Challenge Description
From the challenge description, it is hinted that the “team” is facing some version control difficulties, possibly with Git. Other than this, we are not provided with any more clues.
Let’s understand the challenge by first downloading the challenge.zip file using wget. Unzipping it extracts a directory drop-in, which contains a git repository within it.
Git branches
I cd into the drop-in directory, and run git init to reinitialise the existing Git repository in this directory.
Since the challenge is about collaborative development, I already had a feeling that we have to explore the different branches in the git repository.
PicoCTF Hint:
git branch -awill let you see available branchesThis hint confirms that we are interested in git branches for this challenge.
Git branches
Branching means you diverge from the main line of development and continue to do work without messing with that main line (Git - Branches in a Nutshell, n.d.).
This basically means that a team can work on the same project concurrently, and merge the branches only when they are all satisfied with their work.
Running git branch -a lists 4 different branches, namely feature/part-1, feature/part-2, feature/part-3 and main, which we are currently on.
From my past experiences with Git, I know that we can run git checkout <branch-name> to switch to a different branch.
I first switched to feature/part-1, and ran ls in this branch. There was a file named flag.py in this branch, and I proceeded to cat its contents, which displayed a part of what I expected to be the flag:
picoCTF{t3@mw0rk_
I suspected that the original flag was split into 3 parts, as there are 3 branches with similar names (feature/part-1, feature/part-2 and feature/part-3) within this git repository.
Piecing it together
Hence, I ran git checkout to switch to feature/part-2 branch and checked the flag.py file, where I obtained the second part of the flag:
m@k3s_th3_dr3@m_
I repeated the same steps for the third branch, and found the third and final part of the flag:
w0rk_4c24302f}
We will be able to form the flag by piecing the 3 parts together.
Flag
picoCTF{t3@mw0rk_m@k3s_th3_dr3@m_w0rk_4c24302f}
References
- Git - Branches in a Nutshell. (n.d.). https://git-scm.com/book/en/v2/Git-Branching-Branches-in-a-Nutshell