=pod =head1 NAME SSL_SESSION_free - free an allocated SSL_SESSION structure =head1 SYNOPSIS #include <openssl/ssl.h> void SSL_SESSION_free(SSL_SESSION *session); =head1 DESCRIPTION SSL_SESSION_free() decrements the reference count of B<session> and removes the B<SSL_SESSION> structure pointed to by B<session> and frees up the allocated memory, if the reference count has reached 0. =head1 NOTES SSL_SESSION objects are allocated, when a TLS/SSL handshake operation is successfully completed. Depending on the settings, see L<SSL_CTX_set_session_cache_mode(3)|SSL_CTX_set_session_cache_mode(3)>, the SSL_SESSION objects are internally referenced by the SSL_CTX and linked into its session cache. SSL objects may be using the SSL_SESSION object; as a session may be reused, several SSL objects may be using one SSL_SESSION object at the same time. It is therefore crucial to keep the reference count (usage information) correct and not delete a SSL_SESSION object that is still used, as this may lead to program failures due to dangling pointers. These failures may also appear delayed, e.g. when an SSL_SESSION object was completely freed as the reference count incorrectly became 0, but it is still referenced in the internal session cache and the cache list is processed during a L<SSL_CTX_flush_sessions(3)|SSL_CTX_flush_sessions(3)> operation. SSL_SESSION_free() must only be called for SSL_SESSION objects, for which the reference count was explicitly incremented (e.g. by calling SSL_get1_session(), see L<SSL_get_session(3)|SSL_get_session(3)>) or when the SSL_SESSION object was generated outside a TLS handshake operation, e.g. by using L<d2i_SSL_SESSION(3)|d2i_SSL_SESSION(3)>. It must not be called on other SSL_SESSION objects, as this would cause incorrect reference counts and therefore program failures. =head1 RETURN VALUES SSL_SESSION_free() does not provide diagnostic information. =head1 SEE ALSO L<ssl(3)|ssl(3)>, L<SSL_get_session(3)|SSL_get_session(3)>, L<SSL_CTX_set_session_cache_mode(3)|SSL_CTX_set_session_cache_mode(3)>, L<SSL_CTX_flush_sessions(3)|SSL_CTX_flush_sessions(3)>, L<d2i_SSL_SESSION(3)|d2i_SSL_SESSION(3)> =cut