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 */
128 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
129
130 static unsigned int dtls1_min_mtu(void);
131 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
132 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
133 unsigned long frag_len);
134 static unsigned char *dtls1_write_message_header(SSL *s,
135 unsigned char *p);
136 static 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);
139 static int dtls1_retransmit_buffered_messages(SSL *s);
140 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
141 long max, int *ok);
142
143 static hm_fragment *
dtls1_hm_fragment_new(unsigned long frag_len)144 dtls1_hm_fragment_new(unsigned long frag_len)
145 {
146 hm_fragment *frag = NULL;
147 unsigned char *buf = NULL;
148
149 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
150 if ( frag == NULL)
151 return NULL;
152
153 if (frag_len)
154 {
155 buf = (unsigned char *)OPENSSL_malloc(frag_len);
156 if ( buf == NULL)
157 {
158 OPENSSL_free(frag);
159 return NULL;
160 }
161 }
162
163 /* zero length fragment gets zero frag->fragment */
164 frag->fragment = buf;
165
166 return frag;
167 }
168
169 static void
dtls1_hm_fragment_free(hm_fragment * frag)170 dtls1_hm_fragment_free(hm_fragment *frag)
171 {
172 if (frag->fragment) OPENSSL_free(frag->fragment);
173 OPENSSL_free(frag);
174 }
175
176 /* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
dtls1_do_write(SSL * s,int type)177 int dtls1_do_write(SSL *s, int type)
178 {
179 int ret;
180 int curr_mtu;
181 unsigned int len, frag_off;
182
183 /* AHA! Figure out the MTU, and stick to the right size */
184 if ( ! (SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
185 {
186 s->d1->mtu =
187 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
188
189 /* I've seen the kernel return bogus numbers when it doesn't know
190 * (initial write), so just make sure we have a reasonable number */
191 if ( s->d1->mtu < dtls1_min_mtu())
192 {
193 s->d1->mtu = 0;
194 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
195 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
196 s->d1->mtu, NULL);
197 }
198 }
199 #if 0
200 mtu = s->d1->mtu;
201
202 fprintf(stderr, "using MTU = %d\n", mtu);
203
204 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
205
206 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
207
208 if ( curr_mtu > 0)
209 mtu = curr_mtu;
210 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
211 return ret;
212
213 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
214 {
215 ret = BIO_flush(SSL_get_wbio(s));
216 if ( ret <= 0)
217 return ret;
218 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
219 }
220
221 OPENSSL_assert(mtu > 0); /* should have something reasonable now */
222
223 #endif
224
225 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
226 OPENSSL_assert(s->init_num ==
227 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
228
229 frag_off = 0;
230 while( s->init_num)
231 {
232 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
233 DTLS1_RT_HEADER_LENGTH;
234
235 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
236 {
237 /* grr.. we could get an error if MTU picked was wrong */
238 ret = BIO_flush(SSL_get_wbio(s));
239 if ( ret <= 0)
240 return ret;
241 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH;
242 }
243
244 if ( s->init_num > curr_mtu)
245 len = curr_mtu;
246 else
247 len = s->init_num;
248
249
250 /* XDTLS: this function is too long. split out the CCS part */
251 if ( type == SSL3_RT_HANDSHAKE)
252 {
253 if ( s->init_off != 0)
254 {
255 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
256 s->init_off -= DTLS1_HM_HEADER_LENGTH;
257 s->init_num += DTLS1_HM_HEADER_LENGTH;
258
259 /* write atleast DTLS1_HM_HEADER_LENGTH bytes */
260 if ( len <= DTLS1_HM_HEADER_LENGTH)
261 len += DTLS1_HM_HEADER_LENGTH;
