when the time source is not trusted, verify the valid field of certificates make no sense.

[longlongyang]

We may need a feature control whether to verify the valid field of certificates or not.

spdm-rs/spdmlib/src/crypto/spdm_ring/cert_operation_impl.rs

Lines 159 to 187 in fe472b9

	#[cfg(any(target_os = "uefi", target_os = "none"))]
	let timestamp = {
	if let Some(ts) = sys_time::get_sys_time() {
	ts as u64
	} else {
	return Err(SPDM_STATUS_INVALID_STATE_LOCAL);
	}
	};
	#[cfg(not(any(target_os = "uefi", target_os = "none")))]
	let timestamp = {
	extern crate std;
	if let Ok(ds) = std::time::SystemTime::now().duration_since(std::time::UNIX_EPOCH) {
	ds.as_secs()
	} else {
	return Err(SPDM_STATUS_INVALID_STATE_LOCAL);
	}
	};
	let time = webpki::Time::from_seconds_since_unix_epoch(timestamp);
	let cert = if let Ok(eec) = webpki::EndEntityCert::try_from(ee) {
	eec
	} else {
	return Err(SPDM_STATUS_INVALID_CERT);
	};
	// we cannot call verify_is_valid_tls_server_cert because it will check verify_cert::EKU_SERVER_AUTH.
	if cert
	.verify_cert_chain_with_eku(EKU_SPDM_RESPONDER_AUTH, ALL_SIGALGS, &anchors, inters, time)
	.is_ok()