Full Disclosure mailing list archives
Re: Xfree86 video buffering?
From: "Riad S. Wahby" <rsw () jfet org>
Date: Fri, 25 Feb 2005 08:41:31 -0600
James Tucker <jftucker () gmail com> wrote:
Is it not possible to switch processing modes without switching video modes? Could a fast(er) operation, such as a blank intermediate pallete be loaded to 'wash out' all coloured pixels on the screen?
It seems like worrying about this at startup is the wrong approach. If I'm looking at a root prompt in X, I'm already trusting the entire video infrastructure (card, driver, &c) to be secure to whatever extent I require. If my driver/card combo has this problem with failing to explicitly clear video memory at shutdown, and if my solution is to make sure that the video driver clears the buffer at _startup_, then I'm also implicitly trusting the next piece of software that's going to touch that particular framebuffer not to read it out and send it off to {insert favorite TLA here}. Why extend your trust to a driver over which you perhaps have no control? The driver that is displaying the sensitive data should have the responsibility of clearing same from the video card's memory. Any other solution is only a quick hack; it'll prevent a casual observer from seeing anything sensitive, but not a dedicated adversary. -- Riad S. Wahby rsw () jfet org _______________________________________________ Full-Disclosure - We believe in it. Charter: http://lists.netsys.com/full-disclosure-charter.html
Current thread:
- Re: Xfree86 video buffering?, (continued)
- Re: Xfree86 video buffering? Eric Paynter (Feb 24)
- Re: Xfree86 video buffering? Eric Windisch (Feb 24)
- Re: Xfree86 video buffering? Rodrigo Barbosa (Feb 24)
- Re: Xfree86 video buffering? KF (Lists) (Feb 24)
- Re: Xfree86 video buffering? Rodrigo Barbosa (Feb 24)
- Re: Xfree86 video buffering? Eric Windisch (Feb 24)
- Re: Xfree86 video buffering? Eric Paynter (Feb 24)
- Re: Xfree86 video buffering? KF (Lists) (Feb 24)
- Re: Xfree86 video buffering? Rodrigo Barbosa (Feb 24)
- Re: Xfree86 video buffering? Valdis . Kletnieks (Feb 24)
- RE: Xfree86 video buffering? Allan (Feb 25)
- Re: Xfree86 video buffering? James Tucker (Feb 25)
- Re: Xfree86 video buffering? Riad S. Wahby (Feb 25)
- Re: Xfree86 video buffering? bkfsec (Feb 25)
- Re: Xfree86 video buffering? Stan Bubrouski (Feb 25)
- Re: Xfree86 video buffering? bkfsec (Feb 25)
- Re: Xfree86 video buffering? Stan Bubrouski (Feb 25)