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 *s, size_t frag_off,
47 size_t frag_len);
48 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p);
49 static void dtls1_set_message_header_int(SSL *s, unsigned char mt,
50 size_t len,
51 unsigned short seq_num,
52 size_t frag_off,
53 size_t frag_len);
54 static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len);
55
dtls1_hm_fragment_new(size_t frag_len,int reassembly)56 static hm_fragment *dtls1_hm_fragment_new(size_t frag_len, int reassembly)
57 {
58 hm_fragment *frag = NULL;
59 unsigned char *buf = NULL;
60 unsigned char *bitmask = NULL;
61
62 if ((frag = OPENSSL_malloc(sizeof(*frag))) == NULL) {
63 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
64 return NULL;
65 }
66
67 if (frag_len) {
68 if ((buf = OPENSSL_malloc(frag_len)) == NULL) {
69 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
70 OPENSSL_free(frag);
71 return NULL;
72 }
73 }
74
75 /* zero length fragment gets zero frag->fragment */
76 frag->fragment = buf;
77
78 /* Initialize reassembly bitmask if necessary */
79 if (reassembly) {
80 bitmask = OPENSSL_zalloc(RSMBLY_BITMASK_SIZE(frag_len));
81 if (bitmask == NULL) {
82 ERR_raise(ERR_LIB_SSL, ERR_R_MALLOC_FAILURE);
83 OPENSSL_free(buf);
84 OPENSSL_free(frag);
85 return NULL;
86 }
87 }
88
89 frag->reassembly = bitmask;
90
91 return frag;
92 }
93
dtls1_hm_fragment_free(hm_fragment * frag)94 void dtls1_hm_fragment_free(hm_fragment *frag)
95 {
96 if (!frag)
97 return;
98 if (frag->msg_header.is_ccs) {
99 EVP_CIPHER_CTX_free(frag->msg_header.
100 saved_retransmit_state.enc_write_ctx);
101 EVP_MD_CTX_free(frag->msg_header.saved_retransmit_state.write_hash);
102 }
103 OPENSSL_free(frag->fragment);
104 OPENSSL_free(frag->reassembly);
105 OPENSSL_free(frag);
106 }
107
108 /*
109 * send s->init_buf in records of type 'type' (SSL3_RT_HANDSHAKE or
110 * SSL3_RT_CHANGE_CIPHER_SPEC)
111 */
dtls1_do_write(SSL * s,int type)112 int dtls1_do_write(SSL *s, int type)
113 {
114 int ret;
115 size_t written;
116 size_t curr_mtu;
117 int retry = 1;
118 size_t len, frag_off, mac_size, blocksize, used_len;
119
120 if (!dtls1_query_mtu(s))
121 return -1;
122
123 if (s->d1->mtu < dtls1_min_mtu(s))
124 /* should have something reasonable now */
125 return -1;
126
127 if (s->init_off == 0 && type == SSL3_RT_HANDSHAKE) {
128 if (!ossl_assert(s->init_num ==
129 s->d1->w_msg_hdr.msg_len + DTLS1_HM_HEADER_LENGTH))
130 return -1;
131 }
132
133 if (s->write_hash) {
134 if (s->enc_write_ctx
135 && (EVP_CIPHER_get_flags(EVP_CIPHER_CTX_get0_cipher(s->enc_write_ctx)) &
136 EVP_CIPH_FLAG_AEAD_CIPHER) != 0)
137 mac_size = 0;
138 else
139 mac_size = EVP_MD_CTX_get_size(s->write_hash);
140 } else
141 mac_size = 0;
142
143 if (s->enc_write_ctx &&
144 (EVP_CIPHER_CTX_get_mode(s->enc_write_ctx) == EVP_CIPH_CBC_MODE))
145 blocksize = 2 * EVP_CIPHER_CTX_get_block_size(s->enc_write_ctx);
146 else
147 blocksize = 0;
148
149 frag_off = 0;
150 s->rwstate = SSL_NOTHING;
151
152 /* s->init_num shouldn't ever be < 0...but just in case */
153 while (s->init_num > 0) {
154 if (type == SSL3_RT_HANDSHAKE && s->init_off != 0) {
155 /* We must be writing a fragment other than the first one */
156
157 if (frag_off > 0) {
158 /* This is the first attempt at writing out this fragment */
159
160 if (s->init_off <= DTLS1_HM_HEADER_LENGTH) {
161 /*
162 * Each fragment that was already sent must at least have
163 * contained the message header plus one other byte.
164 * Therefore |init_off| must have progressed by at least
165 * |DTLS1_HM_HEADER_LENGTH + 1| bytes. If not something went
166 * wrong.
167 */
168 return -1;
169 }
170
171 /*
172 * Adjust |init_off| and |init_num| to allow room for a new
173 * message header for this fragment.
174 */
175 s->init_off -= DTLS1_HM_HEADER_LENGTH;
176 s->init_num += DTLS1_HM_HEADER_LENGTH;
177 } else {
178 /*
179 * We must have been called again after a retry so use the
180 * fragment offset from our last attempt. We do not need
181 * to adjust |init_off| and |init_num| as above, because
182 * that should already have been done before the retry.
