CSAW CTF 2014 - Cryptography 200 - Psifer School

This is the first crypto-problem, and it was supposed to be the easiest one. For this reason, I was expecting simple cryptographic algorithms, which turned out to be true.

The problem starts with the following text:

There's no heartbleed here. Why don't we use these ciphers?

nc 54 ...

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A Lit Backdoor

I was never a big fan of MacBooks. Being a penguin user for so long, you learn to stop worrying and love the bomb. But here is a little trick that works for both.

In the victim's machine (presumably a macbook), create the reverse shell in the port 1337 ...

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Getting your Public IP from the Terminal

Public IPv4 addresses are assigned by NIC and belong to CIDR blocks that are unique to the entire internet.

In this little post, I show many ways to find your public IP address form the Linux terminal.

Using Curl

You can curl it from IP websites:

$ curl ifconfig.me

You ...

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Getting started with LAMP and CodeIgniter

Tue 25 February 2014 Category DevOps

LAMP is an acronym for a model of web service solution stacks: Linux, the Apache HTTP Server, the MySQL relational database management system, and the PHP programming language.

Building a MySQL Database

We will use a web interface to access data in our database:

  • Login with your root login/password ...

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JavaScript: Crash Course

Sat 15 February 2014 Category DevOps

Installing & Setting up

JavaScript (JS) is a dynamic computer programming language. Install Google Dev Tools to proceed.

JavaScript 101

To include your example.js in an HTML page (usually placed right before will guarantee that elements are defined when the script is executed):

<script src="/path/to/example.js"></script ...
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Some DNS stuff...


DNS Recursive requests

Where did my packet go?

$ nslookup -q=mx <website>

??????? => => X.root-servers.net => Authoritative server ==> ?

There are lots of different record types:

A: Get an IP address

$ dig @ -t A www.google.com
; (1 server ...
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Grub Configuration

Wed 29 January 2014 Category DevOps

Understanding MBR and EFI

BIOS/MBR is an older partition table type also referred to as Legacy mode. Nowadays, UEFI is in most of the new computer (especially those that came with W8 or W8.1 pre-installed). UEFI always use the gpt partition table type.

To find out each one ...

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Pwning Project Euler


It was freezing outside, so I spent a week solving as much as Project Euler exercises I could. Now, this was a fun time!

Project Euler is a website dedicated to a series of computational and mathematics problems! Check out my solutions here (but give a try yourself first!).

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