🔏 LICENSE KEY GENERATOR (PKI-Based Signing)

A lightweight open-source JavaScript library for signing and verifying software license key using RSA 2048-bit encryption.

⚛️ I'm actively pushing this to be Post-Quantum Computing (PQC) compatible to future-proof security.

✨ Features

• 🔑 Generate RSA Key Pairs
• 🔏 Sign License Keys
• ✅ Verify Signed Licenses
• 🔒 Uses SHA256 + RSA for Security
• 🛠 Minimal & Easy to Integrate
• 🌍 Live API Hosted on Render

📑 Table of Contents

• 🔏 LICENSE KEY GENERATOR (PKI-Based Signing)
• 🚀 How It Works
• 🌍 Live API (No Setup Required!)
  • GET /generate-keys
  • POST /sign-license
  • POST /verify-license
  • 🔹 Try it in Swagger UI
• ⚡ Usage (Local Development)
• 🧪 Running Tests
• 📜 License
• 🤝 Contributions
• 📧 Contact

🚀 How It Works

This API allows you to generate RSA key pairs, sign software license keys, and verify them using cryptographic signing.

1️⃣ Generate an RSA Key Pair – Get a public and private key. The private key is yours to keep.
2️⃣ Sign a License Key – Use your private key to sign a license.
3️⃣ Verify a License – Use the public key to validate the signature.

⚠️ Warning: The API DOES NOT store any keys for you. If you do not save your private key when generated, it will be lost forever! Users manage their own key storage.

🔑 Where Do the Keys Live?

• Generated Keys: When you generate a key pair, the public and private keys exist only in memory until you save them.
• Private Key: This key is meant to be kept secret. If you lose it, you cannot re-create or retrieve it.
• Public Key: You can store and distribute this safely. It is used to verify signed licenses.

🔹 Note: This API DOES NOT store your keys or license data.
👀 If you need a hosted key storage & validation service, stay tuned for our upcoming managed API service!

---

🌍 Live API (No Setup Required!)

The API is deployed on Render and can be accessed directly!

Feature	Details
Base URL	https://license-signing-api.onrender.com
Swagger API Docs	https://license-signing-api.onrender.com/api-docs/

API Endpoints

GET /generate-keys

• Returns: { publicKey: string, privateKey: string }
• Description: Generates a new RSA 2048-bit key pair.
• Example Response:

  {
    "publicKey": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhki...\n-----END PUBLIC KEY-----",
    "privateKey": "-----BEGIN PRIVATE KEY-----\nMIIEvQIBA...\n-----END PRIVATE KEY-----"
  }

POST /sign-license

• Request Body:

  {
    "licenseKey": "USER123-PRODUCT456-EXP20251231",
    "privateKey": "-----BEGIN PRIVATE KEY-----\nMIIEvQIBA...\n-----END PRIVATE KEY-----"
  }

• Returns: { signature: string }
• Description: Signs a license key using the provided private key.
• Example Response:

  {
    "signature": "k7d9f8a8g9s7d9f8a7g9s7d..."
  }

POST /verify-license

• Request Body:

  {
    "licenseKey": "USER123-PRODUCT456-EXP20251231",
    "signature": "k7d9f8a8g9s7d9f8a7g9s7d...",
    "publicKey": "-----BEGIN PUBLIC KEY-----\nMIIBIjANBgkqhki...\n-----END PUBLIC KEY-----"
  }

• Returns: { valid: boolean }
• Description: Verifies if the given license key and signature match the public key.
• Example Response:

  {
    "valid": true
  }

🔹 Try it in Swagger UI

📌 Swagger API Docs: https://license-signing-api.onrender.com/api-docs/

---

⚡ Usage (Local Development)

📦 Installation

To install this package locally, run:

npm install

Requirements

• Node.js 16+
• Express.js (for API)
• Crypto module (built into Node.js)

1️⃣ Generate a Key Pair

To create an RSA public-private key pair, use:

const { generateKeyPair } = require("./src/generateKeys");

const { privateKey, publicKey } = generateKeyPair();
console.log("Private Key:", privateKey);
console.log("Public Key:", publicKey);

---

2️⃣ Sign a License Key

To sign a license key with your private key, use:

const { signLicense } = require("./src/signLicense");

const licenseKey = "USER123-PRODUCT456-EXP20251231";
const signature = signLicense(licenseKey, privateKey);
console.log("🔏 Signature:", signature);

---

3️⃣ Verify a License Key

To verify a license key, use:

const { verifyLicense } = require("./src/verifyLicense");

const isValid = verifyLicense(licenseKey, signature, publicKey);
console.log("✅ Valid License:", isValid);

---

🧪 Running Tests

To run the unit tests:

npm test

or

jest

---

📜 License

This project is licensed under the MIT License.
Feel free to modify and use it in your own projects.

---

🤝 Contributions

Pull requests are welcome! Please follow the contribution guidelines in docs/CONTRIBUTING.md.

I'm pushing this tool to GitHub Marketplace to make it easier for developers and teams to integrate secure license key management into their workflow.

💡 Want to support development?
This project is open for sponsorship! Your contributions help me bring Post-Quantum Security to software licensing.

👉 Sponsor me on GitHub 🚀

---

📧 Contact

• GitHub: https://github.com/tsrinarmwong
• Email: tsrinarmwong.careers@hawk.iit.edu

---

🔥 Happy coding! 🚀