Want to find an SSH key with a specific hash visualization pattern? If so, then this is the tool for you. If not, just don't make me SSH into your servers with their ugly-ass keys.
OpenSSH 5.1 introduced a visual hash representation of public keys. From its changelog:
* Introduce experimental SSH Fingerprint ASCII Visualisation to ssh(1)
and ssh-keygen(1). Visual fingerprinnt display is controlled by a new
ssh_config(5) option "VisualHostKey". The intent is to render
SSH host keys in a visual form that is amenable to easy recall and
rejection of changed host keys. This technique inspired by the
graphical hash visualisation schemes known as "random art[*]", and
by Dan Kaminsky's musings at 23C3 in Berlin.
Fingerprint visualisation in is currently disabled by default, as the
algorithm used to generate the random art is still subject to change.
[*] "Hash Visualization: a New Technique to improve Real-World
Security", Perrig A. and Song D., 1999, International Workshop on
Cryptographic Techniques and E-Commerce (CrypTEC '99)
http://sparrow.ece.cmu.edu/~adrian/projects/validation/validation.pdf
You can visualize your existing keys with the following command:
ssh-keygen -lv -f ~/.ssh/id_rsa.pub
It's probably gibberish, as expected from all the randomness involved. My original key looked like this:
+---[RSA 4096]----+
| **o.ooO|
| *oo.+.B.|
| o E*o** =|
| .o O++=o|
| S . =o+ |
| . o |
| . o |
| oo =|
| .o++o|
+----[SHA256]-----+
Once visualization is introduced, so is aesthetics. This feature presents a great opportunity to fight against truly random key generation in order to trade security for arbitrary human desires.
For example, I wanted a key that looked like this:
+------[RSA]------+
| |
| .OOOO OOO |
| ..OOOO OOO. |
| ...OOOOOOO. |
| ...OOSOO. |
| ...OEO. |
| ..... |
| ... |
| |
+-----[SHA256]----+
In order to get it, draw the desired end state on the keys/E.art and then
start the artist creative process with
./ssh-artist
and kill the artist when patience is depleted.