3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1998-2005 The OpenSSL Project. All rights reserved.
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in
18 * the documentation and/or other materials provided with the
21 * 3. All advertising materials mentioning features or use of this
22 * software must display the following acknowledgment:
23 * "This product includes software developed by the OpenSSL Project
24 * for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
26 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
27 * endorse or promote products derived from this software without
28 * prior written permission. For written permission, please contact
29 * openssl-core@openssl.org.
31 * 5. Products derived from this software may not be called "OpenSSL"
32 * nor may "OpenSSL" appear in their names without prior written
33 * permission of the OpenSSL Project.
35 * 6. Redistributions of any form whatsoever must retain the following
37 * "This product includes software developed by the OpenSSL Project
38 * for use in the OpenSSL Toolkit (http://www.openssl.org/)"
40 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
41 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
43 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR
44 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
45 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
46 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
47 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
48 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
49 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
50 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
51 * OF THE POSSIBILITY OF SUCH DAMAGE.
52 * ====================================================================
54 * This product includes cryptographic software written by Eric Young
55 * (eay@cryptsoft.com). This product includes software written by Tim
56 * Hudson (tjh@cryptsoft.com).
59 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
60 * All rights reserved.
62 * This package is an SSL implementation written
63 * by Eric Young (eay@cryptsoft.com).
64 * The implementation was written so as to conform with Netscapes SSL.
66 * This library is free for commercial and non-commercial use as long as
67 * the following conditions are aheared to. The following conditions
68 * apply to all code found in this distribution, be it the RC4, RSA,
69 * lhash, DES, etc., code; not just the SSL code. The SSL documentation
70 * included with this distribution is covered by the same copyright terms
71 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
73 * Copyright remains Eric Young's, and as such any Copyright notices in
74 * the code are not to be removed.
75 * If this package is used in a product, Eric Young should be given attribution
76 * as the author of the parts of the library used.
77 * This can be in the form of a textual message at program startup or
78 * in documentation (online or textual) provided with the package.
80 * Redistribution and use in source and binary forms, with or without
81 * modification, are permitted provided that the following conditions
83 * 1. Redistributions of source code must retain the copyright
84 * notice, this list of conditions and the following disclaimer.
85 * 2. Redistributions in binary form must reproduce the above copyright
86 * notice, this list of conditions and the following disclaimer in the
87 * documentation and/or other materials provided with the distribution.
88 * 3. All advertising materials mentioning features or use of this software
89 * must display the following acknowledgement:
90 * "This product includes cryptographic software written by
91 * Eric Young (eay@cryptsoft.com)"
92 * The word 'cryptographic' can be left out if the rouines from the library
93 * being used are not cryptographic related :-).
94 * 4. If you include any Windows specific code (or a derivative thereof) from
95 * the apps directory (application code) you must include an acknowledgement:
96 * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
98 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
99 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
100 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
101 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
102 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
103 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
104 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
105 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
106 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
107 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
110 * The licence and distribution terms for any publically available version or
111 * derivative of this code cannot be changed. i.e. this code cannot simply be
112 * copied and put under another distribution licence
113 * [including the GNU Public Licence.]
119 #include "ssl_locl.h"
120 #include <openssl/evp.h>
121 #include <openssl/buffer.h>
122 #include <openssl/pqueue.h>
123 #include <openssl/rand.h>
125 /* mod 128 saturating subtract of two 64-bit values in big-endian order */
126 static int satsub64be(const unsigned char *v1, const unsigned char *v2)
128 int ret, sat, brw, i;
130 if (sizeof(long) == 8)
140 if (is_endian.little)
142 /* not reached on little-endians */
144 * following test is redundant, because input is always aligned,
145 * but I take no chances...
