.\"	$OpenBSD: SSL_CTX_set_timeout.3,v 1.4 2018/03/27 17:35:50 schwarze Exp $
.\"	OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100
.\"
.\" This file was written by Lutz Jaenicke <jaenicke@openssl.org>.
.\" Copyright (c) 2001 The OpenSSL Project.  All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\"
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\"
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in
.\"    the documentation and/or other materials provided with the
.\"    distribution.
.\"
.\" 3. All advertising materials mentioning features or use of this
.\"    software must display the following acknowledgment:
.\"    "This product includes software developed by the OpenSSL Project
.\"    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
.\"
.\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
.\"    endorse or promote products derived from this software without
.\"    prior written permission. For written permission, please contact
.\"    openssl-core@openssl.org.
.\"
.\" 5. Products derived from this software may not be called "OpenSSL"
.\"    nor may "OpenSSL" appear in their names without prior written
.\"    permission of the OpenSSL Project.
.\"
.\" 6. Redistributions of any form whatsoever must retain the following
.\"    acknowledgment:
.\"    "This product includes software developed by the OpenSSL Project
.\"    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
.\"
.\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
.\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
.\" PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
.\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
.\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
.\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
.\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
.\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
.\" OF THE POSSIBILITY OF SUCH DAMAGE.
.\"
.Dd $Mdocdate: March 27 2018 $
.Dt SSL_CTX_SET_TIMEOUT 3
.Os
.Sh NAME
.Nm SSL_CTX_set_timeout ,
.Nm SSL_CTX_get_timeout
.Nd manipulate timeout values for session caching
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft long
.Fn SSL_CTX_set_timeout "SSL_CTX *ctx" "long t"
.Ft long
.Fn SSL_CTX_get_timeout "SSL_CTX *ctx"
.Sh DESCRIPTION
.Fn SSL_CTX_set_timeout
sets the timeout for newly created sessions for
.Fa ctx
to
.Fa t .
The timeout value
.Fa t
must be given in seconds.
.Pp
.Fn SSL_CTX_get_timeout
returns the currently set timeout value for
.Fa ctx .
.Pp
Whenever a new session is created, it is assigned a maximum lifetime.
This lifetime is specified by storing the creation time of the session and the
timeout value valid at this time.
If the actual time is later than creation time plus timeout,
the session is not reused.
.Pp
Due to this realization, all sessions behave according to the timeout value
valid at the time of the session negotiation.
Changes of the timeout value do not affect already established sessions.
.Pp
The expiration time of a single session can be modified using the
.Xr SSL_SESSION_get_time 3
family of functions.
.Pp
Expired sessions are removed from the internal session cache, whenever
.Xr SSL_CTX_flush_sessions 3
is called, either directly by the application or automatically (see
.Xr SSL_CTX_set_session_cache_mode 3 ) .
.Pp
The default value for session timeout is decided on a per-protocol basis; see
.Xr SSL_get_default_timeout 3 .
All currently supported protocols have the same default timeout value of 300
seconds.
.Sh RETURN VALUES
.Fn SSL_CTX_set_timeout
returns the previously set timeout value.
.Pp
.Fn SSL_CTX_get_timeout
returns the currently set timeout value.
.Sh SEE ALSO
.Xr ssl 3 ,
.Xr SSL_CTX_flush_sessions 3 ,
.Xr SSL_CTX_set_session_cache_mode 3 ,
.Xr SSL_get_default_timeout 3 ,
.Xr SSL_SESSION_get_time 3
.Sh HISTORY
.Fn SSL_CTX_set_timeout
and
.Fn SSL_CTX_get_timeout
first appeared in SSLeay 0.6.1 and have been available since
.Ox 2.4 .