Broken Authentication in Restify with Bearer Tokens

Broken Authentication in Restify when using Bearer Tokens typically arises from insecure token handling, weak token generation, or missing validation on the server side. Restify is a Node.js framework for building REST APIs, and when developers use Bearer Tokens without enforcing strict transport security and validation, the authentication mechanism can be bypassed or abused.

One common pattern is issuing a token upon login but failing to validate its integrity or scope on subsequent requests. For example, if the token is not verified against a trusted signing key or if the algorithm is not explicitly set, an attacker may supply a tampered token or none at all. A vulnerable Restify server might look like this:

const restify = require('restify');
const server = restify.createServer();

server.use(restify.plugins.bodyParser());

server.post('/login', (req, res, next) => {
  const { username, password } = req.body;
  if (username === 'admin' && password === 'password123') {
    // Insecure: predictable token, no expiration, no signing
    const token = 'static-secret-token';
    res.send({ token });
  } else {
    res.send(401, { error: 'Unauthorized' });
  }
  return next();
});

server.get('/profile', (req, res, next) => {
  const auth = req.headers.authorization;
  if (auth && auth.startsWith('Bearer ')) {
    const token = auth.split(' ')[1];
    // Insecure: no validation, accepts any string as token
    res.send({ profile: { username: 'admin' } });
  } else {
    res.send(401, { error: 'Unauthorized' });
  }
  return next();
});

server.listen(3000, () => {
  console.log('Server running on port 3000');
});

In this example, the token is static, unverified, and sent without HTTPS enforcement. An attacker can intercept or guess the token and access protected endpoints. Additionally, if the token is transmitted over unencrypted channels, it is susceptible to interception via man-in-the-middle attacks.

Another risk involves improper token parsing. If the server does not strictly check the Authorization header format, an attacker may exploit ambiguous parsing to gain unauthorized access. For instance, missing checks for token type or presence of extra whitespace can lead to logic flaws. Furthermore, if the token is not bound to a specific scope, permissions, or audience, privilege escalation or horizontal/vertical BOLA/IDOR issues may arise.

middleBrick scans detect such misconfigurations by analyzing the API specification and runtime behavior, identifying missing validation, weak token generation, and improper usage of Bearer tokens. Findings are mapped to frameworks like OWASP API Top 10 and include prioritized guidance to harden authentication flows.

To remediate Broken Authentication with Bearer Tokens in Restify, enforce strict token validation, use cryptographically secure token generation, and require HTTPS. Below is a secure implementation example that uses JSON Web Tokens (JWT) with proper verification and expiration handling.

const restify = require('restify');
const jwt = require('jsonwebtoken');

const server = restify.createServer();
server.use(restify.plugins.bodyParser());

const SECRET_KEY = process.env.JWT_SECRET || 'super-secure-secret-change-in-production';

server.post('/login', (req, res, next) => {
  const { username, password } = req.body;
  // In real apps, validate credentials against a secure store
  if (username === 'admin' && password === 'password123') {
    const token = jwt.sign({ sub: username, scope: 'profile' }, SECRET_KEY, {
      algorithm: 'HS256',
      expiresIn: '1h',
      issuer: 'middleBrick-demo',
    });
    res.setHeader('Content-Type', 'application/json');
    res.send(200, { token });
  } else {
    res.send(401, { error: 'Unauthorized' });
  }
  return next();
});

server.use((req, res, next) => {
  const auth = req.headers.authorization;
  if (auth && auth.startsWith('Bearer ')) {
    const token = auth.split(' ')[1];
    try {
      const decoded = jwt.verify(token, SECRET_KEY, { algorithms: ['HS256'] });
      req.user = decoded;
    } catch (err) {
      res.send(401, { error: 'Invalid token' });
      return next(new restify.UnauthorizedError('Invalid token'));
    }
  } else {
    res.send(401, { error: 'Authorization header required' });
    return next(new restify.UnauthorizedError('Missing authorization'));
  }
  return next();
});

server.get('/profile', (req, res, next) => {
  // req.user is verified and contains the payload
  res.send({ profile: { username: req.user.sub, scope: req.user.scope } });
  return next();
});

server.listen(3000, () => {
  console.log('Secure server running on port 3000');
});

Key improvements include using JWT with a strong secret, specifying an algorithm, setting short expiration times, and validating the token on every request. The server explicitly checks the Authorization header format and rejects malformed or missing tokens.

In production, serve the API exclusively over HTTPS to protect token transmission. Avoid hardcoded secrets; use environment variables or a secrets manager. For enhanced security, consider integrating with an identity provider and using asymmetric signing (e.g., RS256). The middleBrick Pro plan supports continuous monitoring of such configurations and can alert you if insecure token handling is detected in your CI/CD pipeline via the GitHub Action or MCP Server integrations.

When scanning with middleBrick, you receive a prioritized list of findings with remediation guidance, including specific checks for Bearer token misuse, missing HTTPS, and weak token generation. This helps you address authentication issues before they can be exploited.