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(RECORD_LAYER_get_rbuf(&s->rlayer));
196 s->packet = rdata->packet;
197 s->packet_length = rdata->packet_length;
198 memcpy(RECORD_LAYER_get_rbuf(&s->rlayer), &(rdata->rbuf),
199 sizeof(SSL3_BUFFER));
200 memcpy(RECORD_LAYER_get_rrec(&s->rlayer), &(rdata->rrec),
201 sizeof(SSL3_RECORD));
203 /* Set proper sequence number for mac calculation */
204 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
210 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
212 DTLS1_RECORD_DATA *rdata;
215 /* Limit the size of the queue to prevent DOS attacks */
216 if (pqueue_size(queue->q) >= 100)
219 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
220 item = pitem_new(priority, rdata);
221 if (rdata == NULL || item == NULL) {
227 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
231 rdata->packet = s->packet;
232 rdata->packet_length = s->packet_length;
233 memcpy(&(rdata->rbuf), RECORD_LAYER_get_rbuf(&s->rlayer),
234 sizeof(SSL3_BUFFER));
235 memcpy(&(rdata->rrec), RECORD_LAYER_get_rrec(&s->rlayer),
236 sizeof(SSL3_RECORD));
240 #ifndef OPENSSL_NO_SCTP
241 /* Store bio_dgram_sctp_rcvinfo struct */
242 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
243 (s->state == SSL3_ST_SR_FINISHED_A
244 || s->state == SSL3_ST_CR_FINISHED_A)) {
245 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
246 sizeof(rdata->recordinfo), &rdata->recordinfo);
251 s->packet_length = 0;
252 memset(RECORD_LAYER_get_rbuf(&s->rlayer), 0, sizeof(SSL3_BUFFER));
253 memset(RECORD_LAYER_get_rrec(&s->rlayer), 0, sizeof(SSL3_RECORD));
255 if (!ssl3_setup_buffers(s)) {
256 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
257 if (rdata->rbuf.buf != NULL)
258 OPENSSL_free(rdata->rbuf.buf);
264 /* insert should not fail, since duplicates are dropped */
265 if (pqueue_insert(queue->q, item) == NULL) {
266 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
267 if (rdata->rbuf.buf != NULL)
268 OPENSSL_free(rdata->rbuf.buf);
277 int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
281 item = pqueue_pop(queue->q);
283 dtls1_copy_record(s, item);
285 OPENSSL_free(item->data);
295 * retrieve a buffered record that belongs to the new epoch, i.e., not
298 #define dtls1_get_unprocessed_record(s) \
299 dtls1_retrieve_buffered_record((s), \
300 &((s)->d1->unprocessed_rcds))
303 int dtls1_process_buffered_records(SSL *s)
307 item = pqueue_peek(s->d1->unprocessed_rcds.q);
309 /* Check if epoch is current. */
310 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
311 return (1); /* Nothing to do. */
313 /* Process all the records. */
314 while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
315 dtls1_get_unprocessed_record(s);
316 if (!dtls1_process_record(s))
318 if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
319 SSL3_RECORD_get_seq_num(RECORD_LAYER_get_rrec(&s->rlayer))) < 0)
325 * sync epoch numbers once all the unprocessed records have been
328 s->d1->processed_rcds.epoch = s->d1->r_epoch;
329 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
336 * Return up to 'len' payload bytes received in 'type' records.
337 * 'type' is one of the following:
339 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
340 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
341 * - 0 (during a shutdown, no data has to be returned)
343 * If we don't have stored data to work from, read a SSL/TLS record first
344 * (possibly multiple records if we still don't have anything to return).
346 * This function must handle any surprises the peer may have for us, such as
347 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
348 * a surprise, but handled as if it were), or renegotiation requests.
