Скачать или смотреть How to Integrate FreeRADIUS, Active Directory, and Google Authenticator for VPN 2FA Authentication

Learn how to set up FreeRADIUS with Active Directory and Google Authenticator to enable two-factor authentication (2FA) for VPN connections. Follow our step-by-step guide for seamless integration.
---
This video is based on the question https://stackoverflow.com/q/59026721/ asked by the user 'Naiame Nel'Theri' ( https://stackoverflow.com/u/6302886/ ) and on the answer https://stackoverflow.com/a/66270197/ provided by the user 'Naiame Nel'Theri' ( https://stackoverflow.com/u/6302886/ ) at 'Stack Overflow' website. Thanks to these great users and Stackexchange community for their contributions.

Visit these links for original content and any more details, such as alternate solutions, latest updates/developments on topic, comments, revision history etc. For example, the original title of the Question was: Freeradius + Active Directory + Google Authenticator

Also, Content (except music) licensed under CC BY-SA https://meta.stackexchange.com/help/l...
The original Question post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license, and the original Answer post is licensed under the 'CC BY-SA 4.0' ( https://creativecommons.org/licenses/... ) license.

If anything seems off to you, please feel free to write me at vlogize [AT] gmail [DOT] com.
---
Setting Up Two-Factor Authentication for VPN Users

In today's digital world, securing access to networks is vital, especially for organizations that use Virtual Private Networks (VPNs). Implementing two-factor authentication (2FA) ensures that only authorized users can access sensitive information. This guide will guide you through configuring FreeRADIUS, Active Directory, and Google Authenticator to authenticate VPN users effectively.

The Problem

You want to set up a VPN that requires two-factor authentication for users connecting to it. Currently, you have a setup involving Cisco Identity Services Engine (ISE), FreeRADIUS Server, and Active Directory. Your configuration allows users to log in with a username and password, but the server does not prompt for a one-time password (OTP) after successful authentication with Active Directory.

Proposed Solution

Step 1: Understanding the Request Process

To successfully implement 2FA, your FreeRADIUS configuration needs to:

Authenticate the user against Active Directory.

Check if the user has provided the OTP from Google Authenticator.

Process the request based on the presence of a state attribute.

Step 2: Configuring FreeRADIUS

Below are detailed configurations that you can set in your FreeRADIUS server.

FreeRADIUS Configuration (/etc/raddb/sites-enabled/default)

Ensure your FreeRADIUS server checks for the state attribute:

[[See Video to Reveal this Text or Code Snippet]]

Clients Configuration (/etc/raddb/clients.conf)

Make sure your client configurations are correct:

[[See Video to Reveal this Text or Code Snippet]]

Authorization Configuration (/etc/raddb/mods-config/files/authorize)

You may include default settings to handle common authentication scenarios:

[[See Video to Reveal this Text or Code Snippet]]

PAM Configuration for Google Authenticator (/etc/pam.d/radiusd)

Ensure that PAM supports Google Authenticator:

[[See Video to Reveal this Text or Code Snippet]]

Step 3: Verifying and Testing

Once you’ve configured FreeRADIUS and associated files properly, follow these steps to test your setup:

Try connecting to the VPN using valid credentials.

After successfully authenticating with Active Directory, you should be prompted for an OTP provided by Google Authenticator.

Enter the OTP and confirm successful access.

Common Issues and Troubleshooting

No OTP Prompt: If you don’t see a prompt for the OTP, ensure that the state attribute is getting set correctly in the FreeRADIUS configuration.

Log Files: Check the FreeRADIUS logs (radius.log) for any error messages that can provide clues to any issues in the authentication process.

Conclusion

By setting up FreeRADIUS with Active Directory and Google Authenticator, you can significantly improve the security of your VPN connections through two-factor authentication. With careful attention to configuration and a clear understanding of the request process, you can ensure that users are authenticated securely.

Implementing these changes not only enhances security but also streamlines the user authentication process, helping safeguard sensitive information from unauthorized access.

For further assistance or questions regarding your configuration, feel free to leave a comment below!