Hello stunnel users,
I am working with what seems to be the standard stunnel HTTPS configuration. I have two instances of stunnel, one as a client and one as a server. The client accepts connections from a browser. The server sits in front of tomcat. If works like a charm (of course!).
What I need to do seems simple, and I will try to keep my description of it generic. In the client stunnel I need to make a small change to the HTTP packet. I need to add some data to it. At the server side I need to access that added data. The server stunnel may close the SSL session based on that data.
So, my question is: can I obtain access to the packet before it's encrypted and sent out over SSL? Can I get access to the decrypted packet before it's sent on to tomcat?
I know that as a proxy stunnel has to be and tries to be general in nature. I am not concerned (right now) with developing a feature that will become available to others later. I don't mind if my changes make my development version of stunnel single-purpose. My work is academic and proof-of-concept in it's nature.
I have collected references and a text book (Network Security with OpenSSL by Viega et al). I will continue to walk through and explore the code. Are there any programmer resources I can obtain? I see the occasional URL in the stunnel source code. I will have to check these URLs.
---
I just now pursued
http://haproxy.1wt.eu/download/1.5/doc/proxy-protocol.txt, and I see that there is a patch that allows stunnel to do an initial modification to the HTTP request to insert a X-Forwarded-For header. This sounds like what I need to do! I am going to look for that patch. I hope the source code for the patch is available.