OAuth Authorization Service in ASP.NET Core

EDIT (01/28/2021): AspNet.Security.OpenIdConnect.Server has been merged into OpenIddict as part of the 3.0 update. To get started with OpenIddict, visit documentation.openiddict.com.

Don't waste your time looking for an OAuthAuthorizationServerMiddleware alternative in ASP.NET Core, the ASP.NET team simply decided not to port it: https://github.com/aspnet/Security/issues/83

I suggest having a look to AspNet.Security.OpenIdConnect.Server, an advanced fork of the OAuth2 authorization server middleware that comes with Katana 3: there's an OWIN/Katana 3 version, and an ASP.NET Core version that supports both the full .NET framework and .NET Core.

https://github.com/aspnet-contrib/AspNet.Security.OpenIdConnect.Server

ASP.NET Core 1.x:

app.UseOpenIdConnectServer(options =>{    options.AllowInsecureHttp = true;    options.TokenEndpointPath = new PathString("/token");    options.AccessTokenLifetime = TimeSpan.FromDays(1);    options.TokenEndpointPath = "/token";    options.Provider = new SimpleAuthorizationServerProvider();});

ASP.NET Core 2.x:

services.AddAuthentication().AddOpenIdConnectServer(options =>{    options.AllowInsecureHttp = true;    options.TokenEndpointPath = new PathString("/token");    options.AccessTokenLifetime = TimeSpan.FromDays(1);    options.TokenEndpointPath = "/token";    options.Provider = new SimpleAuthorizationServerProvider();});

To learn more about this project, I'd recommend reading http://kevinchalet.com/2016/07/13/creating-your-own-openid-connect-server-with-asos-introduction/.

Good luck!

For anyone still looking for the original OAuth Authorization Server in ASP.NET 5, I have ported the code and the original sample here: https://github.com/XacronDevelopment/oauth-aspnet

The port includes backwards compatibility to allow ASP.NET 4.x resource servers to read the access tokens created by the authorization server.

The nuget packages are here: https://www.nuget.org/packages/OAuth.AspNet.AuthServerhttps://www.nuget.org/packages/OAuth.AspNet.Tokenshttps://www.nuget.org/packages/OAuth.Owin.Tokens