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<channel>
	<title>tom's blog &#187; Security</title>
	<atom:link href="http://tom.knaupp.com/category/security/feed/" rel="self" type="application/rss+xml" />
	<link>http://tom.knaupp.com</link>
	<description>free software, security and a bunch of my strange thoughts</description>
	<lastBuildDate>Fri, 21 Jan 2011 00:13:42 +0000</lastBuildDate>
	<language>en</language>
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		<item>
		<title>DNS-Server bei FRITZ!Box umstellen</title>
		<link>http://tom.knaupp.com/2009/06/05/dns-server-bei-fritzbox-umstellen/</link>
		<comments>http://tom.knaupp.com/2009/06/05/dns-server-bei-fritzbox-umstellen/#comments</comments>
		<pubDate>Fri, 05 Jun 2009 19:18:58 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Hardware]]></category>
		<category><![CDATA[Politics]]></category>
		<category><![CDATA[Security]]></category>
		<category><![CDATA[7170]]></category>
		<category><![CDATA[DNS]]></category>
		<category><![CDATA[DNS Server]]></category>
		<category><![CDATA[FRITZ]]></category>
		<category><![CDATA[FRITZ!Box]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/?p=319</guid>
		<description><![CDATA[Getestet mit FRITZ!Box Fon WLAN 7170 &#038; Firmware-Version 29.04.70 &#160; Wenn man etwas sucht, findet man schon einige Anleitungen, daher hier nur die Kurzfassung.. &#160; Telnet-Server auf der FRITZ!Box aktivieren (via Telefon): #96*7* -> telnetd an &#160; Via telnet konnektieren und mit dem Kennwort der Weboberfl&#228;che einloggen. In der Konsole in das Verzeichnis /var/flash/ wechseln [...]]]></description>
			<content:encoded><![CDATA[<p>Getestet mit FRITZ!Box Fon WLAN 7170 &#038; Firmware-Version 29.04.70<br />
&nbsp;<br />
Wenn man etwas sucht, findet man schon einige Anleitungen, daher hier nur die Kurzfassung..<br />
&nbsp;<br />
Telnet-Server auf der FRITZ!Box aktivieren (via Telefon):<br />
<strong>#96*7* </strong> -> telnetd an<br />
&nbsp;<br />
Via telnet konnektieren und mit dem Kennwort der Weboberfl&auml;che einloggen.<br />
In der Konsole in das Verzeichnis <strong>/var/flash/</strong> wechseln und mit <strong>nvi</strong> die Datei <strong>ar7.cfg</strong> bearbeiten.<br />
Hier gibt es (bei meiner Box vier) Eintr&auml;ge f&uuml;r  <strong>overwrite_dns</strong>.<br />
Diese entsprechend anpassen (z.B. f&uuml;r <a href="http://www.opendns.com/" target="_blank">OpenDNS</a>):<br />
<code>&nbsp;&nbsp;overwrite_dns1 = 208.67.220.220;<br />
&nbsp;&nbsp;overwrite_dns2 = 208.67.222.222;</code><br />
&nbsp;<br />
Speichern, beenden und anschliessend die Box mit reboot neustarten.<br />
&nbsp;<br />
Aus Sicherheitsgr&uuml;nden Telnet-Server auf der Box wieder deaktivieren:<br />
<strong>#96*8* </strong> -> telnetd aus<br />
&nbsp;<br />
Ob das ganze geklappt hat, sieht man bei OpenDNS z.B. beim Aufruf der Startseite.<br />
Hier sollte jetzt ein Hinweis &#8220;You&#8217;re using OpenDNS!&#8221; angezeigt werden.<br />
&nbsp;<br />
PS: Basics &uuml;ber den Texteditor <a href="http://www.pro-linux.de/t_programme/vi_tut.html" target="_blank">vim</a> (oder dessen Ableger) sollten vorhanden sein.</p>
]]></content:encoded>
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		</item>
		<item>
		<title>Prevent SSH Brute Force attacks</title>
		<link>http://tom.knaupp.com/2009/02/28/prevent-ssh-brute-force-attacks/</link>
