The Little Things You Find Along the Way

I’m constantly amazed by the little tips and tricks I stumble upon as I’m working to solve problems.  Earlier today, I found this little gem.

Apparently, there is a setting in OpenSSH 5.1 and later for visual remote host fingerprinting.  The basic concept is that it’s much easier for the human brain to notice a change in a visual pattern than in a string of hex digits.  To turn it on, simply add a line that says
VisualHostKey yes to your ~/.ssh/config file. Then, when you go to SSH into a server, you’ll see a visual representation of the remote host fingerprint, in addition to the regular fingerprint, as shown below:

[jsmith@hockey ~]$ ssh
Host key fingerprint is 07:d4:02:db:9f:70:d5:2d:7f:1b:6a:df:83:73:95:1d
+--[ RSA 2048]----+
|      ....  .. . |
|       +. ..  o .|
|      . +..    o |
|         = .   Eo|
|        S +   . B|
|         .   o oo|
|            . o o|
|             o +.|
|              o .|

See, now isn’t that handy?