Outgoing message from WCF client is incomplete when run outside of Visual Studio - wcf-client

Question

I have a WCF client application written in VB.NET 2008 as a Windows forms application. This client app successfully communicates with a remote non-WCF service maintained by another company. The problem is - the communication is only successful when the client app is run from within Visual Studio (VS2008), not when it is run as a built executable. When the client app is run as an executable, the remote service returns this message:
"The HTTP request is unauthorized with client authentication scheme 'Anonymous'. The authentication header received from the server was ''. The remote server returned an error: (401) Unauthorized."
Digging a little deeper, I noticed the reason for this error. The message being sent to the remote service when the client app runs outside of VS is missing a section that it contains when run inside VS. The message sent when the app runs inside VS (i.e. the one that works properly) is shown below with sensitive information replaced with "x":
<HttpRequest xmlns="http://schemas.microsoft.com/2004/06/ServiceModel/Management/MessageTrace">
<Method>POST</Method>
<QueryString></QueryString>
<WebHeaders>
<VsDebuggerCausalityData>uIDPo6ppHQnHmDRGnZfDLPni6RYAAAAAaEkfl5VJXUauv5II8hPneT1AMwBfkoZNgfxEAZ2x4zQACQAA</VsDebuggerCausalityData>
<AUTHORIZATION>xxxxxxxxxxxxxxxxxxxxxxxxxxxx</AUTHORIZATION>
</WebHeaders>
</HttpRequest>
<s:Envelope xmlns:s="http://schemas.xmlsoap.org/soap/envelope/">
<s:Header>
<Action s:mustUnderstand="1" xmlns="http://schemas.microsoft.com/ws/2005/05/addressing/none"></Action>
</s:Header>
<s:Body s:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
<q1:getNewEvents_PPHS xmlns:q1="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxins">
<loginObject href="#id1" xmlns=""></loginObject>
</q1:getNewEvents_PPHS>
<q2:LoginObject id="id1" xsi:type="q2:LoginObject" xmlns:q2="java:zoasis.ws.datamodel.general">
<clinicId xsi:type="xsd:int" xmlns="">xxxxx</clinicId>
<corporateId xsi:type="xsd:int" xmlns="">x</corporateId>
<password xsi:type="xsd:string" xmlns="">xxxxx</password>
<userName xsi:type="xsd:string" xmlns="">xxxx</userName>
</q2:LoginObject>
</s:Body>
</s:Envelope>
When running as a standalone executable, the client app sends out the same as above except that the entire HttpRequest section is missing - everything from <HttpRequest> to </HttpRequest>
Can anyone tell me why running the client app outside Visual Studio would cause the HttpRequest portion of the message to drop off? The app.config file is identical in both cases.
Thanks.
Per Mike's request, here is some more information. The client proxy was created using "Add Service Reference" in Visual Studio 2008.
The code that creates the message that is sent to the service is shown below in three parts.
The first part is a class called AntechServiceReference. It has two relevant methods. Its constructor builds the proxy that will be used to interact with the web service. The other method, called GetPendingDownloads, calls the web service method.
Imports WebServiceInterface.AntechServiceReference
Imports System.Configuration.ConfigurationManager
Imports System.ServiceModel
Imports System.ServiceModel.Security
Imports System.Text
Imports System.IO
Imports System.Xml
Public Class AntechLabDataAccess
' This class controls all data interaction with the remote Antech web service.
Private ClassName As String = "AntechLabDataAccess"
Private mErrText As String
Private mAntServProxy As ZoasisGroupServicesPortClient
Private mLoginObject As WebServiceInterface.AntechServiceReference.LoginObject
Private mLabEventIDs As WebServiceInterface.AntechServiceReference.LabAccessionIdObject()
Public Sub New()
Dim Action As String = ""
Dim CustomBehavior As MessageEndPointBehavior
Try
mErrText = ""
Action = "Creating proxy for web service. "
' Create a proxy to the remote web service for use in this object. Supply client credentials
' from app.config
mAntServProxy = New ZoasisGroupServicesPortClient("ZoasisGroupServicesPort")
' Retrieve access credentials for this web service from app.config.
Action = "Setting up login object. "
mLoginObject = New WebServiceInterface.AntechServiceReference.LoginObject
If Not AppSettings("ClinicID") Is Nothing Then
mLoginObject.clinicId = Integer.Parse(AppSettings("ClinicID"))
End If
If Not AppSettings("CorporateID") Is Nothing Then
mLoginObject.corporateId = Integer.Parse(AppSettings("CorporateID"))
End If
If Not AppSettings("Password") Is Nothing Then
mLoginObject.password = AppSettings("Password")
End If
If Not AppSettings("UserName") Is Nothing Then
mLoginObject.userName = AppSettings("UserName")
End If
' Add our custom behavior to the proxy. This handles creation of the message credentials
' necessary for web service authorization.
