Linux How To Set Password Rules and Policies

Summary

This Linux tutorial demonstrates how to set password rules for user accounts on a Linux system. The video starts by creating a user with a simple '123' password, then moves on to installing the 'libpam-pwquality' library to enforce stronger passwords. It guides viewers through editing the '/etc/pam.d/common-password' file to set minimum password length, require uppercase letters, lowercase letters, digits, and special characters. The tutorial shows how to apply these rules by attempting to change a user's password, illustrating the enforcement of the newly set criteria.

Takeaways

• 😀 The tutorial demonstrates how to set password rules in Linux to enhance security.
• 🛠️ The 'adduser' command is used to create a new user in Linux, but it allows weak passwords by default.
• 🔒 To enforce stronger passwords, a password quality check library must be installed, such as 'libpam-pwquality'.
• 📚 The '/etc/pam.d/common-password' file is where password rules can be configured in Debian-based systems.
• ✏️ Editing the 'common-password' file with root privileges allows setting various password requirements.
• 🔡 The minimum password length can be set by adding 'minlen' followed by the desired number of characters.
• 🔑 The 'ucredit', 'lcredit', 'dcredit', and 'ocredit' options can be used to enforce the inclusion of uppercase letters, lowercase letters, digits, and special characters, respectively.
• 🚫 The script shows that passwords not meeting the new rules will be rejected, prompting users to create stronger passwords.
• 🔄 After making changes to the 'common-password' file, the system will reflect these rules for new passwords.
• 🔄 The tutorial suggests that users can experiment with different options to create a customized set of password rules.
• 🙏 The presenter expresses gratitude for viewing the tutorial and hopes it was informative.

Q & A

What is the purpose of the tutorial?

The purpose of the tutorial is to demonstrate how to set password rules in Linux to enhance security by adding complexity to user passwords.

What command is used to create a new user in Linux?

The command used to create a new user in Linux is 'adduser', which should be executed with root privileges.

Why is the initial password '1 2 3' considered weak?

The initial password '1 2 3' is considered weak because it lacks complexity, being a simple sequence of numbers without any uppercase, lowercase, or special characters.

What is the 'libpam-pwquality' package and why is it needed?

The 'libpam-pwquality' package is a password quality check library used in Linux to enforce password rules. It is needed to set up and enforce password policies.

How can you install the 'libpam-pwquality' package on a Debian-based system?

You can install the 'libpam-pwquality' package on a Debian-based system using the command 'apt-get install libpam-pwquality' with updates.

What file needs to be edited to set password rules in Linux?

The file that needs to be edited to set password rules in Linux is '/etc/pam.d/common-password'.

What does the 'minlen' option do in the password rules configuration?

The 'minlen' option in the password rules configuration sets the minimum length requirement for passwords.

How can you enforce a password to have at least one uppercase character?

To enforce a password to have at least one uppercase character, you can add the option 'ucredit=-1' to the configuration line in the 'common-password' file.

What does the 'lcredit' option represent in the password rules?

The 'lcredit' option in the password rules represents the requirement for lowercase characters in a password.

How can you require a password to have at least one digit?

To require a password to have at least one digit, you can replace 'lcredit' with 'dcredit' and set it to '-1' in the configuration line.

What is the effect of adding 'ocredit=-1' to the password rules?

Adding 'ocredit=-1' to the password rules enforces the requirement for at least one special character in the password.

Outlines

00:00

🛠️ Setting Password Rules in Linux

This paragraph introduces a Linux tutorial focused on establishing password rules for user accounts. The speaker demonstrates creating a user named 'gems' with a weak password ('1 2 3') and then discusses the necessity of a password quality check library. They proceed to install this library on a Debian distribution using the command 'apt-get install libpam-pwquality'. The goal is to enhance password security by setting rules within the '/etc/pam.d/common-password' file, starting with a minimum password length of 12 characters.

05:02

🔒 Enhancing Password Complexity in Linux

The second paragraph delves deeper into customizing password rules by editing the '/etc/pam.d/common-password' file. The speaker outlines how to enforce a password to include at least one uppercase letter by adding 'retry=3 minlen=12 difok=1 ucredit=-1' to the configuration line. They also explain how to require lowercase letters and digits, using 'lcredit' and 'dcredit' options respectively. Additionally, the speaker shows how to mandate the inclusion of special characters by setting 'ocredit=-1'. The paragraph concludes with a reminder to save changes and observe their effects on new user password requirements.

Keywords

💡Linux

Linux is a family of open-source Unix-like operating systems. In the video, the theme revolves around setting password rules within a Linux environment, demonstrating its use for system administration and security purposes.

💡Password Rules

Password rules are the criteria that a password must meet to be considered valid, often including length, complexity, and character diversity. The video focuses on how to set these rules in Linux to enhance account security.

💡User Creation

The process of adding a new user to a system is referred to as user creation. In the script, the command 'add user' is used to create a new user named 'gems', illustrating the initial step before setting password rules.

💡Root Privileges

Root privileges refer to the highest level of access within a Linux system, equivalent to an administrator's rights. The script mentions using root privileges to add a user and change password rules, emphasizing the importance of administrative access for system configuration.

