🛡️ Encrypted Message API (Node.js | AES-256-CBC)

This is a lightweight encryption/decryption REST API built with Node.js using AES-256-CBC encryption.
It’s ideal for learning cryptography basics, red team tooling, or internal message encryption.

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🔧 Features

• AES-256-CBC encryption with random IV
• Key derivation using crypto.scryptSync
• Hex-formatted iv:cipher combo output
• Manual or Express-based server
• Minimalist, OPSEC-aware design
• Ready to test with curl

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🚀 Getting Started

📁 Clone the Repo

git clone https://github.com/YOUR_USERNAME/encrypted-message-api.git
cd encrypted-message-api

📥 Install Dependencies

npm install express

    ✅ crypto is a built-in Node.js core module — no need to install it separately.

▶️ Run the Server

node server.js

Server will run at http://localhost:3000
📁 File Structure

encrypted-message-api/
├── server.js       # Express or raw HTTP server
└── encryptor.js    # Encryption/decryption logic

🔐 API Endpoints
➤ /encrypt

Encrypt a plaintext message using a passphrase.
✅ CURL Example

curl -X POST http://localhost:3000/encrypt \
  -H "Content-Type: application/json" \
  -d '{"message":"Attack at 0400", "key":"0x7l_secret"}'

🔁 Response:

{
  "encrypted": "ivhex:cipherhex"
}

➤ /decrypt

Decrypt an encrypted message using the same key.
✅ CURL Example

curl -X POST http://localhost:3000/decrypt \
  -H "Content-Type: application/json" \
  -d '{"encrypted":"ivhex:cipherhex", "key":"0x7l_secret"}'

🔁 Response:

{
  "decrypted": "Attack at 0400"
}

🛠️ Parameters
Parameter	Type	Required	Used In	Description
message	string	✅	/encrypt	Plaintext message to encrypt
key	string	✅	Both	Secret passphrase used for AES key derivation
encrypted	string	✅	/decrypt	Hex string of format iv:ciphertext
⚙️ Crypto Details

    Algorithm: AES-256-CBC

    Key Derivation: crypto.scryptSync(key, salt, 32)

    IV: 16-byte random buffer per encryption

    Format: iv_hex:ciphertext_hex

🧠 Built By

0x7l