1 /* ssl/record/rec_layer_d1.c */
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>
124 #include "record_locl.h"
126 int DTLS_RECORD_LAYER_new(RECORD_LAYER *rl)
128 DTLS_RECORD_LAYER *d;
130 if ((d = OPENSSL_malloc(sizeof(*d))) == NULL)
136 d->unprocessed_rcds.q = pqueue_new();
137 d->processed_rcds.q = pqueue_new();
138 d->buffered_app_data.q = pqueue_new();
140 if (!d->unprocessed_rcds.q || !d->processed_rcds.q
141 || !d->buffered_app_data.q) {
142 pqueue_free(d->unprocessed_rcds.q);
143 pqueue_free(d->processed_rcds.q);
144 pqueue_free(d->buffered_app_data.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);
158 pqueue_free(rl->d->buffered_app_data.q);
163 void DTLS_RECORD_LAYER_clear(RECORD_LAYER *rl)
165 DTLS_RECORD_LAYER *d;
167 DTLS1_RECORD_DATA *rdata;
168 pqueue unprocessed_rcds;
169 pqueue processed_rcds;
170 pqueue buffered_app_data;
174 while ((item = pqueue_pop(d->unprocessed_rcds.q)) != NULL) {
175 rdata = (DTLS1_RECORD_DATA *)item->data;
176 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 OPENSSL_free(rdata->rbuf.buf);
184 OPENSSL_free(item->data);
188 while ((item = pqueue_pop(d->buffered_app_data.q)) != NULL) {
189 rdata = (DTLS1_RECORD_DATA *)item->data;
190 OPENSSL_free(rdata->rbuf.buf);
191 OPENSSL_free(item->data);
195 unprocessed_rcds = d->unprocessed_rcds.q;
196 processed_rcds = d->processed_rcds.q;
197 buffered_app_data = d->buffered_app_data.q;
198 memset(d, 0, sizeof(*d));
199 d->unprocessed_rcds.q = unprocessed_rcds;
200 d->processed_rcds.q = processed_rcds;
201 d->buffered_app_data.q = buffered_app_data;
204 void DTLS_RECORD_LAYER_set_saved_w_epoch(RECORD_LAYER *rl, unsigned short e)
206 if (e == rl->d->w_epoch - 1) {
207 memcpy(rl->d->curr_write_sequence,
209 sizeof(rl->write_sequence));
210 memcpy(rl->write_sequence,
211 rl->d->last_write_sequence,
212 sizeof(rl->write_sequence));
213 } else if (e == rl->d->w_epoch + 1) {
214 memcpy(rl->d->last_write_sequence,
216 sizeof(unsigned char[8]));
217 memcpy(rl->write_sequence,
218 rl->d->curr_write_sequence,
219 sizeof(rl->write_sequence));
224 void DTLS_RECORD_LAYER_resync_write(RECORD_LAYER *rl)
226 memcpy(rl->write_sequence, rl->read_sequence, sizeof(rl->write_sequence));
229 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
232 /* copy buffered record into SSL structure */
233 static int dtls1_copy_record(SSL *s, pitem *item)
235 DTLS1_RECORD_DATA *rdata;
237 rdata = (DTLS1_RECORD_DATA *)item->data;
239 SSL3_BUFFER_release(&s->rlayer.rbuf);
241 s->rlayer.packet = rdata->packet;
242 s->rlayer.packet_length = rdata->packet_length;
243 memcpy(&s->rlayer.rbuf, &(rdata->rbuf), sizeof(SSL3_BUFFER));
244 memcpy(&s->rlayer.rrec, &(rdata->rrec), sizeof(SSL3_RECORD));
246 /* Set proper sequence number for mac calculation */
247 memcpy(&(s->rlayer.read_sequence[2]), &(rdata->packet[5]), 6);
252 int dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
254 DTLS1_RECORD_DATA *rdata;
257 /* Limit the size of the queue to prevent DOS attacks */
258 if (pqueue_size(queue->q) >= 100)
261 rdata = OPENSSL_malloc(sizeof(*rdata));
262 item = pitem_new(priority, rdata);
263 if (rdata == NULL || item == NULL) {
266 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
270 rdata->packet = s->rlayer.packet;
271 rdata->packet_length = s->rlayer.packet_length;
272 memcpy(&(rdata->rbuf), &s->rlayer.rbuf, sizeof(SSL3_BUFFER));
273 memcpy(&(rdata->rrec), &s->rlayer.rrec, sizeof(SSL3_RECORD));
277 #ifndef OPENSSL_NO_SCTP
278 /* Store bio_dgram_sctp_rcvinfo struct */
279 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
280 (s->state == SSL3_ST_SR_FINISHED_A
281 || s->state == SSL3_ST_CR_FINISHED_A)) {
