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#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
127
128#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
129 if ((end) - (start) <= 8) { \
130 long ii; \
131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
132 } else { \
133 long ii; \
134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
137 } }
138
139#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
140 long ii; \
141 OPENSSL_assert((msg_len) > 0); \
142 is_complete = 1; \
143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
146
147#if 0
148#define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
149 long ii; \
150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
152 printf("\n"); }
153#endif
154
155static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
156static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
157
158/* XDTLS: figure out the right values */
159static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
160
161static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
162static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
163 unsigned long frag_len);
164static unsigned char *dtls1_write_message_header(SSL *s,
165 unsigned char *p);
166static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
167 unsigned long len, unsigned short seq_num, unsigned long frag_off,
168 unsigned long frag_len);
169static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
170 long max, int *ok);
171
172static hm_fragment *
173dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
174 {
175 hm_fragment *frag = NULL;
176 unsigned char *buf = NULL;
177 unsigned char *bitmask = NULL;
178
179 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
180 if ( frag == NULL)
181 return NULL;
182
183 if (frag_len)
184 {
185 buf = (unsigned char *)OPENSSL_malloc(frag_len);
186 if ( buf == NULL)
187 {
188 OPENSSL_free(frag);
189 return NULL;
190 }
191 }
192
193 /* zero length fragment gets zero frag->fragment */
194 frag->fragment = buf;
195
196 /* Initialize reassembly bitmask if necessary */
197 if (reassembly)
198 {
199 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
200 if (bitmask == NULL)
201 {
202 if (buf != NULL) OPENSSL_free(buf);
203 OPENSSL_free(frag);
204 return NULL;
205 }
206 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
207 }
208
209 frag->reassembly = bitmask;
210
211 return frag;
212 }
213
214static void
215dtls1_hm_fragment_free(hm_fragment *frag)
216 {
217
218 if (frag->msg_header.is_ccs)
219 {
220 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
221 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
222 }
223 if (frag->fragment) OPENSSL_free(frag->fragment);
224 if (frag->reassembly) OPENSSL_free(frag->reassembly);
225 OPENSSL_free(frag);
226 }
227
228/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
229int dtls1_do_write(SSL *s, int type)
230 {
231 int ret;
232 int curr_mtu;
233 unsigned int len, frag_off, mac_size, blocksize;
234
235 /* AHA! Figure out the MTU, and stick to the right size */
236 if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
237 {
238 s->d1->mtu =
239 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
240
241 /* I've seen the kernel return bogus numbers when it doesn't know
242 * (initial write), so just make sure we have a reasonable number */
243 if (s->d1->mtu < dtls1_min_mtu())
244 {
245 s->d1->mtu = 0;
246 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
247 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
248 s->d1->mtu, NULL);
249 }
250 }
251#if 0
252 mtu = s->d1->mtu;
253
254 fprintf(stderr, "using MTU = %d\n", mtu);
255
256 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
257
258 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
259
260 if ( curr_mtu > 0)
261 mtu = curr_mtu;
262 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
263 return ret;
264
265 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
266 {
267 ret = BIO_flush(SSL_get_wbio(s));
268 if ( ret <= 0)
269 return ret;
270 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
271 }
272#endif
273
274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */
275
276 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
277 OPENSSL_assert(s->init_num ==
278 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
279
280 if (s->write_hash)
281 mac_size = EVP_MD_CTX_size(s->write_hash);
282 else
283 mac_size = 0;
284
285 if (s->enc_write_ctx &&
286 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
287 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
288 else
289 blocksize = 0;
290
291 frag_off = 0;
292 while( s->init_num)
293 {
294 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
295 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
296
297 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
298 {
299 /* grr.. we could get an error if MTU picked was wrong */
300 ret = BIO_flush(SSL_get_wbio(s));
301 if ( ret <= 0)
302 return ret;
303 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
304 mac_size - blocksize;
305 }
306
307 if ( s->init_num > curr_mtu)
308 len = curr_mtu;
309 else
310 len = s->init_num;
311
312
313 /* XDTLS: this function is too long. split out the CCS part */
314 if ( type == SSL3_RT_HANDSHAKE)
315 {
316 if ( s->init_off != 0)
317 {
318 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
319 s->init_off -= DTLS1_HM_HEADER_LENGTH;
320 s->init_num += DTLS1_HM_HEADER_LENGTH;
321
322 if ( s->init_num > curr_mtu)
323 len = curr_mtu;
324 else
325 len = s->init_num;
326 }
327
328 dtls1_fix_message_header(s, frag_off,
329 len - DTLS1_HM_HEADER_LENGTH);
330
331 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
332
333 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
334 }
335
336 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
337 len);
338 if (ret < 0)
339 {
340 /* might need to update MTU here, but we don't know
341 * which previous packet caused the failure -- so can't
342 * really retransmit anything. continue as if everything
343 * is fine and wait for an alert to handle the
344 * retransmit
345 */
346 if ( BIO_ctrl(SSL_get_wbio(s),
347 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
348 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
349 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
350 else
351 return(-1);
352 }
353 else
354 {
355
356 /* bad if this assert fails, only part of the handshake
357 * message got sent. but why would this happen? */
358 OPENSSL_assert(len == (unsigned int)ret);
359
360 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
361 {
362 /* should not be done for 'Hello Request's, but in that case
363 * we'll ignore the result anyway */
364 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
365 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
366 int xlen;
367
368 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
369 {
370 /* reconstruct message header is if it
371 * is being sent in single fragment */
372 *p++ = msg_hdr->type;
373 l2n3(msg_hdr->msg_len,p);
374 s2n (msg_hdr->seq,p);
375 l2n3(0,p);
376 l2n3(msg_hdr->msg_len,p);
377 p -= DTLS1_HM_HEADER_LENGTH;
378 xlen = ret;
379 }
380 else
381 {
382 p += DTLS1_HM_HEADER_LENGTH;
383 xlen = ret - DTLS1_HM_HEADER_LENGTH;
384 }
385
386 ssl3_finish_mac(s, p, xlen);
387 }
388
389 if (ret == s->init_num)
390 {
391 if (s->msg_callback)
392 s->msg_callback(1, s->version, type, s->init_buf->data,
393 (size_t)(s->init_off + s->init_num), s,
394 s->msg_callback_arg);
395
396 s->init_off = 0; /* done writing this message */
397 s->init_num = 0;
398
399 return(1);
400 }
401 s->init_off+=ret;
402 s->init_num-=ret;
403 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
404 }
405 }
406 return(0);
407 }
408
409
410/* Obtain handshake message of message type 'mt' (any if mt == -1),
411 * maximum acceptable body length 'max'.
412 * Read an entire handshake message. Handshake messages arrive in
413 * fragments.
414 */
415long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
416 {
417 int i, al;
418 struct hm_header_st *msg_hdr;
419 unsigned char *p;
420 unsigned long msg_len;
421
422 /* s3->tmp is used to store messages that are unexpected, caused
423 * by the absence of an optional handshake message */
424 if (s->s3->tmp.reuse_message)
425 {
426 s->s3->tmp.reuse_message=0;
427 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
428 {
429 al=SSL_AD_UNEXPECTED_MESSAGE;
430 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
431 goto f_err;
432 }
433 *ok=1;
434 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
435 s->init_num = (int)s->s3->tmp.message_size;
436 return s->init_num;
437 }
438
439 msg_hdr = &s->d1->r_msg_hdr;
440 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
441
442again:
443 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
444 if ( i == DTLS1_HM_BAD_FRAGMENT ||
445 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
446 goto again;
447 else if ( i <= 0 && !*ok)
448 return i;
449
450 p = (unsigned char *)s->init_buf->data;
451 msg_len = msg_hdr->msg_len;
452
453 /* reconstruct message header */
454 *(p++) = msg_hdr->type;
455 l2n3(msg_len,p);
456 s2n (msg_hdr->seq,p);
457 l2n3(0,p);
458 l2n3(msg_len,p);
459 if (s->version != DTLS1_BAD_VER) {
460 p -= DTLS1_HM_HEADER_LENGTH;
461 msg_len += DTLS1_HM_HEADER_LENGTH;
462 }
463
464 ssl3_finish_mac(s, p, msg_len);
465 if (s->msg_callback)
466 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
467 p, msg_len,
468 s, s->msg_callback_arg);
469
470 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
471
472 /* Don't change sequence numbers while listening */
473 if (!s->d1->listen)
474 s->d1->handshake_read_seq++;
475
476 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
477 return s->init_num;
478
479f_err:
480 ssl3_send_alert(s,SSL3_AL_FATAL,al);
481 *ok = 0;
482 return -1;
483 }
484
485
486static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
487 {
488 size_t frag_off,frag_len,msg_len;
489
490 msg_len = msg_hdr->msg_len;
491 frag_off = msg_hdr->frag_off;
492 frag_len = msg_hdr->frag_len;
493
494 /* sanity checking */
495 if ( (frag_off+frag_len) > msg_len)
496 {
497 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
498 return SSL_AD_ILLEGAL_PARAMETER;
499 }
500
501 if ( (frag_off+frag_len) > (unsigned long)max)
502 {
503 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
504 return SSL_AD_ILLEGAL_PARAMETER;
505 }
506
507 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
508 {
509 /* msg_len is limited to 2^24, but is effectively checked
510 * against max above */
511 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
512 {
513 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
514 return SSL_AD_INTERNAL_ERROR;
515 }
516
517 s->s3->tmp.message_size = msg_len;
518 s->d1->r_msg_hdr.msg_len = msg_len;
519 s->s3->tmp.message_type = msg_hdr->type;
520 s->d1->r_msg_hdr.type = msg_hdr->type;
521 s->d1->r_msg_hdr.seq = msg_hdr->seq;
522 }
523 else if (msg_len != s->d1->r_msg_hdr.msg_len)
524 {
525 /* They must be playing with us! BTW, failure to enforce
526 * upper limit would open possibility for buffer overrun. */
527 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
528 return SSL_AD_ILLEGAL_PARAMETER;
529 }
530
531 return 0; /* no error */
532 }
533
534
535static int
536dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
537 {
538 /* (0) check whether the desired fragment is available
539 * if so:
540 * (1) copy over the fragment to s->init_buf->data[]
541 * (2) update s->init_num
542 */
543 pitem *item;
544 hm_fragment *frag;
545 int al;
546
547 *ok = 0;
548 item = pqueue_peek(s->d1->buffered_messages);
549 if ( item == NULL)
550 return 0;
551
552 frag = (hm_fragment *)item->data;
553
554 /* Don't return if reassembly still in progress */
555 if (frag->reassembly != NULL)
556 return 0;
557
558 if ( s->d1->handshake_read_seq == frag->msg_header.seq)
559 {
560 unsigned long frag_len = frag->msg_header.frag_len;
561 pqueue_pop(s->d1->buffered_messages);
562
563 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
564
565 if (al==0) /* no alert */
566 {
567 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
568 memcpy(&p[frag->msg_header.frag_off],
569 frag->fragment,frag->msg_header.frag_len);
570 }
571
572 dtls1_hm_fragment_free(frag);
573 pitem_free(item);
574
575 if (al==0)
576 {
577 *ok = 1;
578 return frag_len;
579 }
580
581 ssl3_send_alert(s,SSL3_AL_FATAL,al);
582 s->init_num = 0;
583 *ok = 0;
584 return -1;
585 }
586 else
587 return 0;
588 }
589
590
591static int
592dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
593 {
594 hm_fragment *frag = NULL;
595 pitem *item = NULL;
596 int i = -1, is_complete;
597 unsigned char seq64be[8];
598 unsigned long frag_len = msg_hdr->frag_len, max_len;
599
600 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
601 goto err;
602
603 /* Determine maximum allowed message size. Depends on (user set)
604 * maximum certificate length, but 16k is minimum.
