RedirectUri is always null when signing out from MVC app

[sanjeev-saxena-us]

IdentityServer version

7

.NET version

8

Description

On the IdentityServer side running locally, the RedirectUri is always null when making the following call from a client mvc app. Here is the Logout action method in the mvc client app:

public IActionResult Logout()
{
    var props = new AuthenticationProperties()
    {
        RedirectUri = "https://localhost:44300/Home/OnSignedOut"
    };

    //props.Parameters.Add("return-url", "https://localhost:44300/Home/OnSignedOut");
    //await HttpContext.SignOutAsync("oidc", props);
    //return SignOut(prop);
    return SignOut(props, "oidc", "Cookies");
}

Please note, I do not want to specify the PostLogoutRedirectUris property in the Client configurations on the server side

Reproduction steps

No response

Expected behavior

No response

Logs

No response

Additional context

No response

[RolandGuijt]

I'm afraid it is not possible to do this without setting PostLogoutRedirectUris. The protocol demands a way to verify the logout redirect uri just like the redirecturi for the login process needs to be checked with the configuration of the client.
Keep in mind that when using ASP.NET Core that logout uri is not the one you specify in the AuthenticationProperties but the one setup by the authentication middleware. By default: /signout-callback-oidc

[sanjeev-saxena-us]

Got it, thanks @RolandGuijt