Kleines Weihnachtsgeschenk von der DEC

[Christoph Schneider]

I agree, in case of empty chiffre we should throw an exception.

To your second proposal. What is the workflow? Do you really have a chiffre where you dont know, if PKCS#7 padding was added or not?
The problem is from my point of view, if we would offer such check method, we run decrypt two times, one in this check and one after it for getting the result. Than an option for a facultative padding would be better but result in a more complex interface.