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)
129 if (sizeof(long) == 8) do
130 { const union { long one; char little; } is_endian = {1};
133 if (is_endian.little) break;
134 /* not reached on little-endians */
135 /* following test is redundant, because input is
136 * always aligned, but I take no chances... */
137 if (((size_t)v1|(size_t)v2)&0x7) break;
141 if (l>128) return 128;
142 else if (l<-128) return -128;
146 ret = (int)v1[7]-(int)v2[7];
148 brw = ret>>8; /* brw is either 0 or -1 */
151 { brw += (int)v1[i]-(int)v2[i];
158 { brw += (int)v1[i]-(int)v2[i];
163 brw <<= 8; /* brw is either 0 or -256 */
165 if (sat&0xff) return brw | 0x80;
166 else return brw + (ret&0xFF);
169 static int have_handshake_fragment(SSL *s, int type, unsigned char *buf,
171 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap);
172 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap);
173 static DTLS1_BITMAP *dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr,
174 unsigned int *is_next_epoch);
176 static int dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr,
177 unsigned short *priority, unsigned long *offset);
179 static int dtls1_buffer_record(SSL *s, record_pqueue *q,
180 unsigned char *priority);
181 static int dtls1_process_record(SSL *s);
183 /* copy buffered record into SSL structure */
185 dtls1_copy_record(SSL *s, pitem *item)
187 DTLS1_RECORD_DATA *rdata;
189 rdata = (DTLS1_RECORD_DATA *)item->data;
191 if (s->s3->rbuf.buf != NULL)
192 OPENSSL_free(s->s3->rbuf.buf);
194 s->packet = rdata->packet;
195 s->packet_length = rdata->packet_length;
196 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
197 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
199 /* Set proper sequence number for mac calculation */
200 memcpy(&(s->s3->read_sequence[2]), &(rdata->packet[5]), 6);
207 dtls1_buffer_record(SSL *s, record_pqueue *queue, unsigned char *priority)
209 DTLS1_RECORD_DATA *rdata;
212 /* Limit the size of the queue to prevent DOS attacks */
213 if (pqueue_size(queue->q) >= 100)
216 rdata = OPENSSL_malloc(sizeof(DTLS1_RECORD_DATA));
217 item = pitem_new(priority, rdata);
218 if (rdata == NULL || item == NULL)
220 if (rdata != NULL) OPENSSL_free(rdata);
221 if (item != NULL) pitem_free(item);
223 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
227 rdata->packet = s->packet;
228 rdata->packet_length = s->packet_length;
229 memcpy(&(rdata->rbuf), &(s->s3->rbuf), sizeof(SSL3_BUFFER));
230 memcpy(&(rdata->rrec), &(s->s3->rrec), sizeof(SSL3_RECORD));
234 #ifndef OPENSSL_NO_SCTP
235 /* Store bio_dgram_sctp_rcvinfo struct */
236 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
237 (s->state == SSL3_ST_SR_FINISHED_A || s->state == SSL3_ST_CR_FINISHED_A)) {
238 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_GET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
243 s->packet_length = 0;
244 memset(&(s->s3->rbuf), 0, sizeof(SSL3_BUFFER));
245 memset(&(s->s3->rrec), 0, sizeof(SSL3_RECORD));
247 if (!ssl3_setup_buffers(s))
249 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
255 /* insert should not fail, since duplicates are dropped */
256 if (pqueue_insert(queue->q, item) == NULL)
258 SSLerr(SSL_F_DTLS1_BUFFER_RECORD, ERR_R_INTERNAL_ERROR);
269 dtls1_retrieve_buffered_record(SSL *s, record_pqueue *queue)
273 item = pqueue_pop(queue->q);
276 dtls1_copy_record(s, item);
278 OPENSSL_free(item->data);
288 /* retrieve a buffered record that belongs to the new epoch, i.e., not processed
290 #define dtls1_get_unprocessed_record(s) \
291 dtls1_retrieve_buffered_record((s), \
292 &((s)->d1->unprocessed_rcds))
294 /* retrieve a buffered record that belongs to the current epoch, ie, processed */
295 #define dtls1_get_processed_record(s) \
296 dtls1_retrieve_buffered_record((s), \
297 &((s)->d1->processed_rcds))
300 dtls1_process_buffered_records(SSL *s)
304 item = pqueue_peek(s->d1->unprocessed_rcds.q);
307 /* Check if epoch is current. */
308 if (s->d1->unprocessed_rcds.epoch != s->d1->r_epoch)
309 return(1); /* Nothing to do. */
311 /* Process all the records. */
312 while (pqueue_peek(s->d1->unprocessed_rcds.q))
314 dtls1_get_unprocessed_record(s);
315 if ( ! dtls1_process_record(s))
317 dtls1_buffer_record(s, &(s->d1->processed_rcds),
318 s->s3->rrec.seq_num);
322 /* sync epoch numbers once all the unprocessed records
323 * have been processed */
324 s->d1->processed_rcds.epoch = s->d1->r_epoch;
325 s->d1->unprocessed_rcds.epoch = s->d1->r_epoch + 1;
334 dtls1_get_buffered_record(SSL *s)
338 (((PQ_64BIT)s->d1->handshake_read_seq) << 32) |
339 ((PQ_64BIT)s->d1->r_msg_hdr.frag_off);
341 if ( ! SSL_in_init(s)) /* if we're not (re)negotiating,
346 item = pqueue_peek(s->d1->rcvd_records);
347 if (item && item->priority == priority)
349 /* Check if we've received the record of interest. It must be
350 * a handshake record, since data records as passed up without
352 DTLS1_RECORD_DATA *rdata;
353 item = pqueue_pop(s->d1->rcvd_records);
354 rdata = (DTLS1_RECORD_DATA *)item->data;
356 if (s->s3->rbuf.buf != NULL)
357 OPENSSL_free(s->s3->rbuf.buf);
359 s->packet = rdata->packet;
360 s->packet_length = rdata->packet_length;
361 memcpy(&(s->s3->rbuf), &(rdata->rbuf), sizeof(SSL3_BUFFER));
362 memcpy(&(s->s3->rrec), &(rdata->rrec), sizeof(SSL3_RECORD));
364 OPENSSL_free(item->data);
367 /* s->d1->next_expected_seq_num++; */
377 dtls1_process_record(SSL *s)
383 unsigned int mac_size, orig_len;
384 unsigned char md[EVP_MAX_MD_SIZE];
389 /* At this point, s->packet_length == SSL3_RT_HEADER_LNGTH + rr->length,
390 * and we have that many bytes in s->packet
392 rr->input= &(s->packet[DTLS1_RT_HEADER_LENGTH]);
394 /* ok, we can now read from 's->packet' data into 'rr'
395 * rr->input points at rr->length bytes, which
396 * need to be copied into rr->data by either
397 * the decryption or by the decompression
398 * When the data is 'copied' into the rr->data buffer,
399 * rr->input will be pointed at the new buffer */
401 /* We now have - encrypted [ MAC [ compressed [ plain ] ] ]
402 * rr->length bytes of encrypted compressed stuff. */
404 /* check is not needed I believe */
405 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
407 al=SSL_AD_RECORD_OVERFLOW;
408 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_ENCRYPTED_LENGTH_TOO_LONG);
412 /* decrypt in place in 'rr->input' */
415 enc_err = s->method->ssl3_enc->enc(s,0);
417 * 0: (in non-constant time) if the record is publically invalid.
