.. _certificatebased-auth: Certificate based authentication *********************************** If you want to use a certificate to allow TreeSize to identify itself to the authentication service, instead of using user-related login information, the following settings must be made: 1. First you need to `create a self-signed certificate `_. You need to add the ``.cer`` file created in the process to your app registration under Certificates & Secrets. You can then use the ``.pfx`` file to log in via TreeSize. 2. Now add the Sites.Selected permission under API Permissions > Add Permission > SharePoint > Application Permissions. The shared site collections must be configured on your SharePoint beforehand. Please contact your SharePoint administrator for this purpose. You can `find configuration help here `_. Problems with authentication =============================== If authentication is not possible despite a valid certificate, please make sure that claims-based (user-independent) authentication is supported by your SharePoint. Please also check that the site collections have been released correctly.