QRC Decoder

A TypeScript library for encrypting and decrypting QRC lyrics format.

⚠️ Security Warning

This library implements a non-standard, proprietary algorithm that was reverse-engineered from a specific application. It is NOT a standard implementation of DES or 3DES.

DO NOT use this library for any general-purpose security or cryptographic needs. It is intended only for achieving interoperability with the QRC format.

Installation

Install the package using your favorite package manager.

npm:

npm install qrc-decoder

yarn:

yarn add qrc-decoder

Usage

The library exports two main functions, decryptQrc and encryptQrc.

import { decryptQrc, encryptQrc } from 'qrc-decoder';

const encryptedHex = '...';

try {
  const decrypted = decryptQrc(encryptedHex);
  console.log('Decrypted Lyrics:\n', decrypted);
} catch (error) {
  console.error('Decryption failed:', error);
}

API Reference

decryptQrc(encryptedHexString: string): string

Takes a hexadecimal string of encrypted QRC data and returns the decrypted plaintext lyrics as a UTF-8 string. Throws an error if the input is malformed or decryption fails.

encryptQrc(plaintext: string): string

Takes a plaintext lyric string (UTF-8) and returns a hexadecimal string of the encrypted QRC data.

Acknowledgements

This TypeScript project is a port of the LyricDecoder project by SuJiKiNen.

All credit for the original reverse-engineering and algorithm implementation goes to the author of that project. You can find the original repository here: https://github.com/SuJiKiNen/LyricDecoder

License

This project is licensed under the MIT License. See the LICENSE file for details.