.\"	$OpenBSD: SSL_session_reused.3,v 1.5 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_SESSION_REUSED 3
.Os
.Sh NAME
.Nm SSL_session_reused
.Nd query whether a reused session was negotiated during handshake
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft int
.Fn SSL_session_reused "SSL *ssl"
.Sh DESCRIPTION
Query whether a reused session was negotiated during the handshake.
.Pp
During the negotiation, a client can propose to reuse a session.
The server then looks up the session in its cache.
If both client and server agree on the session,
it will be reused and a flag is set that can be queried by the application.
.Sh RETURN VALUES
The following return values can occur:
.Bl -tag -width Ds
.It 0
A new session was negotiated.
.It 1
A session was reused.
.El
.Sh SEE ALSO
.Xr SSL_ctrl 3 ,
.Xr SSL_CTX_set_session_cache_mode 3 ,
.Xr SSL_set_session 3
.Sh HISTORY
.Fn SSL_session_reused
first appeared in SSLeay 0.8.0 and has been available since
.Ox 2.4 .