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
155 static unsigned char bitmask_start_values[] =
156 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
157 static unsigned char bitmask_end_values[] =
158 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
159
160 /* XDTLS: figure out the right values */
161 static const unsigned int g_probable_mtu[] = { 1500, 512, 256 };
162
163 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
164 unsigned long frag_len);
165 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p);
166 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
167 unsigned long len,
168 unsigned short seq_num,
169 unsigned long frag_off,
170 unsigned long frag_len);
171 static long dtls1_get_message_fragment(SSL *s, int st1, int stn, long max,
172 int *ok);
173
dtls1_hm_fragment_new(unsigned long frag_len,int reassembly)174 static hm_fragment *dtls1_hm_fragment_new(unsigned long frag_len,
175 int reassembly)
176 {
177 hm_fragment *frag = NULL;
178 unsigned char *buf = NULL;
179 unsigned char *bitmask = NULL;
180
181 frag = (hm_fragment *)OPENSSL_malloc(sizeof(hm_fragment));
182 if (frag == NULL)
183 return NULL;
184
185 if (frag_len) {
186 buf = (unsigned char *)OPENSSL_malloc(frag_len);
187 if (buf == NULL) {
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 bitmask =
199 (unsigned char *)OPENSSL_malloc(RSMBLY_BITMASK_SIZE(frag_len));
200 if (bitmask == NULL) {
201 if (buf != NULL)
202 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
dtls1_hm_fragment_free(hm_fragment * frag)214 void dtls1_hm_fragment_free(hm_fragment *frag)
215 {
216
217 if (frag->msg_header.is_ccs) {
218 EVP_CIPHER_CTX_free(frag->msg_header.
219 saved_retransmit_state.enc_write_ctx);
220 EVP_MD_CTX_destroy(frag->msg_header.
221 saved_retransmit_state.write_hash);
222 }
223 if (frag->fragment)
224 OPENSSL_free(frag->fragment);
225 if (frag->reassembly)
226 OPENSSL_free(frag->reassembly);
227 OPENSSL_free(frag);
228 }
229
dtls1_query_mtu(SSL * s)230 static int dtls1_query_mtu(SSL *s)
231 {
232 if (s->d1->link_mtu) {
233 s->d1->mtu =
234 s->d1->link_mtu - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
235 s->d1->link_mtu = 0;
236 }
237
238 /* AHA! Figure out the MTU, and stick to the right size */
239 if (s->d1->mtu < dtls1_min_mtu(s)) {
240 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
241 s->d1->mtu =
242 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_QUERY_MTU, 0, NULL);
243
244 /*
245 * I've seen the kernel return bogus numbers when it doesn't know
246 * (initial write), so just make sure we have a reasonable number
247 */
248 if (s->d1->mtu < dtls1_min_mtu(s)) {
249 /* Set to min mtu */
250 s->d1->mtu = dtls1_min_mtu(s);
251 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SET_MTU,
252 s->d1->mtu, NULL);
253 }
254 } else
255 return 0;
256 }
257 return 1;
258 }
259
260 /*
261 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
262 * SSL3_RT_CHANGE_CIPHER_SPEC)
263 */
dtls1_do_write(SSL * s,int type)264 int dtls1_do_write(SSL *s, int type)
265 {
266 int ret;
267 unsigned int curr_mtu;
268 int retry = 1;
269 unsigned int len, frag_off, mac_size, blocksize, used_len;
270
271 if (!dtls1_query_mtu(s))
272 return -1;
273
274 OPENSSL_assert(s->d1->mtu >= dtls1_min_mtu(s)); /* should have something
275 * reasonable now */
276
277 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE)
278 OPENSSL_assert(s->init_num ==
279 (int)s->d1->w_msg_hdr.msg_len +
280 DTLS1_HM_HEADER_LENGTH);
281
282 if (s->write_hash)
283 mac_size = EVP_MD_CTX_size(s->write_hash);
284 else
285 mac_size = 0;
286
287 if (s->enc_write_ctx &&
288 (EVP_CIPHER_mode(s->enc_write_ctx->cipher) & EVP_CIPH_CBC_MODE))
289 blocksize = 2 * EVP_CIPHER_block_size(s->enc_write_ctx->cipher);
290 else
291 blocksize = 0;
292
293 frag_off = 0;
294 s->rwstate = SSL_NOTHING;
295
296 /* s->init_num shouldn't ever be < 0...but just in case */
297 while (s->init_num > 0) {
298 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
299 /* We must be writing a fragment other than the first one */
300
301 if (frag_off > 0) {
302 /* This is the first attempt at writing out this fragment */
303
304 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
305 /*
306 * Each fragment that was already sent must at least have
307 * contained the message header plus one other byte.
308 * Therefore |init_off| must have progressed by at least
309 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
310 * wrong.
311 */
312 return -1;
313 }
314
315 /*
316 * Adjust |init_off| and |init_num| to allow room for a new
317 * message header for this fragment.
318 */
319 s->init_off -= DTLS1_HM_HEADER_LENGTH;
320 s->init_num += DTLS1_HM_HEADER_LENGTH;
321 } else {
322 /*
323 * We must have been called again after a retry so use the
324 * fragment offset from our last attempt. We do not need
325 * to adjust |init_off| and |init_num| as above, because
326 * that should already have been done before the retry.
