Date: Thu, 20 Dec 2007 23:27:38 +0100
From: Marc Haber <mh+linux-kernel@zugschlus.de>
To: linux-kernel@vger.kernel.org
Subject: Re: Why does reading from /dev/urandom deplete entropy so much?
Message-ID: <20071220222738.GA24489@torres.zugschlus.de>
References: <20071204114125.GA17310@torres.zugschlus.de> <20071204161811.GB15974@stusta.de> <47584E35.7030409@tmr.com> <20071208220345.GE20441@stusta.de> <475EAFF9.9020405@tmr.com>
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On Tue, Dec 11, 2007 at 10:42:49AM -0500, Bill Davidsen wrote:
> The original point was that urandom draws entropy from random, and that 
> it is an an inobvious and unintentional drain on the entropy pool. At 
> least that's how I read it.

And you are reading it correct. At least one of the major TLS
libraries does it this way, putting unnecessary stress on the kernel
entropy pool. While I now consider this a bug in the library, there
surely are gazillions of similiarily flawed applications out there in
the wild.

Greetings
Marc

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