In this post, I detail the steps to implement a custom external identity provider in Sitefinity. At the end, you will have a Sitefinity instance configured as a client to a separate IdentityServer application. When a user authenticates to IdentityServer the user will be authenticated to Sitefinity and assigned the 'User' role. This uses the OpenID Connect standard. I do not assume there is a pre-configured IdentityServer application already running. I will cover both the IdentityServer setup and Sitefinity setup. This post uses Sitefinity 11 and IdentityServer 4. The software required for this tutorial is Visual Studio 2017, SQL Server Express, .NET framework 4.7.1, dotnet core 2.0, and git (Optional).

ASP .NET Core MVC comes with dependency injection built in and the options available will cover most use cases. In this post I will summarize what is available and how to configure and use it. This post does not explain the concept of dependency injection or why it is a helpful practice to follow but how it is integrated into the ASP .NET Core MVC framework.