1 /*
2 * Copyright 2005-2025 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 <assert.h>
11 #include <limits.h>
12 #include <string.h>
13 #include <stdio.h>
14 #include "../ssl_local.h"
15 #include "statem_local.h"
16 #include "internal/cryptlib.h"
17 #include "internal/ssl_unwrap.h"
18 #include <openssl/buffer.h>
19
20 #define RSMBLY_BITMASK_SIZE(msg_len) (((msg_len) + 7) / 8)
21
22 #define RSMBLY_BITMASK_MARK(bitmask, start, end) \
23 { \
24 if ((end) - (start) <= 8) { \
25 long ii; \
26 for (ii = (start); ii < (end); ii++) \
27 bitmask[((ii) >> 3)] |= (1 << ((ii) & 7)); \
28 } else { \
29 long ii; \
30 bitmask[((start) >> 3)] |= bitmask_start_values[((start) & 7)]; \
31 for (ii = (((start) >> 3) + 1); ii < ((((end) - 1)) >> 3); ii++) \
32 bitmask[ii] = 0xff; \
33 bitmask[(((end) - 1) >> 3)] |= bitmask_end_values[((end) & 7)]; \
34 } \
35 }
36
37 #define RSMBLY_BITMASK_IS_COMPLETE(bitmask, msg_len, is_complete) \
38 { \
39 long ii; \
40 is_complete = 1; \
41 if (bitmask[(((msg_len) - 1) >> 3)] != bitmask_end_values[((msg_len) & 7)]) \
42 is_complete = 0; \
43 if (is_complete) \
44 for (ii = (((msg_len) - 1) >> 3) - 1; ii >= 0; ii--) \
45 if (bitmask[ii] != 0xff) { \
46 is_complete = 0; \
47 break; \
48 } \
49 }
50
51 static const unsigned char bitmask_start_values[] = {
52 0xff, 0xfe, 0xfc, 0xf8, 0xf0, 0xe0, 0xc0, 0x80
53 };
54 static const unsigned char bitmask_end_values[] = {
55 0xff, 0x01, 0x03, 0x07, 0x0f, 0x1f, 0x3f, 0x7f
56 };
57
58 static void dtls1_fix_message_header(SSL_CONNECTION *s, size_t frag_off,
59 size_t frag_len);
60 static unsigned char *dtls1_write_message_header(SSL_CONNECTION *s,
61 unsigned char *p);
62 static void dtls1_set_message_header_int(SSL_CONNECTION *s, unsigned char mt,
63 size_t len,
64 unsigned short seq_num,
65 size_t frag_off,
66 size_t frag_len);
67 static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype,
68 size_t *len);
69
dtls1_hm_fragment_new(size_t frag_len,int reassembly)70 static hm_fragment *dtls1_hm_fragment_new(size_t frag_len, int reassembly)
71 {
72 hm_fragment *frag = NULL;
73 unsigned char *buf = NULL;
74 unsigned char *bitmask = NULL;
75
76 if ((frag = OPENSSL_zalloc(sizeof(*frag))) == NULL)
77 return NULL;
78
79 if (frag_len) {
80 if ((buf = OPENSSL_malloc(frag_len)) == NULL) {
81 OPENSSL_free(frag);
82 return NULL;
83 }
84 }
85
86 /* zero length fragment gets zero frag->fragment */
87 frag->fragment = buf;
88
89 /* Initialize reassembly bitmask if necessary */
90 if (reassembly) {
91 bitmask = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len));
92 if (bitmask == NULL) {
93 OPENSSL_free(buf);
94 OPENSSL_free(frag);
95 return NULL;
96 }
97 }
98
99 frag->reassembly = bitmask;
100
101 return frag;
102 }
103
dtls1_hm_fragment_free(hm_fragment * frag)104 void dtls1_hm_fragment_free(hm_fragment *frag)
105 {
106 if (!frag)
107 return;
108
109 OPENSSL_free(frag->fragment);
110 OPENSSL_free(frag->reassembly);
111 OPENSSL_free(frag);
112 }
113
114 /*
115 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
116 * SSL3_RT_CHANGE_CIPHER_SPEC)
117 */
dtls1_do_write(SSL_CONNECTION * s,uint8_t type)118 int dtls1_do_write(SSL_CONNECTION *s, uint8_t type)
119 {
120 int ret;
121 size_t written;
122 size_t curr_mtu;
123 int retry = 1;
124 size_t len, frag_off, overhead, used_len;
125 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
126 SSL *ussl = SSL_CONNECTION_GET_USER_SSL(s);
127 uint8_t saved_payload[DTLS1_HM_HEADER_LENGTH];
128
129 if (!dtls1_query_mtu(s))
130 return -1;
131
132 if (s->d1->mtu < dtls1_min_mtu(s))
133 /* should have something reasonable now */
134 return -1;
135
136 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) {
137 if (!ossl_assert(s->init_num == s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH))
138 return -1;
139 }
140
141 overhead = s->rlayer.wrlmethod->get_max_record_overhead(s->rlayer.wrl);
142
143 frag_off = 0;
144 s->rwstate = SSL_NOTHING;
145
146 /* s->init_num shouldn't ever be < 0...but just in case */
147 while (s->init_num > 0) {
148 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
149 /* We must be writing a fragment other than the first one */
150
151 if (frag_off > 0) {
152 /* This is the first attempt at writing out this fragment */
153
154 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
155 /*
156 * Each fragment that was already sent must at least have
157 * contained the message header plus one other byte.
158 * Therefore |init_off| must have progressed by at least
159 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
160 * wrong.
161 */
162 return -1;
163 }
164
165 /*
166 * Adjust |init_off| and |init_num| to allow room for a new
167 * message header for this fragment.
