SSL_SESSION_FREE(3) BSD Library Functions Manual SSL_SESSION_FREE(3)NAMESSL_SESSION_free — free an allocated SSL_SESSION structure
SYNOPSIS
#include <openssl/ssl.h>
void
SSL_SESSION_free(SSL_SESSION *session);
DESCRIPTIONSSL_SESSION_free() decrements the reference count of session and removes
the SSL_SESSION structure pointed to by session and frees up the allo‐
cated memory, if the reference count has reached 0.
NOTES
SSL_SESSION objects are allocated when a TLS/SSL handshake operation is
successfully completed. Depending on the settings, see
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 is completely freed as
the reference count incorrectly becomes 0, but it is still referenced in
the internal session cache and the cache list is processed during a
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(3); see SSL_get_session(3)) or when the SSL_SESSION
object was generated outside a TLS handshake operation, e.g., by using
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.
RETURN VALUESSSL_SESSION_free() does not provide diagnostic information.
SEE ALSOd2i_SSL_SESSION(3), ssl(3), SSL_CTX_flush_sessions(3),
SSL_CTX_set_session_cache_mode(3), SSL_get_session(3)BSD April 29, 2024 BSD
