Automating Authentication Flows in TypeScript on a Zero Budget

In the rapidly evolving landscape of web development, automating authentication workflows is crucial for streamlining user onboarding, session management, and security protocols. For security researchers and developers operating with limited resources or zero budget, leveraging open-source tools and native capabilities becomes essential.

This guide explores how to automate authentication flows using TypeScript without incurring any costs. We will focus on pragmatic strategies for managing OAuth2, OpenID Connect (OIDC), and JWT-based flows, emphasizing security, modularity, and maintainability.

Understanding the challenge

Automated auth flows typically involve redirect-based OAuth interactions, token refresh mechanisms, and secure storage of sensitive data like refresh tokens. Without commercial providers or proprietary SDKs, you need to rely on open standards and lightweight libraries to implement these flows.

Setting up the environment

Start with a clean TypeScript project. If you haven't already, initialize a project:

mkdir auth-automation && cd auth-automation
npm init -y
npm install typescript @types/node ts-node node-fetch
npx tsc --init

Here, node-fetch will serve as a lightweight HTTP client for making network requests.

Implementing OAuth2 Authorization Code Flow

The goal is to automate obtaining access tokens via OAuth2's Authorization Code flow, including token refresh.

1. Generate Authorization URL

Construct the authorization URL with necessary parameters:

import { URLSearchParams } from 'url';

const authEndpoint = 'https://auth.example.com/oauth/authorize';
const clientId = 'YOUR_CLIENT_ID';
const redirectUri = 'http://localhost:3000/callback';
const scope = 'openid profile email';
const state = Math.random().toString(36).substring(2); // Random state

const authUrl = `${authEndpoint}?` + new URLSearchParams({
  response_type: 'code',
  client_id: clientId,
  redirect_uri: redirectUri,
  scope,
  state
}).toString();

console.log('Visit the following URL to authorize:', authUrl);

This URL prompts the user to authenticate. Since we're on a zero budget, your app would need to handle the redirect callback to extract the authorization code.

2. Handling the Redirect and Exchanging Code for Tokens

In a production environment, you'd run a local server to intercept the redirect. For testing or automation, simulate or use a manual step.

import fetch from 'node-fetch';

async function exchangeCodeForToken(code: string) {
  const tokenEndpoint = 'https://auth.example.com/oauth/token';
  const response = await fetch(tokenEndpoint, {
    method: 'POST',
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded'
    },
    body: new URLSearchParams({
      grant_type: 'authorization_code',
      code,
      redirect_uri: redirectUri,
      client_id: clientId,
      client_secret: 'YOUR_CLIENT_SECRET' // If applicable
    })
  });

  const tokens = await response.json();
  console.log('Tokens:', tokens);
  return tokens;
}

3. Managing Token Refresh

Tokens expire, so set up a function to refresh using refresh tokens:

async function refreshAccessToken(refreshToken: string) {
  const response = await fetch('https://auth.example.com/oauth/token', {
    method: 'POST',
    headers: {
      'Content-Type': 'application/x-www-form-urlencoded'
    },
    body: new URLSearchParams({
      grant_type: 'refresh_token',
      refresh_token: refreshToken,
      client_id: clientId,
      client_secret: 'YOUR_CLIENT_SECRET' // If applicable
    })
  });

  const newTokens = await response.json();
  console.log('Refreshed Tokens:', newTokens);
  return newTokens;
}

Security best practices without a budget

• Secure storage: Use environment variables or encrypted local storage mechanisms.
• Validation: Always validate the state parameter and tokens.
• Minimal dependencies: Rely on simple, well-maintained libraries.

Conclusion

Leveraging TypeScript and open standards, security researchers can automate authentication workflows effectively without any paid tools. The key is understanding OAuth/OIDC specifications, setting up local or manual processes for initial authorization, and implementing token lifecycle management with minimal dependencies. This approach emphasizes security, control, and cost-efficiency, proving that resource constraints are no barrier to robust automation.

This methodology can be extended and customized to fit various APIs and identity providers, forming the backbone of cost-effective, automated security testing and research workflows.

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