168 */
169 s->init_off -= DTLS1_HM_HEADER_LENGTH;
170 s->init_num += DTLS1_HM_HEADER_LENGTH;
171 } else {
172 /*
173 * We must have been called again after a retry so use the
174 * fragment offset from our last attempt. We do not need
175 * to adjust |init_off| and |init_num| as above, because
176 * that should already have been done before the retry.
177 */
178 frag_off = s->d1->w_msg_hdr.frag_off;
179 }
180 }
181
182 used_len = BIO_wpending(s->wbio) + overhead;
183 if (s->d1->mtu > used_len)
184 curr_mtu = s->d1->mtu - used_len;
185 else
186 curr_mtu = 0;
187
188 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
189 /*
190 * grr.. we could get an error if MTU picked was wrong
191 */
192 ret = BIO_flush(s->wbio);
193 if (ret <= 0) {
194 s->rwstate = SSL_WRITING;
195 return ret;
196 }
197 if (s->d1->mtu > overhead + DTLS1_HM_HEADER_LENGTH) {
198 curr_mtu = s->d1->mtu - overhead;
199 } else {
200 /* Shouldn't happen */
201 return -1;
202 }
203 }
204
205 /*
206 * We just checked that s->init_num > 0 so this cast should be safe
207 */
208 if (((unsigned int)s->init_num) > curr_mtu)
209 len = curr_mtu;
210 else
211 len = s->init_num;
212
213 if (len > ssl_get_max_send_fragment(s))
214 len = ssl_get_max_send_fragment(s);
215
216 /*
217 * XDTLS: this function is too long. split out the CCS part
218 */
219 if (type == SSL3_RT_HANDSHAKE) {
220 if (len < DTLS1_HM_HEADER_LENGTH) {
221 /*
222 * len is so small that we really can't do anything sensible
223 * so fail
224 */
225 return -1;
226 }
227 dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH);
228
229 /*
230 * Save the data that will be overwritten by
231 * dtls1_write_messsage_header so no corruption occurs when using
232 * a msg callback.
233 */
234 if (s->msg_callback && s->init_off != 0)
235 memcpy(saved_payload, &s->init_buf->data[s->init_off],
236 sizeof(saved_payload));
237
238 dtls1_write_message_header(s,
239 (unsigned char *)&s->init_buf->data[s->init_off]);
240 }
241
242 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len,
243 &written);
244
245 if (type == SSL3_RT_HANDSHAKE && s->msg_callback && s->init_off != 0)
246 memcpy(&s->init_buf->data[s->init_off], saved_payload,
247 sizeof(saved_payload));
248
249 if (ret <= 0) {
250 /*
251 * might need to update MTU here, but we don't know which
252 * previous packet caused the failure -- so can't really
253 * retransmit anything. continue as if everything is fine and
254 * wait for an alert to handle the retransmit
255 */
256 if (retry && BIO_ctrl(SSL_get_wbio(ssl), BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
257 if (!(SSL_get_options(ssl) & SSL_OP_NO_QUERY_MTU)) {
258 if (!dtls1_query_mtu(s))
259 return -1;
260 /* Have one more go */
261 retry = 0;
262 } else
263 return -1;
264 } else {
265 return -1;
266 }
267 } else {
268
269 /*
270 * bad if this assert fails, only part of the handshake message
271 * got sent. but why would this happen?
272 */
273 if (!ossl_assert(len == written))
274 return -1;
275
276 /*
277 * We should not exceed the MTU size. If compression is in use
278 * then the max record overhead calculation is unreliable so we do
279 * not check in that case. We use assert rather than ossl_assert
280 * because in a production build, if this assert were ever to fail,
281 * then the best thing to do is probably carry on regardless.
282 */
283 assert(s->s3.tmp.new_compression != NULL
284 || BIO_wpending(s->wbio) <= (int)s->d1->mtu);
285
286 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
287 /*
288 * should not be done for 'Hello Request's, but in that case
289 * we'll ignore the result anyway
290 */
291 unsigned char *p = (unsigned char *)&s->init_buf->data[s->init_off];
292 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
293 size_t xlen;
294
295 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
296 /*
297 * reconstruct message header is if it is being sent in
298 * single fragment
299 */
300 *p++ = msg_hdr->type;
301 l2n3(msg_hdr->msg_len, p);
302 s2n(msg_hdr->seq, p);
303 l2n3(0, p);
304 l2n3(msg_hdr->msg_len, p);
305 p -= DTLS1_HM_HEADER_LENGTH;
306 xlen = written;
307 } else {
308 p += DTLS1_HM_HEADER_LENGTH;
309 xlen = written - DTLS1_HM_HEADER_LENGTH;
310 }
311
312 if (!ssl3_finish_mac(s, p, xlen))
313 return -1;
314 }
315
316 if (written == s->init_num) {
317 if (s->msg_callback)
318 s->msg_callback(1, s->version, type, s->init_buf->data,
319 s->init_off + s->init_num, ussl,
320 s->msg_callback_arg);
321
322 s->init_off = 0; /* done writing this message */
323 s->init_num = 0;
324
325 return 1;
326 }
327 s->init_off += written;
328 s->init_num -= written;
329 written -= DTLS1_HM_HEADER_LENGTH;
330 frag_off += written;
331
332 /*
333 * We save the fragment offset for the next fragment so we have it
334 * available in case of an IO retry. We don't know the length of the
335 * next fragment yet so just set that to 0 for now. It will be
336 * updated again later.
