SSL_CTX_set_timeout, SSL_CTX_get_timeout - manipulate timeout values for session caching

       Copyright 2001-2022 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (the "License").  You may not use this file except in compliance
       with the License.  You can obtain a copy in the file LICENSE in the source distribution or at
       <https://www.openssl.org/source/license.html>.

3.5.0                                              2025-06-04                          SSL_CTX_SET_TIMEOUT(3SSL)

SSL_CTX_set_timeout() sets the timeout for newly created sessions for ctx to t. The timeout value t must
       be given in seconds.

       SSL_CTX_get_timeout() returns the currently set timeout value for ctx.

       SSL_CTX_set_timeout, SSL_CTX_get_timeout - manipulate timeout values for session caching

       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.

       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.

       The expiration time of a single session can be modified using the SSL_SESSION_get_time(3) family of
       functions.

       Expired sessions are removed from the internal session cache, whenever SSL_CTX_flush_sessions(3) is
       called, either directly by the application or automatically (see SSL_CTX_set_session_cache_mode(3))

       The default value for session timeout is decided on a per protocol basis, see SSL_get_default_timeout(3).
       All currently supported protocols have the same default timeout value of 300 seconds.

       This timeout value is used as the ticket lifetime hint for stateless session tickets. It is also used as
       the timeout value within the ticket itself.

       For TLSv1.3, RFC8446 limits transmission of this value to 1 week (604800 seconds).

       For TLSv1.2, tickets generated during an initial handshake use the value as specified. Tickets generated
       during a resumed handshake have a value of 0 for the ticket lifetime hint.

SSL_CTX_set_timeout() returns the previously set timeout value.

       SSL_CTX_get_timeout() returns the currently set timeout value.

ssl(7), SSL_CTX_set_session_cache_mode(3), SSL_SESSION_get_time(3), SSL_CTX_flush_sessions(3),
       SSL_get_default_timeout(3)

        #include <openssl/ssl.h>

        long SSL_CTX_set_timeout(SSL_CTX *ctx, long t);
        long SSL_CTX_get_timeout(SSL_CTX *ctx);