		<comments>http://tom.knaupp.com/2009/02/28/prevent-ssh-brute-force-attacks/#comments</comments>
		<pubDate>Sat, 28 Feb 2009 14:48:00 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Security]]></category>
		<category><![CDATA[brute force]]></category>
		<category><![CDATA[iptables]]></category>
		<category><![CDATA[ssh]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/?p=208</guid>
		<description><![CDATA[When checking logfiles, I often can see brute force attacks &#8211; especially against the ssh daemon. Of course, best way would be to block all ssh traffic except from your office/home ip. If this is not possible for various reasons, you can make life a little harder for &#8220;intruders&#8221; using iptables. &#160; Aim: If there [...]]]></description>
			<content:encoded><![CDATA[<p>When checking logfiles, I often can see brute force attacks &#8211; especially against the ssh daemon.<br />
Of course, best way would be to block all ssh traffic except from your office/home ip.<br />
If this is not possible for various reasons, you can make life a little harder for &#8220;intruders&#8221; using iptables.<br />
&nbsp;<br />
Aim: <br />
If there are more than three connection attemps within 120 seconds,<br />
all traffic from potential attacker to ssh port (tcp, 22) shall be blocked temporarily.<br />
&nbsp;<br />
<code><br />
#!/bin/bash<br />
#<br />
IPTABLES=`which iptables`<br />
#<br />
### if more than three new connections in 120 sec -> log<br />
$IPTABLES -A INPUT -i eth0 -p tcp --dport 22 -m state --state NEW -m recent \<br />
--rcheck --seconds 120 --hitcount 3 --rttl --name SSH -j LOG --log-level 7 \<br />
--log-prefix "Possible SSH breakin attemp: "<br />
#<br />
### if more than three new connections in 120 sec -> drop requests<br />
$IPTABLES -A INPUT -i eth0 -p tcp --dport 22 -m state --state NEW -m recent \<br />
--update --seconds 120 --hitcount 3 --rttl --name SSH -j DROP<br />
#<br />
### remember new, established connections<br />
$IPTABLES -A INPUT -i eth0 -p tcp --dport 22 -m state --state NEW -m recent \<br />
--set --name SSH -j ACCEPT<br />
#<br />
### generally allow ssh connections<br />
$IPTABLES -A INPUT -i eth0 -p tcp --dport 22 -j ACCEPT<br />
#<br />
# ---<br />
# -I INPUT .. -> iptables chain<br />
# -i eth0 ... -> interface to apply rule to<br />
# -p tcp .... -> use tcp port<br />
# --dport ... -> destination port 22 (SSH)<br />
# -m recent . -> matching state<br />
# --state ... -> can be NEW, ESTABLISHED, RELATED or INVALID<br />
# -rcheck ... -> will check if the source address of the packet is currently in the list<br />
# ---<br />
</code><br />
&nbsp;<br />
&nbsp;<br />
If it works, you should see entries like this in your firewall log<br />
(i.e. in /var/log/firewall [ openSuSE ]):<br />
&nbsp;<br />
<code><br />
Feb 28 15:14:20 cypher kernel: Possible SSH breakin attemp: IN=eth0 OUT= MAC=00:0c:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx:xx SRC=123.xxx.xxx.xxx DST=223.xxx.xxx.xxx LEN=60 TOS=0x00 PREC=0x00 TTL=59 ID=52858 DF PROTO=TCP SPT=38220 DPT=22 WINDOW=5840 RES=0x00 SYN URGP=0<br />
</code></p>
]]></content:encoded>
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		<slash:comments>1</slash:comments>
		</item>
		<item>
		<title>Fixing Astaro 7.202 (when upgrade fails)</title>
		<link>http://tom.knaupp.com/2008/09/24/fixing-astaro-7202-when-upgrade-fails/</link>
		<comments>http://tom.knaupp.com/2008/09/24/fixing-astaro-7202-when-upgrade-fails/#comments</comments>
