Http Proxy

Implements a simple HTTP web proxy that passes requests and data between a web client and a web server with basic socket programming interface. Concurrent connections are handled with multithreading.

Extensions

1. Proxy performs image substitution if the second argument is set to 1. For all the requested images, the requested image is substituted with http://ocna0.d2.comp.nus.edu.sg:50000/change.jpg.

2. Proxy runs in the attacker mode if the third argument is set to 1. For any http request, proxy replies with a HTML page with the string “You are being attacked”.

Telemetry

After fetching objects from the web server and connection to the server is closed, the proxy will print out the following on a single line:

• URL, size of object in bytes

For example, the telemetry output should be a string format like this example:

• http://www.comp.nus.edu.sg, 13433670

Prerequisites

• Target environment: linux
• Browser: firefox
• Supported HTTP versions: HTTP 1.0 and HTTP 1.1
• C++ version 9.4.0

Running proxy

mkdir build && cd build
cmake ..
make
./proxy <port> <image-flag> <attack-flag>

Output

Proxy listening on port 3001
http://ocna0.d2.comp.nus.edu.sg:50000/tc1/, 517
http://ocna0.d2.comp.nus.edu.sg:50000/tc2/, 37139
http://ocna0.d2.comp.nus.edu.sg:50000/tc3/, 539638