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[netbsd-mini2440.git] / crypto / external / bsd / openssl / dist / ssl / d1_pkt.c
blobc9757e1d63f4c740c791248d1244253955150339
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 static void dtls1_clear_timeouts(SSL *s);
183
184 /* copy buffered record into SSL structure */
185 static int
186 dtls1_copy_record(SSL *s, pitem *item)
187 {
188 DTLS1_RECORD_DATA *rdata;
189
190 rdata = (DTLS1_RECORD_DATA *)item->data;
191
192 if (s->s3->rbuf.buf != NULL)
193 OPENSSL_free(s->s3->rbuf.buf);
194
195 s->packet = rdata->packet;
196 s->packet_length = rdata->packet_length;
197 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
198 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
199
200 return(1);
201 }
202
203
204 static int
205 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
206 {
207 DTLS1_RECORD_DATA *rdata;
208 pitem *item;
209
210 /* Limit the size of the queue to prevent DOS attacks */
211 if (pqueue_size(queue->q) >= 100)
212 return 0;
213
214 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
215 item = pitem_new(priority, rdata);
216 if (rdata == NULL || item == NULL)
217 {
218 if (rdata != NULL) OPENSSL_free(rdata);
219 if (item != NULL) pitem_free(item);
220
221 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
222 return(0);
223 }
224
225 rdata->packet = s->packet;
226 rdata->packet_length = s->packet_length;
227 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
228 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
229
230 item->data = rdata;
231
232 /* insert should not fail, since duplicates are dropped */
233 if (pqueue_insert(queue->q, item) == NULL)
234 {
235 OPENSSL_free(rdata);
236 pitem_free(item);
237 return(0);
238 }
239
240 s->packet = NULL;
241 s->packet_length = 0;
242 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
243 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
244
245 if (!ssl3_setup_buffers(s))
246 {
247 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
248 OPENSSL_free(rdata);
249 pitem_free(item);
250 return(0);
251 }
252
253 return(1);
254 }
255
256
257 static int
258 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
259 {
260 pitem *item;
261
262 item = pqueue_pop(queue->q);
263 if (item)
264 {
265 dtls1_copy_record(s, item);
266
267 OPENSSL_free(item->data);
268 pitem_free(item);
269
270 return(1);
271 }
272
273 return(0);
274 }
275
276
277 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
278 * yet */
279 #define dtls1_get_unprocessed_record(s) \
280 dtls1_retrieve_buffered_record((s), \
281 &((s)->d1->unprocessed_rcds))
282
283 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
284 #define dtls1_get_processed_record(s) \
285 dtls1_retrieve_buffered_record((s), \
286 &((s)->d1->processed_rcds))
287
288 static int
289 dtls1_process_buffered_records(SSL *s)
290 {
291 pitem *item;
292
293 item = pqueue_peek(s->d1->unprocessed_rcds.q);
294 if (item)
295 {
296 DTLS1_RECORD_DATA *rdata;
297 rdata = (DTLS1_RECORD_DATA *)item->data;
298
299 /* Check if epoch is current. */
300 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
301 return(1); /* Nothing to do. */
302
303 /* Process all the records. */
304 while (pqueue_peek(s->d1->unprocessed_rcds.q))
305 {
306 dtls1_get_unprocessed_record(s);
307 if ( ! dtls1_process_record(s))
308 return(0);
309 dtls1_buffer_record(s, &(s->d1->processed_rcds),
310 s->s3->rrec.seq_num);
311 }
312 }
313
314 /* sync epoch numbers once all the unprocessed records
315 * have been processed */
316 s->d1->processed_rcds.epoch = s->d1->r_epoch;
317 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
318
319 return(1);
320 }
321
322
323 #if 0
324
325 static int
326 dtls1_get_buffered_record(SSL *s)
327 {
328 pitem *item;
329 PQ_64BIT priority =
330 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
331 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
332
333 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating,
334 nothing buffered */
335 return 0;
336
337
338 item = pqueue_peek(s->d1->rcvd_records);
339 if (item && item->priority == priority)
340 {
341 /* Check if we've received the record of interest. It must be
342 * a handshake record, since data records as passed up without
343 * buffering */
344 DTLS1_RECORD_DATA *rdata;
345 item = pqueue_pop(s->d1->rcvd_records);
346 rdata = (DTLS1_RECORD_DATA *)item->data;
347
348 if (s->s3->rbuf.buf != NULL)
349 OPENSSL_free(s->s3->rbuf.buf);
350
351 s->packet = rdata->packet;
352 s->packet_length = rdata->packet_length;
353 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
354 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
355
356 OPENSSL_free(item->data);
357 pitem_free(item);
358
359 /* s->d1->next_expected_seq_num++; */
360 return(1);
361 }
362
363 return 0;
364 }
365
366 #endif
367
368 static int
369 dtls1_process_record(SSL *s)
370 {
371 int i,al;
372 int clear=0;
373 int enc_err;
374 SSL_SESSION *sess;
375 SSL3_RECORD *rr;
376 unsigned int mac_size;
377 unsigned char md[EVP_MAX_MD_SIZE];
378
379
380 rr= &(s->s3->rrec);
381 sess = s->session;
382
383 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
384 * and we have that many bytes in s->packet
385 */
386 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
387
388 /* ok, we can now read from 's->packet' data into 'rr'
389 * rr->input points at rr->length bytes, which
390 * need to be copied into rr->data by either
391 * the decryption or by the decompression
392 * When the data is 'copied' into the rr->data buffer,
393 * rr->input will be pointed at the new buffer */