418 * 1: if the padding is valid
419 * -1: if the padding is invalid */
422 /* For DTLS we simply ignore bad packets. */
424 s->packet_length = 0;
429 printf("dec %d\n",rr->length);
430 { unsigned int z; for (z=0; z<rr->length; z++) printf("%02X%c",rr->data[z],((z+1)%16)?' ':'\n'); }
434 /* r->length is now the compressed data plus mac */
435 if ((sess != NULL) &&
436 (s->enc_read_ctx != NULL) &&
437 (EVP_MD_CTX_md(s->read_hash) != NULL))
439 /* s->read_hash != NULL => mac_size != -1 */
440 unsigned char *mac = NULL;
441 unsigned char mac_tmp[EVP_MAX_MD_SIZE];
442 mac_size=EVP_MD_CTX_size(s->read_hash);
443 OPENSSL_assert(mac_size <= EVP_MAX_MD_SIZE);
445 /* kludge: *_cbc_remove_padding passes padding length in rr->type */
446 orig_len = rr->length+((unsigned int)rr->type>>8);
448 /* orig_len is the length of the record before any padding was
449 * removed. This is public information, as is the MAC in use,
450 * therefore we can safely process the record in a different
451 * amount of time if it's too short to possibly contain a MAC.
453 if (orig_len < mac_size ||
454 /* CBC records must have a padding length byte too. */
455 (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE &&
456 orig_len < mac_size+1))
458 al=SSL_AD_DECODE_ERROR;
459 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_LENGTH_TOO_SHORT);
463 if (EVP_CIPHER_CTX_mode(s->enc_read_ctx) == EVP_CIPH_CBC_MODE)
465 /* We update the length so that the TLS header bytes
466 * can be constructed correctly but we need to extract
467 * the MAC in constant time from within the record,
468 * without leaking the contents of the padding bytes.
471 ssl3_cbc_copy_mac(mac_tmp, rr, mac_size, orig_len);
472 rr->length -= mac_size;
476 /* In this case there's no padding, so |orig_len|
477 * equals |rec->length| and we checked that there's
478 * enough bytes for |mac_size| above. */
479 rr->length -= mac_size;
480 mac = &rr->data[rr->length];
483 i=s->method->ssl3_enc->mac(s,md,0 /* not send */);
484 if (i < 0 || mac == NULL || CRYPTO_memcmp(md, mac, (size_t)mac_size) != 0)
486 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH+mac_size)
492 /* decryption failed, silently discard message */
494 s->packet_length = 0;
498 /* r->length is now just compressed */
499 if (s->expand != NULL)
501 if (rr->length > SSL3_RT_MAX_COMPRESSED_LENGTH)
503 al=SSL_AD_RECORD_OVERFLOW;
504 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_COMPRESSED_LENGTH_TOO_LONG);
507 if (!ssl3_do_uncompress(s))
509 al=SSL_AD_DECOMPRESSION_FAILURE;
510 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_BAD_DECOMPRESSION);
515 if (rr->length > SSL3_RT_MAX_PLAIN_LENGTH)
517 al=SSL_AD_RECORD_OVERFLOW;
518 SSLerr(SSL_F_DTLS1_PROCESS_RECORD,SSL_R_DATA_LENGTH_TOO_LONG);
523 /* So at this point the following is true
524 * ssl->s3->rrec.type is the type of record
525 * ssl->s3->rrec.length == number of bytes in record
526 * ssl->s3->rrec.off == offset to first valid byte
527 * ssl->s3->rrec.data == where to take bytes from, increment
531 /* we have pulled in a full packet so zero things */
533 dtls1_record_bitmap_update(s, &(s->d1->bitmap));/* Mark receipt of record. */
537 ssl3_send_alert(s,SSL3_AL_FATAL,al);
543 /* Call this to get a new input record.
544 * It will return <= 0 if more data is needed, normally due to an error
545 * or non-blocking IO.
