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[] = {0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80};
156 static unsigned char bitmask_end_values[] = {0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f};
157
158 /* XDTLS: figure out the right values */
159 static unsigned int g_probable_mtu[] = {1500 - 28, 512 - 28, 256 - 28};
160
161 static unsigned int dtls1_guess_mtu(unsigned int curr_mtu);
162 static void dtls1_fix_message_header(SSL *s, unsigned long frag_off,
163 unsigned long frag_len);
164 static unsigned char *dtls1_write_message_header(SSL *s,
165 unsigned char *p);
166 static 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);
169 static long dtls1_get_message_fragment(SSL *s, int st1, int stn,
170 long max, int *ok);
171
172 static hm_fragment *
dtls1_hm_fragment_new(unsigned long frag_len,int reassembly)173 dtls1_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
214 static void
dtls1_hm_fragment_free(hm_fragment * frag)215 dtls1_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) */
dtls1_do_write(SSL * s,int type)229 int 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 */
dtls1_get_message(SSL * s,int st1,int stn,int mt,long max,int * ok)415 long 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
442 again:
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
479 f_err:
480 ssl3_send_alert(s,SSL3_AL_FATAL,al);
481 *ok = 0;
482 return -1;
483 }
484
485
dtls1_preprocess_fragment(SSL * s,struct hm_header_st * msg_hdr,int max)486 static 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
535 static int
dtls1_retrieve_buffered_fragment(SSL * s,long max,int * ok)536 dtls1_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 /* dtls1_max_handshake_message_len returns the maximum number of bytes
591 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but may
592 * be greater if the maximum certificate list size requires it. */
dtls1_max_handshake_message_len(const SSL * s)593 static unsigned long dtls1_max_handshake_message_len(const SSL *s)
594 {
595 unsigned long max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
596 if (max_len < (unsigned long)s->max_cert_list)
597 return s->max_cert_list;
598 return max_len;
599 }
600
601 static int
dtls1_reassemble_fragment(SSL * s,const struct hm_header_st * msg_hdr,int * ok)602 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
603 {
604 hm_fragment *frag = NULL;
605 pitem *item = NULL;
606 int i = -1, is_complete;
607 unsigned char seq64be[8];
608 unsigned long frag_len = msg_hdr->frag_len;
609
610 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len ||
611 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
612 goto err;
613
614 if (frag_len == 0)
615 return DTLS1_HM_FRAGMENT_RETRY;
616
617 /* Try to find item in queue */
618 memset(seq64be,0,sizeof(seq64be));
619 seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
620 seq64be[7] = (unsigned char) msg_hdr->seq;
621 item = pqueue_find(s->d1->buffered_messages, seq64be);
622
623 if (item == NULL)
624 {
625 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
626 if ( frag == NULL)
627 goto err;
628 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
629 frag->msg_header.frag_len = frag->msg_header.msg_len;
630 frag->msg_header.frag_off = 0;
631 }
632 else
633 {
634 frag = (hm_fragment*) item->data;
635 if (frag->msg_header.msg_len != msg_hdr->msg_len)
636 {
637 item = NULL;
638 frag = NULL;
639 goto err;
640 }
641 }
642
643
644 /* If message is already reassembled, this must be a
645 * retransmit and can be dropped. In this case item != NULL and so frag
646 * does not need to be freed.
647 */
648 if (frag->reassembly == NULL)
649 {
650 unsigned char devnull [256];
651
652 while (frag_len)
653 {
654 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
655 devnull,
656 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
657 if (i<=0) goto err;
658 frag_len -= i;
659 }
660 return DTLS1_HM_FRAGMENT_RETRY;
661 }
662
663 /* read the body of the fragment (header has already been read */
664 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
665 frag->fragment + msg_hdr->frag_off,frag_len,0);
666 if ((unsigned long)i!=frag_len)
667 i=-1;
668 if (i<=0)
669 goto err;
670
671 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
672 (long)(msg_hdr->frag_off + frag_len));
673
674 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
675 is_complete);
676
677 if (is_complete)
678 {
679 OPENSSL_free(frag->reassembly);
680 frag->reassembly = NULL;
681 }
682
683 if (item == NULL)
684 {
685 item = pitem_new(seq64be, frag);
686 if (item == NULL)
687 {
688 i = -1;
689 goto err;
690 }
691
692 item = pqueue_insert(s->d1->buffered_messages, item);
693 /* pqueue_insert fails iff a duplicate item is inserted.
