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) {
135 DTLS_RECORD_LAYER_clear(rl);
140 void DTLS_RECORD_LAYER_free(RECORD_LAYER *rl)
146 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
148 DTLS_RECORD_LAYER *d;
151 memset(d, 0, sizeof *d);
154 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
155 static int satsub64be(const unsigned char *v1, const unsigned char *v2)
157 int ret, sat, brw, i;
159 if (sizeof(long) == 8)
169 if (is_endian.little)
171 /* not reached on little-endians */
173 * following test is redundant, because input is always aligned,
174 * but I take no chances...
176 if (((size_t)v1 | (size_t)v2) & 0x7)
189 ret = (int)v1[7] - (int)v2[7];
191 brw = ret >> 8; /* brw is either 0 or -1 */
193 for (i = 6; i >= 0; i--) {
194 brw += (int)v1[i] - (int)v2[i];
199 for (i = 6; i >= 0; i--) {
200 brw += (int)v1[i] - (int)v2[i];
205 brw <<= 8; /* brw is either 0 or -256 */
210 return brw + (ret & 0xFF);
213 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
216 /* copy buffered record into SSL structure */
217 static int dtls1_copy_record(SSL *s, pitem *item)
219 DTLS1_RECORD_DATA *rdata;
221 rdata = (DTLS1_RECORD_DATA *)item->data;
223 SSL3_BUFFER_release(&s->rlayer.rbuf);
225 s->rlayer.packet = rdata->packet;
226 s->rlayer.packet_length = rdata->packet_length;
227 memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER));
228 memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD));
230 /* Set proper sequence number for mac calculation */
231 memcpy(&(s->rlayer.read_sequence[2]), &(rdata->packet[5]), 6);
237 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
239 DTLS1_RECORD_DATA *rdata;
242 /* Limit the size of the queue to prevent DOS attacks */
243 if (pqueue_size(queue->q) >= 100)
246 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
247 item = pitem_new(priority, rdata);
248 if (rdata == NULL || item == NULL) {
254 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
258 rdata->packet = s->rlayer.packet;
259 rdata->packet_length = s->rlayer.packet_length;
260 memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER));
261 memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD));
265 #ifndef OPENSSL_NO_SCTP
266 /* Store bio_dgram_sctp_rcvinfo struct */
267 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
268 (s->state == SSL3_ST_SR_FINISHED_A
269 || s->state == SSL3_ST_CR_FINISHED_A)) {
270 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
271 sizeof(rdata->recordinfo), &rdata->recordinfo);
275 s->rlayer.packet = NULL;
276 s->rlayer.packet_length = 0;
277 memset(&s->rlayer.rbuf, 0, sizeof(SSL3_BUFFER));
278 memset(&s->rlayer.rrec, 0, sizeof(SSL3_RECORD));
280 if (!ssl3_setup_buffers(s)) {
281 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
282 if (rdata->rbuf.buf != NULL)
283 OPENSSL_free(rdata->rbuf.buf);
289 /* insert should not fail, since duplicates are dropped */
290 if (pqueue_insert(queue->q, item) == NULL) {
291 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
292 if (rdata->rbuf.buf != NULL)
293 OPENSSL_free(rdata->rbuf.buf);
302 int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
306 item = pqueue_pop(queue->q);
308 dtls1_copy_record(s, item);
310 OPENSSL_free(item->data);
320 * retrieve a buffered record that belongs to the new epoch, i.e., not
323 #define dtls1_get_unprocessed_record(s) \
324 dtls1_retrieve_buffered_record((s), \
325 &((s)->d1->unprocessed_rcds))
328 int dtls1_process_buffered_records(SSL *s)
332 item = pqueue_peek(s->d1->unprocessed_rcds.q);
334 /* Check if epoch is current. */
335 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
336 return (1); /* Nothing to do. */
338 /* Process all the records. */
339 while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
340 dtls1_get_unprocessed_record(s);
341 if (!dtls1_process_record(s))
343 if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
344 SSL3_RECORD_get_seq_num(&s->rlayer.rrec)) < 0)
350 * sync epoch numbers once all the unprocessed records have been
353 s->d1->processed_rcds.epoch = s->d1->r_epoch;
354 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
361 * Return up to 'len' payload bytes received in 'type' records.
