Tutorial Proggraming Free

tutorial - Password protected GRUB in Ubuntu

Ubuntu installs GNU GRUB as its default boot loader, which allows for great flexibility and recovery options. For example, when you install additional kernel images, these are automatically added as available boot options in the grub menu. Also, by default, alternate boot options are available for each kernel entry that may be used for system recovery.

To add a password for use with grub, first you must generate an md5 password hash using the grub-md5-crypt utility: grub-md5-crypt

The command will ask you to enter a password and offer a resulting hash value as shown below:

Password: (enter new password)
Retype password: (repeat password)
$1$s3YiK$M3lxAbqA6JLm2FbDWnClQ0

Add the resulting hash value to the file /etc/grub/menu.lst in the following format:

password --md5 $1$s3YiK$M3lxAbqA6JLm2FbDWnClQ0

To require use of the password for entering single user mode, change the value of the lockalternative variable in the file /boot/grub/menu.lst to true, as shown in the following example.

# lockalternative=true

Free, facebook, tips, Links, blogging, Downloads, Google, facebookTips, money, news, apps, Social, Media, Website, Tricks, games, Android, software, PIctures, Internet, Security, Web, codes, Review, bloggers, SAMSUNG, Worldwide, Contest, Exitic, Phones, facebookTricks, hacking, London, Olympics, SEO, Youtube, iOS, Adsense, gadgets, iPHONE, widgets, Doodle, twitter, video, Deals, technology, Aircel, Airtel, iPAD, Angry, Birds, BSNL, TechLife, GMAIL, Idea, Microsoft, SmartPhones, Stress, Buster, Windows, Yahoo, Infolinks, Nokia, Scam, Uninor, browsers, Amazon, Euro, CUP, Chat, IDM, JOBS, Modem, Music, Reliance, Results, SSC, Tata, Docomo, bing, freebie, mobile, placements, AIEEE, AlertPay, Chrome, College, Competetive, Exam, Dehradun, Extension, FireFox, GPRS, HTC, IMPACT, Info, MTS, Mark, Zukerberg, Paypal, Promotional, Post, Torrent, UTU, Unlocking, VodaFone, Wall, Paper, apple, books, engineering, iCAR, iTunes, pinterest, rovio, AVG, Admit, Card, Adobe, Affiliate, Marketing, Akhilesh, Amul, Girl, BlackBerry, ChromeBook, Clixsense, Coupon, Digitallife, Discovery, Emoticons, Festival, GATE, GIMP, Income, Tax, International, JSS, JailBreaking, Kindle, Linux, Local, MAX, PAYNE, Mac, Mango, Memory, Speed, Nexus, Online, Shopping, Raakhi, Report, Rising, Stars, Sample, Science, Sony, Syllabus, TabletBooK, Teamviewer, Templates, Dark, Knight, Rises, USA, UPMT, Virgin, Xperia, ZTE, challan, counselling, course, btech, funny, iMOVE, registration

source:http://linuxpoison.blogspot.com/2008/05/135781758016235.html

tutorial - ufw (Uncomplicated Firewall) setup and configuration in Ubuntu

The default firewall configuration tool for Ubuntu is ufw. Developed to ease iptables firewall configuration, ufw provides a user friendly way to create an IPv4 or IPv6 host-based firewall.

The following are some examples of how to use ufw:

First, ufw needs to be enabled. From a terminal prompt enter: sudo ufw enable
To open a port (ssh in this example): sudo ufw allow 22
Similarly, to close an opened port: sudo ufw deny 22
To remove a rule, use delete followed by the rule: sudo ufw delete deny 22
ufw can be disabled by: sudo ufw disable

It is also possible to allow access from specific hosts or networks to a port. The following example allows ssh access from host 192.168.0.2 to any ip address on this host:

sudo ufw allow proto tcp from 192.168.0.2 to any port 22

source:http://linuxpoison.blogspot.com/2008/05/135781758016942.html

tutorial - 20 Awesome Devices That Run Linux (But Weren’t Designed To)

A common attitude among people who believe in free software is to stick it to “the man.” For some people, that translates into spending a ton of free time porting Linux to devices that were never designed for it.

This is one of the things that always amazes me when I read about the latest high-tech devices that been modified to run Linux. Some of these implementations may be incomplete, and I’m not sure why someone would take a brand new device and risk bricking it…

Here’s a short list of devices that make unlikely with Linux. Enjoy!

