MD5

const m = require('md5');

app.get('/', (req, res) => {
  const secret = process.env.SECRET;
  const pwd = req.query.pass;

  if (pwd) {
    if (parseInt(m(secret)) === parseInt(m(pwd))) {
      res.send(`Here is the flag: ${process.env.FLAG}`);
    } else {
      res.send('Nope!');
    }
  } else {
    res.send('Send me a password ("pass") query param!');
  }
});