Base32 Class in ObjectiveC

Hi, I would like an ObjectiveC Class which be used to Base32 Encode/Decode Strings (Files not needed). I know that there are many similar class in C/C++, but I need this one done in ObjactiveC. In addition? to the 'regular' encoding, I'd like the class to be able to use custom character sets. i.e. I believe that the regular encoding uses this character set "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567", but I'd like this class to be able to use different sets. An example of what I mean can be seen here: <[login to view URL]> This PHP class lets you specify a 'safe' character set(csSafe) which prevents users from mixing up letters and numbers(1s and Is and Ls). I'd basically like this class to have two functions: EncodeStringToBase32(string, CharacterSet) DecodeStringFromBase32(string, CharacterSet) e.g. EncodeStringToBase32(string, RegularCharacterSet) or EncodeStringToBase32(string, SafeCharacterSet) and the same for DecodeString. Deliverables: 1. One class which can BASE32 encode/decode strings with either the 'Regular' or 'Safe' character sets. 2. A small application to test the encode/decode. e.g. A single window with 3 TextBoxes(StringBefore, StringAfter, StringDecoded again),a Combo for the Character Set, and a button. If you have any questions, please let me know. Reference links: PHP Class:? <[login to view URL]> C++ Example: <[login to view URL]> RFC for Base32:? <[login to view URL]>