linux-kernel - Re: Why does reading from /dev/urandom deplete entropy so much?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <475AE2ED.3050700@garzik.org>
Date:	Sat, 08 Dec 2007 13:31:09 -0500
From:	Jeff Garzik <jeff@...zik.org>
To:	Theodore Tso <tytso@....edu>, Mike McGrath <mmcgrath@...hat.com>,
	Jon Masters <jonathan@...masters.org>,
	Matt Mackall <mpm@...enic.com>,
	Alan Cox <alan@...rguk.ukuu.org.uk>,
	Ray Lee <ray@...rabbit.org>, Adrian Bunk <bunk@...nel.org>,
	Marc Haber <mh+linux-kernel@...schlus.de>,
	linux-kernel@...r.kernel.org
Subject: Re: Why does reading from /dev/urandom deplete entropy so much?

Theodore Tso wrote:
> On Sat, Dec 08, 2007 at 11:33:57AM -0600, Mike McGrath wrote:
>>> Huh?  What's the concern?  All you are submitting is a list of
>>> hardware devices in your system.  That's hardly anything sensitive....
>> We actually had a very vocal minority about all of that which ended up 
>> putting us in the unfortunate position of generating a random UUID instead 
>> of using a hardware UUID from hal :-/
> 
> Tinfoil hat responses indeed!  Ok, if those folks are really that
> crazy, my suggestion then would be to do a "ifconfig -a > /dev/random"

heh, along those lines you could also do

	dmesg > /dev/random

<grin>

dmesg often has machine-unique identifiers of all sorts (including the 
MAC address, if you have an ethernet driver loaded)

	Jeff



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/