362 * 'type' is one of the following:
364 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
365 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
366 * - 0 (during a shutdown, no data has to be returned)
368 * If we don't have stored data to work from, read a SSL/TLS record first
369 * (possibly multiple records if we still don't have anything to return).
371 * This function must handle any surprises the peer may have for us, such as
372 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
373 * a surprise, but handled as if it were), or renegotiation requests.
374 * Also if record payloads contain fragments too small to process, we store
375 * them until there is enough for the respective protocol (the record protocol
376 * may use arbitrary fragmentation and even interleaving):
377 * Change cipher spec protocol
378 * just 1 byte needed, no need for keeping anything stored
380 * 2 bytes needed (AlertLevel, AlertDescription)
382 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
383 * to detect unexpected Client Hello and Hello Request messages
384 * here, anything else is handled by higher layers
385 * Application data protocol
386 * none of our business
388 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
393 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
395 if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
396 /* Not initialized yet */
397 if (!ssl3_setup_buffers(s))
401 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
402 (type != SSL3_RT_HANDSHAKE)) ||
403 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
404 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
409 * check whether there's a handshake message (client hello?) waiting
411 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
415 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
418 #ifndef OPENSSL_NO_SCTP
420 * Continue handshake if it had to be interrupted to read app data with
423 if ((!s->in_handshake && SSL_in_init(s)) ||
424 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
425 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
426 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
427 && s->s3->in_read_app_data != 2))
429 if (!s->in_handshake && SSL_in_init(s))
432 /* type == SSL3_RT_APPLICATION_DATA */
433 i = s->handshake_func(s);
437 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
443 s->rwstate = SSL_NOTHING;
446 * s->s3->rrec.type - is the type of record
447 * s->s3->rrec.data, - data
448 * s->s3->rrec.off, - offset into 'data' for next read
449 * s->s3->rrec.length, - number of bytes.
451 rr = &s->rlayer.rrec;
454 * We are not handshaking and have no data yet, so process data buffered
455 * during the last handshake in advance, if any.
457 if (s->state == SSL_ST_OK && rr->length == 0) {
459 item = pqueue_pop(s->d1->buffered_app_data.q);
461 #ifndef OPENSSL_NO_SCTP
462 /* Restore bio_dgram_sctp_rcvinfo struct */
463 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
464 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
465 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
466 sizeof(rdata->recordinfo), &rdata->recordinfo);
470 dtls1_copy_record(s, item);
472 OPENSSL_free(item->data);
477 /* Check for timeout */
478 if (dtls1_handle_timeout(s) > 0)
481 /* get new packet if necessary */
482 if ((rr->length == 0) || (s->rlayer.rstate == SSL_ST_READ_BODY)) {
483 ret = dtls1_get_record(s);
485 ret = dtls1_read_failed(s, ret);
486 /* anything other than a timeout is an error */
494 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
499 /* we now have a packet which can be read and processed */
501 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
502 * reset by ssl3_get_finished */
503 && (rr->type != SSL3_RT_HANDSHAKE)) {
505 * We now have application data between CCS and Finished. Most likely
506 * the packets were reordered on their way, so buffer the application
507 * data for later processing rather than dropping the connection.
509 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) <
511 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
519 * If the other end has shut down, throw anything we read away (even in
522 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
524 s->rwstate = SSL_NOTHING;
528 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or
529 * SSL3_RT_HANDSHAKE */
531 * make sure that we are not getting application data when we are
532 * doing a handshake for the first time
534 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
535 (s->enc_read_ctx == NULL)) {
536 al = SSL_AD_UNEXPECTED_MESSAGE;
537 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
544 if ((unsigned int)len > rr->length)
547 n = (unsigned int)len;
549 memcpy(buf, &(rr->data[rr->off]), n);
553 if (rr->length == 0) {
554 s->rlayer.rstate = SSL_ST_READ_HEADER;
558 #ifndef OPENSSL_NO_SCTP
560 * We were about to renegotiate but had to read belated application
561 * data first, so retry.
