1/* ssl/d1_both.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 <limits.h>
117#include <string.h>
118#include <stdio.h>
119#include "ssl_locl.h"
120#include <openssl/buffer.h>
121#include <openssl/rand.h>
122#include <openssl/objects.h>
123#include <openssl/evp.h>
124#include <openssl/x509.h>
125
126
127/* XDTLS: figure out the right values */
128static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
129
130static unsigned int dtls1_min_mtu(void);
131static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
132static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
133 unsigned long frag_len);
134static unsigned char *dtls1_write_message_header(SSL *s,
135 unsigned char *p);
136static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
137 unsigned long len, unsigned short seq_num, unsigned long frag_off,
138 unsigned long frag_len);
139static int dtls1_retransmit_buffered_messages(SSL *s);
140static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
141 long max, int *ok);
142static void dtls1_process_handshake_fragment(SSL *s, int frag_len);
143
144static hm_fragment *
145dtls1_hm_fragment_new(unsigned long frag_len)
146 {
147 hm_fragment *frag = NULL;
148 unsigned char *buf = NULL;
149
150 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
151 if ( frag == NULL)
152 return NULL;
153
154 buf = (unsigned char *)OPENSSL_malloc(frag_len
155 + DTLS1_HM_HEADER_LENGTH);
156 if ( buf == NULL)
157 {
158 OPENSSL_free(frag);
159 return NULL;
160 }
161
162 frag->fragment = buf;
163
164 return frag;
165 }
166
167static void
168dtls1_hm_fragment_free(hm_fragment *frag)
169 {
170 OPENSSL_free(frag->fragment);
171 OPENSSL_free(frag);
172 }
173
174/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
175int dtls1_do_write(SSL *s, int type)
176 {
177 int ret;
178 int curr_mtu;
179 unsigned int len, frag_off;
180
181 /* AHA! Figure out the MTU, and stick to the right size */
182 if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
183 {
184 s->d1->mtu =
185 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
186
187 /* I've seen the kernel return bogus numbers when it doesn't know
188 * (initial write), so just make sure we have a reasonable number */
189 if ( s->d1->mtu < dtls1_min_mtu())
190 {
191 s->d1->mtu = 0;
192 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
193 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
194 s->d1->mtu, NULL);
195 }
196 }
197#if 0
198 mtu = s->d1->mtu;
199
200 fprintf(stderr, "using MTU = %d\n", mtu);
201
202 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
203
204 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
205
206 if ( curr_mtu > 0)
207 mtu = curr_mtu;
208 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
209 return ret;
210
211 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
212 {
213 ret = BIO_flush(SSL_get_wbio(s));
214 if ( ret <= 0)
215 return ret;
216 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
217 }
218
219 OPENSSL_assert(mtu > 0); /* should have something reasonable now */
220
221#endif
222
223 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
224 OPENSSL_assert(s->init_num ==
225 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
226
227 frag_off = 0;
228 while( s->init_num)
229 {
230 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
231 DTLS1_RT_HEADER_LENGTH;
232
233 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
234 {
235 /* grr.. we could get an error if MTU picked was wrong */
236 ret = BIO_flush(SSL_get_wbio(s));
237 if ( ret <= 0)
238 return ret;
239 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH;
240 }
241
242 if ( s->init_num > curr_mtu)
243 len = curr_mtu;
244 else
245 len = s->init_num;
246
247
248 /* XDTLS: this function is too long. split out the CCS part */
249 if ( type == SSL3_RT_HANDSHAKE)
250 {
251 if ( s->init_off != 0)
252 {
253 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
254 s->init_off -= DTLS1_HM_HEADER_LENGTH;
255 s->init_num += DTLS1_HM_HEADER_LENGTH;
256
257 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
258 if ( len <= DTLS1_HM_HEADER_LENGTH)
259 len += DTLS1_HM_HEADER_LENGTH;
260 }
261
262 dtls1_fix_message_header(s, frag_off,
263 len - DTLS1_HM_HEADER_LENGTH);
264
265 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
266
267 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
268 }
269
270 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
271 len);
272 if (ret < 0)
273 {
274 /* might need to update MTU here, but we don't know
275 * which previous packet caused the failure -- so can't
276 * really retransmit anything. continue as if everything
277 * is fine and wait for an alert to handle the
278 * retransmit
279 */
280 if ( BIO_ctrl(SSL_get_wbio(s),
281 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL))
282 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
283 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
284 else
285 return(-1);
286 }
287 else
288 {
289
290 /* bad if this assert fails, only part of the handshake
291 * message got sent. but why would this happen? */
292 OPENSSL_assert(len == (unsigned int)ret);
293
294 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
295 /* should not be done for 'Hello Request's, but in that case
296 * we'll ignore the result anyway */
297 ssl3_finish_mac(s,
298 (unsigned char *)&s->init_buf->data[s->init_off +
299 DTLS1_HM_HEADER_LENGTH], ret - DTLS1_HM_HEADER_LENGTH);
300
301 if (ret == s->init_num)
302 {
303 if (s->msg_callback)
304 s->msg_callback(1, s->version, type, s->init_buf->data,
305 (size_t)(s->init_off + s->init_num), s,
306 s->msg_callback_arg);
307
308 s->init_off = 0; /* done writing this message */
309 s->init_num = 0;
310
311 return(1);
312 }
313 s->init_off+=ret;
314 s->init_num-=ret;
315 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
316 }
317 }
318 return(0);
319 }
320
321
322/* Obtain handshake message of message type 'mt' (any if mt == -1),
323 * maximum acceptable body length 'max'.
324 * Read an entire handshake message. Handshake messages arrive in
325 * fragments.
326 */
327long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
328 {
329 int i, al;
330
331 /* s3->tmp is used to store messages that are unexpected, caused
332 * by the absence of an optional handshake message */
333 if (s->s3->tmp.reuse_message)
334 {
335 s->s3->tmp.reuse_message=0;
336 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
337 {
338 al=SSL_AD_UNEXPECTED_MESSAGE;
339 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
340 goto f_err;
341 }
342 *ok=1;
343 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
344 s->init_num = (int)s->s3->tmp.message_size;
345 return s->init_num;
346 }
347
348 do
349 {
350 if ( s->d1->r_msg_hdr.frag_off == 0)
351 {
352 /* s->d1->r_message_header.msg_len = 0; */
353 memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
354 }
355
356 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
357 if ( i == DTLS1_HM_BAD_FRAGMENT ||
358 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
359 continue;
360 else if ( i <= 0 && !*ok)
361 return i;
362
363 if (s->d1->r_msg_hdr.msg_len == (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
364 {
365 memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
366
367 s->d1->handshake_read_seq++;
368 /* we just read a handshake message from the other side:
369 * this means that we don't need to retransmit of the
370 * buffered messages.
371 * XDTLS: may be able clear out this
372 * buffer a little sooner (i.e if an out-of-order
373 * handshake message/record is received at the record
374 * layer.
