Python Socket Chat

A Discord-like desktop chat application built with Python. Features a modern dark-themed GUI (CustomTkinter), user authentication, encrypted connections, multiple channels, message history, and real-time notifications.

Features

• Discord-inspired UI — Dark theme with channel sidebar, message area, and online user list
• User Authentication — Registration and login with bcrypt-hashed passwords
• Multiple Channels — Create and switch between chat rooms with persistent message history
• Private Messaging — Direct messages between users with /msg
• TLS Encryption — Optional SSL/TLS support for secure connections
• SQLite Database — Persistent storage for users, channels, and messages
• Rate Limiting — Flood protection (5 messages/second per user)
• Input Validation — Username, password, message, and channel name validation
• Desktop Notifications — Toast notifications for messages in other channels and PMs
• Slash Commands — /msg, /me, /quit still work from the message input

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Quick Start

1. Install dependencies

pip install -r requirements.txt

2. Start the server

python server.py --no-tls

Use --no-tls for local development. The server listens on 127.0.0.1:5050 by default.

3. Launch the client

python client.py

A GUI window will open. Register a new account or log in, and you're chatting!

Open multiple client windows to test multi-user chat.

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Screenshots

The client features a three-panel layout inspired by Discord:

• Left sidebar — Channel list with a "+" button to create new channels
• Center — Message area with timestamps and a message input bar
• Right sidebar — Online user list with status indicators

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Server Options

python server.py [OPTIONS]

  --host HOST    Bind address (default: 127.0.0.1)
  --port PORT    Listen port (default: 5050)
  --db PATH      SQLite database file (default: chat_data.db)
  --no-tls       Disable TLS encryption (for development)
  --cert FILE    TLS certificate file (default: certs/server.crt)
  --key FILE     TLS private key file (default: certs/server.key)

TLS Setup

To enable encrypted connections:

python certs/gen_certs.py    # Generate self-signed certificates
python server.py             # Start with TLS enabled

Then check "Use TLS" in the client's Advanced connection settings.

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Slash Commands

Type these in the message input bar:

Command	Description
/msg <user> <message>	Send a private message
/me <action>	Send an action (e.g., /me waves)
/quit	Disconnect and close

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Project Structure

python-socket-chat/
├── server.py                  # Server entry point
├── client.py                  # Client entry point (GUI)
├── requirements.txt
├── certs/
│   └── gen_certs.py           # Self-signed TLS certificate generator
├── shared/
│   ├── protocol.py            # Length-prefixed JSON wire protocol
│   ├── constants.py           # Shared constants and message types
│   └── validators.py          # Input validation and sanitization
├── server_app/
│   ├── chat_server.py         # Multi-threaded chat server
│   ├── auth.py                # bcrypt password hashing, session tokens
│   ├── database.py            # SQLite database layer
│   ├── rate_limiter.py        # Per-user rate limiting
│   └── channel_manager.py     # Channel membership tracking
└── client_app/
    ├── network.py             # Socket connection and TLS
    ├── session.py             # Client-side session state
    └── ui/
        ├── app.py             # Main application window
        ├── login_screen.py    # Login/registration screen
        ├── chat_screen.py     # Chat layout (3-column grid)
        ├── theme.py           # Discord dark theme colors and fonts
        ├── notifications.py   # Desktop notifications
        └── components/
            ├── sidebar_channels.py
            ├── message_area.py
            ├── sidebar_users.py
            ├── message_input.py
            └── top_bar.py

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Technical Details

Protocol

Communication uses a length-prefixed JSON format over TCP:

[4-byte big-endian payload length][UTF-8 JSON payload]

This replaces newline-delimited text, correctly handling multiline messages and structured data.

Database Schema

SQLite stores four tables:

• users — Accounts with bcrypt-hashed passwords
• channels — Chat rooms with descriptions
• messages — Message history (indexed by channel and timestamp)
• sessions — Authentication tokens with expiry

Security

• Passwords hashed with bcrypt (12 rounds)
• Session tokens generated via secrets.token_hex(32)
• Optional TLS/SSL encryption for all traffic
• Input validation on usernames, passwords, messages, and channel names
• Rate limiting prevents message flooding

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Requirements

• Python 3.10+
• Dependencies: customtkinter, bcrypt, plyer, Pillow

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License

MIT