147 if (((size_t)v1 | (size_t)v2) & 0x7)
160 ret = (int)v1[7] - (int)v2[7];
162 brw = ret >> 8; /* brw is either 0 or -1 */
164 for (i = 6; i >= 0; i--) {
165 brw += (int)v1[i] - (int)v2[i];
170 for (i = 6; i >= 0; i--) {
171 brw += (int)v1[i] - (int)v2[i];
176 brw <<= 8; /* brw is either 0 or -256 */
181 return brw + (ret & 0xFF);
184 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
186 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
187 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
188 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
189 unsigned int *is_next_epoch);
191 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
192 unsigned short *priority,
193 unsigned long *offset);
195 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
196 unsigned char *priority);
197 static int dtls1_process_record(SSL *s);
199 /* copy buffered record into SSL structure */
200 static int dtls1_copy_record(SSL *s, pitem *item)
202 DTLS1_RECORD_DATA *rdata;
204 rdata = (DTLS1_RECORD_DATA *)item->data;
206 if (s->s3->rbuf.buf != NULL)
207 OPENSSL_free(s->s3->rbuf.buf);
209 s->packet = rdata->packet;
210 s->packet_length = rdata->packet_length;
211 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
212 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
214 /* Set proper sequence number for mac calculation */
215 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
221 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
223 DTLS1_RECORD_DATA *rdata;
226 /* Limit the size of the queue to prevent DOS attacks */
227 if (pqueue_size(queue->q) >= 100)
230 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
231 item = pitem_new(priority, rdata);
232 if (rdata == NULL || item == NULL) {
238 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
242 rdata->packet = s->packet;
243 rdata->packet_length = s->packet_length;
244 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
245 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
249 #ifndef OPENSSL_NO_SCTP
250 /* Store bio_dgram_sctp_rcvinfo struct */
251 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
252 (s->state == SSL3_ST_SR_FINISHED_A
253 || s->state == SSL3_ST_CR_FINISHED_A)) {
254 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
255 sizeof(rdata->recordinfo), &rdata->recordinfo);
260 s->packet_length = 0;
261 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
262 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
264 if (!ssl3_setup_buffers(s)) {
265 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
266 if (rdata->rbuf.buf != NULL)
267 OPENSSL_free(rdata->rbuf.buf);
273 /* insert should not fail, since duplicates are dropped */
274 if (pqueue_insert(queue->q, item) == NULL) {
275 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
276 if (rdata->rbuf.buf != NULL)
277 OPENSSL_free(rdata->rbuf.buf);
286 static int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
290 item = pqueue_pop(queue->q);
292 dtls1_copy_record(s, item);
294 OPENSSL_free(item->data);
304 * retrieve a buffered record that belongs to the new epoch, i.e., not
307 #define dtls1_get_unprocessed_record(s) \
308 dtls1_retrieve_buffered_record((s), \
309 &((s)->d1->unprocessed_rcds))
312 * retrieve a buffered record that belongs to the current epoch, ie,
315 #define dtls1_get_processed_record(s) \
316 dtls1_retrieve_buffered_record((s), \
317 &((s)->d1->processed_rcds))
319 static int dtls1_process_buffered_records(SSL *s)
324 item = pqueue_peek(s->d1->unprocessed_rcds.q);
326 /* Check if epoch is current. */
327 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
328 return (1); /* Nothing to do. */
334 * We've still got data from the current packet to read. There could
335 * be a record from the new epoch in it - so don't overwrite it
336 * with the unprocessed records yet (we'll do it when we've
337 * finished reading the current packet).
343 /* Process all the records. */
344 while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
345 dtls1_get_unprocessed_record(s);
346 if (!dtls1_process_record(s))
348 if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
349 s->s3->rrec.seq_num) < 0)
355 * sync epoch numbers once all the unprocessed records have been
358 s->d1->processed_rcds.epoch = s->d1->r_epoch;
359 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
366 static int dtls1_get_buffered_record(SSL *s)
370 (((PQ_64BIT) s->d1->handshake_read_seq) << 32) |
371 ((PQ_64BIT) s->d1->r_msg_hdr.frag_off);
373 /* if we're not (re)negotiating, nothing buffered */
377 item = pqueue_peek(s->d1->rcvd_records);
378 if (item && item->priority == priority) {
380 * Check if we've received the record of interest. It must be a
381 * handshake record, since data records as passed up without
384 DTLS1_RECORD_DATA *rdata;
385 item = pqueue_pop(s->d1->rcvd_records);
386 rdata = (DTLS1_RECORD_DATA *)item->data;
388 if (s->s3->rbuf.buf != NULL)
389 OPENSSL_free(s->s3->rbuf.buf);
391 s->packet = rdata->packet;
392 s->packet_length = rdata->packet_length;
393 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
394 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
396 OPENSSL_free(item->data);
399 /* s->d1->next_expected_seq_num++; */
408 static int dtls1_process_record(SSL *s)
414 unsigned int mac_size, orig_len;
415 unsigned char md[EVP_MAX_MD_SIZE];
421 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
422 * and we have that many bytes in s->packet
424 rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]);
427 * ok, we can now read from 's->packet' data into 'rr' rr->input points
428 * at rr->length bytes, which need to be copied into rr->data by either
429 * the decryption or by the decompression When the data is 'copied' into
430 * the rr->data buffer, rr->input will be pointed at the new buffer
434 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
435 * bytes of encrypted compressed stuff.
438 /* check is not needed I believe */
439 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
440 al = SSL_AD_RECORD_OVERFLOW;
441 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
445 /* decrypt in place in 'rr->input' */
446 rr->data = rr->input;
448 enc_err = s->method->ssl3_enc->enc(s, 0);
451 * 0: (in non-constant time) if the record is publically invalid.
452 * 1: if the padding is valid
453 * -1: if the padding is invalid
456 /* For DTLS we simply ignore bad packets. */
458 s->packet_length = 0;
462 printf("dec %d\n", rr->length);
465 for (z = 0; z < rr->length; z++)
466 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
471 /* r->length is now the compressed data plus mac */
472 if ((sess != NULL) &&
473 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
474 /* s->read_hash != NULL => mac_size != -1 */
475 unsigned char *mac = NULL;
476 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
477 mac_size = EVP_MD_CTX_size(s->read_hash);
478 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
481 * kludge: *_cbc_remove_padding passes padding length in rr->type
483 orig_len = rr->length + ((unsigned int)rr->type >> 8);
486 * orig_len is the length of the record before any padding was
487 * removed. This is public information, as is the MAC in use,
488 * therefore we can safely process the record in a different amount
489 * of time if it's too short to possibly contain a MAC.
