Adding the nonce for confidentiality in consumer security constraints with an XPath expression

 

Before you begin

Prior to completing this task, import your application into an assembly tool. For information on how to import your application, see Import enterprise applications.

The following information explains the difference between using an XPath expression and using keywords to specify which part of the message to sign:

XPath expression

Specify any part of the message using an XPath expression. XPath is a language that is used to address parts of an XML document. We can find information on XPath syntax at the following Web site: http://www.w3.org/TR/1999/REC-xpath-19991116.

Keywords

Specify only elements within the message using predefined keywords.

 

Overview

Nonce for confidentiality is used to specify that the nonce is embedded in a particular element within the message and that the element is encrypted. Complete the following steps to check the confidentiality of an element that has nonce embedded in it and is encrypted using an XPath expression when you configure the consumer security constraints for either the response consumer or the request consumer. The response consumer is configured for the client and the request consumer is configured for the server. In the following steps, configure either the client-side bindings in step 2 or the server-side bindings in step 3.

 

Procedure

1. Start the assembly tool and click Window > Open Perspective > J2EE.

2. Optional: Locate the client-side bindings using the Project Explorer window. The Client Deployment Descriptor window is displayed. This Web service contains the extensions that we need to configure. Complete the following steps to locate the client-side bindings:

   1. Expand the Web Services > Client section and double-click the name of the Web service.

   2. Click the WS Extension tab and expand the Response Consumer Configuration section.

3. Optional: Locate the server-side bindings using the Project Explorer window. The Web Services Editor window is displayed. This Web service contains the bindings that we need to configure. Complete the following steps to locate the server-side bindings:

   1. Expand the Web Services > Services section and double-click the name of the Web service.

   2. Click the Extensions tab and expand the Request Consumer Service Configuration Details section.

4. Expand the Required Confidentiality section. Confidentiality refers to encryption while integrity refers to digital signing. Confidentiality reduces the risk of someone intercepting the message as it moves across a network. With confidentiality specifications, the message is encrypted before it is sent and decrypted when it is received at the intended target. For more information on encryption, see XML encryption.

5. Click Add to specify that the element within which a nonce is added and encrypted is checked for confidentiality. The Required Confidentiality Dialog window is displayed. Complete the following steps to specify a configuration:

   1. Specify a name for the confidentiality element in the Required Confidentiality Name field.

   2. Specify a usage type in the Usage type field. This field specifies the requirement for the confidentiality element. The value of this attribute is either Required or Optional.

6. Click Add under the Nonce section of the Required Confidentiality Dialog window. Complete the following steps to specify a nonce dialect and its associate message part:

   1. Select the nonce dialect from the Nonce section. The http://www.w3.org/TR/1999/REC-xpath-19991116 dialect specifies the message part which has an embedded nonce is verified for encryption using an XPath expression.

   2. Specify the message part which has an embedded nonce is verified for encryption using an XPath expression in the Nonce keyword field. For example, to specify that the bodycontent element along with the embedded nonce is checked for confidentiality, you might add the following expression in the Nonce keyword field as one continuous line

      /*[namespace-uri()='http://schemas.xmlsoap.org/soap/envelope/' 
      and local-name()='Envelope']/*[namespace-uri()='http://schemas.xmlsoap.org/
      soap/envelope/' and local-name()='Bodycontent']
      

7. If you have not specify message parts in Required Confidentiality, one can click Add in the Message Parts section to add message parts. You must define at least one message part in Required Confidentiality for specifying Nonce in Required Confidentiality.

8. In the Message Parts section, select the message parts keyword.

9. Click OK to save the configuration changes.

   Note: These configurations on the consumer side and the generator side must match.

   In addition to the nonce, one can specify that the timestamp element is checked for encryption. For more information, see the following articles:

   • Adding time stamps for confidentiality in consumer security constraints with keywords

   • Adding time stamps for confidentiality in consumer security constraints with an XPath expression

 

What to do next

After you specify which message parts to check for encryption, you must specify which method is used to verify the encryption. For more information, see Configuring encryption information for the consumer binding with an assembly tool.

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See Also

XML digital signature

 

Related Tasks

Adding a stand-alone time stamp in consumer security constraints
Adding time stamps for confidentiality in consumer security constraints with keywords
Adding time stamps for confidentiality in consumer security constraints with an XPath expression
Configuring encryption information for the consumer binding with an assembly tool

 

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