1 /* ssl/d1_pkt.c */
2 /*
3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5 */
6 /* ====================================================================
7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 *
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 *
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
19 * distribution.
20 *
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
25 *
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@openssl.org.
30 *
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
34 *
35 * 6. Redistributions of any form whatsoever must retain the following
36 * acknowledgment:
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
39 *
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
53 *
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
57 *
58 */
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
61 *
62 * This package is an SSL implementation written
63 * by Eric Young (eay@cryptsoft.com).
64 * The implementation was written so as to conform with Netscapes SSL.
65 *
66 * This library is free for commercial and non-commercial use as long as
67 * the following conditions are aheared to. The following conditions
68 * apply to all code found in this distribution, be it the RC4, RSA,
69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
70 * included with this distribution is covered by the same copyright terms
71 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
72 *
73 * Copyright remains Eric Young's, and as such any Copyright notices in
74 * the code are not to be removed.
75 * If this package is used in a product, Eric Young should be given attribution
76 * as the author of the parts of the library used.
77 * This can be in the form of a textual message at program startup or
78 * in documentation (online or textual) provided with the package.
79 *
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
82 * are met:
83 * 1. Redistributions of source code must retain the copyright
84 * notice, this list of conditions and the following disclaimer.
85 * 2. Redistributions in binary form must reproduce the above copyright
86 * notice, this list of conditions and the following disclaimer in the
87 * documentation and/or other materials provided with the distribution.
88 * 3. All advertising materials mentioning features or use of this software
89 * must display the following acknowledgement:
90 * "This product includes cryptographic software written by
91 * Eric Young (eay@cryptsoft.com)"
92 * The word 'cryptographic' can be left out if the rouines from the library
93 * being used are not cryptographic related :-).
94 * 4. If you include any Windows specific code (or a derivative thereof) from
95 * the apps directory (application code) you must include an acknowledgement:
96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
97 *
98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
108 * SUCH DAMAGE.
109 *
110 * The licence and distribution terms for any publically available version or
111 * derivative of this code cannot be changed. i.e. this code cannot simply be
112 * copied and put under another distribution licence
113 * [including the GNU Public Licence.]
114 */
115
116 #include <stdio.h>
117 #include <errno.h>
118 #define USE_SOCKETS
119 #include "ssl_locl.h"
120 #include <openssl/evp.h>
121 #include <openssl/buffer.h>
122 #include <openssl/pqueue.h>
123 #include <openssl/rand.h>
124
125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
satsub64be(const unsigned char * v1,const unsigned char * v2)126 static int satsub64be(const unsigned char *v1,const unsigned char *v2)
127 { int ret,sat,brw,i;
128
129 if (sizeof(long) == 8) do
130 { const union { long one; char little; } is_endian = {1};
131 long l;
132
133 if (is_endian.little) break;
134 /* not reached on little-endians */
135 /* following test is redundant, because input is
136 * always aligned, but I take no chances... */
137 if (((size_t)v1|(size_t)v2)&0x7) break;
138
139 l = *((long *)v1);
140 l -= *((long *)v2);
141 if (l>128) return 128;
142 else if (l<-128) return -128;
143 else return (int)l;
144 } while (0);
145
146 ret = (int)v1[7]-(int)v2[7];
147 sat = 0;
148 brw = ret>>8; /* brw is either 0 or -1 */
149 if (ret & 0x80)
150 { for (i=6;i>=0;i--)
151 { brw += (int)v1[i]-(int)v2[i];
152 sat |= ~brw;
153 brw >>= 8;
154 }
155 }
156 else
157 { for (i=6;i>=0;i--)
158 { brw += (int)v1[i]-(int)v2[i];
159 sat |= brw;
160 brw >>= 8;
161 }
162 }
163 brw <<= 8; /* brw is either 0 or -256 */
164
165 if (sat&0xff) return brw | 0x80;
166 else return brw + (ret&0xFF);
167 }
168
169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
170 int len, int peek);
171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
174 unsigned int *is_next_epoch);
175 #if 0
176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
177 unsigned short *priority, unsigned long *offset);
178 #endif
179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
180 unsigned char *priority);
181 static int dtls1_process_record(SSL *s);
182 static void dtls1_clear_timeouts(SSL *s);
183
184 /* copy buffered record into SSL structure */
185 static int
dtls1_copy_record(SSL * s,pitem * item)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 /* Set proper sequence number for mac calculation */
201 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
202
203 return(1);
204 }
205
206
207 static int
dtls1_buffer_record(SSL * s,record_pqueue * queue,unsigned char * priority)208 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
209 {
210 DTLS1_RECORD_DATA *rdata;
211 pitem *item;
212
213 /* Limit the size of the queue to prevent DOS attacks */
214 if (pqueue_size(queue->q) >= 100)
215 return 0;
216
217 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
218 item = pitem_new(priority, rdata);
219 if (rdata == NULL || item == NULL)
220 {
221 if (rdata != NULL) OPENSSL_free(rdata);
222 if (item != NULL) pitem_free(item);
223
224 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
225 return(0);
226 }
227
228 rdata->packet = s->packet;
229 rdata->packet_length = s->packet_length;
230 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
231 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
232
233 item->data = rdata;
234
235 /* insert should not fail, since duplicates are dropped */
236 if (pqueue_insert(queue->q, item) == NULL)
237 {
238 OPENSSL_free(rdata);
239 pitem_free(item);
240 return(0);
241 }
242
243 s->packet = NULL;
244 s->packet_length = 0;
245 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