183 */
184 frag_off = s->d1->w_msg_hdr.frag_off;
185 }
186 }
187
188 used_len = BIO_wpending(s->wbio) + DTLS1_RT_HEADER_LENGTH
189 + mac_size + blocksize;
190 if (s->d1->mtu > used_len)
191 curr_mtu = s->d1->mtu - used_len;
192 else
193 curr_mtu = 0;
194
195 if (curr_mtu <= DTLS1_HM_HEADER_LENGTH) {
196 /*
197 * grr.. we could get an error if MTU picked was wrong
198 */
199 ret = BIO_flush(s->wbio);
200 if (ret <= 0) {
201 s->rwstate = SSL_WRITING;
202 return ret;
203 }
204 used_len = DTLS1_RT_HEADER_LENGTH + mac_size + blocksize;
205 if (s->d1->mtu > used_len + DTLS1_HM_HEADER_LENGTH) {
206 curr_mtu = s->d1->mtu - used_len;
207 } else {
208 /* Shouldn't happen */
209 return -1;
210 }
211 }
212
213 /*
214 * We just checked that s->init_num > 0 so this cast should be safe
215 */
216 if (((unsigned int)s->init_num) > curr_mtu)
217 len = curr_mtu;
218 else
219 len = s->init_num;
220
221 if (len > ssl_get_max_send_fragment(s))
222 len = ssl_get_max_send_fragment(s);
223
224 /*
225 * XDTLS: this function is too long. split out the CCS part
226 */
227 if (type == SSL3_RT_HANDSHAKE) {
228 if (len < DTLS1_HM_HEADER_LENGTH) {
229 /*
230 * len is so small that we really can't do anything sensible
231 * so fail
232 */
233 return -1;
234 }
235 dtls1_fix_message_header(s, frag_off, len - DTLS1_HM_HEADER_LENGTH);
236
237 dtls1_write_message_header(s,
238 (unsigned char *)&s->init_buf->
239 data[s->init_off]);
240 }
241
242 ret = dtls1_write_bytes(s, type, &s->init_buf->data[s->init_off], len,
243 &written);
244 if (ret <= 0) {
245 /*
246 * might need to update MTU here, but we don't know which
247 * previous packet caused the failure -- so can't really
248 * retransmit anything. continue as if everything is fine and
249 * wait for an alert to handle the retransmit
250 */
251 if (retry && BIO_ctrl(SSL_get_wbio(s),
252 BIO_CTRL_DGRAM_MTU_EXCEEDED, 0, NULL) > 0) {
253 if (!(SSL_get_options(s) & SSL_OP_NO_QUERY_MTU)) {
254 if (!dtls1_query_mtu(s))
255 return -1;
256 /* Have one more go */
257 retry = 0;
258 } else
259 return -1;
260 } else {
261 return -1;
262 }
263 } else {
264
265 /*
266 * bad if this assert fails, only part of the handshake message
267 * got sent. but why would this happen?
268 */
269 if (!ossl_assert(len == written))
270 return -1;
271
272 if (type == SSL3_RT_HANDSHAKE && !s->d1->retransmitting) {
273 /*
274 * should not be done for 'Hello Request's, but in that case
275 * we'll ignore the result anyway
276 */
277 unsigned char *p =
278 (unsigned char *)&s->init_buf->data[s->init_off];
279 const struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
280 size_t xlen;
281
282 if (frag_off == 0 && s->version != DTLS1_BAD_VER) {
283 /*
284 * reconstruct message header is if it is being sent in
285 * single fragment
286 */
287 *p++ = msg_hdr->type;
288 l2n3(msg_hdr->msg_len, p);
289 s2n(msg_hdr->seq, p);
290 l2n3(0, p);
291 l2n3(msg_hdr->msg_len, p);
292 p -= DTLS1_HM_HEADER_LENGTH;
293 xlen = written;
294 } else {
295 p += DTLS1_HM_HEADER_LENGTH;
296 xlen = written - DTLS1_HM_HEADER_LENGTH;
297 }
298
299 if (!ssl3_finish_mac(s, p, xlen))
300 return -1;
301 }
302
303 if (written == s->init_num) {
304 if (s->msg_callback)
305 s->msg_callback(1, s->version, type, s->init_buf->data,
306 (size_t)(s->init_off + s->init_num), s,
307 s->msg_callback_arg);
308
309 s->init_off = 0; /* done writing this message */
310 s->init_num = 0;
311
312 return 1;
313 }
314 s->init_off += written;
315 s->init_num -= written;
316 written -= DTLS1_HM_HEADER_LENGTH;
317 frag_off += written;
318
319 /*
320 * We save the fragment offset for the next fragment so we have it
321 * available in case of an IO retry. We don't know the length of the
322 * next fragment yet so just set that to 0 for now. It will be
323 * updated again later.
324 */
325 dtls1_fix_message_header(s, frag_off, 0);
326 }
327 }
328 return 0;
329 }
330
dtls_get_message(SSL * s,int * mt)331 int dtls_get_message(SSL *s, int *mt)
332 {
333 struct hm_header_st *msg_hdr;
334 unsigned char *p;
335 size_t msg_len;
336 size_t tmplen;
337 int errtype;
338
339 msg_hdr = &s->d1->r_msg_hdr;
340 memset(msg_hdr, 0, sizeof(*msg_hdr));
341
342 again:
343 if (!dtls_get_reassembled_message(s, &errtype, &tmplen)) {
344 if (errtype == DTLS1_HM_BAD_FRAGMENT
345 || errtype == DTLS1_HM_FRAGMENT_RETRY) {
346 /* bad fragment received */
347 goto again;
348 }
349 return 0;
350 }
351
352 *mt = s->s3.tmp.message_type;
353
354 p = (unsigned char *)s->init_buf->data;
355
356 if (*mt == SSL3_MT_CHANGE_CIPHER_SPEC) {
357 if (s->msg_callback) {
358 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
359 p, 1, s, s->msg_callback_arg);
360 }
361 /*
362 * This isn't a real handshake message so skip the processing below.
363 */
364 return 1;
365 }
366
367 msg_len = msg_hdr->msg_len;
368
369 /* reconstruct message header */
370 *(p++) = msg_hdr->type;
371 l2n3(msg_len, p);
372 s2n(msg_hdr->seq, p);
373 l2n3(0, p);
374 l2n3(msg_len, p);
375
376 memset(msg_hdr, 0, sizeof(*msg_hdr));
377
378 s->d1->handshake_read_seq++;
379
380 s->init_msg = s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
381
382 return 1;
383 }
384
385 /*
386 * Actually we already have the message body - but this is an opportunity for
387 * DTLS to do any further processing it wants at the same point that TLS would
388 * be asked for the message body.
389 */
dtls_get_message_body(SSL * s,size_t * len)390 int dtls_get_message_body(SSL *s, size_t *len)
391 {
392 unsigned char *msg = (unsigned char *)s->init_buf->data;
393 size_t msg_len = s->init_num + DTLS1_HM_HEADER_LENGTH;
394
395 if (s->s3.tmp.message_type == SSL3_MT_CHANGE_CIPHER_SPEC) {
396 /* Nothing to be done */
397 goto end;
398 }
399 /*
400 * If receiving Finished, record MAC of prior handshake messages for
401 * Finished verification.
