@deftypefun {void} {gnutls_privkey_set_pin_function} (gnutls_privkey_t @var{key}, gnutls_pin_callback_t @var{fn}, void * @var{userdata})

@var{key}: A key of type @code{gnutls_privkey_t} 

@var{fn}: the callback

@var{userdata}: data associated with the callback

This function will set a callback function to be used when

required to access the object. This function overrides any other

global PIN functions.

Note that this function must be called right after initialization

to have effect.

@strong{Since:} 3.1.0

@end deftypefun