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Import OpenSSL 0.9.8c
[dragonfly.git] / crypto / openssl-0.9 / ssl / d1_pkt.c
blobbe6ee323268459a682a6da9e9f20535167064b2a
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
124 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
125 int len, int peek);
126 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
127 PQ_64BIT *seq_num);
128 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
129 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
130 unsigned int *is_next_epoch);
131 #if 0
132 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
133 unsigned short *priority, unsigned long *offset);
134 #endif
135 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
136 PQ_64BIT priority);
137 static int dtls1_process_record(SSL *s);
138 #if PQ_64BIT_IS_INTEGER
139 static PQ_64BIT bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num);
140 #endif
141 static void dtls1_clear_timeouts(SSL *s);
142
143 /* copy buffered record into SSL structure */
144 static int
145 dtls1_copy_record(SSL *s, pitem *item)
146 {
147 DTLS1_RECORD_DATA *rdata;
148
149 rdata = (DTLS1_RECORD_DATA *)item->data;
150
151 if (s->s3->rbuf.buf != NULL)
152 OPENSSL_free(s->s3->rbuf.buf);
153
154 s->packet = rdata->packet;
155 s->packet_length = rdata->packet_length;
156 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
157 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
158
159 return(1);
160 }
161
162
163 static int
164 dtls1_buffer_record(SSL *s, record_pqueue *queue, PQ_64BIT priority)
165 {
166 DTLS1_RECORD_DATA *rdata;
167 pitem *item;
168
169 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
170 item = pitem_new(priority, rdata);
171 if (rdata == NULL || item == NULL)
172 {
173 if (rdata != NULL) OPENSSL_free(rdata);
174 if (item != NULL) pitem_free(item);
175
176 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
177 return(0);
178 }
179
180 rdata->packet = s->packet;
181 rdata->packet_length = s->packet_length;
182 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
183 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
184
185 item->data = rdata;
186
187 /* insert should not fail, since duplicates are dropped */
188 if (pqueue_insert(queue->q, item) == NULL)
189 {
190 OPENSSL_free(rdata);
191 pitem_free(item);
192 return(0);
193 }
194
195 s->packet = NULL;
196 s->packet_length = 0;
197 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
198 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
199
200 if (!ssl3_setup_buffers(s))
201 {
202 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
203 OPENSSL_free(rdata);
204 pitem_free(item);
205 return(0);
206 }
207
208 return(1);
209 }
210
211
212 static int
213 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
214 {
215 pitem *item;
216
217 item = pqueue_pop(queue->q);
218 if (item)
219 {
220 dtls1_copy_record(s, item);
221
222 OPENSSL_free(item->data);
223 pitem_free(item);
224
225 return(1);
226 }
227
228 return(0);
229 }
230
231
232 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
233 * yet */
234 #define dtls1_get_unprocessed_record(s) \
235 dtls1_retrieve_buffered_record((s), \
236 &((s)->d1->unprocessed_rcds))
237
238 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
239 #define dtls1_get_processed_record(s) \
240 dtls1_retrieve_buffered_record((s), \
241 &((s)->d1->processed_rcds))
242
243 static int
244 dtls1_process_buffered_records(SSL *s)
245 {
246 pitem *item;
247
248 item = pqueue_peek(s->d1->unprocessed_rcds.q);
249 if (item)
250 {
251 DTLS1_RECORD_DATA *rdata;
252 rdata = (DTLS1_RECORD_DATA *)item->data;
253
254 /* Check if epoch is current. */
255 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
256 return(1); /* Nothing to do. */
257
258 /* Process all the records. */
259 while (pqueue_peek(s->d1->unprocessed_rcds.q))
260 {
261 dtls1_get_unprocessed_record(s);
262 if ( ! dtls1_process_record(s))
263 return(0);
264 dtls1_buffer_record(s, &(s->d1->processed_rcds),
265 s->s3->rrec.seq_num);
266 }
267 }
268
269 /* sync epoch numbers once all the unprocessed records
270 * have been processed */
271 s->d1->processed_rcds.epoch = s->d1->r_epoch;
272 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
273
274 return(1);
275 }
276
277
278 #if 0
279
280 static int
281 dtls1_get_buffered_record(SSL *s)
282 {
283 pitem *item;
284 PQ_64BIT priority =
285 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
286 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
287
288 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating,
289 nothing buffered */
290 return 0;
291
292
293 item = pqueue_peek(s->d1->rcvd_records);
294 if (item && item->priority == priority)
295 {
296 /* Check if we've received the record of interest. It must be
297 * a handshake record, since data records as passed up without
298 * buffering */
299 DTLS1_RECORD_DATA *rdata;
300 item = pqueue_pop(s->d1->rcvd_records);
301 rdata = (DTLS1_RECORD_DATA *)item->data;
302
303 if (s->s3->rbuf.buf != NULL)
304 OPENSSL_free(s->s3->rbuf.buf);
305
306 s->packet = rdata->packet;
307 s->packet_length = rdata->packet_length;
308 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
309 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
310
311 OPENSSL_free(item->data);
312 pitem_free(item);
313
314 /* s->d1->next_expected_seq_num++; */
315 return(1);
316 }
317
318 return 0;
319 }
320
321 #endif
322
323 static int
324 dtls1_process_record(SSL *s)
325 {
326 int i,al;
327 int clear=0;
328 int enc_err;
329 SSL_SESSION *sess;
330 SSL3_RECORD *rr;
331 unsigned int mac_size;
332 unsigned char md[EVP_MAX_MD_SIZE];
333
334
335 rr= &(s->s3->rrec);
336 sess = s->session;
337
338 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
339 * and we have that many bytes in s->packet
340 */
341 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
342
343 /* ok, we can now read from 's->packet' data into 'rr'
344 * rr->input points at rr->length bytes, which
345 * need to be copied into rr->data by either
346 * the decryption or by the decompression
347 * When the data is 'copied' into the rr->data buffer,
348 * rr->input will be pointed at the new buffer */
349
350 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
351 * rr->length bytes of encrypted compressed stuff. */
352
353 /* check is not needed I believe */
354 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
355 {
356 al=SSL_AD_RECORD_OVERFLOW;
357 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
358 goto f_err;
359 }
360
361 /* decrypt in place in 'rr->input' */
362 rr->data=rr->input;
363
364 enc_err = s->method->ssl3_enc->enc(s,0);
365 if (enc_err <= 0)
366 {
367 if (enc_err == 0)
368 /* SSLerr() and ssl3_send_alert() have been called */
