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akn81

Question on java applets

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Hi there, I''m developing a secure intranet email system for my company. The problem is this- messages cannot be saved to HDD, printed or captured by Printscreen, and the system must be accessible by IE. When it comes to text messages I have no problem (I use an applet), but today I realised- what about attachments?? Attachments have to viewed within the applet as well, so now I need to know how to read and display Microsoft Word/Powerpoint, Adobe PDF and image files (JPG,GIF,TIF,PNG,BMP). Excel files I got no prob since I can use Jakarta-Apache''s POI library. Sigh...any help would be appreciated! =)

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Guest Anonymous Poster
quote:
Original post by akn81
messages cannot be saved to HDD, printed or captured by Printscreen
Are you deliberately trying to piss off people? Anyway, I''m kinda curious if this kind of protection is possible in an applet. There''s no cure for print screen AFAIK.

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Well obviously its not to piss off ppl, but there have been cases where confidential info has been leaked out to rival companies. This mail system is only meant for the confidential message stuff, hence usage will mainly be by senior messages, and it will be infrequent i.e. not every day stuff.

To beat printscreen I will have a standard inbox page (you know like yahoo and hotmail). When you click on the title of the message that you want to view, a window with an applet will popup. This window will be set to your desktop size to maximize viewing space (applet size will be maximized too). To view the message you have to move your mouse cursor within the boundary of the applet window, causing the message to appear.

If your cursor leaves the applet, the window will automatically close. If you press printscreen once your mouse is inside the applet, the applet will clear the windows clipboard. CTRL-N won't work either since the applet can catch keystrokes. I've tested this solution and it works fine, just the attachment problem I'm facing now..=(

Oh yes if you were wondering about applet security, you're right applets are incredibly restricted. But luckily there's a free library by Netscape that allows applets to call javascript functions, hence the power to close the browser window and clear the clipboard

[edited by - akn81 on March 17, 2003 4:40:48 AM]

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We are using Novell Netware at the office, and one of the cool Novell programs is ZenWorks. This program is installed on every client computer and detects any changes to the system registry, so users can''t install programs to capture the screen at intervals. They can''t uninstall ZenWorks either. Personally I think this kinda sucks, but when the corporation has 4000 employees, well...you gotta be secure!

The only way to beat the system is like you said, [digital] cameras. But the purpose of the system is to reduce the info leaks. In fact, only a camera should be able to ''break'' the system.

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Guest Anonymous Poster
quote:
In fact, only a camera should be able to ''break'' the system.
I wouldn''t be so sure. A program that takes screenshots at certain intervals (or from some other button than print screen) and doesn''t copy it to clipboard but directly to disk, wouldn''t need to put anything in registry. And making such a program should be quite simple too.

And if there''s some confidential information and someone wants to give it to rival company, (s)he could just say it to them.. There''s no way to make it bullet proof or even close.

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I''m sorry my mistake. ZenWorks detects any executable that you run, checks against a list of approved .exe/.com/etc. files.

If it is not approved, the server admin will be notified immediately. If the confidential document is a business policy, that''s quite a number of pages to transcribe/commit to memory isn''t it?

Like I said, this can''t completely stop leakages, but it can help narrow down culprits, most managers don''t have enclosed offices, so its going to be obvious if you see a guy staring at his screen writing stuff down for like, an hour...

Personally I think this whole thing is rather silly, in the sense that''s its difficult/impossible, and like you said kinda pointless if you''re really determined to break the system. But I''m just taking orders here so ...

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Some possible solutions to rendering attachments:

1) Look into using ActiveX/OLE/COM components. I''ve never messed around with them myself, but the objects exist to view Office documents (check out Office Web Components @ MS), and I imagine PDF and most other major apps. I don''t know what the state of the art is in getting Java to talk to COM, but having embedded viewer components should give you a lot of control.

2) Convert all attachments to something easily renderable (like HTML) at the server when messages are posted. You can use Office''s COM interface to get it to convert documents programmatically.

3) Spend more time Googling for a 3rd party solution to your entire problem No matter how you decide to handle attachments, they''re going to be a major PITA to deal with -- especially on top of implementing an entire mail system in parallel with your regular mail system.

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I think you can actually handle the printscreen problem, but you have to violate the applet policy and also do even catcher that catches print screen before windows does via JNI.

Good luck.

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Umm printscreen isn''t an issue anymore. I don''t have to use a policy or anything since printscreen will be caught by KeyReleased(), upon which my applet can call javascript''s clipboard clearing function.

Thanks for wishing me luck guys I''m still waiting for some java guru to say ''Hey, that''s impossible!'' or ''Check out this free library that has everything you want!'' Hahaha...

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