337 */
338 dtls1_fix_message_header(s, frag_off, 0);
339 }
340 }
341 return 0;
342 }
343
dtls_get_message(SSL_CONNECTION * s,int * mt)344 int dtls_get_message(SSL_CONNECTION *s, int *mt)
345 {
346 struct hm_header_st *msg_hdr;
347 unsigned char *p;
348 size_t msg_len;
349 size_t tmplen;
350 int errtype;
351
352 msg_hdr = &s->d1->r_msg_hdr;
353 memset(msg_hdr, 0, sizeof(*msg_hdr));
354
355 again:
356 if (!dtls_get_reassembled_message(s, &errtype, &tmplen)) {
357 if (errtype == DTLS1_HM_BAD_FRAGMENT
358 || errtype == DTLS1_HM_FRAGMENT_RETRY) {
359 /* bad fragment received */
360 goto again;
361 }
362 return 0;
363 }
364
365 *mt = s->s3.tmp.message_type;
366
367 p = (unsigned char *)s->init_buf->data;
368
369 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
370 if (s->msg_callback) {
371 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
372 p, 1, SSL_CONNECTION_GET_USER_SSL(s),
373 s->msg_callback_arg);
374 }
375 /*
376 * This isn't a real handshake message so skip the processing below.
377 */
378 return 1;
379 }
380
381 msg_len = msg_hdr->msg_len;
382
383 /* reconstruct message header */
384 *(p++) = msg_hdr->type;
385 l2n3(msg_len, p);
386 s2n(msg_hdr->seq, p);
387 l2n3(0, p);
388 l2n3(msg_len, p);
389
390 memset(msg_hdr, 0, sizeof(*msg_hdr));
391
392 s->d1->handshake_read_seq++;
393
394 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
395
396 return 1;
397 }
398
399 /*
400 * Actually we already have the message body - but this is an opportunity for
401 * DTLS to do any further processing it wants at the same point that TLS would
402 * be asked for the message body.
403 */
dtls_get_message_body(SSL_CONNECTION * s,size_t * len)404 int dtls_get_message_body(SSL_CONNECTION *s, size_t *len)
405 {
406 unsigned char *msg = (unsigned char *)s->init_buf->data;
407 size_t msg_len = s->init_num + DTLS1_HM_HEADER_LENGTH;
408
409 if (s->s3.tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
410 /* Nothing to be done */
411 goto end;
412 }
413 /*
414 * If receiving Finished, record MAC of prior handshake messages for
415 * Finished verification.
416 */
417 if (*(s->init_buf->data) == SSL3_MT_FINISHED && !ssl3_take_mac(s)) {
418 /* SSLfatal() already called */
419 return 0;
420 }
421
422 if (s->version == DTLS1_BAD_VER) {
423 msg += DTLS1_HM_HEADER_LENGTH;
424 msg_len -= DTLS1_HM_HEADER_LENGTH;
425 }
426
427 if (!ssl3_finish_mac(s, msg, msg_len))
428 return 0;
429
430 if (s->msg_callback)
431 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
432 s->init_buf->data, s->init_num + DTLS1_HM_HEADER_LENGTH,
433 SSL_CONNECTION_GET_USER_SSL(s), s->msg_callback_arg);
434
435 end:
436 *len = s->init_num;
437 return 1;
438 }
439
440 /*
441 * dtls1_max_handshake_message_len returns the maximum number of bytes
442 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
443 * may be greater if the maximum certificate list size requires it.
444 */
dtls1_max_handshake_message_len(const SSL_CONNECTION * s)445 static size_t dtls1_max_handshake_message_len(const SSL_CONNECTION *s)
446 {
447 size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
448 if (max_len < s->max_cert_list)
449 return s->max_cert_list;
450 return max_len;
451 }
452
dtls1_preprocess_fragment(SSL_CONNECTION * s,struct hm_header_st * msg_hdr)453 static int dtls1_preprocess_fragment(SSL_CONNECTION *s,
454 struct hm_header_st *msg_hdr)
455 {
456 size_t frag_off, frag_len, msg_len;
457
458 msg_len = msg_hdr->msg_len;
459 frag_off = msg_hdr->frag_off;
460 frag_len = msg_hdr->frag_len;
461
462 /* sanity checking */
463 if ((frag_off + frag_len) > msg_len
464 || msg_len > dtls1_max_handshake_message_len(s)) {
465 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
466 return 0;
467 }
468
469 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
470 /*
471 * msg_len is limited to 2^24, but is effectively checked against
472 * dtls_max_handshake_message_len(s) above
473 */
474 if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
475 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_BUF_LIB);
476 return 0;
477 }
478
479 s->s3.tmp.message_size = msg_len;
480 s->d1->r_msg_hdr.msg_len = msg_len;
481 s->s3.tmp.message_type = msg_hdr->type;
482 s->d1->r_msg_hdr.type = msg_hdr->type;
483 s->d1->r_msg_hdr.seq = msg_hdr->seq;
484 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
485 /*
486 * They must be playing with us! BTW, failure to enforce upper limit
487 * would open possibility for buffer overrun.
488 */
489 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
490 return 0;
491 }
492
493 return 1;
494 }
495
496 /*
497 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a
498 * fatal error.
499 */
dtls1_retrieve_buffered_fragment(SSL_CONNECTION * s,size_t * len)500 static int dtls1_retrieve_buffered_fragment(SSL_CONNECTION *s, size_t *len)
501 {
502 /*-
503 * (0) check whether the desired fragment is available
504 * if so:
505 * (1) copy over the fragment to s->init_buf->data[]
506 * (2) update s->init_num
507 */
508 pitem *item;
509 piterator iter;
510 hm_fragment *frag;
511 int ret;
512 int chretran = 0;
513
514 iter = pqueue_iterator(s->d1->buffered_messages);
515 do {
516 item = pqueue_next(&iter);
517 if (item == NULL)
518 return 0;
519
520 frag = (hm_fragment *)item->data;
521
522 if (frag->msg_header.seq < s->d1->handshake_read_seq) {
523 pitem *next;
524 hm_fragment *nextfrag;
525
526 if (!s->server
527 || frag->msg_header.seq != 0
528 || s->d1->handshake_read_seq != 1
529 || s->statem.hand_state != DTLS_ST_SW_HELLO_VERIFY_REQUEST) {
530 /*
531 * This is a stale message that has been buffered so clear it.
