How to intercept SOAP messages - wcf

Question

As part of my venture into WCF I'm looking at message contracts and seeing how they affect the content of the SOAP message.
What would be really cool is if you could intercept the message and see how it is structured. How would I go about doing this please...
(So far I've looked at Wireshark (too 'low-level') and thought about Microsoft SOAP toolkit but this was retired by microsoft back in 2005)

Answer 1

When you installed .NET 3.5 or up, you should have the WCF Test Client on your machine somewhere (hidden deep inside a directory like C:\Program Files\Microsoft Visual Studio 9.0\Common7\IDE\ or something like that).
This tool allows you to connect to your WCF service, and you can call methods on it - and you can look at the XML request and response in all its beauty :-)
The other option would be to use something like the free version of SoapUI which is designed to test SOAP services and show request and response in XML
SoapUI is a great tool - but it's not WCF specific, it's just a "generic" SOAP/WSDL tool which works great against any SOAP service.
If you're not looking for "on-demand" capturing of requests and responses, but if you're more interested in having a trace of all requests and responses, you should investigate the WCF tracing features and setup them up as needed. You can capture all traffic into a *.svclog file on disk, and there's the WCF Service Trace Viewer (also free with WCF) to inspect those trace files.

Answer 2

I usually use Fiddler to inspect soap messages sent over http.

Answer 3

If you want to write a log record is try using TraceExtension class, below an example,
in this link you will find details about how to implement it, I use it and it worked very well
http://www.systemdeveloper.info/2013/11/trace-soap-requestresponse-xml-with.html
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Web.Services.Protocols;
using System.IO;
using System.Xml;
namespace PruebaServiciosNBC
{
class TraceExtension : SoapExtension
{
private Stream oldStream;
private Stream newStream;
private static XmlDocument xmlRequest;
/// <summary>
/// Gets the outgoing XML request sent to PayPal
/// </summary>
public static XmlDocument XmlRequest
{
get { return xmlRequest; }
}
private static XmlDocument xmlResponse;
/// <summary>
/// Gets the incoming XML response sent from PayPal
/// </summary>
public static XmlDocument XmlResponse
{
get { return xmlResponse; }
}
/// <summary>
/// Save the Stream representing the SOAP request
/// or SOAP response into a local memory buffer.
/// </summary>
/// <param name="stream">
/// <returns></returns>
public override Stream ChainStream(Stream stream)
{
oldStream = stream;
newStream = new MemoryStream();
return newStream;
}
/// <summary>
/// If the SoapMessageStage is such that the SoapRequest or
/// SoapResponse is still in the SOAP format to be sent or received,
/// save it to the xmlRequest or xmlResponse property.
/// </summary>
/// <param name="message">
public override void ProcessMessage(SoapMessage message)
{
switch (message.Stage)
{
case SoapMessageStage.BeforeSerialize:
break;
case SoapMessageStage.AfterSerialize:
xmlRequest = GetSoapEnvelope(newStream);
CopyStream(newStream, oldStream);
break;
case SoapMessageStage.BeforeDeserialize:
CopyStream(oldStream, newStream);
xmlResponse = GetSoapEnvelope(newStream);
break;
case SoapMessageStage.AfterDeserialize:
break;
}
}
/// <summary>
/// Returns the XML representation of the Soap Envelope in the supplied stream.
/// Resets the position of stream to zero.
/// </summary>
/// <param name="stream">
/// <returns></returns>
private XmlDocument GetSoapEnvelope(Stream stream)
{
XmlDocument xml = new XmlDocument();
stream.Position = 0;
StreamReader reader = new StreamReader(stream);
xml.LoadXml(reader.ReadToEnd());
stream.Position = 0;
return xml;
}
/// <summary>
/// Copies a stream.
/// </summary>
/// <param name="from">
/// <param name="to">
private void CopyStream(Stream from, Stream to)
{
TextReader reader = new StreamReader(from);
TextWriter writer = new StreamWriter(to);
writer.WriteLine(reader.ReadToEnd());
writer.Flush();
}
#region NoOp
/// <summary>
/// Included only because it must be implemented.
/// </summary>
/// <param name="methodInfo">
/// <param name="attribute">
/// <returns></returns>
public override object GetInitializer(LogicalMethodInfo methodInfo,
SoapExtensionAttribute attribute)
{
return null;
}
/// <summary>
/// Included only because it must be implemented.
/// </summary>
/// <param name="WebServiceType">
/// <returns></returns>
public override object GetInitializer(Type WebServiceType)
{
return null;
}
/// <summary>
/// Included only because it must be implemented.
/// </summary>
/// <param name="initializer">
public override void Initialize(object initializer)
{
}
#endregion NoOp
}
}