Debian GNU/linux was dependable and released on 16th august 1993,created by a company called debian project.Its available in 63 languages,the type of kernel that's used is monolithic(linux,freeBSD).
Debian is an operating system which composed of software packages that were released as free and opensource software.The mere form of debian gnu/linux uses the linux kernel and GNU OS tools.
It unmask be used as a desktop and server operating system.It focuses most probably on stability and security.APT(advanced packaging tool) handles the installation and
removal of software on debian GNU/LINUX distribution by working with the core libraries,Its a free user interface. APT intially was designed as front-end for dpkg to
work with debian's .deb packages but at a later stage it was modified to work with RPM package manager via APT-rpm. Default user interfaces are GNOME,KDE plasmadesktop etc.
Debian are supported on numerous platforms .Source debian based distributions are based on .deb package format and the dpkg package manager,for example: Elive alive cd
and distribution featuring enlightment as the only windows manager,gibraltar commercial-router firewall distribution etc. The liberal agenda of this project was to develop a
free operating system.Debian was developed by thousands of volunteers all around the world and supported by donation through several organization, cost of developing all the packages on debian was
almost estimated 13 billion us dollars containg approximately 283 million lines of code by using a COCOMO model.Debian is not backed neither supported by a company
it's funded by volunteers. The ecumenical stable version was "lenny" which was released on september 4th 2010.The different supported platforms which debian works
on are alpha,mips,arm etc.Ubuntu,knoppix,damn small linux,linspire,backtrack,dream linux are some of the linux distribution that are based on debian.Debian can also be
set up as a mail and webserver,debian has a search tool which can find online repositories.As software packages are prone to bugs and vulnerablities debian offers tools
to install and update them regularly.Debian uses Clam anti-virus especially used for e-mail scanning on mail gateways.Ubuntu is primarily a debian distribution on the
inside, The credit of ubuntu success largely goes to the debian community for its technical excellence.Linux distribution such as Ubuntu,knoppix,backtrack uses debian
package tools to add more softwares.Debian is extremely stable and reliable.Debian is one of the operating system distribution in which all components can be upgraded
without rebooting the system.
http://en.wikipedia.org/wiki/Debian
linux bible 2010-full
modified
-----------
INTRODUCTION
----------------
Debian GNU/linux was dependable and released on 16th august 1993,created by a company called debian project.Its available in 63 languages,the type of kernel that's used is monolithic(linux,freeBSD).
Debian is an operating system which composed of software packages that were released as free and opensource software.The mere form of debian gnu/linux uses the linux kernel and GNU OS tools.
It unmask be used as a desktop and server operating system.It focuses most probably on stability and security.APT(advanced packaging tool) handles the installation and
removal of software on debian GNU/LINUX distribution by working with the core libraries,Its a free user interface. APT intially was designed as front-end for dpkg to
work with debian's .deb packages but at a later stage it was modified to work with RPM package manager via APT-rpm. Default user interfaces are GNOME,KDE plasmadesktop etc.
Debian are supported on numerous platforms .Source debian based distributions are based on .deb package format and the dpkg package manager,for example: Elive alive cd
and distribution featuring enlightment as the only windows manager,gibraltar commercial-router firewall distribution etc. The liberal agenda of this project was to develop a
free operating system.Debian was developed by thousands of volunteers all around the world and supported by donation through several organization, cost of developing all the packages on debian was
almost estimated 13 billion us dollars containg approximately 283 million lines of code by using a COCOMO model.Debian is not backed neither supported by a company
it's funded by volunteers. The ecumenical stable version was "lenny" which was released on september 4th 2010.The different supported platforms which debian works
on are alpha,mips,arm etc.Ubuntu,knoppix,damn small linux,linspire,backtrack,dream linux are some of the linux distribution that are based on debian.Debian can also be
set up as a mail and webserver,debian has a search tool which can find online repositories.As software packages are prone to bugs and vulnerablities debian offers tools
to install and update them regularly.Debian uses Clam anti-virus especially used for e-mail scanning on mail gateways.Ubuntu is primarily a debian distribution on the
inside, The credit of ubuntu success largely goes to the debian community for its technical excellence.Linux distribution such as Ubuntu,knoppix,backtrack uses debian
package tools to add more softwares.Debian is extremely stable and reliable.Debian is one of the operating system distribution in which all components can be upgraded
without rebooting the system.