349 * Also if record payloads contain fragments too small to process, we store
350 * them until there is enough for the respective protocol (the record protocol
351 * may use arbitrary fragmentation and even interleaving):
352 * Change cipher spec protocol
353 * just 1 byte needed, no need for keeping anything stored
355 * 2 bytes needed (AlertLevel, AlertDescription)
357 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
358 * to detect unexpected Client Hello and Hello Request messages
359 * here, anything else is handled by higher layers
360 * Application data protocol
361 * none of our business
363 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
368 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
370 if (!SSL3_BUFFER_is_initialised(RECORD_LAYER_get_rbuf(&s->rlayer))) {
371 /* Not initialized yet */
372 if (!ssl3_setup_buffers(s))
376 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
377 (type != SSL3_RT_HANDSHAKE)) ||
378 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
379 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
384 * check whether there's a handshake message (client hello?) waiting
386 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
390 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
393 #ifndef OPENSSL_NO_SCTP
395 * Continue handshake if it had to be interrupted to read app data with
398 if ((!s->in_handshake && SSL_in_init(s)) ||
399 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
400 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
401 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
402 && s->s3->in_read_app_data != 2))
404 if (!s->in_handshake && SSL_in_init(s))
407 /* type == SSL3_RT_APPLICATION_DATA */
408 i = s->handshake_func(s);
412 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
418 s->rwstate = SSL_NOTHING;
421 * s->s3->rrec.type - is the type of record
422 * s->s3->rrec.data, - data
423 * s->s3->rrec.off, - offset into 'data' for next read
424 * s->s3->rrec.length, - number of bytes.
426 rr = RECORD_LAYER_get_rrec(&s->rlayer);
429 * We are not handshaking and have no data yet, so process data buffered
430 * during the last handshake in advance, if any.
432 if (s->state == SSL_ST_OK && rr->length == 0) {
434 item = pqueue_pop(s->d1->buffered_app_data.q);
436 #ifndef OPENSSL_NO_SCTP
437 /* Restore bio_dgram_sctp_rcvinfo struct */
438 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
439 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
440 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
441 sizeof(rdata->recordinfo), &rdata->recordinfo);
445 dtls1_copy_record(s, item);
447 OPENSSL_free(item->data);
452 /* Check for timeout */
453 if (dtls1_handle_timeout(s) > 0)
456 /* get new packet if necessary */
457 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) {
458 ret = dtls1_get_record(s);
460 ret = dtls1_read_failed(s, ret);
461 /* anything other than a timeout is an error */
469 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
474 /* we now have a packet which can be read and processed */
476 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
477 * reset by ssl3_get_finished */
478 && (rr->type != SSL3_RT_HANDSHAKE)) {
480 * We now have application data between CCS and Finished. Most likely
481 * the packets were reordered on their way, so buffer the application
482 * data for later processing rather than dropping the connection.
484 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) <
486 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
494 * If the other end has shut down, throw anything we read away (even in
497 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
499 s->rwstate = SSL_NOTHING;
503 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or
504 * SSL3_RT_HANDSHAKE */
506 * make sure that we are not getting application data when we are
507 * doing a handshake for the first time
509 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
510 (s->enc_read_ctx == NULL)) {
511 al = SSL_AD_UNEXPECTED_MESSAGE;
512 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
519 if ((unsigned int)len > rr->length)
522 n = (unsigned int)len;
524 memcpy(buf, &(rr->data[rr->off]), n);
528 if (rr->length == 0) {
529 s->rstate = SSL_ST_READ_HEADER;
533 #ifndef OPENSSL_NO_SCTP
535 * We were about to renegotiate but had to read belated application
536 * data first, so retry.
538 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
539 rr->type == SSL3_RT_APPLICATION_DATA &&
540 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
541 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
542 s->rwstate = SSL_READING;
543 BIO_clear_retry_flags(SSL_get_rbio(s));
544 BIO_set_retry_read(SSL_get_rbio(s));
548 * We might had to delay a close_notify alert because of reordered
549 * app data. If there was an alert and there is no message to read
550 * anymore, finally set shutdown.
552 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
553 s->d1->shutdown_received
554 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
555 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
563 * If we get here, then type != rr->type; if we have a handshake message,
564 * then it was unexpected (Hello Request or Client Hello).
568 * In case of record types for which we have 'fragment' storage, fill
569 * that so that we can process the data at a fixed place.