563 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
564 rr->type == SSL3_RT_APPLICATION_DATA &&
565 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
566 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
567 s->rwstate = SSL_READING;
568 BIO_clear_retry_flags(SSL_get_rbio(s));
569 BIO_set_retry_read(SSL_get_rbio(s));
573 * We might had to delay a close_notify alert because of reordered
574 * app data. If there was an alert and there is no message to read
575 * anymore, finally set shutdown.
577 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
578 s->d1->shutdown_received
579 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
580 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
588 * If we get here, then type != rr->type; if we have a handshake message,
589 * then it was unexpected (Hello Request or Client Hello).
593 * In case of record types for which we have 'fragment' storage, fill
594 * that so that we can process the data at a fixed place.
597 unsigned int k, dest_maxlen = 0;
598 unsigned char *dest = NULL;
599 unsigned int *dest_len = NULL;
601 if (rr->type == SSL3_RT_HANDSHAKE) {
602 dest_maxlen = sizeof s->d1->handshake_fragment;
603 dest = s->d1->handshake_fragment;
604 dest_len = &s->d1->handshake_fragment_len;
605 } else if (rr->type == SSL3_RT_ALERT) {
606 dest_maxlen = sizeof(s->d1->alert_fragment);
607 dest = s->d1->alert_fragment;
608 dest_len = &s->d1->alert_fragment_len;
610 #ifndef OPENSSL_NO_HEARTBEATS
611 else if (rr->type == TLS1_RT_HEARTBEAT) {
612 /* We allow a 0 return */
613 if(dtls1_process_heartbeat(s, SSL3_RECORD_get_data(&s->rlayer.rrec),
614 SSL3_RECORD_get_length(&s->rlayer.rrec)) < 0) {
617 /* Exit and notify application to read again */
619 s->rwstate = SSL_READING;
620 BIO_clear_retry_flags(SSL_get_rbio(s));
621 BIO_set_retry_read(SSL_get_rbio(s));
625 /* else it's a CCS message, or application data or wrong */
626 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
628 * Application data while renegotiating is allowed. Try again
631 if (rr->type == SSL3_RT_APPLICATION_DATA) {
633 s->s3->in_read_app_data = 2;
634 bio = SSL_get_rbio(s);
635 s->rwstate = SSL_READING;
636 BIO_clear_retry_flags(bio);
637 BIO_set_retry_read(bio);
641 /* Not certain if this is the right error handling */
642 al = SSL_AD_UNEXPECTED_MESSAGE;
643 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
647 if (dest_maxlen > 0) {
649 * XDTLS: In a pathalogical case, the Client Hello may be
650 * fragmented--don't always expect dest_maxlen bytes
652 if (rr->length < dest_maxlen) {
653 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
655 * for normal alerts rr->length is 2, while
656 * dest_maxlen is 7 if we were to handle this
657 * non-existing alert...
661 s->rlayer.rstate = SSL_ST_READ_HEADER;
666 /* now move 'n' bytes: */
667 for (k = 0; k < dest_maxlen; k++) {
668 dest[k] = rr->data[rr->off++];
671 *dest_len = dest_maxlen;
676 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
677 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
678 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
681 /* If we are a client, check for an incoming 'Hello Request': */
683 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
684 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
685 (s->session != NULL) && (s->session->cipher != NULL)) {
686 s->d1->handshake_fragment_len = 0;
688 if ((s->d1->handshake_fragment[1] != 0) ||
689 (s->d1->handshake_fragment[2] != 0) ||
690 (s->d1->handshake_fragment[3] != 0)) {
691 al = SSL_AD_DECODE_ERROR;
692 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
697 * no need to check sequence number on HELLO REQUEST messages
701 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
702 s->d1->handshake_fragment, 4, s,
703 s->msg_callback_arg);
705 if (SSL_is_init_finished(s) &&
706 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
707 !s->s3->renegotiate) {
708 s->d1->handshake_read_seq++;
711 if (ssl3_renegotiate_check(s)) {
712 i = s->handshake_func(s);
716 SSLerr(SSL_F_DTLS1_READ_BYTES,
717 SSL_R_SSL_HANDSHAKE_FAILURE);
721 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
722 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
723 /* no read-ahead left? */
726 * In the case where we try to read application data,
727 * but we trigger an SSL handshake, we return -1 with
728 * the retry option set. Otherwise renegotiation may
729 * cause nasty problems in the blocking world
731 s->rwstate = SSL_READING;
732 bio = SSL_get_rbio(s);
733 BIO_clear_retry_flags(bio);
734 BIO_set_retry_read(bio);
741 * we either finished a handshake or ignored the request, now try
742 * again to obtain the (application) data we were asked for
747 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
748 int alert_level = s->d1->alert_fragment[0];
749 int alert_descr = s->d1->alert_fragment[1];
751 s->d1->alert_fragment_len = 0;
754 s->msg_callback(0, s->version, SSL3_RT_ALERT,
755 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
757 if (s->info_callback != NULL)
758 cb = s->info_callback;
759 else if (s->ctx->info_callback != NULL)
760 cb = s->ctx->info_callback;
763 j = (alert_level << 8) | alert_descr;
764 cb(s, SSL_CB_READ_ALERT, j);
767 if (alert_level == SSL3_AL_WARNING) {
768 s->s3->warn_alert = alert_descr;
769 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
770 #ifndef OPENSSL_NO_SCTP
772 * With SCTP and streams the socket may deliver app data
773 * after a close_notify alert. We have to check this first so
774 * that nothing gets discarded.
