=pod

=head1 NAME

SSL_set_session - set a TLS/SSL session to be used during TLS/SSL connect

=head1 SYNOPSIS

 #include <openssl/ssl.h>

 int SSL_set_session(SSL *ssl, SSL_SESSION *session);

=head1 DESCRIPTION

SSL_set_session() sets B<session> to be used when the TLS/SSL connection
is to be established. SSL_set_session() is only useful for TLS/SSL clients.
When the session is set, the reference count of B<session> is incremented
by 1. If the session is not reused, the reference count is decremented
again during SSL_connect(). Whether the session was reused can be queried
with the L<SSL_session_reused(3)> call.

If there is already a session set inside B<ssl> (because it was set with
SSL_set_session() before or because the same B<ssl> was already used for
a connection), SSL_SESSION_free() will be called for that session.
This is also the case when B<session> is a NULL pointer. If that old
session is still B<open>, it is considered bad and will be removed from the
session cache (if used). A session is considered open, if L<SSL_shutdown(3)> was
not called for the connection (or at least L<SSL_set_shutdown(3)> was used to
set the SSL_SENT_SHUTDOWN state).

=head1 NOTES

SSL_SESSION objects keep internal link information about the session cache
list, when being inserted into one SSL_CTX object's session cache.
One SSL_SESSION object, regardless of its reference count, must therefore
only be used with one SSL_CTX object (and the SSL objects created
from this SSL_CTX object).

=head1 RETURN VALUES

The following return values can occur:

=over 4

=item Z<>0

The operation failed; check the error stack to find out the reason.

=item Z<>1

The operation succeeded.

=back

=head1 SEE ALSO

L<ssl(7)>, L<SSL_SESSION_free(3)>,
L<SSL_get_session(3)>,
L<SSL_session_reused(3)>,
L<SSL_CTX_set_session_cache_mode(3)>

=head1 COPYRIGHT

Copyright 2000-2022 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
L<https://www.openssl.org/source/license.html>.

=cut