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