327 */
328 frag_off = s->d1->w_msg_hdr.frag_off;
329 }
330 }
331
332 used_len = BIO_wpending(SSL_get_wbio(s)) + DTLS1_RT_HEADER_LENGTH
333 + mac_size + blocksize;
334 if (s->d1->mtu > used_len)
335 curr_mtu = s->d1->mtu - used_len;
336 else
337 curr_mtu = 0;
338
339 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
340 /*
341 * grr.. we could get an error if MTU picked was wrong
342 */
343 ret = BIO_flush(SSL_get_wbio(s));
344 if (ret <= 0) {
345 s->rwstate = SSL_WRITING;
346 return ret;
347 }
348 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
349 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
350 curr_mtu = s->d1->mtu - used_len;
351 } else {
352 /* Shouldn't happen */
353 return -1;
354 }
355 }
356
357 /*
358 * We just checked that s->init_num > 0 so this cast should be safe
359 */
360 if (((unsigned int)s->init_num) > curr_mtu)
361 len = curr_mtu;
362 else
363 len = s->init_num;
364
365 /* Shouldn't ever happen */
366 if (len > INT_MAX)
367 len = INT_MAX;
368
369 /*
370 * XDTLS: this function is too long. split out the CCS part
371 */
372 if (type == SSL3_RT_HANDSHAKE) {
373 if (len < DTLS1_HM_HEADER_LENGTH) {
374 /*
375 * len is so small that we really can't do anything sensible
376 * so fail
377 */
378 return -1;
379 }
380 dtls1_fix_message_header(s, frag_off,
381 len - DTLS1_HM_HEADER_LENGTH);
382
383 dtls1_write_message_header(s,
384 (unsigned char *)&s->init_buf->
385 data[s->init_off]);
386 }
387
388 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off],
389 len);
390 if (ret < 0) {
391 /*
392 * might need to update MTU here, but we don't know which
393 * previous packet caused the failure -- so can't really
394 * retransmit anything. continue as if everything is fine and
395 * wait for an alert to handle the retransmit
396 */
397 if (retry && BIO_ctrl(SSL_get_wbio(s),
398 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
399 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
400 if (!dtls1_query_mtu(s))
401 return -1;
402 /* Have one more go */
403 retry = 0;
404 } else
405 return -1;
406 } else {
407 return (-1);
408 }
409 } else {
410
411 /*
412 * bad if this assert fails, only part of the handshake message
413 * got sent. but why would this happen?
414 */
415 OPENSSL_assert(len == (unsigned int)ret);
416
417 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
418 /*
419 * should not be done for 'Hello Request's, but in that case
420 * we'll ignore the result anyway
421 */
422 unsigned char *p =
423 (unsigned char *)&s->init_buf->data[s->init_off];
424 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
425 int xlen;
426
427 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
428 /*
429 * reconstruct message header is if it is being sent in
430 * single fragment
431 */
432 *p++ = msg_hdr->type;
433 l2n3(msg_hdr->msg_len, p);
434 s2n(msg_hdr->seq, p);
435 l2n3(0, p);
436 l2n3(msg_hdr->msg_len, p);
437 p -= DTLS1_HM_HEADER_LENGTH;
438 xlen = ret;
439 } else {
440 p += DTLS1_HM_HEADER_LENGTH;
441 xlen = ret - DTLS1_HM_HEADER_LENGTH;
442 }
443
444 ssl3_finish_mac(s, p, xlen);
445 }
446
447 if (ret == s->init_num) {
448 if (s->msg_callback)
449 s->msg_callback(1, s->version, type, s->init_buf->data,
450 (size_t)(s->init_off + s->init_num), s,
451 s->msg_callback_arg);
452
453 s->init_off = 0; /* done writing this message */
454 s->init_num = 0;
455
456 return (1);
457 }
458 s->init_off += ret;
459 s->init_num -= ret;
460 ret -= DTLS1_HM_HEADER_LENGTH;
461 frag_off += ret;
462
463 /*
464 * We save the fragment offset for the next fragment so we have it
465 * available in case of an IO retry. We don't know the length of the
466 * next fragment yet so just set that to 0 for now. It will be
467 * updated again later.
468 */
469 dtls1_fix_message_header(s, frag_off, 0);
470 }
471 }
472 return (0);
473 }
474
475 /*
476 * Obtain handshake message of message type 'mt' (any if mt == -1), maximum
477 * acceptable body length 'max'. Read an entire handshake message. Handshake
478 * messages arrive in fragments.
479 */
dtls1_get_message(SSL * s,int st1,int stn,int mt,long max,int * ok)480 long dtls1_get_message(SSL *s, int st1, int stn, int mt, long max, int *ok)
481 {
482 int i, al;
483 struct hm_header_st *msg_hdr;
484 unsigned char *p;
485 unsigned long msg_len;
486
487 /*
488 * s3->tmp is used to store messages that are unexpected, caused by the
489 * absence of an optional handshake message
490 */
491 if (s->s3->tmp.reuse_message) {
492 s->s3->tmp.reuse_message = 0;
493 if ((mt >= 0) && (s->s3->tmp.message_type != mt)) {
494 al = SSL_AD_UNEXPECTED_MESSAGE;
495 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
496 goto f_err;
497 }
498 *ok = 1;
499 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
500 s->init_num = (int)s->s3->tmp.message_size;
501 return s->init_num;
502 }
503
504 msg_hdr = &s->d1->r_msg_hdr;
505 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
506
507 again:
508 i = dtls1_get_message_fragment(s, st1, stn, max, ok);
509 if (i == DTLS1_HM_BAD_FRAGMENT || i == DTLS1_HM_FRAGMENT_RETRY) {
510 /* bad fragment received */
511 goto again;
512 } else if (i <= 0 && !*ok) {
513 return i;
514 }
515
516 if (mt >= 0 && s->s3->tmp.message_type != mt) {
517 al = SSL_AD_UNEXPECTED_MESSAGE;
518 SSLerr(SSL_F_DTLS1_GET_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
519 goto f_err;
520 }
521
522 p = (unsigned char *)s->init_buf->data;
523 msg_len = msg_hdr->msg_len;
524
525 /* reconstruct message header */
526 *(p++) = msg_hdr->type;
527 l2n3(msg_len, p);
528 s2n(msg_hdr->seq, p);
529 l2n3(0, p);
530 l2n3(msg_len, p);
531 if (s->version != DTLS1_BAD_VER) {
532 p -= DTLS1_HM_HEADER_LENGTH;
533 msg_len += DTLS1_HM_HEADER_LENGTH;
534 }
535
536 ssl3_finish_mac(s, p, msg_len);
537 if (s->msg_callback)
538 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
539 p, msg_len, s, s->msg_callback_arg);
540
541 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
542
543 /* Don't change sequence numbers while listening */
544 if (!s->d1->listen)
545 s->d1->handshake_read_seq++;
546
547 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
548 return s->init_num;
549
550 f_err:
551 ssl3_send_alert(s, SSL3_AL_FATAL, al);
552 *ok = 0;
553 return -1;
554 }
555
dtls1_preprocess_fragment(SSL * s,struct hm_header_st * msg_hdr,int max)556 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr,
557 int max)
558 {
559 size_t frag_off, frag_len, msg_len;
560
561 msg_len = msg_hdr->msg_len;
562 frag_off = msg_hdr->frag_off;
563 frag_len = msg_hdr->frag_len;
564
565 /* sanity checking */
566 if ((frag_off + frag_len) > msg_len) {
567 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
568 return SSL_AD_ILLEGAL_PARAMETER;
569 }
570
571 if ((frag_off + frag_len) > (unsigned long)max) {
572 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
573 return SSL_AD_ILLEGAL_PARAMETER;
574 }
575
576 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
577 /*
578 * msg_len is limited to 2^24, but is effectively checked against max
579 * above
580 *
581 * Make buffer slightly larger than message length as a precaution
582 * against small OOB reads e.g. CVE-2016-6306
583 */
584 if (!BUF_MEM_grow_clean
585 (s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH + 16)) {
586 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, ERR_R_BUF_LIB);
587 return SSL_AD_INTERNAL_ERROR;
588 }
589
590 s->s3->tmp.message_size = msg_len;
591 s->d1->r_msg_hdr.msg_len = msg_len;
592 s->s3->tmp.message_type = msg_hdr->type;
593 s->d1->r_msg_hdr.type = msg_hdr->type;
594 s->d1->r_msg_hdr.seq = msg_hdr->seq;
595 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
596 /*
597 * They must be playing with us! BTW, failure to enforce upper limit
598 * would open possibility for buffer overrun.
