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