Simple SSH

A Simple SSH-like implementation built from scratch (not entirely i indeed used cryptography and pty packages).

I also have a video recorded of me implementing this check it out: https://www.youtube.com/watch?v=mXwZXscztyw&t=2509s

This project implements a secure client-server system with:

• key exchange
• server authentication
• encrypted communication
• remote command execution
• interactive shell using PTY

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Features

• Diffie-Hellman key exchange
• Server authentication (prevents MITM)
• Encrypted communication
• Remote command execution
• Interactive shell (supports cd, nano, etc.)

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Project Structure

server.py  - SSH server
client.py  - SSH client

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How It Works

1. Client connects to server using TCP (insecure channel)
2. Handshake is performed (key exchange + authentication)
3. A shared key is established
4. All communication is encrypted
5. Client interacts with a shell running on the server

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Running the Project

Start the server:

python server.py

Start the client:

python client.py

You should now be able to run commands remotely.

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Notes

• This is a learning project, not production-ready
• Cryptographic primitives are used via libraries
• Designed to understand how SSH works internally

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What You Learn

• Networking (TCP sockets)
• Cryptography basics
• Protocol design
• Process and terminal handling (PTY)

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