Date: Thu, 13 Sep 2007 19:45:37 +0200 From: Roland Smith <rsmith@xs4all.nl> To: RW <fbsd06@mlists.homeunix.com> Cc: freebsd-questions@freebsd.org Subject: Re: /dev/random question Message-ID: <20070913174537.GA11683@slackbox.xs4all.nl> In-Reply-To: <20070913173155.0bad12b2@gumby.homeunix.com.> References: <46E94F9A.6050707@intersonic.se> <20070913153630.GA9448@slackbox.xs4all.nl> <20070913173155.0bad12b2@gumby.homeunix.com.>
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--wRRV7LY7NUeQGEoC Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Sep 13, 2007 at 05:31:55PM +0100, RW wrote: > On Thu, 13 Sep 2007 17:36:30 +0200 > Roland Smith <rsmith@xs4all.nl> wrote: >=20 > > On Thu, Sep 13, 2007 at 04:56:26PM +0200, Per olof Ljungmark wrote: > > > Hi, > > >=20 > > > Could someone on the list point me to a document that explains the=20 > > > functionality of /dev/random in FreeBSD in a little more depth than > > > the man page? In other OS's I've looked at random and urandom are > > > different, here it's a symlink (talking about RELENG-6 onwards). > > =20 > > FreeBSD uses the yarrow algorithm, as mentioned in random(4). See=20 > > http://en.wikipedia.org/wiki/Yarrow_algorithm > > http://www.schneier.com/yarrow.html >=20 > Yarrow is reseeded with interrupt entropy, and is supposedly good > enough not to require the amount of entropy to be tracked. > So /dev/random need not block, and there's no need for a separate > non-blocking device. =20 On the website it says that the original yarrow algorithm is no longer supported. It seems to have been replaced by the fortuna algorithm. I can't see from the source if /usr/src/sys/dev/random/yarrow.* use the original yarrow algorithm, or the improved yarrow-160 aka fortuna. The use = of crypto/rijndael/rijndael-api-fst.h and crypto/sha2/sha2.h seem to indicate the latter though. Roland --=20 R.F.Smith http://www.xs4all.nl/~rsmith/ [plain text _non-HTML_ PGP/GnuPG encrypted/signed email much appreciated] pgp: 1A2B 477F 9970 BA3C 2914 B7CE 1277 EFB0 C321 A725 (KeyID: C321A725) --wRRV7LY7NUeQGEoC Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.4 (FreeBSD) iD8DBQFG6XdBEnfvsMMhpyURAtWdAJ0c45gut0Ge/fmLD7sPDM89Wr2BvgCfVczP RMi8wD9zc8epWJUpUCqBi7c= =ZcFa -----END PGP SIGNATURE----- --wRRV7LY7NUeQGEoC--
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