Cloning of ClientCredentials

Damir Dobric Posts

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The typical WCF client application is often the required to supply the client's credentials. Following code snippet shows how to create the proxy instance with username-password credentials:

ChannelFactory<ITestService> factory =
new ChannelFactory< ITestService>( binding, endpointAddress);

factory.Credentials.UserName.UserName = "damirdobric";
factory.Credentials.UserName.Password = "*******";

. . .


All this works fine as long you do simple things. Imagine now, there is a case which requires that your code
destroy the current instance of the channel factory (see example above) and automatically create the new one. This seems to be a very simple task. All you need is to keep the instance of binding, the endpoint address and credentials itself. Following example shows how this should be typically done:

ChannelFactory<ITestService> newFactory =
new ChannelFactory< ITestService>( binding, endpointAddress);

newFactory.Credentials = oldFactory;

. . .


Unfortunately, this example has more problems than you could imagine. First problem is that the ClientCredentials property is read-only. So, there is no way to set it directly. Because of that the only way is to copy all required properties form old credentials to new one. From the architecture point of view this is not recommended, because you do not know really how to copy credentials.
Do not forget that credentials could also be some custom credentials.

Following code shows how this can be done for any kind of credentials supported by WCF:

ChannelFactory<ITestService> newFactory =
new ChannelFactory< ITestService>( binding, endpointAddress);



. . .

To be honest, the ClientCredentials property has a design I personally do not like much. It is just a bunch of too many properties. By any more sophisticated customization you are never able to know what credentials the caller has set. This makes difficult any manipulation of credentials.
The good thing is that the ClientCredentials clas is WCF behavior class (implements IEndpointBehavior). This makes it possible to manipulate credentials by using of WCF behaviors as shown in the last example.

Posted May 01 2007, 12:18 AM by Damir Dobric
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Andreas Erben wrote re: Cloning of ClientCredentials
on 05-01-2007 2:54

Further reading is interesting in a similar context:

How To: Create Custom Client and Service Credentials

Even though it does not clone the credentials, applying a newly created credentials is pretty much the same.

In general: The ... "remove"-"add" pattern is used often.

What would be interesting to look at in my opinion is, if there might be a valid need to create an new instance of the client credentials by using ".clone()" in this specific context in terms of effects on garbage collection of the channel factory instance that is to be destroyed. (I haven't gone much deeper to check what client credentials references ...) is a .Net Community Blog powered by daenet GmbH.