3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@openssl.org.
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
62 * This package is an SSL implementation written
63 * by Eric Young (eay@cryptsoft.com).
64 * The implementation was written so as to conform with Netscapes SSL.
66 * This library is free for commercial and non-commercial use as long as
67 * the following conditions are aheared to. The following conditions
68 * apply to all code found in this distribution, be it the RC4, RSA,
69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
70 * included with this distribution is covered by the same copyright terms
71 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
73 * Copyright remains Eric Young's, and as such any Copyright notices in
74 * the code are not to be removed.
75 * If this package is used in a product, Eric Young should be given attribution
76 * as the author of the parts of the library used.
77 * This can be in the form of a textual message at program startup or
78 * in documentation (online or textual) provided with the package.
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
83 * 1. Redistributions of source code must retain the copyright
84 * notice, this list of conditions and the following disclaimer.
85 * 2. Redistributions in binary form must reproduce the above copyright
86 * notice, this list of conditions and the following disclaimer in the
87 * documentation and/or other materials provided with the distribution.
88 * 3. All advertising materials mentioning features or use of this software
89 * must display the following acknowledgement:
90 * "This product includes cryptographic software written by
91 * Eric Young (eay@cryptsoft.com)"
92 * The word 'cryptographic' can be left out if the rouines from the library
93 * being used are not cryptographic related :-).
94 * 4. If you include any Windows specific code (or a derivative thereof) from
95 * the apps directory (application code) you must include an acknowledgement:
96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
110 * The licence and distribution terms for any publically available version or
111 * derivative of this code cannot be changed. i.e. this code cannot simply be
112 * copied and put under another distribution licence
113 * [including the GNU Public Licence.]
119 #include "../ssl_locl.h"
120 #include <openssl/evp.h>
121 #include <openssl/buffer.h>
122 #include <openssl/pqueue.h>
123 #include <openssl/rand.h>
125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
126 static int satsub64be(const unsigned char *v1, const unsigned char *v2)
128 int ret, sat, brw, i;
130 if (sizeof(long) == 8)
140 if (is_endian.little)
142 /* not reached on little-endians */
144 * following test is redundant, because input is always aligned,
145 * but I take no chances...
147 if (((size_t)v1 | (size_t)v2) & 0x7)
160 ret = (int)v1[7] - (int)v2[7];
162 brw = ret >> 8; /* brw is either 0 or -1 */
164 for (i = 6; i >= 0; i--) {
165 brw += (int)v1[i] - (int)v2[i];
170 for (i = 6; i >= 0; i--) {
171 brw += (int)v1[i] - (int)v2[i];
176 brw <<= 8; /* brw is either 0 or -256 */
181 return brw + (ret & 0xFF);
184 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
187 /* copy buffered record into SSL structure */
188 static int dtls1_copy_record(SSL *s, pitem *item)
190 DTLS1_RECORD_DATA *rdata;
192 rdata = (DTLS1_RECORD_DATA *)item->data;
194 SSL3_BUFFER_release(&s->rlayer.rbuf);
196 s->packet = rdata->packet;
197 s->packet_length = rdata->packet_length;
198 memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER));
199 memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD));
201 /* Set proper sequence number for mac calculation */
202 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
208 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
210 DTLS1_RECORD_DATA *rdata;
213 /* Limit the size of the queue to prevent DOS attacks */
214 if (pqueue_size(queue->q) >= 100)
217 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
218 item = pitem_new(priority, rdata);
219 if (rdata == NULL || item == NULL) {
225 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
229 rdata->packet = s->packet;
230 rdata->packet_length = s->packet_length;
231 memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER));
232 memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD));
236 #ifndef OPENSSL_NO_SCTP
237 /* Store bio_dgram_sctp_rcvinfo struct */
238 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
239 (s->state == SSL3_ST_SR_FINISHED_A
240 || s->state == SSL3_ST_CR_FINISHED_A)) {
241 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
242 sizeof(rdata->recordinfo), &rdata->recordinfo);
247 s->packet_length = 0;
248 memset(&s->rlayer.rbuf, 0, sizeof(SSL3_BUFFER));
249 memset(&s->rlayer.rrec, 0, sizeof(SSL3_RECORD));
251 if (!ssl3_setup_buffers(s)) {
252 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
253 if (rdata->rbuf.buf != NULL)
254 OPENSSL_free(rdata->rbuf.buf);
260 /* insert should not fail, since duplicates are dropped */
261 if (pqueue_insert(queue->q, item) == NULL) {
262 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
263 if (rdata->rbuf.buf != NULL)
264 OPENSSL_free(rdata->rbuf.buf);
273 int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
277 item = pqueue_pop(queue->q);
279 dtls1_copy_record(s, item);
281 OPENSSL_free(item->data);
291 * retrieve a buffered record that belongs to the new epoch, i.e., not
294 #define dtls1_get_unprocessed_record(s) \
295 dtls1_retrieve_buffered_record((s), \
296 &((s)->d1->unprocessed_rcds))
299 int dtls1_process_buffered_records(SSL *s)
303 item = pqueue_peek(s->d1->unprocessed_rcds.q);
305 /* Check if epoch is current. */
306 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
307 return (1); /* Nothing to do. */
309 /* Process all the records. */
310 while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
311 dtls1_get_unprocessed_record(s);
312 if (!dtls1_process_record(s))
314 if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
315 SSL3_RECORD_get_seq_num(&s->rlayer.rrec)) < 0)
321 * sync epoch numbers once all the unprocessed records have been
324 s->d1->processed_rcds.epoch = s->d1->r_epoch;
325 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
332 * Return up to 'len' payload bytes received in 'type' records.
