.\" $OpenBSD: SSL_CTX_add_session.3,v 1.5 2018/03/27 17:35:50 schwarze Exp $ .\" OpenSSL SSL_CTX_add_session.pod 1722496f Jun 8 15:18:38 2017 -0400 .\" .\" This file was written by Lutz Jaenicke and .\" Geoff Thorpe . .\" Copyright (c) 2001, 2002, 2014 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_ADD_SESSION 3 .Os .Sh NAME .Nm SSL_CTX_add_session , .Nm SSL_CTX_remove_session .Nd manipulate session cache .Sh SYNOPSIS .In openssl/ssl.h .Ft int .Fn SSL_CTX_add_session "SSL_CTX *ctx" "SSL_SESSION *c" .Ft int .Fn SSL_CTX_remove_session "SSL_CTX *ctx" "SSL_SESSION *c" .Sh DESCRIPTION .Fn SSL_CTX_add_session adds the session .Fa c to the context .Fa ctx . The reference count for session .Fa c is incremented by 1. If a session with the same session id already exists, the old session is removed by calling .Xr SSL_SESSION_free 3 . .Pp .Fn SSL_CTX_remove_session removes the session .Fa c from the context .Fa ctx and marks it as non-resumable. .Xr SSL_SESSION_free 3 is called once for .Fa c . .Pp When adding a new session to the internal session cache, it is examined whether a session with the same session id already exists. In this case it is assumed that both sessions are identical. If the same session is stored in a different .Vt SSL_SESSION object, the old session is removed and replaced by the new session. If the session is actually identical (the .Vt SSL_SESSION object is identical), .Fn SSL_CTX_add_session is a no-op, and the return value is 0. .Pp If a server .Vt SSL_CTX is configured with the .Dv SSL_SESS_CACHE_NO_INTERNAL_STORE flag then the internal cache will not be populated automatically by new sessions negotiated by the SSL/TLS implementation, even though the internal cache will be searched automatically for session-resume requests (the latter can be suppressed by .Dv SSL_SESS_CACHE_NO_INTERNAL_LOOKUP ) . So the application can use .Fn SSL_CTX_add_session directly to have full control over the sessions that can be resumed if desired. .Sh RETURN VALUES The following values are returned by all functions: .Bl -tag -width Ds .It 0 The operation failed. In case of the add operation, it was tried to add the same (identical) session twice. In case of the remove operation, the session was not found in the cache. .It 1 The operation succeeded. .El .Sh SEE ALSO .Xr ssl 3 , .Xr SSL_CTX_set_session_cache_mode 3 , .Xr SSL_SESSION_free 3 .Sh HISTORY .Fn SSL_CTX_add_session and .Fn SSL_CTX_remove_session first appeared in SSLeay 0.8.0 and have been available since .Ox 2.4 .