ChatX Advanced - Secure Real-time Chat Application

A modern, secure, and feature-rich real-time chat application built with PHP, WebSockets, and advanced security features.

🚀 Features

Core Features

Real-time messaging with WebSocket support and HTTP fallback
End-to-end message encryption using AES-256-CBC
User authentication with CSRF protection and rate limiting
File sharing with support for images, documents, and media
Message reactions with emoji support
Typing indicators for better user experience
Online/offline status tracking
Message search and conversation history

Security Features

CSRF protection on all forms
Rate limiting for messages and login attempts
Password strength validation with requirements
Account lockout after failed login attempts
File upload validation with type and size restrictions
XSS protection with input sanitization
Secure headers (HSTS, X-Frame-Options, etc.)

Advanced Features

Database support with MySQL/PDO and JSON fallback
WebSocket server for real-time communication
Mobile responsive design
Dark theme with modern UI
Emoji picker with extensive emoji support
User profiles and settings
Message encryption at rest and in transit

📋 Requirements

PHP 7.4 or higher
MySQL 5.7+ (optional, falls back to JSON files)
Composer for dependency management
Modern web browser with WebSocket support

🛠 Installation

1. Clone or Download

# Download the files to your web server directory
# Example: /var/www/html/chatx/

2. Install Dependencies (Optional - for WebSocket support)

composer install

3. Database Setup (Optional)

-- Create database
CREATE DATABASE chatx_advanced;

-- Create user
CREATE USER 'chatx_user'@'localhost' IDENTIFIED BY 'your_secure_password';
GRANT ALL PRIVILEGES ON chatx_advanced.* TO 'chatx_user'@'localhost';
FLUSH PRIVILEGES;

Update database credentials in database_config.php:

private $db_config = [
    'host' => 'localhost',
    'dbname' => 'chatx_advanced',
    'username' => 'chatx_user',
    'password' => 'your_secure_password',
    'charset' => 'utf8mb4'
];

4. Set Permissions

chmod 755 chatx_advanced.php
chmod -R 775 chat_data/

5. Start WebSocket Server (Optional)

php websocket_server.php

🌐 Usage

Basic Setup

Open chatx_advanced.php in your web browser
Register a new account with a strong password
Login and start chatting!

With WebSocket (Advanced)

Start the WebSocket server: php websocket_server.php
The application will automatically use WebSocket for real-time communication
If WebSocket is unavailable, it falls back to HTTP polling

🔧 Configuration

File Upload Settings

Edit the constants in chatx_advanced.php:

define('MAX_FILE_SIZE', 10 * 1024 * 1024); // 10MB
define('ALLOWED_FILE_TYPES', ['jpg', 'jpeg', 'png', 'gif', 'pdf', 'txt', 'docx']);
define('MAX_MESSAGE_LENGTH', 1000);

Rate Limiting

define('RATE_LIMIT_MESSAGES', 30); // messages per minute
define('RATE_LIMIT_LOGIN', 5); // login attempts per hour

Security Settings

Change encryption keys in production
Use HTTPS in production
Configure proper session settings
Set up proper file permissions

🏗 Architecture

File Structure

chatx/
├── chatx_advanced.php      # Main application file
├── database_config.php     # Database abstraction layer
├── websocket_server.php    # WebSocket server
├── websocket_client.js     # WebSocket client
├── composer.json          # Dependencies
├── README.md              # This file
└── chat_data/             # Data directory
    ├── users.json         # User data (if no database)
    ├── messages.json      # Message data (if no database)
    ├── online_users.json  # Online status
    ├── rate_limits.json   # Rate limiting data
    └── uploads/           # File uploads

Database Schema (MySQL)

users - User accounts and profiles
messages - Chat messages with encryption
message_reactions - Message reactions/emojis
online_users - Online status tracking
rate_limits - Rate limiting counters
user_settings - User preferences

🔒 Security Considerations

Production Deployment

Use HTTPS - Always serve over SSL/TLS
Secure database - Use strong passwords and restrict access
File permissions - Set proper file and directory permissions
Rate limiting - Implement reverse proxy rate limiting
Firewall - Configure firewall rules
Monitoring - Set up logging and monitoring
Backups - Regular database and file backups

Password Security

Minimum 8 characters
Must contain uppercase, lowercase, and numbers
Hashed with PHP's password_hash() using bcrypt
Account lockout after failed attempts

File Upload Security

File type validation
Size limits enforced
Files stored outside web root when possible
Virus scanning recommended for production

🎨 Customization

Themes

The application uses CSS custom properties for easy theming:

:root {
    --bg-primary: #0a0a0a;
    --accent-primary: #6366f1;
    --text-primary: #ffffff;
    /* ... more variables */
}

Adding Features

The modular architecture makes it easy to add features:

Add database schema changes
Update the main ChatX class
Add frontend JavaScript
Update WebSocket handlers if needed

🐛 Troubleshooting

Common Issues

WebSocket Connection Failed

Check if WebSocket server is running
Verify firewall settings
Check browser WebSocket support

File Upload Issues

Check PHP upload_max_filesize setting
Verify directory permissions
Check allowed file types

Database Connection Failed

Verify database credentials
Check if database service is running
The app will fall back to JSON files

Rate Limiting Too Aggressive

Adjust rate limit constants
Clear rate_limits.json or database table

Performance Optimization

Use database instead of JSON for better performance
Enable PHP opcache
Use Redis for session storage
Implement CDN for file uploads
Use nginx for static file serving

📝 License

This project is licensed under the MIT License. See LICENSE file for details.

🤝 Contributing

Contributions are welcome! Please:

Fork the repository
Create a feature branch
Make your changes
Add tests if applicable
Submit a pull request

🆘 Support

For support, please:

Check this README
Review the code comments
Open an issue on the repository
Contact the development team

🔄 Updates

Version 2.0 Features

End-to-end encryption
WebSocket real-time communication
Advanced security features
File sharing and reactions
Database support with fallback
Mobile responsive design
Message search and history

Roadmap

ChatX Advanced - Secure, Modern, Real-time Communication 🚀

saifurrdev/ChatX