333 * 'type' is one of the following:
335 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
336 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
337 * - 0 (during a shutdown, no data has to be returned)
339 * If we don't have stored data to work from, read a SSL/TLS record first
340 * (possibly multiple records if we still don't have anything to return).
342 * This function must handle any surprises the peer may have for us, such as
343 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
344 * a surprise, but handled as if it were), or renegotiation requests.
345 * Also if record payloads contain fragments too small to process, we store
346 * them until there is enough for the respective protocol (the record protocol
347 * may use arbitrary fragmentation and even interleaving):
348 * Change cipher spec protocol
349 * just 1 byte needed, no need for keeping anything stored
351 * 2 bytes needed (AlertLevel, AlertDescription)
353 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
354 * to detect unexpected Client Hello and Hello Request messages
355 * here, anything else is handled by higher layers
356 * Application data protocol
357 * none of our business
359 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
364 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
366 if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
367 /* Not initialized yet */
368 if (!ssl3_setup_buffers(s))
372 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
373 (type != SSL3_RT_HANDSHAKE)) ||
374 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
375 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
380 * check whether there's a handshake message (client hello?) waiting
382 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
386 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
389 #ifndef OPENSSL_NO_SCTP
391 * Continue handshake if it had to be interrupted to read app data with
394 if ((!s->in_handshake && SSL_in_init(s)) ||
395 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
396 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
397 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
398 && s->s3->in_read_app_data != 2))
400 if (!s->in_handshake && SSL_in_init(s))
403 /* type == SSL3_RT_APPLICATION_DATA */
404 i = s->handshake_func(s);
408 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
414 s->rwstate = SSL_NOTHING;
417 * s->s3->rrec.type - is the type of record
418 * s->s3->rrec.data, - data
419 * s->s3->rrec.off, - offset into 'data' for next read
420 * s->s3->rrec.length, - number of bytes.
422 rr = &s->rlayer.rrec;
425 * We are not handshaking and have no data yet, so process data buffered
426 * during the last handshake in advance, if any.
428 if (s->state == SSL_ST_OK && rr->length == 0) {
430 item = pqueue_pop(s->d1->buffered_app_data.q);
432 #ifndef OPENSSL_NO_SCTP
433 /* Restore bio_dgram_sctp_rcvinfo struct */
434 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
435 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
436 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
437 sizeof(rdata->recordinfo), &rdata->recordinfo);
441 dtls1_copy_record(s, item);
443 OPENSSL_free(item->data);
448 /* Check for timeout */
449 if (dtls1_handle_timeout(s) > 0)
452 /* get new packet if necessary */
453 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) {
454 ret = dtls1_get_record(s);
456 ret = dtls1_read_failed(s, ret);
457 /* anything other than a timeout is an error */
465 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
470 /* we now have a packet which can be read and processed */
472 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
473 * reset by ssl3_get_finished */
474 && (rr->type != SSL3_RT_HANDSHAKE)) {
476 * We now have application data between CCS and Finished. Most likely
477 * the packets were reordered on their way, so buffer the application
478 * data for later processing rather than dropping the connection.