532 * It is safe to pop this message from the queue even though
533 * we have an active iterator
534 */
535 pqueue_pop(s->d1->buffered_messages);
536 dtls1_hm_fragment_free(frag);
537 pitem_free(item);
538 item = NULL;
539 frag = NULL;
540 } else {
541 /*
542 * We have fragments for a ClientHello without a cookie,
543 * even though we have sent a HelloVerifyRequest. It is possible
544 * that the HelloVerifyRequest got lost and this is a
545 * retransmission of the original ClientHello
546 */
547 next = pqueue_next(&iter);
548 if (next != NULL) {
549 nextfrag = (hm_fragment *)next->data;
550 if (nextfrag->msg_header.seq == s->d1->handshake_read_seq) {
551 /*
552 * We have fragments for both a ClientHello without
553 * cookie and one with. Ditch the one without.
554 */
555 pqueue_pop(s->d1->buffered_messages);
556 dtls1_hm_fragment_free(frag);
557 pitem_free(item);
558 item = next;
559 frag = nextfrag;
560 } else {
561 chretran = 1;
562 }
563 } else {
564 chretran = 1;
565 }
566 }
567 }
568 } while (item == NULL);
569
570 /* Don't return if reassembly still in progress */
571 if (frag->reassembly != NULL)
572 return 0;
573
574 if (s->d1->handshake_read_seq == frag->msg_header.seq || chretran) {
575 size_t frag_len = frag->msg_header.frag_len;
576 pqueue_pop(s->d1->buffered_messages);
577
578 /* Calls SSLfatal() as required */
579 ret = dtls1_preprocess_fragment(s, &frag->msg_header);
580
581 if (ret && frag->msg_header.frag_len > 0) {
582 unsigned char *p = (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
583 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
584 frag->msg_header.frag_len);
585 }
586
587 dtls1_hm_fragment_free(frag);
588 pitem_free(item);
589
590 if (ret) {
591 if (chretran) {
592 /*
593 * We got a new ClientHello with a message sequence of 0.
594 * Reset the read/write sequences back to the beginning.
595 * We process it like this is the first time we've seen a
596 * ClientHello from the client.
597 */
598 s->d1->handshake_read_seq = 0;
599 s->d1->next_handshake_write_seq = 0;
600 }
601 *len = frag_len;
602 return 1;
603 }
604
605 /* Fatal error */
606 s->init_num = 0;
607 return -1;
608 } else {
609 return 0;
610 }
611 }
612
dtls1_reassemble_fragment(SSL_CONNECTION * s,const struct hm_header_st * msg_hdr)613 static int dtls1_reassemble_fragment(SSL_CONNECTION *s,
614 const struct hm_header_st *msg_hdr)
615 {
616 hm_fragment *frag = NULL;
617 pitem *item = NULL;
618 int i = -1, is_complete;
619 unsigned char seq64be[8];
620 size_t frag_len = msg_hdr->frag_len;
621 size_t readbytes;
622 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
623
624 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len || msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
625 goto err;
626
627 if (frag_len == 0) {
628 return DTLS1_HM_FRAGMENT_RETRY;
629 }
630
631 /* Try to find item in queue */
632 memset(seq64be, 0, sizeof(seq64be));
633 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
634 seq64be[7] = (unsigned char)msg_hdr->seq;
635 item = pqueue_find(s->d1->buffered_messages, seq64be);
636
637 if (item == NULL) {
638 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
639 if (frag == NULL)
640 goto err;
641 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
642 frag->msg_header.frag_len = frag->msg_header.msg_len;
643 frag->msg_header.frag_off = 0;
644 } else {
645 frag = (hm_fragment *)item->data;
646 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
647 item = NULL;
648 frag = NULL;
649 goto err;
650 }
651 }
652
653 /*
654 * If message is already reassembled, this must be a retransmit and can
655 * be dropped. In this case item != NULL and so frag does not need to be
656 * freed.
657 */
658 if (frag->reassembly == NULL) {
659 unsigned char devnull[256];
660
661 while (frag_len) {
662 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
663 devnull,
664 frag_len > sizeof(devnull) ? sizeof(devnull) : frag_len, 0, &readbytes);
665 if (i <= 0)
666 goto err;
667 frag_len -= readbytes;
668 }
669 return DTLS1_HM_FRAGMENT_RETRY;
670 }
671
672 /* read the body of the fragment (header has already been read */
673 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
674 frag->fragment + msg_hdr->frag_off,
675 frag_len, 0, &readbytes);
676 if (i <= 0 || readbytes != frag_len)
677 i = -1;
678 if (i <= 0)
679 goto err;
680
681 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
682 (long)(msg_hdr->frag_off + frag_len));
683
684 if (!ossl_assert(msg_hdr->msg_len > 0))
685 goto err;
686 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
687 is_complete);
688
689 if (is_complete) {
690 OPENSSL_free(frag->reassembly);
691 frag->reassembly = NULL;
692 }
693
694 if (item == NULL) {
695 item = pitem_new(seq64be, frag);
696 if (item == NULL) {
697 i = -1;
698 goto err;
699 }
700
701 item = pqueue_insert(s->d1->buffered_messages, item);
702 /*
703 * pqueue_insert fails iff a duplicate item is inserted. However,
704 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
705 * would have returned it and control would never have reached this
706 * branch.
