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>
70 #define DTLS1_VERSION 0xFEFF
71 #define DTLS1_BAD_VER 0x0100
74 /* this alert description is not specified anywhere... */
75 #define DTLS1_AD_MISSING_HANDSHAKE_MESSAGE 110
78 /* lengths of messages */
79 #define DTLS1_COOKIE_LENGTH 32
81 #define DTLS1_RT_HEADER_LENGTH 13
83 #define DTLS1_HM_HEADER_LENGTH 12
85 #define DTLS1_HM_BAD_FRAGMENT -2
86 #define DTLS1_HM_FRAGMENT_RETRY -3
88 #define DTLS1_CCS_HEADER_LENGTH 1
90 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
91 #define DTLS1_AL_HEADER_LENGTH 7
93 #define DTLS1_AL_HEADER_LENGTH 2
97 typedef struct dtls1_bitmap_st
99 unsigned long map; /* track 32 packets on 32-bit systems
100 and 64 - on 64-bit systems */
101 unsigned char max_seq_num[8]; /* max record number seen so far,
102 64-bit value in big-endian
106 struct dtls1_retransmit_state
108 EVP_CIPHER_CTX *enc_write_ctx; /* cryptographic state */
109 EVP_MD_CTX *write_hash; /* used for mac generation */
110 #ifndef OPENSSL_NO_COMP
111 COMP_CTX *compress; /* compression */
115 SSL_SESSION *session;
116 unsigned short epoch;
122 unsigned long msg_len;
124 unsigned long frag_off;
125 unsigned long frag_len;
127 struct dtls1_retransmit_state saved_retransmit_state;
136 struct dtls1_timeout_st
138 /* Number of read timeouts so far */
139 unsigned int read_timeouts;
141 /* Number of write timeouts so far */
142 unsigned int write_timeouts;
144 /* Number of alerts received so far */
145 unsigned int num_alerts;
148 typedef struct record_pqueue_st
150 unsigned short epoch;
154 typedef struct hm_fragment_st
156 struct hm_header_st msg_header;
157 unsigned char *fragment;
160 typedef struct dtls1_state_st
162 unsigned int send_cookie;
163 unsigned char cookie[DTLS1_COOKIE_LENGTH];
164 unsigned char rcvd_cookie[DTLS1_COOKIE_LENGTH];
165 unsigned int cookie_len;
168 * The current data and handshake epoch. This is initially
169 * undefined, and starts at zero once the initial handshake is
172 unsigned short r_epoch;
173 unsigned short w_epoch;
175 /* records being received in the current epoch */
178 /* renegotiation starts a new set of sequence numbers */
179 DTLS1_BITMAP next_bitmap;
181 /* handshake message numbers */
182 unsigned short handshake_write_seq;
183 unsigned short next_handshake_write_seq;
185 unsigned short handshake_read_seq;
187 /* save last sequence number for retransmissions */
188 unsigned char last_write_sequence[8];
190 /* Received handshake records (processed and unprocessed) */
191 record_pqueue unprocessed_rcds;
192 record_pqueue processed_rcds;
194 /* Buffered handshake messages */
195 pqueue buffered_messages;
197 /* Buffered (sent) handshake records */
198 pqueue sent_messages;
200 /* Buffered application records.
201 * Only for records between CCS and Finished
202 * to prevent either protocol violation or
203 * unnecessary message loss.
205 record_pqueue buffered_app_data;
207 unsigned int mtu; /* max wire packet size */
209 struct hm_header_st w_msg_hdr;
210 struct hm_header_st r_msg_hdr;
212 struct dtls1_timeout_st timeout;
214 /* Indicates when the last handshake msg sent will timeout */
215 struct timeval next_timeout;
217 /* Timeout duration */
218 unsigned short timeout_duration;
220 /* storage for Alert/Handshake protocol data received but not
221 * yet processed by ssl3_read_bytes: */
222 unsigned char alert_fragment[DTLS1_AL_HEADER_LENGTH];
223 unsigned int alert_fragment_len;
224 unsigned char handshake_fragment[DTLS1_HM_HEADER_LENGTH];
225 unsigned int handshake_fragment_len;
227 unsigned int retransmitting;
231 typedef struct dtls1_record_data_st
233 unsigned char *packet;
234 unsigned int packet_length;
240 /* Timeout multipliers (timeout slice is defined in apps/timeouts.h */
241 #define DTLS1_TMO_READ_COUNT 2
242 #define DTLS1_TMO_WRITE_COUNT 2
244 #define DTLS1_TMO_ALERT_COUNT 12