Throughout the XenMobile deployments with Certificate Based Authentication(CBA) I came across some items which I thought was worth mentioning.
1. CBA up until Secure Mail 10.6.20 / Secure Hub 10.6.20 was requesting new certificates on SSL exceptions, in effect the exceptions were triggered on every SSL connection error that occurred and thus requesting a new certificate from the PKI, this got resolved in version 10.6.20 by not using Java codes anymore but instead reading the NetScaler Gateway error code which gets presented to the client.
2. The PKI / Credential Provider settings configured with template, validity, CRL and renewal configured on the PKI server won’t work for CBA, this is because CBA is not a payload certificate but only a SIGN method. WiFi certificate which get pushed do honor the validity, renewal and CRL options.
3. With above actions you’ve might get a really large PKI environment which is not necessary and therefore maybe you would need to migrate to a new PKI server, this can be done side by side by creating a new PKI/Credential Provider and configuring those accordingly and migrate in a controlled fashion
4. You might see issued Certificates which aren’t valid anymore or revoked and those devices still get access to the MAM store, this is resolved when you apply CRL mandatory or OCSP mandatory see the following article for some more information regarding CRL: https://docs.citrix.com/en-us/netscaler/12/ssl/manage-cert-revocate-lists.html
Hope these lessons learned help and if there are any comments or questions please feel free to drop them here.