• In this tutorial, I have added the configurations required for ec2 user password authentication for AWS ec2 Linux instances.
• As by default ec2 instance don't have any password .Follow these simple steps to configure password in your linux instance .

Note:- It is not recommended to configure password in cloud instances unless required .Private key-based authentication is always the safest way to access cloud instances.

Step 1: Log in to the linux machine using ssh client of your choice using the private key.

• For Windows machines, you can use putty for connecting to the instance.Click here to know how to use putty on Windows .

• If you are using Mac or Linux, you can use the following command to connect to the instance.
  

ssh-i your-key.pem username@(public-ip-address)

Step 2: Enter the following command to open sshd_config file

sudonano /etc/ssh/sshd_config

Step 3: Find the line containing “PasswordAuthentication” parameter and change its value from “no” to “yes“

Step 4: Now press ctrl + x button and then click on Y button to save the changes

Step 5: Setup ec2 user password using the “passwd” command along with the username.

You need to enter the password twice. For example, if you want to set up a password for “centos” user, use the following command.

sudopasswd centos

In AWS, different ec2 instances have different usernames. Following are the default usernames of some popular ec2 instances.

Step 6: Now, restart the “sshd” service using the following command.

sudoservice sshd restart

Step 7: Once the "sshd" service is restarted successfully , you can log out and log in using the password you set for the user.
For example,

ssh ubuntu@34.10.100.1

I hope this "How to configure password in Amazon ec2 instance" article helps. Let me know in the comment section if you face any errors.