246 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
247
248 if (!ssl3_setup_buffers(s))
249 {
250 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
251 OPENSSL_free(rdata);
252 pitem_free(item);
253 return(0);
254 }
255
256 return(1);
257 }
258
259
260 static int
dtls1_retrieve_buffered_record(SSL * s,record_pqueue * queue)261 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
262 {
263 pitem *item;
264
265 item = pqueue_pop(queue->q);
266 if (item)
267 {
268 dtls1_copy_record(s, item);
269
270 OPENSSL_free(item->data);
271 pitem_free(item);
272
273 return(1);
274 }
275
276 return(0);
277 }
278
279
280 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
281 * yet */
282 #define dtls1_get_unprocessed_record(s) \
283 dtls1_retrieve_buffered_record((s), \
284 &((s)->d1->unprocessed_rcds))
285
286 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
287 #define dtls1_get_processed_record(s) \
288 dtls1_retrieve_buffered_record((s), \
289 &((s)->d1->processed_rcds))
290
291 static int
dtls1_process_buffered_records(SSL * s)292 dtls1_process_buffered_records(SSL *s)
293 {
294 pitem *item;
295
296 item = pqueue_peek(s->d1->unprocessed_rcds.q);
297 if (item)
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
dtls1_process_record(SSL * s)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 /* decryption failed, silently discard message */
413 if (enc_err < 0)
414 {
415 rr->length = 0;
416 s->packet_length = 0;
417 }
418 goto err;
419 }
420
421 #ifdef TLS_DEBUG
422 printf("dec %d\n",rr->length);
423 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
424 printf("\n");
425 #endif
426
427 /* r->length is now the compressed data plus mac */
428 if ( (sess == NULL) ||
429 (s->enc_read_ctx == NULL) ||
430 (s->read_hash == NULL))
431 clear=1;
432
433 if (!clear)
434 {
435 /* !clear => s->read_hash != NULL => mac_size != -1 */
436 int t;
437 t=EVP_MD_CTX_size(s->read_hash);
438 OPENSSL_assert(t >= 0);
439 mac_size=t;
440
441 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
442 {
443 #if 0 /* OK only for stream ciphers (then rr->length is visible from ciphertext anyway) */
444 al=SSL_AD_RECORD_OVERFLOW;
445 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_PRE_MAC_LENGTH_TOO_LONG);
446 goto f_err;
447 #else
448 goto err;
449 #endif
450 }
451 /* check the MAC for rr->input (it's in mac_size bytes at the tail) */
452 if (rr->length < mac_size)
453 {
454 #if 0 /* OK only for stream ciphers */
455 al=SSL_AD_DECODE_ERROR;
456 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
457 goto f_err;
458 #else
459 goto err;
460 #endif
461 }
462 rr->length-=mac_size;
463 i=s->method->ssl3_enc->mac(s,md,0);
464 if (i < 0 || memcmp(md,&(rr->data[rr->length]),mac_size) != 0)
465 {
466 goto err;
467 }
468 }
469
470 /* r->length is now just compressed */
471 if (s->expand != NULL)
472 {
473 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
474 {
475 al=SSL_AD_RECORD_OVERFLOW;
476 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
477 goto f_err;
478 }
479 if (!ssl3_do_uncompress(s))
480 {
481 al=SSL_AD_DECOMPRESSION_FAILURE;
482 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
483 goto f_err;
484 }
485 }
486
487 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
488 {
489 al=SSL_AD_RECORD_OVERFLOW;
490 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
491 goto f_err;
492 }
493
494 rr->off=0;
495 /* So at this point the following is true
496 * ssl->s3->rrec.type is the type of record
497 * ssl->s3->rrec.length == number of bytes in record
498 * ssl->s3->rrec.off == offset to first valid byte
499 * ssl->s3->rrec.data == where to take bytes from, increment
500 * after use :-).
501 */
502
503 /* we have pulled in a full packet so zero things */
504 s->packet_length=0;
505 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
506 return(1);
507
508 f_err:
509 ssl3_send_alert(s,SSL3_AL_FATAL,al);
510 err:
511 return(0);
512 }
513
514
515 /* Call this to get a new input record.
516 * It will return <= 0 if more data is needed, normally due to an error
517 * or non-blocking IO.
518 * When it finishes, one packet has been decoded and can be found in
519 * ssl->s3->rrec.type - is the type of record
520 * ssl->s3->rrec.data, - data
521 * ssl->s3->rrec.length, - number of bytes
522 */
523 /* used only by dtls1_read_bytes */
dtls1_get_record(SSL * s)524 int dtls1_get_record(SSL *s)
525 {
526 int ssl_major,ssl_minor;
527 int i,n;
528 SSL3_RECORD *rr;
529 unsigned char *p = NULL;
530 unsigned short version;
531 DTLS1_BITMAP *bitmap;
532 unsigned int is_next_epoch;
533
534 rr= &(s->s3->rrec);
535
536 /* The epoch may have changed. If so, process all the
537 * pending records. This is a non-blocking operation. */
538 dtls1_process_buffered_records(s);
539
540 /* if we're renegotiating, then there may be buffered records */
541 if (dtls1_get_processed_record(s))
542 return 1;
543
544 /* get something from the wire */
545 again:
546 /* check if we have the header */
547 if ( (s->rstate != SSL_ST_READ_BODY) ||
548 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
549 {
550 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
551 /* read timeout is handled by dtls1_read_bytes */
552 if (n <= 0) return(n); /* error or non-blocking */
553
554 /* this packet contained a partial record, dump it */
555 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
556 {
557 s->packet_length = 0;
558 goto again;
559 }
560
561 s->rstate=SSL_ST_READ_BODY;
562
563 p=s->packet;
564
565 /* Pull apart the header into the DTLS1_RECORD */
566 rr->type= *(p++);
567 ssl_major= *(p++);
568 ssl_minor= *(p++);
569 version=(ssl_major<<8)|ssl_minor;
570
571 /* sequence number is 64 bits, with top 2 bytes = epoch */
572 n2s(p,rr->epoch);
573
574 memcpy(&(s->s3->read_sequence[2]), p, 6);
575 p+=6;
576
577 n2s(p,rr->length);
578
579 /* Lets check version */
580 if (!s->first_packet)
581 {
582 if (version != s->version)
583 {
584 /* unexpected version, silently discard */
585 rr->length = 0;
586 s->packet_length = 0;
587 goto again;
588 }
589 }
590
591 if ((version & 0xff00) != (s->version & 0xff00))
592 {
593 /* wrong version, silently discard record */
594 rr->length = 0;
595 s->packet_length = 0;
596 goto again;
597 }
598
599 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
600 {
601 /* record too long, silently discard it */
602 rr->length = 0;
603 s->packet_length = 0;
604 goto again;
605 }
606
607 /* If we receive a valid record larger than the current buffer size,
608 * allocate some memory for it.