480 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) <
482 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
490 * If the other end has shut down, throw anything we read away (even in
493 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
495 s->rwstate = SSL_NOTHING;
499 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or
500 * SSL3_RT_HANDSHAKE */
502 * make sure that we are not getting application data when we are
503 * doing a handshake for the first time
505 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
506 (s->enc_read_ctx == NULL)) {
507 al = SSL_AD_UNEXPECTED_MESSAGE;
508 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
515 if ((unsigned int)len > rr->length)
518 n = (unsigned int)len;
520 memcpy(buf, &(rr->data[rr->off]), n);
524 if (rr->length == 0) {
525 s->rstate = SSL_ST_READ_HEADER;
529 #ifndef OPENSSL_NO_SCTP
531 * We were about to renegotiate but had to read belated application
532 * data first, so retry.
534 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
535 rr->type == SSL3_RT_APPLICATION_DATA &&
536 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
537 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
538 s->rwstate = SSL_READING;
539 BIO_clear_retry_flags(SSL_get_rbio(s));
540 BIO_set_retry_read(SSL_get_rbio(s));
544 * We might had to delay a close_notify alert because of reordered
545 * app data. If there was an alert and there is no message to read
546 * anymore, finally set shutdown.
548 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
549 s->d1->shutdown_received
550 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
551 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
559 * If we get here, then type != rr->type; if we have a handshake message,
560 * then it was unexpected (Hello Request or Client Hello).
564 * In case of record types for which we have 'fragment' storage, fill
565 * that so that we can process the data at a fixed place.
568 unsigned int k, dest_maxlen = 0;
569 unsigned char *dest = NULL;
570 unsigned int *dest_len = NULL;
572 if (rr->type == SSL3_RT_HANDSHAKE) {
573 dest_maxlen = sizeof s->d1->handshake_fragment;
574 dest = s->d1->handshake_fragment;
575 dest_len = &s->d1->handshake_fragment_len;
576 } else if (rr->type == SSL3_RT_ALERT) {
577 dest_maxlen = sizeof(s->d1->alert_fragment);
578 dest = s->d1->alert_fragment;
579 dest_len = &s->d1->alert_fragment_len;
581 #ifndef OPENSSL_NO_HEARTBEATS
582 else if (rr->type == TLS1_RT_HEARTBEAT) {
583 /* We allow a 0 return */
584 if(dtls1_process_heartbeat(s, SSL3_RECORD_get_data(&s->rlayer.rrec),
585 SSL3_RECORD_get_length(&s->rlayer.rrec)) < 0) {
588 /* Exit and notify application to read again */
590 s->rwstate = SSL_READING;
591 BIO_clear_retry_flags(SSL_get_rbio(s));
592 BIO_set_retry_read(SSL_get_rbio(s));
596 /* else it's a CCS message, or application data or wrong */
597 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
599 * Application data while renegotiating is allowed. Try again
602 if (rr->type == SSL3_RT_APPLICATION_DATA) {
604 s->s3->in_read_app_data = 2;
605 bio = SSL_get_rbio(s);
606 s->rwstate = SSL_READING;
607 BIO_clear_retry_flags(bio);
608 BIO_set_retry_read(bio);
612 /* Not certain if this is the right error handling */
613 al = SSL_AD_UNEXPECTED_MESSAGE;
614 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
618 if (dest_maxlen > 0) {
620 * XDTLS: In a pathalogical case, the Client Hello may be
621 * fragmented--don't always expect dest_maxlen bytes
623 if (rr->length < dest_maxlen) {
624 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
626 * for normal alerts rr->length is 2, while
627 * dest_maxlen is 7 if we were to handle this
628 * non-existing alert...