282 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
283 sizeof(rdata->recordinfo), &rdata->recordinfo);
287 s->rlayer.packet = NULL;
288 s->rlayer.packet_length = 0;
289 memset(&s->rlayer.rbuf, 0, sizeof(s->rlayer.rbuf));
290 memset(&s->rlayer.rrec, 0, sizeof(s->rlayer.rrec));
292 if (!ssl3_setup_buffers(s)) {
293 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
294 OPENSSL_free(rdata->rbuf.buf);
300 /* insert should not fail, since duplicates are dropped */
301 if (pqueue_insert(queue->q, item) == NULL) {
302 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
303 OPENSSL_free(rdata->rbuf.buf);
312 int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
316 item = pqueue_pop(queue->q);
318 dtls1_copy_record(s, item);
320 OPENSSL_free(item->data);
330 * retrieve a buffered record that belongs to the new epoch, i.e., not
333 #define dtls1_get_unprocessed_record(s) \
334 dtls1_retrieve_buffered_record((s), \
335 &((s)->rlayer.d->unprocessed_rcds))
338 int dtls1_process_buffered_records(SSL *s)
342 item = pqueue_peek(s->rlayer.d->unprocessed_rcds.q);
344 /* Check if epoch is current. */
345 if (s->rlayer.d->unprocessed_rcds.epoch != s->rlayer.d->r_epoch)
346 return (1); /* Nothing to do. */
348 /* Process all the records. */
349 while (pqueue_peek(s->rlayer.d->unprocessed_rcds.q)) {
350 dtls1_get_unprocessed_record(s);
351 if (!dtls1_process_record(s))
353 if (dtls1_buffer_record(s, &(s->rlayer.d->processed_rcds),
354 SSL3_RECORD_get_seq_num(&s->rlayer.rrec)) < 0)
360 * sync epoch numbers once all the unprocessed records have been
363 s->rlayer.d->processed_rcds.epoch = s->rlayer.d->r_epoch;
364 s->rlayer.d->unprocessed_rcds.epoch = s->rlayer.d->r_epoch + 1;
371 * Return up to 'len' payload bytes received in 'type' records.
372 * 'type' is one of the following:
374 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
375 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
376 * - 0 (during a shutdown, no data has to be returned)
378 * If we don't have stored data to work from, read a SSL/TLS record first
379 * (possibly multiple records if we still don't have anything to return).
381 * This function must handle any surprises the peer may have for us, such as
382 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
383 * a surprise, but handled as if it were), or renegotiation requests.
384 * Also if record payloads contain fragments too small to process, we store
385 * them until there is enough for the respective protocol (the record protocol
386 * may use arbitrary fragmentation and even interleaving):
387 * Change cipher spec protocol
388 * just 1 byte needed, no need for keeping anything stored
390 * 2 bytes needed (AlertLevel, AlertDescription)
392 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
393 * to detect unexpected Client Hello and Hello Request messages
394 * here, anything else is handled by higher layers
395 * Application data protocol
396 * none of our business
398 int dtls1_read_bytes(SSL *s, int type, int *recvd_type, unsigned char *buf,
404 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
406 if (!SSL3_BUFFER_is_initialised(&s->rlayer.rbuf)) {
407 /* Not initialized yet */
408 if (!ssl3_setup_buffers(s))
412 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
413 (type != SSL3_RT_HANDSHAKE)) ||
414 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
415 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
420 * check whether there's a handshake message (client hello?) waiting
422 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
426 * Now s->rlayer.d->handshake_fragment_len == 0 if
427 * type == SSL3_RT_HANDSHAKE.
