= shift, bitmap->map |= 1UL;
1708 else
1709 bitmap->map = 1UL;
1710 memcpy(bitmap->max_seq_num,seq,8);
1711 }
1712 else {
1713 shift = -cmp;
1714 if (shift < sizeof(bitmap->map)*8)
1715 bitmap->map |= 1UL<<shift;
1716 }
1717 }
1718
1719
dtls1_dispatch_alert(SSL * s)1720 int dtls1_dispatch_alert(SSL *s)
1721 {
1722 int i,j;
1723 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1724 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1725 unsigned char *ptr = &buf[0];
1726
1727 s->s3->alert_dispatch=0;
1728
1729 memset(buf, 0x00, sizeof(buf));
1730 *ptr++ = s->s3->send_alert[0];
1731 *ptr++ = s->s3->send_alert[1];
1732
1733 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1734 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1735 {
1736 s2n(s->d1->handshake_read_seq, ptr);
1737 #if 0
1738 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1739
1740 else
1741 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1742 #endif
1743
1744 #if 0
1745 fprintf(stderr, "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",s->d1->handshake_read_seq,s->d1->r_msg_hdr.seq);
1746 #endif
1747 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1748 }
1749 #endif
1750
1751 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1752 if (i <= 0)
1753 {
1754 s->s3->alert_dispatch=1;
1755 /* fprintf( stderr, "not done with alert\n" ); */
1756 }
1757 else
1758 {
1759 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1760 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1761 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1762 #endif
1763 )
1764 (void)BIO_flush(s->wbio);
1765
1766 if (s->msg_callback)
1767 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1768 2, s, s->msg_callback_arg);
1769
1770 if (s->info_callback != NULL)
1771 cb=s->info_callback;
1772 else if (s->ctx->info_callback != NULL)
1773 cb=s->ctx->info_callback;
1774
1775 if (cb != NULL)
1776 {
1777 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1778 cb(s,SSL_CB_WRITE_ALERT,j);
1779 }
1780 }
1781 return(i);
1782 }
1783
1784
1785 static DTLS1_BITMAP *
dtls1_get_bitmap(SSL * s,SSL3_RECORD * rr,unsigned int * is_next_epoch)1786 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1787 {
1788
1789 *is_next_epoch = 0;
1790
1791 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1792 if (rr->epoch == s->d1->r_epoch)
1793 return &s->d1->bitmap;
1794
1795 /* Only HM and ALERT messages can be from the next epoch */
1796 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1797 (rr->type == SSL3_RT_HANDSHAKE ||
1798 rr->type == SSL3_RT_ALERT))
1799 {
1800 *is_next_epoch = 1;
1801 return &s->d1->next_bitmap;
1802 }
1803
1804 return NULL;
1805 }
1806
1807 #if 0
1808 static int
1809 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1810 unsigned long *offset)
1811 {
1812
1813 /* alerts are passed up immediately */
1814 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1815 rr->type == SSL3_RT_ALERT)
1816 return 0;
1817
1818 /* Only need to buffer if a handshake is underway.
1819 * (this implies that Hello Request and Client Hello are passed up
1820 * immediately) */
1821 if ( SSL_in_init(s))
1822 {
1823 unsigned char *data = rr->data;
1824 /* need to extract the HM/CCS sequence number here */
1825 if ( rr->type == SSL3_RT_HANDSHAKE ||
1826 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1827 {
1828 unsigned short seq_num;
1829 struct hm_header_st msg_hdr;
1830 struct ccs_header_st ccs_hdr;
1831
1832 if ( rr->type == SSL3_RT_HANDSHAKE)
1833 {
1834 dtls1_get_message_header(data, &msg_hdr);
1835 seq_num = msg_hdr.seq;
1836 *offset = msg_hdr.frag_off;
1837 }
1838 else
1839 {
1840 dtls1_get_ccs_header(data, &ccs_hdr);
1841 seq_num = ccs_hdr.seq;
1842 *offset = 0;
1843 }
1844
1845 /* this is either a record we're waiting for, or a
1846 * retransmit of something we happened to previously
1847 * receive (higher layers will drop the repeat silently */
1848 if ( seq_num < s->d1->handshake_read_seq)
1849 return 0;
1850 if (rr->type == SSL3_RT_HANDSHAKE &&
1851 seq_num == s->d1->handshake_read_seq &&
1852 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1853 return 0;
1854 else if ( seq_num == s->d1->handshake_read_seq &&
1855 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1856 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1857 return 0;
1858 else
1859 {
1860 *priority = seq_num;
1861 return 1;
1862 }
1863 }
1864 else /* unknown record type */
1865 return 0;
1866 }
1867
1868 return 0;
1869 }
1870 #endif
1871
1872 void
dtls1_reset_seq_numbers(SSL * s,int rw)1873 dtls1_reset_seq_numbers(SSL *s, int rw)
1874 {
1875 unsigned char *seq;
1876 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1877
1878 if ( rw & SSL3_CC_READ)
1879 {
1880 seq = s->s3->read_sequence;
1881 s->d1->r_epoch++;
1882 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1883 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1884 }
1885 else
1886 {
1887 seq = s->s3->write_sequence;
1888 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1889 s->d1->w_epoch++;
1890 }
1891
1892 memset(seq, 0x00, seq_bytes);
1893 }
1894