Oni Central has posted a CGI script that will generate your Oni controls for you. The Oni Key Configuration Script displays pull-down menus for you to select the key you wish to bind. Once you have set your controls, a text document is generated for you. Simply paste the information into the key_config.txt file in your Oni folder, save, and you're set.

The script was written by My Modem Is On Fire and Yeroen of Bungie, although it is an unsupported tool.