394
395 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
396 * rr->length bytes of encrypted compressed stuff. */
397
398 /* check is not needed I believe */
399 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
400 {
401 al=SSL_AD_RECORD_OVERFLOW;
402 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
403 goto f_err;
404 }
405
406 /* decrypt in place in 'rr->input' */
407 rr->data=rr->input;
408
409 enc_err = s->method->ssl3_enc->enc(s,0);
410 if (enc_err <= 0)
411 {
412 if (enc_err == 0)
413 /* SSLerr() and ssl3_send_alert() have been called */
414 goto err;
415
416 /* otherwise enc_err == -1 */
417 goto decryption_failed_or_bad_record_mac;
418 }
419
420 #ifdef TLS_DEBUG
421 printf("dec %d\n",rr->length);
422 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
423 printf("\n");
424 #endif
425
426 /* r->length is now the compressed data plus mac */
427 if ( (sess == NULL) ||
428 (s->enc_read_ctx == NULL) ||
429 (s->read_hash == NULL))
430 clear=1;
431
432 if (!clear)
433 {
434 /* !clear => s->read_hash != NULL => mac_size != -1 */
435 int t;
436 t=EVP_MD_CTX_size(s->read_hash);
437 OPENSSL_assert(t >= 0);
438 mac_size=t;
439
440 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
441 {
442 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
443 al=SSL_AD_RECORD_OVERFLOW;
444 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
445 goto f_err;
446 #else
447 goto decryption_failed_or_bad_record_mac;
448 #endif
449 }
450 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
451 if (rr->length < mac_size)
452 {
453 #if 0 /* OK only for stream ciphers */
454 al=SSL_AD_DECODE_ERROR;
455 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
456 goto f_err;
457 #else
458 goto decryption_failed_or_bad_record_mac;
459 #endif
460 }
461 rr->length-=mac_size;
462 i=s->method->ssl3_enc->mac(s,md,0);
463 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
464 {
465 goto decryption_failed_or_bad_record_mac;
466 }
467 }
468
469 /* r->length is now just compressed */
470 if (s->expand != NULL)
471 {
472 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
473 {
474 al=SSL_AD_RECORD_OVERFLOW;
475 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
476 goto f_err;
477 }
478 if (!ssl3_do_uncompress(s))
479 {
480 al=SSL_AD_DECOMPRESSION_FAILURE;
481 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
482 goto f_err;
483 }
484 }
485
486 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
487 {
488 al=SSL_AD_RECORD_OVERFLOW;
489 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
490 goto f_err;
491 }
492
493 rr->off=0;
494 /* So at this point the following is true
495 * ssl->s3->rrec.type is the type of record
496 * ssl->s3->rrec.length == number of bytes in record
497 * ssl->s3->rrec.off == offset to first valid byte
498 * ssl->s3->rrec.data == where to take bytes from, increment
499 * after use :-).
500 */
501
502 /* we have pulled in a full packet so zero things */
503 s->packet_length=0;
504 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
505 return(1);
506
507 decryption_failed_or_bad_record_mac:
508 /* Separate 'decryption_failed' alert was introduced with TLS 1.0,
509 * SSL 3.0 only has 'bad_record_mac'. But unless a decryption
510 * failure is directly visible from the ciphertext anyway,
511 * we should not reveal which kind of error occured -- this
512 * might become visible to an attacker (e.g. via logfile) */
513 al=SSL_AD_BAD_RECORD_MAC;
514 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DECRYPTION_FAILED_OR_BAD_RECORD_MAC);
515 f_err:
516 ssl3_send_alert(s,SSL3_AL_FATAL,al);
517 err:
518 return(0);
519 }
520
521
522 /* Call this to get a new input record.
523 * It will return <= 0 if more data is needed, normally due to an error
524 * or non-blocking IO.
525 * When it finishes, one packet has been decoded and can be found in
526 * ssl->s3->rrec.type - is the type of record
527 * ssl->s3->rrec.data, - data
528 * ssl->s3->rrec.length, - number of bytes
529 */
530 /* used only by dtls1_read_bytes */
531 int dtls1_get_record(SSL *s)
532 {
533 int ssl_major,ssl_minor;
534 int i,n;
535 SSL3_RECORD *rr;
536 SSL_SESSION *sess;
537 unsigned char *p = NULL;
538 unsigned short version;
539 DTLS1_BITMAP *bitmap;
540 unsigned int is_next_epoch;
541
542 rr= &(s->s3->rrec);
543 sess=s->session;
544
545 /* The epoch may have changed. If so, process all the
546 * pending records. This is a non-blocking operation. */
547 if ( ! dtls1_process_buffered_records(s))
548 return 0;
549
550 /* if we're renegotiating, then there may be buffered records */
551 if (dtls1_get_processed_record(s))
552 return 1;
553
554 /* get something from the wire */
555 again:
556 /* check if we have the header */
557 if ( (s->rstate != SSL_ST_READ_BODY) ||
558 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
559 {
560 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
561 /* read timeout is handled by dtls1_read_bytes */
562 if (n <= 0) return(n); /* error or non-blocking */
563
564 /* this packet contained a partial record, dump it */
565 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
566 {
567 s->packet_length = 0;
568 goto again;
569 }
570
571 s->rstate=SSL_ST_READ_BODY;
572
573 p=s->packet;
574
575 /* Pull apart the header into the DTLS1_RECORD */
576 rr->type= *(p++);
577 ssl_major= *(p++);
578 ssl_minor= *(p++);
579 version=(ssl_major<<8)|ssl_minor;
580
581 /* sequence number is 64 bits, with top 2 bytes = epoch */
582 n2s(p,rr->epoch);
583
584 memcpy(&(s->s3->read_sequence[2]), p, 6);
585 p+=6;
586
587 n2s(p,rr->length);
