xref: /netbsd-src/external/bsd/ntp/dist/sntp/libevent/include/event2/bufferevent_ssl.h (revision d11b170b9000ada93db553723522a63d5deac310)
1 /*	$NetBSD: bufferevent_ssl.h,v 1.1.1.1 2013/12/27 23:31:31 christos Exp $	*/
2 
3 /*
4  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. The name of the author may not be used to endorse or promote products
15  *    derived from this software without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 #ifndef EVENT2_BUFFEREVENT_SSL_H_INCLUDED_
29 #define EVENT2_BUFFEREVENT_SSL_H_INCLUDED_
30 
31 /** @file event2/bufferevent_ssl.h
32 
33     OpenSSL support for bufferevents.
34  */
35 
36 #include <event2/event-config.h>
37 #include <event2/bufferevent.h>
38 #include <event2/util.h>
39 
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
43 
44 /* This is what openssl's SSL objects are underneath. */
45 struct ssl_st;
46 
47 /**
48    The state of an SSL object to be used when creating a new
49    SSL bufferevent.
50  */
51 enum bufferevent_ssl_state {
52 	BUFFEREVENT_SSL_OPEN = 0,
53 	BUFFEREVENT_SSL_CONNECTING = 1,
54 	BUFFEREVENT_SSL_ACCEPTING = 2
55 };
56 
57 #if defined(EVENT__HAVE_OPENSSL) || defined(EVENT_IN_DOXYGEN_)
58 /**
59    Create a new SSL bufferevent to send its data over another bufferevent.
60 
61    @param base An event_base to use to detect reading and writing.  It
62       must also be the base for the underlying bufferevent.
63    @param underlying A socket to use for this SSL
64    @param ssl A SSL* object from openssl.
65    @param state The current state of the SSL connection
66    @param options One or more bufferevent_options
67    @return A new bufferevent on success, or NULL on failure
68 */
69 struct bufferevent *
70 bufferevent_openssl_filter_new(struct event_base *base,
71     struct bufferevent *underlying,
72     struct ssl_st *ssl,
73     enum bufferevent_ssl_state state,
74     int options);
75 
76 /**
77    Create a new SSL bufferevent to send its data over an SSL * on a socket.
78 
79    @param base An event_base to use to detect reading and writing
80    @param fd A socket to use for this SSL
81    @param ssl A SSL* object from openssl.
82    @param state The current state of the SSL connection
83    @param options One or more bufferevent_options
84    @return A new bufferevent on success, or NULL on failure.
85 */
86 struct bufferevent *
87 bufferevent_openssl_socket_new(struct event_base *base,
88     evutil_socket_t fd,
89     struct ssl_st *ssl,
90     enum bufferevent_ssl_state state,
91     int options);
92 
93 /** Control how to report dirty SSL shutdowns.
94 
95     If the peer (or the network, or an attacker) closes the TCP
96     connection before closing the SSL channel, and the protocol is SSL >= v3,
97     this is a "dirty" shutdown.  If allow_dirty_shutdown is 0 (default),
98     this is reported as BEV_EVENT_ERROR.
99 
100     If instead allow_dirty_shutdown=1, a dirty shutdown is reported as
101     BEV_EVENT_EOF.
102 
103     (Note that if the protocol is < SSLv3, you will always receive
104     BEV_EVENT_EOF, since SSL 2 and earlier cannot distinguish a secure
105     connection close from a dirty one.  This is one reason (among many)
106     not to use SSL 2.)
107 */
108 
109 int bufferevent_openssl_get_allow_dirty_shutdown(struct bufferevent *bev);
110 void bufferevent_openssl_set_allow_dirty_shutdown(struct bufferevent *bev,
111     int allow_dirty_shutdown);
112 
113 /** Return the underlying openssl SSL * object for an SSL bufferevent. */
114 struct ssl_st *
115 bufferevent_openssl_get_ssl(struct bufferevent *bufev);
116 
117 /** Tells a bufferevent to begin SSL renegotiation. */
118 int bufferevent_ssl_renegotiate(struct bufferevent *bev);
119 
120 /** Return the most recent OpenSSL error reported on an SSL bufferevent. */
121 unsigned long bufferevent_get_openssl_error(struct bufferevent *bev);
122 
123 #endif
124 
125 #ifdef __cplusplus
126 }
127 #endif
128 
129 #endif /* EVENT2_BUFFEREVENT_SSL_H_INCLUDED_ */
130