AppleTV: http://www.mactel-linux.org/wiki/AppleTV
Browser: http://www.workspot.com/screenshots/gimp.html
Gmail: http://www.hackaday.com/2005/04/14/run-linux-on-gmail/
GameCube: http://www.linuxdevcenter.com/pub/a/linux/2004/04/01/warp_pipe.html
Dreamcast: http://www.linuxdevices.com/articles/AT7466555948.html
HTC Smartphones: http://wiki.xda-developers.com/index.php?pagename=Xanadux
iPod: http://ipodlinux.org/Main_Page
Mainframes: http://parisc-linux.org/
Palm PDAs: http://palmtelinux.sourceforge.net/
PS2: http://playstation2-linux.com/
Edit: MSN TV2 http://www.toc2rta.com/index.php/?q=node/2
PSP: http://www.extremetech.com/article2/0,1697,1906893,00.asp
Edit: JuiceBox: http://www.makezine.com/blog/archive/2006/02/run_linux_on_a_juicebox.html
Edit: Mac Classic: http://mac.linux-m68k.org/
Wii: http://www.wiili.org/index.php/Main_Page
Windows: http://wubi-installer.org/
http://goodbye-microsoft.com/
http://sourceforge.net/projects/instlux/
Wireless Routers: http://www.dd-wrt.com/wiki/index.php/Installation http://hyperwrt.org/
Xbox: http://www.xbox-scene.com/articles/linux-install.php
Xbox360: http://www.free60.org/wiki/Main_Page

Last but not least, a toaster: http://pics.defcon.org/showphoto.php?photo=53&cat=512

I showed you mine, now you get to show me yours! What would you like to see running Linux?

Edit… PS3, VirtualPC and USB drives were removed.

Here’s another for you all… Your Mom Can Run Linux: http://www.linuxtoday.com/news_story.php3?ltsn=2007-08-03-032-26-OP-DT

[Source: http://www.fsckin.com/]

source:http://linuxpoison.blogspot.com/2008/05/135781758011671.html

tutorial - Installation and Configuration of MySQL in Ubuntu

To install MySQL, run the following command from a terminal prompt:
sudo apt-get install mysql-server

During the installation process you will be prompted to enter a password for the MySQL root user.

Once the installation is complete, restart the MySQL server: sudo /etc/init.d/mysql restart
Check if MySQL is running: sudo netstat -tap | grep mysql
you should see the following line or something similar:

tcp 0 0 localhost.localdomain:mysql *:* LISTEN -

Configuration

You can edit the /etc/mysql/my.cnf file to configure the basic settings -- log file, port number, etc. For example, to configure MySQL to listen for connections from network hosts, change the bind_address directive to the server's IP address:

bind-address = 192.168.0.5

[Note] Replace 192.168.0.5 with the appropriate address.

After making a change to /etc/mysql/my.cnf the mysql daemon will need to be restarted:

sudo /etc/init.d/mysql restart

source:http://linuxpoison.blogspot.com/2008/05/13578175801318.html

tutorial - Ubuntu installer for Windows users

Wubi is an officially supported Ubuntu installer for Windows users that can bring you to the Linux world with a single click. Wubi allows you to install and uninstall Ubuntu as any other Windows application, in a simple and safe way. Are you curious about Linux and Ubuntu? Trying them out has never been easier!

Wubi is Simple
No need to burn a CD. Just run the installer, enter a password for the new account, and click "Install", go grab a coffee, and when you are back, Ubuntu will be ready for you.

Wubi is Safe
You keep Windows as it is, Wubi only adds an extra option to boot into Ubuntu. Wubi does not require you to modify the partitions of your PC, or to use a different bootloader, and does not install special drivers. It works just like any other application. Wubi is spyware and malware free, and being open source, anyone can verify that.

Wubi is Discrete
Wubi keeps most of the files in one folder, and if you do not like it, you can simply uninstall it as any other application.

Wubi is Free
Wubi and Ubuntu cost absolutely nothing (free as in beer), but yet provide a state of the art, fully functional, operating system that does not require any activation and does not impose any restriction on its use (free as in freedom).