491 if (orig_len < mac_size ||
492 /* CBC records must have a padding length byte too. */
493 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
494 orig_len < mac_size + 1)) {
495 al = SSL_AD_DECODE_ERROR;
496 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
500 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
502 * We update the length so that the TLS header bytes can be
503 * constructed correctly but we need to extract the MAC in
504 * constant time from within the record, without leaking the
505 * contents of the padding bytes.
508 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
509 rr->length -= mac_size;
512 * In this case there's no padding, so |orig_len| equals
513 * |rec->length| and we checked that there's enough bytes for
516 rr->length -= mac_size;
517 mac = &rr->data[rr->length];
520 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
521 if (i < 0 || mac == NULL
522 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
524 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
529 /* decryption failed, silently discard message */
531 s->packet_length = 0;
535 /* r->length is now just compressed */
536 if (s->expand != NULL) {
537 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
538 al = SSL_AD_RECORD_OVERFLOW;
539 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
540 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
543 if (!ssl3_do_uncompress(s)) {
544 al = SSL_AD_DECOMPRESSION_FAILURE;
545 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
550 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
551 al = SSL_AD_RECORD_OVERFLOW;
552 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
558 * So at this point the following is true
559 * ssl->s3->rrec.type is the type of record
560 * ssl->s3->rrec.length == number of bytes in record
561 * ssl->s3->rrec.off == offset to first valid byte
562 * ssl->s3->rrec.data == where to take bytes from, increment
566 /* we have pulled in a full packet so zero things */
567 s->packet_length = 0;
571 ssl3_send_alert(s, SSL3_AL_FATAL, al);
577 * Call this to get a new input record.
578 * It will return <= 0 if more data is needed, normally due to an error
579 * or non-blocking IO.
580 * When it finishes, one packet has been decoded and can be found in
581 * ssl->s3->rrec.type - is the type of record
582 * ssl->s3->rrec.data, - data
583 * ssl->s3->rrec.length, - number of bytes
585 /* used only by dtls1_read_bytes */
586 int dtls1_get_record(SSL *s)
588 int ssl_major, ssl_minor;
591 unsigned char *p = NULL;
592 unsigned short version;
593 DTLS1_BITMAP *bitmap;
594 unsigned int is_next_epoch;
600 * The epoch may have changed. If so, process all the pending records.
601 * This is a non-blocking operation.
603 if (dtls1_process_buffered_records(s) < 0)
606 /* if we're renegotiating, then there may be buffered records */
607 if (dtls1_get_processed_record(s))
610 /* get something from the wire */
611 /* check if we have the header */
612 if ((s->rstate != SSL_ST_READ_BODY) ||
613 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) {
614 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
615 /* read timeout is handled by dtls1_read_bytes */
617 return (n); /* error or non-blocking */
619 /* this packet contained a partial record, dump it */
620 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) {
621 s->packet_length = 0;
625 s->rstate = SSL_ST_READ_BODY;
630 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
631 s, s->msg_callback_arg);
633 /* Pull apart the header into the DTLS1_RECORD */
637 version = (ssl_major << 8) | ssl_minor;
639 /* sequence number is 64 bits, with top 2 bytes = epoch */
642 memcpy(&(s->s3->read_sequence[2]), p, 6);
647 /* Lets check version */
648 if (!s->first_packet) {
649 if (version != s->version) {
650 /* unexpected version, silently discard */
652 s->packet_length = 0;
657 if ((version & 0xff00) != (s->version & 0xff00)) {
658 /* wrong version, silently discard record */
660 s->packet_length = 0;
664 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
665 /* record too long, silently discard it */
667 s->packet_length = 0;
671 /* now s->rstate == SSL_ST_READ_BODY */
674 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
676 if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) {
677 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
679 n = ssl3_read_n(s, i, i, 1);
680 /* this packet contained a partial record, dump it */
683 s->packet_length = 0;
688 * now n == rr->length, and s->packet_length ==
689 * DTLS1_RT_HEADER_LENGTH + rr->length
692 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
694 /* match epochs. NULL means the packet is dropped on the floor */
695 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
696 if (bitmap == NULL) {
698 s->packet_length = 0; /* dump this record */
699 goto again; /* get another record */
701 #ifndef OPENSSL_NO_SCTP
702 /* Only do replay check if no SCTP bio */
703 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
706 * Check whether this is a repeat, or aged record. Don't check if
707 * we're listening and this message is a ClientHello. They can look
708 * as if they're replayed, since they arrive from different
709 * connections and would be dropped unnecessarily.
711 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
712 s->packet_length > DTLS1_RT_HEADER_LENGTH &&
713 s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
714 !dtls1_record_replay_check(s, bitmap)) {
716 s->packet_length = 0; /* dump this record */
717 goto again; /* get another record */
719 #ifndef OPENSSL_NO_SCTP
723 /* just read a 0 length packet */
728 * If this record is from the next epoch (either HM or ALERT), and a
729 * handshake is currently in progress, buffer it since it cannot be
730 * processed at this time. However, do not buffer anything while
734 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) {
735 if (dtls1_buffer_record
736 (s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0)
738 /* Mark receipt of record. */
739 dtls1_record_bitmap_update(s, bitmap);
742 s->packet_length = 0;
746 if (!dtls1_process_record(s)) {
748 s->packet_length = 0; /* dump this record */
749 goto again; /* get another record */
751 dtls1_record_bitmap_update(s, bitmap); /* Mark receipt of record. */
758 * Return up to 'len' payload bytes received in 'type' records.
