Web API Authentication in ASP.NET 5

I’ve been studying ASP.NET 5 for some time now and there is something I’m yet confused. To implement authentication in Web API 2 what I used to do was basically use the OWIN OAuth Authentication Server Middleware. It was simple to use, I could configure just what I needed and there wasn’t a bunch of stuff I needed to put on the app without need for it.

Now, at first I didn’t find this in ASP.NET 5 and I thought it was a matter of time to wait the middleware to show up. But yesterday, reading on the issues on the Security repo I found out that apparently there is no intention to port this middleware to the new version of the framework.

Instead, it seems people are encouraged to use Identity Server 3. I took a look on the project and although it is nice and has many usages I really prefer to configure just the minimum I need sometimes. Also, another drawback is that Identity Server 3 needs the full CLR, so if I need to use it in order to provide authentication on my application I would need to stop using Core CLR, which for me is a huge disadvantage since Core CLR is a lot more lightweight.

So, if I don’t want to use the Identity Server 3 on ASP.NET 5, how can I implement authentication for Web API if the OAuth Authentication Server middleware is gone? Has anyone been through that and found a way to deal with it?

How to deal with authentication on ASP.NET 5 Web API without using Identity Server 3?


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Method 1

Indeed, there’ll be no OAuthAuthorizationServerMiddleware in ASP.NET 5.

If you’re looking for the same low-level approach, you should take a look at AspNet.Security.OpenIdConnect.Server: it’s an advanced fork of the OAuth2 authorization server middleware that comes with Katana 3 but that targets OpenID Connect, as you already figured out (
OAuth Authorization Service in ASP.NET Core).


OpenID Connect is itself based on OAuth2 and is basically a superset offering standardized authentication features. Don’t worry: you can, of course, use ANY OAuth2 client with ANY OpenID Connect server, including AspNet.Security.OpenIdConnect.Server.

Don’t miss the MVC 6 sample: https://github.com/aspnet-contrib/AspNet.Security.OpenIdConnect.Server/tree/dev/samples/Mvc

app.UseJwtBearerAuthentication(new JwtBearerOptions
    AutomaticAuthenticate = true,
    AutomaticChallenge = true,
    Audience = "http://localhost:54540/",
    Authority = "http://localhost:54540/"

app.UseOpenIdConnectServer(options =>
    options.Provider = new AuthorizationProvider();

Good luck, and don’t hesitate to ping me if you need help.

Method 2

I ran into the exact same issue when trying to use the OWIN OAuth Authorization Server middleware in ASP.NET 5, so I decided to port the code myself. You can find the source at this GitHub repo https://github.com/XacronDevelopment/oauth-aspnet or just use the NuGet packages OAuth.AspNet.AuthServer and OAuth.AspNet.Tokens. Check out the source code to see how things are wired up; the samples in the source are the same samples Microsoft created here http://bit.ly/1MOGDEJ except with ASP.NET 5 examples added.

All methods was sourced from stackoverflow.com or stackexchange.com, is licensed under cc by-sa 2.5, cc by-sa 3.0 and cc by-sa 4.0

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