dtls1.h revision 280304 
1/* ssl/dtls1.h */
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 <openssl/pqueue.h>
65# ifdef OPENSSL_SYS_VMS
66#  include <resource.h>
67#  include <sys/timeb.h>
68# endif
69# ifdef OPENSSL_SYS_WIN32
70/* Needed for struct timeval */
71#  include <winsock.h>
72# elif defined(OPENSSL_SYS_NETWARE) && !defined(_WINSOCK2API_)
73#  include <sys/timeval.h>
74# else
75#  if defined(OPENSSL_SYS_VXWORKS)
76#   include <sys/times.h>
77#  else
78#   include <sys/time.h>
79#  endif
80# endif
81
82#ifdef  __cplusplus
83extern "C" {
84#endif
85
86# define DTLS1_VERSION                   0xFEFF
87# define DTLS_MAX_VERSION                DTLS1_VERSION
88# define DTLS1_VERSION_MAJOR             0xFE
89
90# define DTLS1_BAD_VER                   0x0100
91
92# if 0
93/* this alert description is not specified anywhere... */
94#  define DTLS1_AD_MISSING_HANDSHAKE_MESSAGE    110
95# endif
96
97/* lengths of messages */
98# define DTLS1_COOKIE_LENGTH                     256
99
100# define DTLS1_RT_HEADER_LENGTH                  13
101
102# define DTLS1_HM_HEADER_LENGTH                  12
103
104# define DTLS1_HM_BAD_FRAGMENT                   -2
105# define DTLS1_HM_FRAGMENT_RETRY                 -3
106
107# define DTLS1_CCS_HEADER_LENGTH                  1
108
109# ifdef DTLS1_AD_MISSING_HANDSHAKE_MESSAGE
110#  define DTLS1_AL_HEADER_LENGTH                   7
111# else
112#  define DTLS1_AL_HEADER_LENGTH                   2
113# endif
114
115# ifndef OPENSSL_NO_SSL_INTERN
116
117#  ifndef OPENSSL_NO_SCTP
118#   define DTLS1_SCTP_AUTH_LABEL   "EXPORTER_DTLS_OVER_SCTP"
119#  endif
120
121/* Max MTU overhead we know about so far is 40 for IPv6 + 8 for UDP */
122#  define DTLS1_MAX_MTU_OVERHEAD                   48
123
124typedef struct dtls1_bitmap_st {
125    unsigned long map;          /* track 32 packets on 32-bit systems and 64
126                                 * - on 64-bit systems */
127    unsigned char max_seq_num[8]; /* max record number seen so far, 64-bit
128                                   * value in big-endian encoding */
129} DTLS1_BITMAP;
130
131struct dtls1_retransmit_state {
132    EVP_CIPHER_CTX *enc_write_ctx; /* cryptographic state */
133    EVP_MD_CTX *write_hash;     /* used for mac generation */
134#  ifndef OPENSSL_NO_COMP
135    COMP_CTX *compress;         /* compression */
136#  else
137    char *compress;
138#  endif
139    SSL_SESSION *session;
140    unsigned short epoch;
141};
142
143struct hm_header_st {
144    unsigned char type;
145    unsigned long msg_len;
146    unsigned short seq;
147    unsigned long frag_off;
148    unsigned long frag_len;
149    unsigned int is_ccs;
150    struct dtls1_retransmit_state saved_retransmit_state;
151};
152
153struct ccs_header_st {
154    unsigned char type;
155    unsigned short seq;
156};
157
158struct dtls1_timeout_st {
159    /* Number of read timeouts so far */
160    unsigned int read_timeouts;
161    /* Number of write timeouts so far */
162    unsigned int write_timeouts;
163    /* Number of alerts received so far */
164    unsigned int num_alerts;
165};
166
167typedef struct record_pqueue_st {
168    unsigned short epoch;
169    pqueue q;
170} record_pqueue;
171
172typedef struct hm_fragment_st {
173    struct hm_header_st msg_header;
174    unsigned char *fragment;
175    unsigned char *reassembly;
176} hm_fragment;
177
178typedef struct dtls1_state_st {
179    unsigned int send_cookie;
180    unsigned char cookie[DTLS1_COOKIE_LENGTH];
181    unsigned char rcvd_cookie[DTLS1_COOKIE_LENGTH];
182    unsigned int cookie_len;
183    /*
184     * The current data and handshake epoch.  This is initially
185     * undefined, and starts at zero once the initial handshake is
186     * completed
187     */
188    unsigned short r_epoch;
189    unsigned short w_epoch;
190    /* records being received in the current epoch */
191    DTLS1_BITMAP bitmap;
192    /* renegotiation starts a new set of sequence numbers */
193    DTLS1_BITMAP next_bitmap;
194    /* handshake message numbers */
195    unsigned short handshake_write_seq;
196    unsigned short next_handshake_write_seq;
197    unsigned short handshake_read_seq;
198    /* save last sequence number for retransmissions */
199    unsigned char last_write_sequence[8];
200    /* Received handshake records (processed and unprocessed) */
201    record_pqueue unprocessed_rcds;
202    record_pqueue processed_rcds;
203    /* Buffered handshake messages */
204    pqueue buffered_messages;
205    /* Buffered (sent) handshake records */
206    pqueue sent_messages;
207    /*
208     * Buffered application records. Only for records between CCS and
209     * Finished to prevent either protocol violation or unnecessary message
210     * loss.
211     */
212    record_pqueue buffered_app_data;
213    /* Is set when listening for new connections with dtls1_listen() */
214    unsigned int listen;
215    unsigned int link_mtu;      /* max on-the-wire DTLS packet size */
216    unsigned int mtu;           /* max DTLS packet size */
217    struct hm_header_st w_msg_hdr;
218    struct hm_header_st r_msg_hdr;
219    struct dtls1_timeout_st timeout;
220    /*
221     * Indicates when the last handshake msg or heartbeat sent will timeout
222     */
223    struct timeval next_timeout;
224    /* Timeout duration */
225    unsigned short timeout_duration;
226    /*
227     * storage for Alert/Handshake protocol data received but not yet
228     * processed by ssl3_read_bytes:
229     */
230    unsigned char alert_fragment[DTLS1_AL_HEADER_LENGTH];
231    unsigned int alert_fragment_len;
232    unsigned char handshake_fragment[DTLS1_HM_HEADER_LENGTH];
233    unsigned int handshake_fragment_len;
234    unsigned int retransmitting;
235    /*
236     * Set when the handshake is ready to process peer's ChangeCipherSpec message.
237     * Cleared after the message has been processed.
238     */
239    unsigned int change_cipher_spec_ok;
240#  ifndef OPENSSL_NO_SCTP
241    /* used when SSL_ST_XX_FLUSH is entered */
242    int next_state;
243    int shutdown_received;
244#  endif
245} DTLS1_STATE;
246
247typedef struct dtls1_record_data_st {
248    unsigned char *packet;
249    unsigned int packet_length;
250    SSL3_BUFFER rbuf;
251    SSL3_RECORD rrec;
252#  ifndef OPENSSL_NO_SCTP
253    struct bio_dgram_sctp_rcvinfo recordinfo;
254#  endif
255} DTLS1_RECORD_DATA;
256
257# endif
258
259/* Timeout multipliers (timeout slice is defined in apps/timeouts.h */
260# define DTLS1_TMO_READ_COUNT                      2
261# define DTLS1_TMO_WRITE_COUNT                     2
262
263# define DTLS1_TMO_ALERT_COUNT                     12
264
265#ifdef  __cplusplus
266}
267#endif
268#endif
269