Stripe CTF: Level #5

Posted on sam. 27 octobre 2012 in Write-up

level05-logo.jpg

You can find the code for this level here.

(sha256: 82b066cca46fd24a16959ada973d6df0d7c693f7791a8b673add276f324a5885)

This level wants to solve a real problem: identification. We have too many online accounts and we have to remember usernames/passwords for everyone of them. It would be way simpler to be able to log into a new …

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Stripe CTF: Level #4

Posted on sam. 27 octobre 2012 in Write-up

level04-logo.jpg

You can find the code for this level here.

(sha256: 07a8338f0ecf92537daedb60709cd8211a790a23f9c25a101e069614b32da2a8)

This level wants you to spread joy over the world. You have a certain amount of karma you can distribute to people. But to be sure that you only send karma to people you really trust to be good …

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Stripe CTF: Level #3

Posted on ven. 26 octobre 2012 in Write-up

level03-logo.png

You can find the code for this level here.

(sha256: 8710c082daed1839806addebeda44c6e5496d44a33f7eb3f23a577b6a5fc26d5)

The company who built the vault of level 0 learned its lesson: you now have to identify before accessing your guarded secrets.

The company kindly tells you that other users have already chosen to use their product, and even …

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Stripe CTF: Level #2

Posted on sam. 13 octobre 2012 in Write-up

level02-logo.png

You can find the code for this level here.

(sha256: d175b624ed888badd795c5474ae855f711e856cc41c0757059594babe8f23413)

This level is a whole social network!

Okay, it's not, it's just a page with a profile picture. But on the bottom of the page, you can see something interesting: "Password for Level 3 (accessible only to members of …

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Stripe CTF: Level #1

Posted on sam. 13 octobre 2012 in Write-up

level01-logo.jpg

You can find the code of this level here.

(sha256: b67c313a1a3bebd8702159efae32f95f1b41885f6e00103ee53e896a53194f43)

So, this level wants you to guess a password, stored in a file named "secret-combination.txt" on the server. If you manage to do it, it'll give you the password for this level. Let's take a look at the …

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Stripe CTF: Level #0

Posted on sam. 13 octobre 2012 in Write-up

level00-logo.png

You can find the code of this level here.

(sha256: da9712a1851597d6d4b5a90224a1d0fcaa4b558f55a10ca0c7a115d18fe9dcb7)

So, this level is a safe that keeps your secrets for you. But it also keeps secrets for other people. Let's find out how we can recover the password for this level.

The page is a simple form with …

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#define AUTHOR Yannick Méheut

Posted on sam. 13 octobre 2012 in Blog

Hi everyone!

My name is Yannick, I'm a 22 year-old student at the French engineer school Télécom ParisTech. I study cryptography and info/netsec. Although I find these topics fascinating, I'm pretty new to this world.

yannick.jpg

Last month, I decided to participate to the Stripe CTF, and, unexpectedly, I managed …

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