609 */
610 if (rr->length > s->s3->rbuf.len - DTLS1_RT_HEADER_LENGTH)
611 {
612 unsigned char *pp;
613 unsigned int newlen = rr->length + DTLS1_RT_HEADER_LENGTH;
614 if ((pp=OPENSSL_realloc(s->s3->rbuf.buf, newlen))==NULL)
615 {
616 SSLerr(SSL_F_DTLS1_GET_RECORD,ERR_R_MALLOC_FAILURE);
617 return(-1);
618 }
619 p = pp + (p - s->s3->rbuf.buf);
620 s->s3->rbuf.buf=pp;
621 s->s3->rbuf.len=newlen;
622 s->packet= &(s->s3->rbuf.buf[0]);
623 }
624
625 /* now s->rstate == SSL_ST_READ_BODY */
626 }
627
628 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
629
630 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
631 {
632 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
633 i=rr->length;
634 n=ssl3_read_n(s,i,i,1);
635 if (n <= 0) return(n); /* error or non-blocking io */
636
637 /* this packet contained a partial record, dump it */
638 if ( n != i)
639 {
640 rr->length = 0;
641 s->packet_length = 0;
642 goto again;
643 }
644
645 /* now n == rr->length,
646 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
647 }
648 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
649
650 /* match epochs. NULL means the packet is dropped on the floor */
651 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
652 if ( bitmap == NULL)
653 {
654 rr->length = 0;
655 s->packet_length = 0; /* dump this record */
656 goto again; /* get another record */
657 }
658
659 /* Check whether this is a repeat, or aged record.
660 * Don't check if we're listening and this message is
661 * a ClientHello. They can look as if they're replayed,
662 * since they arrive from different connections and
663 * would be dropped unnecessarily.
664 */
665 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
666 *p == SSL3_MT_CLIENT_HELLO) &&
667 !dtls1_record_replay_check(s, bitmap))
668 {
669 rr->length = 0;
670 s->packet_length=0; /* dump this record */
671 goto again; /* get another record */
672 }
673
674 /* just read a 0 length packet */
675 if (rr->length == 0) goto again;
676
677 /* If this record is from the next epoch (either HM or ALERT),
678 * and a handshake is currently in progress, buffer it since it
679 * cannot be processed at this time. However, do not buffer
680 * anything while listening.
681 */
682 if (is_next_epoch)
683 {
684 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
685 {
686 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
687 }
688 rr->length = 0;
689 s->packet_length = 0;
690 goto again;
691 }
692
693 if (!dtls1_process_record(s))
694 {
695 rr->length = 0;
696 s->packet_length = 0; /* dump this record */
697 goto again; /* get another record */
698 }
699
700 dtls1_clear_timeouts(s); /* done waiting */
701 return(1);
702
703 }
704
705 /* Return up to 'len' payload bytes received in 'type' records.
706 * 'type' is one of the following:
707 *
708 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
709 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
710 * - 0 (during a shutdown, no data has to be returned)
711 *
712 * If we don't have stored data to work from, read a SSL/TLS record first
713 * (possibly multiple records if we still don't have anything to return).
714 *
715 * This function must handle any surprises the peer may have for us, such as
716 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
717 * a surprise, but handled as if it were), or renegotiation requests.
718 * Also if record payloads contain fragments too small to process, we store
719 * them until there is enough for the respective protocol (the record protocol
720 * may use arbitrary fragmentation and even interleaving):
721 * Change cipher spec protocol
722 * just 1 byte needed, no need for keeping anything stored
723 * Alert protocol
724 * 2 bytes needed (AlertLevel, AlertDescription)
725 * Handshake protocol
726 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
727 * to detect unexpected Client Hello and Hello Request messages
728 * here, anything else is handled by higher layers
729 * Application data protocol
730 * none of our business
731 */
dtls1_read_bytes(SSL * s,int type,unsigned char * buf,int len,int peek)732 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
733 {
734 int al,i,j,ret;
735 unsigned int n;
736 SSL3_RECORD *rr;
737 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
738
739 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
740 if (!ssl3_setup_buffers(s))
741 return(-1);
742
743 /* XXX: check what the second '&& type' is about */
744 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
745 (type != SSL3_RT_HANDSHAKE) && type) ||
746 (peek && (type != SSL3_RT_APPLICATION_DATA)))
747 {
748 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
749 return -1;
750 }
751
752 /* check whether there's a handshake message (client hello?) waiting */
753 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
754 return ret;
755
756 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
757
758 if (!s->in_handshake && SSL_in_init(s))
759 {
760 /* type == SSL3_RT_APPLICATION_DATA */
761 i=s->handshake_func(s);
762 if (i < 0) return(i);
763 if (i == 0)
764 {
765 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
766 return(-1);
767 }
768 }
769
770 start:
771 s->rwstate=SSL_NOTHING;
772
773 /* s->s3->rrec.type - is the type of record
774 * s->s3->rrec.data, - data
775 * s->s3->rrec.off, - offset into 'data' for next read
776 * s->s3->rrec.length, - number of bytes. */
777 rr = &(s->s3->rrec);
778
779 /* We are not handshaking and have no data yet,
780 * so process data buffered during the last handshake
781 * in advance, if any.