375 * XDTLS: exception is that the server needs to
376 * know that change cipher spec and finished messages
377 * have been received by the client before clearing this
378 * buffer. this can simply be done by waiting for the
379 * first data segment, but is there a better way? */
380 dtls1_clear_record_buffer(s);
381
382 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
383 return s->init_num - DTLS1_HM_HEADER_LENGTH;
384 }
385 else
386 s->d1->r_msg_hdr.frag_off = i;
387 } while(1) ;
388
389f_err:
390 ssl3_send_alert(s,SSL3_AL_FATAL,al);
391 *ok = 0;
392 return -1;
393 }
394
395
396static int
397dtls1_retrieve_buffered_fragment(SSL *s, unsigned long *copied)
398 {
399 /* (0) check whether the desired fragment is available
400 * if so:
401 * (1) copy over the fragment to s->init_buf->data[]
402 * (2) update s->init_num
403 */
404 pitem *item;
405 hm_fragment *frag;
406 unsigned long overlap;
407 unsigned char *p;
408
409 item = pqueue_peek(s->d1->buffered_messages);
410 if ( item == NULL)
411 return 0;
412
413 frag = (hm_fragment *)item->data;
414
415 if ( s->d1->handshake_read_seq == frag->msg_header.seq &&
416 frag->msg_header.frag_off <= (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
417 {
418 pqueue_pop(s->d1->buffered_messages);
419 overlap = s->init_num - DTLS1_HM_HEADER_LENGTH
420 - frag->msg_header.frag_off;
421
422 p = frag->fragment;
423
424 memcpy(&s->init_buf->data[s->init_num],
425 p + DTLS1_HM_HEADER_LENGTH + overlap,
426 frag->msg_header.frag_len - overlap);
427
428 OPENSSL_free(frag->fragment);
429 OPENSSL_free(frag);
430 pitem_free(item);
431
432 *copied = frag->msg_header.frag_len - overlap;
433 return *copied;
434 }
435 else
436 return 0;
437 }
438
439
440static int
441dtls1_buffer_handshake_fragment(SSL *s, struct hm_header_st* msg_hdr)
442{
443 hm_fragment *frag = NULL;
444 pitem *item = NULL;
445 PQ_64BIT seq64;
446
447 frag = dtls1_hm_fragment_new(msg_hdr->frag_len);
448 if ( frag == NULL)
449 goto err;
450
451 memcpy(frag->fragment, &(s->init_buf->data[s->init_num]),
452 msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH);
453
454 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
455
456 pq_64bit_init(&seq64);
457 pq_64bit_assign_word(&seq64, msg_hdr->seq);
458
459 item = pitem_new(seq64, frag);
460 if ( item == NULL)
461 goto err;
462
463 pq_64bit_free(&seq64);
464
465 pqueue_insert(s->d1->buffered_messages, item);
466 return 1;
467
468err:
469 if ( frag != NULL) dtls1_hm_fragment_free(frag);
470 if ( item != NULL) OPENSSL_free(item);
471 return 0;
472}
473
474
475static void
476dtls1_process_handshake_fragment(SSL *s, int frag_len)
477 {
478 unsigned char *p;
479
480 p = (unsigned char *)s->init_buf->data;
481
482 ssl3_finish_mac(s, &p[s->init_num - frag_len], frag_len);
483 }
484
485
486static int
487dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st *msg_hdr, int *ok)
488 {
489 int i;
490 unsigned char *p;
491
492 /* make sure there's enough room to read this fragment */
493 if ( (int)msg_hdr->frag_len && !BUF_MEM_grow_clean(s->init_buf,
494 (int)msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH + s->init_num))
495 {
496 SSLerr(SSL_F_DTLS1_PROCESS_OUT_OF_SEQ_MESSAGE,ERR_R_BUF_LIB);
497 goto err;
498 }
499
500 p = (unsigned char *)s->init_buf->data;
501
502 /* read the body of the fragment (header has already been read */
503 if ( msg_hdr->frag_len > 0)
504 {
505 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
506 &p[s->init_num],
507 msg_hdr->frag_len,0);
508 if (i <= 0)
509 {
510 *ok = 0;
511 return i;
512 }
513 }
514
515 if ( msg_hdr->seq > s->d1->handshake_read_seq)
516 dtls1_buffer_handshake_fragment(s, msg_hdr);
517 else
518 OPENSSL_assert(msg_hdr->seq < s->d1->handshake_read_seq);
519
520 return DTLS1_HM_FRAGMENT_RETRY;
521err:
522 *ok = 0;
523 return -1;
524 }
525
526
527static long
528dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
529 {
530 unsigned char *p;
531 unsigned long l, frag_off, frag_len;
532 int i,al;
533 struct hm_header_st msg_hdr;
534 unsigned long overlap;
535
536 /* see if we have the required fragment already */
537 if (dtls1_retrieve_buffered_fragment(s, &l))
538 {
539 /* compute MAC, remove fragment headers */
540 dtls1_process_handshake_fragment(s, l);
541 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
542 s->state = stn;
543 return 1;
544 }
545
546 /* get a handshake fragment from the record layer */
547 p = (unsigned char *)s->init_buf->data;
548
549 /* read handshake message header */
550 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],
551 DTLS1_HM_HEADER_LENGTH, 0);
552 if (i <= 0) /* nbio, or an error */
553 {
554 s->rwstate=SSL_READING;
555 *ok = 0;
556 return i;
557 }
558
559 OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
560
561 p += s->init_num;
562 /* parse the message fragment header */
563
564 dtls1_get_message_header(p, &msg_hdr);
565
566 /*
567 * if this is a future (or stale) message it gets buffered
568 * (or dropped)--no further processing at this time
569 */
570 if ( msg_hdr.seq != s->d1->handshake_read_seq)
571 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
572
573 l = msg_hdr.msg_len;
574 frag_off = msg_hdr.frag_off;
575 frag_len = msg_hdr.frag_len;
576
577 /* sanity checking */
578 if ( frag_off + frag_len > l)
579 {
580 al=SSL_AD_ILLEGAL_PARAMETER;
581 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
582 goto f_err;
583 }
584
585 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
586 p[0] == SSL3_MT_HELLO_REQUEST)
587 {
588 /* The server may always send 'Hello Request' messages --
589 * we are doing a handshake anyway now, so ignore them
590 * if their format is correct. Does not count for
591 * 'Finished' MAC. */
592 if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
593 {
594 if (s->msg_callback)
595 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
596 p, DTLS1_HM_HEADER_LENGTH, s,
597 s->msg_callback_arg);
598
599 s->init_num = 0;
600 return dtls1_get_message_fragment(s, st1, stn,
601 max, ok);
602 }
603 else /* Incorrectly formated Hello request */
604 {
605 al=SSL_AD_UNEXPECTED_MESSAGE;
606 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
607 goto f_err;
608 }
609 }
610
611 /* XDTLS: do a sanity check on the fragment */
612
613 s->init_num += i;
614
615 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
616 {
617 /* BUF_MEM_grow takes an 'int' parameter */
618 if (l > (INT_MAX-DTLS1_HM_HEADER_LENGTH))
619 {
620 al=SSL_AD_ILLEGAL_PARAMETER;
621 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
622 goto f_err;
623 }
624 if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l
625 + DTLS1_HM_HEADER_LENGTH))
626 {
627 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
628 goto err;
629 }
630 /* Only do this test when we're reading the expected message.
631 * Stale messages will be dropped and future messages will be buffered */
632 if ( l > (unsigned long)max)
633 {
634 al=SSL_AD_ILLEGAL_PARAMETER;
635 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
636 goto f_err;
637 }
638
639 s->s3->tmp.message_size=l;
640 }
641
642 if ( frag_len > (unsigned long)max)
643 {
644 al=SSL_AD_ILLEGAL_PARAMETER;
645 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
646 goto f_err;
647 }
648 if ( frag_len + s->init_num > (INT_MAX - DTLS1_HM_HEADER_LENGTH))
649 {
650 al=SSL_AD_ILLEGAL_PARAMETER;
651 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
652 goto f_err;
653 }
654
655 if ( frag_len & !BUF_MEM_grow_clean(s->init_buf, (int)frag_len
656 + DTLS1_HM_HEADER_LENGTH + s->init_num))
657 {
658 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
659 goto err;
660 }
661
662 if ( s->d1->r_msg_hdr.frag_off == 0)
663 {
664 s->s3->tmp.message_type = msg_hdr.type;
665 s->d1->r_msg_hdr.type = msg_hdr.type;
666 s->d1->r_msg_hdr.msg_len = l;
667 /* s->d1->r_msg_hdr.seq = seq_num; */
668 }
669
670 /* XDTLS: ressurect this when restart is in place */
671 s->state=stn;
672
673 /* next state (stn) */
674 p = (unsigned char *)s->init_buf->data;
675
676 if ( frag_len > 0)
677 {
678 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
679 &p[s->init_num],
680 frag_len,0);
681 /* XDTLS: fix this--message fragments cannot span multiple packets */
682 if (i <= 0)
683 {
684 s->rwstate=SSL_READING;
685 *ok = 0;
686 return i;
687 }
688 }
689 else
690 i = 0;
691
692 /* XDTLS: an incorrectly formatted fragment should cause the
693 * handshake to fail */
694 OPENSSL_assert(i == (int)frag_len);
695
696#if 0
697 /* Successfully read a fragment.
