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)
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)
161 for (i=0; i<7; i++) {
163 /* v1 is larger... but by how much? */
164 if (v1[i] != v2[i] + 1)
167 if (v1[i] != 0x00 || v2[i] != 0xff)
168 return 128; /* too much */
170 /* We checked all the way to the penultimate byte,
171 * so despite higher bytes changing we actually
172 * know that it only changed from (e.g.)
173 * ... (xx) ff ff ff ??
174 * to ... (xx+1) 00 00 00 ??
175 * so we add a 'bias' of 256 for the carry that
176 * happened, and will eventually return
177 * 256 + v1[7] - v2[7]. */
180 } else if (v2[i] > v1[i]) {
181 /* v2 is larger... but by how much? */
182 if (v2[i] != v1[i] + 1)
185 if (v2[i] != 0x00 || v1[i] != 0xff)
186 return -128; /* too much */
188 /* Similar to the case above, we know it changed
189 * from ... (xx) 00 00 00 ??
190 * to ... (xx-1) ff ff ff ??
191 * so we add a 'bias' of -256 for the borrow,
192 * to return -256 + v1[7] - v2[7]. */
197 ret += (int)v1[7] - (int)v2[7];
207 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
209 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
210 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
211 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
212 unsigned int *is_next_epoch);
214 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
215 unsigned short *priority,
216 unsigned long *offset);
218 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
219 unsigned char *priority);
220 static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap);
222 /* copy buffered record into SSL structure */
223 static int dtls1_copy_record(SSL *s, pitem *item)
225 DTLS1_RECORD_DATA *rdata;
227 rdata = (DTLS1_RECORD_DATA *)item->data;
229 if (s->s3->rbuf.buf != NULL)
230 OPENSSL_free(s->s3->rbuf.buf);
232 s->packet = rdata->packet;
233 s->packet_length = rdata->packet_length;
234 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
235 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
237 /* Set proper sequence number for mac calculation */
238 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
244 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
246 DTLS1_RECORD_DATA *rdata;
249 /* Limit the size of the queue to prevent DOS attacks */
250 if (pqueue_size(queue->q) >= 100)
253 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
254 item = pitem_new(priority, rdata);
255 if (rdata == NULL || item == NULL) {
261 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
265 rdata->packet = s->packet;
266 rdata->packet_length = s->packet_length;
267 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
268 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
272 #ifndef OPENSSL_NO_SCTP
273 /* Store bio_dgram_sctp_rcvinfo struct */
274 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
275 (s->state == SSL3_ST_SR_FINISHED_A
276 || s->state == SSL3_ST_CR_FINISHED_A)) {
277 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO,
278 sizeof(rdata->recordinfo), &rdata->recordinfo);
283 s->packet_length = 0;
284 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
285 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
287 if (!ssl3_setup_buffers(s)) {
288 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
289 if (rdata->rbuf.buf != NULL)
290 OPENSSL_free(rdata->rbuf.buf);
296 /* insert should not fail, since duplicates are dropped */
297 if (pqueue_insert(queue->q, item) == NULL) {
298 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
299 if (rdata->rbuf.buf != NULL)
300 OPENSSL_free(rdata->rbuf.buf);
309 static int dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
313 item = pqueue_pop(queue->q);
315 dtls1_copy_record(s, item);
317 OPENSSL_free(item->data);
327 * retrieve a buffered record that belongs to the new epoch, i.e., not
330 #define dtls1_get_unprocessed_record(s) \
331 dtls1_retrieve_buffered_record((s), \
332 &((s)->d1->unprocessed_rcds))
335 * retrieve a buffered record that belongs to the current epoch, ie,
338 #define dtls1_get_processed_record(s) \
339 dtls1_retrieve_buffered_record((s), \
340 &((s)->d1->processed_rcds))
342 static int dtls1_process_buffered_records(SSL *s)
347 DTLS1_BITMAP *bitmap;
348 unsigned int is_next_epoch;
351 item = pqueue_peek(s->d1->unprocessed_rcds.q);
353 /* Check if epoch is current. */
354 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
355 return 1; /* Nothing to do. */
362 * We've still got data from the current packet to read. There could
363 * be a record from the new epoch in it - so don't overwrite it
364 * with the unprocessed records yet (we'll do it when we've
365 * finished reading the current packet).
371 /* Process all the records. */
372 while (pqueue_peek(s->d1->unprocessed_rcds.q)) {
373 dtls1_get_unprocessed_record(s);
374 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
375 if (bitmap == NULL) {
377 * Should not happen. This will only ever be NULL when the
378 * current record is from a different epoch. But that cannot
379 * be the case because we already checked the epoch above
381 SSLerr(SSL_F_DTLS1_PROCESS_BUFFERED_RECORDS,
382 ERR_R_INTERNAL_ERROR);
385 #ifndef OPENSSL_NO_SCTP
386 /* Only do replay check if no SCTP bio */
387 if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
391 * Check whether this is a repeat, or aged record. We did this
392 * check once already when we first received the record - but
393 * we might have updated the window since then due to
394 * records we subsequently processed.
