NahamCon CTF 2025 - MISC - I Want Pie

I Want Pie 468 points - Miscellaneous - 83 Solves - medium
Author: @kkevsterrr

If I eat one more piece of pie, I'll die!
If I can't have one more piece of pie, I'll die!
So since it's all decided I must die,
I might as well have one more piece of pie.
As long executing that piece of pie prints out flag, oh my,
Chomp---Gump---'Bye.

Press the Start button on the top-right to begin this challenge.

Running this challenge provides a website that expects an image upload. The repeated use of the word "pie" hints at the Piet esoteric language. Furthermore, the phrase As long as executing that piece of pie prints out flag, oh my, Chomp---Gump---'Bye strongly suggests that the program should print flag, oh my.

This language uses images to store programs. For example, "Hello World" looks like this:

Fortunately, an assembler and compiler are available at github.com/sl236/Piet

I created pie.script file with the following content:

main()
{
  asm{ @"flag, oh my" }
}

I then compiled it:

./piet-compiler print.script | ./piet-assembler > pie.ppm

Finally, I uploaded the resulting pie.ppm file to the website. It returned the expected string and the flag: flag{7deea6641b672696de44e60611a8a429}.