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>
126 int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl)
128 DTLS_RECORD_LAYER *d;
130 if ((d = OPENSSL_malloc(sizeof *d)) == NULL) {
137 d->unprocessed_rcds.q = pqueue_new();
138 d->processed_rcds.q = pqueue_new();
140 if (!d->unprocessed_rcds.q || !d->processed_rcds.q) {
141 if (d->unprocessed_rcds.q)
142 pqueue_free(d->unprocessed_rcds.q);
143 if (d->processed_rcds.q)
144 pqueue_free(d->processed_rcds.q);
153 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl)
155 DTLS_RECORD_LAYER_clear(rl);
156 pqueue_free(rl->d->unprocessed_rcds.q);
157 pqueue_free(rl->d->processed_rcds.q);
162 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
164 DTLS_RECORD_LAYER *d;
166 DTLS1_RECORD_DATA *rdata;
167 pqueue unprocessed_rcds;
168 pqueue processed_rcds;
172 while ((item = pqueue_pop(d->unprocessed_rcds.q)) != NULL) {
173 rdata = (DTLS1_RECORD_DATA *)item->data;
174 if (rdata->rbuf.buf) {
175 OPENSSL_free(rdata->rbuf.buf);
177 OPENSSL_free(item->data);
181 while ((item = pqueue_pop(d->processed_rcds.q)) != NULL) {
182 rdata = (DTLS1_RECORD_DATA *)item->data;
183 if (rdata->rbuf.buf) {
184 OPENSSL_free(rdata->rbuf.buf);
186 OPENSSL_free(item->data);
190 unprocessed_rcds = d->unprocessed_rcds.q;
191 processed_rcds = d->processed_rcds.q;
192 memset(d, 0, sizeof *d);
193 d->unprocessed_rcds.q = unprocessed_rcds;
194 d->processed_rcds.q = processed_rcds;
197 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
200 /* copy buffered record into SSL structure */
201 static int dtls1_copy_record(SSL *s, pitem *item)
203 DTLS1_RECORD_DATA *rdata;
205 rdata = (DTLS1_RECORD_DATA *)item->data;
207 SSL3_BUFFER_release(&s->rlayer.rbuf);
209 s->rlayer.packet = rdata->packet;
210 s->rlayer.packet_length = rdata->packet_length;
211 memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER));
212 memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD));
214 /* Set proper sequence number for mac calculation */
215 memcpy(&(s->rlayer.read_sequence[2]), &(rdata->packet[5]), 6);
221 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
223 DTLS1_RECORD_DATA *rdata;
226 /* Limit the size of the queue to prevent DOS attacks */
227 if (pqueue_size(queue->q) >= 100)
230 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
231 item = pitem_new(priority, rdata);
232 if (rdata == NULL || item == NULL) {
238 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
242 rdata->packet = s->rlayer.packet;
243 rdata->packet_length = s->rlayer.packet_length;
244 memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER));
245 memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD));
249 #ifndef OPENSSL_NO_SCTP
250 /* Store bio_dgram_sctp_rcvinfo struct */
251 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
252 (s->state == SSL3_ST_SR_FINISHED_A
253 || s->state == SSL3_ST_CR_FINISHED_A)) {
254 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
255 sizeof(rdata->recordinfo), &rdata->recordinfo);
259 s->rlayer.packet = NULL;
260 s->rlayer.packet_length = 0;
261 memset(&s->rlayer.rbuf, 0, sizeof(SSL3_BUFFER));
262 memset(&s->rlayer.rrec, 0, sizeof(SSL3_RECORD));
264 if (!ssl3_setup_buffers(s)) {
265 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
266 if (rdata->rbuf.buf != NULL)
267 OPENSSL_free(rdata->rbuf.buf);
273 /* insert should not fail, since duplicates are dropped */
274 if (pqueue_insert(queue->q, item) == NULL) {
275 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
276 if (rdata->rbuf.buf != NULL)
277 OPENSSL_free(rdata->rbuf.buf);
286 int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
290 item = pqueue_pop(queue->q);
292 dtls1_copy_record(s, item);
294 OPENSSL_free(item->data);
304 * retrieve a buffered record that belongs to the new epoch, i.e., not
307 #define dtls1_get_unprocessed_record(s) \
308 dtls1_retrieve_buffered_record((s), \
309 &((s)->rlayer.d->unprocessed_rcds))
312 int dtls1_process_buffered_records(SSL *s)
316 item = pqueue_peek(s->rlayer.d->unprocessed_rcds.q);
318 /* Check if epoch is current. */
319 if (s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch)
320 return (1); /* Nothing to do. */
322 /* Process all the records. */
323 while (pqueue_peek(s->rlayer.d->unprocessed_rcds.q)) {
324 dtls1_get_unprocessed_record(s);
325 if (!dtls1_process_record(s))
327 if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds),
328 SSL3_RECORD_get_seq_num(&s->rlayer.rrec)) < 0)
334 * sync epoch numbers once all the unprocessed records have been
337 s->rlayer.d->processed_rcds.epoch = s->rlayer.d->r_epoch;
338 s->rlayer.d->unprocessed_rcds.epoch = s->rlayer.d->r_epoch + 1;
345 * Return up to 'len' payload bytes received in 'type' records.
