OAuth2 and C# Desktop Apps Don’t Seem To Get Along.

I hadn’t been in Visual Studio for a while now, mostly because I had given up on all of my side projects due to the amount of time they soaked up vs my desire to do better game reviews on here, requiring me to spend more time actually playing the games. I had come up with an idea for a game a while back and was really enjoying developing the concept in my head so I figured it would be good to code up a small application to get my head back in the game before I tackled something a little bit more difficult. One particular idea I had was a Soundcloud downloader/library manager as whilst there are other tools to do this job they’re  a little cumbersome and I figured it couldn’t be too difficult to whip it up in a days worth of coding.

How wrong I was.

The Soundcloud API has a good amount of documentation about it and from what I could tell I would be able to get my stream using it. However since this wasn’t something that was publicly available I’d have to authenticate to the API first through their OAuth2 interface, something which I had done with other sites so I wasn’t too concerned that it would be a barrier. Of course the big difference between those other projects and this one was the fact that this application was going to be a desktop app and so I figured I was either going to have to do some trickery to get the token or manually step through the process in order to get authenticated.

After having a quick Google around it looked like the OAuth library I had used previously, DotNetOpenAuth, would probably be able to fit the bill and it didn’t take me long to find a couple examples that looked like they’d do the job. Even better I found an article that showed an example of the exact problem I was trying to solve, albeit using a different library to the one I was. Great, I thought, I’ll just marry up the examples and get myself going in no time and after a little bit of working around I was getting what appeared to be an auth token back. Strangely though I couldn’t access any resources using it, either through my application or directly through my browser (as I had been able to do in the past). Busting open Fiddler showed that I was getting 401 (unauthorized) errors back, indicating that the token I was providing wasn’t a viable option.

After digging around and looking at some various resources it appears that whilst the OAuth API might still be online it’s not the preferred way of accessing anything and, as far as I can tell, is mostly deprecated. No worries I’ll just hit up the OAuth2 API instead, figuring that it should be relatively simple to authenticate to it since DotNetOpenAuth now natively supports it. Try as I might to find a working example I just simply could not get it to work with Soundcloud’s API, not even using the sample application that DotNetOpenAuth provides. Trying to search for other, more simplistic examples left me empty handed, especially if I tried to search for a desktop application workflow.

I’m willing to admit that I probably missed something here but honestly the amount of code and complexity that appears to be required to handle the OAuth2 authentication process, even when you’re using a library, seems rather ludicrous. Apparently WinRT has it pretty easy but those are web pages masquerading as applications which are able to take advantage of their auth work flow, something which I was able to make work quite easily in the past. If someone knows of a better library or has an example of the OAuth2 process working with a desktop application in C# then I’d love to see it because I simply couldn’t find out how to do it, at least not after half a day of frustration.