SSL_CTX_set_info_callback(3)OpenSSLSSL_CTX_set_info_callback(3)





NAME
       SSL_CTX_set_info_callback, SSL_CTX_get_info_callback,
       SSL_set_info_callback, SSL_get_info_callback - handle
       information callback for SSL connections

SYNOPSIS
        #include <openssl/ssl.h>

        void SSL_CTX_set_info_callback(SSL_CTX *ctx, void (*callback)());
        void (*SSL_CTX_get_info_callback(SSL_CTX *ctx))();

        void SSL_set_info_callback(SSL *ssl, void (*callback)());
        void (*SSL_get_info_callback(SSL *ssl))();

DESCRIPTION
       SSL_CTX_set_info_callback() sets the callback function,
       that can be used to obtain state information for SSL
       objects created from ctx during connection setup and
       use. The setting for ctx is overridden from the setting
       for a specific SSL object, if specified.  When callback
       is NULL, not callback function is used.

       SSL_set_info_callback() sets the callback function, that
       can be used to obtain state information for ssl during
       connection setup and use.  When callback is NULL, the
       callback setting currently valid for ctx is used.

       SSL_CTX_get_info_callback() returns a pointer to the
       currently set information callback function for ctx.

       SSL_get_info_callback() returns a pointer to the cur-
       rently set information callback function for ssl.

NOTES
       When setting up a connection and during use, it is pos-
       sible to obtain state information from the SSL/TLS
       engine. When set, an information callback function is
       called whenever the state changes, an alert appears, or
       an error occurs.

       The callback function is called as callback(SSL *ssl,
       int where, int ret).  The where argument specifies
       information about where (in which context) the callback
       function was called. If ret is 0, an error condition
       occurred.  If an alert is handled, SSL_CB_ALERT is set
       and ret specifies the alert information.

       where is a bitmask made up of the following bits:

       SSL_CB_LOOP
           Callback has been called to indicate state change
           inside a loop.

       SSL_CB_EXIT
           Callback has been called to indicate error exit of a
           handshake function.  (May be soft error with retry
           option for non-blocking setups.)

       SSL_CB_READ
           Callback has been called during read operation.

       SSL_CB_WRITE
           Callback has been called during write operation.

       SSL_CB_ALERT
           Callback has been called due to an alert being sent
           or received.

       SSL_CB_READ_ALERT (SSL_CB_ALERT|SSL_CB_READ)
       SSL_CB_WRITE_ALERT (SSL_CB_ALERT|SSL_CB_WRITE)
       SSL_CB_ACCEPT_LOOP (SSL_ST_ACCEPT|SSL_CB_LOOP)
       SSL_CB_ACCEPT_EXIT (SSL_ST_ACCEPT|SSL_CB_EXIT)
       SSL_CB_CONNECT_LOOP             (SSL_ST_CON-
       NECT|SSL_CB_LOOP)
       SSL_CB_CONNECT_EXIT             (SSL_ST_CON-
       NECT|SSL_CB_EXIT)
       SSL_CB_HANDSHAKE_START
           Callback has been called because a new handshake is
           started.

       SSL_CB_HANDSHAKE_DONE           0x20
           Callback has been called because a handshake is fin-
           ished.

       The current state information can be obtained using the
       SSL_state_string(3) family of functions.

       The ret information can be evaluated using the
       SSL_alert_type_string(3) family of functions.

RETURN VALUES
       SSL_set_info_callback() does not provide diagnostic
       information.

       SSL_get_info_callback() returns the current setting.

EXAMPLES
       The following example callback function prints state
       strings, information about alerts being handled and
       error messages to the bio_err BIO.

        void apps_ssl_info_callback(SSL *s, int where, int ret)
               {
               const char *str;
               int w;

               w=where& ~SSL_ST_MASK;

               if (w & SSL_ST_CONNECT) str="SSL_connect";
               else if (w & SSL_ST_ACCEPT) str="SSL_accept";
               else str="undefined";























               if (where & SSL_CB_LOOP)
                       {
                       BIO_printf(bio_err,"%s:%s\n",str,SSL_state_string_long(s));
                       }
               else if (where & SSL_CB_ALERT)
                       {
                       str=(where & SSL_CB_READ)?"read":"write";
                       BIO_printf(bio_err,"SSL3 alert %s:%s:%s\n",
                               str,
                               SSL_alert_type_string_long(ret),
                               SSL_alert_desc_string_long(ret));
                       }
               else if (where & SSL_CB_EXIT)
                       {
                       if (ret == 0)
                               BIO_printf(bio_err,"%s:failed in %s\n",
                                       str,SSL_state_string_long(s));
                       else if (ret < 0)
                               {
                               BIO_printf(bio_err,"%s:error in %s\n",
                                       str,SSL_state_string_long(s));
                               }
                       }
               }

SEE ALSO
       ssl(3), SSL_state_string(3), SSL_alert_type_string(3)



0.9.7c                     2001-11-SSL_CTX_set_info_callback(3)