396 replayok = dtls1_record_replay_check(s, bitmap);
399 if (!replayok || !dtls1_process_record(s, bitmap)) {
400 /* dump this record */
402 s->packet_length = 0;
406 if (dtls1_buffer_record(s, &(s->d1->processed_rcds),
407 s->s3->rrec.seq_num) < 0)
413 * sync epoch numbers once all the unprocessed records have been
416 s->d1->processed_rcds.epoch = s->d1->r_epoch;
417 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
424 static int dtls1_get_buffered_record(SSL *s)
428 (((PQ_64BIT) s->d1->handshake_read_seq) << 32) |
429 ((PQ_64BIT) s->d1->r_msg_hdr.frag_off);
431 /* if we're not (re)negotiating, nothing buffered */
435 item = pqueue_peek(s->d1->rcvd_records);
436 if (item && item->priority == priority) {
438 * Check if we've received the record of interest. It must be a
439 * handshake record, since data records as passed up without
442 DTLS1_RECORD_DATA *rdata;
443 item = pqueue_pop(s->d1->rcvd_records);
444 rdata = (DTLS1_RECORD_DATA *)item->data;
446 if (s->s3->rbuf.buf != NULL)
447 OPENSSL_free(s->s3->rbuf.buf);
449 s->packet = rdata->packet;
450 s->packet_length = rdata->packet_length;
451 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
452 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
454 OPENSSL_free(item->data);
457 /* s->d1->next_expected_seq_num++; */
466 static int dtls1_process_record(SSL *s, DTLS1_BITMAP *bitmap)
472 unsigned int mac_size, orig_len;
473 unsigned char md[EVP_MAX_MD_SIZE];
479 * At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
480 * and we have that many bytes in s->packet
482 rr->input = &(s->packet[DTLS1_RT_HEADER_LENGTH]);
485 * ok, we can now read from 's->packet' data into 'rr' rr->input points
486 * at rr->length bytes, which need to be copied into rr->data by either
487 * the decryption or by the decompression When the data is 'copied' into
488 * the rr->data buffer, rr->input will be pointed at the new buffer
492 * We now have - encrypted [ MAC [ compressed [ plain ] ] ] rr->length
493 * bytes of encrypted compressed stuff.
496 /* check is not needed I believe */
497 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
498 al = SSL_AD_RECORD_OVERFLOW;
499 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
503 /* decrypt in place in 'rr->input' */
504 rr->data = rr->input;
506 enc_err = s->method->ssl3_enc->enc(s, 0);
509 * 0: (in non-constant time) if the record is publically invalid.
510 * 1: if the padding is valid
511 * -1: if the padding is invalid
514 /* For DTLS we simply ignore bad packets. */
516 s->packet_length = 0;
520 printf("dec %d\n", rr->length);
523 for (z = 0; z < rr->length; z++)
524 printf("%02X%c", rr->data[z], ((z + 1) % 16) ? ' ' : '\n');
529 /* r->length is now the compressed data plus mac */
530 if ((sess != NULL) &&
531 (s->enc_read_ctx != NULL) && (EVP_MD_CTX_md(s->read_hash) != NULL)) {
532 /* s->read_hash != NULL => mac_size != -1 */
533 unsigned char *mac = NULL;
534 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
535 mac_size = EVP_MD_CTX_size(s->read_hash);
536 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
539 * kludge: *_cbc_remove_padding passes padding length in rr->type
541 orig_len = rr->length + ((unsigned int)rr->type >> 8);
544 * orig_len is the length of the record before any padding was
545 * removed. This is public information, as is the MAC in use,
546 * therefore we can safely process the record in a different amount
547 * of time if it's too short to possibly contain a MAC.
549 if (orig_len < mac_size ||
550 /* CBC records must have a padding length byte too. */
551 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
552 orig_len < mac_size + 1)) {
553 al = SSL_AD_DECODE_ERROR;
554 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_LENGTH_TOO_SHORT);
558 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE) {
560 * We update the length so that the TLS header bytes can be
561 * constructed correctly but we need to extract the MAC in
562 * constant time from within the record, without leaking the
563 * contents of the padding bytes.
566 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
567 rr->length -= mac_size;
570 * In this case there's no padding, so |orig_len| equals
571 * |rec->length| and we checked that there's enough bytes for
574 rr->length -= mac_size;
575 mac = &rr->data[rr->length];
578 i = s->method->ssl3_enc->mac(s, md, 0 /* not send */ );
579 if (i < 0 || mac == NULL
580 || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
582 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH + mac_size)
587 /* decryption failed, silently discard message */
589 s->packet_length = 0;
593 /* r->length is now just compressed */
594 if (s->expand != NULL) {
595 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH) {
596 al = SSL_AD_RECORD_OVERFLOW;
597 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,
598 SSL_R_COMPRESSED_LENGTH_TOO_LONG);
601 if (!ssl3_do_uncompress(s)) {
602 al = SSL_AD_DECOMPRESSION_FAILURE;
603 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_BAD_DECOMPRESSION);
608 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH) {
609 al = SSL_AD_RECORD_OVERFLOW;
610 SSLerr(SSL_F_DTLS1_PROCESS_RECORD, SSL_R_DATA_LENGTH_TOO_LONG);
616 * So at this point the following is true
617 * ssl->s3->rrec.type is the type of record
618 * ssl->s3->rrec.length == number of bytes in record
619 * ssl->s3->rrec.off == offset to first valid byte
620 * ssl->s3->rrec.data == where to take bytes from, increment
624 /* we have pulled in a full packet so zero things */
625 s->packet_length = 0;
627 /* Mark receipt of record. */
628 dtls1_record_bitmap_update(s, bitmap);
633 ssl3_send_alert(s, SSL3_AL_FATAL, al);
639 * Call this to get a new input record.
640 * It will return <= 0 if more data is needed, normally due to an error
641 * or non-blocking IO.