694 * However, |item| cannot be a duplicate. If it were,
695 * |pqueue_find|, above, would have returned it and control
696 * would never have reached this branch. */
697 OPENSSL_assert(item != NULL);
698 }
699
700 return DTLS1_HM_FRAGMENT_RETRY;
701
702 err:
703 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
704 *ok = 0;
705 return i;
706 }
707
708
709 static int
dtls1_process_out_of_seq_message(SSL * s,const struct hm_header_st * msg_hdr,int * ok)710 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st* msg_hdr, int *ok)
711 {
712 int i=-1;
713 hm_fragment *frag = NULL;
714 pitem *item = NULL;
715 unsigned char seq64be[8];
716 unsigned long frag_len = msg_hdr->frag_len;
717
718 if ((msg_hdr->frag_off+frag_len) > msg_hdr->msg_len)
719 goto err;
720
721 /* Try to find item in queue, to prevent duplicate entries */
722 memset(seq64be,0,sizeof(seq64be));
723 seq64be[6] = (unsigned char) (msg_hdr->seq>>8);
724 seq64be[7] = (unsigned char) msg_hdr->seq;
725 item = pqueue_find(s->d1->buffered_messages, seq64be);
726
727 /* If we already have an entry and this one is a fragment,
728 * don't discard it and rather try to reassemble it.
729 */
730 if (item != NULL && frag_len != msg_hdr->msg_len)
731 item = NULL;
732
733 /* Discard the message if sequence number was already there, is
734 * too far in the future, already in the queue or if we received
735 * a FINISHED before the SERVER_HELLO, which then must be a stale
736 * retransmit.
737 */
738 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
739 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
740 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED))
741 {
742 unsigned char devnull [256];
743
744 while (frag_len)
745 {
746 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
747 devnull,
748 frag_len>sizeof(devnull)?sizeof(devnull):frag_len,0);
749 if (i<=0) goto err;
750 frag_len -= i;
751 }
752 }
753 else
754 {
755 if (frag_len != msg_hdr->msg_len)
756 return dtls1_reassemble_fragment(s, msg_hdr, ok);
757
758 if (frag_len > dtls1_max_handshake_message_len(s))
759 goto err;
760
761 frag = dtls1_hm_fragment_new(frag_len, 0);
762 if ( frag == NULL)
763 goto err;
764
765 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
766
767 if (frag_len)
768 {
769 /* read the body of the fragment (header has already been read */
770 i = s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
771 frag->fragment,frag_len,0);
772 if ((unsigned long)i!=frag_len)
773 i = -1;
774 if (i<=0)
775 goto err;
776 }
777
778 item = pitem_new(seq64be, frag);
779 if ( item == NULL)
780 goto err;
781
782 item = pqueue_insert(s->d1->buffered_messages, item);
783 /* pqueue_insert fails iff a duplicate item is inserted.
784 * However, |item| cannot be a duplicate. If it were,
785 * |pqueue_find|, above, would have returned it. Then, either
786 * |frag_len| != |msg_hdr->msg_len| in which case |item| is set
787 * to NULL and it will have been processed with
788 * |dtls1_reassemble_fragment|, above, or the record will have
789 * been discarded. */
790 OPENSSL_assert(item != NULL);
791 }
792
793 return DTLS1_HM_FRAGMENT_RETRY;
794
795 err:
796 if (frag != NULL && item == NULL) dtls1_hm_fragment_free(frag);
797 *ok = 0;
798 return i;
799 }
800
801
802 static long
dtls1_get_message_fragment(SSL * s,int st1,int stn,long max,int * ok)803 dtls1_get_message_fragment(SSL *s, int st1, int stn, long max, int *ok)
804 {
805 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
806 unsigned long len, frag_off, frag_len;
807 int i,al;
808 struct hm_header_st msg_hdr;
809
810 redo:
811 /* see if we have the required fragment already */
812 if ((frag_len = dtls1_retrieve_buffered_fragment(s,max,ok)) || *ok)
813 {
814 if (*ok) s->init_num = frag_len;
815 return frag_len;
816 }
817
818 /* read handshake message header */
819 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,wire,
820 DTLS1_HM_HEADER_LENGTH, 0);
821 if (i <= 0) /* nbio, or an error */
822 {
823 s->rwstate=SSL_READING;
824 *ok = 0;
825 return i;
