CTFZone 2017 Forensics/Misc1000: Puzzle Writeup

Written by harrier, participated as 0x000505AD

No victory can dispense with mighty patron, hence the more powerful your supporter is the better. Yesterday you finally managed to get in contact with one secret society. It seems that they might back your candidate if you accomplish the task they sent you as a rite of passage. You may find it easy at first glance but I wouldn’t be so naive…

*flag format: ctfzone{flag_you_found}

For puzzle: The way to the magister’s mystery lies through the five degrees:

1. Find all pieces of the puzzle and solve it.
2. Realize the secret behind the names.
3. Find the ritual book.
4. Involve into ritual
5. Translate the flag

[Cantonese version] //English version at bottom 🙂

Puzzle Forensics/Misc 1000pt 1 solve by us:0)

題目given一個trial.img, 入面係一個Linux 既 raw disk image 黎既. 咁先mount左佢先啦:

然後係 /mnt 入面睇下有咩奇怪野, 係/mnt/home/trial/Desktop/ 入邊有個 layout.png, beglfri 同 translate.txt

 translate.txt 一睇就知係lookup table 啦, old crypto野

file beglfri 出 PNG, 係美國一蚊銀拼圖黎 :0) Eye of Providence and Triangle, 又 Illuminati confirmed ? :0)

layout.png 有個 7*7 既grid, 屌即係砌拼圖啦, 49張 :0)

size of beglfri ~ 32.6KB, 我估全部都係咁上下大細, 又無副檔名啦 :0)

咁咩成個image檔 find 囉, 咁我估file size 都係大概 20KB ~ 40KB, 再加個regex limit 下無extension

咁就搵到曬d圖啦, 49張

by hint, 砌完d名有serect, 咁就砌啦

Result

Dum 去 http://quipqiup.com/ , 發現substitution cipher 黎 (好似係ROT13, whatever)

quipquip完再執下d字 :0)

second degree 你會諗起咩呢 :0) 即刻諗起freemasonry, 前面又secret society又Eye of Providence 又 Triangle都通曬水 (Yes, Eye of providence is from Freemasonry, not Illuminati)

Google look to the east 會搵到 http://www.masoniclib.com/images/images0/345790536304.pdf

頭三個degree既ritual :0) Perfect fit with the hint

跟住就係word play :0) perfect misc question :0)

the path from the second degree -> 咁就去翻果章啦

fourth part -> CEREMONIES OF PASSING

fifth temple -> 搵第五個”temple”

twenty four words silently but twenty fifth word aloud -> conflagrations

between con and rat -> flag :0) 即係岩方向

on the first degree -> 去翻first degree 果章

find where prudence goes with out justice -> search prudence, 得兩個result, 一個下一個字係justice, 一個唔係

then count forty seven steps -> 數 47 個字 -> characteristic

forget your character and say it before tic -> is :0)

最後, then you must answer from where you come and where you are traveling in the mystery language

from where you come and where you are traveling :0) 本書叫 look at the east :0)

so: From the West, and traveling to the East

mystery language 係咩? 一開始張lookup table :0)

-> n0t3l3$$_my$t3ry
flag is n0t3l3$$_my$t3ry -> ctfzone{n0t3l3$$_my$t3ry}

Interesting word play in CTF, 咁都得我地 solve sosad

 

[English version]

It is given with a trial.img, which is a Linux raw disk image, with a root file system in it. so we just mount it on Linux:

Then we search inside /mnt for any strange stuff, and we find layout.png, beglfri and translate.txt in /mnt/home/trial/Desktop

translate.txt is trivially a lookup table, old crypto stuff

file beglfri shows it is a PNG, which is a puzzle of US one dollar bill :0) Eye of Providence and Triangle, Illuminati confirmed? :0)

There is a 7*7 grid shown in layout.png, fuck its really a puzzle :0) with 49 pieces :0)

size of beglfri ~ 32.6KB, I guess all puzzle have similar size and without file extension :0)

So we use find command to our image file, guessing file size ranges between 20KB and 40 KB, with a regex to limit no extension

And we found all 49 puzzle using this

by hint, after we solve the puzzle there will be some serect on the names, then we start solve it

Result

We throw that to http://quipqiup.com/ , and found that it is some sort of substitution cipher (seems ROT13, whatever)

And we make it more meaning by tweaking characters after quipquip :0)

What will you come to mind for “second degree”? :0) Freemasonry of course :0) The hint before (secret society, Eye of Providence, Triangle) all hints you about that

(Yes, Eye of providence is from Freemasonry, not Illuminati)

If you google look to the east, you will found http://www.masoniclib.com/images/images0/345790536304.pdf, which is ritual of first three degree in freemasonry :0) Perfect fit with the hint

Then we have word play :0) perfect misc question :0)

the path from the second degree -> Go to that chapter

fourth part -> CEREMONIES OF PASSING

fifth temple -> Find the fifth existence of word “temple” in that part

twenty four words silently but twenty fifth word aloud -> conflagrations

between con and rat -> flag :0) Seems we are on the right track

on the first degree -> Go back to first degree chapter

find where prudence goes with out justice -> search prudence, we have only two result, with one have justice next to it, one without

then count forty seven steps ->count 47 words -> characteristic

forget your character and say it before tic -> is :0)

Finally, then you must answer from where you come and where you are traveling in the mystery language

from where you come and where you are traveling :0) the book is called look at the east :0)

so: From the West, and traveling to the East

What is mystery language? The lookup table from the beginning :0)

-> n0t3l3$$_my$t3ry
flag is n0t3l3$$_my$t3ry -> ctfzone{n0t3l3$$_my$t3ry}

Interesting word play in CTF, I thought there will be more teams solving this 🙁


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