642 * When it finishes, one packet has been decoded and can be found in
643 * ssl->s3->rrec.type - is the type of record
644 * ssl->s3->rrec.data, - data
645 * ssl->s3->rrec.length, - number of bytes
647 /* used only by dtls1_read_bytes */
648 int dtls1_get_record(SSL *s)
650 int ssl_major, ssl_minor;
653 unsigned char *p = NULL;
654 unsigned short version;
655 DTLS1_BITMAP *bitmap;
656 unsigned int is_next_epoch;
662 * The epoch may have changed. If so, process all the pending records.
663 * This is a non-blocking operation.
665 if (!dtls1_process_buffered_records(s))
668 /* if we're renegotiating, then there may be buffered records */
669 if (dtls1_get_processed_record(s))
672 /* get something from the wire */
673 /* check if we have the header */
674 if ((s->rstate != SSL_ST_READ_BODY) ||
675 (s->packet_length < DTLS1_RT_HEADER_LENGTH)) {
676 n = ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
677 /* read timeout is handled by dtls1_read_bytes */
679 return (n); /* error or non-blocking */
681 /* this packet contained a partial record, dump it */
682 if (s->packet_length != DTLS1_RT_HEADER_LENGTH) {
683 s->packet_length = 0;
687 s->rstate = SSL_ST_READ_BODY;
692 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH,
693 s, s->msg_callback_arg);
695 /* Pull apart the header into the DTLS1_RECORD */
699 version = (ssl_major << 8) | ssl_minor;
701 /* sequence number is 64 bits, with top 2 bytes = epoch */
704 memcpy(&(s->s3->read_sequence[2]), p, 6);
709 /* Lets check version */
710 if (!s->first_packet) {
711 if (version != s->version) {
712 /* unexpected version, silently discard */
714 s->packet_length = 0;
719 if ((version & 0xff00) != (s->version & 0xff00)) {
720 /* wrong version, silently discard record */
722 s->packet_length = 0;
726 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH) {
727 /* record too long, silently discard it */
729 s->packet_length = 0;
733 /* now s->rstate == SSL_ST_READ_BODY */
736 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
738 if (rr->length > s->packet_length - DTLS1_RT_HEADER_LENGTH) {
739 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
741 n = ssl3_read_n(s, i, i, 1);
742 /* this packet contained a partial record, dump it */
745 s->packet_length = 0;
750 * now n == rr->length, and s->packet_length ==
751 * DTLS1_RT_HEADER_LENGTH + rr->length
754 s->rstate = SSL_ST_READ_HEADER; /* set state for later operations */
756 /* match epochs. NULL means the packet is dropped on the floor */
757 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
758 if (bitmap == NULL) {
760 s->packet_length = 0; /* dump this record */
761 goto again; /* get another record */
763 #ifndef OPENSSL_NO_SCTP
764 /* Only do replay check if no SCTP bio */
765 if (!BIO_dgram_is_sctp(SSL_get_rbio(s))) {
768 * Check whether this is a repeat, or aged record. Don't check if
769 * we're listening and this message is a ClientHello. They can look
770 * as if they're replayed, since they arrive from different
771 * connections and would be dropped unnecessarily.
773 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
774 s->packet_length > DTLS1_RT_HEADER_LENGTH &&
775 s->packet[DTLS1_RT_HEADER_LENGTH] == SSL3_MT_CLIENT_HELLO) &&
776 !dtls1_record_replay_check(s, bitmap)) {
778 s->packet_length = 0; /* dump this record */
779 goto again; /* get another record */
781 #ifndef OPENSSL_NO_SCTP
785 /* just read a 0 length packet */
790 * If this record is from the next epoch (either HM or ALERT), and a
791 * handshake is currently in progress, buffer it since it cannot be
792 * processed at this time. However, do not buffer anything while
796 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen) {
797 if (dtls1_buffer_record
798 (s, &(s->d1->unprocessed_rcds), rr->seq_num) < 0)
802 s->packet_length = 0;
806 if (!dtls1_process_record(s, bitmap)) {
808 s->packet_length = 0; /* dump this record */
809 goto again; /* get another record */
817 * Return up to 'len' payload bytes received in 'type' records.
818 * 'type' is one of the following:
820 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
821 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
822 * - 0 (during a shutdown, no data has to be returned)
824 * If we don't have stored data to work from, read a SSL/TLS record first
825 * (possibly multiple records if we still don't have anything to return).
827 * This function must handle any surprises the peer may have for us, such as
828 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
829 * a surprise, but handled as if it were), or renegotiation requests.
830 * Also if record payloads contain fragments too small to process, we store
831 * them until there is enough for the respective protocol (the record protocol
832 * may use arbitrary fragmentation and even interleaving):
833 * Change cipher spec protocol
834 * just 1 byte needed, no need for keeping anything stored
836 * 2 bytes needed (AlertLevel, AlertDescription)
838 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
839 * to detect unexpected Client Hello and Hello Request messages
840 * here, anything else is handled by higher layers
841 * Application data protocol
842 * none of our business
844 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
849 void (*cb) (const SSL *ssl, int type2, int val) = NULL;
851 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
852 if (!ssl3_setup_buffers(s))
855 /* XXX: check what the second '&& type' is about */
856 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
857 (type != SSL3_RT_HANDSHAKE) && type) ||
858 (peek && (type != SSL3_RT_APPLICATION_DATA))) {
859 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
864 * check whether there's a handshake message (client hello?) waiting
866 if ((ret = have_handshake_fragment(s, type, buf, len, peek)))
870 * Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE.