402 */
403 if (*(s->init_buf->data) == SSL3_MT_FINISHED && !ssl3_take_mac(s)) {
404 /* SSLfatal() already called */
405 return 0;
406 }
407
408 if (s->version == DTLS1_BAD_VER) {
409 msg += DTLS1_HM_HEADER_LENGTH;
410 msg_len -= DTLS1_HM_HEADER_LENGTH;
411 }
412
413 if (!ssl3_finish_mac(s, msg, msg_len))
414 return 0;
415
416 if (s->msg_callback)
417 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
418 s->init_buf->data, s->init_num + DTLS1_HM_HEADER_LENGTH,
419 s, s->msg_callback_arg);
420
421 end:
422 *len = s->init_num;
423 return 1;
424 }
425
426 /*
427 * dtls1_max_handshake_message_len returns the maximum number of bytes
428 * permitted in a DTLS handshake message for |s|. The minimum is 16KB, but
429 * may be greater if the maximum certificate list size requires it.
430 */
dtls1_max_handshake_message_len(const SSL * s)431 static size_t dtls1_max_handshake_message_len(const SSL *s)
432 {
433 size_t max_len = DTLS1_HM_HEADER_LENGTH + SSL3_RT_MAX_ENCRYPTED_LENGTH;
434 if (max_len < s->max_cert_list)
435 return s->max_cert_list;
436 return max_len;
437 }
438
dtls1_preprocess_fragment(SSL * s,struct hm_header_st * msg_hdr)439 static int dtls1_preprocess_fragment(SSL *s, struct hm_header_st *msg_hdr)
440 {
441 size_t frag_off, frag_len, msg_len;
442
443 msg_len = msg_hdr->msg_len;
444 frag_off = msg_hdr->frag_off;
445 frag_len = msg_hdr->frag_len;
446
447 /* sanity checking */
448 if ((frag_off + frag_len) > msg_len
449 || msg_len > dtls1_max_handshake_message_len(s)) {
450 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
451 return 0;
452 }
453
454 if (s->d1->r_msg_hdr.frag_off == 0) { /* first fragment */
455 /*
456 * msg_len is limited to 2^24, but is effectively checked against
457 * dtls_max_handshake_message_len(s) above
458 */
459 if (!BUF_MEM_grow_clean(s->init_buf, msg_len + DTLS1_HM_HEADER_LENGTH)) {
460 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_BUF_LIB);
461 return 0;
462 }
463
464 s->s3.tmp.message_size = msg_len;
465 s->d1->r_msg_hdr.msg_len = msg_len;
466 s->s3.tmp.message_type = msg_hdr->type;
467 s->d1->r_msg_hdr.type = msg_hdr->type;
468 s->d1->r_msg_hdr.seq = msg_hdr->seq;
469 } else if (msg_len != s->d1->r_msg_hdr.msg_len) {
470 /*
471 * They must be playing with us! BTW, failure to enforce upper limit
472 * would open possibility for buffer overrun.
473 */
474 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_EXCESSIVE_MESSAGE_SIZE);
475 return 0;
476 }
477
478 return 1;
479 }
480
481 /*
482 * Returns 1 if there is a buffered fragment available, 0 if not, or -1 on a
483 * fatal error.
484 */
dtls1_retrieve_buffered_fragment(SSL * s,size_t * len)485 static int dtls1_retrieve_buffered_fragment(SSL *s, size_t *len)
486 {
487 /*-
488 * (0) check whether the desired fragment is available
489 * if so:
490 * (1) copy over the fragment to s->init_buf->data[]
491 * (2) update s->init_num
492 */
493 pitem *item;
494 piterator iter;
495 hm_fragment *frag;
496 int ret;
497 int chretran = 0;
498
499 iter = pqueue_iterator(s->d1->buffered_messages);
500 do {
501 item = pqueue_next(&iter);
502 if (item == NULL)
503 return 0;
504
505 frag = (hm_fragment *)item->data;
506
507 if (frag->msg_header.seq < s->d1->handshake_read_seq) {
508 pitem *next;
509 hm_fragment *nextfrag;
510
511 if (!s->server
512 || frag->msg_header.seq != 0
513 || s->d1->handshake_read_seq != 1
514 || s->statem.hand_state != DTLS_ST_SW_HELLO_VERIFY_REQUEST) {
515 /*
516 * This is a stale message that has been buffered so clear it.
517 * It is safe to pop this message from the queue even though
518 * we have an active iterator
519 */
520 pqueue_pop(s->d1->buffered_messages);
521 dtls1_hm_fragment_free(frag);
522 pitem_free(item);
523 item = NULL;
524 frag = NULL;
525 } else {
526 /*
527 * We have fragments for a ClientHello without a cookie,
528 * even though we have sent a HelloVerifyRequest. It is possible
529 * that the HelloVerifyRequest got lost and this is a
530 * retransmission of the original ClientHello
531 */
532 next = pqueue_next(&iter);
533 if (next != NULL) {
534 nextfrag = (hm_fragment *)next->data;
535 if (nextfrag->msg_header.seq == s->d1->handshake_read_seq) {
536 /*
537 * We have fragments for both a ClientHello without
538 * cookie and one with. Ditch the one without.
539 */
540 pqueue_pop(s->d1->buffered_messages);
541 dtls1_hm_fragment_free(frag);
542 pitem_free(item);
543 item = next;
544 frag = nextfrag;
545 } else {
546 chretran = 1;
547 }
548 } else {
549 chretran = 1;
550 }
551 }
552 }
553 } while (item == NULL);
554
555 /* Don't return if reassembly still in progress */
556 if (frag->reassembly != NULL)
557 return 0;
558
559 if (s->d1->handshake_read_seq == frag->msg_header.seq || chretran) {
560 size_t frag_len = frag->msg_header.frag_len;
561 pqueue_pop(s->d1->buffered_messages);
562
563 /* Calls SSLfatal() as required */
564 ret = dtls1_preprocess_fragment(s, &frag->msg_header);
565
566 if (ret && frag->msg_header.frag_len > 0) {
567 unsigned char *p =
568 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
569 memcpy(&p[frag->msg_header.frag_off], frag->fragment,
570 frag->msg_header.frag_len);
571 }
572
573 dtls1_hm_fragment_free(frag);
574 pitem_free(item);
575
576 if (ret) {
577 if (chretran) {
578 /*
579 * We got a new ClientHello with a message sequence of 0.