572 unsigned int k, dest_maxlen = 0;
573 unsigned char *dest = NULL;
574 unsigned int *dest_len = NULL;
576 if (rr->type == SSL3_RT_HANDSHAKE) {
577 dest_maxlen = sizeof s->d1->handshake_fragment;
578 dest = s->d1->handshake_fragment;
579 dest_len = &s->d1->handshake_fragment_len;
580 } else if (rr->type == SSL3_RT_ALERT) {
581 dest_maxlen = sizeof(s->d1->alert_fragment);
582 dest = s->d1->alert_fragment;
583 dest_len = &s->d1->alert_fragment_len;
585 #ifndef OPENSSL_NO_HEARTBEATS
586 else if (rr->type == TLS1_RT_HEARTBEAT) {
587 /* We allow a 0 return */
588 if(dtls1_process_heartbeat(s) < 0) {
592 /* Exit and notify application to read again */
594 s->rwstate = SSL_READING;
595 BIO_clear_retry_flags(SSL_get_rbio(s));
596 BIO_set_retry_read(SSL_get_rbio(s));
600 /* else it's a CCS message, or application data or wrong */
601 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
603 * Application data while renegotiating is allowed. Try again
606 if (rr->type == SSL3_RT_APPLICATION_DATA) {
608 s->s3->in_read_app_data = 2;
609 bio = SSL_get_rbio(s);
610 s->rwstate = SSL_READING;
611 BIO_clear_retry_flags(bio);
612 BIO_set_retry_read(bio);
616 /* Not certain if this is the right error handling */
617 al = SSL_AD_UNEXPECTED_MESSAGE;
618 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
622 if (dest_maxlen > 0) {
624 * XDTLS: In a pathalogical case, the Client Hello may be
625 * fragmented--don't always expect dest_maxlen bytes
627 if (rr->length < dest_maxlen) {
628 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
630 * for normal alerts rr->length is 2, while
631 * dest_maxlen is 7 if we were to handle this
632 * non-existing alert...
636 s->rstate = SSL_ST_READ_HEADER;
641 /* now move 'n' bytes: */
642 for (k = 0; k < dest_maxlen; k++) {
643 dest[k] = rr->data[rr->off++];
646 *dest_len = dest_maxlen;
651 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
652 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
653 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
656 /* If we are a client, check for an incoming 'Hello Request': */
658 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
659 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
660 (s->session != NULL) && (s->session->cipher != NULL)) {
661 s->d1->handshake_fragment_len = 0;
663 if ((s->d1->handshake_fragment[1] != 0) ||
664 (s->d1->handshake_fragment[2] != 0) ||
665 (s->d1->handshake_fragment[3] != 0)) {
666 al = SSL_AD_DECODE_ERROR;
667 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
672 * no need to check sequence number on HELLO REQUEST messages
676 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
677 s->d1->handshake_fragment, 4, s,
678 s->msg_callback_arg);
680 if (SSL_is_init_finished(s) &&
681 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
682 !s->s3->renegotiate) {
683 s->d1->handshake_read_seq++;
686 if (ssl3_renegotiate_check(s)) {
687 i = s->handshake_func(s);
691 SSLerr(SSL_F_DTLS1_READ_BYTES,
692 SSL_R_SSL_HANDSHAKE_FAILURE);
696 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
697 if (SSL3_BUFFER_get_left(
698 RECORD_LAYER_get_rbuf(&s->rlayer)) == 0) {
699 /* no read-ahead left? */
702 * In the case where we try to read application data,
703 * but we trigger an SSL handshake, we return -1 with
704 * the retry option set. Otherwise renegotiation may
705 * cause nasty problems in the blocking world
707 s->rwstate = SSL_READING;
708 bio = SSL_get_rbio(s);
709 BIO_clear_retry_flags(bio);
710 BIO_set_retry_read(bio);
717 * we either finished a handshake or ignored the request, now try
718 * again to obtain the (application) data we were asked for
723 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
724 int alert_level = s->d1->alert_fragment[0];
725 int alert_descr = s->d1->alert_fragment[1];
727 s->d1->alert_fragment_len = 0;
730 s->msg_callback(0, s->version, SSL3_RT_ALERT,
731 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
733 if (s->info_callback != NULL)
734 cb = s->info_callback;
735 else if (s->ctx->info_callback != NULL)
736 cb = s->ctx->info_callback;
739 j = (alert_level << 8) | alert_descr;
740 cb(s, SSL_CB_READ_ALERT, j);
743 if (alert_level == SSL3_AL_WARNING) {
744 s->s3->warn_alert = alert_descr;
745 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
746 #ifndef OPENSSL_NO_SCTP
748 * With SCTP and streams the socket may deliver app data
749 * after a close_notify alert. We have to check this first so
750 * that nothing gets discarded.