782 */
783 if (s->state == SSL_ST_OK && rr->length == 0)
784 {
785 pitem *item;
786 item = pqueue_pop(s->d1->buffered_app_data.q);
787 if (item)
788 {
789 dtls1_copy_record(s, item);
790
791 OPENSSL_free(item->data);
792 pitem_free(item);
793 }
794 }
795
796 /* Check for timeout */
797 if (dtls1_handle_timeout(s) > 0)
798 goto start;
799
800 /* get new packet if necessary */
801 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
802 {
803 ret=dtls1_get_record(s);
804 if (ret <= 0)
805 {
806 ret = dtls1_read_failed(s, ret);
807 /* anything other than a timeout is an error */
808 if (ret <= 0)
809 return(ret);
810 else
811 goto start;
812 }
813 }
814
815 /* we now have a packet which can be read and processed */
816
817 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
818 * reset by ssl3_get_finished */
819 && (rr->type != SSL3_RT_HANDSHAKE))
820 {
821 /* We now have application data between CCS and Finished.
822 * Most likely the packets were reordered on their way, so
823 * buffer the application data for later processing rather
824 * than dropping the connection.
825 */
826 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
827 rr->length = 0;
828 goto start;
829 }
830
831 /* If the other end has shut down, throw anything we read away
832 * (even in 'peek' mode) */
833 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
834 {
835 rr->length=0;
836 s->rwstate=SSL_NOTHING;
837 return(0);
838 }
839
840
841 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
842 {
843 /* make sure that we are not getting application data when we
844 * are doing a handshake for the first time */
845 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
846 (s->enc_read_ctx == NULL))
847 {
848 al=SSL_AD_UNEXPECTED_MESSAGE;
849 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
850 goto f_err;
851 }
852
853 if (len <= 0) return(len);
854
855 if ((unsigned int)len > rr->length)
856 n = rr->length;
857 else
858 n = (unsigned int)len;
859
860 memcpy(buf,&(rr->data[rr->off]),n);
861 if (!peek)
862 {
863 rr->length-=n;
864 rr->off+=n;
865 if (rr->length == 0)
866 {
867 s->rstate=SSL_ST_READ_HEADER;
868 rr->off=0;
869 }
870 }
871 return(n);
872 }
873
874
875 /* If we get here, then type != rr->type; if we have a handshake
876 * message, then it was unexpected (Hello Request or Client Hello). */
877
878 /* In case of record types for which we have 'fragment' storage,
879 * fill that so that we can process the data at a fixed place.
880 */
881 {
882 unsigned int k, dest_maxlen = 0;
883 unsigned char *dest = NULL;
884 unsigned int *dest_len = NULL;
885
886 if (rr->type == SSL3_RT_HANDSHAKE)
887 {
888 dest_maxlen = sizeof s->d1->handshake_fragment;
889 dest = s->d1->handshake_fragment;
890 dest_len = &s->d1->handshake_fragment_len;
891 }
892 else if (rr->type == SSL3_RT_ALERT)
893 {
894 dest_maxlen = sizeof(s->d1->alert_fragment);
895 dest = s->d1->alert_fragment;
896 dest_len = &s->d1->alert_fragment_len;
897 }
898 /* else it's a CCS message, or application data or wrong */
899 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
900 {
901 /* Application data while renegotiating
902 * is allowed. Try again reading.
903 */
904 if (rr->type == SSL3_RT_APPLICATION_DATA)
905 {
906 BIO *bio;
907 s->s3->in_read_app_data=2;
908 bio=SSL_get_rbio(s);
909 s->rwstate=SSL_READING;
910 BIO_clear_retry_flags(bio);
911 BIO_set_retry_read(bio);
912 return(-1);
913 }
914
915 /* Not certain if this is the right error handling */
916 al=SSL_AD_UNEXPECTED_MESSAGE;
917 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
918 goto f_err;
919 }
920
921 if (dest_maxlen > 0)
922 {
923 /* XDTLS: In a pathalogical case, the Client Hello
924 * may be fragmented--don't always expect dest_maxlen bytes */
925 if ( rr->length < dest_maxlen)
926 {
927 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
928 /*
929 * for normal alerts rr->length is 2, while
930 * dest_maxlen is 7 if we were to handle this
931 * non-existing alert...
