5 SSL_SESSION_free - free an allocated SSL_SESSION structure
9 #include <openssl/ssl.h>
11 void SSL_SESSION_free(SSL_SESSION *session);
15 SSL_SESSION_free() decrements the reference count of B<session> and removes
16 the B<SSL_SESSION> structure pointed to by B<session> and frees up the allocated
17 memory, if the reference count has reached 0.
18 If B<session> is NULL nothing is done.
22 SSL_SESSION objects are allocated, when a TLS/SSL handshake operation
23 is successfully completed. Depending on the settings, see
24 L<SSL_CTX_set_session_cache_mode(3)>,
25 the SSL_SESSION objects are internally referenced by the SSL_CTX and
26 linked into its session cache. SSL objects may be using the SSL_SESSION object;
27 as a session may be reused, several SSL objects may be using one SSL_SESSION
28 object at the same time. It is therefore crucial to keep the reference
29 count (usage information) correct and not delete a SSL_SESSION object
30 that is still used, as this may lead to program failures due to
31 dangling pointers. These failures may also appear delayed, e.g.
32 when an SSL_SESSION object was completely freed as the reference count
33 incorrectly became 0, but it is still referenced in the internal
34 session cache and the cache list is processed during a
35 L<SSL_CTX_flush_sessions(3)> operation.
37 SSL_SESSION_free() must only be called for SSL_SESSION objects, for
38 which the reference count was explicitly incremented (e.g.
39 by calling SSL_get1_session(), see L<SSL_get_session(3)>)
40 or when the SSL_SESSION object was generated outside a TLS handshake
41 operation, e.g. by using L<d2i_SSL_SESSION(3)>.
42 It must not be called on other SSL_SESSION objects, as this would cause
43 incorrect reference counts and therefore program failures.
47 SSL_SESSION_free() does not provide diagnostic information.
51 L<ssl(3)>, L<SSL_get_session(3)>,
52 L<SSL_CTX_set_session_cache_mode(3)>,
53 L<SSL_CTX_flush_sessions(3)>,
58 Copyright 2000-2016 The OpenSSL Project Authors. All Rights Reserved.
60 Licensed under the OpenSSL license (the "License"). You may not use
61 this file except in compliance with the License. You can obtain a copy
62 in the file LICENSE in the source distribution or at
63 L<https://www.openssl.org/source/license.html>.