776 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
777 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
778 s->d1->shutdown_received = 1;
779 s->rwstate = SSL_READING;
780 BIO_clear_retry_flags(SSL_get_rbio(s));
781 BIO_set_retry_read(SSL_get_rbio(s));
785 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
789 /* XXX: this is a possible improvement in the future */
790 /* now check if it's a missing record */
791 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
793 unsigned int frag_off;
794 unsigned char *p = &(s->d1->alert_fragment[2]);
799 dtls1_retransmit_message(s,
800 dtls1_get_queue_priority
801 (frag->msg_header.seq, 0), frag_off,
803 if (!found && SSL_in_init(s)) {
805 * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
808 * requested a message not yet sent, send an alert
811 ssl3_send_alert(s, SSL3_AL_WARNING,
812 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
816 } else if (alert_level == SSL3_AL_FATAL) {
819 s->rwstate = SSL_NOTHING;
820 s->s3->fatal_alert = alert_descr;
821 SSLerr(SSL_F_DTLS1_READ_BYTES,
822 SSL_AD_REASON_OFFSET + alert_descr);
823 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
824 ERR_add_error_data(2, "SSL alert number ", tmp);
825 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
826 SSL_CTX_remove_session(s->ctx, s->session);
829 al = SSL_AD_ILLEGAL_PARAMETER;
830 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
837 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
839 s->rwstate = SSL_NOTHING;
844 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
845 struct ccs_header_st ccs_hdr;
846 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
848 dtls1_get_ccs_header(rr->data, &ccs_hdr);
850 if (s->version == DTLS1_BAD_VER)
854 * 'Change Cipher Spec' is just a single byte, so we know exactly
855 * what the record payload has to look like
857 /* XDTLS: check that epoch is consistent */
858 if ((rr->length != ccs_hdr_len) ||
859 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
860 i = SSL_AD_ILLEGAL_PARAMETER;
861 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
868 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
869 rr->data, 1, s, s->msg_callback_arg);
872 * We can't process a CCS now, because previous handshake messages
873 * are still missing, so just drop it.
875 if (!s->d1->change_cipher_spec_ok) {
879 s->d1->change_cipher_spec_ok = 0;
881 s->s3->change_cipher_spec = 1;
882 if (!ssl3_do_change_cipher_spec(s))
885 /* do this whenever CCS is processed */
886 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
888 if (s->version == DTLS1_BAD_VER)
889 s->d1->handshake_read_seq++;
891 #ifndef OPENSSL_NO_SCTP
893 * Remember that a CCS has been received, so that an old key of
894 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
897 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
904 * Unexpected handshake message (Client Hello, or protocol violation)
906 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
908 struct hm_header_st msg_hdr;
910 /* this may just be a stale retransmit */
911 dtls1_get_message_header(rr->data, &msg_hdr);
912 if (rr->epoch != s->d1->r_epoch) {
918 * If we are server, we may have a repeated FINISHED of the client
919 * here, then retransmit our CCS and FINISHED.
