1 /*
2 * Copyright 2005-2022 The OpenSSL Project Authors. All Rights Reserved.
3 *
4 * Licensed under the Apache License 2.0 (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
8 */
9
10 #include <limits.h>
11 #include <string.h>
12 #include <stdio.h>
13 #include "../ssl_local.h"
14 #include "statem_local.h"
15 #include "internal/cryptlib.h"
16 #include <openssl/buffer.h>
17 #include <openssl/objects.h>
18 #include <openssl/evp.h>
19 #include <openssl/x509.h>
20
21 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
22
23 #define RSMBLY_BITMASK_MARK(bitmask, start, end) { \
24 if ((end) - (start) <= 8) { \
25 long ii; \
26 for (ii = (start); ii < (end); ii++) bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
27 } else { \
28 long ii; \
29 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
30 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) bitmask[ii] = 0xff; \
31 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
32 } }
33
34 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) { \
35 long ii; \
36 is_complete = 1; \
37 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) is_complete = 0; \
38 if (is_complete) for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0 ; ii--) \
39 if (bitmask[ii] != 0xff) { is_complete = 0; break; } }
40
41 static unsigned char bitmask_start_values[] =
42 { 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80 };
43 static unsigned char bitmask_end_values[] =
44 { 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f };
45
46 static void dtls1_fix_message_header(SSL_CONNECTION *s, size_t frag_off,
47 size_t frag_len);
48 static unsigned char *dtls1_write_message_header(SSL_CONNECTION *s,
49 unsigned char *p);
50 static void dtls1_set_message_header_int(SSL_CONNECTION *s, unsigned char mt,
51 size_t len,
52 unsigned short seq_num,
53 size_t frag_off,
54 size_t frag_len);
55 static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype,
56 size_t *len);
57
dtls1_hm_fragment_new(size_t frag_len,int reassembly)58 static hm_fragment *dtls1_hm_fragment_new(size_t frag_len, int reassembly)
59 {
60 hm_fragment *frag = NULL;
61 unsigned char *buf = NULL;
62 unsigned char *bitmask = NULL;
63
64 if ((frag = OPENSSL_malloc(sizeof(*frag))) == NULL) {
65 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
66 return NULL;
67 }
68
69 if (frag_len) {
70 if ((buf = OPENSSL_malloc(frag_len)) == NULL) {
71 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
72 OPENSSL_free(frag);
73 return NULL;
74 }
75 }
76
77 /* zero length fragment gets zero frag->fragment */
78 frag->fragment = buf;
79
80 /* Initialize reassembly bitmask if necessary */
81 if (reassembly) {
82 bitmask = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len));
83 if (bitmask == NULL) {
84 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
85 OPENSSL_free(buf);
86 OPENSSL_free(frag);
87 return NULL;
88 }
89 }
90
91 frag->reassembly = bitmask;
92
93 return frag;
94 }
95
dtls1_hm_fragment_free(hm_fragment * frag)96 void dtls1_hm_fragment_free(hm_fragment *frag)
97 {
98 if (!frag)
99 return;
100 if (frag->msg_header.is_ccs) {
101 EVP_CIPHER_CTX_free(frag->msg_header.
102 saved_retransmit_state.enc_write_ctx);
103 EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash);
104 }
105 OPENSSL_free(frag->fragment);
106 OPENSSL_free(frag->reassembly);
107 OPENSSL_free(frag);
108 }
109
110 /*
111 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
112 * SSL3_RT_CHANGE_CIPHER_SPEC)
113 */
dtls1_do_write(SSL_CONNECTION * s,int type)114 int dtls1_do_write(SSL_CONNECTION *s, int type)
115 {
116 int ret;
117 size_t written;
118 size_t curr_mtu;
119 int retry = 1;
120 size_t len, frag_off, mac_size, blocksize, used_len;
121 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
122
123 if (!dtls1_query_mtu(s))
124 return -1;
125
126 if (s->d1->mtu < dtls1_min_mtu(s))
127 /* should have something reasonable now */
128 return -1;
129
130 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) {
131 if (!ossl_assert(s->init_num ==
132 s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH))
133 return -1;
134 }
135
136 if (s->write_hash) {
137 if (s->enc_write_ctx
138 && (EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(s->enc_write_ctx)) &
139 EVP_CIPH_FLAG_AEAD_CIPHER) != 0)
140 mac_size = 0;
141 else
142 mac_size = EVP_MD_CTX_get_size(s->write_hash);
143 } else
144 mac_size = 0;
145
146 if (s->enc_write_ctx &&
147 (EVP_CIPHER_CTX_get_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
148 blocksize = 2 * EVP_CIPHER_CTX_get_block_size(s->enc_write_ctx);
149 else
150 blocksize = 0;
151
152 frag_off = 0;
153 s->rwstate = SSL_NOTHING;
154
155 /* s->init_num shouldn't ever be < 0...but just in case */
156 while (s->init_num > 0) {
157 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
158 /* We must be writing a fragment other than the first one */
159
160 if (frag_off > 0) {
161 /* This is the first attempt at writing out this fragment */
162
163 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
164 /*
165 * Each fragment that was already sent must at least have
166 * contained the message header plus one other byte.
167 * Therefore |init_off| must have progressed by at least
168 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
169 * wrong.