HISTORY
------------
(1993-1998)
debian was developed and announced into market on august 16 1993 its founder was Ian murdock,linux(debian) supported x86,alpha,powerpc,ARM etc.due to poor performace,maintence and unable to sort out
bugs in softlanding linux system(SLS) was first linux/GNU distribution made up of various software packages. the distribution was named debian it was a combination of his first IAN and his Girlfriend first
name debra.debain grew slowly and steadly was sponsered by free software foudation GNU's project.the 0.9x version was released during 1994-95 hartmut koptein started the first port for debian
most of them were x-i386 centric,simultaneously 1.x was released during 1996.murdock was replaced by bruce perens later that same year.bruce was the spearhead and mastermind behind developing debian as free software based on public intrest.
debian began to gain market shares and reputation as platform for linux users.
(1999-2004)
Ian jackson replaced bruce in 1998 during the release of 2.x series these included more ports and packages,APT(Advanced package tool) the first linux distribution was started based on debian libranet,corel linux etc.
were started in 1999, during the release of debian 2.0(Hamm) there were approximately around 1500+ packages that were developed by around 400 developers, debian2.2(potato) was the last 2.x series which was released on
august 15th 2000 for intel i386 ,powerpc ARM architectures that had around 3900+ binary packages and 2600+ source packages developed by 450 developers.in 2002 july 3.x series were released with 3.0(woody) being the first one
in the series for intel i386,powerpc ARM architectures that has around 8500 binary packages it was first release that was available on DVD's and CD-ROMS.
(2005)
debian 3.1 (sarge) was released on 6 th august 2005,it had around 15,000+ binary packages that were developed by around 1500 debian developers.debian 3.1(sarge) updated 73% of old software that were existing on previous versions,also 9,000 new packages
were created including thunderbird e-mail client,firefox web browser,openoffice suite.a new installer replaced an age old boot-floppy installer with advanced installation(RAID,LMV and XFS) making installation simple for all architectures was shipped for
2.4 and 2.6 linux kernel series.debian 4.0(etch) was pretty similar to debian 3.1(sarge) which included AMD64 port but dropped support for m68k, but was still availabe in unstable distribution which consist of around 18200 packages.
debian 5.0(lenny) is present version that was released on 14th feburary 2009,it very stable and reliable was developed with 25,000 software packages
WHY USE DEBIAN
-----------------
debian's advanced packet management makes it easy for new linux user to work with.debian helps in detecting the unauthorised users, by using appropriate tools to fix the isssuse, it can limit and the number of
users and permission on your system.it gives you an option to terminate unwanted program and application and limits them to needed services, they are normally done by using tcpwrappers or firewall like filters
1)stability and reliable- debian's server results are very reliable and stable that can be rebooted once a year.
2)less investment - even with a minimal hardware requirements debian shoots up to give an excellent performance,you can set up a full blown enterprise level at very low cost.
3)user-based - it a free software,it spefically developed based on user needs and specification, new version of debian are developed only when changes warrant one.
4)extensive - debian has over 25,000 software packages, with debian you dont have differnt server and workstation is all in one.
5)easy maintence - it can be maintained easily since it got an intergrated packet management system,dependent packages can be updated automatically.systems are updated so they can free from incompatible components.
6)automated patch up- we can run a single command to update system through the internet ,aswell update the os features,security and programs by just running a shell script on routine bases using a scheduler.
7)no copyright-debian uses unix style commands,it helps simultaneously to learn unix another added advantage wouldnt be obsolette very soon.
http://aboutdebian.com/index.htm
http://www.debian.org/doc/manuals/securing-debian-howto/ch2.en.html#s2.1
modified
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WHY JUSTIFY DEBIAN --------------- debian's advanced packet management makes it easy for new linux user to work wear and tear.debian helps in detecting the unauthorised users, by despise aside tools to fix the isssuse,
it underpinning limit and the number of users and permission on your system.it gives you an inject to interest employment program and permit and discards the unwanted program , they are normally done
by using tcpwrappers or firewall like filters 1)stability and reliable- debian's server results are very reliable and stable that uncover be rebooted once a year. 2)less finances - even simple requirements
debian shoots up to give an excellent performance,you can set up a full blown enterprise level at very low cost. 3)user-based - it a free software,it spefically enthusiastic based on user needs and specification, new version of
debian are developed only when changes warrant one. 4)extensive - debian has 25,000 software packages, with debian you dont have differnt server and workstation is all in one. 5)easy maintence - it can be maintained easily since
it got an intergrated packet management system,dependent packages can be updated automatically.systems are updated so they can free from incompatible components. 6)automated patch up-
we can run a single command to update system through the the internet ,aswell update the os features,security and programs by just running a shell script on routine bases using a scheduler.
7)no copyright-debian uses unix style commands,it helps simultaneously to learn unix another added advantage wouldnt be obsolette very soon.