580 * Reset the read/write sequences back to the beginning.
581 * We process it like this is the first time we've seen a
582 * ClientHello from the client.
583 */
584 s->d1->handshake_read_seq = 0;
585 s->d1->next_handshake_write_seq = 0;
586 }
587 *len = frag_len;
588 return 1;
589 }
590
591 /* Fatal error */
592 s->init_num = 0;
593 return -1;
594 } else {
595 return 0;
596 }
597 }
598
599 static int
dtls1_reassemble_fragment(SSL * s,const struct hm_header_st * msg_hdr)600 dtls1_reassemble_fragment(SSL *s, const struct hm_header_st *msg_hdr)
601 {
602 hm_fragment *frag = NULL;
603 pitem *item = NULL;
604 int i = -1, is_complete;
605 unsigned char seq64be[8];
606 size_t frag_len = msg_hdr->frag_len;
607 size_t readbytes;
608
609 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len ||
610 msg_hdr->msg_len > dtls1_max_handshake_message_len(s))
611 goto err;
612
613 if (frag_len == 0) {
614 return DTLS1_HM_FRAGMENT_RETRY;
615 }
616
617 /* Try to find item in queue */
618 memset(seq64be, 0, sizeof(seq64be));
619 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
620 seq64be[7] = (unsigned char)msg_hdr->seq;
621 item = pqueue_find(s->d1->buffered_messages, seq64be);
622
623 if (item == NULL) {
624 frag = dtls1_hm_fragment_new(msg_hdr->msg_len, 1);
625 if (frag == NULL)
626 goto err;
627 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
628 frag->msg_header.frag_len = frag->msg_header.msg_len;
629 frag->msg_header.frag_off = 0;
630 } else {
631 frag = (hm_fragment *)item->data;
632 if (frag->msg_header.msg_len != msg_hdr->msg_len) {
633 item = NULL;
634 frag = NULL;
635 goto err;
636 }
637 }
638
639 /*
640 * If message is already reassembled, this must be a retransmit and can
641 * be dropped. In this case item != NULL and so frag does not need to be
642 * freed.
643 */
644 if (frag->reassembly == NULL) {
645 unsigned char devnull[256];
646
647 while (frag_len) {
648 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
649 devnull,
650 frag_len >
651 sizeof(devnull) ? sizeof(devnull) :
652 frag_len, 0, &readbytes);
653 if (i <= 0)
654 goto err;
655 frag_len -= readbytes;
656 }
657 return DTLS1_HM_FRAGMENT_RETRY;
658 }
659
660 /* read the body of the fragment (header has already been read */
661 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
662 frag->fragment + msg_hdr->frag_off,
663 frag_len, 0, &readbytes);
664 if (i <= 0 || readbytes != frag_len)
665 i = -1;
666 if (i <= 0)
667 goto err;
668
669 RSMBLY_BITMASK_MARK(frag->reassembly, (long)msg_hdr->frag_off,
670 (long)(msg_hdr->frag_off + frag_len));
671
672 if (!ossl_assert(msg_hdr->msg_len > 0))
673 goto err;
674 RSMBLY_BITMASK_IS_COMPLETE(frag->reassembly, (long)msg_hdr->msg_len,
675 is_complete);
676
677 if (is_complete) {
678 OPENSSL_free(frag->reassembly);
679 frag->reassembly = NULL;
680 }
681
682 if (item == NULL) {
683 item = pitem_new(seq64be, frag);
684 if (item == NULL) {
685 i = -1;
686 goto err;
687 }
688
689 item = pqueue_insert(s->d1->buffered_messages, item);
690 /*
691 * pqueue_insert fails iff a duplicate item is inserted. However,
692 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
693 * would have returned it and control would never have reached this
694 * branch.
695 */
696 if (!ossl_assert(item != NULL))
697 goto err;
698 }
699
700 return DTLS1_HM_FRAGMENT_RETRY;
701
702 err:
703 if (item == NULL)
704 dtls1_hm_fragment_free(frag);
705 return -1;
706 }
707
708 static int
dtls1_process_out_of_seq_message(SSL * s,const struct hm_header_st * msg_hdr)709 dtls1_process_out_of_seq_message(SSL *s, const struct hm_header_st *msg_hdr)
710 {
711 int i = -1;
712 hm_fragment *frag = NULL;
713 pitem *item = NULL;
714 unsigned char seq64be[8];
715 size_t frag_len = msg_hdr->frag_len;
716 size_t readbytes;
717
718 if ((msg_hdr->frag_off + frag_len) > msg_hdr->msg_len)
719 goto err;
720
721 /* Try to find item in queue, to prevent duplicate entries */
722 memset(seq64be, 0, sizeof(seq64be));
723 seq64be[6] = (unsigned char)(msg_hdr->seq >> 8);
724 seq64be[7] = (unsigned char)msg_hdr->seq;
725 item = pqueue_find(s->d1->buffered_messages, seq64be);
726
727 /*
728 * If we already have an entry and this one is a fragment, don't discard
729 * it and rather try to reassemble it.
730 */
731 if (item != NULL && frag_len != msg_hdr->msg_len)
732 item = NULL;
733
734 /*
735 * Discard the message if sequence number was already there, is too far
736 * in the future, already in the queue or if we received a FINISHED
737 * before the SERVER_HELLO, which then must be a stale retransmit.
