Subnet Addressing and TLS-Enabled Group Chat

This project combines network configuration using Mininet with the development of a TLS-enabled group chat system.

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⚙️ Components

• Custom Mininet Topology: Subnetted, multi-router network setup using legacy_network.py.
• TLS-Enabled Chat Service: A multi-client server built from the TCP chat service in Assignment 3.
• Certificate Generation: OpenSSL-driven, auto-signed server certificate using certificate_generation.py.

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🖥️ System Requirements

This project is intended to run inside an Oracle VirtualBox VM with a Ubuntu-based Linux OS.

Recommended VM Configuration:

• OS: Ubuntu 20.04+
• Memory: 2 GB+
• Disk: 10 GB+
• Root Access: Required

Software Dependencies

Install the following inside your VM:

sudo apt-get update
sudo apt-get install mininet xterm openssl python3-pip

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🛠️ Setup Instructions

1. Generate TLS Certificates

Run this before launching Mininet:

sudo -E python3 certificate_generation.py

• Common name: tpa4.chat.test
• Passphrase: CST311
• This updates /etc/hosts and creates server-key.pem and server-cert.pem.

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2. Launch the Network

Start the Mininet topology and open chat terminals:

sudo -E python3 legacy_network.py

This script will:

• Configure all hosts and routers
• Assign IP addresses and static routes
• Auto-launch:
  • tpa4_chat_server.py on h4
  • tpa4_chat_client.py on h1, h2, and h3 via xterm

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3. Verify Network Connectivity

In the Mininet CLI, run:

pingall

✅ All hosts should successfully reach each other.

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4. Chat Application Behavior

• Server: Runs on h4 (10.0.1.2) and listens on port 12000
• Clients: Run on h1, h2, and h3, each in its own terminal
• Communication: Encrypted using TLS with a self-signed certificate
• Termination: Typing bye closes the client session

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📚 References

• Mininet
• Python TLS Socket Programming
• OpenSSL Manual