Simple chatApp as offsec playground

A Python-based text messaging chat application designed as a beginner's playground for offensive security learning. This application demonstrates network communication concepts through detailed OSI layer analysis while providing end-to-end encrypted messaging between clients.

🎯 Purpose

This project serves as an educational tool for beginners in offensive security to understand:

• Network communication protocols and the OSI model
• End-to-end encryption implementation and analysis
• Client-server architecture vulnerabilities
• Real-time network traffic analysis
• Process management and system monitoring

⚡ Quick Start

Prerequisites

• Python 3.7+
• Required packages: psutil>=5.9.0

Installation & Launch

# Clone the repository
git clone https://github.com/disWhat/SimpleChatApp.git
cd chatApp

# Install dependencies
pip install -r requirements.txt

# Start the complete application (server + 2 clients)
python main.py

This will automatically:

• Start a TCP server on port 8888
• Launch two client GUI windows
• Begin real-time OSI layer analysis
• Enable end-to-end encryption by default

🛠️ Features

Core Components

• TCP Server: Routes messages between clients (port 8888)
• GUI Clients: Dracula-themed interface with chat and analysis tabs
• OSI Analysis: Real-time tracking through all 7 network layers
• E2E Encryption: XOR + Base64 encryption with toggle controls
• System Monitoring: CPU, memory, and network statistics via psutil

Security Features

• End-to-end encryption (server cannot decrypt messages)
• Encryption status synchronization between clients
• Real-time encryption analysis in OSI layer display
• Process isolation and cleanup mechanisms

📊 Educational Value

For Offensive Security Beginners

• Network Analysis: Understand how messages flow through OSI layers
• Encryption Understanding: Learn basic encryption/decryption concepts
• Process Management: See how applications manage system resources
• Traffic Analysis: Real-time monitoring of network communications
• Vulnerability Research: Analyze client-server communication patterns

Analysis Capabilities

• Layer-by-layer packet analysis simulation
• Encryption algorithm detection and analysis
• System resource monitoring during communications
• Network interface statistics tracking
• Process and connection management

🚀 Usage Examples

Individual Components

# Start server only
python app/server.py

# Start individual client
python app/client.py ClientName

Testing & Analysis

# Test encryption functionality
python tests/test_encryption.py

# Test live encryption with server
python tests/test_live_encryption.py

# Test encryption status features
python tests/test_encryption_status.py

Debugging & Monitoring

# Kill all chat processes
pkill -f "python.*server.py"
pkill -f "python.*client.py"

# Check port usage
lsof -i :8888

# Monitor system processes
ps aux | grep python

🔧 Technical Architecture

Client1 ←→ Server ←→ Client2
   ↓         ↓         ↓
Analysis  Analysis  Analysis
   ↓         ↓         ↓
 Logs/   Console    Logs/

• Communication: Point-to-point messaging through TCP server
• Encryption: Shared key XOR encryption with Base64 encoding
• Analysis: Real-time OSI layer tracking with detailed logging
• GUI: Tabbed interface with chat and analysis views

📁 Project Structure

chatApp/
├── main.py                 # Application entry point
├── app/
│   ├── server.py          # TCP server implementation
│   └── client.py          # GUI client with analysis
├── utils/
│   ├── analyze.py         # OSI layer analysis engine
│   └── decryptedMsg.py    # End-to-end encryption
├── tests/                 # Test scripts for all components
├── logs/                  # Auto-generated analysis logs
└── requirements.txt       # Dependencies

🛡️ Security Considerations

This is an educational tool for learning purposes:

• Uses basic XOR encryption (not production-grade)
• No authentication or authorization mechanisms
• Designed for local network testing only
• Process cleanup may require manual intervention

📚 Learning Objectives

After working with this application, beginners should understand:

1. How network protocols work at different OSI layers
2. Basic encryption/decryption concepts and implementation
3. Client-server communication patterns
4. Network traffic analysis techniques
5. System resource monitoring and process management

🤝 Contributing

This project is designed for educational purposes. Feel free to:

• Extend the analysis capabilities
• Add new encryption algorithms
• Improve the GUI interface
• Create additional test scenarios
• Document security findings

⚠️ Disclaimer

This application is intended for educational purposes only. Use responsibly and only on networks you own or have explicit permission to test.