google-authenticator

google-authenticator binary included in libpam-google-authenticator package

~/.google_authenticator configuration file

Make tokens “time-base”": yes
Update the .google_authenticator file: yes
Disallow multiple uses: yes
Increase the original generation time limit: no
Enable rate-limiting: yes

/etc/pam.d/sshd

pam_tally2

See also

• google-authenticator, qrencode
• PAM, libpam_cracklib, pam_tally2, /etc/pam.d/, /etc/pam.d/sshd, pam_oath, pam_sss, /etc/pam.d/login, pam_unix, pam_krb5
• Google Authenticator, sync, libpam-google-authenticator, google-authenticator-libpam (macOS), google-authenticator
• MFA: FreeOTP, Google Authenticator, Okta Verify, Duo Security, Microsoft Authenticator, Strong customer authentication, Dualshield, HOTP, TOTP, OATH, Authy, Push authentication, google-authenticator, Duo Mobile, DenyAllExceptListedIfNoMFA, Configure MFA on AWS, LastPass Authenticator mobile app