605 */
606 if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
607 max_len = s->max_cert_list;
608 else
609 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
610
611 if ((msg_hdr->frag_off+frag_len) > max_len)
612 goto err;
613
614 /* Try to find item in queue */
615 memset(seq64be,0,sizeof(seq64be));
616 seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
617 seq64be[7] = (unsigned char) msg_hdr->seq;
618 item = pqueue_find(s->d1->buffered_messages, seq64be);
619
620 if (item == NULL)
621 {
622 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
623 if ( frag == NULL)
624 goto err;
625 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
626 frag->msg_header.frag_len = frag->msg_header.msg_len;
627 frag->msg_header.frag_off = 0;
628 }
629 else
630 frag = (hm_fragment*) item->data;
631
632 /* If message is already reassembled, this must be a
633 * retransmit and can be dropped.
634 */
635 if (frag->reassembly == NULL)
636 {
637 unsigned char devnull [256];
638
639 while (frag_len)
640 {
641 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
642 devnull,
643 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
644 if (i<=0) goto err;
645 frag_len -= i;
646 }
647 return DTLS1_HM_FRAGMENT_RETRY;
648 }
649
650 /* read the body of the fragment (header has already been read */
651 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
652 frag->fragment + msg_hdr->frag_off,frag_len,0);
653 if (i<=0 || (unsigned long)i!=frag_len)
654 goto err;
655
656 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
657 (long)(msg_hdr->frag_off + frag_len));
658
659 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
660 is_complete);
661
662 if (is_complete)
663 {
664 OPENSSL_free(frag->reassembly);
665 frag->reassembly = NULL;
666 }
667
668 if (item == NULL)
669 {
670 memset(seq64be,0,sizeof(seq64be));
671 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
672 seq64be[7] = (unsigned char)(msg_hdr->seq);
673
674 item = pitem_new(seq64be, frag);
675 if (item == NULL)
676 {
677 goto err;
678 i = -1;
679 }
680
681 pqueue_insert(s->d1->buffered_messages, item);
682 }
683
684 return DTLS1_HM_FRAGMENT_RETRY;
685
686err:
687 if (frag != NULL) dtls1_hm_fragment_free(frag);
688 if (item != NULL) OPENSSL_free(item);
689 *ok = 0;
690 return i;
691 }
692
693
694static int
695dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
696{
697 int i=-1;
698 hm_fragment *frag = NULL;
699 pitem *item = NULL;
700 unsigned char seq64be[8];
701 unsigned long frag_len = msg_hdr->frag_len;
702
703 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
704 goto err;
705
706 /* Try to find item in queue, to prevent duplicate entries */
707 memset(seq64be,0,sizeof(seq64be));
708 seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
709 seq64be[7] = (unsigned char) msg_hdr->seq;
710 item = pqueue_find(s->d1->buffered_messages, seq64be);
711
712 /* If we already have an entry and this one is a fragment,
713 * don't discard it and rather try to reassemble it.
714 */
715 if (item != NULL && frag_len < msg_hdr->msg_len)
716 item = NULL;
717
718 /* Discard the message if sequence number was already there, is
719 * too far in the future, already in the queue or if we received
720 * a FINISHED before the SERVER_HELLO, which then must be a stale
721 * retransmit.
722 */
723 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
724 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
725 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
726 {
727 unsigned char devnull [256];
728
729 while (frag_len)
730 {
731 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
732 devnull,
733 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
734 if (i<=0) goto err;
735 frag_len -= i;
736 }
737 }
738 else
739 {
740 if (frag_len && frag_len < msg_hdr->msg_len)
741 return dtls1_reassemble_fragment(s, msg_hdr, ok);
742
743 frag = dtls1_hm_fragment_new(frag_len, 0);
744 if ( frag == NULL)
745 goto err;
746
747 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
748
749 if (frag_len)
750 {
751 /* read the body of the fragment (header has already been read */
752 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
753 frag->fragment,frag_len,0);
754 if (i<=0 || (unsigned long)i!=frag_len)
755 goto err;
756 }
757
758 memset(seq64be,0,sizeof(seq64be));
759 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
760 seq64be[7] = (unsigned char)(msg_hdr->seq);
761
762 item = pitem_new(seq64be, frag);
763 if ( item == NULL)
764 goto err;
765
766 pqueue_insert(s->d1->buffered_messages, item);
767 }
768
769 return DTLS1_HM_FRAGMENT_RETRY;
770
771err:
772 if ( frag != NULL) dtls1_hm_fragment_free(frag);
773 if ( item != NULL) OPENSSL_free(item);
774 *ok = 0;
775 return i;
776 }
777
778
779static long
780dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
781 {
782 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
783 unsigned long len, frag_off, frag_len;
784 int i,al;
785 struct hm_header_st msg_hdr;
786
787 /* see if we have the required fragment already */
788 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
789 {
790 if (*ok) s->init_num = frag_len;
791 return frag_len;
792 }
793
794 /* read handshake message header */
795 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
796 DTLS1_HM_HEADER_LENGTH, 0);
797 if (i <= 0) /* nbio, or an error */
798 {
799 s->rwstate=SSL_READING;
800 *ok = 0;
801 return i;
802 }
803 /* Handshake fails if message header is incomplete */
804 if (i != DTLS1_HM_HEADER_LENGTH)
805 {
806 al=SSL_AD_UNEXPECTED_MESSAGE;
807 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
808 goto f_err;
809 }
810
811 /* parse the message fragment header */
812 dtls1_get_message_header(wire, &msg_hdr);
813
814 /*
815 * if this is a future (or stale) message it gets buffered
816 * (or dropped)--no further processing at this time
817 * While listening, we accept seq 1 (ClientHello with cookie)
818 * although we're still expecting seq 0 (ClientHello)
819 */
820 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
821 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
822
823 len = msg_hdr.msg_len;
824 frag_off = msg_hdr.frag_off;
825 frag_len = msg_hdr.frag_len;
826
827 if (frag_len && frag_len < len)
828 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
829
830 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
831 wire[0] == SSL3_MT_HELLO_REQUEST)
832 {
833 /* The server may always send 'Hello Request' messages --
834 * we are doing a handshake anyway now, so ignore them
835 * if their format is correct. Does not count for
836 * 'Finished' MAC. */
837 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
838 {
839 if (s->msg_callback)
840 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
841 wire, DTLS1_HM_HEADER_LENGTH, s,
842 s->msg_callback_arg);
843
844 s->init_num = 0;
845 return dtls1_get_message_fragment(s, st1, stn,
846 max, ok);
847 }
848 else /* Incorrectly formated Hello request */
849 {
850 al=SSL_AD_UNEXPECTED_MESSAGE;
851 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
852 goto f_err;
853 }
854 }
855
856 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
857 goto f_err;
858
859 /* XDTLS: ressurect this when restart is in place */
860 s->state=stn;
861
862 if ( frag_len > 0)
863 {
864 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
865
866 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
867 &p[frag_off],frag_len,0);
868 /* XDTLS: fix this--message fragments cannot span multiple packets */
869 if (i <= 0)
870 {
871 s->rwstate=SSL_READING;
872 *ok = 0;
873 return i;
874 }
875 }
876 else
877 i = 0;
878
879 /* XDTLS: an incorrectly formatted fragment should cause the
880 * handshake to fail */
881 if (i != (int)frag_len)
882 {
883 al=SSL3_AD_ILLEGAL_PARAMETER;
884 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
885 goto f_err;
886 }
887
888 *ok = 1;
889
890 /* Note that s->init_num is *not* used as current offset in
891 * s->init_buf->data, but as a counter summing up fragments'
892 * lengths: as soon as they sum up to handshake packet
893 * length, we assume we have got all the fragments. */
894 s->init_num = frag_len;
895 return frag_len;
896
897f_err:
898 ssl3_send_alert(s,SSL3_AL_FATAL,al);
899 s->init_num = 0;
900
901 *ok=0;
902 return(-1);
903 }
904
905int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
906 {
907 unsigned char *p,*d;
908 int i;
909 unsigned long l;
910
911 if (s->state == a)
912 {
913 d=(unsigned char *)s->init_buf->data;
914 p= &(d[DTLS1_HM_HEADER_LENGTH]);
915
916 i=s->method->ssl3_enc->final_finish_mac(s,
917 sender,slen,s->s3->tmp.finish_md);
918 s->s3->tmp.finish_md_len = i;
919 memcpy(p, s->s3->tmp.finish_md, i);
920 p+=i;
921 l=i;
922
923 /* Copy the finished so we can use it for
924 * renegotiation checks
925 */
926 if(s->type == SSL_ST_CONNECT)
927 {
928 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
929 memcpy(s->s3->previous_client_finished,
930 s->s3->tmp.finish_md, i);
931 s->s3->previous_client_finished_len=i;
932 }
933 else
934 {
935 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
936 memcpy(s->s3->previous_server_finished,
937 s->s3->tmp.finish_md, i);
938 s->s3->previous_server_finished_len=i;
939 }
940
941#ifdef OPENSSL_SYS_WIN16
942 /* MSVC 1.5 does not clear the top bytes of the word unless
943 * I do this.
