The Basics
When you first begin to access your fresh new virtual server, there are a few early steps you should take to make it more secure. Some of the first tasks can include setting up a new user, providing them with the proper privileges, and configuring SSH.
Step One—Root Login
Once you know your IP address and root password, login as the main user, root. You can log in through Terminal on a Mac computer and PutTTy on the PC
It is not encouraged to use root on a regular basis, and this tutorial will help you set up an alternative user to login into your virtual private server with permanently.
ssh [email protected]
The terminal will show:
The authenticity of host '123.45.67.890 (123.45.67.890)' can't be established. ECDSA key fingerprint is 79:95:46:1a:ab:37:11:8e:86:54:36:38:bb:3c:fa:c0. Are you sure you want to continue connecting (yes/no)?
Go ahead and type yes, and then enter your root password.
Step Two—Change Your Password
Currently your root password is the default one that was sent to you when you registered your droplet. The first thing to do is change it to one of your choice.
passwd
Step Three— Create a New User
After you have logged in and changed your password, you will not need to login again as root. In this step we will make a new user and give them all of the root capabilities on the VPS.
You can choose any name for your user. Throughout this tutorial, I will use the name example user
useradd -m exampleuser
The "-m" makes a home directory for your user.
To change your new user's password, use
passwd exampleuser
Step Four— Root Privileges
As of yet, only root has all of the administrative capabilities on the virtual server. We are going to give the new user the root privileges.
When you perform any root tasks with the new user, you will need to use the phrase `sudo` before the command. This is a helpful command for 2 reasons: 1) it prevents the user making any system-destroying mistakes 2) it stores all the commands run with sudo to the file ‘/var/log/secure' which can be reviewed later if needed.
Let’s go ahead and edit the sudo configuration. Vi, the text editor used for this file, does not recognize arrow keys. Move down using `j`, up with `k`, left with `h`, and right with `l`. Additionally, you can begin editing the text by pressing `a`, and delete text by pressing Escape and then `x`
visudo
Find the section called user privilege specification. It will look like this:
# User privilege specification root ALL=(ALL) ALL
下面,添加以下行,向新用户授予所有权限:
exampleuser ALL=(ALL) ALL
Press escape and then Shift ZZ to save and exit the file.
Step Five— Configure SSH
Now it’s time to make the VPS more secure.
Open the configuration file
nano /etc/ssh/sshd_config
Find the following sections and change the information where applicable. Be sure to uncomment the lines as well, otherwise the changes will not take effect. (You can find words and phrases in the file by pressing Control-W)
Port 25000 PermitRootLogin no
Port: Although port 22 is the default, you can change this to any number between 1025 and 65536. In this example, I am using port 25000. Make sure you make a note of the new port number. You will need it to log in in the future. This change will make it more difficult for unauthorized people to log in.
PermitRootLogin: change this from yes to no to stop future root login. You will now only be logging on as the new user.
Step Six— Reload and Done!
Reload SSH, and it will implement the new ports and settings.
systemctl restart sshd
To test the new settings (Do Not Log Out of Root!), open a new terminal window and login as your new user.
Don’t forget to include the new port number.
ssh -p 25000 [email protected]
Your prompt should now say:
[exampleuser@yourhostname ~]$
Once you know you can login into your virtual private server with your new user, you can exit out of root.
See More
After your initial setup you can proceed to install a LAMP server to get a web server up and running.