698 * It may be (1) out of order, or
699 * (2) it's a repeat, in which case we dump it
700 * (3) the one we are expecting next (maybe with overlap)
701 * If it is next one, it may overlap with previously read bytes
702 */
703
704 /* case (1): buffer the future fragment
705 * (we can treat fragments from a future message the same
706 * as future fragments from the message being currently read, since
707 * they are sematically simply out of order.
708 */
709 if ( msg_hdr.seq > s->d1->handshake_read_seq ||
710 frag_off > s->init_num - DTLS1_HM_HEADER_LENGTH)
711 {
712 dtls1_buffer_handshake_fragment(s, &msg_hdr);
713 return DTLS1_HM_FRAGMENT_RETRY;
714 }
715
716 /* case (2): drop the entire fragment, and try again */
717 if ( msg_hdr.seq < s->d1->handshake_read_seq ||
718 frag_off + frag_len < s->init_num - DTLS1_HM_HEADER_LENGTH)
719 {
720 s->init_num -= DTLS1_HM_HEADER_LENGTH;
721 return DTLS1_HM_FRAGMENT_RETRY;
722 }
723#endif
724
725 /* case (3): received a immediately useful fragment. Determine the
726 * possible overlap and copy the fragment.
727 */
728 overlap = (s->init_num - DTLS1_HM_HEADER_LENGTH) - frag_off;
729
730 /* retain the header for the first fragment */
731 if ( s->init_num > DTLS1_HM_HEADER_LENGTH)
732 {
733 memmove(&(s->init_buf->data[s->init_num]),
734 &(s->init_buf->data[s->init_num + DTLS1_HM_HEADER_LENGTH + overlap]),
735 frag_len - overlap);
736
737 s->init_num += frag_len - overlap;
738 }
739 else
740 s->init_num += frag_len;
741
742 dtls1_process_handshake_fragment(s, frag_len - overlap);
743
744 if (s->msg_callback)
745 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
746 (size_t)s->init_num, s,
747 s->msg_callback_arg);
748 *ok=1;
749
750 return s->init_num;
751
752f_err:
753 ssl3_send_alert(s,SSL3_AL_FATAL,al);
754 s->init_num = 0;
755err:
756 *ok=0;
757 return(-1);
758 }
759
760int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
761 {
762 unsigned char *p,*d;
763 int i;
764 unsigned long l;
765
766 if (s->state == a)
767 {
768 d=(unsigned char *)s->init_buf->data;
769 p= &(d[DTLS1_HM_HEADER_LENGTH]);
770
771 i=s->method->ssl3_enc->final_finish_mac(s,
772 &(s->s3->finish_dgst1),
773 &(s->s3->finish_dgst2),
774 sender,slen,s->s3->tmp.finish_md);
775 s->s3->tmp.finish_md_len = i;
776 memcpy(p, s->s3->tmp.finish_md, i);
777 p+=i;
778 l=i;
779
780#ifdef OPENSSL_SYS_WIN16
781 /* MSVC 1.5 does not clear the top bytes of the word unless
782 * I do this.
783 */
784 l&=0xffff;
785#endif
786
787 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
788 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
789 s->init_off=0;
790
791 /* buffer the message to handle re-xmits */
792 dtls1_buffer_message(s, 0);
793
794 s->state=b;
795 }
796
797 /* SSL3_ST_SEND_xxxxxx_HELLO_B */
798 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
799 }
800
801/* for these 2 messages, we need to
802 * ssl->enc_read_ctx re-init
803 * ssl->s3->read_sequence zero
804 * ssl->s3->read_mac_secret re-init
805 * ssl->session->read_sym_enc assign
806 * ssl->session->read_compression assign
807 * ssl->session->read_hash assign
808 */
809int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
810 {
811 unsigned char *p;
812
813 if (s->state == a)
814 {
815 p=(unsigned char *)s->init_buf->data;
816 *p++=SSL3_MT_CCS;
817 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
818 s->d1->next_handshake_write_seq++;
819 s2n(s->d1->handshake_write_seq,p);
820
821 s->init_num=DTLS1_CCS_HEADER_LENGTH;
822 s->init_off=0;
823
824 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
825 s->d1->handshake_write_seq, 0, 0);
826
827 /* buffer the message to handle re-xmits */
828 dtls1_buffer_message(s, 1);
829
830 s->state=b;
831 }
832
833 /* SSL3_ST_CW_CHANGE_B */
834 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
835 }
836
837unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
838 {
839 unsigned char *p;
840 int n,i;
841 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
842 BUF_MEM *buf;
843 X509_STORE_CTX xs_ctx;
844 X509_OBJECT obj;
845
846 /* TLSv1 sends a chain with nothing in it, instead of an alert */
847 buf=s->init_buf;
848 if (!BUF_MEM_grow_clean(buf,10))
849 {
850 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
851 return(0);
852 }
853 if (x != NULL)
854 {
855 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
856 {
857 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
858 return(0);
859 }
860
861 for (;;)
862 {
863 n=i2d_X509(x,NULL);
864 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
865 {
866 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
867 return(0);
868 }
869 p=(unsigned char *)&(buf->data[l]);
870 l2n3(n,p);
871 i2d_X509(x,&p);
872 l+=n+3;
873 if (X509_NAME_cmp(X509_get_subject_name(x),
874 X509_get_issuer_name(x)) == 0) break;
875
876 i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
877 X509_get_issuer_name(x),&obj);
878 if (i <= 0) break;
879 x=obj.data.x509;
880 /* Count is one too high since the X509_STORE_get uped the
881 * ref count */
882 X509_free(x);
883 }
884
885 X509_STORE_CTX_cleanup(&xs_ctx);
886 }
887
888 /* Thawte special :-) */
889 if (s->ctx->extra_certs != NULL)
890 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
891 {
892 x=sk_X509_value(s->ctx->extra_certs,i);
893 n=i2d_X509(x,NULL);
894 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
895 {
896 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
897 return(0);
898 }
899 p=(unsigned char *)&(buf->data[l]);
900 l2n3(n,p);
901 i2d_X509(x,&p);
902 l+=n+3;
903 }
904
905 l-= (3 + DTLS1_HM_HEADER_LENGTH);
906
907 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
908 l2n3(l,p);
909 l+=3;
910 p=(unsigned char *)&(buf->data[0]);
911 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
912
913 l+=DTLS1_HM_HEADER_LENGTH;
914 return(l);
915 }
916
917int dtls1_read_failed(SSL *s, int code)
918 {
919 DTLS1_STATE *state;
920 BIO *bio;
921 int send_alert = 0;
922
923 if ( code > 0)
924 {
925 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
926 return 1;
927 }
928
929 bio = SSL_get_rbio(s);
930 if ( ! BIO_dgram_recv_timedout(bio))
931 {
932 /* not a timeout, none of our business,
933 let higher layers handle this. in fact it's probably an error */
934 return code;
935 }
936
937 if ( ! SSL_in_init(s)) /* done, no need to send a retransmit */
938 {
939 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
940 return code;
941 }
942
943 state = s->d1;
944 state->timeout.num_alerts++;
945 if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
946 {
947 /* fail the connection, enough alerts have been sent */
948 SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
949 return 0;
950 }
951
952 state->timeout.read_timeouts++;
953 if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
954 {
955 send_alert = 1;
956 state->timeout.read_timeouts = 1;
957 }
958
959
960#if 0 /* for now, each alert contains only one record number */
961 item = pqueue_peek(state->rcvd_records);
962 if ( item )
963 {
964 /* send an alert immediately for all the missing records */
965 }
966 else
967#endif
968
969#if 0 /* no more alert sending, just retransmit the last set of messages */
970 if ( send_alert)
971 ssl3_send_alert(s,SSL3_AL_WARNING,
972 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
973#endif
974
975 return dtls1_retransmit_buffered_messages(s) ;
976 }
977
978
979static int
980dtls1_retransmit_buffered_messages(SSL *s)
