I am a beginner to using proxies, so please bear with me. I am currently trying to set up a forward proxy using Sun Java Web Proxy System (SJSWPS) 4.0.7 to connect to another proxy, i.e. proxy chaining. The other proxy requires username and password authentication. For ease of description, I'll name that other proxy as Proxy A. The logical flow is as shown below.
PC ----> SJSWPS -----> Proxy A (requires basic authentication) ---> Internet
Is there any way to configure SJSWPS to display the authentication screen for Proxy A? The authentication screen is similar to the one used for basic authentication to access Administration Server of SJSWPS. Currently, SJSWPS just return 403 forbidden error instead of displaying the authentication screen.