873 #ifndef OPENSSL_NO_SCTP
875 * Continue handshake if it had to be interrupted to read app data with
878 if ((!s->in_handshake && SSL_in_init(s)) ||
879 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
880 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
881 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)
882 && s->s3->in_read_app_data != 2))
884 if (!s->in_handshake && SSL_in_init(s))
887 /* type == SSL3_RT_APPLICATION_DATA */
888 i = s->handshake_func(s);
892 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
898 s->rwstate = SSL_NOTHING;
901 * s->s3->rrec.type - is the type of record
902 * s->s3->rrec.data, - data
903 * s->s3->rrec.off, - offset into 'data' for next read
904 * s->s3->rrec.length, - number of bytes.
909 * We are not handshaking and have no data yet, so process data buffered
910 * during the last handshake in advance, if any.
912 if (s->state == SSL_ST_OK && rr->length == 0) {
914 item = pqueue_pop(s->d1->buffered_app_data.q);
916 #ifndef OPENSSL_NO_SCTP
917 /* Restore bio_dgram_sctp_rcvinfo struct */
918 if (BIO_dgram_is_sctp(SSL_get_rbio(s))) {
919 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *)item->data;
920 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO,
921 sizeof(rdata->recordinfo), &rdata->recordinfo);
925 dtls1_copy_record(s, item);
927 OPENSSL_free(item->data);
932 /* Check for timeout */
933 if (dtls1_handle_timeout(s) > 0)
936 /* get new packet if necessary */
937 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY)) {
938 ret = dtls1_get_record(s);
940 ret = dtls1_read_failed(s, ret);
941 /* anything other than a timeout is an error */
949 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE) {
955 * Reset the count of consecutive warning alerts if we've got a non-empty
956 * record that isn't an alert.
958 if (rr->type != SSL3_RT_ALERT && rr->length != 0)
959 s->cert->alert_count = 0;
961 /* we now have a packet which can be read and processed */
963 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
964 * reset by ssl3_get_finished */
965 && (rr->type != SSL3_RT_HANDSHAKE)) {
967 * We now have application data between CCS and Finished. Most likely
968 * the packets were reordered on their way, so buffer the application
969 * data for later processing rather than dropping the connection.
971 if (dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num) <
973 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
981 * If the other end has shut down, throw anything we read away (even in
984 if (s->shutdown & SSL_RECEIVED_SHUTDOWN) {
986 s->rwstate = SSL_NOTHING;
990 if (type == rr->type) { /* SSL3_RT_APPLICATION_DATA or
991 * SSL3_RT_HANDSHAKE */
993 * make sure that we are not getting application data when we are
994 * doing a handshake for the first time
996 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
997 (s->enc_read_ctx == NULL)) {
998 al = SSL_AD_UNEXPECTED_MESSAGE;
999 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_APP_DATA_IN_HANDSHAKE);
1006 if ((unsigned int)len > rr->length)
1009 n = (unsigned int)len;
1011 memcpy(buf, &(rr->data[rr->off]), n);
1015 if (rr->length == 0) {
1016 s->rstate = SSL_ST_READ_HEADER;
1020 #ifndef OPENSSL_NO_SCTP
1022 * We were about to renegotiate but had to read belated application
1023 * data first, so retry.
1025 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1026 rr->type == SSL3_RT_APPLICATION_DATA &&
1027 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
1028 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)) {
1029 s->rwstate = SSL_READING;
1030 BIO_clear_retry_flags(SSL_get_rbio(s));
1031 BIO_set_retry_read(SSL_get_rbio(s));
1035 * We might had to delay a close_notify alert because of reordered
1036 * app data. If there was an alert and there is no message to read
1037 * anymore, finally set shutdown.
1039 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1040 s->d1->shutdown_received
1041 && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
1042 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1050 * If we get here, then type != rr->type; if we have a handshake message,
1051 * then it was unexpected (Hello Request or Client Hello).
1055 * In case of record types for which we have 'fragment' storage, fill
1056 * that so that we can process the data at a fixed place.
1059 unsigned int k, dest_maxlen = 0;
1060 unsigned char *dest = NULL;
1061 unsigned int *dest_len = NULL;
1063 if (rr->type == SSL3_RT_HANDSHAKE) {
1064 dest_maxlen = sizeof s->d1->handshake_fragment;
1065 dest = s->d1->handshake_fragment;
1066 dest_len = &s->d1->handshake_fragment_len;
1067 } else if (rr->type == SSL3_RT_ALERT) {
1068 dest_maxlen = sizeof(s->d1->alert_fragment);
1069 dest = s->d1->alert_fragment;
1070 dest_len = &s->d1->alert_fragment_len;
1072 #ifndef OPENSSL_NO_HEARTBEATS
1073 else if (rr->type == TLS1_RT_HEARTBEAT) {
1074 dtls1_process_heartbeat(s);
1076 /* Exit and notify application to read again */
1078 s->rwstate = SSL_READING;
1079 BIO_clear_retry_flags(SSL_get_rbio(s));
1080 BIO_set_retry_read(SSL_get_rbio(s));
1084 /* else it's a CCS message, or application data or wrong */
1085 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC) {
1087 * Application data while renegotiating is allowed. Try again
1090 if (rr->type == SSL3_RT_APPLICATION_DATA) {
1092 s->s3->in_read_app_data = 2;
1093 bio = SSL_get_rbio(s);
1094 s->rwstate = SSL_READING;
1095 BIO_clear_retry_flags(bio);
1096 BIO_set_retry_read(bio);
1100 /* Not certain if this is the right error handling */
1101 al = SSL_AD_UNEXPECTED_MESSAGE;
1102 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1106 if (dest_maxlen > 0) {
1108 * XDTLS: In a pathalogical case, the Client Hello may be
1109 * fragmented--don't always expect dest_maxlen bytes
1111 if (rr->length < dest_maxlen) {
1112 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1114 * for normal alerts rr->length is 2, while
1115 * dest_maxlen is 7 if we were to handle this
1116 * non-existing alert...