981 {
982 pqueue sent = s->d1->sent_messages;
983 piterator iter;
984 pitem *item;
985 hm_fragment *frag;
986 int found = 0;
987
988 iter = pqueue_iterator(sent);
989
990 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
991 {
992 frag = (hm_fragment *)item->data;
993 if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 &&
994 found)
995 {
996 fprintf(stderr, "dtls1_retransmit_message() failed\n");
997 return -1;
998 }
999 }
1000
1001 return 1;
1002 }
1003
1004#if 0
1005static dtls1_message_buffer *
1006dtls1_message_buffer_new(unsigned int len)
1007 {
1008 dtls1_message_buffer *msg_buf;
1009
1010 msg_buf = (dtls1_message_buffer *)
1011 OPENSSL_malloc(sizeof(dtls1_message_buffer));
1012 if ( msg_buf == NULL)
1013 return NULL;
1014
1015 memset(msg_buf, 0x00, sizeof(dtls1_message_buffer));
1016
1017 msg_buf->data = (unsigned char *) OPENSSL_malloc(len);
1018 if ( msg_buf->data == NULL)
1019 {
1020 OPENSSL_free(msg_buf);
1021 return NULL;
1022 }
1023
1024 memset(msg_buf->data, 0x00, len);
1025 return msg_buf;
1026 }
1027#endif
1028
1029#if 0
1030static void
1031dtls1_message_buffer_free(dtls1_message_buffer *msg_buf)
1032 {
1033 if (msg_buf != NULL)
1034 {
1035 OPENSSL_free(msg_buf->data);
1036 OPENSSL_free(msg_buf);
1037 }
1038 }
1039#endif
1040
1041int
1042dtls1_buffer_message(SSL *s, int is_ccs)
1043 {
1044 pitem *item;
1045 hm_fragment *frag;
1046 PQ_64BIT seq64;
1047
1048 /* this function is called immediately after a message has
1049 * been serialized */
1050 OPENSSL_assert(s->init_off == 0);
1051
1052 frag = dtls1_hm_fragment_new(s->init_num);
1053
1054 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1055
1056 if ( is_ccs)
1057 {
1058 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1059 DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1060 }
1061 else
1062 {
1063 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1064 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1065 }
1066
1067 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1068 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1069 frag->msg_header.type = s->d1->w_msg_hdr.type;
1070 frag->msg_header.frag_off = 0;
1071 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1072 frag->msg_header.is_ccs = is_ccs;
1073
1074 pq_64bit_init(&seq64);
1075 pq_64bit_assign_word(&seq64, frag->msg_header.seq);
1076
1077 item = pitem_new(seq64, frag);
1078 pq_64bit_free(&seq64);
1079 if ( item == NULL)
1080 {
1081 dtls1_hm_fragment_free(frag);
1082 return 0;
1083 }
1084
1085#if 0
1086 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1087 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1088 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1089#endif
1090
1091 pqueue_insert(s->d1->sent_messages, item);
1092 return 1;
1093 }
1094
1095int
1096dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1097 int *found)
1098 {
1099 int ret;
1100 /* XDTLS: for now assuming that read/writes are blocking */
1101 pitem *item;
1102 hm_fragment *frag ;
1103 unsigned long header_length;
1104 PQ_64BIT seq64;
1105
1106 /*
1107 OPENSSL_assert(s->init_num == 0);
1108 OPENSSL_assert(s->init_off == 0);
1109 */
1110
1111 /* XDTLS: the requested message ought to be found, otherwise error */
1112 pq_64bit_init(&seq64);
1113 pq_64bit_assign_word(&seq64, seq);
1114
1115 item = pqueue_find(s->d1->sent_messages, seq64);
1116 pq_64bit_free(&seq64);
1117 if ( item == NULL)
1118 {
1119 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1120 *found = 0;
1121 return 0;
1122 }
1123
1124 *found = 1;
1125 frag = (hm_fragment *)item->data;
1126
1127 if ( frag->msg_header.is_ccs)
1128 header_length = DTLS1_CCS_HEADER_LENGTH;
1129 else
1130 header_length = DTLS1_HM_HEADER_LENGTH;
1131
1132 memcpy(s->init_buf->data, frag->fragment,
1133 frag->msg_header.msg_len + header_length);
1134 s->init_num = frag->msg_header.msg_len + header_length;
1135
1136 dtls1_set_message_header_int(s, frag->msg_header.type,
1137 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1138 frag->msg_header.frag_len);
1139
1140 s->d1->retransmitting = 1;
1141 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1142 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1143 s->d1->retransmitting = 0;
1144
1145 BIO_flush(SSL_get_wbio(s));
1146 return ret;
1147 }
1148
1149/* call this function when the buffered messages are no longer needed */
1150void
1151dtls1_clear_record_buffer(SSL *s)
1152 {
1153 pitem *item;
1154
1155 for(item = pqueue_pop(s->d1->sent_messages);
1156 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1157 {
1158 dtls1_hm_fragment_free((hm_fragment *)item->data);
1159 pitem_free(item);
1160 }
1161 }
1162
1163
1164unsigned char *
1165dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1166 unsigned long len, unsigned long frag_off, unsigned long frag_len)
1167 {
1168 if ( frag_off == 0)
1169 {
1170 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1171 s->d1->next_handshake_write_seq++;
1172 }
1173
1174 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1175 frag_off, frag_len);
1176
1177 return p += DTLS1_HM_HEADER_LENGTH;
1178 }
1179
1180
1181/* don't actually do the writing, wait till the MTU has been retrieved */
1182static void
1183dtls1_set_message_header_int(SSL *s, unsigned char mt,
1184 unsigned long len, unsigned short seq_num, unsigned long frag_off,
1185 unsigned long frag_len)
1186 {
1187 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1188
1189 msg_hdr->type = mt;
1190 msg_hdr->msg_len = len;
1191 msg_hdr->seq = seq_num;
1192 msg_hdr->frag_off = frag_off;
1193 msg_hdr->frag_len = frag_len;
1194}
1195
1196static void
1197dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1198 unsigned long frag_len)
1199 {
1200 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1201
1202 msg_hdr->frag_off = frag_off;
1203 msg_hdr->frag_len = frag_len;
1204 }
1205
1206static unsigned char *
1207dtls1_write_message_header(SSL *s, unsigned char *p)
1208 {
1209 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1210
1211 *p++ = msg_hdr->type;
1212 l2n3(msg_hdr->msg_len, p);
1213
1214 s2n(msg_hdr->seq, p);
1215 l2n3(msg_hdr->frag_off, p);
1216 l2n3(msg_hdr->frag_len, p);
1217
1218 return p;
1219 }
1220
1221static unsigned int
1222dtls1_min_mtu(void)
1223 {
1224 return
1225 g_probable_mtu[(sizeof(g_probable_mtu) /
1226 sizeof(g_probable_mtu[0])) - 1];
1227 }
1228
1229static unsigned int
1230dtls1_guess_mtu(unsigned int curr_mtu)
1231 {
1232 size_t i;
1233
1234 if ( curr_mtu == 0 )
1235 return g_probable_mtu[0] ;
1236
1237 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1238 if ( curr_mtu > g_probable_mtu[i])
1239 return g_probable_mtu[i];
1240
1241 return curr_mtu;
1242 }
1243
1244void
1245dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1246 {
1247 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1248 msg_hdr->type = *(data++);
1249 n2l3(data, msg_hdr->msg_len);
1250
1251 n2s(data, msg_hdr->seq);
1252 n2l3(data, msg_hdr->frag_off);
1253 n2l3(data, msg_hdr->frag_len);
1254 }
1255
1256void
1257dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1258 {
1259 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1260
1261 ccs_hdr->type = *(data++);
1262 n2s(data, ccs_hdr->seq);
1263}
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 <limits.h>
117#include <string.h>
118#include <stdio.h>
119#include "ssl_locl.h"
120#include <openssl/buffer.h>
121#include <openssl/rand.h>