170 */
171 return -1;
172 }
173
174 /*
175 * Adjust |init_off| and |init_num| to allow room for a new
176 * message header for this fragment.
177 */
178 s->init_off -= DTLS1_HM_HEADER_LENGTH;
179 s->init_num += DTLS1_HM_HEADER_LENGTH;
180 } else {
181 /*
182 * We must have been called again after a retry so use the
183 * fragment offset from our last attempt. We do not need
184 * to adjust |init_off| and |init_num| as above, because
185 * that should already have been done before the retry.
186 */
187 frag_off = s->d1->w_msg_hdr.frag_off;
188 }
189 }
190
191 used_len = BIO_wpending(s->wbio) + DTLS1_RT_HEADER_LENGTH
192 + mac_size + blocksize;
193 if (s->d1->mtu > used_len)
194 curr_mtu = s->d1->mtu - used_len;
195 else
196 curr_mtu = 0;
197
198 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
199 /*
200 * grr.. we could get an error if MTU picked was wrong
201 */
202 ret = BIO_flush(s->wbio);
203 if (ret <= 0) {
204 s->rwstate = SSL_WRITING;
205 return ret;
206 }
207 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
208 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
209 curr_mtu = s->d1->mtu - used_len;
210 } else {
211 /* Shouldn't happen */
212 return -1;
213 }
214 }
215
216 /*
217 * We just checked that s->init_num > 0 so this cast should be safe
218 */
219 if (((unsigned int)s->init_num) > curr_mtu)
220 len = curr_mtu;
221 else
222 len = s->init_num;
223
224 if (len > ssl_get_max_send_fragment(s))
225 len = ssl_get_max_send_fragment(s);
226
227 /*
228 * XDTLS: this function is too long. split out the CCS part
229 */
230 if (type == SSL3_RT_HANDSHAKE) {
231 if (len < DTLS1_HM_HEADER_LENGTH) {
232 /*
233 * len is so small that we really can't do anything sensible
234 * so fail
235 */
236 return -1;
237 }
238 dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH);
239
240 dtls1_write_message_header(s,
241 (unsigned char *)&s->init_buf->
242 data[s->init_off]);
243 }
244
245 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len,
246 &written);
247 if (ret <= 0) {
248 /*
249 * might need to update MTU here, but we don't know which
250 * previous packet caused the failure -- so can't really
251 * retransmit anything. continue as if everything is fine and
252 * wait for an alert to handle the retransmit
253 */
254 if (retry && BIO_ctrl(SSL_get_wbio(ssl),
255 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
256 if (!(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
257 if (!dtls1_query_mtu(s))
258 return -1;
259 /* Have one more go */
260 retry = 0;
261 } else
262 return -1;
263 } else {
264 return -1;
265 }
266 } else {
267
268 /*
269 * bad if this assert fails, only part of the handshake message
270 * got sent. but why would this happen?
271 */
272 if (!ossl_assert(len == written))
273 return -1;
274
275 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
276 /*
277 * should not be done for 'Hello Request's, but in that case
278 * we'll ignore the result anyway
279 */
280 unsigned char *p =
281 (unsigned char *)&s->init_buf->data[s->init_off];
282 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
283 size_t xlen;
284
285 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
286 /*
287 * reconstruct message header is if it is being sent in
288 * single fragment
289 */
290 *p++ = msg_hdr->type;
291 l2n3(msg_hdr->msg_len, p);
292 s2n(msg_hdr->seq, p);
293 l2n3(0, p);
294 l2n3(msg_hdr->msg_len, p);
295 p -= DTLS1_HM_HEADER_LENGTH;
296 xlen = written;
297 } else {
298 p += DTLS1_HM_HEADER_LENGTH;
299 xlen = written - DTLS1_HM_HEADER_LENGTH;
300 }
301
302 if (!ssl3_finish_mac(s, p, xlen))
303 return -1;
304 }
305
306 if (written == s->init_num) {
307 if (s->msg_callback)
308 s->msg_callback(1, s->version, type, s->init_buf->data,
309 (size_t)(s->init_off + s->init_num), ssl,
310 s->msg_callback_arg);
311
312 s->init_off = 0; /* done writing this message */
313 s->init_num = 0;
314
315 return 1;
316 }
317 s->init_off += written;
318 s->init_num -= written;
319 written -= DTLS1_HM_HEADER_LENGTH;
320 frag_off += written;
321
322 /*
323 * We save the fragment offset for the next fragment so we have it
324 * available in case of an IO retry. We don't know the length of the
325 * next fragment yet so just set that to 0 for now. It will be
326 * updated again later.
327 */
328 dtls1_fix_message_header(s, frag_off, 0);
329 }
330 }
331 return 0;
332 }
333
dtls_get_message(SSL_CONNECTION * s,int * mt)334 int dtls_get_message(SSL_CONNECTION *s, int *mt)
335 {
336 struct hm_header_st *msg_hdr;
337 unsigned char *p;
338 size_t msg_len;
339 size_t tmplen;
340 int errtype;
341
342 msg_hdr = &s->d1->r_msg_hdr;
343 memset(msg_hdr, 0, sizeof(*msg_hdr));
344
345 again:
346 if (!dtls_get_reassembled_message(s, &errtype, &tmplen)) {
347 if (errtype == DTLS1_HM_BAD_FRAGMENT
348 || errtype == DTLS1_HM_FRAGMENT_RETRY) {
349 /* bad fragment received */
350 goto again;
351 }
352 return 0;
353 }
354
355 *mt = s->s3.tmp.message_type;
356
357 p = (unsigned char *)s->init_buf->data;
358
359 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
360 if (s->msg_callback) {
361 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
362 p, 1, SSL_CONNECTION_GET_SSL(s),
363 s->msg_callback_arg);
364 }
365 /*
366 * This isn't a real handshake message so skip the processing below.