346 * 'type' is one of the following:
348 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
349 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
350 * - 0 (during a shutdown, no data has to be returned)
352 * If we don't have stored data to work from, read a SSL/TLS record first
353 * (possibly multiple records if we still don't have anything to return).
355 * This function must handle any surprises the peer may have for us, such as
356 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
357 * a surprise, but handled as if it were), or renegotiation requests.
358 * Also if record payloads contain fragments too small to process, we store
359 * them until there is enough for the respective protocol (the record protocol
360 * may use arbitrary fragmentation and even interleaving):
361 * Change cipher spec protocol
362 * just 1 byte needed, no need for keeping anything stored
364 * 2 bytes needed (AlertLevel, AlertDescription)
366 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
367 * to detect unexpected Client Hello and Hello Request messages
368 * here, anything else is handled by higher layers
369 * Application data protocol
370 * none of our business
372 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
377 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
379 if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
380 /* Not initialized yet */
381 if (!ssl3_setup_buffers(s))
385 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
386 (type != SSL3_RT_HANDSHAKE)) ||
387 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
388 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
393 * check whether there's a handshake message (client hello?) waiting
395 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
399 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
402 #ifndef OPENSSL_NO_SCTP
404 * Continue handshake if it had to be interrupted to read app data with
407 if ((!s->in_handshake && SSL_in_init(s)) ||
408 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
409 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
410 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
411 && s->s3->in_read_app_data != 2))
413 if (!s->in_handshake && SSL_in_init(s))
416 /* type == SSL3_RT_APPLICATION_DATA */
417 i = s->handshake_func(s);
421 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
427 s->rwstate = SSL_NOTHING;
430 * s->s3->rrec.type - is the type of record
431 * s->s3->rrec.data, - data
432 * s->s3->rrec.off, - offset into 'data' for next read
433 * s->s3->rrec.length, - number of bytes.
435 rr = &s->rlayer.rrec;
438 * We are not handshaking and have no data yet, so process data buffered
439 * during the last handshake in advance, if any.
441 if (s->state == SSL_ST_OK && rr->length == 0) {
443 item = pqueue_pop(s->d1->buffered_app_data.q);
445 #ifndef OPENSSL_NO_SCTP
446 /* Restore bio_dgram_sctp_rcvinfo struct */
447 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
448 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
449 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
450 sizeof(rdata->recordinfo), &rdata->recordinfo);
454 dtls1_copy_record(s, item);
456 OPENSSL_free(item->data);
461 /* Check for timeout */
462 if (dtls1_handle_timeout(s) > 0)
465 /* get new packet if necessary */
466 if ((rr->length == 0) || (s->rlayer.rstate == SSL_ST_READ_BODY)) {
467 ret = dtls1_get_record(s);
469 ret = dtls1_read_failed(s, ret);
470 /* anything other than a timeout is an error */
478 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
483 /* we now have a packet which can be read and processed */
485 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
486 * reset by ssl3_get_finished */
487 && (rr->type != SSL3_RT_HANDSHAKE)) {
489 * We now have application data between CCS and Finished. Most likely
490 * the packets were reordered on their way, so buffer the application
491 * data for later processing rather than dropping the connection.