632 s->rstate = SSL_ST_READ_HEADER;
637 /* now move 'n' bytes: */
638 for (k = 0; k < dest_maxlen; k++) {
639 dest[k] = rr->data[rr->off++];
642 *dest_len = dest_maxlen;
647 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
648 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
649 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
652 /* If we are a client, check for an incoming 'Hello Request': */
654 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
655 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
656 (s->session != NULL) && (s->session->cipher != NULL)) {
657 s->d1->handshake_fragment_len = 0;
659 if ((s->d1->handshake_fragment[1] != 0) ||
660 (s->d1->handshake_fragment[2] != 0) ||
661 (s->d1->handshake_fragment[3] != 0)) {
662 al = SSL_AD_DECODE_ERROR;
663 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
668 * no need to check sequence number on HELLO REQUEST messages
672 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
673 s->d1->handshake_fragment, 4, s,
674 s->msg_callback_arg);
676 if (SSL_is_init_finished(s) &&
677 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
678 !s->s3->renegotiate) {
679 s->d1->handshake_read_seq++;
682 if (ssl3_renegotiate_check(s)) {
683 i = s->handshake_func(s);
687 SSLerr(SSL_F_DTLS1_READ_BYTES,
688 SSL_R_SSL_HANDSHAKE_FAILURE);
692 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
693 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
694 /* no read-ahead left? */
697 * In the case where we try to read application data,
698 * but we trigger an SSL handshake, we return -1 with
699 * the retry option set. Otherwise renegotiation may
700 * cause nasty problems in the blocking world
702 s->rwstate = SSL_READING;
703 bio = SSL_get_rbio(s);
704 BIO_clear_retry_flags(bio);
705 BIO_set_retry_read(bio);
712 * we either finished a handshake or ignored the request, now try
713 * again to obtain the (application) data we were asked for
718 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
719 int alert_level = s->d1->alert_fragment[0];
720 int alert_descr = s->d1->alert_fragment[1];
722 s->d1->alert_fragment_len = 0;
725 s->msg_callback(0, s->version, SSL3_RT_ALERT,
726 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
728 if (s->info_callback != NULL)
729 cb = s->info_callback;
730 else if (s->ctx->info_callback != NULL)
731 cb = s->ctx->info_callback;
734 j = (alert_level << 8) | alert_descr;
735 cb(s, SSL_CB_READ_ALERT, j);
738 if (alert_level == SSL3_AL_WARNING) {
739 s->s3->warn_alert = alert_descr;
740 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
741 #ifndef OPENSSL_NO_SCTP
743 * With SCTP and streams the socket may deliver app data
744 * after a close_notify alert. We have to check this first so
745 * that nothing gets discarded.
747 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
748 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
749 s->d1->shutdown_received = 1;
750 s->rwstate = SSL_READING;
751 BIO_clear_retry_flags(SSL_get_rbio(s));
752 BIO_set_retry_read(SSL_get_rbio(s));
756 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
760 /* XXX: this is a possible improvement in the future */
761 /* now check if it's a missing record */
762 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
764 unsigned int frag_off;
765 unsigned char *p = &(s->d1->alert_fragment[2]);
770 dtls1_retransmit_message(s,
771 dtls1_get_queue_priority
772 (frag->msg_header.seq, 0), frag_off,
774 if (!found && SSL_in_init(s)) {
776 * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
779 * requested a message not yet sent, send an alert
782 ssl3_send_alert(s, SSL3_AL_WARNING,
783 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
787 } else if (alert_level == SSL3_AL_FATAL) {
790 s->rwstate = SSL_NOTHING;
791 s->s3->fatal_alert = alert_descr;
792 SSLerr(SSL_F_DTLS1_READ_BYTES,
793 SSL_AD_REASON_OFFSET + alert_descr);
794 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
795 ERR_add_error_data(2, "SSL alert number ", tmp);
796 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
797 SSL_CTX_remove_session(s->ctx, s->session);
800 al = SSL_AD_ILLEGAL_PARAMETER;
801 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
808 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
810 s->rwstate = SSL_NOTHING;
815 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
816 struct ccs_header_st ccs_hdr;
817 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
819 dtls1_get_ccs_header(rr->data, &ccs_hdr);
821 if (s->version == DTLS1_BAD_VER)
825 * 'Change Cipher Spec' is just a single byte, so we know exactly
826 * what the record payload has to look like
828 /* XDTLS: check that epoch is consistent */
829 if ((rr->length != ccs_hdr_len) ||
830 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
831 i = SSL_AD_ILLEGAL_PARAMETER;
832 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
839 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
840 rr->data, 1, s, s->msg_callback_arg);
843 * We can't process a CCS now, because previous handshake messages
844 * are still missing, so just drop it.
