Modifying provided key

[sb8244]

Howdy, I was wondering if someone would be able to elaborate on this line: https://github.com/chicks/aes/blob/master/lib/aes/aes.rb#L155. I'm wrapping my head around AES and was confused by the modification of the key here. If a key is 256bit, is it necessary to do this?

[pedro]

+1, spent a lot of time debugging why I couldn't decrypt a string generated from another language, everything just worked once I removed that key modification.