430 #ifndef OPENSSL_NO_SCTP
432 * Continue handshake if it had to be interrupted to read app data with
435 if ((!s->in_handshake && SSL_in_init(s)) ||
436 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
437 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
438 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
439 && s->s3->in_read_app_data != 2))
441 if (!s->in_handshake && SSL_in_init(s))
444 /* type == SSL3_RT_APPLICATION_DATA */
445 i = s->handshake_func(s);
449 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
455 s->rwstate = SSL_NOTHING;
458 * s->s3->rrec.type - is the type of record
459 * s->s3->rrec.data, - data
460 * s->s3->rrec.off, - offset into 'data' for next read
461 * s->s3->rrec.length, - number of bytes.
463 rr = &s->rlayer.rrec;
466 * We are not handshaking and have no data yet, so process data buffered
467 * during the last handshake in advance, if any.
469 if (s->state == SSL_ST_OK && SSL3_RECORD_get_length(rr) == 0) {
471 item = pqueue_pop(s->rlayer.d->buffered_app_data.q);
473 #ifndef OPENSSL_NO_SCTP
474 /* Restore bio_dgram_sctp_rcvinfo struct */
475 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
476 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
477 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
478 sizeof(rdata->recordinfo), &rdata->recordinfo);
482 dtls1_copy_record(s, item);
484 OPENSSL_free(item->data);
489 /* Check for timeout */
490 if (dtls1_handle_timeout(s) > 0)
493 /* get new packet if necessary */
494 if ((SSL3_RECORD_get_length(rr) == 0)
495 || (s->rlayer.rstate == SSL_ST_READ_BODY)) {
496 ret = dtls1_get_record(s);
498 ret = dtls1_read_failed(s, ret);
499 /* anything other than a timeout is an error */
507 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
508 SSL3_RECORD_set_length(rr, 0);
512 /* we now have a packet which can be read and processed */
514 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
515 * reset by ssl3_get_finished */
516 && (SSL3_RECORD_get_type(rr) != SSL3_RT_HANDSHAKE)) {
518 * We now have application data between CCS and Finished. Most likely
519 * the packets were reordered on their way, so buffer the application
520 * data for later processing rather than dropping the connection.
522 if (dtls1_buffer_record(s, &(s->rlayer.d->buffered_app_data),
523 SSL3_RECORD_get_seq_num(rr)) < 0) {
524 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
527 SSL3_RECORD_set_length(rr, 0);
532 * If the other end has shut down, throw anything we read away (even in
535 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
536 SSL3_RECORD_set_length(rr, 0);
537 s->rwstate = SSL_NOTHING;
541 if (type == SSL3_RECORD_get_type(rr)) {
542 /* SSL3_RT_APPLICATION_DATA or
543 * SSL3_RT_HANDSHAKE */
545 * make sure that we are not getting application data when we are
546 * doing a handshake for the first time
548 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
549 (s->enc_read_ctx == NULL)) {
550 al = SSL_AD_UNEXPECTED_MESSAGE;
551 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
558 if ((unsigned int)len > SSL3_RECORD_get_length(rr))
559 n = SSL3_RECORD_get_length(rr);
561 n = (unsigned int)len;
563 memcpy(buf, &(SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)]), n);
565 SSL3_RECORD_add_length(rr, -n);
566 SSL3_RECORD_add_off(rr, n);
567 if (SSL3_RECORD_get_length(rr) == 0) {
568 s->rlayer.rstate = SSL_ST_READ_HEADER;
569 SSL3_RECORD_set_off(rr, 0);
572 #ifndef OPENSSL_NO_SCTP
574 * We were about to renegotiate but had to read belated application
575 * data first, so retry.
