FinishDecrypt
Use this function to finish decrypting after you have decrypted all of the blocks.
FUNCTION FinishDecrypt() as String
Notes:
If the total size of all blocks that you encrypt is not dividable by PaddingBlockSize then you will get 1 to PaddingBlockSize-1 unencrypted bytes at the end. Because of that then you should add at least PaddingBlockSize-1 bytes of random bytes to the end of the encrypted stream to ensure that all of your data gets encrypted.