SSLCTXsesssetgetcb(3) OpenSSL SSLCTXsesssetgetcb(3)

NAME
       SSLCTXsesssetnewcb, SSLCTXsesssetremovecb,
       SSLCTXsesssetgetcb, SSLCTXsessgetnewcb,
       SSLCTXsessgetremovecb, SSLCTXsessgetgetcb - provide callback
       functions for server side external session caching

SYNOPSIS
        #include 

        void SSLCTXsesssetnewcb(SSLCTX *ctx,
                                     int (*newsessioncb)(SSL *, SSLSESSION *));
        void SSLCTXsesssetremovecb(SSLCTX *ctx,
                  void (*removesessioncb)(SSLCTX *ctx, SSLSESSION *));
        void SSLCTXsesssetgetcb(SSLCTX *ctx,
                  SSLSESSION (*getsessioncb)(SSL *, unsigned char *, int, int *));

        int (*SSLCTXsessgetnewcb(SSLCTX *ctx))(struct sslst *ssl, SSLSESSION *sess);
        void (*SSLCTXsessgetremovecb(SSLCTX *ctx))(struct sslctxst *ctx, SSLSESSION *sess);
        SSLSESSION *(*SSLCTXsessgetgetcb(SSLCTX *ctx))(struct sslst *ssl, unsigned char *data, int len, int *copy);

        int (*newsessioncb)(struct sslst *ssl, SSLSESSION *sess);
        void (*removesessioncb)(struct sslctxst *ctx, SSLSESSION *sess);
        SSLSESSION *(*getsessioncb)(struct sslst *ssl, unsigned char *data,
                      int len, int *copy);

DESCRIPTION
       SSLCTXsesssetnewcb() sets the callback function, which is
       automatically called whenever a new session was negotiated.

       SSLCTXsesssetremovecb() 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.

       SSLCTXsesssetgetcb() 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
       SSLCTXsetsessioncachemode(3)).  (SSL/TLS server only.)

       SSLCTXsessgetnewcb(), SSLCTXsessgetremovecb(), and
       SSLCTXsessgetgetcb() allow to retrieve the function pointers of
       the provided callback functions. If a callback function has not been
       set, the NULL pointer is returned.

NNOOTTEESS
       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 d2iSSLSESSION(3) interface.

       The newsessioncb() is called, whenever a new session has been
       negotiated and session caching is enabled (see
       SSLCTXsetsessioncachemode(3)).  The newsessioncb() is passed the
       ssssll connection and the ssl session sseessss. If the callback returns 00, the
       session will be immediately removed again.

       The removesessioncb() 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 SSLCTXfree(3) is called. The removesessioncb() is passed the
       ccttxx and the ssl session sseessss. It does not provide any feedback.

       The getsessioncb() is only called on SSL/TLS servers with the session
       id proposed by the client. The getsessioncb() is always called, also
       when session caching was disabled. The getsessioncb() is passed the
       ssssll connection, the session id of length lleennggtthh at the memory location
       ddaattaa. With the parameter ccooppyy the callback can require the SSL engine
       to increment the reference count of the SSLSESSION object, Normally
       the reference count is not incremented and therefore the session must
       not be explicitly freed with SSLSESSIONfree(3).

SEE ALSO
       ssl(3), d2iSSLSESSION(3), SSLCTXsetsessioncachemode(3),
       SSLCTXflushsessions(3), SSLSESSIONfree(3), SSLCTXfree(3)



0.9.7l                            2003-03-27        SSLCTXsesssetgetcb(3)