🔒 Why Your Login System is a Sitting Duck for Hackers Without reCAPTCHA

In the digital age, login systems are constantly targeted by brute force attacks and malicious bots attempting to compromise user accounts. To combat these threats, developers need robust defenses. One powerful solution is integrating Google reCAPTCHA into your .NET Web API. Here’s how this project demonstrates a secure and user-friendly approach.

🌎 What is CAPTCHA?

CAPTCHA (Completely Automated Public Turing test to tell Computers and Humans Apart) is designed to protect systems from automated bots. Integrating CAPTCHA, such as Google reCAPTCHA, provides multiple benefits:

• Protects against bots overwhelming login endpoints.
• Deters brute force attempts by requiring human validation.
• Enhances the overall security of your application.

🔧 How This Project Implements reCAPTCHA in a .NET 8 Web API

This repository demonstrates a secure, scalable implementation of Google reCAPTCHA in a .NET 8 Web API. Below are the key features and implementation details:

1. Registration Endpoint

This endpoint allows new users to register securely:

• Endpoint: /register
• Method: POST
• Request Body:
• { "username": "string", "password": "string" }
• Response: 200 OK if registration is successful or 400 Bad Request if the username already exists.

2. Basic Login Endpoint (v1)

A straightforward login API for authenticating users without CAPTCHA:

• Endpoint: /v1/login
• Method: POST
• Request Body:
• { "username": "string", "password": "string" }
• Response: 200 OK with a JWT token or 401 Unauthorized for invalid credentials.

3. Login with reCAPTCHA (v2)

This endpoint requires reCAPTCHA validation after multiple failed login attempts:

• Endpoint: /v2/login
• Method: POST
• Request Body:
• { "username": "string", "password": "string", "captchaToken": "string" // Only required after failed attempts }
• Response:
• 200 OK with a JWT token for successful logins.
• 400 Bad Request if reCAPTCHA validation fails.
• 401 Unauthorized for invalid credentials.

4. Secure Endpoint

A protected endpoint to test JWT authentication:

• Endpoint: /secure
• Method: GET
• Response: 200 OK for authenticated users or 401 Unauthorized otherwise.

🔮 Why Use reCAPTCHA?

1. Enhanced Security: Prevents automated login attempts.
2. Human-First Design: Requires minimal effort from genuine users.
3. Scalability: Easily integrates into existing .NET applications.

⚖️ Additional Measures to Mitigate Brute Force Attacks

While reCAPTCHA is a strong deterrent, combining it with other strategies provides comprehensive security:

1. Rate Limiting:
   ▪️Restrict the number of login attempts per IP address within a specific time frame.
   ▪️Example: Allow only 5 login attempts per minute.
2. Account Lockouts:
   ▪️Temporarily lock accounts after multiple failed login attempts.
3. Multi-Factor Authentication (MFA):
   ▪️Add an extra layer of security by requiring OTPs or authenticator apps.
4. Password Policies:
   ▪️Enforce strong passwords to reduce the likelihood of successful brute force attacks.
5. Secure Headers:
   ▪️Use HTTP headers like Content-Security-Policy and Strict-Transport-Security.
6. Logging and Monitoring:
   ▪️Track login attempts and flag unusual activity patterns.

✅ Key Takeaways

Implementing Google reCAPTCHA in your .NET 8 Web API is an effective way to safeguard against brute force and bot attacks. When paired with additional security measures, your application can provide a secure and user-friendly experience.

To learn more or explore the implementation details, check out the full GitHub Repository. Let’s build safer systems together! 🌐✨

Have you implemented reCAPTCHA in your projects? Share your experiences and security tips below! 😊⚡

💻Let’s Connect!

If you have any questions or need further assistance with securing your .NET Core Web API, feel free to reach out:

✨ LinkedIn: https://www.linkedin.com/in/mak11/

✨ Github: https://github.com/mak-thevar

✨ Portfolio: https://mak-thevar.dev

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