Message-ID: <456B4CD2.7090208@cfl.rr.com>
Date: Mon, 27 Nov 2006 15:38:42 -0500
From: Phillip Susi <psusi@cfl.rr.com>
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To: David Wagner <daw-usenet@taverner.cs.berkeley.edu>
CC: linux-kernel@vger.kernel.org
Subject: Re: Entropy Pool Contents
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David Wagner wrote:
> Nope, I don't think so.  If they could, that would be a security hole,
> but /dev/{,u}random was designed to try to make this impossible, assuming
> the cryptographic algorithms are secure.
> 
> After all, some of the entropy sources come from untrusted sources and
> could be manipulated by an external adversary who doesn't have any
> account on your machine (root or non-root), so the scheme has to be
> secure against introduction of maliciously chosen samples in any event.

Assuming it works because it would be a bug if it didn't is a logical 
fallacy.  Either the new entropy pool is guaranteed to be improved by 
injecting data or it isn't.  If it is, then only root should be allowed 
to inject data.  If it isn't, then the entropy estimate should increase 
when the pool is stirred.

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