Setting Up Two-Factor Authentication with TOTP and Google Authenticator on Debian Server

In today's digital age, securing our online accounts has become a crucial task. Many websites and services offer two-factor authentication (2FA) to ensure that users can securely access their accounts. Enabling 2FA on your SSH server is also a great idea, as it adds an extra layer of security to prevent unauthorized access.

To set up two-factor authentication with TOTP and Google Authenticator on Debian server, you will need to install the libpam-google-authenticator package, which is available in the default Debian repository. Here's how you can do it:

First, log into your Debian server and run the following command:

```

sudo apt install -y libpam-google-authenticator

```

Once the installation is complete, you will need to configure Google Authenticator on your server. You can do this by running the google-authenticator command in your terminal window.

```

google-authenticator

```

This command will generate a secret key, verification code, and emergency scratch code. Enter these codes into your terminal window to confirm their correctness.

Next, you will need to scan the QR code using your mobile phone's TOTP app, such as Google Authenticator or FreeOTP. You can enlarge the terminal window by resizing it to view the full QR code. Once scanned, you will see a six-digit one-time password on your phone.

When prompted, answer 'y' to the question 'Do you want authentication tokens to be time-based?' Then, run the following command:

```

google-authenticator

```

This will create a new secret key in your home directory.

To use Google Authenticator with SSH, you will need to install it on your mobile phone. You can download it from the Google Play or Apple app store. The Google Authenticator app is not open-source, but FreeOTP, an open-source TOTP mobile app developed by Red Hat, is an alternative option.

Once installed, follow these steps:

1. Open Google Authenticator on your mobile phone.

2. Scan the QR code displayed in your terminal window using the TOTP app.

3. Enter the six-digit one-time password displayed on your phone when prompted.

4. You will be asked to enter a time-based one-time password. This is computed using the TOTP algorithm, which is an IETF standard.

Enabling two-factor authentication with TOTP and Google Authenticator on Debian server can greatly improve the security of SSH service on your server. With this setup, you will need to enter both a password and a time-based one-time password to log in to your server remotely.

In summary, setting up two-factor authentication with TOTP and Google Authenticator on Debian server is a straightforward process that requires minimal configuration. This tutorial has shown you how to install and configure Google Authenticator on your Debian server using libpam-google-authenticator package, and how to use it with SSH for enhanced security.

Totp google authenticator