944 */
945 l&=0xffff;
946#endif
947
948 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
949 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
950 s->init_off=0;
951
952 /* buffer the message to handle re-xmits */
953 dtls1_buffer_message(s, 0);
954
955 s->state=b;
956 }
957
958 /* SSL3_ST_SEND_xxxxxx_HELLO_B */
959 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
960 }
961
962/* for these 2 messages, we need to
963 * ssl->enc_read_ctx re-init
964 * ssl->s3->read_sequence zero
965 * ssl->s3->read_mac_secret re-init
966 * ssl->session->read_sym_enc assign
967 * ssl->session->read_compression assign
968 * ssl->session->read_hash assign
969 */
970int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
971 {
972 unsigned char *p;
973
974 if (s->state == a)
975 {
976 p=(unsigned char *)s->init_buf->data;
977 *p++=SSL3_MT_CCS;
978 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
979 s->init_num=DTLS1_CCS_HEADER_LENGTH;
980
981 if (s->version == DTLS1_BAD_VER) {
982 s->d1->next_handshake_write_seq++;
983 s2n(s->d1->handshake_write_seq,p);
984 s->init_num+=2;
985 }
986
987 s->init_off=0;
988
989 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
990 s->d1->handshake_write_seq, 0, 0);
991
992 /* buffer the message to handle re-xmits */
993 dtls1_buffer_message(s, 1);
994
995 s->state=b;
996 }
997
998 /* SSL3_ST_CW_CHANGE_B */
999 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1000 }
1001
1002static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1003 {
1004 int n;
1005 unsigned char *p;
1006
1007 n=i2d_X509(x,NULL);
1008 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1009 {
1010 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1011 return 0;
1012 }
1013 p=(unsigned char *)&(buf->data[*l]);
1014 l2n3(n,p);
1015 i2d_X509(x,&p);
1016 *l+=n+3;
1017
1018 return 1;
1019 }
1020unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1021 {
1022 unsigned char *p;
1023 int i;
1024 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1025 BUF_MEM *buf;
1026
1027 /* TLSv1 sends a chain with nothing in it, instead of an alert */
1028 buf=s->init_buf;
1029 if (!BUF_MEM_grow_clean(buf,10))
1030 {
1031 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1032 return(0);
1033 }
1034 if (x != NULL)
1035 {
1036 X509_STORE_CTX xs_ctx;
1037
1038 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1039 {
1040 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1041 return(0);
1042 }
1043
1044 X509_verify_cert(&xs_ctx);
1045 /* Don't leave errors in the queue */
1046 ERR_clear_error();
1047 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1048 {
1049 x = sk_X509_value(xs_ctx.chain, i);
1050
1051 if (!dtls1_add_cert_to_buf(buf, &l, x))
1052 {
1053 X509_STORE_CTX_cleanup(&xs_ctx);
1054 return 0;
1055 }
1056 }
1057 X509_STORE_CTX_cleanup(&xs_ctx);
1058 }
1059 /* Thawte special :-) */
1060 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1061 {
1062 x=sk_X509_value(s->ctx->extra_certs,i);
1063 if (!dtls1_add_cert_to_buf(buf, &l, x))
1064 return 0;
1065 }
1066
1067 l-= (3 + DTLS1_HM_HEADER_LENGTH);
1068
1069 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1070 l2n3(l,p);
1071 l+=3;
1072 p=(unsigned char *)&(buf->data[0]);
1073 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1074
1075 l+=DTLS1_HM_HEADER_LENGTH;
1076 return(l);
1077 }
1078
1079int dtls1_read_failed(SSL *s, int code)
1080 {
1081 if ( code > 0)
1082 {
1083 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1084 return 1;
1085 }
1086
1087 if (!dtls1_is_timer_expired(s))
1088 {
1089 /* not a timeout, none of our business,
1090 let higher layers handle this. in fact it's probably an error */
1091 return code;
1092 }
1093
1094#ifndef OPENSSL_NO_HEARTBEATS
1095 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */
1096#else
1097 if (!SSL_in_init(s)) /* done, no need to send a retransmit */
1098#endif
1099 {
1100 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1101 return code;
1102 }
1103
1104#if 0 /* for now, each alert contains only one record number */
1105 item = pqueue_peek(state->rcvd_records);
1106 if ( item )
1107 {
1108 /* send an alert immediately for all the missing records */
1109 }
1110 else
1111#endif
1112
1113#if 0 /* no more alert sending, just retransmit the last set of messages */
1114 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1115 ssl3_send_alert(s,SSL3_AL_WARNING,
1116 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1117#endif
1118
1119 return dtls1_handle_timeout(s);
1120 }
1121
1122int
1123dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1124 {
1125 /* The index of the retransmission queue actually is the message sequence number,
1126 * since the queue only contains messages of a single handshake. However, the
1127 * ChangeCipherSpec has no message sequence number and so using only the sequence
1128 * will result in the CCS and Finished having the same index. To prevent this,
1129 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1130 * This does not only differ CSS and Finished, it also maintains the order of the
1131 * index (important for priority queues) and fits in the unsigned short variable.
1132 */
1133 return seq * 2 - is_ccs;
1134 }
1135
1136int
1137dtls1_retransmit_buffered_messages(SSL *s)
1138 {
1139 pqueue sent = s->d1->sent_messages;
1140 piterator iter;
1141 pitem *item;
1142 hm_fragment *frag;
1143 int found = 0;
1144
1145 iter = pqueue_iterator(sent);
1146
1147 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1148 {
1149 frag = (hm_fragment *)item->data;
1150 if ( dtls1_retransmit_message(s,
1151 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1152 0, &found) <= 0 && found)
1153 {
1154 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1155 return -1;
1156 }
1157 }
1158
1159 return 1;
1160 }
1161
1162int
1163dtls1_buffer_message(SSL *s, int is_ccs)
1164 {
1165 pitem *item;
1166 hm_fragment *frag;
1167 unsigned char seq64be[8];
1168
1169 /* this function is called immediately after a message has
1170 * been serialized */
1171 OPENSSL_assert(s->init_off == 0);
1172
1173 frag = dtls1_hm_fragment_new(s->init_num, 0);
1174
1175 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1176
1177 if ( is_ccs)
1178 {
1179 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1180 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
1181 }
1182 else
1183 {
1184 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1185 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1186 }
1187
1188 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1189 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1190 frag->msg_header.type = s->d1->w_msg_hdr.type;
1191 frag->msg_header.frag_off = 0;
1192 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1193 frag->msg_header.is_ccs = is_ccs;
1194
1195 /* save current state*/
1196 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1197 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1198 frag->msg_header.saved_retransmit_state.compress = s->compress;
1199 frag->msg_header.saved_retransmit_state.session = s->session;
1200 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1201
1202 memset(seq64be,0,sizeof(seq64be));
1203 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1204 frag->msg_header.is_ccs)>>8);
1205 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1206 frag->msg_header.is_ccs));
1207
1208 item = pitem_new(seq64be, frag);
1209 if ( item == NULL)
1210 {
1211 dtls1_hm_fragment_free(frag);
1212 return 0;
1213 }
1214
1215#if 0
1216 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1217 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1218 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1219#endif
1220
1221 pqueue_insert(s->d1->sent_messages, item);
1222 return 1;
1223 }
1224
1225int
1226dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1227 int *found)
1228 {
1229 int ret;
1230 /* XDTLS: for now assuming that read/writes are blocking */
1231 pitem *item;
1232 hm_fragment *frag ;
1233 unsigned long header_length;
1234 unsigned char seq64be[8];
1235 struct dtls1_retransmit_state saved_state;
1236 unsigned char save_write_sequence[8];
1237
1238 /*
1239 OPENSSL_assert(s->init_num == 0);
1240 OPENSSL_assert(s->init_off == 0);
1241 */
1242
1243 /* XDTLS: the requested message ought to be found, otherwise error */
1244 memset(seq64be,0,sizeof(seq64be));
1245 seq64be[6] = (unsigned char)(seq>>8);
1246 seq64be[7] = (unsigned char)seq;
1247
1248 item = pqueue_find(s->d1->sent_messages, seq64be);
1249 if ( item == NULL)
1250 {
1251 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1252 *found = 0;
1253 return 0;
1254 }
1255
1256 *found = 1;
1257 frag = (hm_fragment *)item->data;
1258
1259 if ( frag->msg_header.is_ccs)
1260 header_length = DTLS1_CCS_HEADER_LENGTH;
1261 else