546 * When it finishes, one packet has been decoded and can be found in
547 * ssl->s3->rrec.type - is the type of record
548 * ssl->s3->rrec.data, - data
549 * ssl->s3->rrec.length, - number of bytes
551 /* used only by dtls1_read_bytes */
552 int dtls1_get_record(SSL *s)
554 int ssl_major,ssl_minor;
557 unsigned char *p = NULL;
558 unsigned short version;
559 DTLS1_BITMAP *bitmap;
560 unsigned int is_next_epoch;
564 /* The epoch may have changed. If so, process all the
565 * pending records. This is a non-blocking operation. */
566 dtls1_process_buffered_records(s);
568 /* if we're renegotiating, then there may be buffered records */
569 if (dtls1_get_processed_record(s))
572 /* get something from the wire */
574 /* check if we have the header */
575 if ( (s->rstate != SSL_ST_READ_BODY) ||
576 (s->packet_length < DTLS1_RT_HEADER_LENGTH))
578 n=ssl3_read_n(s, DTLS1_RT_HEADER_LENGTH, s->s3->rbuf.len, 0);
579 /* read timeout is handled by dtls1_read_bytes */
580 if (n <= 0) return(n); /* error or non-blocking */
582 /* this packet contained a partial record, dump it */
583 if (s->packet_length != DTLS1_RT_HEADER_LENGTH)
585 s->packet_length = 0;
589 s->rstate=SSL_ST_READ_BODY;
594 s->msg_callback(0, 0, SSL3_RT_HEADER, p, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
596 /* Pull apart the header into the DTLS1_RECORD */
600 version=(ssl_major<<8)|ssl_minor;
602 /* sequence number is 64 bits, with top 2 bytes = epoch */
605 memcpy(&(s->s3->read_sequence[2]), p, 6);
610 /* Lets check version */
611 if (!s->first_packet)
613 if (version != s->version)
615 /* unexpected version, silently discard */
617 s->packet_length = 0;
622 if ((version & 0xff00) != (s->version & 0xff00))
624 /* wrong version, silently discard record */
626 s->packet_length = 0;
630 if (rr->length > SSL3_RT_MAX_ENCRYPTED_LENGTH)
632 /* record too long, silently discard it */
634 s->packet_length = 0;
638 /* now s->rstate == SSL_ST_READ_BODY */
641 /* s->rstate == SSL_ST_READ_BODY, get and decode the data */
643 if (rr->length > s->packet_length-DTLS1_RT_HEADER_LENGTH)
645 /* now s->packet_length == DTLS1_RT_HEADER_LENGTH */
647 n=ssl3_read_n(s,i,i,1);
648 if (n <= 0) return(n); /* error or non-blocking io */
650 /* this packet contained a partial record, dump it */
654 s->packet_length = 0;
658 /* now n == rr->length,
659 * and s->packet_length == DTLS1_RT_HEADER_LENGTH + rr->length */
661 s->rstate=SSL_ST_READ_HEADER; /* set state for later operations */
663 /* match epochs. NULL means the packet is dropped on the floor */
664 bitmap = dtls1_get_bitmap(s, rr, &is_next_epoch);
668 s->packet_length = 0; /* dump this record */
669 goto again; /* get another record */
672 #ifndef OPENSSL_NO_SCTP
673 /* Only do replay check if no SCTP bio */
674 if (!BIO_dgram_is_sctp(SSL_get_rbio(s)))
677 /* Check whether this is a repeat, or aged record.
678 * Don't check if we're listening and this message is
679 * a ClientHello. They can look as if they're replayed,
680 * since they arrive from different connections and
681 * would be dropped unnecessarily.
683 if (!(s->d1->listen && rr->type == SSL3_RT_HANDSHAKE &&
684 *p == SSL3_MT_CLIENT_HELLO) &&
685 !dtls1_record_replay_check(s, bitmap))
688 s->packet_length=0; /* dump this record */
689 goto again; /* get another record */
691 #ifndef OPENSSL_NO_SCTP
695 /* just read a 0 length packet */
696 if (rr->length == 0) goto again;
698 /* If this record is from the next epoch (either HM or ALERT),
699 * and a handshake is currently in progress, buffer it since it
700 * cannot be processed at this time. However, do not buffer
701 * anything while listening.
705 if ((SSL_in_init(s) || s->in_handshake) && !s->d1->listen)
707 dtls1_buffer_record(s, &(s->d1->unprocessed_rcds), rr->seq_num);
710 s->packet_length = 0;
714 if (!dtls1_process_record(s))
717 s->packet_length = 0; /* dump this record */
718 goto again; /* get another record */
725 /* Return up to 'len' payload bytes received in 'type' records.
726 * 'type' is one of the following:
728 * - SSL3_RT_HANDSHAKE (when ssl3_get_message calls us)
729 * - SSL3_RT_APPLICATION_DATA (when ssl3_read calls us)
730 * - 0 (during a shutdown, no data has to be returned)
732 * If we don't have stored data to work from, read a SSL/TLS record first
733 * (possibly multiple records if we still don't have anything to return).
735 * This function must handle any surprises the peer may have for us, such as
736 * Alert records (e.g. close_notify), ChangeCipherSpec records (not really
737 * a surprise, but handled as if it were), or renegotiation requests.
738 * Also if record payloads contain fragments too small to process, we store
739 * them until there is enough for the respective protocol (the record protocol
740 * may use arbitrary fragmentation and even interleaving):
741 * Change cipher spec protocol
742 * just 1 byte needed, no need for keeping anything stored
744 * 2 bytes needed (AlertLevel, AlertDescription)
746 * 4 bytes needed (HandshakeType, uint24 length) -- we just have
747 * to detect unexpected Client Hello and Hello Request messages
748 * here, anything else is handled by higher layers
749 * Application data protocol
750 * none of our business
752 int dtls1_read_bytes(SSL *s, int type, unsigned char *buf, int len, int peek)
757 void (*cb)(const SSL *ssl,int type2,int val)=NULL;
759 if (s->s3->rbuf.buf == NULL) /* Not initialized yet */
760 if (!ssl3_setup_buffers(s))
763 /* XXX: check what the second '&& type' is about */
764 if ((type && (type != SSL3_RT_APPLICATION_DATA) &&
765 (type != SSL3_RT_HANDSHAKE) && type) ||
766 (peek && (type != SSL3_RT_APPLICATION_DATA)))
768 SSLerr(SSL_F_DTLS1_READ_BYTES, ERR_R_INTERNAL_ERROR);
772 /* check whether there's a handshake message (client hello?) waiting */
773 if ( (ret = have_handshake_fragment(s, type, buf, len, peek)))
776 /* Now s->d1->handshake_fragment_len == 0 if type == SSL3_RT_HANDSHAKE. */
778 #ifndef OPENSSL_NO_SCTP
779 /* Continue handshake if it had to be interrupted to read
780 * app data with SCTP.
782 if ((!s->in_handshake && SSL_in_init(s)) ||
783 (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
784 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK) &&
785 s->s3->in_read_app_data != 2))
787 if (!s->in_handshake && SSL_in_init(s))
790 /* type == SSL3_RT_APPLICATION_DATA */
791 i=s->handshake_func(s);
792 if (i < 0) return(i);
795 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
801 s->rwstate=SSL_NOTHING;
803 /* s->s3->rrec.type - is the type of record
804 * s->s3->rrec.data, - data
805 * s->s3->rrec.off, - offset into 'data' for next read
806 * s->s3->rrec.length, - number of bytes. */
809 /* We are not handshaking and have no data yet,
810 * so process data buffered during the last handshake
811 * in advance, if any.