826 }
827 /* Handshake fails if message header is incomplete */
828 if (i != DTLS1_HM_HEADER_LENGTH)
829 {
830 al=SSL_AD_UNEXPECTED_MESSAGE;
831 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
832 goto f_err;
833 }
834
835 /* parse the message fragment header */
836 dtls1_get_message_header(wire, &msg_hdr);
837
838 /*
839 * if this is a future (or stale) message it gets buffered
840 * (or dropped)--no further processing at this time
841 * While listening, we accept seq 1 (ClientHello with cookie)
842 * although we're still expecting seq 0 (ClientHello)
843 */
844 if (msg_hdr.seq != s->d1->handshake_read_seq && !(s->d1->listen && msg_hdr.seq == 1))
845 return dtls1_process_out_of_seq_message(s, &msg_hdr, ok);
846
847 len = msg_hdr.msg_len;
848 frag_off = msg_hdr.frag_off;
849 frag_len = msg_hdr.frag_len;
850
851 if (frag_len && frag_len < len)
852 return dtls1_reassemble_fragment(s, &msg_hdr, ok);
853
854 if (!s->server && s->d1->r_msg_hdr.frag_off == 0 &&
855 wire[0] == SSL3_MT_HELLO_REQUEST)
856 {
857 /* The server may always send 'Hello Request' messages --
858 * we are doing a handshake anyway now, so ignore them
859 * if their format is correct. Does not count for
860 * 'Finished' MAC. */
861 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0)
862 {
863 if (s->msg_callback)
864 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
865 wire, DTLS1_HM_HEADER_LENGTH, s,
866 s->msg_callback_arg);
867
868 s->init_num = 0;
869 goto redo;
870 }
871 else /* Incorrectly formated Hello request */
872 {
873 al=SSL_AD_UNEXPECTED_MESSAGE;
874 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL_R_UNEXPECTED_MESSAGE);
875 goto f_err;
876 }
877 }
878
879 if ((al=dtls1_preprocess_fragment(s,&msg_hdr,max)))
880 goto f_err;
881
882 /* XDTLS: ressurect this when restart is in place */
883 s->state=stn;
884
885 if ( frag_len > 0)
886 {
887 unsigned char *p=(unsigned char *)s->init_buf->data+DTLS1_HM_HEADER_LENGTH;
888
889 i=s->method->ssl_read_bytes(s,SSL3_RT_HANDSHAKE,
890 &p[frag_off],frag_len,0);
891 /* XDTLS: fix this--message fragments cannot span multiple packets */
892 if (i <= 0)
893 {
894 s->rwstate=SSL_READING;
895 *ok = 0;
896 return i;
897 }
898 }
899 else
900 i = 0;
901
902 /* XDTLS: an incorrectly formatted fragment should cause the
903 * handshake to fail */
904 if (i != (int)frag_len)
905 {
906 al=SSL3_AD_ILLEGAL_PARAMETER;
907 SSLerr(SSL_F_DTLS1_GET_MESSAGE_FRAGMENT,SSL3_AD_ILLEGAL_PARAMETER);
908 goto f_err;
909 }
910
911 *ok = 1;
912
913 /* Note that s->init_num is *not* used as current offset in
914 * s->init_buf->data, but as a counter summing up fragments'
915 * lengths: as soon as they sum up to handshake packet
916 * length, we assume we have got all the fragments. */
917 s->init_num = frag_len;
918 return frag_len;
919
920 f_err:
921 ssl3_send_alert(s,SSL3_AL_FATAL,al);
922 s->init_num = 0;
923
924 *ok=0;
925 return(-1);
926 }
927
dtls1_send_finished(SSL * s,int a,int b,const char * sender,int slen)928 int dtls1_send_finished(SSL *s, int a, int b, const char *sender, int slen)
929 {
930 unsigned char *p,*d;
931 int i;
932 unsigned long l;
933
934 if (s->state == a)
935 {
936 d=(unsigned char *)s->init_buf->data;
937 p= &(d[DTLS1_HM_HEADER_LENGTH]);
938
939 i=s->method->ssl3_enc->final_finish_mac(s,
940 sender,slen,s->s3->tmp.finish_md);
941 s->s3->tmp.finish_md_len = i;
942 memcpy(p, s->s3->tmp.finish_md, i);
943 p+=i;
944 l=i;
945
946 /* Copy the finished so we can use it for
947 * renegotiation checks
948 */
949 if(s->type == SSL_ST_CONNECT)
950 {
951 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
952 memcpy(s->s3->previous_client_finished,
953 s->s3->tmp.finish_md, i);
954 s->s3->previous_client_finished_len=i;
955 }
956 else
957 {
958 OPENSSL_assert(i <= EVP_MAX_MD_SIZE);
959 memcpy(s->s3->previous_server_finished,
960 s->s3->tmp.finish_md, i);
961 s->s3->previous_server_finished_len=i;
962 }
963
964 #ifdef OPENSSL_SYS_WIN16
965 /* MSVC 1.5 does not clear the top bytes of the word unless
966 * I do this.