759 * 'type' is one of the following:
761 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
762 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
763 * - 0 (during a shutdown, no data has to be returned)
765 * If we don't have stored data to work from, read a SSL/TLS record first
766 * (possibly multiple records if we still don't have anything to return).
768 * This function must handle any surprises the peer may have for us, such as
769 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
770 * a surprise, but handled as if it were), or renegotiation requests.
771 * Also if record payloads contain fragments too small to process, we store
772 * them until there is enough for the respective protocol (the record protocol
773 * may use arbitrary fragmentation and even interleaving):
774 * Change cipher spec protocol
775 * just 1 byte needed, no need for keeping anything stored
777 * 2 bytes needed (AlertLevel, AlertDescription)
779 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
780 * to detect unexpected Client Hello and Hello Request messages
781 * here, anything else is handled by higher layers
782 * Application data protocol
783 * none of our business
785 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
790 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
792 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
793 if (!ssl3_setup_buffers(s))
796 /* XXX: check what the second '&& type' is about */
797 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
798 (type != SSL3_RT_HANDSHAKE) && type) ||
799 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
800 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
805 * check whether there's a handshake message (client hello?) waiting
807 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
811 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
814 #ifndef OPENSSL_NO_SCTP
816 * Continue handshake if it had to be interrupted to read app data with
819 if ((!s->in_handshake && SSL_in_init(s)) ||
820 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
821 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
822 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
823 && s->s3->in_read_app_data != 2))
825 if (!s->in_handshake && SSL_in_init(s))
828 /* type == SSL3_RT_APPLICATION_DATA */
829 i = s->handshake_func(s);
833 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
839 s->rwstate = SSL_NOTHING;
842 * s->s3->rrec.type - is the type of record
843 * s->s3->rrec.data, - data
844 * s->s3->rrec.off, - offset into 'data' for next read
845 * s->s3->rrec.length, - number of bytes.
850 * We are not handshaking and have no data yet, so process data buffered
851 * during the last handshake in advance, if any.
853 if (s->state == SSL_ST_OK && rr->length == 0) {
855 item = pqueue_pop(s->d1->buffered_app_data.q);
857 #ifndef OPENSSL_NO_SCTP
858 /* Restore bio_dgram_sctp_rcvinfo struct */
859 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
860 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
861 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
862 sizeof(rdata->recordinfo), &rdata->recordinfo);
866 dtls1_copy_record(s, item);
868 OPENSSL_free(item->data);
873 /* Check for timeout */
874 if (dtls1_handle_timeout(s) > 0)
877 /* get new packet if necessary */
878 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) {
879 ret = dtls1_get_record(s);
881 ret = dtls1_read_failed(s, ret);
882 /* anything other than a timeout is an error */
890 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
895 /* we now have a packet which can be read and processed */
897 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
898 * reset by ssl3_get_finished */
899 && (rr->type != SSL3_RT_HANDSHAKE)) {
901 * We now have application data between CCS and Finished. Most likely
902 * the packets were reordered on their way, so buffer the application
903 * data for later processing rather than dropping the connection.
905 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) <
907 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
915 * If the other end has shut down, throw anything we read away (even in
918 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
920 s->rwstate = SSL_NOTHING;
924 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or
925 * SSL3_RT_HANDSHAKE */
927 * make sure that we are not getting application data when we are
928 * doing a handshake for the first time
930 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
931 (s->enc_read_ctx == NULL)) {
932 al = SSL_AD_UNEXPECTED_MESSAGE;
933 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
940 if ((unsigned int)len > rr->length)
943 n = (unsigned int)len;
945 memcpy(buf, &(rr->data[rr->off]), n);
949 if (rr->length == 0) {
950 s->rstate = SSL_ST_READ_HEADER;
954 #ifndef OPENSSL_NO_SCTP
956 * We were about to renegotiate but had to read belated application
957 * data first, so retry.
959 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
960 rr->type == SSL3_RT_APPLICATION_DATA &&
961 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
962 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
963 s->rwstate = SSL_READING;
964 BIO_clear_retry_flags(SSL_get_rbio(s));
965 BIO_set_retry_read(SSL_get_rbio(s));
969 * We might had to delay a close_notify alert because of reordered
970 * app data. If there was an alert and there is no message to read
971 * anymore, finally set shutdown.
973 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
974 s->d1->shutdown_received
975 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
976 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
984 * If we get here, then type != rr->type; if we have a handshake message,
985 * then it was unexpected (Hello Request or Client Hello).
989 * In case of record types for which we have 'fragment' storage, fill
990 * that so that we can process the data at a fixed place.
