On 12 Mar 2001, at 12:53, Alexander Kruppa wrote:
> Compiling a forge version with malicious code of Prime95/mprime and
> distributing it is maybe the simples and possibly most devastating
> attack.
Yes. This is much the most likely "exploit". The other putative
exploits are IMHO so unlikely as to be for all practical purposes
safe to ignore.
Certainly anyone who operates _any_ web browser, or _any_ mail
client, or _any_ server - even just ICMP echo - should not be living
in fear of attack through the Prime95 / mprime client.
> Since the complete source (save for the Primenet checksums but
> these could either be reverse-engineered or the fake client could simply
> connect to a fake server) is freely available, it would be extremely
> easy to build a trojan Prime95 client that feels just like the real
> thing.
If the trojan client was communicating with a "fake" server, those of
us who take an interest in following progress wouldn't be fooled for
long ... we'd either start receiving stupid assignments, or stop
seeing the results we'd posted appearing in the database. A
successful trojan has to contain _all_ the functionality of the real
package.
> Right now there are few possibilities to verify the integrity of
> a Prime95 package you get, other than downloading it from the original
> ftp server - but that could be hacked, too.
Those of us that operate software distribution servers are well aware
of the fact. The software on the server I operate is protected from
interference. Now I can't say that I absolutely guarantee to keep
unwanted visitors out (no-one in their right mind would!), but I'm
confident that I will detect any intrusion in reasonably short order.
> I think it would be a good thing if George could get a certified public
> key and issued signatures for the official Prime95 releases. That way a
> forged Prime95 package could quickly be identified and counter measures
> could be taken.
Actually, if George just got a signed PGP key, he could communicate
the CRC32 & MD5 checksums of the various files to us by signed email.
It _may_ be _theoretically_ possible to engineer a trojan with the
same file size, CRC32 & MD5 checksums which does incorporate the
functionality of its genuine counterpart, but the probability of this
happening within the lifetime of Prime95 is pretty close to zero.
Regards
Brian Beesley
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