1120 s->rstate = SSL_ST_READ_HEADER;
1125 /* now move 'n' bytes: */
1126 for (k = 0; k < dest_maxlen; k++) {
1127 dest[k] = rr->data[rr->off++];
1130 *dest_len = dest_maxlen;
1135 * s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
1136 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
1137 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.)
1140 /* If we are a client, check for an incoming 'Hello Request': */
1142 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1143 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1144 (s->session != NULL) && (s->session->cipher != NULL)) {
1145 s->d1->handshake_fragment_len = 0;
1147 if ((s->d1->handshake_fragment[1] != 0) ||
1148 (s->d1->handshake_fragment[2] != 0) ||
1149 (s->d1->handshake_fragment[3] != 0)) {
1150 al = SSL_AD_DECODE_ERROR;
1151 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_HELLO_REQUEST);
1156 * no need to check sequence number on HELLO REQUEST messages
1159 if (s->msg_callback)
1160 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1161 s->d1->handshake_fragment, 4, s,
1162 s->msg_callback_arg);
1164 if (SSL_is_init_finished(s) &&
1165 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1166 !s->s3->renegotiate) {
1167 s->d1->handshake_read_seq++;
1169 ssl3_renegotiate(s);
1170 if (ssl3_renegotiate_check(s)) {
1171 i = s->handshake_func(s);
1175 SSLerr(SSL_F_DTLS1_READ_BYTES,
1176 SSL_R_SSL_HANDSHAKE_FAILURE);
1180 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
1181 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
1184 * In the case where we try to read application data,
1185 * but we trigger an SSL handshake, we return -1 with
1186 * the retry option set. Otherwise renegotiation may
1187 * cause nasty problems in the blocking world
1189 s->rwstate = SSL_READING;
1190 bio = SSL_get_rbio(s);
1191 BIO_clear_retry_flags(bio);
1192 BIO_set_retry_read(bio);
1199 * we either finished a handshake or ignored the request, now try
1200 * again to obtain the (application) data we were asked for
1205 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH) {
1206 int alert_level = s->d1->alert_fragment[0];
1207 int alert_descr = s->d1->alert_fragment[1];
1209 s->d1->alert_fragment_len = 0;
1211 if (s->msg_callback)
1212 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1213 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1215 if (s->info_callback != NULL)
1216 cb = s->info_callback;
1217 else if (s->ctx->info_callback != NULL)
1218 cb = s->ctx->info_callback;
1221 j = (alert_level << 8) | alert_descr;
1222 cb(s, SSL_CB_READ_ALERT, j);
1225 if (alert_level == SSL3_AL_WARNING) {
1226 s->s3->warn_alert = alert_descr;
1228 s->cert->alert_count++;
1229 if (s->cert->alert_count == MAX_WARN_ALERT_COUNT) {
1230 al = SSL_AD_UNEXPECTED_MESSAGE;
1231 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_TOO_MANY_WARN_ALERTS);
1235 if (alert_descr == SSL_AD_CLOSE_NOTIFY) {
1236 #ifndef OPENSSL_NO_SCTP
1238 * With SCTP and streams the socket may deliver app data
1239 * after a close_notify alert. We have to check this first so
1240 * that nothing gets discarded.
1242 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1243 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s))) {
1244 s->d1->shutdown_received = 1;
1245 s->rwstate = SSL_READING;
1246 BIO_clear_retry_flags(SSL_get_rbio(s));
1247 BIO_set_retry_read(SSL_get_rbio(s));
1251 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1255 /* XXX: this is a possible improvement in the future */
1256 /* now check if it's a missing record */
1257 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
1259 unsigned int frag_off;
1260 unsigned char *p = &(s->d1->alert_fragment[2]);
1265 dtls1_retransmit_message(s,
1266 dtls1_get_queue_priority
1267 (frag->msg_header.seq, 0), frag_off,
1269 if (!found && SSL_in_init(s)) {
1271 * fprintf( stderr,"in init = %d\n", SSL_in_init(s));
1274 * requested a message not yet sent, send an alert
1277 ssl3_send_alert(s, SSL3_AL_WARNING,
1278 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1282 } else if (alert_level == SSL3_AL_FATAL) {
1285 s->rwstate = SSL_NOTHING;
1286 s->s3->fatal_alert = alert_descr;
1287 SSLerr(SSL_F_DTLS1_READ_BYTES,
1288 SSL_AD_REASON_OFFSET + alert_descr);
1289 BIO_snprintf(tmp, sizeof tmp, "%d", alert_descr);
1290 ERR_add_error_data(2, "SSL alert number ", tmp);
1291 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1292 SSL_CTX_remove_session(s->session_ctx, s->session);
1295 al = SSL_AD_ILLEGAL_PARAMETER;
1296 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNKNOWN_ALERT_TYPE);
1303 if (s->shutdown & SSL_SENT_SHUTDOWN) { /* but we have not received a
1305 s->rwstate = SSL_NOTHING;
1310 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
1311 struct ccs_header_st ccs_hdr;
1312 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1314 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1316 if (s->version == DTLS1_BAD_VER)
1320 * 'Change Cipher Spec' is just a single byte, so we know exactly
1321 * what the record payload has to look like
1323 /* XDTLS: check that epoch is consistent */
1324 if ((rr->length != ccs_hdr_len) ||
1325 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS)) {
1326 al = SSL_AD_ILLEGAL_PARAMETER;
1327 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_BAD_CHANGE_CIPHER_SPEC);
1333 if (s->msg_callback)
1334 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1335 rr->data, 1, s, s->msg_callback_arg);
1338 * We can't process a CCS now, because previous handshake messages
1339 * are still missing, so just drop it.
