With the release of Single Sign On v4.5.3 we have build in support for SharePoint.
Access the AuthAnvil Manager > Single Sign On > Applications > Add new application > Add an application from the catalog.
Enable the Application.
Select the appropriate user role.
Select Protocol Configuration. Update the following with your SharePoint Base URL.
Reply To URL: https://sharepoint.yourcompany.com/_trust/
Audience URI : https://sharepoint.yourcompany.com/_trust/
Select Save Changes.
Test your access from the SSO Portal.
If you would like to configure SharePoint for Office 365 please see this article https://helpdesk.kaseya.com/entries/46954597