168651Skris=pod
268651Skris
368651Skris=head1 NAME
468651Skris
568651SkrisSSL_SESSION_free - free an allocated SSL_SESSION structure
668651Skris
768651Skris=head1 SYNOPSIS
868651Skris
968651Skris #include <openssl/ssl.h>
1068651Skris
1168651Skris void SSL_SESSION_free(SSL_SESSION *session);
1268651Skris
1368651Skris=head1 DESCRIPTION
1468651Skris
1568651SkrisSSL_SESSION_free() decrements the reference count of B<session> and removes
1668651Skristhe B<SSL_SESSION> structure pointed to by B<session> and frees up the allocated
17194206Ssimonmemory, if the reference count has reached 0.
1868651Skris
1989837Skris=head1 NOTES
2089837Skris
2189837SkrisSSL_SESSION objects are allocated, when a TLS/SSL handshake operation
2289837Skrisis successfully completed. Depending on the settings, see
2389837SkrisL<SSL_CTX_set_session_cache_mode(3)|SSL_CTX_set_session_cache_mode(3)>,
2489837Skristhe SSL_SESSION objects are internally referenced by the SSL_CTX and
2589837Skrislinked into its session cache. SSL objects may be using the SSL_SESSION object;
2689837Skrisas a session may be reused, several SSL objects may be using one SSL_SESSION
2789837Skrisobject at the same time. It is therefore crucial to keep the reference
2889837Skriscount (usage information) correct and not delete a SSL_SESSION object
2989837Skristhat is still used, as this may lead to program failures due to
3089837Skrisdangling pointers. These failures may also appear delayed, e.g.
3189837Skriswhen an SSL_SESSION object was completely freed as the reference count
3289837Skrisincorrectly became 0, but it is still referenced in the internal
3389837Skrissession cache and the cache list is processed during a
3489837SkrisL<SSL_CTX_flush_sessions(3)|SSL_CTX_flush_sessions(3)> operation.
3589837Skris
3689837SkrisSSL_SESSION_free() must only be called for SSL_SESSION objects, for
3789837Skriswhich the reference count was explicitly incremented (e.g.
3889837Skrisby calling SSL_get1_session(), see L<SSL_get_session(3)|SSL_get_session(3)>)
3989837Skrisor when the SSL_SESSION object was generated outside a TLS handshake
4089837Skrisoperation, e.g. by using L<d2i_SSL_SESSION(3)|d2i_SSL_SESSION(3)>.
4189837SkrisIt must not be called on other SSL_SESSION objects, as this would cause
4289837Skrisincorrect reference counts and therefore program failures.
4389837Skris
4468651Skris=head1 RETURN VALUES
4568651Skris
4668651SkrisSSL_SESSION_free() does not provide diagnostic information.
4768651Skris
4889837Skris=head1 SEE ALSO
4968651Skris
5089837SkrisL<ssl(3)|ssl(3)>, L<SSL_get_session(3)|SSL_get_session(3)>,
5189837SkrisL<SSL_CTX_set_session_cache_mode(3)|SSL_CTX_set_session_cache_mode(3)>,
5289837SkrisL<SSL_CTX_flush_sessions(3)|SSL_CTX_flush_sessions(3)>,
5389837Skris L<d2i_SSL_SESSION(3)|d2i_SSL_SESSION(3)>
5489837Skris
5568651Skris=cut
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