1341 if (!s->d1->change_cipher_spec_ok) {
1345 s->d1->change_cipher_spec_ok = 0;
1347 s->s3->change_cipher_spec = 1;
1348 if (!ssl3_do_change_cipher_spec(s))
1351 /* do this whenever CCS is processed */
1352 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1354 if (s->version == DTLS1_BAD_VER)
1355 s->d1->handshake_read_seq++;
1357 #ifndef OPENSSL_NO_SCTP
1359 * Remember that a CCS has been received, so that an old key of
1360 * SCTP-Auth can be deleted when a CCS is sent. Will be ignored if no
1363 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1370 * Unexpected handshake message (Client Hello, or protocol violation)
1372 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1374 struct hm_header_st msg_hdr;
1376 /* this may just be a stale retransmit */
1377 dtls1_get_message_header(rr->data, &msg_hdr);
1378 if (rr->epoch != s->d1->r_epoch) {
1384 * If we are server, we may have a repeated FINISHED of the client
1385 * here, then retransmit our CCS and FINISHED.
1387 if (msg_hdr.type == SSL3_MT_FINISHED) {
1388 if (dtls1_check_timeout_num(s) < 0)
1391 dtls1_retransmit_buffered_messages(s);
1396 if (((s->state & SSL_ST_MASK) == SSL_ST_OK) &&
1397 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS)) {
1398 #if 0 /* worked only because C operator preferences
1399 * are not as expected (and because this is
1400 * not really needed for clients except for
1401 * detecting protocol violations): */
1402 s->state = SSL_ST_BEFORE | (s->server)
1403 ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1405 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1410 i = s->handshake_func(s);
1414 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_SSL_HANDSHAKE_FAILURE);
1418 if (!(s->mode & SSL_MODE_AUTO_RETRY)) {
1419 if (s->s3->rbuf.left == 0) { /* no read-ahead left? */
1422 * In the case where we try to read application data, but we
1423 * trigger an SSL handshake, we return -1 with the retry
1424 * option set. Otherwise renegotiation may cause nasty
1425 * problems in the blocking world
1427 s->rwstate = SSL_READING;
1428 bio = SSL_get_rbio(s);
1429 BIO_clear_retry_flags(bio);
1430 BIO_set_retry_read(bio);
1439 #ifndef OPENSSL_NO_TLS
1440 /* TLS just ignores unknown message types */
1441 if (s->version == TLS1_VERSION) {
1446 al = SSL_AD_UNEXPECTED_MESSAGE;
1447 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1449 case SSL3_RT_CHANGE_CIPHER_SPEC:
1451 case SSL3_RT_HANDSHAKE:
1453 * we already handled all of these, with the possible exception of
1454 * SSL3_RT_HANDSHAKE when s->in_handshake is set, but that should not
1455 * happen when type != rr->type
1457 al = SSL_AD_UNEXPECTED_MESSAGE;
1458 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
1460 case SSL3_RT_APPLICATION_DATA:
1462 * At this point, we were expecting handshake data, but have
1463 * application data. If the library was running inside ssl3_read()
1464 * (i.e. in_read_app_data is set) and it makes sense to read
1465 * application data at this point (session renegotiation not yet
1466 * started), we will indulge it.
1468 if (s->s3->in_read_app_data &&
1469 (s->s3->total_renegotiations != 0) &&
1470 (((s->state & SSL_ST_CONNECT) &&
1471 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1472 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1473 ) || ((s->state & SSL_ST_ACCEPT) &&
1474 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1475 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1478 s->s3->in_read_app_data = 2;
1481 al = SSL_AD_UNEXPECTED_MESSAGE;
1482 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_R_UNEXPECTED_RECORD);
1489 ssl3_send_alert(s, SSL3_AL_FATAL, al);
1494 int dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1498 #ifndef OPENSSL_NO_SCTP
1500 * Check if we have to continue an interrupted handshake for reading
1501 * belated app data with SCTP.
1503 if ((SSL_in_init(s) && !s->in_handshake) ||
1504 (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1505 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK
1506 || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1508 if (SSL_in_init(s) && !s->in_handshake)
1511 i = s->handshake_func(s);
1515 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,
1516 SSL_R_SSL_HANDSHAKE_FAILURE);
1521 if (len > SSL3_RT_MAX_PLAIN_LENGTH) {
1522 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES, SSL_R_DTLS_MESSAGE_TOO_BIG);
1526 i = dtls1_write_bytes(s, type, buf_, len);
1531 * this only happens when a client hello is received and a handshake
1535 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1539 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1540 /* (partially) satisfy request from storage */
1542 unsigned char *src = s->d1->handshake_fragment;
1543 unsigned char *dst = buf;
1548 while ((len > 0) && (s->d1->handshake_fragment_len > 0)) {
1551 s->d1->handshake_fragment_len--;
1554 /* move any remaining fragment bytes: */
1555 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1556 s->d1->handshake_fragment[k] = *src++;
1564 * Call this to write data in records of type 'type' It will return <= 0 if
1565 * not all data has been sent or non-blocking IO.