588
589 /* Lets check version */
590 if (!s->first_packet)
591 {
592 if (version != s->version)
593 {
594 /* unexpected version, silently discard */
595 rr->length = 0;
596 s->packet_length = 0;
597 goto again;
598 }
599 }
600
601 if ((version & 0xff00) != (s->version & 0xff00))
602 {
603 /* wrong version, silently discard record */
604 rr->length = 0;
605 s->packet_length = 0;
606 goto again;
607 }
608
609 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
610 {
611 /* record too long, silently discard it */
612 rr->length = 0;
613 s->packet_length = 0;
614 goto again;
615 }
616
617 /* now s->rstate == SSL_ST_READ_BODY */
618 }
619
620 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
621
622 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
623 {
624 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
625 i=rr->length;
626 n=ssl3_read_n(s,i,i,1);
627 if (n <= 0) return(n); /* error or non-blocking io */
628
629 /* this packet contained a partial record, dump it */
630 if ( n != i)
631 {
632 rr->length = 0;
633 s->packet_length = 0;
634 goto again;
635 }
636
637 /* now n == rr->length,
638 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
639 }
640 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
641
642 /* match epochs. NULL means the packet is dropped on the floor */
643 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
644 if ( bitmap == NULL)
645 {
646 rr->length = 0;
647 s->packet_length = 0; /* dump this record */
648 goto again; /* get another record */
649 }
650
651 /* Check whether this is a repeat, or aged record.
652 * Don't check if we're listening and this message is
653 * a ClientHello. They can look as if they're replayed,
654 * since they arrive from different connections and
655 * would be dropped unnecessarily.
656 */
657 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
658 *p == SSL3_MT_CLIENT_HELLO) &&
659 !dtls1_record_replay_check(s, bitmap))
660 {
661 rr->length = 0;
662 s->packet_length=0; /* dump this record */
663 goto again; /* get another record */
664 }
665
666 /* just read a 0 length packet */
667 if (rr->length == 0) goto again;
668
669 /* If this record is from the next epoch (either HM or ALERT),
670 * buffer it since it cannot be processed at this time. Records
671 * from the next epoch are marked as received even though they
672 * are not processed, so as to prevent any potential resource
673 * DoS attack */
674 if (is_next_epoch)
675 {
676 dtls1_record_bitmap_update(s, bitmap);
677 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
678 rr->length = 0;
679 s->packet_length = 0;
680 goto again;
681 }
682
683 if ( ! dtls1_process_record(s))
684 return(0);
685
686 dtls1_clear_timeouts(s); /* done waiting */
687 return(1);
688
689 }
690
691 /* Return up to 'len' payload bytes received in 'type' records.
692 * 'type' is one of the following:
693 *
694 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
695 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
696 * - 0 (during a shutdown, no data has to be returned)
697 *
698 * If we don't have stored data to work from, read a SSL/TLS record first
699 * (possibly multiple records if we still don't have anything to return).
700 *
701 * This function must handle any surprises the peer may have for us, such as
702 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
703 * a surprise, but handled as if it were), or renegotiation requests.
704 * Also if record payloads contain fragments too small to process, we store
705 * them until there is enough for the respective protocol (the record protocol
706 * may use arbitrary fragmentation and even interleaving):
707 * Change cipher spec protocol
708 * just 1 byte needed, no need for keeping anything stored
709 * Alert protocol
710 * 2 bytes needed (AlertLevel, AlertDescription)
711 * Handshake protocol
712 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
713 * to detect unexpected Client Hello and Hello Request messages
714 * here, anything else is handled by higher layers
715 * Application data protocol
716 * none of our business
717 */
718 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
719 {
720 int al,i,j,ret;
721 unsigned int n;
722 SSL3_RECORD *rr;
723 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
724
725 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
726 if (!ssl3_setup_buffers(s))
727 return(-1);
728
729 /* XXX: check what the second '&& type' is about */
730 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
731 (type != SSL3_RT_HANDSHAKE) && type) ||
732 (peek && (type != SSL3_RT_APPLICATION_DATA)))
733 {
734 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
735 return -1;
736 }
737
738 /* check whether there's a handshake message (client hello?) waiting */
739 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
740 return ret;
741
742 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
743
744 if (!s->in_handshake && SSL_in_init(s))
745 {
746 /* type == SSL3_RT_APPLICATION_DATA */
747 i=s->handshake_func(s);
748 if (i < 0) return(i);
749 if (i == 0)
750 {
751 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
752 return(-1);
753 }
754 }
755
756 start:
757 s->rwstate=SSL_NOTHING;
758
759 /* s->s3->rrec.type - is the type of record
760 * s->s3->rrec.data, - data
761 * s->s3->rrec.off, - offset into 'data' for next read
762 * s->s3->rrec.length, - number of bytes. */
763 rr = &(s->s3->rrec);
764
765 /* We are not handshaking and have no data yet,
766 * so process data buffered during the last handshake
767 * in advance, if any.
