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      1 /*
      2  * Copyright (c) 2009-2012 Niels Provos and Nick Mathewson
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  * 1. Redistributions of source code must retain the above copyright
      8  *    notice, this list of conditions and the following disclaimer.
      9  * 2. Redistributions in binary form must reproduce the above copyright
     10  *    notice, this list of conditions and the following disclaimer in the
     11  *    documentation and/or other materials provided with the distribution.
     12  * 3. The name of the author may not be used to endorse or promote products
     13  *    derived from this software without specific prior written permission.
     14  *
     15  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     16  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     17  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     18  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     19  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
     20  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     21  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     22  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     23  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     24  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     25  */
     26 #ifndef EVENT2_BUFFEREVENT_SSL_H_INCLUDED_
     27 #define EVENT2_BUFFEREVENT_SSL_H_INCLUDED_
     28 
     29 /** @file event2/bufferevent_ssl.h
     30 
     31     OpenSSL support for bufferevents.
     32  */
     33 #include <event2/visibility.h>
     34 #include <event2/event-config.h>
     35 #include <event2/bufferevent.h>
     36 #include <event2/util.h>
     37 
     38 #ifdef __cplusplus
     39 extern "C" {
     40 #endif
     41 
     42 /* This is what openssl's SSL objects are underneath. */
     43 struct ssl_st;
     44 
     45 /**
     46    The state of an SSL object to be used when creating a new
     47    SSL bufferevent.
     48  */
     49 enum bufferevent_ssl_state {
     50 	BUFFEREVENT_SSL_OPEN = 0,
     51 	BUFFEREVENT_SSL_CONNECTING = 1,
     52 	BUFFEREVENT_SSL_ACCEPTING = 2
     53 };
     54 
     55 #if defined(EVENT__HAVE_OPENSSL) || defined(EVENT_IN_DOXYGEN_)
     56 /**
     57    Create a new SSL bufferevent to send its data over another bufferevent.
     58 
     59    @param base An event_base to use to detect reading and writing.  It
     60       must also be the base for the underlying bufferevent.
     61    @param underlying A socket to use for this SSL
     62    @param ssl A SSL* object from openssl.
     63    @param state The current state of the SSL connection
     64    @param options One or more bufferevent_options
     65    @return A new bufferevent on success, or NULL on failure
     66 */
     67 EVENT2_EXPORT_SYMBOL
     68 struct bufferevent *
     69 bufferevent_openssl_filter_new(struct event_base *base,
     70     struct bufferevent *underlying,
     71     struct ssl_st *ssl,
     72     enum bufferevent_ssl_state state,
     73     int options);
     74 
     75 /**
     76    Create a new SSL bufferevent to send its data over an SSL * on a socket.
     77 
     78    @param base An event_base to use to detect reading and writing
     79    @param fd A socket to use for this SSL
     80    @param ssl A SSL* object from openssl.
     81    @param state The current state of the SSL connection
     82    @param options One or more bufferevent_options
     83    @return A new bufferevent on success, or NULL on failure.
     84 */
     85 EVENT2_EXPORT_SYMBOL
     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 EVENT2_EXPORT_SYMBOL
    110 int bufferevent_openssl_get_allow_dirty_shutdown(struct bufferevent *bev);
    111 EVENT2_EXPORT_SYMBOL
    112 void bufferevent_openssl_set_allow_dirty_shutdown(struct bufferevent *bev,
    113     int allow_dirty_shutdown);
    114 
    115 /** Return the underlying openssl SSL * object for an SSL bufferevent. */
    116 EVENT2_EXPORT_SYMBOL
    117 struct ssl_st *
    118 bufferevent_openssl_get_ssl(struct bufferevent *bufev);
    119 
    120 /** Tells a bufferevent to begin SSL renegotiation. */
    121 EVENT2_EXPORT_SYMBOL
    122 int bufferevent_ssl_renegotiate(struct bufferevent *bev);
    123 
    124 /** Return the most recent OpenSSL error reported on an SSL bufferevent. */
    125 EVENT2_EXPORT_SYMBOL
    126 unsigned long bufferevent_get_openssl_error(struct bufferevent *bev);
    127 
    128 #endif
    129 
    130 #ifdef __cplusplus
    131 }
    132 #endif
    133 
    134 #endif /* EVENT2_BUFFEREVENT_SSL_H_INCLUDED_ */
    135