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
100 unsigned long length; /* sizeof the bitmap in bits */
101 PQ_64BIT max_seq_num; /* max record number seen so far */
104 struct dtls1_retransmit_state
106 EVP_CIPHER_CTX *enc_write_ctx; /* cryptographic state */
107 const EVP_MD *write_hash; /* used for mac generation */
108 #ifndef OPENSSL_NO_COMP
109 COMP_CTX *compress; /* compression */
113 SSL_SESSION *session;
114 unsigned short epoch;
120 unsigned long msg_len;
122 unsigned long frag_off;
123 unsigned long frag_len;
125 struct dtls1_retransmit_state saved_retransmit_state;
134 struct dtls1_timeout_st
136 /* Number of read timeouts so far */
137 unsigned int read_timeouts;
139 /* Number of write timeouts so far */
140 unsigned int write_timeouts;
142 /* Number of alerts received so far */
143 unsigned int num_alerts;
146 typedef struct record_pqueue_st
148 unsigned short epoch;
152 typedef struct hm_fragment_st
154 struct hm_header_st msg_header;
155 unsigned char *fragment;
158 typedef struct dtls1_state_st
160 unsigned int send_cookie;
161 unsigned char cookie[DTLS1_COOKIE_LENGTH];
162 unsigned char rcvd_cookie[DTLS1_COOKIE_LENGTH];
163 unsigned int cookie_len;
166 * The current data and handshake epoch. This is initially
167 * undefined, and starts at zero once the initial handshake is
170 unsigned short r_epoch;
171 unsigned short w_epoch;
173 /* records being received in the current epoch */
176 /* renegotiation starts a new set of sequence numbers */
177 DTLS1_BITMAP next_bitmap;
179 /* handshake message numbers */
180 unsigned short handshake_write_seq;
181 unsigned short next_handshake_write_seq;
183 unsigned short handshake_read_seq;
185 /* save last sequence number for retransmissions */
186 unsigned char last_write_sequence[8];
188 /* Received handshake records (processed and unprocessed) */
189 record_pqueue unprocessed_rcds;
190 record_pqueue processed_rcds;
192 /* Buffered handshake messages */
193 pqueue buffered_messages;
195 /* Buffered (sent) handshake records */
196 pqueue sent_messages;
198 /* Buffered application records.
199 * Only for records between CCS and Finished
200 * to prevent either protocol violation or
201 * unnecessary message loss.
203 record_pqueue buffered_app_data;
205 unsigned int mtu; /* max DTLS packet size */
207 struct hm_header_st w_msg_hdr;
208 struct hm_header_st r_msg_hdr;
210 struct dtls1_timeout_st timeout;
212 /* Indicates when the last handshake msg sent will timeout */
213 struct timeval next_timeout;
215 /* Timeout duration */
216 unsigned short timeout_duration;
218 /* storage for Alert/Handshake protocol data received but not
219 * yet processed by ssl3_read_bytes: */
220 unsigned char alert_fragment[DTLS1_AL_HEADER_LENGTH];
221 unsigned int alert_fragment_len;
222 unsigned char handshake_fragment[DTLS1_HM_HEADER_LENGTH];
223 unsigned int handshake_fragment_len;
225 unsigned int retransmitting;
229 typedef struct dtls1_record_data_st
231 unsigned char *packet;
232 unsigned int packet_length;
238 /* Timeout multipliers (timeout slice is defined in apps/timeouts.h */
239 #define DTLS1_TMO_READ_COUNT 2
240 #define DTLS1_TMO_WRITE_COUNT 2
242 #define DTLS1_TMO_ALERT_COUNT 12