262 }
263
264 dtls1_fix_message_header(s, frag_off,
265 len - DTLS1_HM_HEADER_LENGTH);
266
267 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
268
269 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
270 }
271
272 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
273 len);
274 if (ret < 0)
275 {
276 /* might need to update MTU here, but we don't know
277 * which previous packet caused the failure -- so can't
278 * really retransmit anything. continue as if everything
279 * is fine and wait for an alert to handle the
280 * retransmit
281 */
282 if ( BIO_ctrl(SSL_get_wbio(s),
283 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL))
284 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
285 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
286 else
287 return(-1);
288 }
289 else
290 {
291
292 /* bad if this assert fails, only part of the handshake
293 * message got sent. but why would this happen? */
294 OPENSSL_assert(len == (unsigned int)ret);
295
296 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
297 {
298 /* should not be done for 'Hello Request's, but in that case
299 * we'll ignore the result anyway */
300 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
301 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
302 int xlen;
303
304 if (frag_off == 0 && s->client_version != DTLS1_BAD_VER)
305 {
306 /* reconstruct message header is if it
307 * is being sent in single fragment */
308 *p++ = msg_hdr->type;
309 l2n3(msg_hdr->msg_len,p);
310 s2n (msg_hdr->seq,p);
311 l2n3(0,p);
312 l2n3(msg_hdr->msg_len,p);
313 p -= DTLS1_HM_HEADER_LENGTH;
314 xlen = ret;
315 }
316 else
317 {
318 p += DTLS1_HM_HEADER_LENGTH;
319 xlen = ret - DTLS1_HM_HEADER_LENGTH;
320 }
321
322 ssl3_finish_mac(s, p, xlen);
323 }
324
325 if (ret == s->init_num)
326 {
327 if (s->msg_callback)
328 s->msg_callback(1, s->version, type, s->init_buf->data,
329 (size_t)(s->init_off + s->init_num), s,
330 s->msg_callback_arg);
331
332 s->init_off = 0; /* done writing this message */
333 s->init_num = 0;
334
335 return(1);
336 }
337 s->init_off+=ret;
338 s->init_num-=ret;
339 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
340 }
341 }
342 return(0);
343 }
344
345
346 /* Obtain handshake message of message type 'mt' (any if mt == -1),
347 * maximum acceptable body length 'max'.
348 * Read an entire handshake message. Handshake messages arrive in
349 * fragments.
350 */
dtls1_get_message(SSL * s,int st1,int stn,int mt,long max,int * ok)351 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
352 {
353 int i, al;
354 struct hm_header_st *msg_hdr;
355
356 /* s3->tmp is used to store messages that are unexpected, caused
357 * by the absence of an optional handshake message */
358 if (s->s3->tmp.reuse_message)
359 {
360 s->s3->tmp.reuse_message=0;
361 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
362 {
363 al=SSL_AD_UNEXPECTED_MESSAGE;
364 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
365 goto f_err;
366 }
367 *ok=1;
368 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
369 s->init_num = (int)s->s3->tmp.message_size;
370 return s->init_num;
371 }
372
373 msg_hdr = &s->d1->r_msg_hdr;
374 do
375 {
376 if ( msg_hdr->frag_off == 0)
377 {
378 /* s->d1->r_message_header.msg_len = 0; */
379 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
380 }
381
382 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
383 if ( i == DTLS1_HM_BAD_FRAGMENT ||
384 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
385 continue;
386 else if ( i <= 0 && !*ok)
387 return i;
388
389 /* Note that s->init_sum is used as a counter summing
390 * up fragments' lengths: as soon as they sum up to
391 * handshake packet length, we assume we have got all
392 * the fragments. Overlapping fragments would cause
393 * premature termination, so we don't expect overlaps.