369 goto err;
370
371 /* otherwise enc_err == -1 */
372 goto decryption_failed_or_bad_record_mac;
373 }
374
375 #ifdef TLS_DEBUG
376 printf("dec %d\n",rr->length);
377 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
378 printf("\n");
379 #endif
380
381 /* r->length is now the compressed data plus mac */
382 if ( (sess == NULL) ||
383 (s->enc_read_ctx == NULL) ||
384 (s->read_hash == NULL))
385 clear=1;
386
387 if (!clear)
388 {
389 mac_size=EVP_MD_size(s->read_hash);
390
391 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
392 {
393 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
394 al=SSL_AD_RECORD_OVERFLOW;
395 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
396 goto f_err;
397 #else
398 goto decryption_failed_or_bad_record_mac;
399 #endif
400 }
401 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
402 if (rr->length < mac_size)
403 {
404 #if 0 /* OK only for stream ciphers */
405 al=SSL_AD_DECODE_ERROR;
406 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
407 goto f_err;
408 #else
409 goto decryption_failed_or_bad_record_mac;
410 #endif
411 }
412 rr->length-=mac_size;
413 i=s->method->ssl3_enc->mac(s,md,0);
414 if (memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
415 {
416 goto decryption_failed_or_bad_record_mac;
417 }
418 }
419
420 /* r->length is now just compressed */
421 if (s->expand != NULL)
422 {
423 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
424 {
425 al=SSL_AD_RECORD_OVERFLOW;
426 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
427 goto f_err;
428 }
429 if (!ssl3_do_uncompress(s))
430 {
431 al=SSL_AD_DECOMPRESSION_FAILURE;
432 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
433 goto f_err;
434 }
435 }
436
437 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
438 {
439 al=SSL_AD_RECORD_OVERFLOW;
440 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
441 goto f_err;
442 }
443
444 rr->off=0;
445 /* So at this point the following is true
446 * ssl->s3->rrec.type is the type of record
447 * ssl->s3->rrec.length == number of bytes in record
448 * ssl->s3->rrec.off == offset to first valid byte
449 * ssl->s3->rrec.data == where to take bytes from, increment
450 * after use :-).
451 */
452
453 /* we have pulled in a full packet so zero things */
454 s->packet_length=0;
455 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
456 return(1);
457
458 decryption_failed_or_bad_record_mac:
459 /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
460 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
461 * failure is directly visible from the ciphertext anyway,
462 * we should not reveal which kind of error occured -- this
463 * might become visible to an attacker (e.g. via logfile) */
464 al=SSL_AD_BAD_RECORD_MAC;
465 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
466 f_err:
467 ssl3_send_alert(s,SSL3_AL_FATAL,al);
468 err:
469 return(0);
470 }
471
472
473 /* Call this to get a new input record.
474 * It will return <= 0 if more data is needed, normally due to an error
475 * or non-blocking IO.
476 * When it finishes, one packet has been decoded and can be found in
477 * ssl->s3->rrec.type - is the type of record
478 * ssl->s3->rrec.data, - data
479 * ssl->s3->rrec.length, - number of bytes
480 */
481 /* used only by dtls1_read_bytes */
482 int dtls1_get_record(SSL *s)
483 {
484 int ssl_major,ssl_minor,al;
485 int i,n;
486 SSL3_RECORD *rr;
487 SSL_SESSION *sess;
488 unsigned char *p;
489 short version;
490 DTLS1_BITMAP *bitmap;
491 unsigned int is_next_epoch;
492
493 rr= &(s->s3->rrec);
494 sess=s->session;
495
496 /* The epoch may have changed. If so, process all the
497 * pending records. This is a non-blocking operation. */
498 if ( ! dtls1_process_buffered_records(s))
499 return 0;
500
501 /* if we're renegotiating, then there may be buffered records */
502 if (dtls1_get_processed_record(s))
503 return 1;
504
505 /* get something from the wire */
506 again:
507 /* check if we have the header */
508 if ( (s->rstate != SSL_ST_READ_BODY) ||
509 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
510 {
511 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
512 /* read timeout is handled by dtls1_read_bytes */
513 if (n <= 0) return(n); /* error or non-blocking */
514
515 OPENSSL_assert(s->packet_length == DTLS1_RT_HEADER_LENGTH);
516
517 s->rstate=SSL_ST_READ_BODY;
518
519 p=s->packet;
520
521 /* Pull apart the header into the DTLS1_RECORD */
522 rr->type= *(p++);
523 ssl_major= *(p++);
524 ssl_minor= *(p++);
525 version=(ssl_major<<8)|ssl_minor;
526
527 /* sequence number is 64 bits, with top 2 bytes = epoch */
528 n2s(p,rr->epoch);
529
530 memcpy(&(s->s3->read_sequence[2]), p, 6);
531 p+=6;
532
533 n2s(p,rr->length);
534
535 /* Lets check version */
536 if (s->first_packet)
537 {
538 s->first_packet=0;
539 }
540 else
541 {
542 if (version != s->version)
543 {
544 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
545 /* Send back error using their
546 * version number :-) */
547 s->version=version;
548 al=SSL_AD_PROTOCOL_VERSION;
549 goto f_err;
550 }
551 }
552
553 if ((version & 0xff00) != (DTLS1_VERSION & 0xff00))
554 {
555 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_WRONG_VERSION_NUMBER);
556 goto err;
557 }
558
559 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
560 {
561 al=SSL_AD_RECORD_OVERFLOW;
562 SSLerr(SSL_F_DTLS1_GET_RECORD,SSL_R_PACKET_LENGTH_TOO_LONG);
563 goto f_err;
564 }
565
566 /* now s->rstate == SSL_ST_READ_BODY */
567 }
568
569 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
570
571 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
572 {
573 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
574 i=rr->length;
575 n=ssl3_read_n(s,i,i,1);
576 if (n <= 0) return(n); /* error or non-blocking io */
577
578 /* this packet contained a partial record, dump it */
579 if ( n != i)
580 {
581 s->packet_length = 0;
582 goto again;
583 }
584
585 /* now n == rr->length,
586 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
587 }
588 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
589
590 /* match epochs. NULL means the packet is dropped on the floor */
591 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
592 if ( bitmap == NULL)
593 {
594 s->packet_length = 0; /* dump this record */
595 goto again; /* get another record */
596 }
597
598 /* check whether this is a repeat, or aged record */
599 if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
600 {
601 s->packet_length=0; /* dump this record */
602 goto again; /* get another record */
603 }
604
605 /* just read a 0 length packet */
606 if (rr->length == 0) goto again;
607
608 /* If this record is from the next epoch (either HM or ALERT), buffer it
609 * since it cannot be processed at this time.
