# OpenIdConnectProtocolException: Unsupported response type in ASP.NET

**URL:** <https://devforum.okta.com/t/openidconnectprotocolexception-unsupported-response-type-in-asp-net/1477>\
**Category:** OAuth/OIDC\
**Tags:** dotnet\
**Created:** [March 21, 2018, 5:04pm UTC](https://devforum.okta.com/t/openidconnectprotocolexception-unsupported-response-type-in-asp-net/1477 "2018-03-21T17:04:19Z")\
**Posts on this page:** 4\
**Page:** 1

<div class="post-metadata">

**Author:** ![manjeet.soor](https://avatars.discourse-cdn.com/v4/letter/m/278dde/32.png) [@manjeet.soor](https://devforum.okta.com/u/manjeet.soor)\
**Post date:** [March 21, 2018, 5:04pm UTC](https://devforum.okta.com/t/openidconnectprotocolexception-unsupported-response-type-in-asp-net/1477/1 "2018-03-21T17:04:19Z")

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Hi, I am trying to integrate my application with Okta. my Startup.cs code gets executed but it doesn’t display the Okta login page. I am getting the `unsupported_response_type` error.

> Server Error in ‘/’ Application.  
> unsupported\_response\_type  
> Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code.
> 
> Exception Details: Microsoft.IdentityModel.Protocols.OpenIdConnectProtocolException: unsupported\_response\_type
> 
> Source Error:
> 
> An unhandled exception was generated during the execution of the current web request. Information regarding the origin and location of the exception can be identified using the exception stack trace below.
> 
> Stack Trace:
> 
> [OpenIdConnectProtocolException: unsupported\_response\_type]  
> Microsoft.Owin.Security.OpenIdConnect.d\_\_1a.MoveNext() +5677  
> System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw() +26  
> Microsoft.Owin.Security.OpenIdConnect.d\_\_1a.MoveNext() +6419  
> System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +99  
> System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61  
> Microsoft.Owin.Security.Infrastructure.d\_\_0.MoveNext() +571  
> System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +99  
> System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61  
> Microsoft.Owin.Security.Infrastructure.d\_\_0.MoveNext() +255  
> System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +99  
> System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61  
> Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.d\_\_5.MoveNext() +182  
> System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +99  
> System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61  
> Microsoft.Owin.Security.Infrastructure.d\_\_0.MoveNext() +638  
> System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +99  
> System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61  
> Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.d\_\_5.MoveNext() +182  
> System.Runtime.CompilerServices.TaskAwaiter.ThrowForNonSuccess(Task task) +99  
> System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task) +61  
> Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.d\_\_2.MoveNext() +180  
> Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.StageAsyncResult.End(IAsyncResult ar) +69  
> Microsoft.Owin.Host.SystemWeb.IntegratedPipeline.IntegratedPipelineContext.EndFinalWork(IAsyncResult ar) +64  
> System.Web.AsyncEventExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +483  
> System.Web.HttpApplication.ExecuteStepImpl(IExecutionStep step) +132  
> System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +163

Here is my web.config settings:

```
<!-- 1. Replace these values with your Okta configuration -->
<add key="okta:ClientId" value="0oaedp65eskxvzhhY0h7" />
<add key="okta:ClientSecret" value="<secretKey>" />
<add key="okta:Issuer" value="https://dev-874225.oktapreview.com/oauth2/default" />

<!-- 2. Update the Okta application with these values -->
<add key="okta:RedirectUri" value="http://localhost:59896/authorization-code/callback" />
<add key="okta:PostLogoutRedirectUri" value="http://localhost:59896/Account/PostLogout" />