394 * Well, handling overlaps would require something more
395 * drastic. Indeed, as it is now there is no way to
396 * tell if out-of-order fragment from the middle was
397 * the last. '>=' is the best/least we can do to control
398 * the potential damage caused by malformed overlaps. */
399 if ((unsigned int)s->init_num >= msg_hdr->msg_len)
400 {
401 unsigned char *p = (unsigned char *)s->init_buf->data;
402 unsigned long msg_len = msg_hdr->msg_len;
403
404 /* reconstruct message header as if it was
405 * sent in single fragment */
406 *(p++) = msg_hdr->type;
407 l2n3(msg_len,p);
408 s2n (msg_hdr->seq,p);
409 l2n3(0,p);
410 l2n3(msg_len,p);
411 if (s->client_version != DTLS1_BAD_VER)
412 p -= DTLS1_HM_HEADER_LENGTH,
413 msg_len += DTLS1_HM_HEADER_LENGTH;
414
415 ssl3_finish_mac(s, p, msg_len);
416 if (s->msg_callback)
417 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
418 p, msg_len,
419 s, s->msg_callback_arg);
420
421 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
422
423 s->d1->handshake_read_seq++;
424 /* we just read a handshake message from the other side:
425 * this means that we don't need to retransmit of the
426 * buffered messages.
427 * XDTLS: may be able clear out this
428 * buffer a little sooner (i.e if an out-of-order
429 * handshake message/record is received at the record
430 * layer.
431 * XDTLS: exception is that the server needs to
432 * know that change cipher spec and finished messages
433 * have been received by the client before clearing this
434 * buffer. this can simply be done by waiting for the
435 * first data segment, but is there a better way? */
436 dtls1_clear_record_buffer(s);
437
438 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
439 return s->init_num;
440 }
441 else
442 msg_hdr->frag_off = i;
443 } while(1) ;
444
445 f_err:
446 ssl3_send_alert(s,SSL3_AL_FATAL,al);
447 *ok = 0;
448 return -1;
449 }
450
451
dtls1_preprocess_fragment(SSL * s,struct hm_header_st * msg_hdr,int max)452 static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
453 {
454 size_t frag_off,frag_len,msg_len;
455
456 msg_len = msg_hdr->msg_len;
457 frag_off = msg_hdr->frag_off;
458 frag_len = msg_hdr->frag_len;
459
460 /* sanity checking */
461 if ( (frag_off+frag_len) > msg_len)
462 {
463 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
464 return SSL_AD_ILLEGAL_PARAMETER;
465 }
466
467 if ( (frag_off+frag_len) > (unsigned long)max)
468 {
469 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
470 return SSL_AD_ILLEGAL_PARAMETER;
471 }
472
473 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
474 {
475 /* msg_len is limited to 2^24, but is effectively checked
476 * against max above */
477 if (!BUF_MEM_grow_clean(s->init_buf,(int)msg_len+DTLS1_HM_HEADER_LENGTH))
478 {
479 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
480 return SSL_AD_INTERNAL_ERROR;
481 }
482
483 s->s3->tmp.message_size = msg_len;
484 s->d1->r_msg_hdr.msg_len = msg_len;
485 s->s3->tmp.message_type = msg_hdr->type;
486 s->d1->r_msg_hdr.type = msg_hdr->type;
487 s->d1->r_msg_hdr.seq = msg_hdr->seq;
488 }
489 else if (msg_len != s->d1->r_msg_hdr.msg_len)
490 {
491 /* They must be playing with us! BTW, failure to enforce
492 * upper limit would open possibility for buffer overrun. */
493 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
494 return SSL_AD_ILLEGAL_PARAMETER;
495 }
496
497 return 0; /* no error */
498 }
499
500
501 static int
dtls1_retrieve_buffered_fragment(SSL * s,long max,int * ok)502 dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
503 {
504 /* (0) check whether the desired fragment is available
505 * if so:
506 * (1) copy over the fragment to s->init_buf->data[]
507 * (2) update s->init_num