		<pubDate>Wed, 24 Sep 2008 22:46:36 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Security]]></category>
		<category><![CDATA[ASG 7.202 update]]></category>
		<category><![CDATA[ASG 7.202 upgrade]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/?p=136</guid>
		<description><![CDATA[again &#8230; if upgrading from ASG 7.202 to newer versions fails, apply the following fix [as root]: auisys.plx --rpmargs --force Maybe you&#8217;ll have to stay calm until your up2date packages get &#8220;re-new-ed&#8221; .. so, wait a few days if first try fails.]]></description>
			<content:encoded><![CDATA[<p><a href="http://tom.knaupp.com/2008/09/02/fixing-astaro-7200-when-upgrade-fails/">again </a>&#8230;<br />
if upgrading from ASG 7.202 to newer versions fails, apply the following fix [as root]:<br />
<code><br />
auisys.plx --rpmargs --force</code></p>
<p>Maybe you&#8217;ll have to stay calm until your up2date packages get &#8220;re-new-ed&#8221; .. so, wait a few days if first try fails.</p>
]]></content:encoded>
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		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>VMware Server 1.0.7 released</title>
		<link>http://tom.knaupp.com/2008/09/03/vmware-server-107-released/</link>
		<comments>http://tom.knaupp.com/2008/09/03/vmware-server-107-released/#comments</comments>
		<pubDate>Wed, 03 Sep 2008 10:22:26 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Security]]></category>
		<category><![CDATA[Virtualization]]></category>
		<category><![CDATA[VMware]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/?p=134</guid>
		<description><![CDATA[A few days ago, VMware Server 1.0.7 has been released. The update mainly cares about security issues: Security Fix for VMware ISAPI Extension Setting ActiveX killbit Security Fix for Local Privilege Escalation on Host System Update to Freetype 2.3.7 More info can be found in VMware&#8217;s Release Notes]]></description>
			<content:encoded><![CDATA[<p>A few days ago, VMware <a href="http://www.vmware.com/download/server/" target="_blank">Server 1.0.7 </a>has been released.<br />
The update mainly cares about security issues:</p>
<ul>
<li>Security Fix for VMware ISAPI Extension</li>
<li>Setting ActiveX killbit</li>
<li>Security Fix for Local Privilege Escalation on Host System</li>
<li>Update to Freetype 2.3.7</li>
</ul>
<p>More info can be found in <a href="http://www.vmware.com/support/server/doc/releasenotes_server.html#bugfix107" target="_blank">VMware&#8217;s Release Notes</a></p>
]]></content:encoded>
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		<slash:comments>1</slash:comments>
		</item>
		<item>
		<title>Fixing Astaro 7.200 (when upgrade fails)</title>
		<link>http://tom.knaupp.com/2008/09/02/fixing-astaro-7200-when-upgrade-fails/</link>
		<comments>http://tom.knaupp.com/2008/09/02/fixing-astaro-7200-when-upgrade-fails/#comments</comments>
		<pubDate>Tue, 02 Sep 2008 22:15:10 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Security]]></category>
		<category><![CDATA[ASG 7.200 update]]></category>
		<category><![CDATA[ASG 7.200 upgrade]]></category>
		<category><![CDATA[Astaro 7.200 update]]></category>
		<category><![CDATA[Astaro 7.200 upgrade]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/?p=112</guid>