493 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) <
495 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
503 * If the other end has shut down, throw anything we read away (even in
506 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
508 s->rwstate = SSL_NOTHING;
512 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or
513 * SSL3_RT_HANDSHAKE */
515 * make sure that we are not getting application data when we are
516 * doing a handshake for the first time
518 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
519 (s->enc_read_ctx == NULL)) {
520 al = SSL_AD_UNEXPECTED_MESSAGE;
521 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
528 if ((unsigned int)len > rr->length)
531 n = (unsigned int)len;
533 memcpy(buf, &(rr->data[rr->off]), n);
537 if (rr->length == 0) {
538 s->rlayer.rstate = SSL_ST_READ_HEADER;
542 #ifndef OPENSSL_NO_SCTP
544 * We were about to renegotiate but had to read belated application
545 * data first, so retry.
547 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
548 rr->type == SSL3_RT_APPLICATION_DATA &&
549 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
550 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
551 s->rwstate = SSL_READING;
552 BIO_clear_retry_flags(SSL_get_rbio(s));
553 BIO_set_retry_read(SSL_get_rbio(s));
557 * We might had to delay a close_notify alert because of reordered
558 * app data. If there was an alert and there is no message to read
559 * anymore, finally set shutdown.
561 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
562 s->d1->shutdown_received
563 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
564 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
572 * If we get here, then type != rr->type; if we have a handshake message,
573 * then it was unexpected (Hello Request or Client Hello).
577 * In case of record types for which we have 'fragment' storage, fill
578 * that so that we can process the data at a fixed place.
581 unsigned int k, dest_maxlen = 0;
582 unsigned char *dest = NULL;
583 unsigned int *dest_len = NULL;
585 if (rr->type == SSL3_RT_HANDSHAKE) {
586 dest_maxlen = sizeof s->d1->handshake_fragment;
587 dest = s->d1->handshake_fragment;
588 dest_len = &s->d1->handshake_fragment_len;
589 } else if (rr->type == SSL3_RT_ALERT) {
590 dest_maxlen = sizeof(s->d1->alert_fragment);
591 dest = s->d1->alert_fragment;
592 dest_len = &s->d1->alert_fragment_len;
594 #ifndef OPENSSL_NO_HEARTBEATS
595 else if (rr->type == TLS1_RT_HEARTBEAT) {
596 /* We allow a 0 return */
597 if(dtls1_process_heartbeat(s, SSL3_RECORD_get_data(&s->rlayer.rrec),
598 SSL3_RECORD_get_length(&s->rlayer.rrec)) < 0) {
601 /* Exit and notify application to read again */
603 s->rwstate = SSL_READING;
604 BIO_clear_retry_flags(SSL_get_rbio(s));
605 BIO_set_retry_read(SSL_get_rbio(s));
609 /* else it's a CCS message, or application data or wrong */
610 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
612 * Application data while renegotiating is allowed. Try again
615 if (rr->type == SSL3_RT_APPLICATION_DATA) {
617 s->s3->in_read_app_data = 2;
618 bio = SSL_get_rbio(s);
619 s->rwstate = SSL_READING;
620 BIO_clear_retry_flags(bio);
621 BIO_set_retry_read(bio);
625 /* Not certain if this is the right error handling */
626 al = SSL_AD_UNEXPECTED_MESSAGE;
627 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
631 if (dest_maxlen > 0) {
633 * XDTLS: In a pathalogical case, the Client Hello may be
634 * fragmented--don't always expect dest_maxlen bytes
636 if (rr->length < dest_maxlen) {
637 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
639 * for normal alerts rr->length is 2, while
640 * dest_maxlen is 7 if we were to handle this
641 * non-existing alert...