577 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
578 SSL3_RECORD_get_type(rr) == SSL3_RT_APPLICATION_DATA &&
579 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
580 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
581 s->rwstate = SSL_READING;
582 BIO_clear_retry_flags(SSL_get_rbio(s));
583 BIO_set_retry_read(SSL_get_rbio(s));
587 * We might had to delay a close_notify alert because of reordered
588 * app data. If there was an alert and there is no message to read
589 * anymore, finally set shutdown.
591 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
592 s->d1->shutdown_received
593 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
594 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
602 * If we get here, then type != rr->type; if we have a handshake message,
603 * then it was unexpected (Hello Request or Client Hello).
607 * In case of record types for which we have 'fragment' storage, fill
608 * that so that we can process the data at a fixed place.
611 unsigned int k, dest_maxlen = 0;
612 unsigned char *dest = NULL;
613 unsigned int *dest_len = NULL;
615 if (SSL3_RECORD_get_type(rr) == SSL3_RT_HANDSHAKE) {
616 dest_maxlen = sizeof s->rlayer.d->handshake_fragment;
617 dest = s->rlayer.d->handshake_fragment;
618 dest_len = &s->rlayer.d->handshake_fragment_len;
619 } else if (SSL3_RECORD_get_type(rr) == SSL3_RT_ALERT) {
620 dest_maxlen = sizeof(s->rlayer.d->alert_fragment);
621 dest = s->rlayer.d->alert_fragment;
622 dest_len = &s->rlayer.d->alert_fragment_len;
624 #ifndef OPENSSL_NO_HEARTBEATS
625 else if (SSL3_RECORD_get_type(rr) == TLS1_RT_HEARTBEAT) {
626 /* We allow a 0 return */
627 if (dtls1_process_heartbeat(s, SSL3_RECORD_get_data(rr),
628 SSL3_RECORD_get_length(rr)) < 0) {
631 /* Exit and notify application to read again */
632 SSL3_RECORD_set_length(rr, 0);
633 s->rwstate = SSL_READING;
634 BIO_clear_retry_flags(SSL_get_rbio(s));
635 BIO_set_retry_read(SSL_get_rbio(s));
639 /* else it's a CCS message, or application data or wrong */
640 else if (SSL3_RECORD_get_type(rr) != SSL3_RT_CHANGE_CIPHER_SPEC) {
642 * Application data while renegotiating is allowed. Try again
645 if (SSL3_RECORD_get_type(rr) == SSL3_RT_APPLICATION_DATA) {
647 s->s3->in_read_app_data = 2;
648 bio = SSL_get_rbio(s);
649 s->rwstate = SSL_READING;
650 BIO_clear_retry_flags(bio);
651 BIO_set_retry_read(bio);
655 /* Not certain if this is the right error handling */
656 al = SSL_AD_UNEXPECTED_MESSAGE;
657 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
661 if (dest_maxlen > 0) {
663 * XDTLS: In a pathalogical case, the Client Hello may be
664 * fragmented--don't always expect dest_maxlen bytes
666 if (SSL3_RECORD_get_length(rr) < dest_maxlen) {
667 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
669 * for normal alerts rr->length is 2, while
670 * dest_maxlen is 7 if we were to handle this
671 * non-existing alert...
