🔒 File Encryptor Tool (AES-256-GCM)

A simple yet secure File Encryption & Decryption Tool built in Python.
It uses AES-256-GCM for encryption and a password-protected master key for secure key management.

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🚀 Features

• AES-256-GCM file encryption & decryption
• Master key wrapped with password using scrypt (key derivation)
• Change password anytime without re-encrypting files
• Integrity and authenticity validation
• Interactive CLI password prompts
• Built-in unit tests (pytest)
• GitHub Actions CI for test automation

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🧠 Tech Stack

Component	Technology
Language	Python 3.11+
Library	cryptography
Testing	PyTest
Version Control	Git & GitHub
CI/CD	GitHub Actions

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⚙️ Installation & Setup

1️⃣ Clone the repository

git clone https://github.com/Lokeswar72/file-encryptor.git
cd file-encryptor

2️⃣ Create & activate a virtual environment

python -m venv .venv
# Activate (Windows PowerShell)
.venv\Scripts\Activate.ps1

3️⃣ Install dependencies

pip install -r requirements.txt

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🪄 Usage

Generate a master key

python encryptor.py generate-master-key

Creates a new AES master key and encrypts it with a password-derived key (scrypt).
Stores the wrapped key at keys/master_key.bin.enc.

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Encrypt a file

python encryptor.py encrypt examples/secret.txt

Creates an encrypted file: examples/secret.txt.enc.

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Decrypt a file

python encryptor.py decrypt examples/secret.txt.enc

Decrypts the file back to examples/secret.txt.

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Change password

python encryptor.py change-password

Unwraps your master key using the old password and re-wraps it using a new one —
so you can rotate passwords without re-encrypting all files.

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🧪 Running Tests

pytest -q

If everything is working, you’ll see:

..                                                                   [100%]
2 passed in 0.50s

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🧰 GitHub Actions CI

This repository includes a workflow that automatically:

• Sets up Python 3.9, 3.10, and 3.11
• Installs all dependencies
• Runs your PyTest suite

You can see the latest build status at the top of this README.

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✅ Example Output

(.venv) PS> python encryptor.py generate-master-key
Enter password to protect the master key:
Confirm password:
Generated and wrapped master key -> keys\master_key.bin.enc

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📁 Project Structure

file-encryptor/
│
├── encryptor.py                  # Main CLI program
├── tests/
│   └── test_encryptor.py         # Unit tests
├── requirements.txt              # Dependencies
├── .github/workflows/            # CI pipeline
│   └── python-tests.yml
├── keys/                         # Encrypted master key (gitignored)
└── README.md                     # Project documentation

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🛡️ Security Notes

• Keep your keys/master_key.bin.enc backed up safely.
• Never commit or share your master key file or passwords.
• Use strong, unique passwords.
• Test decryption regularly to verify backups.

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🧑‍💻 Author

Lokeswar
GitHub: @Lokeswar72

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📜 License

This project is open source and available under the MIT License.