752 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
753 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
754 s->d1->shutdown_received = 1;
755 s->rwstate = SSL_READING;
756 BIO_clear_retry_flags(SSL_get_rbio(s));
757 BIO_set_retry_read(SSL_get_rbio(s));
761 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
765 /* XXX: this is a possible improvement in the future */
766 /* now check if it's a missing record */
767 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
769 unsigned int frag_off;
770 unsigned char *p = &(s->d1->alert_fragment[2]);
775 dtls1_retransmit_message(s,
776 dtls1_get_queue_priority
777 (frag->msg_header.seq, 0), frag_off,
779 if (!found && SSL_in_init(s)) {
781 * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
784 * requested a message not yet sent, send an alert
787 ssl3_send_alert(s, SSL3_AL_WARNING,
788 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
792 } else if (alert_level == SSL3_AL_FATAL) {
795 s->rwstate = SSL_NOTHING;
796 s->s3->fatal_alert = alert_descr;
797 SSLerr(SSL_F_DTLS1_READ_BYTES,
798 SSL_AD_REASON_OFFSET + alert_descr);
799 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
800 ERR_add_error_data(2, "SSL alert number ", tmp);
801 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
802 SSL_CTX_remove_session(s->ctx, s->session);
805 al = SSL_AD_ILLEGAL_PARAMETER;
806 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
813 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
815 s->rwstate = SSL_NOTHING;
820 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
821 struct ccs_header_st ccs_hdr;
822 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
824 dtls1_get_ccs_header(rr->data, &ccs_hdr);
826 if (s->version == DTLS1_BAD_VER)
830 * 'Change Cipher Spec' is just a single byte, so we know exactly
831 * what the record payload has to look like
833 /* XDTLS: check that epoch is consistent */
834 if ((rr->length != ccs_hdr_len) ||
835 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
836 i = SSL_AD_ILLEGAL_PARAMETER;
837 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
844 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
845 rr->data, 1, s, s->msg_callback_arg);
848 * We can't process a CCS now, because previous handshake messages
849 * are still missing, so just drop it.
851 if (!s->d1->change_cipher_spec_ok) {
855 s->d1->change_cipher_spec_ok = 0;
857 s->s3->change_cipher_spec = 1;
858 if (!ssl3_do_change_cipher_spec(s))
861 /* do this whenever CCS is processed */
862 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
864 if (s->version == DTLS1_BAD_VER)
865 s->d1->handshake_read_seq++;
867 #ifndef OPENSSL_NO_SCTP
869 * Remember that a CCS has been received, so that an old key of
870 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
873 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
880 * Unexpected handshake message (Client Hello, or protocol violation)
882 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
884 struct hm_header_st msg_hdr;
886 /* this may just be a stale retransmit */
887 dtls1_get_message_header(rr->data, &msg_hdr);
888 if (rr->epoch != s->d1->r_epoch) {
894 * If we are server, we may have a repeated FINISHED of the client
895 * here, then retransmit our CCS and FINISHED.
897 if (msg_hdr.type == SSL3_MT_FINISHED) {
898 if (dtls1_check_timeout_num(s) < 0)
901 dtls1_retransmit_buffered_messages(s);
906 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
907 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
908 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
912 i = s->handshake_func(s);
916 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
920 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
921 if (SSL3_BUFFER_get_left(
922 RECORD_LAYER_get_rbuf(&s->rlayer)) == 0) {
923 /* no read-ahead left? */
926 * In the case where we try to read application data, but we
927 * trigger an SSL handshake, we return -1 with the retry
928 * option set. Otherwise renegotiation may cause nasty
929 * problems in the blocking world
931 s->rwstate = SSL_READING;
932 bio = SSL_get_rbio(s);
933 BIO_clear_retry_flags(bio);
934 BIO_set_retry_read(bio);
943 /* TLS just ignores unknown message types */
944 if (s->version == TLS1_VERSION) {
948 al = SSL_AD_UNEXPECTED_MESSAGE;
949 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
951 case SSL3_RT_CHANGE_CIPHER_SPEC:
953 case SSL3_RT_HANDSHAKE:
955 * we already handled all of these, with the possible exception of
956 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
957 * happen when type != rr->type
959 al = SSL_AD_UNEXPECTED_MESSAGE;
960 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
962 case SSL3_RT_APPLICATION_DATA:
964 * At this point, we were expecting handshake data, but have
965 * application data. If the library was running inside ssl3_read()
966 * (i.e. in_read_app_data is set) and it makes sense to read
967 * application data at this point (session renegotiation not yet
968 * started), we will indulge it.
