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();
139 d->buffered_app_data.q = pqueue_new();
141 if (!d->unprocessed_rcds.q || !d->processed_rcds.q
142 || !d->buffered_app_data.q) {
143 if (d->unprocessed_rcds.q)
144 pqueue_free(d->unprocessed_rcds.q);
145 if (d->processed_rcds.q)
146 pqueue_free(d->processed_rcds.q);
147 if (d->buffered_app_data.q)
148 pqueue_free(d->buffered_app_data.q);
157 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl)
159 DTLS_RECORD_LAYER_clear(rl);
160 pqueue_free(rl->d->unprocessed_rcds.q);
161 pqueue_free(rl->d->processed_rcds.q);
162 pqueue_free(rl->d->buffered_app_data.q);
167 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
169 DTLS_RECORD_LAYER *d;
171 DTLS1_RECORD_DATA *rdata;
172 pqueue unprocessed_rcds;
173 pqueue processed_rcds;
174 pqueue buffered_app_data;
178 while ((item = pqueue_pop(d->unprocessed_rcds.q)) != NULL) {
179 rdata = (DTLS1_RECORD_DATA *)item->data;
180 if (rdata->rbuf.buf) {
181 OPENSSL_free(rdata->rbuf.buf);
183 OPENSSL_free(item->data);
187 while ((item = pqueue_pop(d->processed_rcds.q)) != NULL) {
188 rdata = (DTLS1_RECORD_DATA *)item->data;
189 if (rdata->rbuf.buf) {
190 OPENSSL_free(rdata->rbuf.buf);
192 OPENSSL_free(item->data);
196 while ((item = pqueue_pop(d->buffered_app_data.q)) != NULL) {
197 rdata = (DTLS1_RECORD_DATA *)item->data;
198 if (rdata->rbuf.buf) {
199 OPENSSL_free(rdata->rbuf.buf);
201 OPENSSL_free(item->data);
205 unprocessed_rcds = d->unprocessed_rcds.q;
206 processed_rcds = d->processed_rcds.q;
207 buffered_app_data = d->buffered_app_data.q;
208 memset(d, 0, sizeof *d);
209 d->unprocessed_rcds.q = unprocessed_rcds;
210 d->processed_rcds.q = processed_rcds;
211 d->buffered_app_data.q = buffered_app_data;
214 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
217 /* copy buffered record into SSL structure */
218 static int dtls1_copy_record(SSL *s, pitem *item)
220 DTLS1_RECORD_DATA *rdata;
222 rdata = (DTLS1_RECORD_DATA *)item->data;
224 SSL3_BUFFER_release(&s->rlayer.rbuf);
226 s->rlayer.packet = rdata->packet;
227 s->rlayer.packet_length = rdata->packet_length;
228 memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER));
229 memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD));
231 /* Set proper sequence number for mac calculation */
232 memcpy(&(s->rlayer.read_sequence[2]), &(rdata->packet[5]), 6);
238 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
240 DTLS1_RECORD_DATA *rdata;
243 /* Limit the size of the queue to prevent DOS attacks */
244 if (pqueue_size(queue->q) >= 100)
247 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
248 item = pitem_new(priority, rdata);
249 if (rdata == NULL || item == NULL) {
255 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
259 rdata->packet = s->rlayer.packet;
260 rdata->packet_length = s->rlayer.packet_length;
261 memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER));
262 memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD));
266 #ifndef OPENSSL_NO_SCTP
267 /* Store bio_dgram_sctp_rcvinfo struct */
268 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
269 (s->state == SSL3_ST_SR_FINISHED_A
270 || s->state == SSL3_ST_CR_FINISHED_A)) {
271 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
272 sizeof(rdata->recordinfo), &rdata->recordinfo);
276 s->rlayer.packet = NULL;
277 s->rlayer.packet_length = 0;
278 memset(&s->rlayer.rbuf, 0, sizeof(SSL3_BUFFER));
279 memset(&s->rlayer.rrec, 0, sizeof(SSL3_RECORD));
281 if (!ssl3_setup_buffers(s)) {
282 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
283 if (rdata->rbuf.buf != NULL)
284 OPENSSL_free(rdata->rbuf.buf);
290 /* insert should not fail, since duplicates are dropped */
291 if (pqueue_insert(queue->q, item) == NULL) {
292 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
293 if (rdata->rbuf.buf != NULL)
294 OPENSSL_free(rdata->rbuf.buf);
303 int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
307 item = pqueue_pop(queue->q);
309 dtls1_copy_record(s, item);
311 OPENSSL_free(item->data);
321 * retrieve a buffered record that belongs to the new epoch, i.e., not
324 #define dtls1_get_unprocessed_record(s) \
325 dtls1_retrieve_buffered_record((s), \
326 &((s)->rlayer.d->unprocessed_rcds))
329 int dtls1_process_buffered_records(SSL *s)
333 item = pqueue_peek(s->rlayer.d->unprocessed_rcds.q);
335 /* Check if epoch is current. */
336 if (s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch)
337 return (1); /* Nothing to do. */
339 /* Process all the records. */
340 while (pqueue_peek(s->rlayer.d->unprocessed_rcds.q)) {
341 dtls1_get_unprocessed_record(s);
342 if (!dtls1_process_record(s))
344 if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds),
345 SSL3_RECORD_get_seq_num(&s->rlayer.rrec)) < 0)
351 * sync epoch numbers once all the unprocessed records have been
354 s->rlayer.d->processed_rcds.epoch = s->rlayer.d->r_epoch;
355 s->rlayer.d->unprocessed_rcds.epoch = s->rlayer.d->r_epoch + 1;
362 * Return up to 'len' payload bytes received in 'type' records.
