うまく動かなかったやつ

crypter.js

const fs = require('fs')
const crypto = require('crypto')
const readline = require('readline');
const ALGORITHM = 'aes-256-cbc';

// main
// node crypter.js [enc/dec] [in filename] [out filename]
(async () => {
  const args = process.argv.slice(2);

  if (args.length !== 3) { usage() }

  const [subCmd, inFile, outFile] = args;

  let data, key
  switch (subCmd) {
    case 'enc':
      data = fs.readFileSync(inFile);
      key = await getKey('Password: ');
      const encData = encryptBase64(data, key);
      fs.writeFileSync(outFile, encData);
      break;
    case 'dec':
      data = fs.readFileSync(inFile);
      key = await getKey('Password: ');
      console.log(key)
      const decData = decryptBase64(data, key);
      fs.writeFileSync(outFile, decData)
      break;
    default:
      usage();
      break;
  }
})();

function usage() {
  console.log('node crypter.js [enc/dec] [in filename] [out filename]');
  process.exit(1);
}


function encryptBase64(data, keyStr) {
  const key = Buffer.from(keyStr);
  const iv = crypto.randomBytes(16);
  const cipher = crypto.createCipheriv(ALGORITHM, key, iv);
  const encData = cipher.update(Buffer.from(data));
  return Buffer.concat([iv, encData, cipher.final()]).toString('base64');
}

function decryptBase64(data, keyStr) {
  const key = Buffer.from(keyStr);
  const buff = Buffer.from(data, 'base64');
  const iv = buff.slice(0, 16);
  const encData = buff.slice(16);
  const decipher = crypto.createDecipheriv(ALGORITHM, key, iv);
  const decData = decipher.update(encData);
  return Buffer.concat([decData, decipher.final()]).toString('utf8');
}

async function getKey(prompt) {
  const key = await getPassword(prompt);
  if (key.length !== 32) {
    console.error('key length must be 32');
    process.exit(1);
  }
  return key
}

function getPassword(prompt) {
  return new Promise(resolve => {
    const rl = readline.createInterface({
      input: process.stdin,
      output: process.stderr,
    });

    rl.stdoutMuted = true;

    rl.query = prompt;
    rl.question(rl.query, function (password) {
      resolve(password);
      rl.close();
    });

    rl._writeToOutput = function _writeToOutput(stringToWrite) {
      if (rl.stdoutMuted)
        rl.output.write("*");
      else
        rl.output.write(stringToWrite);
    };
  })
}