How do I enable password authentication on a Linux EC2 instance?

Edit /etc/ssh/sshd_config and set PasswordAuthentication to yes. Then restart SSH: sudo systemctl restart sshd. Create a password for a user with: sudo passwd username. Note: AWS disables password auth by default for security; use it only in controlled environments.

Why is password authentication disabled by default on AWS EC2?

AWS disables password authentication by default to prevent brute-force attacks and enhance security. SSH key-pair authentication is significantly more secure than passwords because it requires possession of the private key, which cannot be guessed like a password.

What is the default username for AWS Linux EC2 instances?

Default usernames vary by AMI: ec2-user for Amazon Linux and RHEL, ubuntu for Ubuntu, admin for Debian, centos for CentOS, and bitnami for Bitnami images. The root user is generally disabled for direct login. Use sudo for administrative commands.

Is it secure to enable password authentication on EC2?

Enabling password authentication increases the risk of brute-force attacks. If you must use it, ensure strong passwords are set, use fail2ban to block repeated failed attempts, restrict SSH access to specific IP ranges in your security group, and consider using AWS Systems Manager Session Manager as a more secure alternative.

Configure AWS authentication -

June 29, 2020 / Nirav Shah

In this blog we will learn about how to set up password on your running instance,

Prerequisites

You have ec2 instance running
You have root access to ec2 instance

Step 1

Connect to your Linux ec2 instance via putty (/ssh). Here I am connecting via putty.

Enable Username & Password Authentication for Linux EC2

Step 2

Enable Username & Password Authentication for Linux EC2

Step 3

Execute below command:

sudo passwd ec2-user

And write the password

Enable Username & Password Authentication for Linux EC2

Step 4

Now it’s time to go to the directory

/etc/ssh

and follow below command

sudo vim sshd_config

Enable Username & Password Authentication for Linux EC2

Step 5

After you apply the command, you will see windows like this

Enable Username & Password Authentication for Linux EC2

Press “i” and

Now go to the “passwordauthentication” and write “yes”

After change, it please save it

Perfect

Step 6

Last command is

sudo service sshd restart

Enable Username & Password Authentication for Linux EC2

and disconnect and login again using username and password You will see like this,

Enable Username & Password Authentication for Linux EC2

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Nirav Shah

Nirav Shah is the Director of Eternal Web Pvt Ltd, an AWS Advanced Consulting Partner and certified Odoo Partner based in the UK. With over a decade of experience in cloud computing, digital transformation, and ERP implementation, Nirav helps enterprises adopt the right technology to solve complex business challenges. He specialises in AWS infrastructure, Odoo ERP, and web development solutions for businesses across the UK and beyond.