How to Find Out Which SSH Key Was Used to Login

Check who logged to linux machine

Bash

sudo journalctl  --unit ssh

Bash

sudo cat /var/log/auth.log

Inspect-keys

commandoutput

Bash

ssh-keygen -l -f ~/.ssh/authorized_keys

Bash Session

$ ssh-keygen -l -f ~/.ssh/authorized_keys
256 SHA256:wXXXXXXXXXXXXXXXXXXXXXXWiK9MRm6OhgE durbok (ED25519)
2048 SHA256:JQgAXXXXXXXXXXXXXXXXXXXy2np3hxcs [email protected] (RSA)

Inspect-ur-own-key-fingerprint

commandoutput

Bash

ssh-keygen -l -f ~/.ssh/id_ed25519.pub

Bash Session

$ ssh-keygen -l -f ~/.ssh/id_ed25519.pub
256 SHA256:iXXXXXXXXXXXXXXXXXXXp290qAx05sN8U some_user (ED25519)