		<description><![CDATA[If upgrading from ASG 7.200 to newer versions fails, apply the following fix [as root]: rpm -q ep-asg &#038;&#038; cd /tmp &#038;&#038; wget http://www.astaro.com/content/download/5618/51408/version/1/file/ep-asg-7.2-23.i686.rpm &#038;&#038; rpm -Uvh /tmp/ep-asg-7.2-23.i686.rpm More info at Astaro Knowledge Base Article #288713.]]></description>
			<content:encoded><![CDATA[<p>If upgrading from ASG 7.200 to newer versions fails, apply the following fix [as root]:<br />
<code><br />
rpm -q ep-asg &#038;&#038; cd /tmp &#038;&#038; wget http://www.astaro.com/content/download/5618/51408/version/1/file/ep-asg-7.2-23.i686.rpm &#038;&#038; rpm -Uvh /tmp/ep-asg-7.2-23.i686.rpm<br />
</code><br />
<br />
More info at Astaro Knowledge Base Article <a href="http://portal.knowledgebase.net/article.asp?article=288713&#038;p=5956" target="_blank">#288713.</a></p>
]]></content:encoded>
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		<slash:comments>1</slash:comments>
		</item>
		<item>
		<title>SUSE Linux 10.1 discontinued and out of support</title>
		<link>http://tom.knaupp.com/2008/08/21/suse-linux-101-end-of-life/</link>
		<comments>http://tom.knaupp.com/2008/08/21/suse-linux-101-end-of-life/#comments</comments>
		<pubDate>Thu, 21 Aug 2008 20:34:09 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Distributions]]></category>
		<category><![CDATA[Security]]></category>
		<category><![CDATA[EOL]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/?p=101</guid>
		<description><![CDATA[SUSE Linux 10.1 has reached End of Life : / &#160; Quote from the opensuse-security-announce mailing list: With the release of an mysql security fix on August 13 we have released the last update for SUSE Linux 10.1. (Actually 10.1 was discontinued on May 31st, but the queue took a bit longer to flush from [...]]]></description>
			<content:encoded><![CDATA[<p>SUSE Linux 10.1 has reached End of Life : / </p>
<p>&nbsp;<br />
Quote from the opensuse-security-announce mailing list:</p>
<blockquote><p>With the release of an mysql security fix on August 13 we have released<br />
the last update for SUSE Linux 10.1. (Actually 10.1 was discontinued on<br />
May 31st, but the queue took a bit longer to flush from all updates.)</p></blockquote>
<p>&nbsp;<br />
See: <a href="http://lists.opensuse.org/opensuse-security-announce/2008-08/msg00004.html" target="_blank">http://lists.opensuse.org/opensuse-security-announce/2008-08/msg00004.html</a></p>
]]></content:encoded>
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		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>Critical Bug in Joomla 1.5.5 (and older 1.5.x versions)</title>
		<link>http://tom.knaupp.com/2008/08/18/critical-bug-in-joomla-155/</link>
		<comments>http://tom.knaupp.com/2008/08/18/critical-bug-in-joomla-155/#comments</comments>
		<pubDate>Mon, 18 Aug 2008 11:35:52 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Security]]></category>
		<category><![CDATA[Webapps]]></category>
		<category><![CDATA[Joomla]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/?p=100</guid>
		<description><![CDATA[The password of the user with the lowest ID (typically an administrator) can be reset by an unauthorized user in Joomla 1.5.x installations prior version 1.5.6 because of a bug in the password remind functionality. All 1.5.x installations prior to and including 1.5.5 are affected The Joomla developer team advises to upgrade to 1.5.6 (or [...]]]></description>