993 unsigned int k, dest_maxlen = 0;
994 unsigned char *dest = NULL;
995 unsigned int *dest_len = NULL;
997 if (rr->type == SSL3_RT_HANDSHAKE) {
998 dest_maxlen = sizeof s->d1->handshake_fragment;
999 dest = s->d1->handshake_fragment;
1000 dest_len = &s->d1->handshake_fragment_len;
1001 } else if (rr->type == SSL3_RT_ALERT) {
1002 dest_maxlen = sizeof(s->d1->alert_fragment);
1003 dest = s->d1->alert_fragment;
1004 dest_len = &s->d1->alert_fragment_len;
1006 #ifndef OPENSSL_NO_HEARTBEATS
1007 else if (rr->type == TLS1_RT_HEARTBEAT) {
1008 dtls1_process_heartbeat(s);
1010 /* Exit and notify application to read again */
1012 s->rwstate = SSL_READING;
1013 BIO_clear_retry_flags(SSL_get_rbio(s));
1014 BIO_set_retry_read(SSL_get_rbio(s));
1018 /* else it's a CCS message, or application data or wrong */
1019 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
1021 * Application data while renegotiating is allowed. Try again
1024 if (rr->type == SSL3_RT_APPLICATION_DATA) {
1026 s->s3->in_read_app_data = 2;
1027 bio = SSL_get_rbio(s);
1028 s->rwstate = SSL_READING;
1029 BIO_clear_retry_flags(bio);
1030 BIO_set_retry_read(bio);
1034 /* Not certain if this is the right error handling */
1035 al = SSL_AD_UNEXPECTED_MESSAGE;
1036 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1040 if (dest_maxlen > 0) {
1042 * XDTLS: In a pathalogical case, the Client Hello may be
1043 * fragmented--don't always expect dest_maxlen bytes
1045 if (rr->length < dest_maxlen) {
1046 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1048 * for normal alerts rr->length is 2, while
1049 * dest_maxlen is 7 if we were to handle this
1050 * non-existing alert...
1054 s->rstate = SSL_ST_READ_HEADER;
1059 /* now move 'n' bytes: */
1060 for (k = 0; k < dest_maxlen; k++) {
1061 dest[k] = rr->data[rr->off++];
1064 *dest_len = dest_maxlen;
1069 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
1070 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
1071 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
1074 /* If we are a client, check for an incoming 'Hello Request': */
1076 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1077 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1078 (s->session != NULL) && (s->session->cipher != NULL)) {
1079 s->d1->handshake_fragment_len = 0;
1081 if ((s->d1->handshake_fragment[1] != 0) ||
1082 (s->d1->handshake_fragment[2] != 0) ||
1083 (s->d1->handshake_fragment[3] != 0)) {
1084 al = SSL_AD_DECODE_ERROR;
1085 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
1090 * no need to check sequence number on HELLO REQUEST messages
1093 if (s->msg_callback)
1094 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1095 s->d1->handshake_fragment, 4, s,
1096 s->msg_callback_arg);
1098 if (SSL_is_init_finished(s) &&
1099 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1100 !s->s3->renegotiate) {
1101 s->d1->handshake_read_seq++;
1103 ssl3_renegotiate(s);
1104 if (ssl3_renegotiate_check(s)) {
1105 i = s->handshake_func(s);
1109 SSLerr(SSL_F_DTLS1_READ_BYTES,
1110 SSL_R_SSL_HANDSHAKE_FAILURE);
1114 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
1115 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
1118 * In the case where we try to read application data,
1119 * but we trigger an SSL handshake, we return -1 with
1120 * the retry option set. Otherwise renegotiation may
1121 * cause nasty problems in the blocking world
1123 s->rwstate = SSL_READING;
1124 bio = SSL_get_rbio(s);
1125 BIO_clear_retry_flags(bio);
1126 BIO_set_retry_read(bio);
1133 * we either finished a handshake or ignored the request, now try
1134 * again to obtain the (application) data we were asked for
1139 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
1140 int alert_level = s->d1->alert_fragment[0];
1141 int alert_descr = s->d1->alert_fragment[1];
1143 s->d1->alert_fragment_len = 0;
1145 if (s->msg_callback)
1146 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1147 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1149 if (s->info_callback != NULL)
1150 cb = s->info_callback;
1151 else if (s->ctx->info_callback != NULL)
1152 cb = s->ctx->info_callback;
1155 j = (alert_level << 8) | alert_descr;
1156 cb(s, SSL_CB_READ_ALERT, j);
1159 if (alert_level == SSL3_AL_WARNING) {
1160 s->s3->warn_alert = alert_descr;
1161 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
1162 #ifndef OPENSSL_NO_SCTP
1164 * With SCTP and streams the socket may deliver app data
1165 * after a close_notify alert. We have to check this first so
1166 * that nothing gets discarded.
