mumukshtayal / https-smart-proxy-server

C implementation for Smart Proxy Server for HTTP and HTTPS based URL filtering.

URL_Filter_Project

Proxy Server in C

This project is a simple proxy server used for URL filtering and implemented in C. It supports request caching and URL blocking functionality. There are 2 separate files, one for HTTP proxy and other for HTTPS proxy. Following are the steps and guide based on HTTP Proxy, but similar steps shall be followed for HTTPS proxy file as well.

How to Run

1. Compile the proxy server code using gcc. For example:

gcc -o HTTP_Proxy HTTP_Proxy.c

2. Run the compiled binary. You can specify the port number for the proxy server to listen on using the -p option. For example, to have the proxy server listen on port 8080:

./proxy -p 8080

If you don't specify a port number, the program will prompt you to enter one when it starts.

Blocklist

The proxy server supports blocking specific URLs. The list of blocked URLs is stored in a file named Blocklist.txt in the same directory as the proxy server program.

You can add URLs to the blocklist by entering the a command at the proxy server's command prompt, followed by the URL to block. For example:

Enter a command (a - add, r - remove, l - list, q - quit): r
Enter the URL to remove: www.example.com

You can view the current blocklist by entering the l command at the proxy server's command prompt. For example:

Enter a command (a - add, r - remove, l - list, q - quit): l

The blocklist is saved to the Blocklist.txt file whenever a URL is added or removed. The proxy server also loads the blocklist from this file when it starts.

Cache

The proxy server caches responses from the target servers. The cache size is limited to 10 entries. When the cache is full, the least recently used entry is replaced.

Quitting

You can quit the proxy server by entering the q command at the proxy server's command prompt. For example:

Enter a command (a - add, r - remove, l - list, q - quit): q

Future Ideas

Plans to implement a more robust technique to address queries parallely on HTTPS. Current technique uses multithreading to serve the connections which can be a bottleneck while scaling. Primarily the goal is to minimise the lag due to blocking I/O operations by implementing asynchronous I/O or Event Driven Architecture.