645 s->rlayer.rstate = SSL_ST_READ_HEADER;
650 /* now move 'n' bytes: */
651 for (k = 0; k < dest_maxlen; k++) {
652 dest[k] = rr->data[rr->off++];
655 *dest_len = dest_maxlen;
660 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
661 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
662 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
665 /* If we are a client, check for an incoming 'Hello Request': */
667 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
668 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
669 (s->session != NULL) && (s->session->cipher != NULL)) {
670 s->d1->handshake_fragment_len = 0;
672 if ((s->d1->handshake_fragment[1] != 0) ||
673 (s->d1->handshake_fragment[2] != 0) ||
674 (s->d1->handshake_fragment[3] != 0)) {
675 al = SSL_AD_DECODE_ERROR;
676 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
681 * no need to check sequence number on HELLO REQUEST messages
685 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
686 s->d1->handshake_fragment, 4, s,
687 s->msg_callback_arg);
689 if (SSL_is_init_finished(s) &&
690 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
691 !s->s3->renegotiate) {
692 s->d1->handshake_read_seq++;
695 if (ssl3_renegotiate_check(s)) {
696 i = s->handshake_func(s);
700 SSLerr(SSL_F_DTLS1_READ_BYTES,
701 SSL_R_SSL_HANDSHAKE_FAILURE);
705 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
706 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
707 /* no read-ahead left? */
710 * In the case where we try to read application data,
711 * but we trigger an SSL handshake, we return -1 with
712 * the retry option set. Otherwise renegotiation may
713 * cause nasty problems in the blocking world
715 s->rwstate = SSL_READING;
716 bio = SSL_get_rbio(s);
717 BIO_clear_retry_flags(bio);
718 BIO_set_retry_read(bio);
725 * we either finished a handshake or ignored the request, now try
726 * again to obtain the (application) data we were asked for
731 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
732 int alert_level = s->d1->alert_fragment[0];
733 int alert_descr = s->d1->alert_fragment[1];
735 s->d1->alert_fragment_len = 0;
738 s->msg_callback(0, s->version, SSL3_RT_ALERT,
739 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
741 if (s->info_callback != NULL)
742 cb = s->info_callback;
743 else if (s->ctx->info_callback != NULL)
744 cb = s->ctx->info_callback;
747 j = (alert_level << 8) | alert_descr;
748 cb(s, SSL_CB_READ_ALERT, j);
751 if (alert_level == SSL3_AL_WARNING) {
752 s->s3->warn_alert = alert_descr;
753 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
754 #ifndef OPENSSL_NO_SCTP
756 * With SCTP and streams the socket may deliver app data
757 * after a close_notify alert. We have to check this first so
758 * that nothing gets discarded.
760 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
761 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
762 s->d1->shutdown_received = 1;
763 s->rwstate = SSL_READING;
764 BIO_clear_retry_flags(SSL_get_rbio(s));
765 BIO_set_retry_read(SSL_get_rbio(s));
769 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
773 /* XXX: this is a possible improvement in the future */
774 /* now check if it's a missing record */
775 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
777 unsigned int frag_off;
778 unsigned char *p = &(s->d1->alert_fragment[2]);
783 dtls1_retransmit_message(s,
784 dtls1_get_queue_priority
785 (frag->msg_header.seq, 0), frag_off,
787 if (!found && SSL_in_init(s)) {
789 * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
792 * requested a message not yet sent, send an alert
795 ssl3_send_alert(s, SSL3_AL_WARNING,
796 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
800 } else if (alert_level == SSL3_AL_FATAL) {
803 s->rwstate = SSL_NOTHING;
804 s->s3->fatal_alert = alert_descr;
805 SSLerr(SSL_F_DTLS1_READ_BYTES,
806 SSL_AD_REASON_OFFSET + alert_descr);
807 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
808 ERR_add_error_data(2, "SSL alert number ", tmp);
809 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
810 SSL_CTX_remove_session(s->ctx, s->session);
813 al = SSL_AD_ILLEGAL_PARAMETER;
814 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
821 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
823 s->rwstate = SSL_NOTHING;
828 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
829 struct ccs_header_st ccs_hdr;
830 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
832 dtls1_get_ccs_header(rr->data, &ccs_hdr);
834 if (s->version == DTLS1_BAD_VER)
838 * 'Change Cipher Spec' is just a single byte, so we know exactly
839 * what the record payload has to look like
841 /* XDTLS: check that epoch is consistent */
842 if ((rr->length != ccs_hdr_len) ||
843 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
844 i = SSL_AD_ILLEGAL_PARAMETER;
845 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
852 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
853 rr->data, 1, s, s->msg_callback_arg);
856 * We can't process a CCS now, because previous handshake messages
857 * are still missing, so just drop it.