1168 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1169 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
1170 s->d1->shutdown_received = 1;
1171 s->rwstate = SSL_READING;
1172 BIO_clear_retry_flags(SSL_get_rbio(s));
1173 BIO_set_retry_read(SSL_get_rbio(s));
1177 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1181 /* XXX: this is a possible improvement in the future */
1182 /* now check if it's a missing record */
1183 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
1185 unsigned int frag_off;
1186 unsigned char *p = &(s->d1->alert_fragment[2]);
1191 dtls1_retransmit_message(s,
1192 dtls1_get_queue_priority
1193 (frag->msg_header.seq, 0), frag_off,
1195 if (!found && SSL_in_init(s)) {
1197 * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
1200 * requested a message not yet sent, send an alert
1203 ssl3_send_alert(s, SSL3_AL_WARNING,
1204 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1208 } else if (alert_level == SSL3_AL_FATAL) {
1211 s->rwstate = SSL_NOTHING;
1212 s->s3->fatal_alert = alert_descr;
1213 SSLerr(SSL_F_DTLS1_READ_BYTES,
1214 SSL_AD_REASON_OFFSET + alert_descr);
1215 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
1216 ERR_add_error_data(2, "SSL alert number ", tmp);
1217 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1218 SSL_CTX_remove_session(s->ctx, s->session);
1221 al = SSL_AD_ILLEGAL_PARAMETER;
1222 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
1229 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
1231 s->rwstate = SSL_NOTHING;
1236 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
1237 struct ccs_header_st ccs_hdr;
1238 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1240 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1242 if (s->version == DTLS1_BAD_VER)
1246 * 'Change Cipher Spec' is just a single byte, so we know exactly
1247 * what the record payload has to look like
1249 /* XDTLS: check that epoch is consistent */
1250 if ((rr->length != ccs_hdr_len) ||
1251 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
1252 i = SSL_AD_ILLEGAL_PARAMETER;
1253 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
1259 if (s->msg_callback)
1260 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1261 rr->data, 1, s, s->msg_callback_arg);
1264 * We can't process a CCS now, because previous handshake messages
1265 * are still missing, so just drop it.
1267 if (!s->d1->change_cipher_spec_ok) {
1271 s->d1->change_cipher_spec_ok = 0;
1273 s->s3->change_cipher_spec = 1;
1274 if (!ssl3_do_change_cipher_spec(s))
1277 /* do this whenever CCS is processed */
1278 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1280 if (s->version == DTLS1_BAD_VER)
1281 s->d1->handshake_read_seq++;
1283 #ifndef OPENSSL_NO_SCTP
1285 * Remember that a CCS has been received, so that an old key of
1286 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
1289 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1296 * Unexpected handshake message (Client Hello, or protocol violation)
1298 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1300 struct hm_header_st msg_hdr;
1302 /* this may just be a stale retransmit */
1303 dtls1_get_message_header(rr->data, &msg_hdr);
1304 if (rr->epoch != s->d1->r_epoch) {
1310 * If we are server, we may have a repeated FINISHED of the client
1311 * here, then retransmit our CCS and FINISHED.
1313 if (msg_hdr.type == SSL3_MT_FINISHED) {
1314 if (dtls1_check_timeout_num(s) < 0)
1317 dtls1_retransmit_buffered_messages(s);
1322 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
1323 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
1324 #if 0 /* worked only because C operator preferences
1325 * are not as expected (and because this is
1326 * not really needed for clients except for
1327 * detecting protocol violations): */
1328 s->state = SSL_ST_BEFORE | (s->server)
1329 ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1331 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1336 i = s->handshake_func(s);
1340 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
1344 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
1345 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
1348 * In the case where we try to read application data, but we
1349 * trigger an SSL handshake, we return -1 with the retry
1350 * option set. Otherwise renegotiation may cause nasty
1351 * problems in the blocking world
1353 s->rwstate = SSL_READING;
1354 bio = SSL_get_rbio(s);
1355 BIO_clear_retry_flags(bio);
1356 BIO_set_retry_read(bio);
1365 #ifndef OPENSSL_NO_TLS
1366 /* TLS just ignores unknown message types */
1367 if (s->version == TLS1_VERSION) {
1372 al = SSL_AD_UNEXPECTED_MESSAGE;
1373 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1375 case SSL3_RT_CHANGE_CIPHER_SPEC:
1377 case SSL3_RT_HANDSHAKE:
1379 * we already handled all of these, with the possible exception of
1380 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
1381 * happen when type != rr->type
1383 al = SSL_AD_UNEXPECTED_MESSAGE;
1384 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
1386 case SSL3_RT_APPLICATION_DATA:
1388 * At this point, we were expecting handshake data, but have
1389 * application data. If the library was running inside ssl3_read()
1390 * (i.e. in_read_app_data is set) and it makes sense to read
1391 * application data at this point (session renegotiation not yet
1392 * started), we will indulge it.
1394 if (s->s3->in_read_app_data &&
1395 (s->s3->total_renegotiations != 0) &&
1396 (((s->state & SSL_ST_CONNECT) &&
1397 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1398 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1399 ) || ((s->state & SSL_ST_ACCEPT) &&
1400 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1401 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1404 s->s3->in_read_app_data = 2;
1407 al = SSL_AD_UNEXPECTED_MESSAGE;
1408 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1415 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1420 int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1424 #ifndef OPENSSL_NO_SCTP
1426 * Check if we have to continue an interrupted handshake for reading
1427 * belated app data with SCTP.
