From: Tim Roberts Date: 2012-03-24T14:18:29+09:00 Subject: Re: Write to kernel buffer? ruby rub wrote: > >It isn't possible to clear keyboard buffers? Wow this + lack of ability >to clear kernel buffers makes secure wipes of password from memory >impossible, how unfortunate. Are there bad ways to try to force it from >userspace? You need to define your goal rather precisely. Kernel code is trusted code. You cannot protect kernel information from other kernel consumers. Whatever protection you can do can be subverted. Freed pages are never assigned to user-mode processes without being cleared, so that's not an issue. For USB keyboards, there is no "keyboard buffer" in the kernel. The keystrokes come in one at a time in buffers that get reused, so you won't get the whole password at one time. The password might be stored in a lot of places in your process, especially if you use something like fgets to read it. -- Tim Roberts, timr@probo.com Providenza & Boekelheide, Inc.