813 if (s->state == SSL_ST_OK && rr->length == 0)
816 item = pqueue_pop(s->d1->buffered_app_data.q);
819 #ifndef OPENSSL_NO_SCTP
820 /* Restore bio_dgram_sctp_rcvinfo struct */
821 if (BIO_dgram_is_sctp(SSL_get_rbio(s)))
823 DTLS1_RECORD_DATA *rdata = (DTLS1_RECORD_DATA *) item->data;
824 BIO_ctrl(SSL_get_rbio(s), BIO_CTRL_DGRAM_SCTP_SET_RCVINFO, sizeof(rdata->recordinfo), &rdata->recordinfo);
828 dtls1_copy_record(s, item);
830 OPENSSL_free(item->data);
835 /* Check for timeout */
836 if (dtls1_handle_timeout(s) > 0)
839 /* get new packet if necessary */
840 if ((rr->length == 0) || (s->rstate == SSL_ST_READ_BODY))
842 ret=dtls1_get_record(s);
845 ret = dtls1_read_failed(s, ret);
846 /* anything other than a timeout is an error */
854 if (s->d1->listen && rr->type != SSL3_RT_HANDSHAKE)
860 /* we now have a packet which can be read and processed */
862 if (s->s3->change_cipher_spec /* set when we receive ChangeCipherSpec,
863 * reset by ssl3_get_finished */
864 && (rr->type != SSL3_RT_HANDSHAKE))
866 /* We now have application data between CCS and Finished.
867 * Most likely the packets were reordered on their way, so
868 * buffer the application data for later processing rather
869 * than dropping the connection.
871 dtls1_buffer_record(s, &(s->d1->buffered_app_data), rr->seq_num);
876 /* If the other end has shut down, throw anything we read away
877 * (even in 'peek' mode) */
878 if (s->shutdown & SSL_RECEIVED_SHUTDOWN)
881 s->rwstate=SSL_NOTHING;
886 if (type == rr->type) /* SSL3_RT_APPLICATION_DATA or SSL3_RT_HANDSHAKE */
888 /* make sure that we are not getting application data when we
889 * are doing a handshake for the first time */
890 if (SSL_in_init(s) && (type == SSL3_RT_APPLICATION_DATA) &&
891 (s->enc_read_ctx == NULL))
893 al=SSL_AD_UNEXPECTED_MESSAGE;
894 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_APP_DATA_IN_HANDSHAKE);
898 if (len <= 0) return(len);
900 if ((unsigned int)len > rr->length)
903 n = (unsigned int)len;
905 memcpy(buf,&(rr->data[rr->off]),n);
912 s->rstate=SSL_ST_READ_HEADER;
917 #ifndef OPENSSL_NO_SCTP
918 /* We were about to renegotiate but had to read
919 * belated application data first, so retry.
921 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
922 rr->type == SSL3_RT_APPLICATION_DATA &&
923 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK))
925 s->rwstate=SSL_READING;
926 BIO_clear_retry_flags(SSL_get_rbio(s));
927 BIO_set_retry_read(SSL_get_rbio(s));
930 /* We might had to delay a close_notify alert because
931 * of reordered app data. If there was an alert and there
932 * is no message to read anymore, finally set shutdown.
934 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
935 s->d1->shutdown_received && !BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
937 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
945 /* If we get here, then type != rr->type; if we have a handshake
946 * message, then it was unexpected (Hello Request or Client Hello). */
948 /* In case of record types for which we have 'fragment' storage,
949 * fill that so that we can process the data at a fixed place.
952 unsigned int k, dest_maxlen = 0;
953 unsigned char *dest = NULL;
954 unsigned int *dest_len = NULL;
956 if (rr->type == SSL3_RT_HANDSHAKE)
958 dest_maxlen = sizeof s->d1->handshake_fragment;
959 dest = s->d1->handshake_fragment;
960 dest_len = &s->d1->handshake_fragment_len;
962 else if (rr->type == SSL3_RT_ALERT)
964 dest_maxlen = sizeof(s->d1->alert_fragment);
965 dest = s->d1->alert_fragment;
966 dest_len = &s->d1->alert_fragment_len;
968 #ifndef OPENSSL_NO_HEARTBEATS
969 else if (rr->type == TLS1_RT_HEARTBEAT)
971 dtls1_process_heartbeat(s);
973 /* Exit and notify application to read again */
975 s->rwstate=SSL_READING;
976 BIO_clear_retry_flags(SSL_get_rbio(s));
977 BIO_set_retry_read(SSL_get_rbio(s));
981 /* else it's a CCS message, or application data or wrong */
982 else if (rr->type != SSL3_RT_CHANGE_CIPHER_SPEC)
984 /* Application data while renegotiating
985 * is allowed. Try again reading.
987 if (rr->type == SSL3_RT_APPLICATION_DATA)
990 s->s3->in_read_app_data=2;
992 s->rwstate=SSL_READING;
993 BIO_clear_retry_flags(bio);
994 BIO_set_retry_read(bio);
998 /* Not certain if this is the right error handling */
999 al=SSL_AD_UNEXPECTED_MESSAGE;
1000 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1004 if (dest_maxlen > 0)
1006 /* XDTLS: In a pathalogical case, the Client Hello
1007 * may be fragmented--don't always expect dest_maxlen bytes */
1008 if ( rr->length < dest_maxlen)
1010 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1012 * for normal alerts rr->length is 2, while
1013 * dest_maxlen is 7 if we were to handle this
1014 * non-existing alert...
1018 s->rstate=SSL_ST_READ_HEADER;
1023 /* now move 'n' bytes: */
1024 for ( k = 0; k < dest_maxlen; k++)
1026 dest[k] = rr->data[rr->off++];
1029 *dest_len = dest_maxlen;
1033 /* s->d1->handshake_fragment_len == 12 iff rr->type == SSL3_RT_HANDSHAKE;
1034 * s->d1->alert_fragment_len == 7 iff rr->type == SSL3_RT_ALERT.
