ROM Hack Friend Code Calculations

[Wiimm]

Does anyone know, how NDS games create a friend code (decimal number with 12 digits, 39-40 bits; format 1234-1234-1234) based on the profile id (32-bit number; created by the server (GameSpy or Wiimmfi))?

More background infos: http://wiki.tockdom.com/wiki/Friend_code


EDIT:
A disassembler listing of any game with online support may help.

 

[Wiimm]

All cleared now. I have found some code and can't find out the algorithm. It is like MKWii, but uses a CRC8 checksum instead of MD5. It is already implemented for Wiimmfi.