508 */
509 pitem *item;
510 hm_fragment *frag;
511 int al;
512
513 *ok = 0;
514 item = pqueue_peek(s->d1->buffered_messages);
515 if ( item == NULL)
516 return 0;
517
518 frag = (hm_fragment *)item->data;
519
520 if ( s->d1->handshake_read_seq == frag->msg_header.seq)
521 {
522 pqueue_pop(s->d1->buffered_messages);
523
524 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
525
526 if (al==0) /* no alert */
527 {
528 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
529 memcpy(&p[frag->msg_header.frag_off],
530 frag->fragment,frag->msg_header.frag_len);
531 }
532
533 dtls1_hm_fragment_free(frag);
534 pitem_free(item);
535
536 if (al==0)
537 {
538 *ok = 1;
539 return frag->msg_header.frag_len;
540 }
541
542 ssl3_send_alert(s,SSL3_AL_FATAL,al);
543 s->init_num = 0;
544 *ok = 0;
545 return -1;
546 }
547 else
548 return 0;
549 }
550
551
552 static int
dtls1_process_out_of_seq_message(SSL * s,struct hm_header_st * msg_hdr,int * ok)553 dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
554 {
555 int i=-1;
556 hm_fragment *frag = NULL;
557 pitem *item = NULL;
558 PQ_64BIT seq64;
559 unsigned long frag_len = msg_hdr->frag_len;
560
561 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
562 goto err;
563
564 if (msg_hdr->seq <= s->d1->handshake_read_seq)
565 {
566 unsigned char devnull [256];
567
568 while (frag_len)
569 {
570 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
571 devnull,
572 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
573 if (i<=0) goto err;
574 frag_len -= i;
575 }
576 }
577
578 frag = dtls1_hm_fragment_new(frag_len);
579 if ( frag == NULL)
580 goto err;
581
582 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
583
584 if (frag_len)
585 {
586 /* read the body of the fragment (header has already been read */
587 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
588 frag->fragment,frag_len,0);
589 if (i<=0 || (unsigned long)i!=frag_len)
590 goto err;
591 }
592
593 pq_64bit_init(&seq64);
594 pq_64bit_assign_word(&seq64, msg_hdr->seq);
595
596 item = pitem_new(seq64, frag);
597 pq_64bit_free(&seq64);
598 if ( item == NULL)
599 goto err;
600
601 pqueue_insert(s->d1->buffered_messages, item);
602 return DTLS1_HM_FRAGMENT_RETRY;
603
604 err:
605 if ( frag != NULL) dtls1_hm_fragment_free(frag);
606 if ( item != NULL) OPENSSL_free(item);
607 *ok = 0;
608 return i;
609 }
610
611
612 static long
dtls1_get_message_fragment(SSL * s,int st1,int stn,long max,int * ok)613 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
614 {
615 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
616 unsigned long l, frag_off, frag_len;
617 int i,al;
618 struct hm_header_st msg_hdr;
619
620 /* see if we have the required fragment already */
621 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
622 {
623 if (*ok) s->init_num += frag_len;
624 return frag_len;
625 }
626
627 /* read handshake message header */
628 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
629 DTLS1_HM_HEADER_LENGTH, 0);
630 if (i <= 0) /* nbio, or an error */
631 {
632 s->rwstate=SSL_READING;
633 *ok = 0;
634 return i;
635 }
636 OPENSSL_assert(i == DTLS1_HM_HEADER_LENGTH);
637
638 /* parse the message fragment header */
639 dtls1_get_message_header(wire, &msg_hdr);
640
641 /*
642 * if this is a future (or stale) message it gets buffered
643 * (or dropped)--no further processing at this time
644 */
645 if ( msg_hdr.seq != s->d1->handshake_read_seq)
646 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
647
648 l = msg_hdr.msg_len;
649 frag_off = msg_hdr.frag_off;
650 frag_len = msg_hdr.frag_len;
651
652 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
653 wire[0] == SSL3_MT_HELLO_REQUEST)
654 {
655 /* The server may always send 'Hello Request' messages --
