You can also read this and other writeup on my [Github](https://github.com/quochuyy10217/MyCTFWriteups/tree/main/Digital%20Overdose%202021%20Autumn%20CTF)


This is what you will see when you open the page


When I read what they write in the page, I didn't understand at first. But fortunately, I remember what they write in the title of this chall: "git". So i began to check if this page has /.git page or not. And when i did that, something appeared.


But they told me that I don't have permission to see this. But there are many tools can let me gain the permission to the "./git" page. And the one I chose is GitHacker. With this tool, you can download everything in the "./git" page.


After I had downloaded the source code, i remembered what they said "If only you could read the source code". So I went to look for the content of the index.html page.


You can see that, they encrypt the flag got from the "flag.txt" file, but we don't have that file. So i think that we will change something from the index.html page. I used the privatekey and the ciphertext which I got when open the index page, and run the file again to get the flag.


And bingo! The flag is appear :D


Because the flag will change every time I request a new instance, so I can't show you the flag, but I can show you the way :)))