363 * 'type' is one of the following:
365 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
366 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
367 * - 0 (during a shutdown, no data has to be returned)
369 * If we don't have stored data to work from, read a SSL/TLS record first
370 * (possibly multiple records if we still don't have anything to return).
372 * This function must handle any surprises the peer may have for us, such as
373 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
374 * a surprise, but handled as if it were), or renegotiation requests.
375 * Also if record payloads contain fragments too small to process, we store
376 * them until there is enough for the respective protocol (the record protocol
377 * may use arbitrary fragmentation and even interleaving):
378 * Change cipher spec protocol
379 * just 1 byte needed, no need for keeping anything stored
381 * 2 bytes needed (AlertLevel, AlertDescription)
383 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
384 * to detect unexpected Client Hello and Hello Request messages
385 * here, anything else is handled by higher layers
386 * Application data protocol
387 * none of our business
389 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
394 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
396 if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
397 /* Not initialized yet */
398 if (!ssl3_setup_buffers(s))
402 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
403 (type != SSL3_RT_HANDSHAKE)) ||
404 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
405 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
410 * check whether there's a handshake message (client hello?) waiting
412 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
416 * Now s->rlayer.d->handshake_fragment_len == 0 if
417 * type == SSL3_RT_HANDSHAKE.
420 #ifndef OPENSSL_NO_SCTP
422 * Continue handshake if it had to be interrupted to read app data with
425 if ((!s->in_handshake && SSL_in_init(s)) ||
426 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
427 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
428 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
429 && s->s3->in_read_app_data != 2))
431 if (!s->in_handshake && SSL_in_init(s))
434 /* type == SSL3_RT_APPLICATION_DATA */
435 i = s->handshake_func(s);
439 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
445 s->rwstate = SSL_NOTHING;
448 * s->s3->rrec.type - is the type of record
449 * s->s3->rrec.data, - data
450 * s->s3->rrec.off, - offset into 'data' for next read
451 * s->s3->rrec.length, - number of bytes.
453 rr = &s->rlayer.rrec;
456 * We are not handshaking and have no data yet, so process data buffered
457 * during the last handshake in advance, if any.
459 if (s->state == SSL_ST_OK && rr->length == 0) {
461 item = pqueue_pop(s->rlayer.d->buffered_app_data.q);
463 #ifndef OPENSSL_NO_SCTP
464 /* Restore bio_dgram_sctp_rcvinfo struct */
465 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
466 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
467 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
468 sizeof(rdata->recordinfo), &rdata->recordinfo);
472 dtls1_copy_record(s, item);
474 OPENSSL_free(item->data);
479 /* Check for timeout */
480 if (dtls1_handle_timeout(s) > 0)
483 /* get new packet if necessary */
484 if ((rr->length == 0) || (s->rlayer.rstate == SSL_ST_READ_BODY)) {
485 ret = dtls1_get_record(s);
487 ret = dtls1_read_failed(s, ret);
488 /* anything other than a timeout is an error */
496 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
501 /* we now have a packet which can be read and processed */
503 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
504 * reset by ssl3_get_finished */
505 && (rr->type != SSL3_RT_HANDSHAKE)) {
507 * We now have application data between CCS and Finished. Most likely
508 * the packets were reordered on their way, so buffer the application
509 * data for later processing rather than dropping the connection.
