DNS-sly - v. 1.0
Qurat-Ul-Ann Akbar - quratulannakbar2015@u.northwestern.edu

About 
=====
DNS-sly is a counter-censorship system developed by Qurat-Ul-Ann Akbar and
Aleksandar Kuzmanovic at Northwestern Networks Group.

These files contain the implementation of the DNS-sly server and client in
Python. The server receives requests from clients like a regular DNS server but
for clients who require access to censored websites, it uses DNS queries to send
additional hidden censored information. 

Dependencies
============
0) Ensure you have Python 2.7 or above installed

1) Selenium 3.4 for Python - package to automate web browser interaction from
   Python 
    
    Install using the following command :
    pip install -U selenium 

2) dnspython - DNS toolkit for Python

    All information and documentation can be viewed through the following link:
    http://www.dnspython.org/

3) Libraries -  numpy, json, pandas

Scripts
=======

Scripts are divided into two main categories:

1) Data Collection: This folder contains automated scripts that can be used to
   make the dictionary used by the server to encode hidden information in DNS
   queries. THe description for each file is given below:

   dns_collector.py:  Opens a Firefox browser and records all DNS queries made
   when a certain webpage is requested

   ips_fordomains_collector.py: Makes the mapping from domains to IPs

   makingdict.py: Creates the final dictionary

   Run in the above given order. All files can be run as follows:

   python filename

2) System Src: This folder contains the actual server and client implementation
   scripts. 

   If you dont want to create your own dictionary, we have a default that we
   used by using DNS servers all around the world , named dict_final.json

   encoding.py: This script contains both the encoding and decoding mechanism
   used by client and server

   censor_test.py:  Just a sample test script for unit tests

Note
====

This is a modest implementation and our client is designed for experimental purposes,
rather than for use by live users, the upstream communications are hard-coded. 
Feel free to add anything to the codebase for advanced communication between DNS
servers and clients.

Contact
=======
Question and comments should be directed to Qurat-Ul-Ann Akbar at
quratulannakbar2015@u.northwestern.edu