367 */
368 return 1;
369 }
370
371 msg_len = msg_hdr->msg_len;
372
373 /* reconstruct message header */
374 *(p++) = msg_hdr->type;
375 l2n3(msg_len, p);
376 s2n(msg_hdr->seq, p);
377 l2n3(0, p);
378 l2n3(msg_len, p);
379
380 memset(msg_hdr, 0, sizeof(*msg_hdr));
381
382 s->d1->handshake_read_seq++;
383
384 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
385
386 return 1;
387 }
388
389 /*
390 * Actually we already have the message body - but this is an opportunity for
391 * DTLS to do any further processing it wants at the same point that TLS would
392 * be asked for the message body.
393 */
dtls_get_message_body(SSL_CONNECTION * s,size_t * len)394 int dtls_get_message_body(SSL_CONNECTION *s, size_t *len)
395 {
396 unsigned char *msg = (unsigned char *)s->init_buf->data;
397 size_t msg_len = s->init_num + DTLS1_HM_HEADER_LENGTH;
398
399 if (s->s3.tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
400 /* Nothing to be done */
401 goto end;
402 }
403 /*
404 * If receiving Finished, record MAC of prior handshake messages for
405 * Finished verification.
406 */
407 if (*(s->init_buf->data) == SSL3_MT_FINISHED && !ssl3_take_mac(s)) {
408 /* SSLfatal() already called */
409 return 0;
410 }
411
412 if (s->version == DTLS1_BAD_VER) {
413 msg += DTLS1_HM_HEADER_LENGTH;
414 msg_len -= DTLS1_HM_HEADER_LENGTH;
415 }
416
417 if (!ssl3_finish_mac(s, msg, msg_len))
418 return 0;
419
420 if (s->msg_callback)
421 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
422 s->init_buf->data, s->init_num + DTLS1_HM_HEADER_LENGTH,
423 SSL_CONNECTION_GET_SSL(s), s->msg_callback_arg);
424
425 end:
426 *len = s->init_num;
427 return 1;
428 }
429
430 /*
431 * dtls1_max_handshake_message_len returns the maximum number of bytes
432 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
433 * may be greater if the maximum certificate list size requires it.
434 */
dtls1_max_handshake_message_len(const SSL_CONNECTION * s)435 static size_t dtls1_max_handshake_message_len(const SSL_CONNECTION *s)
436 {
437 size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
438 if (max_len < s->max_cert_list)
439 return s->max_cert_list;
440 return max_len;
441 }
442
dtls1_preprocess_fragment(SSL_CONNECTION * s,struct hm_header_st * msg_hdr)443 static int dtls1_preprocess_fragment(SSL_CONNECTION *s,
444 struct hm_header_st *msg_hdr)
445 {
446 size_t frag_off, frag_len, msg_len;
447
448 msg_len = msg_hdr->msg_len;
449 frag_off = msg_hdr->frag_off;
450 frag_len = msg_hdr->frag_len;
451
452 /* sanity checking */
453 if ((frag_off + frag_len) > msg_len
454 || msg_len > dtls1_max_handshake_message_len(s)) {
455 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
456 return 0;
457 }
458
459 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
460 /*
461 * msg_len is limited to 2^24, but is effectively checked against
462 * dtls_max_handshake_message_len(s) above
463 */
464 if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
465 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_BUF_LIB);
466 return 0;
467 }
468
469 s->s3.tmp.message_size = msg_len;
470 s->d1->r_msg_hdr.msg_len = msg_len;
471 s->s3.tmp.message_type = msg_hdr->type;
472 s->d1->r_msg_hdr.type = msg_hdr->type;
473 s->d1->r_msg_hdr.seq = msg_hdr->seq;
474 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
475 /*
476 * They must be playing with us! BTW, failure to enforce upper limit
477 * would open possibility for buffer overrun.
478 */
479 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
480 return 0;
481 }
482
483 return 1;
484 }
485
486 /*
487 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a
488 * fatal error.
