OAuth Authorization Service in ASP.NET Core - asp.net

Question

In Web API 2, you used to be able to create an endpoint to issue a token by setting up an OAuth Authorization Server via middleware like below:
//Set up our auth server options.
var OAuthServerOptions = new OAuthAuthorizationServerOptions()
{
AllowInsecureHttp = true,
TokenEndpointPath = new PathString("/token"),
AccessTokenExpireTimeSpan = TimeSpan.FromDays(1),
Provider = new SimpleAuthorizationServerProvider()
};
// Sets up the token issue endpoint using the options above
app.UseOAuthAuthorizationServer(OAuthServerOptions);
Perhaps I'm missing it, but I'm trying to figure out how to do this in ASP.NET Core. I've looked through the source (https://github.com/aspnet/Security) but I don't really see anything analogous. Is there a new way to accomplish this? Do I need to just create a controller and do it myself?
I see how OAuth Authentication can be set up via Middleware, but this regards the authorization portion where I issue claims from my API.

Answer 1

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!

Answer 2

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.AuthServer
https://www.nuget.org/packages/OAuth.AspNet.Tokens
https://www.nuget.org/packages/OAuth.Owin.Tokens