As part of the cipher library the function AESEncoder() and AESDecoder() are documented as:
Result$ = AESEncoder(*Input, *Output, Size, *Key, Bits, *InitializationVector [, Mode])
Result$ = AESDecoder(*Input, *Output, Size, *Key, Bits, *InitializationVector [, Mode])
The return type is incorrectly shown as being a string but it is actually the length in bytes of the string placed in the output buffer. The documentation for each of the two functions does not specify anything about what this return value actually contains or how to interpret it.
Also the return value for AESEncoder() equals zero if the input string was unable to be encoded (due to its length being less than 16 bytes).
For discussion related to this see this thread
http://www.purebasic.fr/english/viewtop ... =4&t=43762