738 */
739 if (msg_hdr->seq <= s->d1->handshake_read_seq ||
740 msg_hdr->seq > s->d1->handshake_read_seq + 10 || item != NULL ||
741 (s->d1->handshake_read_seq == 0 && msg_hdr->type == SSL3_MT_FINISHED)) {
742 unsigned char devnull[256];
743
744 while (frag_len) {
745 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
746 devnull,
747 frag_len >
748 sizeof(devnull) ? sizeof(devnull) :
749 frag_len, 0, &readbytes);
750 if (i <= 0)
751 goto err;
752 frag_len -= readbytes;
753 }
754 } else {
755 if (frag_len != msg_hdr->msg_len) {
756 return dtls1_reassemble_fragment(s, msg_hdr);
757 }
758
759 if (frag_len > dtls1_max_handshake_message_len(s))
760 goto err;
761
762 frag = dtls1_hm_fragment_new(frag_len, 0);
763 if (frag == NULL)
764 goto err;
765
766 memcpy(&(frag->msg_header), msg_hdr, sizeof(*msg_hdr));
767
768 if (frag_len) {
769 /*
770 * read the body of the fragment (header has already been read
771 */
772 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
773 frag->fragment, frag_len, 0,
774 &readbytes);
775 if (i<=0 || readbytes != frag_len)
776 i = -1;
777 if (i <= 0)
778 goto err;
779 }
780
781 item = pitem_new(seq64be, frag);
782 if (item == NULL)
783 goto err;
784
785 item = pqueue_insert(s->d1->buffered_messages, item);
786 /*
787 * pqueue_insert fails iff a duplicate item is inserted. However,
788 * |item| cannot be a duplicate. If it were, |pqueue_find|, above,
789 * would have returned it. Then, either |frag_len| !=
790 * |msg_hdr->msg_len| in which case |item| is set to NULL and it will
791 * have been processed with |dtls1_reassemble_fragment|, above, or
792 * the record will have been discarded.
793 */
794 if (!ossl_assert(item != NULL))
795 goto err;
796 }
797
798 return DTLS1_HM_FRAGMENT_RETRY;
799
800 err:
801 if (item == NULL)
802 dtls1_hm_fragment_free(frag);
803 return 0;
804 }
805
dtls_get_reassembled_message(SSL * s,int * errtype,size_t * len)806 static int dtls_get_reassembled_message(SSL *s, int *errtype, size_t *len)
807 {
808 unsigned char wire[DTLS1_HM_HEADER_LENGTH];
809 size_t mlen, frag_off, frag_len;
810 int i, ret, recvd_type;
811 struct hm_header_st msg_hdr;
812 size_t readbytes;
813 int chretran = 0;
814
815 *errtype = 0;
816
817 redo:
818 /* see if we have the required fragment already */
819 ret = dtls1_retrieve_buffered_fragment(s, &frag_len);
820 if (ret < 0) {
821 /* SSLfatal() already called */
822 return 0;
823 }
824 if (ret > 0) {
825 s->init_num = frag_len;
826 *len = frag_len;
827 return 1;
828 }
829
830 /* read handshake message header */
831 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, &recvd_type, wire,
832 DTLS1_HM_HEADER_LENGTH, 0, &readbytes);
833 if (i <= 0) { /* nbio, or an error */
834 s->rwstate = SSL_READING;
835 *len = 0;
836 return 0;
837 }
838 if (recvd_type == SSL3_RT_CHANGE_CIPHER_SPEC) {
839 if (wire[0] != SSL3_MT_CCS) {
840 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE,
841 SSL_R_BAD_CHANGE_CIPHER_SPEC);
842 goto f_err;
843 }
844
845 memcpy(s->init_buf->data, wire, readbytes);
846 s->init_num = readbytes - 1;
847 s->init_msg = s->init_buf->data + 1;
848 s->s3.tmp.message_type = SSL3_MT_CHANGE_CIPHER_SPEC;
849 s->s3.tmp.message_size = readbytes - 1;
850 *len = readbytes - 1;
851 return 1;
852 }
853
854 /* Handshake fails if message header is incomplete */
855 if (readbytes != DTLS1_HM_HEADER_LENGTH) {
856 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
857 goto f_err;
858 }
859
860 /* parse the message fragment header */
861 dtls1_get_message_header(wire, &msg_hdr);
862
863 mlen = msg_hdr.msg_len;
864 frag_off = msg_hdr.frag_off;
865 frag_len = msg_hdr.frag_len;
866
867 /*
868 * We must have at least frag_len bytes left in the record to be read.
869 * Fragments must not span records.
870 */
871 if (frag_len > RECORD_LAYER_get_rrec_length(&s->rlayer)) {
872 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH);
873 goto f_err;
874 }
875
876 /*
877 * if this is a future (or stale) message it gets buffered
878 * (or dropped)--no further processing at this time
879 * While listening, we accept seq 1 (ClientHello with cookie)
880 * although we're still expecting seq 0 (ClientHello)
881 */
882 if (msg_hdr.seq != s->d1->handshake_read_seq) {
883 if (!s->server
884 || msg_hdr.seq != 0
885 || s->d1->handshake_read_seq != 1
886 || wire[0] != SSL3_MT_CLIENT_HELLO
887 || s->statem.hand_state != DTLS_ST_SW_HELLO_VERIFY_REQUEST) {
888 *errtype = dtls1_process_out_of_seq_message(s, &msg_hdr);
889 return 0;
890 }
891 /*
892 * We received a ClientHello and sent back a HelloVerifyRequest. We
893 * now seem to have received a retransmitted initial ClientHello. That
894 * is allowed (possibly our HelloVerifyRequest got lost).
895 */
896 chretran = 1;
897 }
898
899 if (frag_len && frag_len < mlen) {
900 *errtype = dtls1_reassemble_fragment(s, &msg_hdr);
901 return 0;
902 }
903
904 if (!s->server
905 && s->d1->r_msg_hdr.frag_off == 0
906 && s->statem.hand_state != TLS_ST_OK
907 && wire[0] == SSL3_MT_HELLO_REQUEST) {
908 /*
909 * The server may always send 'Hello Request' messages -- we are
910 * doing a handshake anyway now, so ignore them if their format is
911 * correct. Does not count for 'Finished' MAC.