599 */
600 SSLerr(SSL_F_DTLS1_PREPROCESS_FRAGMENT, SSL_R_EXCESSIVE_MESSAGE_SIZE);
601 return SSL_AD_ILLEGAL_PARAMETER;
602 }
603
604 return 0; /* no error */
605 }
606
dtls1_retrieve_buffered_fragment(SSL * s,long max,int * ok)607 static int dtls1_retrieve_buffered_fragment(SSL *s, long max, int *ok)
608 {
609 /*-
610 * (0) check whether the desired fragment is available
611 * if so:
612 * (1) copy over the fragment to s->init_buf->data[]
613 * (2) update s->init_num
614 */
615 pitem *item;
616 hm_fragment *frag;
617 int al;
618
619 *ok = 0;
620 do {
621 item = pqueue_peek(s->d1->buffered_messages);
622 if (item == NULL)
623 return 0;
624
625 frag = (hm_fragment *)item->data;
626
627 if (frag->msg_header.seq < s->d1->handshake_read_seq) {
628 /* This is a stale message that has been buffered so clear it */
629 pqueue_pop(s->d1->buffered_messages);
630 dtls1_hm_fragment_free(frag);
631 pitem_free(item);
632 item = NULL;
633 frag = NULL;
634 }
635 } while (item == NULL);
636
637
638 /* Don't return if reassembly still in progress */
639 if (frag->reassembly != NULL)
640 return 0;
641
642 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
643 unsigned long frag_len = frag->msg_header.frag_len;
644 pqueue_pop(s->d1->buffered_messages);
645
646 al = dtls1_preprocess_fragment(s, &frag->msg_header, max);
647
648 if (al == 0) { /* no alert */
649 unsigned char *p =
650 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
651 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
652 frag->msg_header.frag_len);
653 }
654
655 dtls1_hm_fragment_free(frag);
656 pitem_free(item);
657
658 if (al == 0) {
659 *ok = 1;
660 return frag_len;
661 }
662
663 ssl3_send_alert(s, SSL3_AL_FATAL, al);
664 s->init_num = 0;
665 *ok = 0;
666 return -1;
667 } else
668 return 0;
669 }
670
671 /*
672 * dtls1_max_handshake_message_len returns the maximum number of bytes
673 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
674 * may be greater if the maximum certificate list size requires it.
675 */
dtls1_max_handshake_message_len(const SSL * s)676 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
677 {
678 unsigned long max_len =
679 DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
680 if (max_len < (unsigned long)s->max_cert_list)
681 return s->max_cert_list;
682 return max_len;
683 }
684
685 static int
dtls1_reassemble_fragment(SSL * s,const struct hm_header_st * msg_hdr,int * ok)686 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr, int *ok)
687 {
688 hm_fragment *frag = NULL;
689 pitem *item = NULL;
690 int i = -1, is_complete;
691 unsigned char seq64be[8];
692 unsigned long frag_len = msg_hdr->frag_len;
693
694 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
695 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
696 goto err;
697
698 if (frag_len == 0)
699 return DTLS1_HM_FRAGMENT_RETRY;
700
701 /* Try to find item in queue */
702 memset(seq64be, 0, sizeof(seq64be));
703 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
704 seq64be[7] = (unsigned char)msg_hdr->seq;
705 item = pqueue_find(s->d1->buffered_messages, seq64be);
706
707 if (item == NULL) {
708 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
709 if (frag == NULL)
710 goto err;
711 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
712 frag->msg_header.frag_len = frag->msg_header.msg_len;
713 frag->msg_header.frag_off = 0;
714 } else {
715 frag = (hm_fragment *)item->data;
716 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
717 item = NULL;
718 frag = NULL;
719 goto err;
720 }
721 }
722
723 /*
724 * If message is already reassembled, this must be a retransmit and can
725 * be dropped. In this case item != NULL and so frag does not need to be
726 * freed.
727 */
728 if (frag->reassembly == NULL) {
729 unsigned char devnull[256];
730
731 while (frag_len) {
732 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
733 devnull,
734 frag_len >
735 sizeof(devnull) ? sizeof(devnull) :
736 frag_len, 0);
737 if (i <= 0)
738 goto err;
739 frag_len -= i;
740 }
741 return DTLS1_HM_FRAGMENT_RETRY;
742 }
743
744 /* read the body of the fragment (header has already been read */
745 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
746 frag->fragment + msg_hdr->frag_off,
747 frag_len, 0);
748 if ((unsigned long)i != frag_len)
749 i = -1;
750 if (i <= 0)
751 goto err;
752
753 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
754 (long)(msg_hdr->frag_off + frag_len));
755
756 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
757 is_complete);
758
759 if (is_complete) {
760 OPENSSL_free(frag->reassembly);
761 frag->reassembly = NULL;
762 }
763
764 if (item == NULL) {
765 item = pitem_new(seq64be, frag);
766 if (item == NULL) {
767 i = -1;
768 goto err;
769 }
770
771 item = pqueue_insert(s->d1->buffered_messages, item);
772 /*
773 * pqueue_insert fails iff a duplicate item is inserted. However,
774 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
775 * would have returned it and control would never have reached this
776 * branch.