1035 * (Possibly rr is 'empty' now, i.e. rr->length may be 0.) */
1037 /* If we are a client, check for an incoming 'Hello Request': */
1039 (s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1040 (s->d1->handshake_fragment[0] == SSL3_MT_HELLO_REQUEST) &&
1041 (s->session != NULL) && (s->session->cipher != NULL))
1043 s->d1->handshake_fragment_len = 0;
1045 if ((s->d1->handshake_fragment[1] != 0) ||
1046 (s->d1->handshake_fragment[2] != 0) ||
1047 (s->d1->handshake_fragment[3] != 0))
1049 al=SSL_AD_DECODE_ERROR;
1050 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_HELLO_REQUEST);
1054 /* no need to check sequence number on HELLO REQUEST messages */
1056 if (s->msg_callback)
1057 s->msg_callback(0, s->version, SSL3_RT_HANDSHAKE,
1058 s->d1->handshake_fragment, 4, s, s->msg_callback_arg);
1060 if (SSL_is_init_finished(s) &&
1061 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS) &&
1062 !s->s3->renegotiate)
1064 s->d1->handshake_read_seq++;
1066 ssl3_renegotiate(s);
1067 if (ssl3_renegotiate_check(s))
1069 i=s->handshake_func(s);
1070 if (i < 0) return(i);
1073 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1077 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1079 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1082 /* In the case where we try to read application data,
1083 * but we trigger an SSL handshake, we return -1 with
1084 * the retry option set. Otherwise renegotiation may
1085 * cause nasty problems in the blocking world */
1086 s->rwstate=SSL_READING;
1087 bio=SSL_get_rbio(s);
1088 BIO_clear_retry_flags(bio);
1089 BIO_set_retry_read(bio);
1095 /* we either finished a handshake or ignored the request,
1096 * now try again to obtain the (application) data we were asked for */
1100 if (s->d1->alert_fragment_len >= DTLS1_AL_HEADER_LENGTH)
1102 int alert_level = s->d1->alert_fragment[0];
1103 int alert_descr = s->d1->alert_fragment[1];
1105 s->d1->alert_fragment_len = 0;
1107 if (s->msg_callback)
1108 s->msg_callback(0, s->version, SSL3_RT_ALERT,
1109 s->d1->alert_fragment, 2, s, s->msg_callback_arg);
1111 if (s->info_callback != NULL)
1112 cb=s->info_callback;
1113 else if (s->ctx->info_callback != NULL)
1114 cb=s->ctx->info_callback;
1118 j = (alert_level << 8) | alert_descr;
1119 cb(s, SSL_CB_READ_ALERT, j);
1122 if (alert_level == 1) /* warning */
1124 s->s3->warn_alert = alert_descr;
1125 if (alert_descr == SSL_AD_CLOSE_NOTIFY)
1127 #ifndef OPENSSL_NO_SCTP
1128 /* With SCTP and streams the socket may deliver app data
1129 * after a close_notify alert. We have to check this
1130 * first so that nothing gets discarded.
1132 if (BIO_dgram_is_sctp(SSL_get_rbio(s)) &&
1133 BIO_dgram_sctp_msg_waiting(SSL_get_rbio(s)))
1135 s->d1->shutdown_received = 1;
1136 s->rwstate=SSL_READING;
1137 BIO_clear_retry_flags(SSL_get_rbio(s));
1138 BIO_set_retry_read(SSL_get_rbio(s));
1142 s->shutdown |= SSL_RECEIVED_SHUTDOWN;
1146 /* XXX: this is a possible improvement in the future */
1147 /* now check if it's a missing record */
1148 if (alert_descr == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1151 unsigned int frag_off;
1152 unsigned char *p = &(s->d1->alert_fragment[2]);
1157 dtls1_retransmit_message(s,
1158 dtls1_get_queue_priority(frag->msg_header.seq, 0),
1160 if ( ! found && SSL_in_init(s))
1162 /* fprintf( stderr,"in init = %d\n", SSL_in_init(s)); */
1163 /* requested a message not yet sent,
1164 send an alert ourselves */
1165 ssl3_send_alert(s,SSL3_AL_WARNING,
1166 DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
1171 else if (alert_level == 2) /* fatal */
1175 s->rwstate=SSL_NOTHING;
1176 s->s3->fatal_alert = alert_descr;
1177 SSLerr(SSL_F_DTLS1_READ_BYTES, SSL_AD_REASON_OFFSET + alert_descr);
1178 BIO_snprintf(tmp,sizeof tmp,"%d",alert_descr);
1179 ERR_add_error_data(2,"SSL alert number ",tmp);
1180 s->shutdown|=SSL_RECEIVED_SHUTDOWN;
1181 SSL_CTX_remove_session(s->ctx,s->session);
1186 al=SSL_AD_ILLEGAL_PARAMETER;
1187 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNKNOWN_ALERT_TYPE);
1194 if (s->shutdown & SSL_SENT_SHUTDOWN) /* but we have not received a shutdown */
1196 s->rwstate=SSL_NOTHING;
1201 if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1203 struct ccs_header_st ccs_hdr;
1204 unsigned int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
1206 dtls1_get_ccs_header(rr->data, &ccs_hdr);
1208 if (s->version == DTLS1_BAD_VER)
1211 /* 'Change Cipher Spec' is just a single byte, so we know
1212 * exactly what the record payload has to look like */
1213 /* XDTLS: check that epoch is consistent */
1214 if ( (rr->length != ccs_hdr_len) ||
1215 (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
1217 i=SSL_AD_ILLEGAL_PARAMETER;
1218 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
1224 if (s->msg_callback)
1225 s->msg_callback(0, s->version, SSL3_RT_CHANGE_CIPHER_SPEC,
1226 rr->data, 1, s, s->msg_callback_arg);
1228 /* We can't process a CCS now, because previous handshake
1229 * messages are still missing, so just drop it.