			<content:encoded><![CDATA[<p>The password of the user with the lowest ID (typically an administrator) can be reset by an unauthorized user in Joomla 1.5.x installations prior version 1.5.6 because of a bug in the password remind functionality.<br />
<br />
<strong>All 1.5.x installations prior to and including 1.5.5 are affected</strong><br />
<br />
The Joomla developer team advises to upgrade to 1.5.6 (or patch the  <em>/components/com_user/models/reset.php</em> file with the code below).<br />
<br />
After global $mainframe; on line 113 of reset.php, add:<br />
<code><br />
if(strlen($token) != 32) {<br />
&nbsp;&nbsp;&nbsp;&nbsp;$this-&gt;setError(JText::_('INVALID_TOKEN'));<br />
&nbsp;&nbsp;&nbsp;&nbsp;return false;<br />
}<br />
</code><br />
<br />&nbsp;<br />
See: <a title="Joomla! Developer - Password Remind Functionality" href="http://developer.joomla.org/security/news/241-20080801-core-password-remind-functionality.html" target="_blank">Joomla! Developer &#8211; Password Remind Functionality</a></p>
]]></content:encoded>
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		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>suPHP 0.6.3 released / security fix</title>
		<link>http://tom.knaupp.com/2008/04/11/suphp-063-released-security-fix/</link>
		<comments>http://tom.knaupp.com/2008/04/11/suphp-063-released-security-fix/#comments</comments>
		<pubDate>Fri, 11 Apr 2008 16:17:13 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Security]]></category>
		<category><![CDATA[suPHP]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/?p=85</guid>
		<description><![CDATA[The latestet release of suPHP (v.0.6.3) has been published on Mar 30th, 2008. It&#8217;s a security fix release eliminating two symlink race-conditions. Users are strongly advised to update immediately.]]></description>
			<content:encoded><![CDATA[<p>The latestet release of <a href="http://www.suphp.org/" target="_blank">suPHP</a> (v.0.6.3) has been published on Mar 30th, 2008.<br />
<br />
It&#8217;s a <a href="http://www.suphp.org/download/suphp-0.6.3.tar.gz">security fix release</a> eliminating two symlink race-conditions.<br />
Users are strongly advised to update immediately.</p>
]]></content:encoded>
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		<slash:comments>0</slash:comments>
		</item>
		<item>
		<title>Should I use DNSBL?</title>
		<link>http://tom.knaupp.com/2008/03/05/should-i-use-dnsbl/</link>
		<comments>http://tom.knaupp.com/2008/03/05/should-i-use-dnsbl/#comments</comments>
		<pubDate>Tue, 04 Mar 2008 23:18:25 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Mailserver]]></category>
		<category><![CDATA[Security]]></category>
		<category><![CDATA[backscatter]]></category>
		<category><![CDATA[RBL]]></category>
		<category><![CDATA[spamhaus]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/2008/03/05/should-i-use-dnsbl/</guid>
		<description><![CDATA[RBLs &#8211; yes / no.. a big discussion always.. Right now, I can recommend zen.spamhaus.org &#38; ix.dnsbl.manitu.net (&#60;- especially for german MXs). I&#8217;ve never seen a false positive on these lists .. Nevertheless, use the lists for scoring (i.e. with spamassassin), not for instant blocking! Nowadays, prosecuting &#8220;backscatter&#8221;, sender callouts, etc. seems to be a [...]]]></description>
			<content:encoded><![CDATA[<p><a href="http://en.wikipedia.org/wiki/DNSBL" title="DNSBL" target="_blank">RBLs</a> &#8211; yes / no.. a big discussion always..<br />