610 * Records from the next epoch are marked as received even though they are
611 * not processed, so as to prevent any potential resource DoS attack */
612 if (is_next_epoch)
613 {
614 dtls1_record_bitmap_update(s, bitmap);
615 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
616 s->packet_length = 0;
617 goto again;
618 }
619
620 if ( ! dtls1_process_record(s))
621 return(0);
622
623 dtls1_clear_timeouts(s); /* done waiting */
624 return(1);
625
626 f_err:
627 ssl3_send_alert(s,SSL3_AL_FATAL,al);
628 err:
629 return(0);
630 }
631
632 /* Return up to 'len' payload bytes received in 'type' records.
633 * 'type' is one of the following:
634 *
635 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
636 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
637 * - 0 (during a shutdown, no data has to be returned)
638 *
639 * If we don't have stored data to work from, read a SSL/TLS record first
640 * (possibly multiple records if we still don't have anything to return).
641 *
642 * This function must handle any surprises the peer may have for us, such as
643 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
644 * a surprise, but handled as if it were), or renegotiation requests.
645 * Also if record payloads contain fragments too small to process, we store
646 * them until there is enough for the respective protocol (the record protocol
647 * may use arbitrary fragmentation and even interleaving):
648 * Change cipher spec protocol
649 * just 1 byte needed, no need for keeping anything stored
650 * Alert protocol
651 * 2 bytes needed (AlertLevel, AlertDescription)
652 * Handshake protocol
653 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
654 * to detect unexpected Client Hello and Hello Request messages
655 * here, anything else is handled by higher layers
656 * Application data protocol
657 * none of our business
658 */
659 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
660 {
661 int al,i,j,ret;
662 unsigned int n;
663 SSL3_RECORD *rr;
664 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
665
666 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
667 if (!ssl3_setup_buffers(s))
668 return(-1);
669
670 /* XXX: check what the second '&& type' is about */
671 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
672 (type != SSL3_RT_HANDSHAKE) && type) ||
673 (peek && (type != SSL3_RT_APPLICATION_DATA)))
674 {
675 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
676 return -1;
677 }
678
679 /* check whether there's a handshake message (client hello?) waiting */
680 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
681 return ret;
682
683 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
684
685 if (!s->in_handshake && SSL_in_init(s))
686 {
687 /* type == SSL3_RT_APPLICATION_DATA */
688 i=s->handshake_func(s);
689 if (i < 0) return(i);
690 if (i == 0)
691 {
692 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
693 return(-1);
694 }
695 }
696
697 start:
698 s->rwstate=SSL_NOTHING;
699
700 /* s->s3->rrec.type - is the type of record
701 * s->s3->rrec.data, - data
702 * s->s3->rrec.off, - offset into 'data' for next read
703 * s->s3->rrec.length, - number of bytes. */
704 rr = &(s->s3->rrec);
705
706 /* get new packet if necessary */
707 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
708 {
709 ret=dtls1_get_record(s);
710 if (ret <= 0)
711 {
712 ret = dtls1_read_failed(s, ret);
713 /* anything other than a timeout is an error */
714 if (ret <= 0)
715 return(ret);
716 else
717 goto start;
718 }
719 }
720
721 /* we now have a packet which can be read and processed */
722
723 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
724 * reset by ssl3_get_finished */
725 && (rr->type != SSL3_RT_HANDSHAKE))
726 {
727 al=SSL_AD_UNEXPECTED_MESSAGE;
728 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_DATA_BETWEEN_CCS_AND_FINISHED);
729 goto err;
730 }
731
732 /* If the other end has shut down, throw anything we read away
733 * (even in 'peek' mode) */
734 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
735 {
736 rr->length=0;
737 s->rwstate=SSL_NOTHING;
738 return(0);
739 }
740
741
742 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
743 {
744 /* make sure that we are not getting application data when we
745 * are doing a handshake for the first time */
746 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
747 (s->enc_read_ctx == NULL))
748 {
749 al=SSL_AD_UNEXPECTED_MESSAGE;
750 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
751 goto f_err;
752 }
753
754 if (len <= 0) return(len);
755
756 if ((unsigned int)len > rr->length)
757 n = rr->length;
758 else
759 n = (unsigned int)len;
760
761 memcpy(buf,&(rr->data[rr->off]),n);
762 if (!peek)
763 {
764 rr->length-=n;
765 rr->off+=n;
766 if (rr->length == 0)
767 {
768 s->rstate=SSL_ST_READ_HEADER;
769 rr->off=0;
770 }
771 }
772 return(n);
773 }
774
775
776 /* If we get here, then type != rr->type; if we have a handshake
777 * message, then it was unexpected (Hello Request or Client Hello). */
778
779 /* In case of record types for which we have 'fragment' storage,
780 * fill that so that we can process the data at a fixed place.
