Secure Client-Server Communication using SSL

This project demonstrates a simple SSL (Secure Sockets Layer) based client-server application in Java. It ensures secure communication between a server and a client by encrypting the transmitted data using Java’s built-in SSL capabilities.

🔒 Project Overview

This application sets up a server that listens over SSL and a client that connects securely to it. Both sides exchange messages over an encrypted channel, providing confidentiality and integrity.

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🛠️ Setup & Execution

Step 1: Prerequisites

• Java JDK (8 or later)
• VS Code with Java Extension Pack (recommended)
• Terminal access

Step 2: Generate Keystore

The keystore is required by the server to authenticate itself.

keytool -genkeypair -alias serverkey -keyalg RSA -keysize 2048 -keystore serverkeystore.jks -validity 365
Keystore password: password

You can leave other prompts as default or fill in accordingly.

Step 3: Compile the Code

Navigate to the project directory and run:

javac SSLServer.java SSLClient.java

Step 4: Start the Server

java SSLServer

The server will listen for incoming SSL connections on port 4444.

Step 5: Run the Client (in another terminal)

java SSLClient

Upon successful connection, messages will be exchanged securely.

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🧠 Key Concepts

SSLContext: Sets up the secure socket layer configuration.

Keystore: Stores the server's private key and certificate.

TrustManager: Used on the client side to accept the server’s certificate (here, it accepts all for demo purposes).

Encrypted Communication: All data between client and server is encrypted using SSL.

📌 Important Notes

This project is for educational purposes. The client blindly trusts all certificates, which is not recommended for production use.

For real applications, validate server certificates properly using a TrustStore.

📷 Output (Sample)

Server terminal:

SSL Server is running on port 4444
Client: Hello from Client

Client terminal:

Server: Hello from Server

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