Reliable Message Exchange Using XML Signing
Introduction A well known service oriented scenario is where a client and service application communicate using message exchange over a channel. This channel is either secured, using for instance SSL, or unsecured where the data is send in plain text. One of the commonly used message bases is XML. XML is a standard way of describing relational data, and can be read by most platforms. This makes XML a interoperable message base. On the downside, this message type is easy to read and it therefore easy to change. If a third party where to intercept the message, for instance using a proxy server, it could easily change the content of the message and send it to the original endpoint. This is called tampering. To detect changes to the content, a message send through the channel can be signed. Signing is a way to provide reliable messaging over a non-secure channel. It also provides some sort of authentication because the message can be validate that is was send from the expected cli...