Auth0 Custom Database — Custom Database Connections and User Migration

// Login script for custom database
function login(email, password, callback) {
  const mysql = require('mysql2');
  const connection = mysql.createConnection({
    host: configuration.DB_HOST,
    user: configuration.DB_USER,
    password: configuration.DB_PASSWORD,
    database: configuration.DB_NAME
  });

  connection.query(
    'SELECT id, password_hash, salt FROM users WHERE email = ?',
    [email],
    function(err, results) {
      if (err) return callback(err);
      if (results.length === 0) return callback(new WrongUsernameOrPasswordError(email));

      const user = results[0];
      const hash = crypto.pbkdf2Sync(password, user.salt, 10000, 64, 'sha512').toString('hex');
      if (hash !== user.password_hash) return callback(new WrongUsernameOrPasswordError(email));

      callback(null, {
        user_id: user.id.toString(),
        email: email,
        email_verified: true,
        app_metadata: { legacy_user: true }
      });
    }
  );
}