489 */
dtls1_retrieve_buffered_fragment(SSL_CONNECTION * s,size_t * len)490 static int dtls1_retrieve_buffered_fragment(SSL_CONNECTION *s, size_t *len)
491 {
492 /*-
493 * (0) check whether the desired fragment is available
494 * if so:
495 * (1) copy over the fragment to s->init_buf->data[]
496 * (2) update s->init_num
497 */
498 pitem *item;
499 hm_fragment *frag;
500 int ret;
501
502 do {
503 item = pqueue_peek(s->d1->buffered_messages);
504 if (item == NULL)
505 return 0;
506
507 frag = (hm_fragment *)item->data;
508
509 if (frag->msg_header.seq < s->d1->handshake_read_seq) {
510 /* This is a stale message that has been buffered so clear it */
511 pqueue_pop(s->d1->buffered_messages);
512 dtls1_hm_fragment_free(frag);
513 pitem_free(item);
514 item = NULL;
515 frag = NULL;
516 }
517 } while (item == NULL);
518
519 /* Don't return if reassembly still in progress */
520 if (frag->reassembly != NULL)
521 return 0;
522
523 if (s->d1->handshake_read_seq == frag->msg_header.seq) {
524 size_t frag_len = frag->msg_header.frag_len;
525 pqueue_pop(s->d1->buffered_messages);
526
527 /* Calls SSLfatal() as required */
528 ret = dtls1_preprocess_fragment(s, &frag->msg_header);
529
530 if (ret && frag->msg_header.frag_len > 0) {
531 unsigned char *p =
532 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
533 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
534 frag->msg_header.frag_len);
535 }
536
537 dtls1_hm_fragment_free(frag);
538 pitem_free(item);
539
540 if (ret) {
541 *len = frag_len;
542 return 1;
543 }
544
545 /* Fatal error */
546 s->init_num = 0;
547 return -1;
548 } else {
549 return 0;
550 }
551 }
552
dtls1_reassemble_fragment(SSL_CONNECTION * s,const struct hm_header_st * msg_hdr)553 static int dtls1_reassemble_fragment(SSL_CONNECTION *s,
554 const struct hm_header_st *msg_hdr)
555 {
556 hm_fragment *frag = NULL;
557 pitem *item = NULL;
558 int i = -1, is_complete;
559 unsigned char seq64be[8];
560 size_t frag_len = msg_hdr->frag_len;
561 size_t readbytes;
562 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
563
564 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
565 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
566 goto err;
567
568 if (frag_len == 0) {
569 return DTLS1_HM_FRAGMENT_RETRY;
570 }
571
572 /* Try to find item in queue */
573 memset(seq64be, 0, sizeof(seq64be));
574 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
575 seq64be[7] = (unsigned char)msg_hdr->seq;
576 item = pqueue_find(s->d1->buffered_messages, seq64be);
577
578 if (item == NULL) {
579 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
580 if (frag == NULL)
581 goto err;
582 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
583 frag->msg_header.frag_len = frag->msg_header.msg_len;
584 frag->msg_header.frag_off = 0;
585 } else {
586 frag = (hm_fragment *)item->data;
587 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
588 item = NULL;
589 frag = NULL;
590 goto err;
591 }
592 }
593
594 /*
595 * If message is already reassembled, this must be a retransmit and can
596 * be dropped. In this case item != NULL and so frag does not need to be
597 * freed.
598 */
599 if (frag->reassembly == NULL) {
600 unsigned char devnull[256];
601
602 while (frag_len) {
603 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
604 devnull,
605 frag_len >
606 sizeof(devnull) ? sizeof(devnull) :
607 frag_len, 0, &readbytes);
608 if (i <= 0)
609 goto err;
610 frag_len -= readbytes;
611 }
612 return DTLS1_HM_FRAGMENT_RETRY;
613 }
614
615 /* read the body of the fragment (header has already been read */
616 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
617 frag->fragment + msg_hdr->frag_off,
618 frag_len, 0, &readbytes);
619 if (i <= 0 || readbytes != frag_len)
620 i = -1;
621 if (i <= 0)
622 goto err;
623
624 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
625 (long)(msg_hdr->frag_off + frag_len));
626
627 if (!ossl_assert(msg_hdr->msg_len > 0))
628 goto err;
629 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
630 is_complete);
631
632 if (is_complete) {
633 OPENSSL_free(frag->reassembly);
634 frag->reassembly = NULL;
635 }
636
637 if (item == NULL) {
638 item = pitem_new(seq64be, frag);
639 if (item == NULL) {
640 i = -1;
641 goto err;
642 }
643
644 item = pqueue_insert(s->d1->buffered_messages, item);
645 /*
646 * pqueue_insert fails iff a duplicate item is inserted. However,
647 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
648 * would have returned it and control would never have reached this
649 * branch.
650 */
651 if (!ossl_assert(item != NULL))
652 goto err;
653 }
654
655 return DTLS1_HM_FRAGMENT_RETRY;
656
657 err:
658 if (item == NULL)
659 dtls1_hm_fragment_free(frag);
660 return -1;
661 }
662
dtls1_process_out_of_seq_message(SSL_CONNECTION * s,const struct hm_header_st * msg_hdr)663 static int dtls1_process_out_of_seq_message(SSL_CONNECTION *s,
664 const struct hm_header_st *msg_hdr)
665 {
666 int i = -1;
667 hm_fragment *frag = NULL;
668 pitem *item = NULL;
669 unsigned char seq64be[8];
670 size_t frag_len = msg_hdr->frag_len;
671 size_t readbytes;
672 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
673
674 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
675 goto err;
676
677 /* Try to find item in queue, to prevent duplicate entries */
678 memset(seq64be, 0, sizeof(seq64be));
679 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
680 seq64be[7] = (unsigned char)msg_hdr->seq;
681 item = pqueue_find(s->d1->buffered_messages, seq64be);
682
683 /*
684 * If we already have an entry and this one is a fragment, don't discard
685 * it and rather try to reassemble it.
