code: private byte[] dropPadding(byte[] plainpad) {
      byte plain[] = null;
      int drop = plainpad[plainpad.length - 1]; // last byte gives number of
      // bytes to drop
  
      // reallocate array smaller, dropping the pad bytes.
      plain = new byte[plainpad.length - drop];
      for (int i = 0; i < plain.length; i++) {
        plain[i] = plainpad[i];
        plainpad[i] = 0; // don't keep a copy of the decrypt
      }
      return plain;
    }
docs: This method removes the padding bytes