OSEC

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Subject: Re: Tempfile vulnerabilities
From: Marc Lehmann (marcGIMP.ORG)
Date: Tue Feb 08 2000 - 17:27:43 CST

> > /dev/random -- a world readable device -- should do the following:
> >
> > cat /dev/random > /dev/null &
> >
> > Crypto software which uses those devices should be doing some kind of
> > checking to make sure that they are getting at least good entropy. I

On linux at least, the above is at most a denial of service attack, as
/dev/random does not deliver any data when it runs out of entropy (and
programs usually are prepared to wait for data on that devices for some
time).

On linux/x86, moving my mouse generates >400bytes/s random data (this is
currently specific to x86), and if two processes listen on /dev/random,
both get about half the random data, so it seems that there isn't even a
denial of service attack here. 

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