OWIN middleware implementation mixing Windows and Forms Authentication.

PM> Install-Package OWIN-MixedAuth

Before running the samples, make sure to unlock windowsAuthentication section:

1. Open IIS Manager, select the server node, then Feature Delegation.
2. Set Authentication - Windows to Read/Write

1. Open applicationhost.config located at $:\Users{username}\Documents\IISExpress\config
2. Search for windowsAuthentication section and update overrideModeDefault value to Allow.

 <section name="windowsAuthentication" overrideModeDefault="Allow" />

1. Add reference to MohammadYounes.Owin.Security.MixedAuth.dll

2. Register MixedAuth in Global.asax

//add using statement
using MohammadYounes.Owin.Security.MixedAuth;

public class MyWebApplication : HttpApplication
{
   //ctor
   public MyWebApplication()
   {
     //register MixedAuth
     this.RegisterMixedAuth();
   }
   .
   .
   .
}

3. Use MixedAuth in Startup.Auth.cs

//Enable Mixed Authentication
//As we are using LogonUserIdentity, its required to run in PipelineStage.PostAuthenticate
//Register this after any middleware that uses stage marker PipelineStage.Authenticate

app.UseMixedAuth(cookieOptions);

Important! MixedAuth is required to run in PipelineStage.PostAuthenticate, make sure the use statement is after any other middleware that uses PipelineStage.Authenticate. See OWIN Middleware in the IIS integrated pipeline.

4. Enable Windows authentication in Web.config

<!-- Enable Mixed Auth -->
<location path="MixedAuth">
  <system.webServer>
    <security>
      <authentication>
        <windowsAuthentication enabled="true" />
      </authentication>
    </security>
  </system.webServer>
</location>

Important! Enabling windows authentication for a sub path requires windowsAuthentication section to be unlocked at a parent level.