OpenSSH Cheatsheet

OpenSSH_cheatsheet.md

SSH RSYNC SSHFS Cheatsheet

SSH

Generate RSA 4096 bit key

ssh-keygen -f ~/.ssh/my_key_rsa -t rsa -b 4096

Check is ssh-agent is running

$ ssh-agent -s
SSH_AUTH_SOCK=/tmp/ssh-kdX73wLO6hbu/agent.18081; export SSH_AUTH_SOCK;
SSH_AGENT_PID=18081; export SSH_AGENT_PID;
echo Agent pid 18081;

Add key to ssh-agent

$ ssh-add ~/.ssh/my_key_rsa
Enter passphrase for /home/myaccount/.ssh/my_key_rsa: 
Identity added: /home/myaccount/.ssh/my_key_rsa (/home/myaccount/.ssh/my_key_rsa)

List ssh-agent keys

$ ssh-add -l
4096 SHA256:souHXiVi1bqgysC1cpsoT/stNwdNiWrnTJrMuTgs6rA /home/myaccount/.ssh/my_key_rsa (RSA)

Copy public key to server

ssh-copy-id -i /home/myaccount/.ssh/my_key_rsa.pub user@host

Add IdentityFile to ~/.ssh/config

Host server1
     HostName server1.mydomain
     User myuser
     IdentityFile ~/.ssh/my_key_rsa

Add Host fingerprint to ~/.ssh/knowing_hosts

ssh-keyscan -H 192.168.X.X >> ~/.ssh/known_hosts

Show the fingerprint of the key file

ssh-keygen -l -f ~/.ssh/id_rsa.pub
2048 2e:8c:fd:aa:9f:95:86:9e:b0:d2:a6:1a:7e:d3:3e:74 .ssh/id_rsa.pub (RSA)

Copy public key to clipboard

tr -d '\n' < ~/.ssh/id_rsa.pub | xsel --clipboard --input

Rsync

Copy single file

rsync -avz --progress <file>.sh <remote_user>@<ip_address>:/<remote_path>

SSHFS

Attach host directory to guest

sshfs -o allow_other some_user@some_ip:/path/host /path/guest

e.g

sshfs -o allow_other foo@10.1.1.1:/home/foo /home/guest/foo

Sources:

• [OpenSSH Series (cz)] (https://www.root.cz/serialy/pokrocile-vlastnosti-openssh/)
• [Set-up-ssh-keys] (https://www.digitalocean.com/community/tutorials/how-to-set-up-ssh-keys--2)
• manage-ssh-keys-with-the-ssh-agent
• [ssh-agent-forwarding] (http://www.unixwiz.net/techtips/ssh-agent-forwarding.html)
• [Github - using-ssh-agent-forwarding] (https://developer.github.com/v3/guides/using-ssh-agent-forwarding/)
• [start-ssh-agent-on-login] (https://stackoverflow.com/questions/18880024/start-ssh-agent-on-login?answertab=oldest#tab-top)
• [ssh-agent as user systemd service] (https://unix.stackexchange.com/questions/339840/how-to-start-and-use-ssh-agent-as-systemd-service)
• (GNOME-Keyring SSH Keys) [https://wiki.archlinux.org/index.php/GNOME/Keyring#SSH_keys]
• [Keychain] (https://www.funtoo.org/Keychain)
• [ssh-find-agent] (https://github.com/wwalker/ssh-find-agent)
• [envoy - A systemd friendly ssh/gpg-agent wrapper] (https://github.com/vodik/envoy)