DEF CON CTF 2013 – diehard

DEFCON 2013 CTF - diehard - task description

Die Challenge “diehard” befasst sich mit dem gleichnamigen Film “Stirb Langsam” Dabei soll John McClane eine Bombe entschäfen, indem er Wasser innerhalb zwei verschieden großer Gefäße umfüllt.

Nach dem Verbinden zum Challenge-Server sehen wir zuerst jedoch nur folgende Nachricht:

rup0rt@lambda:~$ nc diehard.shallweplayaga.me 4001
Welcome John McClain...
You are standing at the start of your adventure. You will be tested
on your ability to solve a set of riddles in the minimum amount of
time possible.

As you glance around the room, you realize the problem you seek is
to the north. To the west is a mysterious field.
Exits: n w
>

Offensichtlich müssen wir uns zunächst durch ein Labyrinth im Text-Adventure-Stil arbeiten, bevor wir die “Rätsel” lösen können. Da uns der Weg “im Norden” jedoch bereits vorgegeben ist, navigieren wir promt in diese Richtung.

> n

You go n
You are standing in a long dark hallway. Rays of light flicker off the smooth surfaces around you.
Exits: n s
> n

[...]

You go n
You see a large room with sleek black walls on every side.  The ceiling overhead is smooth and devoid of features. In the center of the room is a small scale that links to a closed door.
A small fountain is gurgling water in the corner. The scale has a small inscription on it.
A red jug is sitting in the room.
A blue jug is sitting in the room.
A fountain is sitting in the room.
A scale is sitting in the room.

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DEF CON CTF 2013 – Grandprix

The grandprix challenges requires us to connect to a server where we can play an ascii game. According to the assignment text, we are advised to avoid the zebras.

Let’s check out the game first using netcat:

$ nc grandprix.shallweplayaga.me 2038
nc: using stream socket
Use 'l' and 'r' to move. Don't crash.
Press return to start
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 |  u  |
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The games starts with an empty field. Obviously, our position is indicated by an u. We fiddle around a little to learn how the game works. Sending an r moves the player one step right, a l one left and a s or an empty line moves the player straight forward.

 r
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 |     |
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 |   u |
 |-----|

The more we move along, the more obstacles appear. A T marks a tree and the Zebras we were warned about are indicated by a Z.
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