Right now, I can recommend <a href="http://www.spamhaus.org" title="Spamhaus" target="_blank">zen.spamhaus.org</a> &amp; <a href="http://www.dnsbl.manitu.net/" title="DNSBL IX" target="_blank">ix.dnsbl.manitu.net</a> (&lt;- especially for german MXs).<br />
I&#8217;ve never seen a false positive on these lists ..<br />
<br />
Nevertheless, use the lists for scoring (i.e. with spamassassin), not for instant blocking!<br />
<br />
Nowadays, prosecuting &#8220;backscatter&#8221;, sender callouts, etc. seems to be a new trend &#8211; and it <em>could</em> be useful in future..<br />
I&#8217;ve tested the only free list I know &#8211; backscatterer.org.<br />
Don&#8217;t you use that one for immediate blocking!<br />
Scoring can be ok, but even there &#8211; watch your logs!<br />
<br />
Some &#8220;hits&#8221; (from a test run) to show what I found:<br />
&#8230;<br />
2008-03-04 17:17:42 H=lizzard.sbs.de [194.138.37.39] &#8211; possible backscatter<br />
2008-03-04 17:21:59 H=mail.space.net [195.30.0.8] &#8211; possible backscatter<br />
2008-03-04 17:25:33 H=relay4.ptmail.sapo.pt [212.55.154.24] &#8211; possible backscatter<br />
2008-03-04 17:32:46 H=<strong>relay23.arbeitsagentur.de</strong> [212.204.77.151] &#8211; possible backscatter<br />
2008-03-04 17:33:38 H=mout1.mail.vrmd.de [81.28.224.19] &#8211; possible backscatter<br />
2008-03-04 17:48:33 H=<strong>dgate1.fujitsu-siemens.com</strong> [217.115.66.35] &#8211; possible backscatter<br />
2008-03-04 17:50:05 H=<strong>mailout05.sul.t-online.de</strong> [194.25.134.82] &#8211; possible backscatter<br />
2008-03-04 17:51:27 H=relay0-0.brigade.com [209.249.158.73] &#8211; possible backscatter<br />
2008-03-04 18:04:42 H=<strong>mailout07.sul.t-online.de </strong>[194.25.134.83] &#8211; possible backscatter<br />
2008-03-04 18:11:21 H=bay0-omc2-s24.bay0.hotmail.com [65.54.246.160] &#8211; possible backscatter<br />
2008-03-04 18:13:37 H=mail.space.net [195.30.0.8] &#8211; possible backscatter<br />
2008-03-04 18:13:42 H=<strong>smtp1.versatel.nl</strong> [62.58.50.88] &#8211; possible backscatter<br />
2008-03-04 18:15:29 H=<strong>mailout09.sul.t-online.de</strong> [194.25.134.84] &#8211; possible backscatter<br />
2008-03-04 18:16:33 H=ip17.be3a.com (be3a.com) [213.92.9.17] &#8211; possible backscatter<br />
2008-03-04 18:18:12 H=gamwsm02.mwga.mailwatch.com [216.157.255.16] &#8211; possible backscatter<br />
2008-03-04 18:20:15 H=aps67.muc.ec-messenger.com [195.140.186.67] &#8211; possible backscatter<br />
2008-03-04 18:22:56 H=mout1.mail.vrmd.de [81.28.224.19] &#8211; possible backscatter<br />
2008-03-04 18:25:46 H=mail.gmx.net [213.165.64.20] &#8211; possible backscatter<br />
2008-03-04 18:27:56 H=<strong>mail004.thyssenkrupp.com</strong> [149.211.153.66] &#8211; possible backscatter<br />
2008-03-04 18:30:43 H=<strong>mailout04.sul.t-online.de</strong> [194.25.134.18] &#8211; possible backscatter<br />
2008-03-04 18:33:06 H=<strong>mailout03.sul.t-online.de</strong> [194.25.134.81] &#8211; possible backscatter<br />
2008-03-04 18:39:33 H=<strong>mail.gmx.net</strong> [213.165.64.20] &#8211; possible backscatter<br />
2008-03-04 18:45:20 H=<strong>mail.schule.bayern.de</strong> [194.95.207.92] &#8211; possible backscatter<br />
2008-03-04 18:48:56 H=skibayf20.kirche-bayern.de [141.78.101.100] &#8211; possible backscatter<br />
&#8230;<br />