1231 if (!s->d1->change_cipher_spec_ok)
1236 s->d1->change_cipher_spec_ok = 0;
1238 s->s3->change_cipher_spec=1;
1239 if (!ssl3_do_change_cipher_spec(s))
1242 /* do this whenever CCS is processed */
1243 dtls1_reset_seq_numbers(s, SSL3_CC_READ);
1245 if (s->version == DTLS1_BAD_VER)
1246 s->d1->handshake_read_seq++;
1248 #ifndef OPENSSL_NO_SCTP
1249 /* Remember that a CCS has been received,
1250 * so that an old key of SCTP-Auth can be
1251 * deleted when a CCS is sent. Will be ignored
1252 * if no SCTP is used
1254 BIO_ctrl(SSL_get_wbio(s), BIO_CTRL_DGRAM_SCTP_AUTH_CCS_RCVD, 1, NULL);
1260 /* Unexpected handshake message (Client Hello, or protocol violation) */
1261 if ((s->d1->handshake_fragment_len >= DTLS1_HM_HEADER_LENGTH) &&
1264 struct hm_header_st msg_hdr;
1266 /* this may just be a stale retransmit */
1267 dtls1_get_message_header(rr->data, &msg_hdr);
1268 if( rr->epoch != s->d1->r_epoch)
1274 /* If we are server, we may have a repeated FINISHED of the
1275 * client here, then retransmit our CCS and FINISHED.
1277 if (msg_hdr.type == SSL3_MT_FINISHED)
1279 if (dtls1_check_timeout_num(s) < 0)
1282 dtls1_retransmit_buffered_messages(s);
1287 if (((s->state&SSL_ST_MASK) == SSL_ST_OK) &&
1288 !(s->s3->flags & SSL3_FLAGS_NO_RENEGOTIATE_CIPHERS))
1290 #if 0 /* worked only because C operator preferences are not as expected (and
1291 * because this is not really needed for clients except for detecting
1292 * protocol violations): */
1293 s->state=SSL_ST_BEFORE|(s->server)
1297 s->state = s->server ? SSL_ST_ACCEPT : SSL_ST_CONNECT;
1302 i=s->handshake_func(s);
1303 if (i < 0) return(i);
1306 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1310 if (!(s->mode & SSL_MODE_AUTO_RETRY))
1312 if (s->s3->rbuf.left == 0) /* no read-ahead left? */
1315 /* In the case where we try to read application data,
1316 * but we trigger an SSL handshake, we return -1 with
1317 * the retry option set. Otherwise renegotiation may
1318 * cause nasty problems in the blocking world */
1319 s->rwstate=SSL_READING;
1320 bio=SSL_get_rbio(s);
1321 BIO_clear_retry_flags(bio);
1322 BIO_set_retry_read(bio);
1332 #ifndef OPENSSL_NO_TLS
1333 /* TLS just ignores unknown message types */
1334 if (s->version == TLS1_VERSION)
1340 al=SSL_AD_UNEXPECTED_MESSAGE;
1341 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1343 case SSL3_RT_CHANGE_CIPHER_SPEC:
1345 case SSL3_RT_HANDSHAKE:
1346 /* we already handled all of these, with the possible exception
1347 * of SSL3_RT_HANDSHAKE when s->in_handshake is set, but that
1348 * should not happen when type != rr->type */
1349 al=SSL_AD_UNEXPECTED_MESSAGE;
1350 SSLerr(SSL_F_DTLS1_READ_BYTES,ERR_R_INTERNAL_ERROR);
1352 case SSL3_RT_APPLICATION_DATA:
1353 /* At this point, we were expecting handshake data,
1354 * but have application data. If the library was
1355 * running inside ssl3_read() (i.e. in_read_app_data
1356 * is set) and it makes sense to read application data
1357 * at this point (session renegotiation not yet started),
1358 * we will indulge it.
1360 if (s->s3->in_read_app_data &&
1361 (s->s3->total_renegotiations != 0) &&
1363 (s->state & SSL_ST_CONNECT) &&
1364 (s->state >= SSL3_ST_CW_CLNT_HELLO_A) &&
1365 (s->state <= SSL3_ST_CR_SRVR_HELLO_A)
1367 (s->state & SSL_ST_ACCEPT) &&
1368 (s->state <= SSL3_ST_SW_HELLO_REQ_A) &&
1369 (s->state >= SSL3_ST_SR_CLNT_HELLO_A)
1373 s->s3->in_read_app_data=2;
1378 al=SSL_AD_UNEXPECTED_MESSAGE;
1379 SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_UNEXPECTED_RECORD);
1386 ssl3_send_alert(s,SSL3_AL_FATAL,al);
1392 dtls1_write_app_data_bytes(SSL *s, int type, const void *buf_, int len)
1396 #ifndef OPENSSL_NO_SCTP
1397 /* Check if we have to continue an interrupted handshake
1398 * for reading belated app data with SCTP.
1400 if ((SSL_in_init(s) && !s->in_handshake) ||
1401 (BIO_dgram_is_sctp(SSL_get_wbio(s)) &&
1402 (s->state == DTLS1_SCTP_ST_SR_READ_SOCK || s->state == DTLS1_SCTP_ST_CR_READ_SOCK)))
1404 if (SSL_in_init(s) && !s->in_handshake)
1407 i=s->handshake_func(s);
1408 if (i < 0) return(i);
1411 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_SSL_HANDSHAKE_FAILURE);
1416 if (len > SSL3_RT_MAX_PLAIN_LENGTH)
1418 SSLerr(SSL_F_DTLS1_WRITE_APP_DATA_BYTES,SSL_R_DTLS_MESSAGE_TOO_BIG);
1422 i = dtls1_write_bytes(s, type, buf_, len);
1427 /* this only happens when a client hello is received and a handshake
1430 have_handshake_fragment(SSL *s, int type, unsigned char *buf,
1434 if ((type == SSL3_RT_HANDSHAKE) && (s->d1->handshake_fragment_len > 0))
1435 /* (partially) satisfy request from storage */
1437 unsigned char *src = s->d1->handshake_fragment;
1438 unsigned char *dst = buf;
1443 while ((len > 0) && (s->d1->handshake_fragment_len > 0))
1446 len--; s->d1->handshake_fragment_len--;
1449 /* move any remaining fragment bytes: */
1450 for (k = 0; k < s->d1->handshake_fragment_len; k++)
1451 s->d1->handshake_fragment[k] = *src++;
1461 /* Call this to write data in records of type 'type'
1462 * It will return <= 0 if not all data has been sent or non-blocking IO.