122#include <openssl/objects.h>
123#include <openssl/evp.h>
124#include <openssl/x509.h>
125
126
127/* XDTLS: figure out the right values */
128static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
129
130static unsigned int dtls1_min_mtu(void);
131static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
132static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
133 unsigned long frag_len);
134static unsigned char *dtls1_write_message_header(SSL *s,
135 unsigned char *p);
136static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
137 unsigned long len, unsigned short seq_num, unsigned long frag_off,
138 unsigned long frag_len);
139static int dtls1_retransmit_buffered_messages(SSL *s);
140static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
141 long max, int *ok);
142static void dtls1_process_handshake_fragment(SSL *s, int frag_len);
143
144static hm_fragment *
145dtls1_hm_fragment_new(unsigned long frag_len)
146 {
147 hm_fragment *frag = NULL;
148 unsigned char *buf = NULL;
149
150 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
151 if ( frag == NULL)
152 return NULL;
153
154 buf = (unsigned char *)OPENSSL_malloc(frag_len
155 + DTLS1_HM_HEADER_LENGTH);
156 if ( buf == NULL)
157 {
158 OPENSSL_free(frag);
159 return NULL;
160 }
161
162 frag->fragment = buf;
163
164 return frag;
165 }
166
167static void
168dtls1_hm_fragment_free(hm_fragment *frag)
169 {
170 OPENSSL_free(frag->fragment);
171 OPENSSL_free(frag);
172 }
173
174/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
175int dtls1_do_write(SSL *s, int type)
176 {
177 int ret;
178 int curr_mtu;
179 unsigned int len, frag_off;
180
181 /* AHA! Figure out the MTU, and stick to the right size */
182 if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
183 {
184 s->d1->mtu =
185 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
186
187 /* I've seen the kernel return bogus numbers when it doesn't know
188 * (initial write), so just make sure we have a reasonable number */
189 if ( s->d1->mtu < dtls1_min_mtu())
190 {
191 s->d1->mtu = 0;
192 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
193 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
194 s->d1->mtu, NULL);
195 }
196 }
197#if 0
198 mtu = s->d1->mtu;
199
200 fprintf(stderr, "using MTU = %d\n", mtu);
201
202 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
203
204 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
205
206 if ( curr_mtu > 0)
207 mtu = curr_mtu;
208 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
209 return ret;
210
211 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
212 {
213 ret = BIO_flush(SSL_get_wbio(s));
214 if ( ret <= 0)
215 return ret;
216 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
217 }
218
219 OPENSSL_assert(mtu > 0); /* should have something reasonable now */
220
221#endif
222
223 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
224 OPENSSL_assert(s->init_num ==
225 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
226
227 frag_off = 0;
228 while( s->init_num)
229 {
230 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
231 DTLS1_RT_HEADER_LENGTH;
232
233 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
234 {
235 /* grr.. we could get an error if MTU picked was wrong */
236 ret = BIO_flush(SSL_get_wbio(s));
237 if ( ret <= 0)
238 return ret;
239 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH;
240 }
241
242 if ( s->init_num > curr_mtu)
243 len = curr_mtu;
244 else
245 len = s->init_num;
246
247
248 /* XDTLS: this function is too long. split out the CCS part */
249 if ( type == SSL3_RT_HANDSHAKE)
250 {
251 if ( s->init_off != 0)
252 {
253 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
254 s->init_off -= DTLS1_HM_HEADER_LENGTH;
255 s->init_num += DTLS1_HM_HEADER_LENGTH;
256
257 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
258 if ( len <= DTLS1_HM_HEADER_LENGTH)
259 len += DTLS1_HM_HEADER_LENGTH;
260 }
261
262 dtls1_fix_message_header(s, frag_off,
263 len - DTLS1_HM_HEADER_LENGTH);
264
265 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
266
267 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
268 }
269
270 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
271 len);
272 if (ret < 0)
273 {
274 /* might need to update MTU here, but we don't know
275 * which previous packet caused the failure -- so can't
276 * really retransmit anything. continue as if everything
277 * is fine and wait for an alert to handle the
278 * retransmit
279 */
280 if ( BIO_ctrl(SSL_get_wbio(s),
281 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL))
282 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
283 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
284 else
285 return(-1);
286 }
287 else
288 {
289
290 /* bad if this assert fails, only part of the handshake
291 * message got sent. but why would this happen? */
292 OPENSSL_assert(len == (unsigned int)ret);
293
294 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
295 /* should not be done for 'Hello Request's, but in that case
296 * we'll ignore the result anyway */
297 ssl3_finish_mac(s,
298 (unsigned char *)&s->init_buf->data[s->init_off +
299 DTLS1_HM_HEADER_LENGTH], ret - DTLS1_HM_HEADER_LENGTH);
300
301 if (ret == s->init_num)
302 {
303 if (s->msg_callback)
304 s->msg_callback(1, s->version, type, s->init_buf->data,
305 (size_t)(s->init_off + s->init_num), s,
306 s->msg_callback_arg);
307
308 s->init_off = 0; /* done writing this message */
309 s->init_num = 0;
310
311 return(1);
312 }
313 s->init_off+=ret;
314 s->init_num-=ret;
315 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
316 }
317 }
318 return(0);
319 }
320
321
322/* Obtain handshake message of message type 'mt' (any if mt == -1),
323 * maximum acceptable body length 'max'.
324 * Read an entire handshake message. Handshake messages arrive in
325 * fragments.
326 */
327long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
328 {
329 int i, al;
330
331 /* s3->tmp is used to store messages that are unexpected, caused
332 * by the absence of an optional handshake message */
333 if (s->s3->tmp.reuse_message)
334 {
335 s->s3->tmp.reuse_message=0;
336 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
337 {
338 al=SSL_AD_UNEXPECTED_MESSAGE;
339 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
340 goto f_err;
341 }
342 *ok=1;
343 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
344 s->init_num = (int)s->s3->tmp.message_size;
345 return s->init_num;
346 }
347
348 do
349 {
350 if ( s->d1->r_msg_hdr.frag_off == 0)
351 {
352 /* s->d1->r_message_header.msg_len = 0; */
353 memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
354 }
355
356 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
357 if ( i == DTLS1_HM_BAD_FRAGMENT ||
358 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
359 continue;
360 else if ( i <= 0 && !*ok)
361 return i;
362
363 if (s->d1->r_msg_hdr.msg_len == (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
364 {
365 memset(&(s->d1->r_msg_hdr), 0x00, sizeof(struct hm_header_st));
366
367 s->d1->handshake_read_seq++;
368 /* we just read a handshake message from the other side:
369 * this means that we don't need to retransmit of the
370 * buffered messages.
371 * XDTLS: may be able clear out this
372 * buffer a little sooner (i.e if an out-of-order
373 * handshake message/record is received at the record
374 * layer.