707 */
708 if (!ossl_assert(item != NULL))
709 goto err;
710 }
711
712 return DTLS1_HM_FRAGMENT_RETRY;
713
714 err:
715 if (item == NULL)
716 dtls1_hm_fragment_free(frag);
717 return -1;
718 }
719
dtls1_process_out_of_seq_message(SSL_CONNECTION * s,const struct hm_header_st * msg_hdr)720 static int dtls1_process_out_of_seq_message(SSL_CONNECTION *s,
721 const struct hm_header_st *msg_hdr)
722 {
723 int i = -1;
724 hm_fragment *frag = NULL;
725 pitem *item = NULL;
726 unsigned char seq64be[8];
727 size_t frag_len = msg_hdr->frag_len;
728 size_t readbytes;
729 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
730
731 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
732 goto err;
733
734 /* Try to find item in queue, to prevent duplicate entries */
735 memset(seq64be, 0, sizeof(seq64be));
736 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
737 seq64be[7] = (unsigned char)msg_hdr->seq;
738 item = pqueue_find(s->d1->buffered_messages, seq64be);
739
740 /*
741 * If we already have an entry and this one is a fragment, don't discard
742 * it and rather try to reassemble it.
743 */
744 if (item != NULL && frag_len != msg_hdr->msg_len)
745 item = NULL;
746
747 /*
748 * Discard the message if sequence number was already there, is too far
749 * in the future, already in the queue or if we received a FINISHED
750 * before the SERVER_HELLO, which then must be a stale retransmit.
751 */
752 if (msg_hdr->seq <= s->d1->handshake_read_seq || msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL || (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) {
753 unsigned char devnull[256];
754
755 while (frag_len) {
756 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
757 devnull,
758 frag_len > sizeof(devnull) ? sizeof(devnull) : frag_len, 0, &readbytes);
759 if (i <= 0)
760 goto err;
761 frag_len -= readbytes;
762 }
763 } else {
764 if (frag_len != msg_hdr->msg_len) {
765 return dtls1_reassemble_fragment(s, msg_hdr);
766 }
767
768 if (frag_len > dtls1_max_handshake_message_len(s))
769 goto err;
770
771 frag = dtls1_hm_fragment_new(frag_len, 0);
772 if (frag == NULL)
773 goto err;
774
775 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
776
777 if (frag_len) {
778 /*
779 * read the body of the fragment (header has already been read
780 */
781 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
782 frag->fragment, frag_len, 0,
783 &readbytes);
784 if (i <= 0 || readbytes != frag_len)
785 i = -1;
786 if (i <= 0)
787 goto err;
788 }
789
790 item = pitem_new(seq64be, frag);
791 if (item == NULL)
792 goto err;
793
794 item = pqueue_insert(s->d1->buffered_messages, item);
795 /*
796 * pqueue_insert fails iff a duplicate item is inserted. However,
797 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
798 * would have returned it. Then, either |frag_len| !=
799 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
800 * have been processed with |dtls1_reassemble_fragment|, above, or
801 * the record will have been discarded.
802 */
803 if (!ossl_assert(item != NULL))
804 goto err;
805 }
806
807 return DTLS1_HM_FRAGMENT_RETRY;
808
809 err:
810 if (item == NULL)
811 dtls1_hm_fragment_free(frag);
812 return 0;
813 }
814
dtls_get_reassembled_message(SSL_CONNECTION * s,int * errtype,size_t * len)815 static int dtls_get_reassembled_message(SSL_CONNECTION *s, int *errtype,
816 size_t *len)
817 {
818 size_t mlen, frag_off, frag_len;
819 int i, ret;
820 uint8_t recvd_type;
821 struct hm_header_st msg_hdr;
822 size_t readbytes;
823 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
824 SSL *ussl = SSL_CONNECTION_GET_USER_SSL(s);
825 int chretran = 0;
826 unsigned char *p;
827
828 *errtype = 0;
829
830 p = (unsigned char *)s->init_buf->data;
831
832 redo:
833 /* see if we have the required fragment already */
834 ret = dtls1_retrieve_buffered_fragment(s, &frag_len);
835 if (ret < 0) {
836 /* SSLfatal() already called */
837 return 0;
838 }
839 if (ret > 0) {
840 s->init_num = frag_len;
841 *len = frag_len;
842 return 1;
843 }
844
845 /* read handshake message header */
846 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, &recvd_type, p,
847 DTLS1_HM_HEADER_LENGTH, 0, &readbytes);
848 if (i <= 0) { /* nbio, or an error */
849 s->rwstate = SSL_READING;
850 *len = 0;
851 return 0;
852 }
853 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
854 if (p[0] != SSL3_MT_CCS) {
855 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
856 SSL_R_BAD_CHANGE_CIPHER_SPEC);
857 goto f_err;
858 }
859
860 s->init_num = readbytes - 1;
861 s->init_msg = s->init_buf->data + 1;
862 s->s3.tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
863 s->s3.tmp.message_size = readbytes - 1;
864 *len = readbytes - 1;
865 return 1;
866 }
867
868 /* Handshake fails if message header is incomplete */
869 if (readbytes != DTLS1_HM_HEADER_LENGTH) {
870 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
871 goto f_err;
872 }
873
874 /* parse the message fragment header */
875 dtls1_get_message_header(p, &msg_hdr);
876
877 mlen = msg_hdr.msg_len;
878 frag_off = msg_hdr.frag_off;
879 frag_len = msg_hdr.frag_len;
880
881 /*
882 * We must have at least frag_len bytes left in the record to be read.
883 * Fragments must not span records.
884 */
885 if (frag_len > s->rlayer.tlsrecs[s->rlayer.curr_rec].length) {
886 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH);
887 goto f_err;
888 }
889
890 /*
891 * if this is a future (or stale) message it gets buffered
892 * (or dropped)--no further processing at this time
893 * While listening, we accept seq 1 (ClientHello with cookie)
894 * although we're still expecting seq 0 (ClientHello)
895 */
896 if (msg_hdr.seq != s->d1->handshake_read_seq) {
897 if (!s->server
898 || msg_hdr.seq != 0
899 || s->d1->handshake_read_seq != 1
900 || p[0] != SSL3_MT_CLIENT_HELLO
901 || s->statem.hand_state != DTLS_ST_SW_HELLO_VERIFY_REQUEST) {
902 *errtype = dtls1_process_out_of_seq_message(s, &msg_hdr);
903 return 0;
904 }
905 /*
906 * We received a ClientHello and sent back a HelloVerifyRequest. We
907 * now seem to have received a retransmitted initial ClientHello. That
908 * is allowed (possibly our HelloVerifyRequest got lost).