1262 header_length = DTLS1_HM_HEADER_LENGTH;
1263
1264 memcpy(s->init_buf->data, frag->fragment,
1265 frag->msg_header.msg_len + header_length);
1266 s->init_num = frag->msg_header.msg_len + header_length;
1267
1268 dtls1_set_message_header_int(s, frag->msg_header.type,
1269 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1270 frag->msg_header.frag_len);
1271
1272 /* save current state */
1273 saved_state.enc_write_ctx = s->enc_write_ctx;
1274 saved_state.write_hash = s->write_hash;
1275 saved_state.compress = s->compress;
1276 saved_state.session = s->session;
1277 saved_state.epoch = s->d1->w_epoch;
1278 saved_state.epoch = s->d1->w_epoch;
1279
1280 s->d1->retransmitting = 1;
1281
1282 /* restore state in which the message was originally sent */
1283 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1284 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1285 s->compress = frag->msg_header.saved_retransmit_state.compress;
1286 s->session = frag->msg_header.saved_retransmit_state.session;
1287 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1288
1289 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1290 {
1291 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1292 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1293 }
1294
1295 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1296 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1297
1298 /* restore current state */
1299 s->enc_write_ctx = saved_state.enc_write_ctx;
1300 s->write_hash = saved_state.write_hash;
1301 s->compress = saved_state.compress;
1302 s->session = saved_state.session;
1303 s->d1->w_epoch = saved_state.epoch;
1304
1305 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1306 {
1307 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1308 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1309 }
1310
1311 s->d1->retransmitting = 0;
1312
1313 (void)BIO_flush(SSL_get_wbio(s));
1314 return ret;
1315 }
1316
1317/* call this function when the buffered messages are no longer needed */
1318void
1319dtls1_clear_record_buffer(SSL *s)
1320 {
1321 pitem *item;
1322
1323 for(item = pqueue_pop(s->d1->sent_messages);
1324 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1325 {
1326 dtls1_hm_fragment_free((hm_fragment *)item->data);
1327 pitem_free(item);
1328 }
1329 }
1330
1331
1332unsigned char *
1333dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1334 unsigned long len, unsigned long frag_off, unsigned long frag_len)
1335 {
1336 /* Don't change sequence numbers while listening */
1337 if (frag_off == 0 && !s->d1->listen)
1338 {
1339 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1340 s->d1->next_handshake_write_seq++;
1341 }
1342
1343 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1344 frag_off, frag_len);
1345
1346 return p += DTLS1_HM_HEADER_LENGTH;
1347 }
1348
1349
1350/* don't actually do the writing, wait till the MTU has been retrieved */
1351static void
1352dtls1_set_message_header_int(SSL *s, unsigned char mt,
1353 unsigned long len, unsigned short seq_num, unsigned long frag_off,
1354 unsigned long frag_len)
1355 {
1356 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1357
1358 msg_hdr->type = mt;
1359 msg_hdr->msg_len = len;
1360 msg_hdr->seq = seq_num;
1361 msg_hdr->frag_off = frag_off;
1362 msg_hdr->frag_len = frag_len;
1363 }
1364
1365static void
1366dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1367 unsigned long frag_len)
1368 {
1369 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1370
1371 msg_hdr->frag_off = frag_off;
1372 msg_hdr->frag_len = frag_len;
1373 }
1374
1375static unsigned char *
1376dtls1_write_message_header(SSL *s, unsigned char *p)
1377 {
1378 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1379
1380 *p++ = msg_hdr->type;
1381 l2n3(msg_hdr->msg_len, p);
1382
1383 s2n(msg_hdr->seq, p);
1384 l2n3(msg_hdr->frag_off, p);
1385 l2n3(msg_hdr->frag_len, p);
1386
1387 return p;
1388 }
1389
1390unsigned int
1391dtls1_min_mtu(void)
1392 {
1393 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1394 sizeof(g_probable_mtu[0])) - 1]);
1395 }
1396
1397static unsigned int
1398dtls1_guess_mtu(unsigned int curr_mtu)
1399 {
1400 unsigned int i;
1401
1402 if ( curr_mtu == 0 )
1403 return g_probable_mtu[0] ;
1404
1405 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1406 if ( curr_mtu > g_probable_mtu[i])
1407 return g_probable_mtu[i];
1408
1409 return curr_mtu;
1410 }
1411
1412void
1413dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1414 {
1415 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1416 msg_hdr->type = *(data++);
1417 n2l3(data, msg_hdr->msg_len);
1418
1419 n2s(data, msg_hdr->seq);
1420 n2l3(data, msg_hdr->frag_off);
1421 n2l3(data, msg_hdr->frag_len);
1422 }
1423
1424void
1425dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1426 {
1427 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1428
1429 ccs_hdr->type = *(data++);
1430 }
1431
1432int dtls1_shutdown(SSL *s)
1433 {
1434 int ret;
1435#ifndef OPENSSL_NO_SCTP
1436 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1437 !(s->shutdown & SSL_SENT_SHUTDOWN))
1438 {
1439 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1440 if (ret < 0) return -1;
1441
1442 if (ret == 0)
1443 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1444 }
1445#endif
1446 ret = ssl3_shutdown(s);
1447#ifndef OPENSSL_NO_SCTP
1448 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1449#endif
1450 return ret;
1451 }
1452
1453#ifndef OPENSSL_NO_HEARTBEATS
1454int
1455dtls1_process_heartbeat(SSL *s)
1456 {
1457 unsigned char *p = &s->s3->rrec.data[0], *pl;
1458 unsigned short hbtype;
1459 unsigned int payload;
1460 unsigned int padding = 16; /* Use minimum padding */
1461
1462 if (s->msg_callback)
1463 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1464 &s->s3->rrec.data[0], s->s3->rrec.length,
1465 s, s->msg_callback_arg);
1466
1467 /* Read type and payload length first */
1468 if (1 + 2 + 16 > s->s3->rrec.length)
1469 return 0; /* silently discard */
1470 hbtype = *p++;
1471 n2s(p, payload);
1472 if (1 + 2 + payload + 16 > s->s3->rrec.length)
1473 return 0; /* silently discard per RFC 6520 sec. 4 */
1474 pl = p;
1475
1476 if (hbtype == TLS1_HB_REQUEST)
1477 {
1478 unsigned char *buffer, *bp;
1479 unsigned int write_length = 1 /* heartbeat type */ +
1480 2 /* heartbeat length */ +
1481 payload + padding;
1482 int r;
1483
1484 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1485 return 0;
1486
1487 /* Allocate memory for the response, size is 1 byte
1488 * message type, plus 2 bytes payload length, plus
1489 * payload, plus padding
1490 */
1491 buffer = OPENSSL_malloc(write_length);
1492 bp = buffer;
1493
1494 /* Enter response type, length and copy payload */
1495 *bp++ = TLS1_HB_RESPONSE;
1496 s2n(payload, bp);
1497 memcpy(bp, pl, payload);
1498 bp += payload;
1499 /* Random padding */
1500 RAND_pseudo_bytes(bp, padding);
1501
1502 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1503
1504 if (r >= 0 && s->msg_callback)
1505 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1506 buffer, write_length,
1507 s, s->msg_callback_arg);
1508
1509 OPENSSL_free(buffer);
1510
1511 if (r < 0)
1512 return r;
1513 }
1514 else if (hbtype == TLS1_HB_RESPONSE)
1515 {
1516 unsigned int seq;
1517
1518 /* We only send sequence numbers (2 bytes unsigned int),
1519 * and 16 random bytes, so we just try to read the
1520 * sequence number */
1521 n2s(pl, seq);
1522
1523 if (payload == 18 && seq == s->tlsext_hb_seq)
1524 {
1525 dtls1_stop_timer(s);
1526 s->tlsext_hb_seq++;
1527 s->tlsext_hb_pending = 0;
1528 }
1529 }
1530
1531 return 0;
1532 }
1533
1534int
1535dtls1_heartbeat(SSL *s)
1536 {
1537 unsigned char *buf, *p;
1538 int ret;
1539 unsigned int payload = 18; /* Sequence number + random bytes */
1540 unsigned int padding = 16; /* Use minimum padding */
1541
1542 /* Only send if peer supports and accepts HB requests... */
1543 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1544 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1545 {
1546 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1547 return -1;
1548 }
1549
1550 /* ...and there is none in flight yet... */
1551 if (s->tlsext_hb_pending)
1552 {
1553 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1554 return -1;
1555 }
1556
1557 /* ...and no handshake in progress. */
1558 if (SSL_in_init(s) || s->in_handshake)
1559 {
1560 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1561 return -1;
1562 }
1563
1564 /* Check if padding is too long, payload and padding
1565 * must not exceed 2^14 - 3 = 16381 bytes in total.
1566 */
1567 OPENSSL_assert(payload + padding <= 16381);
1568
1569 /* Create HeartBeat message, we just use a sequence number
1570 * as payload to distuingish different messages and add
1571 * some random stuff.
