Linux / FreeBSD: PDFCrack A Command Line Password Recovery Tool For PDF Files

Posted on in Categories FreeBSD, Linux, Linux desktop, Security last updated June 6, 2012

I already written about howto remove a password from all PDF files under Ubuntu or any other Linux distribution in a batch mode. However, many user want a simple command to recover password from pdf files. This is useful if you forgotten your password for pdf file. It is also useful for data-archaeologists, computer forensics professionals, people who want to test their password-strength (pdf files generated by webpass) and many more.

Ubuntu / Debian Linux Find Weak OpenSSL keys

Posted on in Categories Debian Linux, Howto, Linux, Linux desktop, Monitoring, Networking, package management, Security, Security Alert, Windows, windows vista last updated June 16, 2008

Luciano Bello discovered that the random number generator in Debian’s openssl package is predictable. This is caused by an incorrect Debian-specific change to the openssl package (CVE-2008-0166). As a result, cryptographic key material may be guessable.

Configure Static Routes In Debian or Red Hat Enterprise Linux

Posted on in Categories CentOS, Debian Linux, Linux, Networking, RedHat/Fedora Linux, Suse Linux, Ubuntu Linux last updated April 13, 2006

Static routes improves overall performance of your network (especially bandwidth saving). They are also useful in stub networks (i.e. there is only one link to the network). For example, each LAN (located at different offices) is connected to HQ IDC (Internet data center) using single T1/LL/Wan links.

For example under Red Hat/Fedora Linux you can add static router for eth0 network interface by editing /etc/sysconfig/network-scripts/route-eth0 file. Under Debian Linux add static route by editing /etc/network/interface file.

Black Screen While Starting X window

Posted on in Categories Debian Linux, Linux, Linux desktop, RedHat/Fedora Linux, Suse Linux, Sys admin, Tips, Troubleshooting, Ubuntu Linux, X server last updated April 2, 2006

My friend is new to Linux, everything was fine until he made some changes to X, which result into this problem. Now whenever he types command startx to start X he get a blank screen. Finally, he contacted me me via yahoo and asked me to get rid rid of this problem.

Step # 1: Reset blank X screen

First, get out of Blank screen by pressing combination of keys Ctrl+Alt+Backspace. If this fails, reboot system.

Step # 2: Reconfigure X server display

At shell, prompt type the following command to reconfigure X display.

If you are using Red Hat /Fedora / CentOS Linux type command:
# redhat-config-xfree86
If you are using Debian Linux type command:
# dpkg-reconfigure xserver-xfree86
OR login as the root user and type command:
# XFree86 -configure

Step # 3: Test new setup

Type startx to test your new settings:
# startx
OR if you used XFree86 –configure command to reconfigure X, then test it with following command:
# XFree86 -xf86config /etc/X11/

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