The dangers of a poorly planned project

Posted on Do 21 November 2013 in Philosophical • Tagged with Architecture, Captcha, Philosophical, Programming, Php, Uncategorized, WordpressLeave a comment

Preface

Do you like to fiddle around with programming projects in your spare time? And do you sometimes start endeavors ambitiously, but you never actually finish them? Are you fucking tired of stacking unsuccessful projects, doing mediocre work while never being thoroughly satisfied in what you do?

If yes, you may be inclined to listen to some words I have to say over my most recent failed project:

The idea was to create my own little captcha plugin for wordpress. You can learn more about the idea by delving into ...

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A tale of a twofold broken wordpress captcha plugin

Posted on Mo 04 November 2013 in Programming • Tagged with Captcha, Security, Programming, ExploitLeave a comment

Last Edit (Effective: 7th November 2013)

It seems like the plugin authors updated the security of the plugin. All the bottom blog entry deals with version 3.8.7. In this new paragraph, I will look whether these recent updates to version 3.8.8 added the necessary security to prevent conducting an...

  • Attack vector one: Parsing the captcha logic.
  • Attack vector two: Reversing the decode() function and just reading the solution from the hidden fields.

Let's get started:

At line 942 of the plugin code (The start of ...

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Create your own font the hard way!

Posted on Mi 16 Oktober 2013 in Learning • Tagged with Captcha, Programming, Design, Glyphs, Learning, FontLeave a comment

Last major update on 23.10.2013

Preface

As promised previously in my last article, I will guide you through the creation process of a rudimentary font. I will use the glyphs of my font to draw captchas and incorportate the implementation in my brand new captcha plugin for wordpress. There are already quite a few captcha plugins out there, some of them are better than mine (RECAPTCHAfor instance translates books and thus solves two problems at the same time), others are worse, because the math equations can simply ...

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Plotting Bézier curves directly and with De Casteljau's algorithm

Posted on So 06 Oktober 2013 in Learning • Tagged with Font, Captcha, Programming, Mathematics, Learning, BézierLeave a comment

Last major Update: 21.10.2013

Github repo that contains the presented code in this post.

Introduction

In this article I will present you a very simple and in no sense optimized algorithm written in Python 3 that plots quadratic and cubic Bézier curves. I'll implement several variants of Bézier rasterization algorithms. Let's call the first version the direct approach, since it computes the corresponding x and y coordinates directly by evaluation of the equation that describes such Bézier curvatures.

The other possibility is De Casteljau's algorithm ...

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