[MISC] QuickR

ctf like, and guessss,

Python 2.7 works for me. It was a fun coding exercise.

I am parsing successfully the qr and sending the result of arithmetics, but it is not working. Any advice please ?
Alright, the format …

Really simple way to solve this that doesn’t require doing any conversions. Fun coding exercise and not too difficult if you break down the process into pseudocode before writing it out. Think of an easier way you can capture the QR code without explicitly referencing the colors.

Type your comment> @scentlxss said:

I am parsing successfully the qr and sending the result of arithmetics, but it is not working. Any advice please ?
Alright, the format …

Sometimes Google can dispel illusions. (Hope I’m not giving away too much)

Wow! I enjoyed it, and learned a lot of stuff.

Heya, can anyone give me a nudge on the submission format? Thanks!

Edit: got it!

Can anyone give me a tip to convert the received info into a image? PIL is not seems to work… thanks in advance

So

  • Found out how to view the response
  • Found a method to do some conversions and decoded it
  • Got the result
  • I’m sending the result back
  • Now I just getting a bunch of numbers (recv()) or nothing at all (recvall())?!

Output of my script (redacted), using recvall()

$ ./QuickR.py 
[+] Opening connection to docker.hackthebox.eu on port 32331: Done
[+] Wrote *** text to quickr.txt
[+] Wrote *** image to quickr.png
[+] *** decodes to: %%%
[+] Cleaned %%%: ###
[+] ### results to: @@@
[+] Send @@@ to docker.hackthebox.eu:32331
[-] Receiving all data: 168B

However, receiving never ends.

EDIT: using recv() gives me numbers, which using char just gives me the final 2 lines, cutting of right after Decoded string

OK, so I’m trying everything to find the right format to send the result back, but nothing. I thought I lifted the “illusion”, but it won’t accept anything. Please help/PM. Thanks.

Edit: I thought that hint meant we should send the accurate value of the float, but apparently not. I don’t get it then, what is with that true machine statement?

Type your comment> @clubby789 said:

Pretty fun challenge, but make sure you don’t get stuck in dependencies here.

@DHIRAL said:
A little tip to everyone. Use python3 instead of python2! As it wasted my whole day?. Otherwise, this is a pretty fun and easy challenge…

Not sure why this is the case, but it is true… I spent an entire day troubleshooting my code, the math spot on… The next day, just converted the code to python3 and it worked.

Greetings all,
I too have successfully got the QR code, converted it, decoded it, answered the question but I’m having trouble sending my answer to the remote machine.

I’ve tried multiple formats to no avail, can someone give me a nudge? I’ve written my solution in Go if it has any impact.

Thanks!

Edit: Reworked the output by validating a few things with Python and it worked :slight_smile:

Hi all!
I’m stuck with this challenge…
I’ve managed to get data from the instance, grab and decode the QR code, do the arithmetic “exactly” and send back the result but I’m always getting the “[-] Wrong!” answer.

I don’t get the “illusion” part… :confused:

Please, can someone help me?
Thank!

Can someone nudge on how to send the result please?

Thanks!

Type your comment> @philomath213 said:

Type your comment> @Drxxx said:

Do I suppose to see the page content as this

e[7m e[0me[7m e[0me[7m e[0me[7m e[0me[7m

or there something wrong with my browser ?

The connection type is raw TCP not HTTP.
You should use sockets in order to solve this challenge.

OK, I think I got it :slight_smile:

Got it! This was a good one.

It's important to realise that this is, in a real sense, an illusion: you simply need the true machine value.
[!] Decoded string: [+] Congratulations! Here is your flag: 

Someone could kindly help here? I’m pretty new on sockets coding and there are some little thing that i’m not undertanding… Could DM me please?

finally got this. it is really nice challenge and lot of fun :wink:

Edit: Nvm that

Thanks @limbernie for hint!
Try different functions when you send calculated result