faster webservice (Saml) authn to office365 endpoints

It takes just a second to access the web service endpoint of Exchange Online setup with federated security. From a windows form,


The code from the sample takes 20s (as it goes about discovering a URL that is actually pretty static in Office365 land and only then bothers to hit the IP-STS):


Slow original sample

Obviously, we are supposed to discover at “connection time” and locally persist the URL – for use the second time!



Computer Programmer who often does network administration with focus on security servers. Very strong in Microsoft Azure cloud!
This entry was posted in office365, SSO. Bookmark the permalink.