967 */
968 l&=0xffff;
969 #endif
970
971 d = dtls1_set_message_header(s, d, SSL3_MT_FINISHED, l, 0, l);
972 s->init_num=(int)l+DTLS1_HM_HEADER_LENGTH;
973 s->init_off=0;
974
975 /* buffer the message to handle re-xmits */
976 dtls1_buffer_message(s, 0);
977
978 s->state=b;
979 }
980
981 /* SSL3_ST_SEND_xxxxxx_HELLO_B */
982 return(dtls1_do_write(s,SSL3_RT_HANDSHAKE));
983 }
984
985 /* for these 2 messages, we need to
986 * ssl->enc_read_ctx re-init
987 * ssl->s3->read_sequence zero
988 * ssl->s3->read_mac_secret re-init
989 * ssl->session->read_sym_enc assign
990 * ssl->session->read_compression assign
991 * ssl->session->read_hash assign
992 */
dtls1_send_change_cipher_spec(SSL * s,int a,int b)993 int dtls1_send_change_cipher_spec(SSL *s, int a, int b)
994 {
995 unsigned char *p;
996
997 if (s->state == a)
998 {
999 p=(unsigned char *)s->init_buf->data;
1000 *p++=SSL3_MT_CCS;
1001 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1002 s->init_num=DTLS1_CCS_HEADER_LENGTH;
1003
1004 if (s->version == DTLS1_BAD_VER) {
1005 s->d1->next_handshake_write_seq++;
1006 s2n(s->d1->handshake_write_seq,p);
1007 s->init_num+=2;
1008 }
1009
1010 s->init_off=0;
1011
1012 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1013 s->d1->handshake_write_seq, 0, 0);
1014
1015 /* buffer the message to handle re-xmits */
1016 dtls1_buffer_message(s, 1);
1017
1018 s->state=b;
1019 }
1020
1021 /* SSL3_ST_CW_CHANGE_B */
1022 return(dtls1_do_write(s,SSL3_RT_CHANGE_CIPHER_SPEC));
1023 }
1024
dtls1_add_cert_to_buf(BUF_MEM * buf,unsigned long * l,X509 * x)1025 static int dtls1_add_cert_to_buf(BUF_MEM *buf, unsigned long *l, X509 *x)
1026 {
1027 int n;
1028 unsigned char *p;
1029
1030 n=i2d_X509(x,NULL);
1031 if (!BUF_MEM_grow_clean(buf,(int)(n+(*l)+3)))
1032 {
1033 SSLerr(SSL_F_DTLS1_ADD_CERT_TO_BUF,ERR_R_BUF_LIB);
1034 return 0;
1035 }
1036 p=(unsigned char *)&(buf->data[*l]);
1037 l2n3(n,p);
1038 i2d_X509(x,&p);
1039 *l+=n+3;
1040
1041 return 1;
1042 }
dtls1_output_cert_chain(SSL * s,X509 * x)1043 unsigned long dtls1_output_cert_chain(SSL *s, X509 *x)
1044 {
1045 unsigned char *p;
1046 int i;
1047 unsigned long l= 3 + DTLS1_HM_HEADER_LENGTH;
1048 BUF_MEM *buf;
1049
1050 /* TLSv1 sends a chain with nothing in it, instead of an alert */
1051 buf=s->init_buf;
1052 if (!BUF_MEM_grow_clean(buf,10))
1053 {
1054 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_BUF_LIB);
1055 return(0);
1056 }
1057 if (x != NULL)
1058 {
1059 X509_STORE_CTX xs_ctx;
1060
1061 if (!X509_STORE_CTX_init(&xs_ctx,s->ctx->cert_store,x,NULL))
1062 {
1063 SSLerr(SSL_F_DTLS1_OUTPUT_CERT_CHAIN,ERR_R_X509_LIB);
1064 return(0);
1065 }
1066
1067 X509_verify_cert(&xs_ctx);
1068 /* Don't leave errors in the queue */
1069 ERR_clear_error();
1070 for (i=0; i < sk_X509_num(xs_ctx.chain); i++)
1071 {
1072 x = sk_X509_value(xs_ctx.chain, i);
1073
1074 if (!dtls1_add_cert_to_buf(buf, &l, x))
1075 {
1076 X509_STORE_CTX_cleanup(&xs_ctx);
1077 return 0;
1078 }
1079 }
1080 X509_STORE_CTX_cleanup(&xs_ctx);
1081 }
1082 /* Thawte special :-) */
1083 for (i=0; i<sk_X509_num(s->ctx->extra_certs); i++)
1084 {
1085 x=sk_X509_value(s->ctx->extra_certs,i);
1086 if (!dtls1_add_cert_to_buf(buf, &l, x))
1087 return 0;
1088 }
1089
1090 l-= (3 + DTLS1_HM_HEADER_LENGTH);
1091
1092 p=(unsigned char *)&(buf->data[DTLS1_HM_HEADER_LENGTH]);
1093 l2n3(l,p);
1094 l+=3;
1095 p=(unsigned char *)&(buf->data[0]);
1096 p = dtls1_set_message_header(s, p, SSL3_MT_CERTIFICATE, l, 0, l);
1097
1098 l+=DTLS1_HM_HEADER_LENGTH;
1099 return(l);
1100 }
1101
dtls1_read_failed(SSL * s,int code)1102 int dtls1_read_failed(SSL *s, int code)
1103 {
1104 if ( code > 0)
1105 {
1106 fprintf( stderr, "invalid state reached %s:%d", __FILE__, __LINE__);
1107 return 1;
1108 }
1109
1110 if (!dtls1_is_timer_expired(s))
1111 {
1112 /* not a timeout, none of our business,
1113 let higher layers handle this. in fact it's probably an error */
1114 return code;
1115 }
1116
1117 #ifndef OPENSSL_NO_HEARTBEATS
1118 if (!SSL_in_init(s) && !s->tlsext_hb_pending) /* done, no need to send a retransmit */
1119 #else
