Credentials are the data Windows Communication Foundation WCF uses to establish either a claimed identity or capabilities.
Selecting a Credential Type
For example, a passport is a credential a government issues to prove citizenship in a country or region. In WCF, credentials can take many forms, such as user name tokens and X. This topic discusses credentials, how they are used in WCF, and how to select the right credential for your application. A license contains data that represents a person's identity and capabilities. It contains proof of possession in the form of the possessor's picture.
The license is issued by a trusted authority, usually a governmental department of licensing. The license is sealed, and can contain a hologram, showing that it has not been tampered with or counterfeited. Presenting a credential involves presenting both the data and proof of possession of the data. WCF supports a variety of credential types at both the transport and message security levels.
For example, consider two types of credentials supported in WCF: user name and X. For the user name credential, the user name represents the claimed identity and the password provides proof of possession. The trusted authority in this case is the system that validates the user name and password. With an X. The following table shows the possible types of client credentials that can be used by a binding in transport security mode.
When creating a service, set the ClientCredentialType property to one of these values to specify the type of credential that the client must supply to communicate with your service.
You can set the types in either code or configuration files. The following table shows the possible credential types that you can use when creating an application that uses message security. You can use these values in either code or configuration files. Negotiation is the process of establishing trust between a client and a service by exchanging credentials. The process is performed iteratively between the client and the service, so as to disclose only the information necessary for the next step in the negotiation process.
In practice, the end result is the delivery of a service's credential to the client to be used in subsequent operations. With one exception, by default the system-provided bindings in WCF negotiate the service credential automatically when using message-level security.
The exception is the BasicHttpBindingwhich does not enable security by default. When SSL security is used with. NET Framework 3. If automatic negotiation is disabled, the service credential must be provisioned at the client prior to sending any messages to the service.In this example, a client is created to use a calculator service and the binding for that client is specified imperatively in code.
The client accesses the CalculatorServicewhich implements the ICalculator interface, and both the service and the client use the BasicHttpBinding class. This procedure assumes that the calculator service is running. The tool generates the client code for accessing the service. The client is built in two parts.
This client application is then constructed by constructing an instance of ClientCalculator and then specifying the binding and the address for the service in code.
For the source copy of this example, see the BasicBinding sample. The client that is generated contains the ICalculator interface that defines the service contract that the client implementation must satisfy. Create an instance of the ClientCalculator that uses the BasicHttpBinding class in a client application, and then call the service operations at the specified address.
Skip to main content. Exit focus mode. To specify a custom binding in code Use Svcutil. ClientBase Of Microsoft. ICalculator Implements Microsoft. Add Return MyBase. Subtract Return MyBase. Multiply Return MyBase. Divide Return MyBase. Divide n1, n2 End Function End Class Create an instance of the ClientCalculator that uses the BasicHttpBinding class in a client application, and then call the service operations at the specified address.
Add value1, value2 ; Console. Subtract value1, value2 ; Console.
Multiply value1, value2 ; Console.When we started WCFing in my current project, the first challenge that we had was to get the WCF Services to impersonate the callers, I had burned a lot of mid night oil trying to figure out the right configuration that would make this happen. The Guidance turned out to be quite helpful and very comprehensive. If you have not gone though that yet, I strongly recommend going to CodePlex and reading it right away. For those who do not have that much time and do not want to go too much into the theoretical side of side of it, I have put together a small how to on setting up WCF Services to Impersonate Client credentials.
Please follow these simple steps and you will be good to go. Configure the service principle name SPN identity under which the WCF service will run, this identity is usually the lower-privilege Network Service account. Use of this account will reduce the attack surface when your application is not impersonating. Note: When impersonating for all operations, the Impersonation property of the OperationBehaviorAttribute applied to each method must also be set to either Allowed or Required.
Perform the following steps for creating a client configuration file from the newly created wcf configuration file. The import blog feature works like a charm. Now I can preview the post before actually publishing it, and make it real cool. This post was written using LiveWriter. Welcome to Geeks with Blogs. Manesh Karunakaran. Hi Manesh, I followed all the instructions you delineate above - and now it's apparent I am impersonating as the client.
By the way, I had to remove the code lines in the wcf: if Thank you a million for posting this! Have a great day! Left by Giovanni on Nov 12, PM. Giovanni: If you are always getting Identification, that means your client configuration is not correct. You need to set the AllowedImpersonationLevel attribute on the client side configuration.
Left by Manesh on Nov 27, PM. From what I see, the need to call: ServiceSecurityContext. Impersonate ; from within the service if the impersonation level is TokenImpersonationLevel. Delegation is not necessary. Impersonation appears to be in effect by the time the method is reached. Can someone confirm this for me please? Thank you! Rich Bergman If you have the set up the client configuration properly, then at the server side you wll get the WindowsIdentity object with the client credentials.
But the Service would still be running under the appPool identity. If you want to impersonate the cliet user then you need to call the Impersonate method on the WindowsIdentity object. Left by Manesh on Dec 11, PM.
Nice tutorial but when I tried to do this using silverlight as the client I was unsuccessfull, would you happen to know a work around for when the client is a silverlight application.