1464 int dtls1_write_bytes(SSL *s, int type, const void *buf, int len)
1468 OPENSSL_assert(len <= SSL3_RT_MAX_PLAIN_LENGTH);
1469 s->rwstate=SSL_NOTHING;
1470 i=do_dtls1_write(s, type, buf, len, 0);
1474 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
1476 unsigned char *p,*pseq;
1477 int i,mac_size,clear=0;
1484 /* first check if there is a SSL3_BUFFER still being written
1485 * out. This will happen with non blocking IO */
1486 if (s->s3->wbuf.left != 0)
1488 OPENSSL_assert(0); /* XDTLS: want to see if we ever get here */
1489 return(ssl3_write_pending(s,type,buf,len));
1492 /* If we have an alert to send, lets send it */
1493 if (s->s3->alert_dispatch)
1495 i=s->method->ssl_dispatch_alert(s);
1498 /* if it went, fall through and send more stuff */
1501 if (len == 0 && !create_empty_fragment)
1508 if ( (sess == NULL) ||
1509 (s->enc_write_ctx == NULL) ||
1510 (EVP_MD_CTX_md(s->write_hash) == NULL))
1517 mac_size=EVP_MD_CTX_size(s->write_hash);
1522 /* DTLS implements explicit IV, so no need for empty fragments */
1524 /* 'create_empty_fragment' is true only when this function calls itself */
1525 if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
1526 && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
1528 /* countermeasure against known-IV weakness in CBC ciphersuites
1529 * (see http://www.openssl.org/~bodo/tls-cbc.txt)
1532 if (s->s3->need_empty_fragments && type == SSL3_RT_APPLICATION_DATA)
1534 /* recursive function call with 'create_empty_fragment' set;
1535 * this prepares and buffers the data for an empty fragment
1536 * (these 'prefix_len' bytes are sent out later
1537 * together with the actual payload) */
1538 prefix_len = s->method->do_ssl_write(s, type, buf, 0, 1);
1539 if (prefix_len <= 0)
1542 if (s->s3->wbuf.len < (size_t)prefix_len + SSL3_RT_MAX_PACKET_SIZE)
1544 /* insufficient space */
1545 SSLerr(SSL_F_DO_DTLS1_WRITE, ERR_R_INTERNAL_ERROR);
1550 s->s3->empty_fragment_done = 1;
1553 p = wb->buf + prefix_len;
1555 /* write the header */
1559 /* Special case: for hello verify request, client version 1.0 and
1560 * we haven't decided which version to use yet send back using
1561 * version 1.0 header: otherwise some clients will ignore it.
1563 if (s->method->version == DTLS_ANY_VERSION)
1565 *(p++)=DTLS1_VERSION>>8;
1566 *(p++)=DTLS1_VERSION&0xff;
1570 *(p++)=s->version>>8;
1571 *(p++)=s->version&0xff;
1574 /* field where we are to write out packet epoch, seq num and len */
1578 /* Explicit IV length, block ciphers appropriate version flag */
1579 if (s->enc_write_ctx)
1581 int mode = EVP_CIPHER_CTX_mode(s->enc_write_ctx);
1582 if (mode == EVP_CIPH_CBC_MODE)
1584 eivlen = EVP_CIPHER_CTX_iv_length(s->enc_write_ctx);
1588 /* Need explicit part of IV for GCM mode */
1589 else if (mode == EVP_CIPH_GCM_MODE)
1590 eivlen = EVP_GCM_TLS_EXPLICIT_IV_LEN;
1597 /* lets setup the record stuff. */
1598 wr->data=p + eivlen; /* make room for IV in case of CBC */
1599 wr->length=(int)len;
1600 wr->input=(unsigned char *)buf;
1602 /* we now 'read' from wr->input, wr->length bytes into
1605 /* first we compress */
1606 if (s->compress != NULL)
1608 if (!ssl3_do_compress(s))
1610 SSLerr(SSL_F_DO_DTLS1_WRITE,SSL_R_COMPRESSION_FAILURE);
1616 memcpy(wr->data,wr->input,wr->length);
1620 /* we should still have the output to wr->data and the input
1621 * from wr->input. Length should be wr->length.
1622 * wr->data still points in the wb->buf */
1626 if(s->method->ssl3_enc->mac(s,&(p[wr->length + eivlen]),1) < 0)
1628 wr->length+=mac_size;
1631 /* this is true regardless of mac size */
1636 wr->length += eivlen;
1638 s->method->ssl3_enc->enc(s,1);
1640 /* record length after mac and block padding */
1641 /* if (type == SSL3_RT_APPLICATION_DATA ||
1642 (type == SSL3_RT_ALERT && ! SSL_in_init(s))) */
1644 /* there's only one epoch between handshake and app data */
1646 s2n(s->d1->w_epoch, pseq);
1650 s2n(s->d1->handshake_epoch, pseq); */
1652 memcpy(pseq, &(s->s3->write_sequence[2]), 6);
1654 s2n(wr->length,pseq);
1656 if (s->msg_callback)
1657 s->msg_callback(1, 0, SSL3_RT_HEADER, pseq - DTLS1_RT_HEADER_LENGTH, DTLS1_RT_HEADER_LENGTH, s, s->msg_callback_arg);
1659 /* we should now have
1660 * wr->data pointing to the encrypted data, which is
1661 * wr->length long */
1662 wr->type=type; /* not needed but helps for debugging */
1663 wr->length+=DTLS1_RT_HEADER_LENGTH;
1665 #if 0 /* this is now done at the message layer */
1666 /* buffer the record, making it easy to handle retransmits */
1667 if ( type == SSL3_RT_HANDSHAKE || type == SSL3_RT_CHANGE_CIPHER_SPEC)
1668 dtls1_buffer_record(s, wr->data, wr->length,
1669 *((PQ_64BIT *)&(s->s3->write_sequence[0])));
1672 ssl3_record_sequence_update(&(s->s3->write_sequence[0]));
1674 if (create_empty_fragment)
1676 /* we are in a recursive call;
1677 * just return the length, don't write out anything here
1682 /* now let's set up wb */
1683 wb->left = prefix_len + wr->length;
1686 /* memorize arguments so that ssl3_write_pending can detect bad write retries later */