1120 if (!SSL_in_init(s)) /* done, no need to send a retransmit */
1121 #endif
1122 {
1123 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1124 return code;
1125 }
1126
1127 #if 0 /* for now, each alert contains only one record number */
1128 item = pqueue_peek(state->rcvd_records);
1129 if ( item )
1130 {
1131 /* send an alert immediately for all the missing records */
1132 }
1133 else
1134 #endif
1135
1136 #if 0 /* no more alert sending, just retransmit the last set of messages */
1137 if ( state->timeout.read_timeouts >= DTLS1_TMO_READ_COUNT)
1138 ssl3_send_alert(s,SSL3_AL_WARNING,
1139 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1140 #endif
1141
1142 return dtls1_handle_timeout(s);
1143 }
1144
1145 int
dtls1_get_queue_priority(unsigned short seq,int is_ccs)1146 dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1147 {
1148 /* The index of the retransmission queue actually is the message sequence number,
1149 * since the queue only contains messages of a single handshake. However, the
1150 * ChangeCipherSpec has no message sequence number and so using only the sequence
1151 * will result in the CCS and Finished having the same index. To prevent this,
1152 * the sequence number is multiplied by 2. In case of a CCS 1 is subtracted.
1153 * This does not only differ CSS and Finished, it also maintains the order of the
1154 * index (important for priority queues) and fits in the unsigned short variable.
1155 */
1156 return seq * 2 - is_ccs;
1157 }
1158
1159 int
dtls1_retransmit_buffered_messages(SSL * s)1160 dtls1_retransmit_buffered_messages(SSL *s)
1161 {
1162 pqueue sent = s->d1->sent_messages;
1163 piterator iter;
1164 pitem *item;
1165 hm_fragment *frag;
1166 int found = 0;
1167
1168 iter = pqueue_iterator(sent);
1169
1170 for ( item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter))
1171 {
1172 frag = (hm_fragment *)item->data;
1173 if ( dtls1_retransmit_message(s,
1174 (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs),
1175 0, &found) <= 0 && found)
1176 {
1177 fprintf(stderr, "dtls1_retransmit_message() failed\n");
1178 return -1;
1179 }
1180 }
1181
1182 return 1;
1183 }
1184
1185 int
dtls1_buffer_message(SSL * s,int is_ccs)1186 dtls1_buffer_message(SSL *s, int is_ccs)
1187 {
1188 pitem *item;
1189 hm_fragment *frag;
1190 unsigned char seq64be[8];
1191
1192 /* this function is called immediately after a message has
1193 * been serialized */
1194 OPENSSL_assert(s->init_off == 0);
1195
1196 frag = dtls1_hm_fragment_new(s->init_num, 0);
1197 if (!frag)
1198 return 0;
1199
1200 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1201
1202 if ( is_ccs)
1203 {
1204 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1205 ((s->version==DTLS1_VERSION)?DTLS1_CCS_HEADER_LENGTH:3) == (unsigned int)s->init_num);
1206 }
1207 else
1208 {
1209 OPENSSL_assert(s->d1->w_msg_hdr.msg_len +
1210 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num);
1211 }
1212
1213 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1214 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1215 frag->msg_header.type = s->d1->w_msg_hdr.type;
1216 frag->msg_header.frag_off = 0;
1217 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1218 frag->msg_header.is_ccs = is_ccs;
1219
1220 /* save current state*/
1221 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1222 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1223 frag->msg_header.saved_retransmit_state.compress = s->compress;
1224 frag->msg_header.saved_retransmit_state.session = s->session;
1225 frag->msg_header.saved_retransmit_state.epoch = s->d1->w_epoch;
1226
1227 memset(seq64be,0,sizeof(seq64be));
1228 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1229 frag->msg_header.is_ccs)>>8);
1230 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1231 frag->msg_header.is_ccs));
1232
1233 item = pitem_new(seq64be, frag);
1234 if ( item == NULL)
1235 {
1236 dtls1_hm_fragment_free(frag);
1237 return 0;
1238 }
1239
1240 #if 0
1241 fprintf( stderr, "buffered messge: \ttype = %xx\n", msg_buf->type);