777 */
778 OPENSSL_assert(item != NULL);
779 }
780
781 return DTLS1_HM_FRAGMENT_RETRY;
782
783 err:
784 if (frag != NULL && item == NULL)
785 dtls1_hm_fragment_free(frag);
786 *ok = 0;
787 return i;
788 }
789
790 static int
dtls1_process_out_of_seq_message(SSL * s,const struct hm_header_st * msg_hdr,int * ok)791 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr,
792 int *ok)
793 {
794 int i = -1;
795 hm_fragment *frag = NULL;
796 pitem *item = NULL;
797 unsigned char seq64be[8];
798 unsigned long frag_len = msg_hdr->frag_len;
799
800 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
801 goto err;
802
803 /* Try to find item in queue, to prevent duplicate entries */
804 memset(seq64be, 0, sizeof(seq64be));
805 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
806 seq64be[7] = (unsigned char)msg_hdr->seq;
807 item = pqueue_find(s->d1->buffered_messages, seq64be);
808
809 /*
810 * If we already have an entry and this one is a fragment, don't discard
811 * it and rather try to reassemble it.
812 */
813 if (item != NULL && frag_len != msg_hdr->msg_len)
814 item = NULL;
815
816 /*
817 * Discard the message if sequence number was already there, is too far
818 * in the future, already in the queue or if we received a FINISHED
819 * before the SERVER_HELLO, which then must be a stale retransmit.
820 */
821 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
822 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
823 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
824 {
825 unsigned char devnull[256];
826
827 while (frag_len) {
828 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
829 devnull,
830 frag_len >
831 sizeof(devnull) ? sizeof(devnull) :
832 frag_len, 0);
833 if (i <= 0)
834 goto err;
835 frag_len -= i;
836 }
837 } else {
838 if (frag_len != msg_hdr->msg_len)
839 return dtls1_reassemble_fragment(s, msg_hdr, ok);
840
841 if (frag_len > dtls1_max_handshake_message_len(s))
842 goto err;
843
844 frag = dtls1_hm_fragment_new(frag_len, 0);
845 if (frag == NULL)
846 goto err;
847
848 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
849
850 if (frag_len) {
851 /*
852 * read the body of the fragment (header has already been read
853 */
854 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
855 frag->fragment, frag_len, 0);
856 if ((unsigned long)i != frag_len)
857 i = -1;
858 if (i <= 0)
859 goto err;
860 }
861
862 item = pitem_new(seq64be, frag);
863 if (item == NULL)
864 goto err;
865
866 item = pqueue_insert(s->d1->buffered_messages, item);
867 /*
868 * pqueue_insert fails iff a duplicate item is inserted. However,
869 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
870 * would have returned it. Then, either |frag_len| !=
871 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
872 * have been processed with |dtls1_reassemble_fragment|, above, or
873 * the record will have been discarded.
874 */
875 OPENSSL_assert(item != NULL);
876 }
877
878 return DTLS1_HM_FRAGMENT_RETRY;
879
880 err:
881 if (frag != NULL && item == NULL)
882 dtls1_hm_fragment_free(frag);
883 *ok = 0;
884 return i;
885 }
886
887 static long
dtls1_get_message_fragment(SSL * s,int st1,int stn,long max,int * ok)888 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
889 {
890 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
891 unsigned long len, frag_off, frag_len;
892 int i, al;
893 struct hm_header_st msg_hdr;
894
895 redo:
896 /* see if we have the required fragment already */
897 if ((frag_len = dtls1_retrieve_buffered_fragment(s, max, ok)) || *ok) {
898 if (*ok)
899 s->init_num = frag_len;
900 return frag_len;
901 }
902
903 /* read handshake message header */
904 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, wire,
905 DTLS1_HM_HEADER_LENGTH, 0);
906 if (i <= 0) { /* nbio, or an error */
907 s->rwstate = SSL_READING;
908 *ok = 0;
909 return i;
910 }
911 /* Handshake fails if message header is incomplete */
912 if (i != DTLS1_HM_HEADER_LENGTH) {
913 al = SSL_AD_UNEXPECTED_MESSAGE;
914 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_UNEXPECTED_MESSAGE);
915 goto f_err;
916 }
917
918 /* parse the message fragment header */
919 dtls1_get_message_header(wire, &msg_hdr);
920
921 len = msg_hdr.msg_len;
922 frag_off = msg_hdr.frag_off;
923 frag_len = msg_hdr.frag_len;
924
925 /*
926 * We must have at least frag_len bytes left in the record to be read.
927 * Fragments must not span records.
928 */
929 if (frag_len > s->s3->rrec.length) {
930 al = SSL3_AD_ILLEGAL_PARAMETER;
931 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL_R_BAD_LENGTH);
932 goto f_err;
933 }
934
935 /*
936 * if this is a future (or stale) message it gets buffered
937 * (or dropped)--no further processing at this time
938 * While listening, we accept seq 1 (ClientHello with cookie)
939 * although we're still expecting seq 0 (ClientHello)
940 */
941 if (msg_hdr.seq != s->d1->handshake_read_seq
942 && !(s->d1->listen && msg_hdr.seq == 1))
943 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
944
945 if (frag_len && frag_len < len)
946 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
947
948 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
949 wire[0] == SSL3_MT_HELLO_REQUEST) {
950 /*
951 * The server may always send 'Hello Request' messages -- we are
952 * doing a handshake anyway now, so ignore them if their format is
953 * correct. Does not count for 'Finished' MAC.