846 if (!s->d1->change_cipher_spec_ok) {
850 s->d1->change_cipher_spec_ok = 0;
852 s->s3->change_cipher_spec = 1;
853 if (!ssl3_do_change_cipher_spec(s))
856 /* do this whenever CCS is processed */
857 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
859 if (s->version == DTLS1_BAD_VER)
860 s->d1->handshake_read_seq++;
862 #ifndef OPENSSL_NO_SCTP
864 * Remember that a CCS has been received, so that an old key of
865 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
868 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
875 * Unexpected handshake message (Client Hello, or protocol violation)
877 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
879 struct hm_header_st msg_hdr;
881 /* this may just be a stale retransmit */
882 dtls1_get_message_header(rr->data, &msg_hdr);
883 if (rr->epoch != s->d1->r_epoch) {
889 * If we are server, we may have a repeated FINISHED of the client
890 * here, then retransmit our CCS and FINISHED.
892 if (msg_hdr.type == SSL3_MT_FINISHED) {
893 if (dtls1_check_timeout_num(s) < 0)
896 dtls1_retransmit_buffered_messages(s);
901 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
902 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
903 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
907 i = s->handshake_func(s);
911 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
915 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
916 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
917 /* no read-ahead left? */
920 * In the case where we try to read application data, but we
921 * trigger an SSL handshake, we return -1 with the retry
922 * option set. Otherwise renegotiation may cause nasty
923 * problems in the blocking world
925 s->rwstate = SSL_READING;
926 bio = SSL_get_rbio(s);
927 BIO_clear_retry_flags(bio);
928 BIO_set_retry_read(bio);
937 /* TLS just ignores unknown message types */
938 if (s->version == TLS1_VERSION) {
942 al = SSL_AD_UNEXPECTED_MESSAGE;
943 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
945 case SSL3_RT_CHANGE_CIPHER_SPEC:
947 case SSL3_RT_HANDSHAKE:
949 * we already handled all of these, with the possible exception of
950 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
951 * happen when type != rr->type
953 al = SSL_AD_UNEXPECTED_MESSAGE;
954 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
956 case SSL3_RT_APPLICATION_DATA:
958 * At this point, we were expecting handshake data, but have
959 * application data. If the library was running inside ssl3_read()
960 * (i.e. in_read_app_data is set) and it makes sense to read
961 * application data at this point (session renegotiation not yet
962 * started), we will indulge it.
964 if (s->s3->in_read_app_data &&
965 (s->s3->total_renegotiations != 0) &&
966 (((s->state & SSL_ST_CONNECT) &&
967 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
968 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
969 ) || ((s->state & SSL_ST_ACCEPT) &&
970 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
971 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
974 s->s3->in_read_app_data = 2;
977 al = SSL_AD_UNEXPECTED_MESSAGE;
978 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
985 ssl3_send_alert(s, SSL3_AL_FATAL, al);
992 * this only happens when a client hello is received and a handshake
996 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1000 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1001 /* (partially) satisfy request from storage */
1003 unsigned char *src = s->d1->handshake_fragment;
1004 unsigned char *dst = buf;
1009 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) {
1012 s->d1->handshake_fragment_len--;
1015 /* move any remaining fragment bytes: */
1016 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1017 s->d1->handshake_fragment[k] = *src++;
1025 * Call this to write data in records of type 'type' It will return <= 0 if
1026 * not all data has been sent or non-blocking IO.
1028 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1032 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1033 s->rwstate = SSL_NOTHING;
1034 i = do_dtls1_write(s, type, buf, len, 0);
1038 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
1039 unsigned int len, int create_empty_fragment)
1041 unsigned char *p, *pseq;
1042 int i, mac_size, clear = 0;
1049 wb = &s->rlayer.wbuf;
1052 * first check if there is a SSL3_BUFFER still being written out. This
1053 * will happen with non blocking IO
1055 if (SSL3_BUFFER_get_left(wb) != 0) {
1056 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1057 return (ssl3_write_pending(s, type, buf, len));
1060 /* If we have an alert to send, lets send it */
1061 if (s->s3->alert_dispatch) {
1062 i = s->method->ssl_dispatch_alert(s);
1065 /* if it went, fall through and send more stuff */
1068 if (len == 0 && !create_empty_fragment)
1071 wr = &s->rlayer.wrec;
1074 if ((sess == NULL) ||
1075 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
1081 mac_size = EVP_MD_CTX_size(s->write_hash);
1086 p = wb->buf + prefix_len;
1088 /* write the header */
1090 *(p++) = type & 0xff;
1093 * Special case: for hello verify request, client version 1.0 and we
1094 * haven't decided which version to use yet send back using version 1.0
1095 * header: otherwise some clients will ignore it.
