You can specify a nonce for confidentiality by using keywords when
you configure the generator 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.
Before you begin
Prior to completing this task, you must import your application into
an assembly tool.
For information on how to import
your application, see Importing
enterprise applications.
About this task
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. Nonce is a randomly generated, cryptographic token. When you add
a nonce to a specific part of a message, it can prevent theft and replay attacks
because a generated nonce is unique. For example, without a nonce, the token
might be intercepted and used in a replay attack when a user name token is
passed from one machine to another machine using a nonsecure transport, such
as HTTP. The user name token can be stolen even if you use XML digital signature
and XML encryption. This situation might be prevented by adding a nonce.
Complete
the following steps. You must configure either the client-side extensions
in step 2 or the server-side extensions in step 3.
Procedure
- Start the assembly tool.
- Switch to the Java 2 Platform, Enterprise Edition (J2EE) perspective.
Click Window > Open Perspective > J2EE.
- 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 must configure.
Complete the following steps to locate the client-side extensions:
- Expand the Web Services > Client section and double-click the
name of the Web service.
- Click the WS Extension tab and expand the Request Generator
Configuration section.
- 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 must configure. Complete
the following steps to locate the server-side extensions:
- Expand the Web Services > Services section and double-click
the name of the Web service.
- Click the Extensions tab and expand the Response Generator
Service Configuration Details section.
- Expand the Confidentiality section. Confidentiality
refers to encryption and 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
.
- Click Add to specify a nonce for integrity. The
Confidentiality Dialog window is displayed. Complete the following steps to
specify a configuration:
- Specify a name for the confidentiality element in the Confidentiality
Name field. For example, you might specify conf_nonce.
- 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.
- Under Nonce, click Add and select the Nonce dialect.
The http://www.ibm.com/websphere/webservices/wssecurity/dialect-was
dialect specifies the message part to which a nonce is added and encrypted.
If you select this dialect, you can select one of the following keywords under
Nonce keyword:
- bodycontent
- Specifies the user data portion of the message. If this keyword is selected,
the nonce is embedded in the Simple Object Access Protocol (SOAP) message
body and the body is encrypted.
- usernametoken
- Specifies a username token that contains the basic authentication information
such as a user name and a password. Usually, the username token is encrypted
so that the user information is secure. If you select this keyword, the nonce
element is embedded in the username token element and it is encrypted.
- digestvalue
- Specifies a unique digest value. When a part of the SOAP message is signed,
a unique digest value is created and is used by the receiving party to check
the integrity of the message. You can encrypt the digestvalue element to secure
the digest value. If you select this keyword, the nonce is embedded in the
digestvalue element and the element is encrypted.
- In the Message Parts section, click Add and select http://www.ibm.com/websphere/webservices/wssecurity/dialect-was
in the Message parts dialect field.
- In the Message Parts section, select the message parts keyword.
Important: You must define at least one message part in
Message Parts section in order to specify a nonce for confidentiality. When
you select the message part, you are encrypting the message part in addition
to the parent element of the nonce.
- Click OK to save the configuration changes.
Note: These
configurations for the generator and the consumer must match.
In
addition to the nonce, you can specify that the timestamp element is encrypted.
For more information, see the following articles:
Example
The following example is a part of a SOAP message where a nonce
is inserted into the bodycontent element and it is encrypted using the bodycontent
keyword and the http://www.ibm.com/websphere/webservices/wssecurity/dialect-was
dialect.
Important: You cannot see the nonce in the message
because it is encrypted.
<soapenv:Body soapenv:encodingStyle="http://schemas.xmlsoap.org/soap/encoding/">
<EncryptedData Id="wssecurity_encryption_id_1669600751905274321"
Type="http://www.w3.org/2001/04/xmlenc#Content" xmlns="http://www.w3.org/2001/
04/xmlenc#">
<EncryptionMethod Algorithm="http://www.w3.org/2001/04/xmlenc#tripledes-cbc"/>
<CipherData>
<CipherValue>pZpVL6Rs6zhvu8UrC7TH3BA2zvOdpPpLeHnwH0dCpmdc7ETz1tUHDdXLFxy143
nYu91MxpzspWt1rWx2Lx9vFGRIfblRSX5lEpV8+0LvezvhJYY/cbTA04mTMUzCfv28v2TI09AZ
Q4TjII4u+cPeh5f0prBVK1E5hLTql4QMcwf/rq9h+tttrJbR7ub3AUgIVo42ucQs5HZbaDijxm
dSuFboBql4lv1Ep24ZfeoB/p7aHzyeWy7pYtO0bshpks/oBwO/78vxSklVJKu4sUseFvZa+B7s
ciFneeNnNuRCqB2JXc/vtH83l3AELUZg60ehd4vqvXkyuvSLohZ/kKnF/A5c+BP5Bo1pgvwmDE
eJItQ5a7LOKkTavLuc2WGtVo1947fnNGm2TN4C6U/cp9ERT7jAB9Lr/1v/8ZqPZYmssyME4pGe
SWLy232WrPvk6HEu96GHfRt+YXWpVNvSEt/gZw==</CipherValue>
</CipherData>
</EncryptedData>
</soapenv:Body>