PicoCTF - like1000

tags: PicoCTF CTF Misc

Challenge: like1000

Background

How to extract nested tar.gz files easily? Shell Script - While

Exploit - Untar 1000 times

• For untar folders

    #! /bin/bash
    PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
    export PATH
    file_name=1000
    for next in ${file_name}.tar
    while [ $file_name > 1 ]
        do
            echo "Untaring - $file_name"
            tar -xvf ${file_name}.tar #-C ./
            file_name=$(($file_name-1))
            mkdir ./$file_name
            mv ${file_name}.tar ./$file_name
            cd ./${file_name}
        done
  

• For getting flag

    #! /bin/bash
    PATH=/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin:~/bin
    export PATH
    file_name=999
    while [ "$file_name" > "0" ]
        do
            cd ./${file_name}
            file_name=$(($file_name-1))
            if [ "$file_name" == "0" ]
                then ls -al
                cat filler.txt
                mv flag.png ~/CTF/PicoCTF/Misc/like1000
            fi
        done
    exit 0
  

Reference

Shell Script 變數相加 How to solve gzip: stdin: not in gzip format error 解压缩报错tar: Error is not recoverable: exiting now In a bash script, using the conditional “or” in an “if” statement