686 */
687 if (item != NULL && frag_len != msg_hdr->msg_len)
688 item = NULL;
689
690 /*
691 * Discard the message if sequence number was already there, is too far
692 * in the future, already in the queue or if we received a FINISHED
693 * before the SERVER_HELLO, which then must be a stale retransmit.
694 */
695 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
696 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
697 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) {
698 unsigned char devnull[256];
699
700 while (frag_len) {
701 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
702 devnull,
703 frag_len >
704 sizeof(devnull) ? sizeof(devnull) :
705 frag_len, 0, &readbytes);
706 if (i <= 0)
707 goto err;
708 frag_len -= readbytes;
709 }
710 } else {
711 if (frag_len != msg_hdr->msg_len) {
712 return dtls1_reassemble_fragment(s, msg_hdr);
713 }
714
715 if (frag_len > dtls1_max_handshake_message_len(s))
716 goto err;
717
718 frag = dtls1_hm_fragment_new(frag_len, 0);
719 if (frag == NULL)
720 goto err;
721
722 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
723
724 if (frag_len) {
725 /*
726 * read the body of the fragment (header has already been read
727 */
728 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
729 frag->fragment, frag_len, 0,
730 &readbytes);
731 if (i<=0 || readbytes != frag_len)
732 i = -1;
733 if (i <= 0)
734 goto err;
735 }
736
737 item = pitem_new(seq64be, frag);
738 if (item == NULL)
739 goto err;
740
741 item = pqueue_insert(s->d1->buffered_messages, item);
742 /*
743 * pqueue_insert fails iff a duplicate item is inserted. However,
744 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
745 * would have returned it. Then, either |frag_len| !=
746 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
747 * have been processed with |dtls1_reassemble_fragment|, above, or
748 * the record will have been discarded.
749 */
750 if (!ossl_assert(item != NULL))
751 goto err;
752 }
753
754 return DTLS1_HM_FRAGMENT_RETRY;
755
756 err:
757 if (item == NULL)
758 dtls1_hm_fragment_free(frag);
759 return 0;
760 }
761
dtls_get_reassembled_message(SSL_CONNECTION * s,int * errtype,size_t * len)762 static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype,
763 size_t *len)
764 {
765 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
766 size_t mlen, frag_off, frag_len;
767 int i, ret, recvd_type;
768 struct hm_header_st msg_hdr;
769 size_t readbytes;
770 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
771
772 *errtype = 0;
773
774 redo:
775 /* see if we have the required fragment already */
776 ret = dtls1_retrieve_buffered_fragment(s, &frag_len);
777 if (ret < 0) {
778 /* SSLfatal() already called */
779 return 0;
780 }
781 if (ret > 0) {
782 s->init_num = frag_len;
783 *len = frag_len;
784 return 1;
785 }
786
787 /* read handshake message header */
788 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, &recvd_type, wire,
789 DTLS1_HM_HEADER_LENGTH, 0, &readbytes);
790 if (i <= 0) { /* nbio, or an error */
791 s->rwstate = SSL_READING;
792 *len = 0;
793 return 0;
794 }
795 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
796 if (wire[0] != SSL3_MT_CCS) {
797 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
798 SSL_R_BAD_CHANGE_CIPHER_SPEC);
799 goto f_err;
800 }
801
802 memcpy(s->init_buf->data, wire, readbytes);
803 s->init_num = readbytes - 1;
804 s->init_msg = s->init_buf->data + 1;
805 s->s3.tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
806 s->s3.tmp.message_size = readbytes - 1;
807 *len = readbytes - 1;
808 return 1;
809 }
810
811 /* Handshake fails if message header is incomplete */
812 if (readbytes != DTLS1_HM_HEADER_LENGTH) {
813 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
814 goto f_err;
815 }
816
817 /* parse the message fragment header */
818 dtls1_get_message_header(wire, &msg_hdr);
819
820 mlen = msg_hdr.msg_len;
821 frag_off = msg_hdr.frag_off;
822 frag_len = msg_hdr.frag_len;
823
824 /*
825 * We must have at least frag_len bytes left in the record to be read.
826 * Fragments must not span records.
827 */
828 if (frag_len > s->rlayer.tlsrecs[s->rlayer.curr_rec].length) {
829 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH);
830 goto f_err;
831 }
832
833 /*
834 * if this is a future (or stale) message it gets buffered
835 * (or dropped)--no further processing at this time
836 * While listening, we accept seq 1 (ClientHello with cookie)
837 * although we're still expecting seq 0 (ClientHello)
838 */
839 if (msg_hdr.seq != s->d1->handshake_read_seq) {
840 *errtype = dtls1_process_out_of_seq_message(s, &msg_hdr);
841 return 0;
842 }
843
844 if (frag_len && frag_len < mlen) {
845 *errtype = dtls1_reassemble_fragment(s, &msg_hdr);
846 return 0;
847 }
848
849 if (!s->server
850 && s->d1->r_msg_hdr.frag_off == 0
851 && s->statem.hand_state != TLS_ST_OK
852 && wire[0] == SSL3_MT_HELLO_REQUEST) {
853 /*
854 * The server may always send 'Hello Request' messages -- we are
855 * doing a handshake anyway now, so ignore them if their format is
856 * correct. Does not count for 'Finished' MAC.