1687 s->s3->wpend_tot=len;
1688 s->s3->wpend_buf=buf;
1689 s->s3->wpend_type=type;
1690 s->s3->wpend_ret=len;
1692 /* we now just need to write the buffer */
1693 return ssl3_write_pending(s,type,buf,len);
1700 static int dtls1_record_replay_check(SSL *s, DTLS1_BITMAP *bitmap)
1704 const unsigned char *seq = s->s3->read_sequence;
1706 cmp = satsub64be(seq,bitmap->max_seq_num);
1709 memcpy (s->s3->rrec.seq_num,seq,8);
1710 return 1; /* this record in new */
1713 if (shift >= sizeof(bitmap->map)*8)
1714 return 0; /* stale, outside the window */
1715 else if (bitmap->map & (1UL<<shift))
1716 return 0; /* record previously received */
1718 memcpy (s->s3->rrec.seq_num,seq,8);
1723 static void dtls1_record_bitmap_update(SSL *s, DTLS1_BITMAP *bitmap)
1727 const unsigned char *seq = s->s3->read_sequence;
1729 cmp = satsub64be(seq,bitmap->max_seq_num);
1733 if (shift < sizeof(bitmap->map)*8)
1734 bitmap->map <<= shift, bitmap->map |= 1UL;
1737 memcpy(bitmap->max_seq_num,seq,8);
1741 if (shift < sizeof(bitmap->map)*8)
1742 bitmap->map |= 1UL<<shift;
1747 int dtls1_dispatch_alert(SSL *s)
1750 void (*cb)(const SSL *ssl,int type,int val)=NULL;
1751 unsigned char buf[DTLS1_AL_HEADER_LENGTH];
1752 unsigned char *ptr = &buf[0];
1754 s->s3->alert_dispatch=0;
1756 memset(buf, 0x00, sizeof(buf));
1757 *ptr++ = s->s3->send_alert[0];
1758 *ptr++ = s->s3->send_alert[1];
1760 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1761 if (s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE)
1763 s2n(s->d1->handshake_read_seq, ptr);
1765 if ( s->d1->r_msg_hdr.frag_off == 0) /* waiting for a new msg */
1768 s2n(s->d1->r_msg_hdr.seq, ptr); /* partial msg read */
1772 fprintf(stderr, "s->d1->handshake_read_seq = %d, s->d1->r_msg_hdr.seq = %d\n",s->d1->handshake_read_seq,s->d1->r_msg_hdr.seq);
1774 l2n3(s->d1->r_msg_hdr.frag_off, ptr);
1778 i = do_dtls1_write(s, SSL3_RT_ALERT, &buf[0], sizeof(buf), 0);
1781 s->s3->alert_dispatch=1;
1782 /* fprintf( stderr, "not done with alert\n" ); */
1786 if (s->s3->send_alert[0] == SSL3_AL_FATAL
1787 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1788 || s->s3->send_alert[1] == DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
1791 (void)BIO_flush(s->wbio);
1793 if (s->msg_callback)
1794 s->msg_callback(1, s->version, SSL3_RT_ALERT, s->s3->send_alert,
1795 2, s, s->msg_callback_arg);
1797 if (s->info_callback != NULL)
1798 cb=s->info_callback;
1799 else if (s->ctx->info_callback != NULL)
1800 cb=s->ctx->info_callback;
1804 j=(s->s3->send_alert[0]<<8)|s->s3->send_alert[1];
1805 cb(s,SSL_CB_WRITE_ALERT,j);
1812 static DTLS1_BITMAP *
1813 dtls1_get_bitmap(SSL *s, SSL3_RECORD *rr, unsigned int *is_next_epoch)
1818 /* In current epoch, accept HM, CCS, DATA, & ALERT */
1819 if (rr->epoch == s->d1->r_epoch)
1820 return &s->d1->bitmap;
1822 /* Only HM and ALERT messages can be from the next epoch */
1823 else if (rr->epoch == (unsigned long)(s->d1->r_epoch + 1) &&
1824 (rr->type == SSL3_RT_HANDSHAKE ||
1825 rr->type == SSL3_RT_ALERT))
1828 return &s->d1->next_bitmap;
1836 dtls1_record_needs_buffering(SSL *s, SSL3_RECORD *rr, unsigned short *priority,
1837 unsigned long *offset)
1840 /* alerts are passed up immediately */
1841 if ( rr->type == SSL3_RT_APPLICATION_DATA ||
1842 rr->type == SSL3_RT_ALERT)
1845 /* Only need to buffer if a handshake is underway.
1846 * (this implies that Hello Request and Client Hello are passed up
1848 if ( SSL_in_init(s))
1850 unsigned char *data = rr->data;
1851 /* need to extract the HM/CCS sequence number here */
1852 if ( rr->type == SSL3_RT_HANDSHAKE ||
1853 rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
1855 unsigned short seq_num;
1856 struct hm_header_st msg_hdr;
1857 struct ccs_header_st ccs_hdr;
1859 if ( rr->type == SSL3_RT_HANDSHAKE)
1861 dtls1_get_message_header(data, &msg_hdr);
1862 seq_num = msg_hdr.seq;
1863 *offset = msg_hdr.frag_off;
1867 dtls1_get_ccs_header(data, &ccs_hdr);
1868 seq_num = ccs_hdr.seq;
1872 /* this is either a record we're waiting for, or a
1873 * retransmit of something we happened to previously
1874 * receive (higher layers will drop the repeat silently */
1875 if ( seq_num < s->d1->handshake_read_seq)
1877 if (rr->type == SSL3_RT_HANDSHAKE &&
1878 seq_num == s->d1->handshake_read_seq &&
1879 msg_hdr.frag_off < s->d1->r_msg_hdr.frag_off)
1881 else if ( seq_num == s->d1->handshake_read_seq &&
1882 (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC ||
1883 msg_hdr.frag_off == s->d1->r_msg_hdr.frag_off))
1887 *priority = seq_num;
1891 else /* unknown record type */
1900 dtls1_reset_seq_numbers(SSL *s, int rw)
1903 unsigned int seq_bytes = sizeof(s->s3->read_sequence);
1905 if ( rw & SSL3_CC_READ)
1907 seq = s->s3->read_sequence;
1909 memcpy(&(s->d1->bitmap), &(s->d1->next_bitmap), sizeof(DTLS1_BITMAP));
1910 memset(&(s->d1->next_bitmap), 0x00, sizeof(DTLS1_BITMAP));
1914 seq = s->s3->write_sequence;
1915 memcpy(s->d1->last_write_sequence, seq, sizeof(s->s3->write_sequence));
1919 memset(seq, 0x00, seq_bytes);