SSH Keypair Setup

When you want to connect to a remote machine, the method is called “Secure Shell”. This creates a connection between the local machine (where your terminal window lives) and the “remote” machine (where the commands you will send actually execute). In order for the local and remote machines to authenticate (trust) each other, we have to create a special password-like files called a keypair. It is called a keypair because there is a public version and a private version. Read more about SSH Keys.

Note

NOTE: You only need to create your ssh public/private keypair one time only. If you already have a public/private keypair on your laptop let us know.

Open a terminal (on your laptop) if not already open. By default, every time you open a terminal it will open in your home directory.
At the command prompt run the following command: ssh-keygen -t rsa -b 2048 and press enter

You will see this prompt, just press enter

Generating public/private rsa key pair.
Enter file in which to save the key (/home/User/.ssh/id_rsa):

You will see this prompt, just press enter

Created directory '/home/User/.ssh'.
Enter passphrase (empty for no passphrase):

You will see this prompt, just press enter
```
Enter same passphrase again:
```

You will see these messages (your randomart will look different) and your keypair has been created.

Your identification has been saved in /home/User_name/.ssh/id_rsa.
Your public key has been saved in /home/User_name/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:xPJtMLmJSO73x/NQo3qMpqF6r6St4ONmshS8QZqfmHA User_name@WinDev1802Eval

The key's randomart image is:
+---[RSA 2048]----+
|                 |
|       . .       |
| .  . . *        |
|+. o . = *       |
|++E o . S o o    |
|.=+o     . o .   |
|+oo o o  +o      |
|+= +.o oo.*.     |
|*+=++ooooo o.    |
+----[SHA256]-----+

See your key files

Open a terminal if not already open
Change to your .ssh directory
- This is a hidden directory so if you list your files using ls you won’t see it. For seeing all files, use ls -la.
- To change into the .ssh directory type cd .ssh

Type pwd to print your current working directory.

Windows users in Powershell will see:

PS C:\\Users\\your_name\.ssh> pwd

Path
----
C:\\Users\\your_name\.ssh


PS C:\\Users\\your_name\.ssh>

Mac users will see:
```
pwd
/Users/myusername/.ssh
```
Linux users will see:
```
$ pwd

/home/myusername/.ssh
```

Next, we need to open the new key file we just made.

Type ls to list the files in the directory.
- What is displayed may look different. You will not have a config file unless you have already created one.
Type ls -la to list all the files in the directory, even the hidden ones.
- What is displayed may look different. You will not have a config file unless you have already created one.

Get your public key info

The file id_rsa is your private key and this file will not leave your computer.
The file id_rsa.pub is the public key, whose contents we will upload to cloud services so you authenticate.

The known_hosts is a file that gets generated as you connect to different remote systems.

This is useful so you know you are connecting to the same server as previous times.

\$ ls -la

total 32

drwxr-xr-x  6  your_name staff   192 May 29 20:39 .
drwxr-xr-x+ 75 your_name staff  2400 May 30 13:35 ..
-rw-r--r--  1  your_name staff   181 May 29 15:50 config
-r--------  1  your_name staff  3243 May 29 15:50 id_rsa
-rw-r--r--  1  your_name staff   742 May 29 15:50 id_rsa.pub
-rw-r--r--  1  your_name staff   363 May 29 20:42 known_hosts

View the contents of your public_key file by running the command cat id_rsa.pub

What is shown is a sample public key, yours will be different

\$ cat id_rsa.pub

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCnKuIRXwZu0JZH0/Q2XNrYYTaJT7bMtXGhGQaSSOZs6MhQ4SkSbHiygO7RauQf741buLnASzY27GKMMMml6InwfxJWrF60KhNK0r869POQkuZa9v9/cmYcEIzmAJe1xRPABEZ2yfbTG9Wq4sg9cU0mwt1Bx7wiN4QNf0Bak62EC8JWTbcKLduuzO1zabIb5xW9gfR9b4K3HwmqRLl18S8bNsfYQZfvtlwd0mCWQUeuEGbDOgqh//nLIj6DeXdyxbD5xrz79iOAuAK2nXAjNCEtKpxNGQr2Py7aWQjlH+U5laDEHVg4hzmBY7yoZ5eC3Ye45yPqpQA1y8JrbXVhPJRP User\@WinDev1802Eval

Extracting your public key

Open a text editor (Notepad on Windows or Textpad on Mac, NOT MICROSOFT WORD) and select the output of your terminal with all the text from the ssh-rsa beginning all the way to the end, and paste it in your text editor as-is. We will use this in the next step.
- You can also just copy/paste from your terminal screen.
- On a Mac, you can also copy the contents of the id_rsa.pub file using
```
pbcopy < id_rsa.pub
```