Connect to your server with SSH keys

SSH is the standard way to log in to a Linux server. An SSH key is safer than a password: it cannot be guessed, and it is not sent over the network. A key has two parts. The private key stays on your computer and is never shared. The public key is safe to share, and goes on the server.

Step 1: check for an existing key

Open a terminal (Linux, macOS) or PowerShell (Windows 10 and 11, which include OpenSSH). Run:

ls ~/.ssh/id_ed25519.pub

On Windows PowerShell use dir $env:USERPROFILE\.ssh\id_ed25519.pub. If the file exists, you can use it and skip to step 3.

Step 2: create an ed25519 key

ssh-keygen -t ed25519 -C "you@example.in"

Press Enter to accept the default file name. Then choose a passphrase. A passphrase protects the key if your laptop is lost or stolen, so we recommend setting one.

This creates two files in the .ssh folder of your user:

• id_ed25519 is the private key. Never send it to anyone, not even to us.
• id_ed25519.pub is the public key.

Step 3: send us the public key

Print the public key:

cat ~/.ssh/id_ed25519.pub

On Windows PowerShell: type $env:USERPROFILE\.ssh\id_ed25519.pub. It is one line that starts with ssh-ed25519. Copy that line into your order enquiry or mail it to support@it-labs.in. We add it to the server. If you do not send a key, we send you a login by mail instead, and you can add your key later.

Step 4: first login

We send you the server’s IP address and login by mail. Log in as root:

ssh root@203.0.113.10

Replace the address with your server’s IP address. The first time, SSH asks you to confirm the server’s fingerprint. Type yes once. If you set a passphrase, enter it when asked.

Good habits

• Create a separate key for each computer. Then you can remove one without affecting the others.
• Do not copy your private key to a shared computer, chat, mail or cloud notes.
• If a private key may have been exposed, create a new key and ask us to replace the public key, or remove the old line from ~/.ssh/authorized_keys on the server.
• After your key works, create a normal user and turn off password login. See “First steps on a new server”.

If login fails

Run ssh -v root@your-server-ip to see details. “Permission denied (publickey)” usually means the server has a different public key than the one you are using. Mail us the output of ssh -v (it holds no secrets) and we will look.