I was just disecting the wikipedia entry :-)<br><br>What I'm running into is a lack of entropy on a server causing a drained condition in /dev/random. The random stuff is used when samhain IDS starts up to create a one-time pad key. If it's not large enough it errors and reuses an old one (?) or hits urandom (?). I can use a configure flag to spec the random device (supports egd as well) but compiled with the default /dev/random. Still in the "lab" on this one so may recompile and spec urandom.<br>
<br><div class="gmail_quote">On Fri, Dec 5, 2008 at 2:04 PM, Mike Fletcher <span dir="ltr"><<a href="mailto:fletch@phydeaux.org">fletch@phydeaux.org</a>></span> wrote:<br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div class="Ih2E3d">Jim Kinney wrote:<br>
> /dev/random and /dev/urandom?<br>
><br>
> /dev/random is very slow and on a newly installed machine `cat<br>
> /dev/random` does little. Same machine `cat /dev/urandom` fills the<br>
> screen quickly.<br>
><br>
</div>Quoth <a href="http://en.wikipedia.org/wiki/Urandom" target="_blank">http://en.wikipedia.org/wiki/Urandom</a><br>
<br>
A counterpart to /dev/random is /dev/urandom ("unlocked" random source)<br>
which reuses the internal pool to produce more pseudo-random bits. This<br>
means that the call will not block, but the output may contain less<br>
entropy than the corresponding read from /dev/random. The intent is to<br>
serve as a cryptographically secure pseudorandom number generator. This<br>
may be used for less secure applications.<br>
<div class="Ih2E3d"><br>
<br>
> Is there a way to "add entropy" to get /dev/random to fill quicker?<br>
</div>Ibid says that priviledged users can write to it and call an ioctl to<br>
change the entropy estimate, but if you're going to do that you probably<br>
might as well be using urandom (unless you're reading from your webcam<br>
watching your lava lamp collection, of course . . .)<br>
<div><div></div><div class="Wj3C7c"><br>
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</div></div></blockquote></div><br><br clear="all"><br>-- <br>-- <br>James P. Kinney III <br><br>