Google-Authenticator-2FA-Notes

Notes for setting up Google Authenticator

Prerequisites

Google Authenticator App

Android - https://play.google.com/store/apps/details?id=com.google.android.apps.authenticator2

iOS - https://itunes.apple.com/us/app/google-authenticator/id388497605

Instructions

WARNING: It is possible that you may become locked out if there are issues during setup. Therefore it is highly suggested that you have the option to physically access the machine you are installing to in the event that you do become locked out.

1. Clone google-authenticator-libpam repo. git clone https://github.com/google/google-authenticator-libpam.git

2. Build and install. ./bootstrap.sh && ./configure --prefix=/usr && make && sudo make install

3. Run google-authenticator and follow the setup instructions.

4. Add ChallengeResponseAuthentication yes to /etc/ssh/sshd_config

5. Add auth required pam_google_authenticator.so to /etc/pam.d/sshd

External Resources

• Arch Linux Wiki for Google Authenticator : https://wiki.archlinux.org/index.php/Google_Authenticator
• Github repository for Google's google-authenticator-libpam : https://github.com/google/google-authenticator-libpam
• Arch Linux Wiki for Secure Shell ( ssh ): https://wiki.archlinux.org/index.php/Secure_Shell
• Arch Linux Wiki for Rate Limiting with UFW : https://wiki.archlinux.org/index.php/Uncomplicated_Firewall#Rate_limiting_with_ufw