Digitally sign PDF, XML and other documents

I need a software and an extension to connect to the SmartCard reader of the A3 digital certificates through the browser. Through this extension / software it should be possible to access the hardware of the smartcard reader, read the token and sign any type of document. It should work as follows: 1. Javascript in the web site that communicates with the extension and sends a string of a file (ASCII (XML) or Base64 (PDF)) of the document to some local authenticator software; 2. The authenticator software receives the string and communicates with the smartcard reader to get the token to authenticate the document; 3. If the document has been correctly authenticated then the authenticator software returns the signed string for the extension. Authentication should be type cades or pades (preferably pades) There are already a lot of plugins on the internet for authentication written in .NET C # but our company does not have the skills to do that, therefore we need help. We'll need the full source code to customize whatever we want.