1567 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1571 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1572 s->rwstate = SSL_NOTHING;
1573 i = do_dtls1_write(s, type, buf, len, 0);
1577 int do_dtls1_write(SSL *s, int type, const unsigned char *buf,
1578 unsigned int len, int create_empty_fragment)
1580 unsigned char *p, *pseq;
1581 int i, mac_size, clear = 0;
1589 * first check if there is a SSL3_BUFFER still being written out. This
1590 * will happen with non blocking IO
1592 if (s->s3->wbuf.left != 0) {
1593 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1594 return (ssl3_write_pending(s, type, buf, len));
1597 /* If we have an alert to send, lets send it */
1598 if (s->s3->alert_dispatch) {
1599 i = s->method->ssl_dispatch_alert(s);
1602 /* if it went, fall through and send more stuff */
1605 if (len == 0 && !create_empty_fragment)
1608 wr = &(s->s3->wrec);
1609 wb = &(s->s3->wbuf);
1612 if ((sess == NULL) ||
1613 (s->enc_write_ctx == NULL) || (EVP_MD_CTX_md(s->write_hash) == NULL))
1619 mac_size = EVP_MD_CTX_size(s->write_hash);
1624 /* DTLS implements explicit IV, so no need for empty fragments */
1627 * 'create_empty_fragment' is true only when this function calls itself
1629 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1630 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1633 * countermeasure against known-IV weakness in CBC ciphersuites (see
1634 * http://www.openssl.org/~bodo/tls-cbc.txt)
1637 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA) {
1639 * recursive function call with 'create_empty_fragment' set; this
1640 * prepares and buffers the data for an empty fragment (these
1641 * 'prefix_len' bytes are sent out later together with the actual
1644 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1645 if (prefix_len <= 0)
1648 if (s->s3->wbuf.len <
1649 (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE) {
1650 /* insufficient space */
1651 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1656 s->s3->empty_fragment_done = 1;
1659 p = wb->buf + prefix_len;
1661 /* write the header */
1663 *(p++) = type & 0xff;
1666 * Special case: for hello verify request, client version 1.0 and we
1667 * haven't decided which version to use yet send back using version 1.0
1668 * header: otherwise some clients will ignore it.
1670 if (s->method->version == DTLS_ANY_VERSION) {
1671 *(p++) = DTLS1_VERSION >> 8;
1672 *(p++) = DTLS1_VERSION & 0xff;
1674 *(p++) = s->version >> 8;
1675 *(p++) = s->version & 0xff;
1678 /* field where we are to write out packet epoch, seq num and len */
1682 /* Explicit IV length, block ciphers appropriate version flag */
1683 if (s->enc_write_ctx) {
1684 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1685 if (mode == EVP_CIPH_CBC_MODE) {
1686 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1690 /* Need explicit part of IV for GCM mode */
1691 else if (mode == EVP_CIPH_GCM_MODE)
1692 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1698 /* lets setup the record stuff. */
1699 wr->data = p + eivlen; /* make room for IV in case of CBC */
1700 wr->length = (int)len;
1701 wr->input = (unsigned char *)buf;
1704 * we now 'read' from wr->input, wr->length bytes into wr->data
1707 /* first we compress */
1708 if (s->compress != NULL) {
1709 if (!ssl3_do_compress(s)) {
1710 SSLerr(SSL_F_DO_DTLS1_WRITE, SSL_R_COMPRESSION_FAILURE);
1714 memcpy(wr->data, wr->input, wr->length);
1715 wr->input = wr->data;
1719 * we should still have the output to wr->data and the input from
1720 * wr->input. Length should be wr->length. wr->data still points in the
1724 if (mac_size != 0) {
1725 if (s->method->ssl3_enc->mac(s, &(p[wr->length + eivlen]), 1) < 0)
1727 wr->length += mac_size;
1730 /* this is true regardless of mac size */
1735 wr->length += eivlen;
1737 if (s->method->ssl3_enc->enc(s, 1) < 1)
1740 /* record length after mac and block padding */
1742 * if (type == SSL3_RT_APPLICATION_DATA || (type == SSL3_RT_ALERT && !