```

And here is my startup.cs code:

```
    public void Configuration(IAppBuilder app)
    {
        // For more information on how to configure your application, visit https://go.microsoft.com/fwlink/?LinkID=316888

        ConfigureAuth(app);
    }

    private void ConfigureAuth(IAppBuilder app)
    {
        app.SetDefaultSignInAsAuthenticationType(CookieAuthenticationDefaults.AuthenticationType);

        app.UseCookieAuthentication(new CookieAuthenticationOptions
        {
            AuthenticationType = CookieAuthenticationDefaults.AuthenticationType,
        });

        var clientId = ConfigurationManager.AppSettings["okta:ClientId"].ToString();
        var clientSecret = ConfigurationManager.AppSettings["okta:ClientSecret"].ToString();
        var issuer = ConfigurationManager.AppSettings["okta:Issuer"].ToString();
        var redirectUri = ConfigurationManager.AppSettings["okta:RedirectUri"].ToString();

        app.UseOpenIdConnectAuthentication(new OpenIdConnectAuthenticationOptions
        {
            ClientId = clientId,
            ClientSecret = clientSecret,
            Authority = issuer,
            RedirectUri = redirectUri,
            ResponseType = "id_token",
            UseTokenLifetime = false,
            Scope = "openid profile",
            PostLogoutRedirectUri = ConfigurationManager.AppSettings["okta:PostLogoutRedirectUri"].ToString(),
            TokenValidationParameters = new TokenValidationParameters
            {
                NameClaimType = "name"
            },
            Notifications = new OpenIdConnectAuthenticationNotifications
            {
                RedirectToIdentityProvider = context =>
                {
                    if (context.ProtocolMessage.RequestType == OpenIdConnectRequestType.LogoutRequest)
                    {
                        var idToken = context.OwinContext.Authentication.User.Claims.FirstOrDefault(c => c.Type == "id_token")?.Value;
                        context.ProtocolMessage.IdTokenHint = idToken;
                    }

                    return Task.FromResult(true);
                },
                AuthorizationCodeReceived = async context =>
                {
                    // Exchange code for access and ID tokens
                    var tokenClient = new TokenClient(
                        issuer + "/v1/token", clientId, clientSecret);
                    var tokenResponse = await tokenClient.RequestAuthorizationCodeAsync(context.ProtocolMessage.Code, redirectUri);

                    if (tokenResponse.IsError)
                    {
                        throw new Exception(tokenResponse.Error);
                    }
                    
                    var userInfoClient = new UserInfoClient(issuer + "/v1/userinfo");
                    var userInfoResponse = await userInfoClient.GetAsync(tokenResponse.AccessToken);

                    var identity = new ClaimsIdentity();
                    identity.AddClaims(userInfoResponse.Claims);

                    identity.AddClaim(new Claim("id_token", tokenResponse.IdentityToken));
                    identity.AddClaim(new Claim("access_token", tokenResponse.AccessToken));
                    if (!string.IsNullOrEmpty(tokenResponse.RefreshToken))
                    {
                        identity.AddClaim(new Claim("refresh_token", tokenResponse.RefreshToken));
                    }

                    var nameClaim = new Claim(ClaimTypes.Name, userInfoResponse.Claims.FirstOrDefault(c => c.Type == "name")?.Value);
                    identity.AddClaim(nameClaim);

                    context.AuthenticationTicket = new AuthenticationTicket(
                        new ClaimsIdentity(identity.Claims, context.AuthenticationTicket.Identity.AuthenticationType),
                        context.AuthenticationTicket.Properties);
                }
            }
        });
    }
}

```

---

<div class="post-metadata">

**Author:** ![nate.barbettini](https://sea1.discourse-cdn.com/oktadev/user_avatar/devforum.okta.com/nate.barbettini/32/385_2.png) [@nate.barbettini](https://devforum.okta.com/u/nate.barbettini)\
**Post date:** [March 22, 2018, 10:47pm UTC](https://devforum.okta.com/t/openidconnectprotocolexception-unsupported-response-type-in-asp-net/1477/2 "2018-03-22T22:47:59Z")

</div>

You’ll get this error if you don’t have both **Authorization Code** and **Implicit - Allow ID Token** turned on in the Application configuration in Okta. Your Application should look like this:

 ![image](https://global.discourse-cdn.com/oktadev/original/1X/e90d433300ab70d34483eaa49e14b7bca5848afb.png)

This is due to a limitation in the OWIN middleware. I’m hoping to work around this limitation in the future. For more info, see this Github discussion: [https://github.com/oktadeveloper/okta-aspnet-mvc-example/issues/18](https://github.com/oktadeveloper/okta-aspnet-mvc-example/issues/18)

---

<div class="post-metadata">

**Author:** ![manjeet.soor](https://avatars.discourse-cdn.com/v4/letter/m/278dde/32.png) [@manjeet.soor](https://devforum.okta.com/u/manjeet.soor)\
**Post date:** [March 23, 2018, 8:45pm UTC](https://devforum.okta.com/t/openidconnectprotocolexception-unsupported-response-type-in-asp-net/1477/3 "2018-03-23T20:45:42Z")

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Thanks, it did work for me.

---

<div class="post-metadata">

**Author:** ![system](https://global.discourse-cdn.com/oktadev/original/1X/589c4c5f80de422d01f47cee7185a7fb8227835c.png) [@system](https://devforum.okta.com/u/system)\
**Post date:** [June 17, 2021, 4:41pm UTC](https://devforum.okta.com/t/openidconnectprotocolexception-unsupported-response-type-in-asp-net/1477/4 "2021-06-17T16:41:09Z")

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