Download wubi exe: here

source:http://linuxpoison.blogspot.com/2008/05/135781758017520.html

tutorial - vsftp server installation and configuration in Ubuntu

vsftpd is an FTP daemon available in Ubuntu. It is easy to install, set up, and maintain. To install vsftpd you can run the following command: sudo apt-get install vsftpd

vsftpd - FTP Server Configuration

You can edit the vsftpd configuration file, /etc/vsftpd.conf, to change the default settings. By default only anonymous FTP is allowed. If you wish to disable this option, you should change the following line:

anonymous_enable=YES

to

anonymous_enable=NO

By default, local system users are not allowed to login to FTP server. To change this setting, you should uncomment the following line:

#local_enable=YES

By default, users are allowed to download files from FTP server. They are not allowed to upload files to FTP server. To change this setting, you should uncomment the following line:

#write_enable=YES

Similarly, by default, the anonymous users are not allowed to upload files to FTP server. To change this setting, you should uncomment the following line:

#anon_upload_enable=YES

The configuration file consists of many configuration parameters. The information about each parameter is available in the configuration file. Alternatively, you can refer to the man page, man 5 vsftpd.conf for details of each parameter.

Once you configure vsftpd you can start the daemon. You can run following command to run the vsftpd daemon:

sudo /etc/init.d/vsftpd start

source:http://linuxpoison.blogspot.com/2008/06/13578175804050.html

tutorial - Tool to find hidden processes and ports

Unhide is a forensic tool to find processes and TCP/UDP ports hidden by rootkits, Linux kernel modules or by other techniques. It includes two utilities: unhide and unhide-tcp.

unhide detects hidden processes using three techniques:
- comparing the output of /proc and /bin/ps
- comparing the information gathered from /bin/ps with the one gathered from system calls (syscall scanning)
- full scan of the process ID space (PIDs bruteforcing)

unhide-tcp identifies TCP/UDP ports that are listening but are not listed in /bin/netstat through brute forcing of all TCP/UDP ports available.

This package can be used by rkhunter in its daily scans.

source:http://linuxpoison.blogspot.com/2008/06/1357817580639.html

tutorial - Interactive packet manipulation Software - Scapy

Scapy is a powerful interactive packet manipulation program. It is able to forge or decode packets of a wide number of protocols, send them on the wire, capture them, match requests and replies, and much more. It can easily handle most classical tasks like scanning, tracerouting, probing, unit tests, attacks or network discovery (it can replace hping, 85% of nmap, arpspoof, arp-sk, arping, tcpdump, tethereal, p0f, etc.). It also performs very well at a lot of other specific tasks that most other tools can't handle, like sending invalid frames, injecting your own 802.11 frames, combining technics (VLAN hopping+ARP cache poisoning, VOIP decoding on WEP encrypted channel, ...), etc. See the quick demo: an interactive session.

Scapy runs natively on Linux, and on most Unixes with libpcap, libdnet and their respective python wrapper. Scapy needs Python 2.4 or upcomming versions.

Download: Here

source:http://linuxpoison.blogspot.com/2008/06/135781758017502.html

tutorial - Monitor Web page changes with Specto

Specto is a desktop application that will watch configurable events (such as website updates, emails, file and folder changes, system processes, etc) and then trigger notifications.

For example, Specto can watch a website for updates (or a syndication feed, or an image, etc), and notify you when there is activity (otherwise, Specto will just stay out of the way). This changes the way you work, because you can be informed of events instead of having to look out for them. Better than clicking the refresh button on Caturdays, huh?

Specto is free and open source software distributed under the GNU GPL license.

Download: Here

source:http://linuxpoison.blogspot.com/2008/06/135781758018076.html

tutorial - Anatomy of Security-Enhanced Linux

Linux has been described as one of the most secure operating systems available, but the National Security Agency (NSA) has taken Linux to the next level with the introduction of Security-Enhanced Linux (SELinux). SELinux takes the existing GNU/Linux operating system and extends it with kernel and user-space modifications to make it bullet-proof. If you're running a 2.6 kernel today, you might be surprised to know that you're using SELinux right now! This article explores the ideas behind SELinux and how it's implemented.

Public networks like the Internet are dangerous places. Anyone who has a computer attached to the Internet (even transiently) understands these dangers. Attackers can exploit insecurities to gain access to a system, to obtain unauthorized access to information, or to repurpose a computer in order to send spam or participate in attacks on other high-profile systems (using SYN floods, as part of a Distributed Denial of Service attacks).