912 */
913 if (wire[1] == 0 && wire[2] == 0 && wire[3] == 0) {
914 if (s->msg_callback)
915 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
916 wire, DTLS1_HM_HEADER_LENGTH, s,
917 s->msg_callback_arg);
918
919 s->init_num = 0;
920 goto redo;
921 } else { /* Incorrectly formatted Hello request */
922
923 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
924 goto f_err;
925 }
926 }
927
928 if (!dtls1_preprocess_fragment(s, &msg_hdr)) {
929 /* SSLfatal() already called */
930 goto f_err;
931 }
932
933 if (frag_len > 0) {
934 unsigned char *p =
935 (unsigned char *)s->init_buf->data + DTLS1_HM_HEADER_LENGTH;
936
937 i = s->method->ssl_read_bytes(s, SSL3_RT_HANDSHAKE, NULL,
938 &p[frag_off], frag_len, 0, &readbytes);
939
940 /*
941 * This shouldn't ever fail due to NBIO because we already checked
942 * that we have enough data in the record
943 */
944 if (i <= 0) {
945 s->rwstate = SSL_READING;
946 *len = 0;
947 return 0;
948 }
949 } else {
950 readbytes = 0;
951 }
952
953 /*
954 * XDTLS: an incorrectly formatted fragment should cause the handshake
955 * to fail
956 */
957 if (readbytes != frag_len) {
958 SSLfatal(s, SSL_AD_ILLEGAL_PARAMETER, SSL_R_BAD_LENGTH);
959 goto f_err;
960 }
961
962 if (chretran) {
963 /*
964 * We got a new ClientHello with a message sequence of 0.
965 * Reset the read/write sequences back to the beginning.
966 * We process it like this is the first time we've seen a ClientHello
967 * from the client.
968 */
969 s->d1->handshake_read_seq = 0;
970 s->d1->next_handshake_write_seq = 0;
971 }
972
973 /*
974 * Note that s->init_num is *not* used as current offset in
975 * s->init_buf->data, but as a counter summing up fragments' lengths: as
976 * soon as they sum up to handshake packet length, we assume we have got
977 * all the fragments.
978 */
979 *len = s->init_num = frag_len;
980 return 1;
981
982 f_err:
983 s->init_num = 0;
984 *len = 0;
985 return 0;
986 }
987
988 /*-
989 * for these 2 messages, we need to
990 * ssl->enc_read_ctx re-init
991 * ssl->rlayer.read_sequence zero
992 * ssl->s3.read_mac_secret re-init
993 * ssl->session->read_sym_enc assign
994 * ssl->session->read_compression assign
995 * ssl->session->read_hash assign
996 */
dtls_construct_change_cipher_spec(SSL * s,WPACKET * pkt)997 int dtls_construct_change_cipher_spec(SSL *s, WPACKET *pkt)
998 {
999 if (s->version == DTLS1_BAD_VER) {
1000 s->d1->next_handshake_write_seq++;
1001
1002 if (!WPACKET_put_bytes_u16(pkt, s->d1->handshake_write_seq)) {
1003 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1004 return 0;
1005 }
1006 }
1007
1008 return 1;
1009 }
1010
1011 #ifndef OPENSSL_NO_SCTP
1012 /*
1013 * Wait for a dry event. Should only be called at a point in the handshake
1014 * where we are not expecting any data from the peer except an alert.
1015 */
dtls_wait_for_dry(SSL * s)1016 WORK_STATE dtls_wait_for_dry(SSL *s)
1017 {
1018 int ret, errtype;
1019 size_t len;
1020
1021 /* read app data until dry event */
1022 ret = BIO_dgram_sctp_wait_for_dry(SSL_get_wbio(s));
1023 if (ret < 0) {
1024 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1025 return WORK_ERROR;
1026 }
1027
1028 if (ret == 0) {
1029 /*
1030 * We're not expecting any more messages from the peer at this point -
1031 * but we could get an alert. If an alert is waiting then we will never
1032 * return successfully. Therefore we attempt to read a message. This
1033 * should never succeed but will process any waiting alerts.
1034 */
1035 if (dtls_get_reassembled_message(s, &errtype, &len)) {
1036 /* The call succeeded! This should never happen */
1037 SSLfatal(s, SSL_AD_UNEXPECTED_MESSAGE, SSL_R_UNEXPECTED_MESSAGE);
1038 return WORK_ERROR;
1039 }
1040
1041 s->s3.in_read_app_data = 2;
1042 s->rwstate = SSL_READING;
1043 BIO_clear_retry_flags(SSL_get_rbio(s));
1044 BIO_set_retry_read(SSL_get_rbio(s));
1045 return WORK_MORE_A;
1046 }
1047 return WORK_FINISHED_CONTINUE;
1048 }
1049 #endif
1050
dtls1_read_failed(SSL * s,int code)1051 int dtls1_read_failed(SSL *s, int code)
1052 {
1053 if (code > 0) {
1054 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1055 return 0;
1056 }
1057
1058 if (!dtls1_is_timer_expired(s) || ossl_statem_in_error(s)) {
1059 /*
1060 * not a timeout, none of our business, let higher layers handle
1061 * this. in fact it's probably an error
1062 */
1063 return code;
1064 }
1065 /* done, no need to send a retransmit */
1066 if (!SSL_in_init(s))
1067 {
1068 BIO_set_flags(SSL_get_rbio(s), BIO_FLAGS_READ);
1069 return code;
1070 }
1071
1072 return dtls1_handle_timeout(s);
1073 }
1074
dtls1_get_queue_priority(unsigned short seq,int is_ccs)1075 int dtls1_get_queue_priority(unsigned short seq, int is_ccs)
1076 {
1077 /*
1078 * The index of the retransmission queue actually is the message sequence
1079 * number, since the queue only contains messages of a single handshake.
1080 * However, the ChangeCipherSpec has no message sequence number and so
1081 * using only the sequence will result in the CCS and Finished having the
1082 * same index. To prevent this, the sequence number is multiplied by 2.
1083 * In case of a CCS 1 is subtracted. This does not only differ CSS and
1084 * Finished, it also maintains the order of the index (important for
1085 * priority queues) and fits in the unsigned short variable.
