Customizing Token Based Authentication (OAuth) in ASP.NET Web API with Existing User Database

ASP.NET Web API project provides built-in OAuth provider to authorize and authenticate users by using access tokens. By default, the user information is stored using OWIN Middleware in the ASP.NET Identity system. The ASP.NET Identity system stores all the user information in a database where it utilizes Entity Framework Code First to implement all of its persistence mechanism. However, sometimes we were faced with a situation where we want to customize our web service to use another or existing database such as ASP.NET Membership, or perhaps our custom made user table. This tutorial will explain the step-by-step procedure to customize built-in token based authentication in ASP.NET Web API to our needs. [Read more]