375 * XDTLS: exception is that the server needs to
376 * know that change cipher spec and finished messages
377 * have been received by the client before clearing this
378 * buffer. this can simply be done by waiting for the
379 * first data segment, but is there a better way? */
380 dtls1_clear_record_buffer(s);
381
382 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
383 return s->init_num - DTLS1_HM_HEADER_LENGTH;
384 }
385 else
386 s->d1->r_msg_hdr.frag_off = i;
387 } while(1) ;
388
389f_err:
390 ssl3_send_alert(s,SSL3_AL_FATAL,al);
391 *ok = 0;
392 return -1;
393 }
394
395
396static int
397dtls1_retrieve_buffered_fragment(SSL *s, unsigned long *copied)
398 {
399 /* (0) check whether the desired fragment is available
400 * if so:
401 * (1) copy over the fragment to s->init_buf->data[]
402 * (2) update s->init_num
403 */
404 pitem *item;
405 hm_fragment *frag;
406 unsigned long overlap;
407 unsigned char *p;
408
409 item = pqueue_peek(s->d1->buffered_messages);
410 if ( item == NULL)
411 return 0;
412
413 frag = (hm_fragment *)item->data;
414
415 if ( s->d1->handshake_read_seq == frag->msg_header.seq &&
416 frag->msg_header.frag_off <= (unsigned int)s->init_num - DTLS1_HM_HEADER_LENGTH)
417 {
418 pqueue_pop(s->d1->buffered_messages);
419 overlap = s->init_num - DTLS1_HM_HEADER_LENGTH
420 - frag->msg_header.frag_off;
421
422 p = frag->fragment;
423
424 memcpy(&s->init_buf->data[s->init_num],
425 p + DTLS1_HM_HEADER_LENGTH + overlap,
426 frag->msg_header.frag_len - overlap);
427
428 OPENSSL_free(frag->fragment);
429 OPENSSL_free(frag);
430 pitem_free(item);
431
432 *copied = frag->msg_header.frag_len - overlap;
433 return *copied;
434 }
435 else
436 return 0;
437 }
438
439
440static int
441dtls1_buffer_handshake_fragment(SSL *s, struct hm_header_st* msg_hdr)
442{
443 hm_fragment *frag = NULL;
444 pitem *item = NULL;
445 PQ_64BIT seq64;
446
447 frag = dtls1_hm_fragment_new(msg_hdr->frag_len);
448 if ( frag == NULL)
449 goto err;
450
451 memcpy(frag->fragment, &(s->init_buf->data[s->init_num]),
452 msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH);
453
454 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
455
456 pq_64bit_init(&seq64);
457 pq_64bit_assign_word(&seq64, msg_hdr->seq);
458
459 item = pitem_new(seq64, frag);
460 if ( item == NULL)
461 goto err;
462
463 pq_64bit_free(&seq64);
464
465 pqueue_insert(s->d1->buffered_messages, item);
466 return 1;
467
468err:
469 if ( frag != NULL) dtls1_hm_fragment_free(frag);
470 if ( item != NULL) OPENSSL_free(item);
471 return 0;
472}
473
474
475static void
476dtls1_process_handshake_fragment(SSL *s, int frag_len)
477 {
478 unsigned char *p;
479
480 p = (unsigned char *)s->init_buf->data;
481
482 ssl3_finish_mac(s, &p[s->init_num - frag_len], frag_len);
483 }
484
485
486static int
487dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st *msg_hdr, int *ok)
488 {
489 int i;
490 unsigned char *p;
491
492 /* make sure there's enough room to read this fragment */
493 if ( (int)msg_hdr->frag_len && !BUF_MEM_grow_clean(s->init_buf,
494 (int)msg_hdr->frag_len + DTLS1_HM_HEADER_LENGTH + s->init_num))
495 {
496 SSLerr(SSL_F_DTLS1_PROCESS_OUT_OF_SEQ_MESSAGE,ERR_R_BUF_LIB);
497 goto err;
498 }
499
500 p = (unsigned char *)s->init_buf->data;
501
502 /* read the body of the fragment (header has already been read */
503 if ( msg_hdr->frag_len > 0)
504 {
505 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
506 &p[s->init_num],
507 msg_hdr->frag_len,0);
508 if (i <= 0)
509 {
510 *ok = 0;
511 return i;
512 }
513 }
514
515 if ( msg_hdr->seq > s->d1->handshake_read_seq)
516 dtls1_buffer_handshake_fragment(s, msg_hdr);
517 else
518 OPENSSL_assert(msg_hdr->seq < s->d1->handshake_read_seq);
519
520 return DTLS1_HM_FRAGMENT_RETRY;
521err:
522 *ok = 0;
523 return -1;
524 }
525
526
527static long
528dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
529 {
530 unsigned char *p;
531 unsigned long l, frag_off, frag_len;
532 int i,al;
533 struct hm_header_st msg_hdr;
534 unsigned long overlap;
535
536 /* see if we have the required fragment already */
537 if (dtls1_retrieve_buffered_fragment(s, &l))
538 {
539 /* compute MAC, remove fragment headers */
540 dtls1_process_handshake_fragment(s, l);
541 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
542 s->state = stn;
543 return 1;
544 }
545
546 /* get a handshake fragment from the record layer */
547 p = (unsigned char *)s->init_buf->data;
548
549 /* read handshake message header */
550 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,&p[s->init_num],
551 DTLS1_HM_HEADER_LENGTH, 0);
552 if (i <= 0) /* nbio, or an error */
553 {
554 s->rwstate=SSL_READING;
555 *ok = 0;
556 return i;
557 }
558
559 OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
560
561 p += s->init_num;
562 /* parse the message fragment header */
563
564 dtls1_get_message_header(p, &msg_hdr);
565
566 /*
567 * if this is a future (or stale) message it gets buffered
568 * (or dropped)--no further processing at this time
569 */
570 if ( msg_hdr.seq != s->d1->handshake_read_seq)
571 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
572
573 l = msg_hdr.msg_len;
574 frag_off = msg_hdr.frag_off;
575 frag_len = msg_hdr.frag_len;
576
577 /* sanity checking */
578 if ( frag_off + frag_len > l)
579 {
580 al=SSL_AD_ILLEGAL_PARAMETER;
581 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
582 goto f_err;
583 }
584
585 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
586 p[0] == SSL3_MT_HELLO_REQUEST)
587 {
588 /* The server may always send 'Hello Request' messages --
589 * we are doing a handshake anyway now, so ignore them
590 * if their format is correct. Does not count for
591 * 'Finished' MAC. */
592 if (p[1] == 0 && p[2] == 0 &&p[3] == 0)
593 {
594 if (s->msg_callback)
595 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
596 p, DTLS1_HM_HEADER_LENGTH, s,
597 s->msg_callback_arg);
598
599 s->init_num = 0;
600 return dtls1_get_message_fragment(s, st1, stn,
601 max, ok);
602 }
603 else /* Incorrectly formated Hello request */
604 {
605 al=SSL_AD_UNEXPECTED_MESSAGE;
606 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
607 goto f_err;
608 }
609 }
610
611 /* XDTLS: do a sanity check on the fragment */
612
613 s->init_num += i;
614
615 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
616 {
617 /* BUF_MEM_grow takes an 'int' parameter */
618 if (l > (INT_MAX-DTLS1_HM_HEADER_LENGTH))
619 {
620 al=SSL_AD_ILLEGAL_PARAMETER;
621 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
622 goto f_err;
623 }
624 if (l && !BUF_MEM_grow_clean(s->init_buf,(int)l
625 + DTLS1_HM_HEADER_LENGTH))
626 {
627 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
628 goto err;
629 }
630 /* Only do this test when we're reading the expected message.
631 * Stale messages will be dropped and future messages will be buffered */
632 if ( l > (unsigned long)max)
633 {
634 al=SSL_AD_ILLEGAL_PARAMETER;
635 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
636 goto f_err;
637 }
638
639 s->s3->tmp.message_size=l;
640 }
641
642 if ( frag_len > (unsigned long)max)
643 {
644 al=SSL_AD_ILLEGAL_PARAMETER;
645 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
646 goto f_err;
647 }
648 if ( frag_len + s->init_num > (INT_MAX - DTLS1_HM_HEADER_LENGTH))
649 {
650 al=SSL_AD_ILLEGAL_PARAMETER;
651 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
652 goto f_err;
653 }
654
655 if ( frag_len & !BUF_MEM_grow_clean(s->init_buf, (int)frag_len
656 + DTLS1_HM_HEADER_LENGTH + s->init_num))
657 {
658 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,ERR_R_BUF_LIB);
659 goto err;
660 }
661
662 if ( s->d1->r_msg_hdr.frag_off == 0)
663 {
664 s->s3->tmp.message_type = msg_hdr.type;
665 s->d1->r_msg_hdr.type = msg_hdr.type;
666 s->d1->r_msg_hdr.msg_len = l;
667 /* s->d1->r_msg_hdr.seq = seq_num; */
668 }
669
670 /* XDTLS: ressurect this when restart is in place */
671 s->state=stn;
672
673 /* next state (stn) */
674 p = (unsigned char *)s->init_buf->data;
675
676 if ( frag_len > 0)
677 {
678 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
679 &p[s->init_num],
680 frag_len,0);
681 /* XDTLS: fix this--message fragments cannot span multiple packets */
682 if (i <= 0)
683 {
684 s->rwstate=SSL_READING;
685 *ok = 0;
686 return i;
687 }
688 }
689 else
690 i = 0;
691
692 /* XDTLS: an incorrectly formatted fragment should cause the
693 * handshake to fail */
694 OPENSSL_assert(i == (int)frag_len);
695
696#if 0
697 /* Successfully read a fragment.