511 if (dtls1_buffer_record(s, &(s->rlayer.d->buffered_app_data),
513 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
521 * If the other end has shut down, throw anything we read away (even in
524 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
526 s->rwstate = SSL_NOTHING;
530 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or
531 * SSL3_RT_HANDSHAKE */
533 * make sure that we are not getting application data when we are
534 * doing a handshake for the first time
536 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
537 (s->enc_read_ctx == NULL)) {
538 al = SSL_AD_UNEXPECTED_MESSAGE;
539 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
546 if ((unsigned int)len > rr->length)
549 n = (unsigned int)len;
551 memcpy(buf, &(rr->data[rr->off]), n);
555 if (rr->length == 0) {
556 s->rlayer.rstate = SSL_ST_READ_HEADER;
560 #ifndef OPENSSL_NO_SCTP
562 * We were about to renegotiate but had to read belated application
563 * data first, so retry.
565 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
566 rr->type == SSL3_RT_APPLICATION_DATA &&
567 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
568 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
569 s->rwstate = SSL_READING;
570 BIO_clear_retry_flags(SSL_get_rbio(s));
571 BIO_set_retry_read(SSL_get_rbio(s));
575 * We might had to delay a close_notify alert because of reordered
576 * app data. If there was an alert and there is no message to read
577 * anymore, finally set shutdown.
579 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
580 s->d1->shutdown_received
581 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
582 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
590 * If we get here, then type != rr->type; if we have a handshake message,
591 * then it was unexpected (Hello Request or Client Hello).
595 * In case of record types for which we have 'fragment' storage, fill
596 * that so that we can process the data at a fixed place.
599 unsigned int k, dest_maxlen = 0;
600 unsigned char *dest = NULL;
601 unsigned int *dest_len = NULL;
603 if (rr->type == SSL3_RT_HANDSHAKE) {
604 dest_maxlen = sizeof s->rlayer.d->handshake_fragment;
605 dest = s->rlayer.d->handshake_fragment;
606 dest_len = &s->rlayer.d->handshake_fragment_len;
607 } else if (rr->type == SSL3_RT_ALERT) {
608 dest_maxlen = sizeof(s->rlayer.d->alert_fragment);
609 dest = s->rlayer.d->alert_fragment;
610 dest_len = &s->rlayer.d->alert_fragment_len;
612 #ifndef OPENSSL_NO_HEARTBEATS
613 else if (rr->type == TLS1_RT_HEARTBEAT) {
614 /* We allow a 0 return */
615 if(dtls1_process_heartbeat(s, SSL3_RECORD_get_data(&s->rlayer.rrec),
616 SSL3_RECORD_get_length(&s->rlayer.rrec)) < 0) {
619 /* Exit and notify application to read again */
621 s->rwstate = SSL_READING;
622 BIO_clear_retry_flags(SSL_get_rbio(s));
623 BIO_set_retry_read(SSL_get_rbio(s));
627 /* else it's a CCS message, or application data or wrong */
628 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
630 * Application data while renegotiating is allowed. Try again
633 if (rr->type == SSL3_RT_APPLICATION_DATA) {
635 s->s3->in_read_app_data = 2;
636 bio = SSL_get_rbio(s);
637 s->rwstate = SSL_READING;
638 BIO_clear_retry_flags(bio);
639 BIO_set_retry_read(bio);
643 /* Not certain if this is the right error handling */
644 al = SSL_AD_UNEXPECTED_MESSAGE;
645 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
649 if (dest_maxlen > 0) {
651 * XDTLS: In a pathalogical case, the Client Hello may be
652 * fragmented--don't always expect dest_maxlen bytes
654 if (rr->length < dest_maxlen) {
655 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
657 * for normal alerts rr->length is 2, while
658 * dest_maxlen is 7 if we were to handle this
659 * non-existing alert...
