npapi - How to make a digital signature in a web application (JavaScript) using a smartcard?

Question

We have written a document management system and would like to digitally sign documents using the web client. Our Java client application is already able to apply and check digital signature, but we would like to make signature even with our web client. This is written in GWT and so, when run on the client side, it is a JavaScript application.

We not want to create a Java applet and download it on the client and execute it. We would like to use the browser security device or the browser API in order to sign a document. We would also like to keep the complete document server side, and move to the client only the document hash.

We feel this should be possible using NSS or npapi/npruntime, but we did not find any information about this. (By the way, is npruntime available also in IE? Should we use ActiveX for achieving the same result with IE?)

Do you have any hints?

Answer 1

After some more googling I found the answer. Mozilla export part of its NSS module via window.crypto object. A more standard way of doing such operation is probably via DOMCrypt, that is currently discusses in W3C. Google Chrome developer will wait W3C to standardize DOMCrypt, while Microsoft require the use of an ActiveX object as explained here (this works even with Firefox/Chrome/Opera on Windows).