<br />
A lot of the BIG players (german companies in this example mainly) are found on the list ..<br />
So don&#8217;t get yourself in trouble with users that complain all day long and think about what you&#8217;re blocking ..<br />
<br />
Any suggestion/comment ist highly appreciated.</p>
]]></content:encoded>
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		<title>Howto: Single Sign On with Squid Proxy and Active Directory</title>
		<link>http://tom.knaupp.com/2007/12/12/howto-single-sign-on-with-squid-proxy-and-active-directory/</link>
		<comments>http://tom.knaupp.com/2007/12/12/howto-single-sign-on-with-squid-proxy-and-active-directory/#comments</comments>
		<pubDate>Wed, 12 Dec 2007 18:30:55 +0000</pubDate>
		<dc:creator>tom</dc:creator>
				<category><![CDATA[Memento]]></category>
		<category><![CDATA[Security]]></category>
		<category><![CDATA[active directory]]></category>
		<category><![CDATA[authentication]]></category>
		<category><![CDATA[kerberos]]></category>
		<category><![CDATA[single sign on]]></category>
		<category><![CDATA[squid]]></category>
		<category><![CDATA[username]]></category>

		<guid isPermaLink="false">http://tom.knaupp.com/2007/12/12/howto-single-sign-on-with-squid-proxy-and-active-directory/</guid>
		<description><![CDATA[Tested on: openSUSE 10.2, Squid 2.6 &#60;-&#62; Windows Server 2003 Goal: User authentication should be possible without &#8220;extra login&#8221; on the squid proxy. Here we go &#8230; First of all, disable nscd (name service cache daemon)! Install winbind, samba client and kerberos tools In this test enviroment, the Domain is &#8220;D1COMP&#8221;; the realm &#8220;D1COMP.LAN&#8221; Edit [...]]]></description>
			<content:encoded><![CDATA[<p>Tested on:  openSUSE 10.2, Squid 2.6 &lt;-&gt; Windows Server 2003<br />
Goal: User authentication should be possible without &#8220;extra login&#8221; on the squid proxy.<br />
<br />
<img src="http://tom.knaupp.com/wp-content/uploads/squidlog.png" alt="Squid Logfile" /><br />
<br />
Here we go &#8230;<br />
<span id="more-76"></span></p>
<ul>
<li>First of all, disable nscd (name service cache daemon)!</li>
<li>Install winbind, samba client and kerberos tools</li>
</ul>
<p>In this test enviroment, the Domain is &#8220;D1COMP&#8221;; the realm &#8220;D1COMP.LAN&#8221;</p>
<ul>
<li>Edit /etc/krb5.conf</li>
</ul>
<p><code><br />
[libdefaults]<br />
default_realm = D1COMP.LAN<br />
clockskew = 300</code><code><br />
[realms]<br />
D1COMP.LAN = {<br />
kdc = 172.31.7.27   ## One of your Domain Controllers<br />
default_domain = d1comp.lan<br />
admin_server = 172.31.7.27<br />
}</code><code><br />
[logging]<br />
kdc = FILE:/var/log/krb5/krb5kdc.log<br />
admin_server = FILE:/var/log/krb5/kadmind.log<br />
default = SYSLOG:NOTICE:DAEMON<br />
</code><code><br />
[domain_realm]<br />
.d1comp.lan = D1COMP.LAN<br />
</code><code><br />
[appdefaults]<br />
pam = {<br />
ticket_lifetime = 1d<br />
renew_lifetime = 1d<br />
forwardable = true<br />
proxiable = false<br />
retain_after_close = false<br />
minimum_uid = 1<br />
}</code></p>
<ul>
<li>obtain Kerberos ticket</li>
</ul>
<p><code><br />
# kinit Administrator@D1COMP.LAN<br />
Password for Administrator@D1COMP.LAN:<br />
#<br />
</code></p>
<ul>
<li>check Kerberos ticket</li>
</ul>
<p><code><br />
# klist<br />
Ticket cache: FILE:/tmp/krb5cc_0<br />
Default principal: Administrator@D1COMP.LAN<br />
--------<br />