768 */
769 if (s->state == SSL_ST_OK && rr->length == 0)
770 {
771 pitem *item;
772 item = pqueue_pop(s->d1->buffered_app_data.q);
773 if (item)
774 {
775 dtls1_copy_record(s, item);
776
777 OPENSSL_free(item->data);
778 pitem_free(item);
779 }
780 }
781
782 /* Check for timeout */
783 if (dtls1_handle_timeout(s) > 0)
784 goto start;
785
786 /* get new packet if necessary */
787 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
788 {
789 ret=dtls1_get_record(s);
790 if (ret <= 0)
791 {
792 ret = dtls1_read_failed(s, ret);
793 /* anything other than a timeout is an error */
794 if (ret <= 0)
795 return(ret);
796 else
797 goto start;
798 }
799 }
800
801 /* we now have a packet which can be read and processed */
802
803 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
804 * reset by ssl3_get_finished */
805 && (rr->type != SSL3_RT_HANDSHAKE))
806 {
807 /* We now have application data between CCS and Finished.
808 * Most likely the packets were reordered on their way, so
809 * buffer the application data for later processing rather
810 * than dropping the connection.
811 */
812 dtls1_buffer_record(s, &(s->d1->buffered_app_data), 0);
813 rr->length = 0;
814 goto start;
815 }
816
817 /* If the other end has shut down, throw anything we read away
818 * (even in 'peek' mode) */
819 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
820 {
821 rr->length=0;
822 s->rwstate=SSL_NOTHING;
823 return(0);
824 }
825
826
827 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
828 {
829 /* make sure that we are not getting application data when we
830 * are doing a handshake for the first time */
831 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
832 (s->enc_read_ctx == NULL))
833 {
834 al=SSL_AD_UNEXPECTED_MESSAGE;
835 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
836 goto f_err;
837 }
838
839 if (len <= 0) return(len);
840
841 if ((unsigned int)len > rr->length)
842 n = rr->length;
843 else
844 n = (unsigned int)len;
845
846 memcpy(buf,&(rr->data[rr->off]),n);
847 if (!peek)
848 {
849 rr->length-=n;
850 rr->off+=n;
851 if (rr->length == 0)
852 {
853 s->rstate=SSL_ST_READ_HEADER;
854 rr->off=0;
855 }
856 }
857 return(n);
858 }
859
860
861 /* If we get here, then type != rr->type; if we have a handshake
862 * message, then it was unexpected (Hello Request or Client Hello). */
863
864 /* In case of record types for which we have 'fragment' storage,
865 * fill that so that we can process the data at a fixed place.
866 */
867 {
868 unsigned int k, dest_maxlen = 0;
869 unsigned char *dest = NULL;
870 unsigned int *dest_len = NULL;
871
872 if (rr->type == SSL3_RT_HANDSHAKE)
873 {
874 dest_maxlen = sizeof s->d1->handshake_fragment;
875 dest = s->d1->handshake_fragment;
876 dest_len = &s->d1->handshake_fragment_len;
877 }
878 else if (rr->type == SSL3_RT_ALERT)
879 {
880 dest_maxlen = sizeof(s->d1->alert_fragment);
881 dest = s->d1->alert_fragment;
882 dest_len = &s->d1->alert_fragment_len;
883 }
884 /* else it's a CCS message, or application data or wrong */
885 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
886 {
887 /* Application data while renegotiating
888 * is allowed. Try again reading.
889 */
890 if (rr->type == SSL3_RT_APPLICATION_DATA)
891 {
892 BIO *bio;
893 s->s3->in_read_app_data=2;
894 bio=SSL_get_rbio(s);
895 s->rwstate=SSL_READING;
896 BIO_clear_retry_flags(bio);
897 BIO_set_retry_read(bio);
898 return(-1);
899 }
900
901 /* Not certain if this is the right error handling */
902 al=SSL_AD_UNEXPECTED_MESSAGE;
903 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
904 goto f_err;
905 }
906
907 if (dest_maxlen > 0)
908 {
909 /* XDTLS: In a pathalogical case, the Client Hello
910 * may be fragmented--don't always expect dest_maxlen bytes */
911 if ( rr->length < dest_maxlen)
912 {
913 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
914 /*
915 * for normal alerts rr->length is 2, while
916 * dest_maxlen is 7 if we were to handle this
917 * non-existing alert...