663 s->rlayer.rstate = SSL_ST_READ_HEADER;
668 /* now move 'n' bytes: */
669 for (k = 0; k < dest_maxlen; k++) {
670 dest[k] = rr->data[rr->off++];
673 *dest_len = dest_maxlen;
678 * s->rlayer.d->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
679 * s->rlayer.d->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
680 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
683 /* If we are a client, check for an incoming 'Hello Request': */
685 (s->rlayer.d->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
686 (s->rlayer.d->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
687 (s->session != NULL) && (s->session->cipher != NULL)) {
688 s->rlayer.d->handshake_fragment_len = 0;
690 if ((s->rlayer.d->handshake_fragment[1] != 0) ||
691 (s->rlayer.d->handshake_fragment[2] != 0) ||
692 (s->rlayer.d->handshake_fragment[3] != 0)) {
693 al = SSL_AD_DECODE_ERROR;
694 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
699 * no need to check sequence number on HELLO REQUEST messages
703 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
704 s->rlayer.d->handshake_fragment, 4, s,
705 s->msg_callback_arg);
707 if (SSL_is_init_finished(s) &&
708 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
709 !s->s3->renegotiate) {
710 s->d1->handshake_read_seq++;
713 if (ssl3_renegotiate_check(s)) {
714 i = s->handshake_func(s);
718 SSLerr(SSL_F_DTLS1_READ_BYTES,
719 SSL_R_SSL_HANDSHAKE_FAILURE);
723 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
724 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
725 /* no read-ahead left? */
728 * In the case where we try to read application data,
729 * but we trigger an SSL handshake, we return -1 with
730 * the retry option set. Otherwise renegotiation may
731 * cause nasty problems in the blocking world
733 s->rwstate = SSL_READING;
734 bio = SSL_get_rbio(s);
735 BIO_clear_retry_flags(bio);
736 BIO_set_retry_read(bio);
743 * we either finished a handshake or ignored the request, now try
744 * again to obtain the (application) data we were asked for
749 if (s->rlayer.d->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
750 int alert_level = s->rlayer.d->alert_fragment[0];
751 int alert_descr = s->rlayer.d->alert_fragment[1];
753 s->rlayer.d->alert_fragment_len = 0;
756 s->msg_callback(0, s->version, SSL3_RT_ALERT,
757 s->rlayer.d->alert_fragment, 2, s,
758 s->msg_callback_arg);
760 if (s->info_callback != NULL)
761 cb = s->info_callback;
762 else if (s->ctx->info_callback != NULL)
763 cb = s->ctx->info_callback;
766 j = (alert_level << 8) | alert_descr;
767 cb(s, SSL_CB_READ_ALERT, j);
770 if (alert_level == SSL3_AL_WARNING) {
771 s->s3->warn_alert = alert_descr;
772 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
773 #ifndef OPENSSL_NO_SCTP
775 * With SCTP and streams the socket may deliver app data
776 * after a close_notify alert. We have to check this first so
777 * that nothing gets discarded.
779 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
780 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
781 s->d1->shutdown_received = 1;
782 s->rwstate = SSL_READING;
783 BIO_clear_retry_flags(SSL_get_rbio(s));
784 BIO_set_retry_read(SSL_get_rbio(s));
788 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
792 /* XXX: this is a possible improvement in the future */
793 /* now check if it's a missing record */
794 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
796 unsigned int frag_off;
797 unsigned char *p = &(s->rlayer.d->alert_fragment[2]);
802 dtls1_retransmit_message(s,
803 dtls1_get_queue_priority
804 (frag->msg_header.seq, 0), frag_off,
806 if (!found && SSL_in_init(s)) {
808 * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
811 * requested a message not yet sent, send an alert
814 ssl3_send_alert(s, SSL3_AL_WARNING,
815 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
819 } else if (alert_level == SSL3_AL_FATAL) {
822 s->rwstate = SSL_NOTHING;
823 s->s3->fatal_alert = alert_descr;
824 SSLerr(SSL_F_DTLS1_READ_BYTES,
825 SSL_AD_REASON_OFFSET + alert_descr);
826 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
827 ERR_add_error_data(2, "SSL alert number ", tmp);
828 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
829 SSL_CTX_remove_session(s->ctx, s->session);
832 al = SSL_AD_ILLEGAL_PARAMETER;
833 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
840 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
842 s->rwstate = SSL_NOTHING;
847 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
848 struct ccs_header_st ccs_hdr;
849 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
851 dtls1_get_ccs_header(rr->data, &ccs_hdr);
853 if (s->version == DTLS1_BAD_VER)
857 * 'Change Cipher Spec' is just a single byte, so we know exactly
858 * what the record payload has to look like
860 /* XDTLS: check that epoch is consistent */
861 if ((rr->length != ccs_hdr_len) ||
862 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
863 i = SSL_AD_ILLEGAL_PARAMETER;
864 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
871 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
872 rr->data, 1, s, s->msg_callback_arg);
875 * We can't process a CCS now, because previous handshake messages
876 * are still missing, so just drop it.
