@deftypefun {void} {gnutls_x509_crt_set_pin_function} (gnutls_x509_crt_t @var{crt}, gnutls_pin_callback_t @var{fn}, void * @var{userdata})
@var{crt}: The certificate structure

@var{fn}: the callback

@var{userdata}: data associated with the callback

This function will set a callback function to be used when
it is required to access a protected object. This function overrides
the global function set using @code{gnutls_pkcs11_set_pin_function()} .

Note that this callback is currently used only during the import
of a PKCS @code{11}  certificate with @code{gnutls_x509_crt_import_url()} .

@strong{Since:} 3.1.0
@end deftypefun