From owner-freebsd-hackers Wed Aug 22 17:11: 7 2001 Delivered-To: freebsd-hackers@freebsd.org Received: from femail25.sdc1.sfba.home.com (femail25.sdc1.sfba.home.com [24.254.60.15]) by hub.freebsd.org (Postfix) with ESMTP id 4518337B406 for ; Wed, 22 Aug 2001 17:10:20 -0700 (PDT) (envelope-from bmah@employees.org) Received: from intruder.bmah.org ([24.176.204.87]) by femail25.sdc1.sfba.home.com (InterMail vM.4.01.03.20 201-229-121-120-20010223) with ESMTP id <20010823001017.JZXU21066.femail25.sdc1.sfba.home.com@intruder.bmah.org>; Wed, 22 Aug 2001 17:10:17 -0700 Received: (from bmah@localhost) by intruder.bmah.org (8.11.5/8.11.3) id f7N0AGf27563; Wed, 22 Aug 2001 17:10:16 -0700 (PDT) (envelope-from bmah) Message-Id: <200108230010.f7N0AGf27563@intruder.bmah.org> X-Mailer: exmh version 2.5 07/13/2001 with nmh-1.0.4 To: Leo Bicknell Cc: freebsd-hackers@FreeBSD.ORG Subject: Re: ssh password cracker - now this *is* cool! In-Reply-To: <20010822195508.B93930@ussenterprise.ufp.org> References: <200108222330.f7MNUUj80882@earth.backplane.com> <20010822195508.B93930@ussenterprise.ufp.org> Comments: In-reply-to Leo Bicknell message dated "Wed, 22 Aug 2001 19:55:08 -0400." From: "Bruce A. Mah" Reply-To: bmah@FreeBSD.ORG X-Face: g~c`.{#4q0"(V*b#g[i~rXgm*w;:nMfz%_RZLma)UgGN&=j`5vXoU^@n5v4:OO)c["!w)nD/!!~e4Sj7LiT'6*wZ83454H""lb{CC%T37O!!'S$S&D}sem7I[A 2V%N&+ X-Image-Url: http://www.employees.org/~bmah/Images/bmah-cisco-small.gif X-Url: http://www.employees.org/~bmah/ Mime-Version: 1.0 Content-Type: multipart/signed; boundary="==_Exmh_-784623144P"; micalg=pgp-sha1; protocol="application/pgp-signature" Content-Transfer-Encoding: 7bit Date: Wed, 22 Aug 2001 17:10:16 -0700 Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG --==_Exmh_-784623144P Content-Type: text/plain; charset=us-ascii If memory serves me right, Leo Bicknell wrote: > On Wed, Aug 22, 2001 at 04:30:30PM -0700, Matt Dillon wrote: > > http://www.vnunet.com/News/1124839 > > Several people on other mailing lists have pointed out that Nagle > should make this much harder, although it's unclear how Nagle and > ssh interact. So far that has resulted in a number of degenerating > discussions of how things work. Of course, Nagle will not help > between two machines on the same ethernet segment, but probably > would make the process described in the paper much harder. Indeed. They also didn't discuss (or I didn't see it) the effects of queueing or jitter in the network on their scheme. This *is* pretty neat, although it is less of a password cracker than a scheme of narrowing down the space of possible passwords. > All of this aruges for Kerberos or some other cryptographic system > so once you're authenticated once there is little or no need to type > additional passwords. ssh-agent(1)/ssh-add(1) does all of its authentication locally, so my extremely naive reading is that it'd be immune to this particular type of attack, since human-typed passphrases never cross the network. Bruce. --==_Exmh_-784623144P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (FreeBSD) Comment: Exmh version 2.3.1+ 05/14/2001 iD8DBQE7hEno2MoxcVugUsMRArNrAJ48wC3f2ohuJPyRsGXgRbPeujFBOwCfaMiQ IGRJRrAlgZcd5LzeTI8mm7E= =mGrn -----END PGP SIGNATURE----- --==_Exmh_-784623144P-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message