Set the client for request signing: choosing the digital signature method

Set the client for request signing: choosing the digital signature method

To configure the client for request signing, specify which message parts to digitally sign when configuring the client.
There is an important distinction between Version 5.x and V6 and later applications. The information in this article supports V5.x applications only that are used with WAS V6.0.x and later. The information does not apply to V6.0.x and later applications. Prior to completing these steps, read either of the following topics to become familiar with the Security extensions tab and the Port binding tab in the Web services client editor within an assembly tool:

Set the client security bindings using an assembly tool
Set the security bindings on a server acting as a client

These two tabs are used to configure the WS-Security extensions and the WS-Security bindings, respectively. You must specify which parts of the message sent by the client must be digitally signed. See Set the client for request signing: digitally signing message parts for more information.
Complete the following steps to specify which message parts to digitally sign when configuring the client for request signing:

Launch an assembly tool.
See the related information on Assembly Tools.
Switch to the Java EE perspective. Click Window > Open perspective > Other > J2EE.
Click Application Client projects > application_name > appClientModule > META-INF.
Right-click the application-client.xml file, select Open with > Deployment Descriptor Editor, and click the WS Binding tab. The Client Deployment Descriptor is displayed.
Expand Security request sender binding configuration > Signing information.
Select Edit to view the signing information and select a digital signature method from the Signature method algorithm field.

The following table describes the purpose of this information. Some of these definitions are based on the XML-Signature specification, which is located at the following Web site http://www.w3.org/TR/xmldsig-core.

Table 1. Digital signature methods

Name Purpose
Canonicalization method algorithm Canonicalizes the <SignedInfo> element before the information is digested as part of the signature operation.
Digest method algorithm Applies to the data after transforms are applied, if specified, to yield the <DigestValue> element. Signing the <DigestValue> element binds the resource content to the signer key. The algorithm selected for the client request sender configuration must match the algorithm selected in the server request receiver configuration.
Signature method algorithm Converts the canonicalized <SignedInfo> element into the <SignatureValue> element. The algorithm selected for the client request sender configuration must match the algorithm selected in the server request receiver configuration.
Signing key name Represents the key entry associated with the signing key locator. The key entry refers to an alias of the key, which is found in the key store and is used to sign the request.
Signing key locator Represents a reference to a key locator implementation class that locates the correct hey store where the alias and the certificate exist.

Select Show only FIPS Compliant Algorithms if we only want the FIPS compliant algorithms to be shown in the Digest method algorithm and Signature method algorithm drop-down lists. Use this option if we expect this application to be run on a WAS that has set the Use the United States FIPS algorithms option in the SSL certificate and key management panel of the WebSphere admin console.

Results

If we configure the client and server signing information correctly, but receive a Soap body not signed error when running the client, we might need to configure the actor. Configure the actor in the following locations on the client in the Web services client editor within an assembly tool:

Click Security extensions > Client service configuration details and indicate the actor information in the Actor URI field.
Click Security extensions > Request sender configuration > Details and indicate the actor information in the Actor field.

You must configure the same actor strings for the Web service on the server, which processes the request and sends the response back. Set the actor in the following locations in the Web services editor within an assembly tool:

Click Security extensions > Server service configuration.
Click Security extensions > Response sender service configuration details > Details and indicate the actor information in the Actor field.

The actor information on both the client and server must refer to the same exact string. When the actor fields on the client and server match, the request or response is acted upon instead of being forwarded downstream. The Actor fields might be different when we have Web services acting as a gateway to other Web services. However, in all other cases, make sure that the actor information matches on the client and server. When Web services are acting as a gateway and they do not have the same actor configured as the request passing through the gateway, Web services do not process the message from a client. Instead, these Web services send the request downstream.
The downstream process that contains the correct actor string processes the request. The same situation occurs for the response. Therefore, it is important that you verify that the appropriate client and server actor fields are synchronized. we have specified which method is used to digitally sign a message when the client sends a message to a server.

Next steps
After you configure the client to digitally sign the message, configure the server to verify the digital signature. See Set the server for request digital signature verification: Verifying the message parts for more information.

Related concepts

XML digital signature
Request sender
Request receiver
Security token
Key locator
Assembly tools

Related tasks

Set the client security bindings using an assembly tool
Set the security bindings on a server acting as a client
Set the client for request signing: digitally signing message parts
Set the server for request digital signature verification: Verifying the message parts
Set key locators using an assembly tool
Set key locators
Secure Web services for V5.x applications using XML digital signature

Name	Purpose
Canonicalization method algorithm	Canonicalizes the <SignedInfo> element before the information is digested as part of the signature operation.
Digest method algorithm	Applies to the data after transforms are applied, if specified, to yield the <DigestValue> element. Signing the <DigestValue> element binds the resource content to the signer key. The algorithm selected for the client request sender configuration must match the algorithm selected in the server request receiver configuration.
Signature method algorithm	Converts the canonicalized <SignedInfo> element into the <SignatureValue> element. The algorithm selected for the client request sender configuration must match the algorithm selected in the server request receiver configuration.
Signing key name	Represents the key entry associated with the signing key locator. The key entry refers to an alias of the key, which is found in the key store and is used to sign the request.
Signing key locator	Represents a reference to a key locator implementation class that locates the correct hey store where the alias and the certificate exist.