Encrypting the message elements in generator security constraints with an XPath expression

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. You 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.

Complete the following steps to specify which message parts to encrypt using an XPath expression when you configure the consumer security constraints for either the request generator or the response generator. The request generator is configured for the client and the response generator is configured for the server. In the following steps, configure either the client-side extensions in step 2 or the server-side extensions in step 3.

1. Click Window > Open Perspective > J2EE.

2. Optional:

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

   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 Request Generator Configuration section.

3. Optional:

   Locate the server-side extensions using the Project Explorer window. The Web Services Editor window is displayed. This Web service contains the extensions that you need to configure. Complete the following steps to configure the server-side extensions:

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

   2. Click the Extensions tab and expand the Response Generator Service Configuration Details section.

4. Expand the 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 which parts of the message to encrypt. The Confidentiality Dialog window is displayed. Complete the following steps to specify a configuration:

   1. Specify a name for the confidentiality element in the Confidentiality Name field. For example, you might specify conf_xpath.

   2. Specify an order in the Order field. The value, which must be a positive integer value, specifies the order in which the encryption is processed. An order value of 1 specifies that the encryption is done first.

6. Click Add under the Message parts section of the Confidentiality Dialog window. Complete the following steps to specify the message parts:

   1. Select the message parts dialect from the Message parts section. The http://www.w3.org/TR/1999/REC-xpath-19991116 dialect specifies which message part is encrypted using an XPath expression.

   2. Specify the message part to be encrypted using an XPath expression in the Message parts keyword field. For example, to specify that the body is encrypted, you might add the following expression in the Message parts 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()='Body']

   Note: These configurations for the generator and the consumer must match.

   In addition to the message parts, you also can specify that WebSphere® Application Server encrypt the nonce and timestamp elements. For more information, see the following articles:

   • Adding time stamps for confidentiality to generator security constraints with keywords

   • Adding time stamps for confidentiality to generator security constraints with an XPath expression

   • Adding the nonce for confidentiality to generator security constraints with keywords

   • Adding the nonce for confidentiality to generator security constraints with an XPath expression

7. Click OK to save your configuration.

After you specify which message parts to encrypt, specify which method is used to encrypt the message parts. For more information, see Configuring encryption information for the generator binding.

• Adding time stamps for confidentiality to generator security constraints with an XPath expression
  

• Adding the nonce for confidentiality to generator security constraints with an XPath expression
  

 

Related tasks

Adding time stamps for confidentiality to generator security constraints with keywords

Adding the nonce for confidentiality to generator security constraints with keywords

Configuring encryption information for the generator binding

---