857 */
858 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
859 if (s->msg_callback)
860 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
861 wire, DTLS1_HM_HEADER_LENGTH, ssl,
862 s->msg_callback_arg);
863
864 s->init_num = 0;
865 goto redo;
866 } else { /* Incorrectly formatted Hello request */
867
868 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
869 goto f_err;
870 }
871 }
872
873 if (!dtls1_preprocess_fragment(s, &msg_hdr)) {
874 /* SSLfatal() already called */
875 goto f_err;
876 }
877
878 if (frag_len > 0) {
879 unsigned char *p =
880 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
881
882 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
883 &p[frag_off], frag_len, 0, &readbytes);
884
885 /*
886 * This shouldn't ever fail due to NBIO because we already checked
887 * that we have enough data in the record
888 */
889 if (i <= 0) {
890 s->rwstate = SSL_READING;
891 *len = 0;
892 return 0;
893 }
894 } else {
895 readbytes = 0;
896 }
897
898 /*
899 * XDTLS: an incorrectly formatted fragment should cause the handshake
900 * to fail
901 */
902 if (readbytes != frag_len) {
903 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH);
904 goto f_err;
905 }
906
907 /*
908 * Note that s->init_num is *not* used as current offset in
909 * s->init_buf->data, but as a counter summing up fragments' lengths: as
910 * soon as they sum up to handshake packet length, we assume we have got
911 * all the fragments.
912 */
913 *len = s->init_num = frag_len;
914 return 1;
915
916 f_err:
917 s->init_num = 0;
918 *len = 0;
919 return 0;
920 }
921
922 /*-
923 * for these 2 messages, we need to
924 * ssl->enc_read_ctx re-init
925 * ssl->s3.read_mac_secret re-init
926 * ssl->session->read_sym_enc assign
927 * ssl->session->read_compression assign
928 * ssl->session->read_hash assign
929 */
dtls_construct_change_cipher_spec(SSL_CONNECTION * s,WPACKET * pkt)930 int dtls_construct_change_cipher_spec(SSL_CONNECTION *s, WPACKET *pkt)
931 {
932 if (s->version == DTLS1_BAD_VER) {
933 s->d1->next_handshake_write_seq++;
934
935 if (!WPACKET_put_bytes_u16(pkt, s->d1->handshake_write_seq)) {
936 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
937 return 0;
938 }
939 }
940
941 return 1;
942 }
943
944 #ifndef OPENSSL_NO_SCTP
945 /*
946 * Wait for a dry event. Should only be called at a point in the handshake
947 * where we are not expecting any data from the peer except an alert.
948 */
dtls_wait_for_dry(SSL_CONNECTION * s)949 WORK_STATE dtls_wait_for_dry(SSL_CONNECTION *s)
950 {
951 int ret, errtype;
952 size_t len;
953 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
954
955 /* read app data until dry event */
956 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(ssl));
957 if (ret < 0) {
958 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
959 return WORK_ERROR;
960 }
961
962 if (ret == 0) {
963 /*
964 * We're not expecting any more messages from the peer at this point -
965 * but we could get an alert. If an alert is waiting then we will never
966 * return successfully. Therefore we attempt to read a message. This
967 * should never succeed but will process any waiting alerts.
968 */
969 if (dtls_get_reassembled_message(s, &errtype, &len)) {
970 /* The call succeeded! This should never happen */
971 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
972 return WORK_ERROR;
973 }
974
975 s->s3.in_read_app_data = 2;
976 s->rwstate = SSL_READING;
977 BIO_clear_retry_flags(SSL_get_rbio(ssl));
978 BIO_set_retry_read(SSL_get_rbio(ssl));
979 return WORK_MORE_A;
980 }
981 return WORK_FINISHED_CONTINUE;
982 }
983 #endif
984
dtls1_read_failed(SSL_CONNECTION * s,int code)985 int dtls1_read_failed(SSL_CONNECTION *s, int code)
986 {
987 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
988
989 if (code > 0) {
990 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
991 return 0;
992 }
993
994 if (!dtls1_is_timer_expired(s) || ossl_statem_in_error(s)) {
995 /*
996 * not a timeout, none of our business, let higher layers handle
997 * this. in fact it's probably an error
998 */
999 return code;
1000 }
1001 /* done, no need to send a retransmit */
1002 if (!SSL_in_init(ssl))
1003 {
1004 BIO_set_flags(SSL_get_rbio(ssl), BIO_FLAGS_READ);
1005 return code;
1006 }
1007
1008 return dtls1_handle_timeout(s);
1009 }
1010
dtls1_get_queue_priority(unsigned short seq,int is_ccs)1011 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1012 {
1013 /*
1014 * The index of the retransmission queue actually is the message sequence
1015 * number, since the queue only contains messages of a single handshake.
1016 * However, the ChangeCipherSpec has no message sequence number and so
1017 * using only the sequence will result in the CCS and Finished having the
1018 * same index. To prevent this, the sequence number is multiplied by 2.
1019 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1020 * Finished, it also maintains the order of the index (important for
1021 * priority queues) and fits in the unsigned short variable.
