[LINUX] Add SSH connectable users to EC2

Contents

Use public key authentication when connecting to EC2 by SSH, and if it is Amazon Linux 2, use other than ec2-user Create a new user to be able to connect.

Target device

EC2(Amazon Linux2)

Reference procedure

The procedure is based on the following AWS formula. [Create a key pair using Amazon EC2](https://docs.aws.amazon.com/ja_jp/AWSEC2/latest/UserGuide/ec2-key-pairs.html#having-ec2-create-your-key -pair) Create a user account

Hands-on

Creating a key pair (using the AWS Management Console)

** If there is a key pair to connect to EC2, it is not necessary. ** **

Log in to the AWS Management Console and select Services ⇒ Computing ⇒ EC2.

From the menu on the left, select [Network & Security] ⇒ [Key Pair].

Click Create Key Pair from the key pair list screen.

Select [Create Key Pair] for [Name] and [File Format], and click [Create Key Pair].

• Select pem this time. Regarding pem and ppk, the following site was easy to understand. I learned a lot. Mutual conversion between pem file and ppk file

User Creation & Settings (Linux)

Connect to EC2 and switch to the root user.

User created

# adduser Inon

Password setting

# passwd Inon
Changing password for user Inon.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

Switch to the created user

# exit
logout

$ su - Inon
Password:

$ whoami
Inon

ssh / authorized_keys settings

Make sure you are in the home directory of the user (Inon) you created

$ pwd
/home/Inon

Create & configure .ssh directory

$ mkdir .ssh
$ ls -la
total 16
drwxrwxr-x 2 Inon Inon   6 Mar 12 01:09 .ssh
$ chmod 700 .ssh
$ ls -la
total 16
drwx------ 2 Inon Inon   6 Mar 12 01:09 .ssh

Obtaining a public key

Transfer the key pair used to connect to EC2 to the server. This time, I placed it under ** / tmp **.

$ ssh-keygen -y -f /<Key pair storage location>/<Created key pair name>.pem 
ssh-rsa ...******<Character strings are lined up in a row>******...

Creating an authorized_keys file

$ touch .ssh/auhthorized_keys
$ chmod 600 .ssh/authorized_keys
$ ll .ssh
total 0
-rw------- 1 Inon Inon 0 Mar 12 01:12 authorized_keys
$ vi .ssh/authorized_keys

Paste the public key obtained with the ssh-keygen command with the vi command.

the end

You can now connect to EC2 with the created user.