Re: CONFIG_RANDOM (compromise?)

lilo (TaRDiS@mail.utexas.edu)
Tue, 21 May 1996 14:42:13 -0500 (CDT)


On Mon, 20 May 1996, Theodore Ts'o wrote:

> If you have a "bad guy" running on your machine, they can constantly
> suck numbers from /dev/random. This will cause a "denial of service
> attack", since /dev/random will only issue random numbers if sufficient
> entropy is available to generate them.

There's nothing to prevent setting up a separate group for this device, call
it random, make the device only accessible from that group and setgid the
programs you want to have access to the random number generator, so that
they run with this group id.

This is not foolproof, but depending on what programs you allow access to
the random number generator, this could make a denial-of-service attack a
bit more difficult.

And, as you say, Linux as it stands is highly-prone to denial-of-service
attacks. IMO this is not even one of the first places to start in fixing
this general problem....

lilo