func TryLoadKeyFromDisk(pkiPath, name string) (crypto.Signer, error) {
	privateKeyPath := pathForKey(pkiPath, name)

	// Parse the private key from a file
	privKey, err := keyutil.PrivateKeyFromFile(privateKeyPath)
	if err != nil {
		return nil, errors.Wrapf(err, "couldn't load the private key file %s", privateKeyPath)
	}

	// Allow RSA and ECDSA formats only
	var key crypto.Signer

			}
		}
	}

	if completed.ServiceAccountSigningKeyFile != "" && len(completed.Authentication.ServiceAccounts.Issuers) != 0 && completed.Authentication.ServiceAccounts.Issuers[0] != "" {
		sk, err := keyutil.PrivateKeyFromFile(completed.ServiceAccountSigningKeyFile)
		if err != nil {
			return CompletedOptions{}, fmt.Errorf("failed to parse service-account-issuer-key-file: %v", err)
		}

func CreateServiceAccountKeyAndPublicKeyFiles(certsDir string, keyType kubeadmapi.EncryptionAlgorithmType) error {
	klog.V(1).Infoln("creating new public/private key files for signing service account users")
	_, err := keyutil.PrivateKeyFromFile(filepath.Join(certsDir, kubeadmconstants.ServiceAccountPrivateKeyName))
	if err == nil {
		// kubeadm doesn't validate the existing certificate key more than this;

		logger.Info("Controller is disabled because there is no private key", "controller", controllerName)
		return nil, false, nil
	}
	privateKey, err := keyutil.PrivateKeyFromFile(controllerContext.ComponentConfig.SAController.ServiceAccountKeyFile)
	if err != nil {
		return nil, true, fmt.Errorf("error reading key for service account token controller: %v", err)
	}

	var rootCA []byte