wiki/wiki/linux/ssh.md

SSH

SSH is a network protocoll to securely connect to a computer. In this article it is assumed that openssh is used.

Usage

Generate New Keys

To generate new ssh keys simply run ssh-keygen -t ed25519 or ssh-keygen -t rsa -b 4096.

The keys can then be added to the authentication agent by as described in the corresponding article

Adding Keys to Authentication Agent

The following line will add a key to the authentication agent.

ssh-add id_rsa

Depending on the name of the certificate inside the ~/.ssh folder the name id_rsa can vary. For example id_ed25519 is the name if the first generation option was chosen.

Enable Root Login via SSH

Edit the /etc/ssh/sshd_config and change the line containing PermitRootLogin to PermitRootLogin yes.

Add Login via SSH Public Key

To enable easy login without password you can add the contents of the file ~/.ssh/id_rsa.pub from your local machine to the file ~/.ssh/authorized_keys on the machine you want to log into. You can use the modified command below for ease of use:

cat ~/.ssh/id_rsa.pub | ssh username@server 'cat >> ~/.ssh/authorized_keys'

Mount Directory With SSHFS

To mount a directory (in this case called directory) from a remote server (in this case called server also can be substituted by something like user@server-ip) on a local mount (in this case mountpoint) run:

sshfs server:/directory mountpoint

Shorten SSH Connection Commands

By adding the following lines to the file ~/.ssh/config the command of an SSH connection can be shortened from ssh user@server.tld to ssh server.

Host server
	HostName server.tld
	User user