From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.saout.de ([127.0.0.1]) by localhost (mail.saout.de [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id ufZEGsR8N8cJ for ; Wed, 5 Oct 2011 14:15:52 +0200 (CEST) Received: from v4.tansi.org (ns.km33513-03.keymachine.de [87.118.94.3]) by mail.saout.de (Postfix) with ESMTP for ; Wed, 5 Oct 2011 14:15:52 +0200 (CEST) Received: from gatewagner.dyndns.org (84-74-163-71.dclient.hispeed.ch [84.74.163.71]) by v4.tansi.org (Postfix) with ESMTPA id 2246A1404001 for ; Wed, 5 Oct 2011 14:15:52 +0200 (CEST) Date: Wed, 5 Oct 2011 14:15:50 +0200 From: Arno Wagner Message-ID: <20111005121550.GA30825@tansi.org> References: <4BC4CC14.6080408@redhat.com> <20100414153050.GA3966@tansi.org> <4BC60CB2.8030902@gmail.com> <20100414233054.GC9776@tansi.org> <20111004182800.GA16389@tansi.org> <20111004224800.GB19598@tansi.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Subject: Re: [dm-crypt] avoid keyloggers: enter password with mouse?(virtual?keyboard) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: dm-crypt@saout.de On Wed, Oct 05, 2011 at 09:37:01AM +0000, Jan wrote: > Arno Wagner writes: > > > I really don't know. If it is just the spare-time project of the > > Internet Cafee owner, you might be right. If it is the project > > of the secret police, recording the video off the cable is > > conveivable, although a bit more expensive than the about $80 > > for the hardware keylogger. > > Usually it sould be a spare time project, since I choose the internet cafe > at random and video grabber cost about $170 (see http://www.keydemon.com/ > ). It would be nice to be protected against hardware keyloggers at least > with the software I proposed. I know some C basics. In case I find some > time, where could I get the mentioned linux knowledge? A C on Linux tutorial should be enough then. Minimal process: 1. Write C-Programm with editor (of your choice, examples: joe, vi, emacs) 2. gcc -o .c This is for a single source file. Should be enough. For screen output, just do a complete screen rewrite line-wise with the "poor man's teminal clear" (write 25 or 50 emtpy lines). You can get c library help either from the GNU info pages ("info libc") or often from the commandline "man 3 ", e.g. "man 3 printf". The "3" refers to section 3 of tha manual which is the C library. You may have to install the C library documentation package. Attacheing a command via its STDIN is a bit more tricky, but can be done with "popen". An example is here: http://stackoverflow.com/questions/70842/execute-program-from-within-a-c-program As usual, Google is your friend, just add "linux" to the C query. > Originally I wanted to find a way to use my GnuPG key in internet cafes > savely. Since as you pointed out, even with the software I proposed, > there is no "absolute" security. Here's my pragmatical solution: > > 0. Use privatix. > 1. Protect against hardware keyloggers with the software I proposed to > defeat the "most common" thread. > 2. Use TWO GnuPG keys with the following user-IDs: > > "My Name > (very safe, your email reaches > me at my save PC at home only) > ", > > "My Name > (not completely safe, your email reaches > me in unsecure internet cafes and at home) > " Make sure the second one is clearly marked as not-that-secure, as the sender has to choose which one to use. > 3. Have two privatix USB sticks, one for at home, the other for internet > cafes etc. The first one never leaves my home. > > This way people who want to send me an encrypted email can decide for > hemselves which level of security their message needs. If they chose the > second key at east internet providers cannot read the content of the email > and send personalized advertisments etc. > > Another question: > When I plug in my USB stick in an internet cafe, boot from it and have > decrcypted it, is there a hardware mechanism known to you that could > automatically copy the DECRYPTED contents of my stick? I think that's unlikely > since the decryption takes place in the OS, ist that right? Nothing standard. The best bet IMO would be to fake the boot using a VM and then read the key from the VM's memory. You are right that decryption is done in the PC, the data that goes over USB is still encrypted. I would say that besides the faked boot via VM, you do not need to worry about it in your scenario. And to fight the faked boot, do a full power cycle with wall socket unplug, not just a reset. Presenting such a faked boot takes some effort though. Arno -- Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: arno@wagner.name GnuPG: ID: 1E25338F FP: 0C30 5782 9D93 F785 E79C 0296 797F 6B50 1E25 338F ---- Cuddly UI's are the manifestation of wishful thinking. -- Dylan Evans If it's in the news, don't worry about it. The very definition of "news" is "something that hardly ever happens." -- Bruce Schneier