932 */
933 FIX ME
934 #endif
935 s->rstate=SSL_ST_READ_HEADER;
936 rr->length = 0;
937 goto start;
938 }
939
940 /* now move 'n' bytes: */
941 for ( k = 0; k < dest_maxlen; k++)
942 {
943 dest[k] = rr->data[rr->off++];
944 rr->length--;
945 }
946 *dest_len = dest_maxlen;
947 }
948 }
949
950 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
951 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
952 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
953
954 /* If we are a client, check for an incoming 'Hello Request': */
955 if ((!s->server) &&
956 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
957 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
958 (s->session != NULL) && (s->session->cipher != NULL))
959 {
960 s->d1->handshake_fragment_len = 0;
961
962 if ((s->d1->handshake_fragment[1] != 0) ||
963 (s->d1->handshake_fragment[2] != 0) ||
964 (s->d1->handshake_fragment[3] != 0))
965 {
966 al=SSL_AD_DECODE_ERROR;
967 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
968 goto err;
969 }
970
971 /* no need to check sequence number on HELLO REQUEST messages */
972
973 if (s->msg_callback)
974 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
975 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
976
977 if (SSL_is_init_finished(s) &&
978 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
979 !s->s3->renegotiate)
980 {
981 ssl3_renegotiate(s);
982 if (ssl3_renegotiate_check(s))
983 {
984 i=s->handshake_func(s);
985 if (i < 0) return(i);
986 if (i == 0)
987 {
988 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
989 return(-1);
990 }
991
992 if (!(s->mode & SSL_MODE_AUTO_RETRY))
993 {
994 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
995 {
996 BIO *bio;
997 /* In the case where we try to read application data,
998 * but we trigger an SSL handshake, we return -1 with
999 * the retry option set. Otherwise renegotiation may
1000 * cause nasty problems in the blocking world */
1001 s->rwstate=SSL_READING;
1002 bio=SSL_get_rbio(s);
1003 BIO_clear_retry_flags(bio);
1004 BIO_set_retry_read(bio);
1005 return(-1);
1006 }
1007 }
1008 }
1009 }
1010 /* we either finished a handshake or ignored the request,
1011 * now try again to obtain the (application) data we were asked for */
1012 goto start;
1013 }
1014
1015 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1016 {
1017 int alert_level = s->d1->alert_fragment[0];
1018 int alert_descr = s->d1->alert_fragment[1];
1019
1020 s->d1->alert_fragment_len = 0;
1021
1022 if (s->msg_callback)
1023 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1024 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1025
1026 if (s->info_callback != NULL)
1027 cb=s->info_callback;
1028 else if (s->ctx->info_callback != NULL)
1029 cb=s->ctx->info_callback;
1030
1031 if (cb != NULL)
1032 {
1033 j = (alert_level << 8) | alert_descr;
1034 cb(s, SSL_CB_READ_ALERT, j);
1035 }
1036
1037 if (alert_level == 1) /* warning */
1038 {
1039 s->s3->warn_alert = alert_descr;
1040 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1041 {
1042 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1043 return(0);
1044 }
1045 #if 0
1046 /* XXX: this is a possible improvement in the future */
1047 /* now check if it's a missing record */
1048 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1049 {
1050 unsigned short seq;
1051 unsigned int frag_off;
1052 unsigned char *p = &(s->d1->alert_fragment[2]);
1053
1054 n2s(p, seq);
1055 n2l3(p, frag_off);
1056
1057 dtls1_retransmit_message(s,
1058 dtls1_get_queue_priority(frag->msg_header.seq, 0),
1059 frag_off, &found);
1060 if ( ! found && SSL_in_init(s))
1061 {
1062 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1063 /* requested a message not yet sent,
1064 send an alert ourselves */
1065 ssl3_send_alert(s,SSL3_AL_WARNING,
1066 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1067 }
1068 }
1069 #endif
1070 }
1071 else if (alert_level == 2) /* fatal */
1072 {
1073 char tmp[16];
1074
1075 s->rwstate=SSL_NOTHING;
1076 s->s3->fatal_alert = alert_descr;
1077 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1078 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1079 ERR_add_error_data(2,"SSL alert number ",tmp);
1080 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1081 SSL_CTX_remove_session(s->ctx,s->session);
1082 return(0);
1083 }
1084 else
1085 {
1086 al=SSL_AD_ILLEGAL_PARAMETER;
1087 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1088 goto f_err;
1089 }
1090
1091 goto start;
1092 }
1093
1094 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1095 {
1096 s->rwstate=SSL_NOTHING;
1097 rr->length=0;
1098 return(0);
1099 }
1100
1101 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1102 {
1103 struct ccs_header_st ccs_hdr;
1104 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1105
1106 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1107
1108 if (s->version == DTLS1_BAD_VER)
1109 ccs_hdr_len = 3;
1110
1111 /* 'Change Cipher Spec' is just a single byte, so we know
1112 * exactly what the record payload has to look like */
1113 /* XDTLS: check that epoch is consistent */
1114 if ( (rr->length != ccs_hdr_len) ||
1115 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1116 {
1117 i=SSL_AD_ILLEGAL_PARAMETER;
1118 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1119 goto err;
1120 }
1121
1122 rr->length=0;
1123
1124 if (s->msg_callback)
1125 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1126 rr->data, 1, s, s->msg_callback_arg);
1127
1128 /* We can't process a CCS now, because previous handshake
1129 * messages are still missing, so just drop it.
1130 */
1131 if (!s->d1->change_cipher_spec_ok)
1132 {
1133 goto start;
1134 }
1135
1136 s->d1->change_cipher_spec_ok = 0;
1137
1138 s->s3->change_cipher_spec=1;
1139 if (!ssl3_do_change_cipher_spec(s))
1140 goto err;
1141
1142 /* do this whenever CCS is processed */
1143 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1144
1145 if (s->version == DTLS1_BAD_VER)
1146 s->d1->handshake_read_seq++;
1147
1148 goto start;
1149 }
1150
1151 /* Unexpected handshake message (Client Hello, or protocol violation) */
1152 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1153 !s->in_handshake)
1154 {
1155 struct hm_header_st msg_hdr;
1156
1157 /* this may just be a stale retransmit */
1158 dtls1_get_message_header(rr->data, &msg_hdr);
1159 if( rr->epoch != s->d1->r_epoch)
1160 {
1161 rr->length = 0;
1162 goto start;
1163 }
1164
1165 /* If we are server, we may have a repeated FINISHED of the
1166 * client here, then retransmit our CCS and FINISHED.