1242 fprintf( stderr, "\t\t\t\t\tlen = %d\n", msg_buf->len);
1243 fprintf( stderr, "\t\t\t\t\tseq_num = %d\n", msg_buf->seq_num);
1244 #endif
1245
1246 pqueue_insert(s->d1->sent_messages, item);
1247 return 1;
1248 }
1249
1250 int
dtls1_retransmit_message(SSL * s,unsigned short seq,unsigned long frag_off,int * found)1251 dtls1_retransmit_message(SSL *s, unsigned short seq, unsigned long frag_off,
1252 int *found)
1253 {
1254 int ret;
1255 /* XDTLS: for now assuming that read/writes are blocking */
1256 pitem *item;
1257 hm_fragment *frag ;
1258 unsigned long header_length;
1259 unsigned char seq64be[8];
1260 struct dtls1_retransmit_state saved_state;
1261 unsigned char save_write_sequence[8];
1262
1263 /*
1264 OPENSSL_assert(s->init_num == 0);
1265 OPENSSL_assert(s->init_off == 0);
1266 */
1267
1268 /* XDTLS: the requested message ought to be found, otherwise error */
1269 memset(seq64be,0,sizeof(seq64be));
1270 seq64be[6] = (unsigned char)(seq>>8);
1271 seq64be[7] = (unsigned char)seq;
1272
1273 item = pqueue_find(s->d1->sent_messages, seq64be);
1274 if ( item == NULL)
1275 {
1276 fprintf(stderr, "retransmit: message %d non-existant\n", seq);
1277 *found = 0;
1278 return 0;
1279 }
1280
1281 *found = 1;
1282 frag = (hm_fragment *)item->data;
1283
1284 if ( frag->msg_header.is_ccs)
1285 header_length = DTLS1_CCS_HEADER_LENGTH;
1286 else
1287 header_length = DTLS1_HM_HEADER_LENGTH;
1288
1289 memcpy(s->init_buf->data, frag->fragment,
1290 frag->msg_header.msg_len + header_length);
1291 s->init_num = frag->msg_header.msg_len + header_length;
1292
1293 dtls1_set_message_header_int(s, frag->msg_header.type,
1294 frag->msg_header.msg_len, frag->msg_header.seq, 0,
1295 frag->msg_header.frag_len);
1296
1297 /* save current state */
1298 saved_state.enc_write_ctx = s->enc_write_ctx;
1299 saved_state.write_hash = s->write_hash;
1300 saved_state.compress = s->compress;
1301 saved_state.session = s->session;
1302 saved_state.epoch = s->d1->w_epoch;
1303 saved_state.epoch = s->d1->w_epoch;
1304
1305 s->d1->retransmitting = 1;
1306
1307 /* restore state in which the message was originally sent */
1308 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1309 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1310 s->compress = frag->msg_header.saved_retransmit_state.compress;
1311 s->session = frag->msg_header.saved_retransmit_state.session;
1312 s->d1->w_epoch = frag->msg_header.saved_retransmit_state.epoch;
1313
1314 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1315 {
1316 memcpy(save_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1317 memcpy(s->s3->write_sequence, s->d1->last_write_sequence, sizeof(s->s3->write_sequence));
1318 }
1319
1320 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1321 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1322
1323 /* restore current state */
1324 s->enc_write_ctx = saved_state.enc_write_ctx;
1325 s->write_hash = saved_state.write_hash;
1326 s->compress = saved_state.compress;
1327 s->session = saved_state.session;
1328 s->d1->w_epoch = saved_state.epoch;
1329
1330 if (frag->msg_header.saved_retransmit_state.epoch == saved_state.epoch - 1)
1331 {
1332 memcpy(s->d1->last_write_sequence, s->s3->write_sequence, sizeof(s->s3->write_sequence));
1333 memcpy(s->s3->write_sequence, save_write_sequence, sizeof(s->s3->write_sequence));
1334 }
1335
1336 s->d1->retransmitting = 0;
1337
1338 (void)BIO_flush(SSL_get_wbio(s));
1339 return ret;
1340 }
1341
1342 /* call this function when the buffered messages are no longer needed */
1343 void
dtls1_clear_record_buffer(SSL * s)1344 dtls1_clear_record_buffer(SSL *s)
1345 {
1346 pitem *item;
1347
1348 for(item = pqueue_pop(s->d1->sent_messages);
1349 item != NULL; item = pqueue_pop(s->d1->sent_messages))
1350 {
1351 dtls1_hm_fragment_free((hm_fragment *)item->data);
1352 pitem_free(item);
1353 }
1354 }
1355
1356
1357 unsigned char *
dtls1_set_message_header(SSL * s,unsigned char * p,unsigned char mt,unsigned long len,unsigned long frag_off,unsigned long frag_len)1358 dtls1_set_message_header(SSL *s, unsigned char *p, unsigned char mt,