1572 * - Message Type, 1 byte
1573 * - Payload Length, 2 bytes (unsigned int)
1574 * - Payload, the sequence number (2 bytes uint)
1575 * - Payload, random bytes (16 bytes uint)
1576 * - Padding
1577 */
1578 buf = OPENSSL_malloc(1 + 2 + payload + padding);
1579 p = buf;
1580 /* Message Type */
1581 *p++ = TLS1_HB_REQUEST;
1582 /* Payload length (18 bytes here) */
1583 s2n(payload, p);
1584 /* Sequence number */
1585 s2n(s->tlsext_hb_seq, p);
1586 /* 16 random bytes */
1587 RAND_pseudo_bytes(p, 16);
1588 p += 16;
1589 /* Random padding */
1590 RAND_pseudo_bytes(p, padding);
1591
1592 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1593 if (ret >= 0)
1594 {
1595 if (s->msg_callback)
1596 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1597 buf, 3 + payload + padding,
1598 s, s->msg_callback_arg);
1599
1600 dtls1_start_timer(s);
1601 s->tlsext_hb_pending = 1;
1602 }
1603
1604 OPENSSL_free(buf);
1605
1606 return ret;
1607 }
1608#endif
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#define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
127
128#define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
129 if ((end) - (start) <= 8) { \
130 long ii; \
131 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
132 } else { \
133 long ii; \
134 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
135 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
136 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
137 } }
138
139#define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
140 long ii; \
141 OPENSSL_assert((msg_len) > 0); \
142 is_complete = 1; \
143 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
144 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
145 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
146
147#if 0
148#define RSMBLY_BITMASK_PRINT(bitmask, msg_len) { \
149 long ii; \
150 printf("bitmask: "); for (ii = 0; ii < (msg_len); ii++) \
151 printf("%d ", (bitmask[ii >> 3] & (1 << (ii & 7))) >> (ii & 7)); \
152 printf("\n"); }
153#endif
154
155static unsigned char bitmask_start_values[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
156static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
157
158/* XDTLS: figure out the right values */
159static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
160
161static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
162static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
163 unsigned long frag_len);
164static unsigned char *dtls1_write_message_header(SSL *s,
165 unsigned char *p);
166static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
167 unsigned long len, unsigned short seq_num, unsigned long frag_off,
168 unsigned long frag_len);
169static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
170 long max, int *ok);
171
172static hm_fragment *
173dtls1_hm_fragment_new(unsigned long frag_len, int reassembly)
174 {
175 hm_fragment *frag = NULL;
176 unsigned char *buf = NULL;
177 unsigned char *bitmask = NULL;
178
179 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
180 if ( frag == NULL)
181 return NULL;
182
183 if (frag_len)
184 {
185 buf = (unsigned char *)OPENSSL_malloc(frag_len);
186 if ( buf == NULL)
187 {
188 OPENSSL_free(frag);
189 return NULL;
190 }
191 }
192
193 /* zero length fragment gets zero frag->fragment */
194 frag->fragment = buf;
195
196 /* Initialize reassembly bitmask if necessary */
197 if (reassembly)
198 {
199 bitmask = (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
200 if (bitmask == NULL)
201 {
202 if (buf != NULL) OPENSSL_free(buf);
203 OPENSSL_free(frag);
204 return NULL;
205 }
206 memset(bitmask, 0, RSMBLY_BITMASK_SIZE(frag_len));
207 }
208
209 frag->reassembly = bitmask;
210
211 return frag;
212 }
213
214static void
215dtls1_hm_fragment_free(hm_fragment *frag)
216 {
217
218 if (frag->msg_header.is_ccs)
219 {
220 EVP_CIPHER_CTX_free(frag->msg_header.saved_retransmit_state.enc_write_ctx);
221 EVP_MD_CTX_destroy(frag->msg_header.saved_retransmit_state.write_hash);
222 }
223 if (frag->fragment) OPENSSL_free(frag->fragment);
224 if (frag->reassembly) OPENSSL_free(frag->reassembly);
225 OPENSSL_free(frag);
226 }
227
228/* send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or SSL3_RT_CHANGE_CIPHER_SPEC) */
229int dtls1_do_write(SSL *s, int type)
230 {
231 int ret;
232 int curr_mtu;
233 unsigned int len, frag_off, mac_size, blocksize;
234
235 /* AHA! Figure out the MTU, and stick to the right size */
236 if (s->d1->mtu < dtls1_min_mtu() && !(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU))
237 {
238 s->d1->mtu =
239 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
240
241 /* I've seen the kernel return bogus numbers when it doesn't know
242 * (initial write), so just make sure we have a reasonable number */
243 if (s->d1->mtu < dtls1_min_mtu())
244 {
245 s->d1->mtu = 0;
246 s->d1->mtu = dtls1_guess_mtu(s->d1->mtu);
247 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
248 s->d1->mtu, NULL);
249 }
250 }
251#if 0
252 mtu = s->d1->mtu;
253
254 fprintf(stderr, "using MTU = %d\n", mtu);
255
256 mtu -= (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
257
258 curr_mtu = mtu - BIO_wpending(SSL_get_wbio(s));
259
260 if ( curr_mtu > 0)
261 mtu = curr_mtu;
262 else if ( ( ret = BIO_flush(SSL_get_wbio(s))) <= 0)
263 return ret;
264
265 if ( BIO_wpending(SSL_get_wbio(s)) + s->init_num >= mtu)
266 {
267 ret = BIO_flush(SSL_get_wbio(s));
268 if ( ret <= 0)
269 return ret;
270 mtu = s->d1->mtu - (DTLS1_HM_HEADER_LENGTH + DTLS1_RT_HEADER_LENGTH);
271 }
272#endif
273
274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu()); /* should have something reasonable now */
275
276 if ( s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
277 OPENSSL_assert(s->init_num ==
278 (int)s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH);
279
280 if (s->write_hash)
281 mac_size = EVP_MD_CTX_size(s->write_hash);
282 else
283 mac_size = 0;
284
285 if (s->enc_write_ctx &&
286 (EVP_CIPHER_mode( s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
287 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
288 else
289 blocksize = 0;
290
291 frag_off = 0;
292 while( s->init_num)
293 {
294 curr_mtu = s->d1->mtu - BIO_wpending(SSL_get_wbio(s)) -
295 DTLS1_RT_HEADER_LENGTH - mac_size - blocksize;
296
297 if ( curr_mtu <= DTLS1_HM_HEADER_LENGTH)
298 {
299 /* grr.. we could get an error if MTU picked was wrong */
300 ret = BIO_flush(SSL_get_wbio(s));
301 if ( ret <= 0)
302 return ret;
303 curr_mtu = s->d1->mtu - DTLS1_RT_HEADER_LENGTH -
304 mac_size - blocksize;
305 }
306
307 if ( s->init_num > curr_mtu)
308 len = curr_mtu;
309 else
310 len = s->init_num;
311
312
313 /* XDTLS: this function is too long. split out the CCS part */
314 if ( type == SSL3_RT_HANDSHAKE)
315 {
316 if ( s->init_off != 0)
317 {
318 OPENSSL_assert(s->init_off > DTLS1_HM_HEADER_LENGTH);
319 s->init_off -= DTLS1_HM_HEADER_LENGTH;
320 s->init_num += DTLS1_HM_HEADER_LENGTH;
321
322 if ( s->init_num > curr_mtu)
323 len = curr_mtu;
324 else
325 len = s->init_num;
326 }
327
328 dtls1_fix_message_header(s, frag_off,
329 len - DTLS1_HM_HEADER_LENGTH);
330
331 dtls1_write_message_header(s, (unsigned char *)&s->init_buf->data[s->init_off]);
332
333 OPENSSL_assert(len >= DTLS1_HM_HEADER_LENGTH);
334 }
335
336 ret=dtls1_write_bytes(s,type,&s->init_buf->data[s->init_off],
337 len);
338 if (ret < 0)
339 {
340 /* might need to update MTU here, but we don't know
341 * which previous packet caused the failure -- so can't
342 * really retransmit anything. continue as if everything
343 * is fine and wait for an alert to handle the
344 * retransmit
345 */
346 if ( BIO_ctrl(SSL_get_wbio(s),
347 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0 )
348 s->d1->mtu = BIO_ctrl(SSL_get_wbio(s),
349 BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
350 else
351 return(-1);
352 }
353 else
354 {
355
356 /* bad if this assert fails, only part of the handshake
357 * message got sent. but why would this happen? */
358 OPENSSL_assert(len == (unsigned int)ret);
359
360 if (type == SSL3_RT_HANDSHAKE && ! s->d1->retransmitting)
361 {
362 /* should not be done for 'Hello Request's, but in that case
363 * we'll ignore the result anyway */
364 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
365 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
366 int xlen;
367
368 if (frag_off == 0 && s->version != DTLS1_BAD_VER)
369 {
370 /* reconstruct message header is if it
371 * is being sent in single fragment */
372 *p++ = msg_hdr->type;
373 l2n3(msg_hdr->msg_len,p);
374 s2n (msg_hdr->seq,p);
375 l2n3(0,p);
376 l2n3(msg_hdr->msg_len,p);
377 p -= DTLS1_HM_HEADER_LENGTH;
378 xlen = ret;
379 }
380 else
381 {
382 p += DTLS1_HM_HEADER_LENGTH;
383 xlen = ret - DTLS1_HM_HEADER_LENGTH;
384 }
385
386 ssl3_finish_mac(s, p, xlen);
387 }
388
389 if (ret == s->init_num)
390 {
391 if (s->msg_callback)
392 s->msg_callback(1, s->version, type, s->init_buf->data,
393 (size_t)(s->init_off + s->init_num), s,
394 s->msg_callback_arg);
395
396 s->init_off = 0; /* done writing this message */
397 s->init_num = 0;
398
399 return(1);
400 }
401 s->init_off+=ret;
402 s->init_num-=ret;
403 frag_off += (ret -= DTLS1_HM_HEADER_LENGTH);
404 }
405 }
406 return(0);
407 }
408
409
410/* Obtain handshake message of message type 'mt' (any if mt == -1),
411 * maximum acceptable body length 'max'.
412 * Read an entire handshake message. Handshake messages arrive in
413 * fragments.