781 */
782 {
783 unsigned int k, dest_maxlen = 0;
784 unsigned char *dest = NULL;
785 unsigned int *dest_len = NULL;
786
787 if (rr->type == SSL3_RT_HANDSHAKE)
788 {
789 dest_maxlen = sizeof s->d1->handshake_fragment;
790 dest = s->d1->handshake_fragment;
791 dest_len = &s->d1->handshake_fragment_len;
792 }
793 else if (rr->type == SSL3_RT_ALERT)
794 {
795 dest_maxlen = sizeof(s->d1->alert_fragment);
796 dest = s->d1->alert_fragment;
797 dest_len = &s->d1->alert_fragment_len;
798 }
799 else /* else it's a CCS message */
800 OPENSSL_assert(rr->type == SSL3_RT_CHANGE_CIPHER_SPEC);
801
802
803 if (dest_maxlen > 0)
804 {
805 /* XDTLS: In a pathalogical case, the Client Hello
806 * may be fragmented--don't always expect dest_maxlen bytes */
807 if ( rr->length < dest_maxlen)
808 {
809 s->rstate=SSL_ST_READ_HEADER;
810 rr->length = 0;
811 goto start;
812 }
813
814 /* now move 'n' bytes: */
815 for ( k = 0; k < dest_maxlen; k++)
816 {
817 dest[k] = rr->data[rr->off++];
818 rr->length--;
819 }
820 *dest_len = dest_maxlen;
821 }
822 }
823
824 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
825 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
826 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
827
828 /* If we are a client, check for an incoming 'Hello Request': */
829 if ((!s->server) &&
830 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
831 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
832 (s->session != NULL) && (s->session->cipher != NULL))
833 {
834 s->d1->handshake_fragment_len = 0;
835
836 if ((s->d1->handshake_fragment[1] != 0) ||
837 (s->d1->handshake_fragment[2] != 0) ||
838 (s->d1->handshake_fragment[3] != 0))
839 {
840 al=SSL_AD_DECODE_ERROR;
841 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
842 goto err;
843 }
844
845 /* no need to check sequence number on HELLO REQUEST messages */
846
847 if (s->msg_callback)
848 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
849 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
850
851 if (SSL_is_init_finished(s) &&
852 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
853 !s->s3->renegotiate)
854 {
855 ssl3_renegotiate(s);
856 if (ssl3_renegotiate_check(s))
857 {
858 i=s->handshake_func(s);
859 if (i < 0) return(i);
860 if (i == 0)
861 {
862 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
863 return(-1);
864 }
865
866 if (!(s->mode & SSL_MODE_AUTO_RETRY))
867 {
868 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
869 {
870 BIO *bio;
871 /* In the case where we try to read application data,
872 * but we trigger an SSL handshake, we return -1 with
873 * the retry option set. Otherwise renegotiation may
874 * cause nasty problems in the blocking world */
875 s->rwstate=SSL_READING;
876 bio=SSL_get_rbio(s);
877 BIO_clear_retry_flags(bio);
878 BIO_set_retry_read(bio);
879 return(-1);
880 }
881 }
882 }
883 }
884 /* we either finished a handshake or ignored the request,
885 * now try again to obtain the (application) data we were asked for */
886 goto start;
887 }
888
889 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
890 {
891 int alert_level = s->d1->alert_fragment[0];
892 int alert_descr = s->d1->alert_fragment[1];
893
894 s->d1->alert_fragment_len = 0;
895
896 if (s->msg_callback)
897 s->msg_callback(0, s->version, SSL3_RT_ALERT,
898 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
899
900 if (s->info_callback != NULL)
901 cb=s->info_callback;
902 else if (s->ctx->info_callback != NULL)
903 cb=s->ctx->info_callback;
904
905 if (cb != NULL)
906 {
907 j = (alert_level << 8) | alert_descr;
908 cb(s, SSL_CB_READ_ALERT, j);
909 }
910
911 if (alert_level == 1) /* warning */
912 {
913 s->s3->warn_alert = alert_descr;
914 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
915 {
916 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
917 return(0);
918 }
919 #if 0
920 /* XXX: this is a possible improvement in the future */
921 /* now check if it's a missing record */
922 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
923 {
924 unsigned short seq;
925 unsigned int frag_off;
926 unsigned char *p = &(s->d1->alert_fragment[2]);
927
928 n2s(p, seq);
929 n2l3(p, frag_off);
930
931 dtls1_retransmit_message(s, seq, frag_off, &found);
932 if ( ! found && SSL_in_init(s))
933 {
934 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
935 /* requested a message not yet sent,
936 send an alert ourselves */
937 ssl3_send_alert(s,SSL3_AL_WARNING,
938 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
939 }
940 }
941 #endif
942 }
943 else if (alert_level == 2) /* fatal */
944 {
945 char tmp[16];
946
947 s->rwstate=SSL_NOTHING;
948 s->s3->fatal_alert = alert_descr;
949 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
950 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
951 ERR_add_error_data(2,"SSL alert number ",tmp);
952 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
953 SSL_CTX_remove_session(s->ctx,s->session);
954 return(0);
955 }
956 else
957 {
958 al=SSL_AD_ILLEGAL_PARAMETER;
959 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
960 goto f_err;
961 }
962
963 goto start;
964 }
965
966 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
967 {
968 s->rwstate=SSL_NOTHING;
969 rr->length=0;
970 return(0);
971 }
972
973 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
974 {
975 struct ccs_header_st ccs_hdr;
976
977 dtls1_get_ccs_header(rr->data, &ccs_hdr);
978
979 if ( ccs_hdr.seq == s->d1->handshake_read_seq)
980 {
981 /* 'Change Cipher Spec' is just a single byte, so we know
982 * exactly what the record payload has to look like */
983 /* XDTLS: check that epoch is consistent */
984 if ( (rr->length != DTLS1_CCS_HEADER_LENGTH) ||
985 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
986 {
987 i=SSL_AD_ILLEGAL_PARAMETER;
988 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
989 goto err;
990 }
991
992 rr->length=0;
993
994 if (s->msg_callback)
