Identityserver4: Extra parameters on endession are not passed along to LogoutRequest

Created on 3 Sep 2020 · 3Comments · Source: IdentityServer/IdentityServer4

Issue / Steps to reproduce the problem

ASP.NET MVC (Owin) client, using latest OpenIdConnect and IdentityServer. Intercept the OpenIdConnectRequestType.Logout request and augment the ProtocolMessage.Parameters collection with a custom name/value pair:

                Notifications = new OpenIdConnectAuthenticationNotifications
                {
                    RedirectToIdentityProvider = async n =>
                    {
                        switch (n.ProtocolMessage.RequestType)
                        {
                            case OpenIdConnectRequestType.Logout:
                                n.ProtocolMessage.SetParameter("logoff_method", n.Request.Path.Value); 
                                break;
                        }
                    }

I can see the parameters on the endsession query string and in the EndSessionRequestValidationLog.Raw collection (see log snippet below).

However, when the logout endpoint in my identity server controller is called and I GetLogoutContextAsync(), the LogoutRequest.Parameters collection is empty:

        [HttpGet("logout")]
        [AllowAnonymous]
        public async Task<IActionResult> Logout([FromQuery] string logoutId)
        {
            var logoutRequest = await _interaction.GetLogoutContextAsync(logoutId);
            if (logoutRequest.Parameters.Count == 0)
                throw new Exception("No additional parameters found in LogoutRequest.");

Relevant parts of the log file


 End session request validation success EndSessionRequestValidationLog {"ClientId":"myclient","ClientName":"my client",…

details
{ClientId: "myclient", ClientName: "my client", SubjectId: "3", PostLogOutUri: "http://localhost:59474/app/v1.0", State: null, 
Raw: {
  post_logout_redirect_uri: "http://localhost:59474/app/v1.0", 
  logoff_method: "/account/logoff", 
  id_token_hint: "***REDACTED***", 
  x-client-SKU: "ID_NET461", 
  x-client-ver: "5.6.0.0"
}, 
_typeTag: "EndSessionRequestValidationLog"}

RequestPath
/connect/endsession
SourceContext
IdentityServer4.Validation.EndSessionRequestValidator

bug report duplicate

Source