954 */
955 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
956 if (s->msg_callback)
957 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
958 wire, DTLS1_HM_HEADER_LENGTH, s,
959 s->msg_callback_arg);
960
961 s->init_num = 0;
962 goto redo;
963 } else { /* Incorrectly formated Hello request */
964
965 al = SSL_AD_UNEXPECTED_MESSAGE;
966 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,
967 SSL_R_UNEXPECTED_MESSAGE);
968 goto f_err;
969 }
970 }
971
972 if ((al = dtls1_preprocess_fragment(s, &msg_hdr, max)))
973 goto f_err;
974
975 if (frag_len > 0) {
976 unsigned char *p =
977 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
978
979 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE,
980 &p[frag_off], frag_len, 0);
981
982 /*
983 * This shouldn't ever fail due to NBIO because we already checked
984 * that we have enough data in the record
985 */
986 if (i <= 0) {
987 s->rwstate = SSL_READING;
988 *ok = 0;
989 return i;
990 }
991 } else
992 i = 0;
993
994 /*
995 * XDTLS: an incorrectly formatted fragment should cause the handshake
996 * to fail
997 */
998 if (i != (int)frag_len) {
999 al = SSL3_AD_ILLEGAL_PARAMETER;
1000 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT, SSL3_AD_ILLEGAL_PARAMETER);
1001 goto f_err;
1002 }
1003
1004 *ok = 1;
1005 s->state = stn;
1006
1007 /*
1008 * Note that s->init_num is *not* used as current offset in
1009 * s->init_buf->data, but as a counter summing up fragments' lengths: as
1010 * soon as they sum up to handshake packet length, we assume we have got
1011 * all the fragments.
1012 */
1013 s->init_num = frag_len;
1014 return frag_len;
1015
1016 f_err:
1017 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1018 s->init_num = 0;
1019
1020 *ok = 0;
1021 return (-1);
1022 }
1023
dtls1_send_finished(SSL * s,int a,int b,const char * sender,int slen)1024 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
1025 {
1026 unsigned char *p, *d;
1027 int i;
1028 unsigned long l;
1029
1030 if (s->state == a) {
1031 d = (unsigned char *)s->init_buf->data;
1032 p = &(d[DTLS1_HM_HEADER_LENGTH]);
1033
1034 i = s->method->ssl3_enc->final_finish_mac(s,
1035 sender, slen,
1036 s->s3->tmp.finish_md);
1037 s->s3->tmp.finish_md_len = i;
1038 memcpy(p, s->s3->tmp.finish_md, i);
1039 p += i;
1040 l = i;
1041
1042 /*
1043 * Copy the finished so we can use it for renegotiation checks
1044 */
1045 if (s->type == SSL_ST_CONNECT) {
1046 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
1047 memcpy(s->s3->previous_client_finished, s->s3->tmp.finish_md, i);
1048 s->s3->previous_client_finished_len = i;
1049 } else {
1050 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
1051 memcpy(s->s3->previous_server_finished, s->s3->tmp.finish_md, i);
1052 s->s3->previous_server_finished_len = i;
1053 }
1054
1055 #ifdef OPENSSL_SYS_WIN16
1056 /*
1057 * MSVC 1.5 does not clear the top bytes of the word unless I do
1058 * this.
1059 */
1060 l &= 0xffff;
1061 #endif
1062
1063 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
1064 s->init_num = (int)l + DTLS1_HM_HEADER_LENGTH;
1065 s->init_off = 0;
1066
1067 /* buffer the message to handle re-xmits */
1068 dtls1_buffer_message(s, 0);
1069
1070 s->state = b;
1071 }
1072
1073 /* SSL3_ST_SEND_xxxxxx_HELLO_B */
1074 return (dtls1_do_write(s, SSL3_RT_HANDSHAKE));
1075 }
1076
1077 /*-
1078 * for these 2 messages, we need to
1079 * ssl->enc_read_ctx re-init
1080 * ssl->s3->read_sequence zero
1081 * ssl->s3->read_mac_secret re-init
1082 * ssl->session->read_sym_enc assign
1083 * ssl->session->read_compression assign
1084 * ssl->session->read_hash assign
1085 */
dtls1_send_change_cipher_spec(SSL * s,int a,int b)1086 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
1087 {
1088 unsigned char *p;
1089
1090 if (s->state == a) {
1091 p = (unsigned char *)s->init_buf->data;
1092 *p++ = SSL3_MT_CCS;
1093 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1094 s->init_num = DTLS1_CCS_HEADER_LENGTH;
1095
1096 if (s->version == DTLS1_BAD_VER) {
1097 s->d1->next_handshake_write_seq++;
1098 s2n(s->d1->handshake_write_seq, p);
1099 s->init_num += 2;
1100 }
1101
1102 s->init_off = 0;
1103
1104 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1105 s->d1->handshake_write_seq, 0, 0);
1106
1107 /* buffer the message to handle re-xmits */
1108 dtls1_buffer_message(s, 1);
1109
1110 s->state = b;
1111 }
1112
1113 /* SSL3_ST_CW_CHANGE_B */
1114 return (dtls1_do_write(s, SSL3_RT_CHANGE_CIPHER_SPEC));
1115 }
1116
dtls1_add_cert_to_buf(BUF_MEM * buf,unsigned long * l,X509 * x)1117 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1118 {
1119 int n;
1120 unsigned char *p;
1121
1122 n = i2d_X509(x, NULL);
1123 if (!BUF_MEM_grow_clean(buf, (int)(n + (*l) + 3))) {
1124 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF, ERR_R_BUF_LIB);
1125 return 0;
1126 }
1127 p = (unsigned char *)&(buf->data[*l]);
1128 l2n3(n, p);
1129 i2d_X509(x, &p);
1130 *l += n + 3;
1131
1132 return 1;
1133 }
1134
dtls1_output_cert_chain(SSL * s,X509 * x)1135 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1136 {
1137 unsigned char *p;
1138 int i;
1139 unsigned long l = 3 + DTLS1_HM_HEADER_LENGTH;
1140 BUF_MEM *buf;
1141
1142 /* TLSv1 sends a chain with nothing in it, instead of an alert */
1143 buf = s->init_buf;
1144 if (!BUF_MEM_grow_clean(buf, 10)) {
1145 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_BUF_LIB);
1146 return (0);
1147 }
1148 if (x != NULL) {
1149 X509_STORE_CTX xs_ctx;
1150
1151 if (!X509_STORE_CTX_init(&xs_ctx, s->ctx->cert_store, x, NULL)) {
1152 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN, ERR_R_X509_LIB);
1153 return (0);
1154 }
1155
1156 X509_verify_cert(&xs_ctx);
1157 /* Don't leave errors in the queue */
