private static RSAPrivateKey getRsaPrivateKey(final String signingSecret) {
        return FunctionUtils.doUnchecked(() -> {
            val resource = ResourceUtils.getResourceFrom(signingSecret);
            val factory = new PrivateKeyFactoryBean();
            factory.setAlgorithm(RsaKeyUtil.RSA);
            factory.setLocation(resource);
            factory.setSingleton(false);
            return (RSAPrivateKey) factory.getObject();
        });
    }
Create a JWT authenticator.

@return the jwt authenticator
support/cas-server-support-token-authentication/src/main/java/org/apereo/cas/token/authentication/TokenAuthenticationSecurity.java