# 🔐 secure-transfer

[![NPM version](https://img.shields.io/npm/v/secure-transfer.svg)](https://www.npmjs.com/package/secure-transfer)

A simple and secure hybrid encryption solution (AES + RSA) for sending encrypted payloads from frontend to backend.

---

## ⚙️ Installation

```bash
npm install secure-transfer
```

🗝️ Key Generation (CLI)

Generate your RSA key pair before using:

npx secure-transfer generate:keys --dir=./keys --passphrase=your-secure-passphrase

✅ This creates:

• keys/private.pem
• keys/public.pem

🌐 Frontend Usage

import { encryptPayload } from "secure-transfer/client/encrypt";

const encrypted = await encryptPayload(payload, "/public-key"); // or full URL

await fetch("/your-endpoint", {
  method: "POST",
  headers: { "Content-Type": "application/json" },
  body: JSON.stringify(encrypted),
});

✅ This:

• Fetches the public key
• Encrypts your payload using AES
• Encrypts AES key using RSA
• Sends { encryptedData, encryptedSecretKey, iv } to backend

🔧 Backend Usage

const { setupSecureTransfer } = require("secure-transfer");
const path = require("path");

const { decryptMiddleware } = setupSecureTransfer({
  keyDir: path.join(__dirname, "keys"),
  passphrase: "your-secure-passphrase",
});

app.post("/your-endpoint", decryptMiddleware, (req, res) => {
  console.log(req.body); // original decrypted payload
  res.send("✅ Securely received");
});

✅ decryptMiddleware:

• Decrypts AES key using RSA private key
• Decrypts data using AES
• Attaches the original payload to req.body

🧪 Testing

npm test

✅ Run tests to verify encryption and decryption behavior.

📝 Notes

• You must host your public key on a known route like /public-key
• Never expose your private key to the frontend
• Always use HTTPS in production