Official xorxorxor Discussion

N!ce easy Challenge and it’s done.

Hint:
Read the code, and find a way to decrypt the flag. cyberchef will not help you this time, but python yes .

I need help, can someone PM me?

I’m hitting a big wall with this one. Would anyone mind PMing me a hint? thank you

Pay close attention to what the source code says it does. Then you can use this encode a known-plaintext which gives you a crib you can use to decode the rest of the string.

Very easy challenge. For people who might have trouble I would recommend going to cryptohack.org and doing the You either know, XOR you don't challenge it has good hints for this

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can someone give me a hint?

Hey Guys, any chance of a hint, I understand what the code is doing but I am at a loss at to what to do

I solved this challenge completely manual - actually I’ve done most of it with pen and paper. I am not sure if this is an intended way to solve it, but I’m not that good with python yet, so this was the easiest way for me to go. I would really appreciate it if someone could PM me, so I can analyze their way of solving this challenge by programming (or to send them my poor code-ideas and have a chat about what I’ve done wrong) :slight_smile:

@Kati if you want you can PM me.

A hint, the XOR has the following properties

A ⊕ A = 0 and is an associative function so
A ⊕ (B ⊕ C) = (A ⊕ B) ⊕ C

There is some stuff you should already know from previous challenges too that might help

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Hi! I have a script worked out and it tells me it finds the key. But its the wrong key(i think). Can I dm anyone for some tips on what is wrong?

Solved manually.

As @Fukurou pointed: XOR is used for symmetric encryption where the same key is used to both encrypt and decrypt a message…

You already know how the flag looks like :expressionless:

Had to solve this manually with a script, but it was a good challenge. Feel free to DM for nudges.

Did anyone have any problems submitting the flag? I solved it and have the flag, but it says incorrect flag…

Hello, all, if someone is able to PM to discuss this challenge, that’d be great! Would be interesting to discuss what I’ve done so far, and where I’m potentially going wrong.

pm, if you still need help.

Just completed this challenge, although I did it manually. Please PM me if you solved it using python, would love to see the solution.

Hi all,

I just finished this challenge manually.
I was wondering if someone finished it using Python code.
Can anybody DM me and explain how to do it in Python?

Kind regards

You don’t need any code/python to do this challenge. All you need is to understand the logic behind XOR. If you some input A and XOR it with some value B, then you easily know the output, C, right?

What if you have the input and the output but not the value you XOR the input with? You should be able to figure out the missing value, right? Since you only need 2 of the 3 values involved in an XOR operation to know the third value. Now think about how this relates to this challenge. What do we know about HTB challenges? Does the script contain any useful information that we can combine with what we already know?

This entire challenge can be done by hand, without computer assistance (and that should be how you do this imo).

  1. The random key is, of course, random every time.
  2. I get that I have two values from other people’s hints, but I don’t understand what the second one is. As far as I can tell, I only have the output.txt.
  3. With only one value and a randomly rotating key, I don’t have anything to xor.

What am I missing here?

@leadOctopus

  1. It’s random BUT does it have any characteristics that are easy to see from how it’s being generated.
  2. If you XOR A with B, you’ll get C as an Output. If you have input A, and output C, how do you get input B?
  3. What do you know about your goal in a HTB challenge? How does it relate to what information you can get from the script.

Anything more is just giving away the solution. Take some time to think about these 3 points. Good luck.