Light Encryption Algorithm (LEA)

Overview

LEA (Light Encryption Algorithm) is a command-line tool written in Go for simple file encryption and decryption on Linux. This project was developed as a university assignment for the KI-ZKR course, focusing on implementing the LEA block cipher and providing a practical CLI for file operations.

⚠️ Disclaimer

"This project has not been validated by formal third-party."

• Do not use LEA for protecting sensitive or production data.
• Use at your own risk.

Features

• 🔒 Strong Encryption: Implements the LEA block cipher with support for ECB, CBC, CFB, OFB, and CTR modes.
• 🛡️ CMAC Authentication: All encrypted files are authenticated with CMAC for robust integrity and authenticity (added in v3.2.0).
• 🎲 Automatic, Secure IV Generation: IVs are generated securely and automatically for every encryption (since v3.1.0).
• 🪟 Windows Compatibility: Improved file handling and terminal support for Windows (since v3.1.0).
• 🗃️ Easy Key Management: Supports 128, 192, and 256-bit keys, easily loaded from files.
• ⚡ Fast and Simple CLI: Easily encrypt and decrypt files from the command line.
• 📊 Progress Bar: Real-time progress bars for multi-file operations.

Installation

Building from source

git clone https://github.com/kopytkg/LEA.git
cd LEA
mkdir build
make
cd build

This will produce binaries for both x86_64 and ARM64 Linux in the build/ directory.

Usage

Run lea --help or lea -h to display the help menu:

lea --help

Command-Line Options

Linux

LEA Encryption Tool
Usage: lea [file] ?[options]

CORE OPERATIONS:
  * -e, --encrypt                Encrypt target file/directory
  * -d, --decrypt                Decrypt target file/directory
    --key=[file]                 Use pre-generated key file (required)
    lea keygen                   Generate new LEA keyfile

KEY MANAGEMENT:
   Generated keys are saved as:
   - key128.lea (128-bit)
   - key192.lea (192-bit)
   - key256.lea (256-bit, default)

   File Format:
   -----BEGIN LEA KEY-----
   Version: 1
   Key: A1B2C3D4:E5F67890:...
   Key Digest: sha256...
   Seed: A1B2C3D4:E5F67890:...
   Seed Digest: sha256...
   -----END LEA KEY-----

ADVANCED:
    --mode=[ecb|cbc|cfb|ofb|ctr]     Encryption mode (default: cbc)
    -r, --recursive              Process directories recursively
    -v, --verbose                Show detailed progress
    --iter=N                     Overwrite N times (default: 3)

DEBUG:
    --version			 Show program version


Examples:
  Encrypt:
    $ lea file.txt -e --key=key256.lea

  Decrypt with raw LEA-generated key:
    $ lea file.txt -d --key=key.256.lea


LEGAL DISCLAIMER:
  This tool is for AUTHORIZED penetration testing only.
  By using this software, you confirm you have permission
  to test the target systems.

Report issues to: <https://github.com/kopytkg/lea/issues>

Example Usage

Generate a Key file:

lea keygen

Please provide key size (128,192,256) [256]: 
17:53:57 INFO Successfully generated key file: key256.lea

Encrypt a file with a 256-bit key (default):

lea myfile.txt -e --key=key256.lea

Decrypt a file:

lea myfile.txt -d --key=key256.lea

Encrypt all files in a folder recursively:

lea folder -e -r --key=key256.lea

Show progress during encryption:

lea folder -e -r -v --key=key256.lea

Security Notice

• This tool is for learning and demonstration only.
• Do not use for real-world or sensitive data encryption.
• The code is not security-audited.

License

This project is licensed under the Creative Commons Zero v1.0 Universal License. See LICENSE for details.