1097 if (s->method->version == DTLS_ANY_VERSION) {
1098 *(p++) = DTLS1_VERSION >> 8;
1099 *(p++) = DTLS1_VERSION & 0xff;
1101 *(p++) = s->version >> 8;
1102 *(p++) = s->version & 0xff;
1105 /* field where we are to write out packet epoch, seq num and len */
1109 /* Explicit IV length, block ciphers appropriate version flag */
1110 if (s->enc_write_ctx) {
1111 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1112 if (mode == EVP_CIPH_CBC_MODE) {
1113 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1117 /* Need explicit part of IV for GCM mode */
1118 else if (mode == EVP_CIPH_GCM_MODE)
1119 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1125 /* lets setup the record stuff. */
1126 wr->data = p + eivlen; /* make room for IV in case of CBC */
1127 wr->length = (int)len;
1128 wr->input = (unsigned char *)buf;
1131 * we now 'read' from wr->input, wr->length bytes into wr->data
1134 /* first we compress */
1135 if (s->compress != NULL) {
1136 if (!ssl3_do_compress(s)) {
1137 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
1141 memcpy(wr->data, wr->input, wr->length);
1142 wr->input = wr->data;
1146 * we should still have the output to wr->data and the input from
1147 * wr->input. Length should be wr->length. wr->data still points in the
1151 if (mac_size != 0) {
1152 if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
1154 wr->length += mac_size;
1157 /* this is true regardless of mac size */
1162 wr->length += eivlen;
1164 if (s->method->ssl3_enc->enc(s, 1) < 1)
1167 /* record length after mac and block padding */
1169 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
1173 /* there's only one epoch between handshake and app data */
1175 s2n(s->d1->w_epoch, pseq);
1179 * else s2n(s->d1->handshake_epoch, pseq);
1182 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1184 s2n(wr->length, pseq);
1186 if (s->msg_callback)
1187 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
1188 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1191 * we should now have wr->data pointing to the encrypted data, which is
1194 wr->type = type; /* not needed but helps for debugging */
1195 wr->length += DTLS1_RT_HEADER_LENGTH;
1197 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1199 if (create_empty_fragment) {
1201 * we are in a recursive call; just return the length, don't write
1207 /* now let's set up wb */
1208 wb->left = prefix_len + wr->length;
1212 * memorize arguments so that ssl3_write_pending can detect bad write
1215 s->s3->wpend_tot = len;
1216 s->s3->wpend_buf = buf;
1217 s->s3->wpend_type = type;
1218 s->s3->wpend_ret = len;
1220 /* we now just need to write the buffer */
1221 return ssl3_write_pending(s, type, buf, len);
1226 int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1230 const unsigned char *seq = s->s3->read_sequence;
1232 cmp = satsub64be(seq, bitmap->max_seq_num);
1234 SSL3_RECORD_set_seq_num(&s->rlayer.rrec, seq);
1235 return 1; /* this record in new */
1238 if (shift >= sizeof(bitmap->map) * 8)
1239 return 0; /* stale, outside the window */
1240 else if (bitmap->map & (1UL << shift))
1241 return 0; /* record previously received */
1243 SSL3_RECORD_set_seq_num(&s->rlayer.rrec, seq);
1247 void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1251 const unsigned char *seq = s->s3->read_sequence;
1253 cmp = satsub64be(seq, bitmap->max_seq_num);
1256 if (shift < sizeof(bitmap->map) * 8)
1257 bitmap->map <<= shift, bitmap->map |= 1UL;
1260 memcpy(bitmap->max_seq_num, seq, 8);
1263 if (shift < sizeof(bitmap->map) * 8)
1264 bitmap->map |= 1UL << shift;
1268 DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1269 unsigned int *is_next_epoch)
1274 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1275 if (rr->epoch == s->d1->r_epoch)
1276 return &s->d1->bitmap;
1278 /* Only HM and ALERT messages can be from the next epoch */
1279 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1280 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1282 return &s->d1->next_bitmap;
1288 void dtls1_reset_seq_numbers(SSL *s, int rw)
1291 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1293 if (rw & SSL3_CC_READ) {
1294 seq = s->s3->read_sequence;
1296 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1297 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1299 seq = s->s3->write_sequence;
1300 memcpy(s->d1->last_write_sequence, seq,
1301 sizeof(s->s3->write_sequence));
1305 memset(seq, 0x00, seq_bytes);