878 if (!s->d1->change_cipher_spec_ok) {
882 s->d1->change_cipher_spec_ok = 0;
884 s->s3->change_cipher_spec = 1;
885 if (!ssl3_do_change_cipher_spec(s))
888 /* do this whenever CCS is processed */
889 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
891 if (s->version == DTLS1_BAD_VER)
892 s->d1->handshake_read_seq++;
894 #ifndef OPENSSL_NO_SCTP
896 * Remember that a CCS has been received, so that an old key of
897 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
900 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
907 * Unexpected handshake message (Client Hello, or protocol violation)
909 if ((s->rlayer.d->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
911 struct hm_header_st msg_hdr;
913 /* this may just be a stale retransmit */
914 dtls1_get_message_header(rr->data, &msg_hdr);
915 if (rr->epoch != s->rlayer.d->r_epoch) {
921 * If we are server, we may have a repeated FINISHED of the client
922 * here, then retransmit our CCS and FINISHED.
924 if (msg_hdr.type == SSL3_MT_FINISHED) {
925 if (dtls1_check_timeout_num(s) < 0)
928 dtls1_retransmit_buffered_messages(s);
933 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
934 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
935 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
939 i = s->handshake_func(s);
943 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
947 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
948 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
949 /* no read-ahead left? */
952 * In the case where we try to read application data, but we
953 * trigger an SSL handshake, we return -1 with the retry
954 * option set. Otherwise renegotiation may cause nasty
955 * problems in the blocking world
957 s->rwstate = SSL_READING;
958 bio = SSL_get_rbio(s);
959 BIO_clear_retry_flags(bio);
960 BIO_set_retry_read(bio);
969 /* TLS just ignores unknown message types */
970 if (s->version == TLS1_VERSION) {
974 al = SSL_AD_UNEXPECTED_MESSAGE;
975 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
977 case SSL3_RT_CHANGE_CIPHER_SPEC:
979 case SSL3_RT_HANDSHAKE:
981 * we already handled all of these, with the possible exception of
982 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
983 * happen when type != rr->type
985 al = SSL_AD_UNEXPECTED_MESSAGE;
986 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
988 case SSL3_RT_APPLICATION_DATA:
990 * At this point, we were expecting handshake data, but have
991 * application data. If the library was running inside ssl3_read()
992 * (i.e. in_read_app_data is set) and it makes sense to read
993 * application data at this point (session renegotiation not yet
994 * started), we will indulge it.
996 if (s->s3->in_read_app_data &&
997 (s->s3->total_renegotiations != 0) &&
998 (((s->state & SSL_ST_CONNECT) &&
999 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1000 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1001 ) || ((s->state & SSL_ST_ACCEPT) &&
1002 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1003 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1006 s->s3->in_read_app_data = 2;
1009 al = SSL_AD_UNEXPECTED_MESSAGE;
1010 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1017 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1024 * this only happens when a client hello is received and a handshake
1028 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1032 if ((type == SSL3_RT_HANDSHAKE)
1033 && (s->rlayer.d->handshake_fragment_len > 0))
1034 /* (partially) satisfy request from storage */
1036 unsigned char *src = s->rlayer.d->handshake_fragment;
1037 unsigned char *dst = buf;
1042 while ((len > 0) && (s->rlayer.d->handshake_fragment_len > 0)) {
1045 s->rlayer.d->handshake_fragment_len--;
1048 /* move any remaining fragment bytes: */
1049 for (k = 0; k < s->rlayer.d->handshake_fragment_len; k++)
1050 s->rlayer.d->handshake_fragment[k] = *src++;
1058 * Call this to write data in records of type 'type' It will return <= 0 if
1059 * not all data has been sent or non-blocking IO.
1061 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1065 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1066 s->rwstate = SSL_NOTHING;
1067 i = do_dtls1_write(s, type, buf, len, 0);
1071 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
1072 unsigned int len, int create_empty_fragment)
1074 unsigned char *p, *pseq;
1075 int i, mac_size, clear = 0;
1082 wb = &s->rlayer.wbuf;
1085 * first check if there is a SSL3_BUFFER still being written out. This
1086 * will happen with non blocking IO
1088 if (SSL3_BUFFER_get_left(wb) != 0) {
1089 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1090 return (ssl3_write_pending(s, type, buf, len));
1093 /* If we have an alert to send, lets send it */
1094 if (s->s3->alert_dispatch) {
1095 i = s->method->ssl_dispatch_alert(s);
1098 /* if it went, fall through and send more stuff */
1101 if (len == 0 && !create_empty_fragment)
1104 wr = &s->rlayer.wrec;
1107 if ((sess == NULL) ||
1108 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
1114 mac_size = EVP_MD_CTX_size(s->write_hash);
1119 p = wb->buf + prefix_len;
1121 /* write the header */
1123 *(p++) = type & 0xff;
1126 * Special case: for hello verify request, client version 1.0 and we
1127 * haven't decided which version to use yet send back using version 1.0
1128 * header: otherwise some clients will ignore it.