1086 */
1087 return seq * 2 - is_ccs;
1088 }
1089
dtls1_retransmit_buffered_messages(SSL * s)1090 int dtls1_retransmit_buffered_messages(SSL *s)
1091 {
1092 pqueue *sent = s->d1->sent_messages;
1093 piterator iter;
1094 pitem *item;
1095 hm_fragment *frag;
1096 int found = 0;
1097
1098 iter = pqueue_iterator(sent);
1099
1100 for (item = pqueue_next(&iter); item != NULL; item = pqueue_next(&iter)) {
1101 frag = (hm_fragment *)item->data;
1102 if (dtls1_retransmit_message(s, (unsigned short)
1103 dtls1_get_queue_priority
1104 (frag->msg_header.seq,
1105 frag->msg_header.is_ccs), &found) <= 0)
1106 return -1;
1107 }
1108
1109 return 1;
1110 }
1111
dtls1_buffer_message(SSL * s,int is_ccs)1112 int dtls1_buffer_message(SSL *s, int is_ccs)
1113 {
1114 pitem *item;
1115 hm_fragment *frag;
1116 unsigned char seq64be[8];
1117
1118 /*
1119 * this function is called immediately after a message has been
1120 * serialized
1121 */
1122 if (!ossl_assert(s->init_off == 0))
1123 return 0;
1124
1125 frag = dtls1_hm_fragment_new(s->init_num, 0);
1126 if (frag == NULL)
1127 return 0;
1128
1129 memcpy(frag->fragment, s->init_buf->data, s->init_num);
1130
1131 if (is_ccs) {
1132 /* For DTLS1_BAD_VER the header length is non-standard */
1133 if (!ossl_assert(s->d1->w_msg_hdr.msg_len +
1134 ((s->version ==
1135 DTLS1_BAD_VER) ? 3 : DTLS1_CCS_HEADER_LENGTH)
1136 == (unsigned int)s->init_num)) {
1137 dtls1_hm_fragment_free(frag);
1138 return 0;
1139 }
1140 } else {
1141 if (!ossl_assert(s->d1->w_msg_hdr.msg_len +
1142 DTLS1_HM_HEADER_LENGTH == (unsigned int)s->init_num)) {
1143 dtls1_hm_fragment_free(frag);
1144 return 0;
1145 }
1146 }
1147
1148 frag->msg_header.msg_len = s->d1->w_msg_hdr.msg_len;
1149 frag->msg_header.seq = s->d1->w_msg_hdr.seq;
1150 frag->msg_header.type = s->d1->w_msg_hdr.type;
1151 frag->msg_header.frag_off = 0;
1152 frag->msg_header.frag_len = s->d1->w_msg_hdr.msg_len;
1153 frag->msg_header.is_ccs = is_ccs;
1154
1155 /* save current state */
1156 frag->msg_header.saved_retransmit_state.enc_write_ctx = s->enc_write_ctx;
1157 frag->msg_header.saved_retransmit_state.write_hash = s->write_hash;
1158 frag->msg_header.saved_retransmit_state.compress = s->compress;
1159 frag->msg_header.saved_retransmit_state.session = s->session;
1160 frag->msg_header.saved_retransmit_state.epoch =
1161 DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1162
1163 memset(seq64be, 0, sizeof(seq64be));
1164 seq64be[6] =
1165 (unsigned
1166 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1167 frag->msg_header.is_ccs) >> 8);
1168 seq64be[7] =
1169 (unsigned
1170 char)(dtls1_get_queue_priority(frag->msg_header.seq,
1171 frag->msg_header.is_ccs));
1172
1173 item = pitem_new(seq64be, frag);
1174 if (item == NULL) {
1175 dtls1_hm_fragment_free(frag);
1176 return 0;
1177 }
1178
1179 pqueue_insert(s->d1->sent_messages, item);
1180 return 1;
1181 }
1182
dtls1_retransmit_message(SSL * s,unsigned short seq,int * found)1183 int dtls1_retransmit_message(SSL *s, unsigned short seq, int *found)
1184 {
1185 int ret;
1186 /* XDTLS: for now assuming that read/writes are blocking */
1187 pitem *item;
1188 hm_fragment *frag;
1189 unsigned long header_length;
1190 unsigned char seq64be[8];
1191 struct dtls1_retransmit_state saved_state;
1192
1193 /* XDTLS: the requested message ought to be found, otherwise error */
1194 memset(seq64be, 0, sizeof(seq64be));
1195 seq64be[6] = (unsigned char)(seq >> 8);
1196 seq64be[7] = (unsigned char)seq;
1197
1198 item = pqueue_find(s->d1->sent_messages, seq64be);
1199 if (item == NULL) {
1200 SSLfatal(s, SSL_AD_INTERNAL_ERROR, ERR_R_INTERNAL_ERROR);
1201 *found = 0;
1202 return 0;
1203 }
1204
1205 *found = 1;
1206 frag = (hm_fragment *)item->data;
1207
1208 if (frag->msg_header.is_ccs)
1209 header_length = DTLS1_CCS_HEADER_LENGTH;
1210 else
1211 header_length = DTLS1_HM_HEADER_LENGTH;
1212
1213 memcpy(s->init_buf->data, frag->fragment,
1214 frag->msg_header.msg_len + header_length);
1215 s->init_num = frag->msg_header.msg_len + header_length;
1216
1217 dtls1_set_message_header_int(s, frag->msg_header.type,
1218 frag->msg_header.msg_len,
1219 frag->msg_header.seq, 0,
1220 frag->msg_header.frag_len);
1221
1222 /* save current state */
1223 saved_state.enc_write_ctx = s->enc_write_ctx;
1224 saved_state.write_hash = s->write_hash;
1225 saved_state.compress = s->compress;
1226 saved_state.session = s->session;
1227 saved_state.epoch = DTLS_RECORD_LAYER_get_w_epoch(&s->rlayer);
1228
1229 s->d1->retransmitting = 1;
1230
1231 /* restore state in which the message was originally sent */
1232 s->enc_write_ctx = frag->msg_header.saved_retransmit_state.enc_write_ctx;
1233 s->write_hash = frag->msg_header.saved_retransmit_state.write_hash;
1234 s->compress = frag->msg_header.saved_retransmit_state.compress;
1235 s->session = frag->msg_header.saved_retransmit_state.session;
1236 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer,
1237 frag->msg_header.
