We have developed a Document Management System in VB.NET 2010. In the management system all types of documents can be added. In general, however, PDF, DOC, DOCX, XLS and XLSX documents are used.
I'm looking for a method to sign the documents with a personal certificate (from store of as a file) from the source code. I'm looking for a general method that can be used to each type of file.
Is there also a possibility to assigning a version number in such technique?