1429 if ((SSL_in_init(s) && !s->in_handshake) ||
1430 (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1431 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
1432 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1434 if (SSL_in_init(s) && !s->in_handshake)
1437 i = s->handshake_func(s);
1441 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,
1442 SSL_R_SSL_HANDSHAKE_FAILURE);
1447 if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
1448 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG);
1452 i = dtls1_write_bytes(s, type, buf_, len);
1457 * this only happens when a client hello is received and a handshake
1461 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1465 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1466 /* (partially) satisfy request from storage */
1468 unsigned char *src = s->d1->handshake_fragment;
1469 unsigned char *dst = buf;
1474 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) {
1477 s->d1->handshake_fragment_len--;
1480 /* move any remaining fragment bytes: */
1481 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1482 s->d1->handshake_fragment[k] = *src++;
1490 * Call this to write data in records of type 'type' It will return <= 0 if
1491 * not all data has been sent or non-blocking IO.
1493 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1497 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1498 s->rwstate = SSL_NOTHING;
1499 i = do_dtls1_write(s, type, buf, len, 0);
1503 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
1504 unsigned int len, int create_empty_fragment)
1506 unsigned char *p, *pseq;
1507 int i, mac_size, clear = 0;
1515 * first check if there is a SSL3_BUFFER still being written out. This
1516 * will happen with non blocking IO
1518 if (s->s3->wbuf.left != 0) {
1519 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1520 return (ssl3_write_pending(s, type, buf, len));
1523 /* If we have an alert to send, lets send it */
1524 if (s->s3->alert_dispatch) {
1525 i = s->method->ssl_dispatch_alert(s);
1528 /* if it went, fall through and send more stuff */
1531 if (len == 0 && !create_empty_fragment)
1534 wr = &(s->s3->wrec);
1535 wb = &(s->s3->wbuf);
1538 if ((sess == NULL) ||
1539 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
1545 mac_size = EVP_MD_CTX_size(s->write_hash);
1550 /* DTLS implements explicit IV, so no need for empty fragments */
1553 * 'create_empty_fragment' is true only when this function calls itself
1555 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1556 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1559 * countermeasure against known-IV weakness in CBC ciphersuites (see
1560 * http://www.openssl.org/~bodo/tls-cbc.txt)
1563 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) {
1565 * recursive function call with 'create_empty_fragment' set; this
1566 * prepares and buffers the data for an empty fragment (these
1567 * 'prefix_len' bytes are sent out later together with the actual
1570 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1571 if (prefix_len <= 0)
1574 if (s->s3->wbuf.len <
1575 (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) {
1576 /* insufficient space */
1577 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1582 s->s3->empty_fragment_done = 1;
1585 p = wb->buf + prefix_len;
1587 /* write the header */
1589 *(p++) = type & 0xff;
1592 * Special case: for hello verify request, client version 1.0 and we
1593 * haven't decided which version to use yet send back using version 1.0
1594 * header: otherwise some clients will ignore it.
1596 if (s->method->version == DTLS_ANY_VERSION) {
1597 *(p++) = DTLS1_VERSION >> 8;
1598 *(p++) = DTLS1_VERSION & 0xff;
1600 *(p++) = s->version >> 8;
1601 *(p++) = s->version & 0xff;
1604 /* field where we are to write out packet epoch, seq num and len */
1608 /* Explicit IV length, block ciphers appropriate version flag */
1609 if (s->enc_write_ctx) {
1610 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1611 if (mode == EVP_CIPH_CBC_MODE) {
1612 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1616 /* Need explicit part of IV for GCM mode */
1617 else if (mode == EVP_CIPH_GCM_MODE)
1618 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1624 /* lets setup the record stuff. */
1625 wr->data = p + eivlen; /* make room for IV in case of CBC */
1626 wr->length = (int)len;
1627 wr->input = (unsigned char *)buf;
1630 * we now 'read' from wr->input, wr->length bytes into wr->data
1633 /* first we compress */
1634 if (s->compress != NULL) {
1635 if (!ssl3_do_compress(s)) {
1636 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
1640 memcpy(wr->data, wr->input, wr->length);
1641 wr->input = wr->data;
1645 * we should still have the output to wr->data and the input from
1646 * wr->input. Length should be wr->length. wr->data still points in the
1650 if (mac_size != 0) {
1651 if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
1653 wr->length += mac_size;
1656 /* this is true regardless of mac size */
1661 wr->length += eivlen;
1663 if (s->method->ssl3_enc->enc(s, 1) < 1)
1666 /* record length after mac and block padding */
1668 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
1672 /* there's only one epoch between handshake and app data */
1674 s2n(s->d1->w_epoch, pseq);
1678 * else s2n(s->d1->handshake_epoch, pseq);
1681 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1683 s2n(wr->length, pseq);
1685 if (s->msg_callback)
1686 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
1687 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1690 * we should now have wr->data pointing to the encrypted data, which is
1693 wr->type = type; /* not needed but helps for debugging */
