xref: /openbsd-src/lib/libssl/dtls1.h (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /* $OpenBSD: dtls1.h,v 1.18 2015/09/10 17:57:50 jsing Exp $ */
2 /*
3  * DTLS implementation written by Nagendra Modadugu
4  * (nagendra@cs.stanford.edu) for the OpenSSL project 2005.
5  */
6 /* ====================================================================
7  * Copyright (c) 1999-2005 The OpenSSL Project.  All rights reserved.
8  *
9  * Redistribution and use in source and binary forms, with or without
10  * modification, are permitted provided that the following conditions
11  * are met:
12  *
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  *
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
19  *    distribution.
20  *
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/)"
25  *
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.
30  *
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.
34  *
35  * 6. Redistributions of any form whatsoever must retain the following
36  *    acknowledgment:
37  *    "This product includes software developed by the OpenSSL Project
38  *    for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)"
39  *
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  * ====================================================================
53  *
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).
57  *
58  */
59 
60 #ifndef HEADER_DTLS1_H
61 #define HEADER_DTLS1_H
62 
63 #include <sys/time.h>
64 
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 
69 #include <openssl/buffer.h>
70 
71 #ifdef  __cplusplus
72 extern "C" {
73 #endif
74 
75 #define DTLS1_VERSION			0xFEFF
76 
77 /* lengths of messages */
78 #define DTLS1_COOKIE_LENGTH                     256
79 
80 #define DTLS1_RT_HEADER_LENGTH                  13
81 
82 #define DTLS1_HM_HEADER_LENGTH                  12
83 
84 #define DTLS1_HM_BAD_FRAGMENT                   -2
85 #define DTLS1_HM_FRAGMENT_RETRY                 -3
86 
87 #define DTLS1_CCS_HEADER_LENGTH                  1
88 
89 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
90 #define DTLS1_AL_HEADER_LENGTH                   7
91 #else
92 #define DTLS1_AL_HEADER_LENGTH                   2
93 #endif
94 
95 #ifndef OPENSSL_NO_SSL_INTERN
96 
97 
98 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
103 					   encoding */
104 } DTLS1_BITMAP;
105 
106 struct dtls1_retransmit_state {
107 	EVP_CIPHER_CTX *enc_write_ctx;	/* cryptographic state */
108 	EVP_MD_CTX *write_hash;		/* used for mac generation */
109 	SSL_SESSION *session;
110 	unsigned short epoch;
111 };
112 
113 struct hm_header_st {
114 	unsigned char type;
115 	unsigned long msg_len;
116 	unsigned short seq;
117 	unsigned long frag_off;
118 	unsigned long frag_len;
119 	unsigned int is_ccs;
120 	struct dtls1_retransmit_state saved_retransmit_state;
121 };
122 
123 struct ccs_header_st {
124 	unsigned char type;
125 	unsigned short seq;
126 };
127 
128 struct dtls1_timeout_st {
129 	/* Number of read timeouts so far */
130 	unsigned int read_timeouts;
131 
132 	/* Number of write timeouts so far */
133 	unsigned int write_timeouts;
134 
135 	/* Number of alerts received so far */
136 	unsigned int num_alerts;
137 };
138 
139 struct _pqueue;
140 
141 typedef struct record_pqueue_st {
142 	unsigned short epoch;
143 	struct _pqueue *q;
144 } record_pqueue;
145 
146 typedef struct hm_fragment_st {
147 	struct hm_header_st msg_header;
148 	unsigned char *fragment;
149 	unsigned char *reassembly;
150 } hm_fragment;
151 
152 typedef struct dtls1_state_st {
153 	unsigned int send_cookie;
154 	unsigned char cookie[DTLS1_COOKIE_LENGTH];
155 	unsigned char rcvd_cookie[DTLS1_COOKIE_LENGTH];
156 	unsigned int cookie_len;
157 
158 	/*
159 	 * The current data and handshake epoch.  This is initially
160 	 * undefined, and starts at zero once the initial handshake is
161 	 * completed
162 	 */
163 	unsigned short r_epoch;
164 	unsigned short w_epoch;
165 
166 	/* records being received in the current epoch */
167 	DTLS1_BITMAP bitmap;
168 
169 	/* renegotiation starts a new set of sequence numbers */
170 	DTLS1_BITMAP next_bitmap;
171 
172 	/* handshake message numbers */
173 	unsigned short handshake_write_seq;
174 	unsigned short next_handshake_write_seq;
175 
176 	unsigned short handshake_read_seq;
177 
178 	/* save last sequence number for retransmissions */
179 	unsigned char last_write_sequence[8];
180 
181 	/* Received handshake records (processed and unprocessed) */
182 	record_pqueue unprocessed_rcds;
183 	record_pqueue processed_rcds;
184 
185 	/* Buffered handshake messages */
186 	struct _pqueue *buffered_messages;
187 
188 	/* Buffered (sent) handshake records */
189 	struct _pqueue *sent_messages;
190 
191 	/* Buffered application records.
192 	 * Only for records between CCS and Finished
193 	 * to prevent either protocol violation or
194 	 * unnecessary message loss.
195 	 */
196 	record_pqueue buffered_app_data;
197 
198 	/* Is set when listening for new connections with dtls1_listen() */
199 	unsigned int listen;
200 
201 	unsigned int mtu; /* max DTLS packet size */
202 
203 	struct hm_header_st w_msg_hdr;
204 	struct hm_header_st r_msg_hdr;
205 
206 	struct dtls1_timeout_st timeout;
207 
208 	/* Indicates when the last handshake msg or heartbeat sent will timeout */
209 	struct timeval next_timeout;
210 
211 	/* Timeout duration */
212 	unsigned short timeout_duration;
213 
214 	/* storage for Alert/Handshake protocol data received but not
215 	 * yet processed by ssl3_read_bytes: */
216 	unsigned char alert_fragment[DTLS1_AL_HEADER_LENGTH];
217 	unsigned int alert_fragment_len;
218 	unsigned char handshake_fragment[DTLS1_HM_HEADER_LENGTH];
219 	unsigned int handshake_fragment_len;
220 
221 	unsigned int retransmitting;
222 	unsigned int change_cipher_spec_ok;
223 
224 
225 } DTLS1_STATE;
226 
227 typedef struct dtls1_record_data_st {
228 	unsigned char *packet;
229 	unsigned int   packet_length;
230 	SSL3_BUFFER    rbuf;
231 	SSL3_RECORD    rrec;
232 } DTLS1_RECORD_DATA;
233 
234 #endif
235 
236 /* Timeout multipliers (timeout slice is defined in apps/timeouts.h */
237 #define DTLS1_TMO_READ_COUNT                      2
238 #define DTLS1_TMO_WRITE_COUNT                     2
239 
240 #define DTLS1_TMO_ALERT_COUNT                     12
241 
242 #ifdef  __cplusplus
243 }
244 #endif
245 #endif
246