1022 */
1023 return seq * 2 - is_ccs;
1024 }
1025
dtls1_retransmit_buffered_messages(SSL_CONNECTION * s)1026 int dtls1_retransmit_buffered_messages(SSL_CONNECTION *s)
1027 {
1028 pqueue *sent = s->d1->sent_messages;
1029 piterator iter;
1030 pitem *item;
1031 hm_fragment *frag;
1032 int found = 0;
1033
1034 iter = pqueue_iterator(sent);
1035
1036 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1037 frag = (hm_fragment *)item->data;
1038 if (dtls1_retransmit_message(s, (unsigned short)
1039 dtls1_get_queue_priority
1040 (frag->msg_header.seq,
1041 frag->msg_header.is_ccs), &found) <= 0)
1042 return -1;
1043 }
1044
1045 return 1;
1046 }
1047
dtls1_buffer_message(SSL_CONNECTION * s,int is_ccs)1048 int dtls1_buffer_message(SSL_CONNECTION *s, int is_ccs)
1049 {
1050 pitem *item;
1051 hm_fragment *frag;
1052 unsigned char seq64be[8];
1053
1054 /*
1055 * this function is called immediately after a message has been
1056 * serialized
1057 */
1058 if (!ossl_assert(s->init_off == 0))
1059 return 0;
1060
1061 frag = dtls1_hm_fragment_new(s->init_num, 0);
1062 if (frag == NULL)
1063 return 0;
1064
1065 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1066
1067 if (is_ccs) {
1068 /* For DTLS1_BAD_VER the header length is non-standard */
1069 if (!ossl_assert(s->d1->w_msg_hdr.msg_len +
1070 ((s->version ==
1071 DTLS1_BAD_VER) ? 3 : DTLS1_CCS_HEADER_LENGTH)
1072 == (unsigned int)s->init_num)) {
1073 dtls1_hm_fragment_free(frag);
1074 return 0;
1075 }
1076 } else {
1077 if (!ossl_assert(s->d1->w_msg_hdr.msg_len +
1078 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num)) {
1079 dtls1_hm_fragment_free(frag);
1080 return 0;
1081 }
1082 }
1083
1084 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1085 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1086 frag->msg_header.type = s->d1->w_msg_hdr.type;
1087 frag->msg_header.frag_off = 0;
1088 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1089 frag->msg_header.is_ccs = is_ccs;
1090
1091 /* save current state */
1092 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1093 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1094 frag->msg_header.saved_retransmit_state.compress = s->compress;
1095 frag->msg_header.saved_retransmit_state.session = s->session;
1096 frag->msg_header.saved_retransmit_state.epoch =
1097 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1098
1099 memset(seq64be, 0, sizeof(seq64be));
1100 seq64be[6] =
1101 (unsigned
1102 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1103 frag->msg_header.is_ccs) >> 8);
1104 seq64be[7] =
1105 (unsigned
1106 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1107 frag->msg_header.is_ccs));
1108
1109 item = pitem_new(seq64be, frag);
1110 if (item == NULL) {
1111 dtls1_hm_fragment_free(frag);
1112 return 0;
1113 }
1114
1115 pqueue_insert(s->d1->sent_messages, item);
1116 return 1;
1117 }
1118
dtls1_retransmit_message(SSL_CONNECTION * s,unsigned short seq,int * found)1119 int dtls1_retransmit_message(SSL_CONNECTION *s, unsigned short seq, int *found)
1120 {
1121 int ret;
1122 /* XDTLS: for now assuming that read/writes are blocking */
1123 pitem *item;
1124 hm_fragment *frag;
1125 unsigned long header_length;
1126 unsigned char seq64be[8];
1127 struct dtls1_retransmit_state saved_state;
1128
1129 /* XDTLS: the requested message ought to be found, otherwise error */
1130 memset(seq64be, 0, sizeof(seq64be));
1131 seq64be[6] = (unsigned char)(seq >> 8);
1132 seq64be[7] = (unsigned char)seq;
1133
1134 item = pqueue_find(s->d1->sent_messages, seq64be);
1135 if (item == NULL) {
1136 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1137 *found = 0;
1138 return 0;
1139 }
1140
1141 *found = 1;
1142 frag = (hm_fragment *)item->data;
1143
1144 if (frag->msg_header.is_ccs)
1145 header_length = DTLS1_CCS_HEADER_LENGTH;
1146 else
1147 header_length = DTLS1_HM_HEADER_LENGTH;
1148
1149 memcpy(s->init_buf->data, frag->fragment,
1150 frag->msg_header.msg_len + header_length);
1151 s->init_num = frag->msg_header.msg_len + header_length;
1152
1153 dtls1_set_message_header_int(s, frag->msg_header.type,
1154 frag->msg_header.msg_len,
1155 frag->msg_header.seq, 0,
1156 frag->msg_header.frag_len);
1157
1158 /* save current state */
1159 saved_state.enc_write_ctx = s->enc_write_ctx;
1160 saved_state.write_hash = s->write_hash;
1161 saved_state.compress = s->compress;
1162 saved_state.session = s->session;
1163 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1164
1165 s->d1->retransmitting = 1;
1166
1167 /* restore state in which the message was originally sent */
1168 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1169 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1170 s->compress = frag->msg_header.saved_retransmit_state.compress;
1171 s->session = frag->msg_header.saved_retransmit_state.session;
1172 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1173 frag->msg_header.