UNDERSTANDING DEBIAN
----------------------------------------
operating systems are the main reason for interaction of hardware and software components, the core component of an operating system is kernel.it communicates with the hardware components such as eg: microprocessors,device controllers
memory etc.kernel translates the request into a machine speaking language helps executing a particular program.user interfaces helps an individual to interact with computer to launch programs and issuse commands,gain control over the
computer.debian linux/GNU uses EXT2 filesystem to store data but can read FAT and FAT32 using VFAT driver.when a debian linux/GNU starts up it intially loads up filesystem,network interfaces and daemons which run on background away from
human intervention.debian is linux one of oldest distribution.
debian packages : first of all check for hardware compatibility,on particular sytem where installation is going to take place,check on manufacture website if linux is compatible, and investigate if you need any appropirate driver to
install it,debian operating system contains software packages that are clustered for better management and distribution purposes.debian is one of the operating sys tem where after installation of all the upgraded component
we need not hav to reboot the system,they follow a strict rules for packaging policies.debian packages are mainly made of 2 types of packages a binary and source.binary packages are those which can be directly extracted
onto the system by package management tools.source package contain build rules and source code ,where debian utilizes these rules to create binary packages.advance features are supported by package management tools which are enabled by the
control data ,there are two special packages that are important meta and virtual package .meta packages depends on numbers of other packages.installating meta will automatically install the related packages that they depend on .virtual
virtual package are used in referencing package interrelationship fields.there are three important files we need to remember before we get started on debian installation process 1)control file : contains version and package interelationship data
interelationship data analyses and gives a set of instruction to package management tool which packets can be installed at same time or not.version is compared with the already installed packages to check if an upgrade is neeed or not.non-compulsory
files like prerm,preinst,postinst,post rm files ask the package management tool to perform functions before and after package installation or removal.configuration files are packages that are stored in conffiles.
linux bible page numbers: 570,571
debian/GNU linux bible page numbers :3,4 and 5
INSTALLATION:
-----------------
Firstly check the hardware configuration of the system or workstation,during installation mostly it might ask for monitor refresh rate,network card being used on system so it is better to investigate the configuration of system before you
go ahead with it.we can check on system manufactures website for upto date linux drivers that are for system before the installation,check how much memory your video card has as system boots up.
HARDWARE REQUIREMENTS:To install debian we require 32MB RAM and 486 processor atleast for the installation.normally debian packages require about 250MB disk space,desktop application requires 2-4 GB,if personal data needs to be stored you require additional space
ISA(Internet security and acceleration server) and NIc card are trusted and supports linux,Servers normally contains basic debian packages to execute some basic service but dont have an graphical interface,server hardware are expensive,important records can be stored on server using RAID array
of storage.
RUNNING INSTALLER: Recent version like "lenny 5.0" just require one stage for complete installation such as apply setting that are required for machine,partition the hard disk and install base system.
Step 1: booting from cd - Type debian on boot prompt to run the debian installer.After the installer has finished booting up,need choose language,region and keyboard configuration by using the arrow keys on keyboard
step 2: network connectivity - if installer detects the NIC card on system then it sends out request to DHCP server requesting the details of the network configuration,this done by using DHCP protocol.once the network setting prompt appears enter your IP address,netmask,gateway address,DNS server address,
hostname and domain name.
step 3: time and domain name - set the date,time,domain and hostname.
step 4: Partition of hard disk - A portion of a hard disk is set aside to install its debian packages,ext3 is filesystem used in debian.homeusers prefer to partition their hard disk in such a way that operating system is given enough space to operate,home directories are given
space of their own as well.
step 5: copying changes - once when you click finish button, the partition is copied or written by installer to disk and filesystems are generated,and the base system is extracted from cd and installed to specified partition on the disk.
step 6: root password - select a pretty good root password for superuser(root) account due to security constraints during login,superuser tend to give approriate privileges to execute application etc,on base system. useraccounts are created for accessing the server for various different day to day tasks to be executed, we also need to assign a password
to useraccount.after the base system installation,can be updated via using internet connectivity.
step 7: required softwares -firstly select and install all default softwares that are useful for a standard desktop enviroment to run.
step8:Package settings-If these installed packages require some extra setting to work well then download these settings once it prompt you.
step9:Install boot loader:last step would be Install the GRUB boot loader,as Default procedure need to Install to master boot record(MBR).Installer will ask you to eject CD and accept changes and continue once enter is pressed,computer will restart with debain system that's installed in system.
step 10: Login as root(super user) as your username and password would be type password that you choose before in earlier step.
step 11: Insert remaining CD's and type in command below, which would scan cd's and DVd's and copy them to system and start installing some driver and other important software that we select.
apt-cdrom add
step 12:Installing GUI :Installing all dependent software which would be prompted with yes or no options.can use command below to carry out these steps of installing GUI,This is final step of debian installation.
