The second step is to make sure the server has our Public Key and for the given server this needs to be done only once. Step 2 – Give the server our Public Key – We only need to do this once. You could also generate a set of keys per server, but that comes with a few extra challenges. Note that the same key can be used for several different SSH servers. Obviously we first will need to actually have a Public and a Private key. Now how does this work when applied to our SSH connection? Max has the “Private key”, allowing him, and only him, to decrypt the secret message. So now Bram sends the encrypted message to Max. The Public key allows Bram to encrypt the secret message.Īfter encryption, not even Bram can decrypt it. To keep the message secret he send Bram a request for such a secret message and includes his “Public Key” with that. Let’s say Max asks Bram to send him a secret message, but Max wants to be sure that no one else can read the message. One to “encode” and one to “decode” a message Ī “ Private Key” to decode (encrypt) a message,Ī “ Public Key” to encode” (decrypt) a message. Note: When using such keys, we typically generate them with OpenSSL tools, more about that later. It can never be used to decrypt a message. The Public Key can only be used to encrypt a message, and can be shared with others without a problem. So what are those and how do they work? Private KeyĪ Private Key can be used to decrypt a message.īecause of that, you should keep a private key private, and never share it with anyone else. When looking at encryption, you quite often see mention of “Public Key” and “Private Key” – something we’re about to use for SSH. The entire matter behind this is something to discuss I’m sure, but in this article I’ll keep it simple.
There is an alternative though, the use of SSH-keys, which not only makes the password very difficult to guess, but also significantly longer. This could be fine for that one time you need access, but it is not the most secure method as passwords are often easy to guess, or relatively easy to break with a brute force attack.
SSH Login Without a Password – How does this work?įolks starting with SSH, especially first few times, will just use a username and password. Windows users on the other hand will see that commands are a little different, since most of these remote machines run one or the other Linux variant. Note: For macOS and Linux users, the command one executes will typically be very similar to what you’ve been used to in a Shell or in Terminal. On most platforms (macOS, Linux, Windows) it will look like you’re working on the local machine, but instead of running it all local, things are executed on the remote machine. See it as a Shell/Terminal/Command Prompt window, directly running on the remote machine. Often to execute one or the other command line statements, typically modifying something or installing/removing something on the remote machine. Personally, I use SSH most often to access the Shell or Terminal on a remote computer, for example my web server, my QNAP NAS, or my Raspberry Pi running LibreElec ( KODI). Example 3: WOL fix for macOS - Wake up a screen with Caffeinateīefore explaining how SSH Login without a password works, a quick look at what SSH really is and when you’d be using it.Example 2: List the root directory, including hidden directories, in long format.Step 3 - Test if SSH Login without a Password actually works.Windows - The long way, since ssh-copy-id does not exist.macOS and Linux - The harder way by using cat.macOS and Linux - The easy way with ssh-copy-id.Step 2 - Give the Server you Public Key (one time only).Step 1 - Generate out Public and Private Key (one time only).3 SSH Login Without a Password - In Practice.Step 3 - For each SSH Login - Give the server our Username and our Public Key.Step 2 - Give the server our Public Key - We only need to do this once.2 SSH Login Without a Password - How does this work?.