site/wiki/pages/openssh.md

published	title	author
true	OpenSSH Basics	Anton McClure, Jake Walker

Unlike antonmcclure.com, most of the interaction with Summit, Tilde.pw, and other UNIX/Linux systems are done with a tool known as SSH. This tool provides a direct connection from your device to a remote device. The text-based interface you are presented with, where commands would be given at, is referred to the shell (hence the name Secure Shell. the secure part comes from the connection being encrypted so nobody can spy on the connection.

Summit, and many other servers with SSH access, use ssh keys rather than passwords. Passwords are insecure and can be very hard to manage. Using key-based authentication adds another layer of security to your accounts and makes the sysadmins job easier since ssh keys are easier to manage than passwords.

How to Make an SSH Key Pair

SSH supports several key types. The most common are ED25519 RSA

RSA is the de-facto standard for SSH and is supported nearly everywhere, however, more and more modern systems are now offering support for ED25519 keys.

Note: Be sure to NEVER share your private key with anyone. Summit staff will NEVER ask for a private key when resolving an issue.

Windows 10

Windows 10 1809 or later has OpenSSH built in, so you need to install third-party tools. If OpenSSH is not enabled, please see Microsofts documentation on OpenSSH in Windows

Generating Your Keypair

1. Open Microsoft PowerShell
2. Create your .ssh directory

mkdir .ssh

3. Create your keypair

a. RSA Key:

ssh-keygen -t rsa -b 4096

b. ED25519 Key:

ssh-keygen -t ed25519 -a 100

4. If you press enter to accept the defaults, your public and private keys will be located at %UserProfile%\.ssh\id_rsa.pub and %UserProfile%\.ssh\id_rsa for RSA keys, or %UserProfile%\.ssh\id_ed25519.pub and %UserProfile%\.ssh\id_ed25519 for ED25519 keys

5. To get your public key, run type %UserProfile%\.ssh\id_rsa.pub or type %UserProfile%\.ssh\id_ed25519.pub depending on your key type.

6. Copy the output and paste it in the appropriate place, whether it be an authorized_keys file, vps creation form, or a shell service signup form.

macOS

macOS, the most popular UNIX operating system, has OpenSSH built in. SSH is enabled by default as a part of the operating system.

Generating Your Keypair

1. Open Terminal
2. Create your .ssh directory

mkdir .ssh

3. Create your keypair

a. RSA Key:

ssh-keygen -t rsa -b 4096

b. ED25519 Key:

ssh-keygen -t ed25519 -a 100

4. If you press enter to accept the defaults, your public and private keys will be located at ~/.ssh/id_rsa.pub and ~/.ssh/id_rsa for RSA keys, or ~/.ssh/id_ed25519.pub and ~/.ssh/id_ed25519 for ED25519 keys

5. To get your public key, run type ~/.ssh/id_rsa.pub or type ~/.ssh/id_ed25519.pub depending on your key type.

6. Copy the output and paste it in the appropriate place, whether it be an authorized_keys file, vps creation form, or a shell service signup form.

UNIX/Linux (Other)

Similarly to macOS, most UNIX systems such as Oracle Solaris, IBM AIX, HP-UX, and Linux systems such as Ubuntu have OpenSSH built in, and enabled by default.

Linux users: if your distro doesnt have SSH installed, look up how to install OpenSSH on your distro.

Generating Your Keypair

1. Open your preferred terminal emulator or Console/TTY1-6
2. Create your .ssh directory

mkdir .ssh

3. Create your keypair

a. RSA Key:

ssh-keygen -t rsa -b 4096

b. ED25519 Key:

ssh-keygen -t ed25519 -a 100

4. If you press enter to accept the defaults, your public and private keys will be located at ~/.ssh/id_rsa.pub and ~/.ssh/id_rsa for RSA keys, or ~/.ssh/id_ed25519.pub and ~/.ssh/id_ed25519 for ED25519 keys

5. To get your public key, run type ~/.ssh/id_rsa.pub or type ~/.ssh/id_ed25519.pub depending on your key type.

6. Copy the output and paste it in the appropriate place, whether it be an authorized_keys file, vps creation form, or a shell service signup form.

How to Connect with SSH

Windows 10

1. Open PowerShell
2. Run ssh <username>@<hostname> -i C:\Users\<LocalUsername>\.ssh\id_rsa or ssh <username>@<hostname> -i C:\Users\<LocalUsername>\.ssh\id_ed25519
3. Enjoy SSH

macOS

1. Open PowerShell
2. Run ssh <username>@<hostname> -i ~/.ssh/id_rsa or ssh <username>@<hostname> -i ~/.ssh/id_ed25519
3. Enjoy SSH

UNIX/Linux (Other)

1. Open PowerShell
2. Run ssh <username>@<hostname> -i ~/.ssh/id_rsa or ssh <username>@<hostname> -i ~/.ssh/id_ed25519
3. Enjoy SSH

Putty Users

If you are attempting to connect to SSH with PuTTY, you'll need to follow the PuTTY guide