656 * we are doing a handshake anyway now, so ignore them
657 * if their format is correct. Does not count for
658 * 'Finished' MAC. */
659 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
660 {
661 if (s->msg_callback)
662 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
663 wire, DTLS1_HM_HEADER_LENGTH, s,
664 s->msg_callback_arg);
665
666 s->init_num = 0;
667 return dtls1_get_message_fragment(s, st1, stn,
668 max, ok);
669 }
670 else /* Incorrectly formated Hello request */
671 {
672 al=SSL_AD_UNEXPECTED_MESSAGE;
673 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
674 goto f_err;
675 }
676 }
677
678 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
679 goto f_err;
680
681 /* XDTLS: ressurect this when restart is in place */
682 s->state=stn;
683
684 if ( frag_len > 0)
685 {
686 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
687
688 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
689 &p[frag_off],frag_len,0);
690 /* XDTLS: fix this--message fragments cannot span multiple packets */
691 if (i <= 0)
692 {
693 s->rwstate=SSL_READING;
694 *ok = 0;
695 return i;
696 }
697 }
698 else
699 i = 0;
700
701 /* XDTLS: an incorrectly formatted fragment should cause the
702 * handshake to fail */
703 OPENSSL_assert(i == (int)frag_len);
704
705 *ok = 1;
706
707 /* Note that s->init_num is *not* used as current offset in
708 * s->init_buf->data, but as a counter summing up fragments'
709 * lengths: as soon as they sum up to handshake packet
710 * length, we assume we have got all the fragments. */
711 s->init_num += frag_len;
712 return frag_len;
713
714 f_err:
715 ssl3_send_alert(s,SSL3_AL_FATAL,al);
716 s->init_num = 0;
717
718 *ok=0;
719 return(-1);
720 }
721
dtls1_send_finished(SSL * s,int a,int b,const char * sender,int slen)722 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
723 {
724 unsigned char *p,*d;
725 int i;
726 unsigned long l;
727
728 if (s->state == a)
729 {
730 d=(unsigned char *)s->init_buf->data;
731 p= &(d[DTLS1_HM_HEADER_LENGTH]);
732
733 i=s->method->ssl3_enc->final_finish_mac(s,
734 &(s->s3->finish_dgst1),
735 &(s->s3->finish_dgst2),
736 sender,slen,s->s3->tmp.finish_md);
737 s->s3->tmp.finish_md_len = i;
738 memcpy(p, s->s3->tmp.finish_md, i);
739 p+=i;
740 l=i;
741
742 #ifdef OPENSSL_SYS_WIN16
743 /* MSVC 1.5 does not clear the top bytes of the word unless
744 * I do this.
745 */
746 l&=0xffff;
747 #endif
748
749 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
750 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
751 s->init_off=0;
752
753 /* buffer the message to handle re-xmits */
754 dtls1_buffer_message(s, 0);
755
756 s->state=b;
757 }
758
759 /* SSL3_ST_SEND_xxxxxx_HELLO_B */
760 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
761 }
762
763 /* for these 2 messages, we need to
764 * ssl->enc_read_ctx re-init
765 * ssl->s3->read_sequence zero
766 * ssl->s3->read_mac_secret re-init
767 * ssl->session->read_sym_enc assign
768 * ssl->session->read_compression assign
769 * ssl->session->read_hash assign
770 */
dtls1_send_change_cipher_spec(SSL * s,int a,int b)771 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
772 {
773 unsigned char *p;
774
775 if (s->state == a)
776 {
777 p=(unsigned char *)s->init_buf->data;
778 *p++=SSL3_MT_CCS;
779 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
780 s->init_num=DTLS1_CCS_HEADER_LENGTH;
781
782 if (s->client_version == DTLS1_BAD_VER)
783 {
784 s->d1->next_handshake_write_seq++;
785 s2n(s->d1->handshake_write_seq,p);
786 s->init_num+=2;
787 }
788
789 s->init_off=0;
790
791 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
792 s->d1->handshake_write_seq, 0, 0);
793
794 /* buffer the message to handle re-xmits */
