@deftypefun {int} {gnutls_x509_ext_import_private_key_usage_period} (const gnutls_datum_t * @var{ext}, time_t * @var{activation}, time_t * @var{expiration})
@var{ext}: the DER encoded extension data

@var{activation}: Will hold the activation time

@var{expiration}: Will hold the expiration time

This function will return the expiration and activation
times of the private key as written in the
PKIX extension 2.5.29.16.

@strong{Returns:} On success, @code{GNUTLS_E_SUCCESS}  (0) is returned, otherwise a
negative error value.

@strong{Since:} 3.3.0
@end deftypefun