Signout support for server-side web applications

The HTTP-based logout specification defines a mechanism for an OpenID Connect provider to inform client applications that a user has signed out. This is performed by creating an <iframe> to a well-known “logout URI” in each client application that the user has signed into. These <iframe>s are rendered on the “signed out” page at the OpenID Connect provider. This allows the <iframe> s to be executed in the context of the user’s browser, thus allowing each client application to clear the user’s session (whatever that means for the application).

To enable this for a client application, the Client configuration must have set the LogoutUri configuration property. By default, the user’s session id is passed as a sid query string parameter and it intended to allow the client application to authenticate the signout notification. This sid parameter can be disabled by setting LogoutSessionRequired to false on the Client configuration.

A MVC client application would then need to handle the signout request with something like this:

public void SignoutCleanup(string sid)
    var cp = (ClaimsPrincipal)User;
    var sidClaim = cp.FindFirst("sid");
    if (sidClaim != null && sidClaim.Value == sid)

To use this technique for signout notification, consult the sample MVC application here.