918 */
919 FIX ME
920 #endif
921 s->rstate=SSL_ST_READ_HEADER;
922 rr->length = 0;
923 goto start;
924 }
925
926 /* now move 'n' bytes: */
927 for ( k = 0; k < dest_maxlen; k++)
928 {
929 dest[k] = rr->data[rr->off++];
930 rr->length--;
931 }
932 *dest_len = dest_maxlen;
933 }
934 }
935
936 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
937 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
938 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
939
940 /* If we are a client, check for an incoming 'Hello Request': */
941 if ((!s->server) &&
942 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
943 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
944 (s->session != NULL) && (s->session->cipher != NULL))
945 {
946 s->d1->handshake_fragment_len = 0;
947
948 if ((s->d1->handshake_fragment[1] != 0) ||
949 (s->d1->handshake_fragment[2] != 0) ||
950 (s->d1->handshake_fragment[3] != 0))
951 {
952 al=SSL_AD_DECODE_ERROR;
953 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
954 goto err;
955 }
956
957 /* no need to check sequence number on HELLO REQUEST messages */
958
959 if (s->msg_callback)
960 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
961 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
962
963 if (SSL_is_init_finished(s) &&
964 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
965 !s->s3->renegotiate)
966 {
967 ssl3_renegotiate(s);
968 if (ssl3_renegotiate_check(s))
969 {
970 i=s->handshake_func(s);
971 if (i < 0) return(i);
972 if (i == 0)
973 {
974 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
975 return(-1);
976 }
977
978 if (!(s->mode & SSL_MODE_AUTO_RETRY))
979 {
980 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
981 {
982 BIO *bio;
983 /* In the case where we try to read application data,
984 * but we trigger an SSL handshake, we return -1 with
985 * the retry option set. Otherwise renegotiation may
986 * cause nasty problems in the blocking world */
987 s->rwstate=SSL_READING;
988 bio=SSL_get_rbio(s);
989 BIO_clear_retry_flags(bio);
990 BIO_set_retry_read(bio);
991 return(-1);
992 }
993 }
994 }
995 }
996 /* we either finished a handshake or ignored the request,
997 * now try again to obtain the (application) data we were asked for */
998 goto start;
999 }
1000
1001 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1002 {
1003 int alert_level = s->d1->alert_fragment[0];
1004 int alert_descr = s->d1->alert_fragment[1];
1005
1006 s->d1->alert_fragment_len = 0;
1007
1008 if (s->msg_callback)
1009 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1010 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1011
1012 if (s->info_callback != NULL)
1013 cb=s->info_callback;
1014 else if (s->ctx->info_callback != NULL)
1015 cb=s->ctx->info_callback;
1016
1017 if (cb != NULL)
1018 {
1019 j = (alert_level << 8) | alert_descr;
1020 cb(s, SSL_CB_READ_ALERT, j);
1021 }
1022
1023 if (alert_level == 1) /* warning */
1024 {
1025 s->s3->warn_alert = alert_descr;
1026 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1027 {
1028 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1029 return(0);
1030 }
1031 #if 0
1032 /* XXX: this is a possible improvement in the future */
1033 /* now check if it's a missing record */
1034 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1035 {
1036 unsigned short seq;
1037 unsigned int frag_off;
1038 unsigned char *p = &(s->d1->alert_fragment[2]);
1039
1040 n2s(p, seq);
1041 n2l3(p, frag_off);
1042
1043 dtls1_retransmit_message(s,
1044 dtls1_get_queue_priority(frag->msg_header.seq, 0),
1045 frag_off, &found);
1046 if ( ! found && SSL_in_init(s))
1047 {
1048 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1049 /* requested a message not yet sent,
1050 send an alert ourselves */
1051 ssl3_send_alert(s,SSL3_AL_WARNING,
1052 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1053 }
1054 }
1055 #endif
1056 }
1057 else if (alert_level == 2) /* fatal */
1058 {
1059 char tmp[16];
1060
1061 s->rwstate=SSL_NOTHING;
1062 s->s3->fatal_alert = alert_descr;
1063 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1064 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1065 ERR_add_error_data(2,"SSL alert number ",tmp);
1066 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1067 SSL_CTX_remove_session(s->ctx,s->session);
1068 return(0);
1069 }
1070 else
1071 {
1072 al=SSL_AD_ILLEGAL_PARAMETER;
1073 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1074 goto f_err;
1075 }
1076
1077 goto start;
1078 }
1079
1080 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1081 {
1082 s->rwstate=SSL_NOTHING;
1083 rr->length=0;
1084 return(0);
1085 }
1086
1087 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1088 {
1089 struct ccs_header_st ccs_hdr;
1090 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1091
1092 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1093
1094 if (s->version == DTLS1_BAD_VER)
1095 ccs_hdr_len = 3;
1096
1097 /* 'Change Cipher Spec' is just a single byte, so we know
1098 * exactly what the record payload has to look like */
1099 /* XDTLS: check that epoch is consistent */
1100 if ( (rr->length != ccs_hdr_len) ||
1101 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1102 {
1103 i=SSL_AD_ILLEGAL_PARAMETER;
1104 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1105 goto err;
1106 }
1107
1108 rr->length=0;
1109
1110 if (s->msg_callback)
1111 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1112 rr->data, 1, s, s->msg_callback_arg);
1113
1114 /* We can't process a CCS now, because previous handshake
1115 * messages are still missing, so just drop it.
1116 */
1117 if (!s->d1->change_cipher_spec_ok)
1118 {
1119 goto start;
1120 }
1121
1122 s->d1->change_cipher_spec_ok = 0;
1123
1124 s->s3->change_cipher_spec=1;
1125 if (!ssl3_do_change_cipher_spec(s))
1126 goto err;
1127
1128 /* do this whenever CCS is processed */
1129 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1130
1131 if (s->version == DTLS1_BAD_VER)
1132 s->d1->handshake_read_seq++;
1133
1134 goto start;
1135 }
1136
1137 /* Unexpected handshake message (Client Hello, or protocol violation) */
1138 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1139 !s->in_handshake)
1140 {
1141 struct hm_header_st msg_hdr;
1142
1143 /* this may just be a stale retransmit */
1144 dtls1_get_message_header(rr->data, &msg_hdr);
1145 if( rr->epoch != s->d1->r_epoch)
1146 {
1147 rr->length = 0;
1148 goto start;
1149 }
1150
1151 /* If we are server, we may have a repeated FINISHED of the
1152 * client here, then retransmit our CCS and FINISHED.
