I am in the situation where I need to test the HTTP header parsing of a particular custom HTTP server.
However, that server is behind a load balancer that check the first line of the header contains
.git/info/refs?service=git-. If it doesn’t, the request isn’t forwarded, but if it does, then everything after the first line is send without modifications (the response channel goes farther because it acts as a raw tcp stream proxy at the load balancer).
I saw American Fuzzing Loop, but I have no idea on how to use it for that purpose.