414 */
415long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
416 {
417 int i, al;
418 struct hm_header_st *msg_hdr;
419 unsigned char *p;
420 unsigned long msg_len;
421
422 /* s3->tmp is used to store messages that are unexpected, caused
423 * by the absence of an optional handshake message */
424 if (s->s3->tmp.reuse_message)
425 {
426 s->s3->tmp.reuse_message=0;
427 if ((mt >= 0) && (s->s3->tmp.message_type != mt))
428 {
429 al=SSL_AD_UNEXPECTED_MESSAGE;
430 SSLerr(SSL_F_DTLS1_GET_MESSAGE,SSL_R_UNEXPECTED_MESSAGE);
431 goto f_err;
432 }
433 *ok=1;
434 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
435 s->init_num = (int)s->s3->tmp.message_size;
436 return s->init_num;
437 }
438
439 msg_hdr = &s->d1->r_msg_hdr;
440 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
441
442again:
443 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
444 if ( i == DTLS1_HM_BAD_FRAGMENT ||
445 i == DTLS1_HM_FRAGMENT_RETRY) /* bad fragment received */
446 goto again;
447 else if ( i <= 0 && !*ok)
448 return i;
449
450 p = (unsigned char *)s->init_buf->data;
451 msg_len = msg_hdr->msg_len;
452
453 /* reconstruct message header */
454 *(p++) = msg_hdr->type;
455 l2n3(msg_len,p);
456 s2n (msg_hdr->seq,p);
457 l2n3(0,p);
458 l2n3(msg_len,p);
459 if (s->version != DTLS1_BAD_VER) {
460 p -= DTLS1_HM_HEADER_LENGTH;
461 msg_len += DTLS1_HM_HEADER_LENGTH;
462 }
463
464 ssl3_finish_mac(s, p, msg_len);
465 if (s->msg_callback)
466 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
467 p, msg_len,
468 s, s->msg_callback_arg);
469
470 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
471
472 /* Don't change sequence numbers while listening */
473 if (!s->d1->listen)
474 s->d1->handshake_read_seq++;
475
476 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
477 return s->init_num;
478
479f_err:
480 ssl3_send_alert(s,SSL3_AL_FATAL,al);
481 *ok = 0;
482 return -1;
483 }
484
485
486static int dtls1_preprocess_fragment(SSL *s,struct hm_header_st *msg_hdr,int max)
487 {
488 size_t frag_off,frag_len,msg_len;
489
490 msg_len = msg_hdr->msg_len;
491 frag_off = msg_hdr->frag_off;
492 frag_len = msg_hdr->frag_len;
493
494 /* sanity checking */
495 if ( (frag_off+frag_len) > msg_len)
496 {
497 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
498 return SSL_AD_ILLEGAL_PARAMETER;
499 }
500
501 if ( (frag_off+frag_len) > (unsigned long)max)
502 {
503 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
504 return SSL_AD_ILLEGAL_PARAMETER;
505 }
506
507 if ( s->d1->r_msg_hdr.frag_off == 0) /* first fragment */
508 {
509 /* msg_len is limited to 2^24, but is effectively checked
510 * against max above */
511 if (!BUF_MEM_grow_clean(s->init_buf,msg_len+DTLS1_HM_HEADER_LENGTH))
512 {
513 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,ERR_R_BUF_LIB);
514 return SSL_AD_INTERNAL_ERROR;
515 }
516
517 s->s3->tmp.message_size = msg_len;
518 s->d1->r_msg_hdr.msg_len = msg_len;
519 s->s3->tmp.message_type = msg_hdr->type;
520 s->d1->r_msg_hdr.type = msg_hdr->type;
521 s->d1->r_msg_hdr.seq = msg_hdr->seq;
522 }
523 else if (msg_len != s->d1->r_msg_hdr.msg_len)
524 {
525 /* They must be playing with us! BTW, failure to enforce
526 * upper limit would open possibility for buffer overrun. */
527 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT,SSL_R_EXCESSIVE_MESSAGE_SIZE);
528 return SSL_AD_ILLEGAL_PARAMETER;
529 }
530
531 return 0; /* no error */
532 }
533
534
535static int
536dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
537 {
538 /* (0) check whether the desired fragment is available
539 * if so:
540 * (1) copy over the fragment to s->init_buf->data[]
541 * (2) update s->init_num
542 */
543 pitem *item;
544 hm_fragment *frag;
545 int al;
546
547 *ok = 0;
548 item = pqueue_peek(s->d1->buffered_messages);
549 if ( item == NULL)
550 return 0;
551
552 frag = (hm_fragment *)item->data;
553
554 /* Don't return if reassembly still in progress */
555 if (frag->reassembly != NULL)
556 return 0;
557
558 if ( s->d1->handshake_read_seq == frag->msg_header.seq)
559 {
560 unsigned long frag_len = frag->msg_header.frag_len;
561 pqueue_pop(s->d1->buffered_messages);
562
563 al=dtls1_preprocess_fragment(s,&frag->msg_header,max);
564
565 if (al==0) /* no alert */
566 {
567 unsigned char *p = (unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
568 memcpy(&p[frag->msg_header.frag_off],
569 frag->fragment,frag->msg_header.frag_len);
570 }
571
572 dtls1_hm_fragment_free(frag);
573 pitem_free(item);
574
575 if (al==0)
576 {
577 *ok = 1;
578 return frag_len;
579 }
580
581 ssl3_send_alert(s,SSL3_AL_FATAL,al);
582 s->init_num = 0;
583 *ok = 0;
584 return -1;
585 }
586 else
587 return 0;
588 }
589
590
591static int
592dtls1_reassemble_fragment(SSL *s, struct hm_header_st* msg_hdr, int *ok)
593 {
594 hm_fragment *frag = NULL;
595 pitem *item = NULL;
596 int i = -1, is_complete;
597 unsigned char seq64be[8];
598 unsigned long frag_len = msg_hdr->frag_len, max_len;
599
600 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
601 goto err;
602
603 /* Determine maximum allowed message size. Depends on (user set)
604 * maximum certificate length, but 16k is minimum.
605 */
606 if (DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH < s->max_cert_list)
607 max_len = s->max_cert_list;
608 else
609 max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
610
611 if ((msg_hdr->frag_off+frag_len) > max_len)
612 goto err;
613
614 /* Try to find item in queue */
615 memset(seq64be,0,sizeof(seq64be));
616 seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
617 seq64be[7] = (unsigned char) msg_hdr->seq;
618 item = pqueue_find(s->d1->buffered_messages, seq64be);
619
620 if (item == NULL)
621 {
622 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
623 if ( frag == NULL)
624 goto err;
625 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
626 frag->msg_header.frag_len = frag->msg_header.msg_len;
627 frag->msg_header.frag_off = 0;
628 }
629 else
630 frag = (hm_fragment*) item->data;
631
632 /* If message is already reassembled, this must be a
633 * retransmit and can be dropped.
634 */
635 if (frag->reassembly == NULL)
636 {
637 unsigned char devnull [256];
638
639 while (frag_len)
640 {
641 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
642 devnull,
643 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
644 if (i<=0) goto err;
645 frag_len -= i;
646 }
647 return DTLS1_HM_FRAGMENT_RETRY;
648 }
649
650 /* read the body of the fragment (header has already been read */
651 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
652 frag->fragment + msg_hdr->frag_off,frag_len,0);
653 if (i<=0 || (unsigned long)i!=frag_len)
654 goto err;
655
656 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
657 (long)(msg_hdr->frag_off + frag_len));
658
659 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
660 is_complete);
661
662 if (is_complete)
663 {
664 OPENSSL_free(frag->reassembly);
665 frag->reassembly = NULL;
666 }
667
668 if (item == NULL)
669 {
670 memset(seq64be,0,sizeof(seq64be));
671 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
672 seq64be[7] = (unsigned char)(msg_hdr->seq);
673
674 item = pitem_new(seq64be, frag);
675 if (item == NULL)
676 {
677 goto err;
678 i = -1;
679 }
680
681 pqueue_insert(s->d1->buffered_messages, item);
682 }
683
684 return DTLS1_HM_FRAGMENT_RETRY;
685
686err:
687 if (frag != NULL) dtls1_hm_fragment_free(frag);
688 if (item != NULL) OPENSSL_free(item);
689 *ok = 0;
690 return i;
691 }
692
693
694static int
695dtls1_process_out_of_seq_message(SSL *s, struct hm_header_st* msg_hdr, int *ok)
696{
697 int i=-1;
698 hm_fragment *frag = NULL;
699 pitem *item = NULL;
700 unsigned char seq64be[8];
701 unsigned long frag_len = msg_hdr->frag_len;
702
703 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
704 goto err;
705
706 /* Try to find item in queue, to prevent duplicate entries */
707 memset(seq64be,0,sizeof(seq64be));
708 seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
709 seq64be[7] = (unsigned char) msg_hdr->seq;
710 item = pqueue_find(s->d1->buffered_messages, seq64be);
711
712 /* If we already have an entry and this one is a fragment,
713 * don't discard it and rather try to reassemble it.
714 */
715 if (item != NULL && frag_len < msg_hdr->msg_len)
716 item = NULL;
717
718 /* Discard the message if sequence number was already there, is
719 * too far in the future, already in the queue or if we received
720 * a FINISHED before the SERVER_HELLO, which then must be a stale
721 * retransmit.
722 */
723 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
724 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
725 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
726 {
727 unsigned char devnull [256];
728
729 while (frag_len)
730 {
731 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
732 devnull,
733 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
734 if (i<=0) goto err;
735 frag_len -= i;
736 }
737 }
738 else
739 {
740 if (frag_len && frag_len < msg_hdr->msg_len)
741 return dtls1_reassemble_fragment(s, msg_hdr, ok);
742
743 frag = dtls1_hm_fragment_new(frag_len, 0);
744 if ( frag == NULL)
745 goto err;
746
747 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
748
749 if (frag_len)
750 {
751 /* read the body of the fragment (header has already been read */
752 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
753 frag->fragment,frag_len,0);
754 if (i<=0 || (unsigned long)i!=frag_len)
755 goto err;
756 }
757
758 memset(seq64be,0,sizeof(seq64be));
759 seq64be[6] = (unsigned char)(msg_hdr->seq>>8);
760 seq64be[7] = (unsigned char)(msg_hdr->seq);
761
762 item = pitem_new(seq64be, frag);
763 if ( item == NULL)
764 goto err;
765
766 pqueue_insert(s->d1->buffered_messages, item);
767 }
768
769 return DTLS1_HM_FRAGMENT_RETRY;
770
771err:
772 if ( frag != NULL) dtls1_hm_fragment_free(frag);
773 if ( item != NULL) OPENSSL_free(item);
774 *ok = 0;
775 return i;
776 }
777
778
779static long
780dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
781 {
782 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
783 unsigned long len, frag_off, frag_len;
784 int i,al;
785 struct hm_header_st msg_hdr;
786
787 /* see if we have the required fragment already */
788 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
789 {
790 if (*ok) s->init_num = frag_len;
791 return frag_len;
792 }
793
794 /* read handshake message header */
795 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
796 DTLS1_HM_HEADER_LENGTH, 0);
797 if (i <= 0) /* nbio, or an error */
798 {
799 s->rwstate=SSL_READING;
800 *ok = 0;
801 return i;
802 }
803 /* Handshake fails if message header is incomplete */
804 if (i != DTLS1_HM_HEADER_LENGTH)
805 {
806 al=SSL_AD_UNEXPECTED_MESSAGE;
807 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
808 goto f_err;
809 }
810
811 /* parse the message fragment header */
812 dtls1_get_message_header(wire, &msg_hdr);
813
814 /*
815 * if this is a future (or stale) message it gets buffered
816 * (or dropped)--no further processing at this time
817 * While listening, we accept seq 1 (ClientHello with cookie)
818 * although we're still expecting seq 0 (ClientHello)
819 */
820 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
821 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
822
823 len = msg_hdr.msg_len;
824 frag_off = msg_hdr.frag_off;
825 frag_len = msg_hdr.frag_len;
826
827 if (frag_len && frag_len < len)
828 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
829
830 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
831 wire[0] == SSL3_MT_HELLO_REQUEST)
832 {
833 /* The server may always send 'Hello Request' messages --
834 * we are doing a handshake anyway now, so ignore them
835 * if their format is correct. Does not count for
836 * 'Finished' MAC. */
837 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
838 {
839 if (s->msg_callback)
840 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
841 wire, DTLS1_HM_HEADER_LENGTH, s,
842 s->msg_callback_arg);
843
844 s->init_num = 0;
845 return dtls1_get_message_fragment(s, st1, stn,
846 max, ok);
847 }
848 else /* Incorrectly formated Hello request */
849 {
850 al=SSL_AD_UNEXPECTED_MESSAGE;
851 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
852 goto f_err;
853 }
854 }
855
856 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
857 goto f_err;
858
859 /* XDTLS: ressurect this when restart is in place */
860 s->state=stn;
861
862 if ( frag_len > 0)
863 {
864 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
865
866 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
867 &p[frag_off],frag_len,0);
868 /* XDTLS: fix this--message fragments cannot span multiple packets */
869 if (i <= 0)
870 {
871 s->rwstate=SSL_READING;
872 *ok = 0;
873 return i;
874 }
875 }
876 else
877 i = 0;
878
879 /* XDTLS: an incorrectly formatted fragment should cause the
880 * handshake to fail */
881 if (i != (int)frag_len)
882 {
883 al=SSL3_AD_ILLEGAL_PARAMETER;
884 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
885 goto f_err;
886 }
887
888 *ok = 1;
889
890 /* Note that s->init_num is *not* used as current offset in
891 * s->init_buf->data, but as a counter summing up fragments'
892 * lengths: as soon as they sum up to handshake packet
893 * length, we assume we have got all the fragments. */
894 s->init_num = frag_len;
895 return frag_len;
896
897f_err:
898 ssl3_send_alert(s,SSL3_AL_FATAL,al);
899 s->init_num = 0;
900
901 *ok=0;
902 return(-1);
903 }
904
905int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
906 {
907 unsigned char *p,*d;
908 int i;
909 unsigned long l;
910
911 if (s->state == a)
912 {
913 d=(unsigned char *)s->init_buf->data;
914 p= &(d[DTLS1_HM_HEADER_LENGTH]);
915
916 i=s->method->ssl3_enc->final_finish_mac(s,
917 sender,slen,s->s3->tmp.finish_md);
918 s->s3->tmp.finish_md_len = i;
919 memcpy(p, s->s3->tmp.finish_md, i);
920 p+=i;
921 l=i;
922
923 /* Copy the finished so we can use it for
924 * renegotiation checks
925 */
926 if(s->type == SSL_ST_CONNECT)
927 {
928 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
929 memcpy(s->s3->previous_client_finished,
930 s->s3->tmp.finish_md, i);
931 s->s3->previous_client_finished_len=i;
932 }
933 else
934 {
935 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
936 memcpy(s->s3->previous_server_finished,
937 s->s3->tmp.finish_md, i);
938 s->s3->previous_server_finished_len=i;
939 }
940
941#ifdef OPENSSL_SYS_WIN16
942 /* MSVC 1.5 does not clear the top bytes of the word unless
943 * I do this.