795 dtls1_buffer_message(s, 1);
796
797 s->state=b;
798 }
799
800 /* SSL3_ST_CW_CHANGE_B */
801 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
802 }
803
dtls1_output_cert_chain(SSL * s,X509 * x)804 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
805 {
806 unsigned char *p;
807 int n,i;
808 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
809 BUF_MEM *buf;
810 X509_STORE_CTX xs_ctx;
811 X509_OBJECT obj;
812
813 /* TLSv1 sends a chain with nothing in it, instead of an alert */
814 buf=s->init_buf;
815 if (!BUF_MEM_grow_clean(buf,10))
816 {
817 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
818 return(0);
819 }
820 if (x != NULL)
821 {
822 if(!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,NULL,NULL))
823 {
824 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
825 return(0);
826 }
827
828 for (;;)
829 {
830 n=i2d_X509(x,NULL);
831 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
832 {
833 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
834 return(0);
835 }
836 p=(unsigned char *)&(buf->data[l]);
837 l2n3(n,p);
838 i2d_X509(x,&p);
839 l+=n+3;
840 if (X509_NAME_cmp(X509_get_subject_name(x),
841 X509_get_issuer_name(x)) == 0) break;
842
843 i=X509_STORE_get_by_subject(&xs_ctx,X509_LU_X509,
844 X509_get_issuer_name(x),&obj);
845 if (i <= 0) break;
846 x=obj.data.x509;
847 /* Count is one too high since the X509_STORE_get uped the
848 * ref count */
849 X509_free(x);
850 }
851
852 X509_STORE_CTX_cleanup(&xs_ctx);
853 }
854
855 /* Thawte special :-) */
856 if (s->ctx->extra_certs != NULL)
857 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
858 {
859 x=sk_X509_value(s->ctx->extra_certs,i);
860 n=i2d_X509(x,NULL);
861 if (!BUF_MEM_grow_clean(buf,(int)(n+l+3)))
862 {
863 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
864 return(0);
865 }
866 p=(unsigned char *)&(buf->data[l]);
867 l2n3(n,p);
868 i2d_X509(x,&p);
869 l+=n+3;
870 }
871
872 l-= (3 + DTLS1_HM_HEADER_LENGTH);
873
874 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
875 l2n3(l,p);
876 l+=3;
877 p=(unsigned char *)&(buf->data[0]);
878 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
879
880 l+=DTLS1_HM_HEADER_LENGTH;
881 return(l);
882 }
883
dtls1_read_failed(SSL * s,int code)884 int dtls1_read_failed(SSL *s, int code)
885 {
886 DTLS1_STATE *state;
887 BIO *bio;
888 int send_alert = 0;
889
890 if ( code > 0)
891 {
892 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
893 return 1;
894 }
895
896 bio = SSL_get_rbio(s);
897 if ( ! BIO_dgram_recv_timedout(bio))
898 {
899 /* not a timeout, none of our business,
900 let higher layers handle this. in fact it's probably an error */
901 return code;
902 }
903
904 if ( ! SSL_in_init(s)) /* done, no need to send a retransmit */
905 {
906 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
907 return code;
908 }
909
910 state = s->d1;
911 state->timeout.num_alerts++;
912 if ( state->timeout.num_alerts > DTLS1_TMO_ALERT_COUNT)
913 {
914 /* fail the connection, enough alerts have been sent */
915 SSLerr(SSL_F_DTLS1_READ_FAILED,SSL_R_READ_TIMEOUT_EXPIRED);
916 return 0;
917 }
918
919 state->timeout.read_timeouts++;
920 if ( state->timeout.read_timeouts > DTLS1_TMO_READ_COUNT)
921 {
922 send_alert = 1;
923 state->timeout.read_timeouts = 1;
924 }
925
926
927 #if 0 /* for now, each alert contains only one record number */
928 item = pqueue_peek(state->rcvd_records);
929 if ( item )
930 {
931 /* send an alert immediately for all the missing records */
932 }
933 else
934 #endif
935
936 #if 0 /* no more alert sending, just retransmit the last set of messages */
937 if ( send_alert)
938 ssl3_send_alert(s,SSL3_AL_WARNING,
939 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