Action = "Adding custom behavior to the proxy. "
CustomBehavior = New MessageEndPointBehavior
mAntServProxy.Endpoint.Behaviors.Add(CustomBehavior)
Catch ex As Exception
mErrText = "Error caught in class [" & ClassName & "], method [New]. Action = " & Action & " Message = " & ex.Message & ". "
If Not ex.InnerException Is Nothing Then
mErrText &= "Additional Info: " & ex.InnerException.ToString & ". "
End If
Throw New Exception(mErrText)
End Try
End Sub
Public Sub GetPendingDownloads()
Dim Action As String = ""
Try
mErrText = ""
Action = "Calling getNewEvents_PPHS. "
mLabEventIDs = mAntServProxy.getNewEvents_PPHS(mLoginObject)
[catches are here]
End Try
End Sub
End Class
In addition to creating the proxy, the constructor above adds an endpoint behavior to it. That behavior is defined in the class shown next. The purpose of this behavior is to add a custom message inspector to inject authorization information into the HTTP header before the message is sent out:
Imports System.ServiceModel.Description
Public Class MessageEndPointBehavior
Implements IEndpointBehavior
' This class is used to make our custom message inspector available to the system.
Public Sub AddBindingParameters(ByVal endpoint As System.ServiceModel.Description.ServiceEndpoint, ByVal bindingParameters As System.ServiceModel.Channels.BindingParameterCollection) Implements System.ServiceModel.Description.IEndpointBehavior.AddBindingParameters
' Not Implemented
End Sub
Public Sub ApplyClientBehavior(ByVal endpoint As System.ServiceModel.Description.ServiceEndpoint, ByVal clientRuntime As System.ServiceModel.Dispatcher.ClientRuntime) Implements System.ServiceModel.Description.IEndpointBehavior.ApplyClientBehavior
' Add our custom message inspector to the client runtime list of message inspectors.
clientRuntime.MessageInspectors.Add(New MessageInspector())
End Sub
Public Sub ApplyDispatchBehavior(ByVal endpoint As System.ServiceModel.Description.ServiceEndpoint, ByVal endpointDispatcher As System.ServiceModel.Dispatcher.EndpointDispatcher) Implements System.ServiceModel.Description.IEndpointBehavior.ApplyDispatchBehavior
' Not Implemented
End Sub
Public Sub Validate(ByVal endpoint As System.ServiceModel.Description.ServiceEndpoint) Implements System.ServiceModel.Description.IEndpointBehavior.Validate
' Not Implemented
End Sub
End Class
The last piece of code is the custom message inspector itself:
Imports System.ServiceModel.Dispatcher
Imports System.ServiceModel.Channels
Imports System.Configuration.ConfigurationManager
Imports System.Text
Public Class MessageInspector
Implements IClientMessageInspector
' This class gives access to the outgoing SOAP message before it is sent so it can
' be customized.
Private mUserName As String
Private mPassword As String
Private mErrText As String
Public Sub New()
Dim CredentialsProvided As Boolean
CredentialsProvided = False
mUserName = AppSettings("CliCredUserName")
If Not mUserName Is Nothing Then
If mUserName.Trim <> "" Then
CredentialsProvided = True
End If
End If
If CredentialsProvided Then
CredentialsProvided = False
mPassword = AppSettings("CliCredPassword")
If Not mPassword Is Nothing Then
If mPassword.Trim <> "" Then
CredentialsProvided = True
End If
End If
End If
If CredentialsProvided Then
mUserName = mUserName.Trim
mPassword = mPassword.Trim
Else
Throw New Exception("This class (MessageInspector) requires information from the app.config file - specifically " _
& "AppSettings values for CliCredUserName and CliCredPassword. One or both of these is missing. ")
End If
End Sub
Public Sub AfterReceiveReply(ByRef reply As System.ServiceModel.Channels.Message, ByVal correlationState As Object) Implements System.ServiceModel.Dispatcher.IClientMessageInspector.AfterReceiveReply
' Not Implemented
End Sub
Public Function BeforeSendRequest(ByRef request As System.ServiceModel.Channels.Message, ByVal channel As System.ServiceModel.IClientChannel) As Object Implements System.ServiceModel.Dispatcher.IClientMessageInspector.BeforeSendRequest
Dim HTTPMsgHdr As HttpRequestMessageProperty
Dim objHTTPRequestMsg As Object = Nothing
Dim Auth As String = ""
Dim Action As String = ""
Dim BinaryData As Byte()
Try
Action = "Checking HTTP headers. "
If request.Properties.TryGetValue(HttpRequestMessageProperty.Name, objHTTPRequestMsg) Then
Action = "Changing existing HTTP header. "
HTTPMsgHdr = CType(objHTTPRequestMsg, HttpRequestMessageProperty)
If Not HTTPMsgHdr Is Nothing Then
If String.IsNullOrEmpty(HTTPMsgHdr.Headers("AUTHORIZATION")) Then
Auth = mUserName & ":" & mPassword
ReDim BinaryData(Auth.Length)
BinaryData = Encoding.UTF8.GetBytes(Auth)
Auth = Convert.ToBase64String(BinaryData)
Auth = "Basic " & Auth
HTTPMsgHdr.Headers("AUTHORIZATION") = Auth
End If
Else
Throw New Exception("Received unexpected empty object HTTPMsgHdr from request properties. " _
