For smart card authentication to a Linux desktop, you must configure the path to the root certificate signed by a certificate authority (CA).

To configure the path to the root CA certificate, modify the /etc/nginx/conf.d/vmwvadc.conf configuration file by uncommenting the lines under ###Enable user certificate(smartcard) authentication such that they appear as follows.
ssl_verify_client optional;
ssl_client_certificate /etc/vmware/ssl/trustCerts.pem;

Copy the CA certificate to trustCerts.pem and place the certificate file in the /etc/vmware/ssl/ directory.

For information on configuring smart card authentication to desktops running specific Linux distributions, see the Setting Up Linux Desktops in Horizon document.