It is sometimes useful to build a WCF CustomBinding equivalent to some other binding. This allows a richer set of customizations. Here is the CustomBinding equivalent to the WSHttpBinding defaults (windows authentication):
Update: Convert bindings automatically using the WCF BindingBox.
The default binding in Wcf 3.0 is WSHttpBinding. Wcf 3.5 brings the new WS2007HttpBinding binding but WSHttpBinding is still the default. These bindings do not interoperate together well due to the fact that WS2007HttpBinding uses some newer standards.
When the client uses WS2007HttpBinding and the server employs WSHttpBinding we may get this exception in the client side:
And the inner exception is:
On the server side trace we see
And the inner exception:
When the client uses WSHttpBinding and the server employs WS2007HttpBinding we would get the same exceptions with http://docs.oasis-open.org/ws-sx/ws-trust/200512/RST/Issue being replaced by http://schemas.xmlsoap.org/ws/2005/02/trust/RST/Issue.
The reason for the errors is the different WS-Trust versions between the bindings. WS-Trust is used when the negotiateServiceCredential or establishSecurityContext settings are set to true (which is the default). In these cases infrastructure messages are exchanged between the client and the server and these messages require the WS-Trust version to match.
We can see the different versions if we use the reflector to check the bindings static constructors.
So, which binding to use? In many cases this does not matter since both bindings expose similar functionality. You might want to consider the following:
WSHttpBinding is supported by .Net 3.0 clients.
WS2007HttpBinding uses WS-* standards while WSHttpBinding uses drafts. You might face a requirement to work with the standard.
Different soap stacks support different standards so if you need to interoperate with a specific framework verify the standards it supports.
In the long run WS2007HttpBinding should be used as it supports the actuall standard.
Nevertheless, for most services this decision will probably only have a very minor effect.
Geospatial and location based services became very popular these days. One concern for developers of such applications is how to represent the data in the system. This includes simple data types such as points or coordinate systems and complex ones such as advanced topologies. The correct approach is of course to use types from the standard schema set of the Open Geospatial Consortium (OGC).
For a .Net developer this may imply the following needs:
Use xsd.exe to generate classes for serizliation
Create .Net 2.0 / WCF web services that utilize these schemas
Consume Wsdl's with these schemas
Unfortunetely the OpenGIS standard schemas are not interoperable with .Net. This has already been noticed by developers for older OpenGIS versions but newer versions seem to be equality incompatible.
If you only want the fix without the details download it here and see in the end of the post the fix details:
Here are some of the errors one gets when trying to consume Gml 3.1.1 and Gml 3.2.1 schemas in .Net:
Gml 3.1.1 - WCF
While using "add service reference" we get this error:
And after this an empty proxy code is generated:
Gml 3.1.1 - .Net 2.0
The wsdl importing stage seems to work fine. Let's build a one line client:
Such a simple client - what can possibly go wrong? Well nothing, except this:
And this is after I have omitted some inner exceptions.
In some cases (depending on .Net 2.0 patch level) the below exception will appear - not much improvement:
Finally, depending in the types we reference, we might get this one as well:
Gml 3.2.1 - WCF
Proxy is generated but the simplest client throws this exception chain:
Gml 3.2.1 - .Net 2.0
Why these errors happen?
The errors appear in run-time when we instantiate the client proxy or web service. At this stage .Net creates the serialization assembly for each type and fails to do it for the proxy. Actually if we have marked the "generate serialization assembly" build option we could already see these errors in compile time.
We need to fix the schemas or the proxy in order to make them interoperable with .Net. The fix must be compatible with the original schema, so it may change the schema syntax but must result in an isomorphic schema.
Making Gml 3.2.1 work
There are two reasons for this schema incomparability:
Cyclic schema references
One way to solve this is to remove deprecatedTypes.xsd altogether - it is not really required. We'll be nicer and just replace inside it the reference to gml.xsd with these direct references:
.Net does not support the xsd:list data type. When the list is of strings it works anyway since unresolved types are treated as strings. But for other types it is not supported. MSDN contains some more information on xsd:list support in .Net.
basicTypes.xsd contains this:
Which becomes this in the .Net proxy:
which causes a run-time error since the XmlTextAttribute is only appropriate on strings.
The solutions is to replace all non-string lists in the schema to strings so the above becomes:
And after this Gml 3.2.1 classes are serializable by .Net!
Making Gml 3.1.1 work
This version has two issues:
Same issue with lists as in 3.2.1 - same fix
I've seen this one a couple of times. Basically when there is a multidimensional array of a type which has a single child element in some cases .Net code generation is incorrect. Don't ask, long story... Just replace in geometryPrimitives.xsd:
And we have 3.1.1 working as well!
I have uploaded the fixed schemas to save your time:
After you extract the zip the fixed schemas are in the below folders:
If you are a WCF developer then sooner or later you are going to meet some cryptic error messages. No, they are not as intimidating as “access violation at address FFFFFF” and the blue screen of death, but is “Keyset does not exist“ and the white screen of trace any better?
This is the first out of a serious of posts in which I'll try to diminish the mystery of these errors. This time I’ll examine an X.509 related issue.
The other day I was configuring my WsHttpBinding with X.509 certificates used for digital signature and encryption. When I ran my client application I got that annoying
I hurried up and configured WCF tracing on my service only to get
This error is not so clear for those of us not familiar with the wire format of web services. However it does contain the essence of the problem: The client and the server are not using matching X.509 certificates. In order for the service to decrypt the message sent by the client it must use an X.509 containing a private key that matches the public key in the X.509 that the client is using for encryption.
Now if you (like me at the time) insist that you are using the correct certificate, I suggest you would double and triple check the X.509 references in your web/app.config. If that doesn't help - remove and reinstall the relevant certificates from the windows certificate store. You’ll be surprised to find out you used an old version of the certificate at the client side or a wrong reference at the server. One common scenario where this can happen is if you are temporarily using the WCF or WSE sample certificates – it seems there are a few versions of them.