940 #endif
941
942 return dtls1_retransmit_buffered_messages(s) ;
943 }
944
945
946 static int
dtls1_retransmit_buffered_messages(SSL * s)947 dtls1_retransmit_buffered_messages(SSL *s)
948 {
949 pqueue sent = s->d1->sent_messages;
950 piterator iter;
951 pitem *item;
952 hm_fragment *frag;
953 int found = 0;
954
955 iter = pqueue_iterator(sent);
956
957 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
958 {
959 frag = (hm_fragment *)item->data;
960 if ( dtls1_retransmit_message(s, frag->msg_header.seq, 0, &found) <= 0 &&
961 found)
962 {
963 fprintf(stderr, "dtls1_retransmit_message() failed\n");
964 return -1;
965 }
966 }
967
968 return 1;
969 }
970
971 int
dtls1_buffer_message(SSL * s,int is_ccs)972 dtls1_buffer_message(SSL *s, int is_ccs)
973 {
974 pitem *item;
975 hm_fragment *frag;
976 PQ_64BIT seq64;
977 unsigned int epoch = s->d1->w_epoch;
978
979 /* this function is called immediately after a message has
980 * been serialized */
981 OPENSSL_assert(s->init_off == 0);
982
983 frag = dtls1_hm_fragment_new(s->init_num);
984
985 memcpy(frag->fragment, s->init_buf->data, s->init_num);
986
987 if ( is_ccs)
988 {
989 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
990 DTLS1_CCS_HEADER_LENGTH <= (unsigned int)s->init_num);
991 epoch++;
992 }
993 else
994 {
995 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
996 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
997 }
998
999 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1000 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1001 frag->msg_header.type = s->d1->w_msg_hdr.type;
1002 frag->msg_header.frag_off = 0;
1003 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1004 frag->msg_header.is_ccs = is_ccs;
1005
1006 pq_64bit_init(&seq64);
1007 pq_64bit_assign_word(&seq64, epoch<<16 | frag->msg_header.seq);
1008
1009 item = pitem_new(seq64, frag);
1010 pq_64bit_free(&seq64);
1011 if ( item == NULL)
1012 {
1013 dtls1_hm_fragment_free(frag);
1014 return 0;
1015 }
1016
1017 #if 0
1018 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1019 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1020 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1021 #endif
1022
1023 pqueue_insert(s->d1->sent_messages, item);
1024 return 1;
1025 }
1026
1027 int
dtls1_retransmit_message(SSL * s,unsigned short seq,unsigned long frag_off,int * found)1028 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1029 int *found)
1030 {
1031 int ret;
1032 /* XDTLS: for now assuming that read/writes are blocking */
1033 pitem *item;
1034 hm_fragment *frag ;
1035 unsigned long header_length;
1036 PQ_64BIT seq64;
1037
1038 /*
1039 OPENSSL_assert(s->init_num == 0);
1040 OPENSSL_assert(s->init_off == 0);
1041 */
1042
1043 /* XDTLS: the requested message ought to be found, otherwise error */
1044 pq_64bit_init(&seq64);
1045 pq_64bit_assign_word(&seq64, seq);
1046
1047 item = pqueue_find(s->d1->sent_messages, seq64);
1048 pq_64bit_free(&seq64);
1049 if ( item == NULL)
1050 {
1051 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1052 *found = 0;
1053 return 0;
1054 }
1055
1056 *found = 1;
1057 frag = (hm_fragment *)item->data;
1058
1059 if ( frag->msg_header.is_ccs)
1060 header_length = DTLS1_CCS_HEADER_LENGTH;
1061 else
1062 header_length = DTLS1_HM_HEADER_LENGTH;
1063
1064 memcpy(s->init_buf->data, frag->fragment,
1065 frag->msg_header.msg_len + header_length);
1066 s->init_num = frag->msg_header.msg_len + header_length;
1067
1068 dtls1_set_message_header_int(s, frag->msg_header.type,
1069 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1070 frag->msg_header.frag_len);
1071
1072 s->d1->retransmitting = 1;