675 s->rlayer.rstate = SSL_ST_READ_HEADER;
676 SSL3_RECORD_set_length(rr, 0);
680 /* now move 'n' bytes: */
681 for (k = 0; k < dest_maxlen; k++) {
682 dest[k] = SSL3_RECORD_get_data(rr)[SSL3_RECORD_get_off(rr)];
683 SSL3_RECORD_add_off(rr, 1);
684 SSL3_RECORD_add_length(rr, -1);
686 *dest_len = dest_maxlen;
691 * s->rlayer.d->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
692 * s->rlayer.d->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
693 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
696 /* If we are a client, check for an incoming 'Hello Request': */
698 (s->rlayer.d->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
699 (s->rlayer.d->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
700 (s->session != NULL) && (s->session->cipher != NULL)) {
701 s->rlayer.d->handshake_fragment_len = 0;
703 if ((s->rlayer.d->handshake_fragment[1] != 0) ||
704 (s->rlayer.d->handshake_fragment[2] != 0) ||
705 (s->rlayer.d->handshake_fragment[3] != 0)) {
706 al = SSL_AD_DECODE_ERROR;
707 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
712 * no need to check sequence number on HELLO REQUEST messages
716 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
717 s->rlayer.d->handshake_fragment, 4, s,
718 s->msg_callback_arg);
720 if (SSL_is_init_finished(s) &&
721 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
722 !s->s3->renegotiate) {
723 s->d1->handshake_read_seq++;
726 if (ssl3_renegotiate_check(s)) {
727 i = s->handshake_func(s);
731 SSLerr(SSL_F_DTLS1_READ_BYTES,
732 SSL_R_SSL_HANDSHAKE_FAILURE);
736 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
737 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
738 /* no read-ahead left? */
741 * In the case where we try to read application data,
742 * but we trigger an SSL handshake, we return -1 with
743 * the retry option set. Otherwise renegotiation may
744 * cause nasty problems in the blocking world
746 s->rwstate = SSL_READING;
747 bio = SSL_get_rbio(s);
748 BIO_clear_retry_flags(bio);
749 BIO_set_retry_read(bio);
756 * we either finished a handshake or ignored the request, now try
757 * again to obtain the (application) data we were asked for
762 if (s->rlayer.d->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
763 int alert_level = s->rlayer.d->alert_fragment[0];
764 int alert_descr = s->rlayer.d->alert_fragment[1];
766 s->rlayer.d->alert_fragment_len = 0;
769 s->msg_callback(0, s->version, SSL3_RT_ALERT,
770 s->rlayer.d->alert_fragment, 2, s,
771 s->msg_callback_arg);
773 if (s->info_callback != NULL)
774 cb = s->info_callback;
775 else if (s->ctx->info_callback != NULL)
776 cb = s->ctx->info_callback;
779 j = (alert_level << 8) | alert_descr;
780 cb(s, SSL_CB_READ_ALERT, j);
783 if (alert_level == SSL3_AL_WARNING) {
784 s->s3->warn_alert = alert_descr;
785 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
786 #ifndef OPENSSL_NO_SCTP
788 * With SCTP and streams the socket may deliver app data
789 * after a close_notify alert. We have to check this first so
790 * that nothing gets discarded.