1238 saved_retransmit_state.epoch);
1239
1240 ret = dtls1_do_write(s, frag->msg_header.is_ccs ?
1241 SSL3_RT_CHANGE_CIPHER_SPEC : SSL3_RT_HANDSHAKE);
1242
1243 /* restore current state */
1244 s->enc_write_ctx = saved_state.enc_write_ctx;
1245 s->write_hash = saved_state.write_hash;
1246 s->compress = saved_state.compress;
1247 s->session = saved_state.session;
1248 DTLS_RECORD_LAYER_set_saved_w_epoch(&s->rlayer, saved_state.epoch);
1249
1250 s->d1->retransmitting = 0;
1251
1252 (void)BIO_flush(s->wbio);
1253 return ret;
1254 }
1255
dtls1_set_message_header(SSL * s,unsigned char mt,size_t len,size_t frag_off,size_t frag_len)1256 void dtls1_set_message_header(SSL *s,
1257 unsigned char mt, size_t len,
1258 size_t frag_off, size_t frag_len)
1259 {
1260 if (frag_off == 0) {
1261 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1262 s->d1->next_handshake_write_seq++;
1263 }
1264
1265 dtls1_set_message_header_int(s, mt, len, s->d1->handshake_write_seq,
1266 frag_off, frag_len);
1267 }
1268
1269 /* don't actually do the writing, wait till the MTU has been retrieved */
1270 static void
dtls1_set_message_header_int(SSL * s,unsigned char mt,size_t len,unsigned short seq_num,size_t frag_off,size_t frag_len)1271 dtls1_set_message_header_int(SSL *s, unsigned char mt,
1272 size_t len, unsigned short seq_num,
1273 size_t frag_off, size_t frag_len)
1274 {
1275 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1276
1277 msg_hdr->type = mt;
1278 msg_hdr->msg_len = len;
1279 msg_hdr->seq = seq_num;
1280 msg_hdr->frag_off = frag_off;
1281 msg_hdr->frag_len = frag_len;
1282 }
1283
1284 static void
dtls1_fix_message_header(SSL * s,size_t frag_off,size_t frag_len)1285 dtls1_fix_message_header(SSL *s, size_t frag_off, size_t frag_len)
1286 {
1287 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1288
1289 msg_hdr->frag_off = frag_off;
1290 msg_hdr->frag_len = frag_len;
1291 }
1292
dtls1_write_message_header(SSL * s,unsigned char * p)1293 static unsigned char *dtls1_write_message_header(SSL *s, unsigned char *p)
1294 {
1295 struct hm_header_st *msg_hdr = &s->d1->w_msg_hdr;
1296
1297 *p++ = msg_hdr->type;
1298 l2n3(msg_hdr->msg_len, p);
1299
1300 s2n(msg_hdr->seq, p);
1301 l2n3(msg_hdr->frag_off, p);
1302 l2n3(msg_hdr->frag_len, p);
1303
1304 return p;
1305 }
1306
dtls1_get_message_header(unsigned char * data,struct hm_header_st * msg_hdr)1307 void dtls1_get_message_header(unsigned char *data, struct hm_header_st *msg_hdr)
1308 {
1309 memset(msg_hdr, 0, sizeof(*msg_hdr));
1310 msg_hdr->type = *(data++);
1311 n2l3(data, msg_hdr->msg_len);
1312
1313 n2s(data, msg_hdr->seq);
1314 n2l3(data, msg_hdr->frag_off);
1315 n2l3(data, msg_hdr->frag_len);
1316 }
1317
dtls1_set_handshake_header(SSL * s,WPACKET * pkt,int htype)1318 int dtls1_set_handshake_header(SSL *s, WPACKET *pkt, int htype)
1319 {
1320 unsigned char *header;
1321
1322 if (htype == SSL3_MT_CHANGE_CIPHER_SPEC) {
1323 s->d1->handshake_write_seq = s->d1->next_handshake_write_seq;
1324 dtls1_set_message_header_int(s, SSL3_MT_CCS, 0,
1325 s->d1->handshake_write_seq, 0, 0);
1326 if (!WPACKET_put_bytes_u8(pkt, SSL3_MT_CCS))
1327 return 0;
1328 } else {
1329 dtls1_set_message_header(s, htype, 0, 0, 0);
1330 /*
1331 * We allocate space at the start for the message header. This gets
1332 * filled in later
1333 */
1334 if (!WPACKET_allocate_bytes(pkt, DTLS1_HM_HEADER_LENGTH, &header)
1335 || !WPACKET_start_sub_packet(pkt))
1336 return 0;
1337 }
1338
1339 return 1;
1340 }
1341
dtls1_close_construct_packet(SSL * s,WPACKET * pkt,int htype)1342 int dtls1_close_construct_packet(SSL *s, WPACKET *pkt, int htype)
1343 {
1344 size_t msglen;
1345
1346 if ((htype != SSL3_MT_CHANGE_CIPHER_SPEC && !WPACKET_close(pkt))
1347 || !WPACKET_get_length(pkt, &msglen)
1348 || msglen > INT_MAX)
1349 return 0;
1350
1351 if (htype != SSL3_MT_CHANGE_CIPHER_SPEC) {
1352 s->d1->w_msg_hdr.msg_len = msglen - DTLS1_HM_HEADER_LENGTH;
1353 s->d1->w_msg_hdr.frag_len = msglen - DTLS1_HM_HEADER_LENGTH;
1354 }
1355 s->init_num = (int)msglen;
1356 s->init_off = 0;
1357
1358 if (htype != DTLS1_MT_HELLO_VERIFY_REQUEST) {
1359 /* Buffer the message to handle re-xmits */
1360 if (!dtls1_buffer_message(s, htype == SSL3_MT_CHANGE_CIPHER_SPEC
1361 ? 1 : 0))
1362 return 0;
1363 }
1364
1365 return 1;
1366 }
1367