SSL_CTX_sess_set_get_cb - SSL_CTX_sess_set_new_cb, SSL_CTX_sess_set_remove_cb, SSL_CTX_sess_set_get_cb, SSL_CTX_sess_get_new_cb, provide callback functions for server side external session caching
#include <openssl/ssl.h> void SSL_CTX_sess_set_new_cb(SSL_CTX *ctx, int (*new_session_cb)(SSL *, SSL_SESSION *)); void SSL_CTX_sess_set_remove_cb(SSL_CTX *ctx, void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *)); void SSL_CTX_sess_set_get_cb(SSL_CTX *ctx, SSL_SESSION (*get_session_cb)(SSL *, unsigned char *, int, int *)); int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(struct ssl_st *ssl, SSL_SESSION *sess); void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(struct ssl_ctx_st *ctx, SSL_SESSION *sess); SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(struct ssl_st *ssl, unsigned char *data, int len, int *copy); int (*new_session_cb)(struct ssl_st *ssl, SSL_SESSION *sess); void (*remove_session_cb)(struct ssl_ctx_st *ctx, SSL_SESSION *sess); SSL_SESSION *(*get_session_cb)(struct ssl_st *ssl, unsigned char *data, int len, int *copy);
OpenSSL SSL_CTX_sess_set_get_cb(3openssl)
NAME
SSL_CTX_sess_set_new_cb, SSL_CTX_sess_set_remove_cb,
SSL_CTX_sess_set_get_cb, SSL_CTX_sess_get_new_cb,
SSL_CTX_sess_get_remove_cb, SSL_CTX_sess_get_get_cb - provide callback
functions for server side external session caching
SYNOPSIS
#include <openssl/ssl.h>
void SSL_CTX_sess_set_new_cb(SSL_CTX *ctx,
int (*new_session_cb)(SSL *, SSL_SESSION *));
void SSL_CTX_sess_set_remove_cb(SSL_CTX *ctx,
void (*remove_session_cb)(SSL_CTX *ctx, SSL_SESSION *));
void SSL_CTX_sess_set_get_cb(SSL_CTX *ctx,
SSL_SESSION (*get_session_cb)(SSL *, unsigned char *, int, int *));
int (*SSL_CTX_sess_get_new_cb(SSL_CTX *ctx))(struct ssl_st *ssl, SSL_SESSION *sess);
void (*SSL_CTX_sess_get_remove_cb(SSL_CTX *ctx))(struct ssl_ctx_st *ctx, SSL_SESSION *sess);
SSL_SESSION *(*SSL_CTX_sess_get_get_cb(SSL_CTX *ctx))(struct ssl_st *ssl, unsigned char *data, int len, int *copy);
int (*new_session_cb)(struct ssl_st *ssl, SSL_SESSION *sess);
void (*remove_session_cb)(struct ssl_ctx_st *ctx, SSL_SESSION *sess);
SSL_SESSION *(*get_session_cb)(struct ssl_st *ssl, unsigned char *data,
int len, int *copy);
DESCRIPTION
SSL_CTX_sess_set_new_cb() sets the callback function, which is
automatically called whenever a new session was negotiated.
SSL_CTX_sess_set_remove_cb() sets the callback function, which is
automatically called whenever a session is removed by the SSL engine,
because it is considered faulty or the session has become obsolete
because of exceeding the timeout value.
SSL_CTX_sess_set_get_cb() sets the callback function which is called,
whenever a SSL/TLS client proposed to resume a session but the session
could not be found in the internal session cache (see
SSL_CTX_set_session_cache_mode(3)). (SSL/TLS server only.)
SSL_CTX_sess_get_new_cb(), SSL_CTX_sess_get_remove_cb(), and
SSL_CTX_sess_get_get_cb() allow to retrieve the function pointers of
the provided callback functions. If a callback function has not been
set, the NULL pointer is returned.
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+--------------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+--------------------------+
|Availability | library/security/openssl |
+---------------+--------------------------+
|Stability | Pass-through uncommitted |
+---------------+--------------------------+
NOTES
In order to allow external session caching, synchronization with the
internal session cache is realized via callback functions. Inside these
callback functions, session can be saved to disk or put into a database
using the d2i_SSL_SESSION(3) interface.
The new_session_cb() is called, whenever a new session has been
negotiated and session caching is enabled (see
SSL_CTX_set_session_cache_mode(3)). The new_session_cb() is passed the
ssl connection and the ssl session sess. If the callback returns 0, the
session will be immediately removed again.
The remove_session_cb() is called, whenever the SSL engine removes a
session from the internal cache. This happens when the session is
removed because it is expired or when a connection was not shutdown
cleanly. It also happens for all sessions in the internal session cache
when SSL_CTX_free(3) is called. The remove_session_cb() is passed the
ctx and the ssl session sess. It does not provide any feedback.
The get_session_cb() is only called on SSL/TLS servers with the session
id proposed by the client. The get_session_cb() is always called, also
when session caching was disabled. The get_session_cb() is passed the
ssl connection, the session id of length length at the memory location
data. With the parameter copy the callback can require the SSL engine
to increment the reference count of the SSL_SESSION object, Normally
the reference count is not incremented and therefore the session must
not be explicitly freed with SSL_SESSION_free(3).
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from
https://www.openssl.org/source/openssl-1.0.2ze.tar.gz.
Further information about this software can be found on the open source
community website at https://www.openssl.org/.
SEE ALSO
ssl(3), d2i_SSL_SESSION(3), SSL_CTX_set_session_cache_mode(3),
SSL_CTX_flush_sessions(3), SSL_SESSION_free(3), SSL_CTX_free(3)
1.0.2ze 2022-05-03
SSL_CTX_sess_set_get_cb(3openssl)