Misc: zipzipzipzip

Task:

Author: botanbell

unzip me pls

Solution:

Attached to the challenge is a password.txt and a file called zip-25000.zip. The zip-25000.zip file is password-encrypted, so you must unlock it with the password contained in password.txt Upon unzipping zip-25000.zip, you will soon figure out that inside the unzipped folder, there is a file called password.txt and zip-24999.zip. This usually means that you'll have to do this process 24999 more times, which, if you do it manually, and assuming you take 5 seconds to unzip one zip file, it would take ~35 hours of nonstop unzipping.

That's crazy. No one wants to do that. (unless you're crazy)

So obviously you want to make a script to automate it. Some used python to solve it, but I used bash (only because it's simpler)

My thought process was to answer all of the following questions:

• How do I automate it?
• How do I loop it?
• Is there a way to make this process more efficient?

From the questions above, I knew I had to implement these:

• Read password, use it on zip
• Unzip
• Loop 25000 times
• Delete the original file (this idea came up later on because I realized it would clog up my storage)

So I made this bash script to help me

#!/bin/bash
j=0
for i in {1..25000}
do
    unzip -P $(strings password.txt) -o $(ls *.zip)
    rm zip-$((25000-$j)).zip
    j=$((j+1))
done

Unzipping all of them gives a flag.txt, which reads:

Flag:

TCP1P{1_TH1NK_U_G00D_4T_SCR1PT1N9_botanbell_1s_h3r3^_^}

Notes:

I believe this code isn't fully optimized, as it took me ~10 minutes to fully unzip all of them. (i'm still learning)