The Purpose of CatChat is to provide a simple chat application that symbolizes some basic chat functionality while also providing secure communcation and authentication for each user.

CatChat was designed to be a groundwork for additional work in the future to provide a more robust chat application. This application features encryption and decryption of messages using symmetric encryption via room join, symbolizing the use of session keys. The application also features authentication via a username and password using various concepts like a salt and a hash to keep the passwords secure in the database and a bloom filter to showcase how a server can check if a username is banned or already in use. The application is modularized and compartmentalized to allow for easy expansion and modification of the application. Additionally, the application features the use of SQLite to store user information and chat history for each room in a lightweight manner, allowing for a more feature rich database to be implemented in the future.

• Python 3.6+
• Node.js 14.15.4+
• npm 6.14.10+
• pip 20.3.3+
• git 2.25.1+
• run pip install -r requirements.txt to install all dependencies for the application in the backend directory.

• Navigate here to clone the repository.
• Navigate the green "Code" button and copy the https link.
• Open a terminal and navigate to the directory you want to clone the repository to.
• Type git clone <https_link> to clone the repository to your local machine.
• Now the repository should be cloned to your local machine.
• Additionally, the repository can be cloned in an IDE like PyCharm or Visual Studio Code by navigating
• to the VCS tab and selecting "Get from Version Control" and pasting the https link into the URL field.

• Create two terminals, one for the frontend and one for the backend.
• In the backend terminal, navigate to the backend folder and then the app folder using cd <directory to CatChat>/backend/.
• Type the following into the backend terminal: python -m venv venv to create a virtual environment for the backend.
• If on windows, type the following into the backend terminal: venv\Scripts\activate to activate the virtual environment.
• If on linux or mac, type the following into the backend terminal: source venv/bin/activate to activate the virtual environment.
• Type the following into the backend terminal: pip install -r requirements.txt to install all dependencies for the backend.
• In the backend terminal, navigate to the app folder using cd app.
• If on windows, type the following into the backend terminal: python app.py to start the backend server.
• If on linux or mac, type the following into the backend terminal: python3 app.py to start the backend server.
• in the frontend terminal, navigate to the frontend folder and then the app folder using cd <directory to CatChat>/frontend/catchat/.
• Type the following into the frontend terminal: npm install to install all dependencies for the frontend.
• Type the following into the frontend terminal: npm start to start the frontend server.
• The application should now be running on localhost:5000.
• A new tab will open up in your default browser for the landing page of the application.
• To stop the application, press ctrl + c in both terminals.

• User Authentication
• User Registration
• User Login
• Password Salting and Hashing
• Password Verification
• Private Messaging (1 to 1)
• Secure Messaging (Symmetric Encryption) (1 to 1)
• Bloom Filter for Username Checking
• Bloom filter for Password Checking
• NIST 800-64 Password Guidelines (At least 8 characters, 1 uppercase, 1 lowercase, 1 number, 1 special character)
• Chat History
• Database Storage (SQLite)

• Multiple Room Chat (1 to many)
• User Profile
• User Profile Picture
• User Status Features
• Access Control
• Account deletion
• Administrator features (ban, kick, etc.)
• Bloom Filter for Banned Users (IP Address)

• When clicking on a chat room, the chat history does not load until a message is sent and the chat card is clicked again.
• SocketIO sometimes loses connection and does not reconnect.

• Kaushal Patel
• Michael Imerman

• 1.0
  • Initial Release

This project has a General Public License (GNU) v3.0 License - see the LICENSE.md file for details

• SQLite
• SocketIO
• React
• W3 Schools