792 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
793 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
794 s->d1->shutdown_received = 1;
795 s->rwstate = SSL_READING;
796 BIO_clear_retry_flags(SSL_get_rbio(s));
797 BIO_set_retry_read(SSL_get_rbio(s));
801 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
805 /* XXX: this is a possible improvement in the future */
806 /* now check if it's a missing record */
807 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
809 unsigned int frag_off;
810 unsigned char *p = &(s->rlayer.d->alert_fragment[2]);
815 dtls1_retransmit_message(s,
816 dtls1_get_queue_priority
817 (frag->msg_header.seq, 0), frag_off,
819 if (!found && SSL_in_init(s)) {
821 * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
824 * requested a message not yet sent, send an alert
827 ssl3_send_alert(s, SSL3_AL_WARNING,
828 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
832 } else if (alert_level == SSL3_AL_FATAL) {
835 s->rwstate = SSL_NOTHING;
836 s->s3->fatal_alert = alert_descr;
837 SSLerr(SSL_F_DTLS1_READ_BYTES,
838 SSL_AD_REASON_OFFSET + alert_descr);
839 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
840 ERR_add_error_data(2, "SSL alert number ", tmp);
841 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
842 SSL_CTX_remove_session(s->ctx, s->session);
845 al = SSL_AD_ILLEGAL_PARAMETER;
846 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
853 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
855 s->rwstate = SSL_NOTHING;
856 SSL3_RECORD_set_length(rr, 0);
860 if (SSL3_RECORD_get_type(rr) == SSL3_RT_CHANGE_CIPHER_SPEC) {
861 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
863 if (s->version == DTLS1_BAD_VER)
867 * 'Change Cipher Spec' is just a single byte, so we know exactly
868 * what the record payload has to look like
870 /* XDTLS: check that epoch is consistent */
871 if ((SSL3_RECORD_get_length(rr) != ccs_hdr_len)
872 || (SSL3_RECORD_get_off(rr) != 0)
873 || (SSL3_RECORD_get_data(rr)[0] != SSL3_MT_CCS)) {
874 i = SSL_AD_ILLEGAL_PARAMETER;
875 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
879 SSL3_RECORD_set_length(rr, 0);
882 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
883 SSL3_RECORD_get_data(rr), 1, s, s->msg_callback_arg);
886 * We can't process a CCS now, because previous handshake messages
887 * are still missing, so just drop it.
889 if (!s->d1->change_cipher_spec_ok) {
893 s->d1->change_cipher_spec_ok = 0;
895 s->s3->change_cipher_spec = 1;
896 if (!ssl3_do_change_cipher_spec(s))
899 /* do this whenever CCS is processed */
900 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
902 if (s->version == DTLS1_BAD_VER)
903 s->d1->handshake_read_seq++;
905 #ifndef OPENSSL_NO_SCTP
907 * Remember that a CCS has been received, so that an old key of
908 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
911 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
918 * Unexpected handshake message (Client Hello, or protocol violation)
920 if ((s->rlayer.d->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
922 struct hm_header_st msg_hdr;
924 /* this may just be a stale retransmit */
925 dtls1_get_message_header(rr->data, &msg_hdr);
926 if (SSL3_RECORD_get_epoch(rr) != s->rlayer.d->r_epoch) {
927 SSL3_RECORD_set_length(rr, 0);
932 * If we are server, we may have a repeated FINISHED of the client
933 * here, then retransmit our CCS and FINISHED.
935 if (msg_hdr.type == SSL3_MT_FINISHED) {
936 if (dtls1_check_timeout_num(s) < 0)
939 dtls1_retransmit_buffered_messages(s);
940 SSL3_RECORD_set_length(rr, 0);
944 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
945 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
946 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
950 i = s->handshake_func(s);
954 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
958 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
959 if (SSL3_BUFFER_get_left(&s->rlayer.rbuf) == 0) {
960 /* no read-ahead left? */
963 * In the case where we try to read application data, but we
964 * trigger an SSL handshake, we return -1 with the retry
965 * option set. Otherwise renegotiation may cause nasty
966 * problems in the blocking world
968 s->rwstate = SSL_READING;
969 bio = SSL_get_rbio(s);
970 BIO_clear_retry_flags(bio);
971 BIO_set_retry_read(bio);
978 switch (SSL3_RECORD_get_type(rr)) {
980 /* TLS just ignores unknown message types */
981 if (s->version == TLS1_VERSION) {
982 SSL3_RECORD_set_length(rr, 0);
985 al = SSL_AD_UNEXPECTED_MESSAGE;
986 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
988 case SSL3_RT_CHANGE_CIPHER_SPEC:
990 case SSL3_RT_HANDSHAKE:
992 * we already handled all of these, with the possible exception of
993 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
994 * happen when type != rr->type
996 al = SSL_AD_UNEXPECTED_MESSAGE;
997 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
999 case SSL3_RT_APPLICATION_DATA:
1001 * At this point, we were expecting handshake data, but have
1002 * application data. If the library was running inside ssl3_read()
1003 * (i.e. in_read_app_data is set) and it makes sense to read
1004 * application data at this point (session renegotiation not yet
1005 * started), we will indulge it.