1158 ERR_clear_error();
1159 for (i = 0; i < sk_X509_num(xs_ctx.chain); i++) {
1160 x = sk_X509_value(xs_ctx.chain, i);
1161
1162 if (!dtls1_add_cert_to_buf(buf, &l, x)) {
1163 X509_STORE_CTX_cleanup(&xs_ctx);
1164 return 0;
1165 }
1166 }
1167 X509_STORE_CTX_cleanup(&xs_ctx);
1168 }
1169 /* Thawte special :-) */
1170 for (i = 0; i < sk_X509_num(s->ctx->extra_certs); i++) {
1171 x = sk_X509_value(s->ctx->extra_certs, i);
1172 if (!dtls1_add_cert_to_buf(buf, &l, x))
1173 return 0;
1174 }
1175
1176 l -= (3 + DTLS1_HM_HEADER_LENGTH);
1177
1178 p = (unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1179 l2n3(l, p);
1180 l += 3;
1181 p = (unsigned char *)&(buf->data[0]);
1182 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1183
1184 l += DTLS1_HM_HEADER_LENGTH;
1185 return (l);
1186 }
1187
dtls1_read_failed(SSL * s,int code)1188 int dtls1_read_failed(SSL *s, int code)
1189 {
1190 if (code > 0) {
1191 fprintf(stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1192 return 1;
1193 }
1194
1195 if (!dtls1_is_timer_expired(s)) {
1196 /*
1197 * not a timeout, none of our business, let higher layers handle
1198 * this. in fact it's probably an error
1199 */
1200 return code;
1201 }
1202 #ifndef OPENSSL_NO_HEARTBEATS
1203 /* done, no need to send a retransmit */
1204 if (!SSL_in_init(s) && !s->tlsext_hb_pending)
1205 #else
1206 /* done, no need to send a retransmit */
1207 if (!SSL_in_init(s))
1208 #endif
1209 {
1210 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1211 return code;
1212 }
1213 #if 0 /* for now, each alert contains only one
1214 * record number */
1215 item = pqueue_peek(state->rcvd_records);
1216 if (item) {
1217 /* send an alert immediately for all the missing records */
1218 } else
1219 #endif
1220
1221 #if 0 /* no more alert sending, just retransmit the
1222 * last set of messages */
1223 if (state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1224 ssl3_send_alert(s, SSL3_AL_WARNING,
1225 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1226 #endif
1227
1228 return dtls1_handle_timeout(s);
1229 }
1230
dtls1_get_queue_priority(unsigned short seq,int is_ccs)1231 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1232 {
1233 /*
1234 * The index of the retransmission queue actually is the message sequence
1235 * number, since the queue only contains messages of a single handshake.
1236 * However, the ChangeCipherSpec has no message sequence number and so
1237 * using only the sequence will result in the CCS and Finished having the
1238 * same index. To prevent this, the sequence number is multiplied by 2.
1239 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1240 * Finished, it also maintains the order of the index (important for
1241 * priority queues) and fits in the unsigned short variable.
1242 */
1243 return seq * 2 - is_ccs;
1244 }
1245
dtls1_retransmit_buffered_messages(SSL * s)1246 int dtls1_retransmit_buffered_messages(SSL *s)
1247 {
1248 pqueue sent = s->d1->sent_messages;
1249 piterator iter;
1250 pitem *item;
1251 hm_fragment *frag;
1252 int found = 0;
1253
1254 iter = pqueue_iterator(sent);
1255
1256 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1257 frag = (hm_fragment *)item->data;
1258 if (dtls1_retransmit_message(s, (unsigned short)
1259 dtls1_get_queue_priority
1260 (frag->msg_header.seq,
1261 frag->msg_header.is_ccs), 0,
1262 &found) <= 0 && found) {
1263 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1264 return -1;
1265 }
1266 }
1267
1268 return 1;
1269 }
1270
dtls1_buffer_message(SSL * s,int is_ccs)1271 int dtls1_buffer_message(SSL *s, int is_ccs)
1272 {
1273 pitem *item;
1274 hm_fragment *frag;
1275 unsigned char seq64be[8];
1276
1277 /*
1278 * this function is called immediately after a message has been
1279 * serialized
1280 */
1281 OPENSSL_assert(s->init_off == 0);
1282
1283 frag = dtls1_hm_fragment_new(s->init_num, 0);
1284 if (!frag)
1285 return 0;
1286
1287 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1288
1289 if (is_ccs) {
1290 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1291 ((s->version ==
1292 DTLS1_VERSION) ? DTLS1_CCS_HEADER_LENGTH : 3) ==
1293 (unsigned int)s->init_num);
1294 } else {
1295 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1296 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1297 }
1298
1299 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1300 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1301 frag->msg_header.type = s->d1->w_msg_hdr.type;
1302 frag->msg_header.frag_off = 0;
1303 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1304 frag->msg_header.is_ccs = is_ccs;
1305
1306 /* save current state */
1307 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1308 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1309 frag->msg_header.saved_retransmit_state.compress = s->compress;
1310 frag->msg_header.saved_retransmit_state.session = s->session;
1311 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1312
1313 memset(seq64be, 0, sizeof(seq64be));
1314 seq64be[6] =
1315 (unsigned
1316 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1317 frag->msg_header.is_ccs) >> 8);
1318 seq64be[7] =
1319 (unsigned
1320 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1321 frag->msg_header.is_ccs));
1322
1323 item = pitem_new(seq64be, frag);
1324 if (item == NULL) {
1325 dtls1_hm_fragment_free(frag);
1326 return 0;
1327 }
1328 #if 0
1329 fprintf(stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1330 fprintf(stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1331 fprintf(stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1332 #endif
1333
1334 pqueue_insert(s->d1->sent_messages, item);
1335 return 1;
1336 }
1337
1338 int
