Google client's GetUserInfo throws ArgumentNullException

[agibalov]

I'm trying to use OAuth2 0.8.25 (the latest one in NuGet). Here's my GoogleClient configuration:

<add clientType="GoogleClient"
     enabled="true"
     clientId="GOODCLIENTIDHERE"
     clientSecret="GOODCLIENTSECRETHERE"
     scope="https://www.googleapis.com/auth/userinfo.email"
     redirectUri="~/Home/AuthCallback" />

Here's where it fails:

var userInfo = googleClient.GetUserInfo(Request.QueryString);

Here's where I am after authentication:

http://localhost/OAuth2Experiment/Home/AuthCallback?code=4/JRhtJvR3WzaZWhR6jHD0ZzCFSdOP.gpR9X3xcBGcRsNf4jSVKMpZw1hfVgAI

Here's a stacktrace:

[ArgumentNullException: Value cannot be null.
Parameter name: source]
   Newtonsoft.Json.Linq.Extensions.Value(IEnumerable`1 value) +112
   OAuth2.Client.Impl.GoogleClient.ParseUserInfo(String content) +125
   OAuth2.Client.OAuth2Client.GetUserInfo() +175
   OAuth2.Client.OAuth2Client.GetUserInfo(NameValueCollection parameters) +77
   OAuth2Experiment.Controllers.HomeController.AuthCallback() in c:\dev\OAuth2Experiment\OAuth2Experiment\Controllers\HomeController.cs:35
   lambda_method(Closure , ControllerBase , Object[] ) +62
   System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters) +14
   System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters) +211
   System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters) +27
   System.Web.Mvc.Async.<>c__DisplayClass42.<BeginInvokeSynchronousActionMethod>b__41() +28
   System.Web.Mvc.Async.<>c__DisplayClass8`1.<BeginSynchronous>b__7(IAsyncResult _) +10
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethod(IAsyncResult asyncResult) +48
   System.Web.Mvc.Async.<>c__DisplayClass39.<BeginInvokeActionMethodWithFilters>b__33() +57
   System.Web.Mvc.Async.<>c__DisplayClass4f.<InvokeActionMethodFilterAsynchronously>b__49() +223
   System.Web.Mvc.Async.<>c__DisplayClass37.<BeginInvokeActionMethodWithFilters>b__36(IAsyncResult asyncResult) +10
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeActionMethodWithFilters(IAsyncResult asyncResult) +48
   System.Web.Mvc.Async.<>c__DisplayClass2a.<BeginInvokeAction>b__20() +24
   System.Web.Mvc.Async.<>c__DisplayClass25.<BeginInvokeAction>b__22(IAsyncResult asyncResult) +102
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +57
   System.Web.Mvc.Async.AsyncControllerActionInvoker.EndInvokeAction(IAsyncResult asyncResult) +43
   System.Web.Mvc.<>c__DisplayClass1d.<BeginExecuteCore>b__18(IAsyncResult asyncResult) +14
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
   System.Web.Mvc.Controller.EndExecuteCore(IAsyncResult asyncResult) +57
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
   System.Web.Mvc.Controller.EndExecute(IAsyncResult asyncResult) +47
   System.Web.Mvc.Controller.System.Web.Mvc.Async.IAsyncController.EndExecute(IAsyncResult asyncResult) +10
   System.Web.Mvc.<>c__DisplayClass8.<BeginProcessRequest>b__3(IAsyncResult asyncResult) +25
   System.Web.Mvc.Async.<>c__DisplayClass4.<MakeVoidDelegate>b__3(IAsyncResult ar) +23
   System.Web.Mvc.Async.WrappedAsyncResult`1.End() +62
   System.Web.Mvc.MvcHandler.EndProcessRequest(IAsyncResult asyncResult) +47
   System.Web.Mvc.MvcHandler.System.Web.IHttpAsyncHandler.EndProcessRequest(IAsyncResult result) +9
   System.Web.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() +9634212
   System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously) +155

[agibalov]

Fixed by changing

scope="https://www.googleapis.com/auth/userinfo.email"

to

scope="https://www.googleapis.com/auth/userinfo.profile https://www.googleapis.com/auth/userinfo.email"

Not sure if it's a workaround or by design.

[titarenko]

Hi,

Thank you for update! And excuse me for late response.

Yes, when there is no (or not enough) persmissions, Google will answer with error instead of access token. That response is not handled properly, causing faceless ArgumentNullException with poor context.

What I will do next is proper handling of error responses for GoogleClient. And yes, this solution described by is closer to "by design" than to "workaround".

Thanks again for helping to ensure better quality of OAuth2 library!

[rtumaykin]

Actually this is not a google that throws this exception. When you ask to provide only email and nothing else, all other properties such as First name, Last name, etc aren't passed back and therefore the method used in UserInfo creation throws an exception as it does not handle null values.

[niemyjski]

Yes, this is logged in a second issue. It has to do with not using SafeGet. Would you mind submitting a pull request for this?

[niemyjski]

I'm closing this as a duplicate of #69.