Re: fixing all buffer overflows --- random magin numbers

[oxymoron () WASTE ORG (Oliver Xymoron)]

On Tue, 14 Sep 1999, Crispin Cowan wrote:

> (post sent as HTML and ASCII because there's a table that's easier to read
> in HTML.  Aleph, go ahead and nuke the HTML if you prefer)

Urg. Pine happily munged it on reply:

> The result looks like this:
>
>             Interface                            Implementation
>
>  Restriction   * Firewalls                          * Bounds checking
>                * TCP Wrappers                       * StackGuard
>                * Randomly renaming system files
>                * Randomly renumbering system
>  Permutation     calls (the hack proposed here      * Randomly munging
>                  by Maniscalco)                       data layout
>                * Fred Cohen's Deception Toolkit

You missed a couple interesting ones. One is randomly offsetting the
stack. Another is having separate stacks for the call chain and local
variables. Obviously wastes a register (or an indirection), but can
probably be proved secure against stack smashing.

--
 "Love the dolphins," she advised him. "Write by W.A.S.T.E.."