3 * DTLS implementation written by Nagendra Modadugu
4 * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
6 /* ====================================================================
7 * Copyright (c) 1999-2005 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).
60 #ifndef HEADER_DTLS1_H
61 # define HEADER_DTLS1_H
63 # include <openssl/buffer.h>
64 # include <openssl/pqueue.h>
65 # ifdef OPENSSL_SYS_VMS
66 # include <resource.h>
67 # include <sys/timeb.h>
69 # ifdef OPENSSL_SYS_WIN32
70 /* Needed for struct timeval */
72 # elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_)
73 # include <sys/timeval.h>
75 # if defined(OPENSSL_SYS_VXWORKS)
76 # include <sys/times.h>
78 # include <sys/time.h>
86 # define DTLS1_VERSION 0xFEFF
87 # define DTLS1_2_VERSION 0xFEFD
88 # define DTLS_MAX_VERSION DTLS1_2_VERSION
90 # define DTLS1_BAD_VER 0x0100
92 /* Special value for method supporting multiple versions */
93 # define DTLS_ANY_VERSION 0x1FFFF
96 /* this alert description is not specified anywhere... */
97 # define DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 110
100 /* lengths of messages */
101 # define DTLS1_COOKIE_LENGTH 256
103 # define DTLS1_RT_HEADER_LENGTH 13
105 # define DTLS1_HM_HEADER_LENGTH 12
107 # define DTLS1_HM_BAD_FRAGMENT -2
108 # define DTLS1_HM_FRAGMENT_RETRY -3
110 # define DTLS1_CCS_HEADER_LENGTH 1
112 # ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
113 # define DTLS1_AL_HEADER_LENGTH 7
115 # define DTLS1_AL_HEADER_LENGTH 2
118 # ifndef OPENSSL_NO_SSL_INTERN
120 # ifndef OPENSSL_NO_SCTP
121 # define DTLS1_SCTP_AUTH_LABEL "EXPORTER_DTLS_OVER_SCTP"
124 /* Max MTU overhead we know about so far is 40 for IPv6 + 8 for UDP */
125 # define DTLS1_MAX_MTU_OVERHEAD 48
127 typedef struct dtls1_bitmap_st {
128 unsigned long map; /* track 32 packets on 32-bit systems and 64
129 * - on 64-bit systems */
130 unsigned char max_seq_num[8]; /* max record number seen so far, 64-bit
131 * value in big-endian encoding */
134 struct dtls1_retransmit_state {
135 EVP_CIPHER_CTX *enc_write_ctx; /* cryptographic state */
136 EVP_MD_CTX *write_hash; /* used for mac generation */
137 # ifndef OPENSSL_NO_COMP
138 COMP_CTX *compress; /* compression */
142 SSL_SESSION *session;
143 unsigned short epoch;
146 struct hm_header_st {
148 unsigned long msg_len;
150 unsigned long frag_off;
151 unsigned long frag_len;
153 struct dtls1_retransmit_state saved_retransmit_state;
156 struct ccs_header_st {
161 struct dtls1_timeout_st {
162 /* Number of read timeouts so far */
163 unsigned int read_timeouts;
164 /* Number of write timeouts so far */
165 unsigned int write_timeouts;
166 /* Number of alerts received so far */
167 unsigned int num_alerts;
170 typedef struct record_pqueue_st {
171 unsigned short epoch;
175 typedef struct hm_fragment_st {
176 struct hm_header_st msg_header;
177 unsigned char *fragment;
178 unsigned char *reassembly;
181 typedef struct dtls1_state_st {
182 unsigned int send_cookie;
183 unsigned char cookie[DTLS1_COOKIE_LENGTH];
184 unsigned char rcvd_cookie[DTLS1_COOKIE_LENGTH];
185 unsigned int cookie_len;
187 * The current data and handshake epoch. This is initially
188 * undefined, and starts at zero once the initial handshake is
191 unsigned short r_epoch;
192 unsigned short w_epoch;
193 /* records being received in the current epoch */
195 /* renegotiation starts a new set of sequence numbers */
196 DTLS1_BITMAP next_bitmap;
197 /* handshake message numbers */
198 unsigned short handshake_write_seq;
199 unsigned short next_handshake_write_seq;
200 unsigned short handshake_read_seq;
201 /* save last sequence number for retransmissions */
202 unsigned char last_write_sequence[8];
203 /* Received handshake records (processed and unprocessed) */
204 record_pqueue unprocessed_rcds;
205 record_pqueue processed_rcds;
206 /* Buffered handshake messages */
207 pqueue buffered_messages;
208 /* Buffered (sent) handshake records */
209 pqueue sent_messages;
211 * Buffered application records. Only for records between CCS and
212 * Finished to prevent either protocol violation or unnecessary message
215 record_pqueue buffered_app_data;
216 /* Is set when listening for new connections with dtls1_listen() */
218 unsigned int link_mtu; /* max on-the-wire DTLS packet size */
219 unsigned int mtu; /* max DTLS packet size */
220 struct hm_header_st w_msg_hdr;
221 struct hm_header_st r_msg_hdr;
222 struct dtls1_timeout_st timeout;
224 * Indicates when the last handshake msg or heartbeat sent will timeout
226 struct timeval next_timeout;
227 /* Timeout duration */
228 unsigned short timeout_duration;
230 * storage for Alert/Handshake protocol data received but not yet
231 * processed by ssl3_read_bytes:
233 unsigned char alert_fragment[DTLS1_AL_HEADER_LENGTH];
234 unsigned int alert_fragment_len;
235 unsigned char handshake_fragment[DTLS1_HM_HEADER_LENGTH];
236 unsigned int handshake_fragment_len;
237 unsigned int retransmitting;
239 * Set when the handshake is ready to process peer's ChangeCipherSpec message.
240 * Cleared after the message has been processed.
242 unsigned int change_cipher_spec_ok;
243 # ifndef OPENSSL_NO_SCTP
244 /* used when SSL_ST_XX_FLUSH is entered */
246 int shutdown_received;
250 typedef struct dtls1_record_data_st {
251 unsigned char *packet;
252 unsigned int packet_length;
255 # ifndef OPENSSL_NO_SCTP
256 struct bio_dgram_sctp_rcvinfo recordinfo;
262 /* Timeout multipliers (timeout slice is defined in apps/timeouts.h */
263 # define DTLS1_TMO_READ_COUNT 2
264 # define DTLS1_TMO_WRITE_COUNT 2
266 # define DTLS1_TMO_ALERT_COUNT 12