944 */
945 l&=0xffff;
946#endif
947
948 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
949 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
950 s->init_off=0;
951
952 /* buffer the message to handle re-xmits */
953 dtls1_buffer_message(s, 0);
954
955 s->state=b;
956 }
957
958 /* SSL3_ST_SEND_xxxxxx_HELLO_B */
959 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
960 }
961
962/* for these 2 messages, we need to
963 * ssl->enc_read_ctx re-init
964 * ssl->s3->read_sequence zero
965 * ssl->s3->read_mac_secret re-init
966 * ssl->session->read_sym_enc assign
967 * ssl->session->read_compression assign
968 * ssl->session->read_hash assign
969 */
970int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
971 {
972 unsigned char *p;
973
974 if (s->state == a)
975 {
976 p=(unsigned char *)s->init_buf->data;
977 *p++=SSL3_MT_CCS;
978 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
979 s->init_num=DTLS1_CCS_HEADER_LENGTH;
980
981 if (s->version == DTLS1_BAD_VER) {
982 s->d1->next_handshake_write_seq++;
983 s2n(s->d1->handshake_write_seq,p);
984 s->init_num+=2;
985 }
986
987 s->init_off=0;
988
989 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
990 s->d1->handshake_write_seq, 0, 0);
991
992 /* buffer the message to handle re-xmits */
993 dtls1_buffer_message(s, 1);
994
995 s->state=b;
996 }
997
998 /* SSL3_ST_CW_CHANGE_B */
999 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1000 }
1001
1002static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1003 {
1004 int n;
1005 unsigned char *p;
1006
1007 n=i2d_X509(x,NULL);
1008 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1009 {
1010 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1011 return 0;
1012 }
1013 p=(unsigned char *)&(buf->data[*l]);
1014 l2n3(n,p);
1015 i2d_X509(x,&p);
1016 *l+=n+3;
1017
1018 return 1;
1019 }
1020unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1021 {
1022 unsigned char *p;
1023 int i;
1024 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1025 BUF_MEM *buf;
1026
1027 /* TLSv1 sends a chain with nothing in it, instead of an alert */
1028 buf=s->init_buf;
1029 if (!BUF_MEM_grow_clean(buf,10))
1030 {
1031 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1032 return(0);
1033 }
1034 if (x != NULL)
1035 {
1036 X509_STORE_CTX xs_ctx;
1037
1038 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1039 {
1040 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1041 return(0);
1042 }
1043
1044 X509_verify_cert(&xs_ctx);
1045 /* Don't leave errors in the queue */
1046 ERR_clear_error();
1047 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1048 {
1049 x = sk_X509_value(xs_ctx.chain, i);
1050
1051 if (!dtls1_add_cert_to_buf(buf, &l, x))
1052 {
1053 X509_STORE_CTX_cleanup(&xs_ctx);
1054 return 0;
1055 }
1056 }
1057 X509_STORE_CTX_cleanup(&xs_ctx);
1058 }
1059 /* Thawte special :-) */
1060 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1061 {
1062 x=sk_X509_value(s->ctx->extra_certs,i);
1063 if (!dtls1_add_cert_to_buf(buf, &l, x))
1064 return 0;
1065 }
1066
1067 l-= (3 + DTLS1_HM_HEADER_LENGTH);
1068
1069 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1070 l2n3(l,p);
1071 l+=3;
1072 p=(unsigned char *)&(buf->data[0]);
1073 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1074
1075 l+=DTLS1_HM_HEADER_LENGTH;
1076 return(l);
1077 }
1078
1079int dtls1_read_failed(SSL *s, int code)
1080 {
1081 if ( code > 0)
1082 {
1083 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1084 return 1;
1085 }
1086
1087 if (!dtls1_is_timer_expired(s))
1088 {
1089 /* not a timeout, none of our business,
1090 let higher layers handle this. in fact it's probably an error */
1091 return code;
1092 }
1093
1094#ifndef OPENSSL_NO_HEARTBEATS
1095 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */
1096#else
1097 if (!SSL_in_init(s)) /* done, no need to send a retransmit */
1098#endif
1099 {
1100 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1101 return code;
1102 }
1103
1104#if 0 /* for now, each alert contains only one record number */
1105 item = pqueue_peek(state->rcvd_records);
1106 if ( item )
1107 {
1108 /* send an alert immediately for all the missing records */
1109 }
1110 else
1111#endif
1112
1113#if 0 /* no more alert sending, just retransmit the last set of messages */
1114 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1115 ssl3_send_alert(s,SSL3_AL_WARNING,
1116 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1117#endif
1118
1119 return dtls1_handle_timeout(s);
1120 }
1121
1122int
1123dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1124 {
1125 /* The index of the retransmission queue actually is the message sequence number,
1126 * since the queue only contains messages of a single handshake. However, the
1127 * ChangeCipherSpec has no message sequence number and so using only the sequence
1128 * will result in the CCS and Finished having the same index. To prevent this,
1129 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1130 * This does not only differ CSS and Finished, it also maintains the order of the
1131 * index (important for priority queues) and fits in the unsigned short variable.
1132 */
1133 return seq * 2 - is_ccs;
1134 }
1135
1136int
1137dtls1_retransmit_buffered_messages(SSL *s)
1138 {
1139 pqueue sent = s->d1->sent_messages;
1140 piterator iter;
1141 pitem *item;
1142 hm_fragment *frag;
1143 int found = 0;
1144
1145 iter = pqueue_iterator(sent);
1146
1147 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1148 {
1149 frag = (hm_fragment *)item->data;
1150 if ( dtls1_retransmit_message(s,
1151 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1152 0, &found) <= 0 && found)
1153 {
1154 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1155 return -1;
1156 }
1157 }
1158
1159 return 1;
1160 }
1161
1162int
1163dtls1_buffer_message(SSL *s, int is_ccs)
1164 {
1165 pitem *item;
1166 hm_fragment *frag;
1167 unsigned char seq64be[8];
1168
1169 /* this function is called immediately after a message has
1170 * been serialized */
1171 OPENSSL_assert(s->init_off == 0);
1172
1173 frag = dtls1_hm_fragment_new(s->init_num, 0);
1174
1175 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1176
1177 if ( is_ccs)
1178 {
1179 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1180 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
1181 }
1182 else
1183 {
1184 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1185 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1186 }
1187
1188 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1189 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1190 frag->msg_header.type = s->d1->w_msg_hdr.type;
1191 frag->msg_header.frag_off = 0;
1192 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1193 frag->msg_header.is_ccs = is_ccs;
1194
1195 /* save current state*/
1196 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1197 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1198 frag->msg_header.saved_retransmit_state.compress = s->compress;
1199 frag->msg_header.saved_retransmit_state.session = s->session;
1200 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1201
1202 memset(seq64be,0,sizeof(seq64be));
1203 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1204 frag->msg_header.is_ccs)>>8);
1205 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1206 frag->msg_header.is_ccs));
1207
1208 item = pitem_new(seq64be, frag);
1209 if ( item == NULL)
1210 {
1211 dtls1_hm_fragment_free(frag);
1212 return 0;
1213 }
1214
1215#if 0
1216 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1217 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1218 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1219#endif
1220
1221 pqueue_insert(s->d1->sent_messages, item);
1222 return 1;
1223 }
1224
1225int
1226dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1227 int *found)
1228 {
1229 int ret;
1230 /* XDTLS: for now assuming that read/writes are blocking */
1231 pitem *item;
1232 hm_fragment *frag ;
1233 unsigned long header_length;
1234 unsigned char seq64be[8];
1235 struct dtls1_retransmit_state saved_state;
1236 unsigned char save_write_sequence[8];
1237
1238 /*
1239 OPENSSL_assert(s->init_num == 0);
1240 OPENSSL_assert(s->init_off == 0);
1241 */
1242
1243 /* XDTLS: the requested message ought to be found, otherwise error */
1244 memset(seq64be,0,sizeof(seq64be));
1245 seq64be[6] = (unsigned char)(seq>>8);
1246 seq64be[7] = (unsigned char)seq;
1247
1248 item = pqueue_find(s->d1->sent_messages, seq64be);
1249 if ( item == NULL)
1250 {
1251 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1252 *found = 0;
1253 return 0;
1254 }
1255
1256 *found = 1;
1257 frag = (hm_fragment *)item->data;
1258
1259 if ( frag->msg_header.is_ccs)
1260 header_length = DTLS1_CCS_HEADER_LENGTH;
1261 else
1262 header_length = DTLS1_HM_HEADER_LENGTH;
1263
1264 memcpy(s->init_buf->data, frag->fragment,
1265 frag->msg_header.msg_len + header_length);
1266 s->init_num = frag->msg_header.msg_len + header_length;
1267
1268 dtls1_set_message_header_int(s, frag->msg_header.type,
1269 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1270 frag->msg_header.frag_len);
1271
1272 /* save current state */
1273 saved_state.enc_write_ctx = s->enc_write_ctx;
1274 saved_state.write_hash = s->write_hash;
