Client Side (javascript/jquery) File Manipulation Before/after Upload/download

I'm just sounding things out about this having looked around for a while and drawn a blank. I'd like to see if this is even possible as so far I can't see a way to do it. I want to

Solution 1:

There is no way to do this using plain Javascript or JQuery due to security restrictions in the browser.

Your best bet is probably taking a open source Flash based upload component like SWFUpload (Flash can much more or the client side) and adding the encryption routines there in ActionScript. Creating a Java applet or an ActiveX control are also valid options.

Depending on what kind of encryption we are talking about, there also may exist ready-made components for the job.

Solution 2:

You can't do this with JavaScript. You can, of course, simply use SSL (e.g., via HTTPS). Dead easy, well-tested, all of that. Otherwise, you'll have to use something non-standard like Flash, Java, or ActiveX.

Solution 3:

The accepted answer is outdated here. It is possible to do this now using HTML5 File API and something like the CryptoJS library.

Solution 4:

I can't speak to other browsers, but I know this should be possible in Firefox by using the file manipulation api to upload/download files from the user to the client-side code (where they may be manipulated), and standard ajax to upload/download files from the client-side code to the server.