909 */
910 chretran = 1;
911 }
912
913 if (frag_len && frag_len < mlen) {
914 *errtype = dtls1_reassemble_fragment(s, &msg_hdr);
915 return 0;
916 }
917
918 if (!s->server
919 && s->d1->r_msg_hdr.frag_off == 0
920 && s->statem.hand_state != TLS_ST_OK
921 && p[0] == SSL3_MT_HELLO_REQUEST) {
922 /*
923 * The server may always send 'Hello Request' messages -- we are
924 * doing a handshake anyway now, so ignore them if their format is
925 * correct. Does not count for 'Finished' MAC.
926 */
927 if (p[1] == 0 && p[2] == 0 && p[3] == 0) {
928 if (s->msg_callback)
929 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
930 p, DTLS1_HM_HEADER_LENGTH, ussl,
931 s->msg_callback_arg);
932
933 s->init_num = 0;
934 goto redo;
935 } else { /* Incorrectly formatted Hello request */
936
937 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
938 goto f_err;
939 }
940 }
941
942 if (!dtls1_preprocess_fragment(s, &msg_hdr)) {
943 /* SSLfatal() already called */
944 goto f_err;
945 }
946
947 if (frag_len > 0) {
948 /* dtls1_preprocess_fragment() above could reallocate init_buf */
949 p = (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
950
951 i = ssl->method->ssl_read_bytes(ssl, SSL3_RT_HANDSHAKE, NULL,
952 &p[frag_off], frag_len, 0, &readbytes);
953
954 /*
955 * This shouldn't ever fail due to NBIO because we already checked
956 * that we have enough data in the record
957 */
958 if (i <= 0) {
959 s->rwstate = SSL_READING;
960 *len = 0;
961 return 0;
962 }
963 } else {
964 readbytes = 0;
965 }
966
967 /*
968 * XDTLS: an incorrectly formatted fragment should cause the handshake
969 * to fail
970 */
971 if (readbytes != frag_len) {
972 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH);
973 goto f_err;
974 }
975
976 if (chretran) {
977 /*
978 * We got a new ClientHello with a message sequence of 0.
979 * Reset the read/write sequences back to the beginning.
980 * We process it like this is the first time we've seen a ClientHello
981 * from the client.
982 */
983 s->d1->handshake_read_seq = 0;
984 s->d1->next_handshake_write_seq = 0;
985 }
986
987 /*
988 * Note that s->init_num is *not* used as current offset in
989 * s->init_buf->data, but as a counter summing up fragments' lengths: as
990 * soon as they sum up to handshake packet length, we assume we have got
991 * all the fragments.
992 */
993 *len = s->init_num = frag_len;
994 return 1;
995
996 f_err:
997 s->init_num = 0;
998 *len = 0;
999 return 0;
1000 }
1001
1002 /*-
1003 * for these 2 messages, we need to
1004 * ssl->session->read_sym_enc assign
1005 * ssl->session->read_compression assign
1006 * ssl->session->read_hash assign
1007 */
dtls_construct_change_cipher_spec(SSL_CONNECTION * s,WPACKET * pkt)1008 CON_FUNC_RETURN dtls_construct_change_cipher_spec(SSL_CONNECTION *s,
1009 WPACKET *pkt)
1010 {
1011 if (s->version == DTLS1_BAD_VER) {
1012 s->d1->next_handshake_write_seq++;
1013
1014 if (!WPACKET_put_bytes_u16(pkt, s->d1->handshake_write_seq)) {
1015 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1016 return CON_FUNC_ERROR;
1017 }
1018 }
1019
1020 return CON_FUNC_SUCCESS;
1021 }
1022
1023 #ifndef OPENSSL_NO_SCTP
1024 /*
1025 * Wait for a dry event. Should only be called at a point in the handshake
1026 * where we are not expecting any data from the peer except an alert.
1027 */
dtls_wait_for_dry(SSL_CONNECTION * s)1028 WORK_STATE dtls_wait_for_dry(SSL_CONNECTION *s)
1029 {
1030 int ret, errtype;
1031 size_t len;
1032 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
1033
1034 /* read app data until dry event */
1035 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(ssl));
1036 if (ret < 0) {
1037 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1038 return WORK_ERROR;
1039 }
1040
1041 if (ret == 0) {
1042 /*
1043 * We're not expecting any more messages from the peer at this point -
1044 * but we could get an alert. If an alert is waiting then we will never
1045 * return successfully. Therefore we attempt to read a message. This
1046 * should never succeed but will process any waiting alerts.
1047 */
1048 if (dtls_get_reassembled_message(s, &errtype, &len)) {
1049 /* The call succeeded! This should never happen */
1050 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
1051 return WORK_ERROR;
1052 }
1053
1054 s->s3.in_read_app_data = 2;
1055 s->rwstate = SSL_READING;
1056 BIO_clear_retry_flags(SSL_get_rbio(ssl));
1057 BIO_set_retry_read(SSL_get_rbio(ssl));
1058 return WORK_MORE_A;
1059 }
1060 return WORK_FINISHED_CONTINUE;
1061 }
1062 #endif
1063
dtls1_read_failed(SSL_CONNECTION * s,int code)1064 int dtls1_read_failed(SSL_CONNECTION *s, int code)
1065 {
1066 SSL *ssl = SSL_CONNECTION_GET_SSL(s);
1067
1068 if (code > 0) {
1069 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1070 return 0;
1071 }
1072
1073 if (!dtls1_is_timer_expired(s) || ossl_statem_in_error(s)) {
1074 /*
1075 * not a timeout, none of our business, let higher layers handle
1076 * this. in fact it's probably an error
1077 */
1078 return code;
1079 }
1080 /* done, no need to send a retransmit */
1081 if (!SSL_in_init(ssl)) {
1082 BIO_set_flags(SSL_get_rbio(ssl), BIO_FLAGS_READ);
1083 return code;
1084 }
1085
1086 return dtls1_handle_timeout(s);
1087 }
1088
dtls1_get_queue_priority(unsigned short seq,int is_ccs)1089 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1090 {
1091 /*
1092 * The index of the retransmission queue actually is the message sequence
1093 * number, since the queue only contains messages of a single handshake.
