I have a Spring application, that acts as an authentication proxy for two backend servers. A user will access the Spring application and be forwarded to the backend once he is successfully authenticated. To prevent unwanted access without prior authentication the backend servers require a certificate as authentication.
My Spring application uses Netflix-Ribbon as a load balancer and Netflix-Zuul as a Proxy for the users requests. How can I configure them to use the client certificate that is required for the authentication on the backend servers?