1130 if (s->method->version == DTLS_ANY_VERSION) {
1131 *(p++) = DTLS1_VERSION >> 8;
1132 *(p++) = DTLS1_VERSION & 0xff;
1134 *(p++) = s->version >> 8;
1135 *(p++) = s->version & 0xff;
1138 /* field where we are to write out packet epoch, seq num and len */
1142 /* Explicit IV length, block ciphers appropriate version flag */
1143 if (s->enc_write_ctx) {
1144 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1145 if (mode == EVP_CIPH_CBC_MODE) {
1146 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1150 /* Need explicit part of IV for GCM mode */
1151 else if (mode == EVP_CIPH_GCM_MODE)
1152 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1158 /* lets setup the record stuff. */
1159 wr->data = p + eivlen; /* make room for IV in case of CBC */
1160 wr->length = (int)len;
1161 wr->input = (unsigned char *)buf;
1164 * we now 'read' from wr->input, wr->length bytes into wr->data
1167 /* first we compress */
1168 if (s->compress != NULL) {
1169 if (!ssl3_do_compress(s)) {
1170 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
1174 memcpy(wr->data, wr->input, wr->length);
1175 wr->input = wr->data;
1179 * we should still have the output to wr->data and the input from
1180 * wr->input. Length should be wr->length. wr->data still points in the
1184 if (mac_size != 0) {
1185 if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
1187 wr->length += mac_size;
1190 /* this is true regardless of mac size */
1195 wr->length += eivlen;
1197 if (s->method->ssl3_enc->enc(s, 1) < 1)
1200 /* record length after mac and block padding */
1202 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
1206 /* there's only one epoch between handshake and app data */
1208 s2n(s->rlayer.d->w_epoch, pseq);
1212 * else s2n(s->d1->handshake_epoch, pseq);
1215 memcpy(pseq, &(s->rlayer.write_sequence[2]), 6);
1217 s2n(wr->length, pseq);
1219 if (s->msg_callback)
1220 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
1221 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1224 * we should now have wr->data pointing to the encrypted data, which is
1227 wr->type = type; /* not needed but helps for debugging */
1228 wr->length += DTLS1_RT_HEADER_LENGTH;
1230 ssl3_record_sequence_update(&(s->rlayer.write_sequence[0]));
1232 if (create_empty_fragment) {
1234 * we are in a recursive call; just return the length, don't write
1240 /* now let's set up wb */
1241 wb->left = prefix_len + wr->length;
1245 * memorize arguments so that ssl3_write_pending can detect bad write
1248 s->rlayer.wpend_tot = len;
1249 s->rlayer.wpend_buf = buf;
1250 s->rlayer.wpend_type = type;
1251 s->rlayer.wpend_ret = len;
1253 /* we now just need to write the buffer */
1254 return ssl3_write_pending(s, type, buf, len);
1259 DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1260 unsigned int *is_next_epoch)
1265 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1266 if (rr->epoch == s->rlayer.d->r_epoch)
1267 return &s->rlayer.d->bitmap;
1269 /* Only HM and ALERT messages can be from the next epoch */
1270 else if (rr->epoch == (unsigned long)(s->rlayer.d->r_epoch + 1) &&
1271 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1273 return &s->rlayer.d->next_bitmap;
1279 void dtls1_reset_seq_numbers(SSL *s, int rw)
1282 unsigned int seq_bytes = sizeof(s->rlayer.read_sequence);
1284 if (rw & SSL3_CC_READ) {
1285 seq = s->rlayer.read_sequence;
1286 s->rlayer.d->r_epoch++;
1287 memcpy(&(s->rlayer.d->bitmap), &(s->rlayer.d->next_bitmap),
1288 sizeof(DTLS1_BITMAP));
1289 memset(&(s->rlayer.d->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1291 seq = s->rlayer.write_sequence;
1292 memcpy(s->d1->last_write_sequence, seq,
1293 sizeof(s->rlayer.write_sequence));
1294 s->rlayer.d->w_epoch++;
1297 memset(seq, 0x00, seq_bytes);