1153 */
1154 if (msg_hdr.type == SSL3_MT_FINISHED)
1155 {
1156 dtls1_retransmit_buffered_messages(s);
1157 rr->length = 0;
1158 goto start;
1159 }
1160
1161 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1162 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1163 {
1164 #if 0 /* worked only because C operator preferences are not as expected (and
1165 * because this is not really needed for clients except for detecting
1166 * protocol violations): */
1167 s->state=SSL_ST_BEFORE|(s->server)
1168 ?SSL_ST_ACCEPT
1169 :SSL_ST_CONNECT;
1170 #else
1171 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1172 #endif
1173 s->new_session=1;
1174 }
1175 i=s->handshake_func(s);
1176 if (i < 0) return(i);
1177 if (i == 0)
1178 {
1179 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1180 return(-1);
1181 }
1182
1183 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1184 {
1185 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1186 {
1187 BIO *bio;
1188 /* In the case where we try to read application data,
1189 * but we trigger an SSL handshake, we return -1 with
1190 * the retry option set. Otherwise renegotiation may
1191 * cause nasty problems in the blocking world */
1192 s->rwstate=SSL_READING;
1193 bio=SSL_get_rbio(s);
1194 BIO_clear_retry_flags(bio);
1195 BIO_set_retry_read(bio);
1196 return(-1);
1197 }
1198 }
1199 goto start;
1200 }
1201
1202 switch (rr->type)
1203 {
1204 default:
1205 #ifndef OPENSSL_NO_TLS
1206 /* TLS just ignores unknown message types */
1207 if (s->version == TLS1_VERSION)
1208 {
1209 rr->length = 0;
1210 goto start;
1211 }
1212 #endif
1213 al=SSL_AD_UNEXPECTED_MESSAGE;
1214 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1215 goto f_err;
1216 case SSL3_RT_CHANGE_CIPHER_SPEC:
1217 case SSL3_RT_ALERT:
1218 case SSL3_RT_HANDSHAKE:
1219 /* we already handled all of these, with the possible exception
1220 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1221 * should not happen when type != rr->type */
1222 al=SSL_AD_UNEXPECTED_MESSAGE;
1223 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1224 goto f_err;
1225 case SSL3_RT_APPLICATION_DATA:
1226 /* At this point, we were expecting handshake data,
1227 * but have application data. If the library was
1228 * running inside ssl3_read() (i.e. in_read_app_data
1229 * is set) and it makes sense to read application data
1230 * at this point (session renegotiation not yet started),
1231 * we will indulge it.
1232 */
1233 if (s->s3->in_read_app_data &&
1234 (s->s3->total_renegotiations != 0) &&
1235 ((
1236 (s->state & SSL_ST_CONNECT) &&
1237 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1238 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1239 ) || (
1240 (s->state & SSL_ST_ACCEPT) &&
1241 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1242 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1243 )
1244 ))
1245 {
1246 s->s3->in_read_app_data=2;
1247 return(-1);
1248 }
1249 else
1250 {
1251 al=SSL_AD_UNEXPECTED_MESSAGE;
1252 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1253 goto f_err;
1254 }
1255 }
1256 /* not reached */
1257
1258 f_err:
1259 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1260 err:
1261 return(-1);
1262 }
1263
1264 int
1265 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1266 {
1267 int i;
1268
1269 if (SSL_in_init(s) && !s->in_handshake)
1270 {
1271 i=s->handshake_func(s);
1272 if (i < 0) return(i);
1273 if (i == 0)
1274 {
1275 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1276 return -1;
1277 }
1278 }
1279
1280 if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1281 {
1282 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1283 return -1;
1284 }
1285
1286 i = dtls1_write_bytes(s, type, buf_, len);
1287 return i;
1288 }
1289
1290
1291 /* this only happens when a client hello is received and a handshake
1292 * is started. */
1293 static int
1294 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1295 int len, int peek)
1296 {
1297
1298 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1299 /* (partially) satisfy request from storage */
1300 {
1301 unsigned char *src = s->d1->handshake_fragment;
1302 unsigned char *dst = buf;
1303 unsigned int k,n;
1304
1305 /* peek == 0 */
1306 n = 0;
1307 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1308 {
1309 *dst++ = *src++;
1310 len--; s->d1->handshake_fragment_len--;
1311 n++;
1312 }
1313 /* move any remaining fragment bytes: */
1314 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1315 s->d1->handshake_fragment[k] = *src++;
1316 return n;
1317 }
1318
1319 return 0;
1320 }
1321
1322
1323
1324
1325 /* Call this to write data in records of type 'type'
1326 * It will return <= 0 if not all data has been sent or non-blocking IO.