1007 if (s->s3->in_read_app_data &&
1008 (s->s3->total_renegotiations != 0) &&
1009 (((s->state & SSL_ST_CONNECT) &&
1010 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1011 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1012 ) || ((s->state & SSL_ST_ACCEPT) &&
1013 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1014 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1017 s->s3->in_read_app_data = 2;
1020 al = SSL_AD_UNEXPECTED_MESSAGE;
1021 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1028 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1035 * this only happens when a client hello is received and a handshake
1038 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1042 if ((type == SSL3_RT_HANDSHAKE)
1043 && (s->rlayer.d->handshake_fragment_len > 0))
1044 /* (partially) satisfy request from storage */
1046 unsigned char *src = s->rlayer.d->handshake_fragment;
1047 unsigned char *dst = buf;
1052 while ((len > 0) && (s->rlayer.d->handshake_fragment_len > 0)) {
1055 s->rlayer.d->handshake_fragment_len--;
1058 /* move any remaining fragment bytes: */
1059 for (k = 0; k < s->rlayer.d->handshake_fragment_len; k++)
1060 s->rlayer.d->handshake_fragment[k] = *src++;
1068 * Call this to write data in records of type 'type' It will return <= 0 if
1069 * not all data has been sent or non-blocking IO.
1071 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1075 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1076 s->rwstate = SSL_NOTHING;
1077 i = do_dtls1_write(s, type, buf, len, 0);
1081 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
1082 unsigned int len, int create_empty_fragment)
1084 unsigned char *p, *pseq;
1085 int i, mac_size, clear = 0;
1092 wb = &s->rlayer.wbuf;
1095 * first check if there is a SSL3_BUFFER still being written out. This
1096 * will happen with non blocking IO
1098 if (SSL3_BUFFER_get_left(wb) != 0) {
1099 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1100 return (ssl3_write_pending(s, type, buf, len));
1103 /* If we have an alert to send, lets send it */
1104 if (s->s3->alert_dispatch) {
1105 i = s->method->ssl_dispatch_alert(s);
1108 /* if it went, fall through and send more stuff */
1111 if (len == 0 && !create_empty_fragment)
1114 wr = &s->rlayer.wrec;
1117 if ((sess == NULL) ||
1118 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
1124 mac_size = EVP_MD_CTX_size(s->write_hash);
1129 p = SSL3_BUFFER_get_buf(wb) + prefix_len;
1131 /* write the header */
1133 *(p++) = type & 0xff;
1134 SSL3_RECORD_set_type(wr, type);
1136 * Special case: for hello verify request, client version 1.0 and we
1137 * haven't decided which version to use yet send back using version 1.0
1138 * header: otherwise some clients will ignore it.
