More and more web-traffic is moving to https instead of http protocol. Because users are using a modern browser that defaults to https or a browser extension like Https-By-Default . A great development from a security- and privacy perspective. But with some side effects as it pointed out that the redirect service offered by our hosting provider does not fully support https which causes a security warning.

Although valid commercial solutions are available this fully triggered my (somewhat rusty) not invented here syndrome. Performing the redirect sounds like a suitable functionality for a simple cloud function. With the additional requirement that it should be able to host the cloud function on the (sub)domain(s) we want to use for our redirects.

This blog post will describe the simple steps to develop a cloud function using Firebase Functions and expose it through Firebase Hosting over https using a valid certificate.

Welcome back to the blog series about how to hack a box! In the first blog I gave an introduction into the steps and prerequisites on How to hack a box. In this second post I’ll guide you through the first step, which is exploration. We will execute the steps on an actual box in Hack The Box, called Blocky.

Welcome to the blog series about how to hack a box! In this first post I’ll guide you through the global steps you can take to hack a box. The steps are universal, so you can use them on any target which you have permission for.

In the next few posts we’ll go through each step in detail and try to hack a box in Hack The Box, called Blocky.

As developer, you probably have to work with APIs. Either you consume them, or perhaps you build them. Most of the time an API provides some sort of JSON response or perhaps XML. When the implementation is complete, it provides documentation as well, using the OpenAPI specification. This however is not what this blog is about.

The goal is to get you started exploring OData. OData is an OASIS Standard that defines the best practice for creating and using RESTful APIs. So in short, it is a web-based protocol for querying and updating data.

RevealJS is an awesome tool made with JavaScript, which allows you create slides for a presentation using HTML or if you use a plugin, Markdown. The great thing about that is, that you could have your slides in git, with proper version control. To run your slides, all you need is a web server which serves static content, for example you could do this locally using Python’s SimpleHttpServer. That’s where GitLab comes in, with GitLab pages you can host any static web content you want, so that’s what I will show in this blog, automatically hosting your RevealJS slides on GitLab with every commit of your slides.

WebFlux is the reactive web framework for Spring. The programming model is easy but using it could be cumbersome if you don’t know the consequences when used incorrectly. This post will show what the consequences are when the reactive-stack is not used correctly. It will answer the question: why is my (health) endpoint sometimes so slow?

TL DR; Don’t block the event loop

Password must be at least 12 characters long, must include lower and upper case letters, must include numbers, must include special characters, must have at least 3 numbers, must have at least 2 special characters, may not include words in the dictionary. Your password is rejected because it does not comply to our policy. A policy that isn’t published anywhere, but you must make one that complies anyway. Your password has expired, make a new one that does not resemble any of the passwords that you have created in the past. And it’s all useless. We’re all doing it wrong.

During my last year at JCore I was given the opportunity to do deep-dive in a self-chosen topic in the form of a 'Specialisation'. For this 1-year project I chose to dive deep into AWS how it works and how I, as a developer, make use of it. Some of the topics I covered during this were: DevOps, CI/CD and Security. As a demo and as use case I created a simple pubquiz application in which you can register and have a custom form for your answers. During the development of this application I faced different challenges that I had to overcome. This blog is about how I created a simple API that is exposed to the internet and how I tried to tackle the challenges of security, scalability and adaptability.

Spring offers several frameworks to implement server side rendered web pages and REST APIS. In this blog I compare three options:

In Clojure we can format a string using Common Lisp format syntax or the Java format string syntax. In the post we will look at the how we can use the Java format string syntax. We must use the format function in the clojure.core namespace. The method delegates to the standard JDK String#format method. The first argument is a format string followed by one or more arguments that are used in the format string. We can look up the syntax of the format string in the Javadoc for the java.util.Formatter class.

In the following example code we use the format function with different format strings:

We have all gotten acquainted with git in the last decade. We have adopted a way of working that has made it easy for all of us to work together in large teams and reduced the times our code changes collided to a minimum. When we do run into problems, they’ve culminated to a single important moment; the merge. We all know the merging feature of git with all its pro’s and con’s. But what about another feature of git: rebase?