[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: the cold-boot attack - a paper tiger?
Phil wrote:
> --- Richard Zidlicky <rz@xxxxxxxxxxxxxx> wrote:
> > .. perfectly feasible
> > with much of todays stock hardware. On multicore
> > systems all you need is
> > a nonpreemptible kernel thread holding part of the
> > key in its CPU registers.
> > That way you do not have the keys in main memory or
> > they can be in main memory
> > but encrypted. The thread would also do the disk
> > encryption so if designed
> > carefully there would never be sufficient
> > information in main memory
> > to recover any data.
>
> Sounds like a solution. How hard would that be to
> implement in loop-aes (is Jari reading?)
I'm reading... but not convinced.
Another half-solution:
http://www.mail-archive.com/cryptography@xxxxxxxxxxxx/msg08939.html
IMO, it is best to not give adversary full access to computer that still has
encryption keys in non-tamper-proof DRAM.
> 1. Which kernels sanitize pipe buffers in the way Jari
> is saying?
Mainline kernels don't.
Here is a patch for 2.4 branch:
--- linux-2.4.36.4/fs/pipe.c 2003-08-25 20:48:23.000000000 +0300
+++ linux-2.4.36.4r1/fs/pipe.c 2008-05-13 21:11:45.000000000 +0300
@@ -304,6 +304,7 @@
if (!PIPE_READERS(*inode) && !PIPE_WRITERS(*inode)) {
struct pipe_inode_info *info = inode->i_pipe;
inode->i_pipe = NULL;
+ memset(info->base, 0, PAGE_SIZE); /* for better security */
free_page((unsigned long) info->base);
kfree(info);
} else {
--
Jari Ruusu 1024R/3A220F51 5B 4B F9 BB D3 3F 52 E9 DB 1D EB E3 24 0E A9 DD
-
Linux-crypto: cryptography in and on the Linux system
Archive: http://mail.nl.linux.org/linux-crypto/