Valid starting     Expires            Service principal<br />
12/12/07 16:16:01  12/13/07 02:16:45  krbtgt/D1COMP.LAN@D1COMP.LAN<br />
renew until 12/13/07 16:16:01<br />
--------<br />
Kerberos 4 ticket cache: /tmp/tkt0<br />
klist: You have no tickets cached<br />
</code></p>
<ul>
<li>Adjust /etc/samba/smb.conf</li>
</ul>
<p><code><br />
[global]<br />
workgroup = D1COMP<br />
printing = cups<br />
printcap name = cups<br />
printcap cache time = 750<br />
cups options = raw<br />
map to guest = Bad User<br />
include = /etc/samba/dhcp.conf<br />
logon path = \\%L\profiles\.msprofile<br />
logon home = \\%L\%U\.9xprofile<br />
logon drive = P:<br />
usershare allow guests = No<br />
idmap gid = 10000-20000<br />
idmap uid = 10000-20000<br />
realm = D1COMP.LAN<br />
security = ADS<br />
template homedir = /home/%D/%U<br />
template shell = /bin/bash<br />
winbind refresh tickets = yes<br />
</code></p>
<ul>
<li>Join the Active Directory</li>
</ul>
<p><code><br />
# net join -S d1comp -UAdministrator%Password<br />
Using short domain name -- D1COMP<br />
Joined 'SERVER' to realm 'D1COMP.LAN'<br />
</code><code><br />
# /etc/init.d/winbind start<br />
Starting Samba WINBIND daemon   ...         done<br />
</code></p>
<ul>
<li>Basic Check:</li>
</ul>
<p><code><br />
# wbinfo -t<br />
checking the trust secret via RPC calls succeeded<br />
</code><code><br />
# wbinfo -g<br />
D1COMP\domain guests<br />
D1COMP\domain users<br />
D1COMP\...<br />
</code></p>
<ul>
<li>Check support of ntlm authentication:</li>
</ul>
<p><code><br />
# wbinfo -a d1comp\\user%password<br />
plaintext password authentication succeeded<br />
challenge/response password authentication succeeded<br />
</code><br />
<em>ntlm_auth requires access to the privileged winbind pipe in order to function properly</em>.</p>
<ul>
<li>Enable this by changing group of the winbind_privileged directory to the group you run Squid as (cache_effective_group setting in squid.conf).</li>
</ul>
<p><code><br />
chgrp squid /var/lib/samba/winbindd_privileged</code></p>
<ul>
<li>Edit squid.conf to enable both the winbind basic and ntlm authenticators. IE will use ntlm and everything else basic:</li>
</ul>
<p><code><br />
auth_param ntlm program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-ntlmssp<br />
auth_param ntlm children 10<br />
#auth_param ntlm max_challenge_reuses 0<br />
#auth_param ntlm max_challenge_lifetime 2 minutes<br />
#auth_param ntlm use_ntlm_negotiate off<br />
auth_param basic program /usr/bin/ntlm_auth --helper-protocol=squid-2.5-basic<br />
auth_param basic children 5<br />
auth_param basic realm Domain Proxy Server<br />
auth_param basic credentialsttl 2 hours<br />
auth_param basic casesensitive off<br />
authenticate_cache_garbage_interval 10 seconds<br />
##<br />
# Credentials past their TTL are removed from memory<br />
authenticate_ttl 0 seconds<br />
##<br />
## acl entries to require authentication:<br />
acl AuthorizedUsers proxy_auth REQUIRED<br />
http_access allow all AuthorizedUsers<br />
</code><br />
<br />
This howto is no guarantee to get it work, but kind of reminder for me : /<br />
Special thanks to <a href="http://wiki.squid-cache.org/ConfigExamples/WindowsAuthenticationNTLM">Adrian Chadd</a> and <a href="http://wiki.squid-cache.org/SquidFaq/ProxyAuthentication">the wiki @ squid-cache.org</a>!</p>
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