1167 */
1168 if (msg_hdr.type == SSL3_MT_FINISHED)
1169 {
1170 dtls1_retransmit_buffered_messages(s);
1171 rr->length = 0;
1172 goto start;
1173 }
1174
1175 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1176 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1177 {
1178 #if 0 /* worked only because C operator preferences are not as expected (and
1179 * because this is not really needed for clients except for detecting
1180 * protocol violations): */
1181 s->state=SSL_ST_BEFORE|(s->server)
1182 ?SSL_ST_ACCEPT
1183 :SSL_ST_CONNECT;
1184 #else
1185 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1186 #endif
1187 s->new_session=1;
1188 }
1189 i=s->handshake_func(s);
1190 if (i < 0) return(i);
1191 if (i == 0)
1192 {
1193 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1194 return(-1);
1195 }
1196
1197 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1198 {
1199 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1200 {
1201 BIO *bio;
1202 /* In the case where we try to read application data,
1203 * but we trigger an SSL handshake, we return -1 with
1204 * the retry option set. Otherwise renegotiation may
1205 * cause nasty problems in the blocking world */
1206 s->rwstate=SSL_READING;
1207 bio=SSL_get_rbio(s);
1208 BIO_clear_retry_flags(bio);
1209 BIO_set_retry_read(bio);
1210 return(-1);
1211 }
1212 }
1213 goto start;
1214 }
1215
1216 switch (rr->type)
1217 {
1218 default:
1219 #ifndef OPENSSL_NO_TLS
1220 /* TLS just ignores unknown message types */
1221 if (s->version == TLS1_VERSION)
1222 {
1223 rr->length = 0;
1224 goto start;
1225 }
1226 #endif
1227 al=SSL_AD_UNEXPECTED_MESSAGE;
1228 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1229 goto f_err;
1230 case SSL3_RT_CHANGE_CIPHER_SPEC:
1231 case SSL3_RT_ALERT:
1232 case SSL3_RT_HANDSHAKE:
1233 /* we already handled all of these, with the possible exception
1234 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1235 * should not happen when type != rr->type */
1236 al=SSL_AD_UNEXPECTED_MESSAGE;
1237 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1238 goto f_err;
1239 case SSL3_RT_APPLICATION_DATA:
1240 /* At this point, we were expecting handshake data,
1241 * but have application data. If the library was
1242 * running inside ssl3_read() (i.e. in_read_app_data
1243 * is set) and it makes sense to read application data
1244 * at this point (session renegotiation not yet started),
1245 * we will indulge it.
1246 */
1247 if (s->s3->in_read_app_data &&
1248 (s->s3->total_renegotiations != 0) &&
1249 ((
1250 (s->state & SSL_ST_CONNECT) &&
1251 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1252 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1253 ) || (
1254 (s->state & SSL_ST_ACCEPT) &&
1255 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1256 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1257 )
1258 ))
1259 {
1260 s->s3->in_read_app_data=2;
1261 return(-1);
1262 }
1263 else
1264 {
1265 al=SSL_AD_UNEXPECTED_MESSAGE;
1266 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1267 goto f_err;
1268 }
1269 }
1270 /* not reached */
1271
1272 f_err:
1273 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1274 err:
1275 return(-1);
1276 }
1277
1278 int
dtls1_write_app_data_bytes(SSL * s,int type,const void * buf_,int len)1279 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1280 {
1281 int i;
1282
1283 if (SSL_in_init(s) && !s->in_handshake)
1284 {
1285 i=s->handshake_func(s);
1286 if (i < 0) return(i);
1287 if (i == 0)
1288 {
1289 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1290 return -1;
1291 }
1292 }
1293
1294 if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1295 {
1296 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1297 return -1;
1298 }
1299
1300 i = dtls1_write_bytes(s, type, buf_, len);
1301 return i;
1302 }
1303
1304
1305 /* this only happens when a client hello is received and a handshake
1306 * is started. */
1307 static int
have_handshake_fragment(SSL * s,int type,unsigned char * buf,int len,int peek)1308 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1309 int len, int peek)
1310 {
1311
1312 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1313 /* (partially) satisfy request from storage */
1314 {
1315 unsigned char *src = s->d1->handshake_fragment;
1316 unsigned char *dst = buf;
1317 unsigned int k,n;
1318
1319 /* peek == 0 */
1320 n = 0;
1321 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1322 {
1323 *dst++ = *src++;
1324 len--; s->d1->handshake_fragment_len--;
1325 n++;
1326 }
1327 /* move any remaining fragment bytes: */
1328 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1329 s->d1->handshake_fragment[k] = *src++;
1330 return n;
1331 }
1332
1333 return 0;
1334 }
1335
1336
1337
1338
1339 /* Call this to write data in records of type 'type'
1340 * It will return <= 0 if not all data has been sent or non-blocking IO.
1341 */
dtls1_write_bytes(SSL * s,int type,const void * buf,int len)1342 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1343 {
1344 int i;
1345
1346 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1347 s->rwstate=SSL_NOTHING;
1348 i=do_dtls1_write(s, type, buf, len, 0);
1349 return i;
1350 }
1351
do_dtls1_write(SSL * s,int type,const unsigned char * buf,unsigned int len,int create_empty_fragment)1352 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1353 {
1354 unsigned char *p,*pseq;
1355 int i,mac_size,clear=0;
1356 int prefix_len = 0;
1357 SSL3_RECORD *wr;
1358 SSL3_BUFFER *wb;
1359 SSL_SESSION *sess;
1360 int bs;
1361 unsigned int len_with_overhead = len + SSL3_RT_DEFAULT_WRITE_OVERHEAD;
1362
1363 /* first check if there is a SSL3_BUFFER still being written
1364 * out. This will happen with non blocking IO */
1365 if (s->s3->wbuf.left != 0)
1366 {
1367 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1368 return(ssl3_write_pending(s,type,buf,len));
1369 }
1370
1371 if (s->s3->wbuf.len < len_with_overhead)
1372 {
1373 if ((p=OPENSSL_realloc(s->s3->wbuf.buf, len_with_overhead)) == NULL) {
1374 SSLerr(SSL_F_DO_DTLS1_WRITE,ERR_R_MALLOC_FAILURE);
1375 goto err;
1376 }
1377 s->s3->wbuf.buf = p;
1378 s->s3->wbuf.len = len_with_overhead;
1379 }
1380
1381 /* If we have an alert to send, lets send it */
1382 if (s->s3->alert_dispatch)
1383 {
1384 i=s->method->ssl_dispatch_alert(s);
1385 if (i <= 0)
1386 return(i);
1387 /* if it went, fall through and send more stuff */
1388 }
1389
1390 if (len == 0 && !create_empty_fragment)
1391 return 0;
1392
1393 wr= &(s->s3->wrec);
1394 wb= &(s->s3->wbuf);
1395 sess=s->session;
1396
1397 if ( (sess == NULL) ||
1398 (s->enc_write_ctx == NULL) ||
1399 (EVP_MD_CTX_md(s->write_hash) == NULL))
1400 clear=1;
1401
1402 if (clear)
1403 mac_size=0;
1404 else
1405 {
1406 mac_size=EVP_MD_CTX_size(s->write_hash);
1407 if (mac_size < 0)
1408 goto err;
1409 }
1410
1411 /* DTLS implements explicit IV, so no need for empty fragments */
1412 #if 0
1413 /* 'create_empty_fragment' is true only when this function calls itself */
1414 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1415 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1416 {
1417 /* countermeasure against known-IV weakness in CBC ciphersuites
1418 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1419 */
1420
1421 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1422 {
1423 /* recursive function call with 'create_empty_fragment' set;
1424 * this prepares and buffers the data for an empty fragment
1425 * (these 'prefix_len' bytes are sent out later
1426 * together with the actual payload) */
1427 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1428 if (prefix_len <= 0)
1429 goto err;
1430
1431 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1432 {
1433 /* insufficient space */
1434 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1435 goto err;
1436 }
1437 }
1438
1439 s->s3->empty_fragment_done = 1;
1440 }
1441 #endif
1442 p = wb->buf + prefix_len;
1443
1444 /* write the header */
1445
1446 *(p++)=type&0xff;
1447 wr->type=type;
1448
1449 *(p++)=(s->version>>8);
1450 *(p++)=s->version&0xff;
1451
1452 /* field where we are to write out packet epoch, seq num and len */
1453 pseq=p;
1454 p+=10;
1455
1456 /* lets setup the record stuff. */
1457
1458 /* Make space for the explicit IV in case of CBC.
