Issue

How to check if an SSH public key is valid.

Solution

You can check if an SSH key is valid by using a PowerShell SSH client on Windows 10 machines.

Command format:

 ssh-keygen -f Public_key_file -e -m pem

Bad key:

ssh-keygen -f twscdp2@ngsycdp2.txt -e -m pem
Load key "twscdp2@ngsycdp2.txt": invalid format

Good key:

ssh-keygen -f opctask@gb128n01.txt -e -m pem
-----BEGIN RSA PUBLIC KEY-----
MIGHAoGBAKN32kur5forbORjenPdOxxW0/uKlrMBqI9vQPLzGo6n9Z8s4+FosWJ3
5W4vIpc+DP/gLTB6BcsX5A9xf60LegE9zlO23EVcrlkkL0wVkqU3MeeeK6457sTH
2JsP1cA6PiPET6B3brsNGE0m3RtJTfwuAl0Qx6gTxOMeDju70n+5AgEj
-----END RSA PUBLIC KEY-----

Bad key:

ssh-keygen -f cdadmin@ngsycdp2.txt -e -m pem
Load key "cdadmin@ngsycdp2.txt": invalid format