WCF authentication issue on a particular machine - windows

Question

I have an issue with my WCF service/application. I am using TCP binding with Windows Authentication (dynamically setting the credentials).
The service is hosted on machine A. With my test client application on machine B, C, D, and E, it works fine. When the test client application is run on machine A (on itself), it is telling me that I have invalid credentials when in fact they are correct.
When hosting the service on machine B, the test client on machine B itself authenticates fine. Even if the test client is on A, it authenticates itself successfully on B.
I would say there is something wrong with machine A but I cannot figure out what.
Any help?
Thanks in advance.
K
Client Config:
public static EndpointAddress BuildServiceEndpointAddress()
{
var host = Settings.Default.Host;
var port = Settings.Default.Port;
string endpointAddress;
if (port == 0)
endpointAddress = string.Format("net.tcp://{0}/Service", host);
else
endpointAddress = string.Format("net.tcp://{0}:{1}/Service", host, port);
Console.WriteLine("Endpoint: {0}", endpointAddress);
//var endpointAddressObj = new EndpointAddress(endpointAddress );
return new EndpointAddress(new Uri(endpointAddress), new DnsEndpointIdentity("MyCert"));
}
public static IChannelFactory<IService> BuildChannelFactory(EndpointAddress endpointAddress)
{
var netTcpBinding = new NetTcpBinding()
{
MaxReceivedMessageSize = int.MaxValue,
Security = new NetTcpSecurity()
{
Mode = SecurityMode.Transport,
Transport = new TcpTransportSecurity()
{
ClientCredentialType = TcpClientCredentialType.Windows,
}
},
TransferMode = TransferMode.Streamed
};
var factory = new ChannelFactory<IService>(netTcpBinding);
factory.Endpoint.Address = endpointAddress;
factory.Credentials.Windows.ClientCredential.Domain = Settings.Default.Domain;
factory.Credentials.Windows.ClientCredential.UserName = Settings.Default.Username;
factory.Credentials.Windows.ClientCredential.Password = Settings.Default.Password;
Console.WriteLine("Opening Channel Factory ... ");
factory.Open();
Console.WriteLine("Opening Channel Factory ... done");
return factory;
}
Service Config:
var netTcpBinding = new NetTcpBinding()
{
MaxReceivedMessageSize = int.MaxValue,
Security = new NetTcpSecurity()
{
Mode = SecurityMode.Transport,
Transport = new TcpTransportSecurity()
{
ClientCredentialType = TcpClientCredentialType.Windows,
}
},
TransferMode = TransferMode.Streamed
};
var endpoint = serviceHost.AddServiceEndpoint(
typeof(IService),
netTcpBinding,
new Uri(string.Format("net.tcp://0:{0}/Service", tcpPort)));
ServiceSecurityAuditBehavior newAudit = new ServiceSecurityAuditBehavior();
newAudit.AuditLogLocation = AuditLogLocation.Application;
newAudit.MessageAuthenticationAuditLevel = AuditLevel.SuccessOrFailure;
newAudit.ServiceAuthorizationAuditLevel = AuditLevel.SuccessOrFailure;
newAudit.SuppressAuditFailure = false;
serviceHost.AddServiceEndpoint(ServiceMetadataBehavior.MexContractName,
MetadataExchangeBindings.CreateMexTcpBinding(),
string.Format("net.tcp://localhost:{0}/Service/mex", tcpPort));
serviceHost.Description.Behaviors.Remove<ServiceSecurityAuditBehavior>();
serviceHost.Description.Behaviors.Add(newAudit);
serviceHost.Opening += (sender, eventArgs) => LogDebug("Opening Connection ...");
serviceHost.Opened += (sender, eventArgs) => LogDebug("Opened Connection ...");
serviceHost.Closing += (sender, eventArgs) => LogDebug("Closing connection ...");
serviceHost.Closed += (sender, eventArgs) => LogDebug("Closed connection ...");
serviceHost.Faulted += (sender, eventArgs) => LogError("Fault detected on WCF host");

Answer 1

I just fixed the issue!
I replaced:
return new EndpointAddress(new Uri(endpointAddress), new
DnsEndpointIdentity("MyCert"));
with
return new EndpointAddress(new Uri(endpointAddress));
since the certificate is not needed for windows authentication.
Although I still am confused why it worked on other machines.