1694 wr->length += DTLS1_RT_HEADER_LENGTH;
1696 #if 0 /* this is now done at the message layer */
1697 /* buffer the record, making it easy to handle retransmits */
1698 if (type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1699 dtls1_buffer_record(s, wr->data, wr->length,
1700 *((PQ_64BIT *) & (s->s3->write_sequence[0])));
1703 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1705 if (create_empty_fragment) {
1707 * we are in a recursive call; just return the length, don't write
1713 /* now let's set up wb */
1714 wb->left = prefix_len + wr->length;
1718 * memorize arguments so that ssl3_write_pending can detect bad write
1721 s->s3->wpend_tot = len;
1722 s->s3->wpend_buf = buf;
1723 s->s3->wpend_type = type;
1724 s->s3->wpend_ret = len;
1726 /* we now just need to write the buffer */
1727 return ssl3_write_pending(s, type, buf, len);
1732 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1736 const unsigned char *seq = s->s3->read_sequence;
1738 cmp = satsub64be(seq, bitmap->max_seq_num);
1740 memcpy(s->s3->rrec.seq_num, seq, 8);
1741 return 1; /* this record in new */
1744 if (shift >= sizeof(bitmap->map) * 8)
1745 return 0; /* stale, outside the window */
1746 else if (bitmap->map & (1UL << shift))
1747 return 0; /* record previously received */
1749 memcpy(s->s3->rrec.seq_num, seq, 8);
1753 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1757 const unsigned char *seq = s->s3->read_sequence;
1759 cmp = satsub64be(seq, bitmap->max_seq_num);
1762 if (shift < sizeof(bitmap->map) * 8)
1763 bitmap->map <<= shift, bitmap->map |= 1UL;
1766 memcpy(bitmap->max_seq_num, seq, 8);
1769 if (shift < sizeof(bitmap->map) * 8)
1770 bitmap->map |= 1UL << shift;
1774 int dtls1_dispatch_alert(SSL *s)
1777 void (*cb) (const SSL *ssl, int type, int val) = NULL;
1778 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1779 unsigned char *ptr = &buf[0];
1781 s->s3->alert_dispatch = 0;
1783 memset(buf, 0x00, sizeof(buf));
1784 *ptr++ = s->s3->send_alert[0];
1785 *ptr++ = s->s3->send_alert[1];
1787 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1788 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
1789 s2n(s->d1->handshake_read_seq, ptr);
1791 if (s->d1->r_msg_hdr.frag_off == 0)
1793 * waiting for a new msg
1796 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1801 "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",
1802 s->d1->handshake_read_seq, s->d1->r_msg_hdr.seq);
1804 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1808 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1810 s->s3->alert_dispatch = 1;
1811 /* fprintf( stderr, "not done with alert\n" ); */
1813 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1814 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1815 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1818 (void)BIO_flush(s->wbio);
1820 if (s->msg_callback)
1821 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1822 2, s, s->msg_callback_arg);
1824 if (s->info_callback != NULL)
1825 cb = s->info_callback;
1826 else if (s->ctx->info_callback != NULL)
1827 cb = s->ctx->info_callback;
1830 j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1];
1831 cb(s, SSL_CB_WRITE_ALERT, j);
1837 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1838 unsigned int *is_next_epoch)
1843 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1844 if (rr->epoch == s->d1->r_epoch)
1845 return &s->d1->bitmap;
1848 * Only HM and ALERT messages can be from the next epoch and only if we
1849 * have already processed all of the unprocessed records from the last
1852 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1853 s->d1->unprocessed_rcds.epoch != s->d1->r_epoch &&
1854 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1856 return &s->d1->next_bitmap;
1864 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
1865 unsigned short *priority, unsigned long *offset)
1868 /* alerts are passed up immediately */
1869 if (rr->type == SSL3_RT_APPLICATION_DATA || rr->type == SSL3_RT_ALERT)
1873 * Only need to buffer if a handshake is underway. (this implies that
1874 * Hello Request and Client Hello are passed up immediately)
1876 if (SSL_in_init(s)) {
1877 unsigned char *data = rr->data;
1878 /* need to extract the HM/CCS sequence number here */
1879 if (rr->type == SSL3_RT_HANDSHAKE ||
1880 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
1881 unsigned short seq_num;
1882 struct hm_header_st msg_hdr;
1883 struct ccs_header_st ccs_hdr;
1885 if (rr->type == SSL3_RT_HANDSHAKE) {
1886 dtls1_get_message_header(data, &msg_hdr);
1887 seq_num = msg_hdr.seq;
1888 *offset = msg_hdr.frag_off;
1890 dtls1_get_ccs_header(data, &ccs_hdr);
1891 seq_num = ccs_hdr.seq;
1896 * this is either a record we're waiting for, or a retransmit of
1897 * something we happened to previously receive (higher layers
1898 * will drop the repeat silently
1900 if (seq_num < s->d1->handshake_read_seq)
1902 if (rr->type == SSL3_RT_HANDSHAKE &&
1903 seq_num == s->d1->handshake_read_seq &&
1904 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1906 else if (seq_num == s->d1->handshake_read_seq &&
1907 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1908 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1911 *priority = seq_num;
1914 } else /* unknown record type */
1922 void dtls1_reset_seq_numbers(SSL *s, int rw)
1925 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1927 if (rw & SSL3_CC_READ) {
1928 seq = s->s3->read_sequence;
1930 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1931 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1933 seq = s->s3->write_sequence;
1934 memcpy(s->d1->last_write_sequence, seq,
1935 sizeof(s->s3->write_sequence));
1939 memset(seq, 0x00, seq_bytes);