xref: /openbsd-src/lib/libssl/dtls1.h (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /* $OpenBSD: dtls1.h,v 1.14 2014/07/10 08:51:14 tedu 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 <openssl/buffer.h>
64 #include <stdio.h>
65 #include <stdlib.h>
66 #include <string.h>
67 #include <sys/time.h>
68 
69 #ifdef  __cplusplus
70 extern "C" {
71 #endif
72 
73 #define DTLS1_VERSION			0xFEFF
74 #define DTLS1_BAD_VER			0x0100
75 
76 /* lengths of messages */
77 #define DTLS1_COOKIE_LENGTH                     256
78 
79 #define DTLS1_RT_HEADER_LENGTH                  13
80 
81 #define DTLS1_HM_HEADER_LENGTH                  12
82 
83 #define DTLS1_HM_BAD_FRAGMENT                   -2
84 #define DTLS1_HM_FRAGMENT_RETRY                 -3
85 
86 #define DTLS1_CCS_HEADER_LENGTH                  1
87 
88 #ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
89 #define DTLS1_AL_HEADER_LENGTH                   7
90 #else
91 #define DTLS1_AL_HEADER_LENGTH                   2
92 #endif
93 
94 #ifndef OPENSSL_NO_SSL_INTERN
95 
96 #ifndef OPENSSL_NO_SCTP
97 #define DTLS1_SCTP_AUTH_LABEL	"EXPORTER_DTLS_OVER_SCTP"
98 #endif
99 
100 typedef struct dtls1_bitmap_st {
101 	unsigned long map;		/* track 32 packets on 32-bit systems
102 					   and 64 - on 64-bit systems */
103 	unsigned char max_seq_num[8];	/* max record number seen so far,
104 					   64-bit value in big-endian
105 					   encoding */
106 } DTLS1_BITMAP;
107 
108 struct dtls1_retransmit_state {
109 	EVP_CIPHER_CTX *enc_write_ctx;	/* cryptographic state */
110 	EVP_MD_CTX *write_hash;		/* used for mac generation */
111 	SSL_SESSION *session;
112 	unsigned short epoch;
113 };
114 
115 struct hm_header_st {
116 	unsigned char type;
117 	unsigned long msg_len;
118 	unsigned short seq;
119 	unsigned long frag_off;
120 	unsigned long frag_len;
121 	unsigned int is_ccs;
122 	struct dtls1_retransmit_state saved_retransmit_state;
123 };
124 
125 struct ccs_header_st {
126 	unsigned char type;
127 	unsigned short seq;
128 };
129 
130 struct dtls1_timeout_st {
131 	/* Number of read timeouts so far */
132 	unsigned int read_timeouts;
133 
134 	/* Number of write timeouts so far */
135 	unsigned int write_timeouts;
136 
137 	/* Number of alerts received so far */
138 	unsigned int num_alerts;
139 };
140 
141 struct _pqueue;
142 
143 typedef struct record_pqueue_st {
144 	unsigned short epoch;
145 	struct _pqueue *q;
146 } record_pqueue;
147 
148 typedef struct hm_fragment_st {
149 	struct hm_header_st msg_header;
150 	unsigned char *fragment;
151 	unsigned char *reassembly;
152 } hm_fragment;
153 
154 typedef struct dtls1_state_st {
155 	unsigned int send_cookie;
156 	unsigned char cookie[DTLS1_COOKIE_LENGTH];
157 	unsigned char rcvd_cookie[DTLS1_COOKIE_LENGTH];
158 	unsigned int cookie_len;
159 
160 	/*
161 	 * The current data and handshake epoch.  This is initially
162 	 * undefined, and starts at zero once the initial handshake is
163 	 * completed
164 	 */
165 	unsigned short r_epoch;
166 	unsigned short w_epoch;
167 
168 	/* records being received in the current epoch */
169 	DTLS1_BITMAP bitmap;
170 
171 	/* renegotiation starts a new set of sequence numbers */
172 	DTLS1_BITMAP next_bitmap;
173 
174 	/* handshake message numbers */
175 	unsigned short handshake_write_seq;
176 	unsigned short next_handshake_write_seq;
177 
178 	unsigned short handshake_read_seq;
179 
180 	/* save last sequence number for retransmissions */
181 	unsigned char last_write_sequence[8];
182 
183 	/* Received handshake records (processed and unprocessed) */
184 	record_pqueue unprocessed_rcds;
185 	record_pqueue processed_rcds;
186 
187 	/* Buffered handshake messages */
188 	struct _pqueue *buffered_messages;
189 
190 	/* Buffered (sent) handshake records */
191 	struct _pqueue *sent_messages;
192 
193 	/* Buffered application records.
194 	 * Only for records between CCS and Finished
195 	 * to prevent either protocol violation or
196 	 * unnecessary message loss.
197 	 */
198 	record_pqueue buffered_app_data;
199 
200 	/* Is set when listening for new connections with dtls1_listen() */
201 	unsigned int listen;
202 
203 	unsigned int mtu; /* max DTLS packet size */
204 
205 	struct hm_header_st w_msg_hdr;
206 	struct hm_header_st r_msg_hdr;
207 
208 	struct dtls1_timeout_st timeout;
209 
210 	/* Indicates when the last handshake msg or heartbeat sent will timeout */
211 	struct timeval next_timeout;
212 
213 	/* Timeout duration */
214 	unsigned short timeout_duration;
215 
216 	/* storage for Alert/Handshake protocol data received but not
217 	 * yet processed by ssl3_read_bytes: */
218 	unsigned char alert_fragment[DTLS1_AL_HEADER_LENGTH];
219 	unsigned int alert_fragment_len;
220 	unsigned char handshake_fragment[DTLS1_HM_HEADER_LENGTH];
221 	unsigned int handshake_fragment_len;
222 
223 	unsigned int retransmitting;
224 	unsigned int change_cipher_spec_ok;
225 
226 #ifndef OPENSSL_NO_SCTP
227 	/* used when SSL_ST_XX_FLUSH is entered */
228 	int next_state;
229 
230 	int shutdown_received;
231 #endif
232 
233 } DTLS1_STATE;
234 
235 typedef struct dtls1_record_data_st {
236 	unsigned char *packet;
237 	unsigned int   packet_length;
238 	SSL3_BUFFER    rbuf;
239 	SSL3_RECORD    rrec;
240 #ifndef OPENSSL_NO_SCTP
241 	struct bio_dgram_sctp_rcvinfo recordinfo;
242 #endif
243 } DTLS1_RECORD_DATA;
244 
245 #endif
246 
247 /* Timeout multipliers (timeout slice is defined in apps/timeouts.h */
248 #define DTLS1_TMO_READ_COUNT                      2
249 #define DTLS1_TMO_WRITE_COUNT                     2
250 
251 #define DTLS1_TMO_ALERT_COUNT                     12
252 
253 #ifdef  __cplusplus
254 }
255 #endif
256 #endif
257