995 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
996 rr->data, 1, s, s->msg_callback_arg);
997
998 s->s3->change_cipher_spec=1;
999 if (!ssl3_do_change_cipher_spec(s))
1000 goto err;
1001
1002 /* do this whenever CCS is processed */
1003 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1004
1005 /* handshake read seq is reset upon handshake completion */
1006 s->d1->handshake_read_seq++;
1007
1008 goto start;
1009 }
1010 else
1011 {
1012 rr->length = 0;
1013 goto start;
1014 }
1015 }
1016
1017 /* Unexpected handshake message (Client Hello, or protocol violation) */
1018 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1019 !s->in_handshake)
1020 {
1021 struct hm_header_st msg_hdr;
1022
1023 /* this may just be a stale retransmit */
1024 dtls1_get_message_header(rr->data, &msg_hdr);
1025 if( rr->epoch != s->d1->r_epoch)
1026 {
1027 rr->length = 0;
1028 goto start;
1029 }
1030
1031 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1032 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1033 {
1034 #if 0 /* worked only because C operator preferences are not as expected (and
1035 * because this is not really needed for clients except for detecting
1036 * protocol violations): */
1037 s->state=SSL_ST_BEFORE|(s->server)
1038 ?SSL_ST_ACCEPT
1039 :SSL_ST_CONNECT;
1040 #else
1041 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1042 #endif
1043 s->new_session=1;
1044 }
1045 i=s->handshake_func(s);
1046 if (i < 0) return(i);
1047 if (i == 0)
1048 {
1049 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1050 return(-1);
1051 }
1052
1053 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1054 {
1055 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1056 {
1057 BIO *bio;
1058 /* In the case where we try to read application data,
1059 * but we trigger an SSL handshake, we return -1 with
1060 * the retry option set. Otherwise renegotiation may
1061 * cause nasty problems in the blocking world */
1062 s->rwstate=SSL_READING;
1063 bio=SSL_get_rbio(s);
1064 BIO_clear_retry_flags(bio);
1065 BIO_set_retry_read(bio);
1066 return(-1);
1067 }
1068 }
1069 goto start;
1070 }
1071
1072 switch (rr->type)
1073 {
1074 default:
1075 #ifndef OPENSSL_NO_TLS
1076 /* TLS just ignores unknown message types */
1077 if (s->version == TLS1_VERSION)
1078 {
1079 rr->length = 0;
1080 goto start;
1081 }
1082 #endif
1083 al=SSL_AD_UNEXPECTED_MESSAGE;
1084 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1085 goto f_err;
1086 case SSL3_RT_CHANGE_CIPHER_SPEC:
1087 case SSL3_RT_ALERT:
1088 case SSL3_RT_HANDSHAKE:
1089 /* we already handled all of these, with the possible exception
1090 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1091 * should not happen when type != rr->type */
1092 al=SSL_AD_UNEXPECTED_MESSAGE;
1093 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1094 goto f_err;
1095 case SSL3_RT_APPLICATION_DATA:
1096 /* At this point, we were expecting handshake data,
1097 * but have application data. If the library was
1098 * running inside ssl3_read() (i.e. in_read_app_data
1099 * is set) and it makes sense to read application data
1100 * at this point (session renegotiation not yet started),
1101 * we will indulge it.
1102 */
1103 if (s->s3->in_read_app_data &&
1104 (s->s3->total_renegotiations != 0) &&
1105 ((
1106 (s->state & SSL_ST_CONNECT) &&
1107 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1108 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1109 ) || (
1110 (s->state & SSL_ST_ACCEPT) &&
1111 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1112 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1113 )
1114 ))
1115 {
1116 s->s3->in_read_app_data=2;
1117 return(-1);
1118 }
1119 else
1120 {
1121 al=SSL_AD_UNEXPECTED_MESSAGE;
1122 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1123 goto f_err;
1124 }
1125 }
1126 /* not reached */
1127
1128 f_err:
1129 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1130 err:
1131 return(-1);
1132 }
1133
1134 int
1135 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1136 {
1137 unsigned int n,tot;
1138 int i;
1139
1140 if (SSL_in_init(s) && !s->in_handshake)
1141 {
1142 i=s->handshake_func(s);
1143 if (i < 0) return(i);
1144 if (i == 0)
1145 {
1146 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1147 return -1;
1148 }
1149 }
1150
1151 tot = s->s3->wnum;
1152 n = len - tot;
1153
1154 while( n)
1155 {
1156 /* dtls1_write_bytes sends one record at a time, sized according to
1157 * the currently known MTU */
1158 i = dtls1_write_bytes(s, type, buf_, len);
1159 if (i <= 0) return i;
1160
1161 if ((i == (int)n) ||
1162 (type == SSL3_RT_APPLICATION_DATA &&
1163 (s->mode & SSL_MODE_ENABLE_PARTIAL_WRITE)))
1164 {
1165 /* next chunk of data should get another prepended empty fragment
1166 * in ciphersuites with known-IV weakness: */
1167 s->s3->empty_fragment_done = 0;
1168 return tot+i;
1169 }
1170
1171 tot += i;
1172 n-=i;
1173 }
1174
1175 return tot;
1176 }
1177
1178
1179 /* this only happens when a client hello is received and a handshake
1180 * is started. */
1181 static int
1182 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1183 int len, int peek)
1184 {
1185
1186 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1187 /* (partially) satisfy request from storage */
1188 {
1189 unsigned char *src = s->d1->handshake_fragment;
1190 unsigned char *dst = buf;
1191 unsigned int k,n;
1192
1193 /* peek == 0 */
1194 n = 0;
1195 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1196 {
1197 *dst++ = *src++;
1198 len--; s->d1->handshake_fragment_len--;
1199 n++;
1200 }
1201 /* move any remaining fragment bytes: */
1202 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1203 s->d1->handshake_fragment[k] = *src++;
1204 return n;
1205 }
1206
1207 return 0;
1208 }
1209
1210
1211
1212
1213 /* Call this to write data in records of type 'type'
1214 * It will return <= 0 if not all data has been sent or non-blocking IO.