970 if (s->s3->in_read_app_data &&
971 (s->s3->total_renegotiations != 0) &&
972 (((s->state & SSL_ST_CONNECT) &&
973 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
974 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
975 ) || ((s->state & SSL_ST_ACCEPT) &&
976 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
977 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
980 s->s3->in_read_app_data = 2;
983 al = SSL_AD_UNEXPECTED_MESSAGE;
984 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
991 ssl3_send_alert(s, SSL3_AL_FATAL, al);
996 int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1000 #ifndef OPENSSL_NO_SCTP
1002 * Check if we have to continue an interrupted handshake for reading
1003 * belated app data with SCTP.
1005 if ((SSL_in_init(s) && !s->in_handshake) ||
1006 (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1007 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
1008 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1010 if (SSL_in_init(s) && !s->in_handshake)
1013 i = s->handshake_func(s);
1017 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,
1018 SSL_R_SSL_HANDSHAKE_FAILURE);
1023 if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
1024 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG);
1028 i = dtls1_write_bytes(s, type, buf_, len);
1033 * this only happens when a client hello is received and a handshake
1037 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1041 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1042 /* (partially) satisfy request from storage */
1044 unsigned char *src = s->d1->handshake_fragment;
1045 unsigned char *dst = buf;
1050 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) {
1053 s->d1->handshake_fragment_len--;
1056 /* move any remaining fragment bytes: */
1057 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1058 s->d1->handshake_fragment[k] = *src++;
1066 * Call this to write data in records of type 'type' It will return <= 0 if
1067 * not all data has been sent or non-blocking IO.
1069 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1073 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1074 s->rwstate = SSL_NOTHING;
1075 i = do_dtls1_write(s, type, buf, len, 0);
1079 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
1080 unsigned int len, int create_empty_fragment)
1082 unsigned char *p, *pseq;
1083 int i, mac_size, clear = 0;
1090 wb = RECORD_LAYER_get_wbuf(&s->rlayer);
1093 * first check if there is a SSL3_BUFFER still being written out. This
1094 * will happen with non blocking IO
1096 if (SSL3_BUFFER_get_left(wb) != 0) {
1097 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1098 return (ssl3_write_pending(s, type, buf, len));
1101 /* If we have an alert to send, lets send it */
1102 if (s->s3->alert_dispatch) {
1103 i = s->method->ssl_dispatch_alert(s);
1106 /* if it went, fall through and send more stuff */
1109 if (len == 0 && !create_empty_fragment)
1112 wr = RECORD_LAYER_get_wrec(&s->rlayer);
1115 if ((sess == NULL) ||
1116 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
1122 mac_size = EVP_MD_CTX_size(s->write_hash);
1127 p = wb->buf + prefix_len;
1129 /* write the header */
1131 *(p++) = type & 0xff;
1134 * Special case: for hello verify request, client version 1.0 and we
1135 * haven't decided which version to use yet send back using version 1.0
1136 * header: otherwise some clients will ignore it.
