Time stamp
A time stamp is the value of an object that indicates the system time at some critical point in the history of the object.
A time stamp is included in a message to reduce the vulnerability of an application to replay attacks. In web services, a replay attack occurs when an HTTP request is intercepted and the content is resent to the provider in its original form.

For both the JAX-RPC and JAX-WS WS-Security run times, 5 minutes is the default message expiration time that is used for the receiver if a value is not specified in the message. If a different expiration is required for a specific client or you are unsure of the target service default value, configure a message expiration time value for the outbound time stamp.

- When the Web Services Security JAX-RPC and JAX-WS run times generate or consume a message, they do not enforce that the integrity of the time stamp is protected.
- The Web Services Security JAX-RPC and JAX-WS run times do not have a default outbound message expiration value. If you want to include a message expiration value in a message, you must configure it. Although the JAX-WS run time does not have a default outbound message expiration value, you can configure an outbound message expiration value in the default general bindings. This value is acquired by all applications at the level for which the default bindings apply. For example, the value might be acquired at the cell or application level.
- For the JAX-RPC run time, the time stamp expiration value is specified in the web services deployment descriptor extension. You cannot modify the web services deployment descriptor extension from the administrative console; you can only view it. To modify the deployment descriptor extension, you must use an assembly tool and add or change the time stamp expiration value for a JAX-RPC application.
- If WS-Security constraints exist to consume a timestamp, the client must send a timestamp.
- WebSphere® Application Server enforces IncludeTimestamp policy assertion. However, many service providers require that <wsu:Timestamp> element in the request, but do not send one in the response. There could also be no Security header in the response at all, much less a timestamp. The following error will occur on a client when IncludeTimestamp is in the policy but no timestamp is returned in the response:
To resolve the issue, either configure the service provider to send a timestamp or configure the client to not require the timestamp by setting the com.ibm.wsspi.wssecurity.consumer.timestampRequired custom property to false in the WS-Security policy bindings. For more information, see Web services security custom properties for more information.CWWSS5730E: A required timestamp is not found.
The JAX-WS WS-Security runtime complies with the OASIS WS-SecurityPolicy 1.2 specification Timestamp Required requirement. If you want to configure an application to not require an inbound time stamp when an outbound time stamp is configured you can add the com.ibm.wsspi.wssecurity.consumer.timestampRequired custom property as either an inbound or an inbound/outbound web services security custom property.
- Set the property com.ibm.wsspi.wssecurity.timestamp.keyword to SecurityFirst.
- Set the property com.ibm.wsspi.wssecurity.timestamp.dialect to http://www.ibm.com/websphere/webservices/wssecurity/dialect-was. The default value for com.ibm.wsspi.wssecurity.timestamp.dialect is dialect-was, but for the desired function to work, the property must be set explicitly.