um-react/src/decrypt-worker/crypto/qtfm/qtfm_device.ts

import { transformBlob } from '~/decrypt-worker/util/transformBlob';
import type { CryptoBase } from '../CryptoBase';
import { DecryptCommandOptions } from '~/decrypt-worker/types';

export class QingTingFM$Device implements CryptoBase {
  cryptoName = 'QingTing FM/Device ID';
  checkByDecryptHeader = false;

  async checkBySignature(_buffer: ArrayBuffer, options: DecryptCommandOptions) {
    return Boolean(/^\.p~?!.*\.qta$/.test(options.fileName) && options.qingTingAndroidKey);
  }

  async decrypt(buffer: ArrayBuffer, options: DecryptCommandOptions): Promise<Blob> {
    const { fileName: name, qingTingAndroidKey } = options;
    if (!qingTingAndroidKey) {
      throw new Error('QingTingFM Android Device Key was not provided');
    }

    return transformBlob(buffer, (p) => p.make.QingTingFM(name, qingTingAndroidKey));
  }

  public static make() {
    return new QingTingFM$Device();
  }
}