921 if (msg_hdr.type == SSL3_MT_FINISHED) {
922 if (dtls1_check_timeout_num(s) < 0)
925 dtls1_retransmit_buffered_messages(s);
930 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
931 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
932 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
936 i = s->handshake_func(s);
940 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
944 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
945 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
946 /* no read-ahead left? */
949 * In the case where we try to read application data, but we
950 * trigger an SSL handshake, we return -1 with the retry
951 * option set. Otherwise renegotiation may cause nasty
952 * problems in the blocking world
954 s->rwstate = SSL_READING;
955 bio = SSL_get_rbio(s);
956 BIO_clear_retry_flags(bio);
957 BIO_set_retry_read(bio);
966 /* TLS just ignores unknown message types */
967 if (s->version == TLS1_VERSION) {
971 al = SSL_AD_UNEXPECTED_MESSAGE;
972 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
974 case SSL3_RT_CHANGE_CIPHER_SPEC:
976 case SSL3_RT_HANDSHAKE:
978 * we already handled all of these, with the possible exception of
979 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
980 * happen when type != rr->type
982 al = SSL_AD_UNEXPECTED_MESSAGE;
983 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
985 case SSL3_RT_APPLICATION_DATA:
987 * At this point, we were expecting handshake data, but have
988 * application data. If the library was running inside ssl3_read()
989 * (i.e. in_read_app_data is set) and it makes sense to read
990 * application data at this point (session renegotiation not yet
991 * started), we will indulge it.
993 if (s->s3->in_read_app_data &&
994 (s->s3->total_renegotiations != 0) &&
995 (((s->state & SSL_ST_CONNECT) &&
996 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
997 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
998 ) || ((s->state & SSL_ST_ACCEPT) &&
999 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1000 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1003 s->s3->in_read_app_data = 2;
1006 al = SSL_AD_UNEXPECTED_MESSAGE;
1007 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1014 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1021 * this only happens when a client hello is received and a handshake
1025 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1029 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1030 /* (partially) satisfy request from storage */
1032 unsigned char *src = s->d1->handshake_fragment;
1033 unsigned char *dst = buf;
1038 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) {
1041 s->d1->handshake_fragment_len--;
1044 /* move any remaining fragment bytes: */
1045 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1046 s->d1->handshake_fragment[k] = *src++;
1054 * Call this to write data in records of type 'type' It will return <= 0 if
1055 * not all data has been sent or non-blocking IO.
1057 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1061 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1062 s->rwstate = SSL_NOTHING;
1063 i = do_dtls1_write(s, type, buf, len, 0);
1067 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
1068 unsigned int len, int create_empty_fragment)
1070 unsigned char *p, *pseq;
1071 int i, mac_size, clear = 0;
1078 wb = &s->rlayer.wbuf;
1081 * first check if there is a SSL3_BUFFER still being written out. This
1082 * will happen with non blocking IO
1084 if (SSL3_BUFFER_get_left(wb) != 0) {
1085 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1086 return (ssl3_write_pending(s, type, buf, len));
1089 /* If we have an alert to send, lets send it */
1090 if (s->s3->alert_dispatch) {
1091 i = s->method->ssl_dispatch_alert(s);
1094 /* if it went, fall through and send more stuff */
1097 if (len == 0 && !create_empty_fragment)
1100 wr = &s->rlayer.wrec;
1103 if ((sess == NULL) ||
1104 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
1110 mac_size = EVP_MD_CTX_size(s->write_hash);
1115 p = wb->buf + prefix_len;
1117 /* write the header */
1119 *(p++) = type & 0xff;
1122 * Special case: for hello verify request, client version 1.0 and we
1123 * haven't decided which version to use yet send back using version 1.0
1124 * header: otherwise some clients will ignore it.
