Setting Up Google Auth on SSH on CentOS-7

Follow Digital Ocean tutorial for the setup: https://www.digitalocean.com/community/tutorials/how-to-set-up-multi-factor-authentication-for-ssh-on-centos-7

Notes on /etc/ssh/sshd_config:

• With UsePAM yes, both password and keyboard-interactive follow /etc/pam.d/sshd
• PasswordAuthentication yes is the same as AuthenticationMethods password

Differences between AuthenticationMethods password and keyboard-interactive:

• password accepts only 1 response from the user
• keyboard-interactive accepts multiple responses from user

Enforcing both password and Google Authenticator to login:

• Use keyboard-interactive to ensure successful authentication with 2FA and password

Prompt differences:

• password: (hugo@192.168.0.14) Password:
• keyboard-interactive: Password:

Time synchronization:

• Crucial for accurate authentication
• For Docker, ensure the host’s clock is synchronized