@deftypefun {gnutls_pin_callback_t} {gnutls_pkcs11_get_pin_function} (void ** @var{userdata})
@var{userdata}: data to be supplied to callback

This function will return the callback function set using
@code{gnutls_pkcs11_set_pin_function()} .

@strong{Returns:} The function set or NULL otherwise.

@strong{Since:} 3.1.0
@end deftypefun