dtls1_retransmit_message(SSL * s,unsigned short seq,unsigned long frag_off,int * found)1339 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1340 int *found)
1341 {
1342 int ret;
1343 /* XDTLS: for now assuming that read/writes are blocking */
1344 pitem *item;
1345 hm_fragment *frag;
1346 unsigned long header_length;
1347 unsigned char seq64be[8];
1348 struct dtls1_retransmit_state saved_state;
1349 unsigned char save_write_sequence[8];
1350
1351 /*-
1352 OPENSSL_assert(s->init_num == 0);
1353 OPENSSL_assert(s->init_off == 0);
1354 */
1355
1356 /* XDTLS: the requested message ought to be found, otherwise error */
1357 memset(seq64be, 0, sizeof(seq64be));
1358 seq64be[6] = (unsigned char)(seq >> 8);
1359 seq64be[7] = (unsigned char)seq;
1360
1361 item = pqueue_find(s->d1->sent_messages, seq64be);
1362 if (item == NULL) {
1363 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1364 *found = 0;
1365 return 0;
1366 }
1367
1368 *found = 1;
1369 frag = (hm_fragment *)item->data;
1370
1371 if (frag->msg_header.is_ccs)
1372 header_length = DTLS1_CCS_HEADER_LENGTH;
1373 else
1374 header_length = DTLS1_HM_HEADER_LENGTH;
1375
1376 memcpy(s->init_buf->data, frag->fragment,
1377 frag->msg_header.msg_len + header_length);
1378 s->init_num = frag->msg_header.msg_len + header_length;
1379
1380 dtls1_set_message_header_int(s, frag->msg_header.type,
1381 frag->msg_header.msg_len,
1382 frag->msg_header.seq, 0,
1383 frag->msg_header.frag_len);
1384
1385 /* save current state */
1386 saved_state.enc_write_ctx = s->enc_write_ctx;
1387 saved_state.write_hash = s->write_hash;
1388 saved_state.compress = s->compress;
1389 saved_state.session = s->session;
1390 saved_state.epoch = s->d1->w_epoch;
1391 saved_state.epoch = s->d1->w_epoch;
1392
1393 s->d1->retransmitting = 1;
1394
1395 /* restore state in which the message was originally sent */
1396 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1397 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1398 s->compress = frag->msg_header.saved_retransmit_state.compress;
1399 s->session = frag->msg_header.saved_retransmit_state.session;
1400 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1401
1402 if (frag->msg_header.saved_retransmit_state.epoch ==
1403 saved_state.epoch - 1) {
1404 memcpy(save_write_sequence, s->s3->write_sequence,
1405 sizeof(s->s3->write_sequence));
1406 memcpy(s->s3->write_sequence, s->d1->last_write_sequence,
1407 sizeof(s->s3->write_sequence));
1408 }
1409
1410 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1411 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1412
1413 /* restore current state */
1414 s->enc_write_ctx = saved_state.enc_write_ctx;
1415 s->write_hash = saved_state.write_hash;
1416 s->compress = saved_state.compress;
1417 s->session = saved_state.session;
1418 s->d1->w_epoch = saved_state.epoch;
1419
1420 if (frag->msg_header.saved_retransmit_state.epoch ==
1421 saved_state.epoch - 1) {
1422 memcpy(s->d1->last_write_sequence, s->s3->write_sequence,
1423 sizeof(s->s3->write_sequence));
1424 memcpy(s->s3->write_sequence, save_write_sequence,
1425 sizeof(s->s3->write_sequence));
1426 }
1427
1428 s->d1->retransmitting = 0;
1429
1430 (void)BIO_flush(SSL_get_wbio(s));
1431 return ret;
1432 }
1433
dtls1_set_message_header(SSL * s,unsigned char * p,unsigned char mt,unsigned long len,unsigned long frag_off,unsigned long frag_len)1434 unsigned char *dtls1_set_message_header(SSL *s, unsigned char *p,
1435 unsigned char mt, unsigned long len,
1436 unsigned long frag_off,
1437 unsigned long frag_len)
1438 {
1439 /* Don't change sequence numbers while listening */
1440 if (frag_off == 0 && !s->d1->listen) {
1441 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1442 s->d1->next_handshake_write_seq++;
1443 }
1444
1445 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1446 frag_off, frag_len);
1447
1448 return p += DTLS1_HM_HEADER_LENGTH;
1449 }
1450
1451 /* don't actually do the writing, wait till the MTU has been retrieved */
1452 static void
dtls1_set_message_header_int(SSL * s,unsigned char mt,unsigned long len,unsigned short seq_num,unsigned long frag_off,unsigned long frag_len)1453 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1454 unsigned long len, unsigned short seq_num,
1455 unsigned long frag_off, unsigned long frag_len)
1456 {
1457 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1458
1459 msg_hdr->type = mt;
1460 msg_hdr->msg_len = len;
1461 msg_hdr->seq = seq_num;
1462 msg_hdr->frag_off = frag_off;
1463 msg_hdr->frag_len = frag_len;
1464 }
1465
1466 static void
dtls1_fix_message_header(SSL * s,unsigned long frag_off,unsigned long frag_len)1467 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1468 unsigned long frag_len)
1469 {
1470 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1471
1472 msg_hdr->frag_off = frag_off;
1473 msg_hdr->frag_len = frag_len;
1474 }
1475
dtls1_write_message_header(SSL * s,unsigned char * p)1476 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1477 {
1478 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1479
1480 *p++ = msg_hdr->type;
1481 l2n3(msg_hdr->msg_len, p);
1482
1483 s2n(msg_hdr->seq, p);
1484 l2n3(msg_hdr->frag_off, p);
1485 l2n3(msg_hdr->frag_len, p);
1486
1487 return p;
1488 }
1489
dtls1_link_min_mtu(void)1490 unsigned int dtls1_link_min_mtu(void)
1491 {
1492 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1493 sizeof(g_probable_mtu[0])) - 1]);
1494 }
1495
dtls1_min_mtu(SSL * s)1496 unsigned int dtls1_min_mtu(SSL *s)
1497 {
1498 return dtls1_link_min_mtu() - BIO_dgram_get_mtu_overhead(SSL_get_wbio(s));
1499 }
1500
1501 void
dtls1_get_message_header(unsigned char * data,struct hm_header_st * msg_hdr)1502 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1503 {
