# The Puzzle

## Task


[ThePuzzle.exe](./src/ThePuzzle.exe)

## Solution

I tried to run the binary first. And here what I saw:


Alright, I need to sort the numbers. I didn't wanna solve this so I fed the binary to ILSpy to watch the sources. I looked for a function which processes the button click. Here it is:

```C#
private void Button1_Click(object sender, EventArgs e)
{
bool flag = true;
for (int i = 0; i < 8; i++)
{
bool flag2 = this.pbMatrix[i / 3, i % 3].Name != "pictureBox" + (i + 1);
if (flag2)
{
flag = false;
}
}
bool flag3 = flag;
if (flag3)
{
bool flag4 = this.first;
if (flag4)
{
MessageBox.Show("Continue :)");
for (int j = 0; j < 9; j++)
{
this.pbMatrix[j / 3, j % 3] = null;
}
this.pictureBox1.Image = Resources.image_part_001;
this.pictureBox2.Image = Resources.image_part_002;
this.pictureBox3.Image = Resources.image_part_003;
this.pictureBox4.Image = Resources.image_part_004;
this.pictureBox5.Image = Resources.image_part_005;
this.pictureBox6.Image = Resources.image_part_006;
this.pictureBox7.Image = Resources.image_part_007;
this.pictureBox8.Image = Resources.image_part_008;
this.Shuffle();
this.label1.Text = "Sort again and then press Check button!";
this.first = false;
}
else
{
this.pbMatrix[2, 2].Image = Resources.image_part_009;
this.pbMatrix[2, 2].Size = new Size(100, 100);
this.pbMatrix[2, 2].SizeMode = PictureBoxSizeMode.StretchImage;
base.Controls.Add(this.pbMatrix[2, 2]);
}
}
else
{
MessageBox.Show("Try Again!");
}
}
```

Seems like flag is being combined from 9 images. Those images are in the Resources, so I went to look at them.There are QR code splited into 9 parts:


So I extracted all parts and combined them to get full QR.


Scanning the code gives us flag(almost).


The flag is: `UUTCTF{9ad589e4c948c9ecd46bf2c55c3049b5}`

Original writeup (https://github.com/0awawa0/CTF-Writeups/tree/master/UUTCTF%202019/Reverse/The%20Puzzle).