1174 saved_retransmit_state.epoch);
1175
1176 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1177 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1178
1179 /* restore current state */
1180 s->enc_write_ctx = saved_state.enc_write_ctx;
1181 s->write_hash = saved_state.write_hash;
1182 s->compress = saved_state.compress;
1183 s->session = saved_state.session;
1184 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1185
1186 s->d1->retransmitting = 0;
1187
1188 (void)BIO_flush(s->wbio);
1189 return ret;
1190 }
1191
dtls1_set_message_header(SSL_CONNECTION * s,unsigned char mt,size_t len,size_t frag_off,size_t frag_len)1192 void dtls1_set_message_header(SSL_CONNECTION *s,
1193 unsigned char mt, size_t len,
1194 size_t frag_off, size_t frag_len)
1195 {
1196 if (frag_off == 0) {
1197 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1198 s->d1->next_handshake_write_seq++;
1199 }
1200
1201 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1202 frag_off, frag_len);
1203 }
1204
1205 /* don't actually do the writing, wait till the MTU has been retrieved */
1206 static void
dtls1_set_message_header_int(SSL_CONNECTION * s,unsigned char mt,size_t len,unsigned short seq_num,size_t frag_off,size_t frag_len)1207 dtls1_set_message_header_int(SSL_CONNECTION *s, unsigned char mt,
1208 size_t len, unsigned short seq_num,
1209 size_t frag_off, size_t frag_len)
1210 {
1211 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1212
1213 msg_hdr->type = mt;
1214 msg_hdr->msg_len = len;
1215 msg_hdr->seq = seq_num;
1216 msg_hdr->frag_off = frag_off;
1217 msg_hdr->frag_len = frag_len;
1218 }
1219
1220 static void
dtls1_fix_message_header(SSL_CONNECTION * s,size_t frag_off,size_t frag_len)1221 dtls1_fix_message_header(SSL_CONNECTION *s, size_t frag_off, size_t frag_len)
1222 {
1223 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1224
1225 msg_hdr->frag_off = frag_off;
1226 msg_hdr->frag_len = frag_len;
1227 }
1228
dtls1_write_message_header(SSL_CONNECTION * s,unsigned char * p)1229 static unsigned char *dtls1_write_message_header(SSL_CONNECTION *s,
1230 unsigned char *p)
1231 {
1232 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1233
1234 *p++ = msg_hdr->type;
1235 l2n3(msg_hdr->msg_len, p);
1236
1237 s2n(msg_hdr->seq, p);
1238 l2n3(msg_hdr->frag_off, p);
1239 l2n3(msg_hdr->frag_len, p);
1240
1241 return p;
1242 }
1243
dtls1_get_message_header(unsigned char * data,struct hm_header_st * msg_hdr)1244 void dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1245 {
1246 memset(msg_hdr, 0, sizeof(*msg_hdr));
1247 msg_hdr->type = *(data++);
1248 n2l3(data, msg_hdr->msg_len);
1249
1250 n2s(data, msg_hdr->seq);
1251 n2l3(data, msg_hdr->frag_off);
1252 n2l3(data, msg_hdr->frag_len);
1253 }
1254
dtls1_set_handshake_header(SSL_CONNECTION * s,WPACKET * pkt,int htype)1255 int dtls1_set_handshake_header(SSL_CONNECTION *s, WPACKET *pkt, int htype)
1256 {
1257 unsigned char *header;
1258
1259 if (htype == SSL3_MT_CHANGE_CIPHER_SPEC) {
1260 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1261 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1262 s->d1->handshake_write_seq, 0, 0);
1263 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS))
1264 return 0;
1265 } else {
1266 dtls1_set_message_header(s, htype, 0, 0, 0);
1267 /*
1268 * We allocate space at the start for the message header. This gets
1269 * filled in later
1270 */
1271 if (!WPACKET_allocate_bytes(pkt, DTLS1_HM_HEADER_LENGTH, &header)
1272 || !WPACKET_start_sub_packet(pkt))
1273 return 0;
1274 }
1275
1276 return 1;
1277 }
1278
dtls1_close_construct_packet(SSL_CONNECTION * s,WPACKET * pkt,int htype)1279 int dtls1_close_construct_packet(SSL_CONNECTION *s, WPACKET *pkt, int htype)
1280 {
1281 size_t msglen;
1282
1283 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt))
1284 || !WPACKET_get_length(pkt, &msglen)
1285 || msglen > INT_MAX)
1286 return 0;
1287
1288 if (htype != SSL3_MT_CHANGE_CIPHER_SPEC) {
1289 s->d1->w_msg_hdr.msg_len = msglen - DTLS1_HM_HEADER_LENGTH;
1290 s->d1->w_msg_hdr.frag_len = msglen - DTLS1_HM_HEADER_LENGTH;
1291 }
1292 s->init_num = (int)msglen;
1293 s->init_off = 0;
1294
1295 if (htype != DTLS1_MT_HELLO_VERIFY_REQUEST) {
1296 /* Buffer the message to handle re-xmits */
1297 if (!dtls1_buffer_message(s, htype == SSL3_MT_CHANGE_CIPHER_SPEC
1298 ? 1 : 0))
1299 return 0;
1300 }
1301
1302 return 1;
1303 }
1304