1459 * (this is a bit of a boundary violation, but what the heck).
1460 */
1461 if ( s->enc_write_ctx &&
1462 (EVP_CIPHER_mode( s->enc_write_ctx->cipher ) & EVP_CIPH_CBC_MODE))
1463 bs = EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
1464 else
1465 bs = 0;
1466
1467 wr->data=p + bs; /* make room for IV in case of CBC */
1468 wr->length=(int)len;
1469 wr->input=(unsigned char *)buf;
1470
1471 /* we now 'read' from wr->input, wr->length bytes into
1472 * wr->data */
1473
1474 /* first we compress */
1475 if (s->compress != NULL)
1476 {
1477 if (!ssl3_do_compress(s))
1478 {
1479 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1480 goto err;
1481 }
1482 }
1483 else
1484 {
1485 memcpy(wr->data,wr->input,wr->length);
1486 wr->input=wr->data;
1487 }
1488
1489 /* we should still have the output to wr->data and the input
1490 * from wr->input. Length should be wr->length.
1491 * wr->data still points in the wb->buf */
1492
1493 if (mac_size != 0)
1494 {
1495 if(s->method->ssl3_enc->mac(s,&(p[wr->length + bs]),1) < 0)
1496 goto err;
1497 wr->length+=mac_size;
1498 }
1499
1500 /* this is true regardless of mac size */
1501 wr->input=p;
1502 wr->data=p;
1503
1504
1505 /* ssl3_enc can only have an error on read */
1506 if (bs) /* bs != 0 in case of CBC */
1507 {
1508 RAND_pseudo_bytes(p,bs);
1509 /* master IV and last CBC residue stand for
1510 * the rest of randomness */
1511 wr->length += bs;
1512 }
1513
1514 s->method->ssl3_enc->enc(s,1);
1515
1516 /* record length after mac and block padding */
1517 /* if (type == SSL3_RT_APPLICATION_DATA ||
1518 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1519
1520 /* there's only one epoch between handshake and app data */
1521
1522 s2n(s->d1->w_epoch, pseq);
1523
1524 /* XDTLS: ?? */
1525 /* else
1526 s2n(s->d1->handshake_epoch, pseq); */
1527
1528 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1529 pseq+=6;
1530 s2n(wr->length,pseq);
1531
1532 /* we should now have
1533 * wr->data pointing to the encrypted data, which is
1534 * wr->length long */
1535 wr->type=type; /* not needed but helps for debugging */
1536 wr->length+=DTLS1_RT_HEADER_LENGTH;
1537
1538 #if 0 /* this is now done at the message layer */
1539 /* buffer the record, making it easy to handle retransmits */
1540 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1541 dtls1_buffer_record(s, wr->data, wr->length,
1542 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1543 #endif
1544
1545 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1546
1547 if (create_empty_fragment)
1548 {
1549 /* we are in a recursive call;
1550 * just return the length, don't write out anything here
1551 */
1552 return wr->length;
1553 }
1554
1555 /* now let's set up wb */
1556 wb->left = prefix_len + wr->length;
1557 wb->offset = 0;
1558
1559 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1560 s->s3->wpend_tot=len;
1561 s->s3->wpend_buf=buf;
1562 s->s3->wpend_type=type;
1563 s->s3->wpend_ret=len;
1564
1565 /* we now just need to write the buffer */
1566 return ssl3_write_pending(s,type,buf,len);
1567 err:
1568 return -1;
1569 }
1570
1571
1572
dtls1_record_replay_check(SSL * s,DTLS1_BITMAP * bitmap)1573 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1574 {
1575 int cmp;
1576 unsigned int shift;
1577 const unsigned char *seq = s->s3->read_sequence;
1578
1579 cmp = satsub64be(seq,bitmap->max_seq_num);
1580 if (cmp > 0)
1581 {
1582 memcpy (s->s3->rrec.seq_num,seq,8);
1583 return 1; /* this record in new */
1584 }
1585 shift = -cmp;
1586 if (shift >= sizeof(bitmap->map)*8)
1587 return 0; /* stale, outside the window */
1588 else if (bitmap->map & (1UL<<shift))
1589 return 0; /* record previously received */
1590
1591 memcpy (s->s3->rrec.seq_num,seq,8);
1592 return 1;
1593 }
1594
1595
dtls1_record_bitmap_update(SSL * s,DTLS1_BITMAP * bitmap)1596 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1597 {
1598 int cmp;
1599 unsigned int shift;
1600 const unsigned char *seq = s->s3->read_sequence;
1601
1602 cmp = satsub64be(seq,bitmap->max_seq_num);
1603 if (cmp > 0)
1604 {
1605 shift = cmp;
1606 if (shift < sizeof(bitmap->map)*8)
1607 bitmap->map <<= shift, bitmap->map |= 1UL;
1608 else
1609 bitmap->map = 1UL;
1610 memcpy(bitmap->max_seq_num,seq,8);
1611 }
1612 else {
1613 shift = -cmp;
1614 if (shift < sizeof(bitmap->map)*8)
1615 bitmap->map |= 1UL<<shift;
1616 }
1617 }
1618
1619
dtls1_dispatch_alert(SSL * s)1620 int dtls1_dispatch_alert(SSL *s)
1621 {
1622 int i,j;
1623 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1624 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1625 unsigned char *ptr = &buf[0];
1626
1627 s->s3->alert_dispatch=0;
1628