1215 */
1216 int dtls1_write_bytes(SSL *s, int type, const void *buf_, int len)
1217 {
1218 const unsigned char *buf=buf_;
1219 unsigned int tot,n,nw;
1220 int i;
1221 unsigned int mtu;
1222
1223 s->rwstate=SSL_NOTHING;
1224 tot=s->s3->wnum;
1225
1226 n=(len-tot);
1227
1228 /* handshake layer figures out MTU for itself, but data records
1229 * are also sent through this interface, so need to figure out MTU */
1230 #if 0
1231 mtu = BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_GET_MTU, 0, NULL);
1232 mtu += DTLS1_HM_HEADER_LENGTH; /* HM already inserted */
1233 #endif
1234 mtu = s->d1->mtu;
1235
1236 if (mtu > SSL3_RT_MAX_PLAIN_LENGTH)
1237 mtu = SSL3_RT_MAX_PLAIN_LENGTH;
1238
1239 if (n > mtu)
1240 nw=mtu;
1241 else
1242 nw=n;
1243
1244 i=do_dtls1_write(s, type, &(buf[tot]), nw, 0);
1245 if (i <= 0)
1246 {
1247 s->s3->wnum=tot;
1248 return i;
1249 }
1250
1251 if ( (int)s->s3->wnum + i == len)
1252 s->s3->wnum = 0;
1253 else
1254 s->s3->wnum += i;
1255
1256 return tot + i;
1257 }
1258
1259 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1260 {
1261 unsigned char *p,*pseq;
1262 int i,mac_size,clear=0;
1263 int prefix_len = 0;
1264 SSL3_RECORD *wr;
1265 SSL3_BUFFER *wb;
1266 SSL_SESSION *sess;
1267 int bs;
1268
1269 /* first check if there is a SSL3_BUFFER still being written
1270 * out. This will happen with non blocking IO */
1271 if (s->s3->wbuf.left != 0)
1272 {
1273 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1274 return(ssl3_write_pending(s,type,buf,len));
1275 }
1276
1277 /* If we have an alert to send, lets send it */
1278 if (s->s3->alert_dispatch)
1279 {
1280 i=s->method->ssl_dispatch_alert(s);
1281 if (i <= 0)
1282 return(i);
1283 /* if it went, fall through and send more stuff */
1284 }
1285
1286 if (len == 0 && !create_empty_fragment)
1287 return 0;
1288
1289 wr= &(s->s3->wrec);
1290 wb= &(s->s3->wbuf);
1291 sess=s->session;
1292
1293 if ( (sess == NULL) ||
1294 (s->enc_write_ctx == NULL) ||
1295 (s->write_hash == NULL))
1296 clear=1;
1297
1298 if (clear)
1299 mac_size=0;
1300 else
1301 mac_size=EVP_MD_size(s->write_hash);
1302
1303 /* DTLS implements explicit IV, so no need for empty fragments */
1304 #if 0
1305 /* 'create_empty_fragment' is true only when this function calls itself */
1306 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1307 && SSL_version(s) != DTLS1_VERSION)
1308 {
1309 /* countermeasure against known-IV weakness in CBC ciphersuites
1310 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1311 */
1312
1313 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1314 {
1315 /* recursive function call with 'create_empty_fragment' set;
1316 * this prepares and buffers the data for an empty fragment
1317 * (these 'prefix_len' bytes are sent out later
1318 * together with the actual payload) */
1319 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1320 if (prefix_len <= 0)
1321 goto err;
1322
1323 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1324 {
1325 /* insufficient space */
1326 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1327 goto err;
1328 }
1329 }
1330
1331 s->s3->empty_fragment_done = 1;
1332 }
1333 #endif
1334
1335 p = wb->buf + prefix_len;
1336
1337 /* write the header */
1338
1339 *(p++)=type&0xff;
1340 wr->type=type;
1341
1342 *(p++)=(s->version>>8);
1343 *(p++)=s->version&0xff;
1344
1345 /* field where we are to write out packet epoch, seq num and len */
1346 pseq=p;
1347 p+=10;
1348
1349 /* lets setup the record stuff. */
1350
1351 /* Make space for the explicit IV in case of CBC.
1352 * (this is a bit of a boundary violation, but what the heck).
1353 */
1354 if ( s->enc_write_ctx &&
1355 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1356 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1357 else
1358 bs = 0;
1359
1360 wr->data=p + bs; /* make room for IV in case of CBC */
1361 wr->length=(int)len;
1362 wr->input=(unsigned char *)buf;
1363
1364 /* we now 'read' from wr->input, wr->length bytes into
1365 * wr->data */
1366
1367 /* first we compress */
1368 if (s->compress != NULL)
1369 {
1370 if (!ssl3_do_compress(s))
1371 {
1372 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1373 goto err;
1374 }
1375 }
1376 else
1377 {
1378 memcpy(wr->data,wr->input,wr->length);
1379 wr->input=wr->data;
1380 }
1381
1382 /* we should still have the output to wr->data and the input
1383 * from wr->input. Length should be wr->length.
