Re: Entropy Pool Contents

From: Phillip Susi
Date: Mon Nov 27 2006 - 15:38:27 EST


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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