1629 memset(buf, 0x00, sizeof(buf));
1630 *ptr++ = s->s3->send_alert[0];
1631 *ptr++ = s->s3->send_alert[1];
1632
1633 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1634 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1635 {
1636 s2n(s->d1->handshake_read_seq, ptr);
1637 #if 0
1638 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1639
1640 else
1641 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1642 #endif
1643
1644 #if 0
1645 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);
1646 #endif
1647 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1648 }
1649 #endif
1650
1651 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1652 if (i <= 0)
1653 {
1654 s->s3->alert_dispatch=1;
1655 /* fprintf( stderr, "not done with alert\n" ); */
1656 }
1657 else
1658 {
1659 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1660 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1661 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1662 #endif
1663 )
1664 (void)BIO_flush(s->wbio);
1665
1666 if (s->msg_callback)
1667 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1668 2, s, s->msg_callback_arg);
1669
1670 if (s->info_callback != NULL)
1671 cb=s->info_callback;
1672 else if (s->ctx->info_callback != NULL)
1673 cb=s->ctx->info_callback;
1674
1675 if (cb != NULL)
1676 {
1677 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1678 cb(s,SSL_CB_WRITE_ALERT,j);
1679 }
1680 }
1681 return(i);
1682 }
1683
1684
1685 static DTLS1_BITMAP *
dtls1_get_bitmap(SSL * s,SSL3_RECORD * rr,unsigned int * is_next_epoch)1686 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1687 {
1688
1689 *is_next_epoch = 0;
1690
1691 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1692 if (rr->epoch == s->d1->r_epoch)
1693 return &s->d1->bitmap;
1694
1695 /* Only HM and ALERT messages can be from the next epoch */
1696 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1697 (rr->type == SSL3_RT_HANDSHAKE ||
1698 rr->type == SSL3_RT_ALERT))
1699 {
1700 *is_next_epoch = 1;
1701 return &s->d1->next_bitmap;
1702 }
1703
1704 return NULL;
1705 }
1706
1707 #if 0
1708 static int
1709 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1710 unsigned long *offset)
1711 {
1712
1713 /* alerts are passed up immediately */
1714 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1715 rr->type == SSL3_RT_ALERT)
1716 return 0;
1717
1718 /* Only need to buffer if a handshake is underway.
1719 * (this implies that Hello Request and Client Hello are passed up
1720 * immediately) */
1721 if ( SSL_in_init(s))
1722 {
1723 unsigned char *data = rr->data;
1724 /* need to extract the HM/CCS sequence number here */
1725 if ( rr->type == SSL3_RT_HANDSHAKE ||
1726 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1727 {
1728 unsigned short seq_num;
1729 struct hm_header_st msg_hdr;
1730 struct ccs_header_st ccs_hdr;
1731
1732 if ( rr->type == SSL3_RT_HANDSHAKE)
1733 {
1734 dtls1_get_message_header(data, &msg_hdr);
1735 seq_num = msg_hdr.seq;
1736 *offset = msg_hdr.frag_off;
1737 }
1738 else
1739 {
1740 dtls1_get_ccs_header(data, &ccs_hdr);
1741 seq_num = ccs_hdr.seq;
1742 *offset = 0;
1743 }
1744
1745 /* this is either a record we're waiting for, or a
1746 * retransmit of something we happened to previously
1747 * receive (higher layers will drop the repeat silently */
1748 if ( seq_num < s->d1->handshake_read_seq)
1749 return 0;
1750 if (rr->type == SSL3_RT_HANDSHAKE &&
1751 seq_num == s->d1->handshake_read_seq &&
1752 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1753 return 0;
1754 else if ( seq_num == s->d1->handshake_read_seq &&
1755 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1756 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1757 return 0;
1758 else
1759 {
1760 *priority = seq_num;
1761 return 1;
1762 }
1763 }
1764 else /* unknown record type */
1765 return 0;
1766 }
1767
1768 return 0;
1769 }
1770 #endif
1771
1772 void
dtls1_reset_seq_numbers(SSL * s,int rw)1773 dtls1_reset_seq_numbers(SSL *s, int rw)
1774 {
1775 unsigned char *seq;
1776 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1777
1778 if ( rw & SSL3_CC_READ)
1779 {
1780 seq = s->s3->read_sequence;
1781 s->d1->r_epoch++;
1782 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1783 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1784 }
1785 else
1786 {
1787 seq = s->s3->write_sequence;
1788 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1789 s->d1->w_epoch++;
1790 }
1791
1792 memset(seq, 0x00, seq_bytes);
1793 }
1794
1795
1796 static void
dtls1_clear_timeouts(SSL * s)1797 dtls1_clear_timeouts(SSL *s)
1798 {
1799 memset(&(s->d1->timeout), 0x00, sizeof(struct dtls1_timeout_st));
1800 }
1801