1073 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1074 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1075 s->d1->retransmitting = 0;
1076
1077 (void)BIO_flush(SSL_get_wbio(s));
1078 return ret;
1079 }
1080
1081 /* call this function when the buffered messages are no longer needed */
1082 void
dtls1_clear_record_buffer(SSL * s)1083 dtls1_clear_record_buffer(SSL *s)
1084 {
1085 pitem *item;
1086
1087 for(item = pqueue_pop(s->d1->sent_messages);
1088 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1089 {
1090 dtls1_hm_fragment_free((hm_fragment *)item->data);
1091 pitem_free(item);
1092 }
1093 }
1094
1095
1096 unsigned char *
dtls1_set_message_header(SSL * s,unsigned char * p,unsigned char mt,unsigned long len,unsigned long frag_off,unsigned long frag_len)1097 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1098 unsigned long len, unsigned long frag_off, unsigned long frag_len)
1099 {
1100 if ( frag_off == 0)
1101 {
1102 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1103 s->d1->next_handshake_write_seq++;
1104 }
1105
1106 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1107 frag_off, frag_len);
1108
1109 return p += DTLS1_HM_HEADER_LENGTH;
1110 }
1111
1112
1113 /* don't actually do the writing, wait till the MTU has been retrieved */
1114 static void
dtls1_set_message_header_int(SSL * s,unsigned char mt,unsigned long len,unsigned short seq_num,unsigned long frag_off,unsigned long frag_len)1115 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1116 unsigned long len, unsigned short seq_num, unsigned long frag_off,
1117 unsigned long frag_len)
1118 {
1119 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1120
1121 msg_hdr->type = mt;
1122 msg_hdr->msg_len = len;
1123 msg_hdr->seq = seq_num;
1124 msg_hdr->frag_off = frag_off;
1125 msg_hdr->frag_len = frag_len;
1126 }
1127
1128 static void
dtls1_fix_message_header(SSL * s,unsigned long frag_off,unsigned long frag_len)1129 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1130 unsigned long frag_len)
1131 {
1132 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1133
1134 msg_hdr->frag_off = frag_off;
1135 msg_hdr->frag_len = frag_len;
1136 }
1137
1138 static unsigned char *
dtls1_write_message_header(SSL * s,unsigned char * p)1139 dtls1_write_message_header(SSL *s, unsigned char *p)
1140 {
1141 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1142
1143 *p++ = msg_hdr->type;
1144 l2n3(msg_hdr->msg_len, p);
1145
1146 s2n(msg_hdr->seq, p);
1147 l2n3(msg_hdr->frag_off, p);
1148 l2n3(msg_hdr->frag_len, p);
1149
1150 return p;
1151 }
1152
1153 static unsigned int
dtls1_min_mtu(void)1154 dtls1_min_mtu(void)
1155 {
1156 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1157 sizeof(g_probable_mtu[0])) - 1]);
1158 }
1159
1160 static unsigned int
dtls1_guess_mtu(unsigned int curr_mtu)1161 dtls1_guess_mtu(unsigned int curr_mtu)
1162 {
1163 size_t i;
1164
1165 if ( curr_mtu == 0 )
1166 return g_probable_mtu[0] ;
1167
1168 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1169 if ( curr_mtu > g_probable_mtu[i])
1170 return g_probable_mtu[i];
1171
1172 return curr_mtu;
1173 }
1174
1175 void
dtls1_get_message_header(unsigned char * data,struct hm_header_st * msg_hdr)1176 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1177 {
1178 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1179 msg_hdr->type = *(data++);
1180 n2l3(data, msg_hdr->msg_len);
1181
1182 n2s(data, msg_hdr->seq);
1183 n2l3(data, msg_hdr->frag_off);
1184 n2l3(data, msg_hdr->frag_len);
1185 }
1186
1187 void
dtls1_get_ccs_header(unsigned char * data,struct ccs_header_st * ccs_hdr)1188 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1189 {
1190 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1191
1192 ccs_hdr->type = *(data++);
1193 }
1194