.NET Core 2.1 Web API Impersonation causes WSALookupServiceEnd while processing error

Question

I'm trying to do impersonation in a .NET Core 2.1 Web-API. So this Web-API calls another Web-API using HttpClient and I need the user that called the first one to also be the one who is executing the second one. The same scenario does work from another Web-API running with the full framework with this call:

((WindowsIdentity)_httpContextAccessor.HttpContext.User.Identity).Impersonate()

Since Impersonate() is not available in .NET Core 2.1 I searched for some samples with WindowsIdentity.RunImpersonated and tried different versions of code similar to this:

WindowsIdentity identity = (WindowsIdentity)m_contextAccessor.HttpContext.User.Identity;
HttpClient client = new HttpClient(new HttpClientHandler { UseDefaultCredentials = true });

await WindowsIdentity.RunImpersonated(identity.AccessToken, async () =>
{
    var request = new HttpRequestMessage(HttpMethod.Get, url);
    var response = await client.SendAsync(request);
});

This throws an error at client.SendAsync and the error message is this:

A call to WSALookupServiceEnd was made while this call was still processing. The call has been canceled ---> System.Net.Http.HttpRequestException

Start of the Stack Trace:

at System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken) --- End of inner exception stack trace --- at System.Net.Http.ConnectHelper.ConnectAsync(String host, Int32 port, CancellationToken cancellationToken) at System.Threading.Tasks.ValueTask`1.get_Result() at System.Net.Http.HttpConnectionPool.CreateConnectionAsync(HttpRequestMessage request, CancellationToken cancellationToken)

Has anyone else seen this error or has any insight on how to solve this? I tried different versions of code for calling RunImpersonated with the HttpContext user and all lead to the same error.

Thanks for any input

Answer 1

Starting with .NET Core 2.1, the SocketsHttpHandler class provides the implementation used by higher-level HTTP networking classes such as HttpClient. try to disable this feature and see if the exception is gone.