1327 */
1328 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1329 {
1330 int i;
1331
1332 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1333 s->rwstate=SSL_NOTHING;
1334 i=do_dtls1_write(s, type, buf, len, 0);
1335 return i;
1336 }
1337
1338 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1339 {
1340 unsigned char *p,*pseq;
1341 int i,mac_size,clear=0;
1342 int prefix_len = 0;
1343 SSL3_RECORD *wr;
1344 SSL3_BUFFER *wb;
1345 SSL_SESSION *sess;
1346 int bs;
1347
1348 /* first check if there is a SSL3_BUFFER still being written
1349 * out. This will happen with non blocking IO */
1350 if (s->s3->wbuf.left != 0)
1351 {
1352 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1353 return(ssl3_write_pending(s,type,buf,len));
1354 }
1355
1356 /* If we have an alert to send, lets send it */
1357 if (s->s3->alert_dispatch)
1358 {
1359 i=s->method->ssl_dispatch_alert(s);
1360 if (i <= 0)
1361 return(i);
1362 /* if it went, fall through and send more stuff */
1363 }
1364
1365 if (len == 0 && !create_empty_fragment)
1366 return 0;
1367
1368 wr= &(s->s3->wrec);
1369 wb= &(s->s3->wbuf);
1370 sess=s->session;
1371
1372 if ( (sess == NULL) ||
1373 (s->enc_write_ctx == NULL) ||
1374 (EVP_MD_CTX_md(s->write_hash) == NULL))
1375 clear=1;
1376
1377 if (clear)
1378 mac_size=0;
1379 else
1380 {
1381 mac_size=EVP_MD_CTX_size(s->write_hash);
1382 if (mac_size < 0)
1383 goto err;
1384 }
1385
1386 /* DTLS implements explicit IV, so no need for empty fragments */
1387 #if 0
1388 /* 'create_empty_fragment' is true only when this function calls itself */
1389 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1390 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1391 {
1392 /* countermeasure against known-IV weakness in CBC ciphersuites
1393 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1394 */
1395
1396 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1397 {
1398 /* recursive function call with 'create_empty_fragment' set;
1399 * this prepares and buffers the data for an empty fragment
1400 * (these 'prefix_len' bytes are sent out later
1401 * together with the actual payload) */
1402 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1403 if (prefix_len <= 0)
1404 goto err;
1405
1406 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1407 {
1408 /* insufficient space */
1409 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1410 goto err;
1411 }
1412 }
1413
1414 s->s3->empty_fragment_done = 1;
1415 }
1416 #endif
1417 p = wb->buf + prefix_len;
1418
1419 /* write the header */
1420
1421 *(p++)=type&0xff;
1422 wr->type=type;
1423
1424 *(p++)=(s->version>>8);
1425 *(p++)=s->version&0xff;
1426
1427 /* field where we are to write out packet epoch, seq num and len */
1428 pseq=p;
1429 p+=10;
1430
1431 /* lets setup the record stuff. */
1432
1433 /* Make space for the explicit IV in case of CBC.
1434 * (this is a bit of a boundary violation, but what the heck).
1435 */
1436 if ( s->enc_write_ctx &&
1437 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1438 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1439 else
1440 bs = 0;
1441
1442 wr->data=p + bs; /* make room for IV in case of CBC */
1443 wr->length=(int)len;
1444 wr->input=(unsigned char *)buf;
1445
1446 /* we now 'read' from wr->input, wr->length bytes into
1447 * wr->data */
1448
1449 /* first we compress */
1450 if (s->compress != NULL)
1451 {
1452 if (!ssl3_do_compress(s))
1453 {
1454 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1455 goto err;
1456 }
1457 }
1458 else
1459 {
1460 memcpy(wr->data,wr->input,wr->length);
1461 wr->input=wr->data;
1462 }
1463
1464 /* we should still have the output to wr->data and the input
1465 * from wr->input. Length should be wr->length.
1466 * wr->data still points in the wb->buf */
1467
1468 if (mac_size != 0)
1469 {
1470 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1471 goto err;
1472 wr->length+=mac_size;
1473 }
1474
1475 /* this is true regardless of mac size */
1476 wr->input=p;
1477 wr->data=p;
1478
1479
1480 /* ssl3_enc can only have an error on read */
1481 if (bs) /* bs != 0 in case of CBC */
1482 {
1483 RAND_pseudo_bytes(p,bs);
1484 /* master IV and last CBC residue stand for
1485 * the rest of randomness */
1486 wr->length += bs;
1487 }
1488
1489 s->method->ssl3_enc->enc(s,1);
1490
1491 /* record length after mac and block padding */
1492 /* if (type == SSL3_RT_APPLICATION_DATA ||
1493 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1494
1495 /* there's only one epoch between handshake and app data */
1496
1497 s2n(s->d1->w_epoch, pseq);
1498
1499 /* XDTLS: ?? */
1500 /* else
1501 s2n(s->d1->handshake_epoch, pseq); */
1502
1503 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1504 pseq+=6;
1505 s2n(wr->length,pseq);
1506
1507 /* we should now have
1508 * wr->data pointing to the encrypted data, which is
1509 * wr->length long */
1510 wr->type=type; /* not needed but helps for debugging */
1511 wr->length+=DTLS1_RT_HEADER_LENGTH;
1512
1513 #if 0 /* this is now done at the message layer */
1514 /* buffer the record, making it easy to handle retransmits */
1515 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1516 dtls1_buffer_record(s, wr->data, wr->length,
1517 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1518 #endif
1519
1520 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1521
1522 if (create_empty_fragment)
1523 {
1524 /* we are in a recursive call;
1525 * just return the length, don't write out anything here
1526 */
1527 return wr->length;
1528 }
1529
1530 /* now let's set up wb */
1531 wb->left = prefix_len + wr->length;
1532 wb->offset = 0;
1533
1534 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1535 s->s3->wpend_tot=len;
1536 s->s3->wpend_buf=buf;
1537 s->s3->wpend_type=type;
1538 s->s3->wpend_ret=len;
1539
1540 /* we now just need to write the buffer */
1541 return ssl3_write_pending(s,type,buf,len);
1542 err:
1543 return -1;
1544 }
1545
1546
1547