859 if (!s->d1->change_cipher_spec_ok) {
863 s->d1->change_cipher_spec_ok = 0;
865 s->s3->change_cipher_spec = 1;
866 if (!ssl3_do_change_cipher_spec(s))
869 /* do this whenever CCS is processed */
870 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
872 if (s->version == DTLS1_BAD_VER)
873 s->d1->handshake_read_seq++;
875 #ifndef OPENSSL_NO_SCTP
877 * Remember that a CCS has been received, so that an old key of
878 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
881 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
888 * Unexpected handshake message (Client Hello, or protocol violation)
890 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
892 struct hm_header_st msg_hdr;
894 /* this may just be a stale retransmit */
895 dtls1_get_message_header(rr->data, &msg_hdr);
896 if (rr->epoch != s->rlayer.d->r_epoch) {
902 * If we are server, we may have a repeated FINISHED of the client
903 * here, then retransmit our CCS and FINISHED.
905 if (msg_hdr.type == SSL3_MT_FINISHED) {
906 if (dtls1_check_timeout_num(s) < 0)
909 dtls1_retransmit_buffered_messages(s);
914 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
915 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
916 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
920 i = s->handshake_func(s);
924 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
928 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
929 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
930 /* no read-ahead left? */
933 * In the case where we try to read application data, but we
934 * trigger an SSL handshake, we return -1 with the retry
935 * option set. Otherwise renegotiation may cause nasty
936 * problems in the blocking world
938 s->rwstate = SSL_READING;
939 bio = SSL_get_rbio(s);
940 BIO_clear_retry_flags(bio);
941 BIO_set_retry_read(bio);
950 /* TLS just ignores unknown message types */
951 if (s->version == TLS1_VERSION) {
955 al = SSL_AD_UNEXPECTED_MESSAGE;
956 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
958 case SSL3_RT_CHANGE_CIPHER_SPEC:
960 case SSL3_RT_HANDSHAKE:
962 * we already handled all of these, with the possible exception of
963 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
964 * happen when type != rr->type
966 al = SSL_AD_UNEXPECTED_MESSAGE;
967 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
969 case SSL3_RT_APPLICATION_DATA:
971 * At this point, we were expecting handshake data, but have
972 * application data. If the library was running inside ssl3_read()
973 * (i.e. in_read_app_data is set) and it makes sense to read
974 * application data at this point (session renegotiation not yet
975 * started), we will indulge it.
977 if (s->s3->in_read_app_data &&
978 (s->s3->total_renegotiations != 0) &&
979 (((s->state & SSL_ST_CONNECT) &&
980 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
981 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
982 ) || ((s->state & SSL_ST_ACCEPT) &&
983 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
984 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
987 s->s3->in_read_app_data = 2;
990 al = SSL_AD_UNEXPECTED_MESSAGE;
991 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
998 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1005 * this only happens when a client hello is received and a handshake
1009 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1013 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1014 /* (partially) satisfy request from storage */
1016 unsigned char *src = s->d1->handshake_fragment;
1017 unsigned char *dst = buf;
1022 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) {
1025 s->d1->handshake_fragment_len--;
1028 /* move any remaining fragment bytes: */
1029 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1030 s->d1->handshake_fragment[k] = *src++;
1038 * Call this to write data in records of type 'type' It will return <= 0 if
1039 * not all data has been sent or non-blocking IO.
1041 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1045 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1046 s->rwstate = SSL_NOTHING;
1047 i = do_dtls1_write(s, type, buf, len, 0);
1051 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
1052 unsigned int len, int create_empty_fragment)
1054 unsigned char *p, *pseq;
1055 int i, mac_size, clear = 0;
1062 wb = &s->rlayer.wbuf;
1065 * first check if there is a SSL3_BUFFER still being written out. This
1066 * will happen with non blocking IO
1068 if (SSL3_BUFFER_get_left(wb) != 0) {
1069 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1070 return (ssl3_write_pending(s, type, buf, len));
1073 /* If we have an alert to send, lets send it */
1074 if (s->s3->alert_dispatch) {
1075 i = s->method->ssl_dispatch_alert(s);
1078 /* if it went, fall through and send more stuff */
1081 if (len == 0 && !create_empty_fragment)
1084 wr = &s->rlayer.wrec;
1087 if ((sess == NULL) ||
1088 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
1094 mac_size = EVP_MD_CTX_size(s->write_hash);
1099 p = wb->buf + prefix_len;
1101 /* write the header */
1103 *(p++) = type & 0xff;
1106 * Special case: for hello verify request, client version 1.0 and we
1107 * haven't decided which version to use yet send back using version 1.0
1108 * header: otherwise some clients will ignore it.
