AJAX, jQuery & how to bypass the same-origin policy

AJAX und Cross-DomainToday’s post is intended to give a brief introduction to the topic of AJAX with jQuery, as well as to cover the topic of cross domain (policy) and to show how you can use small tricks to send AJAX requests across multiple domains. Before we start, however, we will give you a quick introduction to the topic. If you are already familiar with the topic and are only interested in the AJAX cross-domain workaround, you can safely skip the first part of the article.
What is AJAX and how does it work in jQuery?
AJAX is an abbreviation and stands for “Asynchronous JavaScript And XML”. Contrary to the opinion of some people on the Internet, it is not a programming language, but rather a pattern, i.e. a way of programming something. By means of AJAX web content can be retrieved via Javascript, […]

Steganography with PHP – Hide files in images

Steganographie mit PHPIn this article we want to deal with the topic of steganography and implement a small example in PHP. Because PHP is not “only” used to create web pages or to implement forms, as any experienced PHP programmer of larger web agencies will surely confirm.
Besides functions for text processing, PHP also provides methods for image processing as well as for manipulation on bit and byte level. And these are the ones we want to use today. But before we start coding, we will have a short introduction to the topic of steganography.
Steganography is not shorthand
As the title already announced, today’s topic is steganography, the art of hiding information or knowledge in a carrier medium. Wikipedia defines steganography as follows:
Steganography (/ˌstɛɡəˈnɒɡrəfi/) is the practice of concealing a message within another message or a physical object. In computing/electronic contexts, a computer file, message, […]

Basics: Secure password hashing with salts

Passwörter in Plaintext speichernAnyone who develops software and especially if he/she does so in the web environment, has certainly already written one or the other login system or at least had points of contact in this area. Besides the logic of a secure login or user management system, the secure storage of passwords is one of the most important points during implementation.
Even if the actual login code is 100 percent error-free and secure (which should never be assumed in practice), security vulnerabilities in the server software can still lead to intrusions or hacks. There is always a variable that is out of one’s control and thus websites are hacked, compromised and complete databases with usernames and passwords are read every day.
In order to protect users in the best possible way in the event of such a hack, […]

Update Node.js and NPM via commandline

How to update NodeJS and NPM via ShellToday’s article falls into the category “reminder”. Every few months I write smaller projects with Node.js. But before I start, I’d like to update to the latest version, and that’s where the dilemma starts. Every time I forget the command line commands for it.
Therefore, here are the short and concise CMD/Shell/Bash commands for updating Node.js and NPM. Once for macOS (OSX) / Linux and once for Windows.
Update NPM on Linux and macOS (OS X)

sudo npm install -g npm

Whether the update was successful can be tested with the following command.
npm -v
Update NPM on Windows
The following commands have to be set in Powershell (Start -> “powershell” -> right click -> Run as Administrator). Each line corresponds to one command.

Set-ExecutionPolicy Unrestricted -Scope CurrentUser -Force
npm install […]

Check Paypal account balance and transactions via C# API

How to use Paypal-API in CsharpAfter we had a look at how to sent push notifications via C# recently, there are plans for the next C# article today. This time it’s about how to read account balance, sales and transactions and other things of a Paypal account.
First some basic information. Although Paypal is an “online account”, in many ways it differs from an online (giro) account of a “classic” bank. For example, Paypal does not support the Homebanking Computer Interface (HBCI) to retrieve account information or send payments. Instead, Paypal offers different APIs (REST, SOAP, + SDKs, …), which differ not only in structure and technology, but especially in the range of functions. For our purposes we will use the so-called “NVP / SOAP API” and connect to it […]