1275 saved_state.compress = s->compress;
1276 saved_state.session = s->session;
1277 saved_state.epoch = s->d1->w_epoch;
1278 saved_state.epoch = s->d1->w_epoch;
1279
1280 s->d1->retransmitting = 1;
1281
1282 /* restore state in which the message was originally sent */
1283 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1284 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1285 s->compress = frag->msg_header.saved_retransmit_state.compress;
1286 s->session = frag->msg_header.saved_retransmit_state.session;
1287 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1288
1289 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1290 {
1291 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1292 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1293 }
1294
1295 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1296 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1297
1298 /* restore current state */
1299 s->enc_write_ctx = saved_state.enc_write_ctx;
1300 s->write_hash = saved_state.write_hash;
1301 s->compress = saved_state.compress;
1302 s->session = saved_state.session;
1303 s->d1->w_epoch = saved_state.epoch;
1304
1305 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1306 {
1307 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1308 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1309 }
1310
1311 s->d1->retransmitting = 0;
1312
1313 (void)BIO_flush(SSL_get_wbio(s));
1314 return ret;
1315 }
1316
1317/* call this function when the buffered messages are no longer needed */
1318void
1319dtls1_clear_record_buffer(SSL *s)
1320 {
1321 pitem *item;
1322
1323 for(item = pqueue_pop(s->d1->sent_messages);
1324 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1325 {
1326 dtls1_hm_fragment_free((hm_fragment *)item->data);
1327 pitem_free(item);
1328 }
1329 }
1330
1331
1332unsigned char *
1333dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1334 unsigned long len, unsigned long frag_off, unsigned long frag_len)
1335 {
1336 /* Don't change sequence numbers while listening */
1337 if (frag_off == 0 && !s->d1->listen)
1338 {
1339 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1340 s->d1->next_handshake_write_seq++;
1341 }
1342
1343 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1344 frag_off, frag_len);
1345
1346 return p += DTLS1_HM_HEADER_LENGTH;
1347 }
1348
1349
1350/* don't actually do the writing, wait till the MTU has been retrieved */
1351static void
1352dtls1_set_message_header_int(SSL *s, unsigned char mt,
1353 unsigned long len, unsigned short seq_num, unsigned long frag_off,
1354 unsigned long frag_len)
1355 {
1356 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1357
1358 msg_hdr->type = mt;
1359 msg_hdr->msg_len = len;
1360 msg_hdr->seq = seq_num;
1361 msg_hdr->frag_off = frag_off;
1362 msg_hdr->frag_len = frag_len;
1363 }
1364
1365static void
1366dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1367 unsigned long frag_len)
1368 {
1369 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1370
1371 msg_hdr->frag_off = frag_off;
1372 msg_hdr->frag_len = frag_len;
1373 }
1374
1375static unsigned char *
1376dtls1_write_message_header(SSL *s, unsigned char *p)
1377 {
1378 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1379
1380 *p++ = msg_hdr->type;
1381 l2n3(msg_hdr->msg_len, p);
1382
1383 s2n(msg_hdr->seq, p);
1384 l2n3(msg_hdr->frag_off, p);
1385 l2n3(msg_hdr->frag_len, p);
1386
1387 return p;
1388 }
1389
1390unsigned int
1391dtls1_min_mtu(void)
1392 {
1393 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1394 sizeof(g_probable_mtu[0])) - 1]);
1395 }
1396
1397static unsigned int
1398dtls1_guess_mtu(unsigned int curr_mtu)
1399 {
1400 unsigned int i;
1401
1402 if ( curr_mtu == 0 )
1403 return g_probable_mtu[0] ;
1404
1405 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1406 if ( curr_mtu > g_probable_mtu[i])
1407 return g_probable_mtu[i];
1408
1409 return curr_mtu;
1410 }
1411
1412void
1413dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1414 {
1415 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1416 msg_hdr->type = *(data++);
1417 n2l3(data, msg_hdr->msg_len);
1418
1419 n2s(data, msg_hdr->seq);
1420 n2l3(data, msg_hdr->frag_off);
1421 n2l3(data, msg_hdr->frag_len);
1422 }
1423
1424void
1425dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1426 {
1427 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1428
1429 ccs_hdr->type = *(data++);
1430 }
1431
1432int dtls1_shutdown(SSL *s)
1433 {
1434 int ret;
1435#ifndef OPENSSL_NO_SCTP
1436 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1437 !(s->shutdown & SSL_SENT_SHUTDOWN))
1438 {
1439 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1440 if (ret < 0) return -1;
1441
1442 if (ret == 0)
1443 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1444 }
1445#endif
1446 ret = ssl3_shutdown(s);
1447#ifndef OPENSSL_NO_SCTP
1448 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1449#endif
1450 return ret;
1451 }
1452
1453#ifndef OPENSSL_NO_HEARTBEATS
1454int
1455dtls1_process_heartbeat(SSL *s)
1456 {
1457 unsigned char *p = &s->s3->rrec.data[0], *pl;
1458 unsigned short hbtype;
1459 unsigned int payload;
1460 unsigned int padding = 16; /* Use minimum padding */
1461
1462 if (s->msg_callback)
1463 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1464 &s->s3->rrec.data[0], s->s3->rrec.length,
1465 s, s->msg_callback_arg);
1466
1467 /* Read type and payload length first */
1468 if (1 + 2 + 16 > s->s3->rrec.length)
1469 return 0; /* silently discard */
1470 hbtype = *p++;
1471 n2s(p, payload);
1472 if (1 + 2 + payload + 16 > s->s3->rrec.length)
1473 return 0; /* silently discard per RFC 6520 sec. 4 */
1474 pl = p;
1475
1476 if (hbtype == TLS1_HB_REQUEST)
1477 {
1478 unsigned char *buffer, *bp;
1479 unsigned int write_length = 1 /* heartbeat type */ +
1480 2 /* heartbeat length */ +
1481 payload + padding;
1482 int r;
1483
1484 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1485 return 0;
1486
1487 /* Allocate memory for the response, size is 1 byte
1488 * message type, plus 2 bytes payload length, plus
1489 * payload, plus padding
1490 */
1491 buffer = OPENSSL_malloc(write_length);
1492 bp = buffer;
1493
1494 /* Enter response type, length and copy payload */
1495 *bp++ = TLS1_HB_RESPONSE;
1496 s2n(payload, bp);
1497 memcpy(bp, pl, payload);
1498 bp += payload;
1499 /* Random padding */
1500 RAND_pseudo_bytes(bp, padding);
1501
1502 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1503
1504 if (r >= 0 && s->msg_callback)
1505 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1506 buffer, write_length,
1507 s, s->msg_callback_arg);
1508
1509 OPENSSL_free(buffer);
1510
1511 if (r < 0)
1512 return r;
1513 }
1514 else if (hbtype == TLS1_HB_RESPONSE)
1515 {
1516 unsigned int seq;
1517
1518 /* We only send sequence numbers (2 bytes unsigned int),
1519 * and 16 random bytes, so we just try to read the
1520 * sequence number */
1521 n2s(pl, seq);
1522
1523 if (payload == 18 && seq == s->tlsext_hb_seq)
1524 {
1525 dtls1_stop_timer(s);
1526 s->tlsext_hb_seq++;
1527 s->tlsext_hb_pending = 0;
1528 }
1529 }
1530
1531 return 0;
1532 }
1533
1534int
1535dtls1_heartbeat(SSL *s)
1536 {
1537 unsigned char *buf, *p;
1538 int ret;
1539 unsigned int payload = 18; /* Sequence number + random bytes */
1540 unsigned int padding = 16; /* Use minimum padding */
1541
1542 /* Only send if peer supports and accepts HB requests... */
1543 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1544 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1545 {
1546 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1547 return -1;
1548 }
1549
1550 /* ...and there is none in flight yet... */
1551 if (s->tlsext_hb_pending)
1552 {
1553 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1554 return -1;
1555 }
1556
1557 /* ...and no handshake in progress. */
1558 if (SSL_in_init(s) || s->in_handshake)
1559 {
1560 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1561 return -1;
1562 }
1563
1564 /* Check if padding is too long, payload and padding
1565 * must not exceed 2^14 - 3 = 16381 bytes in total.
1566 */
1567 OPENSSL_assert(payload + padding <= 16381);
1568
1569 /* Create HeartBeat message, we just use a sequence number
1570 * as payload to distuingish different messages and add
1571 * some random stuff.
1572 * - Message Type, 1 byte
1573 * - Payload Length, 2 bytes (unsigned int)
1574 * - Payload, the sequence number (2 bytes uint)
1575 * - Payload, random bytes (16 bytes uint)
1576 * - Padding
1577 */
1578 buf = OPENSSL_malloc(1 + 2 + payload + padding);
1579 p = buf;
1580 /* Message Type */
1581 *p++ = TLS1_HB_REQUEST;
1582 /* Payload length (18 bytes here) */
1583 s2n(payload, p);
1584 /* Sequence number */
1585 s2n(s->tlsext_hb_seq, p);
1586 /* 16 random bytes */
1587 RAND_pseudo_bytes(p, 16);
1588 p += 16;
1589 /* Random padding */
1590 RAND_pseudo_bytes(p, padding);
1591
1592 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1593 if (ret >= 0)
1594 {
1595 if (s->msg_callback)
1596 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1597 buf, 3 + payload + padding,
1598 s, s->msg_callback_arg);
1599
1600 dtls1_start_timer(s);
1601 s->tlsext_hb_pending = 1;
1602 }
1603
1604 OPENSSL_free(buf);
1605
1606 return ret;
1607 }
1608#endif