💡Password Quality Check Library

This is a software component used to enforce password policies. The video script describes installing this library to enable the setting of password rules, indicating its necessity for implementing stronger password requirements.

💡Debian Distribution

Debian is a popular Linux distribution known for its stability and security. The script specifies using 'apt-get install', a package handling utility in Debian-based systems, to install the password quality check library.

💡/etc/pam.d

The /etc/pam.d directory contains configuration files for the Pluggable Authentication Modules (PAM) system in Linux. The script mentions navigating to this directory to open and edit the 'common-password' file, which is central to setting password rules.

💡Minimum Length

Minimum length is a common password rule that specifies the shortest acceptable password length. The video demonstrates setting this to 12 characters as an example of a password rule within the 'common-password' file.

💡Uppercase Letters

Requiring at least one uppercase letter in a password is a way to increase its complexity. The script shows how to modify the password rule to enforce this requirement, enhancing password strength.

💡Special Characters

Including special characters in a password adds an extra layer of complexity. The video explains how to set a rule that mandates the inclusion of at least one special character to improve password security.

💡Numerical Values

Numerical values refer to digits used in passwords. The script includes setting a rule that requires at least one digit to be part of the password, which is another common practice to increase password complexity.

Highlights

Introduction to setting password rules in Linux.

Creating a user with the 'adduser' command and setting a weak password.

The importance of password complexity and security.

Installing the 'libpam-pwquality' library for password quality checks.

Accessing the '/etc/pam.d' directory to modify password rules.

Editing the 'common-password' file to set minimum password length.

Setting a minimum password length of 12 characters.

Demonstration of attempting to change a password with less than the required length.

Adding a rule to require at least one uppercase character in the password.

Receiving an error message for not meeting the new password requirements.

Modifying rules to include at least one lowercase character.

Adding a requirement for at least one digit in the password.

Including a special character as part of the password requirements.

Customizing password rules with multiple options for enhanced security.

The necessity of saving changes to reflect new password rules.

Conclusion and thanks for viewing the tutorial.

Transcripts

hello youtube and welcome to another

Linux tutorial so today I'm going to

show you how to set password rules in

Linux so are you ready let's get started

so let's say for example you want to

create a user

so here I'll use the command add user

with root privileges so add user and

let's call it for example gems so here

I'm adding the user called gems so as

you can see it's asking me for a

password so here actually I can put

whenever password I want whenever land

whenever it's upper case or lower case

or anyone or anything I want so for

example I can just enter 1 2 3

and retype it 1 2 3 and it will accept

it

so the user gems has been created using

just password which is a very weak

password one two three so let's say that

we want to change the rule we want to

add more functionality more complexity

to these passwords so in order to do

that the first thing is to make sure

that you have installed what we call a

password quality check library so I will

install it with updates because I'm

using a Debian distribution here

applicate install then the lip ban -

quality check actually password quality

so this is the the level that they

should have be installed

and I hit enter

so it's to see if the library is distort

on that

and if not it will be solid so this is

the first step in order to set up rules

okay so now the library is installed now

I must go to specific actually five and

open it so like I can add my rules so I

will go to a directory called slash etc

slash Bam dot d okay so if I do list

here I can see a bunch of files okay but

there is a very interesting file that I

am going to change in order to set up my

rules which called common password as

you can see here so in order to edit

this file I should have read privileges

so I will just open it using the root

privileges within it editor I want here

I want to use for example Nano

and I'm gonna open this file which is

common password so as you can see here

it is very simple file

so let's say for example that we want to

set the minimum land of the passwords to

12 characters so I'll go to this line

here and just at the end I'll add space

and our right men men land take all to

whenever length I want for example here

I want to set it to 12 okay

so save my file control x2 yes and hit

enter

so now let's change the password for the

user chaps so the current for that case

password

[Music]

and the name of my user which is temps

so here it asking me the new password so

let's give it just for example four

characters and I hit enter as you can

see now it telling me it's a bad

password because we have set up the land

for 12 characters just exit

so I would open once again by five and

this time let's say for example that our

password must have at least one new per

character so I can add to the same line

new parameter I can delete this one so

let's say that we the lead is not

interesting so in order your password to

have at least one

yooper case we have to add option you

credit equal to minus one okay so now

the password must have at least one you

per characters all save yes and hit

enter and simply English changes so

let's just enter some characters so as

you can see now it gave me the message

that the password must contain at least

one upper case letter okay so just

accept over to the my file so you can

add many options that you want your line

here so for example if you want that

password contains at least one lowercase

character see how just to replace to you

with el el credit and always integral

minus one okay if you want your password

to have actually at least one digit so

one numerical value so you press the you

can replace the L by D default digit so

this time your password must have must

have at least one numerical value

if you want I can add money option for

example I want my password to have at

least one digit and at least one special

character so I can add other character

with opportunity or credit equal -1 ok

so in this case my password must have at

least one numerical value one digit and

plus one special character so you can

play with this option as many times as

you want in order to set up rules for

your passwords ok but always you have to

save the file and you will see that the

changes that you have made to this file

actually are reflected to the new

password that you must create for your

new users as always I hope it has been

informative for you and I want to thank

you for viewing but I