Which Certificate (service) is used to integrate with Intune ? Is EKU required both for Server and Client auth?

[Nate Zhang]

Hi Experts,

I'm following the guide to integrating ISE with Intune. 

In the step of 'Export ISE System Certificate', I got stuck since my customer uses all CA signed certificates separated by Admin, Portal, EAP-Auth, pxgrid service.

Which one shall I export in this case? 

Additionally, if it is the one EAP-Auth cert I should export, is it needed to have EKU both client authentication (1.3.6.5.5.7.3.2) and server authentication (1.3.6.1.5.5.7.3.1) in the certificate? 

Currently, we only have Server auth for the purpose of client 802.1x EAP-TLS.

[Mohammed al Baqari · Accepted solution]

Hi,

The certificate is the Admin one because Intune and ISE communicates using
APIs (not EAP).

Regarding the EKU, it has to be client/server authentication for mutual
authentication between Intune and ISE

[Nate Zhang]

Hi Mohammed,

Thank you for your response. Is the EKU mandatory?
I'm referring to doc: https://community.cisco.com/t5/security-documents/how-to-implement-ise-server-side-certificates/ta-p/3630897
It is said only pxgrid cert requires both server/client auth EKU.

If I have to revise my admin cert with both EKU, I think I have to deregister my cluster (8 nodes) and register again with new cert, am I right?

[Mohammed al Baqari]

I replied to your private message :)

[hslai]

What Mohammed al Baqari said appears correct. It appears Microsoft Intune using the ISE admin certificate(s) to validate the requests and, hence, the client auth on them.

[Nate Zhang]

Thank you for your verification.