1384 * wr->data still points in the wb->buf */
1385
1386 if (mac_size != 0)
1387 {
1388 s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1);
1389 wr->length+=mac_size;
1390 }
1391
1392 /* this is true regardless of mac size */
1393 wr->input=p;
1394 wr->data=p;
1395
1396
1397 /* ssl3_enc can only have an error on read */
1398 wr->length += bs; /* bs != 0 in case of CBC. The enc fn provides
1399 * the randomness */
1400 s->method->ssl3_enc->enc(s,1);
1401
1402 /* record length after mac and block padding */
1403 /* if (type == SSL3_RT_APPLICATION_DATA ||
1404 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1405
1406 /* there's only one epoch between handshake and app data */
1407
1408 s2n(s->d1->w_epoch, pseq);
1409
1410 /* XDTLS: ?? */
1411 /* else
1412 s2n(s->d1->handshake_epoch, pseq); */
1413
1414 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1415 pseq+=6;
1416 s2n(wr->length,pseq);
1417
1418 /* we should now have
1419 * wr->data pointing to the encrypted data, which is
1420 * wr->length long */
1421 wr->type=type; /* not needed but helps for debugging */
1422 wr->length+=DTLS1_RT_HEADER_LENGTH;
1423
1424 #if 0 /* this is now done at the message layer */
1425 /* buffer the record, making it easy to handle retransmits */
1426 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1427 dtls1_buffer_record(s, wr->data, wr->length,
1428 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1429 #endif
1430
1431 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1432
1433 if (create_empty_fragment)
1434 {
1435 /* we are in a recursive call;
1436 * just return the length, don't write out anything here
1437 */
1438 return wr->length;
1439 }
1440
1441 /* now let's set up wb */
1442 wb->left = prefix_len + wr->length;
1443 wb->offset = 0;
1444
1445 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1446 s->s3->wpend_tot=len;
1447 s->s3->wpend_buf=buf;
1448 s->s3->wpend_type=type;
1449 s->s3->wpend_ret=len;
1450
1451 /* we now just need to write the buffer */
1452 return ssl3_write_pending(s,type,buf,len);
1453 err:
1454 return -1;
1455 }
1456
1457
1458
1459 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap,
1460 PQ_64BIT *seq_num)
1461 {
1462 #if PQ_64BIT_IS_INTEGER
1463 PQ_64BIT mask = 0x0000000000000001L;
1464 #endif
1465 PQ_64BIT rcd_num, tmp;
1466
1467 pq_64bit_init(&rcd_num);
1468 pq_64bit_init(&tmp);
1469
1470 /* this is the sequence number for the record just read */
1471 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1472
1473
1474 if (pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1475 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1476 {
1477 pq_64bit_assign(seq_num, &rcd_num);
1478 pq_64bit_free(&rcd_num);
1479 pq_64bit_free(&tmp);
1480 return 1; /* this record is new */
1481 }
1482
1483 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1484
1485 if ( pq_64bit_get_word(&tmp) > bitmap->length)
1486 {
1487 pq_64bit_free(&rcd_num);
1488 pq_64bit_free(&tmp);
1489 return 0; /* stale, outside the window */
1490 }
1491
1492 #if PQ_64BIT_IS_BIGNUM
1493 {
1494 int offset;
1495 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1496 pq_64bit_sub_word(&tmp, 1);
1497 offset = pq_64bit_get_word(&tmp);
1498 if ( pq_64bit_is_bit_set(&(bitmap->map), offset))
1499 {
1500 pq_64bit_free(&rcd_num);
1501 pq_64bit_free(&tmp);
1502 return 0;
1503 }
1504 }
1505 #else
1506 mask <<= (bitmap->max_seq_num - rcd_num - 1);
1507 if (bitmap->map & mask)
1508 return 0; /* record previously received */
1509 #endif
1510
1511 pq_64bit_assign(seq_num, &rcd_num);
1512 pq_64bit_free(&rcd_num);
1513 pq_64bit_free(&tmp);
1514 return 1;
1515 }
1516
1517
1518 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1519 {
1520 unsigned int shift;
1521 PQ_64BIT rcd_num;
1522 PQ_64BIT tmp;
1523 PQ_64BIT_CTX *ctx;
1524
1525 pq_64bit_init(&rcd_num);
1526 pq_64bit_init(&tmp);
1527
1528 pq_64bit_bin2num(&rcd_num, s->s3->read_sequence, 8);
1529
1530 /* unfortunate code complexity due to 64-bit manipulation support
1531 * on 32-bit machines */
1532 if ( pq_64bit_gt(&rcd_num, &(bitmap->max_seq_num)) ||
1533 pq_64bit_eq(&rcd_num, &(bitmap->max_seq_num)))
1534 {
1535 pq_64bit_sub(&tmp, &rcd_num, &(bitmap->max_seq_num));
1536 pq_64bit_add_word(&tmp, 1);
1537
1538 shift = (unsigned int)pq_64bit_get_word(&tmp);
1539
1540 pq_64bit_lshift(&(tmp), &(bitmap->map), shift);
1541 pq_64bit_assign(&(bitmap->map), &tmp);
1542
1543 pq_64bit_set_bit(&(bitmap->map), 0);
1544 pq_64bit_add_word(&rcd_num, 1);
1545 pq_64bit_assign(&(bitmap->max_seq_num), &rcd_num);
1546
1547 pq_64bit_assign_word(&tmp, 1);
1548 pq_64bit_lshift(&tmp, &tmp, bitmap->length);
1549 ctx = pq_64bit_ctx_new(&ctx);
1550 pq_64bit_mod(&(bitmap->map), &(bitmap->map), &tmp, ctx);
1551 pq_64bit_ctx_free(ctx);
1552 }
1553 else
1554 {
1555 pq_64bit_sub(&tmp, &(bitmap->max_seq_num), &rcd_num);
1556 pq_64bit_sub_word(&tmp, 1);
1557 shift = (unsigned int)pq_64bit_get_word(&tmp);
1558
1559 pq_64bit_set_bit(&(bitmap->map), shift);
1560 }
1561
1562 pq_64bit_free(&rcd_num);
1563 pq_64bit_free(&tmp);
1564 }
1565
1566
1567 int dtls1_dispatch_alert(SSL *s)
1568 {
1569 int i,j;
1570 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1571 unsigned char buf[2 + 2 + 3]; /* alert level + alert desc + message seq +frag_off */
