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