1138 if (s->method->version == DTLS_ANY_VERSION) {
1139 *(p++) = DTLS1_VERSION >> 8;
1140 *(p++) = DTLS1_VERSION & 0xff;
1142 *(p++) = s->version >> 8;
1143 *(p++) = s->version & 0xff;
1146 /* field where we are to write out packet epoch, seq num and len */
1150 /* Explicit IV length, block ciphers appropriate version flag */
1151 if (s->enc_write_ctx) {
1152 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1153 if (mode == EVP_CIPH_CBC_MODE) {
1154 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1158 /* Need explicit part of IV for GCM mode */
1159 else if (mode == EVP_CIPH_GCM_MODE)
1160 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1166 /* lets setup the record stuff. */
1167 wr->data = p + eivlen; /* make room for IV in case of CBC */
1168 wr->length = (int)len;
1169 wr->input = (unsigned char *)buf;
1172 * we now 'read' from wr->input, wr->length bytes into wr->data
1175 /* first we compress */
1176 if (s->compress != NULL) {
1177 if (!ssl3_do_compress(s)) {
1178 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
1182 memcpy(wr->data, wr->input, wr->length);
1183 wr->input = wr->data;
1187 * we should still have the output to wr->data and the input from
1188 * wr->input. Length should be wr->length. wr->data still points in the
1192 if (mac_size != 0) {
1193 if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
1195 wr->length += mac_size;
1198 /* this is true regardless of mac size */
1203 wr->length += eivlen;
1205 if (s->method->ssl3_enc->enc(s, 1) < 1)
1208 /* record length after mac and block padding */
1210 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
1214 /* there's only one epoch between handshake and app data */
1216 s2n(s->d1->w_epoch, pseq);
1220 * else s2n(s->d1->handshake_epoch, pseq);
1223 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1225 s2n(wr->length, pseq);
1227 if (s->msg_callback)
1228 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
1229 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1232 * we should now have wr->data pointing to the encrypted data, which is
1235 wr->type = type; /* not needed but helps for debugging */
1236 wr->length += DTLS1_RT_HEADER_LENGTH;
1238 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1240 if (create_empty_fragment) {
1242 * we are in a recursive call; just return the length, don't write
1248 /* now let's set up wb */
1249 wb->left = prefix_len + wr->length;
1253 * memorize arguments so that ssl3_write_pending can detect bad write
1256 s->s3->wpend_tot = len;
1257 s->s3->wpend_buf = buf;
1258 s->s3->wpend_type = type;
1259 s->s3->wpend_ret = len;
1261 /* we now just need to write the buffer */
1262 return ssl3_write_pending(s, type, buf, len);
1267 int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1271 const unsigned char *seq = s->s3->read_sequence;
1273 cmp = satsub64be(seq, bitmap->max_seq_num);
1275 SSL3_RECORD_set_seq_num(RECORD_LAYER_get_rrec(&s->rlayer), seq);
1276 return 1; /* this record in new */
1279 if (shift >= sizeof(bitmap->map) * 8)
1280 return 0; /* stale, outside the window */
1281 else if (bitmap->map & (1UL << shift))
1282 return 0; /* record previously received */
1284 SSL3_RECORD_set_seq_num(RECORD_LAYER_get_rrec(&s->rlayer), seq);
1288 void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1292 const unsigned char *seq = s->s3->read_sequence;
1294 cmp = satsub64be(seq, bitmap->max_seq_num);
1297 if (shift < sizeof(bitmap->map) * 8)
1298 bitmap->map <<= shift, bitmap->map |= 1UL;
1301 memcpy(bitmap->max_seq_num, seq, 8);
1304 if (shift < sizeof(bitmap->map) * 8)
1305 bitmap->map |= 1UL << shift;
1309 int dtls1_dispatch_alert(SSL *s)
1312 void (*cb) (const SSL *ssl, int type, int val) = NULL;
1313 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1314 unsigned char *ptr = &buf[0];
1316 s->s3->alert_dispatch = 0;
1318 memset(buf, 0x00, sizeof(buf));
1319 *ptr++ = s->s3->send_alert[0];
1320 *ptr++ = s->s3->send_alert[1];
1322 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1323 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
1324 s2n(s->d1->handshake_read_seq, ptr);
1325 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1329 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1331 s->s3->alert_dispatch = 1;
1332 /* fprintf( stderr, "not done with alert\n" ); */
1334 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1335 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1336 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1339 (void)BIO_flush(s->wbio);
1341 if (s->msg_callback)
1342 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1343 2, s, s->msg_callback_arg);
1345 if (s->info_callback != NULL)
1346 cb = s->info_callback;
1347 else if (s->ctx->info_callback != NULL)
1348 cb = s->ctx->info_callback;
1351 j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1];
1352 cb(s, SSL_CB_WRITE_ALERT, j);
1358 DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1359 unsigned int *is_next_epoch)
1364 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1365 if (rr->epoch == s->d1->r_epoch)
1366 return &s->d1->bitmap;
1368 /* Only HM and ALERT messages can be from the next epoch */
1369 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1370 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1372 return &s->d1->next_bitmap;
1378 void dtls1_reset_seq_numbers(SSL *s, int rw)
1381 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1383 if (rw & SSL3_CC_READ) {
1384 seq = s->s3->read_sequence;
1386 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1387 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1389 seq = s->s3->write_sequence;
1390 memcpy(s->d1->last_write_sequence, seq,
1391 sizeof(s->s3->write_sequence));
1395 memset(seq, 0x00, seq_bytes);