1110 if (s->method->version == DTLS_ANY_VERSION) {
1111 *(p++) = DTLS1_VERSION >> 8;
1112 *(p++) = DTLS1_VERSION & 0xff;
1114 *(p++) = s->version >> 8;
1115 *(p++) = s->version & 0xff;
1118 /* field where we are to write out packet epoch, seq num and len */
1122 /* Explicit IV length, block ciphers appropriate version flag */
1123 if (s->enc_write_ctx) {
1124 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1125 if (mode == EVP_CIPH_CBC_MODE) {
1126 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1130 /* Need explicit part of IV for GCM mode */
1131 else if (mode == EVP_CIPH_GCM_MODE)
1132 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1138 /* lets setup the record stuff. */
1139 wr->data = p + eivlen; /* make room for IV in case of CBC */
1140 wr->length = (int)len;
1141 wr->input = (unsigned char *)buf;
1144 * we now 'read' from wr->input, wr->length bytes into wr->data
1147 /* first we compress */
1148 if (s->compress != NULL) {
1149 if (!ssl3_do_compress(s)) {
1150 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
1154 memcpy(wr->data, wr->input, wr->length);
1155 wr->input = wr->data;
1159 * we should still have the output to wr->data and the input from
1160 * wr->input. Length should be wr->length. wr->data still points in the
1164 if (mac_size != 0) {
1165 if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
1167 wr->length += mac_size;
1170 /* this is true regardless of mac size */
1175 wr->length += eivlen;
1177 if (s->method->ssl3_enc->enc(s, 1) < 1)
1180 /* record length after mac and block padding */
1182 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
1186 /* there's only one epoch between handshake and app data */
1188 s2n(s->rlayer.d->w_epoch, pseq);
1192 * else s2n(s->d1->handshake_epoch, pseq);
1195 memcpy(pseq, &(s->rlayer.write_sequence[2]), 6);
1197 s2n(wr->length, pseq);
1199 if (s->msg_callback)
1200 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
1201 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1204 * we should now have wr->data pointing to the encrypted data, which is
1207 wr->type = type; /* not needed but helps for debugging */
1208 wr->length += DTLS1_RT_HEADER_LENGTH;
1210 ssl3_record_sequence_update(&(s->rlayer.write_sequence[0]));
1212 if (create_empty_fragment) {
1214 * we are in a recursive call; just return the length, don't write
1220 /* now let's set up wb */
1221 wb->left = prefix_len + wr->length;
1225 * memorize arguments so that ssl3_write_pending can detect bad write
1228 s->rlayer.wpend_tot = len;
1229 s->rlayer.wpend_buf = buf;
1230 s->rlayer.wpend_type = type;
1231 s->rlayer.wpend_ret = len;
1233 /* we now just need to write the buffer */
1234 return ssl3_write_pending(s, type, buf, len);
1239 DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1240 unsigned int *is_next_epoch)
1245 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1246 if (rr->epoch == s->rlayer.d->r_epoch)
1247 return &s->rlayer.d->bitmap;
1249 /* Only HM and ALERT messages can be from the next epoch */
1250 else if (rr->epoch == (unsigned long)(s->rlayer.d->r_epoch + 1) &&
1251 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1253 return &s->rlayer.d->next_bitmap;
1259 void dtls1_reset_seq_numbers(SSL *s, int rw)
1262 unsigned int seq_bytes = sizeof(s->rlayer.read_sequence);
1264 if (rw & SSL3_CC_READ) {
1265 seq = s->rlayer.read_sequence;
1266 s->rlayer.d->r_epoch++;
1267 memcpy(&(s->rlayer.d->bitmap), &(s->rlayer.d->next_bitmap), sizeof(DTLS1_BITMAP));
1268 memset(&(s->rlayer.d->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1270 seq = s->rlayer.write_sequence;
1271 memcpy(s->d1->last_write_sequence, seq,
1272 sizeof(s->rlayer.write_sequence));
1273 s->rlayer.d->w_epoch++;
1276 memset(seq, 0x00, seq_bytes);