1359 unsigned long len, unsigned long frag_off, unsigned long frag_len)
1360 {
1361 /* Don't change sequence numbers while listening */
1362 if (frag_off == 0 && !s->d1->listen)
1363 {
1364 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1365 s->d1->next_handshake_write_seq++;
1366 }
1367
1368 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1369 frag_off, frag_len);
1370
1371 return p += DTLS1_HM_HEADER_LENGTH;
1372 }
1373
1374
1375 /* don't actually do the writing, wait till the MTU has been retrieved */
1376 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)1377 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1378 unsigned long len, unsigned short seq_num, unsigned long frag_off,
1379 unsigned long frag_len)
1380 {
1381 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1382
1383 msg_hdr->type = mt;
1384 msg_hdr->msg_len = len;
1385 msg_hdr->seq = seq_num;
1386 msg_hdr->frag_off = frag_off;
1387 msg_hdr->frag_len = frag_len;
1388 }
1389
1390 static void
dtls1_fix_message_header(SSL * s,unsigned long frag_off,unsigned long frag_len)1391 dtls1_fix_message_header(SSL *s, unsigned long frag_off,
1392 unsigned long frag_len)
1393 {
1394 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1395
1396 msg_hdr->frag_off = frag_off;
1397 msg_hdr->frag_len = frag_len;
1398 }
1399
1400 static unsigned char *
dtls1_write_message_header(SSL * s,unsigned char * p)1401 dtls1_write_message_header(SSL *s, unsigned char *p)
1402 {
1403 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1404
1405 *p++ = msg_hdr->type;
1406 l2n3(msg_hdr->msg_len, p);
1407
1408 s2n(msg_hdr->seq, p);
1409 l2n3(msg_hdr->frag_off, p);
1410 l2n3(msg_hdr->frag_len, p);
1411
1412 return p;
1413 }
1414
1415 unsigned int
dtls1_min_mtu(void)1416 dtls1_min_mtu(void)
1417 {
1418 return (g_probable_mtu[(sizeof(g_probable_mtu) /
1419 sizeof(g_probable_mtu[0])) - 1]);
1420 }
1421
1422 static unsigned int
dtls1_guess_mtu(unsigned int curr_mtu)1423 dtls1_guess_mtu(unsigned int curr_mtu)
1424 {
1425 unsigned int i;
1426
1427 if ( curr_mtu == 0 )
1428 return g_probable_mtu[0] ;
1429
1430 for ( i = 0; i < sizeof(g_probable_mtu)/sizeof(g_probable_mtu[0]); i++)
1431 if ( curr_mtu > g_probable_mtu[i])
1432 return g_probable_mtu[i];
1433
1434 return curr_mtu;
1435 }
1436
1437 void
dtls1_get_message_header(unsigned char * data,struct hm_header_st * msg_hdr)1438 dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1439 {
1440 memset(msg_hdr, 0x00, sizeof(struct hm_header_st));
1441 msg_hdr->type = *(data++);
1442 n2l3(data, msg_hdr->msg_len);
1443
1444 n2s(data, msg_hdr->seq);
1445 n2l3(data, msg_hdr->frag_off);
1446 n2l3(data, msg_hdr->frag_len);
1447 }
1448
1449 void
dtls1_get_ccs_header(unsigned char * data,struct ccs_header_st * ccs_hdr)1450 dtls1_get_ccs_header(unsigned char *data, struct ccs_header_st *ccs_hdr)
1451 {
1452 memset(ccs_hdr, 0x00, sizeof(struct ccs_header_st));
1453
1454 ccs_hdr->type = *(data++);
1455 }
1456
dtls1_shutdown(SSL * s)1457 int dtls1_shutdown(SSL *s)
1458 {
1459 int ret;
1460 #ifndef OPENSSL_NO_SCTP
1461 if (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1462 !(s->shutdown & SSL_SENT_SHUTDOWN))
1463 {
1464 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1465 if (ret < 0) return -1;
1466
1467 if (ret == 0)
1468 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 1, NULL);
1469 }
1470 #endif
1471 ret = ssl3_shutdown(s);
1472 #ifndef OPENSSL_NO_SCTP
1473 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_SAVE_SHUTDOWN, 0, NULL);
1474 #endif
1475 return ret;
1476 }
1477
1478 #ifndef OPENSSL_NO_HEARTBEATS
1479 int
dtls1_process_heartbeat(SSL * s)1480 dtls1_process_heartbeat(SSL *s)
1481 {
1482 unsigned char *p = &s->s3->rrec.data[0], *pl;
1483 unsigned short hbtype;
1484 unsigned int payload;
1485 unsigned int padding = 16; /* Use minimum padding */
1486
1487 if (s->msg_callback)
1488 s->msg_callback(0, s->version, TLS1_RT_HEARTBEAT,
1489 &s->s3->rrec.data[0], s->s3->rrec.length,
1490 s, s->msg_callback_arg);
1491
1492 /* Read type and payload length first */