Read more at IBM.com

source:http://linuxpoison.blogspot.com/2008/06/135781758015091.html

tutorial - An authenticating firewall

NuFW lays on Netfilter, the state of the art IP filtering layer from the Linux kernel. It fully integrates with Netfilter and extends its capabilities. The daemons currently run on Linux and software clients are available for Windows, Linux, FreeBSD et Mac OSX.
Its exclusive algorithm allows authenticated filtering even on multiuser computers.

NuFW can be seen as an Identity access management solution, at the network level.

NuFW can :

* Authenticate any connection that goes through your gateway or only from/to a chosen subset or a specific protocol (iptables is used to select the connections to authenticate).
* Perform accounting, routing and quality of service based on users and not simply on IPs.
* Filter packets with criterium such as application and OS used by distant users.
* Log all traffic in SQL with username and application information
* Be the key of a secure and simple Single Sign On system.

Download: Here

source:http://linuxpoison.blogspot.com/2008/06/13578175807379.html

tutorial - Protect SSH from brute force attacks

pam_abl provides auto blacklisting of hosts and users responsible for repeated failed authentication attempts. Generally configured so that blacklisted users still see normal login prompts but are guaranteed to fail to authenticate.

Brute force password discovery attacks involve repeated attempts to authenticate against a service using a dictionary of common passwords. While it is desirable to enforce strong passwords for users this is not always possible and in cases where a weak password has been used brute force attacks can be effective.

The pam_abl module monitors failed authentication attempts and automatically blacklists those hosts (and accounts) that are responsible for large numbers of failed attempts. Once a host is blacklisted it is guaranteed to fail authentication even if the correct credentials are provided.

Blacklisting is triggered when the number of failed authentication attempts in a particular period of time exceeds a predefined limit. Hosts which stop attempting to authenticate will, after a period of time, be un-blacklisted.

Download: Here

Installation:

$ make install
$ cp conf/pam_abl.conf /etc/security

Edit your PAM configuration to include the pam_abl.so module. Here's an example

auth required /lib/security/pam_env.so
auth required /lib/security/pam_abl.so config=/etc/security/pam_abl.conf
auth sufficient /lib/security/pam_unix.so likeauth nullok
auth required /lib/security/pam_deny.so

source:http://linuxpoison.blogspot.com/2008/06/135781758010991.html

tutorial - SmoothWall, the firewall for home users

SmoothWall Express is an open source firewall distribution based on the GNU/Linux operating system. Linux is the ideal choice for security systems; it is well proven, secure, highly configurable and freely available as open source code. SmoothWall includes a hardened subset of the GNU/Linux operating system, so there is no separate OS to install. Designed for ease of use, SmoothWall is configured via a web-based GUI, and requires absolutely no knowledge of Linux to install or use.

SmoothWall Express turns a PC into a dedicated hardware firewall, which sits between your private network and the Internet. It does not allow any unauthorised data to pass through the firewall. There are no services offered to the Internet and SmoothWall Express will not respond to the network messages that hackers use to identify potential targets. It is therefore quite simply invisible to the legions of script kiddies, hackers and crackers looking for an interesting firewall to attack.

Key features

If using analog MODEM, ISDN, USB ADSL, Ethernet connection to the Internet
* network address translation, hide your computer IP address

Stateful packet inspection

* IP address tracking – trace those hackers using the in-build ‘Who is’ feature
* IP address blocking – create your own IP address block list
* Intrusion detection – find out who is ‘probing’ your network
* Comprehensive logging features – all events are logged for evidence
* Monitor network load graphically

No monitor; keyboard or mouse required

* Does not slow down the network or the broadband connection
* Remote access and remote shut down feature

DHCP Server , HTTP Proxy Server
Dynamic DNS
Virtual Private Networking (VPN)
Configuration backup and Secure Shell

Download Smoothwall Express here.

source:http://linuxpoison.blogspot.com/2008/06/135781758017779.html

tutorial - How much do you really know about the GPL?

So your a developer of free software. Now you want to license your code under the GPL. How much do you really know about the GPL?

Take the Free Software License Quiz and find out how much you know (or don’t know) about the GPL and/or LGPL.

This quiz is a very short cgi written in Perl (source available) that tests basic knowledge about the Definition of Free Software, the GPL and the LGPL.

One may wish to review the GPL FAQ before taking the quiz.

Take the quiz and post your results as a comment. You may be surprised.

source:http://linuxpoison.blogspot.com/2008/06/135781758018938.html

Labels