Re: C versus other languages,round 538 or so (Re: CGI scripts in sh)

[Crispin Cowan <crispin () WIREX COM>]

Ben Galehouse wrote:

> In theory, theory in practice are the same, in practice....

One of my favorite parables :-)

Immunix OS http://immunix.org/ offers some solutions to the issues you raise.


> In theory, buffer overflows are avoidable and findable.  In practice,
> they keep popping up, often after years of code audit.

This is part of the motive behind StackGuard:  a C compiler (gcc extension) that
emits programs hardened against buffer overflow attacks.
http://immunix.org/stackguard.html  (my apologies to those who have heard this
song before :-)


> In theory, the unix 2-level trust model provides all the security that
> one could possibly need.  In practice, I'd love an easy way to tell the
> OS to only let a web-browser or email reader access certain files.

This is exactly what SubDomain is designed to do
http://immunix.org/subdomain.html

We've been ranting about SubDomain for some time, and now it's ready for
release.  Immunix OS 7.0 will be shipping in time for COMDEX. It will contain:

   * based on Red Hat 7.0
   * StackGuard all C source programs
   * Format bug protection:  using a #define macro hack that enables printf-like
     functions to count their arguments, so as to detect funny format strings.
     Idea by Mike Frantzen (Purdue), complete implementation by WireX
   * SubDomain:  kernel enforces which files each program can access

StackGuard, as always, is Free Software.  The Format hack is implemented as
extensions to glibc, so it also is Free Software.

SubDomain is a little different:  it will be "free beer" software, with terms
similar to SSH, i.e. you can have one for free, you can give it to your friends,
but it remains proprietary to WireX, and if you want to re-sell it, please
license it.

Beta code will be announced on the stackguard mailing list.  Mail to
stackguard-request () immunix org to subscribe.

Crispin

--
Crispin Cowan, Ph.D.
Chief Research Scientist, WireX Communications, Inc. http://wirex.com
Free Hardened Linux Distribution:                    http://immunix.org
                Olympics:  The Corruption Games