1493 if (1 + 2 + 16 > s->s3->rrec.length)
1494 return 0; /* silently discard */
1495 if (s->s3->rrec.length > SSL3_RT_MAX_PLAIN_LENGTH)
1496 return 0; /* silently discard per RFC 6520 sec. 4 */
1497
1498 hbtype = *p++;
1499 n2s(p, payload);
1500 if (1 + 2 + payload + 16 > s->s3->rrec.length)
1501 return 0; /* silently discard per RFC 6520 sec. 4 */
1502 pl = p;
1503
1504 if (hbtype == TLS1_HB_REQUEST)
1505 {
1506 unsigned char *buffer, *bp;
1507 unsigned int write_length = 1 /* heartbeat type */ +
1508 2 /* heartbeat length */ +
1509 payload + padding;
1510 int r;
1511
1512 if (write_length > SSL3_RT_MAX_PLAIN_LENGTH)
1513 return 0;
1514
1515 /* Allocate memory for the response, size is 1 byte
1516 * message type, plus 2 bytes payload length, plus
1517 * payload, plus padding
1518 */
1519 buffer = OPENSSL_malloc(write_length);
1520 bp = buffer;
1521
1522 /* Enter response type, length and copy payload */
1523 *bp++ = TLS1_HB_RESPONSE;
1524 s2n(payload, bp);
1525 memcpy(bp, pl, payload);
1526 bp += payload;
1527 /* Random padding */
1528 RAND_pseudo_bytes(bp, padding);
1529
1530 r = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buffer, write_length);
1531
1532 if (r >= 0 && s->msg_callback)
1533 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1534 buffer, write_length,
1535 s, s->msg_callback_arg);
1536
1537 OPENSSL_free(buffer);
1538
1539 if (r < 0)
1540 return r;
1541 }
1542 else if (hbtype == TLS1_HB_RESPONSE)
1543 {
1544 unsigned int seq;
1545
1546 /* We only send sequence numbers (2 bytes unsigned int),
1547 * and 16 random bytes, so we just try to read the
1548 * sequence number */
1549 n2s(pl, seq);
1550
1551 if (payload == 18 && seq == s->tlsext_hb_seq)
1552 {
1553 dtls1_stop_timer(s);
1554 s->tlsext_hb_seq++;
1555 s->tlsext_hb_pending = 0;
1556 }
1557 }
1558
1559 return 0;
1560 }
1561
1562 int
dtls1_heartbeat(SSL * s)1563 dtls1_heartbeat(SSL *s)
1564 {
1565 unsigned char *buf, *p;
1566 int ret;
1567 unsigned int payload = 18; /* Sequence number + random bytes */
1568 unsigned int padding = 16; /* Use minimum padding */
1569
1570 /* Only send if peer supports and accepts HB requests... */
1571 if (!(s->tlsext_heartbeat & SSL_TLSEXT_HB_ENABLED) ||
1572 s->tlsext_heartbeat & SSL_TLSEXT_HB_DONT_SEND_REQUESTS)
1573 {
1574 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PEER_DOESNT_ACCEPT);
1575 return -1;
1576 }
1577
1578 /* ...and there is none in flight yet... */
1579 if (s->tlsext_hb_pending)
1580 {
1581 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_TLS_HEARTBEAT_PENDING);
1582 return -1;
1583 }
1584
1585 /* ...and no handshake in progress. */
1586 if (SSL_in_init(s) || s->in_handshake)
1587 {
1588 SSLerr(SSL_F_DTLS1_HEARTBEAT,SSL_R_UNEXPECTED_MESSAGE);
1589 return -1;
1590 }
1591
1592 /* Check if padding is too long, payload and padding
1593 * must not exceed 2^14 - 3 = 16381 bytes in total.
1594 */
1595 OPENSSL_assert(payload + padding <= 16381);
1596
1597 /* Create HeartBeat message, we just use a sequence number
1598 * as payload to distuingish different messages and add
1599 * some random stuff.
1600 * - Message Type, 1 byte
1601 * - Payload Length, 2 bytes (unsigned int)
1602 * - Payload, the sequence number (2 bytes uint)
1603 * - Payload, random bytes (16 bytes uint)
1604 * - Padding
1605 */
1606 buf = OPENSSL_malloc(1 + 2 + payload + padding);
1607 p = buf;
1608 /* Message Type */
1609 *p++ = TLS1_HB_REQUEST;
1610 /* Payload length (18 bytes here) */
1611 s2n(payload, p);
1612 /* Sequence number */
1613 s2n(s->tlsext_hb_seq, p);
1614 /* 16 random bytes */
1615 RAND_pseudo_bytes(p, 16);
1616 p += 16;
1617 /* Random padding */
1618 RAND_pseudo_bytes(p, padding);
1619
1620 ret = dtls1_write_bytes(s, TLS1_RT_HEARTBEAT, buf, 3 + payload + padding);
1621 if (ret >= 0)
1622 {
1623 if (s->msg_callback)
1624 s->msg_callback(1, s->version, TLS1_RT_HEARTBEAT,
1625 buf, 3 + payload + padding,
1626 s, s->msg_callback_arg);
1627
1628 dtls1_start_timer(s);
1629 s->tlsext_hb_pending = 1;
1630 }
1631
1632 OPENSSL_free(buf);
1633
1634 return ret;
1635 }
1636 #endif
1637