698 * It may be (1) out of order, or
699 * (2) it's a repeat, in which case we dump it
700 * (3) the one we are expecting next (maybe with overlap)
701 * If it is next one, it may overlap with previously read bytes
702 */
703
704 /* case (1): buffer the future fragment
705 * (we can treat fragments from a future message the same
706 * as future fragments from the message being currently read, since
707 * they are sematically simply out of order.
708 */
709 if ( msg_hdr.seq > s->d1->handshake_read_seq ||
710 frag_off > s->init_num - DTLS1_HM_HEADER_LENGTH)
711 {
712 dtls1_buffer_handshake_fragment(s, &msg_hdr);
713 return DTLS1_HM_FRAGMENT_RETRY;
714 }
715
716 /* case (2): drop the entire fragment, and try again */
717 if ( msg_hdr.seq < s->d1->handshake_read_seq ||
718 frag_off + frag_len < s->init_num - DTLS1_HM_HEADER_LENGTH)
719 {
720 s->init_num -= DTLS1_HM_HEADER_LENGTH;
721 return DTLS1_HM_FRAGMENT_RETRY;
722 }
723#endif
724
725 /* case (3): received a immediately useful fragment. Determine the
726 * possible overlap and copy the fragment.
727 */
728 overlap = (s->init_num - DTLS1_HM_HEADER_LENGTH) - frag_off;
729
730 /* retain the header for the first fragment */
731 if ( s->init_num > DTLS1_HM_HEADER_LENGTH)
732 {
733 memmove(&(s->init_buf->data[s->init_num]),
734 &(s->init_buf->data[s->init_num + DTLS1_HM_HEADER_LENGTH + overlap]),
735 frag_len - overlap);
736
737 s->init_num += frag_len - overlap;
738 }
739 else
740 s->init_num += frag_len;
741
742 dtls1_process_handshake_fragment(s, frag_len - overlap);
743
744 if (s->msg_callback)
745 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE, s->init_buf->data,
746 (size_t)s->init_num, s,
747 s->msg_callback_arg);
748 *ok=1;
749
750 return s->init_num;
751
752f_err:
753 ssl3_send_alert(s,SSL3_AL_FATAL,al);
754 s->init_num = 0;
755err:
756 *ok=0;
757 return(-1);
758 }
759
760int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
761 {
762 unsigned char *p,*d;
763 int i;
764 unsigned long l;
765
766 if (s->state == a)
767 {
768 d=(unsigned char *)s->init_buf->data;
769 p= &(d[DTLS1_HM_HEADER_LENGTH]);
770
771 i=s->method->ssl3_enc->final_finish_mac(s,
772 &(s->s3->finish_dgst1),
773 &(s->s3->finish_dgst2),
774 sender,slen,s->s3->tmp.finish_md);
775 s->s3->tmp.finish_md_len = i;
776 memcpy(p, s->s3->tmp.finish_md, i);
777 p+=i;
778 l=i;
779
780#ifdef OPENSSL_SYS_WIN16
781 /* MSVC 1.5 does not clear the top bytes of the word unless
782 * I do this.
783 */
784 l&=0xffff;
785#endif
786
787 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
788 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
789 s->init_off=0;
790
791 /* buffer the message to handle re-xmits */
792 dtls1_buffer_message(s, 0);
793
794 s->state=b;
795 }
796
797 /* SSL3_ST_SEND_xxxxxx_HELLO_B */
798 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
799 }
800
801/* for these 2 messages, we need to
802 * ssl->enc_read_ctx re-init
803 * ssl->s3->read_sequence zero
804 * ssl->s3->read_mac_secret re-init
805 * ssl->session->read_sym_enc assign
806 * ssl->session->read_compression assign
807 * ssl->session->read_hash assign
808 */
809int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
810 {
811 unsigned char *p;
812
813 if (s->state == a)
814 {
815 p=(unsigned char *)s->init_buf->data;
816 *p++=SSL3_MT_CCS;
817 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
818 s->d1->next_handshake_write_seq++;
819 s2n(s->d1->handshake_write_seq,p);
820
821 s->init_num=DTLS1_CCS_HEADER_LENGTH;
822 s->init_off=0;
823
824 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
825 s->d1->handshake_write_seq, 0, 0);
826
827 /* buffer the message to handle re-xmits */
828 dtls1_buffer_message(s, 1);
829
830 s->state=b;
831 }
832
833 /* SSL3_ST_CW_CHANGE_B */
834 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
835 }
836
837unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
838 {
839 unsigned char *p;
840 int n,i;
841 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
842 BUF_MEM *buf;
843 X509_STORE_CTX xs_ctx;
844 X509_OBJECT obj;
845
846 /* TLSv1 sends a chain with nothing in it, instead of an alert */
847 buf=s->init_buf;
848 if (!BUF_MEM_grow_clean(buf,10))
849 {
850 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
851 return(0);
852 }
853 if (x != NULL)
854 {
855 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
856 {
857 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
858 return(0);
859 }
860
861 for (;;)
862 {
863 n=i2d_X509(x,NULL);
864 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
865 {
866 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
867 return(0);
868 }
869 p=(unsigned char *)&(buf->data[l]);
870 l2n3(n,p);
871 i2d_X509(x,&p);
872 l+=n+3;
873 if (X509_NAME_cmp(X509_get_subject_name(x),
874 X509_get_issuer_name(x)) == 0) break;
875
876 i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
877 X509_get_issuer_name(x),&obj);
878 if (i <= 0) break;
879 x=obj.data.x509;
880 /* Count is one too high since the X509_STORE_get uped the
881 * ref count */
882 X509_free(x);
883 }
884
885 X509_STORE_CTX_cleanup(&xs_ctx);
886 }
887
888 /* Thawte special :-) */
889 if (s->ctx->extra_certs != NULL)
890 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
891 {
892 x=sk_X509_value(s->ctx->extra_certs,i);
893 n=i2d_X509(x,NULL);
894 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
895 {
896 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
897 return(0);
898 }
899 p=(unsigned char *)&(buf->data[l]);
900 l2n3(n,p);
901 i2d_X509(x,&p);
902 l+=n+3;
903 }
904
905 l-= (3 + DTLS1_HM_HEADER_LENGTH);
906
907 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
908 l2n3(l,p);
909 l+=3;
910 p=(unsigned char *)&(buf->data[0]);
911 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
912
913 l+=DTLS1_HM_HEADER_LENGTH;
914 return(l);
915 }
916
917int dtls1_read_failed(SSL *s, int code)
918 {
919 DTLS1_STATE *state;
920 BIO *bio;
921 int send_alert = 0;
922
923 if ( code > 0)
924 {
925 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
926 return 1;
927 }
928
929 bio = SSL_get_rbio(s);
930 if ( ! BIO_dgram_recv_timedout(bio))
931 {
932 /* not a timeout, none of our business,
933 let higher layers handle this. in fact it's probably an error */
934 return code;
935 }
936
937 if ( ! SSL_in_init(s)) /* done, no need to send a retransmit */
938 {
939 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
940 return code;
941 }
942
943 state = s->d1;
944 state->timeout.num_alerts++;
945 if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
946 {
947 /* fail the connection, enough alerts have been sent */
948 SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
949 return 0;
950 }
951
952 state->timeout.read_timeouts++;
953 if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
954 {
955 send_alert = 1;
956 state->timeout.read_timeouts = 1;
957 }
958
959
960#if 0 /* for now, each alert contains only one record number */
961 item = pqueue_peek(state->rcvd_records);
962 if ( item )
963 {
964 /* send an alert immediately for all the missing records */
965 }
966 else
967#endif
968
969#if 0 /* no more alert sending, just retransmit the last set of messages */
970 if ( send_alert)
971 ssl3_send_alert(s,SSL3_AL_WARNING,
972 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
973#endif
974
