PHP XOR strings

Question

echo BeeABBeeoBodBaBdOdPQBBgDQgDdp^"\n\n\t8b\n\n\t\nb&\nb b  \n%%nb%%%\n%\nQ";

I know PHP casts undefined constants into strings, so the equivalent code is:

echo 'BeeABBeeoBodBaBdOdPQBBgDQgDdp' ^ "\n\n\t8b\n\n\t\nb&\nb b  \n%%nb%%%\n%\nQ";

The output of those are:

Holy Hole In A Donut, Batman!

Can someone explain to me how the XOR of those two strings produce that line of output?

Passerby · Accepted Answer · 2015-12-13 07:07:25Z

11

According to this official example, using XOR on strings will operate on ASCII values of each respectly character, so in your example:

B ^ \n = 66 ^ 10 = 72 = H;
e ^ \n = 101 ^ 10 = 111 = o;
e ^ \t = 101 ^ 9 = 108 = l;
...

3v4l result

answered Dec 13, 2015 at 7:07

Passerby

10.1k2 gold badges37 silver badges53 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Spencer Wieczorek Over a year ago

Well that was unexpected. I have exactly the same answer, although I was busy looking up why 60 ^ 10 = 72 before I noticed that someone answered the question.

Passerby Over a year ago

@SpencerWieczorek That's quite normal in SO :) there's always someone faster than you for just a few seconds. I abandoned so many answer for that reason.

Spencer Wieczorek · Accepted Answer · 2015-12-13 07:10:35Z

1

This is simply applying an xor on two characters at a time throughout the string. This is done by the conversion to ASCII and then the result is the ascii values which is the difference of value between the two converted items. See example 2 in PHP's documentation. So the result:

"B" ^ "\n" => 66 ^ 10 => 72 => "H"

And so on on through the entire string.

answered Dec 13, 2015 at 7:10

Spencer Wieczorek

21.7k7 gold badges46 silver badges57 bronze badges

Collectives™ on Stack Overflow

PHP XOR strings

2 Answers 2

2 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related