Any help would be appreciated. Left by Filipe on Feb 23, AM. Was the wcf service hosted on IIS? Left by Roo on Apr 30, AM.WCF Windows Communication Foundation is a secure, reliable, and scalable messaging platform for developing services in. In WCF, you have a unified programming model that you can leverage for building scalable, robust services. It enables you to configure your services either using configuration files or by using code, i.
Configuring a WCF service has been a pain primarily because of the tedious configuration metadata that you would need to specify to get your WCF service up and running.
You can configure your WCF service either using the service configuration files these are xml files or by writing code. Since there is no support for debugging configuration files, you can configure your service programmatically as well. To get started, let's create a new WCF service. To create a new WCF service, follow these steps. To configure a WCF service you can simply define a static method called Configure.
This method should be defined in the service implementation class as shown below. As you can see in the code listing given below, the service has been configured programmatically and then started.
When you execute the above code listing, the service gets started at the port mentioned in the service url. Note that ServiceMetadataBehavior is used to configure the service metadata and other related information. An instance of ServiceMetadataBehavior is added to the Behaviors collection using this code snippet:.
To use the binding of your choice, you should leverage the appropriate binding class, i. Once all service configuration has been defined, you should make a call to the Open method of the ServiceHost instance to start your service. If there is any error in starting the service, an exception is thrown and the appropriate message is displayed using the catch block.
Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. As Paciv noted in a comment, you can do this through code. Set them with the property ClientCredentials. Windowssomething like this:. Setting the credentials in code is of course unwise.
If you don't set the Windows user programmatically as above, I believe the credentials from the user running the client are sent accross which is perhaps a more typical situation? Note that if you're setting credentials in code you may in fact be looking for UserName authentication. Learn more. How can I set ClientCredentials? Ask Question. Asked 7 years, 7 months ago.
Active 5 years ago. Viewed 57k times. Jeroen 48k 27 27 gold badges silver badges bronze badges. Also please format it so it's readable. Don't rely on the community to fix your formatting. I updated my config, any suggestion please? Active Oldest Votes. Jeroen Jeroen 48k 27 27 gold badges silver badges bronze badges.
Could be. But it answers your question "How can I set client credentials? Are those example credentials in my answer secure?
Heck no. Are the SecureString entries? Is it safe to hardcode credentials in code? Probably not.Security has an important role in any distributed application and Windows Communication Foundation known as WCF or Indigothe new Microsoft communication framework, implements many security standards and has a wide range of features available. One of the most important aspects of security is authentication.
WCF can be configured to use many authentication methods:. In this article I will show you how to configure WCF with certificates to authenticate service clients and server using an alternative approach. If you want to exactly understand my implementation, continue reading the next section.
If you simply want to understand how to configure WCF using certificates jump directly to the Quick start tutorial section. The next sections assume that you are familiar with many WCF and security concepts. See the External resources section if you want to review some of these concepts or for more information. The use of certificates for authentication is not new, but is still one of the most common way to authenticate a subject.
The problem with the default configurations and examples available is that all the certificates must be installed in the Certificate Store, which basically is a central location where Windows saves all the certificates used also for other applications: Internet Explorer, Why this solution causes some problems? The easy answer is because it is not easy to correctly configure all the certificates.
For more details:. These are the reasons behind my decision to try a different approach that I will describe in the following sections. My goal is to find an easy way to use certificates without using Certificate Store. I known that storing certificates on the file system is less secure, but I think that with some attention this can be a useful alternative. See the Disadvantages section for a discussion of the possible problems of my approach.
Consider that with my solution, I simply change how the certificates are loaded, all the advantages of using WCF standards, proved code, Most important you must still use most of the settings required to use certificates.
For a complete and working example, I suggest to look at the sample project in the zip file or follow the Quick start tutorial section to implement this solution on your own project. Loading a certificate from a file is quite easy, you must simply use the System.
XCertificate2 class:.For example, a service can stipulate that the client be authenticated with a certificate. Retrieve metadata from the service's metadata endpoint. The metadata typically consists of two files: the client code in the programming language of your choice the default is Visual Cand an XML configuration file. One way to retrieve metadata is to use the Svcutil. Open the XML configuration file. If you use the Svcutil.
Find the child element that matches the mode value.
An easy way to use certificates for WCF security
Note the value assigned to the clientCredentialType attribute. The actual value depends on which mode is used, transport or message. The following XML code shows configuration for a client using message security and requiring a certificate to authenticate the client. This example sets the security mode to Transport mode and sets the client credential value to an X. The following procedures demonstrate how to set the client credential value on the client in code and configuration.
For more information, see How to: Create a Client. This example sets the property to an X. You can use any of the enumerations of the XFindType class.Part 3 Why and when should we use an abstract class
The subject name is used here in case the certificate is changed due to an expiration date. Using the subject name enables the infrastructure to find the certificate again. Be sure to set the required name attribute to an appropriate value. Set the following attributes to appropriate values: storeLocationstoreNamexFindTypeand findValueas shown in the following code.
For more information about certificates, see Working with Certificates. Also, specify the name of the binding configuration by setting the bindingConfiguration attribute to the binding for the client.
How to: Authenticate with a User Name and Password
If you are using a generated configuration file, the binding's name is automatically generated. In this example, the name is "tcpBindingWithCredential". Skip to main content. Exit focus mode. To determine the client credential type Retrieve metadata from the service's metadata endpoint. Create an instance of the WCF client using the generated code. Transport; b. SetCertificate StoreLocation.