1094 * However, the ChangeCipherSpec has no message sequence number and so
1095 * using only the sequence will result in the CCS and Finished having the
1096 * same index. To prevent this, the sequence number is multiplied by 2.
1097 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1098 * Finished, it also maintains the order of the index (important for
1099 * priority queues) and fits in the unsigned short variable.
1100 */
1101 return seq * 2 - is_ccs;
1102 }
1103
dtls1_retransmit_buffered_messages(SSL_CONNECTION * s)1104 int dtls1_retransmit_buffered_messages(SSL_CONNECTION *s)
1105 {
1106 pqueue *sent = s->d1->sent_messages;
1107 piterator iter;
1108 pitem *item;
1109 hm_fragment *frag;
1110 int found = 0;
1111
1112 iter = pqueue_iterator(sent);
1113
1114 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1115 frag = (hm_fragment *)item->data;
1116 if (dtls1_retransmit_message(s, (unsigned short)dtls1_get_queue_priority(frag->msg_header.seq, frag->msg_header.is_ccs), &found) <= 0)
1117 return -1;
1118 }
1119
1120 return 1;
1121 }
1122
dtls1_buffer_message(SSL_CONNECTION * s,int is_ccs)1123 int dtls1_buffer_message(SSL_CONNECTION *s, int is_ccs)
1124 {
1125 pitem *item;
1126 hm_fragment *frag;
1127 unsigned char seq64be[8];
1128
1129 /*
1130 * this function is called immediately after a message has been
1131 * serialized
1132 */
1133 if (!ossl_assert(s->init_off == 0))
1134 return 0;
1135
1136 frag = dtls1_hm_fragment_new(s->init_num, 0);
1137 if (frag == NULL)
1138 return 0;
1139
1140 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1141
1142 if (is_ccs) {
1143 /* For DTLS1_BAD_VER the header length is non-standard */
1144 if (!ossl_assert(s->d1->w_msg_hdr.msg_len + ((s->version == DTLS1_BAD_VER) ? 3 : DTLS1_CCS_HEADER_LENGTH)
1145 == (unsigned int)s->init_num)) {
1146 dtls1_hm_fragment_free(frag);
1147 return 0;
1148 }
1149 } else {
1150 if (!ossl_assert(s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num)) {
1151 dtls1_hm_fragment_free(frag);
1152 return 0;
1153 }
1154 }
1155
1156 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1157 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1158 frag->msg_header.type = s->d1->w_msg_hdr.type;
1159 frag->msg_header.frag_off = 0;
1160 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1161 frag->msg_header.is_ccs = is_ccs;
1162
1163 /* save current state */
1164 frag->msg_header.saved_retransmit_state.wrlmethod = s->rlayer.wrlmethod;
1165 frag->msg_header.saved_retransmit_state.wrl = s->rlayer.wrl;
1166
1167 memset(seq64be, 0, sizeof(seq64be));
1168 seq64be[6] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1169 frag->msg_header.is_ccs)
1170 >> 8);
1171 seq64be[7] = (unsigned char)(dtls1_get_queue_priority(frag->msg_header.seq,
1172 frag->msg_header.is_ccs));
1173
1174 item = pitem_new(seq64be, frag);
1175 if (item == NULL) {
1176 dtls1_hm_fragment_free(frag);
1177 return 0;
1178 }
1179
1180 pqueue_insert(s->d1->sent_messages, item);
1181 return 1;
1182 }
1183
dtls1_retransmit_message(SSL_CONNECTION * s,unsigned short seq,int * found)1184 int dtls1_retransmit_message(SSL_CONNECTION *s, unsigned short seq, int *found)
1185 {
1186 int ret;
1187 /* XDTLS: for now assuming that read/writes are blocking */
1188 pitem *item;
1189 hm_fragment *frag;
1190 unsigned long header_length;
1191 unsigned char seq64be[8];
1192 struct dtls1_retransmit_state saved_state;
1193
1194 /* XDTLS: the requested message ought to be found, otherwise error */
1195 memset(seq64be, 0, sizeof(seq64be));
1196 seq64be[6] = (unsigned char)(seq >> 8);
1197 seq64be[7] = (unsigned char)seq;
1198
1199 item = pqueue_find(s->d1->sent_messages, seq64be);
1200 if (item == NULL) {
1201 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1202 *found = 0;
1203 return 0;
1204 }
1205
1206 *found = 1;
1207 frag = (hm_fragment *)item->data;
1208
1209 if (frag->msg_header.is_ccs)
1210 header_length = DTLS1_CCS_HEADER_LENGTH;
1211 else
1212 header_length = DTLS1_HM_HEADER_LENGTH;
1213
1214 memcpy(s->init_buf->data, frag->fragment,
1215 frag->msg_header.msg_len + header_length);
1216 s->init_num = frag->msg_header.msg_len + header_length;
1217
1218 dtls1_set_message_header_int(s, frag->msg_header.type,
1219 frag->msg_header.msg_len,
1220 frag->msg_header.seq, 0,
1221 frag->msg_header.frag_len);
1222
1223 /* save current state */
1224 saved_state.wrlmethod = s->rlayer.wrlmethod;
1225 saved_state.wrl = s->rlayer.wrl;
1226
1227 s->d1->retransmitting = 1;
1228
1229 /* restore state in which the message was originally sent */
1230 s->rlayer.wrlmethod = frag->msg_header.saved_retransmit_state.wrlmethod;
1231 s->rlayer.wrl = frag->msg_header.saved_retransmit_state.wrl;
1232
1233 /*
1234 * The old wrl may be still pointing at an old BIO. Update it to what we're
1235 * using now.
