Skip site navigation (1)Skip section navigation (2)
Date:      Sat, 1 Feb 2003 21:53:10 -0600
From:      "Jacques A. Vidrine" <nectar@FreeBSD.org>
To:        Michael Bryan <fbsd-secure@ursine.com>
Cc:        Ralph Dratman <ralph@maxsoft.com>, freebsd-security@FreeBSD.ORG
Subject:   Re: SSHD suddenly takes SIX MINUTES to authenticate
Message-ID:  <20030202035310.GA14640@opus.celabo.org>
In-Reply-To: <3E3B1D71.21CFBD42@ursine.com>
References:  <v04210102ba60a5a98b9c@[192.168.1.27]> <3E3B1D71.21CFBD42@ursine.com>

next in thread | previous in thread | raw e-mail | index | archive | help
On Fri, Jan 31, 2003 at 05:05:53PM -0800, Michael Bryan wrote:
> There was a bug in older versions of OpenSSH, with symptoms exactly
> matching what you're seeing.  For every connection, sshd would do
> a DNS lookup of the special krb5-realm domain.  (It did this even
> if Kerberos support was disabled.)  However, it would start out by
> looking for krb5-realm.yoursubdomain.yourdomain.com, which is fine.
> Then it would start stepping up the tree, checking for krb5-realm.yourdomain.com,
> then krb5-realm.com.   If the nameservers setup to host krb5-realm.com
> stop responding to requests, then these DNS lookups take a long time,
> waiting to eventually timeout.

Actually, that was a Heimdal (not OpenSSH) mis-feature.  See
src/crypto/heimdal/lib/krb5/get_host_realm.c:dns_find_realm
for the current state of affairs.

Cheers,
-- 
Jacques A. Vidrine <nectar@celabo.org>          http://www.celabo.org/
NTT/Verio SME          .     FreeBSD UNIX     .       Heimdal Kerberos
jvidrine@verio.net     .  nectar@FreeBSD.org  .          nectar@kth.se

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-security" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20030202035310.GA14640>