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