apt-get install x-window-system twm
http://www.aboutdebian.com/install5.htm
linux bible 574,575,576,577,579
PACKAGES:
-----------
Package are wrapped software that are already compiled,a packet can be utility,server type program,workstation type program or OS components.package manager are used to add or remove packages,debian package manager uses .deb files.
debian uses 3 main package utilies:
apt-Advanced package tool-its the main package manager used to add,remove install retrieving/installing & searching for packages.apt-get utility maintains a database of all packages in repositories,it automatically upgrades packages.
apt help in downloading appropriate packages to its local cache location directory and insist dpkg tool to perform additonal steps.
io
dpkg-its a kind of sucessor to apt,its a simplest package manager,these tools handle medium level package addition and removal also to certain extent manages package database.it contains two main fields selection and package state.
dselect-A menu driven front-end that uses both apt and dpkg.dselect has two different modes access mode and update mode.access mode additional .deb files are addedd and retrieved to our inventories,in update mode the existing packets gets updated.
dselect searches and gives you a list of programs that you need to install.
other packages : the configuration options are designed and enabled in some packages as they are getting installed,the debconf utility helps in managing the configurations, aswell supports different interfaces such as command prompt and menu-based interfaces.
debain bible 32,33
http://www.aboutdebian.com/packages.htm
linux bible 583,587
SECURITY ON DEBIAN:
------------------
Services can be secured in two different ways on debian.
firstly we can either configure them properly so only legitimate users can have access & have authorization privilges.
secondly must use access points for accessability.
SECURING BY SSH:ssh can be used to secure debian systems because they use crytographic technique to encrypt passwords from remote login and then send it to server for services.The sshd_config file, in /etc/ssh, should be modified to increase security level.
------------------
Listen 192.148.32.46
make ssh listen to a specific or give interface.
Permit rootlogin
allow root login only when is required,root password cant be brute forced in ssh.
Port 666 or ListenAddress 192.168.0.1:666
port 666 changes the listening interface so that intruder is not sure if daemon is running or not.
PasswordAuthentication
it absolutely secure to allow users having ssh-keys which normally placed in ./ssh/authorization_key file location.
Permit emptypasswords no
empty passwords are not permitted,this would devaste the security on debian.
Protocol 2
use protocol2 since protocol 1 has design issuse which makes it very easy in cracking passwords.
Banner
use a banner when the user is connecting to the server.
ssh client
ssh client & ssh server should use similar protocol,by default server uses protocol 2 since protocol 1 has design flaws.
restricting filetransfer
if the filetransfering should be restricted by disabling sftp-server and scp access.
SECURING BY SQUIDS:
----------------------
SQUIDS are most famous proxy/cache server that by default refuses all request from users.As a matter of fact is allows access of debian packages from localhost,just need to configure the browser settings.
squids can be configured in such way so that it can allow trusted users,host or network by definings an access control list on etc/squids.conf.system resources should be taken into point when the squids are configured,
taking into account i.e cache memory & cache directory.when squid is configured in accelartor mode it acts as web server too,but makes squids are less relilable when configured in accelerator mode as webserver.
securing FTP:
-------------
The following line can be added to your proftpd.conf in your global section to enable this chroot feature so the user would be able to view all directories
Defaultroot~
when you want to prevent a Dos attack add following line of code
/etc/proftpd.conf:Denyfilter
Securing access to the X Windows System:
-------------------------------------------
X terminals are used when alot of workstations require one server,Indeed if you type in Xhost+ on your machine you would allow all Xclient to Connect to your system.for more rigid security purpose use Xhost+hostname for allowing access
to particular host.
For more security just encrypt the whole session and tunnelX by using ssh.Excellent security takes place just when you switch off the TCP port 6000 by simple command:
$ startx -- -nolisten tcp
Securing printer access:
-------------------------
printer servers should b secure,so that only trusted users can can access printer services from a set of trusted servers, so just type in etc/hosts.lpd in configfile to add servers you want to allow printing.
Inorder to prevent Dosing your line printer Daemons.
Securing Apache:
-----------------
Apache access can be restricted to outside users by editing the configfile /etc/apache/http.conf in BindAddress or Listen
using Listen:
127.0.0.1:80
using BindAddress:
127.0.0.1
When you Restart APache server only listens on Loopback Interface.
Apache logfiles are owned by user root & group admin with permission 640.after Each sigle rotation permissions always change.so intruder doesnt get access to Apache logfiles or remove old log files entries.
For security measures if want to prevent users from publishing web contents tamper and remove the file.
/etc/apache2/mods-enabled/userdir.load