1572 unsigned char *ptr = &buf[0];
1573
1574 s->s3->alert_dispatch=0;
1575
1576 memset(buf, 0x00, sizeof(buf));
1577 *ptr++ = s->s3->send_alert[0];
1578 *ptr++ = s->s3->send_alert[1];
1579
1580 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1581 {
1582 s2n(s->d1->handshake_read_seq, ptr);
1583 #if 0
1584 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1585
1586 else
1587 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1588 #endif
1589
1590 #if 0
1591 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);
1592 #endif
1593 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1594 }
1595
1596 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1597 if (i <= 0)
1598 {
1599 s->s3->alert_dispatch=1;
1600 /* fprintf( stderr, "not done with alert\n" ); */
1601 }
1602 else
1603 {
1604 if ( s->s3->send_alert[0] == SSL3_AL_FATAL ||
1605 s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1606 (void)BIO_flush(s->wbio);
1607
1608 if (s->msg_callback)
1609 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1610 2, s, s->msg_callback_arg);
1611
1612 if (s->info_callback != NULL)
1613 cb=s->info_callback;
1614 else if (s->ctx->info_callback != NULL)
1615 cb=s->ctx->info_callback;
1616
1617 if (cb != NULL)
1618 {
1619 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1620 cb(s,SSL_CB_WRITE_ALERT,j);
1621 }
1622 }
1623 return(i);
1624 }
1625
1626
1627 static DTLS1_BITMAP *
1628 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1629 {
1630
1631 *is_next_epoch = 0;
1632
1633 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1634 if (rr->epoch == s->d1->r_epoch)
1635 return &s->d1->bitmap;
1636
1637 /* Only HM and ALERT messages can be from the next epoch */
1638 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1639 (rr->type == SSL3_RT_HANDSHAKE ||
1640 rr->type == SSL3_RT_ALERT))
1641 {
1642 *is_next_epoch = 1;
1643 return &s->d1->next_bitmap;
1644 }
1645
1646 return NULL;
1647 }
1648
1649 #if 0
1650 static int
1651 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1652 unsigned long *offset)
1653 {
1654
1655 /* alerts are passed up immediately */
1656 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1657 rr->type == SSL3_RT_ALERT)
1658 return 0;
1659
1660 /* Only need to buffer if a handshake is underway.
1661 * (this implies that Hello Request and Client Hello are passed up
1662 * immediately) */
1663 if ( SSL_in_init(s))
1664 {
1665 unsigned char *data = rr->data;
1666 /* need to extract the HM/CCS sequence number here */
1667 if ( rr->type == SSL3_RT_HANDSHAKE ||
1668 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1669 {
1670 unsigned short seq_num;
1671 struct hm_header_st msg_hdr;
1672 struct ccs_header_st ccs_hdr;
1673
1674 if ( rr->type == SSL3_RT_HANDSHAKE)
1675 {
1676 dtls1_get_message_header(data, &msg_hdr);
1677 seq_num = msg_hdr.seq;
1678 *offset = msg_hdr.frag_off;
1679 }
1680 else
1681 {
1682 dtls1_get_ccs_header(data, &ccs_hdr);
1683 seq_num = ccs_hdr.seq;
1684 *offset = 0;
1685 }
1686
1687 /* this is either a record we're waiting for, or a
1688 * retransmit of something we happened to previously
1689 * receive (higher layers will drop the repeat silently */
1690 if ( seq_num < s->d1->handshake_read_seq)
1691 return 0;
1692 if (rr->type == SSL3_RT_HANDSHAKE &&
1693 seq_num == s->d1->handshake_read_seq &&
1694 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1695 return 0;
1696 else if ( seq_num == s->d1->handshake_read_seq &&
1697 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1698 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1699 return 0;
1700 else
1701 {
1702 *priority = seq_num;
1703 return 1;
1704 }
1705 }
1706 else /* unknown record type */
1707 return 0;
1708 }
1709
1710 return 0;
1711 }
1712 #endif
1713
1714 void
1715 dtls1_reset_seq_numbers(SSL *s, int rw)
1716 {
1717 unsigned char *seq;
1718 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1719
1720 if ( rw & SSL3_CC_READ)
1721 {
1722 seq = s->s3->read_sequence;
1723 s->d1->r_epoch++;
1724
1725 pq_64bit_assign(&(s->d1->bitmap.map), &(s->d1->next_bitmap.map));
1726 s->d1->bitmap.length = s->d1->next_bitmap.length;
1727 pq_64bit_assign(&(s->d1->bitmap.max_seq_num),
1728 &(s->d1->next_bitmap.max_seq_num));
1729
1730 pq_64bit_free(&(s->d1->next_bitmap.map));
1731 pq_64bit_free(&(s->d1->next_bitmap.max_seq_num));
1732 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1733 pq_64bit_init(&(s->d1->next_bitmap.map));
1734 pq_64bit_init(&(s->d1->next_bitmap.max_seq_num));
1735 }
1736 else
1737 {
1738 seq = s->s3->write_sequence;
1739 s->d1->w_epoch++;
1740 }
1741
1742 memset(seq, 0x00, seq_bytes);
1743 }
1744
1745 #if PQ_64BIT_IS_INTEGER
1746 static PQ_64BIT
1747 bytes_to_long_long(unsigned char *bytes, PQ_64BIT *num)
1748 {
1749 PQ_64BIT _num;
1750
1751 _num = (((PQ_64BIT)bytes[0]) << 56) |
1752 (((PQ_64BIT)bytes[1]) << 48) |
1753 (((PQ_64BIT)bytes[2]) << 40) |
1754 (((PQ_64BIT)bytes[3]) << 32) |
1755 (((PQ_64BIT)bytes[4]) << 24) |
1756 (((PQ_64BIT)bytes[5]) << 16) |
1757 (((PQ_64BIT)bytes[6]) << 8) |
1758 (((PQ_64BIT)bytes[7]) );
1759
1760 *num = _num ;
1761 return _num;
1762 }
1763 #endif
1764
1765
1766 static void
1767 dtls1_clear_timeouts(SSL *s)
1768 {
1769 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1770 }
DragonFly BSD