ClearOS Dansguardian accessdenied.php Bypass Script

Using Dansguardian on ClearOS, ClarkConnect, or any basic *unix setup, you can configure a .php script to bypass the content filtering software for a set amount of time using a defined username and password. This walkthrough involves the modification of configuration files and general *unix knowledge. If you need additional assistance please don’t hesitate to contact us via email or phone.

 

This walkthrough requires a fully configured content filter utilizing Dansguardian or Dansguardian-AV utilizing a transparent proxy!

We need to first log into our server via console or SSH. Once logged in we need to locate the first file to edit called dansguardian.conf

To locate the file, as the location varies, I prefer to use the universal *unix find command-



In the case above, the file is located in the /etc/dansguardian-av/ directory. To edit the file, you can use your favorite *unix text editor. In this case I am going to use nano as it’s fairly easy to use-



There are a few settings that must be configured correctly in this file for later us:

  • Set the reporting level to 1 or 2 depending on your needs
  • Point the accessdenied.php script to a file location in which we’ll create later
  • Enable the non-standard delimiter in order to allow dansguardian to correctly pass information to our script



Please note the in above image the ip-address reflects the location of your transparent proxy server.

Now we need to edit the dansguardianf1.conf file which is located in the same location:


There are additional settings we need to change here:

  • Change the temporary bypass denied page setting to -1 which configures dansguardian to use our script file
  • You must generate a md5 key that will be unique to our script (see link below)
  • Change reporting level to match setting in dansguardian.conf file



Follow this link to generate a MD5 Key: Generate MD5 Key

We now have to create our accessdenied.php script. This file is located in the transparent web-proxy public location. To locate it, we’ll use the find command again:


In the case above we notice the public directory resides in /var/webconfig/. Let’s create our accessdenied file in the public directory:


To access an example .pdf document outlining the accessdenied.php script, please click the link below:



An outline of some key settings are displayed below:




The last step is to create a text file containing a username and password used to bypass the filter. You need to place this file outside of the public www directory used by the transparent-proxy. In the following example I placed the file named access.txt a directory below the public www:

The file can contain a simple username and password separated by use of a tab or space:

Once done, save the file, restart the service, and your should be good to go!

cleanspl.exe – Print Spooler Cleaner

If you’ve experienced problems with the spoolsv.exe crashing on your system, or you have been running into issues with printing in general, the cleanspl.exe tool provided by Microsoft may be able to solve your problems.

I have run into issues with HP Laserjet printers, specifically the 10xx models, causing the print spooler on Windows XP to crash.  This tool was easily able to resolve the issue, even after a Windows CD repair did not work.

Please make sure you are informed before using this utility as it has the ability to edit your registry.  Always make backups before performing system changes!

To download the file directly, please follow the link below:


[cleanspl.zip – 34.5KB]

The file is part of the Windows Server 2003 Resource Kit Tools provided by Microsoft.  They are provided directly from Microsoft by following the link below:


[file hosted @ microsoft.com – 11.8MB]

Netflix N8210 Error Fixed!

We’ve been having issues at my school since I’ve updated my content filter to the newer version of ClearOS.  I kept receiving a Netflix error N8210 when attempting to ‘Instantly Watch’ a video from their collection.

ClearOS uses a form of Squid for the transparent proxy on top of Dansguardian-AV.  The solution below should essentially work for anyone that is using a content filter.  The fix is to add these specific domains to your content filter exclusion list.

I located these files after using grep on the dansguardian access.log file to track which servers Netflix was attempting to access during a ‘Instant Stream’ session.  These are:

netflix.com
netflix.net
nflximg.com
nlfxext.com
llwnd.net
edgesuite.com
edgesuite.net

Microsoft Security Essentials

Many people do not know there is a free anti-virus/malware program provided directly by Microsoft.  Why bother installing a paid application when you can get free protection for your computer directly from the software manufacturer?

Microsoft Security Essentials is a free anti-malware solution for your computer provided by Microsoft.  It helps protect against viruses, spyware, and other malicious software.  It’s available for Windows XP SP2(and higher), Windows Vista, and Windows 7.

To download the latest version directly from Microsoft, please follow the link below:

Alternative DNS Servers

Public DNS servers can speed up your web surfing on the internet.  If you’ve had trouble streaming HD YouTube videos or you’re sick of getting redirected when you mistype an address then you might want to switch to a public DNS server.

Most DNS servers are automatically assigned depending upon your ISP.  For most people, the DNS servers assigned automatically will work well enough.  If you’d like to experiment with load times and just see if you can increase performance of your web browsing, changing your DNS server can be a great start.

Google has created a walk-through that will help you configure your network settings to use their public DNS servers, which are listed below.  The walkthrough can also be used for any of the other DNS servers listed below.  The walk-through covers making changes in Windows, Mac OS X, and the Linux environment.

The PDF walk-through can be found here:
Using Google Public DNS

The direct PDF download of the walk-through can be found here:

Google Public DNS Servers
8.8.8.8
8.8.4.4

Level 3 DNS Servers
4.2.2.1
4.2.2.2

OpenDNS Servers
208.67.222.222
208.67.220.220

Audacity

Audacity © is a free and open-source software used for recording and editing sound.  I’ve placed download links below for easy access and backup to the latest versions as of this post*.  There is also the link for the LAME MP3 Encoder which is essential for MP3 exporting.

To download the latest version 1.2.6, then follow this link:

To download the LAME library, which is necessary for MP3 encoding, then click below:

*We are not affiliated with Audacity © and make these files available under the terms of the GNU General Public License (GPL) as published by the Free Software Foundation.

Microsoft WorldWide Telescope

Many people have heard of using Google Earth to explore the world.  Well, Microsoft has had a software that allows you to explore the cosmos in much the same way.  It really is an amazing piece of software.  Below is an except from their website that gives you a brief overview of what the software is.  The direct link for the website and the Microsoft Windows Client are located at the end of the article.

“The WorldWide Telescope (WWT) is a environment that enables your computer to function as a virtual telescope—bringing together imagery from the world’s best ground- and space-based telescopes for the exploration of the universe. WWT blends terabytes of images, information, and stories from multiple sources into a seamless, immersive, rich media experience delivered over the Internet. Students of all ages will feel empowered to explore and understand the cosmos using WWT’s simple and powerful user interface.”

To visit the website for more information, or to access the web-client interface please follow this link: Microsoft WorldWide Telescope

To download the current version for Windows [version 2.8.15] please follow this link:

Smithsonian Wild

Researches at the Smithsonian have recently created a database comprised of over 201,000 pictures of normally elusive animals in their natural habitats.  The process was made possible by the use of motion-activated, automated cameras, spread around the world.  The gallery contains over 200 species of birds and mammals.

Click the link to check it out!

Smithsonian Wild

Arcademic Skill Builders

This is a fantastic website that we use for our K-5 instruction at WWA.  It allows the students to compete against one another in a variety of activities and challenges.  The website is kid-friendly, free of advertisement and best of all free to use!

The website was originally born as a side project in the research department of the University of Kansas School of Education with funding from a NSF grant.  The website began as the idea of Dr. Jerry Chaffin who believes that students in rate-based math practice would lead to higher fluency and automaticity.  The multi-player competition engages students and pushes them to achieve.

You can locate the website at Arcademic Skill Builders

Windows Installer 4.5

This is the direct link to download the Windows Installer 4.5 Redistributable.


[Windows XP Version – File Size: ~3.2MB]