ssh-keygen
Ssh-keygen is a tool for creating new authentication key pairs for SSH. Such key pairs are used for automating logins, single sign-on, and for authenticating hosts.
1. Generate a ssh key
Open the Terminal app and run
$ ssh-keygen
Just hit enter a few times after you run the command ssh-keygen to take default values and you'll see:
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/XXXXXXX/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /Users/XXXXXXX/.ssh/id_rsa.
Your public key has been saved in /Users/XXXXXXX/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:XXXXXXXXXXXX XXXXXXX@XXXXXXX-MacBook-Pro.local
The key's randomart image is:
+---[RSA 2048]----+
| . .= ..|
| o+ ooo|
| o .. oo+|
| .o+o . o+|
| .S o.+ Eo|
| +o = o .|
| ...=++o * . |
| . o++=o.+ + |
| . .==.. o.o. |
+----[SHA256]-----+
above I didn't set any passphrase. If you want extra security you can by running ssh-keygen again as it will overwrite your old key.
2. Copy ssh public key (the file ending in .pub)
Navigate to where ssh keys are stored.
$ cd ~/.ssh
This is where you should be able to find your keys.
If you run ls command you will see this:
$ cd ~/.ssh
$ ls
id_rsa id_rsa.pub
id_rsa.pub is the public key. This is the one which should be added to services (for example Github) that need our ssh public key.
Open id_rsa.pub in your text editor. It should look something like:
ssh-rsa XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX XXXXXXX@XXXXXXX-MacBook-Pro.local
To copy the key to clipboard use pbcopy:
$ cat ~/.ssh/id_rsa.pub | pbcopy
3. Test an ssh connection.
$ ssh <your-user>@<your-server-ip>
for example
$ ssh root@192.168.2.4
Now, you should have access to your server.
