Here's a recipe for accessing Dropbox and using OAuth 1.0a in KRL.
I've added a new entry to the KRL cookbook that shows how to access the Dropbox API, which is protected with OAuth 1.0a, from CloudOS applications. There's lots of KRL goodness there. My primary reason for doing this is to show CloudOS developers how to deal with OAuth protected APIs from within CloudOS applications. While this is for OAuth 1.0a, OAuth 2 is considerably simpler and the techniques in this recipe will be apropos there as well.