1746 /* there's only one epoch between handshake and app data */
1748 s2n(s->d1->w_epoch, pseq);
1752 * else s2n(s->d1->handshake_epoch, pseq);
1755 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1757 s2n(wr->length, pseq);
1759 if (s->msg_callback)
1760 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH,
1761 DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1764 * we should now have wr->data pointing to the encrypted data, which is
1767 wr->type = type; /* not needed but helps for debugging */
1768 wr->length += DTLS1_RT_HEADER_LENGTH;
1770 #if 0 /* this is now done at the message layer */
1771 /* buffer the record, making it easy to handle retransmits */
1772 if (type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1773 dtls1_buffer_record(s, wr->data, wr->length,
1774 *((PQ_64BIT *) & (s->s3->write_sequence[0])));
1777 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1779 if (create_empty_fragment) {
1781 * we are in a recursive call; just return the length, don't write
1787 /* now let's set up wb */
1788 wb->left = prefix_len + wr->length;
1792 * memorize arguments so that ssl3_write_pending can detect bad write
1795 s->s3->wpend_tot = len;
1796 s->s3->wpend_buf = buf;
1797 s->s3->wpend_type = type;
1798 s->s3->wpend_ret = len;
1800 /* we now just need to write the buffer */
1801 return ssl3_write_pending(s, type, buf, len);
1806 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1810 const unsigned char *seq = s->s3->read_sequence;
1812 cmp = satsub64be(seq, bitmap->max_seq_num);
1814 memcpy(s->s3->rrec.seq_num, seq, 8);
1815 return 1; /* this record in new */
1818 if (shift >= sizeof(bitmap->map) * 8)
1819 return 0; /* stale, outside the window */
1820 else if (bitmap->map & (1UL << shift))
1821 return 0; /* record previously received */
1823 memcpy(s->s3->rrec.seq_num, seq, 8);
1827 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1831 const unsigned char *seq = s->s3->read_sequence;
1833 cmp = satsub64be(seq, bitmap->max_seq_num);
1836 if (shift < sizeof(bitmap->map) * 8)
1837 bitmap->map <<= shift, bitmap->map |= 1UL;
1840 memcpy(bitmap->max_seq_num, seq, 8);
1843 if (shift < sizeof(bitmap->map) * 8)
1844 bitmap->map |= 1UL << shift;
1848 int dtls1_dispatch_alert(SSL *s)
1851 void (*cb) (const SSL *ssl, int type, int val) = NULL;
1852 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1853 unsigned char *ptr = &buf[0];
1855 s->s3->alert_dispatch = 0;
1857 memset(buf, 0x00, sizeof(buf));
1858 *ptr++ = s->s3->send_alert[0];
1859 *ptr++ = s->s3->send_alert[1];
1861 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1862 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE) {
1863 s2n(s->d1->handshake_read_seq, ptr);
1865 if (s->d1->r_msg_hdr.frag_off == 0)
1867 * waiting for a new msg
1870 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1875 "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",
1876 s->d1->handshake_read_seq, s->d1->r_msg_hdr.seq);
1878 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1882 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1884 s->s3->alert_dispatch = 1;
1885 /* fprintf( stderr, "not done with alert\n" ); */
1887 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1888 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1889 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1892 (void)BIO_flush(s->wbio);
1894 if (s->msg_callback)
1895 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1896 2, s, s->msg_callback_arg);
1898 if (s->info_callback != NULL)
1899 cb = s->info_callback;
1900 else if (s->ctx->info_callback != NULL)
1901 cb = s->ctx->info_callback;
1904 j = (s->s3->send_alert[0] << 8) | s->s3->send_alert[1];
1905 cb(s, SSL_CB_WRITE_ALERT, j);
1911 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
1912 unsigned int *is_next_epoch)
1917 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1918 if (rr->epoch == s->d1->r_epoch)
1919 return &s->d1->bitmap;
1922 * Only HM and ALERT messages can be from the next epoch and only if we
1923 * have already processed all of the unprocessed records from the last
1926 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1927 s->d1->unprocessed_rcds.epoch != s->d1->r_epoch &&
1928 (rr->type == SSL3_RT_HANDSHAKE || rr->type == SSL3_RT_ALERT)) {
1930 return &s->d1->next_bitmap;
1938 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
1939 unsigned short *priority, unsigned long *offset)
1942 /* alerts are passed up immediately */
1943 if (rr->type == SSL3_RT_APPLICATION_DATA || rr->type == SSL3_RT_ALERT)
1947 * Only need to buffer if a handshake is underway. (this implies that
1948 * Hello Request and Client Hello are passed up immediately)
1950 if (SSL_in_init(s)) {
1951 unsigned char *data = rr->data;
1952 /* need to extract the HM/CCS sequence number here */
1953 if (rr->type == SSL3_RT_HANDSHAKE ||
1954 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC) {
1955 unsigned short seq_num;
1956 struct hm_header_st msg_hdr;
1957 struct ccs_header_st ccs_hdr;
1959 if (rr->type == SSL3_RT_HANDSHAKE) {
1960 dtls1_get_message_header(data, &msg_hdr);
1961 seq_num = msg_hdr.seq;
1962 *offset = msg_hdr.frag_off;
1964 dtls1_get_ccs_header(data, &ccs_hdr);
1965 seq_num = ccs_hdr.seq;
1970 * this is either a record we're waiting for, or a retransmit of
1971 * something we happened to previously receive (higher layers
1972 * will drop the repeat silently
1974 if (seq_num < s->d1->handshake_read_seq)
1976 if (rr->type == SSL3_RT_HANDSHAKE &&
1977 seq_num == s->d1->handshake_read_seq &&
1978 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1980 else if (seq_num == s->d1->handshake_read_seq &&
1981 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1982 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1985 *priority = seq_num;
1988 } else /* unknown record type */
1996 void dtls1_reset_seq_numbers(SSL *s, int rw)
1999 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
2001 if (rw & SSL3_CC_READ) {
2002 seq = s->s3->read_sequence;
2004 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
2005 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
2008 * We must not use any buffered messages received from the previous
2011 dtls1_clear_received_buffer(s);
2013 seq = s->s3->write_sequence;
2014 memcpy(s->d1->last_write_sequence, seq,
2015 sizeof(s->s3->write_sequence));
2019 memset(seq, 0x00, seq_bytes);