1140 if (s->method->version == DTLS_ANY_VERSION) {
1141 *(p++) = DTLS1_VERSION >> 8;
1142 *(p++) = DTLS1_VERSION & 0xff;
1144 *(p++) = s->version >> 8;
1145 *(p++) = s->version & 0xff;
1148 /* field where we are to write out packet epoch, seq num and len */
1152 /* Explicit IV length, block ciphers appropriate version flag */
1153 if (s->enc_write_ctx) {
1154 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1155 if (mode == EVP_CIPH_CBC_MODE) {
1156 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1160 /* Need explicit part of IV for GCM mode */
1161 else if (mode == EVP_CIPH_GCM_MODE)
1162 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1168 /* lets setup the record stuff. */
1169 SSL3_RECORD_set_data(wr, p + eivlen); /* make room for IV in case of CBC */
1170 SSL3_RECORD_set_length(wr, (int)len);
1171 SSL3_RECORD_set_input(wr, (unsigned char *)buf);
1174 * we now 'read' from wr->input, wr->length bytes into wr->data
1177 /* first we compress */
1178 if (s->compress != NULL) {
1179 if (!ssl3_do_compress(s)) {
1180 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
1184 memcpy(SSL3_RECORD_get_data(wr), SSL3_RECORD_get_input(wr),
1185 SSL3_RECORD_get_length(wr));
1186 SSL3_RECORD_reset_input(wr);
1190 * we should still have the output to wr->data and the input from
1191 * wr->input. Length should be wr->length. wr->data still points in the
1195 if (mac_size != 0) {
1196 if (s->method->ssl3_enc->mac(s,
1197 &(p[SSL3_RECORD_get_length(wr) + eivlen]), 1) < 0)
1199 SSL3_RECORD_add_length(wr, mac_size);
1202 /* this is true regardless of mac size */
1203 SSL3_RECORD_set_data(wr, p);
1204 SSL3_RECORD_reset_input(wr);
1207 SSL3_RECORD_add_length(wr, eivlen);
1209 if (s->method->ssl3_enc->enc(s, 1) < 1)
1212 /* record length after mac and block padding */
1214 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
1218 /* there's only one epoch between handshake and app data */
1220 s2n(s->rlayer.d->w_epoch, pseq);
1224 * else s2n(s->d1->handshake_epoch, pseq);
1227 memcpy(pseq, &(s->rlayer.write_sequence[2]), 6);
1229 s2n(SSL3_RECORD_get_length(wr), pseq);
1231 if (s->msg_callback)
1232 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
1233 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1236 * we should now have wr->data pointing to the encrypted data, which is
1239 SSL3_RECORD_set_type(wr, type); /* not needed but helps for debugging */
1240 SSL3_RECORD_add_length(wr, DTLS1_RT_HEADER_LENGTH);
1242 ssl3_record_sequence_update(&(s->rlayer.write_sequence[0]));
1244 if (create_empty_fragment) {
1246 * we are in a recursive call; just return the length, don't write
1252 /* now let's set up wb */
1253 SSL3_BUFFER_set_left(wb, prefix_len + SSL3_RECORD_get_length(wr));
1254 SSL3_BUFFER_set_offset(wb, 0);
1257 * memorize arguments so that ssl3_write_pending can detect bad write
1260 s->rlayer.wpend_tot = len;
1261 s->rlayer.wpend_buf = buf;
1262 s->rlayer.wpend_type = type;
1263 s->rlayer.wpend_ret = len;
1265 /* we now just need to write the buffer */
1266 return ssl3_write_pending(s, type, buf, len);
1271 DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1272 unsigned int *is_next_epoch)
1277 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1278 if (rr->epoch == s->rlayer.d->r_epoch)
1279 return &s->rlayer.d->bitmap;
1281 /* Only HM and ALERT messages can be from the next epoch */
1282 else if (rr->epoch == (unsigned long)(s->rlayer.d->r_epoch + 1) &&
1283 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1285 return &s->rlayer.d->next_bitmap;
1291 void dtls1_reset_seq_numbers(SSL *s, int rw)
1294 unsigned int seq_bytes = sizeof(s->rlayer.read_sequence);
1296 if (rw & SSL3_CC_READ) {
1297 seq = s->rlayer.read_sequence;
1298 s->rlayer.d->r_epoch++;
1299 memcpy(&s->rlayer.d->bitmap, &s->rlayer.d->next_bitmap,
1300 sizeof(s->rlayer.d->bitmap));
1301 memset(&s->rlayer.d->next_bitmap, 0,
1302 sizeof(s->rlayer.d->next_bitmap));
1304 seq = s->rlayer.write_sequence;
1305 memcpy(s->rlayer.d->last_write_sequence, seq,
1306 sizeof(s->rlayer.write_sequence));
1307 s->rlayer.d->w_epoch++;
1310 memset(seq, 0, seq_bytes);