Polhem 

Lightweight OAuth2 sign-in for .NET with Google, Facebook, LINE, Microsoft Entra ID, Auth0 and Okta. Desktop and console applications sign in through the system browser with a loopback redirect and PKCE.

OAuth2 sign-in for ASP.NET Web Forms and MVC applications on System.Web, with Google, Facebook, LINE, Microsoft Entra ID, Auth0 and Okta.

OAuth2 sign-in for ASP.NET Core applications, with Google, Facebook, LINE, Microsoft Entra ID, Auth0 and Okta.