Shallot allows you to create customized .onion addresses for Tor’s hidden services. (By customized, it is meant that part of the address can be selected. Choosing an entire address would take far longer than the universe is believed to have been in existence.)

If you place the RSA private key (including its header and footer) in a file called private_key in the HiddenServiceDir you specified in your torrc, (If you don’t know what that means, read the Tor man page. If you still don’t understand, Shallot probably isn’t for you.) then when you restart your Tor, a hostname file will be created in HiddenServiceDir that contains your shiny new .onion address.

It is sometimes claimed that private keys generated by Shallot are less secure than those generated by Tor. This is false. Although Shallot generates a keypair with an unusually large public exponent e, it performs all of the sanity checks specified by PKCS #1 v2.1 (directly in sane_key), and then performs all of the sanity checks that Tor does when it generates an RSA keypair (by calling the OpenSSL function RSA_check_key).

Shallot has a long history in Onion Land. In its original incarnation, Shallot was originally written by a mysterious Onion Lander called Bebop, who created its predecessor, onionhash-0.0.1, at some unknown time in the distant past. That quickly(?) evolved into onionhash 0.0.2 and 0.0.3, until Bebop and Bebop’s New Home in Onionspace mysteriously vanished. At this point, it was picked up by `Orum, who gave Shallot its current name, and went through three versions until `Orum’s site, hangman - hidden (in plain) site, went down. I (katmagic) got Shallot’s sources from Tas’s site and put them into a Git repository. I made a few modifications, wrote a new README, and put the whole thing up on GitHub for all to see.