Welcome to the forums
From the Smart Card Guide:
"Before you configure smart card authentication
To use a smart card to log on to a Red Hat Linux or CentOS computer,
verify that the computers meet these requirements:
- Are running Red Hat Linux (32- or 64-bit) version 5.6 or later, or CentOS version 5.6 or later, and running the GNOME desktop. The agent does not support use of a smart card with the KDE desktop.
- Have agent version 5.0.4 or later installed (for a single-user card). A multi-user card requires the 5.1 or later agent.
- Are joined to the Windows domain.
- Have a supported smart card reader attached"
https://docs.centrify.com/en/css/suite2017.1/centrify-linux-smartcard.pdf
Note: Don't confuse the CAC/PIV utility for Mac with our Smart Card support for RHEL and CentOS.
I hope this works,
R.P