1236 */
1237 s->rlayer.wrlmethod->set1_bio(s->rlayer.wrl, s->wbio);
1238
1239 ret = dtls1_do_write(s, frag->msg_header.is_ccs ? SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1240
1241 /* restore current state */
1242 s->rlayer.wrlmethod = saved_state.wrlmethod;
1243 s->rlayer.wrl = saved_state.wrl;
1244
1245 s->d1->retransmitting = 0;
1246
1247 (void)BIO_flush(s->wbio);
1248 return ret;
1249 }
1250
dtls1_set_message_header(SSL_CONNECTION * s,unsigned char mt,size_t len,size_t frag_off,size_t frag_len)1251 void dtls1_set_message_header(SSL_CONNECTION *s,
1252 unsigned char mt, size_t len,
1253 size_t frag_off, size_t frag_len)
1254 {
1255 if (frag_off == 0) {
1256 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1257 s->d1->next_handshake_write_seq++;
1258 }
1259
1260 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1261 frag_off, frag_len);
1262 }
1263
1264 /* don't actually do the writing, wait till the MTU has been retrieved */
1265 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)1266 dtls1_set_message_header_int(SSL_CONNECTION *s, unsigned char mt,
1267 size_t len, unsigned short seq_num,
1268 size_t frag_off, size_t frag_len)
1269 {
1270 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1271
1272 msg_hdr->type = mt;
1273 msg_hdr->msg_len = len;
1274 msg_hdr->seq = seq_num;
1275 msg_hdr->frag_off = frag_off;
1276 msg_hdr->frag_len = frag_len;
1277 }
1278
1279 static void
dtls1_fix_message_header(SSL_CONNECTION * s,size_t frag_off,size_t frag_len)1280 dtls1_fix_message_header(SSL_CONNECTION *s, size_t frag_off, size_t frag_len)
1281 {
1282 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1283
1284 msg_hdr->frag_off = frag_off;
1285 msg_hdr->frag_len = frag_len;
1286 }
1287
dtls1_write_message_header(SSL_CONNECTION * s,unsigned char * p)1288 static unsigned char *dtls1_write_message_header(SSL_CONNECTION *s,
1289 unsigned char *p)
1290 {
1291 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1292
1293 *p++ = msg_hdr->type;
1294 l2n3(msg_hdr->msg_len, p);
1295
1296 s2n(msg_hdr->seq, p);
1297 l2n3(msg_hdr->frag_off, p);
1298 l2n3(msg_hdr->frag_len, p);
1299
1300 return p;
1301 }
1302
dtls1_get_message_header(const unsigned char * data,struct hm_header_st * msg_hdr)1303 void dtls1_get_message_header(const unsigned char *data, struct hm_header_st *msg_hdr)
1304 {
1305 memset(msg_hdr, 0, sizeof(*msg_hdr));
1306 msg_hdr->type = *(data++);
1307 n2l3(data, msg_hdr->msg_len);
1308
1309 n2s(data, msg_hdr->seq);
1310 n2l3(data, msg_hdr->frag_off);
1311 n2l3(data, msg_hdr->frag_len);
1312 }
1313
dtls1_set_handshake_header(SSL_CONNECTION * s,WPACKET * pkt,int htype)1314 int dtls1_set_handshake_header(SSL_CONNECTION *s, WPACKET *pkt, int htype)
1315 {
1316 unsigned char *header;
1317
1318 if (htype == SSL3_MT_CHANGE_CIPHER_SPEC) {
1319 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1320 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1321 s->d1->handshake_write_seq, 0, 0);
1322 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS))
1323 return 0;
1324 } else {
1325 dtls1_set_message_header(s, htype, 0, 0, 0);
1326 /*
1327 * We allocate space at the start for the message header. This gets
1328 * filled in later
1329 */
1330 if (!WPACKET_allocate_bytes(pkt, DTLS1_HM_HEADER_LENGTH, &header)
1331 || !WPACKET_start_sub_packet(pkt))
1332 return 0;
1333 }
1334
1335 return 1;
1336 }
1337
dtls1_close_construct_packet(SSL_CONNECTION * s,WPACKET * pkt,int htype)1338 int dtls1_close_construct_packet(SSL_CONNECTION *s, WPACKET *pkt, int htype)
1339 {
1340 size_t msglen;
1341
1342 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt))
1343 || !WPACKET_get_length(pkt, &msglen)
1344 || msglen > INT_MAX)
1345 return 0;
1346
1347 if (htype != SSL3_MT_CHANGE_CIPHER_SPEC) {
1348 s->d1->w_msg_hdr.msg_len = msglen - DTLS1_HM_HEADER_LENGTH;
1349 s->d1->w_msg_hdr.frag_len = msglen - DTLS1_HM_HEADER_LENGTH;
1350 }
1351 s->init_num = (int)msglen;
1352 s->init_off = 0;
1353
1354 if (htype != DTLS1_MT_HELLO_VERIFY_REQUEST) {
1355 /* Buffer the message to handle re-xmits */
1356 if (!dtls1_buffer_message(s, htype == SSL3_MT_CHANGE_CIPHER_SPEC ? 1 : 0))
1357 return 0;
1358 }
1359
1360 return 1;
1361 }
1362