How to use multiple certificates for single HTTP request?

Question

Firstly, I do not understand this topic very deeply, so I may be asking a basic question. Apologies for the same.

I have a system like below A<->B<->C

Here, B = Proxy server, A = Destination, C = Source

So there is one HTTP/HTTPS rest hosted on A, and from CI want to access that. Now I need an SSL certificate(say X) to reach B and another SSL certificate(say Y) to access rest on A.

My question is that how can I wrap the request in certificate X and then in Y so that when it reaches B, Y will verify it and get unwrapped, then to goes to A and verified by X and hence gets executed.

Here, my objective is to just hit the rest, the response doesn't matter.

Thanks in advance.

Answer 1

First, you don't usually need a certificate to access a proxy in the first place. The usual HTTP/HTTPS proxy just creates a tunnel to the final host (A) and then there is normal HTTPS end-to-end encryption where the server (A) provides you with a certificate and the client (C) might optionally provide a certificate too if the server requires it. The same is true with a SOCKS proxy.

Even if you have some proxy which itself speaks TLS (possible but unusual) then you have some outer HTTPS connection to create the tunnel and then some inner HTTPS connection to send the request. The outer and inner connections are established one after the other and only the for each connection relevant certificates are provided at these stages.