& "This error occurred in class ""MessageInspector"" and function ""BeforeSendRequest."" ")
End If
End If
Catch ex As Exception
mErrText = "Error caught in BeforeSendRequest function of MessageInspector class: Action = " _
& Action & "; Message = " & ex.Message & " "
If Not ex.InnerException Is Nothing Then
mErrText &= "Additional Information: " & ex.InnerException.ToString & " "
End If
Throw New Exception(mErrText)
End Try
Return Convert.DBNull
End Function
End Class
Finally, here is the config file:
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<configSections>
</configSections>
<appSettings>
<!-- Client Credentials -->
<add key="CliCredUserName" value="xxxxxxx"/>
<add key="CliCredPassword" value="xxxxxxx"/>
<!-- Login Object Fields -->
<add key="ClinicID" value="xxxxx"/>
<add key="CorporateID" value="x"/>
<add key="Password" value="xxxxx"/>
<add key="UserName" value="xxxx"/>
</appSettings>
<system.serviceModel>
<diagnostics>
<messageLogging logEntireMessage="false" logMalformedMessages="false"
logMessagesAtServiceLevel="false" logMessagesAtTransportLevel="false" />
</diagnostics>
<bindings>
<basicHttpBinding>
<binding name="ZoasisGroupServicesPort" closeTimeout="00:01:00"
openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
allowCookies="false" bypassProxyOnLocal="false" hostNameComparisonMode="StrongWildcard"
maxBufferSize="65536" maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
messageEncoding="Text" textEncoding="utf-8" transferMode="Buffered"
useDefaultWebProxy="true">
<readerQuotas maxDepth="32" maxStringContentLength="118192" maxArrayLength="16384"
maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<security mode="Transport">
<transport clientCredentialType="None" proxyCredentialType="None"
realm="" />
<message clientCredentialType="UserName" algorithmSuite="Default" />
</security>
</binding>
</basicHttpBinding>
</bindings>
<client>
<endpoint address="xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
binding="basicHttpBinding" bindingConfiguration="ZoasisGroupServicesPort"
contract="AntechServiceReference.ZoasisGroupServicesPort" name="ZoasisGroupServicesPort" />
</client>
</system.serviceModel>
<system.net>
<!-- Important: The following setting strips off the "HTTP/1.1 100 Continue" banner from incoming
messages. Unless this is done, incoming XML messages are not recognized as XML. -->
<settings>
<servicePointManager expect100Continue="false"/>
</settings>
</system.net>
</configuration>
As I mentioned earlier, this is a functioning WCF client that successfully calls the service and downloads data - but only when run within Visual Studio, which is the part I don't understand.

Answer 1

This is what I had to do to fix this problem. In the BeforeSendRequest function of the MessageInspector class, I had to add the code indicated below (i.e. the lines between the
rows of exclamation points - !!!!!!)
Action = "Checking HTTP headers. "
If request.Properties.TryGetValue(HttpRequestMessageProperty.Name, objHTTPRequestMsg) Then
Action = "Changing existing HTTP header. "
HTTPMsgHdr = CType(objHTTPRequestMsg, HttpRequestMessageProperty)
If Not HTTPMsgHdr Is Nothing Then
If String.IsNullOrEmpty(HTTPMsgHdr.Headers("AUTHORIZATION")) Then
Auth = mUserName & ":" & mPassword
ReDim BinaryData(Auth.Length)
BinaryData = Encoding.UTF8.GetBytes(Auth)
Auth = Convert.ToBase64String(BinaryData)
Auth = "Basic " & Auth
HTTPMsgHdr.Headers("AUTHORIZATION") = Auth
End If
Else
Throw New Exception("Received unexpected empty object HTTPMsgHdr from request properties. " _
& "This error occurred in class ""MessageInspector"" and function ""BeforeSendRequest."" ")
End If
' !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
' Added this section
Else
Action = "Creating new HTTP header. "
HTTPMsgHdr = New HttpRequestMessageProperty
If String.IsNullOrEmpty(HTTPMsgHdr.Headers("AUTHORIZATION")) Then
Auth = mUserName & ":" & mPassword
ReDim BinaryData(Auth.Length)
BinaryData = Encoding.UTF8.GetBytes(Auth)
Auth = Convert.ToBase64String(BinaryData)
Auth = "Basic " & Auth
HTTPMsgHdr.Headers("AUTHORIZATION") = Auth
End If
request.Properties.Add(HttpRequestMessageProperty.Name, HTTPMsgHdr)
' End of Added section
' !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
End If
For some reason still not clear to me, when I run the application as an executable, the "HttpRequestMessageProperty.Name" property does not exist in the request.properties that are passed into the "BeforeSendRequest" function. I have to explicitly create it - unlike when I run the application in Debug mode in Visual Studio. (Thanks to Mike Parkhill, for suggesting that the "If" conditions might not be executing as I expected. It turns out I needed an extra ELSE clause as shown above.)