This topic shows how to create a custom security token using the SecurityToken class, and how to integrate it with a custom security token provider and authenticator.
A security token is essentially an XML element that is used by the Windows Communication Foundation (WCF) security framework to represent claims about a sender inside the SOAP message. WCF security provides various tokens for system-provided authentication modes. Examples include an X.509 certificate security token represented by the X509SecurityToken class or a Username security token represented by the UserNameSecurityToken class.
Sometimes an authentication mode or credential is not supported by the provided types. In that case, it is necessary to create a custom security token to provide an XML representation of the custom credential inside the SOAP message.
The following procedures show how to create a custom security token and how to integrate it with the WCF security infrastructure. This topic creates a credit card token that is used to pass information about the client’s credit card to the server.
For more information about custom credentials and security token manager, see How to: Create Custom Client and Service Credentials.
See the System.IdentityModel.Tokens namespace for more classes that represent security tokens.
For more information about credentials, security token manager, and provider and authenticator classes, see Security Architecture.
A client application must be provided with a way to specify credit card information for the security infrastructure. This information is made available to the application by a custom client credentials class. The first step is to create a class to represent the credit card information for custom client credentials.
To create a class that represents credit card information inside client credentials
Define a new class that represents the credit card information for the application. The following example names the class .
Add appropriate properties to the class to allow an application set the necessary information required for the custom token. In this example, the class has three properties: , , and .
Next, a class that represents the custom security token must be created. This class is used by the security token provider, authenticator, and serializer classes to pass information about the security token to and from the WCF security infrastructure.
To create a custom security token class
Define a new class derived from the SecurityToken class. This example creates a class named .Pune Stock
Override the Id property. This property is used to get the local identifier of the security token that is used to point to the security token XML representation from other elements inside the SOAP message. In this example, a token identifier can be either passed to it as a constructor parameter or a new random one is generated every time a security token instance is created.
Implement the SecurityKeys property. This property returns a collection of security keys that the security token instance represents. Such keys can be used by WCF to sign or encrypt parts of the SOAP message. In this example, the credit card security token cannot contain any security keys; therefore, the implementation always returns an empty collection.
Override the ValidFrom and ValidTo properties. These properties are used by WCF to determine the validity of the security token instance. In this example, the credit card security token has only an expiration date, so the property returns a DateTime that represents the date and time of the instance creation.
When a new security token type is created, it requires an implementation of the SecurityTokenParameters class. The implementation is used in the security binding element configuration to represent the new token type. The security token parameters class serves as a template that is used to match the actual security token instance to when a message is processed. The template provides additional properties that an application can use to specify criteria that the security token must match to be used or authenticated. The following example does not add any additional properties, so only the security token type is matched when the WCF infrastructure searches for a security token instance to use or to validate.
To create a custom security token parameters class
Define a new class derived from the SecurityTokenParameters class.Bangalore Investment
Implement the CloneCore method. Copy all internal fields defined in your class, if any. This example does not define any additional fields.
Implement the SupportsClientAuthentication read-only property. This property returns if the security token type represented by this class can be used to authenticate a client to a service. In this example, the credit card security token can be used to authenticate a client to a service.
Implement the SupportsServerAuthentication read-only property. This property returns if the security token type represented by this class can be used to authenticate a service to a client. In this example, the credit card security token cannot be used to authenticate a service to a client.
Implement the SupportsClientWindowsIdentity read-only property. This property returns if the security token type represented by this class can be mapped to a Windows account. If so, the authentication result is represented by a WindowsIdentity class instance. In this example, the token cannot be mapped to a Windows account.
Implement the CreateKeyIdentifierClause method. This method is called by WCF security framework when it requires a reference to the security token instance represented by this security token parameters class. Both the actual security token instance and SecurityTokenReferenceStyle that specifies the type of the reference that is being requested are passed to this method as arguments. In this example, only internal references are supported by the credit card security token. The SecurityToken class has functionality to create internal references; therefore, the implementation does not require additional code.
Implement the InitializeSecurityTokenRequirement method. This method is called by WCF to convert the security token parameters class instance into an instance of the SecurityTokenRequirement class. The result is used by security token providers to create the appropriate security token instance.
Security tokens are transmitted inside SOAP messages, which requires a translation mechanism between the in-memory security token representation and the on-the-wire representation. WCF uses a security token serializer to accomplish this task. Every custom token must be accompanied by a custom security token serializer that can serialize and deserialize the custom security token from the SOAP message.
To create a custom security token serializer
Define a new class derived from the WSSecurityTokenSerializer class.
Override the CanReadTokenCore method, which relies on an XmlReader to read the XML stream. The method returns if the serializer implementation can deserialize the security token based given its current element. In this example, this method checks whether the XML reader’s current XML element has the correct element name and namespace. If it does not, it calls the base class implementation of this method to handle the XML element.
Override the ReadTokenCore method. This method reads the XML content of the security token and constructs the appropriate in-memory representation for it. If it does not recognize the XML element on which the passed-in XML reader is standing, it calls the base class implementation to process the system-provided token types.
Override the CanWriteTokenCore method. This method returns if it can convert the in-memory token representation (passed in as an argument) to the XML representation. If it cannot convert, it calls the base class implementation.
Override the WriteTokenCore methodPune Investment. This method converts an in-memory security token representation into an XML representation. If the method cannot convert, it calls the base class implementation.
After completing the four previous procedures, integrate the custom security token with the security token provider, authenticator, manager, and client and service credentials.
To integrate the custom security token with a security token provider
The security token provider creates, modifies (if necessary), and returns an instance of the token. To create a custom provider for the custom security token, create a class that inherits from the SecurityTokenProvider class. The following example overrides the GetTokenCore method to return an instance of the . For more information about custom security token providers, see How to: Create a Custom Security Token Provider.
To integrate the custom security token with a security token authenticatorMumbai Wealth Management
The security token authenticator validates the content of the security token when it is extracted from the message. To create a custom authenticator for the custom security token, create a class that inherits from the SecurityTokenAuthenticator class. The following example overrides the ValidateTokenCore method. For more information about custom security token authenticators, see How to: Create a Custom Security Token Authenticator.
To integrate the custom security token with a security token manager
The security token manager creates the appropriate token provider, security authenticator, and token serializer instances. To create a custom token manager, create a class that inherits from the ClientCredentialsSecurityTokenManager class. The primary methods of the class use a SecurityTokenRequirement to create the appropriate provider and client or service credentials. For more information about custom security token managers, see How to: Create Custom Client and Service Credentials.
To integrate the custom security token with custom client and service credentials
The custom client and service credentials must be added to provide an API for the application to allow specifying custom token information that is used by the custom security token infrastructure created previously to provide and authenticate the custom security token content. The following samples show how this can be done. For more information about custom client and service credentials, see How to: Create Custom Client and Service Credentials.
The custom security token parameters class created previously is used to tell the WCF security framework that a custom security token must be used when communicating with a service. The following procedure shows how this can be done.
To integrate the custom security token with the binding
The custom security token parameters class must be specified in one of the token parameters collections that are exposed on the SecurityBindingElement class. The following example uses the collection returned by SignedEncrypted. The code adds the credit card custom token to every message sent from the client to the service with its content automatically signed and encrypted.
How to: Create a Custom Security Token Provider
Reference
SecurityToken
SecurityTokenParameters
WSSecurityTokenSerializer
SecurityTokenProvider
SecurityTokenAuthenticator
IAuthorizationPolicy
SecurityTokenRequirement
SecurityTokenManager
ClientCredentials
ServiceCredentials
SecurityBindingElement
Concepts
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