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Fri, 21 Jul 2000 22:58:18 EDT
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[log in to unmask] quoted and then wrote:

>+> I don't know how many of you follow the security bulletins
>> in the Unix-world, but there has recently been a lot of
>> trouble with the more widely used FTP daemons (one of them
>> is WU-FTPD).
>I'm not familiar with this particular problem, but many
>security problems in internet clients and servers are the
>result of buffer overflow bugs.  An example is the recent
>flap over Outlook and executable code in MIME headers.
>Please do not be so confident as to assume this doesn't
>happen if you were to implement the code in Ada.  You
>certainly can prevent it in pure Ada code, but if you are
>interfacing to the operating system, you are still subject
>to potential problems.

I am familiar with a relatively large development organization
that makes little use of Ada but has only recently started to
use C in volume.  They seem to do much better than average at
avoiding buffer overflows because of a longstanding discipline
of carefully checking sizes and lengths.  So for the project
proposed, I think the fact that the implementation language
would be Ada might color the degree of discipline of those
doing the programming.

>I recently ported some Ada code which contained an interface
>to the TM time structure (time.h) from Solaris to Linux.  I
>did not carefully examine the Linux include file, just compiled
>the code.  Turns out that the Linux (Slackware) had an extra
>long and char* in the structure that weren't in the Solaris
>definition.  Took me quite awhile to find the bug.  The code
>worked when I had a Text_IO debug statement, but not when I
>removed it.  That's the only clue I had!

But the lesson I take from that is that the proposed FTP project
would end up not being so "portable" as desired even if it were
restricted to the set of Unix-like operating systems (a much
more narrow scope than I would like to see in a premier Ada

My own security experience says that even if you avoid buffer
overflows, there are _many_ additional defects just waiting
to happen in this problem domain, especially if one attempts
a high-performance implementation.