Is there a way to access Apple iCloud using an authentication service like OAuth or another similar service? I am trying to get access to a users calendar data. I have found a way to access their servers using CalDAV and a users login info. However I don't want to be storing sensitive user information in order to access the servers.
My understanding is that iCloud does not offer any such authentication service. The best you can do is to ask the users to create App specific passwords: https://support.apple.com/en-us/HT204397