1126 if (s->method->version == DTLS_ANY_VERSION) {
1127 *(p++) = DTLS1_VERSION >> 8;
1128 *(p++) = DTLS1_VERSION & 0xff;
1130 *(p++) = s->version >> 8;
1131 *(p++) = s->version & 0xff;
1134 /* field where we are to write out packet epoch, seq num and len */
1138 /* Explicit IV length, block ciphers appropriate version flag */
1139 if (s->enc_write_ctx) {
1140 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1141 if (mode == EVP_CIPH_CBC_MODE) {
1142 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1146 /* Need explicit part of IV for GCM mode */
1147 else if (mode == EVP_CIPH_GCM_MODE)
1148 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1154 /* lets setup the record stuff. */
1155 wr->data = p + eivlen; /* make room for IV in case of CBC */
1156 wr->length = (int)len;
1157 wr->input = (unsigned char *)buf;
1160 * we now 'read' from wr->input, wr->length bytes into wr->data
1163 /* first we compress */
1164 if (s->compress != NULL) {
1165 if (!ssl3_do_compress(s)) {
1166 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
1170 memcpy(wr->data, wr->input, wr->length);
1171 wr->input = wr->data;
1175 * we should still have the output to wr->data and the input from
1176 * wr->input. Length should be wr->length. wr->data still points in the
1180 if (mac_size != 0) {
1181 if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
1183 wr->length += mac_size;
1186 /* this is true regardless of mac size */
1191 wr->length += eivlen;
1193 if (s->method->ssl3_enc->enc(s, 1) < 1)
1196 /* record length after mac and block padding */
1198 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
1202 /* there's only one epoch between handshake and app data */
1204 s2n(s->d1->w_epoch, pseq);
1208 * else s2n(s->d1->handshake_epoch, pseq);
1211 memcpy(pseq, &(s->rlayer.write_sequence[2]), 6);
1213 s2n(wr->length, pseq);
1215 if (s->msg_callback)
1216 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
1217 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1220 * we should now have wr->data pointing to the encrypted data, which is
1223 wr->type = type; /* not needed but helps for debugging */
1224 wr->length += DTLS1_RT_HEADER_LENGTH;
1226 ssl3_record_sequence_update(&(s->rlayer.write_sequence[0]));
1228 if (create_empty_fragment) {
1230 * we are in a recursive call; just return the length, don't write
1236 /* now let's set up wb */
1237 wb->left = prefix_len + wr->length;
1241 * memorize arguments so that ssl3_write_pending can detect bad write
1244 s->rlayer.wpend_tot = len;
1245 s->rlayer.wpend_buf = buf;
1246 s->rlayer.wpend_type = type;
1247 s->rlayer.wpend_ret = len;
1249 /* we now just need to write the buffer */
1250 return ssl3_write_pending(s, type, buf, len);
1255 int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1259 const unsigned char *seq = s->rlayer.read_sequence;
1261 cmp = satsub64be(seq, bitmap->max_seq_num);
1263 SSL3_RECORD_set_seq_num(&s->rlayer.rrec, seq);
1264 return 1; /* this record in new */
1267 if (shift >= sizeof(bitmap->map) * 8)
1268 return 0; /* stale, outside the window */
1269 else if (bitmap->map & (1UL << shift))
1270 return 0; /* record previously received */
1272 SSL3_RECORD_set_seq_num(&s->rlayer.rrec, seq);
1276 void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1280 const unsigned char *seq = s->rlayer.read_sequence;
1282 cmp = satsub64be(seq, bitmap->max_seq_num);
1285 if (shift < sizeof(bitmap->map) * 8)
1286 bitmap->map <<= shift, bitmap->map |= 1UL;
1289 memcpy(bitmap->max_seq_num, seq, 8);
1292 if (shift < sizeof(bitmap->map) * 8)
1293 bitmap->map |= 1UL << shift;
1297 DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1298 unsigned int *is_next_epoch)
1303 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1304 if (rr->epoch == s->d1->r_epoch)
1305 return &s->d1->bitmap;
1307 /* Only HM and ALERT messages can be from the next epoch */
1308 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1309 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1311 return &s->d1->next_bitmap;
1317 void dtls1_reset_seq_numbers(SSL *s, int rw)
1320 unsigned int seq_bytes = sizeof(s->rlayer.read_sequence);
1322 if (rw & SSL3_CC_READ) {
1323 seq = s->rlayer.read_sequence;
1325 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1326 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1328 seq = s->rlayer.write_sequence;
1329 memcpy(s->d1->last_write_sequence, seq,
1330 sizeof(s->rlayer.write_sequence));
1334 memset(seq, 0x00, seq_bytes);