Use transforms when preparing the data for signing

When the data is grabbed from the source for signing or verification, it is sometimes necessary to perform certain transformation. The possible transforms are described in XMLDSig specification and SecureBlackbox supports all transforms. To make use of the transforms,

1. create an instance of TElXMLTransformChain class;
2. create one or more instances of transform classes and add those instances to the chain using Add() or Insert() method of TElXMLTransformChain class;
3. assign the instance of TElXMLTransformChain class to TransformChain property of TElXMLReference class.