1504 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1505 msg_hdr->type = *(data++);
1506 n2l3(data, msg_hdr->msg_len);
1507
1508 n2s(data, msg_hdr->seq);
1509 n2l3(data, msg_hdr->frag_off);
1510 n2l3(data, msg_hdr->frag_len);
1511 }
1512
dtls1_get_ccs_header(unsigned char * data,struct ccs_header_st * ccs_hdr)1513 void dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1514 {
1515 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1516
1517 ccs_hdr->type = *(data++);
1518 }
1519
dtls1_shutdown(SSL * s)1520 int dtls1_shutdown(SSL *s)
1521 {
1522 int ret;
1523 #ifndef OPENSSL_NO_SCTP
1524 BIO *wbio;
1525
1526 wbio = SSL_get_wbio(s);
1527 if (wbio != NULL && BIO_dgram_is_sctp(wbio) &&
1528 !(s->shutdown & SSL_SENT_SHUTDOWN)) {
1529 ret = BIO_dgram_sctp_wait_for_dry(wbio);
1530 if (ret < 0)
1531 return -1;
1532
1533 if (ret == 0)
1534 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1,
1535 NULL);
1536 }
1537 #endif
1538 ret = ssl3_shutdown(s);
1539 #ifndef OPENSSL_NO_SCTP
1540 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1541 #endif
1542 return ret;
1543 }
1544
1545 #ifndef OPENSSL_NO_HEARTBEATS
dtls1_process_heartbeat(SSL * s)1546 int dtls1_process_heartbeat(SSL *s)
1547 {
1548 unsigned char *p = &s->s3->rrec.data[0], *pl;
1549 unsigned short hbtype;
1550 unsigned int payload;
1551 unsigned int padding = 16; /* Use minimum padding */
1552
1553 if (s->msg_callback)
1554 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1555 &s->s3->rrec.data[0], s->s3->rrec.length,
1556 s, s->msg_callback_arg);
1557
1558 /* Read type and payload length first */
1559 if (1 + 2 + 16 > s->s3->rrec.length)
1560 return 0; /* silently discard */
1561 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH)
1562 return 0; /* silently discard per RFC 6520 sec. 4 */
1563
1564 hbtype = *p++;
1565 n2s(p, payload);
1566 if (1 + 2 + payload + 16 > s->s3->rrec.length)
1567 return 0; /* silently discard per RFC 6520 sec. 4 */
1568 pl = p;
1569
1570 if (hbtype == TLS1_HB_REQUEST) {
1571 unsigned char *buffer, *bp;
1572 unsigned int write_length = 1 /* heartbeat type */ +
1573 2 /* heartbeat length */ +
1574 payload + padding;
1575 int r;
1576
1577 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1578 return 0;
1579
1580 /*
1581 * Allocate memory for the response, size is 1 byte message type,
1582 * plus 2 bytes payload length, plus payload, plus padding
1583 */
1584 buffer = OPENSSL_malloc(write_length);
1585 if (buffer == NULL)
1586 return -1;
1587 bp = buffer;
1588
1589 /* Enter response type, length and copy payload */
1590 *bp++ = TLS1_HB_RESPONSE;
1591 s2n(payload, bp);
1592 memcpy(bp, pl, payload);
1593 bp += payload;
1594 /* Random padding */
1595 if (RAND_bytes(bp, padding) <= 0) {
1596 OPENSSL_free(buffer);
1597 return -1;
1598 }
1599
1600 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1601
1602 if (r >= 0 && s->msg_callback)
1603 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1604 buffer, write_length, s, s->msg_callback_arg);
1605
1606 OPENSSL_free(buffer);
1607
1608 if (r < 0)
1609 return r;
1610 } else if (hbtype == TLS1_HB_RESPONSE) {
1611 unsigned int seq;
1612
1613 /*
1614 * We only send sequence numbers (2 bytes unsigned int), and 16
1615 * random bytes, so we just try to read the sequence number
1616 */
1617 n2s(pl, seq);
1618
1619 if (payload == 18 && seq == s->tlsext_hb_seq) {
1620 dtls1_stop_timer(s);
1621 s->tlsext_hb_seq++;
1622 s->tlsext_hb_pending = 0;
1623 }
1624 }
1625
1626 return 0;
1627 }
1628
dtls1_heartbeat(SSL * s)1629 int dtls1_heartbeat(SSL *s)
1630 {
1631 unsigned char *buf, *p;
1632 int ret = -1;
1633 unsigned int payload = 18; /* Sequence number + random bytes */
1634 unsigned int padding = 16; /* Use minimum padding */
1635
1636 /* Only send if peer supports and accepts HB requests... */
1637 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1638 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS) {
1639 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1640 return -1;
1641 }
1642
1643 /* ...and there is none in flight yet... */
1644 if (s->tlsext_hb_pending) {
1645 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_TLS_HEARTBEAT_PENDING);
1646 return -1;
1647 }
1648
1649 /* ...and no handshake in progress. */
1650 if (SSL_in_init(s) || s->in_handshake) {
1651 SSLerr(SSL_F_DTLS1_HEARTBEAT, SSL_R_UNEXPECTED_MESSAGE);
1652 return -1;
1653 }
1654
1655 /*
1656 * Check if padding is too long, payload and padding must not exceed 2^14
1657 * - 3 = 16381 bytes in total.
1658 */
1659 OPENSSL_assert(payload + padding <= 16381);
1660
1661 /*-
1662 * Create HeartBeat message, we just use a sequence number
1663 * as payload to distuingish different messages and add
1664 * some random stuff.
1665 * - Message Type, 1 byte
1666 * - Payload Length, 2 bytes (unsigned int)
1667 * - Payload, the sequence number (2 bytes uint)
1668 * - Payload, random bytes (16 bytes uint)
1669 * - Padding
1670 */
1671 buf = OPENSSL_malloc(1 + 2 + payload + padding);
1672 p = buf;
1673 /* Message Type */
1674 *p++ = TLS1_HB_REQUEST;
1675 /* Payload length (18 bytes here) */
1676 s2n(payload, p);
1677 /* Sequence number */
1678 s2n(s->tlsext_hb_seq, p);
1679 /* 16 random bytes */
1680 if (RAND_bytes(p, 16) <= 0)
1681 goto err;
1682 p += 16;
1683 /* Random padding */
1684 if (RAND_bytes(p, padding) <= 0)
1685 goto err;
1686
1687 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1688 if (ret >= 0) {
1689 if (s->msg_callback)
1690 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1691 buf, 3 + payload + padding,
1692 s, s->msg_callback_arg);
1693
1694 dtls1_start_timer(s);
1695 s->tlsext_hb_pending = 1;
1696 }
1697
1698 err:
1699 OPENSSL_free(buf);
1700
1701 return ret;
1702 }
1703 #endif
1704