1548 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1549 {
1550 int cmp;
1551 unsigned int shift;
1552 const unsigned char *seq = s->s3->read_sequence;
1553
1554 cmp = satsub64be(seq,bitmap->max_seq_num);
1555 if (cmp > 0)
1556 {
1557 memcpy (s->s3->rrec.seq_num,seq,8);
1558 return 1; /* this record in new */
1559 }
1560 shift = -cmp;
1561 if (shift >= sizeof(bitmap->map)*8)
1562 return 0; /* stale, outside the window */
1563 else if (bitmap->map & (1UL<<shift))
1564 return 0; /* record previously received */
1565
1566 memcpy (s->s3->rrec.seq_num,seq,8);
1567 return 1;
1568 }
1569
1570
1571 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1572 {
1573 int cmp;
1574 unsigned int shift;
1575 const unsigned char *seq = s->s3->read_sequence;
1576
1577 cmp = satsub64be(seq,bitmap->max_seq_num);
1578 if (cmp > 0)
1579 {
1580 shift = cmp;
1581 if (shift < sizeof(bitmap->map)*8)
1582 bitmap->map <<= shift, bitmap->map |= 1UL;
1583 else
1584 bitmap->map = 1UL;
1585 memcpy(bitmap->max_seq_num,seq,8);
1586 }
1587 else {
1588 shift = -cmp;
1589 if (shift < sizeof(bitmap->map)*8)
1590 bitmap->map |= 1UL<<shift;
1591 }
1592 }
1593
1594
1595 int dtls1_dispatch_alert(SSL *s)
1596 {
1597 int i,j;
1598 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1599 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1600 unsigned char *ptr = &buf[0];
1601
1602 s->s3->alert_dispatch=0;
1603
1604 memset(buf, 0x00, sizeof(buf));
1605 *ptr++ = s->s3->send_alert[0];
1606 *ptr++ = s->s3->send_alert[1];
1607
1608 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1609 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1610 {
1611 s2n(s->d1->handshake_read_seq, ptr);
1612 #if 0
1613 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1614
1615 else
1616 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1617 #endif
1618
1619 #if 0
1620 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);
1621 #endif
1622 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1623 }
1624 #endif
1625
1626 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1627 if (i <= 0)
1628 {
1629 s->s3->alert_dispatch=1;
1630 /* fprintf( stderr, "not done with alert\n" ); */
1631 }
1632 else
1633 {
1634 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1635 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1636 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1637 #endif
1638 )
1639 (void)BIO_flush(s->wbio);
1640
1641 if (s->msg_callback)
1642 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1643 2, s, s->msg_callback_arg);
1644
1645 if (s->info_callback != NULL)
1646 cb=s->info_callback;
1647 else if (s->ctx->info_callback != NULL)
1648 cb=s->ctx->info_callback;
1649
1650 if (cb != NULL)
1651 {
1652 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1653 cb(s,SSL_CB_WRITE_ALERT,j);
1654 }
1655 }
1656 return(i);
1657 }
1658
1659
1660 static DTLS1_BITMAP *
1661 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1662 {
1663
1664 *is_next_epoch = 0;
1665
1666 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1667 if (rr->epoch == s->d1->r_epoch)
1668 return &s->d1->bitmap;
1669
1670 /* Only HM and ALERT messages can be from the next epoch */
1671 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1672 (rr->type == SSL3_RT_HANDSHAKE ||
1673 rr->type == SSL3_RT_ALERT))
1674 {
1675 *is_next_epoch = 1;
1676 return &s->d1->next_bitmap;
1677 }
1678
1679 return NULL;
1680 }
1681
1682 #if 0
1683 static int
1684 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1685 unsigned long *offset)
1686 {
1687
1688 /* alerts are passed up immediately */
1689 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1690 rr->type == SSL3_RT_ALERT)
1691 return 0;
1692
1693 /* Only need to buffer if a handshake is underway.
1694 * (this implies that Hello Request and Client Hello are passed up
1695 * immediately) */
1696 if ( SSL_in_init(s))
1697 {
1698 unsigned char *data = rr->data;
1699 /* need to extract the HM/CCS sequence number here */
1700 if ( rr->type == SSL3_RT_HANDSHAKE ||
1701 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1702 {
1703 unsigned short seq_num;
1704 struct hm_header_st msg_hdr;
1705 struct ccs_header_st ccs_hdr;
1706
1707 if ( rr->type == SSL3_RT_HANDSHAKE)
1708 {
1709 dtls1_get_message_header(data, &msg_hdr);
1710 seq_num = msg_hdr.seq;
1711 *offset = msg_hdr.frag_off;
1712 }
1713 else
1714 {
1715 dtls1_get_ccs_header(data, &ccs_hdr);
1716 seq_num = ccs_hdr.seq;
1717 *offset = 0;
1718 }
1719
1720 /* this is either a record we're waiting for, or a
1721 * retransmit of something we happened to previously
1722 * receive (higher layers will drop the repeat silently */
1723 if ( seq_num < s->d1->handshake_read_seq)
1724 return 0;
1725 if (rr->type == SSL3_RT_HANDSHAKE &&
1726 seq_num == s->d1->handshake_read_seq &&
1727 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1728 return 0;
1729 else if ( seq_num == s->d1->handshake_read_seq &&
1730 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1731 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1732 return 0;
1733 else
1734 {
1735 *priority = seq_num;
1736 return 1;
1737 }
1738 }
1739 else /* unknown record type */
1740 return 0;
1741 }
1742
1743 return 0;
1744 }
1745 #endif
1746
1747 void
1748 dtls1_reset_seq_numbers(SSL *s, int rw)
1749 {
1750 unsigned char *seq;
1751 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1752
1753 if ( rw & SSL3_CC_READ)
1754 {
1755 seq = s->s3->read_sequence;
1756 s->d1->r_epoch++;
1757 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1758 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1759 }
1760 else
1761 {
1762 seq = s->s3->write_sequence;
1763 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1764 s->d1->w_epoch++;
1765 }
1766
1767 memset(seq, 0x00, seq_bytes);
1768 }
1769
1770
1771 static void
1772 dtls1_clear_timeouts(SSL *s)
1773 {
1774 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1775 }
NetBSD on the FriendlyARM MINI2440