975 return dtls1_retransmit_buffered_messages(s) ;
976 }
977
978
979static int
980dtls1_retransmit_buffered_messages(SSL *s)
981 {
982 pqueue sent = s->d1->sent_messages;
983 piterator iter;
984 pitem *item;
985 hm_fragment *frag;
986 int found = 0;
987
988 iter = pqueue_iterator(sent);
989
990 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
991 {
992 frag = (hm_fragment *)item->data;
993 if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 &&
994 found)
995 {
996 fprintf(stderr, "dtls1_retransmit_message() failed\n");
997 return -1;
998 }
999 }
1000
1001 return 1;
1002 }
1003
1004#if 0
1005static dtls1_message_buffer *
1006dtls1_message_buffer_new(unsigned int len)
1007 {
1008 dtls1_message_buffer *msg_buf;
1009
1010 msg_buf = (dtls1_message_buffer *)
1011 OPENSSL_malloc(sizeof(dtls1_message_buffer));
1012 if ( msg_buf == NULL)
1013 return NULL;
1014
1015 memset(msg_buf, 0x00, sizeof(dtls1_message_buffer));
1016
1017 msg_buf->data = (unsigned char *) OPENSSL_malloc(len);
1018 if ( msg_buf->data == NULL)
1019 {
1020 OPENSSL_free(msg_buf);
1021 return NULL;
1022 }
1023
1024 memset(msg_buf->data, 0x00, len);
1025 return msg_buf;
1026 }
1027#endif
1028
1029#if 0
1030static void
1031dtls1_message_buffer_free(dtls1_message_buffer *msg_buf)
1032 {
1033 if (msg_buf != NULL)
1034 {
1035 OPENSSL_free(msg_buf->data);
1036 OPENSSL_free(msg_buf);
1037 }
1038 }
1039#endif
1040
1041int
1042dtls1_buffer_message(SSL *s, int is_ccs)
1043 {
1044 pitem *item;
1045 hm_fragment *frag;
1046 PQ_64BIT seq64;
1047
1048 /* this function is called immediately after a message has
1049 * been serialized */
1050 OPENSSL_assert(s->init_off == 0);
1051
1052 frag = dtls1_hm_fragment_new(s->init_num);
1053
1054 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1055
1056 if ( is_ccs)
1057 {
1058 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1059 DTLS1_CCS_HEADER_LENGTH == (unsigned int)s->init_num);
1060 }
1061 else
1062 {
1063 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1064 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1065 }
1066
1067 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1068 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1069 frag->msg_header.type = s->d1->w_msg_hdr.type;
1070 frag->msg_header.frag_off = 0;
1071 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1072 frag->msg_header.is_ccs = is_ccs;
1073
1074 pq_64bit_init(&seq64);
1075 pq_64bit_assign_word(&seq64, frag->msg_header.seq);
1076
1077 item = pitem_new(seq64, frag);
1078 pq_64bit_free(&seq64);
1079 if ( item == NULL)
1080 {
1081 dtls1_hm_fragment_free(frag);
1082 return 0;
1083 }
1084
1085#if 0
1086 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1087 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1088 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1089#endif
1090
1091 pqueue_insert(s->d1->sent_messages, item);
1092 return 1;
1093 }
1094
1095int
1096dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1097 int *found)
1098 {
1099 int ret;
1100 /* XDTLS: for now assuming that read/writes are blocking */
1101 pitem *item;
1102 hm_fragment *frag ;
1103 unsigned long header_length;
1104 PQ_64BIT seq64;
1105
1106 /*
1107 OPENSSL_assert(s->init_num == 0);
1108 OPENSSL_assert(s->init_off == 0);
1109 */
1110
1111 /* XDTLS: the requested message ought to be found, otherwise error */
1112 pq_64bit_init(&seq64);
1113 pq_64bit_assign_word(&seq64, seq);
1114
1115 item = pqueue_find(s->d1->sent_messages, seq64);
1116 pq_64bit_free(&seq64);
1117 if ( item == NULL)
1118 {
1119 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1120 *found = 0;
1121 return 0;
1122 }
1123
1124 *found = 1;
1125 frag = (hm_fragment *)item->data;
1126
1127 if ( frag->msg_header.is_ccs)
1128 header_length = DTLS1_CCS_HEADER_LENGTH;
1129 else
1130 header_length = DTLS1_HM_HEADER_LENGTH;
1131
1132 memcpy(s->init_buf->data, frag->fragment,
1133 frag->msg_header.msg_len + header_length);
1134 s->init_num = frag->msg_header.msg_len + header_length;
1135
1136 dtls1_set_message_header_int(s, frag->msg_header.type,
1137 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1138 frag->msg_header.frag_len);
1139
1140 s->d1->retransmitting = 1;
1141 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1142 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1143 s->d1->retransmitting = 0;
1144
1145 BIO_flush(SSL_get_wbio(s));
1146 return ret;
1147 }
1148
1149/* call this function when the buffered messages are no longer needed */
1150void
1151dtls1_clear_record_buffer(SSL *s)
1152 {
1153 pitem *item;
1154
1155 for(item = pqueue_pop(s->d1->sent_messages);
1156 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1157 {
1158 dtls1_hm_fragment_free((hm_fragment *)item->data);
1159 pitem_free(item);
1160 }
1161 }
1162
1163
1164unsigned char *
1165dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1166 unsigned long len, unsigned long frag_off, unsigned long frag_len)
1167 {
1168 if ( frag_off == 0)
1169 {
1170 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1171 s->d1->next_handshake_write_seq++;
1172 }
1173
1174 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1175 frag_off, frag_len);
1176
1177 return p += DTLS1_HM_HEADER_LENGTH;
1178 }
1179
1180
1181/* don't actually do the writing, wait till the MTU has been retrieved */
1182static void
1183dtls1_set_message_header_int(SSL *s, unsigned char mt,
1184 unsigned long len, unsigned short seq_num, unsigned long frag_off,
1185 unsigned long frag_len)
1186 {
1187 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1188
1189 msg_hdr->type = mt;
1190 msg_hdr->msg_len = len;
1191 msg_hdr->seq = seq_num;
1192 msg_hdr->frag_off = frag_off;
1193 msg_hdr->frag_len = frag_len;
1194}
1195
1196static void
1197dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1198 unsigned long frag_len)
1199 {
1200 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1201
1202 msg_hdr->frag_off = frag_off;
1203 msg_hdr->frag_len = frag_len;
1204 }
1205
1206static unsigned char *
1207dtls1_write_message_header(SSL *s, unsigned char *p)
1208 {
1209 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1210
1211 *p++ = msg_hdr->type;
1212 l2n3(msg_hdr->msg_len, p);
1213
1214 s2n(msg_hdr->seq, p);
1215 l2n3(msg_hdr->frag_off, p);
1216 l2n3(msg_hdr->frag_len, p);
1217
1218 return p;
1219 }
1220
1221static unsigned int
1222dtls1_min_mtu(void)
1223 {
1224 return
1225 g_probable_mtu[(sizeof(g_probable_mtu) /
1226 sizeof(g_probable_mtu[0])) - 1];
1227 }
1228
1229static unsigned int
1230dtls1_guess_mtu(unsigned int curr_mtu)
1231 {
1232 size_t i;
1233
1234 if ( curr_mtu == 0 )
1235 return g_probable_mtu[0] ;
1236
1237 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1238 if ( curr_mtu > g_probable_mtu[i])
1239 return g_probable_mtu[i];
1240
1241 return curr_mtu;
1242 }
1243
1244void
1245dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1246 {
1247 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1248 msg_hdr->type = *(data++);
1249 n2l3(data, msg_hdr->msg_len);
1250
1251 n2s(data, msg_hdr->seq);
1252 n2l3(data, msg_hdr->frag_off);
1253 n2l3(data, msg_hdr->frag_len);
1254 }
1255
1256void
1257dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1258 {
1259 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1260
1261 ccs_hdr->type = *(data++);
1262 n2s(data, ccs_hdr->seq);
1263}