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 # include <sys/time.h>
82 # define DTLS1_VERSION 0xFEFF
83 # define DTLS_MAX_VERSION DTLS1_VERSION
85 # define DTLS1_BAD_VER 0x0100
88 /* this alert description is not specified anywhere... */
89 # define DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 110
92 /* lengths of messages */
93 # define DTLS1_COOKIE_LENGTH 256
95 # define DTLS1_RT_HEADER_LENGTH 13
97 # define DTLS1_HM_HEADER_LENGTH 12
99 # define DTLS1_HM_BAD_FRAGMENT -2
100 # define DTLS1_HM_FRAGMENT_RETRY -3
102 # define DTLS1_CCS_HEADER_LENGTH 1
104 # ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
105 # define DTLS1_AL_HEADER_LENGTH 7
107 # define DTLS1_AL_HEADER_LENGTH 2
110 /* Max MTU overhead we know about so far is 40 for IPv6 + 8 for UDP */
111 # define DTLS1_MAX_MTU_OVERHEAD 48
113 typedef struct dtls1_bitmap_st {
114 unsigned long map; /* track 32 packets on 32-bit systems and 64
115 * - on 64-bit systems */
116 unsigned char max_seq_num[8]; /* max record number seen so far, 64-bit
117 * value in big-endian encoding */
120 struct dtls1_retransmit_state {
121 EVP_CIPHER_CTX *enc_write_ctx; /* cryptographic state */
122 EVP_MD_CTX *write_hash; /* used for mac generation */
123 # ifndef OPENSSL_NO_COMP
124 COMP_CTX *compress; /* compression */
128 SSL_SESSION *session;
129 unsigned short epoch;
132 struct hm_header_st {
134 unsigned long msg_len;
136 unsigned long frag_off;
137 unsigned long frag_len;
139 struct dtls1_retransmit_state saved_retransmit_state;
142 struct ccs_header_st {
147 struct dtls1_timeout_st {
148 /* Number of read timeouts so far */
149 unsigned int read_timeouts;
150 /* Number of write timeouts so far */
151 unsigned int write_timeouts;
152 /* Number of alerts received so far */
153 unsigned int num_alerts;
156 typedef struct record_pqueue_st {
157 unsigned short epoch;
161 typedef struct hm_fragment_st {
162 struct hm_header_st msg_header;
163 unsigned char *fragment;
164 unsigned char *reassembly;
167 typedef struct dtls1_state_st {
168 unsigned int send_cookie;
169 unsigned char cookie[DTLS1_COOKIE_LENGTH];
170 unsigned char rcvd_cookie[DTLS1_COOKIE_LENGTH];
171 unsigned int cookie_len;
173 * The current data and handshake epoch. This is initially
174 * undefined, and starts at zero once the initial handshake is
177 unsigned short r_epoch;
178 unsigned short w_epoch;
179 /* records being received in the current epoch */
181 /* renegotiation starts a new set of sequence numbers */
182 DTLS1_BITMAP next_bitmap;
183 /* handshake message numbers */
184 unsigned short handshake_write_seq;
185 unsigned short next_handshake_write_seq;
186 unsigned short handshake_read_seq;
187 /* save last sequence number for retransmissions */
188 unsigned char last_write_sequence[8];
189 /* Received handshake records (processed and unprocessed) */
190 record_pqueue unprocessed_rcds;
191 record_pqueue processed_rcds;
192 /* Buffered handshake messages */
193 pqueue buffered_messages;
194 /* Buffered (sent) handshake records */
195 pqueue sent_messages;
197 * Buffered application records. Only for records between CCS and
198 * Finished to prevent either protocol violation or unnecessary message
201 record_pqueue buffered_app_data;
202 /* Is set when listening for new connections with dtls1_listen() */
204 unsigned int link_mtu; /* max on-the-wire DTLS packet size */
205 unsigned int mtu; /* max DTLS packet size */
206 struct hm_header_st w_msg_hdr;
207 struct hm_header_st r_msg_hdr;
208 struct dtls1_timeout_st timeout;
209 /* Indicates when the last handshake msg sent will timeout */
210 struct timeval next_timeout;
211 /* Timeout duration */
212 unsigned short timeout_duration;
214 * storage for Alert/Handshake protocol data received but not yet
215 * processed by ssl3_read_bytes:
217 unsigned char alert_fragment[DTLS1_AL_HEADER_LENGTH];
218 unsigned int alert_fragment_len;
219 unsigned char handshake_fragment[DTLS1_HM_HEADER_LENGTH];
220 unsigned int handshake_fragment_len;
221 unsigned int retransmitting;
222 unsigned int change_cipher_spec_ok;
225 typedef struct dtls1_record_data_st {
226 unsigned char *packet;
227 unsigned int packet_length;
232 /* Timeout multipliers (timeout slice is defined in apps/timeouts.h */
233 # define DTLS1_TMO_READ_COUNT 2
234 # define DTLS1_TMO_WRITE_COUNT 2
236 # define DTLS1_TMO_ALERT_COUNT 12