Re: Ada's Slide To Oblivion ...

["Nick Roberts" <nickroberts@adaos.worldonline.co.uk>]

"Dale Pontius" <pontius@btv.MBI.com.invalid> wrote in message
news:a3eikr$tfo$1@news.btv.ibm.com...

> By today's common programming practices, we have a situation
> where the simplest/easiest way of programming string input gives
> buffer overflows, and there for security holes. In C, that is.
> Don't know about C++, but at least in Ada, the simplest/easiest
> way of programming string input at worst would give a DOS
> problem as the program crashed, and it wouldn't be much harder
> to catch the exception and stop that.

To my mind, it seems more appropriate that DoS (Denial of Service) attack
prevention should be undertaken primarily by the IP router module, not by
TCP (or UDP) service applications. The TCP module, and its service
applications, could help by reporting suspicious activity to the IP router
(which should provide an interface to facilitate this).

Both C and C++ are fundamentally insecure languages, because they require a
'flat' address space, with no differentiation between the executable
(read-only) and variable (read-write) parts. This completely subverts the
security mechanisms (e.g. segments with access controls) most modern
processor architectures support and could otherwise fully deploy. Buffer
overrun exploits are but one manifestation of this problem.

I never cease to be amazed at the number of people -- many who should know
better (or be more honest) -- who expound flat address spaces as universally
advantageous. (I emphasise that I understand there are some cases where they
are indeed advantageous.)

Some processor architectures, specifically for the benefit of C code,
support a style of addressing that permits the use of a machine word to
contain a full address into a segmented space, but with only 32 bits to play
(on 32-bit architectures), this doesn't work very well. Of course 64-bit
architectures solve this problem; but then the problems of porting 32-bit C
and C++ code to 64-bit are many, and make hilarious reading for those of a
strong mental constitution.

--
Nick Roberts