docs: public static byte[] xorAlignRight(byte[] b1, byte[] b2) {
          if (b1.length > b2.length) {
              byte[] b2_ = new byte[b1.length];
              System.arraycopy(b2, 0, b2_, b1.length - b2.length, b2.length);
              b2 = b2_;
          } else if (b2.length > b1.length) {
              byte[] b1_ = new byte[b2.length];
              System.arraycopy(b1, 0, b1_, b2.length - b1.length, b1.length);
              b1 = b1_;
          }
  
          return xor(b1, b2);
      }