Smart card-only authentication (Yubikey) not happening on boot up w/ macOS Big Sur

Hello Lindsay,

Thank you for the suggestion. I referenced the quick troubleshooting guides on Yubico's website and they unfortunately didn't help. I will submit a ticket.

For documentation purposes on this thread for anyone reading in the future, I have so far tried the following:

1. Installed the smart-card only authentication sample profile provided by apple, and enabled smart-card only authentication for the terminal's LOGIN command (both of these can be found in the following article): Configure macOS for smart card-only authentication - Apple Support
2. Ran the following command referenced in this article: Configuring macOS for smart card–only authentication - Apple Support

sudo defaults write /Library/Preferences/com.apple.security.smartcard enforceSmartCard -bool true

I will keep this thread posted as I progress. Thank you!

Jordan

Hi all,

Writing this a couple weeks later. Yubico support got back to me. Apparently it was the fact that FireVault was enabled on my Mac that I couldn't login with my YubiKey at start up. FireVault is a security mechanism in macOS that keeps your entire drive encrypted until your password is entered. This cannot be bypassed at all; not even with a security key. This is why the password is necessary, unless FireVault is turned off.

You can turn it off by going to System Preferences > Security & Privacy > FireVault. This could take a while to accomplish depending on hard drive size. Personally, I just undid my key, since it is a pain to have to use it to log in every single time, but I thought I'd write it down for anyone in the future with this question.

Thanks!

Jordan